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Carnegie
Institution
OF WASHINGTON
Year Book 68
1968-1969
Library of Congress Catalog Card Number 3-16716
Port City Press, Baltimore, Maryland
Contents
page
Officers and Staff v
Report of the President 1
Reports of Departments and Special Studies 95
Mount Wilson and Palomar Observatories 97
Geophysical Laboratory 165
Department of Terrestrial Magnetism 359
Committee on Image Tubes for Telescopes 493
Department of Embryology 497
Department of Plant Biology 559
Genetics Research Unit 651
Bibliography 669
Administrative Reports 671
Report of the Executive Committee 673
Report of Auditors 675
Abstract of Minutes of the Seventieth Meeting of the Board of
Trustees 691
Articles of Incorporation 693
By-Laws of the Institution 697
Index 703
Digitized by the Internet Archive
in 2012 with funding from
LYRASIS Members and Sloan Foundation
http://www.archive.org/details/yearbookcarne68196869carn
President and Trustees
PRESIDENT
Caryl P. Haskins
BOARD OF TRUSTEES
James N. White
Chairman
Henry S. Morgan
Vice-Chairman
Garrison Norton
Secretary
Sir Eric Ashby
Amory H. Bradford
Vannevar Bush
Michael Ference, Jr.
Carl J. Gilbert
William T. Golden
Crawford H. Greenewalt
Caryl P. Haskins
Alfred L. Loomis
Robert A. Lovett
William McC. Martin, Jr.
Keith S. McHugh
Henry S. Morgan
William I. Myers
Garrison Norton
Robert M. Pennoyer
Richard S. Perkins
William M. Roth
William W. Rubey
Frank Stanton
Charles P. Taft
Charles H. Townes
Juan T. Trippe
James N. White
Trustees (continued)
AUDITING COMMITTEE
Keith S. McHugh, Chairman
Alfred L. Loomis
Juan T. Trippe
EXECUTIVE COMMITTEE
Henry S. Morgan, Chairman
Carl J. Gilbert
Crawford H. Greenewalt
Caryl P. Haskins
Keith S. McHugh
William I. Myers
Garrison Norton
Richard S. Perkins
Frank Stanton
James N. White
RETIREMENT COMMITTEE
Frank Stanton, Chairman
Amory H. Bradford
Garrison Norton
Richard S. Perkins
COMMITTEE ON ASTRONOMY
FINANCE COMMITTEE
Richard S. Perkins, Chairman
Crawford H. Greenewalt
Alfred L. Loomis
Keith S. McHugh
Henry S. Morgan
Robert M. Pennoyer
Crawford H. Greenewalt, Chairman
Amory H. Bradford
William McC. Martin, Jr.
COMMITTEE ON BIOLOGICAL SCIENCES
Alfred L. Loomis, Chairman
William I. Myers
Charles P. Taft
NOMINATING COMMITTEE
Garrison Norton, Chairman
Crawford H. Greenewalt
Keith S. McHugh
James N. White
COMMITTEE ON TERRESTRIAL SCIENCES
Juan T. Trippe, Chairman
Richard S. Perkins
Staff
MOUNT WILSON AND
PALOMAR OBSERVATORIES
813 Santa Barbara Street
Pasadena, California 91106
Horace W. Babcock, Director
Halton C. Arp
Ira S. Bowen, Distinguished
Service Member
Edwin W. Dennison
Armin J. Deutsch
Jesse L. Greenstein 1
Robert F. Howard
Jerome Kristian2
Robert B. Leighton 3
Guido Munch4
J. Beverley Oke4
George W. Preston III5
Bruce H. Rule
Allan R. Sandage
Wallace L. W. Sargent 6
Maarten Schmidt4
Arthur H. Vaughan, Jr.
Olin C. Wilson
Harold Zirin7
GEOPHYSICAL LABORATORY
2801 Upton Street, N.W.
Washington, D.C. 20008
Philip H. Abelson, Director
Peter M. Bell
Francis R. Boyd, Jr.
Felix Chayes
Gordon L. Davis
Gabrielle Donnay
Joseph L. England
P. Edgar Hare
Thomas C. Hoering
Thomas E. Krogh
Gunnar Kullerud
Donald H. Lindsley
J. Frank Schairer
Hatten S. Yoder, Jr.
1 Professor of Astrophysics and Executive Of-
ficer for Astronomy, California Institute of
Technology.
2 From September 1, 1968.
8 Professor of Physics, California Institute of
Technology.
4 Professor of Astronomy, California Institute
of Technology.
5 From July 1,1968.
DEPARTMENT OF
TERRESTRIAL MAGNETISM
6241 Broad Branch Road, NW.
Washington, D. C. 20015
Ellis T. Bolton, Director
L. Thomas Aldrich, Associate
Director
Merle A. Tuve, Distinguished
Service Member
Roy J. Britten
Louis Brown
Dean B. Cowie
Scott E. Forbush8
W. Kent Ford, Jr.
Stanley R. Hart
Bill H. Hover9
David E. James 10
David E. Kohne
Richard B. Roberts
Vera C. Rubin
I. Selwyn Sacks
John S. Steinhart11
Kenneth C. Turner
6 Associate Professor of Astronomy, California
Institute of Technology.
7 Professor of Astrophysics, California Insti-
tute of Technology.
8 Retired June 30, 1969.
9 From November 1, 1968.
10 From September 1, 1968.
11 On leave of absence from October 7, 1968,
resigned June 30, 1969.
Staff (continued)
DEPARTMENT OF PLANT BIOLOGY
Stanford, California 94305
C. Stacy French, Director
Olle Bjorkman
Jeanette S. Brown
Jens C. Clausen, Emeritus
David C. Fork
William M. Hiesey 1
Malcolm A. Nobs
James H. C. Smith, Emeritus
DEPARTMENT OF EMBRYOLOGY
US West University Parkway
Baltimore, Maryland 21210
James D. Ebert, Director
Bent G. Boving
Donald D. Brown
Igor B. Dawid
Robert L. DeHaan
Douglas M. Famb rough 2
Elizabeth M. Ramsey
Ronald H. Reeder 2
GENETICS RESEARCH UNIT
Cold Spring Harbor
New York 11724
Alfred D. Hershey, Director
Barbara McClintock, Distinguished
Service Member
Elizabeth Burgi
Cytogenetics Laboratory
Ann Arbor, Michigan
Helen Gay
Retired June 30, 1969. 2 Beginning July 1, 1969.
viii
Staff (continued)
OFFICE OF ADMINISTRATION
1530 P Street, N.W., Washington, D.C. 20005
Caryl P. Haskins President
Edward A. Ackerman Executive Officer, Acting Director of Publications
James W. Boise Bursar; Secretary-Treasurer, Retirement Trust;
Executive Secretary to the Finance Committee
Marjorie H. Walburn Assistant to the President
Sheila A. McGough Editor
Kenneth R. Henard Assistant Bursar; Assistant Treasurer,
Retirement Trust
Pamela W. Thomas Associate Editor
Joseph M. S. Haraburda Assistant to the Bursar
A. Gerald Thompson Assistant to the Director of Publications
Marshall Hornblower Counsel
STAFF MEMBERS IN SPECIAL SUBJECT AREAS
Tatiana Proskouriakoff
Staff (continued)
RESEARCH ASSOCIATES OF THE CARNEGIE INSTITUTION
Mateo Casaverde
Lima, Peru
Richard A. Chase
Johns Hopkins University
Louis B. Flexner
University of Pennsylvania
Irwin Konigsberg
University of Virginia
J. D. McGee
Imperial College of Science and Technology, University of London
Jan H. Oort
University of Leiden
Harry E. D. Pollock
Carnegie Institution
Reynaldo Salgueiro
La Paz, Bolivia
Shigeji Suyehiro
Japan Meteorological Agency
Former Presidents and Trustees
PRESIDENTS
Daniel Coit Gilman, 1902-1904 John Campbell Merriam, 1921-1938;
Robert Simpson Woodward, 1904-1920 President Emeritus 1989-1945
Vannevar Bush. 1939-1955
TRUSTEES
Alexander Agassiz
1904-05
Seth Low
1902-16
George J. Baldwin
1925-27
Wayne MacVeagh
1902-07
Thomas Barbour
1934-46
Andrew W. Mellon
1924-37
James F. Bell
1935-61
Margaret Carnegie Miller
1955-67
John S. Billings
1902-13
Roswell Miller
1933-55
Robert Woods Bliss
1936-62
Darius O. Mills
1902-09
Lindsay Bradford
1940-58
S. Weir Mitchell
1902-14
Omar N. Bradley
1948-69
Andrew J. Montague
1907-35
Robert S. Brookings
1910-29
William W. Morrow
1902-29
John L. Cadwalader
1903-14
Seeley G. Mudd
1940-68
William W. Campbell
1929-38
William Church Osborn
1927-34
John J. Carty
1916-32
James Parmelee
1917-31
Whitefoord R. Cole
1925-34
Wm. Barclay Parsons
1907-32
Frederic A. Delano
1927-49
Stewart Paton
1916-42
Cleveland H. Dodge
1903-23
George W. Pepper
1914-19
William E. Dodge
1902-03
John J. Pershing
1930-43
Charles P. Fenner
1914-24
Henning W. Prentis, Jr.
1942-59
Homer L. Ferguson
1927-52
Henry S. Pritchett
1906-36
Simon Flexner
1910-14
Gordon S. Rentschler
1946-48
W. Cameron Forbes
1920-55
David Rockefeller
1952-56
James Forrestal
1948-49
Elihu Root
1902-37
William N. Frew
1902-15
Elihu Root, Jr.
1937-67
Lyman J. Gage
1902-12
Julius Rosenwald
1929-31
Walter S. Gifford
1931-66
Martin A. Ryerson
1908-28
Cass Gilbert
1924-34
Henry R. Shepley
1937-62
Frederick H. Gillett
1924-35
Theobald Smith
1914-34
Daniel C. Gilman
1902-08
John C. Spooner
1902-07
John Hay
1902-05
William Benson Storey
1924-39
Barklie McKee Henry
1949-66
Richard P. Strong
1934-48
Myron T. Herrick
1915-29
William H. Taft
1906-15
Abram S. Hewitt
1902-03
William S. Thayer
1929-32
Henry L. Higginson
1902-19
James W. Wads worth
1932-52
Ethan A. Hitchcock
1902-09
Charles D. Walcott
1902-27
Henry Hitchcock
1902
Frederic C. Walcott
1931-48
Herbert Hoover
1920-49
Henry P. Walcott
1910-24
William Wirt Howe
1903-09
Lewis H. Weed
1935-52
Charles L. Hutchinson
1902-04
William H. Welch
1906-34
Walter A. Jessup
1938-44
Andrew D. White
1902-03
Frank B. Jewett
1933-49
Edward D. White
1902-03
Samuel P. Langley
1904-06
Henry White
1913-27
Ernest 0. Lawrence
1944-58
George W. Wickersham
1909-36
Charles A. Lindbergh
1934-39
Robert E. Wilson
1953-64
William Lindsay
1902-09
Robert S. Woodward
1905-24
Henry Cabot Lodge
1914-24
Carroll D. Wright
1902-08
Under the original charter, from the date of organization until April 28, 1904, the following
were ex officio members of the Board of Trustees : the President of the United States, the Presi-
dent of the Senate, the Speaker of the House of Representatives, the Secretary of the
Smithsonian Institution, and the President of the National Academy of Sciences.
XI
Report of
the President
My soul can find no staircase to Heaven unless it be through Earth's
loveliness.
Michelangelo
Peace with the earth is the first peace.
Henry Beston — Herbs and the Earth
You are a child of the universe no less than the trees and the stars;
you have a right to be here. And whether or not it is clear to you, no
doubt the universe is unfolding as it should. Therefore be at peace with
God, whatever you conceive Him to be. And whatever your labors and
aspirations, in the noisy confusion of life, keep peace in your soul.
Max Ehrmann — "Desiderata," from The Poems of Max Ehrmann
The year that witnessed the climax of the most audacious and technically
brilliant triumph of exploration in the history of man's wanderings, the
year when the conquest of the moon has lifted the hearts of men and reinforced
their pride in their humanity, has likewise been the year when the deepest social
problems of our age — the intractable welter of urban blight, of academic crises,
of worldwide social unrest, and perhaps most fundamental, of individual aliena-
tion— also reached a climax. This striking conjunction of opposites has been
noted and commented upon many times. It is often primarily seen against the
immediate background of that stringent ratio of limited human and material
resources to almost unlimited requirements that characterizes the combination
of military and civilian demands of our day. The questions of policy inherent
in these contradictory challenges are, as we are all vividly aware, probably the
most critical of the age.
How are we to maintain and nurture those qualities of hope and humility
and reverence that have provided the foundation for all we have done? How
are we to combat the sense of alienation, of total frustration, even of the
fruitlessness of existence, that threaten all too menacingly today? How are we
to preserve — and, where restoration is needed, restore — the sense of an individual
oneness with the world, of a personal anchor in the universe, which is so essential
4 CARNEGIE INSTITUTION
to our spiritual welfare and which, in some quarters, seems to be irrevocably
slipping away?
It is often said that much of this alienation is consonant with the unexampled
enlightenment of our age; that science, as it is often popularly conceived, has
added its share to the spiritual burdens of our time. And so, in this day especially,
it is worth recalling for a moment what science actually is, and its real relation
to the spiritual crises that beset us. For science may have a most important part
to play in these critical times, and its role may be quite the opposite of the one
it is sometimes superficially imagined to play.
The year 1969 was not only the year of the first successful voyage to the moon.
It was not only witness to the most serious social problems that have beset us.
It also marked the centenary of a great scientific achievement by the Swiss bio-
chemist Friedrich Miescher — an historic achievement that will soon be commemo-
rated by the establishment of the first research training group of the Max Planck
Institutes in Germany, the Friedrich Miescher Institute at Tubingen. Miescher
succeeded in chemically isolating a new and peculiar substance, lying deep
within the nuclei of the sperm cells of the salmon which in his day still ascended
the Rhine as far as his home in Basel. Miescher, even then recognizing its funda-
mental distinctness from proteins, and noticing that its occurrence seemed strictly
confined to the nuclei of cells, named the amorphous powder nuclein. Eighty-four
years later two papers were published in England by James Watson and Francis
Crick. They dealt with the molecular structure of that same amorphous white
powder, and visualized the nature of its function in a way that revolutionized our
ideas of the fundamental mechanisms of heredity. Over the decade and a half
following the appearance of those papers in 1953, the tide of newly oriented
investigation that they released has emphasized more specifically and at a deeper
level than we have ever known the basic physical identity of man with all the
rest of living nature: in inheritance, in evolution, perhaps in destiny. After that
discovery and all its consequences, never again could modern man rationally view
himself as other than an integral part of his animate world.
The terms in which that vision was conceived and expressed were peculiarly
suited to our contemporary generation. But in fact, of course, they simply reaf-
firmed in a more powerful and explicit way an insight achieved before Miescher's
time, and emphasized by his discovery. For the isolation and characterization of
DNA followed by only ten years the first publication of the Origin of Species.
Darwin was still being persuaded by certain critics to make some emendations in
its text which we regard in retrospect as less penetrating than the first conclu-
sions of his genius. In many quarters the theory of evolution was still being hotly
argued, was still in its plastic, formative stage, still far from universally affirmed.
Only four years previously Mendel had demonstrated the unitary character of
the elements of inheritance. In retrospect we can discern in that era what we are
experiencing today — the special and highly significant complex of effects that
ensue when man's world view and view of himself in it are suddenly transformed
by a major conceptual advance. In the context of the conjunctions that this year
has brought, it is worth pursuing one of those effects a bit further.
It is believed to have been about the year 270 B.C. when Aristarchus of Samos
propounded the doctrine — probably then wholly novel — that the earth, far from
being the center of the universe, was instead a satellite of the sun. Little record
of the reception accorded this germinal idea survives today save for a comment
REPORT OF THE PRESIDENT 5
of Cleanthes the Stoic. He is reported to have declared that for propounding so
heretical a notion Aristarchus ought to be indicted for impiety.
Beyond that flicker of shock and outrage, the idea itself seems to have sunk
into virtual oblivion for the next eighteen centuries. It was not to reappear in any
commanding way until the publication in 1543 of De Revolutionibus Orbium
Coelestium by Rhaticus, the devoted disciple and expositor of Copernicus. We
know that Copernicus was aware of the thinking of Aristarchus, for he men-
tioned it in a passage of his own work. But except for such faint indications of its
survival in at most a very few minds of originality and genius, the idea of an
earth revolving about a central sun seems never, over eighteen centuries, to have
risen again strikingly in man's consciousness. And even after Copernicus's life
work was done and his theory had become widely current publicly as well as
professionally, a full fifty years were to pass before the notions of a Ptolemaic
universe were finally abandoned.
In the same context some aspects of the initial reception of the Origin of
Species take on special interest. The long and hostile reviews of Richard Owen
and of Bishop Wilberforce may well have been impelled, at least in part, by
other than purely intellectual motives. But the famous debate between Wilber-
force and Thomas Henry Huxley before the British Association for the Advance-
ment of Science in June of 1860 clearly represented a watershed in the history
of man's view of himself and of his place in nature, and it is against this back-
ground that the acerbity of the struggle takes on a special significance. Its
intensity and scope, quite beyond the context of the personal ambitions or special
prejudices of a few of Darwin's countrymen, were emphasized by the castigation
of the Origin in the United States by no less eminent an authority than Louis
Agassiz, who called it "a scientific mistake, untrue in its facts, unscientific in its
methods, and mischievous in its tendencies." In France, there was strong initial
opposition to the theory led by filie de Beaumont and Pierre Flourens. The
French Academy refused to admit Darwin as a Corresponding Member in 1870.
And in England the Royal Society of London, in presenting its Copley Medal to
Darwin, curiously suggested in the accompanying citation that the writing of the
Origin was not reckoned high among the achievements for which the award was
bestowed. Clearly, the reception of the theory of evolution, however enthusiastic
in some quarters, was far from universally favorable. Nor was the opposition to
be short-lived. For not until the great revival of Darwinism in its modern garb
during the middle decades of this century could it be considered to have achieved
a firm base in the thinking of all men.
In this context, again, one recalls the forty-five years of disregard that
attended the work of Mendel following the reading and the publication of his
two-parted paper dealing with the inheritance of genetic characteristics in peas.
It is particularly interesting to note that, although Mendel repeatedly stressed
that his own demonstration of the discrete apportionment of hereditary charac-
teristics from generation to generation clearly showed that, contrary to the
notions of blending inheritance current when Darwin was writing the Origin,
interbreeding of forms does not extinguish variation but actually increases it,
and although he made specific reference to the implications of that demonstra-
tion for the theory of evolution — with which he had thoroughly familiarized
himself after the publication of the Origin — that portion of his work received no
more general attention than the rest. Finally, within the same context, one
6 CARNEGIE INSTITUTION
recalls that more than eight decades separated the findings of Miescher and
the solving of the riddle of DNA.
Some of these long delays had obvious causes. Neither the world's technology
nor the conceptual framework of biological science could, in all probability, have
taken Miescher's findings much further or faster than they did. It has been sug-
gested that the long winter of Mendelism resulted primarily from the fact that
the paper was initially published in a little-known journal. But in fact the
Journal of the Society of Naturalists of Brunn was not particularly obscure.
Indeed it enjoyed a fairly wide circulation among the libraries of the day —
probably at least as wide as that of the Journal of the Royal Horticultural Society
of Great Britain, where its republication in English in 1901 soon caught world-
wide attention. A more likely contributing cause, often suggested, was the wide-
spread lack of understanding and appreciation of mathematics and its use as a
major tool of biological investigation among nineteenth-century naturalists.
Finally, of course, the underlying ideas of organic evolution, though they had
been foreshadowed by a number of English naturalists of a previous generation
— not least Erasmus Darwin himself — were, like the ideas of Aristarchus and Co-
pernicus in their day, of a cast profoundly unfamiliar to the general audience of
their times.
There may be another quality common to the public impact of these great
dividing ranges in human thought that lies deeper than the initial unfamiliarity
of great conceptual advances. That quality may have a more comprehensive
significance for the human condition, especially in our own day. Each of these
conceptual watersheds profoundly altered man's view of himself in his universe.
And often, at the outset, they were interpreted as markedly diminishing the
stature of man in that relationship. The substitution of the notion of man's
planet as a satellite of a remote sun for the picture of his home as the center of
the universe can hardly have been welcome at first. The long delay in its reception
suggests subliminal rejection by many men. Our firmer, broader, and more detailed
knowledge of the early hostility to Darwinism and the delay in its definitive
acceptance in a world already at a stage of scientific enlightenment seemingly
well equipped to appreciate and absorb it speaks for an underlying trauma
inherent in the sudden shift in the image of man's position from that of a
specially created being to that of an integral element of the natural world. Even
after the shift was generally accepted, hostility and resentment were long in
dying.
But as the years rolled on, a curious paradox appeared. It became increasingly
apparent that a corollary to the acceptance of what had once seemed an almost
insupportable diminution in stature for man in his universe was, surprisingly, a
wholly new order of human sensitivity — a wholly new order and intensity of
appreciation of the scope and the wonder and the glory of that universe itself.
Moreover — and especially in connection with the final acceptance of Darwinism —
there came a new feeling for the essential integrity of man with the rest of a
natural system which once he had regarded with uncertainty and fear, which
once had seemed thoroughly alien and hostile: a sense of essential unity with
nature that was soon to be intellectually reinforced. A whole spectrum of
biological discoveries, ranging from the revival of Mendelism by de Vries,
Correns and Tschermak in 1900 to the most recent demonstrations that at the
very level of his genetic code man is truly one with the rest of the living world,
could leave our own society in little reasonable doubt of man's place in nature.
REPORT OF THE PRESIDENT 7
From that ultimate demonstration of his essential and rightful niche in a
system of almost unimaginable beauty, variety, and dynamism there inevitably
followed a reinforced sense of personal identity, a new feeling of security of
place in the workings of the natural universe that may well have been a quite
new and heady experience. And that sense of personal identity, that feeling of
place and significance, has surely been deepened and reinforced over the years by
the highly individual and personal nature of the critical advances of understand-
ing that mark the evolution of all science. Accumulating over the years and
the centuries, this contribution of the scientific way to man's view of him-
self may well represent a contribution to humanity as great as all the specific
and substantive accomplishments of science itself. And never has this contribu-
tion been so intensely relevant as in the present decade.
A prescient observer has recently remarked that the deepest crises of our day,
alike for individuals and for society, which are so often seen as political crises,
are in fact much more profound. One of the damaging misconceptions that cur-
rently afflicts us is that the most severe of the social traumas that we experience,
the confusion and agony which we presently suffer at the level of the individual,
are within reach of direct political remedy. In fact, their essence lies far
deeper. It may lie in a search for meaning, and with it a sense of individual
identification, by a society that has in large measure abandoned the easier
and simpler framework of religious thinking that characterized another era and
now desperately seeks the same values through secular channels. The passion
that motivates this search, and which generates an intensity of overt political
involvement quite new in many ways to the American experience, is in fact the
product of that very same eighteenth-century Enlightenment which, two cen-
turies ago, shaped the American experience and the American civilization. It is
the validations and the forms of this philosophy that are outworn and at hostile
issue in our day and in our world, a world whose secular aspects and demands
have changed beyond all recognition. In this time of crisis, of transition, and of
miasma, it is perhaps worth remembering that the very structure and deepest
values of modern science were also shaped by that same Enlightenment, and that,
of all its manifestations, perhaps the structure and values of modern science have
persisted most faithfully to the present day. It has been suggested that the essential
question of how to maintain the spiritual health of a great civilization too
advanced in size and power and complexity and sophistication to be content with
the older shapes of religious belief, yet still deeply committed to the essence of
that belief, may be on the agenda of this century and the next as their most
central concern. In a day when the real nature of science is perhaps more vulner-
able to public misunderstanding than at any time within recent experience, it is
worth pondering what resources directly pertinent to that problem can be pro-
vided from the experience and the example of the scientific way.
Perhaps there has never been a year when this aspect of the scientific enter-
prise has been more clearly exemplified; never a year when the challenges to
new knowledge have been more compelling, or our mechanical inability to meet
so many of them more frustrating.
In all the long history of man's scanning of the heavens, there has surely never
been a time when the scope and the range of its mysteries have seemed greater
than at this moment, nor the opportunities for new discovery richer or more
8 CARNEGIE INSTITUTION
varied. The radio and infrared galaxies, sources of vast quantities of energy in
ranges of the spectrum quite unexplored by astronomers even a decade ago, con-
tinue to challenge understanding. It is only a very few years since the first quasi-
stellar sources were discovered. Yet now they are thought to number at least a
hundred thousand over the whole sky. Typically they show redshifts in their
spectra of an order wholly new in the experience of astronomy. So great are some
of the redshifts that, if interpreted in conventional fashion, it must be con-
cluded that these energy sources lie at distances so immense as to set, in effect,
new boundaries to the observed universe, redshifts lying far beyond what
astronomers could have imagined a mere ten years ago.
Yet the output of quasars can fluctuate greatly and this surely suggests that
their volumes cannot be very large. How, then, can these bodies, lying at such
vast distances in the heavens, emit sufficient quantities of light to be visible
on earth even through the most powerful telescopes?
The severity of this paradox has led to suggestions that the usual interpretation
of the relationship between the distance of an object in the universe and the red-
shift of its spectrum, based on the fundamental concept of an expanding universe
advanced by Edwin Hubble at the Mount Wilson Observatory a quarter of a
century ago and tested by Hubble and Humason over nearly twenty-five years,
may not be valid in this cosmological environment and that other physical
factors special to the situation of the quasi-stellar sources could invalidate the
conclusion that they lie at such immense distances. In particular it has been
suggested that the redshift may be caused, at least in part, by an actual lengthen-
ing of light waves due to the Einstein redshift of radiation in intense gravita-
tional fields. But, as Greenstein and Schmidt showed some time ago, such an
extreme gravitational field is incompatible with any tenable model of a quasar.
In addition, recent studies of the distribution of quasi-stellar sources throughout
the sky, taken together with the other considerations, strongly suggest at present
that such alternative explanations are unlikely to be correct. So we are returned
to the original interpretation of the spectral shift, and with it to the belief that the
enormity of the distances of the quasars is indeed real. Yet it may still be possible
that there are profound reasons for these great redshifts that are yet to be dis-
covered. The grand mystery, and the grand paradox, in some sense remain.
It was a bare two years ago that Anthony Hewish and his colleagues at Cam-
bridge University discovered an entirely new kind of object in the heavens — a
source of radio energy whose emission came in sharply defined pulses of about
10 to 30 milliseconds at extraordinarily regular intervals. Since that time,
more than 35 sources of this kind have been detected. The great majority emit
their pulses at intervals of 0.5 to 1.5 seconds. So consistent are they that a
single object has been found to hold its pulse intervals predictable to one part in
109 over periods of weeks, although a gradual slowing over longer times seems
characteristic.
With a single exception, all pulsars have been found to emit energy only in the
radio range, and consequently are quite invisible to optical telescopes. That excep-
tion, however, is peculiarly dramatic. The possibility that pulsars might be
associated with the remains of ancient explosions of supernovae was considered
shortly after their discovery. Speculation along these lines was heightened when
a new pulsar, PSR-0833-45, was discovered in the southern hemisphere within
an extensive, roughly circular zone of unusual radio intensity in the constellation
Vela, a zone believed to mark the remnants of an ancient nova. An especially
striking feature of this pulsar was the period of its pulses — at 89 milliseconds
REPORT OF THE PRESIDENT 9
the shortest then detected. In 1968 another "fast" radio pulsar, NP 0532, was
more certainly detected in the vicinity of another supernova, this time the famous
Crab nebula, the explosion of which is known from records in the annals of
Chinese astronomy to have been observed in A.D. 1054. Interestingly, and in
terms of the evolutionary history of pulsars perhaps significantly, this object was
yet " faster" than that in Vela, with a period of only 33 milliseconds, and with two
distinct pulses. Early in 1969 three astronomers of the Steward Observatory at
the University of Arizona succeeded in demonstrating strong optical pulses from
this object, with a period corresponding to that of its pulsations in the radio
region, and with the corresponding two components. Astronomers at the Lick
Observatory, and Kristian, Westphal, and Snellen of the Mount Wilson and
Palomar Observatories, made detailed observations of the phenomenon. So the
first — and thus far the only — optical pulsar had been identified and characterized.
It is especially interesting that the star emitting these pulses is the very one that
Walter Baade and Rudolf Minkowski, twenty-seven years before, had predicted
would be found to constitute the remnant of the supernova itself. In May of this
year (1969) X-ray pulses were detected in the region of the Crab nebula, pulsat-
ing with frequencies clearly matching those of light and radio energy, and almost
certainly proceeding from the same source.
Early in the spring of this year, a startling new observation of pulsars was
made that further complicates their interpretation. Between late February and
early March 1969 the pulsar in the constellation Vela, PSR-0833-45, which,
next to the pulsar in the Crab nebula, has the shortest period known, but which
had shown a consistent gradual slowing of its pulse rate — as is characteristic of
pulsars in general — suddenly speeded up. However, the burst was short-lived.
By mid-March the rate was back to that of late February, before the aberration
had occurred. What had happened to bring about this unexpected, dramatic,
short-lived acceleration? Currently, the cause of the phenomenon remains
uncertain.
What, in fact, are pulsars? Unlike quasars, which appear to occupy regions of
the universe so vastly remote from us, pulsars seem comparatively near neighbors.
Recent distance measurements reported for pulsar CP 0328 suggest that it may
lie less than 3000 light-years away, and the distance of the Crab nebula itself is
reckoned at some 5500 light-years. If these distances are at all typical of the class,
it is conceivable that vast numbers of pulsars may exist within the confines of
our own galaxy. But the question of their basic nature is still open. Opinion of
astrophysicists and cosmologists has increasingly converged to the view that
they may be rotating, oscillating, highly magnetic neutron stars. Yet the surprising
"hiccup" in the pulse rate of pulsar PSR-0833-45 is not easily explained in the
framework of that model, at least in its original version. As with quasars, the
frontier of our understanding of the nature of pulsars stands open, presenting us
with one of the greatest mysteries in our cosmos, and one of great challenge
to future investigation.
When, in 1943, Edwin Hubble and Milton Humason presented their com-
pleted velocity-distance curves, based on the period-luminosity law for distance
of extragalactic nebulae and upon the redshifts, as shown by photographs for the
velocities of recession, a new landmark of cosmology had been set. For the
implication that they carried — that of an ever-expanding universe in which all
the galaxies were moving steadily away from one another — represented a radical
change in man's notions of his environment. Sir Arthur Eddington remarked
10 CARNEGIE INSTITUTION
that it was "so preposterous that I feel almost an indignation that anyone
should believe in it except myself." It posed an alternative, and a sharp chal-
lenge, to the "static" models of the universe that had been current since long
before its day. Even now, a generation later, static theories still have some able
proponents. Yet many telling arguments can be, and have increasingly been,
advanced in favor of the "big-bang" model of the evolution of our universe, as
Hubble's theory has currently come to be called. The sum total of work on
counts of radio sources and of quasars in the heavens offers strong evidence
for it.
Yet difficulties remain. Essential to this concept is the "Hubble constant" —
the factor connecting the distance of a galaxy and the redshift in its spectrum. And
problems in determining the distances of galaxies in space persist — problems
connected with those guideposts of the heavens, the cepheid variables, which in
the northern hemisphere provided the essential yardsticks for Hubble's work.
Indeed, galactic distances today are generally estimated at some ten times the
original figures proposed by Hubble. It has even been suggested that the value of
the constant itself may change with cosmic circumstances. It is upon the concept
of the Hubble constant, of course, that estimates of the enormous distances of
the quasars are based today. And fundamentally, it is upon the accepted value
of the constant that estimates of the elapsed time since the "big-bang" may have
occurred must rest. Clearly few things can be more central to cosmology than an
accurate determination of its value.
That determination, however, faces great experimental difficulties so long as
observations are confined to the skies of the northern hemisphere. The local
anisotropy of the Hubble kinematic field must be mapped for the nearby
galaxies before the Hubble expansion rate, with its associated time scale, can be
accurately determined. This can be done only by combining data from both the
northern and southern hemispheres. It is necessary to establish distances for
southern groups of galaxies by studying their stellar content, using photoelectric
and photographic photometry. A large amount of data must be collected. And in
the heavens of the southern hemisphere lie the Magellanic Clouds, as well as a
series of more distant galaxies, which can provide observational "yardsticks" for
a redetermination of the Hubble constant: a redetermination which could be
of the highest significance to all our concepts of the universe. For such reasons,
and for others only less obviously compelling, the southern hemisphere offers
immense opportunities for astronomy in the future. But even the physical facilities
for exploring them on a truly adequate scale are yet meager. There is surely no
greater need in optical astronomy today than that of a really powerful telescope
in the southern hemisphere.
It is not only in the realms of quasars and pulsars, or of galaxian astronomy —
critical to questions of cosmology — that the great frontiers of astronomy are
expanding in our day. That fact was brought vividly home during the year just
past in the startling detection by Charles H. Townes and his colleagues at the
University of California of the signature of ammonia in the radio spectrum of a
small but dense cloud lying in the direction of Sagittarius, near the center of the
Milky Way and perhaps 30,000 light-years from earth. It was the first time that
a molecule of this order of complexity had been identified in space, and analysis
of its microwave radio spectral lines suggested that it may have been present in
REPORT OF THE PRESIDENT 11
a density of the order of one molecule per liter. Against this discovery, it is
difficult to remember that only forty years ago, or even less, the space between
the stars in our galaxy was thought to be a complete vacuum.
Astronomy is not the only field of research where exciting vistas of new knowl-
edge and understanding have opened during the year just past. Indeed, a con-
vincing case can be made that challenges to our vision as fundamental and
moving, and lying much closer to our own immediate concerns, have been posed
over the past few months by the life sciences.
Some time ago the British biologist N. W. Pirie, discussing the chemical consti-
tution of viruses, remarked: "Twenty years ago it was prudent to stress, in
articles or reviews dealing with the properties of viruses and the processes of
virus infection, that the viruses about which we had any significant amount of
information were not necessarily representative of the group as a whole. Chemical
criteria controlled the selection of viruses for study; chemical uniformity among
them was therefore not surprising. However, so many viruses have now been
purified and investigated that there will be justifiable amazement should one
turn up that does not contain nucleoprotein." That statement may still be
correct. But in the last several years it has received one extraordinary challenge
for which there is, as yet, no satisfactory answer.
For at least two centuries shepherds in several countries have stood in dread
of a mysterious disease. It struck their flocks unexpectedly, and once established
was likely to proceed slowly but inexorably through the whole population, killing
sheep after sheep in a characteristic and curious way. In France, the disease
was given the name la tremblante, reflecting the shivering, the progressive loss
of muscular power and coordination, and the hypersensitivity that were typical
of the disease, and suggesting a primary involvement of the nervous system. In
England it came to be called scrapie from another behavioral peculiarity that
characteristically accompanied the early stages of the disease: the compulsive
rubbing of the afflicted sheep against trees or fence posts, until whole patches of
the body were bared of wool.
Fifty years of research were of no avail in solving the riddle of the nature of
the disease or of its causative agent. Not until 1938 were two investigators, J.
Cuille and P. Chelle, able to produce the disease at will in experimental animals,
particularly goats, using tissues taken from infected sheep. It was even longer
before the infection of small laboratory animals was achieved. A decade of study
of the tissues of infected animals failed to demonstrate the existence of any
viral agent. Electron microscope photographs were negative. Serological studies
failed to detect the production of antibodies in animals with the disease, or to
detect a scrapie antigen. And, whatever the agent might be, it proved astonishingly
resistant to treatments that would be expected to destroy nucleic acids in short
order. Brain tissues from an infected animal, preserved in 10 percent formalin
for from 6 to 28 months, proved capable of transmitting the disease. Heating to
100 °C for half an hour did not destroy the agent or the infectiveness of material
so treated. Exposure to chloroform or phenol did not inactivate it. And very
recently it has been shown that the agent, whatever it may be, is unaffected by
12 CARNEGIE INSTITUTION
doses of ionizing radiation that will virtually destroy a "standard" virus by
wholesale inactivation of its nucleic acid.
Could it be that the agent of scrapie does represent an exception to Pirie's
comment — a first exception to that crucial assumption of virology? Is it possible
that an agent can exist, so minute as to escape the electron microscope, "living" in
the sense that the numbers of its particles can increase within its host, infect new
hosts and yet not contain a core of DNA or RNA?
That would indeed be an extraordinary exception to all that we know of earthly
life at every level, and one that could be accepted pnly after exhaustive proof.
Yet the extraordinary properties of this infective particle, if such it is, for some
years encouraged such speculation in more than one quarter, and the possibility
still remains. But some evidence obtained in the last two or three years may
weigh against so radical a conclusion. It has recently been demonstrated that
when homogenates of scrapie-infected tissues are passed through viral filters
with a pore diameter in the range of 20 to 40 millimicrons their infectivity is
indeed suppressed. If this in fact represents a truly limiting pore dimension, it
suggests a molecular weight for the particle of about 50 million — comparable to
that of some known viruses.
Other recent experiments have demonstrated that, though the agent is indeed
astonishingly resistant to irradiation with ultraviolet, it is not completely im-
mune. So it has been possible to construct a curve relating extent of inactivation
to radiation dose. The portion of the "particle" vulnerable to the radiation can
then be determined by the statistical "target" methods first developed in the
laboratory of Mme. Curie. When this was done, yet another anomaly appeared.
For this target diameter did not turn out to be the 20 to 40 millimicrons indicated
by the filter experiments, but rather proved to be of the order of 7 millimicrons.
A possible interpretation of this discrepancy, retaining the assumption that RNA
or DNA is involved, might be that a small strand of naked nucleic acid, susceptible
to ultraviolet, may bind to the membrane of the infected cell, forming a larger
aggregate which then is somewhat more resistant to the radiation. But a strand
of nucleic acid of these dimensions would hardly seem able to accommodate base-
pairs sufficient to code for a single determinant of structure! The enigma of
scrapie still stands as a highly challenging puzzle at the very frontier of life.
And the challenge, fascinating and fundamental at the theoretical level, goes
further. For scrapie is in some ways remarkably reminiscent of other dread
diseases of the nervous system, such as encephalomyelitis and disseminated
sclerosis. And in many ways it is suggestive of kuru. This strange human nervous
disease, discovered early in the 1950's, is wholly confined to the single, minute
Fore tribe of the eastern New Guinea highlands and to persons who have inter-
married with them. Like scrapie, the disease typically traces a deliberate but
inexorable course to death. The brains of its victims show remarkable etiological
similarities to scrapie-infected neural tissues. Moreover these pathological changes
may simulate to a remarkable degree brain changes sometimes accompanying
extreme normal senility, as though kuru might precociously model such normal
changes.
Is kuru related to scrapie? Is it infective? If so, how does it infect? D. Carlton
Gadjusek and his colleagues, who have supplied much of our information about
kuru, have succeeded in infecting the chimpanzee with the disease and, very
recently, have infected a species of New World spider monkey. Serial transmis-
sion has been achieved with the chimpanzee. But the nature and the size of the
REPORT OF THE PRESIDENT 13
transmitting agent, and its relationship to the agent of scrapie — or to those of
such superficially similar nervous diseases as the recently prominent encephalop-
athy of mink — remain unknown. Ahead lie opportunities for discovery of far-
reaching significance in both biological theory and medical practice.
Exciting and important as these particular frontiers of biology are, they repre-
sent only particular facets of the wide range of challenges that the life sciences pose
today, but one restricted group among hundreds of equally luminous fascination.
If problems involving the structure and functioning of DNA occupied the center
of the stage during the decade that is closing, it is easy to see that during the
next that place will be preempted by far more diverse questions of structure and
function involving the various species of RNA through the action of which the
coded genetic message is brought to reality. Surely the manifold problems of
cell growth, differentiation, and organization; of the maintenance of continuity
and stability in the living organism; of the miracles of embryology and birth
and senescence, will over the coming years provide as stimulating and important
challenges, as multifarious and extensive frontiers, as have ever engaged the
mind of man.
In fact, it is inaccurate to cast such challenges as a part of the future, for already
they are very much a part of the present. Clearly emphasis will shift more and
more in the future to the question of reaction systems in biological research.
There will be issues of the utmost difficulty here — especially since the scientific
method is still ill equipped to formulate them in terms susceptible to experi-
mental test. Yet the significance of even slight alterations of a few components in
biological systems can be profound, and can affect all their evolution. One recalls,
for example, the virtual identity of the amino acid sequences in the alpha chain
of hemoglobin in man and the great apes. Man and the gorilla, for example,
appear to differ in only one out of more than one hundred and forty such amino
acids, and in the chimpanzee the sequences seem to be identical. There has been
little evolutionary divergence here. Yet think what the simple evolution of vocal
cavities in man, and of the ability to use them, has meant for his divergence in
evolution from the great apes !
Indeed, no questions can be more challenging than those involving the mecha-
nisms by which the panoply of cell differentiation and specialization — so charac-
teristic of higher animals is brought about during growth, and how such speciali-
zations are then maintained. Thanks in good part to the powerful and versatile
laboratory -techniques for the hybridization — the base-pair matching — of DNA
and RNA developed in recent years and now employed in a wide variety of investi-
gations, it has become amply clear that in most multicellular organisms every
cell of the body, however specialized its structure and however narrowly cir-
cumscribed its normal functions, carries the full complement of genetic informa-
tion inherited from its parental egg cell, specifying in its own chromosomes every
trait of body and nervous system of the complete organism.
It has been recognized for a long time that mechanisms of the utmost delicacy
and precision must exist to "mask" the great bulk of that potential information
store, permitting translation and expression of only that critical fraction re-
quired in the growth and function of a particular cell of hair or bone, of skin
14 CARNEGIE INSTITUTION
or brain. But the elucidation of the precise means by which this delicate dis-
crimination of information is brought about will surely continue to be an absorb-
ing task through the coming decade.
It is clear, for instance, that selective "masking" of information can be
imposed at different levels in the translation and transcription of the genetic
code. The determination of the significant stage or stages in any particular situa-
tion alone offers a formidable challenge. For various reasons, however, the step
involving selective decoding of the DNA itself has received particular attention.
At one time it was speculated that certain histones, a class of proteins containing
large amounts of arginine and lysine and complexing readily with DNA, might act
as gene regulators. The difficulty with such a concept, however, is that a vast
library of distinct and specific histones would surely be required to selectively
inhibit the wealth of gene-sites on the cell chromosomes. Actually, only about
five types of appropriate histones are known, and they occur in widely varying
amounts in different plants and animals. Their structural range is clearly insuf-
ficient for so delicate and versatile a function.
As is often the case with major conceptual advances, a fertile approach to
this puzzle has been generated from a reversal of viewpoint. It is possible that
histones do indeed "mask" gene action, but in a general and nonselective kind
of way. The essential process of selecting a particular portion of the total store
of genetic information may not be the masking of the unwanted but rather the
unmasking of the wanted, the removal of the "covering" at correct sites in the
DNA at crucial times in the development of the cell and of the organism contain-
ing it. So the critical questions become: What is the nature of the unmasking
agent? And how does such an agent achieve its extraordinary specificity? Prob-
ably many answers will ultimately be revealed. Recently, for example, it has
been proposed that glucagon, a pancreatic hormone inducing the synthesis of
enzymes in liver cells, causes a large increase in the phosphorylation of a particu-
lar fraction of liver histone, and that changes produced by this phosphorylation
could inactivate the repressive effect normal to a histone, thus "uncovering" some
DNA sites in the liver cell.
It is interesting to examine some of these specific questions with reference to
the wider panorama of the general principles around which living things in
general are organized and through which they operate. For the principle of
selectively de-repressing elements normally held in bondage is indeed, as we
are now discovering, a widespread and fundamental element of biological organi-
zation at many levels. It clearly lies at the base of the dramatic reorganization
of tissues that transforms the caterpillar into the butterfly. It is clearly responsi-
ble for the development and the remarkable maintenance of organization in
colonies of the social insects at levels of both structure and behavior. It is empha-
sized in the recent proposal to designate a functionally new class of biological
substances as chalones: substances which, alone or in combination with other
body products such as hormones, can exert a continuing suppressive action on
the normal growth potentials of cells. Such suppression may be released, with
overall adaptive consequences, when the concentration of the inhibitor is lowered.
The effect is well illustrated, for instance, in the accelerated proliferation of tissues
after wounds that reduce the normal concentration of their chalones.
All these observations, of course, address but the tips of the iceberg, as it
were, in the grand panoply of biological organization at the level of molecules and
genes. A theoretical approach to this whole question was made this year by Roy J.
REPORT OF THE PRESIDENT 15
Britten of the Carnegie Institution of Washington and Eric H. Davidson of the
Rockefeller University. It proposes that regulations of this sort could be the
province of special genes which may be present in thousands or even millions of
replicates or near-replicates in the nuclei of the cells of higher organisms. This
concept, which may well prove a "takeoff" point for the achievement of new levels
of understanding of biological systems — and of evolution itself — is described else-
where in this Report.
The whole field of the mechanisms of operation of living systems, for which
quantitative studies of the interaction of cell systems at the biochemical level
form such vivid paradigms, constitutes one of the major biological research
frontiers of our time. The vast and informationally rich situations that include
not only the interactions of cells and the viruses that inhabit them but also those
among the organelles of single cells — spherosomes, lysosomes, provacuoles, teno-
plasts, and the rest — involve analogous dynamic systems. And at the other end
of the spectrum of size and kind, similar principles of biological organization
almost certainly operate in those associations of organisms independently derived
in development which are nonetheless closely associated, physically and func-
tionally. Such associations, of course, may range from the specialized, fused
"individuals" that make up the constitution of that great "jellyfish," the Portu-
guese man-of-war, through the colonies of the social insects that have for so long
captured the human imagination, on to the infinitely complex and contemporary
and urgent problems of human societies. Internal structuring of feedbacks,
especially of a negative sort, or the formation of functional hierarchies in bio-
logical organizations — nowhere more dramatically suggested than in the frag-
mentary evidence that we have of the mode of functioning of the human brain
in its vast and infinitely delicately operating organization of 109 cells or more
— a congeries vastly greater and far more highly evolved in its organization
than the greatest conurbations that the human race has ever known — takes on
special interest in this context. In this context, too, one recalls the contrasting
metamorphoses of the migratory locusts that form the great swarms which
long before Biblical times must have posed a legendary menace to man and
continue to do so today. If such locusts have matured in populations of low
density, they are likely to be solitary, sedentary green insects which may eke
out their lives almost unnoticed. If, on the other hand, they have attained
adulthood in massed crowds, they become restless, long-winged, black-and-yellow
creatures which gather into those immense, ravenous, tireless armies that since
the dawn of argiculture have been the scourge of man. One recalls in this context,
too, the effects of unaccustomed experimental crowding upon mammals ranging
from rats and nutrias to cats and baboons. The onset of organic diseases of
unprecedented severity and with unprecedented frequency, the hypertrophied
adrenal glands, the widespread antisocial behavior, the steady deterioration of
the ordered social structures which mark these experimental populations lead
the observer to wonder about the human condition.
Alfred North Whitehead once remarked that science as we know it could have
arisen only in the matrix of centuries of Christian civilization, since only a
profound faith in the values of the natural order could have provided the initial
impetus for its dedicated and total commitment to the elucidation of that order.
It is indeed in this aspect of science, so vividly memorialized in those multifarious
16 CARNEGIE INSTITUTION
conquests of understanding — in those bursts of vision that over and over have
brought home anew the beauty and intricacy and sometimes the might of our
universe; in those bursts of vision that often enough have seemed at first to
diminish our own stature in the universe, and so on occasion have been greeted
with a popular resentment ultimately converted to a fresh humility — that some
of the finest epics of the human spirit have been written. Clearly, this face of
science provides a resource for the spirit that is enormously significant in our
troubled day, and must remain so for all the future.
A complementary aspect of science, and one of major human significance, has
been conspicuous ever since the days of Francis Bacon. In our workaday world,
indeed, it sometimes preempts attention so effectively as to be regarded as the
essential characteristic of the scientific way. It is "scientific-research-with-a-
goal." The goal is the important one of bettering man's condition through the
control of nature. That control and that betterment, as three centuries of experi-
ence have deeply impressed upon us, are best achieved, in the first instance,
through a better understanding of nature. A predominant part of our material
civilization, of our comfort and affluence, of our physical health, as we are
acutely aware, is the cumulative consequence of investigative work directed to
those ends over a span of at least two hundred years. In our day we should not need
to be reminded — although there is now real and growing evidence that we do need
to be reminded — that, materially as well as spiritually, scientific research is
one of the most significant of all our activities.
At their proximate margins, there is little visible difference between scientific
investigation undertaken with the primary object of understanding nature and
that initiated with the primary object of controlling nature. Indeed, the two
motivations may be inextricably entwined within a common program, as they
so often are, for example, in medical research. Understanding and power can
indeed proceed together.
But despite the fact that both motivations are extremely important to the
progress of science ; despite the fact that they are highly complementary and that,
often enough, the kinds of scientific investigation that they inspire may be quite
indistinguishable, it is undeniable that the motivations themselves do differ in
important ways, and in certain circumstances it is important to distinguish them.
Two reasons for this are worth emphasis. First, the second orientation is
basically derivative, and in that sense is inherently dependent on the first. Typi-
cally, research with predominantly practical motivation extends frontiers of
knowledge already touched by investigations of the first kind, often expanding
and refining them with discrimination and power. But less frequently does it open
wholly novel salients, and rather rarely is it prosecuted consistently in an area
where tangible benefits do not appear within a reasonable length of time. This,
of course, is as it should be. But it also means that if the second motive were ever
to replace the first on a general scale we would be in great difficulty, for a good
share of our initial impetus would necessarily be lost. There is an ever-present
risk here, which, if remote, is also dangerously real. The nature of the practical
world is clearly such that, unless both the distinction between the two motiva-
tions, and their complementarity, are borne constantly in mind, the second view,
instead of interweaving with the first, might indeed come to supplant it. That
would be catastrophic indeed.
REPORT OF THE PRESIDENT 17
The second danger inherent in the failure to make this distinction is more subtle,
and surely even more important. For just as the first motivation of the scientific
way can provide a constantly renewing source spring for the human spirit, the
second, if fully dominant, could, on occasion, stanch the flow of those springs, thus
actually increasing the weight of so many other dangerous forces of our time.
For it is a curious but unmistakable circumstance that the most striking suc-
cesses in controlling the natural world, in contrast to the greatest advances in
understanding it, have on the whole tended in the short run to enhance man's
vision of his stature in the universe. We have been exposed to the heady euphoria
of that experience so often, and with such ever-increasing intensity, over the
past half century, that it is worth reflecting most soberly upon some of the effects
that can follow. Just as the painful experience of a diminution of man's view of
his place and stature that has so often accompanied the great discoveries has
typically been succeeded by a tautening of inner fiber, by a refreshing of inner
wellsprings, by a sense of oneness with a universe enhanced in his respect; so
the euphoric experience of success in control of the natural environment can have
— and often enough is having — precisely the reverse impact. It can lead to
manipulation of the natural world unguided by reverence or comprehension, to
the philosophy of "it works, therefore it is right." Unless we are both wise
and vigilant, such experiences, accumulating through almost every day of
our lives, can ultimately reinforce those spiritual scourges of our time: insecurity;
alienation; total identification of nature with the man-made environments, and
as a corollary to this view, a crushing sense of individual and personal responsi-
bility for all that takes place — and particularly for all that goes wrong — in that
world. Finally, and most seriously, there can be a contrary reaction: the total
personal frustration inherent in the view that the human world is already so
completely molded and fashioned that the only way the individual can make
a significant impact upon that world is by destroying it. These are the dangers
that we face: dangers that are to be mitigated only by a steadfast and wide-
spread cultivation of a deep and sensitive understanding of the very nature of
the scientific way.
As the year 1969 marks the hundredth anniversary of the discovery of DNA
by Friedrich Miescher, it also marks the one hundred and forty-first of another
major scientific accomplishment of a somewhat different kind. In 1828 the
German chemist Friedrich Wohler, student and friend of Gmelin and Berzelius
and collaborator of Liebig, succeeded in producing the compound urea by heating
an aqueous solution of ammonium cyanate, formed in turn from a mixture of
potassium cyanate and ammonium sulfate. In the light of modern chemistry this
was a simple and straightforward reaction, and no one today would pay particu-
lar attention to its first accomplishment. Yet it represented a historic watershed
in man's conquest of nature. For in that day no chemical compound elaborated
by a living organism had been synthesized in the laboratory. Urea was universally
conceived as the product of life — almost as a part of life. The chemist had taken
a step so radical as to seem well-nigh incredible to some.
One speculates what Wohler, the pioneer of that frontier, would have thought
of some of the analogous syntheses of life-materials achieved today — syntheses
so extraordinary that they could only have filled him with wonder, yet which we,
as contemporary and sometimes oversophisticated observers, are all too prone to
18 CARNEGIE INSTITUTION
take for granted. What, for example, would Wohler, were he living at this hour,
have to say about the total laboratory synthesis of the enzyme ribonuclease
achieved for the first time this year independently by two teams, one at the
Rockefeller University and the other at the Merck Sharp and Dohm Labora-
tories of Merck & Company? The approaches of the two teams were wholly
different; yet in each case the final product showed the same biological activity
as the natural one, splitting ribonucleic acid but having no measurable effect on
DNA. If one enzyme which takes so central a part in the direction of life processes
can thus be synthesized in the laboratory, others, equally vital, can and will.
Their potentialities in the combating of disease and in achieving further levels of
understanding of life processes need no emphasis.
One wonders, too, what Wohler would have thought of the artificial synthesis of
polypeptide compounds with properties very similar to those of natural collagen,
completed at the Weizmann Institute during the year just past. Or again, what
would he have thought of the first crystallization of a multienzyme complex, the
fatty acid synthetase, at the Max Planck Institute for Cell Chemistry in Munich ;
or of the transfer-RNA used by the colon bacterium in adapting formyl methio-
nine to recognize starting points of the messages in messenger RNA, through
which the initiation of protein synthesis is effected, at the Laboratory of Molecular
Biology of the British Medical Research Council at Cambridge? This remarkable
accomplishment may well open the door to the use of X-ray crystallography to
determine the tertiary structures of the specific kinds of RNA molecules involved
in translation of the genetic code.
These and similar investigations during recent years have dramatically illus-
trated the rate and scope of growth in our power to create in the laboratory many
of the most central components of life itself, and through that power to manipu-
late life processes with new sophistication and effectiveness. It is a power with
immense and still only dimly understood implications for man's health and
welfare and even his physical destiny.
There are many other approaches to this power. One need only cite such
recently developed techniques as the artificial hybridization of cells from tissues
of animals as different as a man and a mouse. With suitable techniques, hybrid
somatic cells can be produced that include chromosomes of both the contributing
partners within their single nuclei. Such cells can be made to grow and propa-
gate. Over successive cell divisions, however, excess chromosomes in the com-
posite nucleus are gradually lost. The way they disappear, and the kinds of
changes the cells undergo as they are eliminated, is providing extraordinarily
interesting evidence for the study of chromosome dysfunction. Furthermore this
evidence may permit the mapping of human chromosomes with an order of
precision and comprehensiveness never before approached. For example, this
method has made it possible to accurately locate in human somatic chromosomes
certain genes involving deficiency diseases of metabolism. It has been possible to
demonstrate X-linkage for the determinant, or determinants, of 8-azaguanine
resistance in man. Perhaps most exciting, cancerous mouse cells have recently
been fused with noncancerous mouse fibroblasts by Professor Henry Harris and
Dr. 0. J. Miller at Oxford and by Dr. G. Klein, Dr. P. Worst, and Dr. T. Tachi-
bana of the Karolinska Institutet at Stockholm. Similar experiments have been
attempted before, in the hope of exploring a means to suppress cancer, but the
results were discouraging since the hybrid cells turned out to be cancerous. In
this instance, however, malignancy was initially suppressed. But as the descend-
REPORT OF THE PRESIDENT 19
ants of the polyploid hybrids shed chromosomes in the course of further divisions,
the daughter cells reverted to malignancy. Thus it seems clear that the non-
malignant partner contained some chromosome-linked determinant capable of
suppressing malignancy. It may now be possible, through long and patient cyto-
logical work, to "map" the hybrid cell genome for this factor, precisely as with
some human metabolic deficiencies. Extensive work obviously lies ahead, and
certainly no "cancer cure" is even remotely in the offing. Yet even the tentative
location of a cancer-inhibiting genetic locus would be highly significant.
Perhaps even more theoretically important, evidence seems to have been
obtained that histocompatibility antigens can be suppressed under certain condi-
tions. This finding may have even greater significance for the future, particularly
in view of the growing suspicion that a whole range of "autoimmune" reactions
suggesting the attack of certain body cells upon other cells in the same body —
"target" cells perhaps rendered unrecognizable to the attackers by some means-
may be responsible for some of the most intractable of the long-range degenerative
diseases of the general character of kuru and scrapie, and, as such disorders could
be hinting, might possibly be relevant to the very process of aging.
Again, the feat of growing complete organisms from single cells of the body
offers spectacular practical corroboration of the fact, already so well demon-
strated in experiments in DNA hybridization, that the complete range of genetic
information contained in the developing egg of an organism is typically pre-
served in every somatic cell of the mature body. This impressive achievement is
not, to be sure, particularly new in principle, for entire plants were developed in
cultures derived from single somatic cells some years ago. But the accomplish-
ment has recently been extended by J. B. Gurdon and his colleagues at Oxford
University to technically far more difficult animal material. Gurdon and his asso-
ciates succeeded in removing the nucleus from a body cell of the primitive clawed
frog, Xenopus laevis, and implanting it in an unfertilized egg cell, the original
nucleus of which had been inactivated by radiation. A complete individual
developed from this egg, recalling the results of earlier experiments of Briggs and
King made with the more advanced frog Rana. This achievement is of course
technically far more difficult than the corresponding one with plants. But its
striking and vivid character has caught the imagination of those who would extra-
polate our biological future to embrace a capacity of this kind in human terms.
The remarkable technical feat of growing and fertilizing mammalian egg cells
outside the body, accomplished in hamsters some four years ago, has been
extended to human ova by three investigators from Cambridge University and
the Oldham General Hospital in England. This surely represents a new dimen-
sion in the manipulation of life, and may open the way to a detailed future
understanding of the metabolism of human oocytes. In turn, it suggests new means
for interfering with the processes of maturation in human ova — knowledge that
might become of real significance in the general field of birth control.
In yet another arena, techniques developed in recent years to permit the
physical examination of the chromosomes in cells from many tissues of the
human body have enormously extended our powers of diagnosis. These powers
have also increased our awareness of some of the effects that gross chromosome
abnormalities may have on the lives and the happiness of the unfortunate indi-
viduals that bear them. For instance, it has been recognized for a number of years
that the inclusion of an extra chromosome 21 in the human genome is commonly
20 CARNEGIE INSTITUTION
accompanied by characteristic physical and mental abnormalities. But recently
it has become feasible to detect such gross chromosome aberrations in the affected
infant before birth. The sinister effects of LSD and other drugs in inducing
abnormalities of the somatic chromosomes have only recently been fully recog-
nized, thanks largely to techniques of this kind. And such techniques are currently
permitting much more comprehensive research on the still-moot question of
whether the possession of an extra sex chromosome — an X or a Y in the human
male, the XXY and XYY syndromes — is accompanied by a statistically greater
tendency to criminality or violence.
Last but by no means least in this array of latter-day medical conquests come
the remarkable surgical achievements of recent years in the transplantation of
organs — achievements which, although they must be judged differently in different
circumstances, are in any case highly noteworthy. But, like so many other ac-
complishments in the realms of biomedicine, they too are vulnerable to being
popularly cast in a dangerously spectacular role.
Given all these advances in our power over biological nature, reaching so far
beyond what was imaginable only a few years ago, it is little wonder that our
dreams for the future can on occasion run wild — sometimes cruelly, and even
dangerously, wild. It is here, perhaps, that public consequences of the euphoria
that so typically accompanies great strides in the control of nature are to be
viewed with the greatest reserve, and circumscribed with the greatest vigilance.
Uninterrupted progression to the reliable control of cancer, to reliable genetic
engineering eliminating inborn and metabolic diseases on a grand scale, to the
production of identical copies of notable men and women by the methods of cell
cloning that have succeeded in rare and special instances with carrots and with
frogs, to the artificial fertilization and transplantation of human ova as a
standard procedure, to the transplantation of human organs on a wholesale scale
with the establishment of widespread and numerous storage banks for them, all
too often seem to the uninitiated simply further and more imaginative con-
ceptual extensions of the present.
As a result of the confluence of several conceptual streams, we stand today at a
curious crossroad in this aspect of the public concept of science, and particularly
of science in medicine. We live in the grand tradition exemplified by the work of
Wohler and epitomized even more vividly in our day by that epoch-making
paper of 1927, wherein Hermann Muller demonstrated for the first time that
X rays, generated in a wholly man-engineered device, could bring about consider-
able genetic mutations, modifying the very materials of Darwinian evolution
hitherto thought invulnerable to any outer influence. That is the tradition of our
still-growing power to modify life processes in ways and on a scale inconceivable
before our time. Simultaneously we are working in another tradition which a
century of brilliant successes has made so much a part of us that we rarely ques-
tion it — the tradition symbolized by the life and work of Louis Pasteur, the tra-
dition of the germ theory of disease. But as Dr. Philip Burch has presciently
commented, the discovery of the role of bacteria in disease, that brilliant jewel
in the medical and biological crown of another century, and the contemporary
spectacularly successful applications of the vision, have indeed resulted in the
virtual eradication of what in Pasteur's world were among the most severe of
human scourges. But they may also have bequeathed to us a legacy of custom and
orientation that in future could be less helpful. That is the doctrine, understand-
ably entrenched in most public health programs, of "cause-then-cure" — the
REPORT OF THE PRESIDENT 21
doctrine that every disease must be identified with some external causal agent.
The conquest of such diseases, then, is a matter first of identifying the agents with
the conditions which they bring about, and then by suitable large-scale attacks
wiping them out, as we have wiped out typhus and yellow fever in many areas.
But conditions like the genetically mediated metabolic deficiencies, or the count-
less subnormal syndromes in which genetic constitution and some outside agent
seem to cooperate, may be trying to tell us something else. They may be suggest-
ing that the conquests of disease and the challenges of public health in the last
century, magnificent as they were, lay only at the easier peripheries. Increasingly
in our day, and surely in the next century, medicine will be preoccupied with
chronic illnesses — with cardiovascular and malignant disorders, with arthritis
and diabetes, with psychoses and multiple sclerosis. We will surely become
more generally familiar with Sir Macfarlane Burnet's brilliant "forbidden-clone"
theory of autoimmunity: with the idea that single mutant cells in an individual
may, in the course of that individual's life, generate clones of somatic descend-
ants which, either directly or through their products, can then attack cells of
neighboring tissues. As the massiveness and severity of that attack exceed
some limit of tolerance, symptoms of long-term degenerative conditions may
appear. When we have truly comprehended possibilities of this sort and accorded
them equal emphasis with the more conventional philosophy that ascribes dis-
eases wholly to agents entering from outside the body, we may come to regard
certain medical projections that seem particularly apposite and dramatic in our
day in a somewhat different light.
At present, for example, we are greatly — and properly — concerned with the
development of antilymphocyte sera, and we are preoccupied with their use in
suppressing the tendency of the human body to reject the graft of a foreign
organ, such as a heart. At least one hundred and forty-two heart transplants
have been made since the first operation was performed on Louis Washansky on
December 3, 1967. Of these, some thirty-seven patients now survive. At least two
survived for more than a year, and this has been considered a triumph in the
control of rejection reactions. But it is certainly worth consideration that if
selective suppression of host elements that are incompatible with a foreign graft
can thus be achieved, then surely it should also be possible to develop sera to
suppress the cells within the patient that destroyed the organ in the first place.
The development of fully successful means to ensure the acceptance of the
foreign grafts might thus significantly contribute to by-passing the whole
transplantation process itself. Perhaps we shall look on this as a primary objec-
tive of future research on sera. There may be a moral here applying equally
to other of the more immediate and extravagant projections of current laboratory
developments in biological manipulation and control to fields of medicine and
sociology that are so often heard. Surely it is upon further growth in the processes
of understanding that the main thrusts of biology and medicine should be con-
centrated over the next decades.
But there is of course a broader and yet more serious aspect to the tendency of
our day to overweigh the image of science in the direction of practical — indeed
sometimes of wildly practical — application and control. A century ago the great
French physiologist Claude Bernard remarked to his colleagues, "True science
teaches us to doubt, and in ignorance to refrain," or, in Lord Ritchie Calder's
22 CARNEGIE INSTITUTION
contemporary expression: "Science feels its way, with a mine detector, from one
safe foothold to another." This is deeply true. And yet it is a truth often difficult
to keep in mind in an age when the marvels of biological vision surpass all earlier
imagining, when the spread and dominance of computers bid fair to change not
only the styles of our thought but major substantive aspects of our thinking too,
and when the topographies and climates of planets have become of immediate
and practical concern.
Indeed, it is often difficult to keep in mind in this day what science is. Sir
Herbert Dingle has recently pointed out an important and threatening aspect
of this confusion. The circumstance that the final arbiter in science is the crucial
experiment, as it has always been, provides critical assurance of the ultimate
verity of the scientific way. But there is an obverse to this picture which becomes
particularly important in times of fantastically rapid scientific change like the
present. Since this awareness that the ultimate safeguard of confirmation by
experiment is always present lies just below public consciousness, and since,
moreover, controlled speculation indeed forms the essence of the scientific way,
it is but a short step to the popular conclusion that speculation in itself spells
reality — and to the accompanying judgment that, since the court of ultimate
experiment is ever present to exclude the groundless and untenable, unless cur-
rent scientific advances are extrapolated as boldly as they can possibly be, specu-
lation about them is timid and dull, and has somehow not fulfilled its proper
function.
Several things of practical importance, of course, are neglected in such judg-
ments. One is that, whatever the intent of a public speculation or the frame in
which it is made, it is likely to be widely regarded as, in some measure, a predic-
tion, and following experiments may be looked to not primarily as tests but
rather as confirmations. Again, in a world heavily populated with such predic-
tions the competition for the dollars, the time, and above all for the talent that
indiscriminate experimental testing might require could stretch our limited
resources in all these fields far beyond the breaking point. So we would often be
forced to make the dangerous choice of abandoning either the experiment or the
speculation. Further, as Dingle points out, given the very magnitude of the
scientific concerns of our time, even individual validating experimental programs
are unlikely ever again to be transient or minor undertakings. A high propor-
tion become major enterprises, expensive and not infrequently damaging.
Among those who often are asked to take speculation at its face value are
laymen with the most important public responsibilities for ordering the magnitude,
the shape, and the character of science in the nation. Such, notably, are the mem-
bers of the Congress. What are they to do in an atmosphere where uncritical
extrapolation, all too often representing merely the large-scale projection of but
one among many possible sets of ideas, has never been so prevalent or so tempt-
ing? There have been many suggestions of means to provide appropriate and
needed aid. Among them is a recent one that there be set up within the Congress
something like a Joint Committee on Science and Technology with functions
similar to that of the Joint Committee on the Economic Report — to educate,
to investigate, to recommend.
In this connection, J. G. Crowther has recently made an interesting proposal
for Britain. He suggests the formation of an Institute for the Strategy of Science,
analogous, as he points out, to the British Institute for Strategic Studies. The
task of such an Institute would be to supply information of the broadest scientific
REPORT OF THE PRESIDENT 23
nature, including engineering science as well, and embracing relevant aspects of
many other areas — economic, administrative, commercial, historical, political, and
sociological, to name a few. In Crowther's view it is extremely important that
this extensive spectrum of disciplines, centered about science, should be housed
in the same organization, and that every possible provision should be made to
ensure constant and fruitful communication across it. The Institute should be
located within government, to secure maximum accessibility to the wide range of
institutions concerned with problems of science and to provide maximum
coherence and relevance in the information and analyses generated. The very
proposal of this major and difficult idea emphasizes the widespread and growing
recognition that there has never been a time when a public understanding of the
real nature of the scientific way has been more urgently demanded, in terms
not only of our cultural and spiritual welfare, but of our material future too.
Thoughtful students of scientific progress have commented again and again
that the central step in the achievement of any new order of scientific under-
standing is basically nonlogical: truly a step of imagination. As T. S. Kuhn has
cogently observed, in each age all the workers in the mainstream of any branch
of science have typically accepted without serious question a given frame of
reference of work and thought inherited from the founders of the discipline. The
very structure of science, the maintenance of its quantitative excellence, the
assurance of its genuine progress within an arena determined to be sound, demand
such a framework. But the converse is that the adoption of a truly new viewpoint
typically demands a radical fracturing of that structure. Such qualitative change
is not to be achieved through work of ever-greater intensity along the old lines,
nor through the accumulation of more data or the improvement of old, nor by
further refinement in the tools of analysis, nor, above all, by simplistic but
grandiose speculation that merely extends old modes of thinking to more arresting
planes. The process by which major new scientific ideas are generated is, as Bro-
nowski long ago emphasized, closely akin to the great insights of philosophy or
literature or painting. The notions of Copernicus and of Darwin were clearly of
this kind. Numbers of analogous modern examples come to mind: the theory
of an expanding universe, for example, or of continental drift, or of the ultimate
structure of DNA and the mode of its action. In this, its central process, science
is clearly at one with the central processes of literature and art — belying the
old assertions of their separateness. In the genesis of their great ideas scientists,
artists, and writers alike must deal essentially with resemblances, with analogies,
and often enough with ambiguities unresolved. It is only in dealing with those
ambiguities that the single significant distinction, that of the role of experiment,
appears. For in literature and in art the ambiguity remains and must be resolved,
if at all, by the receiver of the message. In science, neither the author of the
ambiguity nor the audience can be allowed to act as the court of last resort. The
court of nature, with experiment as its plea, alone can serve.
Once again, it is strikingly evident that the need for a general public under-
standing of the real nature of the scientific way has never been so great. How is
it to be achieved? There is no one way, of course, no single campaign, no
single plan that can suffice. It can only be attained, gradually and persistently,
at many levels of concept and of execution. The channels are especially important,
and must be especially subtle, at the deeper levels of feeling and philosophy
24 CAENEGIE INSTITUTION
which ultimately must be the most socially significant of all. For it is at precisely
those levels where a truly widespread comprehension of the real nature of the
scientific way could perhaps go farther than any other single factor in helping to
span that disastrously serious gap left by the decline of formal religion in a
society still fundamentally moved by its deep needs for reverence and an abiding
sense of identification with the natural world.
As the nation catches its breath in the wake of the voyage to the moon, as
reflection and planning for the future follow, we are faced with some unpleasant
considerations. One is that the breadth and the depth of the scientific resources
that should stand ready to exploit its results to the full, now and in the future,
have become unfortunately thin and show scant prospect of improvement in the
immediate future. The remarkable academic program of NASA, which gave
effective support to a great number of graduate students at universities in the
early and middle part of the decade, has been drastically sacrificed to the moon
landing. So has the program of more purely investigational space shots — shots
that were not very directly related to the moon program.
Observers of the American scene have long noted a national quality deeply
ingrained among us. Frederick Jackson Turner might have argued — and with
convincing impact — that it is indeed a basic heritage from the American frontier.
We have always shown ourselves conspicuously strong — perhaps the strongest
people in history — in accepting great challenges if they are well-defined; of
organizing ourselves superbly to meet and to conquer them, of concentrating the
whole will of a great people on crossing a lofty and inhospitable mountain
range, as it were, in the faith that beyond that range lie fertile valleys that will
nourish and sustain us and our children; that will bring to us and to those who
follow the blessings that our supreme effort has earned. Countless events in our
earlier history have reaffirmed that faith. Indeed the growth and development of
the nation, in its most formative phases, were deeply rooted in such patterns of
episodic and heroic conquest.
But there is an obverse to this picture which, with the years, may become
increasingly significant. The expected corollary of the windswept range crossed
is indeed for us the smiling, fertile valley beyond. Even late in the twentieth cen-
tury we still instinctively claim that valley as an expected right. At the end of
the First World War we withdrew long before the patterns that should have been
stabilized had even begun to be consolidated, certain that, as we had fought that
war well, respite was properly due: secure in the belief that inevitably the rest
would take care of itself. Even at the end of the Second World War we displayed
a strong inclination to leave the real ordering of the world that was emerging to
others, convinced at heart that our part was completed. Only now is it becoming
evident how much we could have accomplished if we had been willing to stay the
course a little longer. And though the exigencies of the last decades have taught
us something valuable about all this, national traditions that are so ingrained die
hard. Though we were early trained to cross mountain ranges, and to recognize
and honor the strengths and gifts that let us do so, we did not, early on, value so
highly the sustaining talents that would enable us to plod tenaciously through
endless hills of shifting sands, placing our faith not so much in the magnitude of
any one achievement as in the consistency and endurance of continuing effort.
It would spell tragedy if we were to exchange one pattern for the other. Such an
REPORT OF THE PRESIDENT 25
exchange could dim a unique drama of glory. But in a world increasingly crowded,
increasingly inchoate, where clear victories are rare, it is evident beyond all
doubt that we cannot maintain one pattern unless we are also well practiced in
the other. We must learn, at very peril of our existence, that there are deserts to
be crossed as well as ranges, and that to expect those deserts to have boundaries
is illusory. As a wise contemporary American has remarked: "The essential
feature of success in any venture is that it permits you to go on." We must come
to look on that next chance as our highest and most pertinent reward. It will
not be an easy lesson to learn.
That is precisely the lesson that is facing the scientific enterprise in the wake
of the first moon shot. Moon exploration can avail us little, over the coming years,
unless we have the will, and apply the resources, constantly to build the necessary
base of fundamental knowledge. Already Europe is aware that, if the Americans
should neglect the academic aspects of space, it must be Europe that picks up
the pieces, supplying in brains and judgment and diligence what dollars cannot
buy except through the subsidy of consistent, long-range effort in research.
Already some Europeans are wondering whether the coming decade could mark
a return to the pattern of the 1930's — to that "division of labor" where Europe
was predominant in pure research, America in the applied field.
In the year 1964, the government of the Federal Republic of Germany
devoted approximately 1.3 percent of its gross national product to the field of
research and development. By last year that figure had risen to about 2.4 per-
cent, and 2.5 percent or better is projected for 1972. During the period from
1968 to 1971, although the total budget of the German federal government is
expected to expand by only some 6 percent per year, increase in that part devoted
to research and development is projected at the rate of approximately 16 percent
per year. Adding to this the amount contributed by industry, it is anticipated
that the entire expenditure on research and development in the Federal Republic
may; by this next year, total between 13,000 and 14,000 million deutsche marks.
It was only in 1955 that the Germans were permitted to enter the field of large-
scale nuclear development. Since then, propelled by a rapidly growing need for
added sources of energy keenly felt throughout the Federal Republic; rein-
forced by indigenous talented personnel as well as by nationals who had been
trained in nuclear research and technology in the United States and elsewhere
abroad; empowered by funds made available with minimum complication by
the government for the support of well-conceived projects, progress in this field
has been so rapid that in many aspects the German nuclear power program has
now caught up with that of the United States and in some areas has surpassed
it. It is expected that by 1972 the installed capacity of nuclear power stations
will have a capacity of 2300 megawatts. Moreover, it is considered a serious
possibility that by then additional nuclear production will be on order capable,
when completed, of producing 12,000 megawatts of electricity. The merchant
ship, Otto Hahn, was designed especially for nuclear propulsion, and as such is
the most highly developed nuclear-powered vessel in the world today, being
considerably in advance of the U.S.S. Savannah.
Space programs have been very much at the forefront in this spectacular
resurgence. Clearly the Germans are determined to master the technology of
space exploration and research, in the confidence that this field must ultimately
26 CARNEGIE INSTITUTION
become of major industrial significance. It is interesting to note — especially in
the light of our own program — that no less than three of the six experimental
packages designed for a NASA space shot to investigate the magnetosphere were
developed and produced in the German Max Planck Institutes. Equally inter-
esting, an ambitious rocket launch under German management designed to
measure the zodiacal light, planned to take off physically from the United States,
will include six German experiments combined with six complementary American
ones. The plan is to have the flight actually directed from West Germany, under
the control of a 100-meter radio telescope near Bonn planned for completion
during the coming year. The anticipated cost of this enterprise to the West
German government is reported to be in the neighborhood of 200 million deutsche
marks.
The German Federal Ministry for Scientific Research has outlined four clearly
defined "priority programs," all touching current frontiers of industrial develop-
ment as well as basic investigation. They include data processing, space research,
atomic energy, and oceanography. The venture into oceanography is the most
recent. It was prompted, at least in part, by the large expenditures planned in the
United Kingdom and France, as well as by us, and is clearly being approached
with some caution. In the field of data processing, no less than eight regional
computing centers are planned, with an initial contribution from the science
budget of 34 million deutsche marks, in a total program that is expected to
reach a level of at least 500 million deutsche marks expended by 1971.
In France, the proportion of the G.N.P. spent on research has doubled in the
last decade. The budget of the Centre National de la Recherche Scientifique has
been increasing over the past several years on an average of 17 percent per year.
Oceanography is being given a good deal of encouragement, in parallel with
similar movements in the United States.
In Japan, government funding for research and development in 1966 amounted to
1.4 percent of the G.N.P. , and the proportion projected for 1971 is 2.5 percent. This
is particularly impressive when it is recalled that unlike most European countries
and the United States, the proportion spent on research and development for
military purposes is almost negligible. For the Japanese fiscal year 1966 the
total spent on research was reckoned at 1.35 billion yen, exceeding that of 1965
by nearly 15 percent. Later expansion, though not quite so dramatic, has been
continuous. As in Germany, very high priorities have been set by the government
in the fields of space research, including the development of satellites and rockets.
Atomic energy research, with special emphasis on the nuclear powering of ships
and the development of efficient nuclear fuels, is also being pushed very actively.
For centuries the Japanese have been avid investigators and exploiters of the
marine environment, both physical and biological, as we fully recognized for the
first time only in World War II. It is natural, therefore, that programs in marine
science and marine technology should be given a high priority.
All over the world, among developed and developing nations, research is
being accorded an increasingly high priority by governments, and is being sup-
ported at an accelerating rate. In many of the most important of these countries
— notably in Germany and Japan — morale has probably never been higher nor
productivity greater in the sector devoted to research and to development.
Against this background, it is particularly melancholy that our own federal
parsimony in this area, for the third successive year, has had to be so great. To be
sure, the percentage of G.N.P. spent on research in the United States has long
REPORT OF THE PRESIDENT 27
led the world, a fact that has been a particular source of pride, and also of prac-
tical satisfaction. For nothing is more certain in the modern world than the high
correlation between the research activities of a nation and the level of its pros-
perity— and indeed, on occasion, its very survival. So well is this recognized in
Europe that some of the proportionate figures for total expenditure in research in
the United States — such as the 4.3 percent of G.N.P. reckoned for 1966 — have
come to constitute specific goals, to be equaled or if possible surpassed.
Over the decade from 1958 to 1968, federal outlays for research and develop-
ment in the United States grew at a compound rate of about 9 percent per annum.
During the last four years of this period, however, the rate slowed to 6 percent
or less, and for the last two years it has remained almost constant in dollar terms.
However, maintenance at a constant level does not, of course, imply constancy of
support. Not only does ordinary cost inflation drastically affect the level of
research accomplishment at a constant dollar level, but there is a kind of "research
inflation" at work also. As investigation proceeds on a scientific frontier, the field
characteristically grows in sophistication. The tools essential for continued
original investigation typically increase in sensitivity, complexity, and cost.
Expenditure for each investigator will inevitably rise even should there be no
increase in the cost of living, and even if dollar values were to remain constant.
For example, the National Science Foundation, in its budget for fiscal year 1969,
was allotted the total sum of $435 million, including some carryover funding
from the previous year. This represented a very tight restriction indeed, and
one quite drastically disturbing to the equilibrium of federally funded academic
research which over a number of years had become established in the nation.
This year the corresponding total is slightly larger, at $440 million. This appears
to be an advance, however slight — and indeed an advance against heavy odds,
considering the weight of other commitments facing the nation — and it symbolizes
a continuing federal commitment to growth in this area. Unfortunately, however,
the actual impact can only be a token one. The overall effect, indeed, has been
to constrict expected programs by 20 to 25 percent in some 550 institutions in the
country. The National Institutes of Health reduced their existing grants by about
20 percent and may be expected to make about 600 fewer awards than originally
planned. Far from merely holding a ceiling on expansion, it would appear that
the current budgetary commitment actually restricts the scope of the Foundation
to less than that of 1966. The National Aeronautics and Space Administration will
have reduced their commitments to colleges and universities about 30 percent —
precisely in this year of the moon triumph. Fewer federal fellowship awards
were made for the fall of 1968 than were made either in 1967-1968 or in 1966-1967.
It is quite clear that federal funding for research in the nation cannot — and
undoubtedly should not — continue to expand in the coming decade at the rate
which characterized the first half of the last. Persistent maintenance of such a
rate could only result in a serious imbalance in the nation's commitments — and
that in no distant future. It is equally obvious that current competing claims on
the national purse are overwhelming in both magnitude and importance. And
even presuming an early and optimal settlement in Vietnam, other major demands
upon the nation's resources — above all the crucial issues of the cities — must press
very heavily upon federal funding of research and development. These are
"givens" that must be reckoned with.
28 CARNEGIE INSTITUTION
But they are "givens" that characterize a situation none the less difficult and
dangerous on that account. For there can be no such thing as an "equilibrium" in
the quality and the scope of American research and development. Failure to
progress is itself to decline. Decades have passed since Alfred North Whitehead
commented: "In the conditions of modern life the rule is absolute, the race which
does not value trained intelligence is doomed. . . . Today we maintain ourselves.
Tomorrow science will have moved forward yet one more step ; and there will be
no appeal from the judgment which will then be pronounced on the uneducated."
How much more true his words are now!
The internal effects of scientific regression are as damaging as the external.
One of the most conspicuous and significant is the extent to which such currents
tend to be mirrored in the public estimate of the value of scientific research and
education as a national asset, and in the public view of their place in the scale
of national priorities. Equally grave is their reflection in the morale of the
scientific profession itself — in the feeling of the profession for its own place in
the national scheme, and correspondingly in its enthusiasm and verve.
In any generation of scientific investigators, a stationary phase of research
support inevitably tends to affect adversely the very sector that ought to be most
encouraged — the youngest, liveliest, and often the most inherently original group
just entering the arena. This is another grave consequence of the arrest of
growth for any considerable length of time. Even more serious for the nation,
such a pause can markedly affect the numbers and the quality of those from the
oncoming generation who will wish to enter the ranks of science. Already one can
see some effects of the three past years. Already there is visible in some quarters
a disenchantment with science and a derogation of its importance that is at times
truly alarming. This contrasts disturbingly with the optimism and vigor so
characteristic of earlier years, and at present so conspicuous in some other parts
of the world.
In this area we sometimes act almost as though we were running head-on into
an insidious danger which through all history has threatened established leader-
ship in every field — a danger characterized by a growing weariness in sustaining
the role of leadership ; a growing unwillingness to continue to carry undiminished
the burdens that its maintenance and protection demand. And this dangerous dip
coincides in time with the bold and inspiring bid of others for leadership — with
that kindling vigor and hope and energy that the vision of freshening growth can
bring. This recrudescence is of the highest importance for the world, and is some-
thing in which we should surely rejoice. But there can be the most serious failure
— and the most serious material danger, too — for this nation if we do not con-
tinue to uphold the standard that others are quite properly striving to match or
surpass.
Accepting, as we must, the limitations to which we shall be bound over the
next years — conditions some of which grow inevitably from the very order of
energy and success of preceding years — what are we to do? A controlled assured
expansion of federal support, proportioned against the expansion of the G.N.P.
itself, would assist the situation a great deal. A figure of approximately 10 percent
annual growth in the budget for research and development has often been men-
tioned. More important than the precise figure would be the long-term assurance
of growth itself.
But what of the immediate future? Several intrinsic features about support for
science are significant in this context. One is the extraordinary importance, not
REPORT OF THE PRESIDENT 29
so much of amount of support as of its consistency. Nothing is so disastrous for
the conduct of any scientific enterprise (short of serious shortcomings in talent and
in the organization to implement it) as erratic, unanticipated changes in the level
of its material support. This is obvious when support is suddenly withdrawn. It is
not so generally recognized that a situation of equal difficulty arises when support
is suddenly and unexpectedly expanded — as in many instances over the past years
the programs of the National Institutes of Health have illustrated.
The development of a scientific enterprise of real consequence is as precarious
as that of a delicate plant. And to the same degree, it is an organic process. Train-
ing to real research competence involves a long, slow, and expensive growth. The
participants in a new and original program in a difficult field cannot be prepared
overnight, and the more original and difficult the enterprise, the more this will be
true. Thus the sudden and unexpected expansion of a program, especially if it is
forced by the pressing of funds upon it in the hope of attaining a specific objective,
can quickly lead to lowered quality, to dilution of purpose, to waste, and ulti-
mately, often enough to failure. And equally, of course, sudden and unexpected
withdrawal of support from a healthy program can lead to disorganization, disrup-
tion, and, if the contraction be sufficiently severe, to actual inviability. Even con-
siderable swings in expectation of research support can be damaging, though they
may be difficult to avoid. Thus rumors of an impending cut of $100 million — 20 per-
cent— in the total funding of the National Science Foundation were widely dis-
quieting at both federal and academic levels. There followed a rumor that the cut
would be reduced to $50 million, and finally it was established at $80 million. These
fluctuations had adverse effects upon morale through a wide sector of the
scientific community.
All this argues strongly for gradualism in our approaches to the federal fund-
ing of research. But most strongly it argues for the establishment of some stable,
relatively fixed formula for determining a consistent and reliable floor to research
expenditures from year to year. There are many criteria to aid in determining
such a floor. Evidently the definition should be in terms proportionate to the
growth of the economy at some level. But most important of all, it should indeed
be treated as a stable minimum base, even in years when other demands on the
national economy may be unusually great. Perhaps nothing could contribute more
to stability and productiveness in this arena than a widespread knowledge and
understanding of an assurance of public confidence of this kind, however modest
the actual amounts involved might have to be.
There is a particular practical measure which might be of real aid in dealing
with these problems of the federal support for science, and especially in assuring
the continuing healthy deployment of that support in the future. It would simply
involve a return to an older method of federal budgetary accounting. It is extremely
difficult, at any practical level, to make a valid distinction between "pure" and
"applied" research. Volumes have been written on this subject, and, while there
is clearly a discernible and perhaps definable difference at the extremes of the
spectrum, the two activities are often almost identical in their substantive aspects,
identical in their general climates, and identical in the quality and the training
required of those who prosecute them. Moreover they frequently intergrade and
are interwoven functionally in well-nigh inextricable fashion. Accordingly, any
attempt to categorize or to separate activities of research along this line would
clearly be futile, deceptive, and self-defeating.
On the other hand, there are real differences between science and technology.
30 CARNEGIE INSTITUTION
Between an activity having as its primary objective the winning and communica-
tion of new knowledge per se, and one devoted primarily to developing, perfecting,
and distributing specific technical items, clear contrasts in orientation and
methodology are evident. That the two activities can be distinguished was demon-
strated in the structuring of the federal budgets for their support over several
years in the second half of the present decade. Although this procedure was very
successful, it was abandoned in the budget for 1969, for reasons not clear, and
has not been restored. Why should it not be desirable to do so?
The curves of federal support in these two categories have typically varied
independently from year to year. Thus, in the category of "basic" research, it
has been estimated that federal support grew by 29 percent a year between 1956
and 1964, then dropped to 9 percent between that year and 1969. In the "tech-
nology" category the earlier growth rate was 21 percent, the later, 5 percent.
Thus the rate curves for the two classes were preferential to the "basic" category
in both time divisions. But the actual dollar budgeting in the "technology" category
was much the larger of the two. The separation of the two items, therefore, made
possible a continuing real, if modest, increase in the support of research. In the
year 1966-1967, for example, it proved possible, even in the face of quite radically
stringent circumstances, to increase the separated research budget by more than
10 percent — a figure above what many today would regard as an acceptable
increment for the future. Such a move, moreover, noticeably sharpened the con-
cepts that govern the budgeting process. Finally, restoration of this distinction
might well facilitate the establishment of the stable "floor" in budgeting for basic
research that is clearly so very desirable. There indeed seem to be telling reasons
why the policy of separate budgeting in the categories of "research" (including
both "basic" and "applied") and "development" should be restored in future
years.
If one speaks of growth in the federal support of research in the nation for the
coming years on the order of 8 to 10 percent, however, the mechanical problems
of organization and administration become formidable, and multifarious ques-
tions of planning and procedure are insistently posed. They are as comprehensive
as the whole organization of scientific support within government.
One of the more specific of these questions, widely debated at present, relates
to the optimum form that federal support for both research and training in the
universities should take. In this context, it is pertinent to recall that, important
though it be, government support of science and of scientific training forms but
one leg of a tripod in the overall support and conduct of science in the nation. The
others are of course the universities and industry. Government support is criti-
cally important for both the other members. But the support of the universities, in
turn, is altogether vital both to industry and to government, and indeed to the
overall national scientific effort. For by their very nature the universities must
continue to be primary resources, not only for the successful maintenance of
research itself but for the constant renewing of the human resources for both
research and teaching. Those resources are the successive waves of young men
and women who, year after year, are trained at great expense in effort and money
— at great expense both to themselves and their society — and who go out to take
their places in the everlasting renewal of prepared commitment through which
alone we as a nation can survive and prosper.
REPORT OF THE PRESIDENT 31
So there can be few subjects in this whole field more important than the rela-
tionships of support between universities and research institutes and the federal
government. Discussion in this area over the last several years has tended to
become polarized around two extreme patterns, commonly referred to as "institu-
tional" on the one hand, and "project" on the other. In this context the rubric
of "project support" is commonly used to describe the pattern in which specific
research enterprises are individually judged on the basis both of their substantive
importance and of the excellence of the personnel engaged on them, usually by
expert panels comprising professional peers of the potential grantees. This pattern,
of course, is derived from one of long standing in many private foundations. If a
favorable judgment is reached, the grantee may, in extreme cases, retain more or
less personal control over his award. Although it is customarily administered
through some mechanism within his university, often it may be really his, and can
travel with him if he changes his institutional affiliation. This pattern, often in
this extreme form, was widely adopted during the years of most rapid growth of
federal support of science. Much can be said in favor of such a system. The careful
and knowledgeable scrutiny to which the applications for such grants can be
exposed, though it does not guarantee uniformly high quality, surely promotes it.
Unfortunately, the procedure may also, in certain circumstances, tend to reinforce
conventionality in research, sometimes leading to the loss or rejection of striking
new ideas or approaches which, at the outset, may have been difficult to distinguish
from the merely speculative. For such a system inevitably tends to reinforce the
middle ground — the sound proposals of meritorious quality — while reducing the
extremes — the unsound proposals at one end of the spectrum, and the rare flashes
of genius at the other. And in a time of limited budgets, the risk is considerable
that the little-known junior investigator of high potential talent will fare poorly
in competition with the older, better-established applicant of sound reputation and
predictable performance. It should be added, however, that this serious hazard is
well recognized by most scientific investigators. A large proportion of the panel
judges have kept it clearly in mind and have tried to allow for it.
The project system has considerable disadvantages, however, which have
become obvious only in recent years. By its very nature it tends to emphasize
proficiency in research above proficiency in teaching, since the rewards go pre-
dominantly to the research side. Moreover, while the excellence of a research
proposal, and hence of the research capacity of the applicant, can be objectively
judged, such objectivity becomes quite impossible in a field where the require-
ments for and the manifestations of excellence are as complex and varied as in
teaching. With the growing realization of the cardinal necessity of reinforcing
the teaching function in the universities, the shortcomings of the project grant
system in this respect have been brought into sharp focus.
Again, the project grant by its nature shifts the administrative — and possibly
to some degree the moral — responsibility for the conduct of the grant, as well as its
award, from the institution where the awardee operates to the federal government.
An unwise federal centralization of responsibility and obligation for an impossible
welter of detail of both administration and judgment was thus early encouraged
— to which, it must be added, some private institutions have latterly been guilty,
wittingly or unwittingly, of contributing.
Finally, over the years a much graver and longer-term liability has appeared in
the system of project grants, especially when they are fully attached to the indi-
vidual rather than to his institution. It was inevitable that a certain number of
32 CARNEGIE INSTITUTION
new or impoverished academic institutions, seeking to better their status both
economically and in prestige, should have encouraged their more eminent faculty-
members in the sciences to seek grants as energetically as possible. And so an
inevitable, pernicious cycle was initiated. Investigators whose special abilities
might trend more toward mastering the techniques of grant-seeking than toward
highly original work could be — and sometimes were — selectively rewarded in
such institutional environments, with a perceptible lowering of research quality.
This situation likewise provided an obvious opportunity for institutional maneuv-
ering of a kind irrelevant to the best scientific progress, if not actually invidious
to it. A final and most serious effect was that the social "center of gravity"
shifted from institution to individual. There was little reason why an individual
in such an environment should maintain any very special loyalty to, or even
personal identification with, either his institution or his primary teaching respon-
sibility. As serious difficulties of this kind recurred with increasing frequency
over the years, resistance to the project system rose.
These disadvantages of the project system are indeed serious. But it would be
a great mistake to neglect its many virtues, or to fail to appreciate the magnitude
of the growth of scientific knowledge in almost every conceivable field that the
federally supported project system, monitored by its host of dedicated, selfless,
highly qualified consultants, has made possible over the last dozen years. Recog-
nizing all the dangers and the shortcomings of the system, now more widely
evident than ever before, it still would be the gravest error simply and irresponsi-
bly to throw the baby out with the bath.
The institutional system, as its name implies, is designed to operate in opposite
fashion. Support under it is normally given in the form of bloc grants, to be
administered by institutions as they judge best to support both research and
teaching. Such grants have commonly been used to defray expenses of research
and of formal graduate training, and have also helped to meet overhead costs at
the institutions concerned — a subject of particular controversy over a number of
years. The defects of the project grant system are the virtues of the institutional
one. It allows far greater latitude in the expenditure of monies than does the
project system, permitting a more effective distribution between the support of
teaching and research and even making possible a better balance within the
research category itself. Given an able and sensitive university administration,
the institutional system probably permits a more effective expenditure of federal
dollars in the interest of general scientific education. Furthermore, by shifting
the main responsibility both of judgment and administration from the government
to the recipient body, an otherwise impossibly concentrated federal responsibility
is diffused. The system also restores to the university the authority that it needs
so badly in dealing with grantees who are members of its faculty and helps to
sustain the institutional integrity so essential to hard-pressed educational organi-
zations in our time. In the context of generally raising the standard of both
teaching and research in American science, it seems, on the whole, better adapted
to the present day than is the project system. Still it has its own shortcomings. It
will be hard to match the high standards of the best research grants made through
the project system: grants that have made possible some outstanding conquests
of difficult and important frontiers.
In fact, of course, the terms "project grant" and "institutional grant" are
unreal abstractions. They merely signify opposite ends of a long spectrum of
devices through which federal monies can be channeled to the support of science
REPORT OF THE PRESIDENT 33
in nonfederal institutions. Don Price has recently put this general situation very
clearly. He remarks that we have made a "political judgment that our national
purposes will be advanced by supporting and enlarging the amount of scientific
research that is carried on in independent universities." But, "The qualities of
independence and critical scholarship and leadership in basic theory, upon which
the whole research and development enterprise depends, will be threatened
unless the central structure of the universities is made strong enough to sustain
the structure of specialized research grants."
It is both unrealistic and unhelpful to regard the project and institutional sys-
tems as rival or mutually exclusive patterns. The great task over the years to
come in this area will surely not be to decide irrevocably between them, but
rather to combine them in ways that complement their purposes and their
strengths, and that compensate for their respective weaknesses. There can be no
successful project grant system without a strong university structure on which
to base it, and that structure, in the field of science as elsewhere, will be more and
more strongly dependent, as the years go by, on federal institutional grants.
Our vision here is still somewhat occluded by our devotion, ever since World
War II, to the project grant pattern, and by the delusion, perpetuated to the
present in many quarters, that the most important aspect of government support
for science is that of "buying" specific bits of research rather than of building
excellent and comprehensive scientific resources, material and most especially
human. That is a misconception peculiarly damaging to both donor and receiver,
and to the nation at large. Here a close scrutiny of the British experience, as
Christian Arnold has suggested, could serve us well. For in many respects the
British system has developed in an opposite direction from our own. It began
with heavy emphasis on institutional aspects, through the work of the University
Grants Committee, and proceeded to the project grant pattern in a context of
more massive undertakings — an evolution, it must be said, that for all the diffi-
culties attending it may have been more logical than our own. Nowhere, indeed,
has the intimate dependence of the project system upon the institutional founda-
tions which institutional grants alone can sustain been more poignantly illus-
trated than in the British pattern, where external grants for special purposes have
increased from approximately 8 percent of the total research expenditures in the
universities for 1950-1951 to approximately 36 percent in 1966-1967. In this
context it is encouraging to notice the current support for the institutional grant
system provided in a recent report of our own National Science Board.
An inevitable accompaniment of the immense growth in the volume of federal
funding and conduct of science in recent years has been the revival of an old,
difficult, and perhaps deceptive query. Should there be a single central department
or other center of planning and management within government, devoted to the
coordination of all of federal science? The question is not necessarily contingent
upon the present massiveness of federal involvement, although it is clearly under-
lined by that situation. In fact, it was raised by the National Academy of Sciences
as long ago as the latter part of the nineteenth century. The issue of centralized
or diffuse government management of scientific affairs has been debated from time
to time ever since. It has recently been given a new focus by a proposal from the
National Academy for a government organization tentatively called the National
Institutes of Research and Advanced Studies, which perhaps might act as a
central manager of federal science. This model has not been put forward literally,
34 CARNEGIE INSTITUTION
but only to provide an "anchor" for speculation on the relative merits of diffuse
and centralized systems.
Current concern with this question in the United States is no doubt intensified
by the picture of federal research in some of the nations of Europe where the
resurgence of science has been so spectacular. In West Germany, for instance, the
Federal Ministry for Scientific Research has powers of coordination throughout
the government as a whole, and assumes direct charge of programs of high na-
tional priority, including space research, oceanography, and atomic energy.
Further, the Ministry has the responsibility of channeling the federal funds
appropriated for science to a group of autonomous research societies, which also
receive contributions for the same purposes from the various lander governments.
In addition, the Ministry undertakes the critical task of overall scientific plan-
ning, including what appears to be an essentially decisive determination of major
priorities in fields of research and development which shall engage the nation for
some time ahead. This emphasis on planning which is centrally conducted but
nevertheless has the flexibility conferred by close cooperation with the scientific
societies, with the lander governments, and with the universities and industry,
has so far proved remarkably efficient and successful.
Such highly centralized European patterns for the governmental management
of science are echoed in Japan, where the central bureaucracy has customarily
maintained tight controls on the planning and execution of governmentally sup-
ported research, with the universities and industry traditionally functioning as the
other corners of a triangle. A National Council for Science and Technology is
chaired by the Prime Minister and includes several powerful Cabinet members. The
day to day work of assembling and organizing the facts and projections upon which
the Council will base its determination of overall science policy for the nation is
carried out by a Planning Bureau, which also serves as secretariat for the Council.
There are many specialized planning and executive bodies at lower levels which
assume derivative responsibilities for particular aspects: the Atomic Energy
Commission, the Science and Technology Agency, the Space Activities Council,
the Council for Marine Sciences and Technology, the Radiation Council, and, in
a somewhat broader advisory frame, the Science Council of Japan, established in
1949 with the encouragement of the American Occupation. But despite the mul-
tiplicity and the varied nature of these specialized bodies, final authority for a
national policy in science and technology is unmistakably concentrated at the
highest governmental level. Small wonder that the question of a nationally
centralized policy-making body for science in the United States has recently
been raised with renewed urgency.
And what of that question? A first caveat to be observed in all comparisons of
this kind is to recall that science, while an immense practical resource of any
society, is above all a particularly vivid and sensitive expression of that society's
own philosophy, its own history and its own peculiar organizational genius. If the
organization of science policy runs faithfully concurrent with the political
history and aspirations and philosophy of a people, it will successfully serve that
people in the scientific sector of their endeavors and will accurately reflect their
aims. If it fails in this, the overall effort is sure to fail as well. Such concordance
of character and aim has clearly been established in Germany, in Japan, and in
several of the most progressive of the Socialist countries. The essential ques-
tion for us is how concordant this kind of structuring would be with our own
national philosophy. And, indeed, it is a very real question.
REPORT OF THE PRESIDENT 35
There can be no doubt that effectiveness of forward planning has been enhanced
in the countries of Europe which have adopted a centralized pattern, or that its
adoption has accompanied the verve and vigor of a notable scientific revival. On
the purely practical side, however, there is also no question that the situations of
those nations with respect to indigenous resources for research and technology-
are still far more elementary than our own. And it is worth remembering that,
so long as this is the case, technologically advanced nations like the United States
still provide the overall models toward which such countries can direct their
planning. It remains to be seen how effective centralized structuring may prove to
be when these countries have drawn abreast of the most technically advanced
nations, and must assume an equal share of the burden of innovation and real
scientific leadership on a wide scale.
It is also worth recalling that, though governments can often make centralized
and overriding scientific decisions which in particular cases can prove extraordi-
narily efficient — because of the overriding power of implementation which they
can carry — so long as they are correct, governments can also on occasion make
the grossest of mistakes in these difficult areas. They are no more immune than
any other human assembly to following the fashions of the moment, to succumb-
ing to the flashy attractions — and sometimes the real brilliance — of fields of scien-
tific research and development which may offer quite illusory promise. And
when they do this, with power and assurance sufficient to override quieter but
more knowledgeable dissenting voices, major disasters can ensue. As yet this
has not happened to any serious degree in countries with tight central control. It
is to be hoped that wisdom is such that it will not happen. But the record is not
yet long.
There is, however, a danger that is already becoming manifest in some of these
countries, and that could take a serious turn. In a number of the nations that have
evolved most markedly toward centralization in their governmental planning
and conduct of science, all is clearly not well with the universities. Increasingly
some universities, at least, have felt pressured to diminish both their uncommitted
science teaching and their programs of uncommitted scientific investigation, and
to shoulder larger and larger loads of applied work coming to them from govern-
ment. Many members of university faculties are complaining that, though
material resources for research have never appeared so abundant, the precious as-
sets of time and energy free for devotion to basic science are more limited than
they have ever been. These hazards are threatening the universities just when
other difficulties are at a maximum for them — and indeed may be compounding
those difficulties. So far, there are only hints of these possible accompaniments of
extreme centralization in the federal planning and funding of science and technol-
ogy. But they seem real, and they could grow, ultimately causing incalculable
damage both to education and to pluralism of research. It is well to remember that
these could be "type" dangers of overcentralization that might easily threaten
us too.
There seems to be no doubt that a really tightly centralized structure of plan-
ning and administration for science and science support in our federal govern-
ment could be seriously inconsonant with the diversity of concept and action that
has always been a hallmark of American philosophy. It is a philosophy that,
though often inefficient and clumsy, permits a flexibility that throughout our
history has consistently proved salutary. However practically attractive a
36 CARNEGIE INSTITUTION
thoroughly centralized pattern of federal control and planning for federal science
may appear, these are considerations to be kept most seriously in mind.
Whatever may prove to be the ultimate reality of such conjectures, we enjoy
a number of inherent safeguards for continued scientific pluralism. For our own
federal scientific structure, like that of all scientifically vigorous countries, neces-
sarily works in the closest partnership with the other members of that inevitable
triangle — the universities and industry. And we must make quite certain that
these safeguards are not overstrained. The heart of the matter lies in the kinds
of relationships that are formulated and maintained among them. Here we will
do well to bear constantly in mind the essential qualities of the other members
of the partnership and their central roles in the affairs and the fortunes of our
society.
The importance of the role of the universities needs little emphasis. Discussions
and events over the years immediately past have brought their immense contribu-
tions, and their immense problems and vulnerabilities, into sharp public focus.
But perhaps not enough public attention has been focused on the extraordinary
importance of the industrial sector in the research affairs of a nation. In Germany's
resurgent science, industry has supplied an indispensable resource and has regu-
larly been brought into research projects at the earliest possible time. The
nuclear power industry, for instance, has been primarily responsible for the
spectacular German successes in that field. In France, in Japan, and in most other
countries experiencing a fresh surge of scientific effort today, the contribution of
industry is extremely important. These countries are learning apace that indus-
trial laboratories offer fertile resources for the prosecution of government-
financed research — more fertile, often, than the government laboratories them-
selves.
Of all the nations in the world, we are the leaders of this trend — though we do
not always realize it — in time, in magnitude, in variety and ingenuity of arrange-
ment. In a recent survey made by the Economics Department of the McGraw-
Hill publishing company it has been estimated that by the end of the next decade,
in 1978, industry in the United States will be investing some $33.6 billion in
research and development, in comparison with the $17.6 billion expended last
year. In 1978, colleges and universities are expected to conduct $5.6 billion worth
of research, compared with $3.5 billion last year, while the corresponding figure
for nonprofit laboratories is anticipated to reach about $1.6 billion, compared
with $840 million last year. So the contribution of industrial research projected
over the coming decade is, in dollar terms, by far the most spectacular.
Not only is the cumulative expansion of industrial research and development
likely to considerably exceed that of other sectors of the research economy over
the coming decade, but the current cutbacks in research funding that have so
affected the government are not reflected in the industrial scene. The McGraw-
Hill survey predicts that industry will undertake about $19.2 billion of research
this year — a gain of 9 percent over last year. Industrial employment of scientists
and engineers grew at an average rate of 3.2 percent during the past decade. Be-
tween 1969 and 1972 the rate of increase is expected to average 4 percent. In
addition, it is anticipated that over those years there will be a gradual shift in
the proportion of basic and applied research undertaken in industry to favor the
former.
In considerable measure, indeed, it is this faith of industry in the worth of
scientific and technological research that is importantly bridging a time of danger
REPORT OF THE PRESIDENT 37
in the federal sphere. It accounts in large part for the prediction that in 1970
the United States will actually be devoting 4.6 percent of her G.N.P. to research
and development, against an average of 2.5 percent for Europe. Seen against this
background, the picture looks by no means dark. It suggests, moreover, that the
current leveling of federal support may not represent any fundamental shift in
American attitudes toward research and technology, but only a shift in the
major channels of its expression.
Perhaps the deepest and most significantly helpful aspect of this whole matter
has recently been set out with extraordinary clarity by Jean-Jacques Servan-
Schreiber. A predominant factor in American industrial growth, he emphasizes,
is the talent for accepting — and even maneuvering — change. That indeed has
historically been a salient character of American society at least since
de Tocqueville noted it in his travels in North America in 1831, and no doubt even
earlier. It is one of the hallmarks of the frontier and of the germinal experience
of opening and occupying new lands that we have never lost or abandoned. A
second factor, which Servan-Schreiber is able, perhaps, to evaluate with better
perspective than could any American, is the extent to which the American society,
by its very nature, is dedicated, as a principal commitment, to the development
of men and women. Here idealism and practicality can be welded in an effective
partnership, for the investment in men and women that is so characteristic of
America is indeed as much practical as idealistic. It is an investment in brain-
power, and in personal and organizational effectiveness, on a scale probably
unprecedented in world history. The old saw that America gambles far more on
human intelligence than it wastes on gadgets is indeed true. And as Servan-
Schreiber emphasizes, "The wager on man is the origin of America's new dyna-
mism."
It is this wager on man which we must encourage through all the years as the
deepest commitment of American society. Whether in policies of research and
development or through those aspects of substantive science so vital in the larger
context of the human spirit, we have a solemn and a compelling and a continuing
duty to guard and to foster that philosophy in every possible way over the decades
to come. This is a consideration of high importance in planning the organization
of science in the federal government. It must be a unifying consideration in all
that we think and plan and do in the conduct of substantive science itself, now
and as far into the future as we can foresee.
And science, we should insist, better than any other discipline, can hold up
to its students and followers an ideal of patient devotion to the search for
objective truth, with vision unclouded by personal or political motive, not
tolerating any lapse from precision or neglect of any anomaly, fearing only
prejudice and preconception, accepting nature's answers humbly and with
courage, and giving them to the world with an unflinching fidelity. The world
cannot afford to lose such a contribution to the moral framework of its civili-
zation, and science can continue to offer it only if science can remain free.
Sir Henry Hallett Dale — An Autumn Gleaning
Other desires perish in their gratification, but the desire of knowledge never;
the eye is not satisfied with seeing, nor the ear with hearing . . . the sum
of things to be known is inexhaustible, and however long we read we shall
never come to the end of our story book.
A. E. Housman — Introductory Lecture at University College, London, 1892
The Year in Review
"I have . . . learned from others of whom I
made the most careful and particular inquiry."
-Thucydides, Peloponnesian War,
Book I, 22, (Jowett translation)
The Carnegie Institution engages in fundamental scientific research and train-
ing. It is an operating organization using the methods of physics, chemistry,
mathematics, biology, geology, and observational astronomy to investigate the
research frontier of the natural sciences. Integral with its research is a post-
doctoral training program that has been and is a significant source of professors
and scientists for universities and research organizations in the United States
and abroad.
The Carnegie Institution spent $4.9 million in the fiscal year 1968-1969 for
research and fellowship support, its only activities. This report will describe the
specific purposes of the expenditures and the results of operations.
The relevance of science is not that of today's press. Nor is it short-term. It is
one of concentration on the unknown; it is served by dedication, by utmost
economy, by patience, and by an ever-present willingness to admit error. Science
is highly relevant not only to the advancement of thought and understanding,
but also to material progress.
This is the kind of relevance within which the Institution can undertake an
accounting, and for which its operations are designed.
The Institution conducted research in fifteen distinct fields in 1968-1969. All
but two were among the biological and physical sciences. The choice of these
fields has been determined largely in decisions by individual Staff Members or
Fellows, or by collaborating groups of Directors, Staff Members, and Fellows.
In the "system" of scientific research the Institution has always emphasized the
importance of the individual scientist. Although it also recognizes the importance
of other parts of the system, such as the position of the frontier of research in
a field, the "critical mass" of collaborators and colleagues, the availability of
proper equipment, and long-range security, it has built all its programs around
individual research workers. The pattern of activities and results here described
represents a summation of the choices of more than 120 Staff Members and
Fellows who were the Institution during 1968-1969. What they did during the
year has a high degree of relevance to scientific progress and to the cultural and
social progress of the future.
Of the $4.9 million spent by the Institution in 1968-1969, 85 percent was spent
38
Plate 1
Report of the President
Plate 1. Types of galaxies studied by Sandage, Freeman, and Stokes for intrinsic flattening.
Top left: A typical elliptical galaxy of the El type (NGC 4278). Top right: A spheroidal
(SO) galaxy (NGC 1201). Bottom: A spiral galaxy (Sa type) (NGC 3898). All photographs
from A. Sandage, The Hubble Atlas of Galaxies, Carnegie Institution of Washington, 1961.
REPORT OF THE PRESIDENT 39
by the research departments. The Office of Administration and general expenses
accounted for about 15 percent of the Institution's 1968-1969 expenses. Ninety
percent of its operations are carried out through five operating departments:
The Mount Wilson and Palomar Observatories at Pasadena, California; the De-
partment of Terrestrial Magnetism and the Geophysical Laboratory, both at
Washington, D. C; the Department of Embryology at Baltimore, Maryland; and
the Department of Plant Biology at Stanford, California. A sixth group, the
Genetics Research Unit, at Cold Spring Harbor, Long Island, New York, con-
tinues a long tradition of distinguished genetics research within the Institution.
The research and training activities of each of these groups during the year are
described in the pages that follow.
Mount Wilson and Palomar 1968-1969 Expenditures:
Observatories Operating $1,005,663.04*
Equipment $255,710.59f
Ten years ago Allan Sandage wrote in The Hubble Atlas of Galaxies, "A
renaissance is occurring today in astronomy. ... we do stand a chance of under-
standing the universe." The renaissance continues. The 1960's have indeed been
an exciting period for astronomy and astrophysics, one to which Sandage and his
colleagues at the Observatories have contributed so much. The discovery and
optical identification of many quasi-stellar sources, the discovery of pulsars, the
finding of a series of objects with almost incredibly large redshifts, and the
increasing understanding of what may be an appropriate model of the observed
universe are intellectual landmarks of the first magnitude.
The work of the Observatories continued during the year in very much the
same direction as during the preceding years of the decade. Indeed, the scope,
penetration, and profundity of studies undertaken by the Observatories' staff
maintain the position of leadership that has been traditional with them for
sixty-five years, despite mounting support for astronomy elsewhere in the United
States and among other advanced nations. The Observatories are a center not
only for research but also for the training of young astronomers.
Study of Galaxies from the Southern Hemisphere. Pursuing his interest in
achieving a definitive cosmological model, and in a refinement of the Hubble
constant,1 Sandage turned this year to the southern hemisphere, spending most
of the year at the Mount Stromlo and Siding Spring Observatories in Australia.
Observations of southern galaxies are considered crucial both for more accurate
redeterminations of the Hubble constant, and in investigations of the symmetry
of the universe as viewed from the earth. Sandage therefore gave first priority
to studies of galaxies in groups and clusters in the interest of mapping the local
dissymmetry (anisotropy) of the expansion of the universe. Another objective of
the work was to test the possible dependence of the absolute luminosity of the
brightest cluster or group galaxy on the star population of the group. In the
course of the year he obtained 267 spectra of 221 galaxies of elliptical (E) and
spheroidal (SO) galaxies (Plate 1). He also began a survey for the brightest red
*The Observatories (renamed the Hale Observatories in December, 1969) were jointly sup-
ported by California Institute of Technology and the Institution. The sum noted here repre-
sents the Carnegie Institution's expenditures in the operation of the Observatories for the fiscal
year July 1, 1968-June 30, 1969.
f Includes $182,675.47 construction costs of new 60-inch telescope at Palomar.
xThe Hubble constant gives the increase in velocity of an astronomical object with distance
as it recedes from the earth.
40 CARNEGIE INSTITUTION
supergiant stars in the Large and Small Magellanic Clouds, the closest external
galaxies to our own. These form important reference points in the recalibration
of the Hubble constant. The reduction of Sandage's data is not yet complete. But
preliminary calculations suggest that southern galaxies showing recessional veloci-
ties of less than 4000 kilometres per second have smaller redshifts for a given
apparent magnitude than their counterparts in the northern hemisphere. This
could indicate a "local" dissymmetry in the universe as viewed from the two
hemispheres.
Sandage, K. C. Freeman, and R. N. Stokes of the Mount Stromlo Observatory
also studied the intrinsic flattening of elliptical, spheroidal, and spiral galaxies
in the southern hemisphere (Plate 1). It was found that spiral and spheroidal
galaxies are equally flat, with axial ratios of 0.25, but that elliptical galaxies
have a large range of shapes, with axial ratios from 1 to 0.3. Furthermore, the
intensity profiles of the spheroidal component of all three types of galaxies are
remarkably similar. From these studies Sandage and his Australian colleagues
concluded that elliptical and spheroidal galaxies cannot have been directly
connected in evolution. These investigations confirmed that the central spheroidal
component of all these galactic types is formed very rapidly (on the order of a
few hundred million years) from matter having a low angular momentum,
whereas the surrounding disk is formed of material with higher-than-average
angular momentum. The galaxy type was determined essentially by the amount
of free gas left over after collapse into the spheroid.
The importance of southern hemisphere observations in Sandage's cosmo-
logical study at this time underlines the dilemma that at present there are no
major telescopes in the southern hemisphere. In this connection it is gratifying
to report that the Institution took a step toward establishing its own southern
hemisphere optical observatory. Although it established a radio astronomy
observatory at La Plata, Argentina, several years ago, and has studied the seeing
conditions for optical astronomy in the southern hemisphere for several years, an
observatory site was not finally decided upon until this year. The institution has
acquired from the Chilean government a 20,000-hectare property on the boundary
between Coquimbo and Atacama Provinces, known as Las Campanas, about 80
miles northeast of the coastal town of La Serena. Development of the property
will commence in 1969-1970.
Pulsar Observations. One of the more remarkable astronomical discoveries of
the decade has been that of the pulsar. First detected by Hewish and his col-
laborators at Cambridge University, England, early in 1968, pulsars have
commanded the attention of many astronomers and astrophysicists in the months
since. An immediate search for optical pulsars followed the initial discovery. The
first optical identification came almost a year after the radio discovery, when
optical pulsation was detected in the Crab nebula by Cocke, Disney, and Taylor
at the Steward Observatory of the University of Arizona in January 1969. The
Crab nebula pulsar proved to be a star first singled out by W. Baade and R.
Minkowski of the Mount Wilson Observatory in 1942. Baade and Minkowski's
study of this object showed it to have a highly unusual featureless blue continu-
ous spectrum. They considered it to be the central star of the nebula, and the
primary remnant of the spectacular supernova explosion observed in 1054 A.D.
Employing a new specially designed digital data system for analyzing the
rapidly pulsing light signals, J. Kristian, J. A. Westphal, and G. Snellen of the
Mount Wilson and Palomar Observatories studied the Crab pulsar with the
prime-focus photometer of the Palomar 200-inch telescope. They recorded digital
REPORT OF THE PRESIDENT 41
photon counts in time increments of one millisecond. Two distinct pulses were
found in each 33-millisecond period, the main pulse extending only five milli-
seconds. Both the primary and secondary pulses are extremely sharp. The Crab
pulsar has the shortest period of the dozen or so pulsars which have been detected
by radio observation. This very precise photometry revealed a remarkable sta-
bility of pulse shapes and amplitudes, with an accuracy of better than one percent
for one-minute averages compared at intervals of two hours. The optical stability
of pulses differs from the large variations observed at the pulsar's radio wave-
length. The light of the pulses was also shown to be plane-polarized to the extent
of about ten percent.
The physical causes of the pulses and the energy background for the emissions
of the pulsars are of course fascinating subjects for astrophysical theory. T. Gold
of Cornell University has suggested that pulsars are rotating magnetic neutron
stars formed in supernova explosions like that of the Crab nebula. P. Goldreich
of the Astronomy and Geological Sciences Divisions of California Institute of
Technology, and W. Julian, a Research Fellow at the Observatories, have inves-
tigated a simple model of such a star. They have concluded that the star must
possess a dense magnetosphere, that particles within the star's light cylinder 2
rotate with the star, and that magnetic field lines which extend beyond the light
cylinder close in a boundary zone near the supernova shell. Rotational energy lost
by the star is transported out by the magnetic field and transmitted to particles
in the boundary zone.
Another Unusual Quasi-Stellar Source. The investigation of quasi-stellar sources,
another of the remarkable discoveries of the decade, was continued by several
of the Staff Members and Fellows of the Observatories.
D. DuPuy, J. Schmitt, R. McClure, S. van den Bergh, and R. Racine, a Fellow
at the Observatories, studied the remarkable radio source BL Lacertae, a quasi-
stellar object that varied in visual magnitude between 12.0 and 15.5 during a
period of seven months in 1968. Light variations of as much as 0.3 magnitude
per day were observed. This anomalous object has a continuous spectrum, so its
distance remains unknown. According to the assumptions made, it could be
either the nearest quasi-stellar source, or the most luminous object known in the
universe. Other infrared photometric and spectrometric observations by B. Oke,
G. Neugebauer, and E. Becklin suggest the radiation of BL Lacertae is largely
nonthermal.
Studies of Stellar Evolution. Studies of the processes of evolution of stars are
fundamental to the progress of astronomy. Theories of stellar evolution, as
Sandage has expressed it, "consolidate many of the isolated facts in astronomy."
One of the anomalies between observation and theory, hitherto unresolved,
concerns stars in the final stages of degenerate evolution. According to the
Schwarzschild theory the cooling of degenerate stars from the white dwarf
through the red degenerate stages should proceed very slowly. Thus, if there are
large numbers of white dwarfs there also should be large numbers of degenerate
red stars. However, hundreds of white dwarfs have been observed but only about
20 of the degenerates, none of them very faint. J. Greenstein has now shown
that new knowledge of convection outside the core but inside the surface of white
dwarfs resolves the discrepancy. The fainter degenerate stars cool at a rapid rate,
2 A light cylinder, a mathematical concept, has a radius such that, co-rotating with the
star, its surface speed is equal to that of light.
42
CARNEGIE INSTITUTION
and thus pass through the red stage quickly. Therefore they may be expected
to be less numerous, conforming to the observations.
Instrumentation. As in most other physical sciences, progress in instrumenta-
tion plays a vital part in the progress of astronomy itself. In the last few years,
especially, new techniques and auxiliary instrumentation at the Observatories
have added substantially to the number of observations which can be made with
the telescopes, and have increased the sensitivity of these basic instruments. In
addition, a new 60-inch photometric telescope of the most modern design and with
modern auxiliary instrumentation was nearing completion on Palomar Mountain
at the end of the year. Its construction was made possible by National Science
Foundation and National Aeronautics and Space Administration grants, and by
a gift made to the California Institute of Technology by the Oscar G. Mayer
family.
The program for conversion of observational outputs into digitally recorded
form, under the supervision of E. W. Dennison of the California Institute of
Technology Astroelectronics Laboratory, continued its progress during the year.
A program for the adaptation of small computers to direct use at the telescopes
also was started. These computers will be used as Central Processing Units at the
Mount Wilson 100-inch and 60-inch telescopes, and at the Palomar 200-inch and
photometric 60-inch telescopes, as well as at the 150-foot Mount Wilson solar
tower. These new Central Processing Units will permit rapid change in the inter-
relation of important auxiliary devices, such as counters, timers, and encoders,
with the telescope drives. The new computer control systems will be able to set
the telescopes on any object in the sky rapidly and accurately. During the year
integrating TV cameras were used experimentally in an attempt to reduce the
time now required to find, set, and guide the larger telescopes on very faint stars
or galaxies.
For several years these reports have described the image-intensifier tube,
developed under the supervision of the Committee on Image Tubes for Telescopes.
Now in use in many observatories, it has proven a most effective time-saver at
the 200-inch telescope. Indeed, the speed of the image-tube spectrograph used
at the 200-inch is so great that a substantial fraction of the total observing time
is occupied, not in the making of the observations, but actually in loading and
changing plate holders. I. Bowen, former Director of the Observatories and a
Distinguished Service Member of the Institution, and B. Rule have designed a
new reimaging camera with a rapid-change mechanism that will further increase
the effectiveness of this highly useful instrument. The camera functions with
optics of a new design by Bowen that will yield better image quality than that
hitherto available.
Fellows and Students at the Observatories. The place of the Mount Wilson and
Palomar Observatories in postdoctoral training and in graduate study of astron-
omy deserves special mention. The Institution supported five postdoctoral Fellows
at the Observatories in 1968-1969. Another 12 Research Fellows were supported
by funds made available by the California Institute of Technology, and 14
graduate student observers from the Institute studied at the Observatories. The
assistance and advice of Observatories' Staff Members from both the Institution
and the Institute thus were made available to 17 Fellows and 14 graduate students
during 1968-1969. This is one of the major instructional programs in astronomy
and astrophysics in the world. Both graduate students and Fellows have access
to telescopes appropriate to their research programs, and to plate files, data reduc-
tion equipment and computers. Students participate in observing runs at the
REPORT OF THE PRESIDENT 43
major instruments by senior Astronomers. Students from the Institute's Division
of Geological Sciences also regularly conduct research on the moon and planets
with the use of Observatory telescopes and other instruments. A special project
manned largely by graduate students and Research Fellows has been the infrared
sky survey from Mount Wilson, made with a special 62-inch infrared telescope.
Students participate in every phase of Observatory life, including the recon-
struction of instruments. An example is the modernization of the Mount Wilson
60-inch telescope in progress during the year. Student observers voluntarily aided
technical employees in the extensive mechanical, electrical, and optical improve-
ments that will soon give a new usefulness to this famous instrument. The Mount
Wilson 60-inch is the instrument most used by student observers ; a large part of
the available observing time on it is allocated to students.
Geophysical Laboratory 1968-1969 Expenditures:
Operating $736,753.95
Equipment $66,300.42
Dr. Philip H. Abelson, Director of the Geophysical Laboratory, says in the
Introduction of his report: "This past year has been a great one for earth scien-
tists." At the end of the report year, geologists and geophysicists were awaiting
samples from the moon, as well as samples from the deepest sea bottoms.
Although the interest generated by these unprecedented events is great, other
advances have been quite as stimulating for both the professional and the layman.
Outstanding among these has been the accumulation of increasingly convincing
evidence of the widening geographical separation of some of the great land
masses of the earth in the course of geological history.
First proposed in France about 110 years ago 3 and elaborated by A. Wegener
in the early years of this century, the theory of "continental drift" has been
largely ignored by North American geologists and geophysicists until very
recently. Since the discovery of the midocean basalt ridges, to be found in all
of the oceans, and study of the magnetic properties of rocks on the ocean bottom,
the theory of continental drift is receiving increasingly serious consideration as
a working hypothesis in geophysics. Various models have been proposed within
the last year for the primeval grouping of continents (Fig. 1), the dynamics of
the "spreading" of the ocean floors, and the components of the earth's mantle and
crust in movement (Fig. 2) .
One long-standing program of investigation at the Geophysical Laboratory is
designed to produce definitive evidence on the composition of the earth's crust
and mantle. The data and methods of analysis developed at the Laboratory are
most useful in testing models and theories such as these, as they will be in
analyzing new and unusual materials like those from the moon. They are
equally useful in revealing the finer structure of the earth's composition and
history, as in studies on ore minerals, on the origins of petroleum, or indeed in
the discovery of new minerals.
Magnetization of Oceanic Sediments and Lavas. An important part of the
currently available evidence for the continental drift theory and for the "spread-
ing" of the ocean floor is based on measurements of the remnant magnetism of
ocean lavas and sediments. Yet there has been very little systematic study of the
magnetic minerals of the sediments. The reliability of measurements of magnetic
3 A. Snider, La Creation et ses Mysteres Devoiles (Franck), Paris, 1858.
44
CARNEGIE INSTITUTION
Fig. 1. A reconstruction of the world land mass before drift of the continents. The conti-
nental "blocks" having apparent ages of 1700 million years or more (hatched areas) appear in
a coherent grouping within two regions. These blocks are transected and circumscribed by-
belts of younger rocks. Nonmoving ancient nuclei and continental accretion are thought to
have existed up to the time of the great drift. (P. M. Hurley and J. R. Rand, Science,
13 June 1969: 1238.)
orientation in strata on the ocean floor depends on concordance with direction of
the earth's magnetic field at the time of deposition of the sediment. To be a
good indicator of magnetic and stratigraphic history the sediment must be suffi-
ciently mobile for natural realignment of particles to occur under the influence
of the earth's magnetic field at the time of deposition. The source of such mag-
REPORT OF THE PRESIDENT
45
Trench Sediments Eclogite front. Mixed phase
Midocean ridge
////-— Lithospheric plate* — s=r^=i —
//// s~~ Eclogite facies .^^szH
'////r- — High velocity -High Q-_ —_T^
Gravity ///
S/kin^ / ^'==~7>^?-5J? 3^6 g/cm» " — _
A //^Decoupling zone_^ ^ —
^""s. ^ -~ -Rising melt
and residue
V// I Asthenosphere: \ _ "^ / \ — ^/W */' / '/ " '
fl//s Peridotite and basalt meltr\ ^-— ^ \ Migration of basalt melt
/ ~~~" Low velocity- Low Q / / v*> '," '/ / / / l l '
/ 1 yo-3.3 to 3.5 g/cm5 ^ /
/
/
\
/
\
\
\ 1
I / _ \
I
/
\ ',
Fig. 2. One current model of the earth's crust and mantle composition in the oceanic basins.
Volcanic rocks are extruded at the midocean ridge, and a suboceanic "plate" moves gradually
toward a "trench," where the crust is reassimilated into the mantle. (F. Press, Science, 11 July
1969: 175.)
netic mineral material for the oceans as a whole, however, has not been deter-
mined.
S. E. Haggerty, a Fellow of the Geophysical Laboratory, has undertaken a
study of the magnetization of pelagic sediments from the Atlantic, Pacific, and
Indian Oceans, and from beneath the Antarctic ice sheet. He notes that the simple
mechanical breakdown of primary volcanic material, like that observed on the
mid-Atlantic ridges, does not apply to the deep oceans. Haggerty's study has
shown that a major part of the magnetic material in deep-sea sediments is com-
posed of detrital iron-titanium oxides of very small particle size (10 ^m or less).
He believes that atmospheric transportation of these materials from the con-
tinents to the deep oceans is likely. The wide distribution of wind-blown ash
through the atmosphere following violent volcanic eruptions is well known, and
sedimentation rates in the deep oceans (0.5-1 cm per thousand years in the
Pacific Ocean) suggest that this is a reasonable hypothesis.
Conditions determining the magnetization and polarity of certain lavas, also
critical in studies of the ocean floor, have been investigated by Haggerty and
D. H. Lindsley. Systematic correlations have been shown recently between lavas
that exhibit reversed directions of magnetization (i.e., antiparallel to the direc-
tion of the earth's magnetic field) and highly oxidized lavas. The relation between
this reversed polarity and lava oxidation is not understood. In a study of the
stability of the pseudobrookite (Fe2Ti05)-ferropseudobrookite (FeTi205) series,
Haggerty and Lindsley believe they have found an indicator for the question
whether the direction of magnetization in highly oxidized lavas is primary, that
46 CARNEGIE INSTITUTION
is, whether it is developed during the initial cooling. They conclude that the
oxidation of titanomagnetite and ilmenite (FeTi03) in nature to form members of
the pseudobrookite solid solution series takes place between 600° and 800 °C. Oxi-
dation of lavas in this temperature range is most likely to occur during initial
cooling. Field studies of cooling lavas corroborate these laboratory results.
Accordingly, they also conclude that the presence of pseudobrookite suggests
that the remnant magnetization of the rocks in which pseudobrookite appears is
primary — that is, it is parallel to the direction of the earth's field at the time
of cooling.
Mineralogy of the Mantle and Crust. Over the long run the most definitive
evidence about the structure and dynamics of the earth's crust and mantle will
probably depend on mineralogical and penological study. Such investigations
have been pursued by the staff of the Geophysical Laboratory for many years.
More than 40 mineralogy and petrology studies were undertaken at the Geo-
physical Laboratory during this year. Their range and content, methods, and
results may be illustrated by a selection of studies attempting to reveal the con-
tent of the earth's mantle, the relationships of minerals and rocks in the crust,
and crust-mantle relations. Experiments depend heavily upon high temperature-
high pressure apparatus, but the new electron microprobe has been very useful,
and statistical methods have had their place also.
Statistical Petrology. Volcanic rocks have an exceedingly wide distribution in
the earth's crust, particularly in the ocean basins, and on continental margins.
F. Chayes has continued the compilation of a "library" of chemical analyses
of Cenozoic volcanic rocks, which have been placed on computer tapes. The tapes
now contain more than eight thousand analyses that can be processed singly or
in groups, by geographical occurrence, rock name, or any linear combination of
chemical or normative characteristics. During the year Chayes used this data
file to complete a summary study of the chemical composition of andesite, one
of the broad groupings of volcanic rocks. He also made a survey of the relative
frequency of rhyolite and andesite in ocean basins. Using the groupings rhyolite
and andesite and five other classes of volcanic rocks: trachyte, trachyandesite,
basalt, and trachybasalt, Chayes studied the incidence of corundum in more than
3500 analyses.4 He found that the groups arrange themselves according to
corundum content, from the rhyolites, with the highest average corundum per-
centage, to basalts, which have the lowest average content. At the end of the
year Chayes also had under way a study of the "alumina balance" of these rocks,
that is, the ratio of alumina (A1203) to the summation of sodium, potassium,
and calcium (Na20 + K20 + CaO) in the rock.
Crustal Volcanic Materials from the Pacific Ocean Area. Two laboratory
studies have produced interesting new information on technically active areas
within the oceans and seas. The electron microprobe has been used to analyze
the Coral Sea drift pumice, which is produced along the Tonga-Kermadec ridge
in the southwest Pacific. Microprobe analyses by W. B. Bryan, a Fellow at the
Laboratory, showed that the feldspar of the pumice is a more sodic type (by-
townite) than had been determined from prior optical analyses, which showed it
to be anorthite, the most calcic of the plagioclase feldspars.
4 The seven groups of volcanic rocks are composed of varying combinations of feldspar,
quartz, pyroxene minerals, mica, and a number of other minerals in lesser amounts. All of
them contain a sodium potassic or a sodium-calcium feldspar. Rhyolite, for example, con-
tains a potassic feldspar and quartz, whereas basalt contains a sodium-calcic feldspar and
pyroxene minerals.
REPORT OF THE PRESIDENT 47
The drift pumice is of more than passing interest because it may be an im-
portant source of fragmented materials in deep-sea sediments. It is known to
have been transported over thousands of miles by ocean currents, and not infre-
quently in large volume. A pumice "raft" from the 1962 submarine eruption in
the South Sandwich Islands had an estimated area of about 2000 square miles,
and had an estimated volume of about 750 million cubic yards. Bryan considers
that knowledge of the source, composition, and ultimate distribution of the
pumice is essential to a more complete understanding of sedimentations in the
deep oceans and of the geochemical balance between continents and ocean basins.
Bryan also undertook a microprobe study of rocks from the Revillagigedo
Islands (Mexico), located on the East Pacific Rise. Rocks from this area are
considered to have special interest as genetic indicators. The Rise is an area
of thin crust and high heat flow, a setting, according to Bryan, "that seems to
preclude the role of granitic or other typical continental crustal rocks in the
genesis of the lavas." The chemical and mineralogical relations between pan-
tellerite 5 and a closely associated titanium-rich basalt from Socorro Island were
studied. Bryan concluded that the pantellerite could have been derived by frac-
tional crystallization of the basalt at fairly shallow depths, probably above 12
kilometers.
Mineral Composition of the Mantle. The composition of the earth's mantle,
which lies below the crust, and the manner of mineral formation within it are
other subjects of great interest for the Laboratory. In recent years even more
effort has been concentrated on these studies, particularly on the phase equi-
libria of important mineral systems. The phase equilibria studies, of which more
than a score were undertaken at the Laboratory during the year, will be illus-
trated by a set of experiments by F. R. Boyd on one "pyroxene-garnet system,"
and experiments by I. Kushiro, a Fellow of the Laboratory, on melting of the
upper mantle under hydrous conditions.
Boyd's experiments are of special interest because they mark the first time
that electron microprobe techniques have been used at the Geophysical Labora-
tory as a primary means of phase identification in high pressure studies of a
mineral system.
Boyd says in his report that most petrologic models for the upper mantle favor
garnet lherzolite as a major rock type.6 This choice is made because garnet lherzo-
lite is considered a possible parent material for the basaltic lavas commonly
found near the surface. Garnet lherzolite also is abundant among the ultramafic
nodules found in kimberlites,7 which are considered to have been formed within
the mantle. The nodules within which the garnet lherzolite is found are believed
to be relatively unaltered mantle materials.
Garnet lherzolites are composed of only four essential minerals: the olivine
forsterite Mg2(Si04), pyrope garnet, and the pyroxenes enstatite and diopside.
The simplicity of this composition gives promise that the variations of the
minerals in solid solution can be interpreted in considerable detail through experi-
ment. Boyd experimented with the system CaSi03-MgSi03-Al203, which he con-
sidered to model the natural solid solutions closely. The phase relations of this
5 Found also on the Mediterranean Island of Pantelleria, from which the rock received its
name.
6 Lherzolite is a coarse granitoid rock containing olivine and the pyroxenes diopside and
enstatite. A garnet lherzolite contains garnet as well as the olivine and pyroxenes.
7Kimberlite is a granular rock chiefly composed of olivine (Mg-Fe2Si04), biotite mica, and
calcite. It is found in the diamond "pipes" of South Africa and elsewhere.
48 CARNEGIE INSTITUTION
system not only model the mineral assemblage in garnet lherzolites but also have
similarities to the assemblages known in eclogites 8 and grospydites.9 In general
the results of these experiments agree with those of earlier studies on binary
systems undertaken with conventional X-ray and optical methods. However,
they are more detailed and precise. They show that the prior experimentally
determined solvus for diopside in equilibrium with enstatite can be applied to
natural assemblages of minerals in the mantle containing moderate amounts of
alumina.
An understanding of the effect of water on systems of upper mantle components
is necessary to understand the origin of magmas in that region. I. Kushiro, a
Fellow, this year experimented on additional mineral systems containing most
of the major components in hypothesized upper-mantle materials. His studies of
the forsterite-nepheline-anorthite-silica-water system (Fig. 3) showed that the
hypothesized garnet-lherzolite of the upper mantle could form andesitic magmas
in the presence of water at depths of 60-80 km. Other peridotite upper-mantle
rocks could form tholeiitic basalt magmas at the same depths but lower water
contents. The study suggests that the formation of some common volcanic rocks
of the crust is consistent with hypothesized mineralogical composition in parts of
the upper mantle. Further application of the system seems promising when phase
relations within it have been yet more precisely determined.
A Thermal Radiation Barrier in the Mantle. P. M. Bell and H. K. Mao, a
Fellow at the Laboratory, undertook an intriguing study of the crystal field
spectra at high pressure of two minerals considered to be important components
of rocks in the mantle, fayalite (Fe2Si04) and almandite garnet (Fe3AloSi3012).
Their observations suggest that there are mineralogical reasons for a radiation
barrier at great depths in the earth's mantle.
Atoms isolated in space tend to be spherical. In a crystal they are no longer
spherical but are distorted in response to the influence of neighboring atoms, that
is, the crystal field. The effects of the crystal field are especially large in transition
elements such as iron, manganese, chromium, and titanium and can be measured
by means of optical absorption spectra. Exposure of crystals to high pressure
enhances the optical effects because the atoms are forced closer together and
the crystal field is intensified as pressure is increased.
Thermal properties of the earth's mantle are sensitive to crystal field effects
because radiation depends on the amount of absorption in the near-infrared and
infrared regions of the spectrum. There is a broad "transmission window" in
silicates at surface temperatures and pressures. This window is "closed" at high
temperatures but tends to reopen on application of pressure. Bell and Mao also ob-
served strong absorption at approximately 50 kb pressure. The results of the experi-
ments suggest a mechanism for the shielding of thermal radiation within the man-
tle, which could be an important feature affecting its energy states and transfers.
Phase-Equilibrium Studies of Ore Systems. For the past 15 years G. Kullerud
and his collaborators at the Laboratory have studied the mineral phase relations
in a large number of sulfide and arsenide two-member systems that include many
ore minerals. These studies have produced knowledge of the characteristics and
behavior of these systems in previously unparalleled detail and precision. The
binary systems most studied are those of sulfur, selenium, tellurium, arsenic,
8 An eclogite is a coarse-grained mafic rock, mainly pink garnet and green pyroxene, thought
at one time to be a component of the upper mantle, but not favored in recent hypotheses.
9 A grospydite is an inclusion (xenolith) composed of garnet pyroxene and kyanite found in
some kimberlite pipes.
REPORT OF THE PRESIDENT
49
CaAI2Si06
CaAI2Si208
Mg2Si04
MgSi03
Si02
Fig. 3. Phase relations in a quaternary mineral system showing effects of the pressure of
water. The diagram models the forsterite-orthopyroxene liquidus boundaries in the system
forsterite-nepheline-CaAkSiOe-silica-ILO at 20 kb under water-saturated and dry conditions.
antimony, and bismuth. Kullerud states in his report that a "sulfide-type system"
in the past has been understood to include any one of these elements in combina-
tion with one or more typical metals. This generalization has implied that a
typical metal in combination with selenium, tellurium, arsenic, antimony, or
bismuth, would have characteristics at least similar to the same metal in a system
with sulfur. Kullerud and his collaborators have studied more than a hundred
mineral systems that are composed of these five elements in combination with
each other and with 24 metals of six different mineral groups, including nickel,
copper, gold, silver, zinc, aluminum, iron, cobalt, chromium, and others. The
results, classified by Kullerud for the first time this year, now show that the more
than 100 pertinent systems divide into two groups. One is a sulfide type that
includes the sulfides, selenites, and some tellurides. The second system, which
is quite distinct, includes most tellurides, the arsenides, the antimony compounds,
and most bismuth compounds. The bismuthide systems also appear to be transi-
tional into alloy-type systems. Kullerud's classification would appear to have
real value in predicting the behavior of about 40 mineral systems among these
types that have not yet been adequately investigated. It may be considered an
excellent key for future study of a number of minerals in these ore systems.
50 CARNEGIE INSTITUTION
Discovery of New Minerals. Discoveries of new minerals in the experimental
and field studies undertaken by the Laboratory have been reported several times
in earlier accounts. This year has seen the detection of two new minerals. S. E.
Haggerty describes a new iron phosphate mineral which he discovered in a
study of specimens from the extrusive Laco magnetite lava flow in Chile (Plate
2). The new mineral, as yet unnamed, has the formula Fe4(Po4)3. It was found
as minute crystals in cavities interstitial to magnetite and hematite, which are
more common iron-bearing minerals. It is opaque and crystalline, and has a
yellow to bluish gray coloration. It is considered to be a late-stage precipitate
in the lava flow.
The second new mineral, discovered by H. 0. A. Meyer, a Fellow at the
Laboratory, and B. M. French of the NASA Goddard Space Flight Center, has
a somewhat more complex formula. It is thought to be the first example of the
natural occurrence of a /3-quartz solid solution, and is a combination related to
spodumene (LiAlSi206), one of the pyroxene group of minerals. The formula of
this mineral is given as (LiAlSi206)63 (Si02)37- It was found in a specimen of
"Macusani glass" which occurs as pebbles and cobbles in glacial and alluvial
deposits near Macusani, Southern Peru. It is not comparable to any naturally
occurring volcanic glass hitherto observed. The /?-quartz-spodumene mineral
occurs as numerous small rosettes in the glass.
Amino Acids in Organic Earth Materials. As Dr. Philip H. Abelson writes in
the Introduction to his report this year, one of the major puzzles of organic
geochemistry occurs in the process wherein the relatively simple components of
living matter are incorporated into the sediments of the earth. Microorganisms
have long been accorded an important role. However, kerogen, a complex organic
material, comprises the greater part of the organic matter in sediments. And the
nature of kerogen strongly suggests that nonbiological processes must be involved.
Abelson and P. E. Hare have discovered that kerogen itself participates in an
important nonbiological mechanism in sediments leading to the disappearance of
small molecules like amino acids. Starting from a chance observation that both
fatty acid tracers and amino acid tracers were not completely recovered when
exposed to kerogen, they found that kerogen reacts rapidly and irreversibly with
amino acids and peptides. The most reactive amino acids included cystine, argi-
nine, histidine, lysine, phenylalanine, and tyrosine. Most of these are the basic
and longer aliphatic chained amino acids. Only glutamic acid and aspartic acid
remained after exposure of amino acids to kerogen for relatively long periods at
110°C. It is thought that a considerable portion of the nitrogen of the amino acids
is bound into the kerogen, although some of it is evolved as ammonia. Humic
acid, usually found mixed with kerogen, has about the same effect on amino acids
as kerogen. An important nonbiological "sink" thus has been identified for de-
stroying components of living matter in crustal sediments over long periods, at
ambient temperatures.
Seeking additional insight into the amino acid-kerogen reaction Abelson and
Hare conducted a series of experiments whose results suggest some equally
significant inferences about life origins. They are another instructive example
of the importance of chance in science, but the chance that comes to the prepared.
Their experiments started with the reactions of kerogen and the peptides glycyl-
leucine and leucylglycine. In the course of the experiments they observed that
after long-term exposure of one or the other of the two peptides to kerogen, new
peptides appeared. When glycylleucine and kerogen were heated, some leucyl-
glycine was formed, and similarly, glycylleucine was formed from leucylglycine.
Plate 2
Report of the President
100/xm
Plate 2. Photomicrographs of a newly discovered iron phosphate mineral, Fe4(P0i)s. The
mineral (FP) is dark gray, and in photograph (a) it is unaltered and crystallographically
twinned. In photograph (b) thin alteration veinlets have developed along the grain boundaries
and in cracks. The iron phosphate is surrounded by magnetite (M) and hematite (H).
REPORT OF THE PRESIDENT
51
One peptide, leucylglycine, was more stable than the other. Further experiment
without kerogen, in which the cyclic amide diketopiperazine appeared as an inter-
mediate, resulted in production of consistently higher proportions of leucyl-
glycine than glycylleucine from the parent material.
Abelson and Hare conclude their report with the observation that these experi-
ments "have profound implications for the abiotic synthesis of peptides and
proteins since they indicate a preferred production of certain amino-acid se-
quences by a nonbiological, non-genetic code mechanism."
CHOLESTEROL
CHOLESTANE
N nC28H3e
\ /3 CHOLESTANE /"^
\a CHOLESTANE
Fig. 4. Two steranes (steroid deviatives), and cholestane, as they are identified by alumina
chromatography. The relation of the chemical structure of cholestane to cholesterol is shown
by the two models. Cholestane lacks only the 3-hydroxyl group.
52 CARNEGIE INSTITUTION
Steranes in Petroleum. T. C. Hoering, of the Laboratory, succeeded in isolating
some of the optically active components of petroleum. Optically active molecules
are widely synthesized by living organisms but are rarely found in nonliving
systems. A strong argument for the biological origin of petroleums resides in the
optical activity associated with high-boiling, saturated, cyclic hydrocarbon com-
ponents. They include the four-ringed molecules of the sterane class, probably
formed through the hydrogenation of optically active steroids commonly found
in living organisms (Fig. 4) .
With new methods of chromatographic separation and new instrumental meth-
ods of structure determination Hoering has isolated and identified ten sterane
hydrocarbons from a crude oil taken from the Los Angeles Basin. They were
highly active optically and had the molecular structures to be expected from the
hydrogenation of common plant and animal steroids. Hoering's method will
permit the examination of the high-boiling fractions of sedimentary organic
matter in a degree of detail not before possible. Many classes of compounds of
great biogeochemical interest, such as very old petroleums and rocks, are now
open to detailed analysis and characterization.
Department of Terrestrial Magnetism 1968-1969 Expenditures:
Operating $726,419.19
Equipment $172,320.65
Commencing more than 60 years ago with studies of the magnetic properties
of the earth, the Department of Terrestrial Magnetism has gradually broadened
its scope until it now has the widest range of research interests of all the Institu-
tion departments. The Department applies the methods of physics to a great
variety of problems from the evolution of life forms to astrophysics. This year's
report notes astrophysical studies that include optical astronomy, radio astronomy,
nuclear physics, and atomic physics. Geophysical studies, which are described
below, display an increasing convergence of interest on problems generally similar
to those which engage the Geophysical Laboratory. The DTM, however, applies
some different research techniques. Staff Members from the Department and the
Laboratory together form a joint study group that has specialized for some years
on geochronologic study by means of isotopic dating. Besides these techniques,
the DTM also has a very active seismology program, and the year's reports also
show a fruitful and far ranging use of the techniques of geochemistry. As illustra-
tions of the work of the Department, selected studies from the Geophysical
Section and Biophysical Section will be described.
Geophysical and Geochemical Studies Related to the Evolution of the Con-
tinents and Other Parts of the Earth's Crust. Like the Geophysical Laboratory,
the DTM has designed its program in geophysics and geochemistry to attack the
global problems of the evolution of the earth's crust, including both continental
and ocean basin areas.
The objectives of the Geophysics Section,10 which undertakes these studies, are
very fittingly stated in a reference to its seismological observations on the
Andean plateau: ". . .we have sought to describe with increasing depth and
10 L. T. Aldrich, Chairman, S. E. Forbush, S. R. Hart, I. S. Sacks, J. S. Steinhart, M. A.
Tuve, C. Brooks, D. E. James; Fellows: A. J. Erlank, A. T. Linde, G. Saa; Research Asso-
ciates: S. Suyehiro, M. Casaverde, R. Salgueiro; Collaborators: P. Aparicio, A. Rodriguez, D.
Simoni, L. Tamayo, A. A. Giesecke, Jr., E. Deza, J. Frez, E. Kausel, E. Gajardo, F. Volponi,
J. Mendiguren, R. Cabre, L. Fernandez, S. del Pozo, J. Santa Cruz.
REPORT OF THE PRESIDENT 53
precision the physical properties of this unusual part of the earth's crust. These
properties must be satisfied by any model describing the process of continent
formation." The process of continent formation itself was in mind in geochrono-
logical studies of ancient volcanic rocks on the Canadian shield. A contribution
to understanding of sea-floor spreading likewise was the objective of a study of
sea-floor basalts.
Trace Elements in Sea-Floor Basalts. S. R. Hart of the Geophysics Section
notes in his report that the hypothesis of sea-floor spreading includes formation
of an igneous crust on the oceanic ridges and rises, followed by lateral spreading
and re-assimilation of the crust into the mantle along the oceanic trenches (Fig.
2) . The material of the ocean floor appears to be a tholeiitic (high-alumina) basalt
with a low potassium content, and relatively high ratios of potassium to rubidium,
potassium to cesium, and strontium to barium. These characteristics are unlike
continental or oceanic island basalts. Increasing alteration of the sea-floor basalts
with distance from the zone of origin had previously been observed. Hart there-
fore undertook investigation of the possible role of sea water in producing the
anomalous nature and proportions of the trace elements found.
Analyzing specimens from the East Pacific Rise, Hart found severalfold differ-
ences between recent unaltered interior and sea-water-altered rock margins in
the proportions of the elements potassium, rubidium, and cesium that they con-
tained. Little difference in strontium was found. It would appear that as the
basalts move away from the ridges and age they are increasingly altered and
become more difficult to date by isotopic methods. Hart considers the prospects
for accurate potassium-argon dating, a familiar and convenient method, to be
poor for sea-floor basalts.
In collaboration with A. Nalwalk, of the University of Connecticut, Hart also
studied trace elements in much older basalts dredged from the Puerto Rico
Trench. Evidence of alterations in the proportions of calcium, rubidium, cesium,
and strontium, as compared to silica, was found in these specimens. Hart con-
cludes that trace element values for the alkali metals and alkaline earths in the
sea-floor basalts must be regarded with "considerable caution." This, of course,
has obvious meaning for achieving precise geochronology of rocks on the ocean
floor.
Evidence from Strontium Isotopes on the Early Heterogeneity and Continuous
Differentiation of the Earth's Mantle. The evolution of the earth's crust from
earliest time is of no less geological interest than that during recent epochs. Much
of the evidence for an interpretation of this earliest history resides in the great
continental blocks of ancient rocks (greater than 1.7 million years) like the
Canadian shield (Fig. 1). One means of interpreting this history is through a
study of a strontium87-strontium86 ratio. The ratio is a useful tracer because
strontium87 is always formed through natural decay of rubidium87, whereas
strontium86 is nonradiogenic. Information on the evolution of rubidium and
strontium in the mantle can be obtained by calculation of the rate of change in
this ratio of strontium87 to strontium86.
Application of this tool to a study of the evolution of the earth's mantle
depends on the discovery of rocks directly derived from the mantle. Most such
rocks are modern volcanics. But almost no analysis has been undertaken on
ancient volcanics in the old continental blocks. C. Brooks, a Fellow at DTM;
S. R. Hart of DTM, and T. E. Krogh and G. L. Davis of the Geophysical Labora-
tory, undertook to close this data gap on mantle evolution by studying volcanics
54
CARNEGIE INSTITUTION
from the 2.7-million-year-old Superior Province of the Canadian shield. The
rocks analyzed are of zeolite, greenschist, and amphibolite facies, that had been
metamorphosed from original rhyolites and basalts. The basalts are similar in
chemical composition to modern basalts dredged from the ocean basins.
The results of these studies strongly suggest that a higher strontium87 -strontium86
value existed in the earth's mantle 2.7 million years ago than that predicted from
the model in use, which projects linear growth from observed values in meteorites.
The strontium87-strontium86 data also suggest that the variation in this ratio
inferred for the present-day mantle appears also to have existed in the mantle
of 2.7 million years ago. In arriving at these conclusions, Brooks, Hart, Krogh,
and Davis evaluated possible effects of metamorphic processes, crustal contamina-
tion, magma aging, and magma regeneration. They note that present-day hetero-
geneities in the submarine mantle of the earth appear to be somewhat larger than
the inferred ancient mantle values.
On the basis of the data derived from study of these ancient volcanics, Brooks
and Hart have derived a new model for the evolution of rubidium and strontium
in the crust of the earth (Fig. 5). They propose a nonlinear continuous transport
model in which rubidium and strontium are transported from mantle to crust
continuously. They consider their model to be consistent with data on modern
submarine basalts. They note that further testing of the validity of the model will
require analyses of volcanic rocks intermediate between Archaean and modern.
oo
oo
ACHONDRITE
nO.705
- 0.704
- 0.699
Jo:698
2.5 1.5
AGE (TO9 years)
Fig. 5. Diagram for a model of rubidium-strontium evolution. Curves connecting primordial
strontium (Sr87/Sr86 = 0.6990) and modern oceanic strontium (07038) are calculated for a
continuous transport model. K values are the transport parameters; other values are the
initial Rb-Sr ratios required by the model. Also shown is the evolution line of a typical
chronditic meteorite with initial Rb-Sr ratio of 0.25. Black dot at 2.6 billion year age is the
best average value for Archaean metavolcanics determined at the Department of Terrestrial
Magnetism.
REPORT OF THE PRESIDENT 55
If the model proves valid, it would imply a relatively constant rate of continental
growth from Archaean times.
Other studies by Hart, Davis, Brooks, and Krogh showed that the continuous
transport model was consistent with the evolution of cesium, rubidium, and
potassium in the mantle, as well as strontium.
Potassium as a Tracer for Mantle Origins of Crustal Rocks. One important
requirement for accurate determination of mantle parent materials for crustal
rocks is a source of potassium sufficiently abundant to account for the high
potassium contents of alkali basalts, a relatively common rock among modern
volcanics. A. J. Erlank, a DTM Fellow; and I. Kushiro and L. W. Finger, Fellows
at the Geophysical Laboratory, undertook analyses of the distribution of potas-
sium in mafic and ultramafic nodules found especially in the kimberlites of South
Africa. They are thought to represent fragments of the upper mantle. Erlank,
Kushiro, and Finger found that most of the minerals present in these nodules did
not have enough primary potassium to account for the potassic content of alkali
basalts. Only two possible potassium sources were discovered: (1) part of a
pyroxene mineral series known as omphacites, found especially in eclogite
nodules; and (2) a somewhat rare amphibole mineral known as richterite, found
in a mica nodule from a South African kimberlite. According to Erlank and
Finger the richterite may represent the type of amphibole likely to occur in the
upper mantle. If it amounts to even one percent of the upper mantle material it
could account for the potassium in basalt lavas. These analyses were all under-
taken by electron microprobe methods, permitting the measurement of relatively
minute quantities of potassium (as little as 20 parts per million).
Seismological Techniques for Probing the Crust and Mantle. In a currently
accepted model of the dynamics of the crust and mantle (Fig. 2) one of the
clearly stressed regions is where the ocean floor moving out from the "rises"
plunges under continental blocks. The western coast of South America appears
to be such a region. It has been an attractive area for seismological study by the
DTM for a number of years.
This year the DTM staff, in collaboration with the University of Wisconsin,
the Southwest Center for Advanced Studies, the Instituto Geofisico Boliviano,
the Instituto Geofisico del Peru, and the Instituto Geofisico of San Agustin Uni-
versity, Arequipa, Peru, engaged in the most active program of seismological
observation in southern Peru and eastern Bolivia undertaken since 1957. This
newest series of measurements confirmed the earlier anomalously high absorption
of seismic energy in southern Peru, and gave indication that the seismic attributes
of the crust could be fully measured through later observations in Bolivia.
I. S. Sacks, of the DTM staff, G. Saa, a DTM Fellow, and P. Aparicio, of La
Paz, Bolivia, report on a study made at the Carnegie Analysis Center in Lima,
Peru, of the correlation between crustal features like the Andes and anomalous
velocities of earthquake waves in the upper mantle. They find that the Andes
Mountains chain has a "root" of lower velocity material that dips away from
the Pacific Coast. The width of this root is about 100 km, and the length may be
as much as 400 km. The earthquake activity, which also dips away from the
Pacific Coast, lies along the seaward side of the low velocity tongue and may
reach a depth of 600 km. Aside from the low velocity tongue below the Andes, the
behavior of seismic waves between the Pacific Coast and the pampas of western
Brazil appears to be relatively normal. One is tempted to correlate the low
velocity tongue with the dipping "plate" postulated in current hypotheses on
ocean floor movement.
56
CARNEGIE INSTITUTION
An Extraordinarily Sensitive New Seismic Instrument. Probably the most
exciting seismological achievement of the year was the invention by I. S. Sacks
of DTM and D. W. Evertson of the University of Texas, of a borehole strainrate
meter. Dr. Ellis Bolton, the Director of DTM, refers in his report to the remarks
made 60 years ago by H. F. Reid of Johns Hopkins University, describing the
great value that discovery of a method of determining strains would have for
the prediction of earthquakes. Strains in the crust always precede major earth-
quakes. Bolton adds, "Reid's dream may be on the verge of becoming a reality."
Sacks and Evertson's meter is both inexpensive and extraordinarily sensitive.
The principal element of the meter is a water-filled resilient stainless steel tube
in intimate contact with the walls of a borehole (150 ft. deep for the DTM
prototype) . The tube is cemented to the bottom of the borehole, and as the strain
changes in the surrounding rock the tube is deformed, forcing liquid through a
flow sensor into an air space. The sensor used is a linear solion developed at the
Applied Research Laboratory of the University of Texas (Fig. 6) . The meter is
omnidirectional and its frequency response covers many types of geophysical
measurement. Not only are microseisms detected, but also microbarometric pres-
sure influences on solid rock, and the gravitational deformation of the earth by
the moon. Distortions as minute as 10~7 microns (one-thousandth the distance
between atoms in an ordinary chemical bond) are readily detected (Fig. 7). It
has been calculated that strain changes of "somewhat over 1 part in 1013" can
be measured. The system is many times more sensitive than the most precise
strainmeters heretofore available. The prototype meter has operated without
fail for more than a year. One may be confident that this revolutionary new
instrument will accelerate considerably our acquisition of precise knowledge on
the geophysics of the earth. Furthermore, it offers unusual promise of assisting
10 ft
LEAD BALLAST
MATERIAL:
316 STAINLESS 'WATER
CHLOROFORM
SATURATED
,,-,. CERAMIC
^-1 CALIBRATOR
Z^ (STEP VOLUME
CHANGE)
Fig. 6. Prototype borehole strainrate meter, including a schematic drawing of the solion
flow velocity sensor. The cathodes are made from very fine platinum basketweave. The elec-
trolyte is potassium iodide and free iodine, and the solion body is made of Kel-F, a plastic.
The two half cells have a bias voltage of about 0.5 volts applied; the current in each cathode
is a measure of the flow velocity of the electrolyte through the cathodes.
REPORT OF THE PRESIDENT
57
icr
Noise caused by otmospheric pressure fluctuations
100,000
10,000
1000 100
Period (seconds)
1.0
Fig. 7. Frequency response of the prototype strainmeter. The response at short periods
is modified by electronic double integration to reduce the sensitivity in the microseism
range, 6-20 second period.
in the achievement of a long-held dream in earthquake susceptible regions — the
timely prediction of major shocks.
The Biophysics Section. The direct descendant of the interest in biology and
biophysics developed more than 20 years ago by a group of nuclear physicists at
the Department of Terrestrial Magnetism. Its Biophysics Section (E. T. Bolton,
R. J. Britten, J. A. Chiscon, D. B. Cowie, L. J. Grady, B. H. Hoyer, D. E. Kohne,
N. J. Reed, and R. B. Roberts) continued during the year its distinguished pro-
gram of research on molecular processes within individual cells. In recent years
the Section's interest has centered on the distinction between the relation of the
large amounts of repeated DNA sequences in the genomes of higher organisms,
and on the nonrepetitious DNA contained in all living cells. Noteworthy
among the achievements this year, which included detailed studies of the DNA
of many organisms including bacteria, algae, and higher organisms, was the dis-
covery of a new virus infecting blue-green algae, the development of a new and
much more rapid and efficient method of DNA extraction, and, most exciting, the
formulation of a new theory for gene regulation in the cells of higher organisms.
Since the first recognition of repeated sequences in DNA within cell genomes
about four years ago, many different properties of these sequences have been
described. A large number of these descriptions have come from the Biophysics
Section itself, and still others from other departments of the Institution. In this
58 CARNEGIEINSTITUTION
year's report R. J. Britten suggests that the repeated sequences now have a major
role in transcription of messages from the DNA and probably have had such a
role throughout evolution. However, the way in which they originate and the
manner in which they function still remain unknown. Britten summarizes the
knowledge thus far obtained about this apparently important part of the genome:
1. Repeated sequences have been observed in all the species tested thus far
above the level of fungi.
2. Although the definition of a repeated sequence is currently considered some-
what arbitrary, the amount in individual species varies from twenty percent (sea
urchin) to eighty percent (salmon and wheat). Britten believes that future
observations will increase the total quantity of repetitive DNA recognized.
3. The number of repetitions within a single genome among the species observed
varies from fifty times that expected for single copy DNA (the fruit fly, Droso-
phila) to two million times (guinea pig) .
4. There is a wide range of thermal stability for repeated sequences which have
been "reassociated." The "families" of sequences with the highest thermal stability
also have the largest number of members in the family. It is thought that they
originated most recently in the evolutionary process. Since a range of thermal
stabilities may be found within a single genome, it is possible that different stages
of evolution among higher organisms are represented physically in the repeated
sequences.
5. The repeated sequences appear to be scattered throughout the genome, the
interspersion being at a surprisingly fine scale. Fragments of about 1.5 million
daltons 1X appear to contain both repeated and nonrepeated sequences.
6. Some families of repeated sequences apparently are of great age on the
evolutionary scale. This is suggested by the wide degree of difference in nucleotide
sequences among the members of some families. Additional strong inferences are
given by the sequences held in common among organisms such as fish and mam-
mals, whose common ancestors date back hundreds of millions of years.
7. Each species appears to have a distinct pattern of frequency and precision
among the repeated sequences. During the year, for example, Britten and Jean
Smith analyzed the bovine genome and found that calf DNA is dominated by a
66,000-copy component that makes up 37 percent of the original DNA in the
calf genome. In the human being there is a component with about the same
frequency, but it contains much less of the total DNA. The usual pattern appears
to be a small number of "families" of repeated sequence within an individual
species.
8. RNA complementary to the repetitive DNA sequences has been observed in
every cell type examined thus far by the Biophysics Section. It is also known that
individual sets of repetitive sequences are transcribed in different tissues and at
different stages of development. The large redundancy of RNA during the
embryonic development of the toad, Xenopus laevis, which has been studied
extensively by the Department of Embryology, is an example referred to later in
this report.
Blue-Green Algae and Their Viruses. It thus appears that the repetitive se-
quences of DNA may offer an extraordinarily good indicator for pathways of
evolution. One of the groups of organisms on which the Biophysics Section cen-
tered its attention during the year was the class of blue-green algae or Cyano-
11 A dalton is a unit of physical measure equal to about one-sixteenth the mass of the
oxygen atom.
REPORT OF THE PRESIDENT 59
phyta. The blue-green algae and the bacteria both lack well-defined nuclei. In this
they are basically different from all higher cell types, which have true nuclei
bounded by nuclear envelopes. The Section's laboratory studies have brought out
another significant distinction between bacteria and blue-green algae on the one
hand and organisms with nucleated cells on the other: The DNA of the former
is generally nonrepetitive, whereas the DNA of nucleated cells contains large
quantities of repeated DNA sequences in addition to the nonrepetitive DNA. At
the same time the blue-green algae (but not most bacteria) share with the
higher plants the capacity for oxygen-evolving photosynthesis. These character-
istics have led the Section to study the blue-green algae as a system bridging "the
apparent evolutionary discontinuity" between bacteria and higher organisms.
D. B. Cowie and L. K. Prager report this year on their progress in the first
experiments undertaken by the Section on the blue-green algae. Prior studies by
other research workers had resulted in the isolation of a virus (LLP-1) that can
lyse some species of three genera of blue-green algae (Lyngbya, Plectonema, and
Phormidium) . The common viral host-range specificity of these species sug-
gested to Cowie and Prager that they might be evolutionary related. Cowie and
Prager's studies indeed did reveal homologies among them in nucleotide sequences
(Fig. 8) . Furthermore, a high degree of precision in base-pairing was found when
the DNAs of species from the three genera were reacted with each other. However
there were no DNA-DNA reactions between the lysing virus (LLP-1) and the
algae, indicating that the algae virus-host system is similar to those of nonlysogenic
phages and their bacterial hosts.
In the course of experiments with another blue-green species of the genus
Oscillatoria (1270) Cowie and Prager discovered a new lysogenic virus carried
within the algae but capable of infecting the three blue-green species of Lyngbya
(488) , Plectonema (597) , and Phormidium (485) . Hitherto lysogeny 12 has been
known only among bacteria. It would appear that the Oscillatoria virus discovered
during the year is the first lysogenic one known outside the bacterial class.
Further studies designed to test relationships among the lysed and lysogenic
blue-green species disclosed information suggesting some rearrangements in the
prevailing taxonomy of the class of blue-green algae as a whole. For example,
DNA-DNA agar tests showed one species of Lyngbya (621) to be less closely
related to another Lyngbya (488) than to Phormidium (485) and Plectonema
(597). A still more precise reaction with another species (Anacystis nidulans)
strongly suggested a taxonomic reclassification of this species.
The year's studies with blue-green algae thus have yielded a more detailed —
and new — picture of relationships within the class, and have revealed an im-
portant new characteristic shared with bacteria: the possibility of the presence of
a lysogenic virus on the genome of one blue-green species, which is able to
infect at least three others.
New Method of DNA Purification. A new method of DNA purification was
developed during the year by R. J. Britten, M. Pavich, and J. Smith. Mr. Pavich,
a summer student with the Biophysics Section, was making a series of exploratory
measurements on the effect of urea and various concentrations of a phosphate
buffer on the binding of DNA and RNA to hydroxy apatite in a column, a material
customarily employed for this purpose. Unexpectedly, experiments showed that
no RNA was bound when urea and the phosphate buffer were present in certain
u The presence of a virus on the genome of one species benign to it but infective to other
species.
60
CARNEGIE INSTITUTION
700
600
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200
Plectonema (597) DNA fragments
Plectonema (597) DNA- agar
Plectonema (597) DNA fragments,
Lyngbya (488) DNA -agar
Plectonema (597) DNA fragments
Phormidium (485) D N A - agar ,
Temperature, °C
Fig. 8. Thermal elution profiles characteristic of the reaction of radioactive Plectonema
(597) fragments with Plectonema (597) DNA-agar (open circles) ; with Lyngbya (488)
DNA-agar (crosses); and with Phormidium (485) DNA-agar (solid circles). The homologies
of Plectonema with the other two algae are clearly visible in the higher temperature fractions.
concentrations. It was then found that DNA of an unusually high degree of purity
could be prepared directly from tissues by the urea, or MUP, method, as it has
come to be known. DNA of comparable purity, if prepared by standard methods,
requires a lengthy procedure that includes successive stages of enzyme treatment,
deproteinization, and precipitation.
Not only is the MUP method more rapid, less expensive, and more efficient,
but it also appears capable of recovering DNA fractions not hitherto separated
by the standard methods. Britten, Pavich, and Smith found that a low melting
temperature fraction of Neurospora DNA was separated in quantity for the first
REPORT OF THE PRESIDENT 61
time by the MUP method. This DNA fraction amounts to about 25 percent of
the total DNA recovered. A new view of the DNA of a widely used experimental
organism has already been obtained.
The new method has been successfully used for extraction of DNA from tissues
of many widely differing organisms, including blue-green algae, amoebae, Neuro-
spora, Lactobacillus, Escherichia coli, Amphioxus, Brachiopods, King crab,
iguana, chicken, calf, mouse, and man.
Repeated Sequences in Bacterial DNA. The identification last year of nucleo-
tide sequences that code for ribosomal RNA has led J. A. Chiscon and D. E.
Kohne to look for repetitive DNA sequences in bacteria. By employing repeated
cycling in the usual DNA separation procedures they isolated multiple copies of
DNA from Escherichia coli cells. They estimate that these copies may represent
as much as 4-5 percent of the total DNA of the stationary stage of Escherichia
coli cells. The fraction appears to be heterogeneous, with at least two components,
and differing degrees of multiplicity at different stages of culture growth. Chiscon
and Kohne suggest that this multiple copy DNA is not part of the actual bacterial
genome. If this proves to be true, it will be a radical discovery, for, as earlier
stated, it has been generally believed that such replication is characteristically
absent in bacteria and the blue-green algae. The matter will be pursued further,
using a relatively quick and simple method now available for isolation and
characterization of episomal and plasmid DNA.
A New Theory of Gene Regulation for Higher Cells. The observations and
experiments that have gradually enlarged our knowledge of repeated sequences in
the DNA of higher organisms have led R. J. Britten of the Section, and E. H.
Davidson of Rockefeller University to propose a new model of gene regulation
for all higher organisms.
One of the great contemporary issues of biology concerns an understanding of
the mechanisms of cell differentiation. This is a principal objective of the entire
Department of Embryology of the Institution, described later in this report.
Britten and Davidson introduce their model by observing that "Cell differentia-
tion is based almost certainly on the regulation of gene activity, so that for each
state of differentiation a certain set of genes is active in transcription and other
genes are inactive." Evidence for this observation is provided by current knowl-
edge of the genome of the cell. The cells of any given organism generally contain
identical genomes. In higher cell types much of the genome is known to be inac-
tive. Different cell types are known to synthesize different ribonucleic acids.
Britten and Davidson state that their model suggests a contemporary function
for the repeated DNA sequences, and also suggests their possible evolutionary
role as the raw material for creation of new gene sequences.13
Britten and Davidson identify as parts of their model (Fig. 9) producer genes,
receptor genes, integrator genes, sensor genes, and activator RNA. A sensor gene
is a nucleotide sequence serving as a binding site for agents that induce specific
responses in the genome. An integrator gene synthesizes the activator RNA in
response to a signal from the sensor gene. The activator RNA forms a sequence-
specific complex with receptor genes that are linked to producer genes. Britten
and Davidson postulate a single-stranded RNA molecule, but double-stranded
(native) DNA as part of the receptor-producer complex. The receptor gene is
linked to the producer gene, and causes a transcription of the producer gene to
occur when the sequence-specific complex is formed between the receptor and the
"Roy J. Britten and Eric H. Davidson, "Gene Regulation for Higher Cells: A Theory,"
Science, 25 July 1969 : 349-357.
62
CARNEGIE INSTITUTION
Sensor-
ABCDEG
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Fig. 9. A diagram of the Britten-Davidson model, suggesting the existence of overlapping
batteries of genes, and the manner in which control of their transcription might occur. The
dotted lines symbolize the diffusion of activator RNA from its sites of synthesis, the integrator
genes, to the receptor genes. The numbers in parentheses show which sensor genes control the
transcription of the producer genes. At each sensor the battery of producer genes activated
by that sensor is listed. In reality many batteries will be much larger than those shown and
some genes will be part of hundreds of batteries.
(R. J. Britten and E. H. Davidson, Science, 25 July 1969 : 351.)
activator RNA. The producer gene usually is part of a set of producer genes
activated in the process started by the sensor gene. The producer genes yield
template RNA molecules or other species of RNA, excepting those directly con-
cerned with gene regulation. Britten and Davidson mention as examples of the
producer genes those on which the messenger RNA template for a hemoglobin
subunit is synthesized.
They cite in support of their theory previous experimental observations on
regulatory genes, the known sensor elements in physiological systems, the num-
ber of functionally linked enzyme systems, and the known existence of RNAs
for which there is no known function.
Barbara McClintock, of the Genetics Research Unit of the Institution, in
particular has produced evidence of regulator genes through her pioneering studies
of the maize genome. Britten and Davidson consider that McClintock's results
fit their model very well. They further note the functional linkage in at least
16 enzyme systems, more than half of which contain more than ten different
enzymes. The citric acid cycle, for example, has 17 different enzymes associated
with it. Furthermore, the same enzyme is to be found in widely differing types of
tissue. The authors of the theory say that direct contiguity of active producer
genes could not account for such a pattern of overlapping activity if only a
single copy of each gene were present in the genome. A mechanism is required
REPORT OF THE PRESIDENT 63
for coordinating the activity of noncontiguous systems of producer genes for each
state of differentiation.
The existence of many chemically defined agents that can induce large-scale
changes in specific target tissues is cited as fitting the role of sensor elements in
the Britten-Davidson model, including the integrator gene function. Such agents
include steroid hormones, polypeptide hormones, plant hormones, vitamins, and
embryonic inductive agents.
Among the RNAs that have been described thus far are some that appear to
be specific to the nucleus, where the Britten-Davidson activator RNA would be
located. Furthermore, these nuclear-specific RNAs perform experimentally in
the manner assigned to the activator RNAs in the Britten-Davidson model.
Britten and Davidson state that the model supplies a new means of visualizing
the process of the evolution of life. The inactivity of DNA sequences, unless
specifically activated, allows for the accommodation of new and "even useless or
dangerous segments of DNA such as might result from a saltatory replication."
The model appears to have a needed combination of conservatism and flexibility.
Preexisting useful batteries of genes will tend to continue functioning. At the
same time new integrative combinations of preexisting producer genes can occur.
Lastly, a mechanism for divergence is afforded, through base changes in the indi-
vidual sequences within a DNA family. Thus new nonrepetitive DNA sequences
could arise from repetitive ones. Such changes could also be reversible. Britten
and Davidson conclude, "The potentiality for smoothly changing patterns of
integration among many sets of producer genes supplies a mechanism for direct
adjustment by natural selection of the organization of systems of cellular activ-
ity." Selective factors may influence the integrative gene configurations of any
organism. The rate of evolution, and its direction (i.e., toward greater or less
complexity) are thus themselves subject to control by natural selection.
The model stimulates further consideration of a fascinating field — the evolu-
tion of regulatory systems in all life.
Genetics Research Unit 1968-1969 Expenditures:
Operating $186,744.17
Equipment $5,464.43
In an extraordinarily rewarding essay that forms a major part of this report,
Dr. Alfred D. Hershey, Director of the Genetics Research Unit, examines the
relation of microbiological and biochemical genetics to classical genetic theory.
Hershey commences his essay by noting the distinction between genotype, the
genetic constitution of an organism, and its phenotype, or the visible expression
of its genes in an individual, probably first observed by Mendel.14 Mendel's great
contribution against a background of this complex concept was the demonstration
that inheritance depends on unit factors. Mendel indeed set the direction that has
characterized the study of inheritance to this day. Noting the work of T. H.
Morgan and others who followed directly, but much more elaborately, the lines
set by Mendel, Hershey concentrates on the important steps taken in biochemical
genetics after 1940. First came the one gene-one enzyme hypothesis evolved
from the work of Beadle and Tatum and their colleagues on the bread mold,
Neurospora. This important hypothesis, which Hershey restates in terms of
current understanding as "one gene determines the amino acid sequence of one
enzyme," was not accepted until about 1951 when Horowitz and Leupold demon-
11 Gregor Mendel: 1822-1884.
64 CARNEGIE INSTITUTION
strated that only one gene functions in the synthesis of a single enzyme. In
the context of the one gene-one enzyme hypothesis, principal subsequent develop-
ments were the discovery of two subclasses of genes — the regulator genes and
genes that encode the structures of ribosomal and transfer RNA — and of course
the famous elucidation of the structure and function of DNA, the material of the
gene itself.
The initial aim of chemical genetics, Hershey says, was an understanding of
the structural and functional basis of genotypic determination of phenotype. This
has been achieved, thanks to the revelation of the structure of DNA, which com-
menced with the Watson-Crick hypothesis in 1953. He summarizes this knowl-
edge: (1) the genotype resides in DNA; (2) nucleotide sequences in single DNA
strands afford a code for one-to-one transcription in DNA replication, and
synthesis of RNAs; (3) sequences in one of the two DNA strands represent a
second code translatable into amino acid sequences ; and (4) gross structure can
be directly determined by subunit structure. As proof of the latter Hershey cites
the reconstruction of certain virus particles from their molecular constituents, and
the joining of separated bacteriophage tails and heads to make viable virus
particles. The most surprising thing about the denouement in elucidating gene
action, according to Hershey, was its simplicity. The universality of these gene
relations and the exploitation of a common genetic code in all living forms
points to a unique origin of life, "the only economical explanation."
Hershey then goes on to discuss some limitations of the gene theory as it has
been refined by molecular genetics. Perhaps the foremost question is the old one
as to whether or not all heritable characteristics are determined by genes — a
question that has never been finally answered. In spite of the dramatic evidence
yielded by experiments with viruses, Hershey suggests "The inference that all
three-dimensional structure is encoded in nucleotide sequences does not necessarily
follow." Observations on protozoans like Paramecium and Stentor raise serious
questions about such an inference. In Stentor & "primordium" in the cell cortex
(outer membrane) has been shown to be indispensable to development and per-
sistent through both sexual and asexual reproduction. Growth, division, and con-
tinuity thus are exhibited by a cellular element that persists in the cell in only
one copy.
A second question not answered by gene theory is the phenomenon of cell
polarity, shown in experiments with Stentor coeruleus by Tartar and others.15
Cell polarity is the capacity of the cell to reorient itself into normal pattern when
parts are displaced by surgical intervention and then rejoined in abnormal con-
figurations. Polarity has been demonstrated to reside in every part of the cell
cortex.
Hershey adds that supramolecular patterns also are observable in bacterio-
phages, apparently residing in the structures of individual molecules. He con-
siders cortical polarity a phenomenon whose structure and processes should be
analyzable. This poses an intriguing task for future molecular biologists.
DNA Phenotypes. Relatively few years ago it would have been inconceivable
that DNA itself might be considered to manifest a phenotype. Hershey shows,
however, that this concept is now supported by a great variety of experimental
evidence. The discovery in 1953 that the bacteriophages T2, T4, and T6 contain
glucosylated hydroxymethylcytosine led to a series of experiments in which Rom-
berg and others showed that a dozen or more bases, including artificial ones, are
equivalent to the guanine, cytosine, adenine, and thymine of which DNA typically
15 V. Tartar, The Biology of Stentor, Pergamon, London, 1961.
REPORT OF THE PRESIDENT 65
is composed. The genetic message thus is "a specified sequence of four nonequiva-
lent units." The similar chemical differences (methylation of adenine and cyto-
sine) have been observed in strains of Escherichia coli. There are thus optional
phenotypes exhibited in DNA composition among bacteria and phages. Diverse
phenotypes are also seen in DNA structure (rings, terminal repetitions, terminal
cohesive sites, etc.). The amount of DNA per cell also varies. This poses a highly
significant question about the amounts of nongenic DNA: "What functions of
DNA remain to be discovered?" Hershey summarizes the evidence on DNA
variability by saying, "The general implication seems to be that nucleotide se-
quences are subject to evolutionary constraints that have nothing to do with the
genetic message proper."
Hershey concludes with a discussion of recent work in his own laboratory. He
remarks that the most puzzling aspect of DNA phenotypes is the distribution of
nucleotides in the molecules. Nucleotide composition is generally expressed in
terms of the molar fraction of guanine plus cytosine (GC) . More than ten years
ago analyses of a number of bacterial DNAs showed a range from 26 to 74
percent in GC content. Later study (Sueoka, 1961) found no correlation in the
frequencies of the amino acids leucine, valine, and threonine from whole cellular
protein with the GC content of DNA in a number of microbial species. Other
amino acids showed only weak positive or negative correlations. These observa-
tions, together with the fact that proteins also vary phenotypically and that, as
Hershey says, "functional requirements do not impose severe restrictions on the
composition of proteins," led to the conclusion in 1962 that the composition of
DNA was determined mainly by "mutational habit," that is, mutational inter-
conversion between guanine-cytosine pairs and adenine-thymine pairs. If this
conclusion were correct, guanine-cytosine pairs should be distributed at random
among DNA fragments of gene size or larger. However, recent analyses by
A. M. Skalka and H. Yamagishi, Fellows at the Genetics Research Unit, show
that the distributions are never random.
Yamagishi during the year analyzed the DNA of E. coli, and showed that
fragments of the size of individual genes range in GC content from 39 to 56 per-
cent, with an average at 51 percent (Fig. 10). A similar distribution of DNA
was observed in the genome of Bacillus subtilis. In collaboration with I. Taka-
hashi of McMaster University, Yamagishi showed by genetic tests that regions of
exceptional GC content in B. subtilis include typical genes of the species. This
means that local variations in composition do not reflect a temporary condition
of the chromosome.
Skalka examined a number of phage DNA species by density analysis of molecu-
lar halves and smaller fragments. She found that the DNA of some phages
(lambda 434, 82, 21, P2, P22) consist of dissimilar halves containing 37 percent,
43 percent, 48.5 percent and 57 percent GC. Hershey calls these asymmetric
DNAs. Phage lambda, he thinks, may be considered a representative of a class.
If so, "asymmetry of DNA structure, clustering of genes of related function . . .
and propensity toward interspecific genetic recombination form a seemingly har-
monious set of class characteristics."
The conclusions from Skalka's and Yamagishi's experiments may be viewed
in the light of a remark made by Hershey in introducing their experiments.
Noting that GC content is not random in the genome he said, "One must conclude
either that DNA composition does reflect specialized functional adaptations or
that interspecific genetic recombination is frequent with respect to the evolution-
ary time scale. Perhaps both possibilities should be considered likely. In any
66
CARNEGIE INSTITUTION
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Fig. 10. Distribution of guanine + cytosine (GC) content in fragments of Escherichia coli
DNA. Upper: fragments of molecular weight 70 million (about 105 nucleotide pairs). Lower:
fragments of molecular weight 1.3 million (1800 nucleotide pairs). In both parts, histograms
show distributions of DNA with respect to buoyant density in Hg-CsaSCX, and curves show
the GC content of fractions. Single fractions or pooled fractions (indicated by horizontal bars)
were analyzed directly to get the points on the curves.
REPORT OF THE PRESIDENT 67
case, the hypothesis of domination by mutational equilibria loses its force." It is
clear that there are still very important questions before molecular biology, and
that its methods may continue to provide a significant tool of scientific discovery
for some time to come.
Department of Embryology 1968-1969 Expenditures:
Operating $554,348.13
Equipment $96,258.05
The Department of Embryology is devoted to the study of the processes of
development in living organisms. Dr. James D. Ebert, Director of the Depart-
ment, has observed that the spectrum of development grades into the rapid
processes of biochemistry at one end, and into the slow processes of evolution at
the other. Just as the continuous presence of a chemically defined hereditary
material, DNA, in successive generations of a species permits quantitative study
of cause and effect in evolution, the presence of like DNA in all the cells of a
single developing organism is the starting point for the study of developmental
mechanisms. Dr. Ebert further believes that the most fruitful new generalizations
in embryology are likely to emerge from "the frame of perception provided by
molecular genetics: the concept of levels of control and their interactions, [and]
of regulation." The work of the Department during the year reflects this judg-
ment. Molecular biology and genetics are receiving increasing emphasis in a
department that for forty years has been a leader in two other subfields, those of
human embryology and reproductive physiology.
The most important techniques in the current progress of embryology are inter-
disciplinary. The Department's research during the year illustrated this trend,
not only in the application of molecular genetics but also in the use of virology
to probe into developmental processes at the cellular level. Three experimental
research projects, in which seven members of the Departmental staff participated
during the year, illustrate very clearly the Department's judgment as to where the
research frontier in embryology and developmental biology lies. They concern
mechanisms inhibiting genetic transcription, the nature of mitochondrial replica-
tion within a cell, and the relation of tumor-causing viruses to cells.
Experimental Embryology — the Mechanisms of RNA Transcription. A glimpse
of the possibilities that lie ahead in applying the concepts and techniques of
molecular genetics to problems of development is provided by the progress
reported by D. D. Brown, I. B. Dawid, R. H. Reeder, and P. C. Wensink, a Johns
Hopkins graduate student, in their continuing study of the genes coding for
ribosomal RNA. These genes are the first to be isolated from an animal genome.
The ribosomal DNAs of the toad Xenopus laevis and of other amphibians, and
their products, have been analyzed in detail by Brown and others. The object of
the Brown-Dawid-Reeder-Wensink study is a charting of one of the very first
steps in development, the action of rDNA and the formation of ribosomal RNA.
Some parts of the process already are known from studies of Xenopus cells. In
Xenopus, ribosomal RNA sequences are initially transcribed from rDNA as a
large "precursor" molecule (40S), which then cleaves into one 18S and one 28S
rRNA molecule. The precursor contains few (if any) sequences other than those
for 18S and 28S rRNA. DNA sequences for the precursor rRNA correspond to
half the total length of the isolated homogenous DNA component, which has
been designated as ribosomal DNA (rRNA). The precursor sequences have an
average deoxyguanylic-deoxycy tidy lie acid (GC) content of 62 percent. The
other half of the rDNA, called "spacer," is interspersed with the precursor
68 CARNEGIE INSTITUTION
sequences and has a GC content of about 77 percent. The "spacer" sequences are
probably not transcribed in vivo. The precursor and "spacer" sequences alternate
along the length of the DNA. The active and inactive lengths of rDNA have
actually been seen and photographed through the electron microscope for the
first time this year, by 0. L. Miller, Jr., and Barbara R. Beatty of the Oak Ridge
National Laboratory. They are illustrated in the reproduction of their photograph
in Plate 3.
There are two forms of the Xenopus rDNA: that found in oocytes, and a second
distinct rDNA found in somatic cells (present in the nucleolar organism). In
primary oocytes the rDNA is replicated multiply so that an individual oocyte
contains about 4000 nuclear equivalents of rDNA, a thousandfold more rDNA
than would be predicted from its complement of chromosomes. Somatic cell rDNA
does not have this great redundancy.
It has been reported previously that the somatic rDNA and the extra replicas
of oocyte rDNA differ from each other in buoyant density (Year Book 67). The
buoyant density of somatic rDNA is lower by 6 mg/cm3 than that of the extra
copies. Having obtained both the somatic rDNA and extra copies of oocytes in
pure form, Brown and his colleagues were then able to show that the two DNAs
differ in the degree to which they are methylated, the somatic rDNA containing
about 4-5 percent 5-methyl deoxycytidylic acid (MeC) while the extra copies
contain less than 0.2 percent MeC. The presence of methyl groups is known to
lower the density of DNA in cesium chloride and the content of MeC in somatic
rDNA is probably sufficient to account for its lower buoyant density.
At this point the trail on this research frontier becomes less definite. The loca-
tion and description of these genes is only a beginning. Knowledge must be ob-
tained about the way in which gene activities are regulated. What is the basis
for differential gene expression? Little is known about the way in which cyto-
plasmic factors may affect the genome. It is known that in Xenopus, rDNA
functions during oogenesis and again after gastrulation, but not during cleavage.
K. Shiokawa and K. Yamana of Kyushu University have described a cyto-
plasmic factor obtained from cleaving embryos which inhibits the formation of
rDNA when it is added to embryonic cells at stages when the rDNA is otherwise
known to be active. However, the evidence presented does not show whether the
cytoplasmic factor inhibits transcription (i.e., inhibits synthesis of 40S rRNA) or
"processes" 40S rRNA to the 28S and 18S components. The potential importance
of the observation is clear: there are few leads to the isolation of possible repres-
sors in embryonic cells. It will be necessary to establish the level of the inhibition
in order to understand the basis for differential gene expression.
Establishing the level of inhibition and the manner of functioning of the genes
requires: (1) isolation and characterization of both the rDNA and rRNA, and
(2) the development of a system for synthesis of the products of rDNA in vitro.
The first has been accomplished. During the year Brown, Reeder, and their col-
leagues also report substantial progress on the second. Using a system in which
Xenopus rDNA is transcribed by E. coli RNA polymerase they appear to have
obtained high fidelity transcription of rDNA in vitro. They have developed a
sensitive assay which measures how much of each strand of the double-stranded
rDNA is transcribed, as well as the amount and kind of RNA transcribed from
the spacer region of the rDNA. The rDNA contains two strands, the heavy (H),
which is the one transcribed in vivo, and the light (L) strand. The technique
actually separates the two. Studies of the complementary RNA synthesized
from rDNA as template show both rRNA and some RNA corresponding to the
Plate
Report of the President
•°' -- - ■-.•• :':■■;,
3 . * * v *
Plate 3. Electron micrograph of the transcription of precursor RNA from rDNA of a
Xenopus laevis oocyte. The branching patterns show the transcribing segments, which are
separated by "spacer" DNA (thin lines along the main axes). Photograph by O. L. Miller and
B. R. Beatty, Oak Ridge National Laboratory.
REPORT OF THE PRESIDENT 69
spacer DNA. Chain initiation appears to be very accurate in the in vitro system
developed, but chain termination less so. Some polymerase molecules apparently
continue to transcribe beyond the precursor (40S) sequences, moving into the
spacer region of the rDNA.
Mitochondrial DNA. A similar approach is being taken by I. B. Dawid and
his colleague, R. F. Swanson, a Fellow of the U. S. Public Health Service, in
their study of the role of mitochondrial DNA.
Dawid has continued to focus his attention on mitochondrial DNA in Xenopus
and its immediate RNA products. He has now obtained evidence that the 21S
and 13S RNAs of mitochondria differ clearly from the 28S and 18S ribosomal
RNAs previously described. In addition, preliminary hybridization experiments
suggest that the 21S and 13S do not share sequence homologies. It seems likely,
therefore, that different sequences of the mitochondrial DNA act as templates in
their formation.
At the same time Swanson has progressed significantly in studying protein
synthesis in mitochondria isolated from ovaries of Xenopus laevis. It is known that
mitochondria have the ability to synthesize proteins in vitro. However, little is
known of the source of informational RNA, the products themselves, or the
details of the process. Swanson has developed a system in which the three poly-
nucleotides polyuridylic acid, polyadenylic acid, and polycytidylic acid are taken
up by isolated mitochondria. The transport of poly-U across the mitochondrial
membrane results in an increase in the incorporation of phenylalanine. The
system appears to offer promise of identifying the sites of protein synthesis within
mitochondria.
Virus-Cell Relations. Another striking example of the effectiveness of interdis-
ciplinary studies is seen in the relationship between virology and developmental
biology. More than 50 years ago Peyton Rous discovered the tumorigenic virus
that bears his name. In his studies Rous used two pioneering techniques later to
be carried further and exploited by students of development. The first was the
technique of the transplantation of tissue fragments to the membranes of the
chick embryo. This technique was used by several generations of embryologists to
study the differentiation of isolated embryonic tissues and to study the graft-
versus-host reaction. The second pioneering technique was the use of the enzyme
trypsin to liberate cells from clotted plasma on which they were growing. Use
of this enzyme was the forerunner of today's techniques of dissociating tissues into
component cells, now widely employed in studies of the interaction of embryonic
cells to form their characteristic patterns of tissue architecture.
Virology contributed these most useful techniques to the study of development.
But it was an embryologist, Ross Harrison, who contributed the technique of
tissue culture, a method now widely recognized as one of the methodological
cornerstones of virology. Viruses may be now propagated in clonal lines of cells
from a variety of sources, normal and abnormal; and clonally derived cells pro-
vide the most convenient and reproducible material for studying viral destruc-
tion or transformation of cells.
In keeping with this tradition several new research techniques offer promise
for the future. One depends on the knowledge that in order to transform a cell a
tumor virus must first stimulate the synthesis of the cell's DNA. During the year
M. Yoshikawa-Fukada, a Carnegie Fellow, and J. D. Ebert have continued to
probe the mechanism whereby oncogenic viral infection activates part of a cellular
genome. Their earlier studies {Year Book 67) showed that Rous sarcoma virus
RNA (RSV-RNA) contains base sequences complementary to those of DNA
70
CARNEGIE INSTITUTION
(A) Adeno 2
(B) Adeno 4
(C) Adeno 12
0.75
-
7
1
*T 0.5 0
E
O
(0
«A
-
«*. 0.25
O
6
/ \ O'
• >*,o-0"°-o-o*-»-c
o B-B^
0
o-o-o-b-o-0' ^^
1.4060'
1.4040
1.4020
750
250
0 10 0 10 0 10
Tube no.
Fig. 11. Hybridization of P32-labeled Rous sarcoma virus DNA with three adenovirus DNAs.
The homology of "Adeno 12" and Rous sarcoma virus DNA is shown in the right-hand curves.
from a number of sources. They now report further progress in characterizing
these sequences and are attempting to determine their significance in oncogenesis.16
They noted last year that the part of RSV-RNA which hybridizes with DNA
from chicken cells has a high content of adenylic acid. Further studies now reveal
this to be a general pattern. The segment of RSV-RNA that is enriched in adenyl-
ate is also observed in hybrids with fish and mammalian DNAs. This specific seg-
ment of RSV-RNA may be directly involved in the transformation process. It is
noteworthy that DNAs of other oncogenic viruses, like the adenoviruses and
SV 40 virus, also have a high content of deoxyadenylate. There also is evidence
that DNA from oncogenic viruses is integrated into the genome of the host cell.
These and other findings suggest that there may be a "viral oncogenic sequence"
and possibly a corresponding sequence in the cellular genome. If such a "viral
oncogenic sequence" exists, it should be revealed in viral homologies. As a first
test of this hypothesis, Yoshikawa-Fukada and Ebert have studied the relations
between RSV-RNA and the DNAs of three adenoviruses — types 2, 4, and 12.
This family of adenoviruses is especially interesting in that types 2 and 4 are not
oncogenic, while type 12 is highly oncogenic. The results are striking (Fig. 11).
RSV-RNA hybridizes far more extensively with DNA from type 12 (oncogenic)
than with DNAs from types 2 and 4. Moreover, preliminary analyses indicate
that the RSV-RNA combining with adenovirus 12-DNA again has a high adenyl-
ate content. Experiments are in progress further to characterize the part of the
cellular DNA involved and to determine its role.
Human Embryology and Reproductive Physiology. During the current year the
Department of Embryology came to a decision that marked the end of an era
that had extended from its founding in 1914. Almost from its beginning the De-
partment has supported two further lines of research in addition to experimental
embryology — the fields of human embryology and of reproductive physiology.
As Dr. Ebert states in his report: "what were once three relatively small fields of
research, in which the subject matter and techniques could be mastered by one or
two devoted, energetic investigators, have become three vast areas for explora-
tion, requiring a new depth and range of knowledge and technical sophistication.
The 'critical mass' of investigators in each of these areas is no longer one or two."
The Department has decided therefore to concentrate its future efforts on experi-
mental embryology. The programs in human embryology and in reproductive
physiology will gradually be terminated.
Oncogenesis — the origin of neoplasmic (tumor) growth.
REPORT OF THE PRESIDENT 71
This decision has resulted from a gradual shift in the interests of a department
that for more than forty years was outstanding in these fields. Indeed, in human
embryology it was preeminent. But it also follows a pattern within the Institution
of terminating a line of work that has become so well established elsewhere in the
nation that its progress is assured. Research on reproductive physiology, for
example, now is expanding rapidly in the United States under the leadership of
the National Institute of Child Health and Human Development. The build-
ing of a new center for research in human embryology will be assisted by the
Department in the transfer of its unique human embryo collection to Wayne State
University, Detroit, Michigan. Dr. B. G. Boving, a Staff Member of the Depart-
ment, will transfer to the University in 1970. Professor Ronan O'Rahilly, a
Fellow at the Department, also will move to the University upon the expiration
of his fellowship at the Department in 1971 to become Director of Embryology
at the University's Kresge Eye Institute.
Department of Plant Biology 1968-1969 Expenditures:
Operating $254,999.85
Equipment $6,340.36
Another most important realm in the world of life is that of plants which
capture and store the sun's energy. The Department of Plant Biology, whose
work has formed a part of the Institution program since its beginning, centers its
attention on this realm.
The student of plants and vegetative processes who seeks precision must be
patient, for the complexities of the photosynthetic process seem to be just as
recalcitrant to investigation as those of development in higher animals. For
many years now the Department's principal line of research has focused on
these processes of photosynthesis. Such research was undertaken at the Institution
as early as 1911. Much progress has been made, but there is a great deal about
photosynthesis that remains to be discovered, as in other significant fields.
Dr. C. Stacy French, Director of the Department of Plant Biology, in a review
of the status of research in his field says, "The main tide of scientific effort in
photosynthesis flows increasingly toward the more precise refinement of a
theoretical picture describing the interrelations between the pigments, enzymes,
and intermediate compounds that make up the photosynthetic system." In this
system carbon dioxide from the air is turned into the organic components of
living matter by a linked series of complex chemical reactions. The reactions are
oxidation-reduction processes coupled with phosphorylation systems that store
chemical energy. The energy for the system is supplied by light, which causes a
flow of electrons from water to reduce carbon compounds and begin the building
of life materials.
French notes that the recent tide of scientific effort in his field "left an ebb"
in the area from which it originated. The ebb was in descriptive and comparative
plant physiology, currently being revived in the United States under the pressures
to understand ecology. But the Department of Plant Biology has never allowed
its interests in plant physiology to lapse. This continued interest, as will shortly
be illustrated, is one of its current strengths. Largely as a result of it, the Depart-
ment is in a position to apply effectively the intricate concepts of photosynthesis
to broader biological questions, such as those of plant evolution.
Evaluation of a New Photosynthetic Pathway. Until recently it was assumed
that one general system of photosynthesis was universal among plants. This
72 CARNEGIE INSTITUTION
system uses the enzyme carboxydismutase to capture carbon dioxide. In 1965 a
different "pathway" was discovered in Hawaiian sugar cane by G. 0. Burr and
his colleagues. M. D. Hatch and others, working in Australia, subsequently
demonstrated that the same pathway occurs in a number of other tropical plant
species. The new pathway is known as /?-carboxylation photosynthesis. The com-
mon maize used in agriculture proves to be one of the /?-carboxylation species.
The /?-carboxylation of phospho(enol) pyruvate (PEP) is the reaction that makes
this pathway distinctive. It is probably catalyzed by the enzyme PEP carboxyl-
ase. At high light intensities and temperatures many of the species using /?-car-
boxylation are capable of considerably higher rates of C02 fixation than plants
employing the conventional pathway. A peculiarity of the new pathway is that
closely related species may or may not have it. Within each of four different
plant genera some species have the /?-carboxylation pathway, but others use the
carboxydismutase system.
0. Bjorkman, M. A. Nobs, of the Experimental Taxonomy Group, and E.
Gauhl, a Fellow at the Department, describe in their report some interesting
experiments undertaken with two species of the salt bush, Atriplex, a genus widely
distributed in North America and Eurasia. One species, Atrvplex patula, which has
the "normal" carboxydismutase pathway, is found mostly in the salt marshes of
cool areas. Another, Atrvplex rosea, which employs the /?-carboxylation pathway,
typically grows on warm, semiarid sites.
Bjorkman and Gauhl found that the photosynthetic characteristics of these
two species differ greatly. Atriplex patula (from the salt marshes), which has a
high level of enzyme carboxydismutase, showed a marked inhibition of photo-
synthesis in the oxygen concentration of normal air (21 percent) as compared to
low oxygen concentrations (1.5 percent). By contrast Atriplex rosea (warm,
semiarid) , which has a high level of the enzyme PEP carboxylase, showed no
inhibition of photosynthesis by the oxygen concentration present in normal air.
A. rosea was also capable of higher photosynthetic activity at high light intensi-
ties and high temperatures than Atriplex patula (Fig. 12). Atriplex rosea, like all
other known species with the /?-carboxylation photosynthesis, has a highly
specialized leaf anatomy. Large chloroplast-rich cells surround the vascular
bundles of the leaves in a characteristic pattern.
Toward the close of the year Nobs was able to cross the two Atriplex species
and obtain first-generation hybrids. This achievement opens for the first time the
possibility of studying the inheritance of the two pathways of C02 fixation in
photosynthesis. Preliminary studies suggest that the photosynthetic and bio-
chemical characteristics associated with /?-carboxylation photosynthesis are not
transmitted by the plastids of the female parent to the offspring. Instead they
appear to be under control of the nucleus.
In external morphology, internal leaf anatomy, and some biochemical charac-
teristics, the hybrid is intermediate between the parents. The activity of the
enzyme carboxydismutase in the hybrid is about one-half that in Atriplex patula
and the PEP carboxylase activity is about one-tenth that in Atriplex rosea.
Photosynthesis in the hybrid is at least as strongly inhibited by the oxygen con-
tent of normal air as in the Atriplex patula parent. Thus the hybrid is definitely
not intermediate between the parental species in photosynthetic activity. Instead,
the rate of photosynthesis in the hybrid is lower than in either parent under normal
oxygen concentration. It is also interesting that the chlorophyll content of the
leaves in the hybrid is lower than in either of the parental species.
REPORT OF THE PRESIDENT
73
a
13
o
u
21% 02
0 12 3 4 5
Light intensity, ergs cm"2 sec"1 xlO5
Fig. 12. Effect of light intensity on the rate of photosynthesis COa uptake in 1.5 percent and
21 percent oxygen concentrations by Atriplex patula and Atriplex rosea leaves. Leaf tempera-
ture was 25°C and C02 concentration 0.030-0.034 percent. The greater efficiency of the
Atriplex rosea system at higher light intensities is shown under both Oa concentrations.
Attempts are now being made to obtain second-generation hybrids, as well as
backcross progeny with both parent species. If these attempts are successful
they may open the way to an understanding of the physiological, biochemical,
and anatomical characteristics essential in /3-carboxylation photosynthesis. If
this is achieved, our understanding of the molecular mechanism of adapted differ-
entiation and natural selection in plants can be much enhanced.
Biochemical Investigations. The Biochemical Investigations Group of the De-
partment continued its interest in the functional relations between photosynthetic
pigments and associated enzymes. There are two subsystems, which have been
labeled system I and system II, each of which is comprised of a mixture of pig-
ments and enzymes contained within solid particles. The separation of these two
74 CARNEGIE INSTITUTION
systems of chloroplasts is a problem that has compelled the attention of many
laboratories, including the Biochemical Investigations Group itself (C. S.
French, D. C. Fork, J. S. Brown, K. E. Mantai, E. E. Loos, L. 0. Bjorn). These
systems of chloroplasts have different reactions, are composed of different pig-
ments, and show striking contrasts in their absorption spectra.
The biochemical group during the year continued the analysis of the spectral
characteristics of the two systems, with particular attention to comparing the
absorption spectra with the action spectra. Action spectra reveal the light wave-
lengths that cause specific chemical effects, and hence identify the effective pig-
ments only. Absorption spectra characterize all the pigments present, whether
functional or nonfunctional. Dr. French says in the Introduction to his report that
action spectra for system I and system II effects in whole cells and in isolated
chloroplasts have been measured with adequate accuracy. However, for the partial
reactions representing the separate steps of photosynthesis in chloroplast fractions
"the precision so far . . . is lamentable."
Efforts were made in several directions during the year to improve the preci-
sion of measurement and to uncover functional relationships within and among
chloroplast fractions. Thus photochemical reduction of the dye methyl viologen
was tried by E. Loos, a Fellow. His first results showed close agreement between
the action spectra and absorption spectra of system I particles. Loos' technique
gives easily measurable rate determinations at low light intensities.
Another approach to understanding a biological system is to identify the mini-
mum structural unit that can perform a given function. It has long been known
that chlorophyll molecules do not act separately in photosynthesis, but cooperate
in groups. A few hundred molecules make up the unit for primary conversion of
light into chemical energy, but several such units may form larger ones capable
of more complex functions. One such larger grouping may depend on a single
enzyme for its association and activity. Thus the size of such a unit can be deter-
mined if the enzyme molecule can be made ineffective by a single molecule of an
enzyme poison.
L. 0. Bjorn, also a Fellow at the Department, undertook such an experiment
during the year. He studied the delayed light emission (afterglow) given off by
plants transferred from light to darkness. Bjorn found that the application of N-
methylphenazonium methosulfate (PMS) accelerates the emission of a long
wavelength component of the afterglow known as component V. The afterglow
followed the activation of photosystem I by far-red light. Bjorn estimates the
size of the functional unit so measured to be about 100,000 chlorophyll molecules,
the size of a morphological unit called a "thylacoid" that is visible in electron
micrographs of chloroplasts (Plate 4) .
Bjorn's experiments, like almost every other experiment or observation in
such research, emphasizes the complexities of photosynthesis. Component V is
only one of several components of the afterglow emission spectrum. The grouping
of molecules here postulated only applies to component V. As Bjorn observes, "the
other afterglow components may emanate from units of different sizes." The
afterglow is only a secondary phenomenon being used as a small mirror for the
activity of system I.
Fellows and Students
The preceding reports of the Departments' scientific activities have included
many references to work by Fellows and students who are in residence at the
Departments. Two years ago I discussed the place of Fellows in the work of the
Plate 4
Report of the President
< ; <■:• ' rr.
Plate 4, Electron micrograph of a well-developed chloroplast in a vascular bundle cell,
showing thylacoids and their grouping as grana. The cell is a mature leaf of the Fi hybrid
Atriplex rosea X Atriplex patula hastata. (Taken by Dr. John Boynton, Carnegie Institution
Fellow, at the Advanced Instrumentation Center, University of California, Davis, California.)
REPORT OF THE PRESIDENT 75
TABLE 1. Fellows at the Carnegie Institution, 1967-1969
Status as of August 1, 1959
Total
number
Academic
positions
5
16
8
2
9
6
Funda-
mental
research
2
1
2
1
3
3
Industrial
research
Fellows
or
Department
1967-68
1968-69
students
Mount Wilson and
Palomar Observatories
Geophysical Laboratory
Department of Terrestrial
Magnetism
Genetics Research Unit
Department of Embryology
Department of Plant Biology
8
21
10
4
12
7
5a
15b
16c
4d
9°
7f
"i
1
2
7
7
2
2
4
Totals
62
56
46
12
2
24
Number of individuals
... 84s
Individuals' subjects of study :
Biology 36
Geophysics and
geochemistry 35
Astronomy 11
Atomic physics 2
a 4 for second year. e 7 for second year.
b 11 for second year. f 1 for second year.
0 8 for second year. g After subtraction of two-year Fellows.
3 for second year.
Institution.17 Postdoctoral training and the original research of the Fellows
have become such important parts of the Institution's life that it is appropriate
to bring that general account of their work up to date.
During 1967-1968 the number of Fellows reached a peak of 62 in residence at
the five Departments and the Genetics Research Unit. Most were supported from
Institution funds, but some fellowship grants were made from private foundation
funds, notably those of the Carnegie Corporation of New York, and Federal
Government research agencies. In 1968-1969 the number declined by six because
of budget constraints, but a very lively program was continued in all of the
Departments.
As has been usual in the Institution program, more than half of the 1967-
1968 Fellows (34 of 62) remained for a second year. Thus, for two years, 84
individuals participated in the fellowship program. Two-fifths of them were
interested in the several branches of geophysics and geochemistry (35), and
another two-fifths (36) undertook research in the biological fields, which were
about evenly divided between embryology and the two other principal subjects,
genetics and plant biology. Eleven Fellows carried out programs in astronomy:
all but two in optical astronomy.
I have already mentioned the Mount Wilson and Palomar program of graduate
student instruction. In the past every Department has provided some service,
facilities, and guidance to Ph.D. candidates. During 1968-1969 there were 47
graduate students associated with four other Departments, for a total of 61 in
all Institution facilities. Some were supported by Institution predoctoral fellow-
ship grants or by technical assistantships ; all received instruction by members of
the senior staff, and all used the Institution's laboratory or observing equipment.
We value our graduate student programs, but the opportunities the Institution
offers for postdoctoral training are perhaps even more rewarding. In the post-
17 Year Book 66, Report of the President: 68-70.
76 CARNEGIE INSTITUTION
doctoral program, which has been enthusiastically developed by all the Depart-
ments, promising young scientists can investigate problems of their own choosing,
take time to fill in any gaps in their training through seminars and other means,
and benefit from the guidance of senior staff members. Most, if not all, of the
senior staff members are interested in guiding and actively collaborating with
these younger men. The modest numbers and intellectual diversity of the staff at
each of our Departments make it possible for a Fellow to have a broad range
of highly stimulating intellectual experiences. For the postdoctoral Fellows ex-
perience at the Institution generally has led to the attainment of true professional-
ism in their fields in the shortest possible time.
The range of subjects studied by the Fellows covers almost the entire list of
the Table of Contents in the Year Book. The Bibliography of each of the Depart-
ments for this last year, shown at the end of this report, gives most abundant
evidence of the Fellows' productivity and capacity.
When I last reported on our postdoctoral fellowship program in Year Book 66,
I noted that many of our "alumni" either returned to or took up professorships
and other teaching positions. Many of them were considered leaders in their
fields at relatively young ages. I also noted the very high rate of return of foreign
Fellows to responsible academic posts in their own countries. These same state-
ments continued to be true of the Fellows for 1967-1968 and 1968-1969. More
than half (46) of the Fellows have either accepted new positions in academic
institutions or returned to those from which they had leave. An additional 12
turned to positions in fundamental research organizations, and 2 went into indus-
trial research. As of August 1969, 24 of the 84 still remained with the Institution
in fellowship or equivalent status. Of the approximately 400 Fellows who have
become Institution "alumni" since 1952, more than half (215) now hold positions
in universities or other academic institutions. Another 81 are occupied in funda-
mental research, and 28 more are in applied research.
About 40 percent of our Fellows in recent years have been foreign. In 1967-
1969, as before, nearly all the Fellows from foreign lands returned, or will return,
to posts in their own countries. Almost without exception these people seem to
have achieved a sympathetic understanding of the United States in addition to
their professional training.
Concluding Note. As in other years, we count among our highest accomplish-
ments in the year 1968-1969 the provision of a useful, even vital, experience to
young scientific leaders through our resident fellowships. The meaning of this
experience can best be understood by relating it to the earlier descriptions of
research results. The Fellows have been able to witness discovery and invention,
to share in precise experiment and observation, to see, or even share in, the
construction of theory and hypotheses, and to share in searching and methodical
evaluations of research frontiers.
Among discovery and invention at the Institution in 1968-1969 was that of
the strainrate meter, an instrument of most extraordinary sensitivity for measur-
ing the strains preceding earthquakes, and other earth movements ; the invention
of an inexpensive new method of purifying DNA, that recovers fractions hitherto
lost; the discovery of a new lysogenic virus; and the first isolation of genes from
an animal cell.
Experiment and observation in the Institution's program gave new knowl-
edge about the asymmetry of the universe ; added substantially to precise knowl-
edge of rock formation, of the energy balance in the earth, and of continental
movement; showed an important nonbiological route by which the materials of
life disappear into the earth's crust; produced significant information on tumor
REPORT OF THE PRESIDENT
77
virus relations to virally infected cells; charted more precisely the differences
between the two principal photosynthetic "pathways," and produced for the first
time a hybrid incorporating both the pathways.
Theoretical work resulted in the Britten-Davidson model of gene operation,
which distinguishes and articulates the known functional units of DNA and
RNA, and in a new model of the evolution of radiogenic elements within the
earth's crust and mantle from primordial time.
Among the important critical evaluations of research frontiers mentioned in our
reports is one on genetics, another on cosmology, one on the dynamics of the
earth's crust and mantle, and one on the relation of biochemical and biophysical
research to plant physiology.
It has been a rewarding and exciting year at the Institution.
List of Fellows in Residence
Carnegie Institution, 1967-1969
1967-1968
Research Field at
the Institution
Mount Wilson and Palomar Observatories
Arvind Bhatnagar
Robert J. Dickens
Jerome Kristian
Wojciech Krzeminski
John Vincent Peach
Rene Racine
David Maurice Rust
Natarajan Visvanathan
Geophysical Laboratory
G. Malcolm Brown
Wilfred B. Bryan
James R. Craig
magnetic fields in and around
sunspots
dynamic theory of equilib-
rium, forms of globular star
clusters
determination of the Hubble
constant
the eruptions of eclipsing
binary stars
the short-period light
variations of quasars
photometry and spectroscopy
of clustering of reflection
nebulae
solar magnetic field structure
outside active regions
Employment or Fellowship
Status as of
August 1, 1969
Fellow, Carnegie Institution
Royal Greenwich Observatory,
England
Staff Member, Mount Wilson
and Palomar Observatories
Polish Academy of Sciences, In-
stitute of Astronomy, Warsaw
Faculty, Department of Astro-
physics, University Observatory,
Oxford University, England
Faculty, Astronomy Department,
University of Toronto, Canada
Astronomer, Sacramento Peak
Observatory, Sunspot, New
Mexico
interstellar polarization Fellow, Carnegie Institution
pyroxenes and the genesis of
mafic and ultramafic rocks
numerical and statistical
analysis of marine volcanic
petrography
silicate-sulfur relationships
in ore deposits
Professor and Chairman of the
Department of Geology, Univer-
sity of Durham, England
Fellow, Carnegie Institution
Assistant Professor of Geosci-
ences, Texas Technological Col-
lege
78
CARNEGIE INSTITUTION
1967-1968
Larry W. Finger
M. Charles Gilbert
Ahmed El Goresy
Necip Guven
Stephen E. Haggerty
Edward C. Hansen
Hans G. Huckenholz
Jon E. Kalb
Ikuo Kushiro
Henry 0. A. Meyer
Research Field
crystal chemistry and physics
of silicate rock-forming
minerals
high pressure studies of
mineral phase relations
investigation of sulfides
in meteorites
interaction of micas with
X-ray and other radiation
composition of basaltic
iron-titanium oxides
rock deformation under
extreme conditions
mineral phase relations
experimental techniques in
mineralogy
mineral phase relations in the
upper mantle
crystal X-ray and electron
microprobe analysis of dia-
monds and their inclusions
Richard M. Mitterer amino acids in fossils
S. A. Morse
James L. Munoz
Anthony J. Naldrett
Harold R. Puchelt
Stephen W. Richardson
William H. Scott
Josef Zemann
mineral phase relations
stability relations of
staurolite
geologic history of sulfide
minerals in the Sudbury
Basin
fractionation of sulfur iso-
topes in geologic processes
high temperature and high
pressure studies of mineral
phase relations
geophysical processes occur-
ring during tectonic activity
sulfide minerals crystallog-
raphy
Employment or Fellowship
Status as of
August 1, 1969
Staff Member, Geophysical
Laboratory, Carnegie Institution
Assistant Professor of Petrology,
Virginia Polytechnic Institute
Research Associate, Max Planck
Institute fur Kernphysik, Hei-
delberg, Germany
Assistant Professor of Geology,
University of Illinois
Fellow, Carnegie Institution
Shell Development Company,
Houston, Texas
Professor, Institute for Mineral-
ogy and Petrology, University of
Munich, Germany
Graduate Student, American
University
Faculty, Geological Institute,
University of Tokyo, Japan
Fellow, Carnegie Institution
Assistant Professor of Geosci-
ences, Southwest Center for
Advanced Studies
Professor of Geology, Franklin
and Marshall College
Assistant Professor, Department
of Geological Sciences, Univer-
sity of Colorado
Assistant Professor, Department
of Geology, University of To-
ronto, Canada
Faculty, Institute for Mineralogy
and Petrology, University of Tu-
bingen, Germany
Research Assistant, National En-
vironment Research Council,
Grant Institute of Geology, Uni-
versity of Edinburgh, Scotland
Yale University
Professor, Mineralogical Insti-
tute, University of Vienna, Aus-
tria
REPOET OF THE PRESIDENT
79
1967-1968
Research Field
Department of Terrestrial Magnetism
George E. Assousa foil excitation spectroscopy
Christopher Brooks isotopic geochronology
Alfred Chiscon
Kyoichi Ishizaka
David E. James
Peter N. S. O'Brien
Claude Petit jean
Adrian V. Rake
German Saa
Alan Stueber
isolating episomal factor in a
strain of E. coli
isotopic geochronology
explosion seismology
measurements of ground mo-
tions due to large explosions
data on polarization in the
elastic scattering of protons
by lithium-8 nuclei
changes in macromolecular
components of cultured neu-
ral tissue as a result of
electrical stimulation
seismology in western South
America
isotope geology of the upper
mantle
Employment or Fellowship
Status as of
August 1, 1969
Fellow, Carnegie Institution
Faculty, University of Montreal,
Canada
Professor, Department of Bio-
logical Sciences, Purdue Uni-
versity
Faculty, Geological and Mineral-
ogical Institute, Kyoto Univer-
sity, Japan
Staff Member, Department of
Terrestrial Magnetism, Carnegie
Institution
British Petroleum Company,
Ltd., Middlesex, England
Swiss Institute of Nuclear Re-
search, Cyclotron Planning, Zu-
rich
Faculty, Pennsylvania State Uni-
versity
Faculty, Universidad del Norte,
and Universidad de Chile
Faculty, Miami University, Ox-
ford, Ohio
Genetics Research Unit
Phyllis Bear
Shraga Makover
Anna Marie Skalka
Hideo Yamagishi
growth and inheritance in
bacteriophage
replication of DNA in
lambda phage at
molecular sites
DNA structure and function
nucleic acid structure and
function
Department of Embryology
Hayden G. Coon somatic cell hybridization
Associate Professor, Division of
Microbiology and Veterinary
Medicine, University of Wyo-
ming
Fellow, Carnegie Institution
Assistant Member, Department
of Microbiology, Roche Institute
of Molecular Biology, Nutley,
New Jersey
Molecular Biology Laboratory,
Department of Biophysics, Kyoto
University, Japan
Associate Professor of Zoology,
Indiana University
80
CARNEGIE INSTITUTION
1967-1968
Douglas Fambrough
Masako Fukada
Harold R. Kasinsky
(USPHS)
Harold R. Misenhimer
Ronan O'Rahilly
Ronald H. Reeder*
John Sinclair
(USPHS)
Helge Stalsberg
Peter Tuft
Mary C. Weiss
(USPHS)
Shuhei Yuyama
Research Field
clonal culture of muscles
and nerves
nucleic acid chemistry of
cultured animal cells
histone synthesis in cleaving
embryos of Xenopus laevis
placental physiology
study of embryo collection
methods of covalently joining
double-stranded DNA mole-
cules
comparative studies of genes
for ribosomal RNA
controlled growth of specific
parts of chick embryo heart
uptake of water by embryos
and its role in morphogenesis
somatic cell hybridization
quantifying evidence for
stimulation of DNA synthe-
sis by Rous sarcoma virus
Employment or Fellowship
Status as of
August 1, 1969
Staff Member, Department of
Embryology, Carnegie Institu-
tion
Fellow, Carnegie Institution
Assistant Professor of Zoology,
University of British Columbia
Assistant Chief, Obstetrics and
Gynecology, Baltimore City
Hospital
Director of Embryology (desig-
nate), Kresge Institute, Wayne
State University
Staff Member, Department of
Embryology, Carnegie Institu-
tion
Assistant Professor, Department
of Zoology, University of Indi-
ana
Department of Pathology, Ulle-
val Hospital, Oslo, Norway
Faculty, Department of Zoology,
University of Edinburgh, Scot-
land
Centre de Genetique Molecu-
laire, Gif-sur-Yvette, France
Faculty, Department of Zoology,
University of Toronto, Canada
Department of Plant
Eckhard Gauhl
Ulrich Heber
Eckhard E. Loos
Jean-Marie Michel
Marie-Rose Michel
James M. Pickett
photosynthetic reactions
electron transport chain in
mutants of higher plants
deficient in photosynthesis
production of oxygen in
plants during photosynthesis
fractionation of chloroplasts
improved electrode for mea-
suring photosynthesis rates
Botanisches Institut der J. W.,
Goethe Universitat, Frankfurt,
Germany
Professor, Botanisches Institut
der Universitat Dusseldorf, Ger-
many
Fellow, Carnegie Institution
Centre de Recherches de Gor-
sem, St. Trond, Belgium
Assistant Professor, Department
of Botany and Microbiology,
Montana State University
* Helen Hay Whitney Foundation Fellowship.
REPORT OF THE PRESIDENT
81
1967-1968
James H. Silsbury
1968-1969
Research Field
influence of light intensity
on ratio of leaf area to leaf
weight
Employment or Fellowship
Status as of
August 1, 1969
Senior Lecturer in Agronomy,
University of Adelaide, Waite
Agricultural Research Institute,
Glen Osmond, South Australia
Mount Wilson and Palomar Observatories
Arvind Bhatnagar*
Jerome Kristian*
Deane M. Peterson
Rene Racine*
magnetic fields in and
around sunspots
determination of the Hubble
constant
astrophysics; short-period
light variations in stars
photometry and spectroscopy
of clustering of reflection
nebulae
Natarajan Visvanathan* interstellar polarization
Geophysical Laboratory
Wilfred B. Bryan*
Larry W. Finger*
M. Charles Gilbert*
Ahmed El Goresy*
Stephen E. Haggerty*
Edward C. Hansen*
JonE.Kalb*
Ikuo Kushiro*
Ho Kwang Mao
numerical and statistical
analysis of marine volcanic
petrography
crystal chemistry and
physics of silicate rock-
forming minerals
high pressure studies of
mineral phase relations
investigation of sulphides
in meteorites
composition of basaltic iron-
titanium oxides
rock deformation under
extreme conditions
experimental techniques in
mineralogy
mineral phase relations in
the upper mantle
X-ray diffraction studies of
effects of pressure on crystal
structures and lattice
parameters of materials
Fellow, Carnegie Institution
Staff Member, Mount Wilson
and Palomar Observatories
Fellow, Carnegie Institution
Faculty, Astronomy Department,
University of Toronto, Canada
Research Astronomer, Harvard
Observatory, Harvard University
Fellow, Carnegie Institution
Staff Member, Geophysical Labo-
ratory, Carnegie Institution
Assistant Professor of Petrology,
Virginia Polytechnic Institute
Research Associate, Max Planck
Institut fur Kernphysik, Heidel-
berg, Germany
Fellow, Carnegie Institution
Shell Development
Houston, Texas
Graduate Student,
University
Company,
American
Faculty, Geological
University of Tokyo
Institute,
Fellow, Carnegie Institution
* Also a Fellow in 1967-1968.
82
CARNEGIE INSTITUTION
1968-1969
Henry 0. A. Meyer*
S. A. Morse*
H. R. Puchelt
William H. Scott*
Douglas Smith
Lawrence A. Taylor
Research Field
crystal X-ray and electron
microprobe analysis of dia-
monds and their inclusions
mineral phase relations
fractionation of sulfur
isotopes in geological
processes
geophysical processes occur-
ring during tectonic activity
mineral phase relations at
high pressure
geochemistry and experi-
mental petrology
Department of Terrestrial Magnetism
George E. Assousa* atomic physics
Willy Z. Barreda seismology
Christopher Brooks* isotopic geochronology
Alfred Chiscon*
Sandro D'Odorico
Joseph W. Erkes
A. J. Erlank
Leo J. Grady
Jaime Guzman
Kyoichi Ishizaka*
isolating episomal factor in
a strain of E. coli
radio astronomy
radio interferometry and
other aspects of radio
astronomy
trace elements in ultrabasic
rocks
DNA analyses
determination of earth-
quake hypocenters
isotopic geochronology
David E. James* explosion seismology
Alan T. Linde
* Also a Fellow in 1967-1968
seismic studies of the upper
mantle
Employment or Fellowship
Status as of
August 1, 1969
Fellow, Carnegie Institution
Professor of Geology, Franklin
and Marshall College
Faculty, University of Tubingen,
Germany
Yale University
Fellow, Carnegie Institution
Fellow, Carnegie Institution
Fellow, Carnegie Institution
Fellow, Carnegie Institution
Faculty, University of Montreal,
Canada
Professor, Department of Bio-
logical Sciences, Purdue Univer-
sity
Fellow, Carnegie Institution
Fellow, Carnegie Institution
Faculty, Department of Geo-
chemistry, University of Cape-
town, South Africa
Fellow, Carnegie Institution
International Institute of Seis-
mology and Earthquake Engi-
neering, La Paz, Bolivia
Faculty, Geological and Mineral-
ogical Institute, Kyoto Univer-
sity, Japan
Staff Member, Department of
Terrestrial Magnetism
Fellow, Carnegie Institution
REPORT OF THE PRESIDENT
83
1968-1969
Claude Petitjean*
Adrian V. Rake*
German Saa*
Erich Steiner
Research Field
data on polarization in the
elastic scattering of protons
by lithium-8 nuclei
changes in macromolecular
components of cultured neu-
ral tissue as a result of elec-
trical stimulation
seismology in western South
America
nucleic acid interactions
Employment or Fellowship
Status as of
August 1, 1969
Swiss Institute of Nuclear Re-
search, Cyclotron Planning, Zu-
rich
Faculty, Pennsylvania State Uni-
versity
Faculty, Universidad del Norte,
and Universidad de Chile
Fellow, Carnegie Institution
Genetics Research Unit
Shraga Makover*
David H. Parma
Anna Marie Skalka*
Hideo Yamagishi*
replication of DNA in
lambda phage at molecu-
lar sites
structure of stable hetero-
zygotes in T4 phage
Fellow, Carnegie Institution
Postdoctoral Fellow, National
Science Foundation
DNA structure and function Assistant Member, Department
of Microbiology, Roche Insti-
tute of Molecular Biology, Nut-
ley, New Jersey
nucleic acid structure and
function
Molecular Biology Laboratory,
Department of Biophysics, Kyoto
University, Japan
Department of Embryology
Hayden G. Coon* somatic cell hybridization
Douglas Fambrough* clonal culture of muscles and
nerves
Masako Fukada*
oncogenic viral studies
Harold R. Kasinsky* histone synthesis in cleaving
(USPHS) embryos of Xenopus laevis
Harold R. Misenhimer* placental physiology
Ronan O'Rahilly*
study of embryo collection
Associate Professor of Zoology,
Indiana University
Staff Member, Department of
Embryology, Carnegie Institu-
tion
Fellow, Carnegie Institution
Assistant Professor of Zoology,
University of British Columbia
Assistant Chief, Obstetrics and
Gynecology, Baltimore City Hos-
pital
Director of Embryology (desig-
nate), Kresge Institute, Wayne
State University
* Also a Fellow in 1967-1968.
84
CARNEGIE INSTITUTION
1968-1969
Kenjiro Ozato
Ronald H. Reeder*
Yoshiaki Suzuki
Research Field
developmental biology
methods of covalently join-
ing double-stranded DNA
molecules
gene coding in the silkworm
(Bombyx mori)
Employment or Fellowship
Status as of
August 1, 1969
Instructor in Biology, Yoshida
College, Kyoto University
Staff Member, Department of
Embryology, Carnegie Institu-
tion
Fellow, Carnegie Institution
Department of Plant Biology
John E. Boynton
Lars Olof Bjorn
Eckhard Gauhl*
Eckhard E. Loos*
Kenneth E. Mantai
Norio Murata
Colin Wraight
barley chloroplast mutants Fellow, Carnegie Institution
determination of accurate
action spectra in Chlorella
photosynthetic reactions
production of oxygen in
plants during photosynthesis
effects of ultraviolet light
on pigment systems using
fluorescence and absorption
spectroscopy
fluorescence spectra of
photosynthetic pigments and
transfer of energy between
them
influence of conformational
changes on chloroplast
fluorescence
Associate Professor, Lunds Uni-
versitet, Sweden
Botanisches Institut der J. W.
Goethe Universitat, Frankfurt,
Germany
Fellow, Carnegie Institution
Brookhaven National Labora-
tories, Upton, New York
Fellow, Carnegie Institution
Fellow, Carnegie Institution
* Also a Fellow in 1967-1968.
1968-1969 BIBLIOGRAPHIES
Two hundred and four papers were published by Staff Members, Research
Associates, Fellows, and members of technical staffs of the Observatories and
Laboratories in professional journals and books during the year 1968-1969. The
journals were published in 11 different countries and had worldwide circulation.
Reference to each of these papers follows. They have been included in this report
as an indication of the work of Staff Members and Fellows during the year, the
range and importance of their subjects, and their written communication with the
scientific and technological world. This list does not include oral presentations at
scientific meetings, or published abstracts of such presentations.
REPORT OF THE PRESIDENT 85
Mount Wilson and Palomar Observatories
Abt, Helmut, Peter S. Conti, Armin J. Deutsch, and George Wallerstein, The mass and other
characteristics of the magnetic star HD 98088. Astrophys. J., 153, 177-186, 1968.
Adelman, Saul J., Peculiar stars in the Lac OBI association. Publ. Astron. Soc. Pacific, 80, 329-
331, 1968.
Arp, Halton, Optical observations of two Seyfert galaxies. Astron. J., 73, 847-848, 1968.
Arp, Halton, Relation between quasi-stellar radio sources and radio compact and radio N
galaxies. Astrophys. J. (Letters), 163, L33-L38, 1968.
Arp, Halton, Further comments on the ring around M81. Soviet Astron.-AJ, 12, 715-716, 1968.
Bahcall, John N., Jesse L. Greenstein, and Wallace L. W. Sargent, The absorption-line spec-
trum of the quasi-stellar radio source Pks 0237-23. Astrophys. J., 163, 689-698, 1968.
Bahcall, John N., Patrick S. Osmer, and Maarten Schmidt, On the absorption spectrum of
Ton 1530. Astrophys. J. (Letters), 156, L1-L6, 1969.
Barbon, Roberto, The frequency of supernovae in clusters of galaxies. Astron. J., 73, 1016-
1020, 1968.
Baschek, Bodo, and Leonard Searle, The chemical composition of the X Bootis stars. Astrophys.
J., 155, 537-554, 1969.
Bergh, Sidney van den, Observation of the nucleus of the radio galaxy M82. Astrophys. J.
(Letters), 156, L19-L20, 1969,
Bergh, Sidney van den, Globular clusters in the Andromeda nebula. Nature, 221, 48-49, 1969.
Boesgaard, Ann Merchant, Isotopes of magnesium in stellar atmospheres. Astrophys. J., 154,
1185-1190, 1968.
Bradt, H., S. Naranan, S. Rappaport, F. Zwicky, H. Ogelman, and E. Boldt, Upper limit on
X rays from a new supernova. Nature, 218, 856-857, 1968.
Bradt, H., S. Rappaport, W. Mayer, R. E. Nather, B. Warner, M. MacFarlane, and J.
Kristian, X-ray and optical observations of the Pulsar NP 0532 in the Crab Nebula.
Nature, 222, 728-730, 1969.
Bumba, V., and Robert Howard, On the solar source of recurrent geophysical effects. Bull.
Astron. Inst. Czech., 20, 61-62, 1969.
Bumba, V., and Robert Howard, On long-term forecasts of solar activity. Solar Flares and
Space Research, pp. 387-396, Z. Sveska and C. de Jager, eds. North-Holland Publishing
Co., Amsterdam.
Bumba, V., and Robert Howard, Solar activity and recurrences in magnetic-field distribution,
Solar Physics, 7, 28-38, 1969.
Bumba, V., R. Howard, M. Kopecky, and G. V. Kuklin, Some irregularities in the distribution
of large-scale magnetic fields on the Sun. Bull. Astron. Inst. Czech., 20, 18-21, 1969.
Cohen, Judith G., The carbon abundance of Population II stars. Astrophys. Letters (England),
2,163-164,1968.
Cohen, Judith G., A. J. Deutsch, and Jesse L. Greenstein, The spectrum of a2 CVn, 5000-
6700 A. Astrophys. J., 156, 629-652, 1969.
Davis, D. N., and P. C. Keenan, Is there NbO in S-type stars? Publ. Astron. Soc. Pacific, 81,
230-237,1969.
Demarque, Pierre, F. D. A. Hartwick, and M. D. T. Naylor, Some uncertainties in Population
II models near the main sequence. Astrophys. J., 154, 1143-1146, 1968.
Deutsch, Armin J., O. C. Wilson, and P. C. Keenan, High-dispersion classification of K2-M6
giants of high and low velocity. Astrophys. J., 156, 107-115, 1969.
Difley, John A., Two photographic developers for astronomical use. Astron. J., 73, 762-769,
1968.
DuPuy, David, John Schmitt, Robert McClure, Sidney van den Bergh, and Rene Racine,
Optical observations of BL Lac = VRO 42.22.01. Astrophys. J. (Letters), 156, L135-L139,
1969.
Eggen, Olin J., Narrow- and broad-band photometry of red stars, II, Dwarfs. Astrophys. J.,
Suppl. Ser., 16, No. 142, 49-96, 1968.
Eggen, Olin J., Luminosities, colors, motions, and distribution of faint blue stars. Astrophys. J.,
Suppl. Ser., 16, No. 143, 97-142, 1968.
Garrison, Robert F., Erratum re "The spectrum of star No. 1 in NGC 2024." Publ. Astron.
Soc. Pacific, 80, 755, 1968.
Greenstein, Jesse L., Red and black degenerate stars. Comments in Astrophys., 1, 62-72, 1969.
86 CARNEGIE INSTITUTION
Greenstein, Jesse L., Faint, metal-poor, subluminous and red degenerate stars, in Low-
Luminosity Stars, pp. 281-295, S. S. Kumar, ed., Gordon and Breach, Publishers, London,
1969.
Greenstein, Jesse L., and Halton Arp, A spectroscopic flare of Wolf 359. Astrophys. Letters
(England), 8, 149-152, 1969.
Greenstein, Jesse L., and Valdar Oinas, Two K dwarfs with enhanced carbon molecular bands.
Astrophys. J. (Letters), 158, L91-L94, 1968.
Hardorp, J., and M. Scholz, On the surface gravity and temperature of Vega. Z. Astrophys., 68,
350-362, 1968.
Hartwick, F. D. A., A two-dimensional classification for galactic globular clusters. Astrophys.
J., 154, 475-481, 1968.
Hartwick, F. D. A., and Allan Sandage, The color-magnitude diagram for the abnormally
strong-line globular cluster M69. Astrophys. J., 153, 715-722, 1968.
Heintze, J. R. W., Temperature, gravity, and mass of Vega, Sirius, and r Herculis. Bull.
Astron. Inst. Netherlands, 20, 1-25, 1988.
Heintze, J. R. W., A tentative model of the solar atmosphere and the low chromosphere.
Bull. Astron. Inst. Netherlands, 20, 137-153, 1969.
Heintze,, J. R. W., On the temperature scale of B-type stars. Bull. Astron. Inst. Netherlands,
20, 154-162, 1969.
Howard, Robert, Solar research at the Mount Wilson and Palomar Observatories. Solar
Physics, 7, 153-158, 1969.
Julian, William H., Overstability of thin stellar systems. Astrophys. J., 155, 117-122, 1969.
Kodaira, K., Jesse L. Greenstein, and J. B. Oke, Abundances in two horizontal-branch stars.
Astrophys. J., 155, 525-536, 1969.
Kowal, Charles T., The absolute magnitudes of supernovae. Astron. J., 73, 1021-1024, 1968.
Kozlovsky, Ben-Zion, and Harold Zirin, The 0 VI emission from the Sun. Solar Physics, 5,
50-54, 1968.
Kraft, Robert P., and Jesse L. Greenstein, A new method for finding faint members of the
Pleiades, in Low-Luminosity Stars, pp. 65-82, S. S. Kumar, ed., Gordon and Breach,
Publishers, London, 1969.
Kristian, Jerome, An upper limit for the optical luminosity of the pulsating radio sources
CP 0950 and CP 1133. Astrophys. J. (Letters), 154, L99-L100, 1968.
Lambert, D. L., Radiation pressure and the composition of the solar corona. Astrophys. Letters
(England), 2,37-39, 1968.
Lambert, D. L., and B. E. J. Pagel, The dissociation equilibrium of H~ in stellar atmospheres.
Monthly Notices Roy. Astron. Soc, 141, 299-315, 1968.
Lambert, D. L., E. A. Mallia, and B. Warner, The abundances of the elements in the solar
photosphere, VII: Zn, Ga, Ge, Cd, In, Sn, Hg, Tl, and Pb. Monthly Notices Roy. Astron.
Soc, 142, 71-95, 1969.
Lambert, D. L., E. A. Mallia, and B. Warner, Forbidden lines of Ca II in the photospheric
spectrum. Solar Physics, 7, 11-16, 1969.
McClure, Robert D., and Sidney van den Bergh, UBV observations of field galaxies. Astron.
J., 73, 1008-1010, 1968.
Manwell, Tom, and Michal Simon, Application of a random-event quasar model to the optical
variability of 3C 273. Astron. J., 73, 407-411, 1968.
Munch, Guido, Small-scale thermal homogeneity of the Orion Nebula, in Interstellar Ionized
Hydrogen, pp. 507-516, Yervant Terzian, ed., W. A. Benjamin, Inc., New York, 1968.
Neugebauer, G., and R. B. Leighton, Two-Micron Sky Survey, A Preliminary Catalog, Na-
tional Aeronautics and Space Administration, Washington, D. C., 1969.
Neugebauer, G., J. B. Oke, E. E. Becklin, and G. Garmire, A study of visual and infrared
observations of Sco XR-1. Astrophys. J., 155, 1-10, 1969.
Neugebauer, G., E. E. Becklin, J. Kristian, R. B. Leighton, G. Snellen, and J. A. Westphal,
Infrared and optical measurements of the Crab pulsar NP 0532. Astrophys. J. (Letters),
156, L115-L120, 1969.
Newell, E. B., A. W. Rodgers, and Leonard Searle, The blue horizontal-branch stars of w
Centauri. Astrophys. J., 156, 597-608, 1969.
Oke, J. B., Continuum energy distributions of Seyfert galaxies and related objects. Astron. J.,
73, 849-850, 1968.
Oke, J. B., Photoelectric spectrophotometry of the Crab pulsating radio source NP 0532.
Astrophys. J. (Letters), 156, L49-L53, 1969.
Oke, J. B., A multichannel photoelectric spectrometer. Publ. Astron. Soc. Pacific, 81, 11-22,
1969.
REPOBT OF THE PRESIDENT 87
Oke, J. B., and Allan Sandage, Energy distributions, K corrections, and the Stebbins-Whitford
effect for giant elliptical galaxies. Astrophys. J., 154, 21-32, 1968.
Oke, J. B., G. Neugebauer, and E. E. Becklin, Spectrophotometry and infrared photometry
of BL Lacertae. Astrophys. J. (Letters), 156, L41-L43, 1969.
Peach, John V., Optical variations in quasi-stellar objects. Nature, 222, 439-442, 1969.
Preston, George W., The magnetic field of HD 215441. Astrophys. J., 156, 967-982, 1969.
Preston, George W., The nature of the variability of HD 19216, Astrophys. J., 156, 1175-1176,
1969.
Preston, George W., and Kazimierz Stepien, The light, magnetic, and radial veolcity varia-
tions of HD 10783. Astrophys. J., 154, 971-974, 1968.
Preston, George W., Kazimierz Stepien, and Sidney Carne Wolff, The magnetic field and
light variations of 17 Comae and k Cancri. Astrophys. J., 156, 653-660, 1969.
Racine, Rene, The distance of the Cepheid SU Cassiopeiae. Astron. J., 73, 588-589, 1968;
erratum and addendum, ibid., 74, 572, 1969.
Racine, Rene, 2000 globular clusters in M87. J. Roy. Astron. Soc. Canada, 62, 367-376, 1968.
Racine, Rene, Preliminary colors of faint objects around M87. Publ. Astron. Soc. Pacific, 80,
326-^29, 1968.
Rees, M. J., Polarization and spectrum of the primeval radiation in an anisotropic universe.
Astrophys. J. (Letters), 168, L1-L2, 1968.
Rees, M. J., Proton synchrotron emission from compact radio sources. Astrophys. Letters
(England), 2,1-4, 1968.
Rudnicki, Konrad, The dependence of the velocity body of stars on space location, in Vistas
in Astronomy, Vol. 11, pp. 173-180, A. Beer, ed., Pergamon Press, Oxford and New York,
1968.
Rudnicki, Konrad, and Irena Tarrare, Redshifts of six galaxies in the vicinity of the Coma
cluster. Acta Astron., 19, 171-172, 1969.
Sandage, Allan, The time scale for creation (Part I). Astron. Soc. Pacific Leaflet No. 477, 8 pp.,
March 1969; (Part II) ibid., No. 478, 8 pp., April 1969.
Sandage, Allan, and Basil Katem, The color-magnitude diagram for the globular cluster NGC
5897. Astrophys. J., 153, 569-576, 1968.
Sandage, Allan, and Willem J. Luyten, On the nature of faint blue objects in high galactic
latitudes, II, Summary of photometric results for 301 objects in seven survey fields.
Astrophys. J., 155, 913-918, 1969.
Sandage, Allan, and G. A. Tammann, Photometrie des Haufen-Doppel-Cepheiden CE Cas.
Mitt. Astron. Gesellschajt, No. 25, 147, 1968.
Sandage, Allan, Basil Katem, and Jerome Kristian, An indication of gaps in the giant branch
of the globular cluster M15. Astrophys. J. (Letters), 153, L129-L134, 1968.
Sandage, Allan, J. A. Westphal, and Jerome Kristian, Results of five nights of continuous
monitoring of the optical flux from Sco X-l. Astrophys. J., 156, 927-942, 1969.
Sargent, W. L. W., New observations of compact galaxies. Astron. J., 73, 893-895, 1988.
Sargent, W. L. W., The redshifts of galaxies in the remarkable chain VV 172. Astrophys. J.
(Letters), 153, L135-L138, 1968.
Scargle, Jeffrey D., Activity in the Crab Nebula. Astrophys. J., 153, 569-576, 1968.
Schild, Rudolph E., W. A. Hiltner, and N. Sanduleak, A spectroscopic study of the association
Scorpius OB 1. Astrophys. J., 156, 609-616, 1969.
Schmidt, Maarten, Quasistellar objects, in Annual Review of Astronomy and Astrophysics, 7,
Annual Reviews, Inc., Palo Alto, Calif., 1969.
Searle, Leonard, and J. G. Bolton, Redshifts of fifteen radio sources. Astrophys. J. (Letters),
154, L101-L104, 1968.
Searle, Leonard, and Wallace L. W. Sargent, The strength of H/3 in extragalactic objects with
broad emission lines. Astrophys. J., 153, 1003-1006, 1968.
Simon, Michal, Asymptotic form for synchrotron spectra below Razin cutoff. Astrophys. J.,
156, 341-344, 1969.
Simon, Michal, Time dependence on Razin spectra in Type IV solar radio bursts. Astrophys.
Letters (England), 3, 23-24, 1969.
Spinrad, Hyron, Benjamin J. Taylor, and Sidney van den Bergh, The M7 giants in the
nuclear bulge of the Galaxy. Astron. J., 74, 525-528, 1969.
Stephenson, C. B., N. Sanduleak, and Rudolph E. Schild, A new hot, rapid variable star.
Astrophys. Letters (England), 1, 247-248, 1968.
Stoeckly, Robert, and Jesse L. Greenstein, Spectrophotometry of a B-type star in the globu-
lar cluster M13. Astrophys. J., 154, 909-922, 1968.
88 CARNEGIE INSTITUTION
Swings, J. P., D. L. Lambert, and N. Grevesse, Forbidden sulphur lines in the solar spectrum.
Solar Physics, 0, 3-11, 1969.
Terzan, Agop, Six nouveaux amas stellaires (Terzan 3-8) dans la region du centre de la Voie
lactee et les constellations du Scorpion et du Sagittaire. Compt. Rend. Acad. Sci. Paris, 267 ,
1245-1248, 1968.
Trimble, Virginia, Motions and structure of the filamentary envelope of the Crab Nebula.
Astron. J., 73, 535-547, 1968.
Tsuji, Takashi, Model atmospheres of M dwarf stars, in Low-Luminosity Stars, pp. 457-482,
S. S. Kumar, ed., Gordon and Breach, Publishers, London, 1969.
Visvanathan, N., Optical polarization in quasi-stellar sources. Astrophys. J. (Letters), 153,
L19-L22, 1968.
Weart, Spencer R., and Harold Zirin, The birth of active regions. Publ. Astron. Soc. Pacific,
81, 270-273, 1969.
Westphal, J. A., and G. Neugebauer, Infrared observation of Eta Carinae to 20 microns.
Astrophys. J. (Letters), 156, L45-L48, 1969.
Westphal, J. A., Allan Sandage, and Jerome Kristian, Rapid changes in the optical intensity
and radial velocities of the X-ray source Sco X-l. Astrophys. J., 154, 139-156, 1968.
Westphal, J. A., Jerome Kristian, Grant Snellen, Allan Sandage, Maarten Schmidt, J. B. Oke,
Gerry Neugebauer, and E. E. Becklin, On the nature of Ryle and Bailey's candidate star
for the pulsating radio source CP 1919. Astrophys. J., 165, L109-L114, 1969.
Wilcox, John M., and Robert Howard, A large-scale pattern in the solar magnetic field. Solar
Physics, 5, 564-574, 1968.
Wilson, Olin C., Flux measurements at the centers of stellar H and K lines. Astrophys. J.,
153, 221-234, 1968.
Wilson, Olin C, Calibration apparatus at Mt. Wilson and Mt. Palomar. Bull. Am. Astron. Soc,
1, 154, 1969.
Wilson, Olin C, Chromospheric variations in main-sequence stars, in Low-Luminosity Stars,
pp. 103-106, S. S. Kumar, ed., Gordon and Breach, Publishers, London, 1969.
Zirin, Harold, Abundance analyses from extreme-ultraviolet emission lines. Astrophys. J.,
154, 799-801, 1968.
Zirin, Harold, Mass motions in loops, sprays, surges, etc., in Nobel Symposium 9, Mass Mo-
tions in Solar Flares and Related Phenomena, pp. 131-136, Yngve Ohman, ed., John
Wiley & Sons, New York, 1969.
Zirin, Harold, Observations of stellar chromospheres using the He 10830 line, in Nobel Sym-
posium 9, Mass Motions in Solar Flares and Related Phenomena, pp. 239-242, Yngve
Ohman, ed., John Wiley & Sons, New York, 1969.
Zirin, Harold, George Ellery Hale, 1868-1938. Solar Physics, 5, 435-441, 1968.
Zirin, Harold, Two prominence eruptions and the problem of emission. Solar Physics, 7,
243-252, 1969.
Zirin, Harold, and Dora R. Lackner, The solar flares of August 28 and 30, 1966. Solar Physics, 6,
86-103, 1969.
Zwicky, Fritz, Catalogue of Galaxies and of Clusters of Galaxies, Vols. IV and VI, California
Institute of Technology, Pasadena, Calif., 1968.
Zwicky, Fritz, Physics and chemistry on the Moon, in Research in Physics and Chemistry,
Proc. Third Intern. Laboratory (LIL) Symp., 1967, pp. 1-27, C. H. Roadman, H. Strug-
hold, and R. B. Mitchell, eds., Pergamon Press, Oxford and New York, 1969.
Zwicky, Fritz, Physics of the universe, in Proc. 4th Intern. Symp. on Bio astronautics and the
Exploration of Space, pp. 63-81, 527, 533, 595-608, Brooks Air Force Base, Texas, 1969.
Zwicky, Fritz, 1967 Palomar supernova search. Publ. Astron. Soc. Pacific, 80, 462-465, 1968.
Zwicky, Fritz, W. L. W. Sargent, and C. Kowal, The 1968 Palomar supernova search. Publ.
Astron. Soc. Pacific, 81, 224-229, 1969.
Geophysical Laboratory
Bell, P. M., and F. R. Boyd, Phase equilibrium data bearing on the pressure and tempera-
ture of shock metamorphism, in Shock Metamorphism of Natural Materials, pp. 43-50,
B. M. French and N. M. Short, eds., Mono Book Corp., Baltimore, Md., 1968 (Geophysical
Laboratory Paper 1533).
Bell, P. M., and B. T. C. Davis, Melting relations in the system jadeite-diopside at 30 and
40 kb. Am. J. Sci., Schairer Vol., 267 A, 17-32, 1969 (Geophys. Lab. Paper 1521).
Boyd, F. R., Electron-probe study of diopside inclusions from kimberlite. Am. J. Sci., Schairer
Vol., 267 A, 50-69, 1969 (Geophys. Lab. Paper 1522).
REPORT OP THE PRESIDENT 89
Bryan, W. B., L. W. Finger, and F. Chayes, Estimating proportions in petrographic mixing
equations by least-squares approximation. Science, 163, 926-927, 1969 (Geophys. Lab.
Paper 1532).
Chayes, F., A least squares approximation for estimating the amounts of petrographic parti-
tion products. Mineral. Petrogr. Acta, 14, 111-114, 1968 (Geophys. Lab. Paper 1519).
Davis, G. L., S. R. Hart, and G. R. Tilton, Some effects of contact metamorphism on zircon
ages. Earth Planet. Sci. Letters, 5, 27-34, 1968 (Geophys. Lab. Paper 1515).
Donnay, G., and R. Allmann, SiaOio groups in the crystal structure of ardennite. Acta Cryst.,
B24, 845-855, 1968 (Geophys. Lab. Paper 1506) .
El Goresy, A., and G. Donnay, A new allotropic form of carbon from the Ries crater. Science,
161, 363-364, 1968 (Geophys. Lab. Paper 1513).
El Goresy, A., and G. Kullerud, Phase relations in the system Cr-Fe-S, in Meteorite Research,
pp. 638-656, P. M. Millman, ed., D. Reidel Publishing Co., Dordrecht, Holland, 1969 (Geo-
phys. Lab. Paper 1536).
Finger, L. W., and C. W. Burnham, Peak-width calculations for equi-inclination diffraction
geometry. Z. Krist., 127, 101-109, 1968 (Geophys. Lab. Paper 1507).
Gaines, R. V., G. Donnay, and M. H. Hey, Sonoraite. Am. Mineralogist, 53, 1828-1832, 1968
(Geophys. Lab. Paper 1517).
Gilbert, M. C, High-pressure stability of acmite. Am. J. Sci., Schairer Vol., 261 'A, 145-159,
1969 (Geophys. Lab. Paper 1523).
Hadidiacos, C. G., Solid-state temperature controller. J. Geol, 77, 365-367, 1969 (Geophys.
Lab. Paper 1537).
Huckenholz, H. G., Synthesis and stability of Ti-andradite. Am. J. Sci., Schairer Vol., 267 A,
209-323, 1969 (Geophys. Lab. Paper 1524).
Kullerud, G., The lead-sulfur system. Am. J. Sci., Schairer Vol., 267 A, 233-256, 1969 (Geophys.
Lab. Paper 1525).
Kullerud, G., G. Donnay, and J. D. H. Donnay, Omission solid solution in magnetite: keno-
tetrahedral magnetite. Z. Krist., 128, 1-17, 1969 (Geophys. Lab. Paper 1514).
Kushiro, I., The system forsterite-diopside-silica with and without water at high pressures.
Am. J. Sci., Schairer Vol., 267 A, 269-294, 1969 (Geophys. Lab. Paper 1526) .
Kushiro, I., H. S. Yoder, Jr., and M. Nishikawa, Effect of water on the melting of enstatite.
Geol. Soc. Am. Bull, 70, 1685-1692, 1968 (Geophys. Lab. Paper 1516).
Lindsley, D. H., I. S. E. Carmichael, and J. Nicholls, Iron-titanium oxides and oxygen fugacities
in volcanic rocks: a correction. «/. Geophys. Res., 73, 3351-3352, 1968 (Geophys. Lab.
Paper 1504).
Lindsley, D. H., and J. L. Munoz, Subsolidus relations along the join hedenbergite-ferrosilite.
Am. J. Sci., Schairer Vol., 267 A, 295-324, 1969 (Geophys. Lab. Paper 1527).
Naldrett, A. J., and G. Kullerud, Emplacement of ore at the Strathcona Mine, Sudbury,
Canada, as a sulfide-oxide magma in suspension in young noritic intrusions. Intern.
Geol. Congr., 23rd, 7, 197-213, 1968 (Geophys. Lab. Paper 1503).
Richardson, S. W., Staurolite stability in a part of the system Fe-Al-Si-O-H. J. Petrol., 9,
467^88, 1968 (Geophys. Lab. Paper 1509).
Richardson, S. W., P. M. Bell, and M. C. Gilbert, Kyanite-sillimanite equilibrium between
700° and 1500°C. Am. J. Sci., 266, 513-541, 1968 (Geophys. Lab. Paper 1508).
Richardson, S. W., M. C. Gilbert, and P. M. Bell, Experimental determination of kyanite-
andalusite and andalusite-sillimanite equilibria; the aluminum silicate triple point. Am. J.
Sci., 267, 259-272, 1969 (Geophys. Lab. Paper 1518).
Schreyer, W., and F. Seifert, High-pressure phases in the system MgO-ALCVSiCVHaO, Am. J.
Sci., Schairer Vol., 267 A, 407-443, 1969 (Geophys. Lab. Paper 1534) .
Tilton, G. R., and R. H. Steiger, Mineral ages and isotopic composition of primary lead at
Manitouwadge, Ontario. /. Geophys. Res., 74, 2118-2132, 1969 (Geophys. Lab. Paper 1535).
Wones, D. R., and M. C. Gilbert, The fayalite-magnetite-quartz assemblage between 600°
and 800°C. Am. J. Sci., Schairer Vol., 267 A, 480-488, 1969. (Geophys. Lab. Paper 1528).
Yoder, H. S., Jr., and I. Kushiro, Melting of a hydrous phase: phlogopite, Am. J. Sci.,
Schairer Vol., 267 A, 558-582, 1969 (Geophys. Lab. Paper 1529).
Department of Terrestrial Magnetism
Bolton, E. T., The evolution of polynucleotide sequences in DNA, in Mendel Centenary:
Genetics, Development and Evolution, pp. 76-85, R. M. Nardone, ed., Catholic University
of America Press, Washington, D.C., 1968.
Britten, R. J., and D. E. Kohne, Repeated sequences in DNA. Science, 161, 529-540, 1968.
90 CARNEGIE INSTITUTION
Brooks, C, S. R. Hart, T. E. Krogh, and G. L. Davis, Carbonate contents and ^Sr/^Sr
ratios of calcites from Archaean metavolcanics. Earth and Planetary Sci. Letters, 6,
35-38, 1969.
Brown, L., W. K. Ford, Jr., Vera Rubin, W. Trachslin, and W. Brandt, Foil- and gas-excitation
of sodium spectra, in Beam-Foil Spectroscopy, I, pp. 45-77, S. Bashkin, ed., Gordon and
Breach, New York, 1968.
Brown, L., and C. Petitjean, 6Li(p, 3He)4He reaction with polarized protons from 0.4 to
3.2 MeV. Nucl. Phys., A117 , 343-352, 1968.
Davis, G. L., S. R. Hart, and G. R. Tilton, Some effects of contact metamorphism on zircon
ages. Earth and Planetary Sci. Letters, 5, 27-34, 1968.
Erlank, A. J., Microprobe investigation of potassium distribution in mafic and ultramafic
nodules (abstract). Trans. Am. Geophys. Union, 50, 343, 1969.
Falkow, S., and D. B. Cowie, Intramolecular heterogeneity of the deoxyribonucleic acid of
temperate bacteriophages. J. Bacteriol., 96, 777-784, 1968.
Fischer, G. von, W. Schreyer, G. Troll, G. Voll, and S. R. Hart, Homblendealter aus dem
ostbayerischen Grundgebirge. N. Jb. Miner. Mh., 11, 385-404, 1968.
Flexner, L. B., J. B. Flexner, G. De La Haba, and R. B. Roberts, Loss of memory as related
to inhibition of cerebral protein synthesis. J. Neuro-chem., 12, 535-541, 1965.
Forbush, S. E., Variation with a period of two solar cycles in the cosmic-ray diurnal anisot-
ropy and the superposed variations correlated with magnetic activity. J. Geophys. Res.,
74, 3451-3468, 1969.
Forbush, S. E., S. P. Duggal, and M. A. Pomerantz, Monte Carlo experiment to determine
the statistical uncertainty for the average 24-hour wave derived from filtered and
unfiltered data. Can. J. Phys., 46, S985-S989, 1968.
Ford, W. K., Jr., Electronic image intensification, in Annual Review of Astronomy and Astro-
physics, 6. pp. 1-12, L. Goldberg, ed., Annual Reviews, Inc., Palo Alto, Calif., 1968.
Ford, W. K., Jr., A. T. Purgathofer, and Vera C. Rubin, Optical spectra near 1 micron: the
Seyfert galaxy NGC 4151 and the planetary nebula NGC 6543. Astrophys. J., 153, L39-
L40, 1968.
Ford, W. K., Jr., and Vera C. Rubin, The spectrum of the 1968 supernova in NGC 2713. Publ.
Astron. Soc. Pacific, 80, 466-469, 1968.
Hart, S. R., Discussion of 'K/Rb in amphiboles and amphibolites from northeastern Minne-
sota.' Earth and Planetary Sci. Letters, 4, 30-31, 1968.
Hart, S. R., and G. L. Davis, Zircon U-Pb and whole-rock Rb-Sr ages and early crustal
development near Rainy Lake, Ontario. Geol. Soc. Am. Bull., 80, 595-616, 1969.
Hart, S. R., G. L. Davis, R. H. Steiger, and G. R. Tilton, A comparison of the isotopic mineral
age variations and petrologic changes induced by contact metamorphism, in Radio-
metric Dating for Geologists, pp. 73-110, E. I. Hamilton and R. M. Farquhar, eds., Inter-
science Publications, 1968.
Kohne, D. E., Isolation and characterization of bacterial ribosomal RNA cistrons. Biophys. J.,
8, 1104-1118, 1968.
Kohne, D. E., Taxonomic applications of DNA hybridization techniques, in Chemotaxonomy
and Serotaxonomy , 2, pp. 117-130, J. G. Hawkes, ed., Academic Press, Inc, New York, 1968.
Petitjean, C, L. Brown, and R. Seyler, Polarization and phase shifts in 6Li(p,p)6Li from 0.5 to
5.6 MeV. Nucl. Phys., A129, 209-219, 1969.
Roberts, R. B., et al., A Report on National Uses and Needs for Separated Stable Isotopes.
National Academy of Sciences-National Research Council, Washington, D.C., 37 pp.,
July 29, 1968.
Rubin, Vera C, and W. K. Ford, Jr., Spectrographic study of the Seyfert galaxy NGC
3227. Astrophys. J., 154, 431-445, 1968.
Steinhart, J. S., and S. R. Hart, Calibration curves for thermistors. Deep-Sea Res., 15, 497-
503, 1968.
Stueber, A. M., Abundances of K, Rb, Sr and Sr isotopes in ultramafic rocks and minerals
from western North Carolina. Geochim. Cosmochim. Acta, 33, 543-553, 1969.
Tuve, M. A., Letters: An Open Forum, Re: Solid-earth geophysics after the termination of
the Upper Mantle Project. Trans. Am. Geophys. Union, 49, 448-449, 1968.
Tuve, M. A., Odd Dahl at the Carnegie Institution, 1926-1936, in Festskrift til Odd Dahl,
pp. 40-46, Fra Venner Og Kolleger, Bergen, A. S. John Griegs Boktrykkeri, 1968.
Varsavsky, C. M., Dust and atomic hydrogen in interstellar space. Astrophys. J., 163, 627-632,
1968.
REPORT OF THE PRESIDENT 91
Genetics Research Unit
Bear, P. D., and A. Skalka, The molecular origin of lambda prophage mRNA. Proc. Natl. Acad.
Sci. U.S., 62, 385-388, 1969.
Makover, S., A preferred origin for the replication of lambda DNA. Cold Spring Harbor Symp.
Quant. Biol, S3, 621-622, 1968.
Skalka, A., Nucleotide distribution and functional orientation in the deoxyribonucleic acid of
phage 080. J. Virology, 3, 150-156, 1969.
Yamagishi, H., Single strand interruptions in PBS 1 bacteriophage DNA molecule. /. Mol.
Biol, 35, 623-633, 1968.
Department of Embryology
Boving, B. G., and Billingsley, L. M., Rat conceptus spacing. Anat. Rec, 163, 158, 1969.
Coon, H. G., and M. C. Weiss, A quantitative comparison of spontaneous and virus-produced
viable hybrids. Proc. Natl. Acad. Sci. U.S., 62, 852-859, 1969.
Cooper, M. H., and R. O'Rahilly, The development of the human heart at seven postovula-
tory weeks. Anat. Rec, 163, 172, 1969.
Dawid, I. B., Cytoplasmic DNA in differentiation and development. /. Animal Sci., 27, Suppl.
I, 61-69, 1968.
Dawid, I. B., and D. R. Wolstenholme, The structure of frog oocyte mitochondrial DNA, in
Biochemical Aspects of the Biogenesis of Mitochondria, pp. 83-90, E. C. Slater, J. M.
Tager, S. Papa, and E. Quagliariello, eds., Adriatica Editrice, Bari, 1968.
Dawid, LB., and D. R. Wolstenholme, Renaturation and hybridization studies with mito-
chondrial DNA. Ibid., pp. 283-297.
DeHaan, R. L., Emergence of form and function in the embryonic heart. Develop. Biol.,
Suppl, 2., 208-250, 1968.
DeHaan, R. L., Review of Epithelial-Mesenchymal Interactions. Science, 162, 784, 1969.
DeHaan, R. L., and S. H. Gottlieb, The electrical activity of embryonic chick heart cells iso-
lated in tissue culture singly or in interconnected cell sheets. J. Gen. Physiol, 52, 643-
665, 1968.
Ebert, J. D., Preface I, in Dynamics of Development: Experiments and Inferences, pp. v-vi, by
Paul A. Weiss ; Academic Press, New York, 1968.
Ebert, J. D., Discussion, in Symposium on Molecular Aspects of Differentiation, J. Cell. Physiol.,
72 (Suppl. 1), 222-223, 227, 1968.
Ebert, J. D., Levels of control: A useful frame of perception? in Current Topics in Develop-
mental Biology, volume 3, pp. xv-xxv, A. A. Moscona and A. Monroy, eds., Academic
Press, New York, 1968.
Green, H., B. Goldberg, M. Schwartz, and D. D. Brown, The synthesis of collagen during the
development of Xenopus laevis. Develop. Biol, 18, 391^00, 1968.
Harbert, G. M., C. B. Martin, Jr., and E. M. Ramsey, Placenta extrachorialis in rhesus
monkeys. Anat. Rec, 163, 195, 1969.
Manasek, F. J., Myocardial cell death in the embryonic chick ventricle. J. Embryol. Exp.
Morph., 21, 271-284, 1969.
Misenhimer, H. R., and D. F. Kaltreider, Preterm delivery of patients with decreased glucose
tolerance. Obstet. Gynecol, S3, 642-646, 1969.
Ramsey, E. M., Radioangiography of the placenta, in Fetal Homeostasis, Vol. III., pp. 151-170,
Ralph M. Wynn, ed., Appleton-Century-Crofts, New York, N. Y., 1968.
Reeder, R. H., and D. D. Brown, An assay for the control of ribosomal RNA gene transcrip-
tion in vitro. Fed. Proc, 28, 349, 1969.
Stalsberg, H., The origin of heart asymmetry: right and left contributions to the early chick
embryo heart. Develop. Biol, 19, 109-127, 1969.
Stalsberg, H., and R. L. DeHaan, Endodermal movements during foregut formation in the
chick embryo. Develop. Biol, 18, 198-215, 1968.
Stalsberg, H., and R. L. DeHaan, The precardiac areas and formation of the tubular heart in
the chick embryo. Develop. Biol, 19, 128-159, 1969.
Wolstenholme, D. R., and I. B. Dawid, A size difference between the mitochondrial DNA
molecules of urodele and anuran Amphibia. J. Cell Biol, 39, 222-228, 1968.
Wolstenholme, D. R., I. B. Dawid, and H. Ristow, An electron microscope study of DNA
molecules from Chironomus tentans and Chironomus thummi. Genetics, 60, 759-770,
1968.
92 CARNEGIE INSTITUTION
Department of Plant Biology
Bjorkman, Olle, Characteristics of the photosynthetic apparatus as revealed by laboratory
measurements. IBP/PP Technical Meeting, Trebon, Czechoslovakia, Productivity of
Photosynthetic Systems, Models and Methods. Czechoslovakia Academy of Science, ed.,
Preliminary texts of invited papers, 136-148, April 10, 1969 (DPB No. 462).
Fork, David C, and Jan Amesz, Action spectra and energy transfer in photosynthesis. Ann.
Rev. Plant Physiol., 20, Leonard Machlis, ed., Annual Reviews, Palo Alto, Calif., 305-
328,1969 (DPB No. 449).
French, C. S., M. R. Michel-Wolwertz, J. Michel, J. S. Brown, and L. Prager, Naturally occur-
ring chlorophyll types and their functions in photosynthesis. Biochim. Soc. Symposia, 28,
Porphyrins and Related Compounds, T. W. Goodwin, ed., London, 147-162, 1969 (DPB
No. 442).
French, C. S., Biophysics of plastid pigments, Closing Session Summary. Internatl. Congr. of
Photosynthesis Research, Freudenstadt, June 4-8, 1969, Photosynthetica, 3(1), 94-96, 1969
(DPB No. 445).
Gauhl, Eckard, and Olle Bjorkman, Simultaneous measurements on the effect of oxygen
concentration on water vapor and carbon dioxide exchange of leaves. Planta, 88, 187-
191,1969 (DPB No. 454).
Heber, Ulrich, Conformational changes of chloroplasts induced by illumination of leaves in
vitro. Biochim. Biophys. Acta, 180, 302-319, 1969 (DPB No. 446).
Losses . . .
It is with deep regret that I must report the retirement of General Omar N.
Bradley, who was a Trustee of the Institution from 1949 to 1968. General Brad-
ley's magnificent military career and his public service in civil life following
World War II sum to a record that seems hardly possible within the lifetime of
one man. He brought to the Board of the Carnegie Institution the same deep con-
cern and tremendous moral force that he has given the whole nation in war and
in peace. We shall greatly miss his counsel.
Dr. Leason H. Adams, Director of the Geophysical Laboratory from 1938
until his retirement in 1952, died on August 20, 1969. First as a Staff Member, and
then as Director, he served the Laboratory and the Institution for forty-two
years. He was a founder of the American Geophysical Union, and served as its
President from 1944 to 1947. He was also a prominent member of many other
learned and scientific societies, and received many scientific honors, particularly
in the field of his research specialty, the study of high-pressure chemical reactions
of silicate rock, a subject which, after his retirement from the Institution, he
continued to explore and teach at the University of California until only a few
years before his death. We mourn deeply the loss of this distinguished scientist
who spent so many productive years with the Institution and contributed so
much to the development of the Geophysical Laboratory.
In August we also lost Dr. Elias A. Lowe, a Research Associate of the Institu-
tion for three different periods totaling twenty-three years. Dr. Lowe was devoted
to paleography, the science of deciphering and describing ancient writings. He
was checking proofs for the twelfth volume of his monumental Codices Latini
Antiquiores at the time of his death at the age of 89 in Bad Nauheim, Germany.
Two of the Staff Members retiring in 1969 are capping their careers at the
Institution with a final publication in a distinguished series. Dr. William M.
Hiesey, who has headed the Experimental Taxonomy Group at the Department
of Plant Biology from 1956 until this year, has concluded the fifth volume of
REPORT OF THE PRESIDENT 93
the famous series Experimental Studies on the Nature of Species, which will be
published by the Institution during the coming year. Dr. Hiesey's work has
spanned so many and such critical years in the development of his field that he
can truly be considered a creator of his science. One of the men who first formu-
lated the basic questions of the evolution of plant species, he opened avenues of
research that are being entered by more and more investigators. Dr. Hiesey
made original and important contributions to his field of study and a no less
fine contribution to the spirit and operation of our Department of Plant Biology.
We are sorry indeed to lose him as a Staff Member but anticipate a continuing
association with the Department for many years to come.
This year, also, we lose another Carnegie Staff Member, retiring after forty-
two years of service, Mr. Scott E. Forbush of the Department of Terrestrial
Magnetism. His Cosmic-Ray Results, Volume XXII of the Researches of the
Department of Terrestrial Magnetism, completed this year dramatically illus-
trates the progress made in Mr. Forbush's field in recent years. The great body
of cosmic-ray data assembled by Mr. Forbush over many years comprises an
invaluable store of data for future investigators of cosmic-ray patterns. Mr.
Forbush joined the Department in 1927 at age 23, and continued that association
throughout his working life. Shortly after coming to DTM, Mr. Forbush sailed
with the nonmagnetic ship Carnegie. He also worked at the seismic station at
Huancayo, Peru, in its early days. His career has been filled with adventure of
the most scientifically exciting kind.
. . . and Gains
The Board of Trustees at its spring meeting elected to its membership a
distinguished new Trustee, Mr. William T. Golden. Mr. Golden, whose govern-
ment service has associated him over the years with the Atomic Energy Com-
mission, the Bureau of the Budget, the Hoover Commission, and the Department
of State Advisory Committee on Private Enterprise in Foreign Aid, is now Chair-
man of the Board of Federated Mortgage Investors, of United Ventures, Inc., and
of the Kirkeby-Natus Corporation. In addition, he is a Director of Crowell-
Collier and Macmillan, Inc.; of the Paribas Corporation; of Woodward Iron
Co.; of Verde Exploration, Ltd.; and of General American Investors Co., Inc. His
wide experience in public affairs and in finance will be of great service to the
Institution, particularly in this time of change. We are honored and privileged
to have Mr. Golden with us.
With great pleasure I record the following honors accorded to Staff Members
during the past year.
Dr. Alfred D. Hershey, Director of the Genetics Research Unit, together with
Dr. Max Delbriick of the California Institute of Technology and Dr. Salvator
Luria of the Massachusetts Institute of Technology, was awarded the Nobel Prize
for 1969 in Physiology and Medicine for his discoveries in the genetics of viruses.
Dr. Philip H. Abelson, Director of the Geophysical Laboratory, received an
honorary Doctor of Science degree from Southern Methodist University on
May 25, 1969. He was also elected to membership on the Council of the National
Academy of Sciences for a two-year term beginning July 1, 1969.
94 CARNEGIE INSTITUTION
Dr. James D. Ebert, Director of the Department of Embryology, received the
honorary degree of Doctor of Science from Washington and Jefferson College on
June 7, 1969. Dr. Ebert was also elected to the Presidency of the American Society
of Zoologists for 1970.
Dr. H. W. Babcock, Director of the Observatories, was elected an Associate of
the Royal Astronomical Society in February 1969. Dr. Babcock also received the
Bruce Medal from the Astronomical Society of the Pacific in June 1969.
Dr. Elizabeth M. Ramsey of the Department of Embryology was elected an
Associate Fellow (Honorary) of the American College of Obstetricians and Gyne-
cologists.
Dr. Maarten Schmidt of Mount Wilson and Palomar Observatories received
the Rumford Medal from the American Academy of Arts and Sciences in Decem-
ber 1968 and was elected a member of that Academy.
Dr. Jesse L. Greenstein of the Observatories was made Chairman of the United
States Committee of the International Astronomical Union.
Mr. Jan Kowalik of the Department of Plant Biology was awarded the Jurzy-
kowski Award by the Alfred Jurzykowski Foundation on January 24, 1969, in
recognition of his outstanding achievements in the field of bibliography.
Reports of Departments
and Special Studies
Mount Wilson and Palomar Observatories
Geophysical Laboratory
Department of Terrestrial Magnetism
Committee on Image Tubes for Telescopes
Department of Embryology
Department of Plant Biology
Genetics Besearch Unit
Mount Wilson and Palomar
Observatories
Operated by Carnegie Institution of Washington
and California Institute of Technology
Pasadena, California
Horace W. Babcock
Director
OBSERVATORY COMMITTEE
Horace W. Babcock
Chairman
Armin J. Deutsch
Jesse L. Greenstein
Robert B. Leighton
J. Beverley Oke
Olin C. Wilson
Carnegie Institution Year Book 68, 1968-1969
Contents
Introduction 103
Observing Conditions 105
Physics of the Sun 105
Routine solar observations 105
Magnetograms 106
Active regions 106
Solar rotation and velocity fields 106
Solar archives copying project 106
Studies of velocity fields 107
Doppler heliograms 107
Solar spectrum 107
Structure of the chromosphere 107
Coronal physics 107
The quiet sun 108
Composition of the solar photosphere 108
Studies of solar activity 109
Solar magnetic fields 110
Solar X rays 110
Planets and the Moon Ill
Mars Ill
Jupiter Ill
Saturn 112
Infrared limb darkening 112
Stellar Spectroscopy and Photometry 113
White dwarfs 113
Dwarf M stars 113
Model atmospheres for M dwarfs 114
Subdwarf radial velocities 114
CE Cassiopeiae a and b and the calibration of the Cepheid P-L-C relation. . 115
Variation of chromospheric radiation 115
Absolute magnitude criterion 116
Stellar chromospheres in cluster members 116
Stellar composition 117
Magnetic and peculiar A stars 118
Pulsation of /u, Cephei 120
M giants: Balmer-line intensities 121
Mass loss 121
O-type stars 121
Rapid variable, HDE 310376 122
Line identifications 122
Spectrophotometry of symbiotic stars 122
Reddening determination 122
Peculiar objects 122
Infrared Stellar Spectroscopy 122
Infrared sources 122
Orion nebula 123
Galactic center 123
OH sources 123
Red stars 124
Image-converter spectra 124
Absolute Spectrophotometry 124
Star Clusters 125
Main-sequence gap and age of NGC 188 125
Reddening, helium abundance, and age difference of M3, M13, M15, and
M92 126
Photometry of southern globular clusters 126
NGC 6397 and <o Centauri 127
Interstellar Gas and Gaseous Nebulae 127
Interstellar absorption lines 127
Interstellar matter 127
Galactic emission nebulae 127
Infrared Sky Survey 127
Galaxies 128
Nucleus of M31 128
Globular clusters in M31 and Fornax 129
Red supergiants in the Magellanic Clouds 129
The Virgo cluster 129
Galaxies in chains and small groups 130
Redshifts and photometry of southern galaxies 130
New Seyfert and related galaxy types 131
Flattening of SO systems 131
Markarian galaxies 132
H II regions in galaxies 132
Compact galaxies 133
Energy distribution of peculiar galaxies 133
Redshifts of galaxies 134
Braccesi galaxies 134
Colors of elliptical galaxies 134
Radio galaxies 134
Catalog of compact galaxies 135
The Galaxy 135
Local galactic structure 135
Supernovae 135
Supernova search 135
Absolute magnitudes of supernovae 136
Supernovae and the structure of the Virgo cluster 136
Cassiopeia A 136
Slow supernova in NGC 1058 136
Pulsars 137
NP 0532 137
CP 1919 140
Optical pulsar search 140
X-Ray Sources 140
Identification of Centaurus X-2 140
Sco X-l 140
Quasi-Stellar Sources 141
Position measurements 141
Spectroscopy 141
Energy distribution 141
BL Lacertae 142
Distribution 142
Theoretical Studies 142
Theory of pulsars 142
Extragalactic radio sources 143
Type IV solar bursts 143
Interstellar gas 143
Guest Investigators 144
Astroelectronics Laboratory 150
Future data systems 150
Multichannel spectrophotometer 151
Mount Wilson TV tests 152
Other activities 152
Instrumentation 152
Mount Wilson 60-inch modernization 152
Palomar 60-inch photometric telescope 152
Multichannel spectrometer 153
Spectrograph camera 153
Interferometric photometer 153
Photometric calibration of direct plates 153
Fast data system 154
Photographic Laboratory 154
Big Bear Solar Observatory 155
Southern Hemisphere Observatory 155
Bibliography 155
Staff and Organization 160
INTRODUCTION
The Crab nebula, remnant of the
supernova of 1054 A.D. in our Galaxy,
is one of the most fascinating objects in
the sky, particularly now that its central
star has been found to be emitting its
light in the form of pairs of sharp pulses
recurring at a rate of 30 per second. The
nebula, at a distance of some 5500 light
years, has a fragmented, roughly sphe-
roidal filamentary structure, with an ap-
parent major axis of 6 minutes or 10 light
years. It consists of material ejected from
the supernova explosion. The nebula is
expanding at a rate that is measurable
both photographically and spectroscopi-
cally. The Crab emits not only optical
radiation, but also radio pulses and
X rays. Near the center of the nebula
appear two stars of about the 16th mag-
nitude. One is presumably a foreground
object. The other star was found by
Baade and Minkowski at Mount Wilson
in 1942 to show a highly unusual feature-
less blue continuous spectrum. They sug-
gested that it is almost undoubtedly the
central star of the nebula and the pri-
mary remnant of the supernova.
Radio astronomers at Puerto Rico in
1968 found that radio emission from the
source NP 0532 in the approximate posi-
tion of the Crab is in the form of sharp
pulses that recur with great regularity.
Optical astronomers attempted to detect
and identify the pulsing source. Success
came in January 1969 when Cocke, Dis-
ney, and Taylor at the Steward Obser-
vatory detected optical pulsation. The
source was identified a few days later
by Lynds, Maran, and Trumbo at the
Kitt Peak National Observatory as the
star that had been suggested by Baade
and Minkowski. The light arises almost
entirely from the short rapid pulses
emitted at the rate of 30 pairs per second.
The Crab pulsar was observed early
in 1969 by Kristian, Westphal, and
Snellen with the prime- focus photometer
of the 200-inch telescope at Palomar.
For this work they quickly assembled a
digital data system capable of recording
and analyzing the rapidly pulsating light
signals. Digital photon counts were re-
corded in time increments of one milli-
second for extended intervals to permit
later analysis. In each 33-millisecond
period, two distinct pulses occur. The
main pulse is 3 milliseconds wide and
asymmetric, the decline being steeper
than the rise. The secondary pulse occurs
13.5 milliseconds later; its amplitude is
30% that of the main pulse. It also is
asymmetric, but in the opposite sense.
Both the primary pulse and the second-
ary pulse are extremely sharp, the width
of the main peak at 90% of maximum
being less than 300 microseconds. The
light-intensity level between pulses is
very low, but detectable. An upper limit
of a few tenths of an arc second for the
size of the optically pulsating source was
determined by knife-edge occultation of
the pulsar in the focal plane. The precise
photometry accomplished by Kristian
and his colleagues shows a remarkable
stability of pulse shapes and amplitudes,
with accuracy of better than one percent
for one-minute averages compared over
time intervals of two hours. This result
shows that the large variations observed
at radio wavelengths are probably not
inherent in the source, but are most likely
caused by atmospheric scintillation.
Kristian, Visvanathan, Westphal, and
Snellen have shown that the light of the
pulses is plane-polarized to the extent of
about 10%.
Among the dozen or more radio pul-
sars that are known, the Crab pulsar has
the shortest period. A search by Kristian
has failed to show any other radio pul-
sars that are optically detectable. It is
tempting to speculate that as the rapidly
spinning neutron star slows down (as-
suming that Gold's model is correct) , the
103
104
CARNEGIE INSTITUTION
pulse intensity in the optical spectrum
diminishes rapidly.
Turning to the subject of degenerate
stars in the final stages of their evolu-
tion, Greenstein has attempted to resolve
the apparent discrepancy in the number
of white as compared with red degenerate
stars. According to the Schwarzschild
theory, the cooling of degenerate stars
from the white dwarf through the red
stages should proceed very slowly, and
we should expect to find a substantial
proportion of these that are passing
through the red stage on their way to
ultimate extinction. But, observationally
the number of white dwarfs is in the
hundreds, while the search by Eggen and
Greenstein for yellow and red degenerate
stars resulted in the listing of only about
twenty, none of which is fainter than the
16th visual magnitude. Greenstein's study
of the problem shows that new knowl-
edge of convection interior to the surface
but outside the degenerate core of the
star alters the situation. In a white dwarf
having a surface temperature near that
of the sun, it develops from the work of
K.-H. Bohm that convection provides
rapid heat transport. Thus, the core tem-
perature is far lower than that inferred
from the earlier theory. This has the
effect of greatly reducing the specific
heat. Greenstein finds that a simplified
stellar model can be derived in this way,
showing that the fainter degenerate stars
cool at a comparatively rapid rate rather
than on a slow and decelerating time
scale. He concludes that such stars there-
fore pass quickly through the red stage
as they grow fainter, and that they are
therefore much less numerous than had
been predicted. Further tests will come
from surveys of stars to the 20th magni-
tude with an image-tube spectrograph.
The proper-motion catalog being com-
piled by Luyten from plates obtained
with the 48-inch schmidt telescope should
aid by providing candidate stars with
large proper motions.
Preston has made noteworthy progress
on the study of stars with strong mag-
netic fields. It has been known that fields
in excess of about 20 kilogauss are re-
quired to produce resolved Zeeman trip-
lets in stellar spectrograms, but such
fields are very rare ; indeed, the 8th mag-
nitude star HD 215441 with its field of
34 kilogauss is the only known example.
Preston now finds that magnetic fields
stronger than 5 kilogauss can be studied
by concentrating on those occasional lines
showing the anomalous Zeeman effect in
which the most intense -n components
have displacements that are comparable
to those of the o- components. Such a
pattern results in a doublet that is more
readily resolved than is a triplet of the
same width because the central compo-
nent is absent. No analyzer is required
in deriving the absolute value of the
mean field strength. From the measured
separations, a mean value of the surface
field on the disk is found. This shortcut
method significantly supplements the
standard procedure whereby an "effec-
tive" field is measured from blended pat-
terns. From such doublet measurements,
Preston has derived a mean surface field
of 15 kilogauss for 53 Camelopardalis
and one of 6 kilogauss for /? Coronae
Borealis, both at specified phases.
During a year's stay at the Mount
Stromlo and Siding Spring Observatories
of the Australian National University,
Sandage began an observational pro-
gram to obtain redshifts and photom-
etry of elliptical (E) and spheroidal
(SO) galaxies brighter than the 13th
photographic magnitude and within 60°
of the South Pole. He obtained 267 spec-
tra of 221 galaxies, thus observing nearly
95% of the available systems. Observa-
tions of southern galaxies are considered
to be crucial for the problem of finding
the Hubble constant by determining the
anisotropic shear field of the local Hub-
ble flow. First priority was therefore
given to galaxies in groups and clusters
in mapping the local anisotrophy of the
general expansion and in testing the pos-
sible dependence of the absolute lumi-
nosity of the brightest cluster or group
galaxy on group population. While the
reductions are not yet complete, prelimi-
MOUNT WILSON AND PALOMAR OBSERVATORIES
105
nary indications are that southern gal-
axies with velocities less than 4000 km/
sec have smaller redshifts for a given
apparent magnitude than the galaxies in
the northern hemisphere.
Sandage with K. C. Freeman and
R. N. Stokes of the Mount Stromlo Ob-
servatory completed a study of the in-
trinsic flattening of elliptical, spheroidal,
and spiral galaxies. The distribution of
apparent flattening for each class was
determined for all classified galaxies
brighter than photographic magnitude
12.5 in the Reference Catalogue. The
distribution of true flattening was then
obtained from the integral equation of
the problem. In agreement with previous
results, it was concluded that spirals and
SO galaxies are equally flat with an axial
ratio of 0.25. Elliptical galaxies, how-
ever, exist throughout the entire range
of intrinsic flattenings, with axial ratios
from 1 to 0.3. Because flattening is a dy-
namical property that can change only
with extreme slowness, the difference in
the intrinsic distribution of axial ratios
between E and SO galaxies shows that
one form cannot evolve into the other.
The initial conditions at the time of for-
mation must have been different for the
two types. Freeman, analyzing the photo-
metric properties of disks, showed that
the central surface brightness of the ex-
ponential disks in S and SO galaxies is
remarkably constant from one to another
and does not vary along the Hubble clas-
sification sequence. The mass density of
free neutral hydrogen appears to be the
sole systematic variable. These facts,
combined with D. Lynden-BelPs theory
of violent relaxation, led Sandage, Free-
man, and Stokes to a number of signifi-
cant conclusions regarding the formation
of galaxies. They confirmed that the
spheroidal galaxian component is formed
very rapidly, largely from matter having
low angular momentum per unit mass,
whereas the disk is formed from material
having higher-than-average angular mo-
mentum per unit mass. The galaxy type,
the authors conclude, was determined
essentially by the amount of free gas
that was left over in the disk after col-
lapse. No appreciable evolution along the
Hubble sequence has occurred since the
galaxies were formed.
OBSERVING CONDITIONS
Mount Wilson received 81.23 inches
of precipitation during the year, far
above the average of 36 inches. The total
snowfall was 80.5 inches.
Palomar Mountain received a total
rainfall in excess of 60 inches. Storms in
January and February resulted in an
unusually poor observing record for these
two months, with only 8 clear nights and
14 partial nights.
The work of modernizing the 60-inch
required placing this telescope out of
service for several weeks beginning on
June 6, 1969. As limited by this and by
weather conditions, the hours worked
with the major telescopes were as shown
in the tabulation below.
TABLE 1. Observations
Telescope
Complete Partial
Nights Nights
Total
Hours
Worked
60-inch
100-inch
200-inch
203 59
242 56
211 86
2291
2591
2550
PHYSICS OF THE SUN
Routine Solar Observations
Routine solar observations were made
by Adkins, Cragg, Howard, and Utter
on 313 days. The records of various
kinds made between June 1, 1968, and
May 31, 1969, were as follows:
Direct photographs 304
Ha spectroheliograms, 30-foot focus 579
K2 spectroheliograms, 30-foot focus 573
Full-disk magnetograms 237
Sunspot drawings 271
106
CARNEGIE INSTITUTION
Magneto grams
The attempt to obtain daily full-disk
magnetograms at the 150-foot solar tower
telescope continued during the year de-
spite difficulties with some of the elec-
tronic instruments. Observational data
are normally recorded digitally on a tape
recorder, and later the tape is taken to
the Caltech Computing Center where
magnetograms and other results are ex-
tracted. During the year a change in the
basic computer from an IBM 7094 to
an IBM 360/75 necessitated an exten-
sive conversion of the magnetogram pro-
grams. Planning has started for a new
data system that will permit carrying
out most of the data reduction at the
telescope.
A preliminary examination by Howard
of recent data on the polar magnetic
fields of the sun shows that both polar
fields decreased during the summer of
1968 to a value of one or two tenths of a
gauss and remained at about that level
at least through the first two months of
1969. During that period there was no
indication of a polarity reversal at either
pole.
The magnetograph observations and
much of the data reduction continue to
be supported partially by the Office of
Naval Research through contract num-
ber NR 013-230, N00014-66-C-0239.
Active Regions
Mrs. Sara F. Smith of the Lockheed
Solar Observatory, Burbank, California,
and Howard continued their work on the
magnetic classification of solar active
regions using the daily magnetogram
data. The classification scheme includes
the orientation of the magnetic axis of
the region as well as the size and mag-
netic configuration.
scans. The results indicate clearly that
the rotation of the visible layers of the
photosphere is nearly 5% slower than
the rotation of sunspots. It seems very
unlikely that a bias in the proper motion
of preceding sunspots could account for
the entire discrepancy in angular ve-
locity. It is reasonable to assume that
the faster rotation of sunspots results
from the fact that they are rather rigidly
attached by large amounts of magnetic
flux to magnetic-flux tubes in deeper,
more rapidly rotating layers. Thus the
spots are dragged through the slower-
moving photospheric material.
Dopplergrams that are usually ob-
tained along with magnetograms suggest
that large-scale motions occur occasion-
ally. The larger active regions are gen-
erally seen as loci of downward motions.
Only the largest and most magnetically-
complex active regions show both down-
ward and upward motions.
Howard, together with Andrew S. Tan-
nenbaum, John M. Wilcox, and Edward
N. Frazier of the Space Sciences Labora-
tory, University of California, Berkeley,
has analyzed one-dimensional magneto-
graph scans to study the 5-minute pho-
tospheric velocity oscillations and the
supergranulation. The oscillations in wing
brightness lead the oscillations in ve-
locity by less than 90° in the photo-
sphere, and by about 90° in the chromo-
sphere. This suggests that the 5-minute
oscillations are traveling waves at lower
levels and standing waves at higher
levels. Downward flows are observed at
the bright parts of the chromospheric
network, and upward flows are observed
at the centers of network cells. This con-
firms the association of supergranular
cells and network cells. Some of the ob-
servations for this study were obtained
at the Kitt Peak National Observatory.
Solar Rotation and Velocity Fields
Howard has studied 2% years of dif-
ferential-rotation data on Doppler ve-
locity obtained from the magnetogram
Solar Archives Copying Project
During the year, Mrs. Clare Neal and
Mrs. Paula Swanson, under the super-
vision of Howard, microfilmed Mount
MOUNT WILSON AND PALOMAR OBSERVATORIES
107
Wilson solar spectroheliograms from the
plate vault. This material, covering the
period from about 1905 to the present, is
a rich source of fundamental solar data.
Microfilming will ensure the preservation
of the images and make it possible for
solar physicists to obtain these records
in a useful form. As a part of the project,
the original plates are being washed and
placed in new envelopes.
Studies of Velocity Fields
The Mount Wilson fine-scan (aper-
tures 5"X5" and 10"x25") magneto-
grams and Dopplergrams of active solar
regions are being studied by Howard.
Dopplergrams, obtained with the A5250
line, show that the velocity pattern per-
sists for several hours and that the re-
gions of receding velocity are invariably
the most active regions.
Doppler Heliograms
Dr. J. 0. Stenflo of Lund and Bhatna-
ger developed a new technique to obtain
Doppler spectroheliograms directly on a
single plate. The principle is to oscillate
the exit slit between the two wings of a
line profile while a spectroheliogram is
being made. This is achieved by oscillat-
ing two tilted plane-parallel glass plates
in front of the second slit of a spectro-
heliograph. The resulting spectrohelio-
gram made in the wing of a line appears
crossed by a fringe pattern. Successive
fringes correspond to the images obtained
in the two wings of the line profile. The
density differences between the fringes
are directly related to the velocity fields
on the sun. The rate of oscillation and
the scanning speed of the spectrohelio-
graph define the width of the fringes and
thus the angular resolution on the sun.
The advantage of this method is that
one obtains directly a Doppler helio-
gram, without doing elaborate photo-
graphic laboratory work. Preliminary re-
sults show that the sensitivity of the
velocity determination is about 0.1 km/
sec.
Solar Spectrum
Howard and Bhatnagar have analyzed
a very fine solar spectrogram for the
estimation of an upper limit of the mag-
netic field in the granular and inter-
granular regions. The plate was obtained
with the 150-foot solar tower and spectro-
graph combination. From the digital out-
put of the microphotometer of the Sacra-
mento Peak Observatory, the scans made
in the dark, intergranular regions were
separated from those made in the bright,
granular regions. A program written for
the IBM 7094 computes half width,
equivalent width, central density, and
the line positions of the granular and
intergranular regions; a systematic in-
crease of the half width of lines is ob-
served in the darker regions compared
with the spectrum of bright regions. The
relation between the increase of half
width and Zeeman broadening of lines
gave an upper limit to the magnetic field
of 20 ±14 gauss. This investigation shows
that the difference of the magnetic field
between the granular and intergranular
regions is probably below 20 gauss.
Isophotes obtained of the same spec-
trum plate show conspicuous line varia-
tion. Profiles acquire cusp and scallop
shapes in the dark streaks, due to con-
tinuum brightness variations.
Structure of the Chromosphere
Preparatory to attempting eclipse ob-
servations of the chromosphere in the
0.3- to 2-cm band, Simon and Zirin ob-
served the sun at 9 mm with the National
Radio Astronomical Observatory's 36-
foot antenna at Kitt Peak. The ratio of
the flux of the quiet sun to that of the
center of the moon at its last quarter was
found to be 31.2 ±0.8. North-south scans
showed that the brightness distribution
was flat to at least r/Ro~0.7.
Coronal Physics
Lambert, in collaboration with R. A.
Chevalier (Caltech student) has per-
108
CARNEGIE INSTITUTION
formed new calculations of the excitation
of coronal ions responsible for the promi-
nent forbidden lines. The calculations
incorporate several recent improvements
in the necessary collision rates. A novel
feature of these calculations is the intro-
duction of the proton excitation of the
fine-structure collisions with the appro-
priate rates taken from a recent study
(J. N. Bahcall and R. A. Wolf, Astro-
phys.J.,152, 701, 1968).
An initial study was made of the ions
Fe XIII and Ca XV for which the 3P
ground state provides two observable
forbidden lines, 8P2->3P1 and ^-^Po-
The intensity ratio of these lines can be
interpreted without detailed information
on the ionization equilibrium. The mea-
surements available in the literature are
in good agreement with the predicted
intensity ratios. This agreement is not
maintained when the proton collisions
are excluded.
The calculations for ions of Ca, Fe,
and Ni are being used in analyses of
coronal condensations. There is evidence
that the abundances in some condensa-
tions are in excess of the photospheric
values. This result may be attributed to
diffusion processes, as suggested by S.
Chapman and E. Tandberg-Hanssen
{Extremely High Temperatures, p. 139,
H. Fischer and L. C. Mansur, eds., Wiley
and Sons, New York, 1958). The possi-
bility that diffusion processes operate
throughout the corona has been examined.
The observations available in the lit-
erature are insufficiently detailed to pro-
vide information. It is apparent that an
eclipse experiment to measure simulta-
neously the intensities of the coronal
lines of Fe X, XI, XIII, and XIV would
provide much vital information. Of spe-
cial importance are observations at dis-
tances of more than 1 RQ above the solar
limb because at these heights the excita-
tion is primarily radiative and the uncer-
tainties in the collisional rate constants
are negligible.
An analysis of the 1952 eclipse spectra
of a coronal condensation (M. K. Aly,
J. W. Evans, and F. Q. Orrall, Astrophys.
J. 136, 956, 1956) is in progress. This
condensation was apparently symmetri-
cal. Aly et al. derived radial distribution
of the number density of excited ions.
An attempt was made to determine the
temperature profile. No satisfactory so-
lution was found to accommodate the
wide range of ions from Ca XV to Fe X.
This result implies that the condensation
is composed of filaments. Average prop-
erties of the filaments are being deter-
mined.
The Quiet Sun
A program of analysis of eclipse mea-
surements of solar continua, begun by
Weart at the Joint Institute for Labora-
tory Astrophysics, is being continued in
collaboration with Drs. R. N. Thomas
and K. Gebbie of JILA. Their extreme
photosphere limb-darkening curves, the
most accurate available to date, are in
agreement with simple equilibrium the-
ory.
The horizontal motions of spicules,
observed at the sun's limb in Ha movies
by Zirin and Lambert, were analyzed by
Weart. These motions are violent and
complex. The time spectrum of line-of-
sight motions, as indicated by Doppler
shifts, shows no significant peaks, but
resembles a (1/frequency) noise spec-
trum with half height at a period of
roughly 200 sec.
Composition of the Solar Photosphere
Lambert has continued to collaborate
with Dr. E. A. Mallia of the Department
of Astrophysics, Oxford, England, in a
program of analyses of Fraunhofer lines.
Improved observations of the [Ca II]
A7323 line were secured with a spectrom-
eter at a high-altitude station in the
Swiss Alps. The spectrometer is operated
by the Department of Astrophysics in
Oxford, England. The new spectra show
A7323 to be partially resolved from the
blending atmospheric H20 line. The
MOUNT WILSON AND PALOMAR OBSERVATORIES
109
equivalent width of the forbidden Ca II
line is in good agreement with a predic-
tion based upon the calcium abundance
log iV(Ca) = 6.33 that was reported last
year.
Photoelectric scans near A4140 were
searched for lines from (0, 0) band of the
SiH system A2a — X2n. Eleven lines were
positively identified and are the first
convincing identification of SiH in the
spectrum of the solar disk. Isotope shifts
were computed for Si30 and Si29 isotopes.
The solar spectrum is too confused to
permit the identification of the very
weak isotopic lines; the result N (Si30)/
N (Si28)<0.15 is consistent with the ter-
restrial ratio JV(Si30)/N(Si28)=: 0.033.
Other problems under active investi-
gation include a search of the C2 Swan
band for isotopic lines, an analysis of
the neutral calcium autoionization lines
(AA6318, 6342, 6371) and improved
abundance analyses for chlorine, copper,
rubidium, mercury, and thallium.
Studies of Solar Activity
Early in the operation of the Caltech
photoheliograph, it was recognized that
growing active regions observed in Ha
were characterized by very high surface
brightness and by dark parallel streaks,
presumably loop prominences in absorp-
tion. This phenomenon had been noted
earlier by Waldmeier and by Bruzek.
Weart and Zirin now find that such
bright regions with loops (BRL) are
generally characteristic of emerging sun-
spot groups. Weart reports that the ori-
entation of the loops is at first tilted at
an angle to the equator, but this angle
invariably decreases during the first day
or two; sometimes the reorientation oc-
curs in less than an hour. Apparently an
active region begins where a kink in the
latitudinal subsurface field rises to the
surface and straightens out. It is sur-
mised that the greatest activity occurs
in bright regions with loops whose polari-
ties are not oriented in the normal east-
west bipolar configuration.
Zirin has studied the further develop-
ment of sunspot groups in some detail.
The bright regions will often exist for a
few days and disappear. Others will arise
rapidly in ten or fifteen hours to levels
of moderate activity, climaxed by large
flares, and either die out or stabilize into
bipolar spot groups. The major sunspot
groups associated with the largest solar-
flare activity appear to arise out of a
secondary growth in such regions. For
example, a new sunspot group (Mount
Wilson No. 16951) was born September
1, 1968, in the center of the disk at the
end of a long filament. It grew rapidly
to bipolar structure with a moderate
amount of activity and was carried off
the disk September 7. The same region
reappeared on September 27 as a simple
round spot, again with moderate activity.
The spot grew rapidly, however, in its
disk transit, and was fairly active when
it transited the west limb October 7.
When it reappeared October 20, it was
still a large spot of preceding polarity
completely surrounded by magnetic re-
gions of opposite polarity. This peculiar
magnetic configuration resulted in an ex-
tremely high level of flare activity that
persisted to the next rotation. This two-
stage development has been found in a
number of other active regions.
Another important facet is the high
level of activity associated with some
rather simple round spots, which until
now have been considered the end prod-
uct of the sunspot evolution. Mount
Wilson No. 16999, which appeared on
the east limb September 23, 1968, and
was classed ap, was a simple round spot
with no associated plage ; it subsequently
produced a large number of flares, in-
cluding one solar proton event. This phe-
nomenon is not understood.
Subsequent work has shown that great
activity occurs when small sunspots of
following polarity are formed anoma-
lously ahead of a large mature spot of
preceding polarity. Although N and S
polarities coexist stably when the "cor-
rect" one precedes, the situation de-
110
CARNEGIE INSTITUTION
scribed is apparently unstable and gives
rise to many flares. This occurred, for
example, after December 21, 1968, when
Mount Wilson group 17097 appeared on
the east limb as a stable /?p configura-
tion. On the next day small spots of fol-
lowing polarity grew just ahead of the
preceding spots. Flares followed, along
with more spots of the "wrong" polarity,
and a number of large flares occurred.
The reason for the instability of mag-
netic fields when the Hale-Nicholson
polarity law is violated is obviously of
fundamental importance in the theory of
solar activity.
Round-the-clock Ha movies of an ac-
tive region which produced hundreds of
surges during November 1968 show that
surges can occur with great regularity.
Weart, collaborating with Dr. U. Feld-
man and R. Zach of the University of
Tel Aviv, found a number of examples
of surge-producing centers less than
10 arc-sec across, with lifetimes of about
two days, each producing up to a half
dozen nearly identical surges. These cen-
ters are often located along the boundary
between areas of opposite magnetic po-
larities. No existing theory of surge pro-
duction adequately explains them.
Solar Magnetic Fields
By comparing Mount Wilson magneto-
grams with high-resolution photographs
made with the Caltech photoheliograph,
Glen Veeder (graduate student) and
Zirin have reached two interesting con-
clusions:
1. The association between plages
with regional magnetic fields greater
than 30 gauss and Ha brightness, first
pointed out by Howard and Harvey, is
apparently valid only for "following"
polarities. For preceding polarities,
equivalent magnetic-field intensities do
not result in visible Ha brightness, prob-
ably because the bright layer tends to be
masked by an overlying pattern of fi-
bril structure. Therefore, magnetic po-
larity may be inferred (with caution)
from the presence or absence of Ha
brightness in regions determined from
off-band pictures to have large magnetic
fields. In calcium K both the leading and
following plages are bright.
2. In off-band pictures there is a one-
to-one correspondence between dark
structures in the disturbed chromospheric
network and the presence of strong mag-
netic fields of 50 gauss or more. Because
the fields cover only part of the surface,
and the magnetograph is customarily
used with a 17-sec aperture, the bound-
ary of the enhanced chromospheric re-
gion is the 5-gauss contour on the daily
Mount Wilson magnetograms. Where the
field is not too complex, it is easy to draw
the 5-gauss contours on the magneto-
grams directly from these Ha pictures.
The "enhanced network" region is im-
mediately evident on off-band pictures
as an area showing a strong dark net-
work and a reduced level of chromo-
spheric oscillation. Outside of the 5-gauss
contour there is normally a disturbed
region in which the field appears to be
horizontal, bounded by prominences that
mark the change to the chromospheric
network.
Solar X Rays
In a study of the relationship between
optical and X-ray activity, a close col-
laboration was begun between solar
physicists of the Observatories and ex-
perimenters of the University of Cali-
fornia at San Diego and Berkeley. Al-
most every X-ray event observed with
satellite apparatus was found to corre-
spond to some sort of Ha phenomenon,
typically a simple flare. Almost every
small flare appears to produce substan-
tial numbers of X rays in the 7- to
12-kilovolt range and higher. Because
the satellite X-ray measurements are not
directional, great interest attached to an
event behind the west limb on December
2, 1967. As a bright arch arose from
behind the limb of the sun, the X-ray
MOUNT WILSON AND PALOMAR OBSERVATORIES
111
flux increased rapidly to nearly 100
times the quiet sun value. The total
X-ray flux between 7 and 12 kilovolts
was directly proportional to the projected
area of the flare, up to the time of maxi-
mum, when the arch broke up and the
energetic electrons appear to have dis-
appeared. From these data, as well as
the energy distribution on the X rays,
Zirin and William Ingham, collaborating
with Hugh Hudson and David McKenzie
of UCSD, determined a density of
1010 cm-3 for electrons at a temperature
of 50 million degrees in the flare. The de-
cay time of the X-ray burst also gave
maximum values for the electron density
of ambient particles because of the ab-
sence of coulomb braking. These derived
densities were of roughly the same order.
A continuing investigation and compari-
son of Ha data with X-ray observations
is in progress.
PLANETS AND THE MOON
Mars
During the current opposition of Mars,
Munch and Neugebauer have been ob-
serving the planet radiometrically in the
8-14 /x and 4.6-5.2 \x channels at the
Cassegrain focus of the 200-inch tele-
scope. Scans of the planetary disk in
various directions have been made with
apertures as small as 1 arc sec, when the
seeing conditions warrant it. The irradi-
ance of dark areas appears, in general,
higher than that of light ones, although
the correlation between visual darkness
and excess temperature is not yet clear.
Further observations of the brightness of
Mars in the 8-14 fx range will be carried
out prior to the encounter of the Mariner
VI and VII fly-by spacecraft, from
which Neugebauer, Munch, and S. Chase,
of the Santa Barbara Research Center,
will carry out an absolute radiometric
measurement in two spectral channels,
one of them very nearly coinciding with
the 8-14 fi channel used from ground.
In this fashion a fundamental calibration
of the 8-14 [x magnitude system will be
established. Measures in the other chan-
nel, 18-24 fx, of the Mariner radiometer
will also be compared with ground-based
observations which will be carried out
in Hawaii, to establish a calibration of
the 20-ju magnitude system.
Photoelectric observations of the weak
absorption lines in the 5v3 C02 band at
A8690 in the spectrum of Mars are being
carried out at Mount Wilson by Munch
with the Fabry-Perot interferometer
used in the 1967 opposition (Year Book
66, p. 16) . The purpose of the measures
is to detect and measure differences in
the C02 columns above dark and light
areas. Preliminary inspection of data so
far obtained indicates that over dark
areas (Syrtis Major) detectably less
C02 absorption takes place than over
deserts (Arabia).
Jupiter
The brightness distribution of the disk
of Jupiter in the wavelength ranges
4.6-5.2 fx and 8-14 fx is being studied by
Neugebauer and Munch at the Casse-
grain focus of the 200-inch telescope.
The observations in the 5-//, channel are
made through a dichroic filter, which
permits photographing the field being
measured through a boresighted reticle.
In this fashion the nature of the rela-
tion between the 5-fx brightness and the
visual features in the equatorial belt may
be clarified. The observations in the 10-/*
channel are done by driving the telescope
in slow motion along chosen paths cross-
ing the disk. Scans made along directions
normal to the banded structure of the
planet have clearly shown that, contra-
dicting the earlier findings of Murray,
Wildey, and Westphal (Year Book 62,
p. 42), there is a distinct temperature
difference between belts and zones — the
zones being appreciably cooler.
112
CARNEGIE INSTITUTION
The darkening toward the limb of
Jupiter has been measured by Munch on
photographic images taken at the coude*
focus of the 200-inch telescope in a
variety of broad-band wavelength re-
gions. Theoretical limb-darkening curves
for semi-infinite homogeneous atmo-
spheres with various scattering phase
functions have been fitted to the obser-
vations to derive characteristic values
for the single scattering albedo and
asymmetry factors in belts and zones.
On this basis the variations in the
strength of the CH4 absorption bands
over the Jovian disk, measured earlier by
Munch and Younkin, can be quantita-
tively accounted for as arising by diffuse
reflection. Very strong bands, however,
increase in strength at the equatorial
limb, indicating the existence of a thin
high-level gas layer over the scattering
medium. The phase-angle effect shown
by the brightness at the extreme equa-
torial limb cannot be explained in terms
of existing model calculations and pre-
sumably implies a strong forward lobe
in the scattering function.
Spectrograms of Jupiter in the region
of the 3v3 band of CH4 at a10900 have
been obtained by Munch with a Carnegie
image tube at the 72-inch camera of the
200-inch coude. On this basis, differences
in the rotational temperatures at various
points in the planetary disk will be
searched for.
Saturn
The darkening toward the limb of
Saturn has been measured in photo-
graphic images taken by Munch with
various emulsion-filter combinations. As
for Jupiter, the purpose of the measures
is to derive parameters for the scattering
processes in the continuum, which in turn
are needed to interpret the intensity of
absorption bands or lines. For Saturn,
an attempt has been made to rectify the
observed limb-darkening profiles for see-
ing effects. Toward this end a "seeing
smearing function" has been derived
from tracings of the ring system and an
assumed photometric profile. The bright-
ness distribution at the extreme limb,
where the seeing effects are important,
contains information mostly about the
asymmetry factors of the scattering
phase functions. Existing calculations of
diffusely reflecting planetary atmo-
spheres are not sufficiently general to
permit interpretation of these effects.
Infrared Limb Darkening
Using the 200-inch telescope, West-
phal obtained infrared limb-darkening
measurements of several planets with the
highest spatial resolution possible.
Measurements of Venus were made at
wavelengths of 5, 9, 11, 13, 17, and 21 /*.
Measurements of Jupiter and Saturn
could be made at 8-14 and 16.5-22.5 fx.
Attempts to measure the 5-/* limb-dark-
ening of Jupiter led to the discovery of
intense thermal radiation from localized
areas where the brightness temperatures
are at least 310°K. This thermal radia-
tion is apparently coming from regions
where the cloud layer is absent and the
flux can escape from deep in the atmo-
sphere. During April and May 1969 the
flux was being emitted from localized
regions between 5°N and 20 °N latitude,
which appeared extremely dark during
times of excellent seeing.
Limb-darkening measurements of Sat-
urn at 1.2, 1.65, 2.2, and 3.4 /x indicate an
anomalously high albedo for the equa-
torial region at 2.2 /*. This effect, first
seen by Younkin and Munch in 1963 in
the region around 8870 A, is apparently
due to the reduced methane absorption
over cloud layers that are higher in the
atmosphere than the clouds in the sur-
rounding areas.
A similar situation was observed when
scans across the Red Spot on Jupiter at
8870 A on 25 April 1967 indicated a
higher albedo than that of the surround-
ing area. Thus the cloud tops in the Red
Spot are apparently considerably higher
than the general level over the planet.
MOUNT WILSON AND PALOMAR OBSERVATORIES
113
STELLAR SPECTROSCOPY AND PHOTOMETRY
White Dwarfs
Greenstein continued the survey of the
spectroscopic properties of the white
dwarfs at two extremes of their cooling
tracks. The small-proper-motion Lowell
blue stars (the GD series) yielded 54
white dwarfs that were found to have
very low space motions and, preferen-
tially, an abnormally high percentage of
spectroscopically interesting stars. The
DB helium-rich type, in fact, has its
highest frequency in the Lowell GD
list — about 17% of those observed. Re-
examination of the earlier lists of Eggen-
Greenstein objects shows that the DB
stars are progressively more common as
one proceeds toward lower space motion,
with a frequency as low as 4% among
the Population II group. It is interesting
to note that the surface anomaly con-
nected with the next nucleosynthetic
stage, production of C12, which is repre-
sented by the A4670 stars, seems confined
to high- velocity stars, or white dwarfs
in binary systems. Both these results are
somewhat unexpected, since Population I
white dwarfs may, in part, be the cores
of or descendants of massive stars which
burn He4 to C12 (or further) . One would
therefore expect the low-velocity white
dwarfs to be A4670, not DB type. The
subsequent shell-burning, or details of
mixing, may be involved.
While at the Institute for Advanced
Study, Greenstein studied the cooling
times of old white dwarfs. He found that
the rarity of red degenerate stars is con-
nected with the solid-state theory of
cooling at low core temperatures. In a
star like van Maanen 2, which has a sur-
face temperature near the sun, K.-H.
Bohm had found that convection pro-
vides rapid heat transport, and begins
near the degeneracy boundary. The core
temperature is then far lower than on
the Schwarzschild theory — in fact, near
106 °K. If so, not only has ion solidifi-
cation occurred, which changes the spe-
cific heat, but the specific heat is low.
A simplified model can be derived from
the Debye theory of specific heats, which
shows that stars fainter than van
Maanen 2 cool at a rate such that they
fade by one magnitude in 1.3 X 109 years,
rather than on a time scale that increases
with decreasing luminosity. Thus the
faint red degenerates have shortened
lives and are much rarer than previously
expected. Greenstein has attempted to
find cool red degenerate stars by various
methods but with poor success. The total
number of candidates studied spectro-
scopically now approaches 50. A new
compilation of degenerate or possibly
degenerate stars shows that a total of
17 yellow and red degenerates are now
known, as compared to 6 known when
the work of Eggen and Greenstein be-
gan. Nevertheless, few are very cool, and
none is fainter than Mv= +16. Thus the
suspected acceleration of cooling by
solid-state effects seems to be supported
by observational evidence, at least for
stars brighter than mv = 16.5. Only
image-tube spectral surveys of stars to
20th magnitude will make this result
definite.
Oke has continued to obtain spectral-
energy distributions of selected white
dwarfs. Some of the objects studied are
normal A- and B-type objects. Many,
however, are obj ects found by Greenstein
to have peculiar spectra. Observations,
particularly in the near infrared, reveal
many other peculiar spectral features, of
which few have been identified.
Dwarf M Stars
Infrared photometry can provide
nearly complete coverage of the energy
maximum of faint M dwarfs. After the
flare of Wolf 359 was noted by Arp and
Greenstein, Neugebauer and Becklin ob-
served this star and the faint companion
of +4°4048, known as Van Biesbroeck
11, which are the two stars of faintest
114
CARNEGIE INSTITUTION
known visual magnitude for which spec-
tra and far infrared observations can be
made. Both are dMe stars, have flared,
and are representative of the intrinsi-
cally faintest and least massive stars
known. Greenstein has analyzed the data
and restudied the photometry by H. L.
Johnson for other faint M dwarfs (later
than M3) by fitting black-body curves
at the energy maximum, where molecular
bands are weak, and allowing for reason-
able blocking in the UBVRI photometric
band passes (where TiO may be very
strong) . The empirical result is a recali-
bration of the effective temperature-
bolometric-magnitude scale for stars of
low mass. Fitting the energy maximum
suggests very serious depression by TiO
(and atomic lines) must occur even in
the / band, and certainly at all shorter
wavelengths. This disagrees with Tsuji's
theoretical predictions. The effective
temperatures are raised and the bolo-
metric correction increased. The tempera-
ture for Wolf 359 is raised to the range
2625-2750°K, above that given (2200°K)
in Year Book 1967, p. 18. For VB 11 the
temperature is 2250-2375°K. The Mhoh
log Te diagram is then nearly a straight
line down to Afbol=+13. VB 11 is
brighter than expected, and suggests that
the smallest masses so far known are well
above the theoretical lower limit of
0.07 ffie for main-sequence stars.
Model Atmospheres for M Dwarfs
Tsuji has studied convective energy
transport in cool stars, with a result that
raises the surface temperatures over
those obtained with a radiative model
including molecular opacities. The flux is
not substantially changed, with a flux
excess at 1.0 and 1.6 ft but a general
infrared deficiency caused by high mo-
lecular opacity. He suggests an effective-
temperature scale for types M0.5V, M3V,
and M5V as Te = 3600, 3000, and 2600°K,
respectively.
Tsuji also computed a model (Te =
3000 °K) with 1% of the solar metal
abundances to represent a halo M dwarf.
Collisionally induced H2 absorption is
high in the infrared because of high gas
pressure. The TiO opacity is low, while
SiH, MgH, and CaH remain important
in the blue to red spectral regions. He
suggests that a halo M dwarf will also
show flux excess at 1 fx and deficiency at
A>2 fx, with smaller deficiencies at a<1 ll
as compared to dwarfs.
Sub dwarf Radial Velocities
Radial velocities of 112 subdwarf can-
didates, chosen from the unpublished
photometric catalogue of 1700 proper-
motion stars reported in earlier Year
Books, have been obtained by Sandage.
The work has been carried as a stand-by
200-inch coude program from 1962 to
1968 during observing runs scheduled for
other problems on which work was inter-
rupted because of partially cloudy
weather.
Many of the stars have quite large
velocities. The two highest are G64-12 =
LTT 13980 with P= +438.6 km/sec and
G20-8 = LTT 15239 with P= -395.5 km/
sec. There may be nine possible radial-
velocity variables, four of which are
certain.
Photometric parallaxes were estimated
for each star and preliminary UVW
space motions were computed. There is a
good correlation between asymmetrical
drift velocity and the observed ultra-
violet excess 8(0.6), normalized to
B — 7 = 0.60 (to correct for the guillo-
tine) . The velocity dispersions in U and
W also correlate well with 8(0.6), as ex-
pected from prior work by Stromberg,
Oort, Greenstein, and others. The results
can be interpreted by, and generally are
consistent with, the galactic collapse
model of Eggen, Lynden-Bell, and
Sandage. In particular, the good correla-
tion between 8(0.6) and the velocity dis-
persion in W again emphasizes the pres-
ence of a chemical composition gradient
perpendicular to the galactic plane.
A few high- angular-momentum sub-
MOUNT WILSON AND PALOMAR OBSERVATORIES
115
dwarfs which lead the sun in V are pres-
ent in the sample, but there are not yet
enough examples to establish whether a
correlation exists between 8(0.6) and
increasingly positive V velocity. A pro-
gram to find more such stars has been
started by Sandage.
CE Cassiopeiae a and b and the Calibra-
tion of the Cepheid P-L-C Relation
Sandage and G. A. Tammann com-
pleted a two-color photometric investi-
gation of the double Cepheid CE Cas in
the galactic cluster NGC 7790. The bi-
nary consists of two Cepheids separated
by 2'.'3. Separate light curves for each
component in B and V were obtained by
relating (1) photoelectric data of the
combined light of both components mea-
sured with a large aperture, and (2) rela-
tive photometry of short-exposure plates
made between 1956 and 1962 with the
200-inch telescope diaphragmed to
100 inches, where the components are
clearly separated. Final values of (V)
(B — V) for each star are estimated sepa-
rately to be accurate to ±0.02 mag or
better.
The stars differ in color, luminosity,
and period. The data permit a test of the
P(P)1/2 = Q relation. The components of
CE Cas, as well as CF Cas in the same
cluster, obey the relation to within the
probable error set by the photometric
accuracies. This provides evidence that
the formulation of the Cepheid period-
luminosity-color relation via the P(p)1/2
function is valid. The calibration of the
P-L-C relation was rediscussed using the
new data for CE Cas, together with new
data on RS Puppis (Westerlund) at
P=41.4 days, SU Cas (Racine) P=1.95
days, 1 Carinae (P = 35?6), and a Ursae
Minoris (P = 4d) from Fernie. Thirteen
fundamental Cepheids covering the large
period range from 1.95 days to 41 days
are now available. In agreement with
theory, the scatter in the trace of the
full P-L-C relation in the period-
luminosity plane is tightly correlated
with color. Cepheids brighter than aver-
age at a given period are bluer than
average, and conversely. The coefficients
expressing the observed correlation are
AMF/A(P-7)=2.52, &MB/A{B-V) =
3.52, in good agreement with predictions
based on P(P)^2 = Q.
Sandage and Tammann found that the
equations
Mv= -3.425 log P (days) +
2.52 [(B)°-(V)°] -2.459
Mv= -3.425 log P(days) +
3.52 [(B)°-(V)0] -2.459
reproduce absolute magnitudes of the
13 calibrating Cepheids to within
0.064 mag (AD) over the available pe-
riod range. The new calibration differs
from their 1967 discussion, based on a
smaller sample, by 0.05 mag. The new
calibration gives brighter values.
Discussion of the evolutionary history
of the components of CE Cas shows that
in the absence of perturbing effects, such
as rotation, mass loss, or different main-
sequence formation times, the mass-ratio
of the components must now be less than
1.007 for both stars to be in the Cepheid
instability strip. This stringent require-
ment results from the short time scale
for stars in the Cepheid phase compared
to their main-sequence lifetime, and ex-
plains why so few binary stars are Ce-
pheids at any given time.
Variation of Chromospheric Radiation
Wilson has continued his work with
the 100-inch telescope coude scanner and
its associated pulse-counting equipment
in a search for stellar analogs of the
solar cycle. A number of main-sequence
stars are being followed, covering the
spectral-type range F5 to M2. The fluxes
at the center of the H and K lines of
Ca II are measured as frequently as
possible in order to detect changes in the
chromospheric components of the radia-
tion.
As this work was begun in 1966, there
are now observations of some stars in
116
CARNEGIE INSTITUTION
four seasons, extending over a 3-year
period. For most of the later-type stars,
however, observation did not begin until
1967.
With the assistance of Riley, Wilson
has made a preliminary analysis of the
observations. It is found that nearly all
stars whose spectra reveal H and K re-
versals on 10 A/mm spectrograms have
undergone some change in chromospheric
emission. In a number of instances these
changes are well in excess of the stan-
dard deviations for the observing seasons,
which are computed in the usual manner.
No periods can be determined yet, but
the fact that apparently real variations
can be seen over two- or three-year
intervals provides impetus to continue
the work.
The most striking results are those for
61 Cygni A and B. These stars can be
observed during nine months of the year
and have been followed as closely as
possible. Measures in 1967, 1968, and
early 1969 show that the chromospheric
fluxes in both objects are varying in a
roughly cyclical manner. The period for
61 Cyg A appears to be about six and
one-half months, while that for the
fainter star is probably somewhat more
than twice as long. It is not known
whether these are intrinsic cycles of some
kind or whether they are the rotation
periods of the stars. In any case, further
observation is clearly required.
Absolute Magnitude Criterion
A linear correlation between the loga-
rithm of the width of the chromospheric
H and K reversals in stars and the
absolute visual magnitude was estab-
lished by Wilson and Bappu in 1957.
Various studies of this relationship indi-
cate that it may be capable of yielding
rather accurate luminosities. There is,
however, a troublesome question of
whether the correlation depends signifi-
cantly on the metal abundances of the
stellar atmosphere. In an effort to shed
some light on this matter, Wilson has
obtained 10 A/mm spectrograms of sev-
eral stars for which published analysis
show greatly reduced metal abundance
as compared to the Sun. This work was
done with the 200-inch telescope and
proceeds slowly, since most of the stars
concerned are rather faint and require
long exposures even when the seeing is
good.
Of the stars observed, measurable H
and K reversals can be seen in the spec-
tra of HD 26, 165195, and 221170, for
which the published [Fe/H] values are
-0.67, -2.70, and -2.70, respectively.
These spectrograms have not yet been
measured. However, when they are ex-
amined on a comparator against spectra
of ordinary giants, it is seen that the line
widths are very similar. Additional spec-
trograms will be obtained to strengthen
this result.
Stellar Chromospheres in Cluster
Members
The color-magnitude diagrams of the
Pleiades and the Hyades have shown
considerable scatter at the faint end,
with important implications for the
theory of stellar contraction and evolu-
tion and for the Hayashi time scale. For
clarification of this situation, field M
dwarfs must be excluded and good pho-
tometry provided despite the relatively
bright reflection background. Kraft and
Greenstein chose to study the K-line
emission of Ca II, which is expected to
be strong in young stars. (O. C. Wilson
and other investigators found that the
strong chromospheres of young stars fade
in about 4xl08 years.)
Low-dispersion spectrograms (90-400
A/mm) were obtained for 49 stars in
the magnitude range 13-15, presumed to
be cluster members on the basis of
proper motion. It was found that emis-
sion became strong at about K3.5V and
was extremely strong in the M stars.
The equivalent widths approached 5 A.
Comparison with field stars studied by
Wilson showed that the faint stars in the
MOUNT WILSON AND PALOMAR OBSERVATORIES
117
Pleiades have extremely strong emission
features.
The use of the emission-line criterion
for young clusters does, in fact, clear up
the H-R diagrams. The resultant scatter
is very small. In the Hyades, photo-
electric colors and spectral type are
highly correlated ; omission of three stars
without emission lines produces an ap-
parent-magnitude-spectral-type diagram
of negligible scatter, from K5 to M2.
The Pleiades are more difficult because
of the sparse V and B — V data, the effect
of the nebulous background on the photo-
graphic colors, and differential absorp-
tion and reddening. Below 7 = 12.0, the
spread in the color-magnitude diagram is
mainly the result of fairly large observa-
tional errors. The selection of members,
however, is easy. In a B — V (Iriarte)
photoelectric-spectral-type diagram, the
scatter is small. In a V (Johnson and
Mitchell) spectral-type diagram for
members selected on the basis of emis-
sion, the total spread is 1.2 mag and is
nearly symmetrical about the standard
zero-age main sequence. Field stars, i.e.,
stars without emission, deviated up to
4 magnitudes. If any turnaway above
the faint end of the main sequence exists,
it is fainter than Ml. Thus, stars of
My =+10 lie essentially on the main
sequence. At present, theoretical con-
traction times computed for such stars
are longer than the nuclear age of
3xl07 years. Probably the Hayashi
time scales should be reconsidered in the
light of pre-main-sequence evolutionary
stages, such as the T Tauri stars, with
very strong chromospheres and mass loss.
In order to posit that all the Pleiades
stars have the same age as the B stars,
we require a mechanism that accelerates
the Hayashi contraction.
Stellar Composition
A detailed analysis of the extremely
metal-poor star+39°4926 was completed
by Kodaira, Greenstein, and Oke; its
temperature is 7500 °K and log 0 = 1,
with microturbulence 5 km/sec. While
the metal abundance is 1% that in the
sun, abundances of carbon, oxygen, and
nitrogen are essentially normal and in-
sensitive to errors of temperature. There
is an unusually large odd-even alterna-
tion in abundances, absolutely and dif-
ferentially. Rapid synthesis of carbon
and oxygen occurred either when the star
was more massive or in a nearby explo-
sive event with a-particle capture pre-
dominant. The radial velocity seems
variable in a 775-day period, the lumi-
nosity near M-— 3, the mass less than
Tie. The unusual location in the H-R
diagram may be connected with rapid
evolution with mass exchange. Kodaira
has obtained 27-A/mm infrared spectra
of the horizontal-branch A stars HD
86986, 109995, and 161817 at the
200-inch. These very metal-poor stars
(see Year Book 67, p. 24) show the oxy-
gen triplet at A7771 as strong as in stand-
ard A stars, indicating normal oxygen
abundance (as for +39°4926, which is
much more luminous). He is studying
the non-LTE effects in the triplet, com-
pared to weaker oxygen lines in the red.
Mrs. Locanthi is preparing a wave-
length table for lines in S-type stars, and
has partially completed one for V Cancri
(intermediate between the barium and S
stars). With Keenan she studied the evi-
dence for bands of niobium-oxide in S
stars. They conclude that only AA6484,
6591 are suitable, and find them weakly
present in R Cygni at a cool phase.
Much work is being done on Popula-
tion I stars of earlier types. Scholz, col-
laborating with J. Hardorp of Hamburg
and Cambridge, has reinvestigated the
spectrum of a Lyrae, A0 V. They cannot
find an atmospheric model that predicts
the continuum, the metallic-line spec-
trum, and the Balmer lines simultane-
ously. An effective temperature of
9700°K and log g = 3.9 is recommended.
In r Scorpii, Te=32,000°K, log g=4.1;
and for A Leporis, 30,900°K, log g = 4.05,
with microturbulence of 4.5 km/sec.
Kodaira observed 27 bright B3 V stars
118
CARNEGIE INSTITUTION
with the 60-inch Cassegrain scanner. The
1964 Oke system of standards is used
with TC = 9600°K, log # = 4.0 as the pa-
ramaters for a Lyr, based on a 1966
blanketed model by Mihalas. Effective
temperatures for program stars were de-
termined from color and Balmer jump,
and were 16,000-18,000°K. Some rapidly
rotating stars showed an excess Balmer
jump equivalent to a gravity change of
A log 0 = 1. Mihalas also obtained spectra
for velocity variation of these stars over
a period of 11 months.
A detailed model-atmosphere analysis
was carried out by Kodaira and Scholz
for t Herculis (v sin i*=«0), a moderate
rotator r\ Hydrae (v sin i ^ 100 km/sec) ,
and HD 58343, a pole-on rapid rotator
(B3e, v sin i « 30 km/sec) . Spectra were
taken also by Lambert. The parameters
were Te = 18,000 °K, log 0 = 3.75 for i Her
and HD 58343; Te = 20,000 °K, log g = 4.0
for 7] Hya, microturbulence 5.0 km/sec.
The chemical composition of these stars
is not distinguishable from that of the
sun. The He/H abundance, which is of
cosmological importance, is 0.063 by
number, i.e., y = 0.20. A dependence of
rotational velocity on lines used was
found in rj Hya, as predicted by Hardorp
and Strittmatter. A pole-on model of
HD 58343 was used to study the effect of
gravity-darkening on a fine analysis.
The chemical composition scarcely
changes, while the discrepancy between
the temperature derived from the hydro-
gen spectrum and that from ionization
equilibria decreases.
Magnetic and Peculiar A Stars
Preston, K. Stepien (Warsaw Uni-
versity), and S. C. Wolff (University of
Hawaii) have derived a period of 5.08
days for the light and magnetic varia-
tions of 17 Comae A. The star also ex-
hibits periodic spectrum variations of
small amplitude in the lines of Ti II,
Sr II, and Eu II. A provisional period
of 5.00 days was obtained also for k
Cancri, but the light and magnetic ranges
are very small. This star is in need of
further study.
A period of 3.7220 days has been
established for 78 Virginis by Preston.
This period, derived from a study of the
occurrence of the crossover effect in the
line profiles, successfully represents the
magnetic observations, the radial veloc-
ity data, and the occurrence of the
crossover effect during the past 20 years.
R. C. Henry (thesis, Princeton Uni-
versity, 1966; Astrophys. J. Suppl., 18,
No. 156, 1969) recently has given values
of his /c-index for a number of Ap stars.
The /c-index measures the equivalent
width of the K-line of Ca II in A-type
stars. Henry's data clearly indicate
periodic variations of the K-line in 17
Com A and 78 Vir and suggest that
/c-index measurements may be one of the
easiest ways by which to detect periodic
spectrum variables, at least among the
Ap stars of later types.
Preston has found that the radial
velocities and line intensities in the spec-
trum of 21 Persei vary periodically in
the 2.88-day photometric period derived
by Stepien. The velocity curve for the
singly-ionized rare earths consists of two
branches that overlap near primary light
maximum and overlap again one-half
cycle later when a weak secondary light
maximum may occur. The range of the
velocity variation is about 30 km/sec.
The velocity variation for Ti II and
Mn II resembles those for the rare earths,
while lines of Si II, Sr II, and Fe II yield
velocity curves of small amplitude with
double waves. The velocity curve for
Cr II lines varies in antiphase with the
other elements. The line components of
the rare earths appear as sharp, weak,
shortward-displaced features that first
increase and then decrease in strength
as they move longward.
From measurements of the displace-
ments of resolved Zeeman patterns in the
spectrum of HD 215441, Preston has
found evidence for a periodic variation
of the magnetic field. The field appears
to oscillate with a range of about 3000
MOUNT WILSON AND PALOMAR OBSERVATORIES
119
gauss in phase with the 9.5-day light
variation. Comparison of the measured
intensities and displacements of the Zee-
man components with those calculated
for dipoles inclined to the line of sight
indicate that the magnetic field of HD
215441 is not dipolar.
Magnetic fields in excess of about 20
kilogauss are required to produce re-
solved Zeeman triplets in stellar spectro-
grams. However, magnetic fields in the
range 5-20 kilogauss can profitably be
studied by means of those cases of the
anomalous Zeeman effect in which the
most intense -k components have dis-
placements that are comparable to those
of the o- components. The result is a
doublet which, by virtue of the absence
of a central component, is more readily
resolved than is a triplet of similar pat-
tern width. A typical example is the
4P1/2-4Z>°1/2 transition Fe I A4385.38.
Preston has found such doublets in the
spectrum of 53 Camelopardalis near the
phase of positive crossover. The doublet
separations correspond to a mean surface
field over the disk of 15 kilogauss. More
recently, Preston has found a number
of such doublets on very high-dispersion
spectrograms of (3 Coronae Borealis at
the phases of positive and negative cross-
over. The mean surface field derived
from these doublets is 6 kilogauss at
these phases. Within the framework of
the oblique-rotator theory, it can be
shown that this mean surface field is
compatible with the period, v sin i, and
the maximum value of the effective
longitudinal field ( + 1000 gauss) if the
star is viewed at small inclination and if
the magnetic axis lies near the rotational
equator.
Preston is using Zeeman doublets to
study the large (~15 kilogauss) mag-
netic field of HD 126515. Both the mean
surface field and the effective field of this
star appear to vary smoothly in a period
of 130 days.
Stepien (Astrophys. J., 154, 1968) re-
cently reported that HD 19216 (HD
spectral type B9) is a variable star with
a period of 7.7 days and with V, B — V,
and U—B variations similar to those of
a number of Ap stars. Palomar coude
spectrograms (dispersion 9 A/mm) ob-
tained by Preston show that HD 19216
closely resembles the B9 V standard star
v Capricorni. However, the lines are ex-
ceedingly sharp (v sin i < 10 km/sec).
Thus, HD 19216 appears to be an ex-
ample of a normal late B-type star with
two of the secondary characteristics of
the Ap star; viz., slow rotation and a
periodic photometric variation.
Preston is obtaining rotational veloci-
ties from coude spectrograms of all
known Ap stars brighter than the 9th
magnitude and north of 8 =—40°. The
purpose of the program is to delineate
better the rotational velocity-distribu-
tion functions for the various subclasses
of Ap stars.
Preston is also surveying the spectra
of a large number of B0-B5 stars (dis-
persions ~20 A/mm) to determine the
frequency of occurrence of stars like 3
Centauri A in this interval of spectral
type. Rotational velocities are being de-
termined as a by-product of the program.
Miss Judith Cohen has discussed re-
cent observations by Deutsch, Oke, and
Greenstein of the continuum and the
line spectrum of the magnetic-variable
star a2 Canum Venaticorum. She finds
!Te = 12,000oK and log 0 = 4.0, with abun-
dances ranging from <0.05 the normal
value for helium to >106 times the nor-
mal value for europium. Her analysis
takes into account the strong spectrum
variation and is consistent in all respects
with a rigid-rotator model. The chief
problems that remain are the variations
of color with phase, which differential
line-blanketing cannot explain, and the
unknown process that concentrates the
elements in different areas over the sur-
face of the star.
Kodaira and Unno (of Tokyo) re-
examined the oblique-rotator model for
a2 Canum Venaticorum by analyzing Si
II AA4128, 4130 on high-dispersion
spectra with four polarimetric strips,
120
CARNEGIE INSTITUTION
taken at Okayama. They determined the
position angle and effective longitudinal
magnetic-field strength for the lines of
force. The solution is well represented
by the oblique-rotator model developed
by Bohm-Vitense, which also predicts
the strong variations of the profiles of
Eu II (A4129) and Cr II AA4555, 4559.
The star 38 Draconis, which Eggen has
described as "the brightest horizontal-
branch star in the old disk population,"
was found by W. L. W. Sargent and
Adelman to be a new Mn-type peculiar
star. A quantitative analysis revealed
several composition anomalies, including
excesses of Mn, Y, and Zr.
The study of neon lines in Ap stars by
A. I. Sargent, Greenstein, and W. L. W.
Sargent shows that neon is detectable
only in the hotter objects. In those with
temperatures above 13,000°K, indicated
by Q from colors, they find that neon
shares the deficiency of helium, carbon,
and oxygen. In the A4200 Si II stars, the
deficiency of neon exceeds a factor of 3 ;
the Mn stars may also be neon-deficient.
Earlier work on deficiencies of He, C,
and 0 is confirmed.
Kodaira observed the continuous
energy distribution of HD 221568, period
159 days. When the star was red, it
showed a flux excess in the visible to
near-infrared, and a deficiency in the
blue. Broad depressions exist at AA4200,
5300 and in the red phase at A6300. An
unknown opacity source perturbs the
B9 IV-V continuum when the star is in
the red phase. Work continues with
Peterson.
In addition to examining the effects
of C I and N I opacity in the Balmer
continuum, D. M. Peterson has also in-
vestigated the effects of silicon bound-
free absorption on the emergent flux of
the Ap stars. It now appears that at
higher temperatures (Te > 13,000°K),
Si II is a more important opacity source
in the ultraviolet than Si I. Thus the
effects of enhanced silicon abundance on
the atmospheres of these stars are sig-
nificant to much higher temperatures
than originally suggested by Strom.
Furthermore, in those stars with vary-
ing silicon abundance over the surface,
the changing ultraviolet opacities pro-
vide a natural explanation for light vari-
ability through the rotation of the ob-
jects. Thus, it is not necessary to assume
a variable effective temperature over the
surface of the star nor a deformation of
the star due to the pressure of magnetic
fields. To first order, i.e., moderate over-
abundances, the increased ultraviolet
opacity acts simply to backwarm, and
the light and color variations appear as
if due to effective-temperature varia-
tions. With increasing overabundance,
however, the ultraviolet metal continua
begin to contribute significantly to the
flux derivative and hence tend to lower
the surface temperature. This affects
only the strong features in the star. In
particular, the cores of the hydrogen —
and in cooler stars, calcium — line profiles
become wider and deeper. The primary
effect on the colors of the objects is to in-
crease U and V more rapidly than the B
magnitude, which is most sensitive to
the hydrogen-line absorption. In excep-
tional cases, the flux shortward of the
Balmer discontinuity may be affected
also.
Finally, in the cooler Ap objects, large
overabundance will allow silicon to con-
tribute significantly to the opacity in
the visual regions of the spectrum. HD
221568, as recently observed by Kodaira,
seems to represent an example of such an
object.
Pulsation of /x Cephei
From coude spectrograms of fx Cephei,
Deutsch has found this M2 la star to be
in radial pulsation with a period of 1100
days. The amplitude of light variation
is known to be small, and other periods
also occur in the light curve in addition
to the 1100-day cycle. The phase relation
between the changes of radial velocity
and brightness is the same as in classical
MOUNT WILSON AND PALO MAR OBSERVATORIES
121
Cepheids, with maximum expansion
velocity near maximum brightness. If
the mass of /x Cephei is about 12 9ft©, its
pulsation constant Q ~ 0?06, in accord
with theoretical estimates.
The pulsation of fx Cephei is unique be-
cause of the large amplitude (in R) and
the pronounced stratification effects. The
radius of the star is ~lxl03 R0 and, if
the reversing layer moved with the gas,
the pulsation amplitude would be
~R»/5. The strong lines that originate
higher in the atmosphere systematically
lag behind the velocity curve of the
weaker lines by ~90° in phase, and their
velocity amplitude is only about half as
large. At the greatest heights, the cir-
cumstellar envelope produces at least
two distinctive sets of absorption lines
from zero-volt energy levels; these lines
appear to have constant velocities of
expansion.
M Giants: B aimer-Line Intensities
Deutsch, Keenan, and Wilson last year
noted that the absorption lines at Hy
and H8 are subject to large intensity
variations in the spectrum of HR 6128,
and M2.5 III star with a relatively high
velocity. Now Deutsch has found that
the M2 and M3 giants are a generally
heterogeneous group with respect to their
Balmer-line intensities. The differences
among stars are least at Ha and increase
toward the higher Balmer lines, with He
going over into emission in some weak
Balmer-line stars. The M2 III stars show
other differences in the metallic lines on
the damping part of the curve of growth.
These lines are systematically weaker in
some stars than in others — a result like
that recently found in the K giants by
Spinrad and Taylor. Differences also
occur in the doubly reversed profiles of
Ca II H and K. On a time scale of
months, some M giants show large
changes in the Balmer lines, and Deutsch
has some evidence as well for variations
in the damped metallic lines and in the
H and K reversals. The correlations
among these features are not yet clear,
but it seems that the Balmer lines and
the Ca II emissions do not vary together,
although both originate in the stellar
chromosphere.
Mass Loss
Red giant stars of the Mira variable
class include both R Andromedae and
R Cygni of the Se type. Tsuji finds
circumstellar lines of K I and Rb I to
be quite strong. In R And the expansion
velocity is 23 km/sec; the doublet ratio
gives a Doppler parameter of 2 km/sec
for the Rb I atoms, and a surface density
of 4X1011 cm-2. From his earlier work
on shock fronts in this atmosphere, Tsuji
concludes that the circumstellar envelope
is matter ejected in the previous pulsa-
tional cycle. From the normal Rb/H
ratio he finds a total mass loss of 10~5
2tf© per year. So rapid a mass loss sug-
gests that an S star can last only 105
years, consistent with the presence of
technetium in its atmosphere.
Tsuji also obtained spectral scans of
20 carbon stars between 0.4 and 1.1 /x
to study the opacity in these stars and
to interpret the ultraviolet depression.
O-Type Stars
D. M. Peterson has prepared a series
of opacity subroutines for computer cal-
culation of the first four ionization states
of C, N, 0, and Ne utilizing the most re-
cent "quantum defect" and "close cou-
pling" calculations of the bound-free
cross-sections. These elements represent
important sources of opacity in stars
sufficiently hot to emit a substantial
amount of their flux shortward of the
Lyman discontinuity. In addition, C I
and N I have been found to be im-
portant opacity sources between A1440
and the Lyman discontinuity for stars as
cool as the sun. Further computer pro-
grams are being prepared to calculate the
effects of departures from LTE in hydro-
gen and helium in stellar atmospheres.
In collaboration with M. Scholtz, these
122
CARNEGIE INSTITUTION
programs will be used for the construc-
tion of realistic model atmospheres to
be used in the analysis of 0 stars.
Rapid Variable, HDE 310376
Observations of a rapid variable simi-
lar to Scorpius XR-1 have been made
at the Cerro Tololo Interamerican Ob-
servatory by Schild. The star, HDE
310376, exhibits brightness fluctuations
of the order of 0.1 mag in 90 sec and
also shows some night-to-night varia-
tion. No appreciable color change ac-
companies the rapid brightness fluctua-
tions. The spectrum of the star varies
from night to night. It is ordinarily
nearly continuous with emission at A4650
and A4686, similar to that of Sco XR-1.
A hydrogen absorption spectrum is some-
times weakly present; when it is at
maximum strength, a faint helium spec-
trum characteristic of a B5 star is ob-
served. If Sco XR-1 is to be understood
as a hot star below the main sequence,
surrounded by a hot plasma, HDE
310376 may be similar in most respects,
except that the plasma is less well de-
veloped.
Line Identifications
Spectra of the southern slow nova RR
Telescopii (A. D. Thackeray, Monthly
Notices Roy. Astron. Soc, 113, 211,
1953, and 115, 236, 1955) have proved
a fascinating source of unidentified emis-
sion lines. Recently, Thackeray of the
Radcliffe Observatory in South Africa
identified several strong lines as forbid-
den transitions in the ground configura-
tion of Fe IV. Lambert, in collaboration
with Thackeray, has identified four other
lines as forbidden transitions in the
ground configuration of Ni IV. The
newly identified lines include A5041.6,
which has long been a prominent and
unidentified line in the spectra of peculiar
emission-line objects. The relative inten-
sity of the [Ni IV] and [Fe IV] emission
lines is qualitatively consistent with a
normal solar abundance ratio N(Fe)/
N(Ni)=0.05.
Spectrophotometry of Symbiotic Stars
The Cassegrain scanning spectrometer
has been used by Lambert at the 60-inch
and 100-inch telescopes to measure the
flux distribution for several symbiotic
stars. The observations extend from
AA3300 to 11000 and include measures
of prominent emission lines. In 1967,
five stars were observed: CH Cygni,
AG Pegasi, Z Andromedae, AX Persei,
and BX Monocerotis. The program is
continuing and T Coronae Borealis and
MH 2328-116 were observed in 1968.
Reddening Determination
Racine, in collaboration with R. D.
McClure of Kitt Peak National Ob-
servatory, has developed an accurate
reddening-determination method based
on broad- and intermediate-band pho-
tometry of late-type giants. Application
of the method to four high-galactic-
latitude fields gave E{B-V) =0m00±
0™02 m.e. for the globular clusters M3
and M13, and E{B-V) =0™ll±0m02
and 0n?03±0?02 for the spirals M31 and
M33, respectively.
Peculiar Objects
Oke, Neugebauer, and Becklin have
used an infrared photometer and the
multichannel spectrometer to study the
peculiar object BL Lacertae, which is
also a radio source. No spectral features
were detected, so that no redshift was
determined. The spectral-energy distri-
bution suggests that the radiation is
largely nonthermal.
INFRARED STELLAR SPECTROSCOPY
Infrared Sources
Many of the reddest objects identified
on the infrared sky survey have been
measured photometrically by Becklin
and Neugebauer from 1.2 to 3.5 fx on
the 24-inch, 60-inch, and 100-inch Mount
Wilson telescopes. These measurements
are now being extended to 5 and 10 /*
MOUNT WILSON AND PALOMAR OBSERVATORIES
123
and have resulted in the discovery of
several very bright 10-/* sources.
The most interesting source so far
discovered is IRC + 10216, which is the
brightest object known at 5 ^ outside
the solar system, while its visual magni-
tude is probably fainter than 19 mag.
Photometric measurements from 1.2 to
20 fi and spectra in the regions 1.6-1.8 /x,
2.1-2.5 ix, 3.3^.0 ft, 4.5-5.5 fx, and 8.5-
13.5 fi have been made by Becklin,
Frogel, Hyland, and Neugebauer. The
energy distribution is close to that of a
600 °K blackbody, and no molecular ab-
sorption features have been found in the
spectra. The object lies in an unreddened
field in Leo, and appears elliptical on a
48-inch schmidt plate and also on a
200-inch E plate taken by Arp. The exact
nature of this peculiar object is un-
known.
Orion Nebula
For some time it has been known that
the Orion nebula has a rather different
distribution of light in the infrared than
would be indicated by visual photo-
graphs. Accordingly, a study of this
anomaly has been undertaken. Hilge-
man has obtained infrared spectrometer
observations of the nebula during 11
nights on the 60-inch telescope at Mount
Wilson, and photometric observations
from 1.2 to 5 ft on the 24-inch telescope.
The analysis of these data is being un-
dertaken to obtain information on vari-
ous physical properties of the nebula,
such as electron temperature, electron
density, dust temperature, gas-dust ratio,
and particle-size distribution. An aver-
age electron temperature of 5700 °K has
been derived for the central 4' region,
and there is a suggestion that the elec-
tron temperature increases with distance
from the center. The small optical depth
at 2 ix has enabled Hilgeman to derive a
nebular reddening from the infrared to
visual hydrogen-line ratios, and he ob-
tains a value similar to that found for
the trapezium stars. From the He I
1.70-fx triplet line, he has derived an
abundance of helium lower by approxi-
mately a factor of 2 than that found
from the visual observations.
Galactic Center
New observations of the nucleus of
the Galaxy in the wavelength region be-
tween 1.65 and 19.5 fx have been made
by Becklin and Neugebauer. The 10- and
20-/X radiation originates in a source ap-
proximately 1 pc in diameter. The energy
distribution of the galactic-center source
is similar to that measured in the
nuclei of Seyfert galaxies (F. Low and
D. Kleinman, Astron. J., 73, 868, 1968).
Unfortunately, the observations cannot
be used to distinguish between two pos-
sible mechanisms for producing the in-
frared radiation: (1) thermal reemission
of starlight by dust and gas, and (2) non-
thermal radiation.
OH Sources
Infrared photometry to 20 ^ and
spectra in the 2-2. 5- fx region have been
obtained for several infrared stars as-
sociated with OH radio emission. One of
the OH sources associated with an infra-
red star, VY Canis Majoris, has been
found to be one of the brightest sources
in the sky at 20 fx. This source has been
studied in detail by Hyland, Becklin,
and Neugebauer in collaboration with
George Wallerstein of the University
of Washington. Spectra at optical and
infrared wavelengths indicate that it is
a supergiant with an effective tempera-
ture of 2500-3000°K. Its OH emission,
near infrared spectra, and far infrared
energy distribution are similar to those
of the NML Cygnus source, but visually
it is 10 mag brighter. A simple dust-shell
model is proposed to explain the observa-
tions of VY CMa. Reradiation of energy
by the shell is found to be the predomi-
nant source of radiation for wavelengths
longer than 3 fx. The currently available
evidence favors the interpretation that
VY CMa and NML Cyg are evolved
stars.
124
CARNEGIE INSTITUTION
Red Stars
The f/5 Ebert-Fastie spectrometer has
been used by Hyland and Frogel on 30
nights at the Mount Wilson 60-inch and
100-inch telescopes and on 3 nights at
the Cassegrain focus of the 200-inch.
Most of the spectra obtained have been
of the 2.1-2.5-/* and 1.5-1.8-/* regions
with resolutions of 32.5 A and 65 A. Some
have been taken in the 2.6-4.0-/* region.
The major areas of study have been:
1. Spectra of the very red stars identi-
fied from the 62-inch 2-/* survey have
been obtained for classification purposes.
The infrared sources that have been
identified also as 1612 mHz OH sources
have been studied in some detail. Several
of these, unlike the NML Cygnus source
and VY CMa, appear to have many of
the characteristics of normal late-type
Mira stars.
2. Two-micron spectra of Mira varia-
ble stars are being studied around their
cycles to monitor changes. Several strik-
ing changes have been found among as
yet unidentified molecular bands. These
spectra have proved to be very useful in
classifying the spectra of the OH sources.
3. Spectra of M0-M5 supergiants
have been studied to aid in luminosity
classification for late-type stars. The
strength and shape of the 2.3-/* CO bands
prove to be excellent luminosity criteria,
especially for the earlier M stars.
Image-Converter Spectra
Zirin has continued his studies with
the single-stage image converter at the
coude focus of the 200-inch telescope of
late-type stars evincing chromospheric
activity by absorption or emission in the
A10830 helium line. A number of these
stars have been found to change with
time: e Geminorum, which showed
A10830 in emission is now in absorption ;
a strong emission line is now exhibited
by 12 Pegasi, which once showed very
slight emission. These stars are being fol-
lowed. An interesting sidelight on these
investigations has been the comparison
with observations of the CN bands at
AA10867 and 10914. The infrared spectro-
grams that have been extended to this
region show strong CN absorption in e
Gem and 6 Herculis, two of the stars
with strongest chromospheric activity.
According to the Redman and Griffin
catalog, these two stars had abnormally
strong CN absorption in the visual re-
gion. In fact, Redman and Griffin pointed
out that absolute-magnitude differences
do not suffice to explain the great in-
tensity of the CN band in these and
other stars. This observation suggests
that the CN-band intensity may be a
measure of chromospheric activity in
stars.
ABSOLUTE SPECTROPHOTOMETRY
The program of absolute calibration
of the flux of a Lyrae is being continued
by Oke and Schild. The 4-inch telescope
and scanner, together with the portable
data system, are being routinely used in
observations of standard stars and fun-
damental sources.
A new fundamental source in the form
of a blackbody cavity operated at the
temperature of the melting point of
copper has been constructed. The new
source utilizes a pure copper sample sup-
plied by the National Bureau of Stan-
dards. The sample is contained in graph-
ite crucibles, and the blackbody cavity is
immersed in the copper. The copper
sample is heated to its melting point by
a resistive wire surrounding the crucible.
Observations made when the copper
sample is being melted and being frozen
are in excellent agreement.
An additional new standard recently
acquired will permit the calibration to
be related to the fundamental sources
maintained by the Bureau of Standards.
The new source is in the form of a tung-
sten-filament lamp which has been ac-
curately calibrated at a number of wave-
MOUNT WILSON AND PALOMAR OBSERVATORIES
125
lengths by comparison with the gold
furnace maintained by the Bureau. Ob-
servations of the new source will be
made in the coming months.
Three sources are now available for
the calibration of a Lyrae. The platinum
furnace is effective from A3500 to the
near infrared and has been used exten-
sively. The copper furnace is too cool to
be used shortward of A6000, but it pro-
vides an important check on the red
and infrared calibration. The calibrated
lamp has sufficient flux to be used at all
wavelengths.
A new calibration based on observa-
tions of the two blackbody sources and
a Lyrae has recently been completed.
The platinum furnace was observed from
AA3500 to 11400, and the copper furnace
was observed from AA6000 to 11400.
Agreement of the two furnaces is excel-
lent in the region of the overlap. The
new calibration substantiates the revi-
sion recently suggested by Hayes (thesis,
University of California, 1967) from
AA4000 to 7000, but suggests that the re-
vision is too great in the infrared. The
new calibration is still uncertain in the
ultraviolet.
The 4-inch telescope is being used
extensively for observations of bright
stars and extended composite sources.
Observations of a number of bright el-
liptical galaxies in the Coma and Virgo
clusters have been obtained. The energy
distributions of these ellipticals are strik-
ingly similar to one another but suggest
important differences from that of M67.
A number of bright globular and galactic
clusters have been measured also. These
energy distributions will be compared
with one another, and also with synthetic
energy distributions derived from energy
distributions of individual stars added
together with a weighting function based
on density in the H-R diagrams.
STAR CLUSTERS
Main-Sequence Gap and Age of NGC 188
Eggen and Sandage completed discus-
sion of photoelectric data for the old
galactic cluster NGC 188. New UBV
measurements by Eggen with the 200-
inch were combined with the original
data of Sandage to provide high weight
for stars in the magnitude range 16 >
V>11. A gap on the evolving main se-
quence was located between 4.33 >
Mv > 4.53. The feature represents hy-
drogen exhaustion at the center of evolv-
ing stars, followed by gravitational con-
traction and the subsequent firing of a
hydrogen shell immediately outside the
helium-rich core. The presence of the gap
is important for stars of such faint abso-
lute magnitude and such small mass be-
cause it fixes some combination of the
stellar opacity, the core temperature, or
the ratio of the p-p to CNO reaction
rates. Early theoretical calculations of
evolutionary models by Iben, Demarque,
and others failed to predict a gap using
either Keller-Meryott opacities or a spe-
cial set of values without line opacity.
Later models by Demarque, Miller, and
Aizenman using Cox's opacities with
lines have now produced a gap, con-
sistent with the present observations.
Sandage and Eggen calculated a set
of theoretical isochrones in the H-R dia-
gram using models by Iben and by Aizen-
man, Demarque, and Miller. Comparison
with the new observational data gives
ages of T- (9.5 ±0.5) XlO9 years using
the Iben models, or T = 7.7 XlO9 years
with the ADM models.
A slight ultraviolet excess is present
for main-sequence stars, amounting to
8 ~ 0.03 mag relative to the Hyades. A
normal interpretation in terms of a
mental deficiency is uncertain in view of
Spinrad and Taylor's results of strong
metal lines for giant stars in NGC 188.
The problem presents an important and
unsolved anomaly.
The new color-magnitude diagram for
NGC 188 was combined with that for
126
CARNEGIE INSTITUTION
M67 (with the recent extension of its
giant branch incorporating bright stars
found to be members by C. A. Murray's
proper motion studies) and with other
old to intermediate age clusters to form a
new composite color-magnitude diagram.
The funnel effect is well shown — all giant
branches converge to a common region
and presumably terminate on the Ha-
yashi limiting sequence. A new effect ap-
pears to be present in the observations,
as predicted by the calculated isochrones.
Near Mv= + 3, the main sequences cross
over one another due to the special con-
ditions at the phase of hydrogen ex-
haustion in the core. In this luminosity
region the slopes of the evolving main
sequences near the termination point are
not monotonic functions of age. New
data are needed to establish positively
the reality of the effect.
Reddening, Helium Abundance, and Age
Difference of MS, MIS, M15, and M92
Sandage completed the analysis of
photoelectric data for blue horizontal-
branch stars in the four globular clusters
M3, M13, M15, and M92. The data had
previously been obtained with the 200-
inch between 1959 and 1967. Reddening
values were obtained from the U—B,
B — V diagrams, interpreted by using
Mihalas' calculations of 7(A) for line-
blanketed B, A, and F stars over the
relevant range of log g. The low values of
E(B — V) derived in 1964 were confirmed
at 0.00 mag for M3, 0.03 mag for M13,
0.12 mag for M15, and 0.02 mag for M92.
New photometric data of the main-
sequence termination colors of these
clusters, corrected for differential line
blanketing and reddening, agree to within
0.01 mag in {B — V)°, c, indicating equal
ages for M15 and M92, and M3 and
M13 separately to better than At/t <
0.03, or At < 3xl08 years, in agreement
with the galactic collapse model.
The blue-boundary colors of the RR
Lyrae instability gap in the C-M dia-
grams of M3, M15, and M92 are all
within 0.025 mag of (B-V)°, c = 0.175
mag when reddening and differential
blanketing corrections (to the A*S = 6 line-
blanketing system) are applied. The
difference in mean period between the
Oosterhoff-Sawyer groups cannot then be
due to a temperature difference, but may
arise from a luminosity difference of
AMF~0.3 mag, as previously supposed.
From R. F. Christy's calculations, the
color of the blue boundary of the RR
Lyrae gap was found to depend on My,
%)}/fflto, Te, and the helium abundance as
Y= -3.138 0e-O.34 Wl/Wle-
0.16My + 2.830.
Use of this equation with the new ob-
servational data for horizontal-branch
stars gives a mean helium abundance of
y=0.32±0.09 (total range). The helium
abundances for M3, M15, and M92 are
the same to within the observational
error despite the large differences in
metal abundance among the clusters.
If this is a valid way to determine Y,
enough information is available, in prin-
ciple, to make a proper photometric fit
of the four globular clusters to the ap-
propriate age-zero main sequence (whose
position is a function of Y and Z) to
obtain thereby a theoretically correct
age determination. An analysis of the
new photometric data has been started
using these precepts.
Photometry of Southern Globular
Clusters
Direct plates of <o Centauri, 47 Tuca-
nae, M4, and NGC 6398 in B and V were
obtained by Sandage at the f/8 Cas-
segrain focus of the Siding Spring 40-
inch reflector to study fine-structure of
the C-M diagrams. Preliminary mea-
surements of 1000 stars in 47 Tuc on one
pair of plates indicates the presence of
gaps along the giant branch at 7 = 13.3
and 7=12.8. They are similar to gaps
reported last year in M15. The horizontal
branch in 47 Tuc occurs at 7=14.0,
giving A7=0.7 and 1.2 mag for the gap
MOUNT WILSON AND PALOMAR OBSERVATORIES
127
positions relative to the horizontal
branch. The gaps in the much more
metal-poor cluster M15 had previously
been found at A7=0.3, 0.9, and 2.0.
A four-color (UBVR) photoelectric
sequence was obtained in M4. Measure-
ment of this cluster, together with <o Cen
and 47 Tuc, should provide more com-
plete data on the gaps because these
clusters are among the most populous in
the Galaxy, thus providing adequate
statistics.
NGC 6397 and <o Centauri
Searle, in collaboration with Dr. A. W.
Rodgers and E. B. Newell of Mount
Stromlo Observatory, completed a study
of the blue horizontal-branch stars in
the globular clusters NGC 6397 and w
Cen. The surface gravities and effective
temperatures of these stars were obtained
from an analysis of spectroscopic and
photoelectric observations. This work
located the horizontal-branch stars in
the theoretical Hertzsprung-Russell dia-
gram and facilitates a comparison of
observation with the predictions of the
theory of stellar interiors. The mass-to-
luminosity ratio of these stars is also
determined. It is log Wl/Q=-2.0 (in
solar units) and appears to be the same
in both clusters and constant along the
horizontal branch. This value, combined
with measurements of the cluster redden-
ings and distance moduli, leads to a mass
determination $Z = 0.55 2ft© for the glob-
ular cluster horizontal-branch stars.
INTERSTELLAR GAS AND GASEOUS NEBULAE
Interstellar Absorption Lines
Profiles of the interstellar K line in a
number of stars of high galactic latitude
are being obtained by Rickard with the
scanning Fabry-Perot spectrometer at
the 100-inch telescope with a resolution
of 50,000. Several stars brighter than
7 = 7.0 mag previously observed photo-
graphically have been studied with the
purpose of detecting high-velocity clouds
off the galactic plane, which may be de-
tected also in 21-cm line radiation.
Interstellar Matter
An analysis of interferometer observa-
tions by Vaughan and Dr. I. J. Danziger
of Harvard College Observatory in a
search for interstellar lithium in the di-
rection of the star £ Ophiuchi has been
carried out. The observations were de-
signed on the assumption that lithium,
if present, and interstellar Na I may be
distributed alike in radial velocity in the
direction of the star. If the hypothesis
is correct, the present observations imply
an upper limit for [Li7/Si] that is within
a factor 2 of the value for chondritic
meteorites. Further observations to test
this result are planned.
Galactic Emission Nebulae
The spectrum of emission nebulae in
the region of the Paschen 12 line of hy-
drogen, at A8750, is being studied by
Rickard and Munch with the purpose of
verifying the detection of an H2 quadru-
ple emission line recently reported. An
interference photometer specially con-
structed for the purpose is being used at
the Cassegrain focus of various tele-
scopes. To date, only the H II region of
MS has been studied in some detail, and
no indications for the presence of the
H2 line have been found.
INFRARED SKY SURVEY
During the current report period the
catalog of the survey for objects that
radiate at 2.2 p was completed (G.
Neugebauer and R. B. Leighton, Two-
Micron Sky Survey, A Preliminary Cata-
log, National Aeronautics and Space Ad-
ministration, Washington, D. C, 1969).
The infrared catalog includes a total of
128
CARNEGIE INSTITUTION
5600 objects north of declination —33°,
of which approximately three quarters
have been previously identified in the
catalog of the Smithsonian Astrophysical
Observatory; this catalog includes stars
with visual magnitude brighter than
about 7=10.
Preliminary analyses of the catalog
data have been undertaken and were
incorporated in the thesis of E. E.
Hughes. These showed that the reddest
stars observed in the survey could be
seen to distances of roughly 2 kpc. About
200 extremely red stars form an excess
concentration within one or two degrees
of the galactic equator. These excess stars
are interpreted as being supergiants
which are seen to about 5 kpc. The long
baseline available also enabled Hughes
to get an estimate of the gradient of late-
type stars in the Galaxy.
With the effective completion of the
survey catalog, the 62-inch infrared tele-
scope was utilized primarily in two pro-
grams :
1. The normal 2.2-/* survey has shown
that certain of the extremely red stars
vary by as much as 2 magnitudes at
2.2 fx. Although the time-scale of these
variations is generally about a year, very
rapid changes have been noted. Some
200 selected red stars were observed
nearly every second night during the
summer. The merging of this data with
that extending over a four-year period
has yielded valuable information on the
variability of these stars.
2. Certain regions of the sky are
clearly of greater potential interest than
others with respect to investigation of
galactic structure. A program was under-
taken to examine five selected areas with
a slower scanning speed and conse-
quently higher sensitivity than was used
in the normal survey. The data from
these areas are now being reduced.
GALAXIES
Nucleus of MSI
Photoelectric photometry of the cen-
tral ±120" of M31 was completed by
Sandage, Becklin, and Neugebauer using
the 200-inch, 100-inch, and 60-inch tele-
scopes. Intensity profiles with 5" resolu-
tion were obtained from A=0.36 fx to
A = 2.2 ix along the major and minor axes
and along an east-west line passing
through the center. A steep radial color
gradient was found in U — B in the range
40" >|r|>0, but there was no evidence
for a gradient at longer wavelengths.
The color varies from U — B = 0.79 at the
center to t/-£ = 0.60 at |r|=60". The
effect is interpreted either as (1) a
gradient of metal abundance, such that
stars at the center are more metal-rich
than stars farther out, or (2) a change
in the ratio of giants to dwarfs in the
stellar-luminosity function, such that the
CN break at A3889 is progressively di-
luted by increasing dwarf light as one
approaches the center. The existence of
the gradient shows that no radial-orbit
mixing occurs in the center of M31;
otherwise, the effect, once established,
would be destroyed in several mixing
times. This is taken as proof that stars
within |r|~40" of the nucleus of M31
move in predominantly circular orbits.
Combining the I\r\ distributions in the
blue and visual regions with those at
1.6 ix and 2.2 fx shows that M31 has no
excess nuclear infrared radiation as is
present in some Seyfert galaxies and re-
lated objects. The conclusion rests on the
similarity of the I\r\ distributions over
all wavelengths.
The measured surface brightness at
the center of M31 at 2.2 fx, averaged over
the central 13 pc (17//62 along the diam-
eter), is 2.2 X10-28 Wm-2 Hz-1 (D")~x.
This is a factor of 2.4 fainter than that of
the galactic center (measured several
years ago by Neugebauer and Becklin),
averaged over the same equivalent linear
diameter.
OUNT WILSON AND PALOMAR OBSERVATORIES
129
Globular Clusters in MSI and Fornax
Van den Bergh has used the 200-inch
telescope to obtain classification spectra,
radial velocities, and UBV photometry
for the brightest clusters in M31. The
principal results of this study are:
1. The average metallicity of globular
clusters in the Andromeda nebula, as
determined from spectroscopic line
strengths and the photometric metal-
licity parameter Q, is significantly higher
than it is in the Galaxy.
2. There is no clear-cut evidence for
a dependence of cluster metallicity on
position. Some quite strong-lined clusters
occur far out in the halo of M31.
3. Most of the stars in the inner halo
of M31 are not extremely metal poor.
Available evidence indicates that the
globular clusters in M31 are systemati-
cally brighter than are those in the
Galaxy and in M87. This suggests that
considerable caution should be exercised
in using globular clusters to determine
the extragalactic distance scale.
Van den Bergh finds that Baade's best
200-inch plates provide evidence in favor
of the view that the red giants in M31
globulars obey the same relation between
metal abundance and luminosity as do
their counterparts in galactic globular
clusters.
Observations of the highly reddened
cluster B327 in M31 suggest that
Av/E B..v<3.0 in the Andromeda nebula.
Comparison of the colors of galactic
and M31 globulars with similar spectra
yields a galactic foreground reddening
EB-V (BO) =0.09 ±0.02 m.e. in the direc-
tion of the Andromeda nebula.
Spectroscopic observations by van den
Bergh of the globular clusters associated
with the Fornax system show that the
Fornax globulars exhibit a significant
range of metallicity and that the average
metal abundance of the globular cluster
in Fornax is very low.
Red Supergiants in the Magellanic
Clouds
Sandage began a survey for the bright-
est red supergiants in the Large and
Small Magellanic Clouds, using a 5-inch
Zeiss chart-camera and the Uppsala
20/26-inch schmidt telescope at Mount
Stromlo. Previous work on NGC 2403 by
Tammann and Sandage (reported in
Year Book 66, p. 280) suggested that
such stars redder than B — V~2.0 mag
reach a stable upper luminosity of Mv —
— 8.0, which, if true, will provide a new
distance indicator useful in the calibra-
tion of the Hubble constant.
Blue and yellow plates covering the
complete area of the Clouds were taken.
Plates taken with the Zeiss 5-inch give
for the Clouds a relative scale and reso-
lution similar to 100-inch plates of M33.
The plates were blinked by Peter Hooper
and Anthony Wier (summer vacation
scholars at Mount Stromlo), and sev-
eral hundred red supergiants were lo-
cated. Preliminary photometry relative
to known photoelectric sequences in both
Clouds show that MF~— 8.0 applies to
the LMC, whereas the brightest red stars
in the SMC are about 1 magnitude
fainter. This suggests that Mv for the
brightest red stars is a function of total
magnitude of the galaxy. The relation
AfF=/(Af totai) can be calibrated by com-
bining these data with those from dwarf
Sm and Im galaxies in the M81 group
(NGC 2366, IC 2574, HO I, HO II),
together with members of the Local
Group. Sandage and Tammann have be-
gun this more extended phase of the
work. When the calibration is complete,
it is expected that good distances can be
obtained for field galaxies to the modulus
limit of m — M~29, as a continuing step
toward the Hubble constant.
The Virgo Cluster
Using the 48-inch schmidt and Kodak
IHa-J emulsions, Racine has completed
a survey of the Virgo cluster to a limiting
magnitude of £~23.0. This homogene-
130
CARNEGIE INSTITUTION
ous material allows the detection of the
globular clusters of many cluster galaxies
and will be used to study the dependence
of the luminosity of these globulars on
their total population, on the parent-
galaxy type, and to assess their value
for the determination of the extragalactic
distance scale. Preliminary results seem
to indicate that NGC 4486 (M87) has by
far the largest population of globular
clusters and that its brightest clusters
are appreciably more luminous than
those of any other galaxy in Virgo.
Galaxies in Chains and Small Groups
Sargent has completed work on the
determination of redshifts of galaxies in
chains and small groups. Most of the
systems studied are illustrated in Arp's
Atlas of Peculiar Galaxies. In Year Book
67 (p. 35), Sargent summarized results
for the systems VV 144, 150, 165, and
172. During the present year, he deter-
mined redshifts for 4 galaxies in the NGC
833 group, 4 in the VV 169 group, 7 in
the VV 282 group, 3 in the VV 159 group,
5 in the NGC 6027 sextet, 6 in the chain
Arp 330, 3 in the VV 197 group, 5 in the
VV 101 group, and 3 in the VV 208 group.
In addition, UBV photometry was ob-
tained for galaxies in the NGC 833
group, VV 161, VV 169, VV 282, VV 165,
VV 159, NGC 6027 sextet, and VV 208.
Only one group was found to have a
galaxy with a strikingly discrepant ve-
locity similar to VV 172 described last
year. This is the NGC 6027 group, other-
wise known as Seyfert's Sextet. It has
been described by Seyfert {Publ. Astron.
Soc. Pacific, 63, 72, 1951) who published
a photograph obtained by Baade with
the Hale telescope. Seyfert also quoted
Baade's opinion that two of the galaxies
in this group (c and d in Seyfert's illus-
tration) were field galaxies because,
unlike the remaining members, they did
not show signs of tidal distortion.
Sargent finds that four of the galaxies,
including c, have redshifts near 4000 km/
sec, but that d has a redshift of
19,885 km/sec. On grounds of angular
size, Sargent concludes that this object,
a spiral, is probably a background
galaxy. Sargent finds that one chain,
VV 159, which consists of three galaxies
elongated roughly in the direction of the
line joining them, is probably not phys-
ical. The redshift of the central galaxy
differs by 2700 km/sec from the other
two. This would imply a mass-to-light
ratio of 4800 solar units for a bound
system. Application of the virial theorem
shows that rather high mass-to-light
ratios are required to bind most of the
systems; e.g., 59 for VV 165, 74 for
VV 282, 80 for VV 169, 50 for Seyfert's
Sextet (including galaxy d), and 55 for
VV 150. On the other hand, the NGC 833
group requires a more reasonable mass-
to-light ratio of about 10. This work adds
considerably to the available statistics
on galaxies in small groups.
Redshifts and Photometry of Southern
Galaxies
During the year's stay in Australia,
Sandage began a program to obtain red-
shifts and photometry of E and SO
galaxies brighter than mpg~13 south of
8 =—30°. Spectra have been obtained
with the Mount Stromlo 74-inch reflector
using the Cassegrain image-tube spectro-
graph on loan from the Department of
Terrestrial Magnetism. Photometry on a
six-color system [UBVR, 0.35-/X (UGH
filter), and 0.47-/*, (narrow-band inter-
ference filter) ] was started with the 40-
inch reflector at Siding Spring Observa-
tory.
First priority has been given to E and
SO galaxies in groups and clusters (1) to
map the local anisotropy of the general
expansion and (2) to test the depend-
ence, if any, of the absolute luminosity
of the brightest cluster or group galaxy
on group population. Solutions for the
anisotropic shear field of the local Hub-
ble flow are necessary as the next step
in finding the Hubble constant. Obser-
vations of southern galaxies are consid-
ered to be crucial for the problem.
MOUNT WILSON AND PALOMAR OBSERVATORIES
131
During the report year, Sandage ob-
tained 267 spectra of 221 galaxies.
Nearly 95% of the available southern E
and SO systems have been observed. The
reductions are not yet complete, but
preliminary indications suggest that
southern galaxies with cz<4000 km/sec
have smaller redshifts for a given ap-
parent magnitude than galaxies in the
northern hemisphere. The sense of the
anisotropy is consistent with earlier work
by de Vaucouleurs. The Hubble constant
cannot be determined adequately until
the shear field is mapped completely. It
must then be related to the expansion
parameters for redshifts greater than
4000 km/sec via the Hubble diagram at
large distances.
New Seyfert and Related Galaxy Types
A by-product of Sandage's southern
redshift program has been the isolation
of several new Seyfert-like galaxies.
NGC 1705, a particularly interesting
case, is of type E4 or SO, with a bright
starlike object displaced from the cen-
troid by about one third the apparent
diameter of the galaxy. The object was
believed at first to be a superposed fore-
ground star, but photometry showed
quasarlike colors, and spectra show
redshifted narrow emission lines of H/3,
Nl,N2,Ha, [Nil], and [SII].
Other galaxies found to show bright
emission lines are IC 4329 [SO] with very
wide H/3 and Ha (rotal widths 125 A),
but with narrow Nl, N2, [N II], and
[S II] ; and NGC 5643, NGC 5728, and
IC 5063 with intense moderately narrow
(-10 A) Ha, [N II], [S II], Nl, N2,
but moderately intense [O I, A6300],
which is uncommon in non-Seyfert
galaxies.
Flattening of SO Systems
Sandage, K. C. Freeman, and R. N.
Stokes (of the Mount Stromlo Obser-
vatory) completed a study of the in-
trinsic flattening of E, SO, and spiral
galaxies using Hubble's statistical
method. All classified galaxies brighter
than mpg=12.5 that had angular diam-
eter measurements tabulated in the Ref-
erence Catalogue were used to obtain the
distribution of apparent flattenings for
each class. The distribution of true
flattenings follows from the integral
equation of the problem.
In agreement with previous results,
spirals and SO's are equally flat with
(6/a)~0.25, distributed with a dispersion
close to o- = 0.06. Elliptical galaxies exist
throughout the entire range of intrinsic
flattenings from b/a—\ to b/a ~ 0.3,
with indications of a peak near b/a ~ 0.6.
Because flattening is a dynamical
property that cannot change in times
less than ~1014 years, the difference in
the intrinsic distribution of b/a between
E and SO galaxies shows that one form
cannot evolve into the other. The initial
conditions at the time of formation must
then have been different for the two
galaxy types.
Freeman's analysis of the photometric
properties of disks in S and SO galaxies
shows that the central surface brightness
of the exponential disks in such systems
is remarkably constant from galaxy to
galaxy, and does not vary along the
Hubble classification sequence. The only
systematic variable appears to be the
mass density of free, neutral hydrogen.
In addition to these properties, the
intensity profiles, I(r), of the spheroidal
component of S and SO galaxies and
of E systems are remarkably similar.
Furthermore, they have the form of a
pseudo-isothermal-sphere distribution,
which is a relaxed configuration. These
facts, combined with the theory of vio-
lent relaxation by D. Lynden-Bell, led
Sandage, Freeman, and Stokes to the
following conclusions:
1. Stars in the spheroidal component
of all galaxies were formed very rapidly
on a time scale comparable to the col-
lapse time of the protogalaxy (a few
times 108 years) . The argument is inde-
132
CARNEGIE INSTITUTION
pendent of that used in 1961 by Eggen,
Lynden-Bell, and Sandage based on or-
bital characteristics.
2. The halo stars were formed from
matter in the low-angular-momentum
tail of the distribution of angular mo-
mentum per unit mass, i.e., the spheroi-
dal component, during the collapse time.
Other, higher-angular-momentum mat-
ter, collapsed to a disk.
3. The galaxy type was determined
essentially by the amount of free gas left
over in the disk after collapse. No appre-
ciable evolution along the Hubble se-
quence has occurred since the galaxies
were formed.
4. The dominance of the disk in spiral
and SO systems betrays their mean an-
gular momentum per unit mass, higher
than that which exists in less flattened E
galaxies.
5. All stars in the spheroidal compo-
nent of galaxies should be of the same
age to within less than 109 years, in
agreement with observational data on
the ages of halo globular clusters in our
own Galaxy.
Markarian Galaxies
Sargent completed work begun last
year with the Cassegrain image-tube
spectrograph on the spectra of 30 Mar-
karian galaxies with ultraviolet continua.
Twenty-six of the 30 galaxies were found
to have emission lines. Two of these,
Markarian 50 and 69, are new galaxies
of the Seyfert type, with broad B aimer
emission lines and sharper forbidden
lines. Their redshifts are 2 = 0.023 for
Markarian 50 and 2 = 0.076 for 69. Mar-
karian 50 has mp — 15.5 and Mv—— 19.6,
while No. 69 has rap = 16.5 and Mp =
— 21.2. Of the 24 sharp emission-line
galaxies, only 3 have absorption lines, in
each case of early type, detectable at the
dispersion of 190 A/mm used in the sur-
vey. The remaining 21 galaxies have a
range in absolute magnitude of — 14.7 >
Mp>-21.5 with <MP>=-19.6. The
mean size is about 5 kpc and the mean
redshift about 6900 km/sec. The range in
excitation of the emission lines in these
objects is the same as in galactic H II
regions. Some of these objects are prob-
ably Type I irregular galaxies observed
at large distances.
H II Regions in Galaxies
As a necessary preliminary to deter-
mining the Hubble constant from the
sizes of the H II regions in late-type
galaxies, Kristian has completed UBVR
photometry, using the 60-inch and 100-
inch reflectors, of stars in the fields of
35 galaxies for which 200-inch Ha plates
have been obtained by Sandage. The
measurements are needed in order to
correct the size measurements for the
characteristic curve and instrumental
spread function of each plate.
Searle began a survey of the spectra
of gaseous nebulae in external galaxies,
looking for evidence that the composition
of the interstellar medium in one galaxy
differs from that in another. To establish
a standard sequence of spectra, the H II
regions in nearby Sc galaxies were sur-
veyed. With the Cassegrain image-tube
spectrograph of the Hale telescope, spec-
tra of 15 regions in NGC 2403 and 35 in
M33 were obtained.
These spectra can be classified in a
one-parameter sequence, all line ratios
being strictly correlated with, for exam-
ple, the (Nx + NJ/H/? ratio. There are
no detectable differences from one galaxy
to another. There is, however, in each of
the Sc galaxies surveyed a remarkably
strict relation between the distance of
the H II region from the center of the
galaxy and the appearance of its spec-
trum. The (N! + N2)/Hj8 ratio increases
from 0.1 to H II regions located in the
innermost spiral arms to 5 in the outer-
most regions. At a particular distance
from the center, this ratio shows only a
small scatter and is uncorrelated with
surface brightness, size, or appearance of
the H II region.
A program of photoelectric measure-
MOUNT WILSON AND PALO MAR OBSERVATORIES
133
ment of emission-line intensities in these
regions is under way using the multi-
channel spectrometer.
Compact Galaxies
Sargent is completing work begun last
year on a spectroscopic survey of selected
compact galaxies in Zwicky's first five
lists. Additional work during the present
year included spectroscopic observations
of a further 20 galaxies and direct photo-
graphs with the f/3.67 Ross corrector on
the Hale telescope of 30 objects having a
wide variety of spectral characteristics.
An account of the properties of 130
galaxies is in preparation. Some of the
more interesting results are briefly sum-
marized as follows.
1. Two new Seyfert-type galaxies,
II Zw 1 and III Zw 55 were discovered.
Galaxy II Zw 1 has rap = 15.1, Mp =
-21.8, and z = 0.054. Ill Zw 55 has
mp = 14.7, Mp=-20.6, and 2 = 0.025. It
is NGC 1409 and forms an interacting
double system with NGC 1410.
2. Thirty-five of the galaxies show
sharp emission lines on a blue continuum,
with no absorption lines visible on the
available spectra. Examples were men-
tioned in Year Book 67, p. 38. These
galaxies cover a wide range in absolute
magnitude, from Mp=— 14.9 to Mp —
— 22. Their emission lines have a range
in excitation similar to galactic H II
regions, so it is tentatively concluded
that the gas in these galaxies is excited
by hot stars. Some of these galaxies may
be similar to the Haro galaxies. Many of
the sharp emission-line galaxies, how-
ever, are too bright to be distant irreg-
ulars of known types. Several of them
show signs of disruption, and some were
found to be weak radio sources in the
survey by Moffet and Sargent {Year
Booh 67, p. 37) .
3. Most of the galaxies, about 50 in
number, show late-type absorption spec-
tra with prominent H and K lines. The
mean absolute luminosity of these ob-
jects is about Mp=— 20. Most of them
resemble N-type galaxies, with a hard,
sharply bounded core and a faint halo.
Not all of the galaxies have this struc-
ture; two in particular, I Zw 155 and
II Zw 188, have smooth external rings,
about 30 kpc in diameter, around a much
smaller, bright core.
An important problem remaining is
the determination of the compact objects
revealed by the preliminary, more or
less random spectroscopic surveys of
Zwicky's galaxies. Zwicky has under-
taken to survey completely a small re-
gion of the sky in the southern extension
of the Virgo cluster down to a given ap-
parent magnitude, using schmidt plates
provided by Sargent. Spectra of the re-
sulting compact galaxies are to be ob-
tained by Sargent in collaboration with
astronomers at the Mount Stromlo Ob-
servatory. A preliminary investigation
of the spectra of ten galaxies discovered
in this new survey has revealed several
interesting emission-line objects.
Energy Distribution of Peculiar Galaxies
Oke is using the multichannel spec-
trometer to measure absolute spectral-
energy distributions of various kinds
of peculiar galaxies. Included are (1) all
the known N-type galaxies, (2) a selec-
tion of Markarian galaxies, (3) several
radio galaxies, and (4) some of Zwicky's
compact galaxies. The continuum is
being studied to determine what frac-
tions of the radiation are produced by
stars, hot hydrogen gas, and nonthermal
sources. The stronger emission lines are
being measured also.
The multichannel spectrometer is
being used by Oke to obtain spectral-
energy distributions of the more lumi-
nous members of distant clusters of galax-
ies. Up to the present time, only clusters
with redshifts 2<0.20 are being observed,
since the spectrometer is temporarily
limited to 16 channels. More distant
galaxies will be observed as soon as all
32 channels can be operated simultane-
ously.
134
CARNEGIE INSTITUTION
In a continuing program to study cer-
tain subclasses contained in the Atlas of
Peculiar Galaxies, Arp has now com-
pleted an analysis showing that com-
panions on the ends of arms of spiral
galaxies tend to be of higher surface
brightness and earlier spectral type than
the central galaxy. The systems involved
are all spirals characterized by young,
hot stars and loose, open spiral arms.
One of these systems, Atlas 82 (NGC
2535 and NGC 2536) , has a redshift of
about 4000 km/sec. To obtain a picture
of this system in Ha light, use was made
of an interference filter of 100-A trans-
mission half-width centered at the posi-
tion of the redshifted Ha line. Arp and
Vaughan then used the Carnegie image
tube (S-20 cathode) at the prime focus
of the 200-inch to obtain a direct photo-
graph of NGC 2536 in the light of its
own redshifted Ha line. Although the re-
corded field is limited in size, the net
resolution is comparable to that of pho-
tographic plates. The speed of the image
tube permitted this photograph to be
obtained in one hour, whereas with the
normal, unintensified image a prohibi-
tively long exposure time would have
been required.
Some multichannel scanner observa-
tions of the companions on the ends of
spiral arms have been made in coopera-
tion with John Danziger of Harvard Col-
lege Observatory in order to gain more
information on the physical processes
taking place in these companions.
Redshifts of Galaxies
In a continuing investigation of
smaller galaxies that appear, by reason
of their concentration in the vicinity of
larger galaxies, to be statistically asso-
ciated with the larger galaxies, Arp has
continued to measure redshifts with the
Cassegrain image-tube spectrograph at
the 200-inch. Recently reduced are data
for six small galaxies nearest to NGC
2403. Their redshifts are 0.022, 0.022,
0.018, 0.021, 0.014, and 0.023. It should
be emphasized that only when a sufficient
number of redshifts are available can
statistically significant inferences be
drawn about the redshift properties of
these smaller galaxies that are in excess
density about the larger galaxies. In
some parts of this investigation Arp is
informally cooperating with Prof. E. B.
Holmberg of Uppsala University Ob-
servatory, who has recently studied faint
companions around nearby galaxies.
Braccesi Galaxies
In the course of his work on the blue
quasi-stellar objects, Dr. A. Braccesi of
Bologna obtained photographs of a field
at the north galactic pole with a coarse
diffraction grating over the 48-inch
schmidt telescope. This accidentally re-
vealed five galaxies with point secondary
images. Braccesi inferred that these
galaxies must have unusually concen-
trated nuclei and suggested that they
should be observed spectroscopically.
Image-tube spectra of all five objects
were obtained by Sargent. No unusual
spectral features were observed, although
several of the galaxies appeared visually
to have abnormally bright nuclei.
Colors of Elliptical Galaxies
McClure and van den Bergh have ob-
tained UBV colors of 32 noncluster el-
liptical galaxies. These observations
show that the colors of elliptical galaxies
do not depend on cluster membership.
This result suggests that the stellar-
luminosity function and the mean metal
abundance of stars in elliptical galaxies
are not affected by the cluster environ-
ment.
Radio Galaxies
Searle, in collaboration with John
Bolton of C.S.I.R.O., Australia, com-
pleted the study of the spectra of 38
identified radio sources from the Parkes
Catalogue. Redshifts were obtained of
the 15 emission-line objects found in this
survey.
MOUNT WILSON AND PALOMAR OBSERVATORIES
135
Sargent obtained an image-tube spec-
trogram of the radio galaxy PKS
1345 + 12, which C. Hazard pointed out
to have unusual radio properties, imply-
ing very small angular dimensions for
the radio source. The spectrogram re-
vealed very prominent emission lines of
[0 II], 3727 and [0 III], Nx and N2,
leading to a redshift of z = 0.121. No
B aimer emission lines were found; pos-
sibly they are present but exceedingly
broad. The galaxy has mp ~ 17.
The compact radio galaxy 3C 371,
shown by Oke to be variable, has been
studied spectroscopically by Arp, and the
results are being analyzed by Arp and
Visvanathan (Year Book 67, p. 37).
Deep 200-inch photographs have shown
a very low-surface-brightness halo
around the semistellar nucleus. The halo
extends to the nearest galaxies in the
field.
Van den Bergh has obtained red and
infrared plates of the nearby radio
galaxy M82 with the 200-inch telescope.
These plates show that the nuclear region
of this galaxy, which exhibits very com-
plex structure, is much brighter in the
infrared than it is at shorter wavelengths.
A spectrum of the nucleus of M82 does
not exhibit the broad Ha profile that
is characteristic of Seyfert galaxies.
Catalog of Compact Galaxies
Zwicky, as a post-retirement project,
is compiling a catalog of about 5000
compact galaxies, compact parts of
galaxies, and probable post-eruptive
galaxies. This will include objects from
a number of shorter preliminary lists.
Details as to structural features, appar-
ent photographic magnitude, and color
will be given, together with mention of
spectroscopic results obtained by Zwicky
or collaborators for about 500 of the ob-
jects.
THE GALAXY
Local Galactic Structure
Racine's investigation of the spatial
distribution of R associations (young,
hot stars associated with reflection neb-
ulae) shows that these objects outline
the same pattern as the H II regions and
0-B2 clusters, and indicate that gas and
dust are well mixed over distances of a
few hundred parsecs. The interstellar
material in the Orion arm appears dis-
tributed in roughly parallel, overlapping
"sheets" 1.2 kpc long, 0.1 kpc thick, and
tilted by 10° to 15° to the formal galactic
plane, their high side leading in the
galactic rotation. The present survey is
sufficiently complete over a distance of
3 kpc along the Orion arm to reveal the
existence of three such tilted sheets.
Galactic Center
See "Infrared Stellar Spectroscopy,"
p. 122.
SUPERNOVAE
Supernova Search
The supernova search has been re-
organized under the supervision of Oke
and Sargent, with Kowal conducting the
observations. Nineteen supernovae were
discovered at Palomar during the report
period: 10 by Kowal, 8 by F. Zwicky,
and 1 by M. Zwicky. Six of these were
found on plates of the Palomar Sky Sur-
vey, and the rest were discovered during
the course of the monthly supernova
search with the 48-inch schmidt tele-
scope.
Photoelectric magnitudes are being de-
termined by Kowal and Christensen at
the Mount Wilson 100-inch telescope for
selected stars in each of the regular
supernova search fields. It is hoped that
the availability of these "standard stars"
will permit the prompt and accurate de-
termination of supernova light curves.
136
CARNEGIE INSTITUTION
Absolute Magnitudes of Supernovae
In 1968, Kowal derived the absolute
magnitudes of 33 supernovae in terms of
an assumed Hubble constant of 100 km/
sec/Mpc. Type I supernovae were found
to have an average magnitude of iWpg=
— 18.6, and Type II supernovae had an
average of —16.5. In both cases the ob-
served dispersion in absolute magnitude
is 0?6.
Some new data for Type I supernovae
indicate that their absolute magnitudes
may be closer to —18.7 and that the
intrinsic dispersion in their maximum
magnitudes is about 0^3. With the ac-
cumulation of new light curves and radial
velocities, it is hoped that a definitive
redshift-magnitude relation can shortly
be derived for Type I supernovae.
Supernovae and the Structure of the
Virgo Cluster
If the intrinsic dispersion in absolute
magnitude among supernovae is as small
as present data suggest, the supernovae
can be used as excellent indicators of
distance. Kowal has used the apparent
magnitudes of 10 supernovae in the Virgo
cluster to determine the relative dis-
tances of their parent galaxies. The data
support the traditional view that the
Virgo cluster is a single dynamical unit.
The magnitudes of the supernovae, and
therefore the distances of the galaxies,
do not differ by more than the back-to-
front ratio to be expected for such a
large, nearby cluster, thus ruling out any
multiple-group interpretation of the
structure of the cluster.
Cassiopeia A
Van den Bergh and W. W. Dodd of
the University of Toronto are continu-
ing their investigation of the expansion
of the optical remnant of the radio source
Cassiopeia A on 200-inch plates covering
the time interval 1951-1968. No star
brighter than m = 23 is visible within two
standard deviations of the adopted posi-
tion of central expansion. The central
star in Cas A is therefore at least 7 mag
fainter than the central star in the Crab.
A widened spectrogram, at a disper-
sion of 50 A/mm, was obtained of the
central star in the Crab. The spectrum
of this star (which was subsequently
found to be a pulsar) was seen to be
continuous. This observation confirmed
earlier low-dispersion observations by
Minkowski and by Zwicky.
Slow Supernova in NGC 1058
The spectrum of Wild's slow super-
nova in NGC 1058 (SN 1961e) has rela-
tively sharp lines in emission and ab-
sorption. It is related to y Carinae, but
is much more luminous. It was found on
Harvard plates, as early as 1937, near
m = 18 until 1955, and then was found
to brighten from 1960 to the end of 1962,
reaching nearly m=:12. It was still
visible in 1967 near ra = 20. Spectra were
taken by Greenstein until about two
years after the outburst began — one at
18 A/mm. Descriptions of spectra by
Zwicky and Bertola have been published.
The total emission, at a modulus of
29.7, is 1050 erg, in visible light, neglect-
ing any bolometric correction. A con-
servative total thermal energy is between
5 and 23 X 1050 erg, quite comparable to a
typical supernova of Type I, although
not as bright at maximum.
Greenstein finds that the spectrum
evolved with time. The emission lines be-
came sharper, shifted to the red by
1.5 A, and developed P Cygni-type ab-
sorption wings. The mean wavelengths
of the emission give different velocity
shifts; the nebula is at +440 km/sec,
but the supernova hydrogen lines are at
+ 765 km/sec, He I at +650 km/sec,
and Fe II at 960 km/sec. One sharp ab-
sorption line of He I from the 23S meta-
stable level, A3888, is displaced to -320
km/sec, i.e., —760 km/sec with respect
to the nebula. There was a short-lived
outburst when the supernova reached
12th magnitude, which did not substan-
MOUNT WILSON AND PALOMAE OBSERVATORIES
137
tially affect the emission-line spectrum
but which eliminated the A3888 line.
The most startling fact about this
object is the strength of Fe II absorption
and emission lines. Spectra of Type II
supernovae show H, He, and C; the
quasar 3C 273 shows weak Fe II emis-
sion blends. In SN 1961e there are about
40 Fe II lines partially resolved. The
spectrum is so crowded that weaker
metallic ions might not be seen ; a search
for Co II and Ni II (interesting for the
theory of nucleosynthesis) is inconclu-
sive. They are certainly not very strong.
Forbidden lines also are not seen. The
energy-level diagram of Fe II is such
that the lines studied can be produced
by photoexcitation via the ultraviolet
Fe II lines, followed by cascades or by
collisional excitation. Dependent on de-
tails of the excitation process, the abun-
dance Fe/H can vary over a wide range,
but seems to be abnormally high. In
ordinary novae and 3C 273, Fe II emis-
sion is extremely weak compared with
hydrogen emission, but in the supernova
HS is weaker than A4233 of Fe II. In
Merrill's iron star, XX Ophiuchi, many
lines of Fe II and [Fe II] are present far
weaker than Hy.
The mass ejected can be determined
from the H/3 emission, the electron den-
sity, which is high, and an assumed age.
It is at least 0.1 90?©, and may be much
larger. The anomalous composition will
need further detailed study; the parent
star may have been a massive Type II
supernova detonating in a dense gas
cloud. A slow supernova is a contradic-
tion in terms, but in total energy and iron
anomaly this object seems to qualify
as a supernova.
PULSARS
NP 0532
The only pulsating radio source so far
identified with a visible object is NP 0532
in the Crab nebula, first optically ob-
served to be pulsing on January 16, 1969,
by Cocke, Disney, and Taylor at Steward
Observatory, and identified a few days
later by Lynds, Maran, and Trumbo at
Kitt Peak National Observatory as the
"south preceding star" of the pair near
the center of the nebula. This star was
suggested as the central star of the Crab
by Baade and Minkowski in 1942, on the
basis of its position near the center of
expansion and its spectroscopic pecu-
liarity (a featureless blue continuum).
It is seen on photographic plates as a star
of about 16.5 mag; in fact, the light
arises almost entirely from the 60 short
pulses emitted each second. The object
has been observed by Kristian, West-
phal, and Snellen with the prime-focus
photometer of the 200-inch. Photon
counts were averaged at multiples of the
known period of the pulsar and simul-
taneously recorded directly on digital
magnetic tape with 1-msec integration
times for later analysis.
Two distinct pulses occur during each
33-msec period (Fig. 1). The main pulse
is 5-msec wide and asymmetric, the trail-
ing edge being steeper than the leading
edge. It is followed 13.5 msec later by a
secondary pulse having an amplitude
30% that of the main pulse and 55%
as much energy as the main pulse. The
secondary pulse is also asymmetric, but
in the opposite sense. Both pulses are
extremely sharp near the peak. With a
time resolution of 60 microsec, the peaks
are still cusps, and the full width of the
main peak at 90% of maximum is less
than 300 microsec.
The light level following the main
pulse is slightly higher than that follow-
ing the secondary pulse. The latter has a
very long, shallow tail, with a nonzero
slope up to within at least 2 msec of the
beginning of the succeeding main pulse.
The intensity level between pulses, how-
ever, is very low. At its lowest point,
it is within a few percent of the nearby
nebular background of the Crab, as
138
CARNEGIE INSTITUTION
OPTICAL PULSAR
NP0532
3/15/69
2 PERIODS
r
69
_AAJLA
33.1 m sec
2/10/69
MAIN PULSE
ft
4
y*^*Y»fsJ?
..•*
10 m sec
Fig. 1. Light curves of the optical pulsar in the Crab nebula. The data were obtained by averag-
ing photon counts from the 200-inch prime-focus photometer in a 1024-channel multiscaler, cycled
at twice the pulsar period. The time resolution is 66 A<.sec per point. Upper: A 2-minute average
recorded on 15 March 1969. Note the very sharp peaks on both the main and the secondary
pulses; the asymmetry of both pulses; the higher background level following the main pulse;
and the long nonzero slope following the secondary pulse. Lower: A 1-minute average recorded
on 10 February 1969. The detail of the main pulse only is shown, with an expanded time scale.
A comparison with the upper light curve indicates the stability in pulse shape on a time scale
of a month.
shown by a drift scan in which the edge
of the focal-plane diaphragm was al-
lowed to occult the pulsar. This experi-
ment also sets an upper limit of a few
tenths of an arc second for the size of
the pulsating source. At the 2-kpc dis-
tance of the Crab, this corresponds to
about 500 astronomical units, which is
107 times larger than the diameter of
the speed-of-light cylinder for an object
MOUNT WILSON AND PALOMAR OBSERVATORIES
139
rotating at 30 Hz. It therefore is not a
stringent limit for rotating neutron star
models.
The data that have so far been ana-
lyzed in detail show a remarkable stabil-
ity of pulse shapes and amplitudes, with
accuracies ranging from a factor of a
few for successive pulses to less than 1%
for 1-min averages compared over times
of the order of 2 hours. This indicates
that the large variations that are ob-
served at radio wavelengths are prob-
ably caused by scintillation, either
interstellar or at the source, as has been
suggested by several authors.
On time scales of months and years,
Kristian has examined plates in the files
and finds no changes in the integrated
intensity of the pulsar from 1920 to the
present, with an uncertainty of 30%
from 1939 to the present and 45% from
1920 to 1939. The mechanism that pro-
duces the pulses is clearly a stable, long-
lived feature of the source.
Polarization measurements of the
Crab pulsar were made by Kristian,
Visvanathan, Westphal, and Snellen.
These show plane polarization of the
order of 10% in both pulses, and an
upper limit of 5% for circular polariza-
tion. The nebular background (when the
pulses are off) has a plane polarization
of 10.3% in position angle 156°. This is
the same position angle and about 40%
of the amount of the general polarization
of the Crab nebula at the position of the
pulsar. Absolute timing was lost between
measurements at successive analyzer
angles, so the data do not give direct in-
formation on the crucial question of pos-
sible changes of polarization during the
pulses.
On April 26, 1969, Kristian measured
the absolute arrival times of the pulses,
as did R. E. Nather and his colleagues
at McDonald Observatory, in order to
compare these with the pulse arrival
times in the X-ray region of the spec-
trum, as measured by Bradt, Rappaport,
and Mayer of M.I.T., using a rocket-
borne X-ray detector. After correction
for the difference in light-travel times
from the pulsar to Palomar, White Sands,
and McDonald, the optical and X-ray
pulses were found to arrive simultane-
ously to within the measuring uncer-
tainty of 1 msec. Assuming that there is
no dispersion along the light path at
optical and X-ray frequency, this means
that the X-ray and optical pulses are
generated within 300 km of one another.
Alternatively, if it is assumed that the
X-ray and optical pulses are generated
at the same place, it implies that the
velocity of light at the two wavelengths
is the same to less than 1 part in 1014.
The X-ray pulses are qualitatively simi-
lar to the optical pulses, although there
is more relative energy in the secondary
X-ray pulses. Most of the energy of the
pulsar is in the short wavelength (X-ray)
region of the spectrum.
The spectral-energy distribution of
NP 0532 has been studied by Oke. The
star-sky chopper of the multichannel
spectrometer was synchronized with the
pulsar period and operated in such a way
that the aboslute-energy distributions of
the pulses themselves were obtained.
After correcting for interstellar redden-
ing, the energy distribution in the pulses
in the optical region can be fitted ac-
curately to a Planck function with T —
10,000°K. This fit should not be inter-
preted as meaning that there is a thermo-
dynamic blackbody present, since the
energy density must be enormously
higher than that of a 10,000 °K black-
body.
Coordinated observations of the pulsed
component of NP 0532 were made at
2.2 /a, 1.65 /x, and in the visual region by
Neugebauer, Becklin, and Kristian. The
pulse shapes, relative amplitudes, and
spacing were consistent between the vis-
ual and infrared. The infrared amplitude
fits smoothly onto the visual data of Oke,
but the data suggest that the energy
spectrum is not smooth throughout the
visual, infrared, and radio regions.
140
CARNEGIE INSTITUTION
CP 1919
Additional attempts were made by
Westphal, Kristian, Snellen, Sandage,
and Schmidt to detect variations in Ryle
and Bailey's candidate for the pulsar
CP 1919, following earlier reports of such
variations by other observers. The light
from the star was found to be constant,
with an accuracy as high as 0.1%. On the
basis of a spectral scan by Oke, an infra-
red measurement at 2.2 fi by Neugebauer
and Becklin, and UBV photometry of
stars in the field by Sandage and Kris-
tian, it was concluded that the star is a
normal main-sequence star of spectral
type near F0, unrelated to the pulsar.
Optical Pulsar Search
The search for optical objects asso-
ciated with other pulsating radio sources
has been continued by Kristian, using
averaging techniques to look for pulsa-
tions at the known radio frequencies.
No pulsing optical objects have been
found in the fields of CP 0328, CP 0808,
AP 0823, PSR 0833-45 (the Vela pulsar) ,
CP 0834, CP 0950, CP 1133, HP 1506,
PSR 1749-28, AP 2015, or PSR 2045-16,
with limits ranging from 20th to almost
25th magnitude.
X-RAY SOURCES
Identification of Centaurus X-2
Working from an improved position
(due to Lewin, Clark, and Smith of
M.I.T.) for the highly variable X-ray
source Cen X-2, Eggen, Freeman, and
Sandage made a probable optical identi-
fication with the irregular blue variable
WX Centauri. The optical position at
oc(1950)=13h09m38s, 8=-63°08' is
within the 1?5 error radius of the X-ray
position at a(1950) =13h09m, 8= -62°.
Photometry by Eggen at Siding Spring
Observatory showed that WX Cen varies
by 0.4 mag from night to night and has
the unusual colors B — V = 0A, U — B =
— 0.7, similar to those of the positively
identified Scorpius X-l.
Image-tube spectrograms taken by
Sandage and Freeman with the Mount
Stromlo 74-inch reflector show strong
emission lines of Ha, H/3, H8, He II
A4686, He II A5412, C IV A5802, together
with many fainter lines. The unusual
spectrum closely resembles that of Sco
X-l in the overlap region 4300<A<
5000 A, where the broad diffuse high-
excitation band near 4640 A, due to
N III, C III, and possibly O II, is
present.
Sandage attempted to identify the
Vela X-ray source from the new posi-
tion at a(1950) =8h57m, 8 = 41°15' by the
American Science and Engineering X-ray
group. Two-color plates were taken with
the Uppsala schmidt at Mount Stromlo,
but no candidate object was found. The
limit of the search was B = 15 mag.
Sco X-l
In May 1969 a number of observations
of Sco X-l were made by Kristian, si-
multaneously with other observers, in an
attempt to correlate changes in the
source photoelectrically and spectro-
scopically. The Palomar observations
were made with Oke's multichannel spec-
trophotometer at the Cassegrain focus of
the 200-inch. Complete spectral scans
were obtained continuously, every one
minute or less, for periods up to 90
minutes. One such measurement was
made simultaneously with a measure-
ment in the far ultraviolet by the Wis-
consin Experimental Package of the
Orbiting Astronomical Observatory,
launched in December. The Wisconsin
group detected the source near the limit
of their equipment, and preliminary data
indicate that the spectrum is approxi-
mately flat between 2700 and 5500 A.
Other measurements were made in con-
MOUNT WILSON AND PALOMAR OBSERVATORIES
141
junction with spectroscopic observations
by C. R. Lynds at Kitt Peak National
Observatory and satellite X-ray observa-
tions by H. Hudson of the University of
California at San Diego. These observa-
tions are being reduced and correlated.
QUASI-STELLAR SOURCES
Position Measurements
Kristian and Sandage have carried
out a program of position measurements
of the optical objects associated with 45
unresolved radio sources, mostly previ-
ously identified quasi-stellar sources. The
measurements were made on plates taken
with the 48-inch schmidt telescope, using
the newly refurbished and digitized x-y
machine at the Santa Barbara Street
offices. Position accuracies of the order of
0.2 arc seconds have been achieved by
the use of a large number of AGK refer-
ence stars, typically 20 on each plate.
This program was carried out in co-
operation with Dr. C. M. Wade of the
National Radio Astronomy Observatory,
who has measured the radio positions of
the same sources with the 3-element in-
terferometer at Green Bank. The esti-
mated accuracy of the radio positions is
also a few tenths of an arc second, and
the agreement between the radio and
optical positions is entirely satisfactory.
This program will supply a fundamental
reference grid of well-determined radio-
source positions.
Spectroscopy
Spectroscopic observations of quasi-
stellar radio sources are being continued
by Schmidt. Most of the sources are 4C
radio sources in the declination range
+ 20° to +40°, for which identifications
are being published by Edward T. Olsen,
now at the University of Michigan. Fur-
ther identifications in this declination
zone have been supplied by radio astron-
omers at Parkes and at the National
Radio Astronomical Observatory. It is
expected that a sample of quasi-stellar
sources complete to well-defined optical
and radio limits will be obtained, allow-
ing the determination of optical- and
radio-luminosity functions and their
variation with redshift.
Schmidt is continuing systematic spec-
troscopic work on the blue stellar objects
identified by Sandage and Luyten in a
number of fields at intermediate and
high galactic latitude. This should even-
tually yield an optical-luminosity func-
tion of radio-weak or radio-quiet qua-
sars, as well as its variation with redshift.
Bahcall, B. A. Peterson, and Schmidt
have studied the absorption spectrum
of the radio-quiet quasar Ton 1530,
which has an emission redshift 0em=r2.O5.
Following a method first used by Bahcall
on PKS 0237-23, three acceptable ab-
sorption redshifts (zabs = 1.9365, 1.9215,
and 1.8866) were found, as well as one
plausible redshift {zahs = 1.9800). The
same method applied to similar but ran-
dom absorption spectra yielded on the
average only 0.1 acceptable redshift.
Oke and Wampler (at the Lick Ob-
servatory) are continuing to monitor 3C
446 to determine whether the emission
lines are variable. No positive results
have yet been obtained, indicating that
the time scale for changes is at least one
year.
Energy Distribution
Oke, Neugebauer, and Becklin have
completed a study of the energy distribu-
tion of quasi-stellar sources. Twenty-five
objects have been observed from 0.33 ^
to 2.2 ix with the prime-focus scanner, the
multichannel spectrometer, and infrared
photometers. Eighteen additional quasi-
stellar sources have been observed at
2.2 fi. It is found that the continuum
energy distributions can be represented
reasonably well by power-law spectra,
fvo:va, with 0.0<a<-1.7. There is in
no sense a "universal" continuum energy
142
CARNEGIE INSTITUTION
distribution that represents all QSS. A
comparison of the optical and radio fluxes
leaves completely open the question of
whether most of the radiation from a
QSS is in the infrared. Only for 3C 273
has such been demonstrated to be the
case. The equivalent widths of the emis-
sion lines Ha, Lyman a, and AA1550
of C IV are remarkably constant. The
number of photons in Ly a is signifi-
cantly smaller than the number beyond
the Lyman limit predicted by extrapo-
lating the observed continuous energy
distribution. This suggests that a sub-
stantial part of the Lyman continuum
radiation may escape from the object.
The almost constant ratio of intensity
of A1550 to Ly a may put very severe
limitations on the electron temperature
and carbon-to-hydrogen abundance.
BL Lacertae
The remarkable radio source VRO
42.22.01 = BL Lacertae has been studied
by DuPuy, Schmitt, McClure, van den
Bergh, and Racine. During the period
April-November 1968, the visual magni-
tude of this object varied between 12.0
and 15.5. Light variations as fast as 0.3
mag per day were observed. The spec-
trum of this object is continuous, so that
its distance remains unknown. The very
bright apparent magnitude of BL Lac at
maximum light makes it improbable that
this object is a normal quasi-stellar
source. BL Lac would have to be the
nearest quasi-stellar if it has a typical
QSO luminosity. On the other hand, a
distance greater than that of 3C 273
would make it the most luminous object
known in the universe.
Distribution
Over the past few years, Arp has
studied the distribution of QSS on the
sky. Recently he has concentrated on an
analysis of 93 QSS with known redshifts.
Using the California Institute of Tech-
nology 7094 computer with a program
designed by F. Bartlett, he reports the
result that the distribution of these QSS
on the sky is significantly nonrandom.
He believes that the distribution changes
markedly as a function of apparent mag-
nitude (7) of the QSS, such that the
fainter QSS are concentrated in the
vicinity of the brighter galaxies in the
sky.
The densest grouping of faint QSS,
according to Arp, is centered near the
position of the exploding galaxy NGC
520 (Atlas of Peculiar Galaxies, No.
157) . In an analysis recently completed,
he discusses the statistical relationships
of the properties of the QSS, such as their
radio spectral indices and flux strengths
as well as their optical apparent magni-
tudes and redshift with respect to the
galaxies in the same region of the sky.
THEORETICAL STUDIES
Theory of Pulsars
T. Gold of Cornell University has sug-
gested that pulsars are rotating magnetic
neutron stars which formed in super-
nova explosions. P. Goldreich of the
Astronomy and Geological Sciences Di-
visions and W. Julian (1969) have in-
vestigated the simplest such model, one
in which the magnetic dipole moment is
aligned with the rotation axis, and have
reached the following conclusions. Not-
withstanding its intense surface gravity,
the star must possess a dense magneto-
sphere. The particles in the region
threaded by those field lines which close
within the light cylinder (of radius
5 X 109 P cm, where P is the stellar rota-
tion period in seconds) rotate with the
star. In the corotating zone the space
charge density is 7 X 10~2 Bz/P electronic
charges per cm3, where Be is the com-
ponent of magnetic field parallel to the
rotation axis in gauss. The field lines
which extend beyond the light cylinder
MOUNT WILSON AND PALOMAR OBSERVATORIES
143
close in a boundary zone near the super-
nova shell. Charged particles escape
along these lines and are electrostatically
accelerated up to energies of 3 X 1012
ZR63 B12P~2 eV in the boundary zone.
(The stellar radius is .R6xl06 cm,
and the polar surface magnetic field is
£12xl012 gauss.) Beyond the light cyl-
inder, the magnetic field becomes pre-
dominantly toroidal. Its strength is
6xl0-9 R63 B12P~2 rvc~x gauss at a dis-
tance of rpc parsecs from the central star.
The magnetic torque on the star causes
its rotational period to lengthen at the
rate P"1 dP /dt = 10~8 B122 i?64 P~2 M'1
yr_1 for an M solar mass star. The rota-
tional energy lost by the star is trans-
ported out by the electromagnetic field
and is then transmitted to the particles
in the boundary zone.
Extragalactic Radio Sources
In a continuing study of the variable
extragalactic radio sources, Simon in-
vestigated the possibility that the posi-
tive curvature in the high-frequency
radio spectra of such sources might be
due to the suppression of synchrotron
radiation in an ionized medium (Razin
effect). Analytic formulae valid for fre-
quencies below the Razin cutoff were cal-
culated for the spectrum radiated by
relativistic electrons. It could be shown,
on the basis of the best available data,
that the Razin effect is not likely to be
responsible for the cutoff observed in 3C
120 and 3C 273, and that synchrotron
self-absorption continues to be the most
reasonable explanation. In the simplest
models that have been suggested to
explain these sources, the variable flux
arises in an expanding component emit-
ting synchrotron radiation. From an
analysis of the millimeter wavelength
data for the 1966-1967 variable com-
ponent of 3C 273 it was shown that there
is evidence that the model is breaking
down at an early stage of the evolution
of the source because the synchrotron
and Compton losses of the relativistic
electrons are very severe then. Since later
observations of the same source at longer
wavelengths fit the model well, this pro-
vides evidence for a continued accelera-
tion of electrons during the first few
months of the bursts' existence. The in-
trinsic size of the source, over which
particle acceleration must have taken
place, was ~0.4 pc. Work on possible
stochastic acceleration mechanisms is
continuing.
Type IV Solar Bursts
The analytic formulae developed for
the asymptotic form of synchrotron
spectra below the Razin cutoff were used
to test the hypothesis that the low-
frequency cutoff in Type IV solar bursts
is due to the Razin effect. If the observed
frequency cutoff is caused by the Razin
effect, then the coronal electron density
may be derived from the intensity varia-
tion in the burst as it propagates out-
wards from the Sun. Bohlin and Simon
analyzed the moving Type IV burst ob-
served by Boischot and Clavelier, and
showed that the electron density profiles
obtained from K-coronameter data (ap-
propriate to 1.125 < r/RQ < 2) and from
the radio data (2.2 < r/RQ < 2.5) form
a continuous distribution. It is possible
to conclude then that the cutoff was due
to the Razin effect, that the radiation
in the burst is due to relativistic electrons
having a steep inverse power-law energy
distribution, and that the coronal mag-
netic field at r/RQ = 2.2 was 0.26 gauss
at the time of the burst.
Interstellar Gas
K.-H. Schmidt of the University Ob-
servatory, Jena, Germany, and van den
Bergh have studied the ejection of dust
from the Galaxy by radiation pressure.
They find that significant dust loss can
occur when a dust cloud arches over a
bright spiral arm. It is found that the
heavy-element abundance and the inter-
stellar gas might be a decreasing fun-
144
CARNEGIE INSTITUTION
tion of time if a significant fraction of
the heavy elements are locked up in
grains. Dust ejection is expected to be
particularly important during the early
high-luminosity phase of galactic evolu-
tion.
GUEST INVESTIGATORS
Dr. George 0. Abell of the University
of California at Los Angeles has recently
determined the luminosity function of
the elliptical galaxies in the central
6.6° X 6.6° region of the Virgo cluster.
The luminosity function of the Virgo
ellipticals resembles that found by Abell
for the elliptical galaxies in other clusters
(Coma, Corona Borealis, Abell 151, and
Abell 2199) . However, if the luminosity
functions of the Virgo cluster and the
Coma cluster are compared, the ratio of
the distance of the Coma to that of the
Virgo cluster is found to be about 50%
greater than the ratio derived from the
difference in apparent magnitudes of the
first brightest cluster galaxies.
On the other hand, the Virgo cluster
is much less rich than the other clusters
investigated, and the critical part of the
Virgo luminosity function represents
only about the 20 brightest galaxies in
the observed field. To obtain a sample
of Virgo galaxies roughly twice that
previously available, Abell, in March,
obtained sets of 48-inch schmidt plates
covering four additional fields in the
cluster surrounding the central field al-
ready studied. It is expected that the
reduction of magnitudes of the addi-
tional galaxies in these fields will be
complete by September 1969, and com-
parison with the earlier results should
be possible then.
Dr. Lawrence Aller and Dr. Stanley J.
Czyzak of the University of California
at Los Angeles used the 60-inch telescope
with Oke's Cassegrain scanner to obtain
photoelectric observations of five plane-
tary nebulae in the visible and blue re-
gions. Companion stars were observed
in each case. Coude spectrograms of two
of the objects were obtained with the
100-inch telescope, but the program was
hampered by unfavorable weather. The
study of physical processes in gaseous
nebulae is proceeding on the basis of the
photoelectric and photographic pho-
tometry with the latest theoretical re-
sults on collision strengths.
Dr. J. M. Beckers of the Sacramento
Peak Observatory, Sunspot, New Mexico,
and Dr. J. 0. Stenflo of the Astronomical
Observatory, Lund, Sweden, in a joint
investigation with Howard used the solar
magnetograph with 10-second resolution,
together with high-resolution spectro-
grams of A5250, to study very small re-
gions of high magnetic-field strength
("magnetic knots") that occur near sun-
spots. While the resolution achieved was
not really adequate for the purpose,
many interesting details were recorded
and these are now being examined by
Dr. Stenflo.
A program intended to detect the faint
outer regions of galaxies has been carried
out by Dr. F. Bertola of the Astrophysi-
cal Observatory of Asiago, Italy, in col-
laboration with Arp. Plates obtained
with the 48-inch schmidt telescope on
the new Hla-J emulsion were analyzed
with the isodensitometer. Several ellipti-
cal galaxies were found to possess faint
extended halos. Faint extensions of M87,
the large elliptical radio-source galaxy
in the Virgo cluster, have been detected
out to a diameter corresponding to
300 kpc.
Spectra of the galaxies NGC 128, NGC
1808, NGC 3077, and NGC 7753 were
secured with the image-tube spectro-
graph (dispersion 80 A/mm) at the Cas-
segrain focus of the 200-inch reflector
for dynamical study. NGC 128 is a
peculiar SO galaxy well suited for the
determination of the rotation curve from
both the absorption and emission lines.
In the spectra of the nuclear region of
NGC 1808, a galaxy with hot spots,
MOUNT WILSON AND PALOMAR OBSERVATORIES
145
taken with the slit set at three different
position angles, the emission lines are
strongly inclined or broken, suggesting
the occurrence of some kind of explosion.
Spectra of NGC 3077, morphologically
similar to M82 and belonging to the same
group, were taken for a precise de-
termination of the velocity field. The
study of the rotation curve of NGC 7753,
the main component of an M51-type
system, may permit conclusions as to
dynamic stability.
Professor Alessandro Braccesi of the
Istituto di Fisica di Bologna, Italy, has
continued his program of investigation of
the radio-quiet quasi-stellar objects,
using the method of the infrared excess.
Five high-galactic-latitude fields were
observed with the Palomar 48-inch
schmidt. Reductions have been com-
pleted for one field, and the number-
magnitude relation for the QSO has been
shown to be rather steep, in agreement
with the cosmological evolution sug-
gested by Schmidt.
Dr. John G. Bolton, of the Radio-
physics Laboratory, C.S.I.R.O., Aus-
tralia, obtained a series of two-color
plates centered on Sky Survey centers
taken for the region Dec 0° between R.A.
17h and 13h. Exposures were 8 min in the
blue and 1 hour in the ultraviolet. The
purpose of these plates was to aid in the
identification of radio sources as quasi-
stellar objects from the Parkes survey
of Dec ±4° at 2700 MHz. An average
of 3 QSO per plate have been identified
for most of the region where the radio-
survey limit is 0.35 flux units, and as
many as 10 per plate in selected areas
where the radio-survey limit is 0.08 flux
units.
Examination of the plates in the posi-
tions of previously unidentified sources
from the Parkes general catalog had dis-
closed 2 QSO that have become visible
since the original Sky Survey was made.
The sources are PKS 0950 + 00 and
1218-02. (The same happened in the
case of 3C2, which was not visible on
the Sky Survey plates.) Twenty-four
position plates of new identifications
were taken to provide additional position
calibrators.
In an investigation of rotation and in-
ternal motion in galaxies, Dr. G. Courtes
of the Marseilles Observatory made in-
tensive observations of M33, NGC 6496,
NGC 253, and NGC 6888 with the 200-
inch telescope. He used a Fabry-Perot
interferometer of his own design, work-
ing on the Ha line with a dispersion of
25 A/mm. In M33, five interferograms
were taken on the major axis and radial
velocities of 2500 points have been
measured. Courtes confirmed the exist-
ence of the disk of diffuse ionized hydro-
gen, as well as the fact that its circular
velocity is 15 km/sec slower than that
of the spiral arms.
Strong noncircular motions were found
in NGC 6946 and NGC 253. A prelimi-
nary examination of plates of M31 gave
more than 60 radial velocities in a field
6' in diameter; it confirmed the absence
of expansion in the arms.
Dr. I. J. Danziger, in collaboration
with graduate students at Harvard, has
analyzed high-dispersion spectra of the
bright K giant, £ Cygni. It is a mod-
erately pronounced example of a Ba II
star, the brightest now known, with en-
hancements among the s-process ele-
ments. Danziger and Jura have analyzed
high-dispersion spectra of HD 137569,
a halo B star. The helium abundance ap-
pears to be normal, but silicon and
magnesium are very underabundant.
This star has a low surface gravity
(log gr = 2.3) and appears to have a varia-
ble radial velocity. It may be a member
of a sequence of early evolved stars of
Population II which so far are unac-
counted for theoretically.
Danziger is continuing a program of
observations of centers of normal gal-
axies of various types containing radio
sources. Low-resolution scans of approxi-
mately 30 objects have been obtained
with the Mount Wilson scanner and the
Palomar multichannel scanner. There is
significant variety in the continuous
146
CARNEGIE INSTITUTION
spectra, which are receiving further
study.
Mr. Joseph R. Bruman of the Jet
Propulsion Laboratory used the 48-inch
schmidt during the lunar eclipse of Octo-
ber 1968 in a search for the reported
clouds of dust circling the earth near the
libration points of the moon's orbit. It
was possible to make the observations
near the zenith, but neither diffuse clouds
nor discrete objects were found.
Dr. Robert F. Garrison of the David
Dunlap Observatory used the 100-inch
telescope and Newtonian spectrograph
for five nights for four different pro-
grams. These included a search for
physical members of the association II
Scorpii among the faint apparent com-
panions to the bright stars, a search for
variations in the spectra of the peculiar
B stars in II Sco, and obtaining spectro-
grams of selected Mira-type variables
near minimum light.
Dr. Hugh M. Johnson of the Lockheed
Palo Alto Research Laboratory used the
48-inch schmidt telescope with 5 X 7-inch
plates centered on positions of the X-ray
sources GX9 + 9, GX5-1, GX9 + 1,
GX13 + 1, GX17 + 2, Serpens XR-1,
Cygnus X — 1, Cygnus X — 3, Cygnus
X — 4, and Cassiopeia A. Five exposures
per plate, shifted 4", were the standard
procedure in a search for rapid variable
stars that might be candidates for optical
identification, but so far the examination
of the fields has not produced a positive
result. Exposures on Cas A in various
passbands were made to improve the
composite-plate imaging of the yellow
continuum reported in 1967, and to com-
pare the yellow imaging directly with Ha
(filamentary) imaging.
The one coude run at Palomar and
the two with the 100-inch at Mount Wil-
son were used by Dr. Philip C. Keenan
of Ohio State University primarily to
obtain spectrograms of Mira variables
for the pending revision of the catalog
of their spectral types. A slight modifica-
tion of the classification of the coolest
M-S was found necessary on the basis
of the spectrograms of x Cygni in the
blue region. In most M stars the number
of blue TiO bands observable continues
to increase at least as far as type M8,
but in the M-S stars the bands from
vibrational levels with v = 3 or higher can
remain very weak or invisible, while
bands originating in the lowest vibra-
tional levels increase. This is the same
effect that is conspicuous in the yellow
region, and apparently reflects the lesser
absolute concentration of TiO in M-S
stars. Consistent temperature classifica-
tion of these stars can be carried out by
using such band ratios as 4395 (8, 3)/
4422 (4,0).
Following the discovery at Flagstaff
of peculiarities in the spectrum of the
B star HD 191980, coude spectrograms
were taken to confirm the abnormally
strong C II/He I line ratio. Since a 1963
spectrogram of the red region in this
spectrum was available, the coude plates
provided the following radial velocities:
Pc 7484, -15.0 ±0.7 km/sec, August 12,
1963; Ce 191287, 8, -15.4 ±1.0, August
9, 1968.
Because these velocities are much
more accurate than the earlier published
values from Lick and Victoria, the large
disagreements between the new and old
sets do not necessarily indicate variation.
The mean of the interstellar D-line
velocities in 1963 and 1968 was +11.7
km/sec.
In cooperation with O. C. Wilson and
A. J. Deutsch, Keenan completed the
paper on classification of K and M giants
by line ratios (Astrophys. J., 156, 107,
1969).
Dr. Willem J. Luyten of the Uni-
versity of Minnesota, working with the
48-inch schmidt, has continued taking
second-epoch plates for comparison with
the National Geographic Society-Palo-
mar Observatory Sky Survey. To date,
833 fields of a total of 936 have been re-
peated in this Proper Motion Survey.
MOUNT WILSON AND PALOMAR OBSERVATORIES
147
Luyten has completed examination and
analysis of the North Polar Cap and
has published a General Catalogue giv-
ing proper motions for more than 10,500
stars north of Dec +75°.
Dr. T. B. McCord of M.I.T. used the
60-inch, 100-inch, and 200-inch tele-
scopes for a variety of projects concern-
ing solar-system objects. A special two-
beam photometer was used to observe the
spectral reflectivity, 0.30 to 1.10 /x (AA c±
200 A), of the rings and some bands of
Saturn and of the satellites of Saturn at
several positions in their orbits. Also,
several asteroids were observed at vari-
ous points in their spin period.
The spectral reflectivity of the bright-
est satellites of Jupiter was observed
also. This is part of a complementary
program carried out on the Mount Wil-
son 24-inch telescope by Mr. T. John-
son, a graduate student, to observe the
changes in reflectivity of the satellites
as a function of orbital position.
During the early spring of 1969, Mr.
Carl Pilcher, another graduate student,
and McCord used the 60-inch telescope
to measure the spectral reflectivity of
various bands on Jupiter. These observa-
tions are being analyzed along with simi-
lar observations made with the prime-
focus scanner of the 200-inch telescope.
The 24-inch telescope was used by
McCord and several graduate students to
observe the larger satellites of Jupiter
and some asteroids. The spectral reflec-
tivity (0.30-2.5 /x) of various regions
on the lunar surface also was studied.
Dr. D. H. McNamara of Brigham
Young University obtained intermediate-
band photometric observations of several
RR Lyrae variables in the globular star
clusters M92, M3, and M15. These ob-
servations have proved to be extremely
useful in showing that the color excesses
of M92 and M3 are essentially zero,
while M15 is definitely reddened. They
also have proved useful for estimating
the metal abundance of the RR Lyrae
variables in these clusters.
In November 1968, McNamara at-
tempted to secure some spectrograms of
metal-strong RR Lyrae variables at
minimum light for the purpose of esti-
mating the line blanketing in the ultra-
violet. The program was unsuccessful be-
cause of poor weather conditions. The
program was revised, however, and good
high-dispersion spectrograms of several
bright Cepheids were secured. These
spectrograms are proving useful for esti-
mating the effects of line blanketing on
narrow-band photometric indices. The
spectrograms were exposed very strongly
in the ultraviolet for the purpose of
gaining information on absorption-line
strengths in the wavelength region of
AA3200-3800.
Dr. Walter E. Mitchell, Jr., of Ohio
State University used the Snow Tele-
scope on Mount Wilson in August and
September 1968 to obtain solar-spectrum
observations with the McMath-Hulbert
spectrometer. The instrument was used
in the double-pass mode to obtain a high-
resolution atlas of integrated sunlight,
a mosaic of flat mirrors being used to
feed the spectrograph. The atlas, requir-
ing 17 observing days, covers the spectral
range AA3900-5900. This atlas, being re-
corded near time of solar maximum, will
serve for the intercomparison of Fraun-
hofer-line central intensities with a simi-
lar atlas made near the time of the
minimum of solar activity in 1964.
A number of digitally recorded spec-
tral scans were made at the center of the
sun's disk in the ultraviolet range short-
ward of A3010.
Also, the program of photoelectric
limb scans for the measurement of mean
chromospheric heights was extended to
include one polar limb as well as an
equatorial limb. Scans in the H/3 and
Ca II H lines were obtained simultane-
ously in the core and continuum.
Dr. Jeffrey D. Scargle of the Lick Ob-
servatory, working with the 48-inch
schmidt, obtained plates of a number of
quasi-stellar objects (with £~2.0) using
narrow filters to isolate their Lyman-a
emission. The goal was to detect possible
148
CARNEGIE INSTITUTION
reemission of Lyman-a from intergalac-
tic hydrogen near the QSO, most likely
in the form of clouds. Such emission
would be produced by direct scattering,
and also could be the result of recom-
bination if enough ionizing radiation es-
caped from the QSO. So far no circum-
QSO emission has definitely been
detected, a result that places an upper
limit on the density of intergalactic
hydrogen.
Plates were taken also of the Crab
nebula and the Cygnus Loop using
G-emulsion and a Wratten 15 filter, a
combination that avoids all but a few
weak emission lines. In the case of the
Crab, the aim was to go as deep in the
continuum as possible to see if there is a
halo of synchrotron emission from elec-
trons escaping from the nebula.
Dr. Jan 0. Stenflo of the Astronomical
Observatory of Lund, who was in resi-
dence for several months, worked on a
number of solar problems, mostly with
the magnetograph of the 150-foot tower
telescope. He recorded the magnetic field
near the north and south heliographic
poles on most days during the period
July 3 to August 23, 1968. The aperture
was 5" X 5", but on some days with very
good seeing in the morning the 2'/3
aperture was used also. The main reduc-
tion and the isogauss drawings were
made on the IBM 7094 computer at
Caltech, with funds provided by the
Office of Naval Research. A computer
program was written to draw the iso-
gauss contours in a polar coordinate sys-
tem to show the sun as viewed along its
axis.
These polar synoptic charts show that
the magnetic field was directed predom-
inantly outward at both poles of the sun ;
i.e., the situation during this observa-
tional period was similar to that during
the preceding maximum of solar activity.
If these synoptic charts are given a
straightforward interpretation, they
mean that the field at the north pole
had already reversed sign, but that the
field at the south pole had not.
To investigate the problems of inter-
pretation of solar-magnetograph obser-
vations, Stenflo made a number of mag-
netograph records with the 17'.'5 aperture
in the lines Fe I A5250, Fe II A6149, Ca I
A6103, Si I A5690, Cr I A5248, and in the
Zeeman-insensitive lines Fe I A5576 and
Fe I A5124. Smaller apertures were also
used. The analysis of these observations
is under way.
A method to obtain a map of solar
magnetic fields directly in one spectro-
heliogram was developed and success-
fully tested with the spectroheliograph
in the 60-foot tower. The principle of
the method is to modulate the light with
a reversible quarter-wave plate while
the spectroheliograph is scanning. The
method was extended in cooperation with
Dr. A. Bhatnagar to make it possible
to obtain maps of solar-velocity fields
as well.
Stenflo investigated theoretically the
transformation of the kinetic energy of
rotational motion of a sunspot to electro-
magnetic energy in filamentary electric
currents. With this mechanism, the time
needed for preconditioning the solar at-
mosphere for a flare may be of the order
of minutes for small flares and of the
order of hours or days for large flares.
A spectrogram of the O-type star
Von Zeipel 1128 in the globular cluster
M3 was obtained with the Carnegie
image-tube spectrograph at the Hale
telescope by Dr. S. E. Strom of the
Smithsonian Astrophysical Observatory.
From analysis of the spectrum it was
concluded that this unusual object had
Wl > 0.6 3K0 and a He/H ratio close to
that of Population I 0 and B stars.
Despite the fact that other stars in M3
have metal deficiencies of at least a fac-
tor of 10, the measured strength of N III
and 0 II lines suggests much higher
metal abundances in Von Zeipel 1128.
Various arguments concerning its evo-
lutionary history lead to the tentative
conclusion that this star is in a post-
double-shell source phase and most likely
has a carbon-burning core. Spectra were
MOUNT WILSON AND PALOMAR OBSERVATORIES
149
obtained of several A stars in the young
galactic cluster NGC 2264, which falls
below the zero-age main sequence. Anal-
ysis of these spectra is currently under
way.
As a guest investigator, Dr. G. A.
Tammann of the University of Basel
completed in eight nights at the 48-inch
schmidt telescope the three-color obser-
vations for four fields, including a field
around h and x Persei. The plates, taken
in the R, G, U system, will be used for
W. Becker's extensive program of in-
vestigation of the density and luminosity
functions in different directions of the
Galaxy and for the photometry of the
galactic clusters contained on the plates.
Since photoelectric sequences are known
in all four fields, the reduction of the
fields can be begun immediately.
Tammann rediscovered on a 48-inch
schmidt plate, taken on November 19/20,
1968, the periodic comet Perrine-Mrkos
(1968h). He has completed, in coopera-
tion with Sandage, a photometric in-
vestigation of the cluster double-Cepheid
CE Cassiopeia. The results, which in-
clude a calibration of the period-color-
luminosity relation for galactic Cepheids
and the indication that the components
of CE Cas suffer mass loss, are in press.
Dr. A. Terzan of the Lyons Ob-
servatory was a guest investigator for
two months in the summer of 1968. He
worked with the 48-inch schmidt tele-
scope, obtaining three-color {B,V,R)
plates of the central region of the Gal-
axy. The aims were to investigate red
and extremely red objects for interstellar
absorption; to detect new variable stars,
in particular those of RR Lyr type; to
establish sequences of B,V,R magnitudes
for certain globular clusters situated in
the direction of the Galactic center; and
to attempt resolution of the stars in the
large observing cloud "C." Six new star
clusters were discovered, to be further
investigated with the 1.93-meter tele-
scope of the Haute-Provence Observa-
tory. Sequences were established in the
vicinity of NGC 6304, and the ampli-
tudes of 83 variables in the field of the
cluster were determined. Numerous other
variables will be studied with the blink
comparator of the Lyons Observatory.
Dr. R. van Helden of York University,
Toronto, used the coude spectrograph of
the 100-inch telescope to obtain UV
spectrograms of a number of B-type
stars. This is the first phase of a pro-
gram to investigate the hydrogen content
of early-type supergiants.
Dr. N. Visvanathan of the Harvard
College Observatory has used the multi-
channel scanner of the 200-inch telescope
to acquire linear polarization and con-
tinuum measurements of BL Lacertae
from AA5820 to 7980. UBV data and
polarization observations at 4700 A have
been obtained at the Cassegrain focus of
the 100-inch telescope. The continuum is
highly polarized (10.8%), and the polar-
ization is constant in the wavelength
range observed. The red and infrared
continuum is smooth and straight, hav-
ing a steep slope P (rj) a?f2-78 that fits
nicely to all the observed scanner points.
There is no indication of any strong
emission lines or bands in the region
between AA5820 and 10,860. These re-
sults can be explained if the major por-
tion of the continuum of BL Lac is of
synchrotron origin. Further identification
of the radio source VRO 42.22.01 with
BL Lac can be taken to confirm the non-
thermal nature of the continuum of BL
Lac.
Polarization observations of the Crab
pulsar at about 4700 A were made by
Visvanathan in collaboration with Kris-
tian at the prime focus of the 200-inch
telescope. The observations were made at
position angles 0, 90, 180, 270, 0, 30, 120,
210, 300, 30, 60, 150, 240, 330, and 60
degrees. Each angle was observed con-
tinuously for about 2 minutes with a time
resolution of 1 msec. The areas under the
main pulse and the secondary pulse have
been computed for each angle, and the
radiation is found to be polarized. Polar-
ization is the same for the two pulses
and is equal to 10% ±0.2% ; the position
150
CARNEGIE INSTITUTION
angle of the electric vector is 98° (mea-
sured from north toward east). Back-
ground radiation, which is composed
mainly of nebular background, has been
analyzed for polarization. It is constant
in all parts of the light curve and is
equal to 11% ±0.2%; the position angle
of the electric vector is 159° ±1°. The
position angle of the electric vector of
the nebular background within 50 sec
of arc around the pulsar is nearly con-
stant. These observations show that the
polarization of pulses is different from
that of the background radiation. Fur-
ther, the energy emitted between the
pulses has the same polarization angle as
the surrounding nebula.
Visvanathan has observed the follow-
ing optically variable QSS, N-type or
Seyfert galaxies for both polarization
and color: 3C 279, 3C 345, 3C 454.3,
3C 446, 3C 147, PKS 1510-08, 3C 371,
3C 390.3, ZW 1727 + 50, 3C 109. Some
of these objects were observed many
times during the year. All were found to
be polarized in the range from 3 to 10%.
Except for 3C 454.3 and ZW 1727 + 50,
all were faint and therefore were ob-
served at the 200-inch prime focus or
Cassegrain focus. Those that have been
observed frequently showed variation of
position angle from 9° to 80°. The source
3C 454.3 showed variation of position
angle from 48° to 82° and change of
polarization from 5 to 3%. Wavelength
dependence of polarization, both with
multichannel scanner and filter, showed
the following important results: (1)
Lines of Mg II in 3C 446, 3C 345 are
found to be unpolarized; and (2) 3C 371
(N-type galaxy) showed a strong wave-
length dependence of polarization similar
to NGC 1068:— Pv = 10%, 0=57°)
PB = 7%, (9=56°; PF = 5%, 0 = 56°. Thus
there is clearly a mixture of thermal
(galactic) and nonthermal in the con-
tinuum of 3C 371.
Dr. G. Wallerstein of the University
of Washington obtained spectrograms of
the C13-rich CH star HD 209621 in
September 1968. An analysis has been
completed and submitted for publica-
tion. The composition is similar to that
of the C13-poor CH stars in that the
metals are deficient by a factor of 20 as
compared to normal stars. The rare
earths are enhanced, relative to the
metals, by a factor of 8. There is some
evidence that the nitrogen content is
high, which may be expected from the
CNO cycle reactions when C13 is en-
hanced.
Spectrograms of the 45-day Cepheid
SV Vulpeculae have been taken during
rising light to study the behavior of Ha
and other lines formed at various optical
depths. Metallic lines show the expected
effect that high-excitation lines of Si II
begin their shift to the violet first, while
zero-volt lines of Sr II are last affected
by the progressing wave. Ha absorption
is double at minimum light, then single
and displaced to the red of the metallic
lines by 50 km/sec. At maximum a new
absorption component of Ha appears
displaced 40 km/sec to the violet of the
metallic lines. From maximum to at least
phase 0.10 both components are present.
This behavior is entirely different from
that reported by Kraft for the 16-day
Cepheid X Cygni.
ASTROELECTRONICS LABORATORY
Future Data Systems
With a staff of twelve, under the
supervision of Dennison, the Laboratory
has started a program to adapt small
computers for use directly at the tele-
scopes. The current plans call for these
computers to be used as Central Proces-
sing Units (CPU) with the 100-inch,
60-inch, and the 150-foot tower at Mount
Wilson, and the 200-inch and the new
photometric 60-inch at Palomar Moun-
tain. The concept for the new CPU sys-
tems was created by Sachs and Hall to
improve efficiency and to satisfy the spe-
MOUNT WILSON AND PALOMAR OBSERVATORIES
151
cial requirements of modern photoelec-
tric observing instruments. The goal of
this effort was to find the best data and
programming system that would provide
for the maximum possible flexibility at
reasonable cost. The possibility of chang-
ing the inter-relationship of peripheral
telescopic devices; i.e., counters, timers,
encoders, telescope drives, etc., is essen-
tial to a system of this type. With the
new concept, these changes can be ac-
complished by altering only the program
that is stored in the CPU memory. Fur-
thermore, new peripheral devices can be
added without changing any of the exist-
ing circuitry. In addition to handling
data, these new systems will be capable
of controlling the telescopes, setting on
any object in the sky rapidly and ac-
curately. Projects for the 150-foot tower
at Mount Wilson and the 200-inch and
60-inch telescopes at Palomar Mountain
are in progress. Work on the Mount Wil-
son 100-inch and 60-inch telescopes will
begin as soon as funds become available.
Multichannel Spectrophotometer
The largest single project completed
in the last year was the multichannel
spectrophotometer electronic system,
which was installed on the 200-inch dur-
ing July. This project was carried on by
the Laboratory staff in consultation with
Oke. The spectrophotometer itself has
32 photomultipliers used for simultane-
ous pulse-counting photometry. The
high-speed pulse-amplifier discrimina-
tors are mounted on the spectrophotome-
ter, and 32 coaxial cables conduct the
signals from the Cassegrain observing
location to the data room for the 200-
inch.
A special observer-oriented control
panel was designed and constructed for
the spectrophotometer. This display
panel indicates the angle of the grating,
as well as which of several gratings is in
place. It further indicates the slit mask
for the red and blue cold boxes, and
which of the pairs of entrance apertures
is in place. All of this information is
transmitted by multiconductor cables
from the spectrophotometer to the data
room for display and subsequent record-
ing.
The data system for the spectropho-
tometer is the basic 200-inch data system
that was installed last year. At present,
this system records raw data from the
spectrophotometer counters, the grating
wavelength, slit-mask position, grating
number, and aperture size, as well as the
sidereal time, civil time, data-acquisition
time, telescope coordinates, the star
name, and other miscellaneous informa-
tion. All of this information is recorded
on summary punch cards and printed
paper tape.
The spectrophotometer has two circu-
lar entrance apertures: one admits the
light from the observed object plus the
night-sky background, and the other ad-
mits light from an equivalent area of
the sky. A motor-driven mechanical
chopper wheel alternately covers the
apertures. A phase-reference signal is
generated by a magnetic pick-up near
the outer edge of the chopper wheel.
Electronic counters accumulate the pulses
that are generated by the light that is
detected by the 32 photomultipliers. Af-
ter all the data have been recorded on
punched cards, the computer at a later
time can calculate the difference between
the two apertures, and thereby give the
net star intensity.
This design was reevaluated last year.
The system will now be revised by using
16 counter pairs (32 counters total) in-
stead of the 32 counter pairs (64 counters
total) that were originally planned. In
the new system, after each half cycle of
the chopper (approximately 16 msec)
the contents of the counters will be
transferred to a small computer and the
differences calculated for display on a
television-type monitor. A small monitor
will be placed in the observing cage near
the observer to permit him to examine
the data being collected. The basic raw
data and pertinent observing informa-
152
CARNEGIE INSTITUTION
tion will be recorded on magnetic tape
for later computer analysis.
Mount Wilson TV Tests
With the advent of instruments such
as the multichannel spectrophotometer
and the new image-tube spectrograph,
which are capable of measuring radia-
tion from objects that cannot be seen
in a telescope eyepiece, it is imperative
that additional visual aids be developed
for field viewing. To explore the possibil-
ity of using closed-circuit television, ar-
rangements were made with Dr. John
Lowrance of the Princeton University
Observatory to use the 60-inch telescope
for evaluation tests. The purpose of these
tests was to allow the Princeton group
to test their cameras and equipment un-
der good conditions with a large tele-
scope, dark sky, and typical star images;
and to provide an opportunity for eval-
uation of a well-designed system operat-
ing under typical conditions.
The two camera tubes were tested, a
Westinghouse Secon and an RCA Image
Isocon. Observations were made of a
number of different astronomical objects.
One was a cluster in which stars ranging
from magnitude 13 to 22 had been mea-
sured photoelectrical^. Extended objects
such as the Ring nebula in Lyrae and
the nucleus of a galaxy were also ex-
amined. Observations were made with a
bright sky caused by the moon and Los
Angeles lights, and with a dark sky after
moonset and while the valley was cov-
ered by a dense fog. The camera system
uses integration times that are multiples
of 12 seconds. Both systems in times
of the order of one minute or less could
detect stars as faint as magnitude 20.
At the same time, experienced observers
were able consistently to see stars of
magnitude 17. Thus, apart from integra-
tion time considerations, both TV camera
tubes are capable of detecting stars ap-
proximately 3 mag fainter than those
which are visible to the unaided eye.
It can be anticipated that these TV
systems will work effectively with large
telescopes such as the 200-inch. A finite
integration time of 10 sec will require
new guiding techniques, but develop-
ments in this area appear to be relatively
straightforward. The use of integrating
TV cameras will substantially reduce the
time required to find, set, and guide on
very faint stars or galaxies.
Other Activities
Numerous small projects were carried
out in the Astroelectronics Laboratory,
in addition to maintenance of all the
electronic instrumentation for the Ob-
servatories. Approximately 220 trips
were made to the mountain tops to set
up and check out electronic equipment
prior to observing runs. This procedure
reduced lost observing time resulting
from electronic failures to an almost
negligible level.
INSTRUMENTATION
Mount Wilson 60-Inch Modernization
With general coordination by Vaughan,
the 60-inch telescope drive, gears, and
auxiliary mechanical subassemblies have
been completed, and final installation
along with a temporary control console
will be completed shortly. The installa-
tion includes a new declination gear and
both polar axis and declination drive
systems, as well as new cables and wiring
compatible with other Mount Wilson and
Palomar telescope drive and data sys-
tems. The coude flat-mirror mechanism
has been modified for use with the new
coude spectrograph. This work is being
funded under NASA Contract NSR 09-
140-001.
Palomar 60-Inch Photometric Telescope
The 60-inch photometric telescope
mount fabrication and shop assembly
tests under the supervision of Rule were
MOUNT WILSON AND PALOMAR OBSERVATORIES
153
completed on schedule in March. All
components have now been shipped to
Palomar, and are awaiting erection after
the Oscar G. Mayer Memorial Dome has
been completed, about midsummer. Me-
chanical and electrical components of the
telescope have been constructed under
National Science Foundation Grant
GP-5566.
The Oscar G. Mayer Memorial Dome
is nearing completion, although construc-
tion was delayed somewhat by severe
winter rains and by road and manpower
problems of the contractors. Concrete
construction, steel dome room partitions,
and all of the building's mechanical sys-
tems are finished, with final hardware,
dome drives, and auxiliary systems to be
installed by late July 1969.
Multichannel Spectrometer
The multichannel spectrometer has
now been in operation for one year. All
32 photomultipliers have been installed
and any 20 of these can be selected for
operation. A small computer has been
purchased and is being interfaced with
the instrument and the data system.
Within the next few months, when in-
stallation is complete, it will be possible
to operate all 32 channels simultane-
ously. A magnetic-tape output is also
being incorporated into the system. This
will eliminate the one hour of observing
time per night now devoted to punching
the large number of output cards. The
reliability of the over-all system has
proved to be excellent. Occasional com-
ponent failures still occur, but these are
usually detected and corrected before
observing runs begin. The rate of acqui-
sition of data is at least as high as that
predicted when the instrument was being
designed.
Spectrograph Camera
The speed of the Cassegrain image-
intensifier-tube spectrograph installed at
Palomar in 1967 is so high that exposures
in the blue are limited by the sky back-
ground to 15 or 20 minutes. Because of
this, a substantial fraction of the observ-
ing time is used in loading and changing
plate holders. To reduce this operating
time, Bowen and Rule have designed a
new reimaging camera that will use
IIa-0 emulsion on 16-mm Estar-base
motion picture film and will have a
rapid-change mechanism. The camera
reimages the phosphor on the film at 1 : 1
and is of a solid block, all-reflecting de-
sign with an effective focal ratio on each
side of f/1.6. A field of 4x38 mm is
covered with all the light from a point
source falling in an 8-micron circle.
To reduce the instabilities of the film,
the change mechanism provides for each
section of the film to be open to ambient
conditions for two exposure periods prior
to its own exposure. During the exposure,
the film is sealed against the fused silica
block of the camera.
Inter jerometric Photometer
A photoelectric photometer with a
Fabry-Perot scanning filter has been
constructed under the supervision of
Munch and Rickard, to be used for the
observation of extended emission-line
sources. The instrument utilizes a pres-
sure-scanned etalon with 1-inch clear
aperture and interference filters for or-
der isolation. It is designed for operation
at the Cassegrain focus in pulse-counting
modes.
Photometric Calibration oj Direct Plates
A new technique for photographic pho-
tometry has been successfully tested by
Racine with the 60-inch and 200-inch
reflectors. In the converging beam ahead
of the photographic plate, he inserts a
small optical wedge that produces sec-
ondary images of field stars, bearing a
calculable intensity ratio to the primary
images. He has succeeded in reproducing
photoelectrically calibrated sequences
with a systematic accuracy better than
01?! at the plate limit. The method can
154
CARNEGIE INSTITUTION
be used to set up reliable photometric
sequences to the limit of any direct pho-
tograph, a few bright photoelectric stan-
dards being sufficient to determine the
zero point of the magnitude scale. The
main advantage of this technique is that
both the primary and secondary images
are obtained simultaneously on the same
plate and under identical conditions of
guiding, seeing, and transparency, thus
ensuring identical photometric charac-
teristics for the two sets of images.
Fast Data System
To permit an early and effective at-
tack on the problem of measuring very
rapid light variations in pulsars and
other objects, Kristian assembled a
special portable data system. Its main
components are a 1024-channel signal-
averaging computer for averaging photo-
electric data at the telescope, a digital
magnetic-tape recorder for recording the
data from the averager and for collecting
raw photon pulse counts with integration
times down to 100 microsec, and a fre-
quency synthesizer with a very good
quartz-crystal time base and 8-digit fre-
quency resolution. Interfacing was done
by G. H. Snellen of the Caltech Comput-
ing Center.
PHOTOGRAPHIC LABORATORY
The Photographic Laboratory, under
the general supervision of Miller with
Difley assisting, continued the program
of routine tests of all photographic ma-
terials obtained for use at the Mount
Wilson and Palomar telescopes. These
tests assure quality control of the photo-
graphic materials reaching the astrono-
mers and provide the observers with
emulsion-sensitivity data useful in esti-
mating exposure times. Development of
improved testing apparatus is proceed-
ing.
Consultation with staff and visiting
astronomers on photographic aspects of
research programs is a routine service
by the Photographic Laboratory. Effort
is made to have the latest and best in-
formation immediately available on all
aspects of astronomical photography.
Requests for work prints and publica-
tion prints have been heavy. Difley has
performed most of the routine plate tests
and measurements as well as many ex-
periments required to solve problems in
commercial packaging of the Observa-
tories' new MWP-2 photographic de-
veloper. This new developer, reported last
year, is in great demand. It has become
standard for most photographic work
done on Mount Wilson and Palomar
Mountain, and has been adopted by a
number of other observatories. Full de-
tails concerning the developer have been
published and a patent application is in
preparation.
Equipment was tested and installed at
Palomar for baking 10 X 10-inch and 14 X
14-inch plates for the 48-inch schmidt
telescope. Such baking makes possible
application of the relatively new Kodak
Type IHa-J plates with an increase of
nearly 2 magnitudes in the limiting mag-
nitude of the 48-inch telescope.
Miller was appointed chairman of the
American Astronomical Society's Work-
ing Group on Photographic Materials
and in this capacity has initiated in-
vestigations of a number of problems
related to astronomical photography. In-
formation of general interest gathered
by the Group will be published in a new
series of papers called the AAS Photo
Bulletin.
In connection with the centennial of
the birth of George Ellery Hale, several
displays of material related to the his-
tory of the Observatories and Hale's
contributions to astronomy were pre-
pared. These exhibits have traveled
widely.
MOUNT WILSON AND PALOMAR OBSERVATORIES
155
BIG BEAR SOLAR OBSERVATORY
Construction was begun on the tower
and laboratory of the Big Bear Solar Ob-
servatory at Big Bear Lake in the San
Bernardino Mountains in October 1968
and completed in April 1969 by the J.
Putnam Hank Construction Company.
Great difficulties were occasioned by the
unusually severe winter, which necessi-
tated suspension of the work for some
time. Installation of the dome by tech-
nicians of the solar group is under way,
and it is expected that the solar equa-
torial telescope and the coude spectro-
graph will be installed during the sum-
mer. Scientific activity at the new site is
scheduled to begin in July 1969.
The California Institute of Technol-
ogy has purchased the land formerly
leased from the Bear Valley Develop-
ment Company with the exception of the
strip of land under the lake, which is
still under long-term lease from the Bear
Valley Mutual Water Company.
SOUTHERN HEMISPHERE OBSERVATORY
After a careful appraisal of the avail-
able observatory sites in Chile, and with
consideration of the technical, legal, and
political factors, a decision was made to
acquire an area including Las Campanas,
an 8100-foot mountain at a latitude of
about 29°02'S. Steps were taken to pur-
chase 20,800 hectares (208 square kilo-
meters) from the Government of Chile
and, after authorization by the Congress,
as well as approval by the Ministry of
Lands and by the President of the Re-
public, the transaction was scheduled for
final completion in July 1969.
Under the supervision of Adkison,
who was appointed Associate for Admin-
istration on October 1, 1968, the work of
the project was organized to provide for
development of water, construction of an
access road, protection from interfering
mining claims, and detailed topographic
mapping of the summit ridge, among
other requirements. Plans developed
earlier by Rule for mountain-top instal-
lation of observatory facilities and ser-
vices are now being reviewed by Rule and
Adkison to adapt them to requirements
of the new location. Meteorological ob-
servations are being continued on Las
Campanas.
Property known as Colina El Pino in
La Serena was purchased as a site for a
future project office, warehouse, and
vehicle yard.
BIBLIOGRAPHY
Abt, Helmut, Peter S. Conti, Armin J. Deutsch,
and George Wallerstein, The mass and other
characteristics of the magnetic star HD 98088.
Astrophys. J., 153, 177-186, 1968.
Adelman, Saul J., Peculiar stars in the Lac OBI
association. Publ. Astron. Soc. Pacific, 80,
329-331, 1968.
Arp, Halton, Optical observations of two Sey-
fert galaxies. Astron. J., 73, 847-848, 1968.
Arp, Halton, Relation between quasi-stellar
radio sources and radio compact and radio N
galaxies. Astrophys. J. (Letters), 153, L33-
L38, 1968.
Arp, Halton, Further comments on the ring
around M81. Soviet Astron.-AJ, 12, 715-716,
1968.
Arp, Halton, see also Greenstein, Jesse L.
Bahcall, John N., Jesse L. Greenstein, and
Wallace L. W. Sargent, The absorption-line
spectrum of the quasi-stellar radio source
Pks 0237-23. Astrophys. J., 315, 689-698, 1968.
Bahcall, John N., Patrick S. Osmer, and
Maarten Schmidt, On the absorption spec-
trum of Ton 1530. Astrophys. J. (Letters),
156, L1-L6, 1969.
Barbon, Roberto, The frequency of supernovae
in clusters of galaxies. Astron. J., 73, 1016—
1020, 1968.
Baschek, Bodo, and Leonard Searle, The
chemical composition of the \ Bootis stars.
Astrophys. J., 155, 537-554, 1969.
156
CARNEGIE INSTITUTION
Becklin, E. E., see Neugebauer, G.; Oke, J. B.;
Westphal, J. A.
Bergh, Sidney van den, Observation of the
nucleus of the radio galaxy M82. Astrophys.
J. (Letters), 156, L19-L20, 1969.
Bergh, Sidney van den, Globular clusters in the
Andromeda nebula. Nature, 221, 48-49, 1969.
Bergh, Sidney van den, see also DuPuy, David;
McClure, Robert D.; Schmidt, Karl-Heinz;
Spinrad, Hyron.
Boesgaard, Ann Merchant, Isotopes of mag-
nesium in stellar atmospheres. Astrophys. J.,
154, 1185-1190, 1968.
Boldt, E., see Bradt, H.
Bolton, J. G., see Searle, Leonard.
Bradt, H., S. Naranan, S. Rappaport, F. Zwicky,
H. Ogelman, and E. Boldt, Upper limit on
X ravs from a new supernova. Nature, 218,
856-857, 1968.
Bradt, H., S. Rappaport, W. Mayer, R. E.
Nather, B. Warner, M. MacFarlane, and J.
Kristian, X-ray and optical observations of
the Pulsar NP 0532 in the Crab Nebula.
Nature, 222, 728-730, 1969.
Bumba, V., and Robert Howard, On the solar
source of recurrent geophysical effects. Bull.
Astron. Inst. Czech., 20, 61-62, 1969.
Bumba, V., and Robert Howard, On long-term
forecasts of solar activity. Solar Flares and
Space Research, pp. 387-396, Z. Svestka and
C. de Jager, eds., North-Holland Publishing
Co., Amsterdam, 1969.
Bumba, V., and Robert Howard, Solar activity
and recurrences in magnetic-field distribution.
Solar Physics, 7, 28-38, 1969.
Bumba, V., R. Howard, M. Kopecky, and G. V.
Kuklin, Some irregularities in the distribu-
tion of large-scale magnetic fields on the Sun.
Bull. Astron. Inst. Czech., 20, 18-21, 1969.
Bumba, V., see also Howard, Robert.
Cohen, Judith G., The carbon abundance of
Population II stars. Astrophys. Letters (En-
gland), 2, 163-164, 1968.
Cohen, Judith G., A. J. Deutsch, and Jesse L.
Greenstein, The spectrum of a2 CVn, 5000-
6700 A. Astrophys. J., 156, 629-652, 1969.
Conti, P. S., and Armin J. Deutsch, Color
anomalies and metal deficiencies in solar-
type disk-population stars. Bull. Astron. Inst.
Czech., 19, 263-264, 1968.
Conti, Peter S., see Abt, Helmut.
Davis, D. N., and P. C. Keenan, Is there NbO
in S-type stars? Publ. Astron. Soc. Pacific, 81,
230-237, 1969.
Demarque, Pierre, F. D. A. Hartwick, and
M. D. T. Naylor, Some uncertainties in
Population II models near the main sequence.
Astrophys. J ., 154, 1143-1146, 1968.
Deutsch, Armin J., O. C. Wilson, and P. C.
Keenan, High-dispersion classification of
K2-M6 giants of high and low velocity.
Astrophys. J., 156, 107-115, 1969.
Deutsch, Armin J., see also Abt, Helmut;
Cohen, Judith G.; Conti, P. S.
Difley, John A., Two photographic developers
for astronomical use. Astron. J., 73, 762-769,
1968.
DuPuy, David, John Schmitt, Robert McClure,
Sidney van den Bergh, and Rene Racine,
Optical observations of BL Lac = VRO
42.22.01. Astrophys. J. (Letters), 156, L135-
L139, 1969.
Eggen, Olin J., Narrow- and broad-band pho-
tometry of red stars, II, Dwarfs. Astrophys.
J., Suppl. Ser., 16, No. 142, 49-96, 1968.
Eggen, Olin J., Luminosities, colors, motions,
and distribution of faint blue stars. Astro-
phys. J., Suppl. Ser., 16, No. 143, 97-142,
1968.
Garmire, G., see Neugebauer, G.
Garrison, Robert F., Erratum re "The spectrum
of star No. 1 in NGC 2024." Publ. Astron.
Soc. Pacific, 80, 755, 1968.
Greenstein, Jesse L., Astronomy, in Americana
Annual, pp. 103, 105-106, The Americana
Corporation, New York, 1969.
Greenstein, Jesse L., The pulsars: cosmic riddle,
in Americana Annual, p. 104, The Americana
Corporation, New York, 1969.
Greenstein, Jesse L., Red and black degenerate
stars. Comments in Astrophys., 1, 62-72, 1969.
Greenstein, Jesse L., A night on Palomar
Mountain. Engineering and Science, 32,
12-14, 1969.
Greenstein, Jesse L., Introductory address, in
Low-Luminosity Stars, pp. xv-xviii, S. S.
Kumar, ed., Gordon and Breach, Publishers,
London, 1969.
Greenstein, Jesse L., Faint, metal-poor, sub-
luminous and red degenerate stars, in Low-
Luminosity Stars, pp. 281-295, S. S. Kumar,
ed., Gordon and Breach, Publishers, London,
1969.
Greenstein, Jesse L., and Halton Arp, A spec-
troscopic flare of Wolf 359. Astrophys. Letters
(England), 3, 149-152, 1969.
Greenstein, Jesse L., and Valdar Oinas, Two K
dwarfs with enhanced carbon molecular
bands. Astrophys. J. (Letters), 163, L91-L94,
1968.
MOUNT WILSON AND PALOMAR OBSERVATORIES
157
Greenstein, Jesse L., see also Bahcall, John N.;
Cohen, Judith G.; Kodaira, K.; Kraft,
Robert P.; Stoeckly, Robert.
Grevesse, N., see Swings, J. P.
Hardorp, J., and M. Scholz, On the surface
gravity and temperature of Vega. Z. Astro-
phys., 68, 350-362, 1968.
Hartwick, F. D. A., A two-dimensional clas-
sification for galactic globular clusters. Astro-
phys. J., 154, 475-481, 1968.
Hartwick, F. D. A., and Allan Sandage, The
color-magnitude diagram for the abnormally
strong-line globular cluster M69. Astrophys.
J., 153, 715-722, 1968.
Hartwick, F. D. A., see also Demarque, Pierre.
Heintze, J. R. W., Temperature, gravity, and
mass of Vega, Sirius, and r Herculis. Bull.
Astron. Inst. Netherlands, 20, 1-25, 1968.
Heintze, J. R. W., A tentative model of the
solar atmosphere and the low chromosphere.
Bull. Astron. Inst. Netherlands, 20, 137-153,
1969.
Heintze, J. R. W., On the temperature scale of
B-type stars. Bull. Astron. Inst. Netherlands,
20, 154-162, 1969.
Hiltner, W. A., see Schild, Rudolph E.
Howard, Robert, An astronomer in Czechoslo-
vakia. Engineering and Science, 32, 22-24,
1969.
Howard, Robert, Reply to K. R. Sivaraman.
Solar Physics, 6, 154, 1969.
Howard, Robert, Solar research at the Mount
Wilson and Palomar Observatories. Solar
Physics, 7, 153-158, 1969.
Howard, Robert, and V. Bumba, On forecasts
of interplanetary and geophysical conditions.
Solar Flares and Space Research, pp. 397-404,
Z. Svestka and C. de Jager, eds., North-
Holland Publishing Co., Amsterdam, 1969.
Howard, Robert, see also Bumba, V.; Wilcox,
John M.
Julian, William H., Overstability of thin stellar
systems. Astrophys. J., 155, 117-122, 1969.
Katem, Basil, see Sandage, Allan.
Keenan, P. C, see Davis, D. N.; Deutsch,
Armin J.
Kodaira, K., Jesse L. Greenstein, and J. B. Oke,
Abundances in two horizontal-branch stars.
Astrophys. J., 155, 525-536, 1969.
Kopecky, M., see Bumba, V.
Kowal, Charles T., The absolute magnitudes
of supernovae. Astron. J., 73, 1021-1024, 1968.
Kowal, Charles T., see also Zwicky, Fritz.
Kozlovsky, Ben-Zion, and Harold Zirin, The
O VI emission from the Sun. Solar Physics, 5,
50-54, 1968.
Kraft, Robert P., and Jesse L. Greenstein,
A new method for finding faint members of
the Pleiades, in Low-Luminosity Stars, pp.
65-82, S. S. Kumar, ed., Gordon and Breach,
Publishers, London, 1969.
Kristian, Jerome, An upper limit for the optical
luminosity of the pulsating radio sources
CP 0950 and CP 1133. Astrophys. J. (Let-
ters), 154, L99-L100, 1968.
Kristian, Jerome, see also Bradt, H.; Neuge-
bauer, G.; Sandage, Allan; Westphal, J. A.
Kuklin, G. V., see Bumba, V.
Lackner, Dora R.
Zirin, Harold.
Lambert, D. L., Radiation pressure and the
composition of the solar corona. Astrophys.
Letters (England), 2, 37-39, 1968.
Lambert, D. L, and B. E. J. Pagel, The dis-
sociation equilibrium of H" in stellar at-
mospheres. Monthly Notices Roy. Astron.
Soc, 141, 299-315, 1968.
Lambert, D. L., E. A. Mallia, and B. Warner,
The abundances of the elements in the solar
photosphere, VII: Zn, Ga, Ge, Cd, In, Sn,
Hg, Tl, and Pb. Monthly Notices Roy.
Astron. Soc, 142, 71-95, 1969.
Lambert, D. L., E. A. Mallia, and B. Warner,
Forbidden lines of Ca II in the photospheric
spectrum. Solar Physics, 7, 11-16, 1969.
Lambert, see also Swings, J. P.
Leighton, R. B., see Neugebauer, G.
Luyten, Willem J., see Sandage, Allan.
McClure, Robert D., and Sidney van den
Bergh, UBV observations of field galaxies.
Astron. J., 73, 1008-1010, 1968.
McClure, Robert D., see also DuPuy, David.
MacFarlane, M., see Bradt, H.
Mallia, E. A., see Lambert, D. L.
Manwell, Tom, and Michal Simon, Application
of a random-event quasar model to the
optical variability of 3C 273. Astron. J., 73,
407-411, 1968.
Mayer, W., see Bradt, H.
Miinch, Guido, Small-scale thermal homo-
geneity of the Orion Nebula, in Interstellar
Ionized Hydrogen, pp. 507-516, Yervant
Terzian, ed., W. A. Benjamin, Inc., New
York, 1968.
Naranan, S., see Bradt, H.
Nather, R. E., see Bradt, H.
Naylor, M. D. T., see Demarque, Pierre.
158
CARNEGIE INSTITUTION
Neugebauer, G., and R. B. Leighton, Two-
Micron Sky Survey, A Preliminary Catalog,
National Aeronautics and Space Administra-
tion, Washington, D. C, 1969.
Neugebauer, G., J. B. Oke, E. E. Becklin, and
G. Garmire, A study of visual and infrared
observations of Sco XR-1. Aslrophys. J., 155,
1-10, 1969.
Neugebauer, G., E. E. Becklin, J. Kristian,
R. B. Leighton, G. Snellen, and J. A. West-
phal, Infrared and optical measurements of
the Crab pulsar NP 0532. Astrophys. J.
(Letters), 156, L115-L120, 1969.
Neugebauer, G., see also Oke, J. B.; Westphal,
J. A.
Newell, E. B., A. W. Rodgers, and Leonard
Searle, The blue horizontal-branch stars of
u Centauri. Astrophys. J., 156, 597-608, 1969.
Ogelman, H., see Bradt, H.
Oinas, Valdar, see Greenstein, Jesse L.
Oke, J. B., Continuum energy distributions of
Seyfert galaxies and related objects. Astron.
J., 73, 849-850, 1968.
Oke, J. B., Photoelectric spectrophotometry of
the Crab pulsating radio source NP 0532.
Astrophys. J. (Letters), 156, L49-L53, 1969.
Oke, J. B., A multichannel photoelectric spec-
trometer. Publ. Astron. Soc. Pacific, 81, 11-22,
1969.
Oke, J. B., and Allan Sandage, Energy distribu-
tions, K corrections, and the Stebbins-Whit-
ford effect for giant elliptical galaxies. Astro-
phys. J., 154, 21-32, 1968.
Oke, J. B., G. Neugebauer, and E. E. Becklin,
Spectrophotometry and infrared photometry
of BL Lacertae. Astrophys. J. (Letters), 156,
L41-L43, 1969.
Oke, J. B., see also Kodaira, K.; Neugebauer,
G.; Westphal, J. A.
Osmer, Patrick S., see Bahcall, John N.
Pagel, B. E. J., see Lambert, D. L.
Peach, John V., Optical variations in quasi-
stellar objects. Nature, 222, 439^42, 1969.
Preston, George W., The magnetic field of
HD 215441. Astrophys. J., 156, 967-982, 1969.
Preston, George W., The nature of the variabil-
ity of HD 19216. Astrophys. J., 156, 1175-
1176, 1969.
Preston, George W., and Kazimierz Stepien,
The light, magnetic, and radial velocity
variations of HD 10783. Astrophys. J., 154,
971-974, 1968.
Preston, George W., Kazimierz Stepien, and
Sidney Carne Wolff, The magnetic field and
light variations of 17 Comae and k Cancri.
Astrophys. J., 156, 653-660, 1969.
Racine, Rene, The distance of the Cepheid
SU Cassiopeiae. Astron. J., 73, 588-589, 1968;
erratum and addendum, ibid., 74, 572, 1969.
Racine, Rene, 2000 globular clusters in M87.
J. Roy. Astron. Soc. Canada, 62, 367-376,
1968.
Racine, Rene, Preliminary colors of faint ob-
jects around M87. Publ. Astron. Soc. Pacific,
80, 326-329, 1968.
Racine, Rene, see also DuPuy, David.
Rappaport, S., see Bradt, H.
Rees, M. J., Polarization and spectrum of
the primeval radiation in an anisotropic uni-
verse. Astrophys. J. (Letters), 153, L1-L2,
1968.
Rees, M. J., Proton synchrotron emission from
compact radio sources. Astrophys. Letters
(England), 0,1-4, 1968.
Rodgers, A. W., see Newell, E. B.
Rudnicki, Konrad, The dependence of the
velocity body of stars on space location, in
Vistas in Astronomy, Vol. 11, pp. 173-180,
A. Beer, ed., Pergamon Press, Oxford and
New York, 1968.
Rudnicki, Konrad, and Irena Tarrare, Red-
shifts of six galaxies in the vicinity of the
Coma cluster. Acta Astron., 19, 171-172, 1969.
Sandage, Allan, The time scale for creation
(Part I), Astron. Soc. Pacific Leaflet No. 477,
8 pp., March 1969; (Part II) ibid., No. 478,
8 pp., April 1969.
Sandage, Allan, Age of creation, in Science
Year 1968, World Book Science Annual, pp.
56-69, World Book Field Enterprises Educa-
tional Services, Chicago, 111., 1969.
Sandage, Allan, and Basil Katem, The color-
magnitude diagram for the globular cluster
NGC 5897. Astrophys. J., 153, 569-576, 1968.
Sandage, Allan, and Willem J. Luyten, On the
nature of faint blue objects in high galactic
latitudes, II, Summary of photometric results
for 301 objects in seven survey fields. Astro-
phys. J., 155, 913-918, 1969.
Sandage, Allan, and G. A. Tammann, Photo-
metrie des Haufen-Doppel-Cepheiden CE
Cas. Mitt. Astron. Gesellschaft, No. 25, 147,
1968.
Sandage, Allan, Basil Katem, and Jerome Kris-
tian, An indication of gaps in the giant
branch of the globular cluster M15. Astro-
phijs. J. (Letters), 153, L129-L134, 1968.
MOUNT WILSON AND PALOMAR OBSERVATORIES
159
Sandage, Allan, J. A. Westphal, and Jerome
Kristian, Results of five nights of continuous
monitoring of the optical flux from Sco X-l.
Astrophys. J., 156, 927-942, 1969.
Sandage, Allan, see also Hartwick, F. D. A.;
Oke,J.B.; Westphal, J. A.
Sanduleak, N., see Schild, Rudolph, E.;
Stephenson, C. B.
Sargent, W. L. W., New observations of com-
pact galaxies. Astron. J., 73, 893-895, 1968.
Sargent, W. L. W., The redshifts of galaxies in
the remarkable chain VV 172. Astrophys. J.
{Letters), 153, L135-L138, 1968.
Sargent, W. L. W., see also Bahcall, John;
Searle, Leonard ; Zwicky, Fritz.
Scargle, Jeffrey D., Activity in the Crab
Nebula. Astrophys. J., 153, 569-576, 1968.
Schild, Rudolph E., W. A. Hiltner, and N.
Sanduleak, A spectroscopic study of the asso-
ciation Scorpius OB 1. Astrophys. J., 156,
609-616, 1969.
Schild, Rudolph E., see also Stephenson, C. B.
Schmidt, Karl-Heinz, and Sidney van den
Bergh, Zur zeitlichen Variation des Metallge-
haltes in der Galaxis. Astron. Nachr., 291,
115-124, 1969.
Schmidt, Maarten, Quasistellar objects, in Ann.
Rev. Astron. Astrophys., 7, pp. 527-552,
Annual Reviews, Inc., Palo Alto, Calif., 1969.
Schmidt, Maarten, see also Bahcall, John N.;
Westphal, J. A.
Schmidt, Maarten, Quasi-stellar radio sources
and objects, in Intern. Astron. Union Symp.
No. 29, Instability Phenomena in Galaxies,
pp. 239-244, M. Arakeljan, ed., Mezdunarod-
naja Kniga, Moscow, 1967.
Schmitt, John, see DuPuy, David.
Scholz, M., see Hardorp, J.
Searle, Leonard, and J. G. Bolton, Redshifts
of fifteen radio sources. Astrophys. J. {Let-
ters), 154, L101-L104, 1968.
Searle, Leonard, and Wallace L. W. Sargent,
The strength of H/3 in extragalactic objects
with broad emission lines. Astrophys. J., 153,
1003-1006, 1968.
Searle, Leonard, see also Baschek, Bodo;
Newell, E. B.
Simon, Michal, Asymptotic form for synchro-
tron spectra below Razin cutoff. Astrophys.
J., 156, 341-344, 1969.
Simon, Michal, Time dependence of Razin
spectra in Type IV solar radio bursts. Astro-
phys. Letters (England), 3, 23-24, 1969.
Simon, Michal, see also Manwell, Tom.
Snellen, G., see Neugebauer, G.; Westphal,
J. A.
Spinrad, Hyron, Benjamin J. Taylor, and
Sidney van den Bergh, The M7 giants in the
nuclear bulge of the Galaxy. Astron. J., 74,
525-528, 1969.
Stenflo, J. O., see Bhatnagar, A.
Stephenson, C. B., N. Sanduleak ,and Rudolph
E. Schild, A new hot, rapid variable star.
Astrophys. Letters (England), 1, 247-248,
1968.
Stepien, Kazimierz, see Preston, George W.
Stoeckly, Robert, and Jesse L. Greenstein,
Spectrophotometry of a B-type star in the
globular cluster M13. Astrophys. J., 164, 909-
922, 1968.
Swings, J. P., D. L. Lambert, and N. Grevesse,
Forbidden sulphur lines in the solar spec-
trum. Solar Physics, 6, 3-11, 1969.
Tammann, G. A., see Sandage, Allan.
Tarrare, Irena, see Rudnicki, Konrad.
Taylor, Benjamin J., see Spinrad, Hyron.
Terzan, Agop, Six nouveaux amas stellaires
(Terzan 3-8) dans la region du centre de la
Voie lactee et les constellations du Scorpion
et du Sagittaire. Compt. Rend. Acad. Sci.
Paris, 267, 1245-1248, 1968.
Trimble, Virginia, Motions and structure of the
filamentary envelope of the Crab Nebula.
Astron. J., 73, 535-547, 1968.
Tsuji, Takashi, Model atmospheres of M dwarf
stars, in Low-Luminosity Stars, pp. 457-482,
S. S. Kumar, ed., Gordon and Breach, Pub-
lishers, London, 1969.
Visvanathan, N., Optical polarization in quasi-
stellar sources. Astrophys. J. {Letters), 153,
L19-L22, 1968.
Wallerstein, George, see, Abt, Helmut.
Warner, B., see, Bradt, H.; Lambert, D. L.
Weart, Spencer R., and Harold Zirin, The birth
of active regions. Publ. Astron. Soc. Pacific,
81, 270-273, 1969.
Westphal, J. A., and G. Neugebauer, Infrared
observation of Eta Carinae to 20 microns.
Astrophys. J. {Letters), 156, L45-L48, 1969.
Westphal, J. A., Allan Sandage, and Jerome
Kristian, Rapid changes in the optical in-
tensity and radial velocities of the X-ray
source Sco X-l. Astrophys. J., 154, 139-156,
1968.
160
CARNEGIE INSTITUTION
Westphal, J. A., Jerome Kristian, Grant Snel-
len, Allan Sandage, Maarten Schmidt, J. B.
Oke, Gerry Neugebauer, and E. E. Becklin,
On the nature of Ryle and Bailey's candidate
star for the pulsating radio source CP 1919.
Astrophys. J., 155, L109-L114, 1969.
Westphal, J. A., see also Neugebauer, G.; San-
dage, Allan.
Wilcox, John M., and Robert Howard, A large-
scale pattern in the solar magnetic field.
Solar Physics, 5, 564-574, 1968.
Wilson, Olin C., Flux measurements at the
centers of stellar H and K lines. Astrophys.
J., 153, 221-234, 1968.
Wilson, Olin C., Calibration apparatus at Mt.
Wilson and Mt. Palomar. Bull. Am. Astron.
Soc, 1, 154, 1969.
Wilson, Olin C, Chromospheric variations in
main-sequence stars, in Low-Luminosity
Stars, pp. 103-106, S. S. Kumar, ed., Gordon
and Breach, Publishers, London, 1969.
Wilson, Olin C, see also Deutsch, Armin J.
Wolff, Sidney Carne, see Preston, George W.
Zirin, Harold, Abundance analyses from ex-
treme-ultraviolet emission lines. Astrophys.
J., 154, 799-801, 1968.
Zirin, Harold, Mass motions in loops, sprays,
surges, etc., in Nobel Stjmposium 9, Mass
Motions in Solar Flares and Related Phe-
nomena, pp. 131-136, Yngve Ohman, ed.,
John WTiley & Sons, New York, 1969.
Zirin, Harold, Observations of stellar chromo-
spheres using the He 10830 line, in Nobel
Symposium 9, Mass Motions in Solar Flares
and Related Phenomena, pp. 239-242, Yngve
Ohman, ed., John Wiley & Sons, New York,
1969.
Zirin, Harold, George Ellery Hale, 1868-1938.
Solar Physics, 5, 435-441, 1968.
Zirin, Harold, Two prominence eruptions and
the problem of emission. Solar Physics, 7,
243-252, 1969.
Zirin, Harold, and Dora R. Lackner, The solar
flares of August 28 and 30, 1966. Solar Physics,
6, 86-103, 1969.
Zirin, Harold, see also Kozlovsky, Ben-Zion;
Weart, Spencer R.
Zwicky, Fritz, Catalogue of Galaxies and of
Clusters of Galaxies, Vols. IV and VI, Cali-
fornia Institute of Technology, Pasadena,
California, 1968.
Zwicky, Fritz, Discovery, Invention, Research,
The Macmillan Co., New York, 1969.
Zwicky, Fritz, Physics and chemistry on the
Moon, in Research in Physics and Chemistry,
Proc. Third Intern. Laboratory (LIL) Symp.,
1967, pp. 1-27, C. H. Roadman, H. Strughold,
and R. B. Mitchell, eds., Pergamon Press,
Oxford and New York, 1969.
Zwicky, Fritz, Physics of the universe, in Proc.
4th Intern. Symp. on Bioastronautics and the
Exploration of Space, pp. 63-81, 527, 533,
595-608, Brooks Air Force Base, Texas, 1969.
Zwicky, Fritz, 1967 Palomar supernova search.
Publ. Astron. Soc. Pacific, 80, 462-465, 1968.
Zwicky, Fritz, Zukunftsbild eines Astrophy-
sikers, in Was Wird M or gen Anders Seinf,
pp. 1-12, O. Herreche, ed., Walter Verlag,
Olten, Switzerland, 1969.
Zwicky, Fritz, W. L. W. Sargent, and C. Kowal,
The 1968 Palomar supernova search. Publ.
Astron. Soc. Pacific, 81, 224-229, 1969.
Zwicky, F., see also Bradt, H.
STAFF AND ORGANIZATION
Dr. Sidney van den Bergh of the Uni-
versity of Toronto came to the Observa-
tories as Research Associate for one year.
While here, he engaged in a number of
investigations, including especially the
study of globular clusters in M31.
Sandage spent the year on leave, work-
ing on a variety of Southern Hemisphere
problems at the Mount Stromlo and
Siding Spring Observatories in Australia.
Research Division
Distinguished Service Member, Carnegie In-
stitution of Washington
Ira S. Bowen
Staff Members
Halton C. Arp
Horace W. Babcock, Director
Edwin W. Dennison
Armin J. Deutsch
Jesse L. Greenstein x
Robert F. Howard
Jerome Kristian
Robert B. Leighton 2
Guido Munch 3
J. Beverley Oke 3
George W. Preston III
Bruce H. Rule, Chief Engineer
Allan R. Sandage
Wallace L. W. Sargent 4
Leonard T. Searle
MOUNT WILSON AND PALOMAR OBSERVATORIES
161
Maarten Schmidt 3
Arthur H. Vaughan, Jr.
Olin C. Wilson
Harold Zirin 5
Staff Members Engaged in Post-Retirement
Studies
Alfred H. Joy
Henrietta H. Swope
Fritz Zwicky
Research Associate
Sidney van den Bergh
Staff Associates
Bruce C. Murray 6
Gerry Neugebauer 7
James A. Westphal 8
Carnegie Fellows
Arvind Bhatnagar
Deane M. Peterson
Rene Racine 9
Natarajan Visvanathan 10
Research Fellows
J. David Bohlin
Ardon R. Hyland
William H. Julian
Keiichi Kodaira
Ben-Zion Kozlovsky 1X
David L. Lambert
James J. Rickard
Rudolph E. Schild 9
Michael Scholz
Michal Simon
Takashi Tsuji 10
Spencer R. Weart
Senior Research Assistants
Sylvia Burd
Dorothy D. Locanthi
A. Louise Lowen
Anneila Sargent
Research Assistants
John M. Adkins
Frank J. Brueckel
Thomas A. Cragg
Basil N. Katem
Charles Kowal
James D. Pederson
Malcolm S. Riley
Merwyn G. Utter 12
Grace D. Vess
Graduate Student Observers
Saul J. Adelman
Dennis D. Baker
Clark G. Christensen
Jay A. Frogel
Theodore Hilgeman
Torrence V. Johnson
Hugh H. Kieffer
Dennis L. Matson
Robert W. O'Connell
Valdar Oinas
Patrick S. Osmer
Sven E. Persson
Edward W. Ritz
Donna E. Weistrop
Photographic Laboratory
William C. Miller, Research Photographer
John A. Difley, Photographer
Clare Neal, Solar Photographic Assistant 13
Paula Swanson, Solar Photographic Assis-
tant
Librarians
Charlotte Fournier 14
Marjorie A. Henderson
Instrument Design and Construction
Lawrence E. Blackee, Supervisor, Elec-
tronic Services
Maynard K. Clark, Senior Engineering As-
sistant
John P. Cowley, Laboratory Specialist
Floyd E. Day, Head Optician
Stephen Doro, Machinist
Raymond Dreiling, Machinist
Eugene B. Fair, Optician
Robert D. Georgen, Machinist
Donn M. Hall, Electronics Engineer
Joseph P. Hsu, Associate Electronics Engi-
neer
Fred Idzinga, Senior Electronics Specialist
Melvin W. Johnson, Optician
Margaret Katz, Technical Assistant
Wilfred H. Leckie, Draftsman
Ernest 0. Lorenz, Engineering Field Assis-
tant
Richard Lucianio, Engineering Assistant15
Martin J. Olsiewski, Electronics Specialist
Frederick G. O'Neil, Machinist
Gerald Preston, Technical Aide 16
John D. Raphael, Electronics Specialist 17
Edward H. Rehnborg, Senior Engineer
Rudolf E. Ribbens, Designer and Shop
Superintendent
Howard G. Sachs, Senior Engineer
162
Benny W. Smith, Electronics Specialist18
Robert G. Stiles, Optician
David Thompson, Senior Technical Assis-
tant
William Thompson, Electronics Technician
Eli A. Tilajef, Junior Engineer
Virgal Z. Vaughan, Electronics Specialist
Madeline B. Williams, Draftswoman
Ralph W. Wilson, Machinist 19
Felice Woodworth, Draftswoman-Illustra-
tor
Maintenance and Operation
Mount Wilson Observatory and Offices
Fern V. Borgen, Telephone Operator-
Typist
Clyde B. Bornhurst, Mechanic
Herman E. Carpentier, Carpenter
Hugh T. Couch, Superintendent of Build-
ings and Grounds
Helen S. Czaplicki, Typist-Editor
Sue H. DeWitt, Secretary
Hazel M. Fulton, Stewardess
Eugene L. Hancock, Night Assistant
Elsie Hanlon, Stewardess
Judith A. Harstine, Secretary
Anne Hopper, Accountant 20
Mario Jacques, Night Assistant
Rienaldo M. Jacques, Head Steward
Ethel Marzalek, Stewardess 20
Frances Maynor, Stewardess 20
Alfred H. Olmstead, Custodian
William D. St. John, Construction Aide
Glen Sanger, Driver
Henry P. Schaefer, Night Assistant
CARNEGIE INSTITUTION
Clair E. Sharp, Accountant
Elizabeth M. Shuey, Secretary 1X
Benjamin B. Traxler, Mountain Super-
intendent
Frank Trylko, Custodian
Frederick P. Woodson, Assistant to the
Director
Palomar Observatory and Robinson Labora-
tory
Ray L. Ballard, Senior Administrative As-
sistant
Doris J. Brenner, Secretary
Betty Browne, Secretary
Jan Adriian Bruinsma, Painter and Gen-
eral Maintenance
Maria J. Bruinsma, Lodge Stewardess
Eleanor Ellison, Librarian
Beulah Greenlee, Lodge Stewardess
Frank V. Greenlee, Sr., Custodian
Daniel J. Hargraves, Mechanic and Relief
Night Assistant
Liselotte M. Hauck, Secretary
Victor A. Hett, Night Assistant
Helen Holloway, Secretary
Charles E. Kearns, Assistant Mountain
Superintendent
J. Luz Lara, Mechanic
Carl D. Palm, Night Assistant
Catherine T. Paul, Secretary
Marilynne J. Rice, Secretary
Kenneth R. Robinson, Night Assistant and
Maintenance
Robert T. Snow,21 Temporary Assistant
Gary M. Tuton, Senior Night Assistant
William C. Van Hook, Mountain Superin-
tendent
Ardith Walthers, Secretary
1 Professor of Astrophysics and Executive
Officer for Astronomy, California Institute of
Technology.
2 Professor of Physics, California Institute of
Technology.
3 Professor of Astronomy, California Insti-
tute of Technology.
Associate Professor of Astronomy, Cali-
fornia Institute of Technology.
5 Professor of Astrophysics, California Insti-
tute of Technology.
6 Professor of Planetary Science, California
Institute of Technology.
7 Associate Professor of Physics, California
Institute of Technology.
8 Senior Research Fellow in Planetary Sci-
ence, California Institute of Technology.
9 Resigned June 30, 1969.
10 Resigned September 30, 1968.
11 Resigned March 31, 1969.
12 Terminated March 27, 1969.
13 Resigned February 28, 1969.
14 Resigned October 18, 1968.
15 Resigned September 27, 1968.
10 Resigned August 11, 1968.
17 Resigned January 24, 1969.
18 Resigned January 31, 1969.
19 Resigned March 15, 1969.
20 Resigned November 30, 1968.
21 Resigned August 15, 1968.
MOUNT WILSON AND PALOMAR OBSERVATORIES
163
Warren L. Weaver, Mechanic and Elec-
trician
Carnegie Southern Observatory Project
Pasadena, California
Bruce Adkison, Associate for Adminis-
tration
Wilma J. Berkebile, Secretary
La Serena, Chile
Manuel Blanco, Laborer
Donald L. Buck, Project Supervisor
Manuel Casanova, Foreman 22
Pedro La Paz, Laborer
Fernando Peralta, Foreman
Roberto Ramos, Laborer
Manfred Wagner, Camp Chief
22 Resigned May 7, 1969.
Geophysical Laboratory
Washington, District of Columbia
Philip H. Abelson
Director
Carnegie Institution Year Book 68, 1968-1969
Contents
Introduction 169
Petrography 174
Experimentation in the electronic stor-
age and manipulation of large num-
bers of rock analyses (Chayes) . 174
The rock file 174
The normative color index and
plagioclase content of andesite . 174
The so-called andesites of the oceanic
islands 175
Rhyolites of the oceanic islands . . 177
On the amounts of silica and norma-
tive quartz in analyses of andes-
ite, dacite, and rhyodacite . . 177
On the occurrence of corundum in
the norms of the common vol-
canic rocks 179
On selecting the centrally located
members of a large group of
analyses 182
Chemical and mineralogical petrogra-
phy 186
Mineralogy of Coral Sea drift pumice
(Bryan) 187
Mineralogy of a mugearite from
Clarion Island, Mexico (Bryan) . 190
Alkaline and peralkaline rocks of
Socorro Island, Mexico (Bryan) . 194
The simplified or idealized "Skaer-
gaard" model (Chayes) ... 200
Phase-Equilibrium Studies, Chiefly of
Silicates and Oxides 202
Pyroxenes and related systems . . . 202
Critical planes and flow sheet for a
portion of the system CaO-MgO-
Al203-Si02 having petrological
applications (Schairer and
Yoder) 202
The join akermanite-spinel- anor-
thite and the akermanite-spinel
portion of the coplanar join
akermanite-spinel-gehlenite-
forsterite 203
The join diopside-spinel-anorthite
and its relations to coplanar
Di-Fo-CaTs-Sp 207
The join akermanite-spinel-diop-
side and its relations to co-
planar Fo-Geh-Ak-Sp ... 207
The join Ca-Tschermak's molecule
(CaTs)-diopside and its rela-
tionship to coplanar Ak-Geh-
Di-CaTs 207
The join diopside-spinel .... 209
Positions of the joins studied in
the tetrahedron CaO-MgO-
Al203-Si02 210
Petrologic applications to rocks
and a possible solution to the
plagioclase-melilite dilemma . 213
The system CaSiOa-MgSiOs-AloOa
(Boyd) 214
Quenching experiments in the sys-
tems jadeite (NaAlSi2Oe)-forster-
ite (Mg2Si04) and jadeite (NaAl
Si2Oe)-anorthite (CaAl2Si208)
(Mao and Schairer) .... 221
Diopside solid solutions in the sys-
tem diopside-anorthite-albite at
1 atm and at high pressures
(Kushiro and Schairer) . . . 222
Stability field of iron-free pigeonite
in the system MgSiOs-CaMg
Si206 (Kushiro and Yoder) . . 226
Stability of iron-rich orthopyroxene
(Smith) 229
Stability of potassic richterite (Ku-
shiro and Erlank) 231
Potassium contents of synthetic
pyroxenes at high temperatures
and pressures (Erlank and Ku-
shiro) 233
Hydrous systems 236
Phlogopite-H20-C02 : An example of
the multicomponent gas problem
(Yoder) 236
Systems bearing on melting of the
upper mantle under hydrous
conditions (Kushiro) .... 240
The system forsterite-nepheline-
silica-H20 240
The system forsterite-CaAl2Si06-
silica-H20 241
The system forsterite-nepheline-
CaAl2Si06-silica-H20 ... 243
Stability of amphibole and phlogo-
pite in the upper mantle (Ku-
shiro) 245
Formation of amphibole in peri-
dotite composition .... 245
Stability of phlogopite in the pres-
ence of pyroxene .... 247
Oxides and others 247
Stability of the pseudobrookite (Fe2
Ti05)-ferropseudobrookite (Fe
Ti2Os) series (Haggerty and
Lindsley) 247
High-pressure phase transformation
in magnetite (Mao, Bassett, and
Takahashi) 249
Study of lead up to 180 kb (Mao,
Takahashi, and Bassett) ... 251
Crystal-field spectra at high pressure
(Bell and Mao) 253
Phase-Equilibrium Studies of Sulfide
Systems 256
Sulfide- and arsenide-type binary sys-
tems (Kullerud) 256
Low-temperature phase relations in the
Fe-S system (Taylor) .... 259
Monoclinic pyrrhotite 259
Hexagonal pyrrhotite 264
Thermal expansion data .... 266
Smythite, Fe3+xS* 267
The Ni-Sb-S system (Williams and
Kullerud) 270
The system Cu-S-0 (Taylor and Kul-
lerud) 273
High-pressure differential thermal
analysis 276
Acanthite-type compounds (Bell and
Kullerud) 276
Pressure-temperature diagram for
Cr2FeS4 (Bell, El Goresy, En-
gland, and Kullerud) .... 277
Crystallography 278
Fifty years of X-ray crystallography at
the Geophysical Laboratory, 1919—
1969 (Donnay, Wyckoff, Barth,
and Tunell) 278
Refinement of the crystal structure of
an anthophyllite (Finger) . . . 283
Progress report on ewaldite (Donnay
and Preston) 288
Refinement of the crystal structure of
triphylite (Finger and Rapp) . . 290
Further use for the Pauling-bond con-
cept (Donnay) 292
X-ray study of echinoderm skeletons
(Donnay and Pawson) .... 296
Biogeochemistry 297
Uptake of amino acids of kerogen
(Abelson and Hare) 297
Optically active steranes in a Miocene
petroleum (Hoering) .... 303
Isotopic Investigations in Geochemistry
and Geochronology (Davis, Krogh,
Hart, Brooks, and Erlank) ... 307
The age of metamorphism in the Gren-
ville province, and the age of the
Grenville Front 307
Metamorphism 1700 ±100 m.y. and
900 ± 100 m.y. ago in the north-
west part of the Grenville prov-
ince in Ontario (Krogh and
Davis) 308
Isotopic ages along the Grenville
Front in Ontario (Krogh and
Davis) 309
The Grenville Front in the Chi-
bougamau-Surprise Lake area,
Quebec (Krogh, Brooks, Hart,
and Davis) 313
Sr isotope variations in Archean green-
stones and the differentiation of
the earth's mantle 315
Mineralogy 315
Inclusions in diamonds (Meyer and
Boyd) 315
The occurrence of potassic richterite
in a mica nodule from the Wessel-
ton kimberlite, South Africa (Er-
lank and Finger) 320
Kimberlite diopsides (Boyd and
Nixon) 324
The Laco magnetite lava flow, Chile
(Haggerty) 329
A new iron-phosphate mineral (Hag-
gerty) 330
Magnetic minerals in pelagic sediments
(Haggerty) 332
Annealing experiments with naturally
and experimentally shocked feld-
spar glasses (Bell and Chao) . . 336
Andalusite and "/3-quartz8s" in Macu-
sani glass, Peru (French and
Meyer) 339
Staff Activities 342
Washington Crystal Colloquium . . 342
Journal of Petrology 342
Lectures 343
Penologists' Club 344
Bibliography 344
References Cited 346
Personnel 355
INTRODUCTION
If man is to have an enduring future,
he must learn to husband his environ-
ment and to live with its realities. Some
of the important realities of the en-
vironment are the physical and chemical
nature of the planet itself and the pro-
cesses that have shaped it and are even
now changing it. Thus man must con-
tinue to exploit resources of the earth,
but he will devote increasing attention
to management of the earth — controlling
erosion, pollution, and the like. At the
same time a restless planet will command
fearful concern with floods, earthquakes,
and volcanism.
Of great interest during the next dec-
ades will be exploration of that great
frontier the sea bottom, which represents
72% of the earth's surface. All these fac-
tors together guarantee continued inter-
est in the earth sciences. There is yet
another factor. Man will continue to
study the earth because he is a curious
animal. He wonders, what and why.
This past year has been a great one
for earth scientists. The sediments be-
neath the oceans have been made acces-
sible to intensive study. The moon awaits
further exploration. During the report
year specimens from the deep sea and
the moon were not yet distributed. In
coming years, however, these materials
will surely be the source of much new
information. As these materials become
available for study the Geophysical
Laboratory will participate in studies in
which our knowledge, techniques, and
equipment are especially relevant. At
the same time we will continue investiga-
tions of basic problems of long-term sig-
nificance. During the past year some of
these areas of geochemical and peno-
logical research have been fruitful as new
ideas, techniques, and instrumentation
have facilitated the work or created new
opportunities. In the following para-
graphs highlights of some of the year's
work at the Geophysical Laboratory are
reviewed.
With the activation of our medium-
speed computer terminal, Chayes re-
sumed work on his library of chemical
analyses of Cenozoic volcanic rocks. The
library tape now contains over 8000
analyses that can be referenced, singly or
in groups, by area of occurrence, rock
name(s), or any linear combination of
chemical or normative parameters. He
has completed a summary study of the
chemical composition of andesite, an ex-
amination of the compositional relations
between andesite, dacite, and rhyodacite,
and a survey of the relative frequencies
of analyses of rhyolite and andesite in
ocean basins. A detailed study of the
"alumina balance" — i.e., the molar ratio
of A1203 to the sum (Na20+K20 + CaO)
— and a restudy of the oceanic basalt-
trachyte association are in progress.
Meyer and Boyd show that silicate in-
clusions in natural diamonds from a
variety of sources in Africa and South
America resemble, in kind, the minerals
of ultramafic xenoliths from kimberlite.
In detail, however, the chemical compo-
sitions of the inclusions show a number
of consistent and characteristic differ-
ences that are independent of provenance
and age. It is notable, for instance, that
the garnet, olivine, chromite, and ensta-
tite inclusions in diamond are particu-
larly rich in Cr. These differences cannot
yet be rationalized satisfactorily, but it
seems possible that the diamonds crystal-
lized from silicate magmas, and that the
inclusions, armored by diamond, reflect
crystal-liquid equilibria, whereas the
minerals of the xenoliths have equili-
brated below the solidus.
Boyd has used the electron probe to
determine the compositions of coexisting
phases in high-pressure runs in the sys-
tem CaSi03-MgSi03-Al203 at 1200°C
and 30 kb. This study is the first to be
169
170
CARNEGIE INSTITUTION
published in our report in which electron-
probe techniques, rather than more con-
ventional X-ray and optical methods,
were the primary means of phase identifi-
cation. Probe analysis can sometimes
provide a much more detailed view of
phase relations in a complex system than
has hitherto been possible. Phase rela-
tions in the system CaSi03-MgSi03-
AI0O3 closely model the mineral assem-
blage found in garnet lherzolites and also
show similarities to the assemblages of
eclogites, corundum eclogites, and gros-
pydites. Synthetic pyroxenes containing
3 to 4 wt °fo ALO3 in equilibrium with
garnet in this system have Ca/(Ca + Mg)
ratios that are little changed from Al-free
pyroxenes on the join CaMgSi206-Mg
Si03 at the same temperature and pres-
sure. Hence, the experimentally deter-
mined solvus for diopside in equilibrium
with enstatite can safely be applied to
natural assemblages containing moderate
amounts of A1203.
Bryan has continued optical and elec-
tron-microprobe studies of minerals in
volcanic rocks. Microprobe analysis of
plagioclase in Coral Sea drift pumice
shows that it is bytownite rather than
anorthite, as previously deduced from
optical data; substitution of iron for
aluminum apparently causes the anoma-
lously high refractive index. Unusual in
both mineralogy and bulk composition,
this pumice seems to be produced in
relatively large volume along the Tonga-
Kermadec ridge and is widely distributed
by ocean currents.
Electron-microprobe analyses of min-
erals in basalt associated with pantel-
lerite both in the type area at Pantelleria,
and at Socorro Island, Mexico, provide
new evidence for a genetic relation be-
tween basalt and pantellerite. In both
areas, aluminous titanaugite and titanif-
erous magnetite are important constitu-
ents of the basalts. Using the least-
squares calculation described last year
(Bryan, Finger, and Chayes, Year Book
67), Bryan has shown that relatively
large amounts of pantellerite could be
derived from the basalt at Socorro Island.
The removal of aluminous titanaugite
and titaniferous magnetite from the
basalt could yield a residue having the
alumina deficiency and high iron/tita-
nium ratio characteristic of pantellerite.
Petrologic and meteoritic evidence sug-
gests that iron oxides are important
components of the earth's mantle. Mao
has studied the behavior of magnetite
(Fe304) under pressures as high as 300
kb. This work is a continuation of studies
begun with Bassett and Takahashi at the
University of Rochester. By X-ray iden-
tification of products formed in a dia-
mond-anvil cell, Mao has found that
magnetite undergoes a first-order phase
transformation at approximately 250 kb.
This phase reverts to the original spinel
structure on release of pressure to 1 bar.
Mao, Takahashi, and Bassett have also
found that ordinary lead with face-
centered cubic structure starts to trans-
form to the hexagonal close-packing
structure at 130 ±10 kb and room tem-
perature. They also observed that the
two phases of lead can coexist in a range
of 60 kb. This transformation is pre-
sumably the same one first observed by
Balchan and Drickamer at 160 kb, which
is currently widely used as a pressure
calibration point. The uncertainty aris-
ing from the broad pressure range of the
phase transition leads to the suggestion
that precautions must be taken when
this transformation is used for calibra-
tion.
One of the major puzzles of organic
geochemistry is the process by which
the relatively simple components of liv-
ing matter disappear in sediments. Mi-
croorganisms have been accorded an im-
portant role in the process, but kerogen,
which makes up the bulk of the organic
matter in sediments, is different in nature
from ordinary biological substances.
Other factors must be involved. Abelson
and Hare have uncovered an important
nonbiological mechanism in sediments
for the disappearance of small molecules
such as amino acids. They have found
GEOPHYSICAL LABORATORY
171
that kerogen reacts rapidly and ir-
reversibly with amino acids and peptides.
The most reactive amino acids include
cystine and the basic amino acids fol-
lowed by the aromatic and longer ali-
phatic chained amino acids. The reac-
tions yield substantial amounts of
ammonia and involve, at least in some
instances, attachment of portions of the
amino acid moiety to the kerogen. For
example, reaction of arginine with kero-
gen changed the C/N ratio of the kerogen
from 14.4 to 8.2.
Optically active molecules are synthe-
sized routinely by living organisms but
are rarely produced by nonbiological
systems. The presence of optical activity
in petroleums (due mainly to steranes)
is a strong argument for the biological
origin of crude oils. Hoering has de-
veloped new methods for the chromato-
graphic separation of steranes from
petroleum and applied new instrumental
methods of structure determination. He
has isolated and identified ten sterane
hydrocarbons from a crude oil from the
Ventura Basin. The steranes were highly
optically active and had molecular struc-
tures expected from a hydrogenation of
common plant and animal steroids. The
methods are generally applicable and
permit study of steranes in very old
petroleums and rocks.
One of the major developments of the
1960's was the accumulation of evidence
of continental drift. Much of this evi-
dence is based on measurements of the
remanent magnetism of oceanic sedi-
ments. Oddly enough, there has been
little systematic study of the magnetic
minerals of the sediments. Such a study
of the magnetic mineralogy of pelagic
sediments from the Atlantic, Pacific, and
Indian Oceans and from beneath the
Antarctic ice sheet has been undertaken
by Haggerty. His results show that a
major portion of the magnetic material
in deep-sea sediments consists of detrital
iron-titanium oxides. These phases are
considered to have been wind-trans-
ported from the continents.
Kushiro studied the system forsterite-
nepheline - anorthite -silica-water and
showed that the liquids formed by partial
melting of peridotitic compositions in
the presence of water are tholeiitic or
andesitic up to at least 20 kb. The results
are important for understanding the ori-
gin of tholeiitic and andesitic magmas.
Kushiro has also determined the pres-
sure-temperature conditions of crystal-
lization of amphibole from a peridotite
composition and the stability of phlogo-
pite in the presence of diopside and en-
statite. The results indicate that amphi-
bole and phlogopite could be present at
considerable depths in the upper mantle
where water pressure is high. Kushiro
and Erlank showed, however, that potas-
sic richterite, an alkali amphibole found
in a nodule in kimberlite, is not stable in
eclogites and garnet-bearing peridotites
and appears to be stable only in rocks
in which potassium is present in excess
over aluminum.
The effects of a multicomponent gas on
the behavior of some of the minerals
important in the mantle are being studied
by Yoder. The melting of the hydrous
phase phlogopite was found to be sup-
pressed by the presence of C02. The
C02, relatively insoluble in the silicate
liquid, reduces the effective pressure of
H20. The presence of C02 will greatly
affect, therefore, the melting temperature
of the hydrous rocks now believed to be
present in the mantle. Furthermore, the
assumption of vapor-absent conditions
in magmas in the mantle may not be
valid if a relatively insoluble gaseous
component is present. Rocks such as
kimberlite will vary greatly in their
thermal behavior, depending on the ratio
of C02 to H20 in the gas phase, if a gas
phase exists.
Important advances have been made
during the past few years in our knowl-
edge of the crystallization relations in
basalts and related alkaline rocks. From
the many studies reported from this
Laboratory it became obvious that be-
fore attempting to interpret detailed re-
172
CARNEGIE INSTITUTION
lations in the quinary system Na20-
CaO-MgO-Al203-Si02, it was necessary
to know more about relations in the
tetrahedron akermanite-diopside-anor-
thite-spinel in the quaternary system
CaO-MgO-Al203-Si02, without the com-
plication of Na20. During the past year
Schairer and Yoder determined the pre-
cise relations in this tetrahedron.
Important clues in the crystallization
behavior of the melilite-bearing rocks
were uncovered in this tetrahedron, and
a possible solution of the plagioclase-
melilite dilemma was evolved. The co-
existence of clinopyroxenes and spinel,
commonly observed in nature, was ob-
served experimentally. A new flow sheet
for the system CaO-MgO-AL03-Si02
was developed, which shows in detail the
thermal relations between four of the
most important oxides present in rocks.
Boyd and Nixon have found that the
distribution of the ratio Ca/(Ca + Mg)
in diopsidic pyroxenes from African kim-
berlite concentrates and nodules appears
to be markedly bimodal. Interpretation
of this distribution in terms of the con-
tinuous solvus curve in the system
CaMgSi206-MgSi03 suggests that these
kimberlites have originated under two
distinct temperature regimes, perhaps at
two separate levels in the mantle. Such
an origin seems improbable, however, and
Boyd and Nixon suggest that the bi-
modal distribution may be due to un-
discovered features in the phase diagram
for CaMgSi206-MgSi03 at pressures well
above 30 kb.
Kushiro and Yoder continued their
study of the stability field of iron-free
pigeonite and showed that this material
is stable, at least in the pressure range
5 to 20 kb and at near-solidus tempera-
tures. Kushiro and Schairer confirmed
that the system diopside-anorthite-albite
is not ternary and showed that the di-
opside solid solutions crystallized from
this system at 1 atm probably contain
several percent of enstatite and Tscher-
mak's components. Erlank and Kushiro
measured potassium contents of clino-
pyroxenes and garnets made at high pres-
sures in the presence of phlogopite and
potassium-bearing liquids and found that
only a very small amount (<200 ppm)
of potassium can enter the clinopyroxenes
and garnets. The results indicated that
these minerals in the upper mantle are
not the major source of potassium in
basalts.
The stability of iron-rich orthopyrox-
ene relative to the compositionally
equivalent assemblage of olivine + quartz
has been investigated by Smith. The
stability relationships determined for
these phases at low pressure provide a
necessary basis for subsolidus investiga-
tions in the iron-rich portion of the py-
roxene quadrilateral. With increasing
pressure, orthopyroxenes of progressively
greater iron content become stable. Be-
cause the reaction of orthopyroxene to
olivine + quartz is pressure sensitive, the
presence of the phases in a rock may
serve as a guide to the depth at which
it crystallized.
Meyer and French have discovered the
first natural occurrence of a member of
the /3-quartz-spodumene solid solution
series. This new mineral has the composi-
tion (LiAlSi206)62(3Si02)38 mole °/o and
has a hexagonal ^-quartz type structure.
It occurs as crystals in a unique glass
obtained from near the town of Macusani
in southern Peru. In this same glass they
have found the first occurrence of an-
dalusite that has apparently grown in
equilibrium with a melt.
Lindsley pursued his interests in the
iron-titanium oxides on a variety of
fronts. An uncompleted study of the
magnetite-ulvospinel join confirms that
the critical temperature of the miscibility
gap lies at or below 600 °C. A joint study
with Haggerty on the stability of inter-
mediate pseudobrookite solid solutions
places important constraints on the oxi-
dation temperatures of certain oxidized
basalts of paleomagnetic significance. In
addition, Lindsley spent the last 6
months of the report year preparing a
review of the experimental petrology,
GEOPHYSICAL LABORATORY
173
synthesis, and crystal chemistry of the
iron-titanium oxide minerals.
Bell and Chao have determined the
effects of annealing on dense feldspar
glasses produced by shock-wave experi-
ments and by natural meteorite impacts.
By relating annealing temperatures and
times with the effects of the shock-release
adiabats they provide a qualitative in-
terpretation of the pressure-temperature
history of feldspar glasses that are found
in debris produced by meteorite impact.
Such interpretations will be useful for
samples returned to the earth from the
surfaces of other celestial bodies.
Bell and Mao have measured the crys-
tal-field spectra of the olivine and spinel
forms of fayalite (Fe2Si04), and of
almandite garnet (Fe3Al2Si3012) , at 1
atm and at 100 kb. They observed spec-
tral shifts that slightly open the "win-
dow" for radiative transfer of heat at
high pressure. In addition, strong absorp-
tion was observed in fayalite, presumably
because of the onset of nucleation of the
spinel phase. This strong absorption may
provide a heat barrier at great depths in
the earth's mantle.
Finger has refined the crystal structure
of an anthophyllite from Montana and
determined the occupancies of the octa-
hedral sites with the bulk composition
constrained to agree with the chemical
analysis. The sample has a very ordered
distribution, suggesting a low tempera-
ture of formation or annealing.
Finger and Rapp have refined the
crystal structure of the mineral triphy-
lite, Li(Fe,Mn)P04, from South Dakota,
as a first step in the study of a solid-state
reaction in which the lithium is removed
from the structure and the iron or
manganese converted from the divalent
to the trivalent state.
Erlank and Finger have described the
occurrence of an amphibole with high
potassium and low aluminum content.
This amphibole is in the form of sub-
hedral grains contained within diopside
in a mica pyroxenite nodule from the
Wesselton kimberlite pipe, South Africa.
The chemical analysis of a new min-
eral species often leads to more than one
possible structural formula. Sonoraite,
Fe2Te2Oi0H6, is a case in point; the
structural formulae Fe2Te204(OH)6, Fe2
Te205(OH)4-H20, Fe2Te206(OH)2-
2H20, and Fe2Te207-3H20 are equally
likely. X-ray diffraction data lead to the
oxygen coordinates but do not reveal
hydrogen positions. Using the principle
of local neutralization of charge first
formulated by L. Pauling in 1929, G.
Donnay has suggested a general pro-
cedure that distinguishes oxygen ions
from hydroxyl groups and from water
molecules and gives information on hy-
drogen bonding that may be present.
Kullerud has classified and grouped
binary systems containing As, Bi, S, Sb,
Se, and Te, based on the behavior of such
systems in both the liquid and solid
states, into the sulfide and arsenide types.
This classification points up certain dis-
crepancies between the reported and pre-
dicted behavior of many systems and
thus identifies the systems that should
be restudied with modern methods.
Pyrite and the various species of pyr-
rhotite, the commonest sulfide minerals,
are compounds in the binary system
Fe-S. Because of retrograde equilibra-
tion, the high-temperature chemistry of
many Fe-S phases is masked by the low-
temperature phase relations. Taylor has
investigated the Fe-S system and has
significantly extended our knowledge of
the important low-temperature regions
of this system.
By combining the results of age de-
terminations made on a rock and on the
minerals separated from that rock, Krogh
and Davis have been able to determine
within close limits the time of occurrence
of significant events during the history
of the rock. They show that in the Gren-
ville province in Ontario, gneissic rocks
were formed from preexisting sediments
174
CARNEGIE INSTITUTION
during a period of major metamorphism
1800 m.y. ago and that these rocks were
then subjected to a period of less intense
metamorphism 900 m.y. ago. They also
show that some of the structural features
of the Front zone of the province are at
least 1600 m.y. old and probably as old
as 1800 m.y.
PETROGRAPHY
Experimentation in the Electronic
Storage and Manipulation of Large
Numbers of Rock Analyses *
F. Chayes
In January of the report year, after
nearly a year of delay and improvisation,
regular communication was established
between a medium-speed data terminal
at the Geophysical Laboratory and the
University of Maryland's Univac 1108
computer. The work is done under a
multiprogramming monitor, so that turn-
around is ordinarily very rapid. Once re-
ceived at the central facility, our work is
processed exactly as if it had been sub-
mitted through an on-site card reader;
in our programming we may accordingly
take full advantage of the speed, large
core memory, and immense mass storage
capacity of a third generation computer
operating under optimum conditions.
This section of the petrography report
is a review of work made physically
practical by the presence of the terminal
in the laboratory. The programming has
benefited greatly from the generous as-
sistance of L. W. Finger.
The Rock File
A collection of rock analyses on
punched cards, begun in connection with
a study of published Harker diagrams
(Chayes, 1964), has been expanded
gradually into a library of analyses of
Cenozoic volcanic rocks. For some time
the library has been too large for effi-
cient exploitation by physical manipula-
tion of the cards, and the first major
petrographic application of the data
* Supported in part by National Science
Foundation grant GA 1612.
terminal was the transfer of this infor-
mation to magnetic tape. The library
tape in use at the present writing, from
which most of the information summa-
rized below was drawn, is a preliminary
version, completed in mid-February. It
contains 8300 analyses that can be refer-
enced, individually or in groups, geo-
graphically, by modified Troger numbers
denoting rock names used in the source
publications, and by a variety of chemi-
cal and/or normative criteria. The geo-
graphic reference is essentially an acces-
sion number; the world is divided into
large, numbered areas, and within each
of these the analyses are grouped in
numbered suites, the analyses in each
suite being obtained either from a single
publication or from a number of publica-
tions describing the same occurrence.
Each suite of the card library is a logical
record of the library tape. The tape
generator contains updating options
which permit deletion or replacement of
existing records as well as insertion of
new ones.
The Normative Color Index and Plagio-
clase Content of Andesite
Andesite, the most abundant volcanic
rock in the circumoceanic environment, is
common throughout orogenic belts on
the present continental land masses and
rare or lacking in the ocean basins. A
resume of the chemical composition of
andesite, prepared for a recent field sym-
posium at Eugene, Oregon, and published
in its proceedings (Chayes, 1969), was
carried through as a pilot operation of
the rock analysis storage project. Copies
were made (mostly by D. Velde) of all
andesite analyses in the punched card
library, and from this set a precursor of
GEOPHYSICAL LABORATOKY
175
the library tape was prepared; the tape-
building program now in use was tested
and corrected with the andesite data, and
a few months later, when our terminal
was finally activated, the current version
of the library tape was generated from
the andesite tape by an extended series
of editings.
The distributions of two normative
parameters of considerable interest, color
index and an content of plagioclase, were
not available at the time of the Eugene
summary; they are given here in Table 1.
The normative color index of the calcula-
tion is essentially the complement of the
CIPW statistic "Sumsal," i.e., it is the
sum of all normative parameters other
TABLE 1. Distribution of (I) Normative Color
Index and (II) Normative Ratio (lOOan/pl)
in 1775 Analyses of Andesite (Upper-Class
Mark of Class k = Origin + k Times
Class Width)
I II
Average
21.32
50.0
Standard deviation
6.13
11.0
Origin
9.00
0.0
Class width
1.00
3.3
Class Number
Frequencies
1
24
0
2
21
2
3
23
1
4
37
6
5
44
11
6
69
14
7
92
20
8
90
32
9
113
35
10
122
53
11
111
97
12
114
128
13
120
184
14
100
217
15
92
238
16
90
231
17
83
188
18
72
135
19
70
99
20
45
48
21
52
20
22
48
10
23
29
2
24
23
1
25
27
0
26
11
27
6
28
4
29
3
30
2
than Q, or, ab, an, ne, and Ic. Although
the current version of the library tape
contains 1946 analyses of rocks called
andesite in the source references, only
the analyses used in the summaries com-
piled for the Eugene symposium have
been included in the preparation of Table
1; for a bibliography of source refer-
ences the reader is referred to the pub-
lished proceedings of the symposium.
The So-Called Andesites of the Oceanic
Islands
All petrologists agree that andesites
are very rare in the ocean basins, and
probably most believe that andesites do
not occur at all in this environment. As
of the present writing, nevertheless, 57
of the analyses of oceanic island vol-
canics on the library tape are of rocks
called andesite in the source references.
Over half of these are from the Pacific
basin, viz., one from West Maui; five
each from East Maui and Kohala; six
from Mauna Kea; three each from Pit-
cairn, the Tubuai archipelago, and the
Marquesas; two each from Easter and
the Galapagos ; and one from the Society
Islands.
Of the seventeen Hawaiian analyses,
only seven contain more than 50% and
only two more than 52% of Si02; fifteen
are ol and thirteen ne normative; only
one — the one richest in Si02 — contains
less than 2% of Ti02; in the remainder
Ti02 ranges from 2.09 to 5.10%. These
are preeminently the rocks for which
Iddings proposed and Macdonald re-
vived the name hawaiite. The analyses
are decidedly richer in alkalies and
poorer in MgO than most Hawaiian
basalts, which in other respects they
closely resemble. As Macdonald points
out, they are certainly not andesites, and
in Iddings' definition hawaiite denotes
andesine basalt.
The other fourteen Pacific basin "an-
desites" are much like the Hawaiian
examples; thirteen are ol and seven ne
normative; ten contain less than 52%
176
CARNEGIE INSTITUTION
of Si02 and only the other four contain
less than 2% of Ti02; all contain con-
siderably more alkalies than would be
expected in feldspathoid-free basalt; the
alkali content of the four relatively
siliceous examples ranges from 8.5 to
10%, far more than is found in andesite.
With the possible exception of one
specimen from Easter Island, none of
these rocks appears to be an andesite
in the now fairly standard usage of that
term. Six might qualify as one or other
variety of trachyandesite. For most of
the remaining twenty-four, hawaiite
would be a suitable varietal name but
mugearite might be more appropriate for
the more siliceous ones. In a few — one
each from the Galapagos, Pitcairn, the
Marquesas, and the Tubuai archipelago
— Si02 is less than 50%, normative ne
is scarce or lacking, and an equals or ex-
ceeds ab; these seem to be ordinary
oceanic-island basalts. Andesites, which
abound along much of the margin of
the Pacific, do indeed seem to be lacking
in the Pacific basin despite the fact that
the name andesite has been attached to
more than 5% of the published analyses
of rocks from that region.
The tape library now contains sixteen
analyses of Atlantic island rocks called
andesite in the source references, one
from Possession, three from the Canaries,
and twelve from the Azores. Of these,
thirteen are ol and 11 ne normative.
Three of the Azores specimens and all
from Possession and the Canaries are far
too poor in silica to be called andesite
and far too rich in alkalies to be called
basalt.* Like much of the Pacific ma-
terial, they are trachybasalts for which
either hawaiite or mugearite would be
appropriate varietal names. The silica
content of the remaining nine Azores
analyses is, with one exception, between
50.5 and 53.8%, within but certainly at
the low end of the normal andesite range,
but the alkali content of the six that lack
* In the journal and reference literature the
name basalt is rarely applied to a rock con-
taining more than 3% Na20.
normative Q is far too high for andesite ;
they are trachyandesites of one variety
or other. We are left with three quartz
normative analyses; one contains only
47.6% Si02, the highest normative Q
(4.3%) occurs in one containing only
50.5% Si02, and in all three Ti02 is well
over 2%. In the continental or circum-
oceanic environments, where andesites
abound, not one of these specimens would
be given that name. The name is never-
theless assigned, in the source references,
to nearly 3% of the analyses of speci-
mens from the Atlantic basin, and in a
recent summary essay (Gaskell, 1962)
the volcanism of the Azores is confidently
described as "andesitic." f
To my knowledge, no analyzed samples
of rocks called andesite have been de-
scribed from oceanic islands of the Arctic
or Antarctic, but if Reunion is accepted
as an oceanic island the current library
tape contains ten examples from the
Indian Ocean. Six of the ten are highly
aluminous, with normative c in amounts
far too large to be explained away as
analytical error: five of these also con-
tain normative Q; in one Q is 28%
though Si02 is only 61.2%, and in an-
other Q is 20.7% though Si02 is only
52.4%. Probably all six corundiferous
norms are of laterized or hj^drothermally
altered specimens. There are in addition
four analyses, all of specimens from
Piton des Neiges, whose norms lack both
Q and c ; three of these are ne normative,
though the amount of ne is small. Two
of the four contain less than 47% Si02
but are rather rich (3.18%, 3.57%) in
Na20 for basalt; either basalt or trachy-
basalt would do as a group name for
them, but andesite is clearly inappro-
f This author states (op. cit., p. 305), "there
is no doubt that both Bermuda and the Azores
would be placed to landward of the andesite
line if they were in the Pacific." But surely
there is very considerable doubt! As we have
just seen, the published analyses of Azores
specimens called andesite offer no support what-
ever for this dictum, and all of some 62 other
published Azores analyses are of drastically
nonandesitic materials.
GEOPHYSICAL LABORATORY
177
priate. The other two contain sufficient
Si02 for andesite, but the total alkali
content of one is 6.68% and of the other
9.62%. The first is perhaps marginally
admissible as a highly aberrant andesite,
the second is clearly trachyandesite.
In sum, although more than 4% of the
1325 analyses of oceanic volcanics now
on the library tape are named andesite
in the source references, only two of the
specimens in question, one from Reunion
and one from Easter Island, have chemi-
cal and normative compositions appro-
priate for andesite, and these two barely
qualify.
Rhyolites of the Oceanic Islands
The library tape now contains twenty
analyses of oceanic island volcanics
called rhyolite in the source references,
nine from the Canaries, four from Easter
Island, three from Reunion, and one
each from American Samoa, Bouvet, As-
cension, and Waianae. Although fewer
in number than oceanic "andesites," the
oceanic rhyolites seem a much more co-
hesive group.
Although less than 23% of the 485
named rhyolites on the library tape are
peralkaline, 60% of the analyses of
oceanic rhyolites fall in this category;
twelve of the twenty norms are acmitic
but only two contain ns. Nine of eleven
specimens from the Atlantic islands, two
of six from the Pacific, and one of three
from the Indian Ocean are ac normative.
Five of the eight remaining analyses are
c normative and in two (both from Re-
union) normative corundum is so abun-
dant as to suggest that the specimens are
extensively altered, whether by hydro-
thermal action or weathering. The char-
acteristic rhyolite of the oceanic islands
is evidently a peralkaline rock with a
marked (molar) excess of alkalies over
available A1203. Peralkalinity is less
pronounced than in the famous rhyolites
of Pantelleria, in which there is usually
an excess, and often a very considerable
excess, of alkalies over the sum (A1203 +
Fe203) . Oceanic rhyolite is perhaps more
similar to comendite; it is on the whole
an exceedingly rare rock but there can be
no question that it does indeed occur in
the oceanic island basalt-trachyte as-
sociation.
On the Amounts of Silica and Normative
Quartz in Analyses of Andesite,
Dacite, and Rhyodacite
Innumerable text and reference books
encourage the petrographer to suppose
that, in silica and normative quartz con-
tents, dacites are intermediate between
andesite and rhyolite. In terms of group
averages this generalization is both im-
portant and correct. The words andesite,
dacite, and rhyodacite are primarily
names applied to individual rocks, how-
ever, and the now generally accepted
notions of their relative silica and norma-
tive quartz contents, usually offered both
as broad genetic insights and as practical
aids in classification, prove of little tax-
onomic value.
The distributions of Si02 and norma-
tive quartz in analyses of Cenozoic rocks
called andesite, dacite, and rhyodacite
stored on the current library tape are
summarized in Table 2 and Fig. 1. An
analyzed lava of this general type con-
taining less than 66% Si02 is far more
likely to be called andesite than dacite
or rhyodacite, and 56% of the 338 dacites
stored on the library tape contain less
than 66% Si02; further, the probability
that a rock containing more than 66%
Si02 will be called andesite, though
small, is not negligible. Similarly, an
analyzed lava of this type whose norm
shows less than 27% normative quartz
is far more likely to be called andesite
than dacite, and in the norms of more
than two-thirds of the dacite analyses
stored on the tape, Q is in fact less than
27%. The overlap between rhyodacite
and dacite is even more extreme than
that between dacite and andesite. The
same hopelessly broad overlap charac-
terizes the distributions of other im-
178
CARNEGIE INSTITUTION
TABLE 2. Distribution of Si02 and Normative Q in Analyses of
(A) 1864 Andesites, (B) 338 Dacites, (C) 36 Rhyodacites
Si02
Q
A
B
C
A
B
C
Average
57.91
65.34
69.09
13.49
24.00
30.30
Standard deviation
4.24
4.44
3.40
6.79
8.10
8.13
Origin
44.00
44.00
44.00
0.00
0.00
0.00
Class width
1.00
1.00
1.00
1.50
1.50
1.50
Class Number
Frequencies
1
41
0
2
0
55
1
3
7
67
0
4
6
89
1
5
16
132
2
6
14
108
0
0
7
29
129
4
1
8
50
159
8
9
92
0
161
10
10
111
2
147
13
1
11
118
167
18
12
171
3
116
22
13
164
7
108
23
14
189
4
0
92
30
3
15
187
10
1
75
25
1
16
168
14
55
22
1
17
136
15
45
32
2
18
121
18
1
24
19
5
19
66
25
16
20
1
20
65
24
14
16
1
21
62
33
1
4
17
3
22
30
33
2
6
11
4
23
27
29
1
5
8
2
24
9
32
3
0
7
25
5
31
9
0
5
6
26
4
17
4
0
6
1
27
4
12
5
2
4
28
5
6
4
1
6
2
29
1
10
3
0
3
30
3
2
0
1
1
1
>30
0
11
2
1
4
1
portant chemical and normative vari-
ables in rocks called andesite and dacite.
Nowadays usually mocked or conde-
scendingly ignored, classification and
nomenclature are as important in petrol-
ogy as in every other branch of natural
science, and our inability to agree upon
a satisfactory classification of igneous
rocks must bear a heavy share of respon-
sibility for the relative stagnation of
our subject. It is the first requirement
of a sound classification that the different
names used in it denote appreciably dif-
ferent sets of properties. Barring redefi-
nition so extreme as to be utterly unrealis-
tic, a petrographic system retaining the
names andesite and dacite probably can-
not satisfy this requirement. These, like
certain other common rock names, are
old bottles into which it is unwise, if not
actually impossible, to pour the new wine
of sound taxonomy. Unappealing and
foolish as they may sometimes seem, sys-
tems that impose a completely synthetic
nomenclature — the Linnaean academi-
cism of CIPW, the nonsense syllables of
Holmes, the symbolism of Shand — prob-
ably offer more hope of success than
those that attempt, whether by fiat or
plebiscite, to impose consistency and
mutual exclusiveness on the common
names of common rocks. No matter how
democratically — or arbitrarily — we de-
cide how these names ought to be used in
the future, we can do nothing about how
they have been used in the past.
GEOPHYSICAL LABORATORY
179
360
340
320-
300-
280-
260-
240-
£220
^200
a
o ISO
CD
■f 160
140
120
100
80
60
40
Si02
-I
50
' 1 I 1 1 I ' ' I
J]
Normative Q
60
Weight per cent
1 I ' ' I
18 27 36
Weight per cent
>45
Fig. 1. Distribution of Si02 and normative quartz in andesite (solid lines) and dacite (dashed
lines). Data from Table 2.
On the Occurrence of Corundum in the
Norms of the Common Volcanic Rocks
In a norm computed according to the
standard CIPW conventions, c will occur
if and only if the molar inequality A1203
>(Na20+K20 + CaO) is satisfied. Of
the essential minerals of the eruptive
rocks, only certain aluminous micas sat-
isfy the limiting inequality. These are
rarely abundant, and the peraluminous
character they would otherwise give to
the rock analysis is usually counterbal-
anced by associated amphiboles, chlo-
rites, or other micas. There is thus no
reason why the norms of most eucrystal-
line eruptive rocks should be corundifer-
ous, and, in the absence of modal
corundum — on the whole a very rare
mineral — the presence of c in the norm of
an intrusive rock is usually taken as
evidence either of alteration or of a
questionable analysis.
Modal corundum is virtually unknown
in extrusive rocks, and except in the
andesites, the occurrence of c in the
norms of such rocks seems to have at-
tracted little attention. It has long been
known that a little c is not at all un-
common in the norms of andesites, and
this is usually considered additional evi-
dence that the assimilation of aluminous
sediments or metamorphic rocks plays
an important role in their formation.
(The principal evidence for this view is
the restriction of andesites to the oro-
genic environment and the not-infre-
quent occurrence in them both of meta-
morphic minerals, such as garnet and
cordierite, and of inclusions of sedi-
mentary and metamorphic rocks.)
180
CARNEGIE INSTITUTION
Little has previously been known about
the distribution of c in the norms of
Cenozoic volcanics, but the existence of
the library tape makes it possible to
survey this matter in any desired detail.
Some of the results of a preliminary sur-
vey are shown in Table 3. The rock
names shown there require some explana-
tion, since all are used as broad group
designations. Specifically, their denota-
tions are:
A. Rhyolite. Rocks identified in the
source references as rhyolite, quartz-
porphyry, nevadite, liparite, tordrillite,
comendite, cantalite, pantellerite, del-
lenite, or pitchstone, modified by any
one or combination of the following:
aegerine, riebeckite, arfvedsonite, amphi-
bole, soda, plagi-, and comendite.
B. Dacite. Rocks identified in the
source references as dacite, santorinite,
weiselbergite, shastaite, peleeite, or
bandaite, with mineral modifiers.
C. Trachyte. Rocks identified in the
source references as trachyte, arsoite,
vulsinite, sanidinite, orendite, modified
by one or more of the following: fayalite,
mica, nepheline, sodalite, hauyne, teph-
ritic, soda.
D. Andesite. Rocks identified in the
source references as andesite, palatinite,
tholeiite in the sense of Troger, alboran-
ite, aleutite, modified by any one or
combination of the following: mica, bio-
tite, hornblende, augite, hypersthene,
oligoclase, andesine, labradorite (all ne-
normative analyses rejected).
E. Trachy andesite. Rocks identified in
the source references as latite, latite-
phonolite, vulsinite-vicoite, dancalite,
ordanchite, or trachyandesite, modified
by the names of feldspathoids.
F. Trachybasalt. Rocks identified in
the source references as ciminite, kohala-
ite, mugearite, hawaiite, andesine basalt,
dorgalite, trachybasalt, trachydolerite,
with mineral name modifiers.
G. Basalt, basanite, tephrite. Rocks
identified in the source references as
basalt, ankaramite, oceanite, basanite,
tephrite, limburgite, scanoite, atlantite,
vesuvite, braccianite, modified by one or
more of the following: plagioclase, labra-
dorite, leucite, analcime, hauyne, soda-
lite, mica, hornblende, olivine, hyper-
sthene, picrite, basaltic, alkali.
The most important and unexpected
information in the table is that the rela-
tive frequency of c in the various groups
varies inversely with average CaO and
TABLE 3. Incidence of Normative Corundum in Some Common Volcanic
Rocks, and Related Sample Statistics
No of
% in
which
c>
Averages, %
Group
Analyses
0
1%
2%
c
Si02
AL03
CaO
A
491
58.5
37.9
19.3
1.05
71.83
13.04
1.25
B
338
44.4
22.2
10.1
0.63
65.34
15.63
4.44
C
216
36.6
19.4
10.6
0.63
61.91
17.45
1.99
D
1864
18.7
9.3
4.8
0.30
57.91
17.26
6.96
E
104
9.6
4.8
3.8
0.17
56.73
17.45
5.17
F
133
5.3
3.0
1.5
0.10
48.78
16.79
8.08
G
425
1.9
1.2
0.9
0.05
46.21
14.65
9.99
All
3571
24.9
13.7
7.0
A. Rhyolites, complete tape search.
B. Dacites, complete tape search.
C. Trachytes, complete tape search.
D. Andesites, complete tape search.
E. Trachyandesites associated with trachyte on oceanic islands.
F. Trachybasalts associated with trachyte on oceanic islands.
G. Basalts, basanites, and tephrites associated with trachyte and trachy-
andesite or trachybasalt on oceanic islands.
GEOPHYSICAL LABORATORY
181
directly (and also monotonically) with
average Si02. It does not appear to vary
meaningfully with average A1203. Andes -
ite is not the only common volcanic rock
the norms of which often contain c; the
relative frequency of normative c is far
greater in trachytes, dacites, and rhyo-
lites.
It is to be noted, however, that the
amounts of c under consideration are
nearly always very small. It is present,
to be sure, in almost a quarter of the
3571 norms under review but in almost
half of the corundiferous norms the
amount of c is less than 1%, and in well
over 70% of them it is less than 2%.
Even for the trachytes and dacites
the average value of c is probably not
an impossible result for a passable analy-
sis of a material lacking normative c,
and except for rhyolite the other aver-
ages are well within analytical tolerances.
It is to be remembered that, like the con-
ventional analytical value for A1203,
normative c is not a direct estimate. Its
variance cumulates many perfectly
legitimate uncertainties attaching to
analytical values for oxides other than
A1203. Considering a rather unlikely
source of interaction, for instance, an
overestimate of K20 in the partitioning
of alkalies would tend to generate c in a
norm calculated from an otherwise error-
less analysis of a material containing no
molar excess of A1203 over (Na20 +
K20 + CaO) . If the rock in question were
sufficiently high in CaO, the norm could
easily be free of c, the alumina misbal-
ance finding expression only in a ratio
of an to di somewhat greater than the
true value. Since the true value of this
ratio is unknown, the effect would prob-
ably escape detection altogether. If the
CaO content were low enough, however,
the molar excess of CaO over (A1203 —
Na20 — K20) might well be too small to
compensate for the error in alkali parti-
tion, and the norm would then contain c.
Errors in the partition of CaO and MgO
would have similar effects. Effects of this
kind are generated largely by the CIPW
calculating conventions, but more direct
analytical interactions are of course pos-
sible; the monotonic variation of average
Si02 with relative frequency of occur-
rence of normative corundum certainly
suggests that the amount of Si02 that
may be identified as A1203 varies directly
with the amount of Si02 in the rock. (The
interactions discussed here are those that
might occur in a classical wet analysis,
for so far the library tape contains very
few analyses done by X-ray spectrog-
raphy, nuclear activation, etc.)
The gist of this discussion is that the
amounts and relative frequencies of
normative c in Table 3 should not be
taken as an indication that either the
rocks in question or the immediate parent
magmas are commonly peraluminous.
Should one then use the occurrence of
normative c in the absence of satisfactory
modal rationalization as a means of
identifying faulty or inadequate analy-
ses? Under the circumstances, one can-
not help thinking that a norm contain-
ing more than a few percent of c indicates
either a very unusual analysis or a very
unusual rock, and if modal information
does not support the latter possibility
the former clearly cannot be ignored.
The mere occurrence of c in any amount,
however, is not a desirable criterion for
rejection; in the greatly oversimplified
analytical situation described above, for
instance, such a criterion would eliminate
analyses in which the ratio K20/Na20
had been overestimated, but not those in
which it had been underestimated. The
long-range effect would be to introduce a
bias leading to overestimates of Na20.
In dealing with so many interdepen-
dent variables it is probably wise to re-
frain from imposing fixed rejection cri-
teria. For specific purposes analyses will
certainly have to be rejected, and some-
times in considerable number, but re-
jection criteria suitable for one situation
may be wasteful, ineffective or mislead-
ing in another.
Whatever the detailed interpretation
of c, in norms of volcanic rocks, there
182
CARNEGIE INSTITUTION
seems little doubt that its occurrence in
amounts of the order of 2% or less is
either a consequence of surficial or hy-
drothermal alteration or a combined ana-
lytical-computational artifact. In il-
lustration of the former possibility, c is
present in the norms of only 13% of the
andesite analyses containing less than
2% H20 but in almost 32% of the norms
of those containing over 2% H20. Both
factors no doubt contribute to a striking
result obtained as a by-product of work
described below, in which norms were
generated for the 200 andesite analyses
selected, by a systematic ranking pro-
cedure, as closest to the grand mean for
the group. Although, as already noted,
18.7% of all andesite analyses on the
current library tape are c normative,
only two of this central subset of 200
yielded norms containing c. At the time
of writing, similar calculations have not
been carried through on the dacites, tra-
chytes, and rhyolites.
On Selecting the Centrally Located
Members of a Large Group of Analyses
Nothing is better calculated to reveal
the inadequacy of the sampling concepts
of descriptive petrography than careful
study of a really well-exposed complex.
The availability of a large reservoir of
readily retrieved rock analyses places
broader petrological and geochemical no-
tions— such matters as the definitions of
petrographic provinces or major rock
types, for instance — in similar jeopardy.
Questions that seem reasonably clear and
specific so long as there is no possibility
of answering them definitely may prove
vague, tenuous, and decidedly unclear
as emerging technology provides means
by which, in principle at least, answers
could be provided. Accustomed to sup-
pose that the central difficulty in each
specific instance is the lack of a demon-
strably sound answer, we are then often
chagrined to discover that what is actu-
ally lacking is an answerable question.
A case in point, and perhaps the sim-
plest of all possible examples, is the selec-
tion of analyses thought to be similar to
each other. This is of course a nearly triv-
ial operation if only a single variable is
involved. "Complete" rock analyses con-
tain estimates of at least ten variables,
however, and the assertion that the mem-
bers of a subset of such analyses resemble
each other more closely than they do the
remaining members of the set is essen-
tially meaningless without some specifi-
cation of what is meant by resemblance.
In most practical work the master set
is reasonably small, each of the analyses
is examined by the petrologist making
the selection, and the subset finally se-
lected is small enough so that it can be
published in full in a table occupying
at most a few pages and usually no more
than a single page. Under these circum-
stances it usually does not matter much
that the purveyor does not provide and
the consumers do not demand an explicit
specification of resemblance. Each uses
his own implicit specification, and al-
though no two of these may agree ex-
actly, most have so much in common that
serious differences of opinion about the
closeness of the suggested resemblances
are quite rare.
To some extent this is perhaps because
the function of tables of this sort is often
largely ornamental, but I believe there
is more to it than that. The standard
techniques of descriptive petrography are
both very old and very stable. Early in
our careers we are all taught what little
there is to know about the astatistical
comparison of analyses. We suppose we
are all doing about the same thing when
we examine sets of allegedly similar
analyses, and our intuition is probably
substantially correct even though we
cannot — or, at any rate, do not — say
just what it is we are doing. If really
large numbers of analyses are to be
sorted, however, time alone dictates that
the sorting be by machine, and the back-
ground of common petrographic experi-
ence that makes it unnecessary to de-
fine operating procedures explicitly is of
GEOPHYSICAL LABORATORY
183
no use whatever when we attempt to
transfer the selection function to the
computer. Unless the selection process
can be completely and explicitly speci-
fied, it cannot be computerized.
A reviewer of the andesite work de-
scribed in an earlier section requested
the identities and source references for
a subset of chemically typical andesites,
i.e., andesites whose analyses were in
some sense central. Given an appropriate
definition of "centrality," this is a
straightforward problem in data re-
trieval. The definition finally adopted,
and some of its numerical properties, are
described here.
Oxide ranks and the rank sum. Dis-
tance from the group mean is of course
the criterion one would apply to any
oxide individually, but because of ex-
treme variance differences the distances
for all oxides are not readily compounded
into a single statistic meaningfully char-
acterizing the centrality of a whole
analysis. If the unweighted distances
are used, the net distance will be essen-
tially that of a few components only.
The simplest escape, and the one taken
here, is to abandon deviations in favor
of ranks, using the sum of ranks rather
than of deviations as a centrality sta-
cation retention of the signs of the devia-
tions would introduce considerable am-
biguity. Because of the closure restraint
the sum of deviations in any analysis
is in principle zero and in fact very
nearly zero; thus the sum of ranks as-
signed from the signed deviations for a
particular analysis might fall close to
the mean rank sum either because the
individual oxide ranks all lie close to the
mean oxide rank or because oxide ranks
far above and below the mean oxide rank
contribute to it. The appropriate remedy
is to assign oxide ranks from the absolute
or unsigned deviations, so that the more
central a particular analysis, the smaller
its rank sum.
Mean and variance of the oxide rank
and rank sum. If Xi} is the rank of oxide
; in analysis i, j=l, k and i=l, n, the
mean oxide rank is
*=72W = (n+l)/2
(1)
for all ;, and the average rank sum is
y=kx=k(n+l)/2, (2)
a rather large number even for fairly
small values of k and n.
The variance of an oxide rank if there
are no ties is
*« (*>=^[iw>)-Ki(^1=T (3)
tistic. In the absence of ties, this has
the effect of giving equal weight to all
oxides; in fact, however, the range of
the minor oxides is so small that in any
large collection of analyses the incidence
of tie ranks for them will be very large
and, in general, the more ties in the
rankings for a particular oxide, the less
that oxide contributes to differences be-
tween rank sums. (A weighting of devia-
tions would probably involve less loss of
information than their abandonment, but
the selection of weights involves difficult
and rather arbitrary decisions.)
In most work of this type it is probably
desirable to assign ranks from the signed
deviations, but in this particular appli-
again the same for all ;. If the X's were
independent the expected variance of the
rank sum would be
Var (7)=/cvar (X)
kn(n+l)
12 ;
(4)
and Y, being the sum of k uniformly
distributed numbers, would be asymp-
totically normal about k(n + l)/2 with
standard deviation (/cn(n+l)/12)J.
The variance of the rank sum, however,
is always considerably larger than indi-
cated by equation 4. In the oxide ranking
procedure used here each element of a tie
extending from ranks ; through k inclu-
sive is assigned the rank (;'+/c)/2. Ties
have no effect on oxide rank means, for
184
CARNEGIE INSTITUTION
the sum of the untied ranks would be
;+0'+l) + (j+2)+ . . • +k =
(fc-j+U (;+fc)A
but it was at first feared they might be
responsible for the excess of observed
over expected variance. In fact, however,
their effect on variance, whatever its
magnitude, must be in the opposite di-
rection. Although a tie treated in this
fashion contributes to the sum exactly
what would be contributed by the same
sequence of untied ranks, its contribution
to the sum of squares is always less than
that of the untied ranks it replaces. Thus
ties must always reduce the first but can-
not affect the second term inside the
square bracket of equation 3, with the
result that if ties do in fact occur the
oxide rank variance must be smaller than
its expectation calculated from equa-
tion 3. On the hypothesis of independence
the expected variance of the rank sum is
merely the sum of the expected oxide
rank variances; treatment of ties can
therefore not be responsible for the excess
of observed over expected rank sum
variance.
There is only one other assumption in-
volved in calculation of the expected
variance of the rank sum which is not
realized in the practical situation,
namely, that the oxide ranks are inde-
pendent. If there is interdependence, the
term in covariance cannot be ignored
and equation 4 becomes
Var (7)=/cvar (X)
+ ycov(Xi)Xm). (5)
Now the oxide ranks are uniformly dis-
tributed about the same mean for all
oxides and are assigned from the absolute
values of deviations whose algebraic sum
in any analysis is actually or nearly zero ;
under the circumstances there must be
positive correlation between oxide ranks,
high rank in any constituent being as-
sociated with high rank in one or more
of the others. Clearly, rank sum vari-
ances greater than expectations calcu-
lated from equation 4 should have been
anticipated; indeed, observed rank sum
variances may be used to obtain an
estimate of the average covariance be-
tween oxide ranks.
Recalling that the oxide rank variance
is the same for all oxides, we may re-
state equation 5 as
k
1 [var (7) 1
-l[_/cvar(X) J
(6)
where p is the correlation calculated from
the average covariance between pairs of
oxides. Estimates of p obtained by using
the observed variance of the rank sum
for var (7) in equation 6 are so far
rather small; for the world andesite
group of Table 4, for instance, r is only
TABLE 4. Some Sample Statistics for Rank Sums in Groups of Analyses of
Rhyolites, Andesites, and Basalts
Bl
B2
B3
B4
Number of analyses
Average rank sum, x
Expected standard deviation (from eq. 4)
Observed standard deviation, s
Number of rank sums ^ (x — 3s)
Number of rank sums ^ (x — 2s)
Number of rank sums > (x + 2s)
Number of rank sums > {x -f 3s)
Percentage of rank sums outside a5 ± 2s
Percentage of rank sums outside x ± 3s
528
778
189
134
1946
1880
645
3895
950
675
9735
9405
482.45
710.67
172.99
122.78
1776.90
1716.65
638.02
1115.05
221.89
178.80
2587.82
2150.96
0
0
0
0
0
0
14
5
3
0
18
29
15
23
9
22
42
39
1
0
0
0
3
0
5.5
3.6
6.3
6.1
3.1
3.6
0.19
0
0
0
0.15
0
A. Rhyolites (Troger numbers 40-44, 47^9, 72, 96, 102, 118).
B. Andesites (Troger numbers 127, 154, 324, 340, 342, 343, 890) : 1, Japan; 2, Kuriles, Kamchatka,
Aleutians; 3, Mexico, Central America; 4, world.
C. Basalts (Troger numbers 151, 159-162, 344, 378-382, 384-387, 407-410, 801, 855, 864, 888).
GEOPHYSICAL LABORATORY
185
0.114. It is a striking illustration of the
difference between significance testing
and estimation that a correlation too
small to warrant rejection of the hy-
pothesis of zero covariance between any
pair of variables except in very large
samples may more than double the vari-
ance of the sum of ten variables.
The coefficient of concordance sug-
gested by Kendall (1948) provides an-
other means for summarizing the inter-
dependence of oxide ranks. If the oxide
ranks were perfectly concordant, i.e., if
the ranks for all oxides in each analysis
were the same (and there were no ties),
the rank sums would be k, 2k, 3k, . . .,
nk. The variance of these perfectly con-
cordant rank sums is k2n{n + 1)/12 * and
no other arrangement of k sets of n ranks
can have a larger variance. Kendall's co-
efficient of concordance is the ratio of
the observed rank sum variance to that
for perfect concordance, or
W=12s2y/k2n(n+l),
which clearly lies in the interval 0, 1. In
terms of this statistic, incidentally, equa-
tion 6 may be written P=(kW— 1)/
(k-1).
As we have seen, if the oxide ranks
were independent, the expected variance
of the rank sum would be kn(n + l)/12.
For this null point, accordingly,
Wi=hv&T (X)/[k2n(n+l)/12]=l/k.
Sample values greater than 1/k indicate
some degree of concordance, and those
less than 1/k some degree of discordance,
between ranks ; concordance, in turn, re-
sults from a net positive, and discordance
from a net negative, correlation between
the variables being ranked. Every sample
value of W so far computed is greater
than 0.1, the null value for A; = 10. The
excess, however, is never large; for the
world andesite group of Table 4, for ex-
ample, W= 0.203.
*If ;=1, 2, 3, . . ., n, then, from (3), var
(;) =n(n -f 1)/12, and for any constant, k,
var (kj) =/cavar (;).
Some examples. As already mentioned,
the work on rank sums was stimulated
by a request for a set of analyses "typi-
cal" of the andesites on the library tape.
A program was constructed that would
search all or any part(s) of the library
tape for analyses of rocks denoted by
any of a set of names, save all such
analyses and their tape locations in a
temporary file, generate rank sums for
all analyses in this file, and print out each
of the i smallest rank sums, together with
the number of the logical record contain-
ing the analysis that gave rise to it and
the sequence number of the analysis
within that record. (From this latter in-
formation the analysis itself, associated
analyses, and source reference or refer-
ences are easily reclaimed.) The parts of
the tape to be searched, the names of
the rocks whose analyses are to be pro-
cessed, and the number of rank sums to
be printed out are at the option of the
user. The desired information was thus
readily obtained — although the whole
procedure would have been impractical
or impossible on anything but a very fast
and very large computer — but the rank
sums were much larger than had been
anticipated, the smallest in each of a
considerable set of rankings being of the
order of two to three times the number
of analyses being ranked.
The work described above, prompted
by these excessively large minimum rank
sums, soon showed, however, that the
average rank sum (equation 2) would
be a very large number indeed and sug-
gested that the observed minimum
values, far from being too large, were
too small; in samples of the sizes used,
values as small as those found would
not occur in anything like the observed
frequency if the parent population was
indeed normal with mean and variance
as indicated by equations 2 and 4. Ac-
cordingly, the program was modified so
that it would find the sample mean and
standard deviation of the rank sum and
generate a sample frequency distribution
with class width equal to one-third of the
186
CARNEGIE INSTITUTION
(observed) standard deviation. Results
of some of the runs made with the modi-
fied program are summarized in Table 4.
The average rank sum is precisely that
given by equation 2, but the observed
variance is always considerably larger
than indicated by equation 4; in the ex-
amples shown in the table the ratio of
observed to expected standard deviation
ranges from 1.24 to 1.66, so the observed
variance may be 1.5 to 2.75 times as large
as that calculated from equation 4. In
the three largest samples, the relative
frequency of rank sums distant from
the mean rank sum by more than 2s is
somewhat less than the normal expecta-
tions of 5%, and that of values distant
from the mean by more than 3s is far
less than the expected 1%. Thus a disper-
sion markedly greater than normal
against a standard deviation calculated
on the hypothesis that the oxide ranks
are independent is in fact subnormal
against the sample standard deviation.
Chemical and Mineralogical
Petrography
Knowledge of the chemical composi-
tion of individual minerals in volcanic
rocks is essential both for proper classifi-
cation of the rock and for an under-
standing of fractionation trends arising
from crystal-melt equilibria. Traditional
gravimetric analysis undoubtedly re-
mains the most accurate method for
properly purified, homogeneous mineral
concentrates, but the minerals of rapidly
cooled volcanic rocks are rarely homo-
geneous, and the purification of fine min-
eral intergrowths is sufficiently tedious
and wasteful of material that such analy-
ses can hardly be produced routinely. In
such a situation the electron microprobe
is of obvious value; with its aid all but
the most minute mineral grains can be
identified and analyzed. Though the indi-
vidual analyses are of considerable value,
qualitative comparisons of phenocryst
and groundmass crystals of a given min-
eral or scans across marginal zones of
phenocrysts with the probe beam provide
important information on possible varia-
tion trends in both minerals and residual
liquids. Examined in this detail, most
volcanic rocks prove to be much more
complex than traditional thin-section
study would suggest.
All electron-microprobe * analyses
were made with standards and correction
procedures described by Boyd {Year
Book 66) and Boyd, Finger, and Chayes
{Year Book 67), except that a natural
cossyrite analyzed and described by Zies
(1966) was used as a standard for Na
and Ti in the aenigmatite (cossyrite)
from Socorro Island. The ratio a/ VW,
where N is the mean count and o- is the
standard deviation, provides a useful
measure of homogeneity and is given for
the major elements; a value greater than
3 indicates a distinctly inhomogeneous
mineral.
Volcanic rocks examined during the re-
port year include material from Aus-
tralia, Pantelleria, the Revillagigedo
Islands on the East Pacific Rise, and
drift pumice, collected from beaches in
Australia but probably originating in the
Tonga-Kermadec volcanic zone north of
New Zealand. Over fifty minerals have
been analyzed so far, many of them
replicated against different standards or
with different operating conditions as a
check on the procedures used. The min-
erals discussed here, along with the rocks
in which they occur or with which they
are associated, represent some of the
more important observations and the
petrologic problems toward which the
work has been directed.
Among the common silicate minerals
in the rocks examined this year, zoning
is usually most pronounced in feldspar,
and the next most variable mineral is
olivine. Pyroxenes are usually relatively
homogeneous in terms of the major ele-
ments but typically show considerable
* The electron probe was purchased with the
assistance of the National Science Foundation
under grant GP 4384.
GEOPHYSICAL LABORATORY
187
sympathetic variation in titanium and
aluminum. Alkali feldspars range from
potassic oligoclase to sodic sanidine or
anorthoclase with a composition close to
the "dry" eutectic of Ab650r35. In the
basalts examined, feldspar consists of a
relatively uniform core of intermediate
plagioclase, surrounded by a narrow zone
of potash oligoclase in which there is a
rapid transition to a rim of anorthoclase.
This partitioning of sodium between
plagioclase and alkali feldspar probably
largely accounts for the common obser-
vation that modal plagioclase is dis-
tinctly more calcic than normative
plagioclase. The discrepancy may dis-
appear if normative albite is partitioned
between normative anorthite and ortho-
clase, on the assumption that the alkali
feldspar has the eutectic composition. As
a practical matter, grains sufficiently free
from zoning for reliable microprobe
analysis can usually be found, but it
must be realized that such an analysis
may not correspond to the average com-
position for the whole assemblage of
crystals of that mineral phase in the rock.
Indeed, the problem of determining the
bulk composition of a feldspar in a rock,
discussed by Suzuki and Chayes (Year
Book 60, pp. 169-172), appears to apply
in a less extreme way to all other mineral
phases.
In volcanic areas one can usually be
sure that magmas having the composi-
tions of each of the major rock types did
in fact exist, and the sequence of mag-
matic development can sometimes be in-
ferred with reasonable assurance. With
regard to plutonic rock complexes the
situation is very different. Although
chilled margins may provide direct evi-
dence of magma composition, the other
facies of a complex are not merely frozen
magma; rather, they are fractionation
products that in general must be pre-
sumed to differ in composition both from
the magma that precipitated them and
from the magma remaining after their
precipitation. Reconstruction of the path
of magmatic development is nevertheless
of prime interest. It is nearly always
accomplished by graphical devices, and
there is probably little to choose between
solving a "partition" problem by graphi-
cal or analytical means if the numerical
work is to be done by hand. If a pro-
grammed computer or a good desk calcu-
lator is available, however, an analytical
solution will ordinarily be more reliable
and much more quickly reached than a
graphical one. An analytical solution for
the composition of successive liquids in
the important "Skaergaard model" — in
which a single mass of magma of some
known or assumed composition is par-
titioned into a number of zones or frac-
tions, one of which is unexposed — is
briefly described here. An application of
the procedure to summary data for the
well known Skaergaard complex has been
published elsewhere (Chayes, 1970) ; the
burden of the argument is that the ex-
posed portion of the complex may be a
very much smaller part of the whole than
Wager (1960) suggests, and that there is
no evidence for the progressive alkali
enrichment indicated by his graphical
analysis.
Mineralogy oj Coral Sea Drift Pumice
W. B. Bryan
Pumice that accumulates on main-
land beaches and barrier reef islands of
Queensland, Australia, probably origi-
nates from submarine eruptions along
the Tonga-Kermadec volcanic zone north
of New Zealand. Menard (1964, p. 58)
has considered the effect of sea water
pressure on the vesiculation of magma
and concludes that the possibility of ex-
plosive volcanism increases very rapidly
above a depth of 1500 meters. Many
submarine volcanoes along the Tonga-
Kermadec zone extend above this depth
and could have been the source of the
pumice. The samples described here were
collected in November 1966, by Dr. J. C.
Yaldwyn, of the Australian National
Museum, from the beach on One Tree
Island near the southern end of the Great
188
CARNEGIE INSTITUTION
Barrier Reef. In megascopic appearance
and in terms of refractive index of the
glass and plagioclase (Table 5) this
pumice appears identical to that col-
lected on the Herald Cays, Queensland,
in December 1964, and to that which ap-
peared on beaches of the Fiji Islands in
March 1965. Optical data and chemical
analyses of light and dark varieties of
the Herald Cays pumice have been pub-
lished previously (Bryan, 1968) .
The One Tree Island pumice may be
readily subdivided into light, dark, and
intermediate varieties on the basis of the
color of the glass. As was true of the
Herald Cays and Fiji samples, the light
pumice forms the largest pieces, some
lumps measuring 3-4 inches in diameter,
and the intermediate and dark pumice
lumps average about 1 inch in diameter.
The light pumice is almost pure white or
chalky in hand specimen, with yellowish
or brownish iron oxide stain along frac-
tures. The glass appears colorless under
the microscope. The intermediate pumice
is pale tan in hand specimen, but small
fragments also appear almost clear in
transmitted light. The dark pumice is a
dark chocolate brown color, appearing
reddish brown in small fragments under
the microscope. Small nodules, 1-2 mm
in diameter, are especially common in
the light and dark varieties; they are
aggregates of interlocking green clino-
pyroxene, hypersthene, and calcic plagio-
TABLE 5. Refractive Index of Pumice Glass
and Plagioclase from Herald Cays, One Tree
Island, and Fiji
Pumice Variety
Light
Inter-
mediate
Dark
Pumice Glass
One Tree Island 1.508
Herald Cays* 1.5075
Fiji* 1.5075
Plagioclase a' on (
1.523
1.5220
1.5212
Cleavage
1.532
1.5300
1.5306
One Tree Island 1.576
Herald Cays* 1.5760
Way a Island, Fiji * 1.5755
1.5773
1.5740
clase with minor amounts of magnetite.
Microprobe analyses of the light
pumice glass (Table 6) and minerals
(Table 7) reveal the same compositional
peculiarities noted in the Herald Cays
pumice. Chemically and mineralogically
this material may be classified as a
dacite, but the high ratio of lime to
alkalies, and especially the low potash,
are unusual in a rock containing over
70% Si02, even among the relatively
calcic circumpacific lavas.
Analyses of the plagioclase indicate a
distinctly less calcic composition than
would be inferred from the a' refractive
index on cleavage fragments, although
the extinction a' A 010 on 001 cleavage
fragments averages about 23°, giving a
composition of An83 on the determinative
chart of Deer, Howie, and Zussman
(1963, p. 137), in good agreement with
the compositions obtained by microprobe
analysis. The refractive index is appar-
ently raised appreciably by the relatively
high iron content of the feldspar. As care
TABLE 6. Chemical Analyses of Pumice and
Pumice Glass
Si02
72.3
73.38
73.50
65.84
73.04
A120»
11.4
12.66
11.90
12.02
13.61
Ti02
0.45
0.45
0.58
0.76
0.30
Fe203
1.11
0.76
1.05
0.69
FeO
4.34
2.84
4.84
8.25
2.13
MnO
0.13
0.06
0.00
0.13
0.08
MgO
0.62
0.84
0.63
1.29
0.50
CaO
3.59
3.79
3.80
6.22
3.25
Na20
3.50
3.09
2.81
2.66
4.66
K20
0.80
1.52
0.75
0.77
0.67
P205
0.00
0.09
Tr
0.12
H20+
<0.10
0.46
0.84
1.04
H20"
0.03
0.16
0.04
Totals
97.13
99.77
100.12
99.99
100.13
* Bryan, 1968.
Note: Values are midpoints of ranges given
in Table 1 (op. cit.).
1. Interstitial glass, pumice C, One Tree
Island, Queensland. Partial analysis by electron
microprobe.
2. Pumice glass, Metis Shoals, Tonga. E.
Jarosewich, analyst (Melson, 1969).
3. Light pumice, Herald Cays, Queensland,
L. J. Sutherland, analyst (Bryan, 1968).
4. Drift pumice, 1928 Falcon Island eruption,
Tonga. A. LaCroix, analyst (LaCroix, 1939).
5. Pumice, 1962 eruption, South Sandwich
Islands. P. G. Harris and M. Kerr, analysts
(Gass, Harris, and Holdgate, 1963).
GEOPHYSICAL LABORATORY
189
TABLE 7. Composition of Plagioclase, Pyroxene, and Magnetite from
Gabbroic Nodules in Drift Pumice, One Tree Island, Queensland
1
2
3
4
5
Si02
48.7
3 46.2
3
51.4 1
51.7 1
0.12
A1203
32.1
4 33.3
4
0.73
1.19
2.21
1
Ti03
0.19
0.31
12.4
2
Fe203
0.90
3 0.89
2
50.3
2
FeO
26.4' 2
14.6 1
32.4
MnO
o.oi
1.02
0.57
0.48
MgO
0.08
0.11
2
18.1 2
12.8 1
1.46
1
CaO
16.6
4 17.8
5
1.68 2
19.5 1
0.03
Na20
2.07
4 1.24
5
0.00
0.13
K20
0.01
0.00
0.00
0.00
Cr203
ils
9
Tr
0.00
0.66
Tot;
100.5
9.6
99.5
100.2
99.4
0
32.00
32.00
6.00
6.00
32.00 .
Si
Al
8.902^
8.570"
1.9751
0.025,
► 2.000
1.9601
0.040J
> 2.000
0.035
Al
6.921
-15.946
7564
> 15.959
0.008]
0.013]
0.764
Ti
0.005
0.009
2.725
Fe3+
0.i23
0.i'25
11.096
Fe2+
0.849
0.443
7.924
►23 ai
Mn
•>
"i
0.033
> 2.002
0.018
-2.009
0.120
Mg
0.022
0.030
1.038
0.725
0.637
Ca
3.241
► 3.999
3.525 I 40O1
0.069
0.792
0.009
Na
0.734
0.445 1 ,u
. . .
0.009
K
0.002.
••J
• • •.
....
Ca
82.0
Ca
89.0 Ca
3.5 Ca
40.4
Na
18.0
Na
11.0 Fe
43.4 Fe
22.6
K
0.0
K
0.0 Mg
53.1 Mg
37.0
1. Bytownite, pumice A nodule, all Fe as Fe203.
2. Calcic bytownite, pumice C nodule, all Fe as Fe203.
3. Orthopyroxene, pumice A nodule, all Fe as FeO.
4. Clinopyroxene, pumice A nodule, all Fe as FeO.
5. Titanomagnetite, pumice C nodule, recalculated to give FeO and Fe203
on ilmenite-magnetite basis.
Note : Numbers in italics are a/ wlr?
was taken to select especially clear crys-
tals for analysis, and inclusions are easily
avoided with the probe beam, the iron
must be contained in the feldspar struc-
ture. In both analyses alumina is insuffi-
cient to balance the alkalies, and iron
may be presumed to make up the defi-
ciency. Apparently this iron content does
not seriously affect the optic orientation.
The pyroxenes in such a siliceous rock
might be expected to be relatively en-
riched in iron, but the analyzed composi-
tions are in fact more typical of a gab-
broic rock. These pyroxenes, along with
the very calcic plagioclase, would not
be expected to be in equilibrium with a
magma of this composition. It seems
more likely that the rock nodules are
small xenoliths incorporated into the
frothy pumice magma during its ascent
in the volcanic vent. The mixture of at
least three pumice varieties, presumably
erupted almost simultaneously at the
same vent, is also suggestive of hybrid-
ization of acid and basic material in the
magma chamber. It is strange, however,
that in none of the three separate col-
lections from Fiji, from the Herald Cays,
and from One Tree Island do any of the
pumice fragments show banding or tran-
sitional compositional features; each
fragment seems to fall distinctly into one
of the three categories.
Drift pumice may be an important
source of fragmental material in deep-sea
sediments, and the transport of pumice
for thousands of miles by ocean currents
provides effective distribution over a
190
CARNEGIE INSTITUTION
large area. The transfer of material from
oceanic sites of eruption to distant sites
of deposition on the sea floor or on the
continental shelves may have important
geochemical implications that have yet to
be evaluated. Fiske (1969) has discussed
criteria by which pumice fragments,
often overlooked in marine sedimentary
rock, may be recognized. He described
examples dating back to the Pre-
cambrian. The size and ultimate dis-
tribution of pumice rafts may be judged
from a few recent examples. Richards
(1958) cited linear dimensions of 64 to
324 miles for the pumice raft from the
eruption of San Benedicto Island, Mex-
ico; although he gave no estimate of
the volume of the raft, the estimated
volume of tephra in the new cone pro-
duced by the 1952 San Benedicto erup-
tion is 350 million cubic yards (Richards,
1959). If the eruption had been sub-
marine, all of this material would have
been ejected into the sea. Pumice from
this eruption drifted at least as far as
the Marshall Islands, a distance of 4700
miles. Pumice from the 1962 submarine
eruption in the South Sandwich Islands
circled the Antarctic continent in the
"roaring forties." The area of the original
pumice raft was estimated to be about
2000 square miles, with an estimated
volume of pumice of about 750 million
cubic yards or about 0.15 cubic mile
(Gass, Harris, and Holdgate, 1963).
The frequency of submarine pumice
eruptions is very poorly established; of
those observed or detected, probably
most are never reported in geologic
literature. If such eruptions average only
four per year, a reasonable figure, they
could easily produce about one-half
cubic mile of pumice per year. Even
allowing for void space in the pumice,
this amount would represent almost two-
tenths of a cubic mile of rock, a signifi-
cant figure compared with other esti-
mates of material moved by erosion or
produced by terrestrial eruptions. For
example, Gilluly (1955) suggested 13.6
km3, about three and one-quarter cubic
miles, as the amount of material removed
annually from the continents by erosion.
Wilson (1952) noted that the building
of the continents to their present size
by accretion through available geologic
time requires an addition of about one-
third of a cubic mile of material per year,
and he suggested that the rate of ter-
restrial volcanic eruption alone is suffi-
cient to add this amount. It is difficult
to estimate the proportion of eroded ma-
terial that bypasses the continental shelf
and is lost to the ocean basins ; similarly,
it is not yet possible to estimate the
proportion of material transported as
drift pumice that becomes incorporated
in sediments on the continental shelves.
It is clear, however, that knowledge of
the source, composition, and ultimate
distribution of drift pumice is essential
to a more complete understanding of
sedimentation in the deep oceans and of
the geochemical balance between conti-
nents, ocean basins, and active volcanic
areas in and around the oceans.
Mineralogy of a Mugearite from Clarion
Island, Mexico
W. B. Bryan
Chayes (1963a) showed that bulk
chemical analyses of alkaline rocks of
composition intermediate between basalt
and trachyte are relatively rare in the
literature. Even less detailed information
is available on the mineralogy of these
rocks. Muir and Tilley (1961) gave data
for olivines, pyroxenes, feldspars, and
iron-titanium oxides for eighteen rocks
that they then classified as mugearite;
of these, only three lie in or close to the
"Daly gap" as defined by Chayes's histo-
grams. In a later paper, Tilley and Muir
(1964) discussed the nomenclature of
rocks lying in the "Daly gap" and noted
that, though most would be called
trachyandesite, this term has been too
loosely used to be meaningful. They sug-
gested instead the names "tristanite" for
the potassic varieties and "benmoreite"
for the sodic variants. Under this termi-
GEOPHYSICAL LABORATORY
191
nology, the "mugearite trachyte" from
Totardor, Skye, and the "mugearite" of
Ben More, Mull, described in their earlier
paper, are now defined as benmoreite.
For these two rocks the earlier paper
gave analyses only for the pyroxenes, and
no new mineral data were given in the
later paper. Baker et al. (1964) pro-
vided data on trachyandesites (tristan-
ites) from Tristan da Cunha, but further
accounts of tristanites and benmoreites
from other areas remain minimal. Ac-
cordingly, it has seemed desirable to ex-
amine in more detail the mineralogy of
some rocks lying in or near the Daly gap.
The trachyandesite described here is of
particular interest, as it is one of the
very few intermediate alkaline rocks
known from volcanic islands along the
East Pacific Rise and is also sufficiently
well crystallized to permit satisfactory
microprobe analyses of most groundmass
minerals as well as of phenocrysts. The
rock has been briefly described elsewhere
(Bryan, 1967, p. 1468); its chemical
analysis is given in Table 8.
The bulk chemical composition of this
rock resembles more nearly some of the
rocks described as mugearite by Muir
TABLE 8. Chemical Analysis and CIPW Norm
of Trachyandesite CL-16, Clarion Island,
Mexico, and a Mugearite from Hawaii
1
2
1
2
Si03
53.17
51.84
Q
4.56
Ti02
2.40
2.18
Or
18.35
11.95
A1203
17.70
18.11
Ab
38.77
39.43
Fe203
6.26
2.41
Ne
5.81
FeO
3.54
7.27
An
ieii
16.54
MnO
0.14
0.24
Di
7.74
MgO
2.07
3.25
Hy
5.20
CaO
4.20
5.93
01
9.08
Na20
4.56
5.95
Mt
4.87
3.48
K20
3.09
2.04
11
4.56
4.26
P205
0.73
0.55
Ap
1.68
1.34
H20+
1.47
0.28
C
0.92
H20"
0.24
0.09
Hm
2.88
C02
0.00
99.58
100.14
Rest
Totals
1.71
0.37
Totals
99.52
100.00
1. Trachyandesite, Clarion Island, Mexico.
H. B. Wiik, analyst (Bryan, 1967, p. 1468).
2. Mugearite, Hawi volcanic series, Hawaii.
J. H. Scoon, analyst (Muir and Tilley, 1961,
p. 192).
and Tilley (1961), being distinctly lower
in Si02 and total alkalies than the type
examples of benmoreite and tristanite
described by Tilley and Muir (1964).
It most closely resembles the mugearite
from the Hawi volcanic series, Hawaii,
with which it is compared in Table 8.
The greatest differences in the norm are
due to the different ratio of ferric to
ferrous iron, the much higher ferrous iron
in the Hawaiian rock being largely re-
sponsible for the normative olivine and
nepheline. The Clarion trachyandesite
also appears to lie well outside the limits
of hawaiite as defined by Macdonald
(1960) ; in particular it is distinctly lower
in dark minerals, the normative color
index being 19.2, compared to 38.3 for the
average hawaiite cited by Macdonald.
The ratio of Na20 to K20 is also well
outside the limit of 2:1 set by Mac-
donald.
Microprobe analyses of the principal
minerals of the trachyandesite are set out
in Table 9. The plagioclase phenocrysts
range in size from 1 to 2 mm in length
and are subhedral and often marginally
corroded, with an outer zone clouded with
opaque oxides, largely magnetite. On
many phenocrysts, including the one
analyzed, the outer zone of alkali feld-
spar is separated from the core by a
narrow zone of more calcic plagioclase,
ranging up to An55-eo, as indicated by
the relative intensity of the CaKoo peak.
Groundmass plagioclase laths may be as
calcic as An60 ; they are marginally zoned
to calcic anorthoclase and are surrounded
by blocky unzoned crystals of alkali feld-
spar. Comparison of Koc intensities for
Na, K, and Ca with those of the alkali
feldspar rims on plagioclase shows that
these crystals are also calcic anortho-
clase.
The olivine, a small microphenocryst,
was selected for analysis both because
it is free from impurities and because it
appears typical in composition among
the grains tested with the probe beam.
Only a few of the grains show the elonga-
tion noted by Muir and Tilley (1961, p.
192
CARNEGIE INSTITUTION
TABLE 9. Microprobe
Analyses of Minerals from Trachyandesite CL-16,
Clarion Island, Mexico
1
2
3
4
5
Si02
59.3
34.8
0.02
49.6
49.7
A1203
24.5
3.69
3.89
Ti02
50.7'
1.38
1.73
Fe203
0*26
6.36
. . .
FeO
. . .
35.7'
37.7
10.1
12*6"
MnO
0.00
0.97
0.80
0.33
0.28
MgO
0.02
28.4
3.99
14.5
16.6
CaO
7.05
0.25
0.01
19.6
8.95
Na20
6.99
0.51
4.04
K20
0.90
0.00
1.21
Totals
99.0
100.1
99.6
99.7
98.4
0
32.000
4.000
6.000
6.000
O
23.000
Si
10.722
0.975
o.oor
1.8641
> 2.000
Si
7.230]
Al
5214
0.136J
Al
0.668 f 8.000
Al
• 15.972
0.027:
Ti
0.102 1
Ti
1.881
.4 001 0039
►a.uui 031g
Ti
0.088]
Fe
0.036.
0.835]
1.790
Mg
3.593 f 5.000
Mn
}«**»
0.034
0.010
,2.034
Fe
1.319J
Mg
0.004^
0.294
0.814
Fe
0.137]
Ca
1.366
> 4.030
0.008 J
0.001
0.789
Mn
S 2.000
Na
2.452
0.037
Ca
K
0.208 J
0.000
Na
Na
K
0.433 J
Atomic Re
itios
Ca
33.9
Ca
0.4 Ilm
94.
0 Ca
40.9
Ca + Alk 35.2
Na
60.9
Mg
57.8 R20
6.
0 Mg
42.2
Fe + Mn 19.0
K
5.2
Mn + Fe 41.9
Mn + Fe
17.0
Mg
45.8
1. Plagioclase phenocryst, all Fe as Fe203.
2. Olivine microphenocryst, all Fe as FeO.
3. Ilmenite phenocryst, FeO and Fe203 computed on assumption of ideal ilmenite-hematite
mixture.
4. Augite microphenocryst, all Fe as FeO.
5. Groundmass amphibole, all Fe as FeO.
194) , but the composition lies within the
range of average values they obtained
from X-ray data.
Iddingsite forms pseudomorphs of
much of the phenocryst olivine ; qualita-
tive examination with the probe beam
shows that it also has an Fe/Mg ratio
similar to the olivine, and the amounts
of other elements, except Si, are neg-
ligible.
Pyroxene is present as stubby pris-
matic microphenocrysts up to 0.5 mm in
diameter and as interstitial groundmass
granules. The larger crystals, like the one
analyzed, have optic angles of 35°-45°,
but in some groundmass grains the angle
approaches 10°-15°; nevertheless, all
grains tested with the probe beam con-
tained appreciable calcium. Possibly the
low 2V is due to entry of Ti and Al into
the structure, but this question has not
been satisfactorily resolved. Although the
rock is not sufficiently well crystallized
for an accurate point count, olivine seems
more abundant than pyroxene and cer-
tainly is if iddingsite is included with the
olivine. This observation again is in
agreement with the observations of Muir
and Tilley (1961, p. 194).
Ilmenite apparently was not common
in mugearites examined by Muir and
Tilley, who stated (1961, p. 197) that
"no ilmenite has crystallized directly as
a separate phase." In the Clarion rock,
ilmenite appears as a conspicuous pheno-
cryst over 2 mm in length and is also
abundant in the groundmass, where it is
joined by magnetite. The latter mineral
GEOPHYSICAL LABORATORY
193
is usually partly oxidized to maghemite,
which appears both as veins and as more
indistinct patches. Ilmenite is rarely
present as exsolved blebs or lamellae in
magnetite but is mostly present as dis-
tinct crystals. These ilmenites may be
xenocrysts derived from basic inclusions
described below. Pyrite appears in traces,
associated with magnetite.
An alkaline amphibole is closely asso-
ciated with iddingsite and magnetite in
the groundmass, where it usually forms
irregular patches less than 0.1 mm in
diameter, interstitial to feldspar. The
analysis in Table 9 is an average of two
such grains. The amphibole is weakly
pleochroic with a, very pale yellow; (3,
pink; and y, pale greenish yellow. The
grains analyzed show normal extinction
and are almost identical in composition.
Other grains, however, which show more
intense pink absorption for (3 and patchy,
anomalous extinction colors, may not be
of the same composition. The optic angle
is also variable, being always negative
but ranging in size from about 10° up to
more than 40°. The optical properties
and composition indicate that the min-
eral is intermediate in composition be-
tween arfvedsonite and richterite. Apa-
tite is a conspicuous accessory mineral,
forming stout rounded prisms up to 0.3
mm long, pale pink in color, with abun-
dant acicular inclusions parallel to the
c axis.
An inclusion, 1.5 cm in diameter, con-
sists of optically continuous, dark brown
kaersutite, which ophitically encloses
rectangular crystals of plagioclase and
rounded crystals of ilmenite and titanif-
erous magnetite. The plagioclase yields
CaKcc intensities identical with those
given by the cores of groundmass plagio-
clase laths. The contact between kaersu-
tite and enclosed plagioclase is sharp
and without evidence of reaction, but
where it is in contact with the ground-
mass of the rock or with enclosed iron-
titanium oxides the kaersutite is bordered
by a reaction rim, 5-20 mm thick, which
consists of a very fine-grained mixture
of magnetite, plagioclose, hematite, and
reddish-brown granules, resembling id-
dingsite. The groundmass of the rock
immediately adjacent to these rims also
is enriched in finely divided magnetite,
hematite, and iddingsite. It is possible
that the bulk composition of this rock
was derived by reaction of trachytic
liquid with a more mafic rock, the latter
now represented by the kaersutite-bear-
ing inclusion. The kaersutite may have
formed by reaction of olivine or augite
with hydrous alkaline magma, as de-
scribed by Aoki (1959, p. 304). Gabbroic
nodules have been observed in older
basalt flows on Clarion (Bryan, 1967,
p. 1465). Reaction with a relatively
calcic contaminant is also suggested by
the reverse zoning in the phenocrysts of
sodic plagioclase and by the mixture of
anorthoclase and labradorite appearing
in the groundmass. In view of the pos-
sibility of contamination or hybridiza-
tion, the composition of this rock should
not be accepted as that of a liquid on a
genetic "line of descent" from basalt to
trachyte.
If Chayes's (19636) specifications for
the "Daly gap" are taken literally, the
Clarion rock qualifies on two criteria and
fails on two others. The weight percent-
age of Si02 falls just above the lower
limit of the specified interval ; the weight
percentage of CaO is well within it; the
Thornton-Tuttle index is about 2 points
below, and the total iron is more than
1.0% above the specified intervals. There
is of course no reason to suppose that a
perfect correlation exists between these
four criteria, such that they will all be
simultaneously satisfied by any given
rock, and this will be especially true of
marginal cases. A purely numerical and
chemical definition will probably prove
to be as unsatisfactory for intermediate
alkaline rocks as it has proved to be for
other aspects of rock classification; a
number of the rocks listed by Tilley and
Muir (1964) as typical intermediate
rocks also fall slightly outside one or
more of the defined chemical and norma-
194
CARNEGIE INSTITUTION
tive limits. As more mineralogical data
become available it may be increasingly
possible to set modal qualifications for
membership in the clan of intermediacy,
but criteria for entry must be based on
far more information than is now avail-
able.
Alkaline and Peralkaline Rocks of
Socorro Island, Mexico
W. B. Bryan
A peralkaline rock as formally defined
by Shand (1943, p. 190) contains a mo-
lecular proportion of alumina which is
less than that of soda and potash com-
bined. Perhaps the best known occur-
rence of such rocks is on the island of
Pantelleria in the Mediterranean, the
type area for the oversaturated peralka-
line rock pantellerite. Pantellerites from
the type area and from many other
localities around the world have been the
subject of numerous papers in recent
years. Descriptions of the natural rock
occurrences have stimulated experimen-
tal studies (Carmichael and MacKenzie,
1963; Bailey and Schairer, 1966; Thomp-
son and MacKenzie, 1967) and have
prompted discussions of alternative and
presumably more informative methods
of graphical representation of the rock
data (Bailey and Schairer, 1964; Bailey
and MacDonald, 1969). Most of the
discussion has centered on rocks and syn-
thetic mixtures lying in or close to the
oversaturated "Residua System" NaAl
Si308-KAlSi308-Si02. Although basalt
has been recognized on Pantelleria at
least since the work of Foerstner (1883)
and has been reanalyzed by Washington
(1913), Zies (1962), and Romano (1968),
the possibility of deriving pantellerite
from this basalt has not been seriously
considered. Genesis of pantellerite from
associated alumina-saturated trachyte
poses problems for which no entirely
satisfactory solution has been offered.
The development of alumina deficiency
is generally attributed to the "plagioclase
effect" (see, for example, discussions by
Yoder and Tilley, 1962, p. 416; Car-
michael and MacKenzie, 1963, pp. 394-
395; Bailey and Schairer, 1964, p. 1205;
Thompson and MacKenzie, 1967, pp.
730-731), but demonstrations of this
mechanism in natural rocks are ex-
tremely rare. The best example (Car-
michael, 1964) has been observed in
phonolite rather than in pantellerite or
in trachyte associated with pantellerite.
Bailey and Schairer (1966, pp. 147-148)
considered briefly the possibility that
peralkaline rocks may be derived from
basalt and suggested that aluminous
minerals other than feldspar may be
effective in producing the alumina de-
ficiency that is the critical characteristic
of peralkaline rocks. However, such ef-
fects have not been demonstrated within
suites of natural rocks.
The volcanic rocks of Socorro Island
provide an excellent opportunity to ex-
amine some of the genetic problems noted
above. The island is located on the East
Pacific Rise, an area of thin crust and
high heat flow, a setting that seems to
preclude the role of granitic or other
typical continental crustal rocks in the
genesis of the lavas. The general geology
and eruptive history have been discussed
elsewhere (Bryan, 1966), and it has been
shown that an earlier period of extrusive
activity was terminated with formation
of a caldera. Renewed activity, pre-
dominantly explosive, accompanied fault-
ing along a north-south rift and nearly
filled the caldera, building a central
volcanic peak composed of numerous
overlapping pyroclastic cones. Each of
the explosive central eruptions typically
ended with quiet extrusion of trachyte or
pantellerite domes into the crater of the
pyroclastic cone. The most recent erup-
tions are confined to low-level flank ex-
trusions along well-defined rifts, with
little or no preliminary explosive activ-
ity, and basalt appears only as flows of
relatively small volume erupted from
low-level flank vents. It was suggested
that these relationships could be ex-
plained by a stratified magma column
GEOPHYSICAL LABORATORY
195
beneath the caldera, in which basalt is
overlain by an accumulation of volatile-
poor trachytic or pantelleritic liquid,
topped by a highly vesicular, vapor-rich
salic liquid (Bryan, 1966, pp. 474^80).
In many respects the topography and
geologic history of Socorro Island appear
very similar to those outlined for Pantel-
leria by Washington (1913, pp. 665-670) .
Petrography. The basalts of Socorro
Island contain modal and normative
olivine and small to large amounts of
normative hypersthene, the latter mainly
reflecting different degrees of oxidation.
Total alkali ranges from slightly over
4.00% to over 5.00% in the analyzed
rocks, the latter being similar to the typi-
cal hawaiite as defined by Macdonald
(1960). The least siliceous and least
alkalic basalt, S141, is also probably the
youngest. As this basalt is well crystal-
lized and is closely associated with recent
domes of pantellerite obsidian on the
north rift zone of Socorro, its mineralogy
has been studied in the greatest detail.
The chemical analysis and norm of
basalt S141 are given in Table 10, where
it is compared with the basalt PRC 2006
from Pantelleria, analyzed by Zies
TABLE 10. Chemical Analyses and Norms of
Olivine Basalts from Pantelleria and
Socorro Island
Chemic
al Analyses
1 2
CIPW Norms
1
2
Si02
46.31
46.96
Or
6.40
6.97
Ti02
3.94
3.07
Ab
27.17
26.15
ALOa
14.18
13.53
An
21.09
19.56
Fe203
1.91
6.44
Di
16.85
15.72
FeO
11.76
7.28
Hy
2.17
12.21
MnO
0.23
0.18
01
12.48
1.03
MgO
5.43
7.14
Mt
2.78
9.34
CaO
10.07
9.06
11
7.48
5.83
Na20
321
3.09
Ap
3.16
1.97
K20
1.08
1.18
Rest
0.63
0.54
P206
1.33
0.85
H20+
0.36
0.43
H20"
0.11
Totals
100.14
99.32
1. PRC 2006, Pantelleria; E. G. Zies, analyst
(Zies, 1962). Includes Cr2Os 0.01, V2Os 0.11,
BaO + SrO 0.04, S 0.06, CI 0.06, F 0.09.
2. S141, Socorro Island; H. B. Wiik, analyst.
(1962). The two rocks differ most
notably in the ratio of ferric to ferrous
iron. As the basalt PRC 2006 was col-
lected from a small intrusive dike, it
probably more nearly reflects the true
oxidation state of the magma. The ferric-
ferrous ratio of S141, collected near the
surface of a lava flow, is similar to those
given by Romano (1968, p. 777) for new
analyses of basalt lavas and scoria from
Pantelleria.
The basalt PRC 2006 has been de-
scribed elsewhere (Zies, 1962, p. 177) and
little need be added here, except with
regard to the "brown and black globu-
lites," which have been examined in more
detail in reflected light. They consist
of two generations of titaniferous mag-
netite and a skeletal groundmass ilmen-
ite. The first magnetite forms subhedral
crystals 10-50 jum in diameter, often with
a sutured or dendritic outer boundary
zone, intergrown with groundmass sili-
cate crystallites. The core is slightly
anisotropic, and a traverse of several
grains with the microprobe shows that
it is unusually rich in magnesium. The
outer rim, extending into the dendritic
overgrowths, is distinctly less magnesian
and relatively enriched in titanium,
chromium, and aluminum. Some grains
show small exsolved lenses of spinel,
probably hercynite. The second genera-
tion of magnetite consists of barblike
skeletal groundmass crystallites, which
may be partly replaced by blebs of
maghemite. These crystallites are too
tiny for satisfactory probe analysis but
appear to be similar in composition to
the outer zones of the first-generation
magnetite. The skeletal ilmenite can be
distinguished from the skeletal magnetite
both by its stronger anisotropism and by
its blocky habit, each plate being made
up in detail of tiny interlocking rectangu-
lar segments.
The Socorro Island basalt S141 is
much better crystallized than PRC 2006,
the texture being virtually that of a
microgabbro or diabase. The average
grain size is about 0.5 mm, and olivine
196
CARNEGIE INSTITUTION
forms conspicuous phenocrysts up to
1.5 mm in diameter. A point count in-
dicated about 12.5 volume % olivine,
considerably in excess of the normative
amount. This is almost certainly due to
surface oxidation of the flow, resulting in
too high a value for Fe203 with conse-
quent reduction in the amount of iron
expressed as silicate in the norm. Pale
pink augite is in subophitic intergrowth
with plagioclase and opaque oxides. The
latter share many of the features of the
titanomagnetite and ilmenite in PRC
2006, although slower cooling and com-
plete crystallization have precluded the
formation of second generation "quench"
magnetite. For the same reason, the
paragenesis is not as evident, but the
texture and zoning in the titanomagnetite
again suggest that ilmenite is the later
of the two minerals. The magnetite forms
relatively stout subhedral crystals, zoned
similarly to those in PRC 2006, although
the effect is much less extreme. Chro-
mium is higher and magnesium is lower,
and again chromium, aluminum, and
titanium are concentrated toward the
edge of the crystals. Irregular veins of
hematite traverse some grains. The
ilmenite has the typical platy habit, ap-
pears much more uniform in composition
than the magnetite, and shows no un-
usual compositional features. Plagioclase
consists of randomly oriented laths in
which the cores are almost homogeneous
labradorite, An60. Many grade margin-
ally through a narrow transition zone to
rims of alkali feldspar. Most of the latter
mineral, however, tends to be concen-
trated in the interstitial triangular areas
between plagioclase laths.
Microprobe analyses of magnetite and
augite of PRC 2006, and of all the min-
erals of S141 except the interstitial alkali
feldspar, are given in Table 11. Among
the more interesting features are the rela-
tively high iron in the plagioclase, which
appears essential to fill out the tetra-
hedral site, and the very aluminous
titanaugite in both rocks.
Trachybasalt appears on the south
flank of Socorro Island as flows of very
restricted extent. Microphenocrysts of
augite are sparingly distributed in a very
fine-grained groundmass in which plagio-
clase laths up to 0.1 mm in length are
arranged in subparallel clusters, giving
a distinct platy structure and flow-
banded texture to the rock. There are
rare rounded phenocrysts of plagioclase
with distinct albite twinning. Olivine ap-
pears in the groundmass, where it may
TABLE 11. Microprobe Analyses of Minerals in Olivine Basalts S141, Socorro Island, and
PRC 2006, Pantelleria
Basalt S141
e
Basalt PRC 2006
Plagioclase
Olivine
Ilmenite
Magnetite
Augit
Augite
Magnetite
Si02
52.9
1
38.3
1
0.21
0.21
46.4
2
46.0
0.10
Ti02
50.3 8
24.8
5
4.18
6
3.27
27
18.3 2
AU)3
28.9
2
0.08
1.26
4
5.86
7
5.95
9
2.71 4
FesOa
0.57
2
4.90
34.2
33.0
FeO
21.6
12
40.9 1
35.6
2
9.13
2
10.1
8
40.4 1
MnO
0.29
0.73
0.58
0.18
050
0.41
MgO
o.ii
39.7
7
2.14 2
1.89
1
12.3
2
12.6
8
5.17 1
CaO
12.6
2
0.31
0.05
0.05
21.3
1
21.1
8
Na^O
4.40
2
0.55
0.52
K20
029
Cr203
als
1.69
20
0.03
0.03
Tot
99.8
100.2
99.3
100.3
99.9
99.8
100.2
Mole %
Ca
60.3
Ca
0.5
Ilm
95.1
Usp
702
Ca
46.8
Ca
45.4
Usp 49.7
Na
38.1
Mg
76.0
R20
a 4.9
Mgt
29.8
Mg
37.5
Mg
37.7
Mgt 50.3
K
1.6
Mn + Fe
23.5
Fe
15.6
Fe
16.9
Note : Numbers in italics are a/ Vn
GEOPHYSICAL LABORATORY
197
be associated with aggregates of tiny-
magnetite grains. Microprobe analyses
show the composition of the plagioclase
phenocryst to be about An47, whereas
an analyzed groundmass microlite is
about An42. Analyzed groundmass olivine
is about Fo40. The presence of augite
microphenocrysts suggests that augite is
on the liquidus, in contrast to its in-
variable late crystallization in the ba-
salts. Analyses of two augite micro-
phenocrysts (Table 12) give some indica-
tion of the changes in augite composition
as crystallization proceeds. One of the
largest microphenocrysts is a normal
augite; one of the smallest, virtually a
groundmass augite, is distinctly enriched
in titanium and aluminum. This enrich-
ment is consistent with the experimental
data and natural examples discussed by
Yagi and Onuma (1969, p. 546).
A distinct compositional hiatus exists
between the trachybasalt and trachyte
on Socorro (Bryan, 1964) . In mineralogy
and composition the trachytes range
through increasingly peralkaline types
to pantellerite. Trachyte S84, the most
calcic of the analyzed trachytes, is the
only one that contains plagioclase. The
latter is a potassic oligoclase that forms
abundant phenocrysts marginally zoned
to lime-poor alkali feldspar. The oligo-
clase is zoned outward to lime-poor alkali
feldspar. Groundmass feldspar is ex-
tremely variable in composition, but the
average composition is that of a sodic
anorthoclase. There are a very few large,
rounded phenocrysts of fayalitic olivine.
Ferroaugite forms scattered small eu-
hedral phenocrysts. An alkali amphibole
pleochroic in pink and violet is abundant
in the groundmass. Magnetite, appar-
ently originally titaniferous, shows
abundant exsolved ilmenite lamellae and
blebs of hematite, apparently due to
secondary oxidation. Microprobe analy-
ses of all major minerals except the
magnetite are given in Table 12.
Pantelleritic trachytes contain pheno-
crysts of lime-poor anorthoclase, close
to Ab65 in composition. No appreciable
zoning or exsolution has been detected
in these feldspars. Olivine is common
and is almost pure fayalite; ferroheden-
bergite forms scattered phenocrysts and
also appears in the groundmass with an
alkaline amphibole. Quartz may appear
as irregular watery patches in the
groundmass but never appears as pheno-
crysts. The more peralkaline varieties
may contain a few phenocrysts of aenig-
matite, and in these rocks the ferro-
hedenbergite is relatively more sodic.
Opaque oxides are not abundant. Ilmen-
ite typically predominates over magnet-
ite, the ferric iron apparently being taken
up by amphibole and ferrohedenbergite.
Chemical analyses of three pantellerite
obsidians, widely separated in the field,
are nearly identical; one of these, S138,
is given in Table 13. The pantellerites are
found almost invariably as obsidian
domes that may have been breached on
one side to yield very rough, blocky
flows. Where exposed by marine erosion,
the interiors of the domes are badly al-
tered to a gray, chalky rock completely
unsuitable for mineralogical study. The
obsidian contains phenocrysts of anor-
thoclase, sodic ferrohedenbergite, and
aenigmatite, with traces of ilmenite. The
glass contains abundant microlites of
anorthoclase, aenigmatite, and ferro-
hedenbergite. Quartz does not appear
among the modal minerals in any of
these rocks. They most resemble the
hyalopantellerites of Pantelleria, al-
though the samples from Socorro contain
a much higher proportion of microlites
in the glass. Analyses of the phenocryst
minerals of S138 are given in Table 12.
Pedogenesis. A complete account of
the relations between the various lavas
of Socorro Island is being prepared for
publication, and only a brief summary
will be given here. The possibility of
deriving trachyte, pantellerite, and
trachybasalt from appropriate parent
magmas as deduced from field associa-
tion has been tested with the least-
squares approximation described by
Bryan, Finger, and Chayes (1969). The
198
CARNEGIE INSTITUTION
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GEOPHYSICAL LABORATORY
199
TABLE 13. Chemical Analyses and CIPW
Norms of Pantellerite S138, Socorro Island,
Mexico, and Pantellerite PRC 2007, Pantelleria
Chemical Analyses
CIPW Norms
Si02
ALOs
F&Oa
FeO
MgO
CaO
Na*0
K20
MnO
Ti02
P2O5
H20+
H20"
68.91
10.83
2.91
4.56
0.22
0.24
6.96
4.46
0.25
0.40
0.02
0.26
0.10
69.56
11.27
1.87
4.18
0.23
0.44
6.28
4.60
0.28
0.47
0.10
0.13
0.02
Q
z
19.84
21.34
0.11
Or
26.36
27.17
Ab
30.88
32.57
Ac
8.42
5.41
Ns
4.30
2.70
Di
0.94
1.19
Hv
8.23
7.41
Wo
11
0.76
0.90
Ap
0.05
0.24
HI
0.63
Rest
0.36
0.21
Totals 100.12 99.90
100.14 998.8
1. Pantellerite S138, Socorro Island, Mexico;
H. B. Wiik, analyst.
2. Pantellerite PRC 2007, Pantelleria; E. G.
Zies, analyst (Zies, 1960). Includes Zr02 0.12,
S03 0.06, CI 0.38.
calculations show that it is quite feasible
to derive the salic rocks from the basalts
with which they are most closely associ-
ated. In spite of the apparent chemical
gradation from trachyte to pantellerite,
however, calculations do not support a
parental relation of trachyte to pantel-
lerite. As might have been anticipated
from the relevant experimental work,
it appears impossible to derive pantel-
lerite from alumina-saturated trachyte
by crystallizing any combination of the
minerals appearing as phenocrysts in the
trachyte. Calculations using peralkaline
trachyte as parent yield lower sums of
squares, but the discrepancies remain too
large for the mechanism to appear very
convincing.
A test of the possible genesis of pantel-
lerite S138 from basalt S141, with which
it is closely associated on the north
rift zone of Socorro, is far more success-
ful. Table 14 shows the results of a least-
squares solution, using a linear combina-
tion of the pantellerite and minerals
observed in the basalt (Table 11) to cal-
culate an approximation to the basalt
composition. The sum of squares is satis-
factory, and the amount of pantellerite
TABLE 14. Least-Squares Estimate of the
Composition of Basalt S141, Calculated as a
Linear Combination of Pantellerite S138 and
Minerals Observed in the Basalt
SiO,
ALO3
FeO
MgO
CaO
Na20
K20
MnO
Ti02
P205
1 2
47.84 47.85
13.79 13.78
13.21 13.32
7.35 7.28
9.20
3.32
1.21
0.19
3.41
0.91
9.23
3.15
1.20
0.18
3.13
0.87
Pantellerite S138 24.90
Plagioclase S141 33.66
Olivine S141 12.52
Augite S141 17.08
Magnetite S141 10.18
Apatite* 2.11
Sum of squares of residuals = 0.1286
1. Composition of basalt S141 estimated by
least-squares approximation.
2. Observed composition of basalt S141.
3. Rock and mineral variables used in cal-
culation (see Tables 11 and 13 for composi-
tions) .
4. Proportions of pantellerite and minerals
in basalt S141, wt <%.
* Not analyzed ; ideal calcium phosphate
formula assumed.
that could be extracted from the basalt
is about twice that necessary to account
for the total amount of salic eruptive
rocks observed on the island (Bryan,
1966, p. 473). The crystallization of
aluminous titanaugite and titaniferous
magnetite in particular appears essential
to derive the proportions of alumina and
iron oxide characteristic of pantellerite.
Basalts associated with pantellerite at
Pantelleria and at Socorro are relatively
rich in titanium, and perhaps this is the
critical factor in the genesis of pantel-
lerite. The conditions favoring crystal-
lization of aluminous titanaugite have
been discussed by Kushiro (1960), who
suggested that relatively low silica con-
tent in the magma causes substitution
of alumina for silica, with simultaneous
substitution of titanium in the octahedral
site to balance charges. Verhoogen (1962)
suggested that the partial pressure of
oxygen may be the controlling factor, a
high po2 favoring precipitation of iron
as an oxide, and titanium in the silicate
phase. In this case, substitution of
alumina for silica to balance charges
200
CARNEGIE INSTITUTION
would be a consequence, rather than a
cause, of the entry of titanium into the
structure. It seems clear that low silica,
a relatively high po2, and a relatively
high titanium/iron ratio in the magma
will all favor the crystallization of
aluminous titanaugite, and a delicate
balance of all three factors may operate
in natural magmas. Kushiro (1960, p.
553) cited several well-known intrusive
complexes in which variation in titanium
content of pyroxenes does not seem to
correlate with variation in titanium in
the bulk rock composition, but noted that
as he has not considered the role of
iron-titanium oxides, the influence of
Ti02 concentration on the composition
of pyroxene cannot be ruled out.
Crystal fractionation of basalt leading
to a peralkaline residual liquid would
have to take place within the volcanic
cone, and if the magma chamber model
outlined by Bryan (1966, p. 473) is valid,
this crystallization would have taken
place at a depth of about 12 km below
sea level, implying pressures of not more
than 4 kb. It is evident that the appro-
priate distribution of elements can be
achieved at low pressures, as the basaltic
mineral assemblage used in the calcula-
tion crystallized in a surface flow. Mac-
Gregor (1969) has suggested that tita-
nium-rich basalts may be expected to
form by partial fusion at relatively high
pressures and hence at relatively great
depths in the mantle. On the crest of the
East Pacific Rise, however, the thin crust
and high heat flow (Menard, 1964, p.
129) would probably permit melting at
relatively shallow depths, so that it is
not essential to postulate a deep-mantle
origin.
At present, then, the evidence is largely
circumstantial. At Socorro, as at Pantel-
leria, association of pantellerite with
titaniferous basalt suggests a parental
role for the latter in the genesis of pantel-
lerites. Calculations show that the ob-
served mineral assemblage in the Socorro
basalt, separated in appropriate propor-
tions, could yield a residual liquid having
the composition of pantellerite found in
close association with that basalt. Sepa-
ration of aluminous titanaugite and ti-
taniferous magnetite seems essential to
account for the observed balance of
alumina, iron, and titanium between ba-
salt and pantellerite, and these minerals
are also found in the basalt at Pantel-
leria.
The Simplified or Idealized "Skaergaard"
Model
F. Chayes
Whether performed graphically or
numerically, derivation of the successive
residual liquids of the Skaergaard (or
other similar complex) presumes a very
simple but restrictive descriptive hy-
pothesis, namely, that a single mass of
magma of some known or assumed com-
position is partitioned into a number of
zones or fractions, one of which is un-
exposed. Using compositions, relative
ages, and relative magnitudes of the ex-
posed zones estimated from field obser-
vation and chemical analyses of rock
specimens, we wish also to estimate —
perhaps, more properly, to calculate ex
hypothesis — the compositions of the un-
exposed portion of the complex and of
residual liquids at successive stages of
solidification. The magnitude of the un-
exposed portion of the complex may be
estimated either by extrapolating from
data concerning the shape and dimen-
sions of the intrusion or by materials-
balance calculations based on the compo-
sitions of the assumed parent magma
and the exposed portion of the complex.
Obviously preferable in principle, the
former procedure is nearly always im-
practicable. The materials-balance solu-
tion is outlined here.
Notation. Xj is a vector whose ith. ele-
ment, Xn, is the estimated percentage
of constituent i in
(a) the unexposed portion of
the complex if ; = 1
(b) the (; — l)th exposed zone or
facies if ;>1.
GEOPHYSICAL LABORATORY
201
M is a vector whose ;th element, ;>1,
is the value, for the (;'— l)th exposed
zone, of the sample statistic used as an
estimator of the magnitudes of the ex-
unexposed portion of the complex is
(K — l)/K of the whole, the ratio of the
exposed portion to the whole is 1/K, and
the vector P may be written
"LV K )'\K3(M))'\K2,(M))' ' ' ''\KX(M))j (4)
posed zones.
P is a vector whose ;th element, j>l,
is the proportion of the whole complex
formed by the ;th zone, hidden or ex-
posed.
Lj is a vector whose ith. element, Z/#,
is the percentage of constituent i in the
liquid existing just before the ;th zone,
j> 1, begins to solidify.
Compositions of the exposed and un-
exposed portions of the complex. If there
are n zones and the first is unexposed,
the estimated composition of the exposed
portion of the complex is
=™/i
(Md,
(1)
in which Y is the matrix formed of
(column) vectors Xj} j=2, n, in order.
Since by definition no element of Xx,
the composition vector of the unexposed
portion of the complex, may be negative,
it will be necessary to use a multiple, K,
of parent magma equal to or greater
than the largest ratio of analogous ele-
ments of E and L1; i.e., K> (^i/Lix)max.
Specifically, if the maximum ratio of E{
to Lix occurs for, say, i=b, and Xbl=B,
then
K=(Eb-B)/(Lbl-B). (2)
For B = 0, the supply of magma is just
sufficient if all of the critical constituent
reports in the visible facies.
The total supply of magma is pro-
portional to K, the amount contained
in the unexposed portion of the complex
is proportional to (K— 1), and the com-
position vector of the unexposed portion
is
X1=(XLl-E)/(Z-l). (3)
Relative magnitudes of the zones. The
in which the summation of M is over the
range 2, n, and the ;th element of P is,
as previously specified, the proportion of
the entire complex formed by zone ;.
Pi=(K — l)/K is the proportion of un-
exposed material compatible with the as-
sumptions that (a) the exposed zones of
the complex are partition products drawn
from the proposed parent magma and (b)
the unexposed portion of the complex
contains B% the constituent undergoing
maximum enrichment during the parti-
tion process.
The amounts and compositions of
residual liquids. The proportion of the
initial magma solidified after the con-
solidation of, say, zone k is evidently
k
^yPj- The proportion of the original liq-
uid surviving at this time is
('-?"')•
and its composition vector is
Lttl = (h1-f/(P^l))j(l-'ZP^ (5)
for k in the range 0</c<n.
It is to be noted that the calculated
composition of liquid 2, the magma re-
maining after separation of the hidden
zone, is in fact the estimated composition
of the exposed portion of the complex. A
direct consequence of the definitions in-
volved, this identity is perhaps not im-
mediately obvious; symbolically, solving
(3) for E and (5) at k = l, we have at
once that Lo^E^KLx- (K-1)XX. From
this point onward, accordingly, the as-
sumed initial liquid, whatever its compo-
sition, exerts no influence on the further
development of the magma.
202
CARNEGIE INSTITUTION
PHASE-EQUILIBRIUM STUDIES, CHIEFLY OF
SILICATES AND OXIDES
PYROXENES AND RELATED SYSTEMS
Critical Planes and Flow Sheet for
a Portion of the System CaO-MgO-
Al203-Si02 Having Petrological
Applications
/. F. Schairer and H. S. Yoder, Jr.
Important advances have been made
during the past few years in our knowl-
edge of the crystallization relations in
basalts and related alkaline rocks.
Schairer and Yoder {Year Book 63, pp.
65-74) showed the relations in the
expanded basalt tetrahedron nepheline-
forsterite-silica-larnite between quartz-
normative (tholeiitic) and nepheline-
normative (alkaline) rocks where the
feldspar is nearly pure albite, i.e., a
highly sodic plagioclase with only a small
anorthite content. Since most basaltic
rocks carry a feldspar with a moderate
to large anorthite content, it was clearly
necessary to ascertain phase-equilibrium
relations on synthetic analogues in which
anorthite plays the dominant role.
Schairer, Tilley, and Brown {Year Book
66, pp. 467-471) studied the join nephe-
line-diopside-anorthite and showed the
complex relationships between the solid
phases nepheline, spinel, anorthite, oli-
vine, and diopsidic pyroxenes at liquidus
temperatures and with melilites below
liquidus temperatures. Schairer and
Yoder {Year Book 65, p. 206, Fig. 2;
Year Book 67, pp. 104-105, respectively)
studied the joins albite-anorthite-fors-
terite and albite-anorthite-akermanite
where the whole range of plagioclases are
present with olivines or with melilites,
diopsidic pyroxenes, and wollastonite
solid solutions. Kushiro and Schairer
have just studied (this report) a line be-
tween diopside and the feldspar albite50
anorthite50 in the system albite-anor-
thite-diopside. Schairer and Yoder in
their study of albite-anorthite-akerman-
ite clearly indicated that this join is a
triangular section through a system that
is not quaternary but quinary. It be-
came obvious that before attempting to
interpret detailed relations in the quinary
system Na20-CaO-MgO-Al203-Si02 it
was necessary to ascertain the precise re-
lations between forsterite, diopside solid
solutions, the melilites gehlenite and
akermanite, anorthite, and spinel in the
system CaO-MgO-Al203-Si02 without
the complication of Na20.
Considerable previous data on the
petrologically important portion of CaO-
MgO-Al203-Si02 were available. The
system diopside-anorthite- akermanite
was studied by deWys and Foster (1958) .
Segnit (1956) reported on the section
CaSi03-MgSi03-Al203. Hytonen and
Schairer {Year Book 60, p. 135, Fig. 28)
also provided information on the join
MgSi03-CaSi03-Al203 and at the same
time (pp. 125-139) presented some data
on the join CaTs (Ca-Tschermak's mole-
cule, CaO-Al203-Si02) -diopside. O'Hara
and Schairer {Year Book 62, p. 108, Fig.
32) provided additional data on MgSi03-
CaSi03-Al203. Chinner and Schairer
(1962, p. 619, Fig. 4), on the basis of
previous studies and with additional data
on the single join grossularite-pyrope at
1 atm, drew a flow sheet for the silica-
rich portion of CaO-MgO-Al203-Si02.
Subsequently O'Hara and Schairer {Year
Book 62, p. 114, Fig. 37) suggested that
three different quaternary invariant
points may replace the points C and D
of the Chinner and Schairer flow sheet.
Recently O'Hara and Biggar (1969) and
Biggar and O'Hara (1969) presented ad-
ditional data to confirm this contention.
Clark, Schairer, and de Neufville {Year
Book 61, pp. 59-68) presented additional
data on the join CaTs-diopside. Kushiro
and Schairer {Year Book 64, p. 101,
Fig. 21) gave some information on the
join diopside-spinel. W. R. Foster (per-
sonal communication) and his students
are now studying the join akermanite-
anorthite-forsterite and have located the
GEOPHYSICAL LABORATORY
203
field of diopside solid solutions as pre-
dicted by Chinner and Schairer (1962,
p. 624, Fig. 6) . Some years ago DeVries
and Osborn (1957, especially Fig. 9)
studied the Al203-rich portion of CaO-
MgO-Al203-Si02 and obtained data on
four quaternary invariant points which
we have integrated with the data in our
new flow sheet, shown below as Fig. 11.
We now present the data on CaO-MgO-
Al203-Si02 that we have obtained during
the past year.
The Join Akermanite-Spinel- Anorthite
and the Akermanite-Spinel Portion of
the Coplanar Join Akermanite-Spinel-
Gehlenite-Forsterite
As shown in Fig. 2, there are three
piercing points of univariant lines: K,
mel + montss + sp + liquid at 1368° ±3°C;
L, mel + an + sp + liquid at 1248° ±2°C;
and F, corundum + an + sp + liquid at
1485° ±5°C. All points in the side aker-
manite-spinel, except Ak96Sp4 (which
consists of a melilite and a forsterite
solid solution when completely crystal-
line) , pass during crystallization through
the quaternary invariant point mel +
montss + foss + sp + liquid at 1348° ±2°C.
The three compositions Ak8oSpi7An3,
Ak82Spi4An4, Ak77Sp15An8 also pass
through this same quaternary invariant
point (labeled S in Fig. 11) during crys-
tallization.
Four compositions in the join aker-
manite - spinel -anorthite (Ak80Sp17An3,
Ak82Spi4An4, Ak77Spi5An8, and Ak76Sp13
Anlx) produce liquids during crystalliza-
tion that go down the univariant line
mel + foss + sp + liquid to the quaternary
Spinel
2l35°i R Mg0AI203
Akermanite 10
2CaOMgO-2Si02
90 Anorthite
Ca0AI203-2Si02-
Weight per cent
Fig. 2. Phase-equilibrium diagram for the join akermanite-spinel-anorthite. Black dots indicate
compositions studied by the method of quenching. C is the piercing point of the tie line between
melilite and diopside solid solutions. Dashed lines outline assemblages at the solidus described in
the text.
204
CARNEGIE INSTITUTION
invariant point diss + foss + sp + mel + liq-
uid at 1238° ±2°C (labeled Q in Fig. 11) .
Seven compositions in the join aker-
manite-spinel-anorthite yield liquids dur-
ing crystallization that go down the uni-
variant line mel + an + sp + liquid to the
quaternary invariant point mel + an + sp
+ diss + liquid at 1238° ±2°C (labeled R
in Fig. 11). The seven compositions are
Ak55Sp5An4o, Ak50Sp10An4o, Ak52Sp5An43,
Ak5oSp5An45, Ak41.57Sp5.42An53.01, Ak35.82
Sp9.35An54.83, Aki2Spi3An75. There are two
compositions in the join akermanite-
spinel-anorthite (Ak55Spi5An30 and Ak70
Spi0An20) where sp + mel + liquid are
joined by both an and diss at the
quaternary invariant point mel + an +
sp + diss + liquid at 1238° ±2°C (22 of
Fig. 11).
The join CaTs-diopside pierces the
join akermanite-spinel-anorthite at
•^-^35.82feP9.S5-A-n54_83 &U v^^ 1 S57.32 J-/I42.68J
and the join grossularite-pyrope * pierces
it at Ak41.57Sp5.42An53.01 at grossular-
ite74.39pyrope25.6i.
The dashed lines radiating from C
divide the join akermanite-spinel-anor-
thite into several areas of complete
crystallization. The point C is the pierc-
ing point of the tie line connecting the
maximum solid solutions of melilite and
diopside solid solution at the solidus and
is only known approximately because of
the complexities of the solid solutions.
1. Compositions that lie in C An Sp
consist of mel + sp + an + diss( maximum) at
and below the temperature of R (Fig.
11) atl238°±2°C.
2. Compositions that lie in C X Sp
consist of mel + sp + fo8S + diss( maximum) at
* Chinner and Schairer (1962, p. 617, Fig. 2)
show the complication "pyroxene + other
phases." We have just shown that grossular-
ite74.39pyrope25.<n cuts the join akermanite-spinel-
anorthite. During crystallization, liquid pro-
duced in that composition goes down the uni-
variant line mel + an -f sp + liquid and is
joined by dies at 1238° ± 2°C, the temperature
of R in the flow sheet shown later in Fig. 11.
There is never any fo.B present in grossular-
ite74.39pyrope2B.e1.
and below the temperature of Q (Fig.
11) atl238°±2°C.
3. Compositions that lie in C A An
consist of mel + diss( maximum ) + an + wo at
and below the temperature of B (Fig.
11), which is not known precisely.
4. Compositions that lie in C A Ak con-
sist of mel + diss( maximum >+ wo at and
below some temperature between 1350 °C
and that of B (Fig. 11).
5. Compositions that lie in C X Ak
consist of mel + diss(maximum) + foss at and
below some temperature between 1357 °C
and that of Q (Fig. 11) at 1238° ±2°C.
The phase diagram for akermanite-
spinel is shown here in Fig. 3. In the
system akermanite-spinel the following
reaction occurs: akermanite (Ca2
MgSi207)+spinel (MgAl204) -> forster-
ite (M_g2Si04)+gehlenite (Ca2Al2Si07) .
There is probably some monticellite in
solid solution in the forsterite phase as
well, and there may be more complex
solid solutions in the akermanite to yield
the melilite phase. Attention is called
to the behavior of pure akermanite com-
position as described by Schairer, Yoder,
and Tilley {Year Book 65, pp. 217-218).
Only pure akermanite crystals are pres-
ent between the congruent melting tem-
perature 1454° ±2°C and 1385°C. At this
latter temperature crystals of pseudo-
wollastonite appeared, and then at 1345°
±10°C crystals of wollastonite solid
solution also appeared. Both of them
were present over a range of about 40°C,
below which only twinned crystals of
wollastonite solid solution were present
with the melilite crystals. Finally, at
1240°±10°C diopside crystals appeared
along with the wollastonite solid solution
crystals, both of them well distributed
in the melilite. The products of all the
quenching experiments were examined
for the presence of monticellite, but none
was observed. In the join akermanite-
spinel the composition Ak96Sp4 was the
richest in akermanite studied. A melilite
is present on the liquidus at 1428°C;
monts8 appears as an additional solid
phase at 1402°C; foss appears at 1363°C;
GEOPHYSICAL LABORATORY
205
1500
o
. 1350
1300
1250
1200
\ ^mel-i-mont+fo-Hiq
/Sx mel + mont + liq
osp+mont+mel+liq
- -I348±2°
mel+fo + liq
mel+fo
mel +fo + sp + liq
I238±2C
mel+fo + sp+diss
Akermanite 5
2Ca0MgO2Si02
10
20
Spinel — -*-
MgO-AI203
Weight per cent
Fig. 3. Phase-equilibrium diagram for the join akermanite-spinel. This join is coplanar with
akermanite-spinel-gehlenite-forsterite. Abbreviations: mel, melilite; fo, forsterite solid solutions
with monticellite ; mont, monticellite solid solutions; sp, spinel; di8s, diopside solid solutions with
CaTs and possibly MgSiOa; liq, liquid.
montS8 disappears at 1353°C; there is
mel + f oss + liquid below this temperature
to 1295° ±5°C, where it becomes com-
pletely solid with the two phases mel
+ foss. No crystals of pseudowollastonite,
wollastonite solid solution, or diss were
observed in this composition at any tem-
perature at or above the solidus.
In the join akermanite-spinel a hori-
zontal line is drawn at 1348° ±2°C. In
all compositions studied between 8 and
20% spinel, montgS is present at 1350°C
but absent at 1345 °C, and the horizontal
line is drawn on the basis of the presence
or absence of montgs. In the compositions
Ak80Sp20, Ak84Sp16, and Ak86Sp14, foss ap-
pears at a temperature slightly above
this horizontal line, represented by the
three circles shown, presumably because
our run times were too short for equi-
librium. In Ak88Spi2, Ak90Sp10, and Ak92
Sp8, foss appears as monticellite disap-
pears at 1348°C. We have already shown
that three compositions in the join aker-
206
CARNEGIE INSTITUTION
manite-spinel-anorthite yield this same
temperature of disappearance of moritss
at 1348 °C. It is concluded that the
change of solid solution in monticellite
is apparently small. The results of Biggar
and O'Hara (1969) suggest that con-
siderable solid solution of forsterite in
monticellite exists at this temperature.
The (211) spacings for the melilite
present in runs at 1200 °C in the join
akermanite-spinel are plotted in Fig. 4.
The spacing changes measurably from
pure akermanite to about 7 wt % spinel
and then approaches constant composi-
tion. In the absence of liquid, metastable
solid solutions persist and equilibrium
between the four solid phases does not
obtain, thereby accounting for the vari-
ability of the spacings in the mel + foss +
Akermanite 2
6 8 10 12 14
Weight per cent spinel
Fig. 4. (211) X-ray spacings for the melilites
present in runs at 1200°C in the join akerman-
ite-spinel.
sp + diss region. Because akermanite-
spinel is coplanar with gehlenite-forster-
ite, the X-ray data suggest that the
maximum solid solution of gehlenite in
Spinel
2I35°A MgOAI203
Diopside 10
CaO MgO-2Si02
40 127412° 50 60
Weight per cent
90 Anorthite
CaO-AI203 2Si02
Fig. 5. Phase-equilibrium diagram for the join diopside-spinel-anorthite. Abbreviations: an,
anorthite; others as in Fig. 3.
GEOPHYSICAL LABORATORY
207
akermanite for the assemblage mel +
foss + sp is about 16wt%, assuming no
other types of solid solution are present.
The Join Diopside-Spinel-Anorthite and
Its Relations to Coplanar
Di-Fo-CaTs-Sp
As shown in Fig. 5 there are three
piercing points of univariant lines: C,
foss + an + sp + liquid at 1305° ±2°C; D,
foss + diss + an + liquid at 1273° ±2°C;
and F, corundum + an + sp + liquid at
1468° ±3°C. The behavior of points in
the side line diopside-spinel will be dis-
cussed later. Four compositions — Di70
Sp20An10, Di48Sp12An40, Di35Sp10An55, and
Di2oSp12An68 — yield liquids that during
crystallization go down the univariant
line foss + an + sp + liquid to the quater-
nary invariant point an + diss + f oss + sp
+ liquid at 1238° ±2°C (P in Fig. 11).
Five other compositions — Di7oSp10An2o,
Di61Sp17An22, Di60Sp14An26, Di60Sp10An3o,
and DiggSp^Anso — yield liquids that dur-
ing crystallization go down the univari-
ant line foss + an + diss + liquid to the
same quaternary univariant point, an +
diss + foS8 + sp + liquid, at 1238° ±2°C
(P of Fig. 11).
In Fig. 5 the dashed line Y An divides
the join into two portions. Those in the
area Y Sp An when completely crystal-
line Consist Of an + foss + Sp + diss( maximum)
at 1238° ±2°C, the temperature of point
P, shown below in the flow sheet
(Fig. 11). Those in the area Y Di An
when completely crystalline consist only
of the three solid phases an + f oss + diss
because Di-Fo-CaTs-Sp are coplanar.
However, if the diss involves enstatite
as well as CaTs there may be two small
triangular areas near the diopside corner
of the join with the three solid phases
woss + diss + mel and foss + diss + mel, as
well as the narrow fields of an + diss +
mel and sp + diss + mel. None of the
necessary data were collected to test this
possibility.
The Join Akermanite-Spinel-Diopside
and Its Relations to Coplanar
Fo-Geh-Ak-Sp
Only three compositions were prepared
in the join akermanite-spinel-diopside,
and the data on these points indicate the
relations as shown in the diagram for
this join given here as Fig. 6. There are
three piercing points of univariant lines :
K, mel + montss + sp + liquid; N, mel+
sp + f Oss + liquid ; and 0, mel + diss + f oss
+ liquid. The exact temperatures and
compositions of these three piercing
points were not determined, and bound-
ary curves are shown as dashed lines.
The light dashed line XY divides the
join into two areas. Compositions that
are in the area X Sp Y when completely
crystalline consist of the four solid
pnaSeS melSS( maximum) 4" 0.1SS( maximum) T Sp
+ f oss and begin to melt at the tempera-
ture 1238° ±2°C of the quaternary in-
variant point Q of the flow sheet shown
below as Fig. 11. As a first approxima-
tion, those compositions in the area Ak
X Y Di would be expected to consist of
the three solid phases mel + diSs + foss.
These relations result from the coplanar
character of Fo-Geh-Ak-Sp; however,
more complex relations may arise in the
vicinity of Di if some enstatite is also in
solid solution with the aluminous diop-
side. The three compositions prepared in
the join akermanite-spinel-diopside
should contain sp when completely crys-
talline in addition to the three phases
foss, diSs, and mel. However, if present,
there was too little sp to show in the
X-ray diagrams or to be observed under
the microscope.
The Join Ca-Tschermak's Molecule
(CaTs) -Diopside and Its Relationship
to Coplanar Ak-Geh-Di-CaTs
During the past year we have obtained
considerable new data on this join. We
prepared a batch of CaTs85Di15 and a
new batch of CaTs90Dii0. We crystallized
the latter at 1470 °C first to get crystals
208
CARNEGIE INSTITUTION
Spinel
2135° i R MgOAI20j
Akermanite 10
2Ca0-Mg0-2Si02
40 50 i36Q5i K 60
Weight per cent
90 Diopside
Ca0-MgO2Si02
Fig. 6. Phase-equilibrium diagram for the join akermanite-spinel-diopside. Abbreviations: foB
forsterite solid solution with monticellite ; others as in Fig. 3.
of CAG (CaO-6Al203) instead of meta-
stable corundum and then at lower tem-
peratures to get an, mel, and sp. From
both of these batches we obtained the
value 1360° ±5°C for the quaternary in-
variant point CAq + an + mel + sp + liq-
uid. The composition Ak35.82Sp9.35An54.g3
in the join akermanite-spinel-anorthite
also has the composition CaTs57.32Di42.68
and, as shown before, reaches the point R
at 1238° ±2°C of the flow sheet shown
below as Fig. 11.
The data for the join CaTs-Di are
plotted in Fig. 7. It should be noted that
geh-an-sp and ak-an-sp cut this join.
The composition CaTs50Di5o during crys-
tallization produces liquids that follow
the surface an + sp + liquid, and these
phases are joined by both diS8 and mel
at 1238° ±2°C, the temperature of point
R, shown below in the flow sheet (Fig.
11). The composition CaTs35Di65 during
crystallization produces liquids that fol-
low the surface diss + an + liquid and
these phases are joined by both mel and
sp at 1238° ±2°C, the temperature of
point R (Fig. 11). The two compositions
CaTs55Di45 and CaTs40Di60 during crys-
tallization follow the univariant line
an + diss + sp + liquid where they are
joined by mel at the quaternary in-
variant point mel + sp -I- an + diSs + liquid
at 1238° ±2°C, the temperature of point
R (Fig. 11). The dotted line at about
CaTs33Di67 is an observational line to the
right of which sp was not observed. The
constancy of the melting relations sug-
gests that the phase is there and not
GEOPHYSICAL LABORATORY
209
1600
1000
Geh+An+Sp
cuts
Ak+An+Sp
cuts
CaOAI203Si02 90 80
Calcium Tschermak's Molecule
70
60 50 40
Weight per cent
30
10 CaOMg02Si02
Diopside
Fig. 7. Phase-equilibrium diagram for the join CaTs-diopside. This join is coplanar with aker-
manite-gehlenite-diopside-CaTs. Abbreviations: CAe, CaOGALAj; An, anorthite; Geh, gehlenite;
Ak, akermanite; others as in Fig. 3.
readily observable. Alternatively, the diss
may contain enstatite as well as CaTs
and the polyhedron an-diss-mel would be
cut by CaTs-Di. CaTs-Di is coplanar
with Ak-Geh.
The Join Diopside-Spinel
Data for this join are plotted in Fig. 8.
Two compositions, Di70Sp3o and Di75.27
Sp24.73, produce liquids during crystal-
lization that go down the univariant line
sp + foss + an + liquid to the quaternary
invariant point diss + foss + sp + an + liq-
uid at 1238° ±2°C (P of Fig. 11). Two
compositions, Di80Sp20 and Di85Sp15, pro-
duce liquids during crystallization that
go down the univariant line diss + foS8+
an + liquid to this same quaternary in-
variant point (P of Fig. 11) . Two compo-
sitions, Di95Sp5 and Di90Sp10, become
completely crystalline with the three
solid phases diss + foss + mel in the ex-
periments, but there is reason to believe
the melilite persists or grows metastably.
Experimental difficulties were encoun-
tered in our study of this join. Melilite
crystallizes readily and in excessively
large amounts even in those composi-
tions where it is a metastable phase. In
order to circumvent this we found it
necessary to hold appropriate composi-
tions at temperatures above the appro-
priate quaternary invariant point, X-ray
them to be sure no metastable melilite
was present, and then lower the tempera-
ture to that of the quaternary invariant
point. Only by this means were we able to
ascertain the correct equilibrium relations
with no metastable solid phases. How-
ever, in the compositions Di95Sp5 and
Di90Sp10 metastable melilite appeared
during crystallization at 1200 °C, and
because so little liquid is present it per-
sists metastably at temperatures just
210
CARNEGIE INSTITUTION
1550
-foss+sp-fan + liq
Diopside 5
10
15 20 25
30
35
40 — * Spinel
Ca0-Mg0-2Si02
Weight per cent
Mg0-Al203
Fig. 8. Phase-equilibrium diagram for the join diopside-spinel. This join is coplanar with forster-
ite-CaTs. Abbreviations as in Fig. 5.
above the beginning of melting, as indi-
cated by the dotted line in Fig. 8.
The diagram for diopside-spinel given
by Schairer and Kushiro {Year Book 64,
p. 101, Fig. 21) suggests that some of the
liquids freeze up at Q (Fig. 11). In their
study, as well as in the early stages of
this study, however, the excessively large
amounts of melilite indicate its meta-
stability.
Positions of the Joins Studied in the
Tetrahedron CaO-MgO-Alfi3-Si02
The relationship of the various joins
studied in the context of the CaO-MgO-
Al203-Si02 tetrahedron are displayed in
Fig. 9. The three principal planes studied
and the data on Di-An-Ak by deWys and
Foster (1958) form the subtetrahedron
An-Di-Ak-Sp. As will be demonstrated
below, at least two of the three most
critical invariant points of the entire
system lie within this subtetrahedron.
Because of the extensive solid solution
in Ak and Di, primarily in the direction
of Geh and CaTs, respectively, the com-
positions of phases crystallizing at the
solidus are more closely represented by
the dashed lines outlining An-Sp-Akss-
Diss and consequent Fo-Sp-Akss-Diss. In
short, the subtetrahedra just described
are not only compositional tetrahedra
but also represent the final products
obtained in the experiments.
As determined by experiment the array
of primary phase volumes for the princi-
pal portion of CaO-MgO-Al203-Si02 can
be outlined. These subsolidus tetrahedra
are displayed in Fig. 10 as an exploded
view. The lettered tetrahedra correspond
to the quaternary invariant points shown
in the flow sheet presented below as Fig.
11. In brief, liquids generated in tetra-
hedron P fractionate along an + fo8S +
sp + liquid and an + diss -f- fos8 + liquid
through the face An-Diss-Sp into
tetrahedron R. Liquids generated in
the tetrahedron Q fractionate through
GEOPHYSICAL LABORATORY
211
Al203
CaO
Mol per cent
MgO
Fig. 9. Relationship of the joins studied in the tetrahedron CaO-MgO-Al203-Si02 (in mole %).
The dashed lines represent an estimate of the subtetrahedron anorthite-spinel-melilite-diopside
solid solution at the solidus as determined by experiment.
Fig. 10. Subsolidus tetrahedra in CaO-MgO-Al203-Si02 as determined by experiment. Upper-case
letters in the tetrahedra and prisms represent assemblages at the solidus corresponding to the
quaternary invariant points similarly lettered in Fig. 11. The liquids at the quaternary invariant
points do not necessarily lie in these volumes.
212
CARNEGIE INSTITUTION
(CMS)
(MAS)
(CMS)
1430°
mont
AN-
WOL
PWOL
MEL (CAS)
1265°
o\
fo
fo mon
me! '
1 mel f0
Q sp
S sp
Dl-"""
'l238i3o"F0' 7
I348i2°
FO
, dl MEL lmont
SP
fo SP mel
MEL J
- mel MONT
sp
357c
(CMS)
, l450-ca6
ca6 CA2 a^ mel CAg
sp CA6 ™! sp MEL
MEL 1 2
SP l475'
CO
CA6
AN
SP
Fig. 11. Flow sheet for the geologically relevant portion of the quaternary system CaO-MgO-
Al203-Si02. Diagram showing univariant lines and their relation to ternary invariant points (indi-
cated by a small bar) in limiting systems and to quaternary invariant points (large black dots and
upper-case letters). These lines and points do not lie in a plane. Only their relations to one
another are shown in this diagram, which is not intended to depict their angular spatial relations.
The lengths of lines and the position of temperature maxima or minima on a line are arbitrary
and without significance. Arrows indicate the direction of falling temperature. Abbreviations:
wol, wollastonite solid solutions; pwol, pseudowollastonite ; tr, tridymite; an, anorthite; mel,
melilite; di, diopside solid solutions; sp, spinel; fo, forsterite solid solutions; mont, monticellite
solid solutions; CA2, CaO-2Al203; CAe, CaO6Al203; co, corundum; mu, mullite; sap, sapphirine;
cord, cordierite; en, enstatite. Attention is called to the three eutectics H, Y, and / and to the
two minima W and Z. There are four univariant lines that originate in portions of CaO-MgO-
Al203-SiOa not considered here.
the face Mel-Dis8-Sp along mel + foss +
sp + liquid and mel + diss + foss + liquid.
The piercing points on the bounding faces
of An-Di-Sp and Ak-Di-Sp indicate that
the invariant points P and Q must lie
in An-Mel-Diss-Sp. The invariant point
R may lie in its own tetrahedron An-Sp-
Mel-Di88 as a eutectic or may lie in a
subsidiary polyhedron An-Mel-Diss, in
which case it becomes a reaction point
leading to a minimum positioned in the
same subsidiary polyhedron. The data
on the plane Di-An-Ak studied by de-
Wys and Foster (1958) are not suffi-
cient to arrive at an unambiguous choice.
The temperature of their "eutectic,"
which is presumably a piercing point, at
1226°C (see Schairer and Yoder, Year
Book 67, p. 104) is lower than R, and,
therefore, suggests but is not conclusive
evidence that R may be a reaction point.
However, if R is a reaction point, then
a small field of spinel should appear on
the liquidus of the join Di-An-Ak. Reli-
GEOPHYSICAL LABORATORY
213
ance is placed on their temperature data
(given in their Table 1, eutectic hori-
zontal data) and the flow sheet, drawn
accordingly.
From the experimental data on the
joins presented we have seen that (1) all
compositions studied in the join diopside-
spinel-anorthite and four of the composi-
tions studied in diopside-spinel (Di70Sp3o,
Di75.27Sp24.73, Di80Sp2o, and Di85Sp15)
have their final crystallization at P (Fig.
11) ; (2) four compositions in the join
akermanite-spinel-anorthite crystallize
completely at Q (Fig. 11) ; (3) nine com-
positions in the join akermanite-spinel-
anorthite and four compositions in the
join CaTs-Di became completely crystal-
line at R (Fig. 11). In the discussion of
Fig. 2, the join akermanite-spinel-anor-
thite, we have shown that compositions
that lie in the area C A An become all
crystalline at B (Fig. 11).
Because of the analogy between the
flow sheet of Schairer and Yoder (Year
Book 63, p. 72, Fig. 8) for compositions
where the feldspar is nearly pure albite,
Schairer, Tilley, and Brown (Year Book
66, p. 470, Fig. 70) , in their flow sheet for
the corresponding compositions where
the feldspar is anorthite, show the points
F', C, and L with a temperature maxi-
mum in F'C. They had no experimental
evidence for this maximum, which was
based on the analogy. Attention is called
to the close proximity in temperature be-
tween F', C, and L at 1155°, 1152°, and
1148°C (all ±3°), respectively. Note
the similarity between the quaternary
invariant points P, Q, and R of the flow
sheet for CaO-MgO-Al203-Si02 in Fig.
11. These three points lie at 1238° ±3°C,
that is, at the same temperature within
experimental error. These same three
points, investigated by O'Hara and Big-
gar (1969), are 1233.5°, 1232°, and
1230°C, respectively, that is, in an in-
terval of only 3.5 °C. From an examina-
tion of data in their Table 4 (pp. 374-
375), it may be seen that there is no
evidence indicating temperatures along
their curve di + sp + fo + liquid, although
they show an arrow for falling tempera-
ture, from P to Q of our flow sheet,
Fig. 11.
In view of the lack of experimental
temperature evidence and the absence
of petrographic observations on an anor-
thite reaction relation with liquid, it
seems more likely that there is a tem-
perature maximum in the small tempera-
ture range along PQ of our flow sheet,
Fig. 11. The absence of piercing points in
the plane fo-di-sp tends to support this
interpretation.
Attention is called to the nature of
some of the solid solutions. The melilites
are not pure akermanite or pure gehlenite
but an akermanite-rich melilite (usually
with approximately 16 wt °/o gehlenite).
The clinopyroxene is not pure diopside
but must have CaTs in solid solution
and might also have an appreciable en-
statite content. The forsterite should
have appreciable monticellite in solid
solution, and even the spinel may not
bepureMgOAl203.
Petrologic Applications to Rocks and a
Possible Solution to the Plagioclase-
Melilite Dilemma
The flow sheet presented in Fig. 11 is
in fact that for the expanded basalt
tetrahedron, based not on nepheline and
albite but on calcium Tschermak's mole-
cule and anorthite. The presence of spinel
in the geologically relevant assemblages,
however, limits its application to magma
fractionation problems. The occurrence
of clinopyroxene and spinel, herein con-
firmed, has already been pointed out by
O'Hara and Schairer (Year Book 62, p.
115) and O'Hara and Biggar (1969).
However, spinel appears to react out
early in the fractionation scheme when
Na20 is added to the system, as outlined
by Schairer, Tilley, and Brown (Year
Book 66, p. 470) , and is not represented
among the final products of the common
alkali igneous rocks. With the present
construction of the flow sheet, liquids
fractionating from olivine gabbro would
214
CARNEGIE INSTITUTION
then pass into regions (R of Figs. 10 and
11) of composition more calcic than those
represented by natural magmas. Such
rocks appear to be generated mainly by
assimilation of limestone as illustrated
at Scawt Hill, northern Ireland (Tilley
and Harwood, 1931). The reaction be-
havior assigned by Chinner and Schairer
(1962) , p. 630) to the aluminous pyroxene
does not appear to be operative ; in fact,
the pyroxene may become slightly more
aluminous with the onset of melilite.
Liquids generated in Q would be repre-
sented by the olivine melilite nephelin-
ites. Accepting the maximum on P-Q
(for which there are no experimental
data), the liquid at Q would fractionate
on the loss of olivine toward R with
calcium enrichment of the liquid. The
high liquidus temperatures of the natural
olivine-melilite nephelinites support the
view that they have a liquid line inde-
pendent of the olivine gabbros at 1 atm.
Ignoring this limitation for purposes of
discussion, it is seen that the assemblage
at P is essentially representative of an
olivine gabbro.
The new subtetrahedra point to a pos-
sible solution of the plagioclase-melilite
dilemma described in detail last year by
Yoder and Schairer (Year Book 67, p.
101). Although plagioclase and melilite
do not occur together in igneous rocks,
those phases were stable together in liq-
uid over a wide range of bulk composi-
tions and conditions in the laboratory.
Examination of the volume enclosed by
An-Ak-Di-Fo-Sp (see Fig. 10) reveals
that Ak is stable with An only in the ab-
sence of Fo. That is, the more calcium-
rich assemblage An-Ak-Di-Sp is found
only in the metamorphic rocks, whereas
the assemblage Fo-Ak-Di-Sp has repre-
sentatives among the igneous rocks. In
brief, plagioclase and melilite are indeed
stable together in certain assemblages,
but not in those characteristic of the igne-
ous rocks. If Sp in the above-named as-
semblages is replaced by Ne, then the as-
semblages are those displayed in Fig. 12.
These assemblages are just those deduced
Fig. 12. The generalized volume plagioclase
(PI) -nepheline(Ne) -olivine(Ol) -melilite (Mel) -
clinopyroxene(Cpx), illustrating the coexistence
of plagioclase and melilite in the absence of
olivine and their incompatibility in the presence
of olivine. The tetrahedron Pl-Ne-Ol-Cpx repre-
sents the basanites; Mel-Ne-Ol-Cpx represents
the olivine melilite nephelinites; and Pl-Ne-
Cpx-Mel, metamorphic rocks or those resulting
from assimilation.
by Schairer, Tilley, and Brown [Year
Book 66, p. 470) in their flow sheet at the
points F', C, and L. It appears that the
incompatibility of plagioclase and meli-
lite can be explained in the presence of
olivine; however, the melilite nephelin-
ites do not have this constraint. The
commitment to that particular fractiona-
tion trend may have been made at an
earlier stage, as suggested in the flow
sheet by Schairer and Yoder ( Year Book
63, p. 72).
The System CaSi03-MgSi03-Al203
F. R. Boyd
Most petrologic models for the upper
mantle favor garnet lherzolite as a major
rock type. Among the reasons for this
choice is the belief that it is a possible
parent material for basaltic lavas. Gar-
net lherzolite is also abundant among
GEOPHYSICAL LABORATORY
215
the ultramafic nodules that have been
recovered from kimberlites, and these
nodules are believed to be relatively-
unaltered mantle rocks.
Garnet lherzolites contain only four
essential minerals: forsterite, pyrope-
rich garnet, enstatite, and diopside. The
simplicity of this assemblage offers hope
that compositional variations of the con-
stituent minerals can be interpreted in
considerable detail from studies on syn-
thetic systems. Solid solutions in garnet,
in pyroxenes, and between garnets and
pyroxenes are sensitive to temperature
and pressure and are the most important
aspects of these phase relations. The sys-
tem CaSi03-MgSi03-Al203 models the
natural solid solutions rather well. This
system contains the joins pyrope-grossu-
larite and enstatite-diopside and shows
the solid solutions of these pyroxenes
toward A1203. This ternary also contains
the composition CaAl2Si06, or "calcium
Tschermak's molecule," a pyroxene that
is stable under limited conditions of high
temperature and pressure.
Subsolidus synthesis relations in the
system CaSi03-MgSi03-Al203 have been
determined at 1200 °C and 30 kb with
analysis by electron probe as the means
of establishing the compositions of co-
existing phases. This is the first phase
study to be published in an Annual Re-
port in which the probe has been used
as the principal analytical instrument,
rather than the petrographic microscope
and the X-ray diffractometer. Electron-
probe techniques have many advantages
over optical and X-ray methods. They
are more accurate and more direct, and
for complex equilibria they are faster.
A disadvantage is that the grain size of
a synthetic run must be at least 6-8 /xm
to permit accurate probe analysis. Never-
theless, this minimum grain size can be
obtained in silicate systems under favor-
able circumstances.
Phase Relations
Phase relations in CaSi03-MgSi03-
A1203 appear to be completely ternary
at 1200°C and 30 kb. Figure 13 shows
the whole ternary, and portions of it
together with plots of the analytical data
are shown in expanded form in Figs. 14
and 15. Explanations of abbreviations
used in these figures and in the text are
given in Table 15. The ternary contains
four three-phase fields, one of which
Diss+Enss+Mg-Gtss is of primary geo-
logic interest because it models the gar-
net-lherzolite assemblage. There is a
very extensive solid solution of diopside
toward CaAl2Si06 (CaTs) extending to
a composition of 56 wt °fo CaTs. This
solid solution "finger" pierces the garnet
join and interrupts the extensive solid
solution between pyrope and grossularite.
CaTs is not a stable phase at 1200°C
and 30 kb. At higher temperatures and
lower pressures it becomes a stable phase
(Hays, Year Book 65; Hijikata and
Yagi, 1967) and the solid solution along
the join diopside-CaTs becomes complete
(Clark, Schairer, and de Neufville, Year
Book 61).
The compositions of diopsidic pyrox-
enes in equilibrium with garnet in this
system are of particular interest because
they reveal the effect of aluminum on
the solid solution of enstatite in diopside.
The basic phase relations for this part
of the ternary were outlined and dis-
cussed on a theoretical basis by O'Hara
and Mercy (1963) and Banno (1965).
These authors correctly deduced that
solid solution toward garnet would re-
duce the solid solution of enstatite in
diopside. O'Hara and Yoder (1967) have
provided experimental data in support
of the theoretical treatments. The diop-
side solution field (Fig. 14) lies along
the join CaMgSi206-CaAl2Si06, extend-
ing to compositions considerably richer
in Mg at the low-Al203 end. As the A1203
contents of these pyroxenes increase, the
extension of this field toward MgSi03
decreases.
Nevertheless, there is an inflection in
the boundary of the diopside solid solu-
tion field (Fig. 14) such that diopside in
equilibrium with both enstatite and gar-
Al203
I200°C 30kb
Mg3AI2Si30|2
CaSi03 10
90 MgSi03
Fig. 13. Synthesis diagram for phase relations in the system CaSiOs-MgSiOs-ALOa at 1200° C
and 30 kb. Data points are shown in Figs. 14 and 15.
I200°C 30 kb
Ca3A!2Si30|2 ■*■
CaSi03 -<=
Weight per cent
Mg3Ar2Si30i2
■>■ MgSi03
Fig. 14. A portion of the system CaSi03-MgSi03-Al203 at 1200° C and 30 kb showing the solid
solution field for diopside. Open points represent analyses of phases in two-phase assemblages,
and solid points are for phases in three-phase assemblages. Circles are pyroxenes, and squares are
garnets. Point a is the Di(en) solvus in the system CaMgSi20a-MgSi03 determined by Davis and
Boyd (1966).
GEOPHYSICAL LABORATORY
— 1 1 1 1 1 1 1
217
26
.^22
f
Din two-phase assemblage
■ In three-phase assemblage
A
1 — r
J L
j L
Ca3AI2Si30i2 10 20 30 40 50 60 70
Weight per cent Mg/(Mg + Ca)
90 Mg3AI2Si30|2
B
O*5
' Ca-Gt
+
Woss + Diss
"57.
C
\\io
O In two -phase assemblage
© In three-phase assemblage
I200°C 30 kb
Mg-Gt\\
+ \
Diss + Enss
CaSi03 5
10
->-MgSi03 CaSi03-e
Weight per cent
95 1 MgSi03
b
Fig. 15. Portions of the system CaSi03-MgSi03-AL>03 showing the analytical data. (A) The
garnet join with wt % A1203 plotted against the weight ratio Mg/(Mg+Ca) in order to
expand the AL>03 axis. Vertical bars on the points are error limits of ± 2 relative %
A1203. (B) The wollastonite solid solution field. (C) The enstatite solid solution field. Point b
is the En (wo) solvus in the system CaMgSi20e-MgSi03 determined by Davis and Boyd (1966),
and point c is the En (co) solvus in the system MgSiOs-MgaAlaSiaOia determined by Boyd and
England ( Year Book 63) .
net has a Ca/(Ca+Mg) ratio that is
only slightly larger than that of a diop-
side in equilibrium with enstatite on the
join CaMgSi206-MgSi03. Specifically,
TABLE 15. Abbreviations Used in this Report
Di Diopside, CaMgSi2Oe
En Orthorhombic enstatite, MgSiOa
Wo Wollastonite, CaSi03
Mg-Gt Mg-rich garnet on the join MgsAL
SisO^-CosALSisOia
Ca-Gt Ca-rich garnet on the join Mg3AL
SisOis-CosALSisOis
CaTs Ca-Tschermak's molecule, CaAl3
SiOe
Co Corundum, A1203
woxenvcOz Composition (x + y + z = 100 wt
%)
ss Subscript denoting solid solution
En ( co ) Notation indicating the solvus for
the component A1203 in enstatite
diopside in the three-phase field Diss+
Enss+Mg-Gtss at 1200°C and 30 kb con-
tains 3.0 ±0.1 wt % A1203 and has a
Ca/(Ca + Mg) ratio of 0.43 + 0.01 (mole
fraction), compared with 0.42 ±0.01 for
Al-free diopside in equilibrium with en-
statite at the same pressure and tempera-
ture. Thus application of the pure Di(en)
solvus (Davis and Boyd, 1966) to garnet
peridotites in which the pyroxenes con-
tain only a few percent of A1203 would
be in error because of the effect of Al
by an amount which is clearly small in
relation to other uncertainties. These
other uncertainties include an uncer-
tainty in the experimental location of
the Di(en) solvus of about ±0.01 in
218
CARNEGIE INSTITUTION
mole fraction CaSi03 where the data are
best, as well as uncertainties about the
effects on this solvus of small amounts
of Na, Cr, Fe2+ and Fe3+, in the natural
pyroxenes.
Boyd (1967) has suggested that the
ALO3 content of enstatite in equilibrium
with garnet might be used in combina-
tion with the Ca/(Ca + Mg) ratio of
coexisting diopside to fix the P-T con-
ditions of equilibration of garnet perido-
tites. O'Hara (1967) has more fully de-
veloped an analogous approach using the
R0O3 content and Ca/(Ca + Mg) ratio
of diopside in equilibrium with enstatite
+ forsterite + "an Al203-rich phase."
O'Hara's treatment takes into account
the interrelationships of these solid solu-
tions, and it is interesting to note that
the experimental determination of the
three-phase field Diss-\-Enss+Mg-Gtss
described in this report fits his pro-
visional diagram (op. tit., p. 396, Fig.
12.4) relatively well. As shown above the
Ca/(Ca + Mg) ratio of diopside in equi-
librium with enstatite is slightly affected
by several percent of A1203. The A1203
content of enstatite in equilibrium with
garnet is affected in a similar way by
solid solution of diopside in the enstatite.
Data in Fig. 15 show that the A1203
content of enstatite that coexists with
pyrope on the join MgSi03-Mg3Al2Si3012
at 1200°C and 30 kb is 5.8 wt %, whereas
enstatite in equilibrium with garnet and
diopside under these conditions contains
about 4 wt % A1203. There is a discrep-
ancy in the AL03 analyses of duplicate
runs on this point (Fig. 15), but the ap-
parent effect of Ca on the solid solution
of enstatite toward garnet is most likely
real. When more data on these ternary
equilibria become available, it is prob-
able that the A1203 content of enstatite
will be of more use in constructing a
P-T grid for peridotites than will the
analogous solid solution in diopside, be-
cause natural enstatites contain less
Cr203 and show less solid solution toward
jadeite and acmite than do the coexisting
diopsides.
The experimental determination of the
Diss+Enss+Mg-Gtss field is compared in
Fig. 16 with analytical results for two
garnet-lherzolite nodules from kimber-
lite. The agreement for the point of in-
tersection of the three-phase field with
the garnet join is remarkable. Experi-
mental results obtained by Kushiro,
Syono, and Akimoto (1967a) are also
shown (Fig. 16). They determined the
cell dimensions of garnets coexisting with
enstatite and diopside solid solutions in
runs crystallized in the pressure range
18-96 kb and found a systematic varia-
tion corresponding to a compositional
range of 81-88 mole % pyrope. Results
on the garnets are thus concordant.
Nevertheless, there is a large variation
in the points of intersection of the three-
phase field with the solid solution fields
for diopside and enstatite. The A-3
nodule (Fig. 16) has a calcic diopside,
typical of most diopsidic pyroxenes from
kimberlites, whereas the diopside in the
E-3 nodule is of the rarer, subcalcic
variety. Elsewhere in this report Boyd
and Nixon suggest that these results may
not be understandable in terms of present
experimental data and that studies at
higher pressures are needed.
The pair of three-phase fields for
corundum, garnet, and pyroxenes (Fig.
13) seem to model the mineral assem-
blages found in grospydite and kyanite-
eclogite xenoliths in kimberlite. These
rocks sometimes contain corundum, but
more frequently kyanite is the highly
aluminous phase. The garnets in the
grospydites and kyanite eclogites contain
10-35% almandine, and the pyroxenes
are omphacites containing 30-50% jade-
ite. Hence, application of the phase re-
lations from the ternary studied in this
investigation to these rocks involves a
long reach. O'Hara and Mercy (1966)
have projected compositions of garnets
and pyroxenes from a corundum eclogite
and grospydite from Yakutia and garnet
from a kyanite eclogite from the Roberts
Victor mine onto the plane CaSi03-
MgSi03-Al203 and obtained an arrange-
GEOPHYSICAL LABORATORY
219
Mg3AI2Si30|2
CaSi03^
CaMgSi206
Mol per cent
MgSi03
Fig. 16. A portion of the system CaSiOa-MgSiOs-ALAj showing the experimental determination
of the phase field Mg-Gt + Diss + Enss at 1200° C and 30 kb together with analytical data for
the pyroxenes and garnets of two lherzolite nodules. A-3, O'Hara and Mercy (1963) ; E-3, Nixon,
von Knorring, and Rooke (1963), Boyd (1969). The range of garnet compositions obtained in
experiments by Kushiro, Syono, and Akimoto (1967) is shown as bracket k. The two natural
garnets are assumed to lie on the join CasAUSisOis-MgsAlaSisO^. For the natural pyroxenes
"Al2O3" = 0.5[Al — Na(Al/Al-f- Cr + Fe3+)], where Al, etc., are in atomic proportions.
ment of three-phase fields similar to that
determined by experiment (Fig. 13).
However, Sobolev, Kuznetsova, and
Zyuzin (1968) have presented a large
number of analyses of pyroxenes and
garnets from grospydites and kyanite
eclogites and concluded that there is a
complete solid solution between gros-
sularite and pyrope under the P-T condi-
tions of grospydite equilibration. The
relatively high almandine contents of the
garnets they analyzed leave some un-
certainty about this conclusion. One
would certainly expect that the pyrope-
grossularite join would be continuous at
pressures high enough to stabilize dia-
mond. Diamonds have been found in
eclogites (Sobolev, 1968), although ap-
parently not in kyanite eclogites or gros-
pydites. In this connection it is interest-
ing to note that one of the garnet
inclusions from diamond described by
Meyer and Boyd (this report) is very
similar to those from kyanite eclogites.
Both the wollastonite and corundum in
this system show detectable solid solu-
tions, but they are rather small. Analyses
for wollastonites in three assemblages are
plotted in Fig. 15, and it can be seen
that the wollastonite dissolves 1-2%
MgSi03 but only about 0.1-0.2% Al2Os.
The corundum in these assemblages is
too fine grained to permit accurate
analysis. However, significant signals for
Mg, Ca, and Si were obtained. They are
extremely variable but correspond to a
solid solution of about 1% MgSi03 and
2% CaSi03 in corundum in the assem-
blage Coss + Diss-\-Ca-Gt. Silicon is defi-
nitely present in the corundum, but the
analyses made were not of sufficient ac-
curacy to make it certain that the com-
position of the corundum is in the plane
CaSi03-MgSi03-Al203.
All the probe analyses of garnets ob-
tained in these runs are shown in Fig. 15
in a plot of wt % Ca/(Ca + Mg) against
wt % A1203. This plot permits expansion
220
CARNEGIE INSTITUTION
of the ALO3 axis, and it can be seen that
although most of the garnet analyses fall
on the garnet join within expectable error
limits, there are a number that fall sig-
nificantly below. Ringwood (1967) has
shown that a large solid solution of gar-
net toward pyroxene develops at pres-
sures on the order of 100 kb. The onset
of this solid solution with increasing
pressure is rather abrupt in the experi-
ments he describes, but it is possible
that with the greater sensitivity of elec-
tron-probe techniques in comparison to
cell size measurements a beginning of
this solid solution might be detected at
lower pressures. If best-fit curves were
drawn through the garnet analyses in
Fig. 15, they would lie below the garnet
join and might be taken as evidence of
such a solid solution. Nevertheless, the
scatter in these results does not support
such an interpretation and suggests in-
stead that the garnets in some runs have
incorporated minute inclusions of pyrox-
enes that could not be detected and
avoided during analysis.
There are several discrepancies be-
tween the phase relations shown in Figs.
13-15 and earlier work on binary joins.
Chinner, Boyd, and England (Year Book
59) reported a complete solid solution
on the join pyrope-grossularite at 30 kb
and 1250°C on the basis of cell edge
and refractive-index measurements. Pres-
ent results (Fig. 13) show that this solid
solution is interrupted in the composition
interval 23-51 wt % (25-54 mole %)
pyrope. The pressure listed by Chinner
et al. contained a —8% friction correc-
tion, whereas it is our present practice
to list load pressures. Using the load-
pressure convention, the pressure of the
runs made by Chinner et al. was 32.3 kb.
It is possible that garnet-pyroxene phase
relations change sufficiently rapidly with
pressure that the increment of 2.3 kb in
pressure over the pressure of the present
study is sufficient to stabilize this garnet
solid solution.
The probe determinations reported
here show that solid solutions between
enstatite and diopside and in enstatite
toward pyrope are consistently more re-
stricted than indicated by earlier work
(Davis and Boyd, 1966; Boyd and En-
gland, Year Book 63). These discrep-
ancies are small (Figs. 14 and 15), and
it is questionable whether they are sig-
nificant. The earlier determinations were
made by optical identification of one or
two phases in runs closely spaced in
composition. Possibly trace amounts of
garnet mixed with enstatite or trace
amounts of one pyroxene mixed with
another were consistently missed. There
may also be a small bias in the probe
analyses in that one tends to avoid grains
that give somewhat extreme counts be-
cause they usually indicate intergrowths.
This tendency could lead to a small but
consistent underestimate of solid solu-
tions.
Experimental Technique
Starting materials for the high-pres-
sure runs made to determine these phase
relations were prepared as powdered
glass and were moistened with small
amounts of H20. They were loaded in
platinum capsules. Inasmuch as the cap-
sules were not sealed by welding, the H20
diffused away in the course of a run.
Samples were held at temperature and
pressure for 2-5 hours. This technique
sometimes yields run products with a
grain size up to 50 /xm, but grain growth
is very erratic. At times too much H20
was added and the samples melted; at
other times grain growth was inadequate
for electron-probe analysis. Approxi-
mately a third of the total number of
runs that were made could be probed.
They were mounted in epoxy on glass
slides, and each was polished to as thin
a section as practical.
It proved very difficult to distinguish
individual grains under the probe in
many samples. Use of transmitted light is
helpful, but small differences in relief,
cathodoluminescence, cleavage, etc., were
also employed. At least a dozen grains of
GEOPHYSICAL LABORATORY
221
each phase in each assemblage were ana-
lyzed for Ca, Mg, and Al, and the output
was processed by computer programs
described by Boyd, Finger, and Chayes
(Year Book 67). An addition to program
ABFAN converted the Ca and Mg
analyses to CaSi03 and MgSi03 and
formed a total with A1203. Thirty-three
out of thirty-six analyses of individual
phases totaled between 98.0 and 102.0,
and the remaining three are only slightly
outside these limits.
The analytical techniques used in this
study have been shown to yield an ac-
curacy within ±2% of the amount of
a major element present in a relatively
coarse-grained sample (Boyd, 1969) . The
fine-grained run products produced in
these experiments are inherently more
difficult to analyze, but the reproducibil-
ity and internal consistency of a major-
ity of the results shown in Figs. 14 and
15 are within error limits of ±2 rela-
tive %. Inasmuch as the absolute error
of a probe analysis depends upon the
amount of an element present, this error
will generally not be the same for each
element in a given analysis. Ideally, the
points plotted in Figs. 14 and 15 should
show this variable absolute error, but to
do so obscures the visual presentation of
the data. A simpler but less rigorous
procedure has been adopted wherein the
size of the data points in Figs. 14 and 15
corresponds to a relative error of ±1%
for a composition in the center of the
ternary.
Phase relations for two of the bounding
joins, CaMgSi206-MgSi03 (Davis and
Boyd, 1966) and MgSi03-Mg3Al2Si3012
(Boyd and England, Year Book 63),
have been reversed by the same high-
pressure techniques at the same pressure
and temperature as were used to study
ternary compositions. Reversing ternary
solid solution fields is obviously a more
complex problem than reversing solvus
curves in binary systems. Reversal ex-
periments within the ternary have not
yet been attempted, and it will be neces-
sary to study the ternary under P-T con-
ditions where these solid solution fields
are both more extensive and more limited
to provide starting materials for such
experiments.
Quenching Experiments in the Sys-
tems Jadeite (NaAlSi206) -Forsterite
(Mg2Si04) and Jadeite (NaAlSi206)-
Anorthite (CaAl2Si208)
H. K. Mao and J. F. Schairer
Behavior of the components jadeite,
forsterite, and anorthite is important in
the interpretation of deep-seated igneous
processes. During the past year we have
prepared mixtures of pure jadeite, jadeite
with 5, 15, 25, and 35 wt °fo of forsterite,
and jadeite with 5, 15, 25, and 35 wt %
of anorthite to carry out a study of these
systems at low and high pressure. This
report describes results obtained by the
quenching method at 1 atm.
Schairer and Yoder {Year Book 64,
p. 106) studied the system forsterite-
nepheline-silica. Jadeite-forsterite is a
join through this system. Results of the
present quenching experiments agree
with the value of 1068° ±5°C (Greig and
Barth, 1938) for the binary eutectic be-
tween nepheline and albite. The value
1138° ±5°C (Yoder, 1950, p. 316) was
confirmed for the nepheline liquidus for
jadeite composition. Additional con-
firmation was obtained for the value
1058° ±5°C (Schairer and Yoder, Year
Book 60, p. 142) for the ternary eutectic
among nepheline, albite, and forsterite
from the compositions Jd95Fo5, Jd85Fo15,
Jd75Fo25, and Jd65Fo35. New data for the
join jadeite-forsterite include the appear-
ance of nepheline as a second solid phase
at 1098° ±5°C in all cases and the
forsterite liquidus temperatures of 1197°,
1358°, 1428°, and 1478°C, respectively.
The join jadeite-anorthite lies in the
system nepheline-albite-anorthite, and
the results of quenching experiments on
the compositions Jd95An5, Jd85An15, Jd75
An25, and Jd65An35 are in good agreement
with the data previously obtained by
Schairer (unpublished data on the system
222
CARNEGIE INSTITUTION
nepheline-anorthite-silica ; see Schairer,
1957, p. 232, Fig. 35). In Jd95An5 the
crystalline assemblage nepheline 4-
plagioclase began to melt at 1048° ± 5 °C
and the nepheline liquidus was at 1153°
±5°C.In Jd85An15,Jd75An5,andJd65An35,
respectively, nepheline + plagioclase be-
gan to melt at 1058°, 1073°, and 1085°C,
the temperature shift being in response
to the changing compositions of plagio-
clase. The plagioclase liquidus tempera-
tures for these compositions were 1268°,
1333°, and 1378°C; nepheline appeared
as a second solid phase at 1168°, 1197°,
and 1213°C.
Experiments on the liquidus and in
the subsolidus region in the range 10-50
kb have been started for all of the com-
positions prepared at 1 atm. It is hoped
that an understanding of the influence
of anorthite and forsterite on the be-
havior of jadeite at high pressure will
be gained from these experiments. Com-
binations of anorthite, forsterite, and
jadeite will clarify the roles of anorthite,
calcium Tschermak's molecule, and diop-
side in the pressure-temperature stabil-
ization of omphacite.
Diopside Solid Solutions in the Sys-
tem Diopside-Anorthite-Albite at
1 Atm and at High Pressures
I. Kushiro and J. F. Schairer
The liquidus relations in the system
diopside-anorthite-albite were studied by
Bowen (1915) at 1 atm for an under-
standing of the crystallization behavior
of basaltic and dioritic magmas. Bowen
(1928) described this system as the
simplest example of a ternary system
with a binary series of solid solutions.
Osborn (1942) found, however, that the
join diopside-anorthite is not binary and
showed that diopside crystallizing from
this join is not pure diopside but a solid
solution containing some alumina. This
result was confirmed by Hytonen and
Schairer {Year Book 60, pp. 125-141)
and Clark, Schairer, and de Neufville
{Year Book 61, pp. 59-68). Schairer and
Yoder (1960) also found that the join
diopside-albite is not binary and showed
that the feldspar crystallizing from this
join is not pure albite but is a solid solu-
tion containing a small amount of the
anorthite component and that the diop-
side is also a solid solution. These results
suggest that the system diopside-anor-
thite-albite is not ternary and that the
diopside crystallizing within this system
is not pure diopside but a solid solution.
The join diopside-plagioclase (An5oAb5o
wt %) has been studied carefully to as-
certain and define the nature of the di-
opside solid solution. Four compositions
were selected along this join: (1) Di70
An15Ab15, (2) Di50An25Ab25, (3) Di42An29
Ab29 and (4) Di40An30Ab30 (wt %).
Starting materials were glasses crystal-
lized at temperatures between 1050° and
1175°C for 10 to 22 days.
The liquidus temperatures are 1318°,
1268°, 1237°, and 1233°C for composi-
tions 1, 2, 3, and 4, respectively. Diopside
solid solution is the liquidus phase for
compositions 1, 2, and 3, and both diop-
side solid solution and plagioclase are the
liquidus phases for composition 4. Com-
position 4 is, therefore, at the liquidus
boundary between diospide solid solu-
tion and plagioclase. These liquidus
results are nearly the same as those ob-
tained by Bowen (1915) ; the tempera-
tures at which diopside solid solution and
plagioclase began to crystallize simul-
taneously, however, are 1251°, 1246°,
1237°, and 1233°C for compositions 1,
2, 3, and 4, respectively. Since the un-
certainties of these temperatures are
±3°, these differences are significant. If
diopside is of pure CaMgSi206 composi-
tion, diopside should be joined by plagio-
clase at the same temperature for all of
these mixtures. The present results in-
dicate, therefore, that diopside crystal-
lizing in this system is not pure CaMg
Si206 but a solid solution.
Determination of the temperature of
beginning of melting was not easy be-
cause of the difficulty of detecting a small
amount of glass in the fine-grained
GEOPHYSICAL LABORATORY
223
products. In the present experiments, the
temperature of beginning of melting has
been estimated by whether the products
are loose powder or fritted. If the prod-
ucts are barely fritted or fritted, the
temperature of the run is considered to
be above the beginning of melting. It is
noted that temperatures estimated by
this method could be slightly different
from the temperature of beginning of
melting. The glasses for these experi-
ments were crystallized at 1080 °C, a
little below the beginning of melting,
for 7 to 15 days. The temperatures of
"beginning of melting" thus estimated
are 1103°, 1115°, 1140°, and 1145°C for
mixtures 1, 2, 3, and 4, respectively. They
are considerably lower than 1200°C, the
temperature of beginning of melting
given by Bowen (1915) for the composi-
tion DisoiAniAbiho (mole %), which
lies very close to the present join. The
temperature of "beginning of melting"
increases systematically from composi-
tion 1 to composition 4. This evidence
also indicates that diopside crystallizing
in this system is a solid solution whose
composition is off the plane diopside-
anorthite-albite. The composition of liq-
uids formed at temperatures at or near
the "beginning of melting" (1100°-
1150°C) should be very rich in albite,
on the basis of the liquidus diagram of
Bowen (1915). As suggested below, how-
ever, the liquid may be enriched in silica
and off the plane diopside-anorthite-
albite.
The unit-cell dimensions of diopside
solid solutions crystallized from the mix-
tures Di7oAn15Ab15 and Di5oAn25Ab25 (wt
% ) have been determined to ascertain the
nature of the solid solution. Least-
squares refinement of the data from the
powder X-ray diffraction patterns was
carried out on the basis of C2/c sym-
metry, with a program for the IBM 7094
digital computer by Burnham (Year
Book 61, pp. 132-135). The reflections
measured against the internal silicon
standard were 223, 150, 510, 402, 041,
121, 331, 330, 311, 221, 002, T31, 311, 310,
221, 220, and 021. The results are shown
in Table 16, with the unit-cell dimen-
sions of pure diopside determined by
Clark, Schairer, and de Neufville {Year
Book 61, pp. 59-68) and diopsides crys-
tallized at high pressures from the mix-
tures Di7oAn15Ab15 and Di5oAn25Ab25. As
TABLE 16. Unit-Cell Dimensions
in the System Diopside-Anorthite
of Diopside Solid Solutions Crystallized
-Albite at 1 Atm and at High Pressures
a, A
b, A
c,k
]8, deg.
V, As
Pure diopside
9.745
8.925
5.248
105.87
439.08
(Clark, Schairer, and
±0.001
±0.001
±0.001
±0.01
±0.07
de Neufville, Year
Book 61)
a
DiroAnisAbis
9.741
8.918
5.253
105.98
438.72
1 atm, 1250°C,
±0.002
±0.001
±0.001
±0.02
±0.19
3 days
b
DiToAni5Abi5
9.722
8.905
5.254
106.12
436.96
1 atm, 1080°C,
8 days
Di5oAn25Ab25
±0.003
±0.002
±0.003
±0.03
±0.38
c
9.738
8.914
5.253
106.06
438.19
1 atm, 1235°C,
±0.002
±0.001
±0.001
±0.02
±0.20
7 days
d
DiooAn25Ab25
9.715
8.884
5.265
106.23
436.31
1 atm, 1080° C,
±0.004
±0.003
±0.003
±0.03
±0.38
8 days
e
DiToAnisAbis
9.672
8.855
5.263
106.28
432.67
25 kb, 1350° C,
±0.005
±0.004
±0.004
±0.06
±0.53
2 hours
f
DLWAn2sAb25
9.622
8.787
5.267
106.52
426.93
30 kb, 1350°C,
±0.007
±0.004
±0.004
±0.06
±0.55
2 hours
224
CARNEGIE INSTITUTION
shown in the table, the unit-cell dimen-
sions of the diopsides crystallized at
1 atm are significantly different from
that of pure diopside ; a, b, and unit-cell
volume V of these four diopsides are
smaller and c and (B are slightly larger
than those of pure diopside. Particularly,
the diopsides crystallized at 1080 °C for
8 days show greater differences of unit-
cell parameters from those of pure di-
opside. The diopsides crystallized at
1240 °C from the mixture Di70An15Ab15
and at 1235 °C from the mixture Di50
An25Ab25 coexisted only with liquid,
whereas those crystallized at a subsolidus
temperature of 1080 °C coexisted with
plagioclase. The variation in the unit-cell
parameters is similar to those observed
for the clinopyroxenes formed in the
joins diopside-CaALSiOe and diopside-
anorthite at high pressures (Clark,
Schairer, and de Neufville, Year Book
61, pp. 59-68; Kushiro, 1969) , suggesting
that the differences between the unit-cell
dimensions of these diopside solid solu-
tions and those of pure diopside are
mainly due to the presence of Ca-Tscher-
mak's component. However, the MgSi03
component would also be present in these
clinopyroxenes, since the diopside solid
solutions in the join diopside-anorthite
contain measurable amounts of excess
MgSi03 at about 1150°C, as shown by
Hytonen and Schairer {Year Book 60,
pp. 125-141). Jadeite solid solution is
also possible but would not be significant
at 1 atm. On the assumption that the
differences in the unit-cell dimensions of
these diopsides are essentially due to the
presence of the Ca-Tschermak's com-
ponent, the contents of the Ca-Tscher-
mak's component can be estimated
roughly from the relations between the
unit-cell parameters and compositions of
the clinopyroxenes crystallized from the
joindiopside-CaALSi06 (Clark, Schairer,
and de Neufville, Year Book 61, pp.
59-68) . The contents thus estimated are
about 3, 10, 5, and 13 wt % CaAl2Si06
for diopsides a, b, c, and d in Table 16,
respectively. The content of CaAl2Si06 is
larger for the clinopyroxene crystallized
from the more plagioclase-rich mixture
and also at lower temperatures. If the
relation between composition and d
values of the (510) and (150) planes of
diopside solid solutions given by Hytonen
and Schairer is used, the present diopside
solid solutions contain about 3 to 7%
A1203 and up to about 8% excess MgSi03.
The presence of the CaAl2Si06 and
excess MgSi03 components (and possibly
a very small amount of NaAlSi206) in
diopside solid solutions crystallizing from
the present system indicates that the
liquids coexisting with the diopside solid
solutions must be off the plane diopside-
anorthite-albite and contain excess silica
and CaSi03 components, and that free
silica must exist at temperatures below
the solidus at 1 atm. No reflections of
silica minerals were detected, however,
in the powder X-ray diffraction patterns
of the mixtures crystallized at subsolidus
temperatures. This could be explained by
a diopside solid solution containing a
small amount of excess silica, suggested
by Schairer and Kushiro (Year Book 63,
pp. 130-132), but the amount of excess
silica would be very small at tempera-
tures below 1300°C, as they suggested.
Even if the silica mineral is present in the
products, it may be in too small amount
to be detected by X ray. Under the
microscope, crystals formed at subsolidus
temperatures are very fine grained and
the presence of the silica mineral was not
confirmed.
The subsolidus phase relations in the
join diopside-plagioclase (An5oAb5o wt
°fo) have been studied in the pressure
range 15 to 31 kb at 1150° and 1350°C
with the solid-media, piston-cylinder ap-
paratus. The starting materials were
glass and glass crystallized at 1 atm.
At 1150°C, only glass was used because
the crystalline mixtures did not react at
this temperature even in long runs. At
1350°C, it was shown that the results
obtained from glass are identical with
those obtained from the crystalline mix-
tures. The subsolidus phase relations at
GEOPHYSICAL LABORATORY
225
1150°C are shown in Fig. 17. As shown in
the figure, the range of the clinopyroxene
(diopside solid solution) + quartz assem-
blage expands to about 30 wt % CaAl2
Si208 + NaAlSi308 at 20 kb and 1150°C.
indicating that the clinopyroxene con-
tains about 25 wt % CaALSi06 and
NaAlSi206 components at 20 kb and
1150°C. The range of the solid solution
may attain its maximum at about 25 kb
and 1150°C. More detailed subsolidus
phase relations are described elsewhere
(Kushiro, 1969) .
The unit-cell dimensions of diopside
solid solutions crystallized from the mix-
tures Di70An15Abi5 and Di5oAn25Ab25 at
25 and 30 kb at a subsolidus temperature
of 1350°C are shown in Table 16. The
parameters a, b, and V of these clino-
pyroxenes are much smaller than those
of pure diopside and the diopside solid
solutions crystallized at 1 atm. These
high-pressure diopside solid solutions,
which coexist only with quartz, must
contain jadeite as well as Ca-Tscher-
mak's component.
The results of the present experiments
indicate that diopside or augite crystal-
lizing from silica-saturated basaltic mag-
mas at 1 atm would contain small
amounts (up to several weight percent)
of CaAl2Si06 and excess MgSi03 com-
ponents. Those crystallizing from silica-
undersaturated basaltic magmas would
contain more CaAl2Si06 and less MgSi03
components, on the basis of the results
of Hytonen and Schairer (Year Book 60,
pp. 125-141) and de Neufville and
Schairer [Year Book 61, pp. 56-59) . Pres-
ent results also indicate that the plane
35-
30-
w25
t/)
20
1 1
i
I
i l 1 " J i
-
Cpx + Qz
V
V
\
\
\
Cpx
+
Gar
+
Qz
/
/ Cpx+Oar+Ky + Qz
7 .
/ Cpx+Gar+Pl + Qz
-
U u
□
-
/o
Cpx + PI ■+■ Qz
-
—
/
/
/
i i
D
l
1
i i i i i
— ■
15
CaMgSigOe
50
Weight per cent
CaAl2Si208(50)
4NaAISi308(50)
Fig. 17. Subsolidus phase-equilibrium relations on the join diopside-plagioclase (AnsoAbso wt
%) at 1150°C. Abbreviations: Cpx, clinopyroxene (diopside solid solution); Gar, garnet; Ky,
kyanite; PI, plagioclase; Qz, quartz.
226
CAENEGIE INSTITUTION
diopside-anorthite-albite is not ternary
and is not a thermal barrier between
silica-saturated and silica-undersatu-
rated compositions at 1 atm nor at high
pressures.
Stability Field of Iron -Free Pigeonite
in the System MgSi03-CaMgSi206
/. Kushiro and H. S. Yoder, Jr.
Iron-free "pigeonite" has been syn-
thesized on the join diopside-enstatite at
20 kb, and its stability field at 20 kb has
been outlined (Kushiro, Year Book 67,
pp. 80-83; 1969). Since pigeonite occurs
in igneous rocks crystallized on or near
the surface of the earth's crust, it is im-
portant to understand the stability field
of pigeonite at lower pressures. There-
fore, additional experiments have been
undertaken to determine the stability
field of iron-free "pigeonite" at lower
pressures. The starting materials used in
the present experiments were several dif-
ferent crystalline mixtures and glass of
the composition Di20En80 (wt %) whose
Ca/(Ca + Mg) atomic ratio is very close
to the Ca/(Ca + Mg + Fe2+) ratios of
natural pigeonites. In the previous ex-
periments a mixture of this composition
was crystallized to a single-phase pi-
geonitic clinopyroxene at 1630°C and
20 kb. In the present experiments a solid-
media, piston-cylinder apparatus was
used for the runs at pressures higher than
10.5 kb and a gas-media, internally
heated apparatus for those at and below
10 kb. The gas-media apparatus is con-
sidered to generate hydrostatic pressure,
whereas the piston-cylinder apparatus
has some shearing effects.
The experimental results are shown in
the pressure-temperature diagram (Fig.
18). The boundary between the field of
a single-phase pigeonitic clinopyroxene
and that of orthoenstatite solid solution
+ pigeonitic clinopyroxene for the com-
position Di20En80 is about 1540°C at
20 kb, about 1480°C at 15 kb, and about
1430°C at 12.5 kb. The lower stability
limit of the pigeonitic clinopyroxene,
which is more important, may be a little
below 1480°C at 20 kb, about 1450°C at
17.5 kb, and a little above 1400 °C at
12.5 kb. At 17.5 and 20 kb, the amount
or orthoenstatite solid solution relative
to that of pigeonitic clinopyroxene in the
Pig + Enss field decreases with increasing
temperature. These relations are inter-
preted in a schematic diagram of the
enstatite-rich part of the join diopside-
enstatite at 17.5 kb (Fig. 19).
At and below 10 kb, three or four
different starting materials were used in
a single run. Many of the results are
different for different starting material,
and they are described below in more
detail. At 10 kb, clinoenstatite and di-
opside solid solutions were not reacted
but converted to a mixture of ortho-
enstatite and diopside solid solutions,
held for 4 hours at 1350° and 1375°C
and for 2 hours at 1400° and 1425 °C.
Orthoenstatite solid solution grew from
a single-phase pigeonitic clinopyroxene,
and glass was crystallized to orthoensta-
tite and diopside solid solutions at 1350°
and 1375 °C. The results indicate that
pigeonitic clinopyroxene is not stable
but orthoenstatite and diopside solid
solutions are stable at 1350° and 1375°C
at 10 kb. At 1450 °C, neither the mixtures
of clinoenstatite and diopside solid solu-
tions nor orthoenstatite and diopside
solid solutions were reacted, and mixtures
of orthoenstatite and diopside solid solu-
tions were obtained in the 4-hour run;
however, glass was crystallized into a
single-phase pigeonitic clinopyroxene
under the same conditions. The tempera-
tures at least above 1400 °C would be in
the stability field of pigeonitic clino-
pyroxene at 10 kb if the stability field
determined at pressures higher than
12.5 kb can be extrapolated to 10 kb.
Therefore, three runs made on the crys-
talline mixtures at 1400°, 1425°, and
1450 °C do not agree with the phase
relations determined at higher pressures,
although the runs made on glass at
1350°, 1375°, and 1450°C are consistent
with those at higher pressure. In the
GEOPHYSICAL LABORATORY
227
1600
1500
1400
p 1300
1200
MOO
1000
i i i
i 1 1 1 1 1 i 1 r
So'
,\\<^
Pig
^ ap,g+Enss3
En« + D
SS ' ^'SS
rss 7
10
15
Pressure, Kb
20
Fig. 18. Pressure-temperature plane for composition DisoEnso (wt '%). Abbreviations: Pig,
pigeonitic clinopyroxene ; Di88, diopside solid solution; Enss, orthoenstatite solid solution; L,
liquid; Pr88, protoenstatite solid solution. Symbols: solid square, Pig formed from Enss + Diss or
clinoenstatitess + Diss; half-solid square, Pig -f- Ens8 formed from Ens8 + Diss or clinoenstatite8s
+ Dis8; shaded square, Pig unchanged; half -shaded square, Pig + EnS8 formed from Pig; square
with vertical line, Ens8 + Di88 formed from clinoenstatiteS8 + Di88; open square, Ens8 + DiS8
formed from Pig; square with diagonal line, run that is not satisfactorily interpreted (see text).
Dashed line A-A' is the lower stability limit of pigeonite (Woi.eEnio.i-Fssi.T mole '%) determined
by Brown (Year Book 66, pp. 347-353).
solid-media apparatus, orthoenstatite
and diopside solid solutions were reacted
to form a single-phase pigeonitic clino-
pyroxene at 10.5 kb and 1450°C in the
3 -hour run, whereas they were not re-
acted at 10 kb and 1450 °C in the 4-hour
run made with the gas-media apparatus.
The discrepancy between the results ob-
tained by the gas-media and the solid-
media apparatus suggests that the non-
hydrostatic pressure in the solid-media
apparatus stabilizes the pigeonitic clino-
pyroxene in wider P-T ranges or the re-
action rate is greater in the solid-media
apparatus than in the gas-media ap-
paratus.
At 5 kb and 1375°C, a mixture of
orthoenstatite and diopside solid solu-
tions was reacted to form orthoenstatite
solid solution and pigeonitic clinopyrox-
ene, and glass crystallized to pigeonitic
clinopyroxene in the 6-hour run. These
results indicate that the composition
Di2oEn80 is in the field of pigeonitic
clinopyroxene or of pigeonitic clino-
pyroxene + orthoenstatite solid solution
at 1375 °C. At 1325 °C, glass was crystal-
lized to pigeonitic clinopyroxene, and
228
CARNEGIE INSTITUTION
600
o3 1500
CD
CD
E
,<u 1400
1300
MgSi03 10 20 30
Weight per cent CaMgSizOe
Fig. 19. Schematic diagram showing the phase relations for composition Di20En8o (wt %) at
17.5 kb. Abbreviations as in Fig. 18.
pigeonitic clinopyroxene was unchanged ;
however, a mixture of clinoenstatite and
diopside solid solutions was converted to
a mixture of orthoenstatite and diopside
solid solutions in the 24-hour run. These
results are ambiguous, presumably be-
cause of the different starting materials.
The results obtained from glass and
pigeonitic clinopyroxene suggest the sta-
bility of pigeonitic clinopyroxene at
1325 °C, but the result obtained from the
mixture of clinoenstatite and diopside
solid solutions fails to confirm this pos-
sibility. This same problem is encoun-
tered at 10 kb and 1450°C. At 2 kb, the
results obtained at 1300° and 1250°C
are nearly the same as those obtained at
5 kb and 1325°C. These results strongly
suggest that the reaction rates, particu-
larly those of the homogenization of two
pyroxenes and the breakdown of a single
pyroxene, are very slow at relatively low
pressures and temperatures.
Although there are problems with re-
action rates and a discrepancy in the re-
sults between the solid-media and gas-
media apparatus, the present experiments
indicate that the stability field of pi-
geonitic clinopyroxene exists near the
composition Di2oEn80 in the pressure
range at least between 20 and 5 kb
and near the solidus temperatures. It is
likely that the stability field of pigeonitic
clinopyroxene extends to lower pressures
and possibly to 1 atm. At pressures lower
than 2 kb, however, the field of proto-
enstatite solid solution may appear even
near the composition Di20En80 and the
phase relations may be more complicated.
In the iron-bearing system the stability
field of pigeonite will be more easily de-
termined because of a more favorable
reaction rate. For the compositions Wo7.6
En40.7Fs51.7 (mole %), Brown (Year
Book 66, pp. 347-353) determined the
lower stability limit of pigeonite in the
GEOPHYSICAL LABORATORY
229
pressure range 1 atm to 20 kb, shown
for comparison in Fig. 18. Comparison
of the present results and those of Brown
suggests that the lower stability limit of
pigeonite drops about 300 °C from the
iron-free composition to the composition
having the ratio Fe/(Mg + Fe) =0.56 in
the pressure range from near 1 atm to
20 kb. It should be mentioned that
temperatures of basaltic and andesitic
magmas (1250°-1100°C) are between
the lower stability limit of pigeonite esti-
mated in the iron-free system and that
in the ratio Fe/(Mg + Fe) =0.56 at pres-
sures lower than 5 kb. The evidence that
the natural pigeonites have Fe2+/(Mg +
Fe2+) ratios larger than 0.3 can be ex-
plained by the magma temperatures
crossing the lower stability limit of pi-
geonite at the Fe2+/(Mg+Fe2+) ratio
near 0.3, as first suggested by Hess
(1941).
Stability of Iron -Rich Orthopyroxene
Douglas Smith
Orthopyroxene occurs in most rocks
instead of the compositionally equiva-
lent assemblage of olivine + quartz. In
rocks with high Fe/Mg ratios, however,
the assemblage olivine + quartz is more
common than orthopyroxene. The iron
end member of the orthopyroxene series,
ferrosilite, was shown to be stable at
high pressures relative to fayalite and
quartz by Lindsley, MacGregor, and
Davis {Year Book 63, pp. 174-176) and
by Akimoto, Fujisawa, and Katsura
(1964). The purposes of this investiga-
tion were (1) to establish limits of ortho-
pyroxene stability as a function of pres-
sure and composition for possible use as
a barometer for rocks of crustal origin
and (2) to provide a basis for subsolidus
investigations in the iron-rich portion
of the pyroxene quadrilateral. The only
previous comprehensive investigation of
the relative stabilities of orthopyroxene
and olivine in the system FeO-MgO-Si02
was made by Bowen and Schairer
(1935) ; experimental limitations at that
time precluded studies with iron-rich
synthetic phases at temperatures much
below 1000°C.
The relative stabilities of these min-
erals were investigated over a range of
pressures and temperatures. Either or-
thopyroxene or olivine + silica was used
as a starting material for each experi-
ment. Equimolar mixtures of silica and
olivine of the desired compositions were
made from oxide mixes in evacuated
silica glass tubes and in controlled gas
mixtures. Silica was present as glass,
quartz, and tridymite in various starting
materials. Orthopyroxenes were synthe-
sized at 20 kb from mixtures of olivine +
silica in a large volume, piston-cylinder
apparatus. All hydrothermal runs were
conducted in the presence of excess silica,
added to saturate the fluid phase.
The experimental results shown in Fig.
20 clearly establish that the most iron-
rich orthopyroxene stable at tempera-
tures of 800° to 950 °C and pressures of
0.3 to 1 kb is more magnesian than
En25Fs75. The results suggest that the
actual composition of the most iron-rich
orthopyroxene stable under these condi-
tions is close to En30Fs70. In runs at
1000 °C in evacuated silica glass tubes,
orthopyroxenes of compositions En30Fs7o
and En25Fs75 broke down to yield ortho-
pyroxene, olivine, silica, and minor mul-
tiply twinned clinopyroxene in the
quench product. The clinopyroxene pre-
sumably inverted from a proto form
(Boyd and Schairer, 1964, p. 297).
In hydrothermal experiments at 1 kb
and 800°C, olivine (Fo2oFa8o) reacted
with silica to form some orthopyroxene,
whereas orthopyroxene (En20Fs80) par-
tially broke down to olivine and silica.
These results establish a point in the
three-phase field orthopyroxene-olivine-
silica in the system FeO-MgO-Si02. The
hydrothermal experiments at 800 °C in
which olivine reacted with silica lasted
about 80 days. In contrast, the hydro-
thermal experiments at 900° and 950 °C
lasted only a few days, and olivine as
magnesian as Fo35Fa65 failed to react
230
CARNEGIE INSTITUTION
1000°-
o
o
CD
Z5
a
a3
cl
E
,15
950(
900°-
850c
800°-
□ opx, no reaction
EH opx— »opx + oH-Si02
BB opx^ ol +Si02
• 0I + S1O2 no reaction
3 0H-S1O2— ^ opx+ ol -hSi02
□
CD
9
\
\
9
CM
opx
o '
opx +
+ Si02
□
m
ol 4-SJ02
[■■'
• 1
0.6
0.7 0.8
Fe/(Fe + Mg) —
Mole proportions
0.9
1.0
Fig. 20. Experimental results on orthopyroxene and on olivine plus quartz at low pressures. The
brackets by the temperature axis of the figure indicate that the plotted experiments were con-
ducted at 800°, 900°, 950°, and 1000°C, not at temperatures slightly above and below these values.
Hydrothermal experiments at 800°C were conducted at 1 kb, and those at 900° and 950°C were
conducted at 0.3 kb. Experiments at 1000 °C were performed in evacuated silica-glass tubes. The
amount of shading is approximately proportional to the amount of olivine + silica in the reaction
products. The quartz-tridymite inversion and the inversion of orthopyroxene to a proto form
have been ignored in drawing this diagram.
with silica during these time periods.
Likewise, olivine and silica failed to re-
act in evacuated tube experiments at
1000°C. Medaris (1969) has studied the
partition of Fe and Mg between coexist-
ing orthopyroxene and olivine at tem-
peratures from 700° to 900°C. The Fe/
(Fe + Mg) ratios of the two phases co-
existing with silica should lie on the
boundaries of the three-phase field as
drawn in Fig. 20. The studies of Medaris
show that the field (Fig. 20) should ex-
tend over an interval of Fe/ (Fe + Mg)
of about 0.1. Further experiments are
being carried out to define more pre-
cisely the position of the three-phase
field.
Experiments at high pressure at 900 °C
(Fig. 21) bracket at least part of the
three-phase field orthopyroxene-olivine-
silica within the pressure interval 10 to
11 kb for a bulk composition with Fe/
(Fe + Mg) =0.9 and within the interval
12 to 13 kb for Fe/ (Fe + Mg) =0.95. At
GEOPHYSICAL LABORATORY
231
900°C
opx
/
/
/
ol+Si02
V
0.8 0.9 1.0
Fe/(Fe + Mg)— >
Fig. 21. Experimental results on orthopyrox-
ene and on olivine + quartz at 900° C and
high pressures. Symbols are the same as in
Fig. 20.
900°C, pure orthorhombic ferrosilite was
found to be stable above 14.5 kb. These
experiments were conducted in a solid-
media piston-cylinder apparatus by the
modified piston-out procedure of Rich-
ardson, Bell, and Gilbert (1968, p. 517),
and nominal, uncorrected pressures are
reported here.
The experimental results establish that
the most iron-rich orthopyroxene stable
from 800° to 950 °C at pressures lower
than 1 kb is somewhat more magnesian
than En25Fs75. This value contrasts with
the limit of about En15Fs85 suggested by
Bowen and Schairer (1935, Fig. 8). The
present results also show that with in-
creasing pressure, orthopyroxenes of
progressively greater iron enrichment be-
come stable, pure ferrosilite being stable
at 900°C above 14.5 kb. Natural ortho-
pyroxenes more iron-rich than En25Fs75
have been described (e.g., Henry, 1935;
Kuno, 1954). Some such orthopyroxenes
may have been stabilized by the presence
of minor elements like calcium and
manganese. Some may have formed at
low pressure but at temperatures con-
siderably below 800 °C in a possible low-
temperature expansion of the ortho-
pyroxene field. Others may have been
stabilized by high pressure. For instance,
Wheeler (1965) described an olivine
adamellite with complex intergrowths of
calcic pyroxene, orthopyroxene, fayalitic
olivine, and quartz in which the oli-
vine and quartz apparently formed
by the breakdown of orthopyroxene.
Lindsley and Munoz (1969, p. 319) sug-
gested that the orthopyroxene was ini-
tially stabilized by pressure. In this and
other instances, the presence of high-iron
orthopyroxene may serve as a useful
geobarometer. At a given temperature
and neglecting minor elements, the com-
position of orthopyroxene in the three-
phase assemblage orthopyroxene-olivine-
quartz uniquely characterizes the pres-
sure of equilibration. The occurrence of
iron-rich orthopyroxene alone may be
useful in establishing a minimum pres-
sure of formation if the temperature can
be estimated by other means.
Stability of Potassic Richterite
/. Kushiro and A. J. Erlank*
The occurrence of potassic richterite,
a member of the alkali amphiboles, in a
diopside-phlogopite nodule in the Wes-
selton kimberlite pipe, South Africa, is
described in the preceding section. This
discovery suggests that potassic richterite
is a possible amphibole in the upper
mantle. To examine this possibility, pre-
liminary experiments have been con-
ducted on the stability of potassic rich-
terite at high pressures.
The starting material was a potassic
richterite from a leucite lamprophyre
from Wolgidee, Australia, collected by
B. Mason. Partial analysis (Table 17)
shows that it is similar in composition to
that described originally by Wade and
Prider (1940). The chemical composi-
tion of this richterite indicates that its
chemical formula is close to KNaCa-
(Mg,Fe,Ti)5Si8022(OH)2. Mixtures of
this richterite and synthetic minerals
were also used. The experiments were
conducted in solid-media, piston-cylinder
apparatus in sealed Pt capsules with
water contents varying from 4.7 to 10.5
wt %.
* Department of Terrestrial Magnetism.
232
CARNEGIE INSTITUTION
TABLE 17. Partial Analyses of Potassic
Richterites by Electron Microprobe
1
2
3
4
3.0
Core
Rim
0.5
Core
3.0
Rim
0.6
Ti02
32
0.6
MgO
21.3
22.0
23.7
21.5
23.6
21.2
CaO
6.9
7.3
8.8
7.1
7.8
7.1
Na20
3.6
3.6
3.0
3.5
3.3
3.2
K20
5.6
5.6
4.6
5.7
5.0
4.7
1. Potassic richterite, starting material. Lo-
cality : Wolgidee, Australia.
2. Potassic richterite run at 30 kb, 1000°C,
3 hours.
3. Potassic richterite run at 30 kb, 1100°C,
2% hours.
4. Potassic richterite, average of three grains,
mica nodule, Wesselton kimberlite pipe, South
Africa.
Potassic richterite in the runs at 30 kb,
1100°, and 1000°C, showed euhedral-
subhedral crystals and appeared to have
been well recrystallized. Very small
amounts of rutile and very fine-grained
unidentified granular crystals were ob-
served with the richterite. Some rela-
tively large richterite crystals had cores,
which were slightly different in color
and refractive indices from the marginal
parts of the crystals. The cores would
represent the original richterite, sur-
rounded by the newly recrystallized
richterite. These features suggested that
electron-probe analysis of the products
of these two runs would be worthwhile.
Partial analyses of a few of the larger
grains of this material, of the starting
material, and of the Wesselton richterite
described previously are given in Table
17. Analyses 1, 2, and 3 have not been
corrected for matrix interference effects,
as in the case of analysis 4. Because of
the overall similarity of these materials,
however, the trends shown in Table 17
are relatively accurate. It is clear from
the analyses that the cores of the richter-
ites in the runs at 1000° and 1100°C are
similar to the starting material and the
rims of these materials differ in composi-
tion, supporting the recrystallization
process. The marked decrease in Ti02 in
the rim is readily accounted for by the
presence of rutile in the reaction prod-
ucts. The slight depletion in Na20 and
K20 is presumably related to solution in
the vapor phase, whereas the increase in
the CaO and MgO contents is simply a
reflection of the above-mentioned de-
creases in concentration. Our second ob-
servation concerns the similarity in com-
position between the analyzed rims
(recrystallized potassic richterites) and
the potassic richterite found in the Wes-
selton kimberlite nodule. In particular
the similarity in the low Ti02 contents is
striking. Because the original Ti02-rich
richterite is believed to have formed at
very low pressures, it appears that the
Ti02 content of potassic richterite de-
pends on pressure as well as bulk chemi-
cal composition.
In the run on the 1:1 mixture (by
weight) of the richterite and pure diop-
side at 24 kb and 1000°C, richterite and
diopside were well recrystallized and no
other phases were observed after the run.
These results indicate that, under water-
saturated conditions, potassic richterite
would be stable at least at 30 kb at
1100° and 1000°C and at least at 24 kb
and 1000°C in the presence of diopside.
In the run on the 2:1 mixture by weight
of the richterite and the mixture of
garnet composition (pyrope 2 grossular
1, by mole) at 20 kb and 1000°C, a con-
siderable amount of phlogopite was crys-
tallized and the assemblage was phlogo-
pite + clinopyroxene + richterite. It is
evident that potassic richterite and a mix-
ture of garnet composition reacted to
form phlogopite. In the event of com-
plete reaction, the simplified process
may be as follows.
KNaCaMg5Si8022 (OH) 2 + CaMg2Al2Si3012 =
potassic richterite pyrope 2 grossular 1
KMg3 AlSi3O10 (OH) 2 + 2CaMgSi206 • NaAlSi206 + 3MgSiOs
phlogopite omphacite enstatite
GEOPHYSICAL LABORATORY
233
Part or all of enstatite may be dissolved
in omphacite to make a complex clino-
pyroxene solid solution. In the present
experiment the mole ratio of potassic
richterite and garnet is nearly 1:1;
potassic richterite is still present after
the run, however, probably because of
incomplete reaction or the effect of solid
solution. Because of the fine-grained
nature of the products, electron-probe
analysis was not successful in determin-
ing in detail the compositions of pyroxene
phases. The present experiment suggests
that in the presence of garnet, potassic
richterite reacts to form phlogopite and
clinopyroxene or clinopyroxene + ortho-
pyroxene. In the presence of spinel, po-
tassic richterite may also react to form
phlogopite, clinopyroxene, and forsterite.
Potassic richterite and Ca-Tschermak's
pyroxene component are also isochemical
with phlogopite + omphacite. The phlog-
opite+diopside assemblage is stable in a
wide pressure range, as shown elsewhere
in this report, and the phlogopite + clino-
pyroxene (omphacite) assemblage would
also be stable in a wide pressure range.
It is suggested, therefore, that potassic
richterite is not stable in the presence of
garnet, spinel, or aluminous pyroxenes.
The alumina content of diopside from
the Wesselton nodule is only 0.71 wt %.
To conclude, potassic richterite would
not be expected to occur in eclogites and
garnet- or spinel-bearing peridotites un-
der equilibrium conditions. To the best of
our knowledge it has not been found in
rocks of this type occurring in kimber-
lite. Potassic richterite may, however, oc-
cur in alumina-poor pyroxenites and
peridotites or in the rocks in which K is
in excess over Al and is still present after
forming phlogopite and/or other potas-
sium minerals (e.g., K-feldspar and
leucite). The occurrence of potassic
richterite in the Wesselton nodule is ex-
plained by the presence of excess K over
Al.
Potassium Contents of Synthetic
Pyroxenes at High Temperatures
and Pressures
A. J. Erlank * and I. Kushiro
Electron-probe analyses of presumed
upper-mantle materials, in particular
kimberlite nodules, have revealed that
olivines, garnets, and orthopyroxenes in
general contain <30 ppm potassium and
hence do not play an important role in
the distribution of potassium in the
upper mantle. The K content of clino-
pyroxenes is considerably larger and is
crucial when considering the production
of basaltic liquids with K contents vary-
ing from 0.05 to 1.5%.
Garnet peridotites, such as those found
in kimberlites, are often assumed to be
the dominant rock type present in the
upper mantle. Chrome diopsides from
these nodules generally contain on the
order of 100 ppm K or less. The highest
concentrations measured to date by elec-
tron-probe analysis have been observed
in two subcalcic diopsides (Boyd, Year
Book 66, pp. 331-334) ; concentrations of
280 and 340 ppm K in these two pyrox-
enes have been measured in this study.
Even allowing for 15% modal abundance
for diopsides in garnet peridotite, the
K content of the resultant assemblage
does not satisfactorily account for the
high K contents of alkali basalts, pro-
vided at least 1% direct partial melting
is involved in the production of the
basalt.
Potassium contents of eclogitic ompha-
cites from African kimberlites are more
difficult to interpret. Electron-probe
analyses given elsewhere in this report
demonstrate that the K distribution of
omphacites is apparently bimodal, with
some containing 20-150 ppm K and
others 800-1400 ppm K. The comments
expressed above with respect to the diop-
sides obviously apply to the low K
omphacites. The K content of the second
group is larger than expected, however,
* Department of Terrestrial Magnetism.
234
CARNEGIE INSTITUTION
and is difficult to explain on crystal-
chemical grounds. It is clear that the
presence of clinopyroxene with K con-
tents of this order as an upper-mantle
phase would be important for controlling
the distribution of K in basaltic liquids.
Hence, it appeared desirable to seek con-
firmation for this feature.
We have attempted to determine ex-
perimentally the amount of K that could
enter the clinopyroxene structure under
upper-mantle conditions by reacting
together, at high temperatures and pres-
sures, various clinopyroxenes and potas-
sium-rich phases and measuring the
potassium content of the resultant pyrox-
enes by electron-probe analysis. The
experiments were made in the pressure
range 15 to 32 kb with a piston-cylinder
type apparatus similar to that designed
by Boyd and England (1960). Sealed Pt
tubes were used for the hydrous runs. The
starting materials are mechanical mix-
tures of the following materials: syn-
thetic pure diopside made by Hytonen
and Schairer; a mixture of phlogopite
composition consisting of forsterite,
quench forsterite, and glass; a mixture
crystallized at 1 atm from a glass of
composition anorthite 50 forsterite 50
(mole %) ; a natural omphacite from
Kaminaljuyu, Guatemala, originally de-
scribed by Foshag (1957) , with a compo-
sition close to diopside 45 jadeite 55
(mole %) (Clark and Papike, 1968);
and a natural potassic richterite from
Wolgidee, Australia, which is similar in
composition to that analyzed by Wade
and Prider (1940) and is described else-
where in this report (see Table 17, No. 1) .
In all the hydrous runs, diopside and
omphacite were recrystallized to eu-
hedral or subhedral crystals even at sub-
solidus temperatures. During the elec-
tron-probe analysis for K the other two
spectrometers were set for Ca and Mg,
and comparison of the starting materials
and reactants indicated the recrystalliza-
tion of the clinopyroxenes. Additional
measurements for Na also revealed the
nature of the pyroxenes formed. Phlogo-
pite occurs as hexagonal plates forming
thick books; when glass is present, how-
ever, it often appears as feathery crys-
tals, believed to be quench crystals.
Richterite that had been ground finely
was also recrystallized to relatively large,
euhedral or subhedral crystals. Because
of recrystallization in the presence of ex-
cess vapor, equilibrium is believed to have
been attained in the hydrous runs. In the
anhydrous run made for the 1 : 1 mixture
of diopside and phlogopite composition,
the temperature was raised above the
solidus to secure equilibrium.
A great deal of difficulty has been ex-
perienced in making the electron-probe
measurements. The small size of the re-
action products necessitated the use of a
1-2 fim electron beam and low sample
current (0.025 ^a), with resultant low
intensity. The main problem has, how-
ever, been caused by the presence of
minute inclusions and intergrowths of
these crystals with K-rich phases (phlog-
opite and glass), frequently resulting
in anomalously high K contents for ap-
parently clear clinopyroxene grains. Con-
sequently several runs have been dis-
carded, and only those measurements in
which a fair amount of consistency has
been established are reported here. Par-
ticular care has been taken in making
background measurements, often by
using the pure starting materials, which
were always mounted together with the
reaction products. It is to be noted that
the results have been corrected only for
background and drift, but it is believed
that they are accurate to within 10-20%
of their true values; this level of ac-
curacy is adequate for present purposes.
A detailed account of the technique used
will be given elsewhere.
The assembled data are listed in Table
18. It is immediately apparent that re-
gardless of variation in mineral assem-
blage, temperature, pressure, and water
content, the amount of K that has en-
tered the clinopyroxene reaction prod-
ucts is small, <150 ppm. Even where
clinopyroxene has crystallized directly
GEOPHYSICAL LABORATORY
235
TABLE 18. Potassium Contents of Synthetic Clinopyroxenes and Garnets
K in Clino-
Duration,
H20
pyroxene,
Reactants
P,kb
T,°C
hours
%
Products
ppm
Di + AnhyPhl(l:l)
15
1100
4
11.4
Di, Fo, Phi, Gl, gl
140
30.5
1150
3%
13.1
Di, Fo, Phi, Gl, gl
90
32
1000
4
4.6
Di, Phi, gl
70
21
1450
2%
Di, Fo, Gl
140
Omph + Anhy Phi (1:1)
25
1000
5y6
5.6
Omph, Phi
110
(2:1)
25
1000
6
40.0
Cpx, Phi, Fo, gl
50
(1:1)
26.5
1050
4
7.4
Cpx, Phi, Gl
<50
30
1100
3
22.2
Cpx, Fo, Phi, gl
50
Rich + AniFoi (2:1)
20
1000
3
4.7
Rich, Phi, Cpx
120
Rich + Di (1:1)
24
1000
2
10.4
Rich, Cpx
<50
K in garnet,
30
1100
3
12.6
Gt, Cpx, Phi
ppm
AnhyPhl + AniFoi(l:4)
<50
Phi*
70
1500
%
Gt,Phl,q-Phl,X
<100
* Run prepared by Kushiro, Syono, and Akimoto (1967).
Abbreviations: Di, diopside; Anhy Phi, anhydrous phlogopite composition; Phi, phlogopite;
Fo, forsterite; Gl, glass; gl, glass balls considered to be quenched vapor; Omph, omphacite; Cpx,
clinopyroxene solid solution; Rich, potassic richterite; Gt, garnet; AniFd, crystalline mixture
of anorthite and forsterite (1:1 by mole) = pyrope-grossular (2:1 by mole); q-Phl, quench
phlogopite; X, unknown phase.
from liquid under anhydrous conditions
and in the absence of phlogopite, nearly
all the K has remained in the liquid, as
measured by the K content of ~13% in
the glass. At this stage it is not clear to
what extent variations in temperature,
pressure, and sodium content affect the
substitution of potassium. These re-
sults seem in accord with the natural
diopsides and low K omphacites previ-
ously discussed, and no experimental
evidence has been found to explain
the presence of 1000-1500 ppm K in
omphacite. The most likely explana-
tion appears to be that these high K
contents are due to the presence of sub-
microscopic intergrowths of amphibole
in the omphacite structure, as suggested
by J. J. Papike (personal communica-
tion, 1968) on the basis of X-ray studies.
This possibility has important implica-
tions regarding the genesis of eclogites
and basaltic lavas, and requires further
confirmation. In the runs with amphibole
and pyroxene no reaction has occurred
between these minerals.
Also given in Table 18 are measure-
ments made on garnets produced in two
runs. Potassium was not detected in
either one. One of the runs had previ-
ously been analyzed with an electron
probe, and up to 5.8% K was reported
in the garnets (Kushiro, Syono, and
Akimoto, 19676). The original electron-
probe section was available, and further
study showed that the earlier analysis
was in error. The discrepancy is most
likely due to the beam overlapping high
K mica in the original analysis. During
the analysis of this section, one of the
breakdown products of phlogopite was
found to have a very high potassium con-
tent (phase X in Table 18) . Semiquanti-
tative analysis indicates that this phase
has on the order of 29% K20 and 32%
MgO but an anomalously low Si02 con-
tent of 1% or less. Unfortunately, the
fine-grained nature of this phase and
poor surface of the section prevented
proper analysis, and it is not possible at
this stage to identify this phase. It seems
clear that clinopyroxenes and garnets
will not accept sufficient potassium in
their structures, even at high tempera-
tures and pressures, to provide that re-
quired to form basalt by simple partial
236
CARNEGIE INSTITUTION
melting. In this case, the rocks that are
parental to basalt must contain potas-
sium-rich phases such as phlogopite
and/or K-rich amphibole.
HYDROUS SYSTEMS
Phlogopite-H20-C02: An Example of
the multicomponent gas problem
H. S. Yoder, Jr.
The study of phlogopite-H20 by Yoder
and Kushiro (1969) revealed extensions
of the stability field of phlogopite in the
absence of a gas phase and documented
the existence of new melting relationships
of hydrous phases where gas is absent.
It was suggested that melting in the
mantle was best approximated by gas-
absent conditions rather than gas-present
conditions because of the belief that the
H20 content of the mantle was very
small and was mainly in hydrous min-
erals.
Many rocks contain other potentially
gaseous components in addition to water,
and it is pertinent to investigate the
effects of these components on the melt-
ing behavior of hydrous minerals. For
example, excluding those minerals in
rock fragments adventitiously incorpo-
rated, the rock kimberlite consists pri-
marily of olivine, phlogopite, and cal-
cite. The presence of the latter two
minerals implies H20 and C02 in the
magma if such existed. Inclusions in
olivine from some nodules in kimberlite
contain both liquid and gaseous C02, as
well as H20 (Roedder, 1965, p. 1760,
1764). The effect of C02 on the melting
of phlogopite is, therefore, relevant to
the general problem of melting under
conditions where the H20 pressure is less
than the total pressure.
Phlogopite-H20
The join K20-6MgO-Al203-6Si02-
H20 was first restudied in the more
H20-rich compositions (Fig. 22), follow-
ing the experimental procedures of Yoder
and Kushiro (1969). The boundary be-
tween the forsterite (Fo) + liquid (L) +
gas (G) region and the Fo + G region
was delineated for P = 10 kb and T =
1225 °C. The criterion was the presence
or absence of interstitial glass, which was
presumed to represent in part the more
siliceous liquid phase distinct from glass
spheres believed to represent a portion
of the less siliceous gas phase. The rela-
tions deduced from these data are shown
in projection on the plane leucite:kalsi-
lite (1:1 mole)-forsterite-H20. Only the
gas compositions in the G region are be-
lieved to lie on the plane. The ratio of
dissolved silicate to H20 in the less
siliceous gas in the Fo+L + G region ap-
pears to be about 1 : 1 by weight, whereas
the ratio of silicate to water in the more
siliceous liquid phase was previously de-
termined to be about 4:1. Partial con-
firmation of the H20 content of the more
siliceous liquid is obtained from an ex-
amination of the inclusions in the larger
forsterite crystals. Several types of in-
clusions were observed, which contained
the following phases after quenching to
room temperature and an undetermined
pressure.
Most of the inclusions consisted of a
glass with a very low index of refraction,
containing a globule of liquid in which
was suspended a small gas bubble in
constant thermal motion. The relations
in an exceptionally symmetrical inclu-
sion from the Fo + L + G region are
shown in the photograph of Plate 1A. As-
suming that the inclusion is circular in
cross-section, was entrapped at the con-
ditions of the experimental run, and is
solely representative of the total fluid
phase, the volume proportions of silicate
to H20 can be calculated, neglecting
mutual solubility at containment condi-
tions and diffusion through the forsterite
crystal. The silicate :H20 is approxi-
mately 56:44 by volume and is approxi-
mately 74:26 by weight. In the light of
the large possible errors, the agreement
with the composition of the more silice-
ous liquid phase estimated by construc-
tion is surprising.
GEOPHYSICAL LABORATORY
237
P=IOKb
T=I225°C
I Mol
Fo+Ks+Lc+L
PHLOGOPITE'
Weight per cent
Fo
Fig. 22. The join phlogopite-H20 in the pseudoternary section Fo-H20-Lc:Ks (1:1 mole) at
1225°C and 10 kb. Fo, forsterite; Ks, kalsilite; Lc, leucite; Ph, phlogopite; G, gas; L, liquid.
A second type of inclusion consisted of
minute (<1 /xm) spheres of water-rich
fluid having a gas bubble in constant
thermal motion. Glass may coat the in-
side of the sphere, but it was not resolved
optically with certainty. This type of in-
clusion is presumed to be related to the
gas phase; the proportions of its present
constituents, however, seem to be at
variance with the inferred gas composi-
tion. A third rare type consisted of glass,
having a very low index of refraction
relative to the forsterite, with a minute
immobile bubble. It is believed to be
representative of the less siliceous gas
phase under the conditions of the run.
The inclusions in the forsterite in the
Fo + G region were usually less than
1 (xm in diameter. A few were about 2 /mi
in diameter and where resolvable ap-
peared to be a water solution with a
minute gas bubble in rapid thermal mo-
tion. The presence or absence of glass
could not be ascertained with certainty.
Phlogopite-H20-C02
Known amounts of carbon dioxide were
added to the K20-6MgO-Al203-6Si02-
H20 join by using (1) requisite amounts
of KHC03 with the remainder of the con-
stituents as glass or (2) synthetic sanidine
and a natural magnesite from Brazil.
Two compositional lines were studied by
adding various amounts of water to these
powders in platinum capsules sealed by
238
CARNEGIE INSTITUTION
welding. The resulting compositions run
at 1225 °C and 10 kb total pressure are
plotted in Fig. 23 along with those from
Fig. 22. The products in the two major
fields Fo + L + G and Ph + Fo + G will be
described. In the region Fo + L + G (Fig.
23) the products were euhedral to sub-
hedral forsterite, balls of glass having a
low, variable index of refraction, and
some quench mica, concentrated mainly
on the surface of the forsterite crystals.
The glass balls were considered to repre-
sent part of the gas phase. No glass was
observed that could be attributed to the
liquid phase with certainty; the evidence
provided by the inclusions in forsterite
described immediately below, however,
indicates the presence of a liquid phase
during the run. The variation of index of
refraction of the glass balls (due to diffu-
sion of water out of the balls during and
after quench) does not preclude the pos-
sibility that some of the glass balls may
in fact represent liquid. On the other
hand, supercritical phenomena may be
involved where liquid and gas are no
longer distinguishable. The forsterite
contained a variety of inclusions, usually
less than 2 ^m and rarely reaching 10 /mi
on the longest dimension. Most consisted
of a liquid with a minute gas bubble
in rapid motion. Glass may coat the in-
side of the inclusion, and it is presumed
that the C02 is in solution in the liquid or
forms a thin invisible film of liquid C02
on the surface of the gas bubble. Rarely
Phlogopite A B
K20-6Mg0AI2036Si02
Fo + L
Weight per cent
H20
Fig. 23. The section K2O6Mg0 -AUVGSiCVEUO-COa showing the compositions studied along
three compositional joins. Points A-D are also illustrated in Fig. 22.
GEOPHYSICAL LABORATORY
239
a liquid (mainly H20) inclusion was ob-
served, containing a slowly moving large
bubble of another liquid (mainly C02)
which in turn contained a minute gas
bubble (mainly C02) in rapid motion.
Again, glass is assumed to coat the inside
of the inclusion. Some inclusions con-
sisted of glass with a liquid bubble
(mainly H20) of moderate size (Plate
IB). The existence of these latter types
of inclusion is taken as evidence that a
liquid phase existed during the run, and
the two former types of inclusion are
taken as variant representatives of the
gas phase.
In the region Ph + Fo + G (Fig. 23) the
phases observed were faceted phlogopite
(Ph) , anhedral forsterite (Fo) , and skins
of glass of low index of refraction, giving
way to glass balls as the H20 content of
the run increased to the boundary phlo-
gopite-Z£. The glass skins and balls are
interpreted as part of the gas (G) phase.
The forsterite crystals contained minute
inclusions, usually irresolvable in char-
acter, diminishing in number with de-
creasing H20 content of the run. Where
resolvable they consisted of glass with
a minute immobile gas bubble or glass
with a large liquid bubble containing a
minute gas bubble in rapid motion. In
one run a spectacular display of rela-
tively large inclusions occurred in which
glass, often containing a faceted crystal,
held a liquid (mainly H20) having a
large bubble of another liquid (mainly
C02) and moving slowly under the heat
from the microscope illumination (Plate
1C). Phlogopite contained no discernible
inclusions, and many crj^stals of forster-
ite contained no inclusions (Plate ID).
Crystals of both minerals may be found
in glass inclusions (Plate IE) and appear
to be faceted. Complex combinations of
these inclusions were also observed
(Plate IF).
It was hoped that the study of the
inclusions would aid in defining the
nature of the fluid in both major assem-
blages. However, the wide variety of in-
clusions, the uncertainty of conditions
under which the inclusions were in-
corporated in the growing crystal, i.e.
during run-up or under the run condi-
tions, the heterogeneous distribution of
inclusions within and between crystals,
and the changing of the immediate
chemical environment about the growing
crystal cast doubts on interpretation.
Both forsterite and phlogopite grow ex-
ceptionally fast relative to other silicates
in the laboratory, and yet one commonly
entraps the surrounding fluid and the
other does not. These phenomena of crys-
tal growth preclude a definitive conclu-
sion on the character of the fluid phase
at the present state of knowledge. Simi-
lar difficulties arise from the interpre-
tation of the variety of some of the fluid
inclusions found in rocks from Ascension
Island (Roedder and Coombs, 1967).
The region between Fo + L + G and
Ph + Fo + G in Fig. 23 is presumed to
consist of Ph + Fo + L + G, one fluid being
relatively enriched in silicate components
and the other relatively enriched in
volatile components. Only two runs
yielded products that suggested two fluid
phases. There are too few data in the
H20-poor region to the left of the join
phlogopite-C02 to outline the various
fields. The assemblage Ph + Fo + Lc + G
was obtained where some H20 was ini-
tially present, and Fo + Ks-f-Lc was ob-
tained in the absence of H20. No data
were obtained in the Ph + Fo+L or
Fo+L region except in the absence of
C02.
The principal observation is the ex-
pansion of the stability region of phlogo-
pite in the presence of C02. Melting of
phlogopite appears to be suppressed be-
cause of the relative insolubility of C02
in the liquid in equilibrium with phlogo-
pite. Evaluation of these surprising re-
sults must await further study at other
temperatures and pressures. It is likely
that the proportions of C02:H20 in the
gas phase, determined herein to be about
1:4 at 1225°C and 10 kb, will change
rapidly with T and P. The assumption of
vapor-absent conditions in the mantle
240
CARNEGIE INSTITUTION
will have to be reexamined if C02 and
other gases relatively insoluble in sili-
cate magmas are present in appreciable
amounts. These factors also have im-
portant bearing on the genesis of dia-
mond in kimberlite pipes, on kimberlite
itself, and on the association of carbona-
tites with alkalic rocks.
Systems Bearing on Melting of the
Upper Mantle under Hydrous
Conditions
I. Kushiro
To understand the origin of magmas
formed in the upper mantle, it is im-
portant to evaluate the effect of water
on the liquidus relations of the systems
containing components present in upper-
mantle materials. Last year the liquidus
relations of the system forsterite-diop-
side-silica-H20 were studied at 20 kb
(Kushiro, Year Book 67, pp. 158-161).
The experiments have been extended to
the systems forsterite-nepheline-silica-
H20 and forsterite-CaAl2Si06-silica-H20,
which contain most of the major com-
ponents present in the suggested upper-
mantle materials.
The System Forsterite-Nepheline-Silica-
H20
Four compositions have been studied
in the system forsterite-nepheline-silica-
H20 to determine the liquidus boundary
between forsterite and enstatite solid
solution, since this boundary is most rele-
vant to the melting of the peridotitic
composition. The compositions of four
mixtures are shown by circles in Fig. 24.
The experiments were carried out in
the pressure range 17.5 to 30 kb with a
solid-media, piston-cylinder apparatus
similar to that designed by Boyd and
England (1960) and with sealed Pt cap-
sules surrounded by powdered alumina.
On the basis of the experimental results
on the four compositions and those on
the join forsterite-silica-H20 at 20 kb
(Kushiro, Year Book 67, pp. 158-159) ,
the forsterite-orthopyroxene liquidus
boundary at 20 kb is drawn (Fig. 24).
It is noted that the boundary is projected
from the H20 apex onto the plane forster-
ite-nepheline-silica. The projected liq-
uidus boundary at 17.5 kb is also
shown in this figure. The water contents
in these experiments were relatively high
(22.8 to 42.5 wt %), and glass balls with
low refractive index were observed in
most of the runs. The glass balls are
considered to be "quenched vapor" (Ku-
shiro, Yoder, and Nishikawa, 1968;
Yoder and Kushiro, 1969), and the ex-
periments were under water-saturated or
vapor-present conditions. Experiments
have also been conducted with water
content less than 9 wt %. In these ex-
periments the orthopyroxene liquidus
field is considerably expanded relative
to that of forsterite.
The boundary and phase relations
close to the join nepheline-silica are not
certain because of the possible appear-
ance of glaucophane on the liquidus in
this low-temperature area. However, it
is certain that the forsterite-orthopyrox-
ene liquidus boundary under water-
saturated conditions extends into the Ne-
normative region at 20 kb above the
temperature range where glaucophane
could appear.
In Fig. 24, the forsterite-orthopyrox-
ene liquidus boundary at 20 kb under
anhydrous conditions determined by
Kushiro (1968) is shown for comparison.
It is nearly parallel with the boundary
under water-saturated conditions at the
same pressure but is located considerably
on the silica-poor side of the latter.
On the basis of the results of the pres-
ent experiments, it is indicated that the
first liquid formed by melting of peri-
dotitic mixtures consisting of forsterite
and enstatite solid solution with small
amounts of jadeite (or albite) component
and water is silica saturated at 17.5 kb or
less ; however, the first liquid is critically
silica undersaturated or Ne-normative at
20 kb. If partial melting proceeds at 20
kb, the composition of the liquid changes
GEOPHYSICAL LABORATORY
241
NaAISi04
Mg?SiO.
MgSi03
SiOc
Weight per cent
Fig. 24. The forsterite-orthopyroxene liquidus boundaries in the system forsterite-nepheline-
silica-HoO at 20 and 17.5 kb under water-saturated conditions, and at 20 kb under dry conditions.
The boundaries under water-saturated conditions are projected from the H20 apex onto the plane
forsterite-nepheline-silica. Point G indicates the composition of anhydrous glaucophane.
from Ne-normative to (Ol + Hy) norma-
tive and further to Qz-normative. That
the first liquid formed by partial melting
of a peridotitic mixture is Ne-normative
and the liquid formed after further melt-
ing is (Ol + Hy) normative and even Qz-
normative appears to agree with the hy-
pothesis on the genesis of alkali basalt
and tholeiite proposed by Gast (1968)
on the basis of the trace-element abun-
dances in these basalts.
The present experimental results indi-
cate that orthopyroxene may crystallize
from the liquids of Ne-normative com-
position at pressures higher than 20 kb
under water-saturated conditions as well
as under anhydrous conditions. This may
agree with some of the experiments by
Baltitude and Green (1967), although
their observation that the field of ortho-
pyroxene expands relative to that of
olivine under hydrous conditions is not
in accord with the present results.
The System Forsterite-
CaAl2SiOG-Silica-H20
The system forsterite-CaAl2Si06-silica-
H20 is also important for understanding
the liquids formed in the upper mantle
under hydrous conditions. Five mixtures
have been studied in the pressure range
242
CARNEGIE INSTITUTION
15 to 33 kb and in the temperature range
1100° to 1150°C. The forsterite-ortho-
pyroxene liquidus boundary at 20 kb is
shown in Fig. 25, which is projected from
the H20 apex onto the plane forsterite-
CaALSiOe-silica. The water content of
the experiments ranges from 17.2 to
31.7 wt °fo (most of them are more than
20 wt %), and glass balls with low re-
fractive index ("quenched vapor") were
found in most of the runs. The conditions
of the experiments are, therefore, con-
sidered to be water saturated or nearly
water saturated. As shown in Fig. 25, the
projected forsterite-orthopyroxene liqui-
dus boundary under water-saturated
conditions lies on the silica side of the
join enstatite-anorthite, i.e., in the Qz-
normative region at least at 20 kb. At
30 kb, forsterite is still on the liquidus
for the mixture EAN-40, indicating that
at least a part of the forsterite-orthopy-
roxene boundary is still on the silica side
of the join enstatite-anorthite at 30 kb.
Therefore, the first liquid formed by
melting of a mixture consisting of for-
sterite, enstatite solid solution, and small
amounts of anorthite or garnet of the
pyrope-grossular series is silica saturated
up to about 30 kb under water-saturated
conditions. Under anhydrous conditions,
however, the forsterite-orthopyroxene
liquidus boundary lies in the (Ol + Hy)
normative area in the pressure range
about 10 to at least 30 kb (Kushiro,
1968) . The boundary at 20 kb under an-
hydrous conditions is shown in Fig. 25 for
comparison. It is parallel to but much to
the silica-poor side of the boundary
under water-saturated conditions. These
results also indicate that the liquids
formed by melting of peridotitic mixtures
under hydrous conditions are consider-
CaA!2Si06
Mg2SiO«
MgSi03
5i02
Weight per cent
Fig. 25. The forsterite-orthopyroxene liquidus boundaries in the system forsterite-CaAl2Si06-
silica-H20 at 20 kb under water-saturated and dry conditions. The boundary under water-satu-
rated conditions is projected from the H20 apex onto the plane forsterite-CaALSiOo-silica.
GEOPHYSICAL LABORATORY
243
ably more silica rich than those under
anhydrous conditions.
The System F orsterite- Nepheline-
CaA l2Si06-Silica-H20
For a better understanding of the com-
positions of liquids formed under upper-
mantle conditions, the liquidus relations
in the system forsterite-nepheline-CaAl2
Si06-silica-H20 should be known. This
system consists of the two systems de-
scribed in the previous sections and in-
cludes most of the major components in
the upper-mantle materials, except iron.
Two mixtures on the plane enstatite-
anorthite-albite (En24.6An35.4Ab4o.o and
En32.8-An47.2Ab2o.o wt %) and two mix-
tures on the plane forsterite-anorthite-
albite (Fo20.i6An39.84Ab4o.o and Fo36.8
An33.2Ab3o.o) have been studied in the
pressure range 20 to 30 kb and in the
temperature range 1000° to 1150°C. The
water content of the experiments ranged
from 21.7 to 30.9 wt %.
Among the four mixtures studied, the
mixture En32.8An47.2Ab20.o, which is on
the plane enstatite-anorthite-albite, was
found to be most critical for the under-
standing of the melting relations of
peridotitic mixtures in this system. At
20 kb and 1050°C the assemblage for
this mixture is f orsterite + orthopyroxene
with glass and quench crystals, whereas
at 1025 °C the assemblage is f orsterite +
orthopyroxene + clinopyroxene + garnet
with glass and quench crystals. All the
crystals show euhedral or subhedral form.
Glass balls ("quenched vapor") were ob-
served in very small amount. Therefore,
six phases coexist together at this tem-
perature and pressure. If compositions of
garnet and pyroxenes remain in the sys-
tem forsterite-CaAl2Si06-nepheline-
silica, this six-phase assemblage repre-
sents a univariant relation or isobaric
invariant relation; that is, the liquid is
just at the isobaric invariant point. If
the composition of pyroxene or garnet is
outside the system mentioned above, this
assemblage represents the isobaric uni-
variant relation. The composition of gar-
net is slightly out of the system, as shown
below, and the compositions of clino-
pyroxene and orthopyroxene may also be
out of the system. Their deviations would
be relatively small, however, and in the
following discussion the relations at
1025 °C and 20 kb are taken to be iso-
baric invariant as an approximation. The
composition of the liquid at this "point"
is most relevant to the melting of garnet-
lherzolite; that is, the first liquid formed
by melting of the mixture, f orsterite +
orthopyroxene + clinopyroxene + garnet
with a small amount of water, has this
composition, which is clearly in the
silica-saturated (Qz-normative) region
at 20 kb and probably up to 25 kb under
water-saturated conditions. At this
"point," forsterite reacts with liquid to
form probably two pyroxenes and garnet.
Amphibole is not involved at this
"point," but it crystallizes at 1000°C
with orthopyroxene, clinopyroxene, and
garnet. The unit-cell dimension of garnet
formed at 1000°C is 11.569 A, which cor-
responds to that of pyrope 72 grossular
28 (by mole) on the basis of the unit-
cell-composition curve for pyrope-gros-
sular garnet (Chinner, Boyd, and En-
gland, Year Book 59, pp. 76-78).
On the basis of these experimental re-
sults and those in the systems forsterite-
nepheline-silica-H20 and forsterite-
CaAl2Si06-silica-H20, the projection of
the forsterite-orthopyroxene liquidus
boundary at 20 kb under water-saturated
conditions is shown in the system for-
sterite-nepheline-CaAl2Si06-silica (plane
A-Q-U-S in Fig. 26) . Point A is the pro-
jection of the composition of the liquid
under the "isobaric invariant" conditions
described above. It may be a piercing
point, if the conditions are isobaric uni-
variant. Even so, the true isobaric in-
variant point would be close to point A.
Along the line AS, forsterite, ortho-
pyroxene, and garnet coexist with liquid
and vapor, and along the line A-Q, for-
sterite, orthopyroxene, and clinopyroxene
coexist with liquid and vapor. In the
244
CARNEGIE INSTITUTION
CaAI2Si06
CaAI2Si208
Mg2Si04
MgSi03
Si02
Fig. 26. The forsterite-orthopyroxene liquidus boundaries in the system forsterite-nepheline-
CaALSiOe-silica-HoO at 20 kb under water-saturated and dry conditions. The dotted line indicates
a trace of the intersection of the plane MgSi03-CaAl3Si208-NaAlSi308 with the volume A-Q-U-S-
T-V-R-B.
present experiments, the exact positions
of point A and the lines AS and A-Q
at 20 kb could not be determined. At
lower pressures, point A would also lie in
the Qz-normative region; spinel or plagi-
oclase would appear instead of garnet at
lower pressures, however, and the phase
relations are not the same as those at 20
kb. The forsterite-orthopyroxene liquidus
boundary at 20 kb under anhydrous con-
ditions is shown for comparison in Fig. 26
(plane B-R-V-T). Point B is probably
in the Ne-normative region at 20 kb.
The first liquid formed by partial
melting of garnet-lherzolite in the pres-
ence of water is silica saturated at pres-
sures up to 25 kb. The composition of the
liquid is not certain, but the solidified
liquid appears to be andesitic. Accord-
ingly, it is possible that andesite magmas
could be generated by direct partial melt-
ing of the upper mantle in the presence of
water at depths of 60-80 km. The possi-
bility of generation of andesite magma
by direct partial melting of the upper
mantle has been suggested by O'Hara
(1965) and discussed in more detail by
Yoder (1969).
In Fig. 26, if partial melting of perido-
titic mixtures with small amounts of
water proceeds as a closed system, water
vapor disappears and the liquid leaves
point A and changes its composition to-
ward B along the dashed line A-B. The
liquid becomes undersaturated with
water. The composition of liquid is Qz-
normative and may be andesitic at A;
when the liquid crosses the plane en-
statite-anorthite-albite, however, its com-
position becomes (Ol + Hy) normative.
The compositions of liquids may change
from andesite to tholeiite and olivine tho-
leiite. If the liquid crosses the plane for-
sterite-anorthite-albite, it becomes Ne-
normative, although this possibility was
not tested in the present experiments. How
GEOPHYSICAL LABORATORY
245
far the liquid can move from A toward B
depends on the water content of the ini-
tial material melted. If the water content
is lower, the liquid may reach a point
closer to B. Of course, the first liquid is
always A regardless of the water content,
its amount being smaller for the lower
water content of the initial material.
Thus, the peridotitic materials with the
lower water content can generate less
silicic liquids as far as the process of
partial melting can proceed, to a con-
siderable extent at constant pressure. It
may be possible, therefore, that tholeiitic
and olivine tholeiitic magmas can be gen-
erated by direct partial melting of the
peridotite upper mantle with lower water
contents, at depths at least near 60-80
kb. If the water content is high, a con-
siderable amount of silica-rich andesitic
magma may be produced by direct par-
tial melting of the upper mantle. The
results of the present study suggest in-
teresting possibilities on the relationship
between tholeiites and alkali basalts and
on the origin of andesites, and determina-
tion of the compositions near points A
and B is important in the further appli-
cation of the system.
Stability of Amphibole and Phlogo-
pite in the Upper Mantle
/. Kushiro
Amphibole is a possible hydrous mineral
in the upper mantle. It has been found in
the peridotites of the St. Paul's Rocks
(Tilley, 1947; Melson et al, 1967) and in
some peridotite inclusions in basaltic
rocks (e.g., Lausen, 1927; White, 1966;
Kuno, 1967). In addition, high-pressure
experiments on amphibole suggest that
same amphibole can be stable under
the P-T conditions of the upper mantle
(Yoder and Tilley, 1962; Ernst, 1968;
Lambert and Wyllie, 1968; Gilbert, Year
Book 67, pp. 167-170; M. Nishikawa,
unpublished data). Phlogopite is also a
possible hydrous mineral in the upper
mantle. The possibility of the presence
of phlogopite in the upper mantle has
been suggested recently by several in-
vestigators (e.g., Nicholls, 1967; Kushiro,
Syono, and Akimoto, 19676; Green,
1968; Yoder and Kushiro, 1969). In the
present studies, stability of amphibole
and phlogopite has been examined at
high pressures in the presence of minerals
of the upper mantle.
Formation of Amphibole in Peridotite
Composition
Amphibole has been shown to form
from various basalt compositions up to at
least 10 kb under hydrous conditions
(Yoder and Tilley, 1962). Yoder {Year
Book 65, pp. 269-279) has also shown
that amphibole forms from synthetic
f orsterite + anorthite (1:1 by mole) com-
position. Kushiro, Syono, and Akimoto
(1968) carried out experiments on a
natural lherzolite under hydrous condi-
tions in the pressure range 26 to 50 kb
at temperatures above 980 °C and deter-
mined the solidus temperatures, but they
did not find amphibole or other hydrous
minerals within the P-T range of their
experiments. The present experiments
have been conducted on the same lherzo-
lite under hydrous conditions in the
pressure range 15 to 28 kb to determine
the P-T range of crystallization of
amphibole if it forms in the lherzolite +
H20 composition.
The experiments have been performed
with the solid-media, piston-cylinder ap-
paratus and with sealed Pt capsules. The
water content of the capsules ranged
from 5.8 to 9.3 wt %. The starting ma-
terial used was a spinel-bearing lherzol-
ite, which occurs as a nodule in the tuff
of Salt Lake crater, Hawaii, and has
been described by Kuno (1969).
The results are shown in Fig. 27. As
shown in the figure, the upper limit of
the amphibole-bearing assemblage has a
negative slope. At 1030°C and 15 kb,
no amphibole was found and feathery
quench crystals were observed with glass,
indicating that the solidus temperature
at 15 kb is 1015°±15°C, consistent with
246
CARNEGIE INSTITUTION
30
o20
10
0
600
Garnet -
Iherzolite + V £
Amphibole
Iherzolite
Iherzolite + V
\
I
Plagioclase- /\
Iherzolite / \
800 1000 1200
Temperature, °C
Fig. 27. Pressure-temperature diagram for
a Iherzolite nodule from the tuff of Salt Lake,
Hawaii, in the presence of excess water. The
solidus under dry conditions and a part of the
solidus in the presence of excess water are
from Kushiro, Syono, and Akimoto (1968).
Symbols : shaded square, olivine + orthopy-
roxene + clinopyroxene + amphibole ± garnet ;
half-solid square, olivine + orthopyroxene +
clinopyroxene ± garnet ; square with vertical
line, olivine -f- orthopyroxene + clinopyroxene
+ quench crystals and glass.
the results obtained by Kushiro, Syono,
and Akimoto (1968). In the present ex-
periments, the water content is consider-
ably higher than that required for the
formation of amphibole. As suggested by
Yoder and Kushiro (1969) , hydrous min-
erals have the maximum thermal stabil-
ity at solidus temperatures when the
water contents are the same as those
of the corresponding hydrous minerals.
If the water content of the experiments
is lower, therefore, amphibole may per-
sist to temperatures above the solidus of
the Iherzolite.
The amphibole obtained in the present
experiments is almost colorless or very
pale green. It is thin and prismatic, its
average length being 0.05 mm. The com-
position of the amphibole was not deter-
mined but is probably pargasitic. The
amounts of amphibole in the five runs
are estimated to be about 10% or less
from the intensity of reflection in the
powder X-ray diffraction patterns and
from the microscopic observation. Clino-
pyroxene, orthopyroxene, and garnet are
euhedral to subhedral and appear to be
well recrystallized. Olivine also shows
euhedral to subhedral form but the
centers of many of the crystals are
cloudy. Garnet crystallizes at 900 °C at
20 kb or higher, and at 950° and 1000°C
at 23 kb, although its amount is very
small; it does not crystallize, however,
at 1000 °C and 20 kb. The unit-cell di-
mension of garnet formed at 28 kb and
875 °C is 11.571 A, indicating that the
garnet is pyrope and almandine rich. In
the previous experiments by Kushiro,
Syono, and Akimoto (1968), garnet was
not found in the run conducted at 26 kb
and 980 °C for one-half hour. The dura-
tion of the run was probably too short
for the formation of garnet at subsolidus
temperatures and at pressures relatively
close to the transition. No other hydrous
minerals were found to form in the pres-
ent experiments.
The stability of synthetic pure pargas-
ite has been studied by Boyd (1959) at
pressures below 2 kb and by Gilbert
{Year Book 67, pp. 167-170) at 30 and
40 kb. Gilbert has shown that pure par-
gasite is stable up to at least 900 °C at
20 kb in the presence of clinopyroxene
and is not stable at 950 °C and higher
near 30 kb or at 900°C and higher near
40 kb. Although the data are too few
for comparison, the stability field of pure
pargasite in the presence of clinopyroxene
is not much different from the field of
crystallization of amphibole in natural
Iherzolite.
The present results would be useful in
estimating the maximum depth of forma-
tion of amphibole in the upper mantle if
the upper-mantle materials are similar in
chemical composition to the present
GEOPHYSICAL LABORATORY
247
lherzolite. Assuming that the geotherms
in the oceanic and continental areas are
represented by those given by Clark and
Ringwood (1964) and the water pressure
is nearly equal to the total pressure in the
upper mantle, it would be predicted that
amphibole could form at pressures up
to about 20 and 27 kb or at depths of
about 60 and 85 km in the oceanic and
continental areas, respectively. If the
water pressure is less that the total pres-
sure, amphibole breaks down at lower
temperatures and would not be stable to
such depths.
Stability of Phlogopite in the Presence
of Pyroxene
Pure phlogopite is stable up to at least
37.5 kb at about 1200°C in the presence
of forsterite (Yoder and Kushiro, 1969) ,
and a natural phlogopite is stable up to
at least 72 kb at about 1000°C (Kushiro,
Syono, and Akimoto, 19676) . The stabil-
ity field of phlogopite, however, may
change in the presence of other phases.
Lambert and Wyllie (1968) noted that in
the presence of "mantle pyroxenes" phlo-
gopite would become unstable at lower
pressures than pure phlogopite and as-
sumed that phlogopite is not stable at
pressures higher than about 20 kb at
about 900 °C. In the present preliminary
experiments, therefore, phlogopite + en-
statite and phlogopite + diopside assem-
blages have been examined at high pres-
sures.
The starting materials are a 1:1 mix-
ture (by weight) of synthetic pure diop-
side and a mixture of anhydrous pure
phlogopite composition, and a 1:1 mix-
ture (by weight) of synthetic pure ortho-
enstatite and a mixture of anhydrous
pure phlogopite composition. Three runs
were conducted on the diopside + phlogo-
pite composition — at 15 kb and 1100°C,
at 30.5 kb and 1150°C, and at 32 kb and
1000 °C — with sealed Pt capsules having
water contents of 11.4, 13.1, and 4.6
wt %, respectively. In all the runs a
large amount of phlogopite crystallized,
and the assemblage is phlogopite + diop-
side + forsterite with or without a small
amount of glass, including glass balls
condensed from vapor. Phlogopite crys-
tals are mostly euhedral. Diopside is also
well recrystallized. Crystallization of
forsterite indicates that vapor or liquid
would dissolve excess potassium and
alumina over phlogopite composition, as
already shown by Yoder and Kushiro
(1969). These experimental results in-
dicate that the diopside + phlogopite as-
semblage is stable up to at least 32 kb
at about 1000°C.
Two runs were conducted on the ensta-
tite + phlogopite assemblage, at 26 and
33 kb and 1100°C, with water contents
of 22.4 and 15.4 wt %, respectively. In
these runs a large amount of phlogopite
crystallized, and the assemblage was
phlogopite + orthoenstatite + forsterite
with a small amount of glass balls and
glass coatings. Phlogopite crystals are
mostly euhedral; orthoenstatite is also
well recrystallized and mostly euhedral.
These experimental results indicate that
the phlogopite + orthoenstatite assem-
blage is stable up to at least 33 kb at
1100°C. As shown above, the presence of
diopside and enstatite does not seem to
change significantly the stability field
of phlogopite. Although the effect of iron
and other elements on the stability of
the phlogopite + pyroxene assemblage is
not known, it is suggested from the above
experimental results that phlogopite may
be stable at depths of at least 100 kb if
the water pressure is equal or nearly
equal to total pressure and the tempera-
ture is not much higher than 1100 °C.
OXIDES AND OTHERS
Stability of the Psetjdobrookite
(Fe2Ti05) -Ferropseudobrookite
(FeTi205) Series
S. E. Haggerty and D. H. Lindsley
Members of the pseudobrookite series
are ubiquitous as high-temperature oxi-
dation products of titanomagnetite and
248
CARNEGIE INSTITUTION
ilmenite, and a knowledge of the lower
thermal stability limit of the series has
now become significant in terms of mag-
netic mineral studies because the series
can serve as a temperature indicator.
Recent investigations relating magnetic
properties with petrography have re-
vealed that systematic correlations exist
between lavas that show reversed direc-
tions of magnetization (i.e., antiparallel
to the direction of the earth's magnetic
field) and lavas that are highly oxidized
(Wilson and Haggerty, 1966) . Although
self-reversing physiochemical models
have been proposed, they are rarely
demonstrable in the laboratory. The re-
lationship between reversed polarity and
lava oxidation is not understood. An in-
sight into the mechanism controlling
these correlations obviously depends,
first of all, on whether it can be proved
that magnetization and mineral oxida-
tion are coeval or are separated in time.
Our results suggest that in highly oxi-
dized lavas a possible mineralogical
method of deciding whether a direction
of magnetization is primary, having
developed during the initial cooling, or
whether the polarity is secondary and
developed at some later time, can be
made on the presence or absence of
pseudobrookite as an oxidation product.
The alteration of titanomagnetite and
ilmenite, in nature, to members of the
pseudobrookite series is a nonequilibrium
oxidation process. Although the thermal-
stability determinations described here
are equilibrium values, they nevertheless
provide an important and initial frame-
work for delineating the problem.
Akimoto, Nagata, and Katsura (1957)
have shown that the pseudobrookite
series is complete above 1150°C; this ob-
servation has been confirmed in the pres-
ent study. Results from quenched, evacu-
ated silica-glass-tube experiments are
presented in Fig. 28, for the temperature
range 750°-1150°C; other points in-
cluded on the diagram are hydrothermal
experiments at 2 kb and the j0i of the
-erropsejdobrookite
reTi205 10 20
30
40
50
60
Pseudobrookite
70 80 90 Fe2Ti05
1
i
i
1
1
1
' 1
1 1 1
B Hemss(orIlmss)+Rut-* Pbss(orFpb5S)
I40±I0
S
D Pbss(or Fpbss)^ Hemss(orIlmss) + Rut
MOO
' \ \
■ Hem5S(orIlmS5) + Rut-H»Pbs5(orFpbss) _
-1- Hemss(orIlmss) + Rut
A
\
R Pbss(or FpbS5) = PbS5(or Fpbss) +
Hemss(orI!mss)+ Rut
1000
- \
\
\
a
aV
■
Pbss
-
Pbss+R+I3s
900
»
a
a
a >v
■
B
B
■ B
W+R \
a
a
a
\"
a
■
B B B
800
- 1
1
a a
a
a\
D
D
B B B
a
a
a
\
700
—
B B -■
Pbss+R+Hss
600
I
I
I
1
1
1
-I
c
Hematite+Rutile
1 1 1
FeTi03 + Ti02
Ilmenite +Rutile
Mole per cent
Fig. 28. Stability relations in the pseudobrookite-ferropseudobrookite series.
Fe2O3 + Ti02
Hematite+Rutile
GEOPHYSICAL LABORATORY
249
buffer controlled by hematite + hydrogen
peroxide. Starting material for the pri-
mary breakdown experiments consisted
of crystalline pseudobrookite; and re-
versible experiments, to establish true
equilibrium, were carried out by reacting
rutile and members of the ilmenite-
hematite solid solution series in 1:1
ratios.
Ferropseudobrookite (FeTi205) de-
composes to FeTi03+Ti02 at 1140° ±
10°C, and the pseudobrookite (Fe2Ti05)
end member (based on hydrothermal ex-
periments) breaks down to Fe203 + Ti02
at 585°±10°C. Intermediate members
break down between 700° and 800°C, but
the decomposition curve between the two
end members is not linear. The effect of
Mn and Mg (elements that are known
to be present in small quantities in
titanomagnetite and ilmenite) on the
stability limit of the series has not been
determined.
The silica-glass-tube technique has a
limited application below 800 °C in this
system because of very slow reaction
rates; Fe2Ti05-rich members and mem-
bers of the series having intermediate
compositions, for example, remained only
partially reacted, at 750°C, even after
3 years. The Pb0-Pb50 region above
750 °C is relatively simple, and three
distinct fields — (a) ilmenite + rutile, (b)
ilmenite + rutile + pseudobrookite, (c)
pseudobrookite — have been defined. The
Pb5o-Pb10o region, which has a direct ap-
plication to magnetic mineral studies,
however, is far more complex and has not
yet been fully resolved.
Identification of the synthetic phases
was made by X-ray powder diffraction
and in polished section. An interesting
feature demonstrated by compositions in
the pseudobrookite field is that crystals
frequently show a tendency to be zoned
by a rim that is darker and shows a
lower reflectivity than the central core.
Electron-probe scans for Fe and Ti
across the core and the rim showed no
observable variation in concentration,
and it is inferred that the rim represents
a quenched polymorphic inversion prod-
uct of pseudobrookite. Attempts to grow
large crystals for a detailed X-ray study
have been made but have not yet been
successful. In experiments containing the
assemblages ilmenite + rutile and ilmen-
ite + rutile + pseudobrookite these min-
erals occur as discrete grains or in mutual
intergrowths. Textures resembling the ex-
solution or oxidation products that, are
observed in nature do not occur in the
synthetic phases.
It is concluded that the oxidation of
titanomagnetite and ilmenite in nature
to form members of the pseudobrookite
solid solution series in association with
rutile and titanohematite must take place
between 600° and 800°C. For lavas, oxi-
dation in this temperature range is most
likely to occur during initial cooling. The
presence of migrating oxidation zones in
the cooling Makaopuhi lava lake be-
tween 550° and 750 °C (Sato and Wright,
1966), the systematic oxidation zones
that are observed in single lava units
(Watkins and Haggerty, 1967), and the
presence of pseudobrookite toward the
center of these units (Haggerty, 1968)
support this conclusion and the high-
temperature deuteric origin of pseudo-
brookite. On the basis of these high
temperatures the presence of pseudo-
brookite would suggest that a measured
direction of thermoremanent magnetiza-
tion would be primary and would have
occurred concurrently with mineral oxi-
dation.
High-Pressure Phase Transformation
in Magnetite
H. K. Mao, W. A. Bassett* and T. Takahashi*
Knowledge of the phase relations in
the system Fe304 under high P-T condi-
tions is useful for an understanding of
the mineralogy of the earth's mantle.
Iron oxides are important mantle com-
ponents, as indicated in petrologic and
meteoritic occurrences. Magnetite (Fe3
^University of Rochester, Rochester, New
York.
250
CARNEGIE INSTITUTION
04) with spinel structure is stable at
1 atm. In most proposed mantle models,
a major phase transformation of (Mg,
Fe)2Si04 from the spinel structure to a
high-pressure phase or phase assemblage
is predicted to occur in the lower part of
the transition zone. This high-pressure
phase or phase assemblage should pre-
dominate in the lower mantle. So far, this
transformation in (Mg,Fe)2Si04 spinel
has not been discovered in nature, nor
has it been observed in the laboratory.
By analogy, the high-pressure phase of
magnetite may offer information on
which a good prediction of the high-
pressure phase of (Mg,Fe)2Si04 spinel
might be based.
Thermodynamic calculations of free
energy and entropy data on the basis of
conditions at room temperature and pres-
sure and high-pressure compression data
indicate that magnetite has a higher
free energy than either the assemblage
hematite + wiistite or the assemblage
hematite -}-e iron at pressures above 150
kb (Mao, 1967). Theoretically, experi-
ments above 150 kb should transform
magnetite into one of these two assem-
blages or possibly to an unknown state,
kinetics permitting. In the present study,
a pressure-induced, first-order phase
transformation in magnetite was ob-
served in a diamond anvil, high-pressure
X-ray diffraction cell. Natural magnetite
from Mineville, New York {a0 = 8.394 ±
0.002 A), was used as starting material.
The present technique has been de-
scribed by Bassett, Takahashi, and
Stook (1967). Experiments were con-
ducted at temperatures up to 310°C and
pressures up to 300 kb, equivalent to the
pressures predicted for a depth of 800 km
in the earth. The pressure cell was heated
to 310 °C momentarily after the pressure
was applied, in order to accelerate the
phase transformation. All X-ray diffrac-
tion photographs were taken after the
samples had been cooled to room tem-
perature but were still under high pres-
sure. The pressures were determined by
using the lattice constant of NaCl, or
in some runs, the lattice constant of the
low-pressure magnetite phase as internal
standard. The exact pressure during
heating was unknown, but it was be-
lieved to be somewhat lower than the
pressure after cooling.
In both heated and unheated runs,
magnetite underwent a phase transfor-
mation at approximately 250 kb but re-
verted to the original spinel structure
with the original aQ value upon release of
pressure to 1 bar. The reaction was very
sluggish at room temperature, and the
true equilibrium pressure might be far
below 250 kb. No reversion of the high-
pressure form to magnetite was observed
above 50 kb. At 1 bar, remnants of the
high-pressure form can persist for a few
weeks to a month before completely
reverting to magnetite.
The crystal structure of the high-pres-
sure form has not been determined. Its
X-ray powder diffraction pattern, in
comparison with the magnetite pattern,
is given in Table 19. Many of its diffrac-
tion lines overlap those of magnetite, but
the intensities are very different. This
pattern could not be indexed as a single
cubic phase nor as a single tetragonal
or hexagonal phase with a reasonably
small unit cell.
It is interesting to note that the d
TABLE 19. d Values of the High-Pressure Form
of Magnetite and of Magnetite, Both at
250 Kb, 25°C
High-Pressure
Magnetite
Form
No. d,k
I/ho*
(hkl)
d,k
///10*
(111)
4.671
1
(220)
2.860
3
1 2.60
10
2 2.44
1
(311)
2.439
10
3 2.34
3
(222)
2.335
1
4 2.14
1
5 2.03
4
(400)
2.023
3
6 1.90
4
7 1.79
2
(422)
1.651
2
8 1.55
4
(333) (511)
1.557
4
9 1.40
5
(440)
1.430
5
10 1.23
1
(533)
1.234
1
* Intensities were estimated by eye.
Note : MoKcCi radiation was used.
GEOPHYSICAL LABORATORY
251
values and intensities of diffraction lines
1, 2, 4, and 7 (Table 19) are remarkably
close to those of the (104), (110), (113),
(204), and (115) reflections, respectively,
of hematite at the same pressure. It is
not likely that the high-pressure assem-
blage contains hematite, which is stable
at atmospheric oxygen pressure. If hema-
tite formed from magnetite at high pres-
sure, it could not revert to magnetite
when the pressure was released and the
sample exposed to the air. The X-ray
pattern does not correspond to that of
an assemblage containing wiistite or e
iron, according to the data measured at
250 kb by Mao et al. (1969) and Mao,
Bassett, and Takahashi (1967). No
transformation was observed in wiistite
at300kband325°C.
The complete reversion of the high-
pressure form to magnetite at atmo-
spheric oxygen pressure suggests a single
phase instead of a phase assemblage.
Overlapping of a large part of the X-ray
pattern of the high-pressure form with
magnetite lines may be due to a
reordering in magnetite, probably involv-
ing a move of iron from tetrahedral oxy-
gen coordination into octahedral coor-
dination. Such a coordination change in
the magnetite structure requires decrease
in the intensity of the (311) reflection,
with corresponding increases in the in-
tensities of the (222), (400), and (440)
reflections. All of these requirements are
consistent with our observations.
Study of Lead up to 180 kb
H. K. Mao, T. Takahashi* and W. A. Bassett *
The lead transformation was first
recognized by Balchan and Drickamer
(1961), reportedly at 161 kb and room
temperature, on the basis of a 23% in-
crease in electrical resistance. The crys-
tal structure of the high-pressure phase
was not determined, but under room con-
ditions lead is in a face-centered cubic
* University of Rochester, Rochester, New
York.
(fee) structure. Currently, this trans-
formation is used as a pressure calibra-
tion point.
In the present study at room tempera-
ture, the high-pressure phase of lead has
been identified. In addition, its trans-
formation pressure has been correlated
with the fixed-point pressure of oc-»e
iron at 130 kb and with the pressure-
volume equation of state of iron. The
P-V equation of state of lead was also
determined. This was accomplished by
the X-ray diffraction method, with a
polycrystalline sample compressed in a
diamond-anvil, high-pressure cell (Bas-
sett, Takahashi, and Stook, 1967).
The sample of lead used for this study
is a high purity ingot (99.999% Pb) sup-
plied by the American Smelting and Re-
fining Company.
Determination of the High-Pressure
Phase
Zr-filtered MoKoc radiation was used
to study lead under pressure in the dia-
mond-anvil cell. X-ray diffraction lines
were recorded on a cylindrical film hav-
ing a radius of 50 mm, allowing disper-
sion of a maximum angle of 48° 20.
Seventeen diffraction lines of the high-
pressure phase of lead were observed.
They can all be indexed as hexagonal
with c/a ratios of 1.650. Systematic ex-
tinctions in the pattern are consistent
with a hexagonal close-packed (hep)
structure.
The d values and intensities of a set of
diffractions observed at 139 ±10 kb are
compared in Table 20 with the calculated
d values and intensities for a hep struc-
ture of lead. The calculated lattice pa-
rameters are a = 3.265 ±0.004 A and c =
5.387 ±0.007 A. Observed and calculated
d values agree within the experimental
uncertainty. The observed and calculated
intensities were generally in good agree-
ment, with the exception of (100) and
(110) reflections, for which the observed
intensities are considerably higher than
the calculated ones. A possible explana-
252
CARNEGIE INSTITUTION
TABLE 20. Observed and Calculated d Values and Intensities for hep
Lead at 139 ± 10 Kb and 25 °C
(hkl)
dobs, A
Clcalc, A
U//ioo)obB
(7/7lOo)calc
100
2.820
2.827
75
23
002
2.685
2.694
32
27
101
2.507
2.504
100
100
102
1.947
1.951
12
17
110
1.633
1.632
71
21
103
1.514
1.516
22
25
200
. . .
1.414
3
112
1.397
1.396
'33
26
201
1.367
1.367
36
18
004
. . .
1.347
4
202
1254
1.252
"5
5
104
*
1.216
*
4
203
1.110
1.111
17
9
210
1.069
1
211
1.047
1.048
'is
16
114
*
1.039
*
10
105
*
1.007
*
8
212
0.9927
0.9933
9
6
204
0.9752
3
300
0.9426
5
213
0.9195
0.9183
'is
14
006
0.8984
1
302
' *
0.8897
' *
8
* Observed in other photograph but not in this one, which is the best for
intensity measurement; (...) indicates not observed.
Note : MoKoc radiation was used.
tion is that the X-ray diffraction pattern
of the high-pressure form was always
spotty, probably due to preferred orien-
tation, even though we started with a fee
lead having a perfectly smooth pattern. If
the change from fee to hep only involves
a glide along the (111) plane of fee,
equivalent to the (002) plane of hep,
then shear stress along this plane should
favor the transformation. In the dia-
mond-anvil cell the maximum shearing
stress is parallel to the anvil face, and
consequently the (002) plane would tend
to be so oriented. If this parallelism of
(002) occurs, the planes perpendicular
to (002) should be in better orientation
for diffraction. Thus (100) and (110)
would have higher intensities in a dia-
mond-anvil cell than those calculated on
the basis of random orientation.
Precise Measurement of the
Transformation
Two samples of lead, one intimately
mixed with an iron standard and the
other alone, were used to study the trans-
formation pressure. In experiments with
the lead-iron mixture, pressures were de-
termined from the known P-V relations
of iron (Takahashi, Bassett, and Mao,
1968) . In the pure lead sample, pressures
were determined from the P-V data for
the fee form of lead determined in the
Fe + Pb experiments. The effect of pres-
sure on the volume of the fee lead was
first studied by Bridgman (1945) up to
100 kb at room temperature. It was re-
determined in the present study of the
iron-lead mixture, based on the seven dif-
fraction lines (111), (200), (220), (311),
(222), (331), and (420) of the fee phase.
The results can be fitted to a first-order
Birch equation of state: P=% B0[V0/
V)%— (V0/V)to], where B0 represents
the zero pressure isothermal bulk nodules,
£o=:458 ±30 kb; V0 and V are volumes
at zero pressure and pressure P, respec-
tively. Our results agree within 0.5%
with those of Bridgman (1945), and B0
is close to the value (£0 = 439 kb) cal-
culated from the elastic constant at zero
pressure (Swift and Tyndall, 1942).
GEOPHYSICAL LABORATORY
253
To avoid overshooting the transforma-
tion, pressure was increased at an ex-
tremely slow rate (less than 1 kb per
hour) . The onset of the lead transforma-
tion was determined by the first appear-
ance of the (101) diffraction line of hep
lead. In the lead-iron mixture the onset
of the lead transformation occurred close
to but always at lower pressure than the
fixed point of 130 kb for the onset of the
a — > e iron transformation. In both the
lead-iron mixture and the pure lead
sample, the onset pressure of the fec-hep
transformation was determined to be
130 ±10 kb by internal-standard calibra-
tion (lattice constants of iron or fee
lead), but the transformation was not
completed until 160 ±10 kb in the lead-
iron mixture and 145 ± 10 kb in the pure
lead sample. In both samples, when pres-
sure was reduced remnants of the hep
lead persisted to pressures as low as
100 ±10 kb before completely reverting
to fee. The total observed range of co-
existing fec-hep lead was P = 100 kb to
P = 160 kb, or 7fcc = 15.58 cm3/mole,
7hcp = 15.41 cm3/mole, to Vtcc = 14.65
cm3/niole, Vhcp= 14.54 cm3/mole, respec-
tively.
The volume change for the fec-hep
phase transformation was determined
when these two phases coexisted in the
high-pressure cell. On the basis of twelve
measurements, the change was deter-
mined to be —0.18 ±0.06 cm3/mole, or
1% in a7/70, where V0 = 18.269 cm3/
mole is the molar volume of fee lead
under room conditions. Since the volume
change is small, it increases confidence
that the coexisting fee and hep phases
were at the same pressure. The pressure
inhomogeneity in an intimate mechanical
mixture of NaCl and Nb reported by
Jamieson and Olinger (1968) did not
exist in the coexisting fee and hep lead.
If the hep phase were at a higher pres-
sure the volume change would have been
overestimated, and therefore the true
volume decrease would have been less
than 1% but still larger than zero. A 1%
change in AV/V0 at 130 kb is only
equivalent to 9 kb in the P-V relation of
fee lead, setting an upper limit for the
possible pressure difference between the
two coexisting phases.
Using a belt apparatus Bundy (1967)
found, in agreement with Balchan and
Drickamer (1961), that the electrical-
resistance change of the lead transforma-
tion was 30 kb higher than that of the
iron transformation and was always
sharp. The discrepancy between their re-
sults and the present ones may be due to
the following factors : the length of time
of the runs (resistance measurement is on
the order of minutes, and the present
technique is on the order of months) ;
the stress distribution in different types
of apparatus; and the type of observa-
tion (resistance versus X-ray). As de-
scribed above, in the present study a
range of 60 kb for coexistence of fee and
hep lead was observed. Precaution must
therefore be taken when the lead trans-
formation is used as a calibration point
in other than X-ray diffraction methods.
Crystal-Field Spectra at High
Pressure
P. M. Bell and H. K. Mao
Theory
An ion loses its spherically sym-
metrical environment when bonded in a
crystal. Cations commonly occur in octa-
hedral and tetrahedral coordination with
oxygen atoms in mineral structures and
as a result are influenced by the crystal
field. Primarily, the effect of pressure as
a parameter is to increase the field in-
tensity, because of the closer proximity
of neighboring electronic fields, and to
alter the d and / electronic levels in a
transition metal cation.
For the transition elements the Hund
rule of maximum spin multiplicity de-
scribes the ground state in a weak or zero
field. Owing to filling of the lowest crys-
tal-field levels, a different ground state
occurs in strong fields. Competition be-
tween spin-pairing energy and crystal-
254
CARNEGIE INSTITUTION
field energy determines whether the
strong or weak field case results.
Another effect is the prediction of
molecular orbital theory for the occur-
rence of more states at higher energies.
Here transitions may occur from orbitals
having predominantly d characteristics
to those having ligand character, i.e.,
transitions of d electrons to s and p
levels.
In actually relating the crystal-field
strength to pressure, Zahner and Drick-
amer (1961) have calculated the differ-
ence in energy between a free ion and
one in an octahedral field. This energy,
sometimes called the crystal-field param-
eter A or 10 Dq, should vary as R~5 for
a point charge and R~6 for point dipoles
in a cubic field (R = interatomic dis-
tance). Clearly, compression causing a
decrease in R is the important factor.
One should be able to make the following
observations: a shift of spectral absorp-
tion bands with pressure; an increase of
A with pressure, which will be inde-
pendent of the transition (in the zeroth
order) ; and a shift with pressure of
certain electronic transitions (such as
charge transfer) .
Minerals that contain transition ele-
ments are subject to crystal-field effects,
which become increasingly important at
high pressure. Excellent reviews of this
subject have been recently completed by
Burns and Fyfe (1967) and Burns
(1969) . Three of the recognized effects of
interest in geophysics are pressure-sensi-
tive transitions, control of geochemical
fractionation of the transition elements,
and thermal properties of minerals at
great depths in the earth. Geologically,
the most important elements showing
crystal-field effects are iron, manganese,
chromium, and titanium.
Two distinct types of pressure transi-
tion involving iron have been predicted,
and some observations have been made.
The first, spin-pairing, was suggested by
Fyfe (1960) and is described in detail
by Burns (1969) ; the second, a change
in the oxidation state of iron, was ob-
served by Drickamer (1965). Spin-pair-
ing results in a shift or transition of iron
in the high-spin state to the low-spin
state, with a sharp transition. The depths
in the earth where this type of transition
might occur have been calculated for
several minerals by Burns (1969). The
oxidation-state effect is one of the reduc-
tion of Fe3+ to Fe2+ and has been ob-
served as occurring gradually with pres-
sure in organic compounds. Drickamer,
Lewis, and Fung (1969) made this ob-
servation at pressures of the order of
100 kb using the Mossbauer technique.
Crystal fields tend to lower the free
energy of a compound containing a tran-
sition element, i.e., the crystal-field
energy of a transition ion in an octa-
hedral or tetrahedral site tends to stabil-
ize this ion relative to a nontransition
ion. Chromium has the highest crystal-
field stabilization energy (CFSE), and
starting at this highest point, Curtis
(1964) has demonstrated a striking cor-
relation of the fractionation of transition
elements in ultramafic deposits with their
relative CFSE's. Burns (1969) observed
the concentration of transition elements
in carbonaceous chondrites and drew
analogies with the upper and deep mantle
of the earth. El Goresy, Bell, and En-
gland {Year Book 67, pp. 197-198) re-
ported an iron-chrome sulfide from a
meteorite which is stable at high pres-
sure. In a high-pressure environment the
transition elements should be concen-
trated in the first solids to crystallize
from a melt. Results of a study by Meyer
and Boyd (this report) of inclusions in
natural diamonds are in agreement with
this prediction.
Thermal properties of the earth's
mantle are sensitive to crystal-field ef-
fects because the radiative component of
heat transfer will depend on the amount
of absorption in the near infrared (NIR)
and infrared (IR) regions. Clark (1957)
observed a broad transmission window in
silicates at 1 atm and room temperature,
but Fukao, Mizutani, and Uyeda (1968)
have shown that crystal-field absorption
GEOPHYSICAL LABORATORY
255
bands tend to limit transmission severely
at high temperature. Shankland (1969)
observed the opposite effect in olivine
with increasing pressure, but below 50 kb
the pressure effect is not strong enough
to cancel the temperature effect.
Preliminary Experiments
We have employed a diamond cell of
the type described by Weir, Van Valken-
burg, and Lippincott (1962) to make
measurements of crystal-field spectra at
high pressure. This cell is mounted on the
stage of a Leitz polarizing microscope,
through which the beam of a Perkin-
Elmer spectrophotometer is transmitted.
A lead-sulfide detector and a photo-
multiplier sample the beam for absorp-
tion bands in the NIR and visible regions.
This apparatus, described by Lippin-
cott, Whatley, and Duecker (1966), is
located in the U. S. National Bureau of
Standards. The instrument had previ-
ously been used in the visible region only,
and difficulties were encountered in the
NIR, owing to strong absorption by the
optical elements of the microscope. These
difficulties could have been overcome by
placing a microscope in the reference
beam as well as the sample beam (Burns,
1966) , but it was not possible to modify
the borrowed instrument. Therefore, it
was necessary to determine the absorp-
tion of the microscope without sample or
diamond cell so the overlapping absorp-
tion bands could be subtracted.
Powdered samples were used because
the diamonds caused multiple scattering,
making the measurement of polarized
spectra of a single crystal sample diffi-
cult. No attempt was made to assign
bands.
Crystal-field spectra were measured in
the NIR for fayalite and spinel (both
Fe2Si04) and almandine-garnet (Fe3Al2
S13O12). Additional measurements of
olivine were made in the visible region.
In all measurements strong absorption
bands due to the crystal field were ob-
served.
At low pressure a strong crystal-field
band was observed at 1.22 /xm. This shifts
toward higher energy by 100 nm (nanom-
eters) at approximately 100 kb, and the
phenomenon is entirely consistent with
the widening of the transmission window
observed by Shankland (1969) at 50 kb.
(The band defining the lower limit of the
window is at approximately 5 /xm in the
IR and was not measured in the present
study.)
Spinel measured in this study was syn-
thesized at approximately 80 kb by F. R.
Boyd. The crystal-field absorption band
was observed at 1.35 /xm at 1 atm and
shifted by 50 nm toward higher energy
at approximately 100 kb. Maximum
transmission at 1 atm was observed at
1.6 /mi; at 100 kb, transmission was a
maximum at 1.68 /xm. These results sug-
gest that spinel transmits well in the low-
energy region at least to 2 nm.
Almandine-garnet used in the study
was synthetic, supplied by H. S. Yoder.
Two absorption bands were observed:
at 1 atm they occurred at 1.23 and 1.70
/xm; at high pressure they shifted to
higher energy by 100 and 150-200 nm,
in agreement with the observations of
Balchan and Drickamer (1961).
Observations of fayalite in the ultra-
violet (UV) -visible (V) were intriguing.
At 1 atm the visible cut-off of the charge-
transfer band occurred at 380 nm. At
about 50 kb this absorption edge had
shifted to 400 nm. Above 50 kb strong
absorption centers appeared with in-
creasing pressure, and very rapidly ab-
sorption was complete throughout the
visible region. The effect was reversible
without hysteresis, probably because of
incipient formation of the high-pressure
phase (spinel). Similar phenomena are
well known to occur at polymorphic
transitions, presumably owing to the
scattering of light in minute nucleation
particles (Burns, 1969). In this case it
could also be due to the rather strong
absorption in the visible region of spinel,
which we have observed to be continuous
256
CARNEGIE INSTITUTION
to about 800 nm, where a sharp edge
occurs. Burns (1969) has pointed out
that strong absorption at a phase transi-
tion will shield thermal radiation. This
process could be important in the earth's
mantle.
PHASE-EQUILIBRIUM STUDIES
SYSTEMS
OF SULFIDE
Sulfide- and Arsenide-Type Binary
Systems
G. Kullerud
During the past 15 years we have
studied the phase relations in a con-
siderable number of binary sulfide- and
arsenide-type systems. We have ap-
proached this study from the mineral-
ogical point of view and have concen-
trated on those systems that contain
compounds with mineral equivalents.
Compilation of our data and those pro-
duced in metallurgical studies (reviewed
by Hansen and Anderko, 1958, and
Elliott, 1965) brings out some interesting
features that may serve to classify or
group these systems. Such grouping of
empirical systems, if properly executed,
is useful for numerous purposes. For in-
stance, comparison of the behavior of one
such group with that of another can (1)
lead to conclusions of general value not
attainable by comparison of large num-
bers of individual systems, (2) lead to
prediction of the behavior of systems not
yet investigated, and (3) point up dis-
crepancies between reported (mostly in
the old literature) and predicted be-
havior of many systems and thus single
out those systems which should be re-
studied with modern methods.
The distinguishing features that per-
mit classification pertain to the behaviors
of the individual systems both in the
liquid and solid states. In this first effort
at grouping we shall emphasize melting
relations and the liquid state.
Sulflde-Type Systems
In experimental work sulfide-type sys-
tems generally are considered to involve
selenides and tellurides as well as sul-
fides. We shall first examine binary sys-
tems containing two of these group VIA
elements and then the binary relations of
each of these elements to the elements
arsenic, antimony, and bismuth from
group VA; germanium, tin, and lead from
group IVA; aluminum, gallium, indium,
and thallium from group IIIA; zinc, cad-
mium, and mercury from group IIB;
copper, silver, and gold from group IB;
nickel, palladium, platinum, cobalt, rho-
dium, iridium, and iron from group VIII ;
Mn from group VIIB; and chromium,
molybdenum, and tungsten from group
VIB.
Data on melting relations in these sys-
tems are compiled in columns 1-3 of
Table 21. It is noted that in each of the
S-Se, S-Te, and Se-Te systems homoge-
neous liquid exists above the liquidus
over its entire length. Congruently melt-
ing compounds do not exist in these sys-
tems. Column 1 of Table 21 shows that
liquid immiscibility fields exist in all
other sulfide systems.
About one-half of the listed sulfide
systems on which information exists con-
tain one liquid immiscibility field,
whereas the others contain two. A cur-
sory look down the sulfur column does
not give the impression of orderly group-
ing of one versus two liquid immiscibility
field systems. We shall make no attempt
as yet to group or classify these systems
on the basis of the occurrence of one or
two liquid immiscibility fields. Such a
classification is premature for several
reasons, the main one being lack of
knowledge of melting relations in the
sulfur-rich portions of the systems. Only
recently have methods been devised to
yield this kind of information, and so
far the sulfur-rich portions of only the
GEOPHYSICAL LABORATORY 257
TABLE 21. Melting Relations in Binary Sulfide- and Arsenide-Type Systems
VIA
Te
hom I, no cc,
Se
eut
hom I, no cc,
hom I,
eut
Te
'As
1 im Z,
1-2 cc
no inf
hom I, eut,
1 cc
As
VA<
Sb
2 imZ,
1 cc
1 im Z,
1 cc
hom Z, eut,
1 cc
hom Z, ss
Sb
,Bi
1 im I,
1 cc
1 im Z, eut,
1 cc
hom I, eut,
1 cc
hom Z, no cc
hom Z, ss
Bi
'Ge
2 im I,
no inf
hom I, eut,
hom Z,
hom Z, eut,
hom Z, no cc
2 cc
no cc
eut(?),
2 cc(?)
no cc
IVX<
Sn
2 im Z,
1 im Z,
hom Z, eut,
hom I, eut,
hom I,
hom Z, eut,
2 cc
2 cc, eut
1 cc
2 cc
no cc
no cc
Pb
2 im I,
2 im Z,
hom I, eut,
hom Z, eut,
hom I, eut,
hom I, eut,
'Al
1 cc
1 im I,
1 cc
1 cc
no cc
no inf
no cc
hom I,
no cc
i hom Z, eut,
hom I, eut,
1 im I,
1 cc
! 1 cc
1 cc
1 cc
no cc
Ga
no inf
no inf
1 im Z,
hom Z,
hom I, eut,
1 im Z, eut,
IIIA^
2 co
1 cc
1 cc
no cc
In
1 im I,
no inf
1 im I,
hom Z, eut,
hom I, eut,
hom I, eut,
1 cc
2 cc
_l.cc ,
1 cc
2 cc
Tl
2 im I,
2 im Z,
1 im Z,
i im~Z~, i
hom Z, eut,
hom Z, eut,
1 cc
2 im I,
2 cc
no inf
1 cc, eut
no cc, eut J
hom I, eut,
no cc
hom Z, eut,
1 cc
fZn
hom I, 1 cc
hom Z, eut,
1 cc
2 cc
1 cc
no cc
IIB^Cd
2 im Z,
2 im Z,
hom Z, 1 cc
hom I, eut,
hom Z, eut,
hom I, eut,
1 cc
1 cc
1 cc
1 cc
no cc
[Hg
2 im Z,
1 cc
2 im Z,
no inf
2 im Z,
no inf
no inf
hom I, eut,
no inf
hom Z, eut,
hom I, no cc
'Cu
1 im Z, eut,
hom I, eut,
1 cc
1 cc
1 cc
1 cc
1 cc
no cc
Ag
2 imZ,
2 im Z,
1 im Z, eut,
hom Z, eut,
hom I, eut,
hom I, eut,
IB'
Au
1 cc
1 im I,
1 cc
1 im Z,
1 cc
no co
hom Z, eut,
no cc
hom I, eut,
no cc
hom Z, eut,
hom Z, eut,
.
1 cc(?)
1 cc(?)
1 cc
no cc
no cc
no cc
-Ni
1 im I, eut,
1 im Z, eut,
no inf
hom I, eut,
hom I, eut,
hom I, eut,
2 cc
2 cc
2 or 3 cc
2 cc
no cc
Pd
1 im Z,
no inf
hom I, eut,
no inf
hom I, eut,
hom I, eut,
1 cc(?)
1 cc
2 cc
1 cc
Pt
no inf
no inf
no inf
hom I, eut,
hom Z, eut,
hom I, eut,
Co
1 im Z, eut,
1 im Z, eut,
hom I, eut,
no cc
hom Z, eut,
1 cc
hom I, eut,.
1 cc
eut, no cc,
VIII <
Rh
2 cc
no inf
1 cc(?)
no inf
1 cc
no inf
1 cc
no inf
1 cc
hom Z, eut,
1 im I
hom Z, eut,
Ir
no inf
no inf
no inf
no inf
no cc
hom Z, eut,
no cc
eut, 1 cc,
no cc
1 im I
Fe
1 im Z, eut,
2 im Z,
no inf
hom I, eut,
hom I, eut,
eut, no cc,
1 cc
1 cc
2 or 3 cc
1 cc
1 im I
VIIB.
' Mn
2 im Z,
no inf
no inf
hom I, eut,
hom Z, eut,
eut, no cc,
1 cc
2 cc
1 cc
1 im Z
[°r
2 im I,
1 cc
no inf
no inf
no inf
hom I, eut,
1 cc
eut, no cc,
1 im Z
VIBJMo
1 im Z,
1 or 2 cc
no inf
no inf
no inf
no inf
no inf
r
1 im I, eut,
1 cc
no inf
no inf
no inf
no inf
no inf
Abbreviations: hom I, homogeneous liquid; im Z, immiscible liquids; eut, eutectic; cc, congruently melting
compound; ss, complete solid solution between end members; no inf, no information on melting relations.
mineralogically important systems have
been investigated. Additional study is
likely to increase the number of systems
having two liquid immiscibility fields. It
is interesting to note that those systems
that contain a true compound (i.e., a
compound that melts at an invariant
temperature to a liquid of the same com-
position as the solid in the presence of a
vapor that has the same composition as
the solid and liquid) also contain two
liquid immiscibility fields. In these sys-
tems one liquid immiscibility field occurs
on the metal side of the true compound
and one on the sulfur side.
The generalization emerging from the
data in column 1 of Table 21, that all
binary metal-sulfur systems contain one
or two fields of liquid immiscibility, may
perhaps be expanded. The extended rule
258
CARNEGIE INSTITUTION
would include the statement that when a
true compound occurs in a binary metal-
sulfur system a field of liquid immiscibil-
ity exists on the metal side as well as the
sulfur side of the compound. It does not
follow that a compound is "true" if liquid
immiscibility fields occur on both its
metal and sulfur sides.
The metal-sulfur systems without ex-
ception each contain one or two con-
gruently melting compounds (Table 21,
column 1). Classification of these sys-
tems based on the number of compounds
does not appear feasible at this stage,
although as many as seventeen of the
listed systems contain one congruently
melting compound and only six systems
contain two such compounds.
The selenide systems behave very
much like the sulfide systems, as noted
from column 2 of Table 21. The only
exception to the general rule of liquid im-
miscibility is displayed by the aluminum-
selenium system, in which a homoge-
neous liquid field reportedly transects the
entire system. The experimental data
(obtained by Chikashige and Aoki, 1917)
are incomplete, especially in the Al-
Al2Se3 portion of the system. A restudy
with modern equipment might reveal the
existence of a liquid immiscibility field
in this region.
The tellurides are more metallic than
the sulfides and the selenides and display
very different band structures and op-
tical properties. The melting relations
of sulfide and selenide systems, on the
one hand, and telluride systems, on the
other, are markedly different. Binary
tellurium systems involving the elements
from groups V and IVA all contain
homogeneous liquids over their entire
width. The MA elements-tellurium sys-
tems contain immiscible liquid fields.
The only recorded exception again ap-
pears to be provided by aluminum. Re-
interpretation of the experimental data
obtained by Chikashige and Nose (1917) ,
however, indicates that liquid immiscibil-
ity probably exists above 800 °C in the
Al-Al2Te3 portion of the Al-Te system.
The group IIB and group VIII metals-
tellurium binary systems apparently con-
tain homogeneous liquids, as does the
Au-Te system, whereas the other group
IB metals, copper and silver, produce
immiscible liquid fields when associated
with tellurium.
Perusal of Table 21 demonstrates that
tellurium in the majority of the listed
systems behaves much more like arsenic
than like sulfur or selenium. Therefore
the term sulfide-type system should, in
general, be applied to sulfide and selenide
systems only, and tellurides should be
classified with the arsenide-type systems.
The systems As-S, Sb-S, Bi-S, and As-Se,
Sb-Se, and Bi-Se belong to the sulfide-
type systems, not to the arsenide-type.
Arsenide-Type Systems
The melting relations in arsenide-type
systems are characterized by the exis-
tence of a homogeneous liquid field along
the entire length of the liquidus. The
arsenide-metal systems listed in Table 21
indicate only one exception to this rule,
namely, Tl-As. The phase relations in
this system were studied by Mansuri
(1922), who employed open crucibles.
The antimony-metal systems all be-
have like the arsenic-type systems, with
formation of homogeneous liquids. Most
of the bismuth systems behave like the
arsenide systems, but because of the
metallic character of bismuth a number
of them are essentially alloy systems.
Bismuth does not take on the role of
anion and therefore contrasts to sulfur
and selenium, which are the anions in
all their metal compounds, and to tel-
lurium, arsenic, and antimony, which are
generally anions.
Conclusions
The term sulfide-type system in the
past has been commonly used to indicate
a system that, in addition to one or more
typical metals, also contains one or more
of the elements sulfur, selenium, tel-
lurium, arsenic, antimony, or even bis-
GEOPHYSICAL LABORATOKY
259
muth. This term would imply that the
behavior of systems containing a typical
metal together with any one of the last
five elements should be at least similar
to that of the system involving the same
metal and sulfur. In other words, the
sulfide-type systems would be expected
to behave somewhat like the sulfide sys-
tem. Compilation of experimental data
on melting relations in more than 100
pertinent binary systems shows that such
similarity in behavior does not exist. If
the term sulfide type is to have any rele-
vance to classification or grouping of
binary systems, it must be confined to
sulfides and selenides. Only a few tel-
luride systems (those involving the IIIA
and IB groups of metals) are of the
sulfide type.
If we accept this limitation, a general
rule emerges for which no exception is
known: Binary sulfide-type systems con-
tain one or two fields of liquid immisci-
bility as well as one or two congruently
melting compounds.
The arsenide-type systems, according
to the present classification, include all
binary arsenic and antimony systems as
well as most tellurium and bismuth sys-
tems. These systems, without exception,
each contain a homogeneous liquid field;
liquid immiscibility does not occur. Most
of the arsenide-type systems contain one
congruently melting compound, although
very many contain none, a fair number
contain two, and a few three.
All sulfide and selenide binary systems
are of the sulfide type, and all arsenide
and antimonide systems are of the
arsenide type. Telluride systems are
transitional but most belong to the arse-
nide type. Bismuthide systems are tran-
sitional between the arsenide-type and
alloy-type systems but most are of the
arsenide type.
Low-Temperature Phase Relations in
the Fe-S System
L. A. Taylor
It has repeatedly been shown (e.g.,
Desborough and Carpenter, 1965) that
all pyrrhotites in nature represent low-
temperature assemblages that are defi-
nitely stable below 320°C and probably
near 25 °C, regardless of the initial
temperature of deposition. Thus, the
high-temperature chemistry of many
pyrrhotites is masked by the low-tem-
perature phase relations.
As a result of the present investigation,
knowledge of the phase relations involv-
ing the various species of pyrrhotite be-
low 320 °C has been extended by means
of X-ray diffraction studies at controlled
temperatures and by shear pressure ex-
periments. In addition, a new find of the
mineral smythite (Fe3+a.S4) has permitted
a systematic study of its chemical and
physical properties and its relationship
to the other iron sulfide phases. This
smythite from Cobalt, Ontario, is dis-
tinctly different from the type specimens
from Indiana.
Monoclinic Pyrrhotite
Monoclinic pyrrhotite (abbreviated
hereafter as m-po), generally referred to
as Fe7S8, is the most common of the
pyrrhotite minerals and possesses a
measurable solid solution field. This is
shown in Fig. 29, which summarizes the
low-temperature phase relations in the
central portion of the Fe-S system.
Compositional limits. The sulfur-rich
limit of m-po, the subject of much recent
concern (e.g. Arnold, 1969; Yund and
Hall, 1969; Clark, 1966) , was reexamined
in the present study by the following
method. Fe^S with 46.0 atomic % Fe,
synthesized as a homogeneous phase at
700 °C, was annealed at various tempera-
tures between 290° and 75 °C for periods
of up to 12 weeks. The Fex_J3 exsolved
pyrite (py), became monoclinic, as de-
termined by X-ray examination of super-
cell reflections, and adjusted to a compo-
260
CARNEGIE INSTITUTION
400
300
200
140
100-
Troilite
Hexogonal high-temperature / Hexagonal high-temperature
pyrrhotite /
S2Qf
Hexagonal low-temperature
pyrrhotite+pyrite
292°
Hexagonal low-temperature
pyrrhotite
Monoclinic pyrrhotite
+
pyrite
Troilite
+
Hexagonal
low-temperature
pyrrhotite
-75'
Monoclinic pyrrhotite
FVA
1
50 49 48 47 46
Atomic per cent Fe
45
44
Fig. 29. Phase relations at low temperatures in the region from 44 to 50 atomic '% Fe in the
condensed Fe-S system.
sition on the m-po solvus.* This m-po
was annealed at 330°C for 5-10 minutes
and thereby was converted completely
to hexagonal pyrrhotite (h-po) , the com-
postion of which was determined from
the curve for dil0.2) versus composition
of Arnold (1962). The present study in-
dicates that m-po coexisting with py
* Arnold (1969) has reported that equilibrium
is not atttained in such experiments. When
using etching techniques for phase identifica-
tion, he always observed h-po -f- m-po + py as
products, and on the basis of the relative pro-
portions of these phases, he interpreted his re-
sults as indicating that m-po is a metastable
phase with respect to h-po + py.
contains more sulfur (i.e., ~0.25 atomic
% at 200°C, -0.35 atomic % at 100°C)
than indicated by the Fe7S8 formula (see
Fig. 29). The solvus below 250°C is,
within the experimental error, in good
agreement with the experimental findings
of Clark (1966) and Yund and Hall
(1969) and with the reported composi-
tions of m-po in ores (Arnold, 1967) .
The iron-rich limit of the m-po solid
solution field was investigated in the
present study by exsolution experiments
conducted by annealing homogeneous
high-temperature pyrrhotites with vari-
ous compositions between 47.5 and 46.5
GEOPHYSICAL LABORATORY
261
atomic % Fe at temperatures from 280°
to 200°C. Difficulties were encountered
in obtaining consistent results in these
"appearance of phase" experiments be-
cause (1) an uncertainty exists in the
optical identification of small amounts
of h-po occurring with m-po even when
etching techniques are used and (2) the
intensities of the split "10-2" peaks of
m-po are not necessarily indicative of
the presence or absence of h-po, as ex-
plained below. Therefore, supercell re-
flections were used to identify the pres-
ence of h-po and/or m-po. Figure 29
shows the iron-rich solvus of the m-po
phase as a nearly vertical line below
290°C with a composition of 46.75±0.10
atomic °fo Fe.
Thermal stability. The maximum ther-
mal stability of m-po, in equilibrium
with vapor, has been variously reported
as 320°C (Gr0nvold and Haraldsen,
1952), 310°C (Kullerud, 1967), 308°C
(Clark, 1966) , and 304°C (Arnold, 1969) .
However, none of these investigators was
able to successfully reverse the reaction
m-po <=± h-po + py. During the present
study it was determined that m-po broke
down to h-po + py only above 310°C.
This breakdown can be represented by
the reaction m-po <=± h-pOi — »h-po2 + py,
where the subscripts refer to different
compositions of the h-po. The m-po
transforms rapidly (in minutes at330°C)
to an h-po of the same composition ; this
h-po only slowly (in months at 312 °C)
exsolves py and adjusts to a composition
on the pyrrhotite solvus. Therefore, the
inversion of m-po to an h-po of the same
composition was investigated during the
present study.
Monoclinic pyrrhotite of Fe7S8 compo-
sition was found to invert to h-po of
Fe7S8 composition rapidly and reversibly
at 292°±4°C, and unit-cell dimensions
of m-po were determined at various
temperatures below the inversion. A
19-cm Debye-Scherrer camera on a
modified Unicam unit, calibrated with
Si {a25° = 5.4306 A), was used to X-ray
the samples in sealed, evacuated silica
capillaries at elevated temperatures. Fig-
ure 30 shows detailed cell data obtained
from this study after a least-squares re-
finement (LCLSQ) of the X-ray data
according to the program of Burnham
(Year Book 61). The h-po reflection data
obtained at 300 °C were given monoclinic
indices and resulted in the calculated cell
parameters, based on the m-po unit cell,
shown in Fig. 30. Theoretically, the
breakdown of m-po to h-po + py must
occur at a slightly lower temperature
than the inversion to the metastable
h-po; however, the maximum thermal
stability of m-po is stated here as 292° ±
4°C. The high-temperature, single-crys-
tal study of Corlett (1968) indicated a
somewhat lower inversion temperature
for m-po *± h-po, 225°±10°C, whereas
Yund and Hall (1969) concluded that
m-po is metastable above 290°C and
possibly lower.
Although h-po of Fe7S8 composition is
metastable above 292 °C, it is not pos-
sible to retain this hexagonal species as
a product of "normal" quench experi-
ments with annealing temperatures be-
low 310 °C. Consideration of the kinetics
involved in the isochemical reaction of
h-po to m-po explains the discrepancy
between the high-temperature X-ray
(292 °C) and quenching experiments
(310°C). An m-po (Fe7S8) that is an-
nealed at 330°C for 10 minutes to con-
vert it to h-po and then is rapidly cooled
by immersion of the silica tube in water
yields an h-po having the same composi-
tion as the original m-po. In an experi-
ment conducted at 330°C, the silica tube
was allowed to cool in air for 15 seconds
before being chilled to 25°C. The h-po
completely reverted to the monoclinic
structure in these few seconds, a finding
previously reported by Taylor (1968).
An m-po annealed at 304°±1°C and
rapidly chilled in water produced m-po,
whereas an original m-po annealed at the
same temperature but quenched by im-
mersion in liquid N2 gave X-ray evidence
of having retained the hexagonal struc-
ture. Therefore, the determination of the
262
CARNEGIE INSTITUTION
100
200
90.10
300
Temperoture,°C
Fig. 30. Data on unit-cell parameters versus temperature for monoclinic pyrrhotite of Fe7S8
composition. For the cell used a = 2AVS, b = 2A, c = <lC. Maximum thermal stability of the
monoclinic phase is shown by the wavy line at 292°C. The 300°C data are explained in the text.
upper stability temperature in this man-
ner is largely a matter of quenching rate.
Attempts to synthesize m-po from its
presumed equilibrium breakdown prod-
ucts, h-po + py, produced m-po at 280°C
but not at 296 °C and thus agree with
the 292 °C upper stability temperature
obtained from the X-ray study. Experi-
ments with reactants of h-po (48.0
atomic % Fe) +py and h-po (47.0 atomic
GEOPHYSICAL LABORATORY
263
% Fe) + py at 296°C equilibrated to an
assemblage of h-po + py; the h-po com-
positions plot on an approximate ex-
tension of the high-temperature pyrrho-
tite solvus (i.e., ~47.35 atomic % Fe).
At 280°C a charge of h-po (47.5 atomic
% Fe) + py, after 86 days and several
regrindings, had partially reacted to
produce m-po.
"10-2" reflections. X-ray diffraction
charts of m-po usually show a character-
istic splitting of the "10-2" reflection
into two peaks, the (408) -(228) and the
(108) -(228) reflections. With a mixture
of m-po + h-po, the (10-2) of the h-po is
superimposed on the (408) -(228) peak of
the m-po, usually resulting in a greater
intensity for this peak versus the (108)-
(228). Thus, when the lower 20— i.e., the
(408) -(228)— peak is the larger of the
two resolved peaks, it is usually at-
tributed to the presence of h-po in addi-
tion to the m-po (Arnold, 1966). Fre-
quently, however, the reverse situation is
encountered (i.e., /ios^^s). Kullerud
(1967) suggested that this "reversed" in-
tensity situation may be a function of
the temperature of formation of the
m-po. During the present study it was
determined that the resolution and rela-
tive intensities of the (408) -(228) and
(408) -(228) reflections are not correla-
tive with annealing temperature but are
largely a function of grain size and
smear-mount preparation for X-ray
study. Different portions of the same
smear mount may show grossly different
relative intensities.
From X-ray diffraction studies at
25 °C of m-po formed by annealing previ-
ously synthesized high-temperature h-po
of Fe7S8 composition at 300°, 200°, and
100 °C, it was found by least-squares re-
finement based on 15 reflections that the
/? angle does not vary as a function of
the temperature of formation, as sug-
gested by von Gehlen {Year Book 62)
based on the resolution and measure-
ment of the "10-2" peaks. The (3 angle
does change slightly as a result of ther-
mal expansion (see Fig. 30), but the
higher temperature /3 angle is not pre-
served upon cooling to 25 °C.
Effects of grinding and pelletizing. In
order to hasten the attainment of equi-
librium, certain techniques are routinely
incorporated as part of the experimental
procedure; charges are commonly (1)
finely ground to produce more fresh sur-
face areas for reaction and/or (2)
pressed into pellets to provide more inti-
mate contact for the reacting phases.
The effects of shear pressures introduced
by these techniques, however, can lead to
contradictory results (Taylor, 1968).
The effect of grinding on the X-ray
powder diffraction pattern of m-po is
pronounced. An m-po of Fe7S8 composi-
tion was subjected to various durations
of regular hand grinding under toluene
(to prevent oxidation) . At the end of
each grinding interval, a portion of the
ground material was X-rayed. Examina-
tion of the diffractometer tracings re-
vealed that the (408) -(228) and (108)-
(228) reflections of m-po became diffuse
and were gradually replaced, with in-
creased grinding time, by a single reflec-
tion. Supercell reflections became diffuse
and could not be positively identified
because of the weak intensities encoun-
tered. The thermal effects of grinding
were not large; a thermocouple placed in
the toluene during grinding showed a
temperature increase of <1°C. Grinding
may have transformed the monoclinic
phase into a hexagonal one, or broaden-
ing of the (408) -(228) and (¥08) -(228)
reflections may have caused them to
merge.
Monoclinic pyrrhotite of Fe7S8 com-
position was also subjected to directed
pressure in a small cylinder press to see
if simple deformation of the crystals
would cause the "10-2" and supercell re-
flections to become diffuse. Instead, after
only 5 minutes, the (408) -(228) and
(408) -(528) peaks of the m-po were re-
placed by a single sharp peak. Supercell
reflections remain relatively sharp; al-
though the results obtained from several
experiments are not entirely reproducible,
264
CARNEGIE INSTITUTION
the general effect of this pressure was to
produce new supercell reflections, listed
below for a typical experiment (Table
22).
The significance of these shear-pres-
sure induced effects is not known at
present. Monoclinic pyrrhotite might be
a stable phase in the condensed system,
the pressures produced during grinding
or pelletizing transforming it into a high-
pressure modification of h-po, or perhaps
m-po is a metastable phase in the con-
densed system, as originally suggested by
Hall and Yund (1966) and recently
stressed by Arnold (1969) . The effects of
shear pressure on m-po should be con-
sidered when we interpret results ob-
tained using reactants that have been
subjected to grinding or pelletizing.
Hexagonal Pyrrhotite
Compositional limits. The low-tem-
perature iron-rich limit of h-po (coexist-
ing with troilite [tr] as shown in Fig. 29)
was investigated by exsolution experi-
ments in which previously synthesized
homogeneous po exsolved to a mixture
of tr and h-po. A diffractogram of the
charge showed a split "10-2" peak simi-
lar in appearance to that of m-po ; how-
ever, one peak was from tr and the other
was from the h-po. The d values of these
peaks were used to obtain the composi-
tion of the phases. The tr was always
stoichiometric, and the compositions of
the h-po are in good agreement with the
results of Yund and Hall (1968) but
differ slightly from those of Arnold
(1969). It is this splitting of the "10-2"
that led Moh and Kullerud (Year Book
63) to believe that they had synthesized
TABLE 22. Effects of Pelletizing on Supercell
Reflections of Monoclinic Pyrrhotite (Fe7S8)
Total Time of
Applied Pressure,
minutes Supercell Reflections, A
0
10
40
2520
4.70 ... 5.27 5.72 ...
... 4.92 5.29 5.72 ...
... 4.92 ... 5.74 5.88
... 4.90 ... 5.72 5.87
m-po from FeS + S in aqueous solutions
held at 100°C for 11 days; they produced
a tr + h-po assemblage whose composi-
tions were similar to those found during
the present study.
The sulfur-rich limit of the low-tem-
perature h-po field from ~290°C down is
depicted as approximately vertical in
Fig. 29, in agreement with the observa-
tion that h-po in association with m-po
in natural assemblages is restricted in
composition (Arnold, 1967). A point of
47.35 ±0.10 atomic % Fe at 296°C was
determined during the present investiga-
tion. This value is in agreement with
previous values of 47.45 (Yund and Hall,
1969) and 47.2 atomic % Fe (Arnold,
1969).
X-ray diffraction at elevated tempera-
tures. High-temperature X-ray data
were obtained on hexagonal pyrrhotites
with the Unicam unit. The pyrrhotites
were prepared at 700 °C, quenched to
25°C, and then annealed at 250°C for
1 month prior to X-ray examination. At
least 15 reflections between 40° and 180°
20 (FeKa) were measured. Most of the
unit-cell data presented refer to the
simple NiAs cell. This convention was
adopted because it would provide some
common factors for comparison at vari-
ous temperatures and compositions and
because of the uncertainties associated
with the presence of various Fe^S
supercells, many of which are undoubt-
edly quench products.
The maximum thermal stability of the
troilite superstructure (i.e., a transition),
in equilibrium with vapor, has been vari-
ously reported by Roberts (1935),
Haraldsen (1941), Moh and Kullerud
{Year Book 63), Sugaki and Shima
(1965), and Arnold (1969) as 139°-144°,
138°, 139°, 155°, and 150°C, respec-
tively. High-temperature X-ray exami-
nation of FeS during the present study
places this transition temperature at
140°±5°C, confirming the earlier ex-
perimental work.
Figure 31 shows the breaks in slope in
a plot of cell volume versus temperature
GEOPHYSICAL LABORATORY
265
59
100
200 300
Temperature, °C
400
500
Fig. 31. Data on unit-cell volume versus temperature for selected Fei_xS compositions. The
simple NiAs (B8) cell was used.
of FeS due to the a and (3 transitions at
140° and 320°C, respectively. The AV
associated with the a transition is
^ + 0.22 A3/mole-FeS and the effect of
pressure on the transition, using the AH
from Robie and Waldbaum (1968),
would be to raise the temperature about
2.3°C/kb. However, Kullerud, Bell, and
England (Year Book 64) determined the
curve by differential thermal analysis
from about 2 to 19.7 kb and found that
pressure lowers this transition tempera-
ture by 2.2°C/kb, indicating a negative
A7. This apparent discrepancy suggests
that a high-pressure polymorph of FeS
becomes stable below 2 kb, resulting in
an arrangement of univariant curves
similar to those reported for Ni3S4 by
Kullerud ( Year Book 67) .
At temperatures below the a transition,
FeS has the troilite superstructure. Above
140 °C but below 320 °C several weak
reflections were observed for FeS, as well
as for the other compositions examined,
which could not be indexed on the basis
of the simple NiAs cell, suggesting the
presence of some supercell. Systematic
changes in these reflections were not ob-
served, however, possibly owing to the
insensitive nature of the examination of
the specimens — as powder samples.
Above 320 °C no such reflections were
observed, and it is concluded that Fei_J3
above the /? transition possesses the
simple hexagonal BS structure of NiAs.
In a refinement based on 41 reflec-
tions, troilite (with supercell a=V3A,
c = 2C) at 25 °C was determined to have
a = 5.966±0.001 A, c = 11.755 ±0.003 A,
and V = 362.2 ±0.1 A3, in close agreement
with values previously reported.
Hexagonal pyrrhotites of various com-
postions were also examined at elevated
temperatures. Figure 31 depicts plots of
cell volume versus temperature for pyr-
rhotites with 50.0 (FeS) , 49.0 (Fe0.96iS) ,
and 48.0 (Fe0.923S) atomic % Fe. It
should be noted that the 25 °C volumes
for the last two compositions do not plot
on an extension of the higher temperature
266
CARNEGIE INSTITUTION
data and may be related to the discon-
tinuity in the plot of cell parameters
versus composition described by Fleet
(1968). The pyrrhotites with 48 and 49
atomic % Fe at 25 °C are within the tr +
h-po + 7 univariant field (Fig. 29) and
are thus metastable at this temperature.
Thermal Expansion Data
Thermal expansion is commonly ex-
pressed by means of the thermal-expan-
sion coefficient: cc= 1/7 (dV/dT) P. The
pressure over Fe-S phases within the
temperature range of examination are
low (/s2^ 10-50 to 10-5 atm), and for all
practical purposes, a ^ 1/V0 {dV/dT) ,
where V0 represents the volume at some
reference temperature.
The procedures for obtaining the ther-
mal-expansion data were described in
the previous sections. Figure 32 shows
isotherms at 50 °C intervals for the ho-
mogeneous Fe^S field. Thermal-expan-
Fig. 32. Data on unit-cell volume versus composition at elevated temperatures for Fei-sS
compositions. The simple NiAs (B8) cell was used.
GEOPHYSICAL LABORATORY
267
TABLE 23. Thermal Expansion Data for the Fe-S Compounds
Temperature
Aa/100°C,
Ac/100°C,
Composition *
Range, °C
a,rxi^t
%t
%t
FeuoooS
25-140
4.5
0.25
—0.34
140-320
12.5
0.84
—0.37
320^50
7.2
0.28
—0.04
Feo.MiS
115-320
11.6
0.67
—0.24
320-450
6.1
0.30
—0.05
Feo.923S
75-320
12.6
0.70
—0.17
320-450
6.9
0.34
—0.02
Feo.8750
25-292 §
9.0
0.54
-0
292-320 II
~8
0.43
—0.22
Fe3.25S4 (smythite)
25-75
15.7
0.74
-0
75-155
11.1
0.38
+0.37
FeS2 IT (pyrite)
25-300
1.1
0.11
* All compounds listed are synthetic except for the smythite, which was
found at Cobalt, Ontario.
f oc= l/Vo(dV/dT), where Vo represents the volume at the lowest tem-
perature of the temperature range under consideration.
t a and c are not strictly linear functions of temperature ; however, the
cell parameters versus temperature were plotted and a "best-fit" straight
line was drawn through the data points. % Aa/100°C=Aa X 100/a0 X 100°C,
where a0 represents the a dimension at the lowest temperature of the tem-
perature range under consideration.
§ Refers to the monoclinic cell, a = 2-4V3, 6 = 2.4, c = &C.
II Metastable hexagonal pyrrhotite.
H a25o = 5.4175 ± 0.0001 A.
sion coefficients (a) determined during
this study for several h-po compositions
and for other iron sulfides are compiled
in Table 23.
Anisotropy in pyrrhotite is well dis-
played by the thermal data obtained dur-
ing this study. At a given temperature,
the c dimension varies greatly with com-
position, whereas the a dimension varies
much less. For a given composition, how-
ever, a increases greatly and c actually
decreases slightly with increasing tem-
peratures ; the net effect is an increase in
volume with increase in temperature.
This volume increase with temperature
is much larger than that reported for any
other sulfide mineral except pentlandite
(Morimoto and Kullerud, Year Book 63) .
Smythite, Fes+xS^
Smythite was discovered with calcite
and sulfide minerals in a nearly hori-
zontal cross vein closely associated with
silver-bearing veins at the Silverfields
Mine, Cobalt, Ontario. Chemical and
physical data show that this smythite is
distinctly different from that of the type
locality at Bloomington, Indiana (Erd,
Evans, and Richter, 1957) .
Smythite from Cobalt occurs in two
distinct mineral assemblages. In one it is
associated with pyrite, marcasite, and
sphalerite containing 9±1 mole % FeS;
in the other with galena, chalcopyrite,
monoclinic pyrrhotite, and sphalerite
containing 13 ±1 mole % FeS (sphalerite
compositions were determined by micro-
probe analyses) . Bladed pyrite inclusions
within smythite contain 5.4 wt % Ni.
This Ni content is one of the highest
reported for a natural pyrite and is not
consistent with the "dry" phase relations
as determined at low temperatures in
the Fe-Ni-S system; it may be related
to the metastable pyrite compositions
described by Clark and Kullerud (1963).
Electron-microprobe analyses of the
smythites from these two assemblages
are shown in Table 24. No other elements
in amounts greater than 0.1 wt % were
detected. The analyses show a difference
in the compositions of the smythites ; the
one coexisting with monoclinic pyrrhotite
268
CARNEGIE INSTITUTION
TABLE 24. Electron-Microprobe Analyses of Smythites from Cobalt,
Ontario, wt %
Smythite
Theoretical Formulae
po py
Assemblage Assemblage
Precision
Fe3Si Fe3.2RS4
Fe 58.5 58.1
Ni 0.4 0.5
S 40.9 41.5
0.2
0.1
0.3
56.64 58.60
43.36 41.40
contains 0.4 wt % more Fe than the one
with pyrite, but the difference is near the
limits of precision. These compositions
indicate a metal/sulfur ratio of ap-
proximately 13/16, halfway between
Fe7S8 (monoclinic pyrrhotite) and Fe3S4
(stoichiometric smythite) , and lead to the
formula Fe3+J34, where x ~ 0.25 (see
theoretical formula in Table 24), a cell
content of 'FeH5Fe2^25Si2-
Density determinations with Clerici
solution were made at 25 °C on the
smythite from Cobalt and gave 4.33 ±
0.01 g/cc. The calculated density, for a
composition of Fe3.25S4 and the cell pa-
rameters mentioned below, is 4.319 g/cc.
In comparison, the Indiana specimen has
a measured density of 4.06 g/cc and a
calculated density of 4.09 g/cc (Erd,
Evans, and Richter, 1957).
Smythite does not break down readily
upon heating in sealed, evacuated silica
tubes. After 194 days at 210° ±5°C, only
partial breakdown to monoclinic pyr-
rhotite and pyrite was observed, a result
compatible with the phase relations as
shown in Fig. 29. Attempts to synthesize
smythite in the "dry" Fe-S system with
pelletized mixtures of monoclinic pyr-
rhotite (Fe7S8) + pyrite and monoclinic
pyrrhotite + S were unsuccessful. A hexa-
gonal pyrrhotite of 46.0 atomic % Fe
presynthesized at 700 °C was observed to
exsolve pyrite and change to the mono-
clinic form at temperatures down to
75 °C, suggesting that smythite is stable
only below this temperature.
The unit-cell parameters of the smyth-
ite from Cobalt were determined at
various temperatures (Fig. 33) by the
high-temperature X-ray technique previ-
ously described. At 25°C, a = 3.4651 +
0.0005 A, c = 34.34±0.02 A, 7 = 357.1±
0.2 A3, referred to the cell used by Erd,
Evans, and Richter (1957), apparently
not the true cell (see below). These di-
mensions are approximately the same as
those of the original samples from In-
diana (i.e., a = 3.47 A, c = 34.5 A). Fig-
ure 33 shows a discontinuity in the cell
volume of smythite as a function of
temperature at approximately 75 °C.
These curves were determined by X-ray
analysis of smythite, first at 25 °C, and
then at successively higher temperatures,
followed by a reexamination of each
temperature, proceeding from 152 °C
down to 25 °C. The exact nature of this
break is not known at present; the ap-
parent "transition" is reversible, how-
ever, and may be indicative of the pres-
ence of a high-temperature polymorph of
this smythite.
Monoclinic pyrrhotite and smythite
are indistinguishable in polished section
and were identified with certainty only
by X-ray diffraction studies. Precession
photographs of smythite single crystals
showed that twinning by reticular mero-
hedry (twin law: 180° rotation about
[00-1]) is universal; an intensity study
indicated equal volumes for the two indi-
viduals of the twin. The basal cleavage
that is very prominent in the Indiana
specimens is completely lacking in the
Cobalt samples. Additional Fe between
S layers of the basic Fe3S4 sheet struc-
ture, with accompanying omission of Fe
from other sites, could account for this
physical property. Precession photo-
graphs of powdered smythite from Co-
balt show complete randomness of orien-
GEOPHYSICAL LABOEATOEY
362
269
25
50 75 100
Temperature, °C
Fig. 33. Data on unit-cell volume versus temperature for smythite from Cobalt, Ontario.
tation. The very weak basal reflections
in diffractometer tracings obtained on
powder-smear mounts of the Cobalt
samples are probably caused by this
general absence of basal cleavage, which
if present would produce some preferred
orientation.
The space group of the Indiana smyth-
ite was given as R3m (Erd, Evans, and
Richter, 1957). Precession photographs
of the smythite from Cobalt contain dif-
fuse spots which would require a cell with
a doubling of the a axis. This larger cell,
the true cell, does not possess the Rxx
aspect of the subcell. Preliminary in-
vestigations show the diffraction aspect
of the true cell to be of lower symmetry,
possibly monoclinic.
Much of the smythite at Cobalt is
present as single pure masses. The oc-
currence of monoclinic pyrrhotite and
pyrite in the correct proportions to react
upon cooling to form smythite with no
excess pyrrhotite or pyrite seems ex-
ceedingly unlikely. The chemical inert-
ness of pyrite is also not favorable to
such a reaction. It therefore appears
probable that this smythite was de-
posited directly from solution at a low
temperature.
A second compound of Fe3S4 composi-
tion has been reported as the mineral
greigite (Skinner, Erd, and Grimaldi,
1964). Actual polymorphic relationship
between greigite and smythite, as sug-
gested in the literature, has never been
demonstrated. The 2 wt % Fe in the
Cobalt smythite in excess of that present
in an Fe3S4 formula would seem to indi-
cate that these minerals are not poly-
morphs. By analogy with other M3S4-
type sulfides, Kullerud (Year Book 67)
concluded that if smythite and greigite
are polymorphs, smythite should be the
higher temperature phase. Therefore, the
breakdown of smythite, with increasing
temperature, should be to monoclinic
pyrrhotite (composition near Fe0.875S)
and pyrite (see Fig. 29) . Equations 1 and
2 show this reaction for stoichiometric
270
smythite and iron-rich smythite, respec-
tively.
Fe3S4^> 2.667 Fe0.875S + 0.667 FeS2 (1)
Fe3.25S4<F± 3.333 Fe0.875S
+ 0.333 FeS2 (2)
At ~75°C, using the cell volumes as
calculated from the thermal-expansion
data given in the previous section and
assuming that the thermal-expansion co-
efficient for Fe3S4 is approximately the
same as for Fe3.25S4, we obtain for equa-
tions 1 and 2 :
72.78 cm3 = 46.86 cm3 + 16.02 cm3
A7=-9.90cm3 (1)
72.25 cm3 = 58.54 cm3 + 8.01 cm3
A7=-5.70cm3 (2)
These A 7 values, the largest calculated
to date for any sulfides, indicate that
the upper stability curve for smythite
should have a decided negative slope, a
factor perhaps responsible for the scar-
city of smythite in nature.
The calculations above also suggest
that pressure tends to favor the forma-
tion of the iron-rich variety, a suggestion
compatible with the occurrence of stoi-
chiometric smythite in geodes at Bloom-
ington, Indiana, and the formation of
iron-rich smythite in the silver-bearing
veins at Cobalt, Ontario. The composi-
tion of smythite may be indicative of
the pressures existing during its for-
mation.
The Ni-Sb-S System
K. L. Williams * and G. Kullerud
Antimonides and sulfantimonides are
constituents of many sulfide ore deposits,
but despite the existence of at least four
binary compounds in the Ni-Sb system,
nickel antimonides appear to be rare in
nature. The only one described to date
is the mineral breithauptite (NiSb).
Ullmannite (NiSbS) is the only mineral
belonging to the Ni-Sb-S system that has
been reported. The present study was
undertaken to clarify confusing aspects
concerning the existence and stabilities
of phases in the Ni-Sb binary system
* The Australian National University.
CARNEGIE INSTITUTION
and to determine the phase relations
in the ternary Ni-Sb-S system. Isotherms
at 500° and 350°C in the Ni-Sb-S system
were studied by quenching experiments,
followed by optical, X-ray diffraction,
and electron-microprobe examination of
the quenched products. Experiments were
performed at temperatures between 350°
and 500 °C to resolve previous conflicts
in that portion of the Ni-Sb phase dia-
gram of geological interest and to estab-
lish solid solution limits.
Nickel takes considerable amounts of
antimony into solid solution. All runs
of bulk compositions between 20 and 40
wt % Sb contained this (Ni,Sb)88 phase
saturated on Sb. It is readily identified
in polished sections by its creamy white
color and high reflectivity. No substan-
tial change in composition with tem-
perature was observed; analyses of (Ni,
Sb)ss from four runs between 335° and
500°C all showed 15.5 ±1.0 wt % Sb.
Ni3Sb was identified in all runs of bulk
composition between 20 and 42 wt % Sb.
It is characterized in reflected light by a
distinctive mauvish brown color; it is
weakly anisotropic, with no detectable
"reflection pleochroism." Its X-ray dif-
fraction pattern is identical with that
given by Furst and Halla (1938). Re-
sults of microprobe analyses were in
agreement with the stoichiometric com-
position (40.9wt%Sb).
The Ni5Sb2 phase was produced in all
runs of bulk composition between 46 and
62 wt % Sb. In reflected light it is pale
brownish in color, with weak bireflection ;
it is moderately anisotropic, with brown
polarization colors. Microprobe analyses
showed a composition of 45.0 ±0.5 wt %
Sb for this phase in all runs of bulk
composition between 46 and 62 wt % Sb ;
this result agrees well with the Ni5Sb2
formula proposed by Eremenko and
Kruchinina (1951) rather than the Ni7
Sb3 formula (47.1 wt % Sb) suggested
by Sibata (1941). No variation of com-
position with annealing temperature was
observed.
NiSb was identified in all binary runs
of bulk composition between 46 and 80
wt % Sb. In reflected light it is super-
ficially similar to Ni5Sb2, but NiSb is
more pinkish in color, with higher reflec-
GEOPHYSICAL LABORATORY
271
tivity and bireflectance, and is more
strongly anisotropic.
Microprobe analyses showed the com-
position of homogeneous NiSb to vary
from 64.0 wt % Sb (when in equilibrium
with Ni5Sb2) to 67.5 wt % Sb (in equi-
librium with NiSb2) ; the latter is the
composition of stoichiometric NiSb.
Neither limit showed any significant
variation with annealing temperature.
The NiSb2 phase was observed in all
binary runs containing more than 70 wt
% Sb. It is creamy white in reflected
light, with moderately high reflectivity,
and is fairly strongly anisotropic. Micro-
probe analyses showed a compositional
range from 80.7 wt °fo Sb (corresponding
almost exactly to stoichiometric NiSb2)
to 84.0 wt % Sb (close to 83.8 wt % Sb,
the composition of Ni2Sb5). These data
support the formula NiSb2+a! given by
Rosenqvist (1953) and indicate that x
may range from 0 to 0.5 ; the latter agrees
with the formula Ni2Sb5 proposed by
Osawa and Sibata (1940) . No change in
the limiting compositions of NiSb2+a, was
observed over the temperature range in-
vestigated. Microprobe analyses of Sb in
equilibrium with NiSb2+a; confirmed the
negligible solubility of Ni — of the order
of 0.2 wt % or less.
The only ternary compound known in
the Ni-Sb-S system is NiSbS, correspond-
ing to the mineral ullmannite. Ullman-
nite is cubic, space group P2X3, a0 = 5.88
A, Z = 4, S.G. = 6.90 (Takeuchi, 1957).
Its structure resembles that of pyrite,
with the S2 group in pyrite replaced by
SbS. In natural occurrences, cobalt and
small amounts of iron may substitute for
nickel, and arsenic and bismuth for anti-
mony. It occurs most frequently in asso-
ciation with other nickel minerals, such
as gersdorffite, niccolite, and breithaupt-
ite. Ternary isotherms for 500° and
350°C are shown in Figs. 34 and 35 (all
500°C
Fig. 34. Phase relations in the Ni-Sb-S system at 500°C. All
coexist with vapor.
272
CARNEGIE INSTITUTION
350°C
N'3Sb Ni5Sb2
NiSb
NiSb2
Fig. 35. Phase relations in the Ni-Sb-S system at 350°C. All phases and phase assemblages
coexist with vapor.
phases and phase assemblages coexist
with vapor) .
The solubility of the third element in
each of the binary compounds was in-
vestigated by microprobe analysis of
phases from appropriate runs. The solu-
bilities were found to be uniformly low,
in no run exceeding 0.2% and in most
runs being lower than the detection
limits.
Within the limits of experimental and
analytical error, NiSbS showed no de-
parture from stoichiometry in any of the
equilibrium assemblages. Its thermal
stability was investigated by differential
thermal analysis on homogeneous syn-
thetic material, and melting was ob-
served at 752° ±6°C.
The compositions of Nil-* and NiSb
in various three-phase (+ vapor) assem-
blages were investigated by X-ray dif-
fraction and microprobe analyses. At
500 °C ccNii-^S coexisting with Sb2S3 and
NiSbS was, from interplanar spacings,
found to contain 36.5 wt °fo S, whereas in
equilibrium with NiSb and NiSbS it con-
tains 35.5 wt °fo S. Microprobe analyses
were consistent with these average com-
positions but again showed some internal
variation ( + 0.3 wt % S). At 350°C
ccNii-^S coexisting with Sb2S3 was, from
microprobe analyses, found to contain
36.8±0.3 wt % S, and /JNi^S contained
35.8 ±0.2 wt °fo S. These compositions
are all consistent with the data of Kul-
lerudand Yund (1962).
The compositions of NiSbS8 when co-
existing with Ni3S2, Ni7S6, or NiS, de-
GEOPHYSICAL LABORATORY
273
termined by microprobe analysis, all fall
within the range 64.8 ±0.2 wt % Sb at
500°C and 64.7±0.4 wt % Sb at 350°C.
This study shows that the compounds
Ni3Sb and Ni5Sb2 can exist only under
very low sulfur fugacities, consistent in
magnitude with those stabilizing heazle-
woodite (Ni3S2). Under such conditions,
attained for instance during serpentiniza-
tion of peridotites, the activity of anti-
mony is generally too low to stabilize
Ni3Sb and Ni5Sb2 as mineral species.
Breithauptite (NiSb) is not uncommon
in ores. The phase relations diagramed in
Figs. 34 and 35 show that it coexists
stably with minerals such as millerite
(NiS) and ullmannite. The NiSb2 com-
pound has not been reported as a mineral
species. Since it can coexist with breit-
hauptite and ullmannite or with ullmann-
ite and antimony, which has been re-
ported from many localities, we expect
NiSb2 to occur as a mineral in many ores.
The System Cu-S-0
L. A. Taylor and G. Kullerud
Minerals of the Cu-Fe-S-0 and Cu-
S-O-H systems occur in thousands of
localities, and knowledge of the Cu-S-0
system is prerequisite to exploration of
these geologically important quaternary
systems. The metallurgical literature
contains abundant data on the Cu-S-0
system, obtained from high-temperature
experiments performed in containers
open to the air or in apparatus designed
to measure vapor pressures. With the
exception of a few publications (e.g.,
Reinders and Goudriaan, 1923) , the pres-
ence of a ternary liquid phase is not
mentioned. Kullerud and Yund (Year
Book 61) conducted a preliminary ex-
amination in this system and found that
a liquid field transects the system, pro-
hibiting tie lines between the ternary and
binary sulfide phases even at tempera-
tures as low as 250 °C.
The ternary solid phases encountered
during our current investigation are
CuS04, corresponding to the mineral
chalcocyanite, and CuO-CuS04, corres-
ponding to the mineral dolerophanite. No
evidence was found for the stable exis-
tence of Cu2S04 or any other ternary
compounds above 200°C. Both CuS04 and
CuO-CuS04 are stable from 200°C to
temperatures in excess of 700 °C.
Figure 36 shows a schematic plot of
the phase relations at 500°C. The as-
semblage Cu + Cu20 + Cu2S is stable
from high temperatures (>850°C). Tie
lines between Cu20 and CuS04 are stable
below 510°±5°C. Above this tempera-
ture the ternary liquid field expands to
intersect this join. With decreasing tem-
perature the homogeneous liquid field is
divided into two fields by the establish-
ment of tie lines between Cu9S5 and
CuS04 at 434°±5°C, as determined by
quenching experiments. The presence of
H20 in the CuS04 drastically lowers this
temperature (i.e., to below 360°C). The
Cu2S-CuS04 join is stable below 390°C.
The vapor pressures on the sulfur side of
this join are appreciable. A DTA tube
containing a mixture of very pure CuS04
and Cu9S5 broke at 520 °C in spite of an
external confining pressure of 65 bars,
and the internal pressure must have been
well in excess of 150 bars. The gaseous
species are mainly sulfur oxides, prin-
cipally S02. Even higher vapor pressures
are encountered on the CuS-CuS04 join.
A silica tube containing a mixture of CuS
and CuS04 exploded at — 270°C. One
containing a mixture of CuS04 and S
exploded below 200°C, and the vapor
pressure over this assemblage must ap-
proximate that of pure S02 (i.e., ~100
barsatl80°C).
Charges consisting of CuO and CuS04
react to form CuO-CuS04 at tempera-
tures from 700° to 200 °C. The positions
and intensities of X-ray reflections of the
synthetic phase are not wholly consistent
with the data for the mineral doleropha-
nite (Mrose, 1961). Tie lines between
Cu20 and CuO • CuS04 are stable at high
temperatures (i.e., >500°C) but are not
observed at 350°C. The details of the
changes in phase relations as a conse-
274
CARNEGIE INSTITUTION
500 °C
Atomic per cent
Fig. 36. Phase relations in the Cu-S-0 system at 500°C. All phases and phase assemblages are
in equilibrium with vapor. Portions of the system are schematic.
quence of the disruption of the Cu20-
CuO-CuS04 join are not known at
present.
The establishment of the Cu2S-CuS04
join restricts the positions of liquid fields
as shown schematically in Fig. 37. The
liquid present in the Cu20-Cu2S-CuS04
field persists with decreasing tempera-
ture, to a ternary eutectic at 340° ±4°C,
as determined by quench-type and DTA
experiments. The ternary liquid is ruby
red to resinous brown and is readily
quenched to a glass; this behavior is
unique for liquids containing metal, sul-
fur, and oxygen. Depending on the cool-
ing rate, the liquid partially crystallizes
to a mixture of Cu20, CuS04, and Cu2S.
Below 340 °C the remaining ternary
liquid field is restricted to the S side of
the Cu2-J3 + CuS04 join, and with de-
creasing temperature the boundaries of
this liquid field withdraw toward the
S-0 join, which apparently is reached at
about 100 °C. Tie lines exist between
Cu2-arS (CunS5) and this liquid to below
260°C, prohibiting stable coexistence of
CuS and CuS04.
Mixtures of CuS and CuS04 heated at
250° ±5°C for 90 days show partial reac-
tion to produce a small amount of Cu9S5
and possible liquid, suggesting that the
CuS-CuS04 join becomes stable below
250 °C. This ternary liquid cannot be
quenched but crystallizes, on even the
fastest possible chilling, to sulfur and
a waterlike phase, which in turn com-
monly partially crystallizes below 50°C
to icelike needles, interpreted here as be-
ing a form of CuS04. A silica tube con-
taining this ternary liquid at 25 °C pos-
sesses a vapor pressure in excess of 1 atm,
for the tube will "pop" when broken and
the liquid evaporates rapidly (in sec-
onds), giving off a very strong S02 odor.
The behavior of this liquid field at low
GEOPHYSICAL LABORATORY
275
350°C
Atomic per cent
Cu20
Fig. 37. Phase relations in the Cu-S-0 system at 350°C. All phases and phase assemblages are
in equilibrium with vapor. Portions of the system are schematic.
temperatures near the sulfur-oxygen join
was not determined.
Below the ternary eutectic tempera-
ture of 340°C, the assemblage Cu20 +
Cu2S+CuS04 remains stable with de-
creasing temperature to 215° ±15°C, the
temperature of the reaction point repre-
sented by the equation Cu20 + CuS04 +
F<f±Cu2S + CuO. At 215°C tie lines are
established between Cu2S and CuO; this
assemblage is stable to below 130 °C and
may well exist at room temperature.
Tie lines between Cu9S5 and CuS04
exist to temperatures below 130 °C. At
some lower temperature, as yet unde-
termined, the assemblage CuS + CuO be-
comes stable, as represented by the equa-
tion Cu9S5 + CuS04 + 7^±CuO + CuS.
Additional complications exist at low
temperatures in this portion of the sys-
tem as a result of developments on the
Cu-S join (e.g., stabilization of blue-re-
maining covellite, djurleite, and anilite
[Cu7S4]).
The mineral assemblages of geologic
interest within the Cu-S-0 system at low
temperatures but above 157°C are native
copper + cuprite + chalcocite, cuprite +
tenorite + chalcocite, and digenite + ten-
orite + covellite. The copper oxide min-
erals are widespread in occurrence and
are common in oxidation zones of many
copper deposits, where they generally oc-
cur as alteration products of chalcocite,
chalcopyrite, and other copper sulfides.
The present study shows that even
though the assemblage copper + cuprite
+ chalcocite is stable to high tempera-
ture (>850°C), the assemblage cuprite
+ tenorite + chalcocite is stable only be-
low 215 °C and the assemblage digenite +
tenorite + covellite (aside from complica-
tions discussed above) is stable only to
a temperature, as yet undetermined,
below 130 °C. Occurrences of the minerals
chalcocyanite and dolerophanite are very
restricted in nature and are reported
from fumaroles associated with recent
276
CARNEGIE INSTITUTION
eruptions of Mt. Vesuvius. That they are
very unstable in the presence of water
accounts for their rarity. Although many
sulfates of copper are found in nature,
most are hydrous and belong to the com-
plex Cu-S-O-H system.
High-Pressure Differential Thermal
Analysis
Acanthite-Type Compounds
P. M. Bell and G. Kullerud
The acanthite group of compounds
contains about twenty known species, of
which more than a dozen have been re-
ported to occur as minerals. These com-
pounds are sulfides, selenides, and tellu-
rides of group IB metals and have a
cation-to-anion ratio of, or about, 2:1.
The common minerals acanthite (Ag2S)
and chalcocite (Cu2S) belong to this
group. In the condensed system these
compounds all have been reported to
occur in at least two distinctly different
crystallographic forms, of which the
room-temperature polymorph apparently
is monoclinic in all instances and the
high-temperature form, which is non-
quenchable, is cubic.
We have performed high-pressure dif-
ferential thermal analysis (DTA) ex-
periments on synthetic Ag2S to increase
our knowledge of the behavior of this
mineral and particularly to gain a better
general understanding of the acanthite
type of compounds.
Kracek (1946) found that in the con-
densed system the monoclinic form of
Ag2S is stable at room temperature and
inverts at 177°C to a body-centered
cubic polymorph, which in turn inverts
to a face-centered cubic form at 586 °C
when excess Ag is present and at 622 °C
when excess S occurs. Stoichiometric syn-
thetic Ag2S, which was used in our ex-
periments, inverts in the presence of
vapor to the face-centered cubic form at
about 600°C.
Roy, Majumdar, and Hulbe (1959)
studied the effect of pressure on the
temperature of the monoclinic ^± body-
centered cubic inversion and found that
pressures up to 1225 atm increase the
inversion temperature by about 4°C/kb.
Bridgman (1937) found Ag2S to have a
high-pressure nonquenchable polymor-
phic form. The data by Bridgman (1937)
and by Roy, Majumdar, and Hulbe
(1959) are incorporated in the pressure-
temperature diagram of Fig. 38. As re-
corded by our method, the heat effect
associated with the transition reported
by Bridgman (1937) is very weak and
diffuse. The crystal structure of the high-
pressure form is not known, and the form
is not preserved on cooling and release
of pressure. In analogy with the behavior
of Cu2S under pressure, as reported by
Skinner, Boyd, and England (1964), the
high-pressure form of Ag2S (which we
shall refer to as the 8 form) may have
tetragonal crystal structure. Extrapola-
tion of the monoclinic ^± 8Ag2S reaction
curve toward decreasing temperature
indicated that the 8 form may be stable
in the condensed system at temperatures
below about -100°C.
The monoclinic <=± body-centered cubic
inversion manifests itself very strongly
on the high-pressure DTA charts. It is
readily recorded both on heating and on
cooling, as seen in Fig. 38. The slope of
the P-T curve is about 2.2°C/kb, accord-
ing to our results.
Extrapolation of the monoclinic <=±
body-centered cubic and the monoclinic
^ 8 reaction curves indicates intersection
of these curves in a point situated at
about 25 kb and 230°C. At this point
the three forms of Ag2S — monoclinic,
body-centered cubic, and 8 — apparently
coexist stably. If this is correct, a third
curve delineating the reaction 8 <=± body-
centered cubic must exist. Strong DTA
peaks believed to be caused by this re-
action were recorded as noted in Fig. 38.
The high-temperature body-centered
cubic <=± face-centered cubic inversion
could not be detected with our equip-
ment. The enthalpy of this reaction is
small, about one-tenth that of the mono-
clinic ^± body-centered cubic reaction,
GEOPHYSICAL LABORATORY
277
300
250
150
Ag,S
Cubic (bcc)
./ -J=-
/
,-hF-
-After Roy et al.,1959
Monoclinic
Tetragonal(?)
After Bridgman, 1937
Curves
Uni variant
Implied univariant
-- Possible metastable
DTA Signals (chromel vs. constanton)
IE Sharp
| Broad
J I I .
20 25 30
Pressure, Kb
35
40
45
Fig. 38. Proposed phase diagram for Ag2S.
according to Rosenqvist (1949) and
Richardson and Jeffes (1952).
Pressure-Temperature Diagram for
Cr,FeSt
P. M. Bell, A. El Goresy, J. L. England, and
G. Kullerud
Daubreelite (Cr2FeS4) is a common
mineral in chondritic, achondritic, and
iron meteorites ; a better knowledge of its
chemical behavior might provide infor-
mation useful in geophysical correlation.
The present study is an attempt to
determine the P-T phase diagram of
daubreelite (Year Book 67, pp. 197-198) .
The results of Rooymans and Albers
(1967) for a system of nearly the same
composition included a phase boundary
with a negative slope. The possibility
that a similar phenomenon might exist in
daubreelite was examined with high-
pressure differential thermal analysis
(DTA) . The results indicate a boundary
that is nearly horizontal with the pres-
sure axis but with a slight dip in the
central portion of the curve, shown in
Fig. 39. No other significant DTA signals
were observed (except for melting of the
gold capsule at temperatures approach-
ing and above 1100°C at low pressures).
The dip in the curve suggested the pos-
sibility that another phase boundary was
involved, but this could not be verified
with DTA. Quenching experiments with
1:1 mixtures of the low- and high-pres-
sure forms of daubreelite showed that a
phase boundary existed. Procedures iden-
tical with those of Richardson, Bell, and
Gilbert {Year Book 66, pp. 392-397) for
examination of solid reactions with 1:1
mixtures produced the results that are
also shown in Fig. 39. The sharp nega-
tive slope of the boundary obtained from
quenching experiments intersects the
DTA boundary at about 800°C, 14 kb.
At 1 atm a strong DTA signal was
observed at 1060 °C, with the low-pres-
sure phase always forming during the
quench. Several exploratory experiments
at temperatures above 1100°C and at
pressures high enough to avoid melting
of the gold capsule were performed. No
DTA signals were observed, and in every
experiment the quench product was the
high-pressure form of daubreelite. This
278
CARNEGIE INSTITUTION
1100
1000
900
800
O 700
O)
3 600
S. 500
E
400
300
200
100
n 1 — -i 1 1 1 r— t
Possible High-Temperature Field
i 1 1 1 r
--3E3S-
/3 — monoclinic
a — cubic
Daubre'elite
Explanation of Symbols^ dimensions give precision, not absolute accuracy
t D.T.A. Signals (Chromel/Constantan)
-1- thermo couple
□ a + /3-*a \ . •. ,
.on ) quench experiments
I 2 3 4 5 6 7 8 9 10 II 12 13 14 15
Pressure, kilobars
Fig. 39. Pressure-temperature diagram for Cr2FeSi.
19 20 21 22 23 24 25
phenomenon is difficult to explain be-
cause the quench occurred in the low-
pressure field. Possibly the high-pressure
form crystallized upon crossing the meta-
stable extension of the high-pressure
stability curve. X-ray diffraction and
microprobe analyses showed no differ-
ences between these products, all the
other experimental products, and the
starting materials.
That the high-temperature field is very
likely a breakdown curve is based on a
strong analogy with the polydymite sys-
tem (Ni3S4) (see Kullerud, Year Book
67, p. 181, Fig. 68). Except for its loca-
tion in P-T space, the diagram of Fig. 39
is nearly identical with the one for poly-
dymite.
On the basis of the present information
it is clearly difficult to determine the P-T
history of daubreelite in meteorites with-
out supporting textural evidence.
CRYSTALLOGRAPHY
Fifty Years of X-ray Crystallography
at the Geophysical Laboratory,
1919-1969
Gabrielle Donnay, with the help of R. W. G.
Wyckofj, T. F. W. Barth, and George Tunell
It is difficult for us today to realize
the rudimentary state of the art of
structural crystallography in 1919, only
seven years after Laue's discovery of
X-ray diffraction. A letter of December
22, 1920, from Dr. Arthur L. Day, the
first Director of the Geophysical Labora-
tory, to Dr. Ralph W. G. Wyckoff, its
first structural crystallographer (1919-
1927), telling Wyckoff of his first raise,
conveys the vision of this Director, whose
birth dates back one hundred years, to
1869:
"The field of activity in which your
work falls is entirely new to this Labora-
tory, and for the most part new in this
country. It is, I think, rare that a man
at the outset of his career has such an
unusual opportunity to enter and exploit
a field of such vital importance to our
knowledge of the structure of matter, a
field, by the way, which will probably
take you far beyond the immediate ap-
plication which this Laboratory will wish
to make of it. I heartily commend both
GEOPHYSICAL LABORATORY
279
your choice and your opportunity, and
wish you every success in your work."
Dr. Day's good wishes were fulfilled:
of the many honors and recognitions later
bestowed on Dr. Wyckoff, we need only
mention that he became President of the
International Union of Crystallography,
which was founded in 1948.
The only laboratories in the United
States where crystal-structure work was
being attempted prior to 1919 were found
at Massachusetts Institute of Technol-
ogy, the General Electric Company in
Schenectady, and the Chemistry Depart-
ment of Cornell University, where gradu-
ate student Wyckoff, under the guidance
of Professor Shoji Nishikawa, became
acquainted with space-group theory and
its usefulness to X-ray diffraction. In
1919 the M.I.T. group moved to the Cali-
fornia Institute of Technology, and Dr.
Wyckoff joined the staff of the Geo-
physical Laboratory of the Carnegie
Institution in Washington, D. C; only in
these two places has X-ray crystallogra-
phy been carried on continuously ever
since.
The first determinations of atomic
positions in crystals were inspired guesses
supported by the few X-ray diffraction
intensities that could be obtained with
the primitive spectrometers then avail-
able. Additional data were needed if
many more structures were to be ana-
lyzed, and some orderly procedure was
required for finding possible atomic ar-
rangements from which the correct choice
could be made. Wyckoff grasped the
fact that space-group theory offered the
means of enumerating possible struc-
tures, and following Nishikawa, he saw
in the original patterns of Laue a promis-
ing source of additional data. These ideas
were developed in his early publications
from the Geophysical Laboratory. R. G.
Dickinson, moving from M.I.T. to Pasa-
dena, spent a short time at the Labora-
tory, familiarizing himself with these
methods of approach, and Wyckoff sup-
plemented this visit by working during
the following year at the newly estab-
lished California Institute of Technol-
ogy. The work in Pasadena expanded
rapidly, first under Dickinson and then
under Linus Pauling; under Pauling it
has played a dominant role in the
development of structural chemistry
throughout the world. In contrast, crys-
tallography at the Geophysical Labora-
tory has remained in the hands of a very
few people. Nevertheless, their contribu-
tions have dealt with many aspects of
their science, such as theoretical crystal-
lography, crystal-structure determina-
tions and their interpretations and re-
finements, solid solutions, computing
techniques, and biocrystallography.
Compilations of crystallographic data,
beginning with Wyckoff's "Survey of
existing crystal structure data," filling
68 pages in 1923, his first edition of The
Structure of Crystals in 1927, through
Donnay and co-workers' Determinative
Tables of Crystal Data, comprising 1300
pages in 1963, show how aware of the
retrieval problem were the "isolated"
crystallographers at the Laboratory.
Let us look back at some of the high-
lights of the contributions, as we judge
them now, for in our present-day group
approach to scientific research, such a
miniature crystallographic laboratory as
the one at the Geophysical Laboratory
might be called upon to justify its
existence.
The value of space-group theory was
not quickly recognized by the crystal-
lographic fraternity, and Wyckoff's Ana-
lytical Expression of the Results of the
Theory of Space Groups could not find
a publisher. It finally appeared in 1922,
as a publication of the Carnegie Institu-
tion of Washington, through the personal
interest and intervention of Dr. Robert
S. Woodward, originally a mathema-
tician, who was President of the Institu-
tion. This book was the forerunner of the
International Tables of X-ray Crystal-
lography, the third edition of which is
now in preparation and in which, as in
the preceding editions, the atomic posi-
tions in the 230 space groups will be
280
CARNEGIE INSTITUTION
designated by their Wyckoff letters. Of
the sixty-four crystallographic publica-
tions that came out of the Geophysical
Laboratory during the nine-year period
when Wyckoff was here, we need mention
only the first crystal-structure determi-
nation to illustrate how much new infor-
mation could then be packed into one
structure paper. This one dealt with the
"Crystal structures of some carbonates
of the calcite group" and covered 44
pages in the American Journal of Science.
In addition to determining the correct
unit cell of calcite and the structures of
magnesite, rhodochrosite, smithsonite,
and siderite, and recognizing that dolo-
mite would have a different structure, the
author proved the existence of planar
C03= groups, which Bragg's determina-
tion of the calcite structure with the
X-ray spectrometer had failed to do,
since the oxygen atoms could not be lo-
cated. By making C03= the anions, the
close relation of the calcite structure to
the NaCl structure became evident. It
was stressed that NaN03 and CaC03 are
even more closely isostructural than
CaC03 and MnC03. The faces of calcite
were explained by recognizing that the
nodes of a nonstructural lattice, based
on the cleavage rhombohedron, are oc-
cupied by morphologically equivalent
Ca2+ and C03= ions. The extinction cri-
terion for a rhombohedral lattice ( — h +
k + £ = 3n) was derived; the relation of
the gnomonic projection to the Laue
photograph was elucidated and a ruler
to construct the projection directly from
the photograph was described. All this,
in 1920!
Experimental work with gas X-ray
tubes was very difficult and time-con-
suming in the early days, and the Labo-
ratory was fortunate in having a Swiss-
trained instrument maker, C. J. Ksanda,
employed at the Laboratory from 1914
to 1940, who carried out much of the
laboratory work and in 1932 designed
the Ksanda twin gas tubes, which were
built by a local firm.
A Laboratory colleague who was intro-
duced to X-ray crystallography by
Wyckoff was Dr. Eugene Posnjak (Staff
Member, 1913-1947). Russian by birth,
he was trained in physical chemistry at
Leipzig, Germany, and had joined the
Laboratory after a year with A. A. Noyes
at M.I.T. Posnjak published "The crys-
tal structure of ammonium chloroplati-
nate" jointly with Wyckoff in 1922. The
authors proved once and for all the valid-
ity of Werner's Coordination Theory,
which until then had been only a hy-
pothesis: platinum is octahedrally sur-
rounded by six chlorine ions. The struc-
ture is of the fluorite type with PtCl6=
replacing Ca2+ and NH4+ replacing F~.
Also jointly, they described the alkali
halides and cuprous halide. Posnjak de-
termined the crystal structure of the
alkali metal potassium and together with
Dr. Sosman discovered the naturally oc-
curring ferromagnetic iron-deficient mag-
netite of composition Fe203, to which the
name maghemite was later given. In 1928
he published the cell dimensions of spinel
(MgALGi) and other compounds of the
spinel group. He had exceptional skill in
preparative and experimental work, and
in order to study the magnetic properties
of crystals, he produced various com-
pounds and solid solutions containing
both ferrous and ferric iron. He had be-
gun a study of the powder diagrams of
such samples exhibiting spinel structure
when Dr. Tom F. W. Barth joined the
Laboratory in 1929.
Barth (Staff Member, 1929-1936) had
received his introduction to the field
from the greatest geochemist of the time,
V. M. Goldschmidt, then a professor at
the University of Oslo, Norway. Barth
let his active interest in petrology guide
his choice of crystallographic problems
and concentrated his efforts on important
rock-forming minerals. He soon joined
forces with Posnjak on the spinel prob-
lem, and this happy collaboration re-
sulted in 1931 in their classical paper
"The spinel structure: an example of
variate atom equipoints," in which it was
proved that crystallographically equiva-
GEOPHYSICAL LABORATORY
281
lent sites can be occupied by chemically-
different atoms. Five months later they
showed that the structure of lithium fer-
rite, Li2Fe204, belongs to the NaCl type,
with univalent lithium and trivalent iron
substituting randomly for each other on
the sites of one and the same crystal-
lographic position. The new concept of
"variate atom equipoints" proved to be
essential for understanding and solving
most mineral crystal structures. Alumi-
num, for example, to some extent re-
places silicon in all aluminosilicates, and
studies of gehlenite, sodalite, related
minerals, and the feldspars clarified the
principle involved. Barth also studied
the cristobalite structure, showed that
nonsilicates can exist with the same
structure type, and recognized con-
siderable solid solution in the system
Si02-Na2Al204, also with the cristobalite
structure.
Dr. Sterling B. Hendricks, who had
been a Fellow at the time of Wyckoff,
was back in Washington, at the Fixed
Nitrogen Laboratory, and cooperated
throughout the thirties with the crystal-
lographic group at the Laboratory. In
1931 and 1932 Hendricks, Kracek, and
Posnjak verified Pauling's hypothesis
that in sodium nitrate and ammonium
nitrate molecular rotation takes place in
the solid state. This was another new
phenomenon first described at the Geo-
physical Laboratory. Brandenberger had
pointed out that in the case of sodium
nitrate there exists a particular station-
ary position for the N03 group which
would be difficult to distinguish from the
rotating group. It was important, there-
fore, that Barth could prove the existence
of two polymorphic forms of KN03 : one
in which the nitrate group was rotating
and another in which it had the location
predicted by Brandenberger.
Dr. George Tunell (Staff Member,
1925-1947) , a Harvard-trained economic
geologist, mineralogist, and crystallogra-
pher, specialized in ore minerals. He
promptly became the friend of Tom
Barth and learned from him the tech-
niques of crystal-structure determination.
With his wife Ruth helping with the
computations, he determined the struc-
tures of tenorite, calaverite, sylvanite,
and krennerite, and later published a
paper with Linus Pauling on "The atomic
arrangement and bonds of the gold-silver
ditellurides." Tunell also derived the
Lorentz correction factor for equi-incli-
nation Weissenberg films, without which
the photographic intensities of diffracted
X rays could not be used. He had taken
great interest in the computing of Fourier
syntheses, as is evidenced by the "Patter-
son-Tunell stencils and strips," which
rapidly became popular and helped crys-
tallographers in their laborious calcula-
tions of the precomputer era. (They are,
to this day, used as a teaching aid to
make the student appreciate what really
goes on in a Fourier summation.)
By 1933 the X-ray laboratory was so
well equipped — it had a Weissenberg
camera, the first to be converted to equi-
inclination outside of M.I.T., an oscilla-
tion camera, several powder cameras,
including one in which the sample could
be studied at high temperature — that Dr.
Barth could report to Dr. Day: "for a
considerable length of time we have had
the best X-ray goniometer [Weissenberg
camera] in the U.S. and probably in the
world" and "we have concrete problems
already well under way which we believe
are of more than ordinary interest, as is
evidenced, for example, by the fact that
Dr. [J. D. H.] Donnay, Professor of
Mineralogy at the Johns Hopkins Uni-
versity, desires to study with us in the
fall and that Professor Palache has sent
us his assistant, Mr. Berman, for advice
and instruction." The association with
the morphological crystallographers of
Harvard and of Johns Hopkins was both
a fruitful and a happy one, as witness the
formation of the delightful "Calaverite
Club," composed of Palache, Peacock,
Donnay, Tunell, and Barth. Calaverite
is a mineral whose morphology appar-
ently violates the Law of Rationality
and which, even now, is not fully under-
282
CARNEGIE INSTITUTION
stood. In those days all the papers on
calaverite were written by members of
the club! The enthusiastic cooperation
also led to a joint publication in 1934 on
"Various modes of attack in crystal-
lographic investigations."
The association with Professor Donnay
continues to the present time. His wife,
Dr. Gabrielle Donnay, joined the Labo-
ratory in 1950 as a Fellow and in 1955
as a Staff Member. Her undergraduate
training in chemistry at U.C.L.A. was
followed by a Ph.D. in crystallography
under M. J. Buerger at M.I.T. Her first
research problem at the Laboratory, car-
ried out with the help of the Director,
Dr. L. H. Adams, was a test of the pre-
cision of the then-new powder diffrac-
tometer and led to the cell dimensions
and cell volumes of a complete solid-
solution series of well-documented alkali
feldspars. It showed the existence of a
high-order transition. A study of chalco-
pyrite, performed jointly with Drs. L. M.
Corliss, J. D. H. Donnay, N. Elliott, and
J. M. Hastings at Brookhaven National
Laboratory, led to the first application
of "generalized symmetry" to magnetic-
structure determinations. Complex crys-
talline edifices resulting from twinning (in
digenite), epitaxy, and syntaxy (in the
bastnaesite-vaterite series) have been
studied. Solid solutions, omission as well
as substitution and organic as well as
inorganic, have been investigated, and
the theory of limited solid solutions be-
tween end members of different structure
types has been considered. In addition to
describing five new minerals (among
them ewaldite, a simple new carbonate
structure), a novel building block com-
posed of three corner-linked Si04 groups
we found in the structure of the rare
silicate mineral ardennite. Together the
Donnays have investigated the relation
of morphology to structure, which led to
further generalizations of the Law of
Bravais. Most recently an X-ray survey
of the orientation relations between crys-
tallographic axes and morphological fea-
tures of calcite "biocrystals" in Echino-
dermata was carried out with Dr. David
L. Pawson of the Smithsonian Insti-
tution.
The tremendous help which modern
computers can give crystallographers has
not been overlooked at the Laboratory.
Computing and its use for structure re-
finement to obtain meaningful tempera-
ture factors was of special interest to
another student of Professor Buerger, Dr.
Charles W. Burnham, who became a Fel-
low in 1961 and was a Staff Member
from 1963 to 1966. He refined the struc-
tures of sillimanite and kyanite and
wrote several computer programs that
are now widely used.
This account would not be complete
without mentioning the following post-
doctoral Fellows who contributed to the
crystallographic output: J. V. Smith
(1951-1954), N. Morimoto (1957-1960,
seven months in 1962, three months in
1963, and four months in 1966-1967),
E. W. Radoslovich (1962-1963), N.
Guven (1965-1967), and L. W. Finger
(1967-1969) . Dr. Finger became a Staff
Member on July 1, 1969. He is working
on order-disorder problems in amphi-
boles and is now setting up a second
X-ray laboratory.
A bibliography of 183 crystallographic
publications that have come out of the
Laboratory in the period 1919-1969 is
available on request.
Looking back at the historical facts, it
seems to us that the Geophysical Labora-
tory was different from most other places
in its approach to X-ray crystallography.
Most early workers in this field were
classical physicists rather than crystal-
lographers. After the initial discovery,
the methods employed in working out
actual crystal structures were slow and
cumbersome, and lacked the elegance and
ease that only crystallographic theory
could provide. It was fortunate for the
Geophysical Laboratory that Wyckoff,
who demonstrated the use of the theory
of space-groups and always insisted
on applying it in his work, became
the first X-ray crystallographer of the
GEOPHYSICAL LABORATORY
283
Laboratory. The same approach was
used by Tunell and Barth, both educated
in classical crystallography; this trend
was strengthened by the inspiring co-
operation of morphological and optical
crystallographers, in and out of the
Laboratory, who brought in the best
traditions of the European schools. To-
gether with this mode of approach, the
freedom of research that has been the
rule at the Geophysical Laboratory has
served its crystallographers well. It is a
pleasure, in conclusion, to quote Profes-
sor Barth's enthusiastic reply to our call
for help when we started writing this
short history: "I shall be happy to do
so ; I spent the most pleasant time of my
life at the Geophysical Laboratory."
Refinement of the Crystal Structure
of an anthophyllite
L. W. Finger
The anthophyllite structure models
proposed by Warren and Modell (1930)
and Ito and Morimoto (1950) have been
refined as part of the continuing in-
vestigation of Fe-Mg ordering in the
ferromagnesian amphiboles. The speci-
men (no. 30 of Rabbitt, 1948) is from
the Dillon Complex, Beaverhead and
Madison Counties, Montana (U. S. Na-
tional Museum, catalogue no. 117227).
The chemical formula from an analysis
is Mg5.53Fe1.47Si8022(OH)2. Single crys-
tals of this material display diffraction
symmetry mmmPn-a, which corresponds
to space group Pnma if centric or Pn2xa
if noncentric. A satisfactory refinement
was accomplished with the centrosym-
metric space group. The unit-cell param-
eters were determined from back-reflec-
tion Weissenberg photographs taken
about the b and c axes with Cu (AKai =
1.54051 A, Asa, = 1.54433 A) and Fe
(XKa= 1.93597 A, \Ka= 1.93991 A) radi-
ations. The data were refined with the
use of program LCLSQ of Burnham
{Year Book 61, pp. 132-135), with cor-
rection terms for absorption, film shrink-
age, and eccentricity errors. The resulting
cell parameters at 23 °C are a = 18.560 ±
0.003 A, b = 18.013 ±0.002 A, c = 5.2818
±0.0009 A, 7 = 1765.8±0.7 A3. There
are four formula units per cell. A cleav-
age fragment, 0.15x0.26x0.40 mm in
size, was selected for intensity collection
at the U. S. Geological Survey, Wash-
ington, D. C, on a Picker four-circle
automated diffractometer, equipped with
a scintillation detector. All nonequivalent
reflections with sin 0<O.5 for MoKa
(A = 0.7107 A) radiation were measured
using a Nb filter and the 20-scan tech-
nique, with the scan range calculated ac-
cording to Alexander and Smith (1964).
The resulting data were corrected for
background, Lorentz and polarization
effects, and absorption (^ = 20.07 cm-1).
The reflections with a negative integrated
intensity were assigned the most prob-
able value of the structure factor for a
centric crystal (Hamilton, 1955) . Any re-
flection with an intensity less than three
times its standard deviation based on
counting statistics was marked for special
treatment in the refinement. These data
will henceforth be called "less-thans."
A total of 2656 symmetry-independent
reflections were measured, of which 532
were less-thans.
Because the site nomenclature used by
Warren and Modell (1930) did not agree
with that of Ito and Morimoto (1950)
and neither scheme agreed with previous
work on the clinoamphiboles, the nomen-
clature has been changed to reflect the
relationship of the structure to the
C-centered monoclinic amphiboles. In
addition, we have tried to conform as
closely as possible to the conventions
proposed by Burnham et al. (1967) for
clinopyroxenes and to agree with the
work of Whittaker (1969) on holm-
quistite which is isostructural with an-
thophyllite.
The anthophyllite structure may be
imagined as a unit of the cummingtonite
structure, composed of a strip of octa-
hedra sandwiched between two double
chains of tetrahedra. In cummingtonite
the chains are symmetrically related by
284
CARNEGIE INSTITUTION
two-fold axes and the two halves of a
chain are related by a mirror plane. In
anthophyllite the mirror exists but the
two-fold axes are not present, and the
two chains are not related by symmetry.
In accord with the structure of clino-
ferrosilite (Burnham, Year Book 65, pp.
285-290), the more extended or regular
chain has been labeled the A chain and
the distorted chain, the B chain. The
number of crystallographically distinct
octahedral cations is not affected, and
they are called Ml, M2, M3, and M4 as
in cummingtonite. Within a chain, the
conventional nomenclature shown in Fig.
40 is used. The chain-linking oxygens 05
and 06 create a slight problem. The dis-
tortion from the ideal chain causes the
hole in the double chain to be deformed
from a pseudohexagonal to a pseudoditri-
gonal shape. The selection of 06 is made
such that the bond angle O6-O7-06 is
less than the bond angle 05-07-05, as
shown (cf. cummingtonite, Ghose, 1961;
Fischer, 1966). This choice could not be
made a priori for both chains since the
tetrahedra of the A chain are rotated in
the opposite sense from the rotation of
chains in cummingtonite, a point which
will be discussed later. To complete the
site nomenclature, 03 is the hydroxyl
atom that is not bonded to a tetrahedron,
and the A site, which is empty in antho-
phyllite, lies between the backs of two
tetrahedral chains. Table 25 shows the
correspondence between the site nomen-
clature used here and those of Warren
and Modell, and Ito and Morimoto.
Full matrix least-squares refinement
was accomplished with the use of pro-
Fig. 40. Site nomenclature for idealized amphibole double chain projected parallel to a*
GEOPHYSICAL LABORATORY
285
TABLE 25. Anthophyllite Site Nomenclature
Derived from Clinoamphiboles Compared
with Schemes Proposed Previously
This
Warren and
Ito and
Study
Modell
Morimoto
Ml
Mgi
Mgi
M2
Mg2
Mg2
M3
Mgi
Mg4
M4
Mg3
Mg3
TL4
Si*
Sii(2)
TIB
Si!
Sii(l)
T2A
Si3
Sin (2)
T2B
Si2
Sin(l)
01 A
Os
On(2)
015
02
0„(1)
02A
09
Ox(2)
02B
Oi
Oi(l)
03A
(0H)2
(0H)a
03B
(OH)!
(OH)!
04A
OlO
Ov(2)
045
05
Ovd)
05A
0l3
Ovn(2)
05B
Oe
Ovi(l)
06A
Ou
Ovi(2)
06B
07
Ovii(l)
07A
On
Om(2)
07B
03
Oin(l)
gram RFINE, with scattering curves
for neutral atoms from Cromer and
Mann (1968) and the anomalous disper-
sion coefficients of Cromer (1965) for Si,
Mg, and Fe, the anomalous scattering of
oxygen being ignored. The positional
parameters of Warren and Modell
(1930), isotropic temperature factors of
0.5, • and fully disordered occupancies
were selected as the initial values. The
program minimized the function 2w(|-^o|
— |^c|)2, and the weights, w, were the in-
verse of the variance of the structure
factors as computed from counting sta-
tistics. In the refinement the less-thans
were not included in the least-squares
solution, but the structure factors were
computed for comparison of the observed
and calculated values. The positional
parameters and the scale factor were re-
fined for three cycles, and the isotropic
temperature factors were then refined for
one cycle. At this stage of the refinement
the occupancies were varied, with the use
of the chemical constraints described
in Year Book 67 (pp. 216-217). The
sum of Fe-fMg for each octahedral site
was required to be unity, and the total
amount of iron was restricted to 1.47
atoms per formula unit. The structure
converged in four cycles. At this point
the structure factor data were investi-
gated to determine if any of the highly
discrepant values were due to previously
undetected diffractometer errors. Ap-
proximately 45 reflections were found
to be affected by interference. Because
the unit cell of anthophyllite has two
axial lengths of approximately 18 A and
is primitive, the diffraction from neigh-
boring planes is closely spaced for Mo
radiation. For those data in question,
the background measurement was made
after the scan had intercepted the dif-
fracted ray from the next hkl plane, and
therefore the integrated intensity was too
small. A better value for the intensity
was obtained by estimating the true
background from the strip-chart record
and recalculating. Because this procedure
is not very accurate, the reflections re-
calculated in this fashion were marked
as less-thans so they could not influence
the least-squares solutions obtained later.
With the data revised as outlined
above, the structure converged in three
cycles. Next, the M sites were converted
to anisotropic temperature factors, and
the parameters were refined. Finally, all
the atoms were refined with anisotropic
temperature factors. The weighted resid-
uals were tested according to Hamilton
(1965), the results showing that the hy-
pothesis that the oxygens vibrate isotrop-
ically may be rejected at the 0.005 level.
The final value of the weighted residual,
r=[$w(\F0\-\Fc\)2/ZwF02¥, was 0.040
for all data and 0.027 for the unrejected
reflections. The corresponding values for
the conventional residual, R = 2\\F0\ —
\FC\\/Z\F0\, were 0.063 and 0.044. The
final values for the occupancies, posi-
tional parameters, and equivalent iso-
tropic temperature factors (Hamilton,
1959) are presented in Table 26. The
error for the occupancy of M4 is derived
from propagation of error considerations,
neglecting any error in the analysis, and
286
CARNEGIE INSTITUTION
TABLE 26. Atomic Coordinates, Equivalent Isotropic Temperature Factors,
and Site Chemistry for Anthophyllite
Atom
X
V
z
B
Occupancy
Ml
0.12489(9)
0.16329(7)
0.3911(3)
0.54(3)
0.960(3) Mg
M2
0.12488(9)
0.07317(7)
—0.1099(3)
0.55(3)
0.973(3) Mg
M3
0.12579(14)
y±
—0.1089(5)
0.49(4)
0.966(4) Mg
M4
0.12371(4)
—0.00982(4)
0.3877(2)
0.78(2)
0.349(4) Mg
T1A
0.23039(7)
—0.16540(7)
—0.4344(2)
0.37(2)
Si
TIB
0.01863(8)
—0.16626(7)
0.2760(2)
0.38(2)
Si
T2A
0.22731(8)
—0.07956(7)
0.0622(2)
0.38(2)
Si
T2B
0.02469(8)
—0.08177(7)
—0.2227(2)
0.43(2)
Si
01 A
0.1825(2)
0.1635(2)
0.0573(6)
0.43(6)
01B
0.0685(2)
0.1635(2)
—0.2746(6)
0.52(6)
02A
0.1855(2)
0.0777(2)
—0.4377(6)
0.43(5)
02B
0.0630(2)
0.0773(2)
0.2187(6)
0.54(5)
OSA
0.1822(3)
%
—0.4437(8)
0.51(8)
OH
035
0.0694(3)
%
02267(9)
0.49(8)
OH
044
0.1869(2)
—0.0011(2)
0.0721(6)
0.59(6)
045
0.0668(2)
—0.0065(2)
—0.2920(6)
0.70(6)
05A
0.1978(2)
—0.1168(2)
0.3293(6)
0.59(5)
05B
0.0508(2)
—0.1112(2)
0.0570(6)
0.54(5)
06A
02009(2)
—0.1303(2)
—0.1739(6)
0.67(5)
065
0.0484(2)
—0.1402(2)
—0.4493(6)
0.68(5)
07A
0.2027(3)
-44
0.5397(8)
0.72(8)
07B
0.0450(3)
-44
0.2221(9)
0.71(8)
Note: Standard deviations, <r, are in parentheses.
is therefore a measure of the internal
consistency of the structure- factor data.
Discussion
The refined structure of anthophyllite
shows a high degree of cation ordering in
the M sites with very little iron in the
small octahedral sites, probably indica-
ting a relatively low temperature of for-
mation or annealing. This material would
therefore be a good sample for the deter-
mination of equilibrium distributions at
Fig. 41. A partial projection of the anthophyllite structure projected parallel to a.
GEOPHYSICAL LABORATORY
287
various temperatures. The fine details of
the ordering are similar to those in the
refined structures of cummingtonite
(Fischer, 1966) and grunerite (Finger,
1969) and are essentially as predicted by
Ghose (1965). Ml and M3 have similar
Fe:Mg ratios, whereas M2 is more en-
riched in Mg and M4 is greatly enriched
in iron.
A partial projection of the structure
on (100) is presented in Fig. 41, with
selected bond distances in Table 27 and
the bond angles of the silicate double
chains in Table 28. The major difference
between the cummingtonite-grunerite
structure (Ghose and Hellner, 1959;
Ghose, 1961; Fischer, 1966; and Finger,
1969) and the anthophyllite structure
concerns the coordination of M4. In each
structure there are four M-0 bonds in the
range 2.0-2.1 A. Grunerite has two bonds
at about 2.8 A, and the next closest oxy-
gens are at a distance of about 3.3 A. In
order to accommodate the smaller Mg
ion in M4, the packing must be denser in
this region of the structure. To accomp-
lish this the B chain is distorted from the
06-05-06 angle of 172°C in grunerite to
an angle of 157° in anthophyllite, allow-
ing both of the chain-linking oxygens to
be 2.87 A from M4. In addition, the A
chain is distorted in the opposite sense
TABLE 27. Selected Interatomic Distances (in
Anthophyllite
Angstroms) from
Distance
Distance
Atoms A Chain B Chain Atoms
A Chain B Chain
Tl tetrahedron
Tl-01
Tl-05
Tl-06
Tl-07
Tl-0
01-05
01-06
01-07
05-06
05-07
06-07
1.618(3)
1.640(3)
1.611(3)
1.615(2)
1.621
2.664(4)
2.657(4)
2.643(5)
2.636(5)
2.646(3)
2.635(4)
0-0 2.647
T2 tetrahedron
T2-02
T2-04
T2-05
T2-06
T2-0
02-04
02-05
02-06
04-05
04-06
05-06
1.619(3)
1.601(3)
1.655(3)
1.621(3)
1.624
2.742(4)
2.679(4)
2.627(4)
2.496(4)
2.677(4)
2.669(5)
0-0 2.648
Tetrahedral chains
Tl-Tl 3.049(2)
Tl-T2(+z) 3.045(2)
Tl-T2(— z) 3.076(2)
1.618(3)
1.636(3)
1.622(3)
1.617(2)
1.623
2.667(4)
2.648(5)
2.649(5)
2.659(5)
2.649(3)
2.632(4)
2.651
1.630(3)
1.608(3)
1.643(3)
1.653(3)
1.634
2.753(4)
2.638(4)
2.654(4)
2.655(4)
2.570(4)
2.725(5)
2.666
3.017(2)
3.055(2)
3.044(2)
Octahedral strip
Ml-01
Ml-02
Ml-03
Ml-0
M2-01
M2-02
M2-04
M2-0
M3-01(2z)
M3-03
M3-0
M4-02
M4-04
M4-05
M4-06
Ml-Ml
Ml-M2(— z)
Ml-M2(-fz)
Ml-M3(2x)
M1-M4
M2-M3
M2-M4(— z)
M2-M4(+z)
2.062(3) 2.053(4)
2.112(3) 2.133(3)
2.082(3) 2.063(3)
2.084
2.138(3) 2.121(3)
2.067(3) 2.082(3)
2.010(3) 2.037(3)
2.076
2.075(3)
2.055(5)
2.079(3)
2.059(5)
2.070
2.156(3) 2.128(3)
2.044(3) 1.996(3)
2.387(3) 2.867(3)
3.481(3) 2.865(3)
3.124(2)
3.104(2)
3.095(2)
3.068(3)
3.118(1)
3.185(1)
3.046(2)
3.024(2)
Note : Standard deviations, c, are in parentheses.
288
CARNEGIE INSTITUTION
TABLE 28. Selected Interatomic Angles
(in Degrees) from Anthophyllite
Atoms
Angle
A Chain
B Chain
Tl tetrahedron
Ol-Tl-05
Ol-Tl-06
Ol-Tl-07
05-T1-06
05-T1-07
06-T1-07
T2 tetrahedron
109.7(2)
110.8(2)
109.7(2)
108.4(2)
108.8(2)
109.5(2)
116.7(2)
109.8(2)
108.3(2)
100.1(2)
112.4(2)
109.1(2)
141.4(3)
138.0(2)
140.8(2)
169.2(2)
110.1(2)
109.6(2)
109.9(2)
109.4(2)
109.0(2)
108.7(2)
02-T2-04
02-T2-05
02-T2-06
04-T2-05
04-T2-06
05-T2-06
Chains
116.5(2)
107.4(2)
107.9(2)
109.5(2)
104.0(2)
111.5(2)
T1-07-T1
T1-05-T2
T1-06-T2
06-05-06
137.8(3)
136.3(2)
137.8(2)
157.5(2)
Note: Standard deviations,
theses.
a, are m paren-
from the equivalent chain in grunerite,
allowing 05A to be 2.4 A from M4. If
anthophyllite were to be transformed into
cummingtonite, one of the M4-0 bonds
would have to be broken. In addition,
alternate strips of octahedra would have
to be rotated approximately 180° about
the a* axis to form the cummingtonite
stacking sequence. Therefore, a polymor-
phic transition, if it exists, must be re-
constructive, not displacive.
The effect of these changes on the mo-
lar volume is shown in Fig. 42. The curve
is for the cummingtonite-grunerite series
as determined by Klein and Waldbaum
(1967). The dashed portion is the extra-
polation of their curve outside the com-
positional limits of their samples and is
not intended to portray the stability
range of anthophyllite. The points
plotted are for aluminum-poor antho-
phyllites from this study, Johansson
(1930), Greenwood (1963), and Linde-
mann (1965). Clearly, the anthophyllite
structure allows denser packing, as noted
by Whittaker (1960).
The assistance of the crystallographers
at the U. S. Geological Survey in the data
collection and reduction is gratefully ac-
knowledged. In addition, Drs. J. J.
Papike and M. Ross contributed greatly
to the nomenclature scheme and to the
description of the structure.
Progress Report on Ewaldite
G. Donnay and H. Preston *
The first description of ewaldite {Year
Book 67, pp. 218-219) appeared under
* Chemistry Dept., U. of Maryland.
280
275
270
265
260
Fig. 42. Molar volumes for ferromagnesian amphiboles. The curve for the monoclinic varieties
is drawn as a solid line in the compositional range of samples used to determine the curve. The
points are plotted for aluminum-poor anthophyllites.
GEOPHYSICAL LABORATORY
289
the heading " 'Mckelveyite,' a syntactic
intergrowth of two phases." The mineral
as well as its name has now been ap-
proved by the I.M.A. Commission on
New Minerals and Mineral Names. Its
chemical analysis was performed by Dr.
Max H. Hey on previously X-rayed
single crystals that showed only the
faintest reflections due to mckelveyite.
Dr. Hey's results (in wt %) follow:
BaO, 45.0; CaO, 7.6; Ln203, equivalent
to 6.5% Y203, a spectroscopic analysis of
the rare earths is underway; Na20, 5.6;
K20, 1.4; SrO, 0.8; Fe203, 2.0; insolubles,
5.4; C02 29.3 (calculated), 30.8 (ob-
served) ; sum, 103.6.
We collected 321 symmetry-indepen-
dent reflections on the Supper-Pace auto-
mated diffractometer with MoKa radia-
tion. The Miller indices range from 0 to 4
for h, from 0 to 5 for k and from —16 to
+ 16 for I. The space group is P63mc.
The cell dimensions of the actual crystal
used were obtained from a back-reflec-
tion Weissenberg photograph taken with
CuKccx (1.54051 A) and CuKa2 (1.54434
A) radiations. They are a = 5.284 ±7, c =
12.78 ±1 A. The intensities were cor-
rected with Lorentz and polarization
factors and for absorption with the
GNABS program. A linear absorption
coefficient of 103.9 cm-1 was assumed,
based on the chemical analysis of mckel-
veyite (Milton et al., 1965) , because the
ewaldite analysis was not available at
the time. The value we would use now
is 98.3 cm-1, not significantly different.
A three-dimensional Patterson synthe-
sis revealed four cations in position 2(6)
at Vb, 2/s, z; %, y3, %+z. The heavier
cation was placed at z = 0; the lighter
one was found at 2 = 0.304. Electron-
density syntheses, with the phases based
on cation contributions, show one car-
bonate group in position 2(a) with z —
0.424 and one in position 2(6) with
2 = 0.675. There is evidence for omission
of carbonate ions in the 2(6) position.
We therefore converted the chemical
analysis to a structural formula with a
total of four cations after subtracting
the insolubles and the Fe203, which elec-
tron-probe study has shown to be present
in the form of hematite inclusions only
(Year Book 67, p. 219).
The cell content can then be written
as: (Bai.68Ko.1eNao.12Sro.04) (Na0.92Ca0.76
Y0.32) (C03)3.56 where the cations are
grouped by "effective ionic radius"
(Shannon and Prewitt, 1969) . The ions in
the first parentheses, which have co-
ordination number 9, have a weighted
average radius of 1.38 A. Those in the
second parentheses have coordination
number 6 and a weighted average radius
of 0.99 A.
In order to compare the ewaldite struc-
ture type with the most important two
structure types of alkaline earth carbo-
nates, those of calcite and of aragonite
(Table 29) , let us look at their idealized
forms. Calcite is a deformed NaCl-type
structure; its cations and its carbonate
groups are in pseudo-cubic close packing
along c. Each oxygen has two nearest
cation neighbors; each cation is octahe-
drally surrounded by six oxygens. Arago-
nite is a deformed NiAs type with Ni (at
0, 0, 0; 0, 0, y2) replaced by C03= and
As at (y3, %, z; %, %, z + Y2) replaced
by Ca2+; only its cations repeat in pseu-
dohexagonal close packing along c. Each
oxygen has three nearest cation neigh-
bors; each cation is surrounded by a
trigonal prism of six anions.
Ewaldite has a cell edge a large enough
to accommodate the carbonate groups in
the (0001) plane, and thus has true hex-
agonal symmetry. Its density is corre-
spondingly lower than that of calcite and
TABLE 29. Comparison of Crystal Structures
of Composition (Bao.eCao.-OCOa with Ewaldite
Ewaldite
Aragonite
Calcite Type
Type (Alstonite)
Space group
P6smc
R3c
Pmcn
a, A
5.284
5.12
5.00
b, A
8.79
c, A
12.78
18.2
6.12
Z
4
6
4
Dczic. (g/cm3)
2.884
3.818
3.912
290
CARNEGIE INSTITUTION
aragonite (Table 29), suggesting a low-
pressure stability field on a phase dia-
gram. The structure differs further from
the aragonite type in that it is noncen-
tric, its cations have two kinds of coor-
dination polyhedra, and the anions form
double hexagonal close-packed layers
(Table 30) . If, for the purpose of classi-
fication, we consider the carbonate
groups to be represented by large spheres,
the complete ewaldite structure can be
described as a layer structure. With the
conventional notation of A, B, C for the
layers that have atoms at 0, 0, zA ; %,
■y, ,
Zb J % , V% , Zc we obtain :
I
II
III
IV
B
B
C
B
( C03, 2 = 0.924)
(Ba. ., 2 = 0.000)
( C03, 2 = 0.175)
(Na.., 2 = 0.304)
( C03, 2 = 0.424)
(Ba. ., 2 = 0.500)
( C03, 2 = 0.675)
(Na.., 2 = 0.804)
A ( C03, 2 = 0.924)
Thus we may describe ewaldite as a
quadruple hexagonal close-packed cry-
stal structure (q.h.c.p.).
(Ba. . .) has nine oxygen neighbors at
nearly equal distances (~2.87 A), six
below it and three above it. The cation
is less than one-third of the way above
the bottom layer, thus giving a polar
character to the atomic distribution along
2. The six oxygens below Ba fall at the
corners of a truncated equilateral tri-
angle, outlining a six-sided polygon with
alternating short (2.25 A) and long (2.97
A) edges. The short edges are shared
TABLE 30. Atomic Coordinates of Ewaldite
Coordinates
Wyckoff -
Atom
Position
X
y
z
(Ba...)
2(b)
Vz
%
0.000
(Ui.sel I0.44)
2(6)
%
y3
0.175
(O4.0sO1.32)
6(c)
0.543
0.457
0.175
(Na...)
2(6)
y3
%
0.304
C
2(a)
0
0
0.424
O
6(c)
0.143
0557
0.424
with C03 groups ; the long edges connect
oxygens of translation-equivalent C03
groups. In the oxygen layer above Ba, the
nearest oxygen neighbors outline a regu-
lar triangle, edge length 2.97 A, with the
corners above the midpoints of the long
oxygen edges in the six-sided polygon
below. This face is shared with the
(Na. . .) polyhedron, which consists of
a trigonal antiprism, with the central
cation at half-height.
Temperature factors of most ions are
still too high to be acceptable, and posi-
tional disorder involving the 2 coor-
dinates is being studied now.
Refinement of the Crystal Structure
of Triphylite*
L. W. Finger and G. R. Rapp, Jr. t
The crystal structure of a specimen of
triphylite from the Dan Patch Mine,
Keystone, South Dakota, has been re-
fined as the first step of an investigation
of a solid-state oxidation reaction. In this
reaction the composition LiFe2VJMn2+a;
P04 (triphylite-lithiophylite series) may
be oxidized to the composition LiiCFe3+i_a?
Mn2^P04 by the action of an oxidizer
less electropositive than Mn. This is the
composition of sicklerite, a naturally oc-
curring member of the series. Finally, the
remaining lithium may be removed, the
manganese oxidized, and the composition
converted to Fe3+1_^Mn3%P04. In this
study we propose to investigate the de-
tails of the crystal structures at each
step, and we hope to use the same crystal
for each determination. In addition, for
any reactions that proceed relatively
slowly, an attempt will be made to ob-
serve the reaction kinetics with X-ray
diffraction techniques.
The triphylite studied has been ana-
lyzed by C. O. Ingamells (personal com-
* This work was supported in part by Na-
tional Science Foundation grant GA 707 awarded
to the University of Minnesota.
t Department of Geology and Geophysics,
University of Minnesota, Minneapolis, Minne-
sota.
GEOPHYSICAL LABORATORY
291
munication) , and its composition is very
nearly that of LiFeo.TeMno^PO^ the
composition used in the refinement.
Single crystals of the material display
diffraction symmetry mmmP-nb, con-
sistent with the space group Pmnb found
by Geller and Durand (1960). Note that
this is a reorientation (00T/0T0/T00)
from the cells of Gossner and Strunz
(1932) and Destenay (1950). The unit-
cell parameters were determined from
back-reflection Weissenberg photographs
taken at 23 °C about the b and c axes
with Cu radiation (AK«i = 1.54051 A,
AK«2 = 1.54433 A, AKi8 = 1.39217 A), and
the data were refined with the lattice-
constant refinement program of Burn-
ham (Year Book 61, pp. 132-135). The
resulting values are a= 6.0285 ±0.0006 A,
b = 10.3586 ±0.0009 A, c = 4.7031 ±0.0003
A, and V =293.70 ±0.07 A3. There are
four formula units per unit cell, giving
a calculated density of 3.562 g/cm3 com-
pared with an observed density range of
3.42-3.56 g/cm3 (Destenay, 1950).
The X-ray diffraction data were col-
lected at the U. S. Geological Survey,
Washington, D. C., on the Picker four-
circle automated diffractometer, which is
equipped with a scintillation counter.
The crystal used was a cleavage frag-
ment, 0.13x0.16x0.30 mm in size. All
nonequivalent reflections having sin 0
<0.7forMoKoc (A =0.7107 A) radiation
were measured with the use of a Nb
filter and the 20-scan technique, with the
scan range calculated according to the
method of Alexander and Smith (1964).
The resulting data were corrected for
background, Lorentz and polarization
effects, and absorption (/**= 54.31 cm-1).
The reflections with a negative integrated
intensity were assigned the most proba-
ble intensity (Hamilton, 1955). A total
of 1240 reflections were measured. The
173 reflections that had an integrated
intensity less than three times its stan-
dard deviation were treated as unob-
served reflections in later refinement.
Starting with the coordinates of Geller
and Durand (1960), the structure was
refined with the program RFINE. Statis-
tical weights, the scattering factors of
Cromer and Mann (1968) for neutral
atoms, and the anomalous dispersion co-
efficients of Cromer (1965) were used
throughout this study. After convergence
with isotropic temperature factors, the
conventional residual, R = %\\F0\ — \FC\\
/%\F0\, was 0.053 for all data and 0.042
for the 1067 reflection data with intensi-
ties greater than the minimum observa-
ble. The corresponding values for the
weighted residual, r= [$u(\F0\ -\FC\)2
/%oF02]*, were 0.047 and 0.039. The
atoms were then allowed to have aniso-
tropic temperature factors, and the re-
finement was continued. After conver-
gence, the residuals were R — 0.047 and
r = 0.045 for all data, and R = 0.037 and
r = 0 036 for the data with intensities
greater than the minimum observable.
Applying the significance test of Hamil-
ton (1965) , the hypothesis that the atoms
of this structure vibrate isotropically
may be rejected at the 0.005 level. Some
of the important bond distances and
angles in the structure are presented in
Tables 31 and 32. These quantities and
their errors were computed with the un-
published program BADTEA of Finger,
and the errors include the full-matrix
propagation-of-error formula, including
the errors in the lattice constants.
The Keystone triphylite is isostruc-
tural with monticellite and consists of
serrated bands of edge-sharing octahedra
(Birle et al., 1968) cross-linked by phos-
phate tetrahedra. Each distorted lithium
octahedron shares edges with two other
Li06 groups, two Fe06 octahedra, and
two P04 tetrahedra; each iron octa-
hedron shares edges with two lithium
octahedra and one tetrahedron ; and each
phosphate group shares edges with two
lithium and one iron octahedra. With this
amount of edge-sharing present, there is
a great deal of distortion in the poly-
hedra (Table 31) from shortening of
the shared 0-0 edges; the metal-oxygen
bonds, however, are reasonably regular.
292
CARNEGIE INSTITUTION
TABLE
31.
Selected Bond Distances
(in
Angstroms)
for
Triphylite
Atoms
Distance
Atoms
Distance
POi tetrahedron
P-Ol
P-02
P-03(2x)
1.535(3)
1.536(3)
1.553(2)
P-0
1.544
01-02
01-03(2s)
02-03 (2a;)
03-03
2.556(4)
2.579(3)
2.479(3)
2.442(4)
0-0
2.519
LiOe octahedron
Li-01(2s)
Li-02(2a;)
Li-03(2a;)
2.181(2)
2.097(2)
2.183(2)
Li-0
2.154
01-02 (2a;)
01-02(2a;)
01-03(2z)
01-03(2x)
02-03 (2a;)
02-03 (2a;)
2.980(4)
3.070(1)
2.907(3)
3.255(3)
2.479(3)
3.490(3)
0-0
3.030
FeOe octahedron
Fe-01
2.205(3)
Fe-02
2.110(3)
Fe-03(2a;)
2.081(2)
Fe-03(2a;)
2.251(2)
Fe-0
2.163
01-03(2s)
2.907(3)
01-03(2*0
3.055(3)
02-03 (2a;)
3.281(3)
02-03(2a;)
2.958(3)
03-03 (2a;)
2.995(2)
03-03
2.442(4)
03-03
3.587(4)
0-0
3.035
Note: Standard deviations, <r, are in parentheses.
TABLE 32. Selected Interatomic Angles (in
Degrees) in Triphylite
Atoms
Angles
PO4 tetrahedron
Ol-P-02
01-P-03(2x)
02-P-03(2a;)
03-P-03
LiOo octahedron
112.7(2)
113.2(1)
106.7(1)
103.6(2)
01-Li-02(2s)
Ol-Li-O2(2a0
Ol-Li-O3(2a0
02-Li-03(2a;)
02-Li-03(2a;)
FeOe octahedron
88.3(1)
91.7(1)
83.5(1)
70.8(1)
109.2(1)
Ol-Fe-02
01-Fe-03(2a;)
Ol-Fe-03(2a;)
02-Fe-03(2x)
02-Fe-03(2a;)
03-Fe-03
O3-Fe-O3(2a0
03-Fe-03(2a;)
03-Fe-03
178.7(1)
81.4(1)
90.8(1)
89.8(1)
97.5(1)
65.7(1)
87.4(1)
152.7(1)
119.0(1)
Note: Standard deviations, <r, are in paren-
theses.
The deviations of the internal angles
(Table 32) from the values for regular
polyhedra also show the distortions, as
does Fig. 43, in which the details of the
octahedral strip and the cross-linking
tetrahedra are presented.
The authors gratefully acknowledge
the assistance of Drs. D. E. Appleman,
J. R. Clark, and J. J. Papike, of the U. S.
Geological Survey, who aided in the col-
lection of intensities and preliminary re-
duction of the data.
Further Use for the Pauling-Bond
Concept
Gabrielle Donnay
It frequently happens that the chemi-
cal analysis of a new mineral cannot
distinguish hydroxyl groups from water
molecules incorporated in the crystal
structure. A crystal-structure determina-
tion will locate all oxygen ions, but un-
less extreme care can be taken in data
GEOPHYSICAL LABORATORY
b
293
Fig. 43. A partial projection of the triphylite structure parallel to c showing the bands of
octahedra cross-linked by phosphate tetrahedra.
collecting, it will not detect protons.
Neutron-diffraction data would do this
but are not readily available. We wish
to draw attention to the fact that Paul-
ing's principle of local neutralization of
charge (Pauling, 1929) can be readily
applied to solve the problem at hand.
As far as the writer knows, only one
paper by Zachariasen (1963) has de-
scribed a related but not identical ap-
plication for borate structures. We shall
illustrate the proposed procedure with
the example of sonoraite (Gaines, Don-
nay, and Hey, 1968), whose structure
determination was recently completed
(Donnay, Stewart, and Preston, 1969).
The chemical analysis of sonoraite
showed that Fe3+ and Te4+ were present
as the only cations in the atomic ratio
1:1. The only other product of the analy-
sis was water. The electron-density map
showed eight Fe and eight Te ions in
general fourfold position of space group
P21/c and in addition forty oxygen ions,
also in general position. The overall
formula thus has to be written Fe2Te2
Oi0H6, the six protons being needed to
balance the charges. We still had to de-
cide among the formulae Fe2Te204 (OH) 6,
Fe2Te205 (OH) 4 • H20, Fe2Te206 (OH) 2 •
2H20, and Fe2Te207-3H20. When the
structure determination was completed
(with residual R for 1884 reflections
equal to 6.2%) bond lengths were known
to better than 1% (Table 33), and as-
suming that the observed bond length
uniquely determines the bond valence,
we proceeded to estimate these Pauling-
294
CARNEGIE INSTITUTION
TABLE 33. Bond Lengths (A) and Estimated Bond Valences (v.u.) for FeTe03(OH) -H30
Oxygen
Oxygen
Associations
Atoms
with
(numbered)
Te(l)
Te(2)
Fe(l)
Fe(2)
22
Protons
0(1)
2.163(15)
0.25
025
H20
0(2)
f2.015(ll)
J 0.49
1 2.009(12)
10.50
0.99
OH-
0(3)
1.888(13)
1.34
1.943(14)
0.62
1.96
0=
0(4)
2.000(12)
0.52
1.983(10)
0.54
1.06
OH-
0(5)
1.857(12)
1.34
1.938(11)
0.62
1.96
0=
0(6)
1.893(10)
1.33
1.990(12)
0.54
1.87
0=
0(7)
0
H20
0(8)
1.905(11)
1.33
f2.061(ll)
J 0.41
12.055(12)
lo.42
2.16
Or
0(9)
1.895(13)
1.33
2.040(12)
0.45
1.78
0=
0(10)
1.890(11)
1.33
1.983(11)
0.54
1.87
0=
21
4.00
4.00
2.96
2.95
Average bond
length
1.892
1.884
2.013
2.017
Note: 21 =
valence sum
of bonds emanating from cation.
22 = valence
sum of bonds reaching
anion.
bond valences.* The Te-0 bonds pre-
sented no problem ; they range only from
1.857(12) to 1.905(11) A, where the
parentheses contain the standard devia-
tions expressed in units of the last deci-
mal quoted. They overlap within three
standard deviations, and we therefore as-
sign valence 1.33 v.u. to each of the long-
est two bonds and 1.34 v.u. to the short-
est bond emanating from each Te ion.
The Fe-0 bonds, on the other hand, range
from 1.943(14) to 2.163(15) A, and we
need an experimental curve for Fe3+-0
bond valence versus bond length. Zach-
ariasen (1963, Tables 8 and 9) employed
five experimentally determined points to
plot the B-0 curve and four points for
the H-0 curve. These points were based
on his numerous refined borate-structure
* The term "Pauling-bond strength" has been
used in the past ; it is here replaced by Pauling-
bond valence, which is free from physical impli-
cation and can naturally be expressed in valence
units (v.u.), introduced by Zachariasen (1963).
determinations. The intermediate range
of these plots can be approximated by a
straight line, a relation we were obliged
to use in any case since only two refer-
ence points were available in the litera-
ture (International Tables, 1962, Vol. 3,
p. 269). These points correspond to the
average viFe3+-0, and ivFe3+-0 distances,
2.01 and 1.86 A, respectively. (The
Roman superscript is used to desig-
nate the coordination number.) The cor-
responding bond valences are, of course,
%=0.50 v.u. and % = 0.75 v.u. Starting
with the experimentally determined so-
noraite bond lengths, we read from the
plot valences that range from 0.62 to
0.25 v.u.; the valence sum of the six
bonds coming from an Fe3+ ion is 2.96 v.u.
in one case, 2.95 v.u. in the other, values
that are close enough to the integral
value of 3 to show that the linear rela-
tion is an acceptable approximation. The
valence sum of the bonds that reach any
oxygen ion leaves no doubt as to the cor-
GEOPHYSICAL LABOEATOEY
295
responding proton association. Values of
0.25 and 0.00 v.u. for 0(1) and 0(7)
identify them as part of water molecules ;
0(2) and 0(4) must belong to hydroxyl
groups on the basis of their bond-valence
sums, 0.99 and 1.06, respectively. The
remaining six oxygens are not associated
with protons. The formula is thus found
to be FeTeOs(OH) -H20, with 8 formula
units per cell.
The example of sonoraite involves only
cations that have more than one oxygen-
coordination number, since tellurium is
also known to have four nearest oxygen
neighbors. If the observed Te-0 bond
lengths had indicated the need, a
straight-line plot through two points
from the literature (Zemann, 1968)
would have been used: mTe4+-0 with
bond valence % has average bond length
1.95 A, and ivTe4+-0 with bond valence
1.00 has average bond length 2.0 A. What
can be done, however, when a cation oc-
curs with only one coordination number?
We have learned that the oxygen-co-
ordination number affects the bond
length, but we have no direct way of
obtaining a reference point with a differ-
ent bond-valence value. We must proceed
in the reverse direction. Let us consider
the case of Si as an example. Before
viSi4+ had been discovered in stishovite,
we used a straight line for Si-0 which
was obtained from accurately determined
silicate structures, in which no substitu-
tion of Si4+ by Al3+, Fe3+, etc., occurs and
all but the Si-0 bonds can have their
valences estimated. The Si-0 bond va-
lences were chosen so as to make the
valence sum of bonds reaching the oxy-
gen atoms about Si equal to 2.00. This
straight line was found to agree closely
with the one now used, which passes
through 1.61 A for bond valence 1.00 and
1.80 A for bond valence %.
In mineral crystal-structure deter-
minations, cation substitution further
complicates the interpretation of bond
lengths. To use the example of Si again,
the average tetrahedral bond length (Si,
Al)-0 in an aluminosilicate has been
used to determine the Si/Al atomic ratio
on the position in question. Such a de-
termination can be refined to take the
average oxygen-coordination number into
account, but it cannot otherwise allow for
variations in bond lengths that are due
to the range in bond valence observed
for a single chemical cation. By consider-
ing only the average bond length in a
coordination polyhedron, errors thus in-
troduced are kept to a minimum.
Taking into account the coordination
number of the oxygen ions as well as that
of the cations for refinement purposes is
now feasible thanks to the compilation of
"Effective ionic radii in oxides and
fluorides" (Shannon and Prewitt, 1969)
in which different oxygen radii for dif-
ferent coordination numbers are given.
These data are based on a survey of all
pertinent accurate structure determina-
tions and therefore represent the best
values now available. In sonoraite, al-
though the effect of coordination number
on bond length is strikingly evident —
average Fe-mO bond length is 1.98 A,
average Fe-"0 bond length is 2.04 A;
Te-mO bond length is 1.905(11) A, aver-
age Te-^O bond length is 1.88 A— the
refinement was not needed. In general,
for locating protons in an oxide structure,
the rough approximations used here will
be adequate.
A table of bond lengths and bond
valences in a description of an ionic
structure has additional advantages: it
enables one to see at a glance the co-
ordination numbers of all the anions as
well as those of the cations, gives aver-
age bond lengths for the cations, and
shows the departures of the sums of bond
valences from their ideal integral values.
If such a departure amounts to more than
~25%, experience has shown that the
structure determination is open to sus-
picion.
296
CARNEGIE INSTITUTION
X-Ray Study of Echinoderm
Skeletons
G. Donnay and D. L. Pawson *
Echinoderms have skeletons and spines
made of magnesium-rich calcite. Arago-
nite, which is a common constituent of
skeletons of other sea animals, has never
been observed in echinoderm plates. The
nature of the individual plates had re-
mained uncertain; they were described
as subparallel aggregates and as single
crystals in the literature (Raup, 1966;
Towe, 1967). The shapes and surfaces
of the plates are strikingly noncrystallo-
graphic. Even on a micrometer scale,
scanning electron microscopy shows only
curved, spongelike structures, and no
planar crystal faces and no constant in-
terfacial angles. It has not been possible
to grow any crystal shapes like these in
the laboratory, and the biological control
leading to their production in the living
organism is a fascinating mystery.
We surveyed the orientation relation
between crystallographic directions (a
and c) and the plate and body shape of
the animal. The orientation relations we
are reporting are such as to permit find-
ing the desired reciprocal lattice row
on an initial precession orientation pho-
tograph. Judging from X-ray preces-
sion (MoKcc) and Weissenberg (CuKa)
patterns, the skeletal elements studied
are indistinguishable from those of
cleavage rhombohedra of perfect Ice-
land spar of comparable size: they are
single crystals. Some plates were ex-
amined optically between crossed nicols;
they all showed strain effects when
viewed down their c axes. No twinning
was observed except mechanical twinning
induced in echinoid plates when their
tubercles are cut off. The tubercles them-
selves were examined in detail because
optical studies on thin sections have led
to the impression that they are powders
or, at most, crystalline aggregates (Raup,
1965) . The tubercles were selected to be
* Smithsonian Institution, Washington, D. C.
representative of those with different
functions: spine-bearing and nonspine-
bearing, of different ages, and of loca-
tions on different parts of the skeletons.
They were taken from the species Eve-
chinus chloroticus (Valenciennes) , Stron-
gylocentrotus droebachiensis (Muller) ,
and Cidaris rugosa (Clark) and were
studied in situ on plates. They all bore
out the fact that tubercles form as part
of the single crystal of the plate on which
they grow. Nothing happens to change
them when they are nonspine-bearing,
as observed, for example, in rudimentary
(adapical) tubercles of Cidaris rugosa.
If, however, they carry spines, their sur-
face becomes pulverized with time, and
eventually all of the tubercle may con-
sist only of powder grains, although pre-
serving the rounded shape of the original
single-crystal protuberance. The break-
ing up of the crystal into a powder is
very likely brought about mechanically
by rubbing of the spine upon the tubercle.
Dr. H. U. Nissen, of Zurich, has con-
firmed this interpretation of our X-ray
diffraction data with scanning electron-
microscope photographs of a tubercle we
had X-rayed.
The spines of the four species of sea
urchins (Echinoidea) that we studied
are elongated parallel to c. No correla-
tion of a with shape was found. Each
echinoid tooth is an extremely hard sub-
parallel aggregate of single-crystal plates
and whiskers; its c and a directions lie
normal to the length of the tooth. The
whiskers are aligned along its length so
that they are elongated normal to c. The
plates are curved, difficult to separate,
and randomly oriented. In five species
of sea cucumbers (Holothuroidea), the
c axis is perpendicular to the plates.
When the plate carries a spine, the latter
is part of the same crystal, and the c
axis points along the length of the spine.
These plates show pseudohexagonal rows
of perforations, which point along the a
directions. In three species of sea stars
(Asteroidea) , the furrow spines are elon-
gated along c; those that show a plane
GEOPHYSICAL LABORATORY
297
of flattening have a either in the plane or
perpendicular to it. Oral interradial
plates in Patiriella regularis (Verrill)
show c perpendicular to the plate and a
along its direction of elongation. The
brittle star Ophionereis fasciata (Hut-
ton) (Ophiuroidea) has arm spines elon-
gated along c, with a parallel or perpen-
dicular to the plane of flattening of the
spine. Each ventral arm plate studied has
a normal to the plate and c along its
length. In two species of sea lilies
(Crinoidea) , the c axis parallels the axial
canal in the cirrus, the stem, the arm,
and the pinnule. An a axis is directed
normal to the plane that contains the
cirrus. An axis of morphological pseudo-
symmetry, often 5-fold, parallels c in the
stem; an a axis lies along the juncture of
two repeat patterns. No morphological
feature could be correlated to the a di-
rection in the arm. The pinnule has a
ridge ; a is perpendicular to it.
Although the present studies are
limited to a very small number of species,
we are confident that an orientation rela-
tion between crystallographic a and c
axes and skeletal shape is to be found
throughout the group of Echinodermata.
BIOGEOCHEMISTRY
Uptake of Amino Acids by Kerogen
P. H. Abelson and P. E. Hare
The degradation and disappearance of
amino acids and other relatively small
organic molecules in organic-rich sedi-
ments are usually ascribed primarily to
microorganisms. Although microorga-
nisms undoubtedly play a significant role
in such processes, the experiments re-
ported here demonstrate the existence of
another mechanism of degradation, a
nonbiological mechanism. This mecha-
nism has a significant role today ; it must
have been important in the pre-life era
of earth's history. We have found that
kerogen itself, free of any biological ac-
tivity, reacts rapidly and to a large de-
gree irreversibly with free amino acids
and peptides.
Initial observations leading to these
experiments involved the chance obser-
vation that fatty-acid tracers were not
recovered in experiments with the kero-
gen from the Tertiary Green River shale
and that amino-acid tracers disappeared
when exposed to kerogen from the Pre-
cambrian gunflint chert. The major
amino acids vary substantially in their
hydrophilic-hydrophobic character and
include a variety of side chains and
functional groups; thus the amino acids
seem well suited to a comparative study
of uptake and reactivity. In our experi-
ments we have noted a wide variation
among the individual amino acids in
the rate of their irreversible reaction
with kerogen and humic acid. We have
surveyed the role of a number of experi-
mental variables, including time, tem-
perature, concentration, and pH. We
have shown that an important factor in
the disappearance of the amino acids is
reactions involving amine groups.
The kerogens used in this study were
isolated from recent mud from the San
Pedro basin. On the basis of wet weight,
the thick mud had an organic chemical
content of 2%. Direct experiments with
the mud itself were marginally feasible,
but they were difficult to carry out be-
cause of contamination of the amino-acid
analyzer with cations such as iron. In
addition, many of the results would have
been suspect because of the flora in the
mud. Accordingly, kerogen was prepared
by a series of treatments, including ex-
traction with 6 N HC1, and a hydro-
fluoric acid digest, followed by repeated
hydrochloric acid extractions. Near the
end of the procedure, the light, suspended
kerogen was decanted, leaving behind
heavy or refractory minerals, such as
pyrite. The product was thoroughly
298
CAKNEGIE INSTITUTION
washed and dried. On ignition a weight
loss of 94% was noted. The crude kerogen
was actually partly humic acid. For
many experiments the crude mixture was
employed. Humic acid was also isolated
from the kerogen, however, so that the
two components could be tested sepa-
rately. The humic acid was extracted by
stirring the crude kerogen with 0.1 N
NaOH for a day and was precipitated
from the extract by adjusting to pH 1.
About 20% of the crude kerogen was iso-
lated as humic acid.
Reactions of the amino acids with
humic acid were qualitatively similar to
those with kerogen. Quantitative differ-
ences were observed but did not seem
significant enough to justify extended
studies involving isolated humic acid
versus kerogen. Accordingly, most of our
experiments were conducted with the
crude kerogen.
To determine the interaction of kero-
gen with various amino acids a series of
experiments was performed on a solu-
tion of standard amino acids sealed under
nitrogen with a portion of kerogen, usu-
ally in the ratio of 1 ml solution to 50 mg
kerogen. For most experiments each
amino acid initially was at a concentra-
tion of 0.2 fxM/m\, with the pH adjusted
to 8.5. At the end of the incubation period
the pH was noted and then adjusted with
HC1 to pH 2. The suspension was centri-
fuged, and an aliquot of the supernatant
was applied directly to the ion-exchange
column of the amino-acid analyzer.
Table 34 summarizes data concerning the
effect of time and temperature on the
recovery of amino acids from a series of
runs at temperatures from 25° to 110°C
for various lengths of time. To normalize
results with respect to aliquot size the
data are expressed in terms of percentage
recovery of each individual amino acid,
with aspartic acid taken as 100%. We
have found consistently that with mod-
erate times and temperatures of incuba-
tion aspartic acid reacts only slightly
with kerogen.
A wide range of reactivity among the
various amino acids can be seen in the
data in Table 34. Cystine is the most
reactive, followed by the basic amino
acids, arginine, lysine, histidine ; then the
aromatic amino acids, phenylalanine and
tyrosine; then leucine and isoleucine.
After 8 days at 110°C only aspartic and
glutamic acids are relatively abundant.
Even at room temperature substantial
TABLE 34. Percentage Recovery of Amino Acids as a Function of Time and Temperature
from Kerogen-Amino Acid Mixtures*
25°C
52°C
80°C
110°C
97
8
83
1
2
8
2
4
8
Amino Acid
lhr
days
days
days
day
days
days
6hr
days
days
days
Lysine
95
13
0
0
6
0
0
0
0
0
0
Histidine
90
10
tr
tr
11
0
0
5
0
0
0
Arginine
90
4
0
0
2
0
0
0
0
0
0
Threonine
98
64
77
27
65
65
36
60
24
13
6
Serine
98
71
79
37
68
69
42
66
31
18
9
Glutamic acid
98
97
100
95
87
90
90
91
76
61
60
Glycine
99
43
64
38
77
57
35
59
32
24
18
Alanine
99
80
81
61
61
60
52
65
35
22
15
Half cystine
29
0
0
0
0
0
0
0
0
0
0
Valine
83
80
62
57
61
54
26
50
19
9
3
Methionine
61
43
31
6
35
25
14
10
0
0
0
Isoleucine
82
66
47
38
46
36
11
33
11
0
0
Leucine
88
60
32
23
40
21
2
16
0
0
0
Tyrosine
36
19
9
3
29
6
0
10
0
0
0
Phenylalanine
30
12
2
1
16
2
0
7
0
0
0
* 0.2 /xM of each amino acid originally. Data expressed as percentage recovery with aspartic
acid normalized to 100%.
GEOPHYSICAL LABORATORY
299
amounts of many amino acids react with
kerogen. The trend of the reactions at
the lower temperatures is similar to the
trend of the reactions at 110°C.
In the absence of kerogen little or no
disappearance of any amino acids would
be observed at the temperatures and
times indicated in Table 34. Even the
most unstable of these amino acids en-
dure for at least several thousand years
at 25 °C in solutions free of reactive ma-
terials. The data show that kerogen is an
effective scavenger for amino acids and
might be expected to reduce the level of
many of the free amino acids in the
natural environment within a relatively
short period of time.
The percentage rate of disappearance
of amino acids is strongly affected by
initial concentration. In an experiment
conducted for 83 days at 52 °C, three con-
centrations of amino acids were em-
ployed—0.02, 0.20, and 2.0 /xM/ml. Re-
sults are shown in Table 35. With the
exception of aspartic and glutamic acids,
a strong concentration effect was ob-
served.
At a level of 2 /*M/ml, cystine reacts
completely with kerogen. At the same
concentration most of the basic amino
TABLE 35. Effect of Concentration on
Percentage Recovery of Amino Acids*
Amino Acid
2.0
/tM/ml
0.20
/ttM/ml
0.02
/iM/ml
Lysine
Histidine
Arginine
13
21
8
0
tr
0
0
tr
0
Threonine
Serine
Glutamic acid
70
81
99
27
37
95
14
21
86
Glycine
Alanine
Half cystine
85
99
0
38
61
0
29
49
0
Valine
Methionine
Isoleucine
99
60
88
57
6
38
40
4
13
Leucine
Tyrosine
Phenylalanine
95
41
35
23
3
1
10
0
0
* Data expressed as percentage recovery with
aspartic acid normalized to 100%. 83 days at
52°C.
acids and a significant amount of the
aromatic amino acids disappear. At a
concentration of 0.02 /xM of each amino
acid the reactions are virtually complete
for the basic and aromatic amino acids
and most of the remaining acids have dis-
appeared. In natural environments like
soils and sediments the free amino-acid
concentrations are in the range 0.01-400
/Ag/g of dry sediment (Degens, 1965).
Depending on the water content, which
in sediments is well over 50%, these
amounts of amino acids are in the range
of the amino-acid concentrations used
in this study. A mud containing 2% or-
ganic matter and 20 /*g total amino acids
per gram would have a ratio of kerogen
to amino acids similar to that of the
0.02 fjM column of Table 35.
The effect of pH on the amino acid-
kerogen reactions was tested in a series
of experiments conducted at 80 °C for
24 hours with solutions ranging in pH
from strong acid to 12.3. The best re-
covery was effected in 6 N HC1, but even
in this medium nearly half of the cystine
and substantial amounts of the methio-
nine and tyrosine disappeared (Table
36). The basic amino acids react faster
at all of the higher pH values, whereas
the leucines and aromatics react best in
the intermediate pH range, being re-
covered fairly well at both low and high
pH values. The data show that in the
normal pH range found in natural en-
vironments there is not an important pll
effect.
To determine the extent to which the
reactions of kerogen and amino acids are
irreversible, samples of kerogen were
hydrolyzed with 6 N HC1 before and
after the treatment with amino acids. In
every case, only a small fraction of the
reacted amino acids could be recovered.
In addition, the amount of ammonia
found in the supernatant was signifi-
cantly greater after reaction with the
amino-acid mixture, showing that am-
monia was being produced from the
degradation of the amino acids. Five
amino acids — aspartic acid, isoleucine,
300
CARNEGIE
INSTITUTION
TABLE 36.
Effect of pH on
Amino-Acid Recovery *
Amino Acid
6iVHCl liVHCl
pH2
pH5
pH8.8
pH11.3
pH
12.3
Lysine
Histidine
Arginine
100
100
85
78
18
57
71
39
52
10
5
2
6
11
1
2
14
2
7
11
6
Threonine
Serine
Glutamic acid
98
97
100
93
87
65
71
69
50
68
72
76
63
65
81
54
60
76
63
82
100
Glycine
Alanine
Half cystine
100
100
52
100
99
10
83
81
7
80
80
0
71
77
0
58
72
0
73
98
0
Valine
Methionine
Isoleucine
100
63
90
95
9
85
86
33
66
90
26
61
90
28
61
85
34
59
94
64
85
Leucine
Tyrosine
Phenylalanine
100
64
80
69
47
29
51
39
24
42
25
14
44
27
16
41
29
21
100
64
59
* Data expressed as percentage recovery with aspartic acid normalized
to 100%. 80°C for 24 hours.
phenylalanine, lysine, and arginine —
were incubated separately at a concen-
tration of 40 /xM/ml with 50 mg kerogen
at pH 8.5 for 5 days at 110°C. An aliquot
of kerogen was similarly incubated with
water, with the pH adjusted to 8.5. The
concentrations of amino acid employed
were unusually great, and the duration
of incubation was long so that products
of incubation could be readily detected.
In each instance, including the control
with H20, some NH3 (2.4 fxM) appeared,
and in each incubation with amino acid
some of the latter disappeared. Subtract-
ing the amount of NH3 contributed by
the control from that observed, the ad-
justed results are as follows: Of an initial
40 /xM, 11 yM aspartic acid disappeared
and 4 /xM NH3 appeared. Other corre-
sponding values are 19 /xM isoleucine,
9.3 /xM NH3 ; 25 (jM phenylalanine, 10.5
/xM NHS; 29 /xM lysine, 17 ^M NH3;
and 32 ^M arginine, 24 /xM NH3. In a
control run with 40 /xM NH4S04, 12 /xM
NH3 disappeared. Thus one would not
expect to observe an exact correspon-
dence of disappearance of amino acids
with appearance of NH3. From previous
experiments (see Tables 34-36) the order
of reactivity of these amino acids from
least reactive to most reactive is aspartic
acid, isoleucine, phenylalanine, lysine,
and arginine. This is exactly the order
of ammonia production, with aspartic
acid producing the least and arginine
the most.
The kerogen that had been incubated
with arginine was later hydrolyzed for
22 hours with 6 N HC1. The supernatant
contained 1.2 /xM. Our experience with
long and repeated hydrolysis of kerogen
is that prolonged hydrolysis might have
brought off a total of 2.4 /xM arginine
out of the 32 /xM bound. Clearly arginine
had disappeared irrevocably. On the
other hand, only trifling amounts of urea,
citrulline, ornithine, or any other amino
acid appeared during the original incuba-
tion. The 6 N HC1 hydrolysis of the
kerogen yielded small amounts of the
usual amino acids, as expected. Thus, it
appeared that the arginine molecule was
largely incorporated into the kerogen.
An analysis of the carbon and nitrogen
values of the kerogen residue confirms
this observation. The C/N molar ratio
of kerogen incubated with water was
14.4, whereas the C/N ratio of the kero-
gen incubated with arginine dropped to
8.2. To account for such a change, three
of the nitrogen atoms of arginine must
be incorporated in the kerogen. Most of
the fourth nitrogen atom of arginine ap-
pears in the supernatant as NH3.
GEOPHYSICAL LABORATORY
301
Operation of our amino-acid analyzer
was conducted in two modes ; one facili-
tated resolution of acidic and neutral
amino acids, and the other was con-
venient for identifying basic amino acids
and amines. Thus, if interaction of the
amino acids with the kerogen gave rise
to ninhydrin-sensitive entities, such as
amines, we could have easily found and
identified them. We can state that no
appreciable amount of amines was re-
leased. The disappearance of alanine, for
example, was not accompanied by the
appearance of ethyl amine. These obser-
vations rule out simple decarboxylation
as the primary mechanism for disappear-
ance of the amino acids. Moreover for
lysine, simple deamination is not the
mechanism of disappearance. Simple de-
amination would have yielded a detect-
able residue.
In the hydrolysis of kerogen samples
with 6 N HC1 a small but significant
amount of amino-acid material was re-
leased. This was surprising in view of
the fact that the preparation of the
kerogen involved exposure to hot 6 N
HC1 for long periods of time, which
should have hydrolyzed any normally
peptide-bound amino acids. After an
initial hydrolysis, a second hydrolysis
also yielded substantial though smaller
amounts of amino acids. To determine
the extent of the release of amino acids
from kerogen by hydrochloric acid treat-
ment a 7-g sample of kerogen was con-
tinuously subjected to hot 6 iV HC1
extraction for 5 weeks in a Soxhlet
apparatus. The HC1 was evaporated and
analyzed for amino acids at 1-week in-
tervals, after each of which the Soxhlet
was filled with fresh, constantly boiling
HC1 for the next period. Four such
samples were taken; the final sample
covers 2 weeks, and each of the other
three covers 1 week. The results are sum-
marized in Table 37 in namomoles (10-9
moles) per gram of ash-free kerogen. For
most of the amino acids half or more was
released in the first week of Soxhlet ex-
traction. The unusually large amount of
cystine is noteworthy. For certain amino
acids, e.g., tyrosine and phenylalanine,
the ratios change, indicating perhaps
that some are more tightly bound to the
kerogen than others.
It seems unlikely that we are dealing
with normal peptide bonds in the release
of amino acids from kerogen. It may be
that the amino acids recovered are highly
adsorbed but have not yet reacted with
the kerogen. Incubation of kerogen with
water alone results in a marked decrease
in the recovery of amino acids on later
treatment with 6 N HC1. For example,
after incubation at 110°C for 30 hours
with water, adjusted to pH 8.5, subse-
quent acid treatment yielded only about
50% as much of the amino acids as did
acid treatment of the original kerogen.
TABLE 37. Extraction of Amino Acids in Kerogen *
Amino Acid
1st Week
2nd Week
3rd Week
4th and
5th Weeks
Aspartic acid
Threonine
Serine
1500
530
290
490
87
85
110
14
13
90
15
7
Glutamic acid
Glycine
Alanine
980
2900
950
320
1850
350
57
340
86
65
420
105
Half cystine
Valine
Methionine
1250
2150
170
384
470
28
95
150
74
100
Isoleucine
Leucine
Tyrosine
Phenylalanine
2130
1220
450
700
460
330
310
200
120
73
90
44
120
85
104
64
Data expressed in nanomoles (10~9 moles) per gram of ash-free kerogen.
302
CARNEGIE INSTITUTION
This result suggests that part of the
amino acids are initially bound by ad-
sorption and that these loosely adsorbed
amino acids are irreversibly incorporated
into the kerogen itself on incubation.
To gain further insight into the mecha-
nism of the amino acid-kerogen reaction
a series of experiments with peptides and
kerogen were carried out. The two pep-
tides glycylleucine and leucylglycine dif-
fer only in the position of the amino
acids. The individual constituent amino
acids differ in their reactivity with kero-
gen, leucine being much more reactive
than glycine. In glycylleucine the amino
group of glycine is free to react, whereas
in leucylglycine only the amino group
of leucine is free. Breaking of the peptide
bond while in solution would of course
release equal amounts of both free amino
acids, which in turn could react with
kerogen. These peptides can be resolved,
by ion-exchange chromatography, from
each other and from glycine and leucine,
making it possible to monitor both pep-
tides and any free glycine and leucine
produced during the course of the re-
actions.
In Table 38 are summarized the results
of an experiment in which the two pep-
tides were exposed to kerogen. Although
only a small fraction of the peptides was
recovered as free glycine and leucine, the
TABLE 38. Reaction of Peptides with
Kerogen *
1% 6V2 1 4
Start hr hr day days
Glycylleucine + kerogen at 110°C, pH 8.8
Glycine 0 13 5 7
Leucine 0 15 8 8
Glycylleucine 100 84 49 18 6
Leucylglycine 0 tr 1 4
Leucylglycine + kerogen at 110°C, pH 8.8
Glycine 0 2 4 7 11
Leucine 0 tr 1 2 3
Leucylglycine 100 86 57 40 15
Glycylleucine 0 112 4
* Data expressed as percentage of original
peptide. 6 N HC1 hydrolysis of the 4-day
kerogen residue yielded less than 10% of the
glycine and leucine originally present.
proportion of glycine and leucine was
consistently different in each peptide. In
glycylleucine free leucine always ex-
ceeded free glycine; in leucylglycine the
reverse was true, glycine exceeding leu-
cine to an even greater extent. These re-
sults indicate that the peptide-kerogen
reactions involve the free amino group of
the peptide. Following attachment to the
kerogen, some of the peptide bonds have
split.
Although leucine is more reactive than
glycine, the peptide glycylleucine is
somewhat more reactive than leucyl-
glycine. In these experiments the produc-
tion of NH3 was again observed. Thus
our studies point toward an important
role for the amine group in reactions of
amino acids with kerogen. All our ob-
servations point toward a mechanism in
which the amino acids reacting with
kerogen lose NH3 and the residual por-
tion is bonded to the kerogen, presum-
ably by a carbon-carbon bond.
In our studies of the interaction of
kerogen and peptides we observed that
after long-term exposures new peptides
appeared. When glycylleucine was
heated, some leucylglycine was formed,
and similarly glycylleucine was formed
from leucylglycine. That kerogen was
not involved was shown by heating each
peptide alone, forming in each case the
opposite configuration. Our experiments
showed that one peptide configuration,
leucylglycine, was more stable than the
other, and an equilibrium proportion was
obtained after prolonged heating. The
low recovery of the peptides and con-
stituent amino acids after reaction (with-
out kerogen) indicated that much of the
original material was in a ninhydrin-
negative form — probably a ring structure
such as diketopiperazine. Hydrolysis
with 6 N HC1 permitted recovery of the
total amount of glycine and leucine
originally present. On passage through
Dowex-50 in the sodium form of solu-
tions at pH 3 the diketopiperazine was
not retarded and could be freed from any
free amino acids and peptides present.
GEOPHYSICAL LABORATORY
303
Heating of solutions of this diketopipera-
zine produced leucylglycine, glycylleu-
cine, and some free glycine and leucine.
Consistently higher proportions of leu-
cylglycine were formed. These experi-
ments have profound implications for the
abiotic synthesis of peptides and proteins
since they indicate a preferred produc-
tion of certain amino-acid sequences by
a nonbiological, nongenetic code mecha-
nism.
Optically Active Steranes in a
Miocene Petroleum
T. C. Hoering
The optical activity of many petro-
leums is associated primarily with high-
boiling, saturated, cyclic hydrocarbons.
These include the four-ringed molecules
of the sterane class. Optically active
steroids are common constituents of liv-
ing organisms. After deposition in sedi-
mentary rocks, they are fully saturated
with hydrogen to form steranes (see Fig.
44).
This report describes the development
and application of a procedure for isolat-
ing sterane hydrocarbons from sedi-
mentary organic matter. A petroleum of
Miocene age from the Los Angeles Basin,
California, was chosen in order that large
amounts of starting material would be
readily available. Phillipi (1965) has
made a detailed study of the geology and
petroleum genesis in this area. He kindly
provided a quantity of a typical crude oil,
which corresponds to sample 36 of his
CHOLESTEROL
CHOLESTANE
Fig. 44. Structure of a typical steroid, cholesterol. The conventional numbering of the carbon
atoms in the molecule and the designation of the rings are shown. A sterane hydrocarbon, choles-
tane, would result if the double bond at C5 were saturated with hydrogen and the hydroxyl group
at C3 were replaced by hydrogen. The naturally occurring classes of steroids are grouped on the
basis of the structure of the side chain bonded at C-17. Ergostane has a methyl group substituted
at C-24, and sitostane has an ethyl group at C-24. Two forms of steranes are considered. They
differ only in the configuration at the juncture of rings A and B. If the added hydrogen at C5
projects below the plane of the ring, the molecule is designated as 5a and ring A lies in the same
plane as the other rings. If the added hydrogen projects above the plane of the rings, the
molecule is designated 5/3 and ring A projects downward at an angle to the other rings.
304
CARNEGIE INSTITUTION
publication. He had shown by mass
spectrometer analysis that the oil was
rich in four-ringed alkanes, but the dis-
tribution and types of molecular struc-
tures in the sterane fraction were un-
known.
The optically active fractions of petro-
leum are extremely complex mixtures,
but new types of chromatographic sepa-
ration and instrumental methods of
analysis make it possible to isolate and
characterize individual components. For
example, the Bendix-Ericson automatic
polarimeter is capable of routinely de-
tecting 0.001° of rotation. It is possible
to use samples that are 1 to 2 orders of
magnitude smaller than employed by
conventional polarimetry. Combined gas-
liquid chromatography and mass spec-
trometry makes possible the separation
of complex mixtures and the simultane-
ous measurement of the mass spectra of
microgram quantities of individual com-
ponents. The mass spectra of sterane
hydrocarbons have been studied in great
detail by Tokes (1965). Their spectra
are unique, and detailed information on
molecular weight, number of carbons in
the aliphatic side chain, the nature of
the juncture between rings A and B, and
the presence of extra methyl substituents
is easily obtained. Mass spectrometry,
however, does not give useful informa-
tion on the structure of the side chain
at C-17.
Pure steranes are needed for develop-
ing the separation procedures and for
calibrating the gas chromatograph and
the mass spectrometer. Most of them are
not available commercially. They were
synthesized from readily available ster-
oids by well-established chemical reac-
tions. A set of steranes in both the 5a
and 5/3 configuration was assembled.
In the study of the crude oil, the gen-
eral experimental procedure was as fol-
lows. Saturated hydrocarbons were iso-
lated from the petroleum by alumina
and silica-gel column chromatography.
They were distilled into thirty-five nar-
row-boiling-range fractions. Over 90% of
the optical activity was concentrated
into 7 wt % of the hydrocarbons. A series
of separations, selective to molecular size
and shape was employed on the fractions
containing the optical activity. Straight-
chained hydrocarbons were removed by
forming their urea adduct. Thiourea
forms an adduct with hydrocarbons of
bulkier size. Using the synthetic pure
compounds, it was found that 5a chole-
stane and 5a ergostane could be selec-
tively removed from a mixture. Haug
(1963) found that five-ringed hydro-
carbons are selectively adsorbed by Linde
molecular sieve 13X. When the optical
activity concentrate from the petroleum
was chromatographed on a 6-foot column
of the molecular sieve in CC14, fractions
enriched in steranes and free of hydro-
carbons with higher number of rings
could be obtained. Gel permeation chro-
matography substrates, compatible with
organic solvents, have become available
recently. A 10-foot column of Sephadex
LH-20, expanded in acetone-tetrahydro-
furan, was effective in concentrating
four-ringed hydrocarbons from linear
and cyclic hydrocarbons. Adsorption
chromatography on a 25-foot column of
alumina at low sample loadings was very
effective in separating steranes. A chro-
matogram is shown in Fig. 45.
The individual separation steps were
combined as follows. The branched cyclic
hydrocarbons in the optical activity con-
centrate were treated with thiourea and
separated into two classes, the adducti-
nated and the nonadductinated. Each
of these was then chromatographed suc-
cessively on the molecular sieve, the gel
permeation medium, and the alumina
column. Fractions of pure four-ringed
hydrocarbons resulted. High-resolution
mass spectrometry and field-ionization
mass spectrometry showed them to be
exclusively steranes of the formulae
C26H46, O27H48, G28H50, U29H52, O30H54,
and C3iH56.
About one-fourth of the sterane frac-
tion formed a thiourea adduct and gave
the relatively simple gas-liquid chro-
GEOPHYSICAL LABORATORY
305
\ nC28H58
/ \ ft CHOLESTANE f*^
a CHOLESTANE
180 ml
Fig. 45. Separation of hydrocarbon classes by alumina chromatography. A column of neutral
alumina, 25 feet X 0.375 inch in diameter, was used. Ten milligrams of a mixture of normal hydro-
carbon, n-octacosane, CusHss; a highly branched hydrocarbon, squalane, C3oH62; and two sterane
hydrocarbons, 5a and 50 cholestane, CswILs, was placed on the column and eluted with hexane.
Ten milliliter fractions of the eluate were collected and analyzed by gas-liquid chromatography.
matogram shown in Fig. 46. This sample
was highly optically active, having a
specific rotation of 28.3, as compared to
0.9 for the total hydrocarbons in the
petroleum. The individual compounds
were separated and identified by com-
bined gas-liquid chromatography and
mass spectrometry.
The steranes that did not form a
stable thiourea adduct were a complex
mixture but could be resolved by gas-
liquid chromatography. The mass spectra
of over thirty components have been
measured. The components are princi-
pally isomeric cholestanes, ergostanes,
and sitostanes. The mass spectra of every
compound examined so far are typical
of the 5a configuration. Hence, the
steranes in this petroleum differ pri-
marily in the degree of branching of the
side chain at C-17.
A number of interesting minor com-
ponents have been identified. Figure 46
shows the presence of a sterane with a
seven-carbon side chain. The correspond-
ing steroid is very rare. This compound
may represent a cholesterol with one of
the carbons in the side chain removed
during petroleum genesis. A series of
steranes without the 19-methyl grouping
(19-nor steranes) is present. There are a
number of steranes with extra methyl
substituents on rings A and B.
There is little doubt that the steranes
in this petroleum represent fossil steroids
from once-living organisms. They are
highly optically active, and the most
abundant ones — cholestane, ergostane,
and sitostane — are just the ones to be ex-
pected from reduction of the major ste-
roid types. An examination of much
older sedimentary organic matter may
yield information on the biochemical
evolution of steroids (Bergman, 1958).
The presence of steranes in predomi-
nantly the 5a configuration, but with
isomerized side chains, shows that dur-
ing hydrogenation of steroids in sedi-
306
CARNEGIE INSTITUTION
-
THIOUREA
3
ADDUCTINATED
D
!
STERANES
UJ
z
o
Q-
LU
01
o
h-
o
LU
LaJ
Q
p
F
>
\ A
^ ——>___ IV A»- _ r^l
U
Uv_
ELUTION TIME -*
Fig. 46. Gas chromatogram of sterane hydrocarbons isolated from petroleum. The chromatogram
was made with a 100-foot X 0.010-inch capillary column coated with Apiezon L and a head pres-
sure of 30 psi at 265°C. The identifications were made by combined gas-liquid chromatography
and mass spectrometry. (A) 5a sterane, C26H46, with a 7-carbon side chain at C-17. (B) 5a choles-
tane, C27H48. (C) 5a sterane, C27H48, isomeric to cholestane. (D) 5a ergostane, C28H50. (E) 5a
cholestane with two additional methyl groups on rings A or B, C30H52. (F) 5a sitostane, C30H52.
mentary rocks the stereochemically more
stable ring structure is preferred. A con-
siderable amount of rearrangement of
alkyl groups must have already occurred
in this geologically young sample.
No detectable optical activity occurred
in the lower boiling fraction of the hy-
drocarbons. Several of them were greatly
enriched in the compounds pristane and
phytane, the major hydrocarbons pres-
ent. They are believed to be formed from
the phytol side chain of chlorophyll.
However, phytol alcohol is optically ac-
tive, and its hydrogenation products
would be expected to be active also. It is
difficult to imagine how these compounds
could be so thoroughly racemized under
the conditions of petroleum formation.
This report shows that it is possible
GEOPHYSICAL LABORATORY
307
to examine the high-boiling fractions
of sedimentary organic matter in detail
that has not been possible before. Many
classes of compounds of great biogeo-
example, if a range of five-ringed satu-
rated hydrocarbon standards were avail-
able, it would be possible to examine
triterpanes, which are probably derived
chemical interest await exploration. For from plant triterpenoids.
ISOTOPIC INVESTIGATIONS IN GEOCHEMISTRY
AND GEOCHRONOLOGY
G. L. Davis, T. E. Krogh, and S. R. Hart* with C. Brooks* and A. J. Erlank*
The Age of Metamorphism in the
Grenville Province, and the Age op
the Grenville Front
The Grenville province of the Cana-
dian shield is an area of great extent
having structures and rock types that in-
dicate deep burial. Its metamorphic
grade is usually higher than that of the
Superior, Southern, and Churchill prov-
inces, which bound the Grenville province
on the northwest. This boundary, the
Grenville Front, is a major northeast-
trending zone of both plastic and brittle
deformation that extends from Georgian
Bay on Lake Huron to the Labrador
trough and perhaps as far as the Labra-
dor coast, a distance of about 1800 km.
In the Georgian Bay-Sudbury area of
Ontario, age relationships between the
Grenville gneisses south of the Front
and the lower temperature, higher level
Huronian metasediments north of the
Front were studied by many eminent
Canadian geologists of earlier times. The
Grenville gneisses in this area have been
considered to be older, equivalent to, and
younger than the Huronian rocks that
were deposited at least 2150 m.y. ago
(Van Schmus, Wetherill, and Bickford,
1963), as well as equivalent to the Gren-
ville series in southeastern Ontario that
was deposited between 1300 and 1000
m.y. ago (Krogh and Hurley, 1968).
The most detailed geological investiga-
tion of this area was published in 1930
by Quirke and Collins, who entitled their
memoir "The disappearance of the
* Department of Terrestrial Magnetism.
Huronian." These authors concluded that
the Huronian formation, traceable east-
ward for 225 km from Sault Ste. Marie,
does not terminate at the Grenville Front
but exists south of the Front in a highly
recrystallized and metamorphosed state.
Phemister (1961) reached a similar con-
clusion after a study of the transition
southeast of Sudbury.
A great divergence of opinion regard-
ing the age of the metamorphism of the
gneisses existed among the early workers.
In the past 15 years, however, more than
a hundred radiometric age values be-
tween 900 and 1300 m.y. have been de-
termined for minerals from various parts
of the Grenville province. These ages
have been widely accepted as indicating
that the major metamorphism occurred
about 1000 m.y. ago.
In the past few years we have been
able to show that many of the gneisses
south of the Front were metamorphosed
more than 1500 m.y. ago and that the age
of deposition of these rocks is more than
1700 m.y., the age of numerous granites
in the region. Because of this, the area
provides a unique opportunity to deter-
mine the extent of migration of the dat-
ing elements during a regional meta-
morphism, in this case about 1000 m.y.
ago. A technique based on isotopic de-
terminations of rubidium and strontium
in layered paragneisses has been devel-
oped. This is the only direct method
available to determine the time of meta-
morphism if all mineral systems have
undergone subsequent isotopic exchange.
This report gives the results of a study
308
CARNEGIE INSTITUTION
of the paragneiss that indicates a time
of major metamorphism 1800 ±100 m.y.
ago, with isotopic exchange taking place
during a younger metamorphism, 900
m.y. ago, restricted in extent to a few
millimeters. The older age for the first
metamorphism was confirmed by our de-
termination of muscovite ages of 1630
m.y. in a pegmatite 1.5 km south of the
Grenville Front.
The proximity of these older gneisses
with the plastically deformed northeast-
trending migmatitic zone in the Grenville
Front implies the same age for the Front
itself. We have made considerable prog-
ress toward dating the nonrock-forming
structural events in the Grenville Front
in areas where most of the mineral sys-
tems suitable for measurement have been
open to exchange during the younger
metamorphism. The centers of coarse
muscovite crystals yield ages as old as
1630 m.y. in a syndeformational pegma-
tite and as old as 1470 m.y. in postdefor-
mational pegmatites in the Front zone.
Preliminary whole-rock determinations
on these pegmatites suggest that their
true ages may be as much as 1800 ±
100 m.y.
An age of 1570 m.y. has been deter-
mined for a series of elongate granitic
bodies that occur along the Front be-
tween Sudbury and Georgian Bay for a
distance of more than 65 km. These in-
trusives commonly have a very limited
contact metamorphic effect where they
intrude the fine-grained Huronian rocks
to the northwest, but they are bounded
on the southeast by coarsely crystalline
gneisses. Field evidence suggests that the
late-stage brittle deformation found
along the Grenville Front occurred both
before and after the emplacement of this
granite.
Our results to date imply that the
gneisses both in this part of the Gren-
ville province and in the Grenville Front
zone underwent metamorphism and de-
formation between 1500 and 1800 m.y.
ago and that the Front zone was again
a line of dislocation and probable uplift
about 1000 m.y. ago.
Metamorphism 1700±100 m.y. and
900 ±100 m.y. Ago in the Northwest
Part of the Grenville Province
in Ontario
T. E. Krogh and G. L. Davis
Paragneiss from the Georgian Bay
area 55 miles southeast of the Grenville
Front. In Year Book 67 we presented the
variations in Rb and Sr found in a
layered felsic paragneiss sample collected
south of Pointe au Baril on highway 69
{Year Book 67, location 11). To date we
have analyzed five 2-cm to 3-cm slices
from the 20-cm block, as well as plagio-
clase and microcline from two of the
slices, and a single biotite.
The data for microcline and plagio-
clase shown in Fig. 47 indicate isotopic
exchange of strontium between these two
minerals in each of the two samples ana-
lyzed (11-2, 11-9) at about 930 m.y. The
biotite from sample 11-2 yields a slightly
lower age, 890 m.y.
In Fig. 47 the data for the whole-rock
samples lie on an isochron for 1800 m.y.
Even the three adjacent samples (11-7,
11-8, 11-9), which had distinctly differ-
ent isotopic compositions during the
younger metamorphism, do not indicate
any signfiicant between-sample isotopic
mixing.
These whole-rock and mineral data
demonstrate that the isotopic composi-
tion of strontium was homogeneous
within this 20-cm section of rock about
1800 m.y. ago and that isotopic mixing
since then has been restricted to local
exchange between adjacent minerals. In
a microcline-plagioclase host, Sr87, once
released from its production site, behaves
as a relatively nondiffusing trace ele-
ment.
Paragneiss from the French River
area. In Year Book 66 we discussed the
Rb and Sr variations that occur in a
layered paragneiss, situated about 30
miles southeast of the Grenville Front in
GEOPHYSICAL LABORATORY
309
.900
.880
.860
.840
S .820
co
.700
i 1 r
WHOLE ROCK ISOCHRON
1807 my
1 1 T
II-4TR
•2M
I-2TR
II-2P
1.0
2.0 3.0
4.0
5.0 6.0 7.0
.0 9.0 1 0.0
Rb87/Sr86
Fig. 47. Isochron plot for the Georgian Bay, Pointe au Baril, paragneiss sample. Solid line is the
whole-rock isochron. Broken line is the mineral isochron.
the French River area. Of special interest
are the plagioclase-quartz-biotite layers
that appear to form as a result of meta-
morphic reactions between the micro-
cline-bearing layers and the mafic layers
(amphibole, plagioclase, biotite). As a
test of isotopic mixing during the younger
metamorphism, plagioclase from four
adjacent layers (2 to 4 cm thick), in-
cluding a plagioclase-rich reaction zone,
was analyzed. The results obtained, as
shown in Fig. 48, demonstrate that the
isotopic composition of Sr in plagioclase
is different in each of the adjacent layers.
If these metamorphic layers developed
during the younger metamorphism, each
part of this 12 cm of rock would have
strontium with the same isotopic compo-
sition. We propose that the isotopic
composition of the strontium was the
same across this section at some time
between 1500 and 1800 m.y. ago and that
the metamorphic changes to form the
minerals now present occurred then. Be-
tween the first and the second meta-
morphism each layer developed a differ-
ent Sr87/Sr86 ratio in accordance with its
Rb87/Sr86 ratio. During the 900-m.y.
thermal event each plagioclase exchanged
strontium with the minerals in its own
layer.
Isotonic Ages Along the Grenville Front
in Ontario
T. E. Krogh and G. L. Davis
The Grenville Front southeast of Sud-
bury, Ontario. Isotopic dating of a peg-
matite body situated in the northeast-
trending migmatitic Grenville Front zone
provides our best estimate of the time
of formation of this major structural
310
CARNEGIE INSTITUTION
.750
.740
CD
00
c/5
00
00
.730
.720
.710
.700
1
AGES FROM
1 1 1 1
PLAGIOCLASE -WHOLE /M 3D
ROCK JOINS ARE BETWEEN m& 3G
800 AND 900 my „/ :
yy 66-88
' /^—REFERENCE
_
/ / ISOCHRON
y / 1600 my
/'
1/ 3H
S /
/ I IC
3H,P /
X 2AB
3 I, P / S
1 1
/ IA
»/ 2A,P
/
1 I 1 1
0.5
1.5
2.0
2.5
Rb87/Sr86
Fig. 48. Isochron plot for the French River paragneiss sample. Solid line is the whole-rock
isochron. Broken line is the mineral isochron.
feature. The body, which contains kya-
nite and garnet, apparently was intro-
duced between the layers of the gneiss
during a period of plastic deformation.
Phemister (1961) reported that many
paragneiss inclusions within the pegma-
tite strike northeast and dip to the south-
east parallel to the host rocks. In places,
pegmatite and gneiss are interlayered on
a scale of a few centimeters, and together
they are folded with the southeast-
plunging lineation typical of the Front
zone. These relationships imply that the
age of emplacement for the pegmatite is
the time of plastic deformation in this
part of the Front.
Analysis of the magnetic and non-
magnetic zircons from this pegmatite
yields a probable diffusion age between
1600 and 1700 m.y. (Fig. 50) . The centers
of two large muscovite crystals from the
pegmatite yield Rb-Sr ages of 1630 m.y.
These muscovites, formed during the
major regional metamorphism, are the
first ever measured within the Grenville
province that give ages approaching that
of the earlier metamorphism. A single
whole-rock aliquot from a 38-kg pegma-
GEOPHYSICAL LABORATORY
311
tite sample has a ratio of Rb to Sr of 9.0.
It yields an age of 1880 m.y. for the
pegmatite if an initial ratio (Sr87/Sr86)
of 0.705 is assumed. These results imply
that the Front zone may be as old as
1880 m.y. and that the region did not
cool until about 1600 m.y. ago.
Killarney Bay, Bell Lake, and Chief
Lake areas. In the Sudbury-Georgian
Bay area a series of elongated granitic
bodies occur along the Grenville Front
for a distance of more than 70 km. Along
their northwest intrusive contact they
have a very limited contact metamorphic
effect on the Huronian rocks. Occasion-
ally zones of brecciated quartzite occur.
Toward the southeast their contact with
the Grenville gneisses is probably intru-
sive, but the relationships are obscured
by development of northeast-trending
orthogneisses within the granites as well
as a late-stage pervasive mylonite.
Quirke and Collins (1930), who did the
most detailed early geological work in
the area, suggested that the granite
seems to have followed a break in the
crust and to have been crushed into a
zone of weakness.
The authors of recent geological in-
vestigations in these areas include M. J.
Frarey (paper in preparation) in the
Killarney-Bell Lake area, Henderson
(1967) in the Chief Lake area, and
Brooks (1967) in part of the Bell Lake
area. Previous whole-rock Rb-Sr analy-
ses {Year Books 65 and 67) indicated an
age of about 1700 m.y. for the Chief
Lake batholith in the eastern part of the
area, but points for some samples were
below the isochron.
The results obtained for samples from
three localities are presented in Fig. 49:
i r
REFERENCE ISOCHRON 1700m y-^
235-2
2135
235-1
2136
235-0 //
-REFERENCE ISOCHRON 1590 my
D5
234-3
KG
69-9
4.0 5.0 6.0
Rb87/Sr86
7.0 8.0 9.0
Fig. 49. Isochron plot for granite samples from along the Grenville Front in the Georgian Bay-
Sudbury area. Sample designated KG is from the Killarney granite, sample 69-9 is from the Bell
Lake granite, and other samples are from the area mapped as the Chief Lake batholith.
312
CARNEGIE INSTITUTION
the Killarney granite (designated KG)
occurs near Georgian Bay, the Bell Lake
granite (designated 69-9) occurs about
20 km to the northeast, and the Chief
Lake batholith (other points) is situated
up to 70 km to the northeast. Two ages
of granite emplacement are now apparent
from both the whole-rock and zircon
data: about 1590 and 1700 m.y. (Figs.
49 and 50) . The older granite occurs only
in the northern part of the area called
the Chief Lake batholith, whereas the
younger granites are distributed along
the Grenville Front from Georgian Bay
to near Conniston, southeast of Sudbury.
A major northeast-trending structure,
the Grenville Front must have developed
prior to the emplacement of this younger
granite almost 1600 m.y. ago. Many of the
least deformed granite samples from the
Chief Lake batholith area are found to
be parts of the younger granite. Much of
the mylonitization of the Chief Lake
body is probably older than this granite.
In other areas, however, the younger
granites are also intensely deformed, sug-
gesting that these granites were actually
emplaced during the late-stage brittle
deformation of the Grenville Front.
Rb-Sr ages of 1440-1470 m.y. were
measured on coarse muscovite crystals
from pegmatites that cut (1) the linea-
tions immediately north of the Bell Lake
granite, (2) the foliation in coarse-
grained impure quartzite immediately
south of this granite, and (3) the
mylonitized granite about 2.5 km south
of the Grenville Front. The muscovite
ages provide only a minimum age for
these features because of the probable
loss of radiogenic strontium by diffusion
prior to the cooling of the region. De-
formation that is later than some of these
pegmatites is also apparent. The real age
of the pegmatites is uncertain, but they
may be as old as 1700 m.y., an age ob-
tained for a single whole-rock pegmatite
0.3
0.2-
-
i 1
1
I500mv^'^//
1700 my^-^^^
-
1300 my ^
/&
^^ 68-17
9 00 my .X \gJ>^68-34
69-9
68-I7M
500my y
y° 68-34 M
1.0
2.0
Pb207/u235
3.0
5.0
Fig. 50. Concordia diagram for zircons from the pegmatite in the Grenville Front zone near
Sudbury (68-34, 68-34M), the Bell Lake granite (69-9, 69-9M), the pegmatite in the Front zone
near North Bay (68-17, 68-17M), and the Killarney granite (2231). Parts of continuous diffusion
lines are shown for zircons 1500 m.y., 1700 m.y., and 2800 m.y. old.
GEOPHYSICAL LABORATORY
313
sample based on an assumed initial ratio
of 0.705.
Rb-Sr ages of ten muscovite samples
collected north of the Front in the Chief
Lake area vary systematically between
1050 and 1950 m.y. as the sample dis-
tance from the migmatites of the Gren-
ville province increases from 1 to 5 miles.
In one critical location a silty impure
quartzite is folded about the southeast-
plunging axis of lineation typical of the
Front zone. Muscovite from this re-
crystallized and folded silty layer has a
Rb-Sr age of 1390 m.y., but the coarser
muscovite from a pegmatite that appears
to cut the folding on this outcrop has a
Rb-Sr age of 1665 m.y.
The Grenville Front north of North
Bay, Ontario. In Year Books 65 and 67
we reported the presence of an Archean
granite body (about 2600 m.y. old) about
12 km south of the Grenville Front, as
mapped by Johnston (1954).
A recent study of a pegmatite that
cuts across the northeast-trending folia-
tion in a migmatitic granite 0.4 km south
of the Front produced some surprising
results. The zircons in this dike, although
discordant, indicate a U-Pb diffusion age
of at least 2700 m.y. (sample 68-17,
Fig. 50) ; the Rb-Sr muscovite age is
2270 m.y., and the plagioclase-microcline
line on a Rb-Sr isochron diagram has a
slope of 1550 m.y.
These results show that the migmatitic
granite probably formed 2700 m.y. ago.
It became aligned parallel to the Front
at this time or some time before 1550
m.y. ago. The Rb-Sr data for the feld-
spars indicate that a significant Gren-
ville (1000 m.y.) thermal event did not
occur at this location.
The Grenville Front in the
Chibougamau^Surprise Lake
Area, Quebec
T. E. Krogh, C. Brooks* S. R. Hart*
and G. L. Davis
A metamorphic transition in the Sur-
* Department of Terrestrial Magnetism.
prise Lake area near Chibougamau,
Quebec, was studied and described as a
transitional Grenville Front by Deland
(1956). A brief report of preliminary re-
sults was included in Year Book 67. The
Rb-Sr ages of muscovites and biotites
from this metamorphic transition are
shown in Fig. 51. Figure 52 presents the
isotopic data for several whole-rock
samples.
It is clear from the muscovite ages that
the metamorphic transition had occurred
and the region had cooled earlier than
2500 m.y. ago. Biotite Rb-Sr ages, on
the other hand, range from a minimum
value of about 900 m.y. in the south-
eastern part of the map area to 2100 m.y.
in the northwest. When two biotites were
analyzed the coarser fraction always
yielded an older age, and biotites from
the granites gave older age values than
those from the metasediments. The bio-
tites have lost different amounts of radio-
genic strontium by diffusion, probably
about 900 m.y. ago, whereas under the
same conditions the muscovites have re-
tained almost all of their radiogenic
strontium.
The occurrence of the Archean meta-
morphic transition near the Grenville
metamorphic zone may be simply a co-
incidence, but an alternative explanation
is possible. A metamorphic gradient,
which developed vertically 2500 m.y.
ago, may have been exposed in a lateral
direction as a result of later uplift and
erosion, perhaps at 900 m.y. The time of
formation of mineral isograds in the
rocks exposed by this mechanism along
the Grenville Front would be older than
the Front itself.
Isotopic analysis of whole-rock samples
of granite from several locations does
not show any marked effect of the
younger metamorphism. A poorly de-
fined isochron with a slope of 2500 ± 100
m.y. was obtained from several samples
from a single outcrop area. Samples from
other locations suggest a similar age but
had an anomalously high initial ratio.
These results are inconclusive.
314
CARNEGIE INSTITUTION
::^jZm.
LEGEND
ii
\' ■' ■ 1 Granite
/—
EE3 "
High grade
mi
• Metavolcanics
'■ Cr^
Lower grade
o
2325 ■ ;.
960 ¥:
■: y--
m i
113
Lower grade J
0 I 2 3miles
i 1 1 1
Fig. 51. Mineral age values for muscovite (m) and biotite (b) in the Surprise Lake area, Quebec.
,79
.78
.77
£ -75-
CO
r>
Chibougomau Granite
Q38I
1.0 1.5
Rb97/Sr86
Fig. 52. Isochron diagram for the Surprise Lake granite.
Q 23
Pegmatite
2.5
GEOPHYSICAL LABORATORY
315
Sr Isotope Variations in Archean
Greenstones and the Differentiation
of the Earth's Mantle
The isotopic abundance of Sr87 in-
creases by natural radioactive decay in
proportion to the time elapsed and the
abundance of Rb87. The isotopic varia-
tions of strontium from modern volcanic
rocks indicate that small differences in
the Rb/Sr ratio have existed in their
mantle source region for some time. The
relative abundance of these trace ele-
ments varies, as does that of K and Ca,
during the extraction of crustal ma-
terial from the earth's mantle. Thus,
strontium isotopes are sensitive tracers
that can be used to investigate the dif-
ferentiation history of the earth.
In our recent studies we have at-
tempted to determine the isotopic com-
position of strontium in the oldest vol-
canic rocks available in North America
(2700 m.y.) . The metamorphism of these
rocks to the zeolite, greenschist, or
amphibolite facies, as well as the neces-
sity to correct for radiogenic additions
of Sr87, complicates the determination of
the primary isotopic ratios.
Our results suggest that the Sr87/Sr86
ratio in the mantle 2700 m.y. ago was
higher than would be predicted from a
linear evolution model based on meteor-
ite and modern basalt strontium. Samples
from the Michipicoten area, situated
just east of Lake Superior in Ontario,
indicate a probable difference in the
isotopic composition of strontium be-
tween the upper and lower series in a
single volcanic pile. This difference is
supported by similar results for other
metavolcanic belts of the Canadian
shield and suggests that variations in the
Rb/Sr ratio had existed in the mantle
more than 2700 m.y. ago.
The discovery that calcite veins in
these volcanics contain radiogenically
enriched Sr and our observation that the
dating elements in some of the rhyolites
have undergone migration subsequent to
their extrusion require that we interpret
initial strontium ratios with caution.
Further details of these topics are
discussed in the current Annual Report
of the Director of the Department of
Terrestrial Magnetism under the fol-
lowing titles:
"Carbonate contents and Sr87/Sr86
ratios of calcites from Archean meta-
volcanics," by C. Brooks, T. E. Krogh,
S. R. Hart, and G. L. Davis.
"The initial Sr87/Sr86 ratios of the
upper and lower series Michipicoten
metavolcanics, Ontario, Canada," by C.
Brooks, T. E. Krogh, S. R. Hart, and
G. L. Davis.
"Initial Sr87/Sr86 ratios of regionally
distributed metavolcanics from the
Canadian shield," by C. Brooks, S. R.
Hart, T. E. Krogh, and G. L. Davis.
"Rb-Sr mantle evolution models," by
S. R. Hart and C. Brooks.
"The K, Rb, Cs, and Sr geochemistry
of Archean metavolcanics," by S. R.
Hart, G. L. Davis, C. Brooks, and T. E.
Krogh.
MINERALOGY
Inclusions in Diamonds
H. O. A. Meyer and F. R. Boyd
Investigation of inclusions in diamonds
over the past several years has revealed
a number of singular chemical and physi-
cal characteristics. These characteristics
are clues to the process by which natural
diamonds have formed and clues to the
nature of the earth's mantle at the great
depths at which diamonds have origi-
nated. Nevertheless, the interpretation of
these characteristics is enigmatic at
present. Understanding the chemical and
textural features of igneous and meta-
morphic minerals requires more than
their accurate description. It requires
duplication of the essential features by
316
CARNEGIE INSTITUTION
experiment or by the calculation of
models based on limited and reasonable
assumptions. Our study of diamond in-
clusions has provided some of the raw
data required to design experiments and
provide constraints in the construction of
models. The task of synthesis remains.
The most significant feature to emerge
this year is the remarkable similarity of
inclusions of garnet, olivine, and chromite
from one geographic region to another.
It should be understood that these in-
clusions have unique chemical composi-
tions that distinguish them from similar
minerals found in kimberlite or in ultra-
mafic xenoliths. Yet inclusions showing
these particular chemical characteristics
have been found in diamonds * from
southern Africa, Sierre Leone, Venezuela,
and Ghana. Diamonds we have studied
from southern Africa and Sierre Leone
were erupted in Mesozoic time, whereas
diamonds from Venezuela and Ghana are
Precambrian. Evidently the process by
which natural diamonds have crystal-
lized and incorporated inclusions with
unique compositions has been uniform in
space and time.
Inclusions of chrome pyrope are un-
usually rich in chromium relative to py-
ropes of other origins, and this feature is
also shown by the inclusions of chromite,
olivine, and enstatite. Why chromium
is concentrated in these inclusions is not
understood at present. Indeed there are
as yet very few phase studies in silicate
systems with Cr203 and virtually none at
high pressures.
Examination of nearly 200 inclusions
from over 50 diamonds shows that the
order of abundance is Mg-rich olivine,
*The assistance and generosity of Mr. R.
Winston, of Harry Winston, Inc., Mr. W.
Cotty, of the Diamond Producers Association,
and Dr. George Switzer, of the Smithsonian
Institution, in supplying diamonds from vari-
ous localities is gratefully acknowledged. Dr.
J. W. Harris, of University College London,
generously allowed us to analyze inclusions
that he has obtained from diamonds from
Ghana.
chrome pyrope, chromite, enstatite, and
diopside. Pyroxenes appear to be rela-
tively more abundant in mafic and ultra-
mafic xenoliths from kimberlite than as
diamond inclusions. So far only two in-
clusions have been found that contain
more than one phase. One consists of
olivine + chromite, and the other is a
chrome pyrope which itself contains a
small (<5 jam) birefringent inclusion —
possibly olivine or pyroxene. Positive
identification of this birefringent inclu-
sion is difficult because of its small size
and the absorption of X rays by the
garnet host. The olivine and chromite
pair are in firm contact along an ap-
parently plane face. Analyses of other
olivine and chromite grains from the
same diamond (GL47) that contains the
bimineralic inclusion are given in Tables
39 and 42.
Another aspect of this year's study
has been the analysis of several groups of
inclusions from individual diamonds, i.e.,
of minerals of different varieties that
have been found as separate inclusions in
the same diamond host. Olivine-garnet
(GL24) , olivine-enstatite (G10) , olivine-
chromite (GL47), and garnet-chromite
(G20) "assemblages" have been studied.
It will be suggested hereafter that these
diamonds and their inclusions have crys-
tallized from magmas. If this is true it is
likely that separate, monomineralic in-
clusions in a given diamond form an
equilibrium assemblage because they
were at one time in equilibrium with the
same liquid. Of course, there could have
been a temperature difference in the
magma between the times of incorpora-
tion of two separate inclusions, but this
is unlikely to have been a major effect
because there is a relative constancy of
composition within varietal groups of in-
clusions. The data in Figs. 53-56 show
that the chrome pyropes are all similar,
as are the enstatites and the olivines.
There appear to be two groups of
chromites.
The data in Figs. 53-56 summarize
GEOPHYSICAL LABORATORY
317
o
-p 0.06
-
1 1
•
~
OLIVINES
# Inclusions in Diamond
fPeridotite Xenoliths
O i in Kimberlite and
L Kimberlite concentrate
,0, fPeridotite Xenoliths
59 Lin Basalt
• ®
®
• ®
1
n °
100 95 90
Forsterite mole per cent
Fig. 53. Comparison of the Cr203 (wt %) con-
tents of olivine inclusions from natural dia-
monds with olivines from peridotite xenoliths
in kimberlite (O'Hara and Mercy, 1963 ; Nixon,
von Knorring, and Rooke, 1963) and basalt
(Ross, Foster, and Myers, 1954) and from
kimberlite concentrate (Stockdale pipe, Kan-
sas, Year Book 67, p. 132).
the chemical results obtained in the past
two years and compare the compositions
of diamond inclusions with similar min-
erals from other environments. The sig-
nificant features shown by these dia-
grams are summarized as follows:
1. Cr2Os contents of Mg-rich olivines
range up to about 0.1 wt % (Fig. 53).
On an average, olivines included in dia-
mond are richer in Cr than those from
other environments and they are mark-
edly richer in Cr than olivines from
ultramafic xenoliths in kimberlite and
kimberlite concentrates.
2. Garnets included in diamond (Fig.
54) are predominantly chrome pyrope,
but Cr-poor pyrope-almandine inclusions
have been found. The pyrope-almandines
resemble eclogite garnets, whereas the
chrome pyropes are akin to the garnets of
the lherzolite and harzburgite xenoliths.
In this regard its is interesting to note
that rare inclusions of enstatite and di-
opside have been found in diamonds, but
inclusions of omphacite, the character-
istic pyroxene of eclogites, have not yet
been discovered.
3. The chrome-pyrope inclusions (Fig.
54) show a range of Cr content, as do
'
r r
I j i i
-
GARNETS
• Inclusions in Diamond
80
'
0 Peridotite Xenoliths
u ond Kimberlite
"
80
~
"
„ Eclogite Xenoliths
69 in Kimberlite
-
-
O
-
60
o
-
2 60
<
r7o
o
(M
<
+
to
% 40
o
•
_
40
•
-
o •
• •
- • o
o •
• o
•
•
20
o
"
20
o
9p
'
<§P 6>
«#
0
c
i m «. » d«S ffi/pi ® t
<S> . •
0
)0 (
i afP«S& rmt*. « i
) 20 40 60
80
K
) 20 40
Mgo „.„
Ca0 -100
MqOl
-FeOI™
[CaO + MgOf "ww
Fig. 54. Analyses of garnet inclusions from natural diamonds compared with garnets from perido-
tite xenoliths, from kimberlite, and from eclogite xenoliths in kimberlite (O'Hara and Mercy, 1963;
Nixon, von Knorring, and Rooke, 1963; Fiala, 1965; Brookins, 1967; Kushiro and Aoki, 1968;
Nixon and Hornung, 1968).
318
CARNEGIE INSTITUTION
0.5
0.4
0.3-
0.2-
0.t
1
i 1
o
1 '
•
•
•
ENSTATITES
• Inclusions in Diamond
O Peridotite Xenoliths in
Kimberlite
oo
o
o
o
%
"
o
I
o
O
1 1
-
0.2
0.6 0.8 1.0
CaO Weight per cent
1.2
1.4
Fig. 55. Analyses of enstatite inclusions from natural diamonds and from peridotite xenoliths in
kimberlite (O'Hara and Mercy, 1963; Nixon, von Knorring, and Rooke, 1963; Banno, Kushiro,
and Matsuii, 1963; MacGregor and Ringwood, Year Book 68, p. 163).
100
80
60
40
20
O
O
o
o
o
o
CHROMITES
•
Inclusions in Diamond
<g>
Kimberlite concentrate
o
Peridotite Xenoliths
in Basalt
(ft*
iw
I
i
80
o
-
-
60
£
-
s>
-
40
~
-
20
-
-
• .
i
20
40
Cr
CCr + AI3
60
XIOO
80
100 0
Fe'
20
[Fe'^Cr+AI]
XIOO
Fig. 56. Plot (after Irvine, 1967) of analyses of chromite inclusions from natural diamonds and
from peridotite xenoliths in basalt (Ross, Foster, and Myers, 1954) and from kimberlite con-
centrate (Nixon, von Knorring, and Rooke, 1963).
GEOPHYSICAL LABORATORY
319
their counterparts from xenoliths in kim-
berlite and kimberlite concentrates. On
an average, however, the inclusions con-
tain more Cr, somewhat more Mg, and
notably less Ca. The Mg content of the
chrome pyropes is in fact the highest
yet recorded for any natural garnet.
4. Enstatites (Fig. 55) that occur as
inclusions in diamond have higher Cr
and lower Al and Ca contents than most
enstatites from peridotite xenoliths in
kimberlite.
5. Chromite inclusions from diamond
(Fig. 56) contain more Cr than those
from any other terrestrial environment.
Nevertheless, they resemble chromites
from pallasites and from silicate inclu-
sions in metallic meteorites (Bunch, Keil,
and Olsen, 1969; Bunch and Keil, 1969).
It is now clear that the chemical
history of the diamond inclusions has
been in some way different than the
history of the similar minerals of perido-
tite and eclogite xenoliths with which
diamonds are associated and sometimes
even intergrown. Possibly the diamonds
and their inclusions are relics of igneous
events, whereas the minerals of the
peridotites, and perhaps the eclogites,
have established their present composi-
tions by reaction and equilibration after
cooling below the solidus. It seems pos-
sible that the monomineralic inclusions
in diamond, being armored, failed to
participate in subsolidus equilibration;
their compositions may reflect earlier,
crystal-liquid equilibria. Little quantita-
tive support of this hypothesis can be
mustered at the present time, but Ken-
nedy and Nordlie (1968) have presented
other arguments that diamond formation
is an igneous process. Meyer and Boyd
(Year Book 67, p. 130) suggested that
the monomineralic nature of diamond in-
clusions might indicate a subsolidus
growth process because in an igneous
crystallization, diamond might be ex-
pected to include droplets of liquid that
would crystallize to polymineralic aggre-
gates. We now doubt this suggestion, but
in fact we need to better understand the
way in which growing crystals include
or exclude foreign matter at their sur-
faces.
The detailed analyses * of diamond in-
clusions that have been carried out this
year are presented in Tables 39—42. The
olivines (Table 39) show little variation
from an average composition of fo93ja7
and most of them are relatively rich in
Cr. The enrichment in Cr cannot be due
solely to crystallization in a Cr-rich en-
vironment because olivines associated
with chromitites in the Stillwater Com-
plex contain less than 0.01 wt % Cr203
(E. D. Jackson, personal communica-
tion). Analyses for Ni have been made
for the olivines described in Year Book
67 (p. 132, Table 4), and the results are
in accord with those presented in Table
39.
New analyses of chrome-pyrope in-
clusions from Venezuela, Ghana, and
Sierre Leone are given in Table 40; in
their high Mg and Cr contents and rela-
tively low Ca they resemble those previ-
ously analyzed (Meyer, 1968 and Year
Book 67, p. 133, Table 5). Garnet inclu-
sion GL16 (Table 40) from an unknown
locality is a pyrope-almandine, and it is
similar to the garnets from eclogite
xenoliths in kimberlite. Inclusion D15
(Table 40) is a high-Ca garnet (12.0
wt % CaO) from a South African dia-
mond. It is similar to those in kyanite-
eclogites from the Zagadochnaya pipe in
Yakutia described by Sobolev, Kutz-
netsova, and Zyuzin (1968), and to a
garnet in a kyanite-eclogite from the
Roberts Victor pipe described by O'Hara
and Mercy (1963). The discovery in
diamond of garnet inclusions with eclo-
gite affinities is interesting in view of the
fact that diamond has been found in
eclogite xenoliths from kimberlite (Sobo-
lev, 1968) .
* These analyses were made with a Ma-
terials Analysis Co. model 400 electron probe
purchased with the assistance of the National
Science Foundation under grant GP 4384.
320
CARNEGIE INSTITUTION
TABLE 39. Analyses of Olivine Inclusions
Venezuela
i
Ghana
GL24c
GL29b
GL47*
GlOb
G16a
G17a
Si02
41.0
40.2
41.1
41.3
40.8
41.2
TiOs
0.00
0.00
0.00
0.00
0.00
0.00
A1203
0.02
0.02
0.00
0.05
0.02
0.02
Cr20a
0.07
0.07
0.08
0.05
0.02
0.07
FeO
6.65
7.14
6.21
6.91
7.10
8.34
MgO
52.7
51.9
52.7
51.6
52.5
50.7
CaO
0.01
0.04
0.01
0.04
0.03
0.06
MnO
0.10
0.12
0.10
0.11
0.11
0.11
NiO
0.38
0.40
0.40
0.42
0.43
0.40
Totals
100.9
99.9
100.6
100.5
101.0
100.9
0.986\0Qg7
o.ooir0,987
Number of Cations on the Basis of 4
Oxygens
^0.984
°o»«
Si
Al
0.9811 0QS2 0.9891 0QSQ
0.001 /U'982 0.000/ u,ysy
fflo*»
0.983'
0.001
Cr
0.001'
0.001'
0.002^
0.001'
0.000'
0.001'
Fe2+
0.134
0.146
0.125
0.140
0.143
0.169
Mg
Ca
1.890
0.000
- 2.034
1.887
0.001
.oniK 1.892
zmb 0.000
-2.029
1.858
0.001
^2.010
1.886
0.001
-2.040
1.831
0.001
-2.012
Mn
0.002
0.002
0.002
0.002
0.002
0.002
Ni
0.007J
0.008J
0.008,
0.008J
0.008J
0.008 J
93.4
92.8
Forsterite, mole %
93.0
91.6
93.8
93.0
Analyst H. 0. A
. Meyer.
Analyses of enstatite inclusions (Table
41) from diamonds from Sierre Leone
and Ghana are the first to be made of
this variety of inclusion. They show
little solid solution toward diopside, and
on an average they contain less Al and
more Cr than do enstatites from perido-
tite nodules in kimberlite (Fig. 56) . Boyd
and England (Year Book 63, p. 157)
showed that increase of pressure in the
P-T region where pyrope is stable re-
duces the solubility of A1203 in enstatite.
Hence, it is not surprising that these
enstatite inclusions in diamond contain
very little A1203.
Three chromite inclusions from Ghana
and Venezuela (Table 42) have proved
to be Mg-rich in contrast to the Fe-rich
chromites discovered last year (Year
Booh 67, p. 134, Table 6). All of these
chromites have unusually high chrome
contents, however, comparable only to
those found in meteorites.
The Occurrence of Potassic Richter-
ite in a Mica Nodule from the
Wesselton Kimberlite, South Africa
A. J. Erlanlc* and L. W. Finger
The presence of amphibole as a con-
stituent of the upper mantle has been
suggested by several workers, and cogent
geochemical and geophysical arguments
have been presented in support of this
contention (Oxburgh, 1964; Ringwood,
1966; Hart and Aldrich, 1967). Amphi-
bole, usually in the form of hornblende
or pargasite, has been observed in many
rocks of possible upper-mantle origin,
such as the amphibole peridotites from
St. Paul's Rocks on the Mid-Atlantic
Ridge, and as xenocrysts and in xenoliths
from basic volcanic rocks and tuffs
(Mason, 1968) but to our knowledge has
not been recorded as a definite primary
constituent of the mafic and ultramafic
* Department of Terrestrial Magnetism.
GEOPHYSICAL LABORATORY
321
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tq O Tf4 • . CD. i-j rt4
d co r-4 ; ; oq os i>
* CM to
odooogol g ,&„*«*
-■s-s 5sa .a
3
cr
CU
S-i
CU
W)
S-I
a
-3
o
J»
^_;
03
X>
o3
CM
CO
O
O
-1-3
v-'
+
•d
CU
>>
Ph
o
on
pq
03
CU
«
Ph
Ph"
"e3
(h
3
CU
a
o
S-I
<i
CU
<-"
322
CARNEGIE INSTITUTION
TABLE 41. Analyses of Enstatite Inclusions
Sierre Leone
Ghana
GL27a
GL28a
G3a
GlOa
Si02
57.7
57.0
56.9
57.3
TiOa
0.00
0.00
0.00
0.00
AL03
0.78
0.97
0.67
0.44
Cr203
0.31
0.48
0.55
0.33
FeO
4.36
4.48
4.43
4.29
MgO
36.2
35.8
35.9
37.0
CaO
0.42
0.45
0.49
0.35
MnO
0.09
0.12
0.12
99.1
0.12
Totals
99.9
99.3
99.8
Number of Cations on the Basis
of 6 Oxygens
Si
Al
1.9761
0.032 f
1.9661
2.008 o.040 f 2.008
1.9691
0.027 f 1-996
1.9661
0.018 f 1-984
Cr
0.008^
0.013^
0.015^
0.009<
Fe2+
0.125
0.129
0.128
0.123
Mg
1.845 y
1.997 1-839 1 2.001
1.849 U.013
1-889 U.037
Ca
0.016
0.117
0.018 (
0.013
Mn
0.003 J
0.003J
Enstatite, mole %
0.003 J
0.003 J
93.5
93.3
93.5
93.9
Analyst H. O. A. Meyer.
TABLE 42. Analyses of Chromite Inclusions
Ghana
Venezuela
G4a
G20b
GL47e
Si02
0.26
0.23
0.26
Ti02
0.05
0.03
0.00
Ab03
6.74
5.94
5.81
Cr,03
63.3
64.0
65.3
FeO
14.4
15.1
10.3
MgO
14.4
13.8
16.4
CaO
0.01
0.00
0.05
MnO
<0.01
99.2*
0.00
0.00
Totals
99.1*
98.1*
Number of Cations on the
Basis of 4 Oxygens
Si
0.009^
O.OOS-i
0.001
0.231^2.000
1.667
0.093 J
0.009^
0.000
0.224^2.000
1.686
0.081 J
Ti
0.001
Al
0.260^ 1.997
Cr
1.635
Fe^t
0.092 J
Fe2+
Mg
0.3011 - 000
0.699 yL-wu
o^} 1.000
0-1991 x ooo
0.799 ^-UUU
Ca
0.000 J
0.000 1
0.002 J
End Members,
mole %
MgCr.O*
70.0
67.7
80.0
FeCr.O*
11.9
15.7
4.4
FeALO,
13.5
12.0
11.8
FeFe.O,
4.6
4.6
3.8
* Does not include V2O3 and ZnO, both <1.0 wt. %, respectively.
t Fe8+ calculated from total Fe as Fe2+ to satisfy charge requirements.
Analyst H. O. A. Meyer.
GEOPHYSICAL LABORATORY
323
nodules found in South African kimber-
lite pipes.
During the course of electron-probe
analysis of a mica pyroxenite nodule
from the Wesselton kimberlite pipe,
South Africa, a mineral with an unusual
potassium content was encountered and
subsequently identified as the rare
amphibole potassic richterite (magnoph-
orite). These nodules, also referred
to as phlogopite nodules, are distinctive
in that they consist almost entirely of
phlogopite (>90%) , with minor amounts
of diopside. Garnet, olivine, and ortho-
pyroxene are absent. A petrographic de-
scription and chemical analysis of the
nodule in question, WESS 156, are given
by Williams (1932, pp. 347, 350) .
The potassic richterite found in this
nodule is in the form of small subhedral
grains, usually about 100 /xm in length,
contained within the diopside and ap-
pears to be of primary origin. Optical
characteristics are consistent with those
available for other richterites. Three of
these grains, together with the associated
diopside, have been analyzed by electron
probe, and a fourth, identified by probe
analysis in a grain mount of separated
diopside grains, has been partially iso-
lated and analyzed by single-crystal
X-ray diffraction.
Relevant chemical data are presented
in Table 43. Multiple measurements show
each grain to be homogeneous, with very
little, if any, variation between grains.
Compared with the type analysis for
potassic richterite (Wade and Prider,
1940), the Wesselton richterite has
slightly differing FeO and K20 contents,
but the most striking difference is the
lower Ti02 content of the Wesselton
TABLE 43. Electron-Microprobe Analyses of Kimberlitic Potassic
Richterites and Diopside
Richterite
1
2
3
Diopside
Si02
54.3
54.4
54.1
54.2
Ti02
0.59
0.60
0.59
0.10
AL03
1.22
1.25
1.24
0.71
FeO*
4.36
4.34
4.22
5.07
MnO
0.07
0.07
0.07
0.17
MgO
20.9
21.4
21.2
16.0
CaO
7.06
7.14
7.15
20.7
Na20
3.19
3.20
3.34
1.50
K20
4.70
4.77
4.69
0.01
Cr203
0.07
0.06
0.04
0.42
Totals 96.5
97.2
96.6
98.8
Number of Ions on the Basis of
Number of Ions on the
23 Oxygens
Basis (
Df 6 Oxygens
1
2
3
Si
7.801
0.20/8.00
7.751
7.761
Si
2.010
Al
0.21 1 8.00
0.21
>8.00
Ti
0.003 >
Ti
0.04 J
0.03^
Al
0.031
Al
o.oii
Ca
0.820
Ti
0.06
0.02]
0.031
Cr
0.012
Mg
Cr
4.46^5.00
0.01
tn K00
4.52
0.01 1
>5.00
Fe
Mn
0.157
0.005
> 2.018
Fe
0.46 J
0.42 J
0.44 J
Ca
0.820
Fe
0.051
o.ioi
0.07i
Mg
0.881
Mn
!S"°
0.01 I
0.01 1
Na
0.108
Ca
1.09 [2.00
1.10 1
'2.00
K
0.001 J
Na
0.84^
0.80 J
0.82J
Na
K
0.05\091
0.86J u,yi
087|0.95
S2J}°*
* Total Fe expressed as FeO.
324
CARNEGIE INSTITUTION
potassic richterite (0.6% Ti02) com-
pared with the value of 3.5% Ti02 given
by Wade and Prider. The significance
of this feature and its possible depen-
dence on pressure are discussed elsewhere
in this report. The average of the three
analyses, expressed in the amphibole for-
mula, is (Ko.ssNao.os) (Nao.s2Cai.09Mno.01
Fe0.07) (Feo.45Mg4-.51Tio.04Oro.01) (S17.77
Al0.21Ti0.02)O22(OH)2.
The composition of the enclosing di-
opside is given for comparison. It has a
lower chrome content than diopsides that
occur in the peridotite nodules and is
similar to a diopside inclusion from a
diamond studied by Boyd {Year Book
67, pp. 133-135).
The Wesselton potassic richterite grain
examined by single-crystal techniques
was only partially separated from the
enclosing diopside because of difficulties
in handling small grains. The interfering
diffraction pattern handicapped the ori-
entation of the grain, but the following
cell data were obtained from precession
photographs: a = 10.00 A, 6 = 18.00 A,
c = 5.26 A, 0 = 104.8°, 7=917 A3. The
cell data of the diopside at 23 °C were
measured from back-reflection Weissen-
berg photographs and yielded the follow-
ing results: a = 9.734 ±0.002 A, 6 = 8.9135
±0.0005 A, c = 5.261 ±0.006 A, p =
106.06° ±0.03°, 7 = 438.6±0.6 A3.
It is difficult at this stage to assess the
importance of the occurrence of potassic
richterite in the mica nodule. Certainly
it appears to be of primary origin, and
work described elsewhere in this report
shows that in the absence of phases other
than diopside it is stable to higher tem-
peratures and pressures than any other
amphibole examined so far. Hence, al-
though it occurs only as a trace con-
stituent in the nodule examined, it may
indicate the type of amphibole likely to
occur in the upper mantle. Preliminary
work described elsewhere in this report,
however, indicates that it may not be
stable in the presence of nonpotassic
aluminous phases such as garnet. Never-
theless, if 1% potassic richterite of the
type analyzed occurs in upper-mantle
material, the resulting K content of 400
ppm is sufficient, when such material is
subjected to partial melting and frac-
tionation along the lines suggested by
O'Hara (1968), to account for the K
content of most basaltic lavas. This
would also apply to other elements re-
lated to K, specifically Rb and Ba, and
hence it would be of interest to determine
the trace element content of potassic
richterites.
KlMBERLITE DlOPSIDES
F. R. Boyd and P. H. Nixon*
Pyroxenes in mafic and ultramafic
rocks have particular petrogenetic value
because their compositions are sensitive
to variations in the conditions of equili-
bration or to changes in magmatic com-
position. They reveal magmatic frac-
tionation by an increase in the ratio
Fe/(Fe + Mg). They can also provide in-
formation on the conditions of subsolidus
equilibrium through the degree of solid
solution shown by coexisting Ca-rich
and Ca-poor pyroxenes and by the solid
solution of these pyroxenes toward garnet
or other aluminous phases.
Primary pyroxenes in kimberlite are
found as individual crystals and in perid-
otite and eclogite nodules. Many of the
individual crystals undoubtedly come
from disaggregated nodules, but there is
a possibility that silicate magma is in-
volved in some kimberlite eruptions and
that some of the individual crystals may
be true phenocrysts rather than frag-
ments of mantle rocks. Opinions differ
on this point, and the problem is in-
sufficiently studied for the answer to be
clear. Pyroxenes from kimberlites rarely
show exsolution, in contrast to pyroxenes
from tholeiitic basalts and gabbros. They
have evidently crystallized as coarse-
grained, relatively homogeneous phases
at depth in the mantle and been erupted
sufficiently rapidly to become quenched.
Most clinopyroxenes from African
* Department of Mines, Maseru, Lesotho.
GEOPHYSICAL LABORATORY
325
kimberlites show restricted solid solu-
tion toward enstatite and jadeite and
contain an average of 1.3% Cr203, 2.0%
A1203, and 2.8% Fe as FeO. A much less
abundant group from eclogitic assem-
blages shows a large solid solution toward
jadeite. Data presented herein show that
there is a third, subcalcic group, ex-
amples of which are rare but widely
distributed in African kimberlites. Clino-
pyroxenes in this group exhibit much
solid solution toward MgSi03, having
compositions near a mean of wo31en62fs7.
Nixon, von Knorring, and Rooke
(1963) first recognized the unusual com-
position of these subcalcic diopsides and
gave analytical data for one they dis-
covered in a garnet lherzolite nodule
(E-3) from the Thaba Putsoa pipe in
Lesotho (formerly Basutoland). Boyd
(1969) described a second, chemically
similar specimen from an alluvial deposit
in the Shinyanga district, Tanzania.
These localities are about 1800 miles
apart. Further work described below has
led to the discovery of four more sub-
calcic diopsides, and it now appears that
diopsidic pyroxenes from African kim-
berlites, apart from omphacites, fall into
two well-defined groups that differ chiefly
in their Ca/(Ca + Mg) ratio. Diopsides
in the subcalcic group show a greater
solid solution toward enstatite than di-
opsides from other plutonic rocks.
New analytical results are given in
Tables 44 and 45 and are shown along
TABLE 44. Electron-Probe Analyses of Diopsides from Kimberlite
GL-50
E-5
E-14
Weight %
Si02
54.7
1
55.2
8
54.0 3
Ti02
0.2
0.15
0.39 . . .
A1203
2.64
'hi
2.67
"l
2.55 1
Cr203
1.36
17
0.71
1
0.24 . . .
FeO*
2.37
6
4.40
1
5.94 3
MnO
0.1
0.14
0.14 . . .
CaO
18.9
"l7
14.0
"k
14.5 3
MgO
17.5
8
21.9
1
20.6 2
Na20
2.1
15
1.70
3
1.63 1
K20
0.05
0.02
0.02
Totals
99.9
100.9
100.0
Atomic %
Si
1.9731
1.9551
1.9501
Ti
0.004
> 2.000
0.007
> 2.000
0.011
> 2.000
Al
0.023
0.038
0.039 J
Al
0.0891
0.0741
0.0701
Cr
0.039
0.020
0.007
Fe
0.072
0.130
0.179
Mn
Mg
0.003
0.941
*2.021
0.004
1.155
'2.031
0.004
1.107
>2.041
Ca
0.730
0.531
0.559
Na
0.145
0.116
0.114
K
0.002^
0.001>
0.001^
Ca
41.9
29.2
30.3
Mg
54.0
63.6
60.0
Fe
4.1
7.2
9.7
Ca/(Ca + Mg)
0.437
0.315
0.335
* Total Fe as FeO.
Note : Italicized values are for a J V JV, where <r is the standard deviation
and N is the mean count. GL-50: Diopside intergrown with diamond and
titaniferous phlogopite, South Africa. E-5: Diopside from garnet wehrlite
nodule, Thaba Putsoa pipe, Lesotho. See Nixon, von Knorring, and Rooke
(1963) for a mode of this nodule. E-14: Diopside from diopside nodule,
Thaba Putsoa pipe, Lesotho. Partial wet-chemical analysis by M. H. Kerr
shows Na20 = 1 .84% and Cr203 = 0.24% .
326
CARNEGIE
INSTITUTION
TABLE 45. Partial Analyses
of Kimberlite Diopsides
Weight %
Atomic %
Ca/
(Ca
+ Mg)
Locality
CaO
MgO
A1203
FeO
Cr203
Ca
Ma
Fe
E-10*
Sekameng
18.9
16.5
2.3
2.1
2.7
43
53
4
45
1108*
KaO
19.5
14.7
4.7
1.3
2.2
48
50
2
49
S58-1
Solane
14.2
20.7
2.6
4.2
0.7
31
62
7
33
S58-2
Solane
21.4
17.2
2.0
1.9
1.5
46
51
3
47
S58-4
Solane
19.9
16.2
2.3
2.5
1.6
45
51
4
47
S58-5
Solane
21.5
17.3
2.0
1.9
1.5
46
51
3
47
2611 f
Kimberley area
19.4
17.6
2.2
2.6
1.2
42
53
4
44
2623 t
Dutoitspan
18.6
16.2
2.6
2.5
2.5
43
52
5
45
1083A-1
Moroto
22.4
16.9
2.3
2.2
1.0
47
49
4
49
1083A-2
Moroto
20.1
16.3
6.1
2.0
0.9
45
51
4
47
1083A-3
Moroto
22.8
17.7
1.7
1.8
0.9
47
50
4
48
PHN-5
Shinyanga
15.0
20.0
2.3
4.4
0.7
32
60
7
35
* With pyrope.
t In garnet lherzolite nodule.
Note: Other specimens are single crystals from heavy mineral concentrates.
with earlier electron-probe analyses
(Boyd, 1969) in Fig. 57. The fifteen new
analyses bring the total number of probe
analyses of these diopsides to sixty-two,
of which six are subcalcic. These speci-
mens were collected from about fifteen
different pipes in South Africa, Lesotho,
Uganda, and Tanzania and are thus be-
lieved to be a representative sample.
Some of the diopsides shown in Fig.
57 are from nodules, but the bulk of them
have been picked from heavy mineral
1300
1400° 3Q
MgSi03
-^^CaFeSi206
Mol per cent
Fig. 57. Electron-probe analyses of diopsidic pyroxenes from African kimberlites plotted in a
portion of the pyroxene quadrilateral. Analytical data for 15 new analyses are given in Tables
44 and 45. An additional analysis is from Erlank (this report) ; the remaining 46 are from Boyd
(1969). The analysis shown as an open triangle is for an inclusion from diamond (Boyd, 1969).
The temperatures shown are for the diopside solvus in the system CaMgSiaOe-MgSiOs (Davis and
Boyd, 1966).
GEOPHYSICAL LABORATORY
327
I
concentrates formed in the course of
mining or prospecting kimberlite for
diamond. Twelve of the sixty-two diop-
sides are from nodules that also con-
tain enstatite, and two of these are sub-
calcic. The distribution and range of
analyses in this subgroup of diopsides
that are known to coexist with enstatite
are similar to the distribution and range
shown by the whole group. It is probable
that most of the diopsides in Fig. 57 are
saturated with MgSi03 because enstatite-
bearing garnet lherzolite is a very com-
mon rock type among the nodules and
because many of the single crystals ap-
pear to be from disaggregated nodules.
The analyses in Fig. 57 show that there
are significant variations of Fe/(Fe-h
Mg) and Ca/(Ca-f-Mg) within the sub-
calcic and calcic groups. The former
variation could be reasonably interpreted
as due to minor igneous fractionation,
and the latter variation might reflect a
range in equilibration temperature. In
the event that these diopsides crystal-
lized under static conditions in the
mantle, a range in equilibration tempera-
ture could reflect simply a range in depth
of equilibration. Points on the diopside
solvus in the system CaMgSi206-MgSi03
at 30 kb (Davis and Boyd, 1966) are
given in the margin of Fig. 57, and they
give an idea of the dependence of the
composition of diopside (in equilibrium
with enstatite) on temperature.
The large difference in Ca/(Ca + Mg)
between the calcic and subcalcic groups
is less easy to understand, however. Con-
ceivably this difference could also be due
to a difference in equilibration tempera-
ture. But if so, it would then be a par-
ticular problem to understand why these
kimberlites had been erupted from two
very distinct regions or levels in the
mantle. One would certainly expect that
some diopsides of intermediate origin
would be found.
Moreover, if the subcalcic diopsides
are interpreted as having been erupted
in kimberlite that originated at a higher
temperature and a greater depth than the
calcic group, it is difficult to understand
why this kimberlite did not pick up ma-
terial from a range of lower temperatures
and shallower levels in the mantle during
eruption. The total absence of diopsides
with compositions intermediate between
the calcic and subcalcic groups is very
awkward to explain by any model that
attempts to relate composition and tem-
perature by a continuous solvus curve
of the sort found in the system CaMg
Si206-MgSi03 at pressures up to 30 kb
(Boyd and Schairer, 1964; Davis and
Boyd, 1966).
An alternative explanation for the di-
vision of these diopsides into calcic and
subcalcic groups can be sought in the
possibility that there is a miscibility gap
between them. The phase relations de-
termined for the Ca-rich portion of the
join CaMgSi206-MgSi03 at pressures up
to 30 kb do not show such a gap, but it is
probable that these kimberlite diopsides
have equilibrated at pressures well above
30 kb because of their association with
diamond. The principal two-pyroxene
field dividing the Ca-rich and Ca-poor
pyroxenes is actually a transition loop
because the Ca-rich pyroxenes are mono-
clinic whereas enstatite and hypersthene
are orthorhombic. It is possible, however,
that a true miscibility gap in a struc-
turally continuous series of diopsides de-
velops at high pressures in addition to
the main two-pyroxene field.
Another possibility is suggested by the
narrow field for pigeonite found by Ku-
shiro (Year Book 67) on the join CaMg
Si206-MgSi03 at 20 kb. This field is
limited to temperatures between 1450°
and 1650°C and has a maximum width
in composition of 6 wt % di. Its axis is at
a composition of en82di18 (wt %). If the
subcalcic diopside analyses are projected
onto the join CaMgSi206-MgSi03, they
group around a composition of en31di69.
This composition is thus far removed
from the pigeonite field at 20 kb, but it
is conceivable that higher pressures could
shift this field to more Ca-rich composi-
tions. If so, it is possible that these sub-
328
CARNEGIE INSTITUTION
calcic diopsides crystallized as pigeonites
in equilibrium with enstatite or calcic
diopside or both. It must be emphasized
that there is at present no experimental
evidence to support either of these al-
ternatives. These suggestions are purely
hypothetical.
The cell size and symmetry of one of
these subcalcic diopsides (Table 46, E-5)
have been determined by Joan R. Clark.
The space group is C2/c, which together
with the cell parameters indicates diop-
side structure rather than pigeonite. The
E-5 pyroxene shows very sparse exsolu-
tion lamellae, and these have been identi-
fied on the basis of the cell parameters
by Clark as being a clinoenstatite-like
structure. The relationships between
composition and cell parameters in these
pyroxenes are not yet sufficiently well
understood to permit a precise estimate
of the Ca content of these lamellae. Ex-
solution of Mg-rich pyroxene from di-
opside or augite as monoclinic rather
than orthorhombic lamellae is normal,
although the energetics of this relation-
ship are not yet understood (Boyd and
Brown, 1969; Bown and Gay, 1960).
Hence, if the E-5 diopside had crystal-
lized as primary pigeonite it would be
necessary to assume that it had inverted
to diopside during eruption.
It is interesting to note that in one
case both calcic and subcalcic diopsides
have been erupted from the same kimber-
lite pipe. Analyses of four diopsides
picked from a heavy mineral concen-
trate from the Solane pipe in Lesotho
TABLE 46. X-Ray Data for Kimberlite
Diopsides
E-5*
Diopside
Host
Exsolved
Clino- GL-50 1
enstatite
a, A
b,k
c, A
Space group
9.67
8.86
5.26
106°45'
C2/c
9.67
8.86
5.18
108° 40'
P2i/c
9.69
8.87
5.26
106°43'
* Measured by Joan R. Clark.
t Measured by J. W. Harris.
are given in Table 45. One (S58-1) is
subcalcic, and the other three are calcic.
So far, calcic and subcalcic types have
not been found in the same nodule. If
their stable association were to be pos-
sible, one would expect it to be rare, be-
cause it would require a bulk composition
rich in Ca pyroxene relative to Mg py-
roxene; i.e., a wehrlite rather than the
more abundant lherzolites.
One of the complete analyses (Gl-50)
in Table 44 is of a chrome diopside inter-
grown with diamond. A small crystal of
diopside from this intergrowth was
kindly supplied by J. W. Harris, and the
cell dimensions determined by him are
given in Table 46. This pyroxene is a
normal, calcic, chrome diopside. It differs
from the single diopside inclusion from
diamond thus far analyzed (Fig. 57 and
Meyer and Boyd, Year Book 67) in being
markedly poorer in Fe and Mn and
richer in Al and Cr. As suggested by
Meyer and Boyd elsewhere in this report,
the diamond inclusions have probably
experienced a crystallization history very
different from that of the nodule minerals
with which diamonds are sometimes
inter grown.
New, complete analyses of two sub-
calcic diopsides (E-5 and E-14) from
Thaba Putsoa, Lesotho, are also given
in Table 44. These are very similar to
the analyses of the E-3 and PHN-4 sub-
calcic diopsides previously published
(Boyd, 1969). It was suspected on the
basis of the earlier analyses that the sub-
calcic diopsides might prove to be un-
usually rich in potassium. However, the
K20 contents of E-5 and E-14 are not
especially high and are within the range
established for the calcic group. The sub-
calcic diopsides are slightly richer in Fe
than the calcic group (Fig. 57) and on an
average they contain less Cr, but the
major difference is in the ratio Ca/
(Ca + Mg).
Values for a/ Vn for the analyses in
Table 44 show that the two subcalcic
diopsides are unusually homogeneous,
GEOPHYSICAL LABORATORY
329
which is characteristic of the group as a
whole. Kimberlite diopsides are usually
not zoned, but some of the calcic ones
show variable counts for Al and Cr in
particular (e.g., Table 44, GL-50).
Two of the partial analyses in Table
45 (2611 and 2623) are for diopsides
that earlier wet-chemical analyses had
indicated to be intermediate between the
calcic and subcalcic groups (Boyd, 1969,
Fig. 1). The new probe analyses (Table
45) show that these diopsides are mem-
bers of the calcic group, although they
are more Mg-rich than the average.
Further experimental and analytical
data are obviously needed to provide an
understanding of the chemical composi-
tions of these pyroxenes. It is possible that
phase studies in the system CaMgSi206-
MgSi03 at pressures higher than 30 kb
would clarify the problem. It would also
be interesting to know whether subcalcic
diopsides occur in kimberlites from
continents other than Africa. More de-
tailed study of pyroxenes from kimber-
lite pipes such as Solane, where both
calcic and subcalcic diopsides have been
found, would also be illuminating.
The Laco Magnetite Lava Flow, Chile
S. E. Haggerty
An ore microscopic examination of the
Laco magnetite lava flows that occur in
the highlands of northern Chile has been
made as a first step in what is to be a de-
tailed study of the mineralogy of this
unique occurrence.* The Laco iron-oxide
flows were first discovered in 1958, but
only very brief field descriptions have
since been reported in the literature
(Parks, 1961; Rogers, 1968). The flows
occur in an area of volcanic activity and
are considered to be Quaternary in age.
Field-relationship studies indicate that
the iron-oxide bodies were partially in-
truded into basic tuffs and in places
* Material for this study was obtained from
D. P. Rogers, Texas Gulf Sulfur Company;
their cooperation is gratefully acknowledged.
erupted to the surface in large blocky
masses of magnetite. The flows are highly
vesicular, contain gas tubes, show good
contorted banding and ropy surfaces, and
in general have all the characteristics of
a basalt lava.
The mineralogy of these metallic flows
is simple: magnetite and hematite are
the primary iron oxides; the acces-
sory minerals include feldspar, calcic
pyroxene, apatite, calcite, and a new
iron-phosphate mineral. The ore contains
up to 98% iron oxide and in many in-
stances this concentration does not fall
below 80%. Magnetite and hematite oc-
cur in euhedral crystals, which grow up
to several centimeters in diameter. These
primary oxides are free of exsolution
intergrowths, and spectral scans of mag-
netite and hematite, with the electron-
probe microanalyzer, reveal that no de-
tectable concentrations of other elements
are present.
Secondary hematite and maghemite
develop extensively as oxidation prod-
ucts of the magnetite. Although there
are no chemical variations in the mag-
netite, crystals are nevertheless strongly
zoned in a very unusual manner. The
zoning is crystallographically controlled
with respect to morphology (Plate 2A)
but becomes apparent only as selective
oxidation of the magnetite takes place;
the process of maghematization, on the
other hand, does not reveal this zoning.
By heating polished specimens of the
ore for 1 minute at 920 °C, it has been
shown that certain concentric zones
within the magnetite are more suscepti-
ble to oxidation than others, thus demon-
strating that the natural observed zona-
tion is an inherent feature and is not
due to the crystallization of successive
generations of magnetite and hematite
from the primary melt. The nature of this
zoning is not fully understood but a pos-
sible explanation is that the zones reflect
metastable intermediate members of the
oxidation series Fe304-Fe203 and are
therefore analogous to the kenotetra-
hedral magnetites described by Kullerud,
330
CARNEGIE INSTITUTION
Donnay, and Donnay (Year Book 66).
Colloform goethite is present as a late-
stage vesicle and veinlet infilling, and
complex overgrowths of goethite and
goethite-hematite intergrowths develop
on the sharp crystal terminations of pri-
mary magnetite and hematite that have
grown into open cavities (Plate 2B).
Ilmenite has been identified in one
specimen only. This sample contains
abundant calcic pyroxene, and the ilmen-
ite is in an advanced stage of alteration
to sphene, titanohematite, and rutile.
Large bodies of iron oxide that appear
to be intrusive and are considered to be
magmatic in origin are characterized by
high titanium contents and concentra-
tions of apatite in the ore that are fre-
quently as high as 30% by volume
(Philpotts, 1967). Although the dis-
covery of these recent metallic flows in
Chile at first appeared to confirm the
opinions held for the igneous origin of
such ore deposits, these lavas contain
neither high concentrations of titanium
nor of phosphorous. The absence of ti-
tanium is particularly striking in view
of the high concentrations that are pres-
ent in basaltic magnetite and in mag-
netite associated with large layered in-
trusions. Analysis of coequilibrated
titanomagnetite and ilmenite from nat-
urally occurring oxide-apatite rocks in-
dicate temperatures of formation in the
range 850°-1000°C (Philpotts, 1967). If
the Laco magnetite deposits were ex-
truded as molten oxides, temperatures
in excess of 1500 °C would be necessary.
The porous nature of these flows, how-
ever, indicates that large amounts of gas
were present, thus suggesting that a
process other than liquid extrusion was
involved.
A New Iron-Phosphate Mineral
S. E. Haggerty
An iron-phosphate mineral to which
the formula Fel+Fe3+(P04)3 is tenta-
tively assigned, on the basis of electron-
microprobe results, has been discovered
in specimens of extrusive Laco magne-
tite. The phase occurs as minute crystals
(maximum 300 /mi) in open cavities in-
terstitial to magnetite and hematite. The
mineral is opaque and crystalline and
shows good polysynthetic twinning
(Plate 2C). It is strongly pleochroic and
anisotropic in polished sections. The
maximum color variation on rotation of
the microscope stage, under oil immer-
sion, is from yellow to bluish gray. The
mineral has an estimated reflectivity
value in the 10-15% range (cf. magne-
tite, 22%; hematite, 25%); it is softer
than magnetite and takes a good surface
polish. Initial breakdown of the mineral
takes place along cracks and grain
boundaries (Plate 2D). The breakdown
product becomes darker in color but con-
tinues to retain its strong optical aniso-
tropy. Electron-microprobe scans across
these alteration veinlets show no varia-
tion in either Fe or P, and it is concluded
that the darkening is due simply to the
oxidation of ferrous to ferric iron. More
advanced alteration produces hematite
and an unidentified granular phase,
which still contains only iron and phos-
phorous. This breakdown product is
weakly anisotropic, in color tones that
are similar to that of the primary phase,
and is distinguished from the parent
mineral by having deep-red internal re-
flections.
Electron-microprobe analysis of the
new mineral gives Fe, 44.05%; P,
17.93% ; in good agreement with the for-
mula Fe4 (P04) 3. Recalculating the values
in terms of oxides we obtain FeO,
42.49%; Fe203, 15.74%; and P205,
41.08%; giving a total of 99.31%. The
theoretical oxide concentrations for Fe4
(P04)3 are FeO, 42.41% ; Fe203, 15.71%;
and P205, 41.88%. Individual grains are
compositionally homogeneous, and spec-
tral scans show that no other elements
heavier than Na are present in detectable
quantities.
Small quantities of the uncontaminated
phase were carefully extracted for X-ray
purposes from the surface of polished
GEOPHYSICAL LABORATOEY
331
sections by the microsampling technique
described by Kingston (1966). Three
Debye-Scherrer patterns (A, B, and C;
Table 47) of the new phase, from differ-
ent hand specimens, have been measured
using a 114.6-mm camera and Mn-
filtered FeKa radiation (A = 1.9373).
Strong lines corresponding to spacings
3.31 A, 3.19 A, 2.09 A, and 1.60 A coin-
cide with strong reflections for the syn-
thetic phase lipscombite, Fe2+Fe|+ (P04)2
(OH)2 (Gheith, 1953), but the resem-
blance ends there; many other strong
lines of the two phases do not agree.
Polished sections of synthetic lipscombite
have been made from material kindly
supplied by Professor M. A. Gheith. The
color, reflectivity, and degree of optical
anisotropy of the synthesized phase are
quite distinct from those of the new min-
eral. Furthermore, lipscombite is hy-
drated; it contains 42.8% Fe and 15.8%
P, compared with 44.1% Fe and 17.9% P
for Fe4(P04)3. The X-ray powder data
for naturally occurring manganoan lips-
combite (Lindberg, 1962) also differ
significantly from this new phase. At-
tempts to index the powder data on the
TABLE 47. X-Ray Powder Data for Three Debye-Scherrer Patterns of
a New Iron-Phosphate Mineral Compared with Synthetic Lipscombite
(Mn-filtered, FeKa radiation)
Lipscombite *
New Phase
A
B
C
hkl
d,A
/
d,A
d,k
d,k
/
101
4.864
3.669
3.544
1
2.5
1
3.827
3.856
3.861
4
3.464
3.489
3.479
3
103
3.329
10
3.314
3.311
3.308
10
004
3200
2.880
1
f
3.191
2.928
2.822
3.211
2.943
2.825
3.218
7
0.5
3
2.704
2.686
2.70i
1
200
2.616
2
2.612
2.618
2.607
1
2.544
f
2.529
2.545
2.546
6
2.422
1
2.378
2.374
2.371
1
2.267
f
2.286
2.313
2.289
1
2.084
2.082
2.079
6
213
2.056
2.036
1562
5.5
1.5
1
2.042
2.064
2.041
0.5
1.845
2
1.842
1.855
1.839
0.25
1.773
1
017
1.747
1
1.735
1.737
1.736
1
206
1.664
5
1.653
1.656
1.655
0.5
208
1.604
6
1.598
1.601
1.483
1.597
1.486
9
1
1.449
1.5
1.438
1.445
1.445
0.25
1.441
1
1.402
1.404
1.401
2
1.374
1
1.371
1.371
1.371
4
1.312
1.319
1.294
1
1.236
1.235
1.234
1
1.147
1.153
1.076
1.145
1.077
1
1
1.042
1.040
1.042
1
0.9978
0.9978
0.9974
2
0.9958
0.9961
0.9959
1
* Gheith (1953, experiment 99B).
332
CARNEGIE INSTITUTION
basis of the lipscombite structure have
been unsuccessful (tetragonal, body-
centered, a = 5.37 A, c = 12.81 A; Katz
and Lipscomb, 1951) .
The iron phosphate is easily broken
down at 500 °C in air as well as in
evacuated silica glass tubes. In both
types of experiment the product becomes
transparent. In the runs conducted in air,
finely textured filaments of hematite are
produced that closely resemble the nat-
ural breakdown product. Accurate elec-
tron-probe analysis of the altered phase
was not obtained because of widespread
inhomogeneity.
From the textural relations it is clear
that the new mineral is a late-stage pre-
cipitate in the Laco magnetite lava flow.
In a few instances the mineral occurs
with apatite but in general apatite and
other calcium-bearing minerals are ab-
sent. The new mineral has not been found
in association with goethite or colloform
hematite (also late-stage products), and
this is not surprising in view of its high
ferrous iron content.
Magnetic Minerals in Pelagic
Sediments
S. E. Haggerty
In sediment cores from the deep
oceans, extremely good magnetic and
fossil stratigraphic correlations have been
successfully extended over wide areas
of the sea floor (Opdyke et at., 1966;
Watkins and Goodell, 1967) . These cor-
relations suggest that large areas of
active sedimentation are being simul-
taneously magnetized, the direction of
magnetization being either normal or
reversed, depending on the direction of
the earth's magnetic field.
The present study indicates that high-
temperature detrital Fe-Ti oxides are
probably responsible for most, if not all,
of the magnetic remanence. These min-
erals have a high magnetic susceptibility
and a strong, previously inherited ther-
moremanent direction. The later dia-
genetic crystallization of new phases,
however, and the concurrent acquisition
of new chemically derived magnetic di-
rections are mineralogical factors that
will modify and perhaps eventually de-
stroy the primary depositional directions
of magnetization. A thorough knowledge
of these minerals and the possible post-
depositional changes that are likely to
occur in oceanic sediments is therefore a
necessary prerequisite for a full interpre-
tation of the magnetic record.
One hundred and ten samples from
twenty-two sediment cores * from the
equatorial and north Pacific, Atlantic,
and Indian Oceans and from below the
Antarctic ice sheet have been examined.
These sediments consist of lutites, cal-
careous oozes, and red-brown clays.
Paleomagnetic stratigraphy is a unique
method of dating and correlating deep-
sea sedimentary cores, and yet few di-
rect attempts have been made to identify
the magnetic mineral component. In the
studies by Keen (1960) and Opdyke
et al. (1966) thermomagnetic analyses
were used to show the presence of magne-
tite. The only other study to appear in
the literature is the report by Harrison
and Peterson (1965). In their X-ray
determination a magnetic mineral "be-
tween" magnetite and maghemite in
structure was found and was considered
(although it was not directly observed)
to be an oxidation product of magnetite.
Optical observations are particularly
important because of the fine textural
distinctions that can be made on the
opaque minerals. In contrast, X-ray
studies and thermomagnetic analyses
give no direct information on whether
the phases are discrete or whether they
are present in complex exsolution or oxi-
dation intergrowths. Furthermore, clues
to the possible origin of magnetic con-
stituents can only be obtained by di-
rectly observing the nature and form of
these phase intergrowths and noting their
* The sediment cores in this study were ob-
tained from the Lamont-Doherty Geological
Observatory, Columbia University; their co-
operation is gratefully acknowledged.
GEOPHYSICAL LABORATORY
333
disposition toward the sedimentary
matrix.
In the present study, examination of
polished sections of the core material
has yielded unequivocal identification of
the magnetic minerals. Vacuum impreg-
nation with an epoxy resin gives the
samples sufficient coherence and durabil-
ity for dry polishing with fine alumina
powders (1, 0.3, 0.05 ^m) on closely
woven metallographic laps.
Mineralogy
The opaque minerals identified consist
of oxides, oxy hydroxides, and sulfides.
These phases are fine grained (<10 ^m)
and are present in quantities ranging
from 1 to 5% by volume. Exceptions are
the oxides and oxyhydroxides of man-
ganese, which occur commonly as small
discrete nodules but may also form in
high concentrations and large masses.
Oxides. The oxides observed in the
core material are members of the mag-
netite-ulvospinel solid solution series and
members of the hematite-ilmenite solid
solution series. Homogeneous titanomag-
netite and titanomagnetite with oxida-
tion lamellae of ilmenite are extremely
common. Alteration products of these
intergrowths are ferri-rutile, rutile, ti-
tanohematite, and pseudobrookite ; the
extent of oxidation, however, is highly
variable in any single core sample. Crys-
tals of titanomagnetite are generally eu-
hedral to subhedral in form and are
rarely rounded. These oxides occur
mostly as single discrete grains but are
also present in detrital fragments of crys-
talline lava, in volcanic ash fragments,
and in devitrified glass shards. Exsolu-
tion and alteration of these oxides are of
the type observed in lavas (Watkins
and Haggerty, 1967) and shown by ex-
periment to form at high temperatures
(Lindsley, Year Books 61 and 62; Hag-
gerty and Lindsley, this report).
Maghemite (yFe203) is ferrimagnetic
and is by far the most common low-
temperature oxidation product of titano-
magnetite. It occurs typically in curved
conchoidal cracks in the titanomagnetite ;
it is either white or pale blue in color and
is optically isotropic. Maghemite is
known to invert to the stable a form
(hematite) between 250° and 500°C
(Gheith, 1952; Lepp, 1957); hence, the
material observed in these sediments
must have developed below this limit.
The effect of titanium on this limiting
temperature range is considered to be
small but has not been experimentally
determined. Akimoto andKushiro (1960)
and Baker and Haggerty (1967) have
shown that maghemite can develop as
an oxidation product of titanomagnetite
during active weathering of basaltic
lavas. Unless there has been systematic
and controlled sampling of the parent
rock, however, alteration products due to
superficial weathering cannot be readily
distinguished from those products that
develop during the waning stages of
deuteric cooling. Subsequent diagenetic
alteration complicates the problem even
further. Therefore, since alteration may
be assigned to any one of a number of
processes at low to intermediate tem-
peratures, it must be concluded that the
time of formation of maghemite as an
oxidation product cannot be accurately
assessed.
Although members of the rhombo-
hedral series (Fe203-FeTi03) are com-
mon in these oceanic cores, homogeneous
hematite is the most abundant phase
present. Members of the hematite-ilmen-
ite series are regarded as high-tempera-
ture phases, but Fe203 may also form
authigenically as a primary mineral or
as an oxidation product; thus, unless
exsolution or alteration intergrowths sug-
gest a high concentration of titanium,
formation in situ must be considered.
There are no diagnostic textural features
in homogeneous hematite, such as collo-
form banding, that would confirm its for-
mation in situ at low to intermediate
temperatures, or indeed whether it is a
pseudomorph after magnetite. Grains
showing mutual exsolution intergrowths
334
CARNEGIE INSTITUTION
of titanohematite and ferri-ilmenite are
widespread. Titanohematite-rutile inter-
growths and titanohematite-rutile-ilmen-
ite intergrowths similar to those de-
scribed by Ramdohr (1950) have also
been observed. These intergrowths are
characteristic of deep-seated and slow-
cooling conditions in igneous rocks and
are texturally different in form and mode
of occurrence from the somewhat similar
mineral assemblage that develops by
simple high-temperature oxidation. One
would infer from these observations that
minerals containing these intergrowths in
deep-sea sediments are detrital.
Oxyhydr oxides. Birnessite (7 A,
SMn02) , todorokite (9.7 A, SMn02) , and
ranciete (calcium manganese oxide),
which are common in manganese nodules
(Roy, 1968), are known to be magnetic
(Powell and Ballard, 1968), and the for-
mation of these phases at low to inter-
mediate temperatures in highly oxidiz-
ing environments on the sea floor is
generally accepted (Mero, 1962; Bonatti
and Nayudu, 1965). The layered and
colloform textures, as well as the radial
and concentric syneresis cracks that de-
velop as a result of contraction when a
gel hardens, are diagnostic of a meta-
colloidal origin. Manganese micronod-
ules, which are highly abundant in the
core samples, are typical and are similar
to those described in the literature
(Sorem and Gunn, 1967) .
Goethite has been observed to form in
minute (1-5 }xm) spherical or subspheri-
cal accumulations, which bear a striking
resemblance to the fossil bacterial forms
that have been observed in Precambrian
iron ore formations (LaBerge, 1967) . Col-
loform banded goethite, similar to the
ferromanganese micronodules, has also
been observed. Goethite occurs exten-
sively as an alteration product of pyrite.
Such grains contrast with the colloidal
forms because of their irregular shape,
and many of them are seen to contain
relic areas of the primary sulfide phase.
Goethite is magnetic (Strangway et al.,
1968) and has an upper thermal stability
limit in the region of 140°C (Tunell and
Posnjak, 1931) ; it is hydrated and there
is little doubt that its presence in oceanic
sediments is authigenic.
Sulfides. Iron sulfides are abundant
in the deep-sea sediments examined and
occur as discrete grains or in thin parallel
bands. Paramagnetic pyrite and ferro-
magnetic pyrrhotite have been observed
only rarely as 10-/mi grains; the ferro-
magnetic Fe3S4 minerals are very similar
to pyrrhotite in color, and although
greigite is optically isotropic and smyth-
ite is anisotropic, even these distinguish-
ing features prove difficult to identify on
minute single crystals. Sulfides in deep-
sea sediments are generally regarded as
authigenic in origin. No problem arises
in providing a primary source of iron, as
is evidenced by the presence and forma-
tion of ferromanganese nodules, goethite,
and hematite. The bacterial generation
of hydrogen sulfide in reducing environ-
ments and in association with organic
debris is well known. Framboidal struc-
tures of the type described by Love and
Amstutz (1966), however, have not been
observed.
Sediment, Magnetic, and Mineralogical
Relationships
In the specimens we have examined,
detrital minerals are ubiquitous, regard-
less of sediment type, depth within a
core, or geographical location. The oxy-
hydroxides are confined almost entirely
to the clay-rich sediments. Sulfides are
commonly present in dark-brown sedi-
ments and are characteristically absent
in the manganese-enriched cores. The
Antarctic cores are unique in that these
sediments contain large proportions of
ice-rafted material.
Members of the magnetite-ulvospinel
solid solution series contribute signifi-
cantly to the magnetic properties of
marine sediments. Members of the ilmen-
ite-hematite series are ferromagnetic
over a very narrow range of solid solu-
bility, and toward the Fe203 end are only
GEOPHYSICAL LABORATORY
335
weakly magnetic. Pseudobrookite mem-
bers are paramagnetic, and the poly-
morphs of Ti02 (rutile, brookite, and
anatase) that form as oxidation products
are also paramagnetic, with weak sus-
ceptibility values in the region of 0.05 X
10-6 emu/g (Pankey and Senftle, 1959) .
How far the magnetic behavior of the
sediment is influenced by the occurrence
of the ferromagnetics in intergrowths
such as exsolution or by-products of oxi-
dation depends on the condition under
which the intergrowths formed and the
way in which the component minerals
acquired their magnetization. The authi-
genic manganese micronodules, goethite,
and the magnetic iron sulfides will also
contribute and will have an overall in-
fluence on the magnetic moment.
Opdyke et al. (1966) have observed
that the quality and resolution of the
magnetic stratigraphy are sometimes lost
at depth. An examination of nine polished
samples from the Vema 21-177 core (lat.
33° 52' N; Ion. 160° 08' W) has shown
that the disruption of the magnetic vector
can be qualitatively * correlated with
an increase in manganese micronodule
content. The core is 1030 cm in length
and varies from a yellowish brown clay
at the top to a dusky brown clay at the
base. The manganese micronodule con-
tent is moderate between 21 and 361 cm
and abundant between 461 and 927 cm.
At 475 cm the coercivity decreases
abruptly and the polarity oscillates with
great rapidity down to the base of the
core. This loss of a coherent magnetic
polarity pattern suggests that the in-
crease in manganese content has taken
place during diagenesis and that effective
remagnetization of the sediment has fol-
lowed. Lynn and Bonatti (1965) have
shown that manganese will dissolve in a
reducing environment and also that it
has a tendency to migrate to zones of
higher oxidation. Manganese nodules
* Accurate quantitative opaque petrographic
study of deep-sea sediments by optical methods
is unreliable because of the extremely fine grain
sizes involved.
may contain up to 21% Fe (Cronan and
Tooms, 1969), and a direct consequence
of the preferential migration of Mn
(since differential rates of solubility and
mobility exist for Fe and Mn) is that
an iron-enriched residue will prevail in
the reduced zones; these accumulations
could give rise to the spontaneously mag-
netic iron sulfides, greigite and smythite,
by bacterial precipitation (Berner, 1964;
Doyle, 1968) and are therefore equally
likely to be responsible for remagnetiza-
tion of the sediment.
The reliability of magnetic strati-
graphic measurements depends on the
extent to which the direction of mag-
netization is the direction of the earth's
magnetic field at the time of deposition.
Magnetic measurements of the upper-
most part of deep-sea sediment cores,
which would permit examination of this
matter, have been unsuccessful because
of the fluidal state of the water-sediment
interface. Since major polarity bound-
aries, as well as minor events within
major epochs, can be stratigraphically
correlated over wide areas of the ocean,
the sediment must still be sufficiently
mobile for natural realignment of detrital
particles to take place under the influence
of the earth's magnetic field.
The present study suggests that the
vector properties of the magnetic moment
in oceanic sediments are acquired by
depositional or detrital remanence. The
source of the magnetic mineral detritus
is a problem, however. The simple me-
chanical breakdown of primary volcanic
material, such as that described by Fox
and Heezen (1965) on the slopes of the
Mid-Atlantic Ridge, cannot be evoked
for the deep oceans. Since a large pro-
portion of the grains are 10 /mi or less,
aeolian transportation from the conti-
nents to the deep oceans is a likely
mechanism. It is well known, for ex-
ample, that a wide distribution of wind-
blown ash will follow violent volcanic
eruptions, and in this context it is of
interest to note that in the Pacific the
336
CARNEGIE INSTITUTION
average sedimentation rate is of the
order of 0.5-1 cm per 1000 years.
Annealing Experiments with
Naturally and Experimentally
Shocked Feldspar Glasses
P. M. Bell and E. T. C. Chao *
The present study is an attempt to
understand meteorite impact phenomena
on the earth's surface. Presumably this
knowledge can also be used to aid in the
interpretation of impact debris from the
surfaces of other planets. Previously,
Bell and Chao (Year Book 67, pp. 126-
130) reported the results of annealing ex-
periments with dense feldspar glasses
that had been prepared statically at
high pressure (10-45 kb) . In the present
study the same annealing techniques
have been applied to dense glasses that
were formed during experimental and
nautral shock-wave events.
Two of the natural feldspar glasses
are plagioclase (An4i, An22) ; the other
is an alkali feldspar (Or39Ab6i) . All three
are from the Ries Crater in Bavaria.
Two synthetically shocked glasses were
formed from labradorite crystals (An67)
from Lake County, Oregon (the same
material studied statically in last year's
report) . Preparation of the shocked syn-
thetic glasses involved shock pressures
of approximately 285 kb for one sample
and 325 kb for the other. No vestiges of
crystallinity could be observed in either
sample. Paul De Carli and Thomas
Ahrens, of the Stanford Research Insti-
tute, carried out the shock-wave prepa-
rations.
Petrographic Setting of the Natural
Specimens
All three Ries Crater samples are from
brecciated rock fragments known as
suevite. The breccias have been inter-
preted as fallout debris from a meteorite
impact (Shoemaker and Chao, 1961).
Two microprobe analyses of the An41
* U. S. Geological Survey.
glass are given in Table 48. The glass
fragments (RC641-14) were extracted
from a medium-grained gabbroic rock
collected from the Otting quarry. The
rock consists essentially of the feldspar
glass and oxidized and deformed green
monoclinic pyroxene, with accessory
apatite and opaque minerals.
The An22 glass has been described
petrographically and analyzed by micro-
probe by James (1969). The composi-
tion is An22Ab720r6. It occurs in a biotite-
bearing amphibolite (RC647-67) from
the Bollstadt quarry. This fine-grained,
foliated rock consists of the plagioclase
glass with green amphibole (wavy ex-
tinction) and oxidized brown biotite,
which contains minute opaque particles.
James has recognized a few microscopic
inclusions of jadeite in some of the
shocked glass.
The Or39Ab61 glass is calcium free but
contains a small amount of barium, as
noted in its chemical analysis (Table 48,
RC647-41). It occurs in an amphibole-
bearing biotite granodiorite (RC647-41)
from the Bollstadt quarry. This medium-
grained rock contains the alkali-feldspar
glass, shocked and mostly isotropic
quartz, saussuritized plagioclase, strongly
kinked brown biotite, and a deep-green
amphibole (lamellar twinning). Acces-
TABLE 48. Probe Analyses of Naturally
Shocked Feldspar Glasses
RC641-14
wt %
RC647-41,
1
2
wt %
Si02
58.9
58.1
64.3
ALOa
26.7
26.5
18.6
CaO
8.41
8.31
Na20
6.36
6.48
6.67
K20
0.24
0.32
6.49
BaO
0.8
H20
3.1*
Totals
100.6
99.7
(100.0)
Mole %
Ab
57.0
57.4
61. 0t
An
41.6
40.7
Or
1.4
1.9
39.6
Analyst P. M. Bell.
* H20 by subtraction,
t BaO ignored.
GEOPHYSICAL LABORATORY
337
sory sphene, apatite, and an opaque min-
eral are present.
Experimental Procedure
In general, the index of refraction of
each grain was measured prior to and
after annealing at 850 °C in a platinum
furnace. Each grain was mounted on a
spindle stage. In the previously reported
study a gradational filter for monochro-
matic light was used with specially
calibrated immersion oils to measure the
index of refraction to a precision of
±0.0004 or better. In the present study
indices of refraction were also measured
with immersion oils but with an inter-
ference microscope that has a precision
of ±0.0002.
After measurement of the index of re-
fraction, each grain was individually
wrapped in platinum foil. A grain of
dense feldspar glass produced at static
pressures (Year Book 67, pp. 126-130)
was also wrapped in platinum and in-
cluded as a control sample. In each ex-
periment the two platinum packets were
welded to a Pt/Pt-lORh thermocouple
before rapid insertion into the horizontal
annealing furnace. As soon as the ther-
mocouple junction reached a preselected
temperature (850°C or lower), the
packets were quickly removed from the
furnace and quenched in an air jet. The
time necessary for the sample to come to
temperature was recorded. In practice
runs the quench time was measured to
be 0.5 to 1 second. After the quench, both
the sample and control grains were re-
mounted on the spindle stage, and the
indices of refraction were again measured.
Annealing Data
Results are shown in Fig. 58. The
maximum change of index of refraction
of the An41 glass was from 1.5250 to
1.5242, a drop of 0.0008. The annealing
behavior of this glass is similar to that
of statically synthesized and experi-
mentally shocked dense glasses.
The An22 and Or39Ab61 glasses vesicu-
lated extensively during heating, pre-
sumably due to the release of water
vapor. Water could have been incorpo-
rated in the glass structure during impact
or at a later time. Microscopic examina-
tion of less severely shocked grains from
the same specimens showed crystalline
feldspars of the same composition to be
relatively unaltered, suggesting that the
water was meteoritic in origin. Vesicules
were observed in the alkali-feldspar glass
at temperatures as low as 450 °C. An22
glass showed partial vesiculation above
700 °C, suggesting a much lower water
content. Figure 59 shows the data for
An22. Measurements of indices of re-
fraction of the control sample, An23 (syn-
thesized statically at 10 kb) , are also in-
cluded for comparison. Vesiculation did
not severely affect the results on the
An22 glass.
Vesiculation in the alkali-feldspar
glass was so severe that it appeared
cloudy, and the indices of refraction
could not be measured. In order to drive
off the contained water, several grains
of alkali-feldspar glass were heated over-
night at various temperatures. Indices
of refraction measured after heating are
plotted as a function of heating tempera-
ture in Fig. 60. In summary, the index
of refraction changes rapidly at low tem-
peratures (300°C) ; apparently the water
was bonded into the high-pressure, dense
glass structure. The index of refraction
was still falling at 800 °C. Relaxation
of the high-pressure density probably
affects refractive index more than water
loss.
The indices of refraction of An22 and
Or39Ab6i glasses decreased by 0.0011 and
0.0145 as a result of heating at 300 °C
overnight; further heat treatment and
annealing of these glasses was not ac-
companied by massive vesiculation. Fig-
ure 58 shows the changes in index of
refraction after these preheated samples
have been annealed.
The two An61 glasses, produced by
.0085
.0080
.0075
.0070
.0065
.0060
.0055
.0050
c .0045
.0040
.0035
.0030
.0025
.0020
.0015
.0010
.0005
.0000
l I i I r
A800°C
i I I r
i — r
D800°C
/0
850°C
1 S*
800°C
______ »850°C
800°C
//
/
//
^A850°C
-700°in/700oC f/700-C
600°C //_ //
- A
750°C /
//750°C/
lin //
II /
- II l
600°C
101
i,525°C
/
5-25Pg8o°c
^>800!C. 0850°C
EXPLANATION
An4,RC64l-l4
A
An22RC647-67
D
Or39AI61RC647-4l
DA-24
1 I I I I
DA-21
J L
J I L
2 3
5 6
8 9 10 II 12 13 14 15 16 17 18 19 20
Time, (Seconds)
Fig. 58. Change of index of refraction (An) during annealing of Ann, A1123, OraaAbei, DA-21, and
DA-24. The change in index occurred as the temperature was raised to the noted value in the time
indicated. An is negative.
\ ' ' '
1 ] 1 1 1 1
1 1 1 1
\
\
\
\
_ \
\
\
\
. >- ^ two samples of 0r39Ab6|_
\ \^^"treated
identically
—
—
-
-
\
\
1 I 1
1 1 1 1 1 1
1 1 1 1
Fig. 59. Annealing data for An22 and con-
trol sample An23.
100 200 300400 500 600700 800 900 1000 1200 1400
Temperature, °C (overnight)
Fig. 60. Overnight heat treatment of two
grains of O^Aboi.
GEOPHYSICAL LABORATORY
339
1.562
,1.561
1.560
1.559
1.558
1557
1.556
1.555
1.554
1.553
1.552
1.551
1.550
1.549
1.548
1.547
1.546
1.545
1.544
285 Kb Glass
■325 Kb Glass
I 2 3 4 5 6 7 8 9 10 II 12 13 14
Time, (Seconds)
Fig. 61. Annealing data for two synthetically
shocked glasses, DA-21 and DA-24.
shock waves at 285 kb (sample DA-21)
and 325 kb (sample DA-24), were
treated by the standard annealing pro-
cedure. Figure 58 shows change of index
with annealing for these and other glasses
studied. The final indices, measured after
the quench, are shown in Fig. 61.
Interpretation of the Results
It is well known that the maximum
density of a feldspar glass at peak shock
pressure is not preserved on culmination
of the shock event. Ahrens and Rosen-
berg (1968) gave a Rankine-Hugoniot
plot of feldspar at two shock pressures,
showing that the final density is more de-
pendent on the release adiabat than on
the peak pressure. In fact, with higher
shock pressures, the effects of the release
adiabat can be more severe. Comparison
of the changes in the indices of refraction
measured in the present study of shocked
glasses from the Ries Crater with those
of the dense glasses produced at static
pressure (Year Book 67) suggests that a
shock density corresponding to only
about 10 kb is preserved in the Ries
glasses.
Great changes in the index of refrac-
tion occurred during these short anneal-
ings, suggesting that the temperatures
during the shock events were not high.
For example, the two synthetically
shocked glasses, DA-21 and DA-24, ex-
hibited rapid changes above 550°-600°C.
The natural glasses exhibited similar be-
havior but the times were even shorter
(1-3 seconds) . The present set of experi-
ments has involved rapid annealment,
with times in seconds, like those to be
expected in natural impacts. The results
could be helpful in interpreting observa-
tions on extraterrestrial samples.
Andalusite and "/3-Quartzss
Macusani Glass, Peru
IN
Bevan M. French* and H. 0. A. Meyer
Andalusite and a "/3-quartz solid solu-
tion" along the join LiAlSi206-Si02 have
been identified in glass collected by
Barnes (see Barnes et al., 1970) from
near the town of Macusani, southern
Peru. This is believed to be the first re-
port of the natural occurrence of a
"/3-quartz solid solution" and also the
first chemically substantiated account of
andalusite occurring in possible equi-
librium with a presumably volcanic glass.
Macusani glass, which occurs as
pebbles and cobbles in glacial and al-
luvial deposits, is unique because it is not
comparable in composition with tektites
nor with any naturally occurring vol-
canic glass (Linck, 1926; Martin and de
Sitter-Koomans, 1955; Elliott and Moss,
1965). It is characterized (Table 49) by
a high content of alumina and min-
eralizers. Barnes et al. (1970) have
shown that the glass composition is simi-
lar to that of a sillar (altered ash flow)
that outcrops near the glacial deposits
that contain the Macusani glass; further-
more, the K/Ar ages of glass and sillar
*Planetology Branch, National Aeronautics
and Space Administration, Goddard Space
Flight Center, Maryland.
340
CARNEGIE INSTITUTION
TABLE 49. Analyses of Minerals from Macusani Glass
Macusani
Glass *
Andalusite "/3-Quartz88"
Chromite
Spinel t
Si02 71.6
36.3
77.4
0.02
0.09
Ti02 0.04
0.00
0.16
0.02
AloOa 16.7
63.2
17.0
9.41
56.0
Cr203
51.6
<0.01
FeO 0.6
0.39 0.00
31.4
17.0
MgO tr
0.00 0.00
5.98
0.5
CaO 0.4
0.00 0.00
0.00
0.0
MnO 0.05
0.45
0.3
ZnO
27.0
Li20 0.8
~5$
Na20 4.7
<0.1
K20 3.6
<0.1
B203 0.4
P205 0.4
F 1.4
H20 0.2
Totals 100.4
99.9
(99.4)
99.0
(100.9)
(less O = F =
0.6)
* Elliott and Moss, 1965.
f Matrix effects for Zn approximated.
} Determined qualitatively by laser microprobe.
are comparable at 3-4 million years. In
an attempt to discover the origin and
chemical history of this glass, we have
analyzed several discrete mineral phases
that occur with the glass, namely, an-
dalusite, "/?-quartzss," quartz, chromite,
and gahnite.
Andalusite
Andalusite occurs as clear, almost eu-
hedral, prismatic crystals elongated par-
allel to a well-defined flow banding.
Many of the crystals are boudinaged,
suggesting that they were present during
flowage and consolidation of the glass.
From optical properties, Linck (1926)
identified similar crystals in comparable
glass from Paucartambo (approximately
100 miles northwest of Macusani) as
andalusite. The ideal composition Al2
Si05 has been proved by us for the crys-
tals in the Macusani glass (Table 49).
Also the preliminary X-ray diffraction
powder data agree with that obtained
for a standard andalusite.
The only other occurrence known to
the authors of andalusite in a volcanic
glass is in the pyrometamorphosed sedi-
ments of the Asama volcano, Japan
(Aramaki, 1961). In this occurrence,
however, it appears that the andalusite is
a relict from the sediments, for when it
occurs in the glassy part of the rock it
shows evidence of resorption. The stable
aluminum-silicate mineral in the Asama
glass is a silica-deficient sillimanite,
whose composition is reported to be
about halfway between ideal sillimanite
and ideal mullite. Sillimanite was also
identified in the Macusani glass (Linck,
1926; Martin and de Sitter-Koomans,
1955), occurring as very small elongated
crystals. This phase is much less abun-
dant than andalusite and has not yet
been verified by us.
In the systems Al203-Si02 (Bowen and
Greig, 1924; Aramaki and Roy, 1962),
Al203-Si02-(Na,K)20 (Schairer and
Bowen, 1955, 1956) a composition equiv-
alent to that of Macusani glass (exclud-
ing volatites) would produce mullite in
equilibrium with the melt at a minimum
temperature of about 1100°C. Unfortu-
nately the reactions andalusite or silli-
manite — » mullite and quartz are not
clearly understood. G. C. Kennedy (in
preparation) has demonstrated the exist-
ence of a solid solution relationship be-
tween mullite and sillimanite. This rela-
GEOPHYSICAL LABOKATORY
341
tionship complicates the andalusite-silli-
manite boundary, but below 3 kb and
above 700 °C the amount of sillimanite
in mullite is restricted to less than 10%.
The recent work of Richardson, Gilbert,
and Bell (1969), however, demonstrates
that it is possible to obtain andalusite on
the liquidus if one considers the inter-
section of the minimum melting curve for
granitic systems containing excess H20
(Luth, Jahns, and Tuttle, 1964) with the
andalusite-sillimanite equilibrium curve.
The occurrence of andalusite (and sil-
limanite?) in the Macusani glass may
result from the presence of sufficient
volatiles in the melt (as evidenced by the
presence of B, F, H20 in the glass) to
lower the liquidus below the andalusite— >
sillimanite -» mullite reaction tempera-
ture. The possible presence of small,
minor sillimanite crystals in the Macu-
sani glass suggests that the temperature
lay close to the andalusite — » sillimanite
boundary.
"f3-Quartzss"
The mineral interpreted as a member
of the /3-quartz and spodumene solid
solution series occurs as numerous small
rosettes, which together form bands par-
allel to the flow banding in the glass.
These rosettes have the appearance of
quench crystals, whose present distribu-
tion may reflect slight compositional dif-
ferences in adjacent layers of glass. Elec-
tron-probe analysis (Table 49) of this
material, together with the high Li20
content of the glass (0.8% ; Elliott and
Moss, 1965) , suggested that this mineral
might contain appreciable lithium. This
belief was confirmed by laser microprobe
analysis,* which indicated a greater con-
centration of lithium in the mineral phase
(~5 wt % Li20) than in the glass.
From the analysis (Table 49) this
phase would have a composition approxi-
* This analysis was performed qualitatively
by J. J. Bussey, of Jarrell-Ash Division, Fisher
Scientific Company, Waltham, Massachusetts.
mating to (LiAlSi206)62(3Si02)38 mole
%. Preliminary cell data based on a
^-quartz type structure are a = 5.14 A,
c=5.46 A. These values give a chemical
composition (Munoz, Year Book 67, p.
138) of (LiAlSi206) 63 (3Si02) 37, in excel-
lent agreement with the analytical value.
The mineral in the Macusani glass is
believed to be the first reported occur-
rence in nature of a mineral having such
a composition and structure.
Phases having the same structure as
hexagonal /3-quartz (cf. LiAlSi206-III,
Li, 1968) have been synthesized along
the join Si02-LiAlSi206 at pressures
above 10 kb (Munoz, Year Book 67).
Unfortunately there is much confusion
in the literature with regard to the
identification of "/?-eucryptitess" and
"/?-quartzss" in the phase studies that
have been done at 1 atm. This confusion
has arisen from the similarity of X-ray
powder data for the two series. Single-
crystal work is essential for positive
identification. Until such work is com-
pleted the status of true /3-quartz struc-
tures along the join spodumene-quartz
at 1 atm must remain in doubt.
It seems likely that the formation of
andalusite, which was aided by the
presence of volatiles, was inhibited when
the temperature suddenly dropped as
quenching (loss of volatiles?) took place.
At this point, rapid but limited growth
of the "/3-quartzss" occurred. Perhaps,
in view of the work of Richardson, Gil-
bert, and Bell (1969) on the andalusite-
sillimanite equilibrium, we may suggest
a possible maximum temperature of
formation for the glass and andalusite
in the region of 850°C.
Quartz, Chromite, and Gahnite
Other minerals that occur within the
glass from Macusani and have been
identified by electron-probe analysis in-
clude quartz, spinel, and chromite. The
quartz is present as a single crystal whose
edges show some resorption. The chro-
mite is of the magnesiochromite variety
342
CARNEGIE INSTITUTION
(a = 8.36 A) , whereas the spinel is an iron
gahnite (Table 49) . Both these spinellids
were obtained from HF residue, and their
petrographic relations to the glass and
other minerals are uncertain. The occur-
rence of two spinellids of such diverse
composition in a homogeneous glass is
puzzling; one (or both) could be relicts
from sediments assimilated by a super-
heated granitic magma.
STAFF ACTIVITIES
Washington Crystal Colloquium
Beginning in September 1968 the
Washington Crystal Colloquium, an in-
formal monthly assembly of crystallog-
raphies from the Baltimore- Washington-
Virginia area, moved its meeting place
from the George Washington University
campus to the Geophysical Laboratory.
Attendance varied between twenty and
fifty persons. The following eight lectures
were presented :
"The crystal structure, at 5.5 A resolu-
tion, of the hemoglobin from Glycera
dibranchiata, a marine annelid worm,"
by Eduardo A. Padlan (The University
of the Philippines) , presented by Warner
E. Love (The Johns Hopkins Univer-
sity) , September 26, 1968.
"Recent investigations on the sala-
mander toxin" and "The crystal structure
of the 7T complex of picric acid with 1
bromo-2 amino naphthalene," by Ger-
hard G. Habermehl (Institute for Or-
ganic Chemistry, Darmstadt, Germany) ,
October 25, 1968.
"The crystal structure of low chalco-
cite," by Howard T. Evans, Jr. (U. S.
Geological Survey) , November 22, 1968.
"Crystal structures of anti-radiation
drugs and of products of photo rearrange-
ments," by Louise I. Karle (pro te?n.,
Universitat Marburg) and Isabella L.
Karle (U. S. Naval Research Labora-
tory) , December 19, 1968.
"Crystal structures and crystal chem-
istry of two borate minerals, veatchite
and howlite," by Joan R. Clark (U. S.
Geological Survey), January 31, 1969.
"High-pressure X-ray diffraction stud-
ies of single crystals; the crystal struc-
ture of benzene at 25 kb," by Stanley
Block (U. S. National Bureau of Stand-
ards) , March 6, 1969.
"The crystal structure of a 1,3-diglyc-
eride and its relevance to the study of
biological membranes," by Albert Hybl
(University of Maryland), April 18,
1969.
"Cyclotetradepsipeptide," by J. Kon-
nert (U. S. Naval Research Laboratory) ,
and "The crystal structure of 8,14-anhy-
drodigitoxigenin, a variant of the car-
diac-active steroid, digitoxigenin," by
R. D. Gilardi (U. S. Naval Research
Laboratory), May 16, 1969.
Journal of Petrology
Two of the founding members of the
Editorial Board of the Journal of Petrol-
ogy have retired from their posts this
year after ten years of service. Dr. H. S.
Yoder, Jr., is succeeded as Coeditor by
Dr. E. D. Jackson, U. S. Geological Sur-
vey (Menlo Park, California). The post
of Senior Managing Editor held by Prof.
G. Malcolm Brown will not be filled;
however, Dr. J. D. Bell of Oxford Uni-
versity has been added to the staff of
Managing Editors. Both men will con-
tinue to serve the Journal as members
of the Honorary Advisory Board.
Volume 9 for 1968 consisted of 488
pages and contained a contribution by a
Fellow of the Laboratory. Members of
the staff of the Laboratory act as review-
ers along with their international col-
leagues. The Journal of Petrology con-
tinues to provide a format of outstanding
quality for data papers of long lasting
value.
GEOPHYSICAL LABORATORY
343
Lectures
During the report year Staff Members
and Fellows were invited to present
lectures as follows :
P. H. Abelson made a total of 16 in-
vited public appearances. He made
speeches in the following capacities: As
Distinguished Lecturer ("Science and
Society") at the University of Arkansas,
Fayetteville ; as organizer and partici-
pant in a Symposium on Science and
Engineering Policies in Transition at the
Carnegie Institution of Washington; as
a participant in a Symposium on "The
New View of the Origin of Life" ("Chem-
ical Reactions on the Primitive Earth")
at the annual meeting of the American
Association for the Advancement of Sci-
ence at Dallas, Texas; as speaker ("Sci-
ence, Technology, and Ethics — An
Agenda for the Future") at the dedica-
tion of a new Science Center and lecturer
("Chemical Events on the Primitive
Earth") at a seminar at St. Olaf Col-
lege, Northfield, Minnesota; as speaker
("Challenges for Tomorrow") at Centen-
nial Year Symposium at Oregon State
University, Corvallis; as speaker ("Sci-
ence and Engineering Policies") at dinner
of International Symposium on "A Criti-
cal Review of the Foundations of Rela-
tivists and Classical Thermodynamics"
at the Department of Chemical and Pe-
troleum Engineering, University of Pitts-
burgh; and as a participant in a special
meeting sponsored by the British and
American Associations for the Advance-
ment of Science at Boulder, Colorado.
P. M. Bell gave a series of three talks
at the Geology Department, University
of Cincinnati. He also addressed the De-
partment of Geology at Northwestern
University and the Department of Geo-
chemistry and Mineralogy at Pennsyl-
vania State University.
Gabrielle Donnay served as guest
lecturer at the Sulfide Institute at Lehigh
University.
P. E. Hare gave invited lectures at a
Symposium on Organic Geochemistry of
the Precambrian at the Annual Meeting
of the Geological Society of America at
Mexico City, a Symposium on Penetra-
tion of CaC03 Substrates by Lower
Plants and Invertebrates at the Annual
Meeting of the American Association for
the Advancement of Science at Dallas,
and a Symposium on Calcification and
Skeletal Mineralogy at a Meeting of the
Southeastern Section of the Geological
Society of America at Columbia, S. C.
He also addressed the Paleontological
Society of Washington, the Institute of
Molecular Evolution at the University of
Miami, the Geology Department at Indi-
ana University, and the Lamont Geo-
logical Observatory of Columbia Uni-
versity.
T. C. Hoering lectured on "Organic
Geochemistry and the Record of Ancient
Life" at a Symposium on the Origin of
Life at California State College at Los
Angeles.
T. E. Krogh addressed the Miller Geol-
ogy Club at the Geology Department
of Queen's University at Kingston, On-
tario.
G. Kullerud continued as Adjunct Pro-
fessor in Geochemistry at Lehigh Uni-
versity where he supervised the sulfide
research program and lectured on sulfide
phase equilibria. He served as a Visiting
Professor at Heidelberg University and
as Consulting Professor to the Depart-
ment of Geosciences, Texas Technologi-
cal College, Lubbock, Texas, where he
also presented lectures on ore deposits.
He served as director of a six-week Sum-
mer Institute in Sulfide Phase Equilibria
and their Applications to Ores for Col-
lege Teachers of Economic Geology spon-
sored by the National Science Founda-
tion. In addition, he lectured at the Max
Planck Institut fur Kernphysik in Hei-
delberg, at the University in Tubingen,
and at the University in Clausthal, Ger-
many. He addressed the Geology Club
at the Franklin and Marshall College,
Lancaster, Pennsylvania, and lectured in
the Department of Geology, University
of Toronto, and the Mineral Sciences Di-
344
CARNEGIE INSTITUTION
vision, Department of Energy, Mines,
and Resources, at Ottawa, Canada. He
was elected to the Council of the Min-
eralogical Society of America.
D. H. Lindsley addressed the Depart-
ment of Geology at Queen's University,
Kingston, Ontario. He spent the first six
months of 1969 as Visiting Associate
Professor at the Division of Geological
Sciences, California Institute of Tech-
nology, where he led a seminar on ex-
perimental petrology.
H. 0. A. Meyer participated in a
meeting at Cologne to celebrate the 60th
anniversary of the Deutsche Mineralo-
gische Gesellschaft. He addressed the
Geological Society of Washington and
gave an invited lecture at the Depart-
ment of Geological Sciences of Virginia
Polytechnic Institute. In addition, he
presented lectures at the Planetology
Branch, National Aeronautics and Space
Administration, Goddard Space Flight
Center, and at the Department of Geo-
chemistry and Mineralogy of the Penn-
sylvania State University.
H. S. Yoder, Jr., presented a talk on
the "Experimental Data Bearing on the
Calcalkaline Andesites" at the Andesite
Conference in Eugene and Bend, Oregon,
sponsored by the University of Oregon
Center for Volcanology and the Inter-
national Upper Mantle Committee. He
participated in the discussions at the In-
ternational Volcanological Association
meeting at the University of Laguna,
Tenerife, Canary Islands, and jointly
presented a paper with Dr. Schairer. In-
vited lectures were also given by Yoder
at Amherst College, University of Mas-
sachusetts, and Pennsylvania State Uni-
versity. He gave the principal address
entitled "Major Problems of the Alkali
Magma Series" at the Alkaline Rock
Symposium held in conjunction with the
joint annual meeting of the Geological
Association of Canada and the Min-
eralogical Association of Canada in
Montreal, Quebec.
Penologists' Club
Five meetings were held during the
58th year of the Penologists' Club. The
following lectures were presented:
"Experimental studies of metamorphic
reactions of haplopelites within the sys-
tem K20-MgO-AL03-Si02-H20," by
Freidrich Seifert (The Ruhr University,
Bochum, Germany) , October 15, 1968.
"Mineralogy and petrology of an oli-
vine diabase sill and associated unusually
potassic granophyres in central Arizona,"
by Douglas Smith (Geophysical Labo-
ratory), January 14, 1969.
"State of water in the upper mantle
and role of water in the formation of
crustal materials," by I. Kushiro (Geo-
physical Laboratory) , February 18, 1969.
"Meteorites, analytical error, kimber-
lite nodules, secondary alteration, and
the composition of the upper mantle,"
by A. J. Erlank (Department of Ter-
restrial Magnetism) , April 1, 1969.
"A petrogenetic grid in the system
Al203-K20-FeO-Si02-H20 and its ap-
plication to the basement rocks of the
Venezuelan Andes," by L. Kovisars
(University of Pennsylvania), May 27,
1969.
BIBLIOGRAPHY
Allmann, R., see Donnay, G.
Bell, P. M., and F. R. Boyd, Phase equilibrium
data bearing on the pressure and tempera-
ture of shock metamorphism, in Shock Meta-
morphism of Natural Materials, B. M. French
and N. M. Short, eds., Mono Book Corp.,
Baltimore, Md., 43-50, 1968 (Geophysical
Laboratory Paper 1533) .
Bell, P. M., and B. T. C. Davis, Melting rela-
tions in the system jadeite-diopside at 30
and 40 kb, Am. J. Sci., Schairer Vol., 267A,
17-32, 1969 (G. L. Paper 1521).
Bell, P. M., see also Richardson, S. W.
Boyd, F. R., Electron-probe study of diopside
inclusions from kimberlite, Am. J. Sci., Schai-
GEOPHYSICAL LABORATORY
345
rer Vol., 267A, 50-69, 1969 (G. L. Paper
1522).
Boyd, F. R., see also Bell, P. M.
Bryan, W. B., L. W. Finger, and F. Chayes,
Estimating proportions in petrographic mix-
ing equations by least-squares approxima-
tion, Science, 163, 926-927, 1969 (G. L.
Paper 1532).
Burnham, C. W., see Finger, L. W.
Carmichael, I. S. E., see Lindsley, D. H.
Chayes, F., A least squares approximation for
estimating the amounts of petrographic par-
tition products, Mineral. Petrogr. Acta, 14,
111-114, 1968 (G. L. Paper 1519).
Chayes, F., see also Bryan, W. B.
Davis, B. T. C, see Bell, P. M.
Davis, G. L., S. R. Hart, and G. R. Tilton,
Some effects of contact metamorphism on
zircon ages, Earth Planet. Sci. Letters, 5,
27-34, 1968 (G. L. Paper 1515).
Donnay, G., and R. Allmann, SisOio groups in
the crystal structure of ardennite, Acta Cryst.,
B24, 845-855, 1968 (G. L. Paper 1506).
Donnay, G., see also El Goresy, A.; Gaines,
R.V.;Kullerud, G.
Donnay, J. D. H., see Kullerud, G.
El Goresy, A., and G. Donnay, A new allo-
tropic form of carbon from the Ries crater,
Science, 161, 363-364, 1968 (G. L. Paper
1513).
El Goresy, A., and G. Kullerud, Phase rela-
tions in the system Cr-Fe-S, in Meteorite
Research, P. M. Millman, ed., D. Reidel
Publishing Co., Dordrecht, Holland, 638-
656, 1969 (G. L. Paper 1536).
Finger, L. W., and C. W. Burnham, Peak-
width calculations for equi-inclination dif-
fraction geometry, Z. Krist., 127, 101-109,
1968 (G.L. Paper 1507).
Finger, L. W., see also Bryan, W. B.
Gaines, R. V., G. Donnay, and M. H. Hey,
Sonoraite, Am. Mineralogist, 53, 1828-1832,
1968 (G.L. Paper 1517).
Gilbert, M. C, High-pressure stability of ac-
mite, Am. J. Sci., Schairer Vol., 261 A, 145-
159,1969 (G.L. Paper 1523).
Gilbert, M. C, see also Richardson, S. W.;
Wones, D. R.
Hadidiacos, C. G., Solid-state temperature con-
troller, /. Geol., 77, 365-367, 1969 (G. L.
Paper 1537).
Hart, S. R., see Davis, G. L.
Hey, M. H., see Gaines, R. .'.
H ickenholz, H. G., Synthesis and stability of
Ti-andradite, Am. J. Sci., Schairer Vol., 267 A,
209-323, 1969 (G. L. Paper 1524).
Kullerud, G., The lead-sulfur system, Am. J.
Sci., Schairer Vol., 267 A, 233-256, 1969 (G. L.
Paper 1525).
Kullerud, G., G. Donnay, and J. D. H. Don-
nay, Omission solid solution in magnetite:
kenotetrahedral magnetite, Z. Krist., 128,
1-17, 1969 (G. L. Paper 1514).
Kullerud, G., see also El Goresy, A.; Naldrett,
A.J.
Kushiro, I., The system forsterite-diopside-
silica with and without water at high pres-
sures, Am. J. Sci., Schairer Vol., 267 A, 269-
294, 1969 (G. L. Paper 1526).
Kushiro, I., H. S. Yoder, Jr., and M. Nishikawa,
Effect of water on the melting of enstatite,
Geol. Soc. Am. Bull, 79, 1685-1692, 1968 (G.
L. Paper 1516).
Kushiro, I., see also Yoder, H. S., Jr.
Lindsley, D. H., I. S. E. Carmichael, and J.
Nicholls, Iron-titanium oxides and oxygen
fugacities in volcanic rocks: a correction,
J. Geophys. Res., 73, 3351-3352, 1968 (G. L.
Paper 1504).
Lindsley, D. H., and J. L. Munoz, Subsolidus
relations along the join hedenbergite-ferro-
silite, Am. J. Sci., Schairer Vol., 267 A, 295-
324, 1969 (G. L. Paper 1527).
Munoz, J. L., see Lindsley, D. H.
Naldrett, A. J., and G. Kullerud, Emplace-
ment of ore at the Strathcona Mine, Sud-
bury, Canada, as a sulfide-oxide magma in
suspension in young noritic intrusions, In-
tern. Geol Congr., 23rd, 7, 197-213, 1968
(G.L. Paper 1503).
Nicholls, J., see Lindsley, D. H.
Nishikawa, M., see Kushiro, I.
Richardson, S. W., Staurolite stability in a
part of the system Fe-Al-Si-O-H, J. Petrol,
9, 467-488, 1968 (G. L. Paper 1509).
Richardson, S. W., P. M. Bell, and M. C.
Gilbert, Kyanite-sillimanite equilibrium be-
tween 700° and 1500°C, Am. J. Sci., 266, 513-
541, 1968 (G. L. Paper 1508).
Richardson, S. W., M. C. Gilbert, and P. M.
Bell, Experimental determination of kyanite-
andalusite and andalusite-sillimanite equi-
libria; the aluminum silicate triple point,
Am. J. Sci., 267, 259-272, 1969 (G. L. Paper
1518).
Schreyer, W., and F. Seifert, High-pressure
phases in the system MgO-ALOs-SiOa-HaO,
Am. J. Sci., Schairer Vol., 267 A, 407-443,
1969 (G.L. Paper 1534).
346
CARNEGIE INSTITUTION
Seifert, F., see Schreyer, W.
Steiger, R. H., see Tilton, G. R.
Tilton, G. R., and R. H. Steiger, Mineral ages
and isotopic composition of primary lead at
Manitouwadge, Ontario, J. Geophys. Res.,
74, 2118-2132, 1969 (G. L. Paper 1535).
Tilton, G. R., see also Davis, G. L.
Wones, D. R., and M. C. Gilbert, The fayalite-
magnetite-quartz assemblage between 600°
and 800°C, Am. J. Sci., Schairer Vol., 267 A,
480-488, 1969 (G. L. Paper 1528).
Yoder, H. S., Jr., and I. Kushiro, Melting of a
hydrous phase: phlogopite, Am. J. Sci.,
Schairer Vol., 267 A, 558-582, 1969 (G. L.
Paper 1529).
Yoder, H. S., Jr., see also Kushiro, I.
REFERENCES CITED
Ahrens, T. J., and J. T. Rosenberg, Shock
metamorphism : experiments on quartz and
plagioclase, in Shock Metamorphism of Na-
tural Materials, B. M. French and N. M.
Short, eds., Mono Book Corp., Baltimore,
Md., 59-85, 1968.
Akimoto, S., H. Fujisawa, and T. Katsura, Syn-
thesis of FeSiOa pyroxene (ferrosilite) at
high pressures, Proc. Japan Acad., Ifi, 272-
275, 1964.
Akimoto, S., and I. Kushiro, Natural occur-
rence of titanomaghemite and its relevance
to the unstable magnetization of rocks, J.
Geomag. Geoelec, 11, 94-110, 1960.
Akimoto, S., T. Nagata, and T. Katsura, The
TiFe205-Ti2Fe05 solid solution series, Nature,
179, 37-38, 1957.
Alexander, L. E., and G. S. Smith, Single-crystal
diffractometry : The improvement of ac-
curacy in intensity measurements, Acta
Cryst., 17, 1195-1201, 1964.
Aoki, K., Petrology of alkali rocks of the Iki
Island and Higashi-Matsuura district, Japan,
Sci. Rept. Tohoku Univ., Third Ser., 6,
261-310, 1959.
Aramaki, S., Sillimanite and cordierite from
volcanic xenoliths, Am. Mineralogist, Jfi,
1156-1165, 1961.
Aramaki, S., and R. Roy, Revised phase dia-
gram for the system ALOs-SiC^, J . Am.
Ceram. Soc, 45, 229-242, 1962.
Arnold, R. G., Mixtures of hexagonal and
monoclinic pyrrhotite and the measurement
of the metal content of pyrrhotite by X-ray
diffraction, Am. Mineralogist, 51, 1221-1227,
1966.
Arnold, R. G., Range in composition and struc-
ture of 82 natural terrestrial pyrrhotites, Can.
Mineralogist, 9, 31-50, 1967.
Arnold, R. G., Pyrrhotite phase relations be-
low 304° ± 6° C at <1 atm total pressure,
Econ. Geol, 64, 405-419, 1969.
Bailey, D. K., and R. MacDonald, Alkali-feld-
spar fractionation trends and the derivation
of peralkaline liquids, Am. J . Sci., 267, 242-
248, 1969.
Bailey, D. K., and J. F. Schairer, Feldspar-liquid
equilibria in peralkaline liquids — the ortho-
clase effect, Am. J. Sci., 262, 1198-1206, 1964.
Bailey, D. K., and J. F. Schairer, The system
Na^O-AloOs-FeaOs-SiC^ at 1 atmosphere, and
the petrogenesis of alkaline rocks, J. Petrol.,
7, 114-170, 1966.
Baker, I., and S. E. Haggerty, The alteration of
olivine in basaltic and associated lavas,
Part II, Intermediate and low-temperature
alteration, Contrib. Mineral. Petrol, 16, 258-
273, 1967.
Baker, P. E., I. G. Gass, P. G. Harris, and R. W.
LeMaitre, The volcanological report of the
Royal Society expedition to Tristan de
Cunha, 1962, Phil. Trans. Roy. Soc. London,
Ser. A, 256, 439-578, 1964.
Balchan, A. S., and H. G. Drickamer, High
pressure electrical resistance cell, and cali-
bration points above 100 kb, Rev. Sci. Instr.,
32, 308-313, 1961.
Baltitude, R. J., and D. H. Green, Experi-
mental study at high pressures on the origin
of olivine nephelinite and olivine melilitite
nepheline magmas, Earth Planet. Sci. Letters,
3, 325-337, 1967.
Banno, S., Garnet-pyroxene equilibrium in
granulite facies rocks and inclusions in kim-
berlite and alkali basalt, Japan. J. Geol.
Geography, 36, 23-36, 1965.
Banno, S., I. Kushiro, and Y. Matsuii, Notes
on rock-forming minerals (20) : Enstatite
from a garnet-peridotite inclusion in kim-
berlite, J. Geol. Soc. Japan, 69, 157-159, 1963.
Barnes, V. E., G. Edwards, W. A. McLaughlin,
I. Friedman, and D. Joensuu, Macusanite oc-
currence, age, and composition, Macusani,
Peru, Geol. Soc. Am. Bull., in press, 1970.
GEOPHYSICAL LABORATORY
347
Bassett, W. A., T. Takahashi, and P. W. Stook,
X-ray diffraction and optical observations
on crystalline solids up to 300 kb, Rev. Sci.
Instr., 38, 37-42, 1967.
Bergman, W., Evolutionary aspects of the ster-
ols, in Cholesterol, R. P. Cook, ed., Aca-
demic Press, New York, 435-444, 1958.
Berner, R. A., Stability fields of iron minerals
in anaerobic marine sediments, /. Geol., 72,
826-834, 1964.
Biggar, G. M., and M. J. O'Hara, Temperature
control and calibration in quench furnaces
and some new temperature measurements in
the system CaO-MgO-Al203-Si02, Mineral.
Mag., 37, 1-15, 1969.
Birle, J. D., G. V. Gibbs, P. B. Moore, and
J. V. Smith, Crystal structures of natural oli-
vines, Am. Mineralogist, 53, 807-824, 1968.
Bonatti, E., and Y. R. Nayudu, Origin of
manganese nodules on the ocean floor, Am.
J. Sci., 263, 17-39, 1965.
Bowen, N. L., The crystallization of haploba-
saltic, haplodioritic and related magmas, Am.
J. Sci., 40, 161-185, 1915.
Bowen, N. L., Evolution of Igneous Rocks,
Princeton University Press, 1928.
Bowen, N. L., and J. W. Greig, The system
Al203-Si02, /. Am. Ceram. Soc, 7, 238-256,
1924.
Bowen, N. L., and J. F. Schairer, The system
MgO-FeO-Si02, Am. J. Sci., 29, 151-217, 1935.
Bown, M. G., and P. Gay, An X-ray study of
exsolution phenomena in the Skaerga^rd py-
roxenes, Mineral. Mag., 32, 379-388, 1960.
Boyd, F. R., Hydrothermal investigations of
amphiboles, in Researches in Geochemistry,
Vol. 1, P. H. Abelson, ed., John Wiley and
Sons, Inc., New York, 377-396, 1959.
Boyd, F. R., Petrological problems in high
pressure research, in Researches in Geochem-
istry, Vol. 2, P. H. Abelson, ed., John Wiley
and Sons, Inc., New York, 593-618, 1967.
Boyd, F. R., Electron-probe study of diopside
inclusions from kimberlite, Am. J. Sci.,
Schairer Vol., 267 A, 50-69, 1969.
Boyd, F. R., and G. M. Brown, Electron-probe
study of pyroxene exsolution, Mineral. Soc.
Am. Spec. Paper, 2, 211-216, 1969.
Boyd, F. R., and J. L. England, Apparatus for
phase-equilibrium measurements at pressures
up to 50 kb and temperatures up to 1750° C,
J. Geophys. Res., 65, 741-748, 1960.
B^yd, F. R., and J. F. Schairer, The system
MgSi03-CaMgSi206, J. Petrol., 5, 275-309,
1964.
Bridgman, P. W., Polymorphic transitions of
35 substances to 50,000 kg/cm2, Proc. Am.
Acad. Arts Sci., 72, 45-136, 1937.
Bridgman, P. W., The compression of twenty-
one halogen compounds and eleven other
simple substances to 100,000 kg/cm2, Proc.
Am. Acad. Arts Sci., 76, 1-7, 1945.
Brookins, D. G., Re-examination of pyrope
from the Stockdale kimberlite, Riley Co.,
Kansas, Mineral. Mag., 36, 450-452, 1967.
Brooks, E. R., Multiple metamorphism along
the Grenville Front, north of Georgian Bay,
Ontario, Geol. Soc. Am. Bull, 78, 1267-1280,
1967.
Bryan, W. B., Relative abundance of interme-
diate members of the oceanic basalt-trachyte
association: evidence from Clarion and So-
corro Islands, Revillagigedo Islands, Mexico,
J. Geophys. Res., 69, 3047-3049, 1964.
Bryan, W. B., History and mechanism of
eruption of soda-rhyolite and alkali basalt,
Socorro Island, Mexico, Bull. Volcanol., 29,
453-480, 1966.
Bryan, W. B., Geology and petrology of Cla-
rion Island, Mexico, Geol. Soc. Am. Bull, 78,
1461-1476, 1967.
Bryan, W. B., Low-potash dacite drift pumice
from the Coral Sea, Geol. Mag., 105, 431-439,
1968.
Bryan, W. B., L. W. Finger, and F. Chayes,
Estimating proportions in petrographic mix-
ing equations by least-squares approxima-
tion, Science, 163, 926-927, 1969.
Bunch, T. E., and K. Keil, Chromite and
ilmenite from non-chondritic meteorites, sub-
mitted to Am. Mineralogist, 1969.
Bunch, T. E., K. Keil, and E. Olsen, Mineral
compositions and petrology of silicate inclu-
sions in iron meteorites, Contrib. Mineral.
Petrol., in press, 1969.
Bundy, F. P., Fe-Co and Fe-V alloys for pres-
sure calibration in the 130- to 300-kb region,
J. Appl. Phys., 38, 2446-2449, 1967.
Burnham, C. W., J. R. Clark, J. J. Papike, and
C. T. Prewitt, A proposed crystallographic
nomenclature for clinopyroxene structures,
Z. Krist., 125, 109-119, 1967.
Burns, R. G., Apparatus for measuring polar-
ized absorption spectra of small crystals, J.
Sci. Instr., 43, 58-60, 1966.
Burns, R. G., Optical absorption in silicates, in
The Application of Modern Physics to the
Earth and Planetary Interiors, S. K. Run-
corn, ed., John Wiley and Sons, Inc., New
York, in press, 1969.
348
CARNEGIE INSTITUTION
Burns, R. G., and W. Fyfe, Crystal-field theory
and the geochemistry of transition ele-
ments, in Researches in Geochemistry, Vol. 2,
P. H. Abelson, ed., John Wiley and Sons,
Inc., 259-285, 1967.
Carmichael, I. S. E., Natural liquids and the
phonolitic minimum, Geol. J., 4, 55-60, 1964.
Carmichael, I. S. E., and W. S. MacKenzie,
Feldspar-liquid equilibria in pantellerites : an
experimental study, Am. J. Sci., 261, 382-
396, 1963.
Chayes, F., Relative abundance of intermedi-
ate members of the oceanic basalt-trachyte
association, /. Geophys. Res., 68, 1519-1534,
1963a.
Chayes, F., Author's reply to the preceding
discussion, J. Geophys. Res., 68, 5108-5109,
19636.
Chayes, F., Variance-covariance relations in
some published Harker diagrams of vol-
canic suites, J. Petrol, 5, 219-237, 1964.
Chayes, F., The chemical composition of Ceno-
zoic andesites, in "Proceedings of the Andesite
Conference," A. R. McBirney, ed., Oregon
Dept. Geol. Mineral Ind. Bull, 65, 1-11, 1969.
Chayes, F., On estimating the magnitude of
the hidden zone and the compositions of
the residual liquids of the Skaergaard layered
series, J. Petrol, in press, 1970.
Chikashige, M., and T. Aoki, Metallographic
investigation of the system aluminum-sele-
nium, Mem. Coll. Sci. Kyoto Imperial Univ.,
2, 249-254, 1917.
Chikashige, M., and J. Nose, Metallographic
investigation of the system aluminum-tellu-
rium, Mem. Coll Sci. Kyoto Imperial Univ.,
2, 227-232, 1917.
Chinner, G. A., and J. F. Schairer, The join
CasALSiaOia-MgsAkSisO^ and its bearing on
the system CaO-MgO-Al203-Si02 at atmo-
spheric pressure, Am. J. Sci., 260, 611-634,
1962.
Clark, A. H., Stability field of monoclinic pyr-
rhotite, Trans. Inst. Mining Met., Sect. B,
75, 232-235, 1966.
Clark, J. R., and J". J. Papike, Crystal-chemical
characterization of omphacites, Am. Mineral-
ogist, 53, 840-868, 1968.
Clark, L. A., and G. Kullerud, The sulfur-rich
portion of the Fe-Ni-S system, Econ. Geol,
58, 853-885, 1963.
Clark, S. P., Jr., Infrared spectra of minerals,
Am. Mineralogist, 42, 732-740, 1957.
Clark, S. P., and A. E. Ringwood, Density dis-
tribution and constitution of the mantle, Rev .
Geophys., 2, 35-88, 1964.
Corlett, M., Low-iron polymorphs in the
pyrrhotite group, Z. Krist., 126, 124-134, 1968.
Cromer, D. T., Anomalous dispersion correc-
tions computed from self-consistent field
relativistic Dirac-Slater wave functions,
Acta Cryst., 18, 17-23, 1965.
Cromer, D. T., and J. B. Mann, X-ray scatter-
ing factors computed from numerical Hartree-
Fock wave functions, Acta Cryst., A24, 321-
324, 1968.
Cronan, D. S., and J. S. Tooms, The geo-
chemistry of manganese nodules and asso-
ciated pelagic deposits from the Pacific
and Indian Oceans, Deep-Sea Res., 16, 1-25,
1969.
Curtis, C. D., Applications of the crystal-field
theory to the inclusion of trace transition
elements in minerals during magmatic dif-
ferentiation, Geochim. Cosmochim. Acta, 28,
389-403, 1964.
Davis, B. T. C, and F. R. Boyd, The join
Mg2Si2OG-CaMgSi206 at 30 kb pressure and
its application to pyroxenes from kimberlites,
J. Geophys. Res., 71, 3567-3576, 1966.
Deer, W. A., R. A. Howie, and J. Zussman,
Rock-Forming Minerals, Vol. 4, John Wiley
and Sons, Inc., New York, 1963.
Degens, E. T., Geochemistry of Sediments,
Prentice-Hall, Inc., Englewood Cliffs, N. J.,
1965.
Deland, A. N., The boundary between the Ti-
miskaming and Grenville subprovince in
the Surprise Lake area, Quebec, Proc. Geol.
Assoc. Can., 8, 127-141, 1956.
Desborough, G. A., and R. H. Carpenter, Phase
relations of pyrrhotite, Econ. Geol, 60,
1431-1450, 1965.
Destenay, D., Structure cristalline de la tri-
phyline, Mem. Soc. Roy. Sci. Liege, 10, no. 3,
5-28, 1950.
DeVries, R. C, and E. F. Osborn, Phase equi-
libria in high-alumina part of the system
CaO-MgO-Al203-Si02, J. Am. Ceram. Soc,
40, 6-15, 1957.
Donnay, G., J. M. Stewart, and H. Preston, The
crystal structure of sonoraite, Fe3+Te4+03
(OH)-H20, Tschermaks Mineral. Petrog.
Mitt., in press, 1969.
Doyle, R. W., Identification and solubility of
iron sulfide in anaerobic lake sediment, Am.
J. Sci., 266, 980-994, 1968.
Drickamer, H. G., The effect of high pressure
on the electronic structure of solids, Solid
State Phys., 17, 1-133, 1965.
GEOPHYSICAL LABORATORY
349
Drickamer, H. G., G. K. Lewis, Jr., and S. C.
Fung, The oxidation state of iron at high
pressure, Science, 163, 885-890, 1969.
Elliott, C. J., and A. A. Moss, Natural glass
from Macusani, Peru, Mineral. Mag., 85,
423-424, 1964.
Elliott, R. P., Constitution of Binary Alloys,
1st Suppl., McGraw-Hill Book Co., Inc.,
New York, 1965.
Erd, R. C., H. T. Evans, and H. D. Richter,
Smythite, a new iron sulfide and associated
pyrrhotite from Indiana, Am. Mineralogist,
42, 309-333, 1957.
Eremenko, V. N., and G. I. Kruchinina, On
the composition diagram of the system nickel-
antimony, Tr. Inst. Chernoi Met. Kiev, 5,
110-122, 1951.
Ernst, W. G., Amphiboles ; Crystal Chemistry,
Phase Relations, and Occurrence, Springer-
Verlag, New York, 1968.
Fiala, J., Pyrope of some garnet peridotites of
the Czech massif, Krystalinikum, 3, 55-74,
1965.
Finger, L. W., The crystal structure and cat-
ion distribution of a grunerite, Mineral. Soc.
Am. Spec. Paper, 2, 95-100, 1969.
Fischer, K., A further refinement of the crystal
structure of cummingtonite, (Mg,Fe)7Sis022
(OH) 2, Am. Mineralogist, 51, 814-818, 1966.
Fiske, R. S., Recognition and significance of
pumice in marine pyroclastic rocks, Geol.
Soc. Am. Bull., 80, 1-8, 1969.
Fleet, M. E., On the lattice parameters and
superstructures of pyrrhotites, Am. Mineralo-
gist, 53, 1846-1855, 1968.
Foerstner, H., Das Gestein der Insel Ferdinan-
dea (1831) und seine Beziehungen zu den
jungsten Laven Pantellerias und des Aetnas,
Tschermaks Mineral. Petrog. Mitt., 5, 388-
396, 1883.
Foshag, W. F., Mineralogical studies on Guate-
malan jade, Smithsonian Inst. Misc. Collec-
tions, 135, no. 5, Publ. 4307, 60 pp., 1957.
Fox, P. J., and B. C. Heezen, Sands of the
Mid-Atlantic Ridge, Science, 149, 1367-1370,
1965.
Fukao, Y., H. Mizutani, and S. Uyeda, Optical
absorption spectra at high temperatures and
radiative thermal conductivity of olivines,
Phys. Earth Planet. Interiors, 1, 57-62, 1968.
Furst, U., and F. Halla, Rontgenographische
Untersuchungen in den Systemen Mn-Bi,
Co-Sb, Ni-Sb, Z. Physik. Chem., Abt. B,
40, 285-307, 1938.
Fyfe, W., The possibility of d-electron cou-
pling in olivine at high pressures, Geochim.
Cosmochim. Acta, 19, 141-143, 1960.
Gaines, R. V., G. Donnay, and M. H. Hey,
Sonoraite, Am. Mineralogist, 53, 1828-1832,
1968.
Gaskell, T. F., Comparisons of Pacific and At-
lantic Ocean floors in relation to ideas of
continental displacement, in Continental
Drift, S. K. Runcorn, ed. Academic Press,
New York, 299-307, 1962.
Gass, I. G., P. G. Harris, and M. W. Holdgate,
Pumice eruption in the area of the South
Sandwich Islands, Geol. Mag., 100, 321-330,
1963.
Gast, P. W., Trace element fractionation and
the origin of tholeiitic and alkaline magma
types, Geochim. Cosmochim. Acta, 32, 1057-
1086, 1968.
Geller, S., and J. L. Durand, Refinement of the
structure of LiMnPOi, Acta Cryst., IS, 325-
331, 1960.
Gheith, M. A., Differential thermal analysis of
certain iron oxides and oxide hydrates, Am.
J. Sci., 250, 677-695, 1952.
Gheith, M. A., Lipscombite, a new synthetic
"iron lazulite," Am. Mineralogist, 88, 612-
628, 1953.
Ghose, S., The crystal structure of a cumming-
tonite, Acta Cryst., 14, 622-627, 1961.
Ghose, S., A scheme of cation distribution in
the amphiboles, Mineral. Mag., 35, 46-54,
1965.
Ghose, S., and E. Hellner, The crystal structure
of a grunerite and observations on the Mg-
Fe distribution, J. Geol, 67, 691-701, 1959.
Gilluly, J., Geological contrasts between con-
tinents and ocean basins, Geol. Soc. Am.
Spec. Paper, 62, 7-18, 1955.
Gossner, B., and H. Strunz, Uber strukturelle
Beziehungen zwischen Phosphaten (Triphy-
lin) und Silicaten (Olivin) und liber die
chemisehe Zusammensetzung von Ardennit,
Z. Krist., 83, 415-421, 1932.
Green, D. H., Origin of basalt magmas, in
Basalts: The Poldervaart Treatise on Rocks
of Basaltic Composition, Vol. 2, H. H. Hess
and A. Poldervaart, ed., Interscience Pub-
lishers, New York, 835-862, 1968.
Greenwood, H. J., The synthesis and stability
of anthophyllite, /. Petrol, 4, 317-351, 1963.
Greig, J. W., and T. F. W. Barth, The system
Na20-Al203-2Si02 (nepheline, carnegieite)-
Na20-Al203-6Si02 (albite), Am. J. Sci., 35 A,
113-125, 1938.
350
CARNEGIE INSTITUTION
Gr0nvold, F., and H. Haraldsen, On the phase
relations of synthetic and natural pyrrhotites
(Fea-xS), Acta Chem. Scand., 6, 1452-1469,
1952.
Haggerty, S. E., The Fe-Ti oxides in Icelandic
basic rocks and their significance in rock
magnetism, unpublished Ph.D. thesis, Uni-
versity of London, 1968.
Hall, H. T., and R. A. Yund, Pyrrhotite phase
relations below 325 °C (abstract), Geol.
Soc. Am. Spec. Paper, 101, 82-83, 1966.
Hamilton, W. C, On the treatment of un-
observed reflexions in the least-squares ad-
justment of structures, Acta Cryst., 8, 185-
186, 1955.
Hamilton, W. C, On the isotropic temperature
factor equivalent to a given anisotropic tem-
perature factor, Acta Cryst., 12, 609-610, 1959.
Hamilton, W. C, Significance tests on the
crystallographic R factor, Acta Cryst., 18,
502-510, 1965.
Hansen, M., and K. Anderko, Constitution of
Binary Alloys, McGraw-Hill Book Co., Inc.,
New York, 2nd ed., 1958.
Haraldsen, H., Uber die Hocktemperaturum-
wandlungen der Eisen (Il)-Sulfidmisch-
kristalle, Z. Anorg. Allgem. Chem., 246, 195-
226, 1941.
Harrison, C. G. A., and M. N. A. Peterson, A
magnetic mineral from the Indian Ocean,
Am. Mineralogist, 50, 704-712, 1965.
Hart, S. R., and L. T. Aldrich, Fractionation of
potassium/rubidium by amphiboles: Impli-
cations regarding mantle composition, Sci-
ence, 155, 325-327, 1967.
Haug, P. A., Applications of mass spectrometry
to organic geochemistry, Ph.D. thesis, Uni-
versity of California, Berkeley, 1963.
Henderson, J. R., Structural and petrographic
relations across the Grenville province-
Southern province boundary, Sudbury dis-
trict, Ontario, unpublished Ph.D. thesis,
McMaster University, October 1967.
Henry, N. F. M., Some data on the iron-rich
hypersthenes, Mineral. Mag., 24, 221-226,
1935.
Hess, H. H., Pyroxenes of common mafic mag-
mas, Part 2, Am. Mineralogist, 26, 573-594,
1941.
Hijikata, K., and K. Yagi, Phase relations of
Ca-Tschermak's molecule at high pressures
and temperatures, J. Fac. Sci. Hokkaido
Univ., Ser. IV, 13, 407-417, 1967.
International Tables of X-Ray Crystallography,
Vol. 3, Kynoch Press, England, 1962.
Irvine, T. N., Chromian spinel, a petrogenetic
indicator, Part 2, Petrologic applications,
Can. J. Earth Sci., 4, 71-103, 1967.
Ito, T., and N. Morimoto, Anthophyllite, in
X-Ray Studies on Polymorphism, Maruzen
Co., Ltd., Tokyo, 42-49, 1950.
James, O. B., in Geological Survey Research
1969, U. S. Geol. Surv. Prof. Paper, in press,
1969.
Jamieson, J. C, and B. Olinger, Pressure in-
homogeneity — a possible source of error in
using internal standards for pressure gages, in
Symposium on the Accurate Characterization
of the High-Pressure Environment, October
1968, U. S. Department of Commerce, Na-
tional Bureau of Standards, 1968.
Johansson, K., Vergleichende Untersuchungen
an Anthophyllits, Grammatit und Cumming-
tonit, Z. Krist., 73, 31-51, 1930.
Johnston, W. G. Q., Geology of the Temiskam-
ing-Grenville contact southeast of Lake
Temagami, northern Ontario, Canada, Bull.
Geol. Soc. Am., 65, 1047-1074, 1954.
Katz, L., and W. N. Lipscomb, The crystal
structure of iron lazulite, a synthetic mineral
related to lazulite, Acta Cryst., 4, 345-348,
1951.
Keen, M. J., Magnetization of sediment cores
from the eastern Atlantic Ocean, Nature,
187, 220-222, 1960.
Kendall, M. G., Rank Correlation Methods,
Griffin & Co., London, 1948.
Kennedy, G. C, and B. E. Nordlie, The genesis
of diamond deposits, Econ. Geol., 63, 495-503,
1968.
Kingston, G. A., The occurrence of platinoids
and bismuthotellurides in the Merensky
reef at Rustenburg platinum mine in the
western Bushveld, Mineral. Mag., 35, 815-834,
1966.
Klein, C, Jr., and D. R. Waldbaum, X-ray
crystallographic properties of the cumming-
tonite-grunerite series, J. Geol, 75, 379-392,
1967.
Kracek, F. C, Phase relations in the system
sulfur-silver and the transitions in silver
sulfide, Trans. Am. Geophys. Union, 27, 364-
374, 1946.
Krogh, T. E., and P. M. Hurley, Strontium iso-
tope variation and whole-rock isochron stud-
ies, Grenville province of Ontario, J. Geo-
Res., 73, 7107-7125, 1968.
Kullerud, G., Sulfide studies, in Researches in
Geochemistry, Vol. 2, P. H. Abelson, ed.,
John Wiley and Sons, Inc., New York, 286-
321, 1967.
GEOPHYSICAL LABOKATORY
351
Kullerud, G., and R. A. Yund, The Ni-S sys-
tem and related minerals, J. Petrol, 8, 126-
175, 1962.
Kuno, H., Study of orthopyroxenes from vol-
canic rocks, Am. Mineralogist, 89, 30-46, 1954.
Kuno, H., Mafic and ultramafic nodules from
Itinome-gata, Japan, in Ultramafic and Re-
lated Rocks, P. J. Wyllie, ed., John Wiley
and Sons, Inc., New York, 337-342, 1967.
Kuno, H., Mafic and ultramafic nodules in ba-
saltic rocks of Hawaii, Geol. Soc. Am. Mem.,
Poldervaart Vol., in press, 1969.
Kushiro, I., Si-Al relation in clinopyroxenes
from igneous rocks, Am. J. Sci., 258, 548-554,
1960.
Kushiro, I., Compositions of magmas formed by
partial zone melting in the earth's upper
mantle, J. Geophys. Res., 78, 619-634, 1968.
Kushiro, I., Clinopyroxene solid solutions
formed by reactions between diopside and
plagioclase at high pressures, Mineral. Soc.
Am. Spec. Paper, 2, 179-191, 1969.
Kushiro, I., and K. Aoki, Origin of some eclog-
ite inclusions in kimberlite, Am. Mineralo-
gist, 58, 1347-1367, 1968.
Kushiro, I., Y. Syono, and S. Akimoto, Effect
of pressure on garnet-pyroxene equilibrium
in the system MgSi03-CaSi03-Al203, Earth
Planet. Sci. Letters, 2, 460-464, 1967a.
Kushiro, I., Y. Syono, and S. Akimoto, Sta-
bility of phlogopite at high pressures and
possible presence of phlogopite in the earth's
upper mantle, Earth Planet. Sci. Letters, 3,
197-203, 19676.
Kushiro, I., Y. Syono, and S. Akimoto, Melt-
ing of a peridotite nodule at high pressures
and high water pressures, J. Geophys. Res.,
73, 6023-6029, 1968.
Kushiro, I., H. S. Yoder, Jr., and M. Nishikawa,
Effect of water on the melting of enstatite,
Geol. Soc. Am. Bull, 79, 1685-1692, 1968.
LaBerge, G. L., Microfossils and Precambrian
iron formations, Geol. Soc. Am. Bull., 78,
331-342, 1967.
LaCroix, A., Les ponces dacitiques flottant sur
l'ocean, entre des Fiji, les Nouvelles-
Hebrides, et la Nouvelle-Caledonie, Compt.
Rend., 208, 853-857, 1939.
Lambert, I. B., and P. J. Wyllie, Stability of
hornblende and a model for the low velocity
zone, Nature, 219, 1240-1241, 1968.
Lausen, C., The occurrence of olivine bombs
near Globe, Arizona, Am. J. Sci., 14, 293-
306, 1927.
Lepp, H., Stages in the oxidation of maghemite,
Am. Mineralogist, 42, 679-681, 1957.
Li, C. T., The crystal structure of LiAlSi206
III (high-quartz solid solution), Z. Krist.,
127, 327-348, 1968.
Linck, G., Ein neuer kristallfuhrender Tektit
von Paucartambo in Peru, Chem. Erde, 2,
157-174, 1926.
Lindberg, M. L., Manganoan lipscombite from
the Sapucaia pegmatite mine, Minas Gerais,
Brazil; first occurrence of lipscombite in
nature, Am. Mineralogist, 47, 353-359, 1962.
Lindemann, W., Beitragzur Struktur des Antho-
phyllits (abstract), Fortschr. Mineral., 4%,
205, 1965.
Lindsley, D. H., and J. L. Munoz, Subsolidus
relations along the join hedenbergite-ferro-
silite, Am. J. Sci., Schairer Vol., 267 A, 295-
324, 1969.
Lippincott, E. R., L. S. Whatley, and H. C.
Duecker, Microtechniques using miniaturized
diamond optics, in Applied Infrared Spec-
troscopy, D. Kendall, ed., Reinhold Book
Corp., New York, 435-461, 1966.
Love, L. G., and G. C. Amstutz, Review of
microscopic pyrite from the Devonian Chat-
tanooga Shale and Rammelsberg Banderz,
Fortschr. Mineral, 43, 273-309, 1966.
Luth, W. C, R. H. Jahns, and O. F. Tuttle, The
granite system at pressures of 4 to 10 kb,
J. Geophys. Res., 69, 759-773, 1964.
Lynn, D. C, and E. Bonatti, Mobility of man-
ganese in diagenesis of deep-sea sediments,
Marine Geol, 3, 457^74, 1965.
Macdonald, G. A., Dissimilarity of continental
and oceanic rock types, J. Petrol, 1, 172-
177, 1960.
MacGregor, I. D., The system MgO-Si02-Ti02
and its bearing on the distribution of Ti02
in basalts, Am. J. Sci., Schairer Vol, 267 A,
342-363, 1969.
Mansuri, Q. A., Intermetallic actions; the sys-
tem thallium-arsenic, J. Inst. Metals, 28,
453-468, 1922.
Mao, H. K., The pressure dependence of the
lattice parameters and volume of ferromag-
nesian spinels and its implications to the
earth's mantle, Ph.D. thesis, University of
Rochester, Rochester, New York, 1967.
Mao, H. K., W. A. Bassett, and T. Takahashi,
Effect of pressure on crystal structure and
lattice parameters of iron up to 300 kb, /.
Appl. Phys., 38, 272-276, 1967.
Mao, H. K, T. Takahashi, W. A. Bassett, J. S.
Weaver, and S. Akimoto, Effect of pressure
and temperature on the molar volumes of
352
CARNEGIE INSTITUTION
wiistite and of three (Fe,Mg)2Si04 spinel
solid solutions, J. Geophys. Res., 74, 1061-
1069, 1969.
Martin, R., and C. de Sitter-Koomans, Pseudo-
tectites from Colombia and Peru, Leidse
Geol. Mededel, 20, 151-164, 1955.
Mason, B., Kaersutite from San Carlos, Arizona,
with comments on the paragenesis of this
mineral, Mineral Mag., 86, 997-1002, 1968.
Medaris, L. G., Jr., Partitioning of Fe++ and
Mg++ between coexisting synthetic olivine
and orthopyroxene, Am. J. Sci., 267, 945-968,
1969.
Melson, W. G., 1967-1968 eruption of Metis
Shoal, Tonga: description and petrology,
Smithsonian Contrib. Earth Sci., in press,
1969.
Melson, W. G., E. Jarosewich, V. T. Bowen,
and G. Thompson, St. Peter and St. Paul
Rocks: A high temperature, mantle-derived
intrusion, Science, 155, 1532-1535, 1967.
Menard, H. W., Marine Geology of the Pacific,
McGraw-Hill Book Co., New York, 1964.
Mero, J. L., Ocean floor manganese nodules,
Econ. Geol, 57, 747-767, 1962.
Meyer, H. 0. A., Chrome pyrope: an inclu-
sion in natural diamond, Nature, 160, 1446-
1447, 1968.
Milton, C, B. Ingram, J. R. Clark, and E. J.
Dwornik, Mckelveyite, a new hydrous so-
dium barium rare-earth uranium carbonate
mineral from the Green River formation,
Wyoming, Am. Mineralogist, 50, 593-312,
1965.
Mrose, M. E., Vernadskite discredited: pseudo-
morphs of antlerite after dolerophanite, Am.
Mineralogist, 46, 146-154, 1961.
Muir, I. D., and C. E. Tilley, Mugearites and
their place in alkali igneous rock series, J.
Geol, 69, 186-203, 1961.
Nicholls, G. D., Geochemical studies in the
ocean as evidence for the composition of
the mantle, in Mantle of the Earth and
Terrestrial Planets, S. K. Runcorn, ed.,
Interscience Publishers, New York, 285-304,
1967.
Nixon, P. H., and G. Hornung, A new chro-
mium garnet end member, knorringite, from
kimberlite, Am. Mineralogist, 53, 1833-
1840, 1968.
Nixon, P. H., O. von Knorring, and J. M.
Rooke, Kimberlites and associated inclusions
of Basutoland: A mineralogical and geo-
chemical study, Am. Mineralogist, 48, 1090-
1132, 1963.
O'Hara, M. J., Primary magmas and the origin
of basalts, Scot. J. Geol, 1, 19-40, 1965.
O'Hara, M. J., Mineral parageneses in ultra-
basic rocks, in Ultramafic and Related Rocks,
P. J. Wyllie, ed., John Wiley and Sons, Inc.,
New York, 393-403, 1967.
O'Hara, M. J., The bearing of phase equilibria
studies in synthetic and natural systems on
the origin and evolution of basic and ultra -
basic rocks, Earth Sci. Rev., 4, 69-133, 1968.
O'Hara, M. J., and G. M. Biggar, Diopside +
spinel equilibria, anorthite and forsterite re-
action relationships in silica-poor liquids
in the system CaO-MgO-AUVSiOa at at-
mospheric pressure and their bearing on the
genesis of melilites and nephelinites, Am. J.
Sci., Schairer Vol., 267 A, 364-390, 1969.
O'Hara, M. J., and E. L. P. Mercy, Petrology
and petrogenesis of some garnetiferous peri-
dotites, Trans. Roy. Soc. Edinburgh, 65, 251-
314, 1963.
O'Hara, M. J., and E. L. P. Mercy, Exception-
ally calcic pyralspite from South African
kyanite eclogite, Nature, 212, 68-69, 1966.
O'Hara, M. J., and H. S. Yoder, Jr., Formation
and fractionation of basic magmas at high
pressures, Scot. J. Geol, 3, 67-117, 1967.
Opdyke, N., B. Glass, J. D. Hays, and J. Fos-
ter, Paleomagnetic study of Antarctic deep-
sea cores, Science, 154, 349-357, 1966.
Osawa, A., and N. Sibata, An X-ray investi-
gation of nickel-antimony alloys, Nippon
Kinzohu Gakkaishi, 4, 362-368, 1940.
Osborn, E. F., The system CaSi03-diopside-
anorthite, Am. J. Sci., 240, 751-788, 1942.
Oxburgh, E. R., Petrological evidence for the
presence of amphibole in the upper mantle
and its petrogenetic and geophysical impli-
cations, Geol. Mag., 101, 1-19, 1964.
Pankey, T., and F. Senftle, Magnetic suscepti-
bility of natural rutile, anatase, and brookite,
Am. Mineralogist, 44, 1307-1309, 1959.
Parks, C. F., A magnetite "flow" in northern
Chile, Econ. Geol, 56, 431-436, 1961.
Pauling, L., The principles determining the
structure of complex ionic crystals, J. Am.
Chem. Soc, 51, 1010-1026, 1929.
Phemister, T. C, The boundary between the
Timiskaming and Grenville subprovinces in
the townships of Neelon, Dryden, Dill, and
Broder, District of Sudbury, Ontario Dept.
Mines Prelim. Rept., 1961-5, 1961.
Phillipi, G. T., On the depth, time and mecha-
nism of petroleum generation, Geochim. Cos-
mochim. Acta, 29, 1021-1049, 1965.
GEOPHYSICAL LABORATORY
353
Philpotts, A. R., Origin of certain iron-titanium
oxide and apatite rocks, Econ. Geol., 62,
303-315, 1967.
Powell, H. E., and L. N. Ballard, Magnetic
susceptibility of 34 manganese-bearing min-
erals, U. S. Bur. Mines Inform. Circ, 8359,
1-10, 1968.
Quirke, T. T., and W. H. Collins, The disap-
pearance of the Huronian, Geol. Surv. Can.
Mem., 160, 1930.
Rabbitt, J. C, A new study of the anthophyllite
series, Am. Mineralogist, 33, 263-323, 1948.
Ramdohr, P., Die Erzmineralien und ihre Ver-
wachsungen, Akademie-Verlag, Berlin, 1950.
Raup, D. M., Crystal orientations in the echi-
noid apical system, J. Paleont., 39, 934-951,
1965.
Raup, D. M., The endoskeleton, in Physiology
of Echinodermata, R. A. Boolootian, ed.,
Interscience Publishers, New York, 379-395,
1966.
Reinders, W., and F. Goudriaan, Die Rostreak-
tionsarbeit bei Kupfer; Gleichgewichte in
System Cu-S-O, Z. Anorg. Chem., 126, 85-
103, 1923.
Richards, A. F., Transpacific distribution of
floating pumice from Isla San Benedicto,
Mexico, Deep-Sea Res., 5, 29-35, 1958.
Richards, A. F., Geology of the Islas Revillagi-
gedo, Mexico, 1, Birth and development of
Volcan Barcena, Isla San Benedicto, Bull.
Volcanol, 22, 73-123, 1959.
Richardson, F. D., and J. H. E. Jeffes, The
thermodynamics of substances of interest in
iron and steel making; III, Sulfides, /. Iron
Steel Inst. (London), 171, 1034-1038, 1952.
Richardson, S. W., P. M. Bell, and M. C. Gil-
bert, Kyanite-sillimanite equilibrium be-
tween 700° and 1500° C, Am. J. Sci., 266, 513-
541, 1968.
Richardson, S. W., M. C. Gilbert, and P. M.
Bell, Experimental determination of kyanite-
andalusite and andalusite-sillimanite equi-
libria; the aluminum silicate triple point,
Am. J. Sci., 267, 259-272, 1969.
Ringwood, A. E., Mineralogy of the mantle, in
Advances in Earth Science, P. M. Hurley, ed.,
M.I.T. Press, Cambridge, Mass., 357-399,
1966.
Ringwood, A. E., The pyroxene-garnet trans-
formation in the earth's mantle, Earth
Planet. Sci. Letters, 2, 255-263, 1967.
Roberts, H. S., Polymorphism in the FeS-S
solid solution, I, Thermal study, /. Am. Chem.
Soc, 57, 1034-1038, 1935.
Robie, R. A., and D. R. Waldbaum, Thermo-
dynamic properties of minerals and related
substances at 298.15°K (25.0°C) and 1
atmosphere (1.013 bars) pressure and at
higher temperatures, U. S. Geol. Surv. Bull.,
1259, 1968.
Roedder, E., Liquid C02 inclusions in olivine-
bearing nodules and phenocrysts from basalts,
Am. Mineralogist, 50, 1746-1782, 1965.
Roedder, E., and D. S. Coombs, Immiscibility
in granitic melts, indicated by fluid inclu-
sions in ejected granitic blocks from Ascen-
sion Island, /. Petrol, 8, 417-451, 1967.
Rogers, D. P., The extrusive iron oxide de-
posits, "El Laco," Chile (abstract), Geologi-
cal Society of America, Program with Ab-
stracts of the 1968 Annual Meetings, Mexico
City, Mexico, 252-253, 1968.
Romano, R., New petrochemical data of vol-
canites from the island of Pantelleria (Chan-
nel of Sicilv), Geol. Rundschau, 57, 773-
783, 1968.
Rooymans, C, and W. Albers, High-pressure
polymorphism of Cr2FeS4 and related com-
pounds, preprint, pp. 63-66, 1967.
Rosenqvist, T., A thermodynamic investiga-
tion of the system silver-silver sulfide, Trans.
Am. Inst. Mining Met. Engrs., 185, 451-460,
1949.
Rosenqvist, T., Magnetic and crystallographic
studies on the higher antimonides of iron,
cobalt, and nickel, Acta Met., 1, 761-763,
1953.
, C. S., M. D. Foster, and A. T. Myers,
Origin of dunites and of olivine-rich inclu-
sions in basaltic rocks, Am. Mineralogist, 39,
693-737, 1954.
Roy, R., A. J. Majumdar, and C. W. Hulbe,
The Ag2S and Ag2Se transitions as geologic
thermometers, Econ. Geol., 54, 1278-1280,
1959.
Roy, S., Mineralogy of the different genetic
types of manganese deposits, Econ. Geol., 63,
760-786, 1968.
Sato, M., and T. L. Wright, Oxygen fugacities
directly measured in magmatic gases, Sci-
ence, 153, 1103-1105, 1966.
Schairer, J. F., Melting relations of the com-
mon rock-forming oxides, J. Am. Ceram.
Soc, 40, 215-235, 1957.
Schairer, J. F., and N. L. Bowen, The system
K20-Al203-Si02, Am. J. Sci., 253, 681-746,
1955.
Schairer, J. F., and N. L. Bowen, The system
Na20-Al203-Si02, Am. J. Sci., 254, 129-195,
1956.
354
CARNEGIE INSTITUTION
Schairer, J. F., and H. S. Yoder, Jr., The nature
of residual liquids from crystallization, with
data on the system nepheline-diopside-silica,
Am. J. Sci., 258A, 273-283, 1960.
Segnit, E. R., The section CaSiOs-MgSiOs-AloOs,
Mineral. Mag., 31, 255-264, 1956.
Shand, S. J., Eruptive Rocks, John Wiley and
Sons, Inc., New York, 1943.
Shankland, T. J., The pressure shift of in-
frared absorption bands in minerals and its
effect on radiative heat transport (abstract),
Trans. Am. Geophys. Union, 50, 357, 1969.
Shannon, R. D., and C. T. Prewitt, Effective
ionic radii in oxides and fluorides, Acta
Cryst., in press, 1969.
Shoemaker, E. M., and E. C. T. Chao, New
evidence for the impact origin of the Ries
Basin, Bavaria, Germany, J. Geophys. Res.,
££,3371-3378,1961.
Sibata, N., Equilibrium diagram of the nickel-
antimony system, Sci. Rept. Tohoku Univ.,
First Ser., 29, 697-727, 1941.
Skinner. B. J., F. R. Boyd, and J. L. England,
A high-pressure polymorph of chalcocite,
Cu2S (abstract), Trans. Am. Geophys. Union,
45, 121-122, 1964.
Skinner, B. J., R. C. Erd, and F. S. Grimaldi,
Greigite, the thio-spinel of iron; a new min-
eral, Am. Mineralogist, Ifi, 543-555, 1964.
Sobolev, N. V., Jr., The xenoliths of eclogites
from the kimberlite pipes of Yakutia as frag-
ments of the upper mantle substance, Intern.
Geol. Congr., 23rd, vol. 1, 155-163, 1968.
Sobolev, N. V., Jr., I. K. Kuznetsova, and N. I.
Zyuzin, The petrology of grospydite xeno-
liths from the Zagadochnaya kimberlite pipe
in Yakutia, J. Petrol, 9, 253-280, 1968.
Sorem, R. K., and D. W. Gunn, Mineralogy of
manganese deposits, Olympic Peninsula,
Washington, Econ. Geol, 62, 22^56, 1967.
Strangway, D. W., R. M. Honea, B. E. Mc-
Mahon, and E. E. Larson, The magnetic
properties of naturally occurring goethite,
Geophys. J., 15, 345-359, 1968.
Sugaki, A., and H. Shima, Synthetic sulfide
minerals (1), Mem. Fac. Eng., Yamaguchi
Univ., 15, 15-31, 1965.
Swift, I. H., and E. T. P. Tyndall, Elasticity
creep of lead single crystals, Phys. Rev., 61,
359-364, 1942.
Takahashi, T., W. A. Bassett, and H. K. Mao,
Isothermal compression of the alloys of iron
up to 300 kb at room temperature: iron-
nickel alloys, J. Geophys. Res., 73, 4717-
4725, 1968.
Takeuchi, Y., The absolute structure of ull-
mannite, NiSbS, Mineral. J. (Sapporo), 2, 90-
102, 1957.
Taylor, L. A., The system Ag-Fe-S: phase
equilibria and geologic applications, Ph.D.
thesis, Lehigh University, 1968.
Thompson, R. N., and W. S. MacKenzie, Feld-
spar-liquid equilibria in peralkaline acid
liquids: an experimental study, Am. J. Sci.,
265, 714-734, 1967.
Tiliey, C. E., The dunite-mylonites of St.
Paul's Rocks (Atlantic), Am. J. Sci., 245,
483-491, 1947.
Tiliey, C. E., and H. F. Harwood, The doler-
ite-chalk contact of Scawt Hill, Co. An-
trim, Mineral. Mag., 22, 439-468, 1931.
Tiliey, C. E., and I. D. Muir, Intermediate
members of the oceanic basalt trachyte asso-
ciation, Geol Foren. Stockholm Forh., 85,
434-443, 1964.
Tokes, L. G., Mass spectrometric fragmenta-
tion mechanisms in the steroid series, Ph.D.
thesis, Stanford University, Palo Alto, 1965.
Towe, K. N., Echinoderm calcite: single crys-
tal or polycrystalline aggregate, Science, 157,
1048-1050, 1967.
Tunell, G., and E. Posnjak, The stability rela-
tionships of goethite and hematite, Econ.
Geol, 26, 337-343, 1931.
Van Schmus, W. R., G. W. Wetherill, and
M. E. Bickford, Rb-Sr age determinations of
the Nipissing diabase, north shore of Lake
Huron, Ontario, Canada, J. Geophys. Res.,
68, 5589-5593, 1963.
Verhoogen, J., Distribution of titanium be-
tween silicates and oxides in igneous rocks,
Am. J. Sci., 260, 211-220, 1962.
Wade, A., and R. T. Prider, The leucite-bear-
ing rocks of the west Kimberley area, West-
ern Australia, Quart. J. Geol. Soc. London, 96,
39-98, 1940.
Wager, L. R., The major element variation of
the layered series of the Skaergaard intru-
sion and a re-estimation of the average com-
position of the hidden layered series and of
the successive residual magmas, /. Petrol, 1,
364-398, 1960.
Warren, B. E., and D. I. Modell, The struc-
ture of anthophyllite H2Mg7(Si03)8, Z. Krist.,
75, 161-178, 1930.
Washington, H. S., The volcanoes and rocks of
Pantelleria, Part II, /. Geol, 21, 683-713, 1913.
Watkins, N. D., and H. D. Goodell, Geomag-
netic polarity change and faunal extinction
in the Southern Ocean, Science, 156, 1083-
1087, 1967.
GEOPHYSICAL LABORATORY
355
Watkins, N. D., and S. E. Haggerty, Primary
oxidation variation and petrogenesis in a
single lava, Contrib. Mineral. Petrol., 15, 251-
271, 1967.
Weir, C. E., A. Van Valkenburg, and E. R.
Lippincott, Optical studies at high pres-
sures using diamond anvils, in Modern
Very High Pressure Techniques, R. H. Wen-
torf, Jr., ed., Butterworths, Washington,
51-69, 1962.
Wheeler, E. P., II, Fayalitic olivine in north-
ern Newfoundland-Labrador, Can. Mineralo-
gist, 8, 339-346, 1965.
White, R. W., Ultramafic inclusions in basaltic
rocks from Hawaii, Contrib. Mineral. Petrol.,
12, 245-314, 1966.
Whittaker, E. J. W., The crystal chemistry of
the amphiboles, Acta Cryst., 13, 291-298,
1960.
Whittaker, E. J. W., The structure of the ortho-
rhombic amphibole, holmquistite, Acta
Cryst., B25, 394-397, 1969.
Williams, A. F., The Genesis of the Diamond,
2 vol., E. Benn Ltd., London, 1932.
Wilson, J. T., Orogenesis as the fundamental
geological process, Trans. Am. Geophys.
Union, 33, 444-449, 1952.
Wilson, R. L., and S. E. Haggerty, Reversals
of the earth's magnetic field, Endeavour, 25,
104-109, 1966.
deWys, E. C, and W. R. Foster, The system
diopside-anorthite-akermanite, Mineral. Mag.,
31, 736-743, 1958.
Yagi, K., and K. Onuma, An experimental
study on the role of titanium in alkalic
basalts in light of the system diopside-aker-
manite-nepheline-CaTiAlaOe, Am. J. Sci.,
Schairer Vol., 261 A, 509-549, 1969.
Yoder, H. S., Jr., The jadeite problem, Am.
J. Sci., 248, 312-334, 1950.
Yoder, H. S., Jr., Calcalkalic andesites: Experi-
mental data bearing on the origin of their
assumed characteristics, in "Proceedings of
the Andesite Conference," A. R. McBirney,
ed., Oregon Dept. Geol. Mineral. Ind. Bull.
65, 77-89, 1969.
Yoder, H. S., Jr., and I. Kushiro, Melting of
a hydrous phase: phlogopite, Am. J. Sci.,
Schairer Vol., 261 A, 558-582, 1969.
Yoder, H. S., Jr., and C. E. Tilley, Origin of
basalt magmas: An experimental study of
natural and synthetic rock systems, J
Petrol, 3, 342-532, 1962.
Yund, R. A., and H. T. Hall, The miscibility
gap between FeS and Fei-sS, Mater. Res.
Bull., 3, 779-784, 1968.
Yund, R. A., and H. T. Hall, Hexagonal and
monoclinic pyrrhotites, Econ. Geol., 64, 420-
423, 1969.
Zachariasen, W. H., The crystal structure of
metaboric acid, Acta Cryst., 16, 385-389,
1963.
Zahner, J. C, and H. G. Drickamer, Effect of
pressure on crystal-field energy and co valency
in octahedral complexes of Ni2+, Co3+, and
Mn2+, J. Chem. Phys., 35, 1483-1490, 1961.
Zemann, J., The crystal chemistry of the tel-
lurium oxide and tellurium oxosalt minerals,
Z. Krist., 121, 319-326, 1968.
Zies, E. G., Chemical analyses of two panteller-
ites, J. Petrol, 1, 304-308, 1960.
Zies, E. G., A titaniferous basalt from the island
of Pantelleria, J. Petrol, 8, 177-180, 1962.
Zies, E. G., A new analysis of cossyrite from
the island of Pantelleria, Am. Mineralogist,
51, 200-205, 1966.
PERSONNEL
Scientific Staff
Director: P. H. Abelson
Emeritus Research Associate: E. G. Zies,
Chemist
Physical Chemists: F. R. Boyd, T. C. Hoer-
ing,1 J. F. Schairer
Penologists: F. Chayes, D. H. Lindsley,2
1 On leave of absence at Space Sciences Lab-
oratory, University of California, Berkeley,
from September 1, 1968.
2 On leave of absence at Division of Geo-
logical Sciences, California Institute of Tech-
nology, from January through June 1969.
H. S. Yoder, Jr.
Geochemists: G. L. Davis, T. E. Krogh, G.
Kullerud
Organic Geochemist: P. E. Hare
Geophysicist : P. M. Bell
Physicist : J. L. England
Crystallographer : Gabrielle Donnay
Fellows: W. B. Bryan, University of Queens-
land, Brisbane, Australia; A. El Goresy,
Max Planck Institut fiir Kernphysik,
Heidelberg, Germany; 3 L. W. Finger,
8 Appointment terminated November 30,
1968, to return to position at Heidelberg.
356
CARNEGIE INSTITUTION
University of Minnesota; 4 M. C. Gilbert,
University of California at Los Angeles; 5
S. E. Haggerty, Imperial College of Sci-
ence and Technology, University of Lon-
don, England; E. Hansen, Yale Univer-
sity; 6 J. E. Kalb, American University; 7
I. Kushiro, University of Tokyo; 8 H. K.
Mao, University of Rochester; 9 H. 0. A.
Meyer, University College, London; S. A.
Morse, Franklin and Marshall College; 10
H. R. Puchelt, University of Tubingen,
Germany; 21 W. H. Scott, Yale Univer-
sity; 12 D. Smith, California Institute of
Technology; 13 L. A. Taylor, Lehigh Uni-
versity.9
Guest Investigators: M. Bird, U. S. Geo-
logical Survey; E. Chao, U. S. Geological
Survey; J. D. H. Donnay, Johns Hopkins
University; K. Fink, University of Maine;
M. C. Gilbert, Virginia Polytechnic In-
stitute; S. Hafner, University of Chicago;
Odette James, U. S. Geological Survey;
K. King, Lamont Geological Observatory;
J. Kutina, Lehigh University (visiting from
Charles University, Prague, Czechoslo-
vakia); W. R. Lees, Texas Technological
College; V. R. Meenakshi, Duke Univer-
sity; G. Moh, University of Heidelberg,
Germany; R. G. Piatt, University of West-
ern Ontario; G. R. Rapp, Jr., University of
Minnesota; Dr. Friedrich Seifert, Bochum
University, Germany; A. Shiny aye v, Soviet
Academy of Sciences, Baikov Institute of
Metallurgy, Moscow; A. C. Turnock, Uni-
versity of Manitoba; D. Veblen, Harvard
University; J. F. Wehmiller, Lamont Geo-
logical Observatory.
Operating and Maintenance Staff
Executive Officer: A. D. Singer
Accountant: C. B. Petry
Editor and Librarian: Dolores M. Thomas
Stenographers : Patricia S. Garrett, Marjorie
E. Imlay
Clerk :TL. J. Lutz
Electronic Technician: C. G. Hadidiacos
Research Assistant: J. F. Kocmaneck, W. D.
Stanbro 14
Chief Mechanician: F. A. Rowe
Instrument Makers: C. A. Batten, L. C.
Garver, W. H. Lyons, G. E. Speicher
Mechanic and Carpenter: E. J. Shipley
Machinists: W. R. Reed, J. R. Thomas
Building Engineer: R. L. Butler,15 H. L.
Moore 16
Mechanic's Helper: M. Ferguson
Janitor: D. B. Patrick, 17 L. B. Patrick18
* Appointment terminated June 30, 1969, to
accept position as Crystallographer on Geo-
physical Laboratory staff from July 1, 1969.
5 Appointment terminated August 31, 1968,
to accept position as Assistant Professor of
Petrology, Virginia Polytechnic Institute,
Blacksburg, Virginia.
6 Appointment terminated December 31,
1968, to accept position with Shell Develop-
ment Company, Houston, Texas.
7 Appointment terminated December 31,
1968.
8 Appointment terminated June 30, 1969, to
return to position at University of Tokyo.
9 Appointment from September 1, 1968.
10 Appointment terminated August 31, 1968,
to return to position at Franklin and Marshall
College.
11 Appointment terminated September 30,
1968, to return to position at University of
Tubingen.
12 Appointment terminated June 30, 1969.
13 Appointment from October 1, 1968.
14 Appointment on a part-time basis from
June 2, 1969.
15 Retired December 31, 1968.
18 Appointment from November 1, 1968.
17 Appointment from July 1 through 3, 1968.
18 Appointment from July 15, 1968.
PLATES
Plate 1. All products from runs at 1225°C and 10 kb. (A) Large forsterite crystal containing
inclusion consisting of glass holding a liquid in which moves a bubble of gas. Free balls of
glass and quench mica also exhibited in photograph. Initial total water content = 23.1 wt % ;
no C02 was present. From products of run interpreted to be from Fo + L + G region. (B)
Several elongated forsterite crystals containing inclusions consisting of glass holding a liquid
bubble. Note large number of free glass balls. Initial H20 content = 65.8 wt % and C02 =
3.4 wt %. From products of run interpreted to be from Fo + Z/ + G region. (C) Left center:
Inclusion in forsterite showing glass holding a crystal (bright spot) and a liquid with a large
gas bubble. Initial H20 content = 15.4 wt % and C02 = 8.4 wt %. From products of run
interpreted to be from Ph -f- Fo + G region. (D) Two forsterite crystals among books of
phlogopite having, respectively, several and no inclusions. Initial H20 content = 5.6 wt %
and C02 = 9.4 wt %. From products of run interpreted to be from Ph + Fo + G region. (E)
Forsterite crystal holding glass inclusion in which are a large faceted phlogopite crystal and
at least two forsterite (?) crystals (bright dots to the immediate right of the phlogopite crystal).
Liquid and vapor bubbles were not discernible. Initial H20 content = 15.4 wt % and C02 =
8.4 wt %. From products of run interpreted to be from Ph -f- Fo + G region. (F) Large
crystal of forsterite containing several complex inclusions. Initial H20 content = 10.0 wt %
and C02= 8.9 wt %. From products of run interpreted to be from Ph -f Fo + G region.
Plate 1
Geophysical Laboratory
iiill
.it:
%
€L.
. ? v
:
i i i i i i
o
fim
10
Plate 2. (A) An aggregate of euhedral crystals of zoned magnetite that show various stages
of oxidation to hematite. Note that certain concentric zones are selectively oxidized, but
that oxidation also takes place along (111) planes. (B) Sharply terminating crystal faces of
hematite, pseudomorphous after magnetite, showing complex radiating, fibrous, and collo-
form overgrowths of goethite and hematite. (C) A new iron-phosphate mineral, Fe^POJa,
showing good polysynthetic twinning. The phase is interstitial to magnetite. Incipient oxida-
tion of magnetite, to maghemite and hematite, is present along grain boundaries and cracks.
(Crossed nicol 10°.) (D) Iron phosphate containing dark, irregular veinlets of oxidized ma-
terial. This phase shows no difference in Fe or P content and is considered to be due to the
oxidation of Fe2+ to Fe3+. The surrounding magnetite is in an advanced stage of oxidation to
hematite.
Plate 2
Geophysical Laboratory
D
100/i.m
Department
of Terrestrial Magnetism
Washington, District of Columbia
Ellis T. Bolton
Director
L. Thomas Aldrich
Associate Director
Carnegie Institution Year Book 68, 1968-1969
Contents
Introduction 363
Astrophysics 364
Optical astronomy 364
Radio astronomy 366
Nuclear physics 370
Atomic physics 374
Biophysics 374
Observed properties of repeated DNA sequences (April 1969) 376
A bovine genome 378
Fractionation of rat repeated sequences according to thermal stability . . . 386
DNA sequences present as multiple copies in E. coli 388
Cyanophyta and their viruses 391
DNA of the defective bacteriophage of E. coli strain 15 397
A new method for DNA purification 400
Brain 402
Geophysics 403
Geochemistry and geochronology 403
Sea floor basalts 403
The Grenville front in the Chibougamau-Surprise Lake area 408
Rb-Sr relationships for igneous rocks of the Corryong Province, Victoria,
Australia 410
Discussion of the use of Rb-Sr isochron regression treatments .... 413
Potassium-rubidium ratio of Red Sea brines 417
Sr-isotopic evidence bearing on the early heterogeneity and continuous dif-
ferentiation of earth's mantle 419
Carbonate contents and Sr87/Sr86 ratios of calcites from Archaean
metavolcanics 420
The initial Sr87/Sr86 ratios of the upper and lower series, Michipicoten
metavolcanics, Ontario, Canada 422
Initial Sr87/Sr86 ratios of regionally sampled metavolcanics from the
Canadian Shield 425
Rb-Sr mantle evolution models 426
The K, Rb, Cs, and Sr geochemistry of Archaean metavolcanics . . . 429
Distribution of potassium in mafic and ultramafic nodules 433
Potassium contents of synthetic pyroxenes at high temperatures and
pressures 439
The occurrence of potassic richterite in a mica nodule from the Wesselton
kimberlite, South Africa 442
Stability of potassic richterite 443
Strontium isotope abundances in layered ultramafic rocks 444
Cosmic-ray research 446
Seismology 448
A sensitive borehole strain-rate meter 448
Time anomalies and structure beneath the Andes 453
Explosion studies in the altiplano 459
Model seismology 462
Change in earthquake spectrum before and after the Matsushiro swarm . 471
Difference in the relationship of magnitude to frequency of occurrence
between aftershocks and foreshocks for an earthquake of magnitude
5.1 in central Japan 475
References cited 482
Bibliography 485
Personnel 487
INTRODUCTION
One of the truly profound sources of
energy in the earth is held within the
strain fields of rock formations at depths
ranging from the surface to several
hundred kilometers. As the strain is re-
leased, physical dislocation within the
rock occurs, often resulting in readily de-
tectable events at the surface — dramati-
cally signified by earthquakes. When
these occur "pent-up aching rivers" pour
forth in a few seconds their energies and
shake the solid ground as though it were
jelly. Occurring in or near the sea, great
waves, tsunamis, may be generated to
smash against shores thousands of miles
from the source. Lakes inland are tilted
and their waters oscillate like those in a
tipped saucer, sloshing from one end to
the other until gravitational influence
quiets them.
Anyone who has ever felt an apprecia-
ble earthquake has experienced deeply
the fearful and mysterious maturation of
his Mother Earth which, for all her nur-
turing, lasting solidity, shudders with un-
certainty as she struggles to form herself
into a space ball of maximum conformity
to the physical laws of the Universe. For
him this once imperturbable foundation
has been shaken and is no longer the
ultimate immutability.
Man has long known of, but until
recently little appreciated, the lessons
potential in an earthquake. Even the
great earthquake of April 18, 1906, along
the San Andreas fault, which effected
large scale change in the visible earth,
not to mention the equally significant
change in human endeavor in California,
went relatively unnoticed after the initial
human shock wore off, except for the con-
tinuing interest of a small band of in-
trepid men, until the Carnegie Institution
of Washington stepped in and bailed out
a laggard local legislature by publishing
the first coherent report of damage, dis-
ruption, and desecration brought upon
the land. This work was completed in
the years 1908 and 1910 as CIW Publica-
tion No. 87.
In this first truly comprehensive at-
tempt to understand earthquake mechan-
ics scientifically, which comprises volume
II, 1910, of CIW Publication 87, The
California Earthquake of April 18, 1906,
one finds on page 31 these words of
Harry Fielding Reid of Johns Hopkins
University: "As strains always precede
the rupture and as the strains are suf-
ficiently great to be easily detected be-
fore the rupture occurs, in order to
foresee tectonic earthquakes it is merely
necessary to devise a method of deter-
mining the existence of the strains . . ."
Wise and prophetic words, these, but
easier said than done in 1910. Now,
sixty years later, Reid's dream may be
on the verge of becoming reality as a re-
sult of the invention of an inexpensive
and extraordinarily sensitive volume
strain rate meter by Dr. I. Selwyn Sacks,
Staff Member of the Department and
Mr. Dale Evertson of the Applied Re-
search Laboratories of the University of
Texas at Austin. This omnidirectional
strain rate meter is concreted into solid
rock in a 150-foot-deep hole on the DTM
grounds and has worked continuously
since its installation in August 1968. The
cost of the installation, including drilling
the hole and the cost of subsidiary re-
cording devices, was a little over $2000.
Its frequency response covers a wide
range of geophysical interests — from
strain changes induced by microseisms
through those caused by microbarometric
pressure influences on the solid rock to
those resulting from the gravitational de-
formation of the earth by the moon.
Distortions as minute as 10~7 microns
(.001 A, or a thousandth the distance be-
tween atoms in an ordinary chemical
bond) are readily detected and strain
363
364
CARNEGIE INSTITUTION
changes of somewhat over 1 part in 1014
can, in principle, be detected. As a prac-
tical matter, for a single instrument,
earth noise of the order of 10~10 domi-
nates the records in the 6-20 second
period range while the earth tide induces
changes of about 4 x 10-8 at Washington's
latitude. The system is many times more
sensitive than the most sensitive strain
meters heretofore available. This new
device bids fair to add much to our
knowledge of the structure of the earth
and the causes of earthquakes. It is de-
scribed in the pages which follow and
some illustrative results are presented.
Of course, many other areas of en-
deavor are described. One will find a
number of fascinating and important new
discoveries in fields as different as astro-
physics and biophysics as well as in the
various aspects of geophysics. Almost
every topic discussed has been under-
taken by the Staff in cooperation with
Fellows in the Department and with
scientists and institutions elsewhere. This
spirit of symbiotic personal working re-
lationships is traditional at DTM, lend-
ing immeasurable support and giving
great strength to the diversity which
we enjoy in our activities.
ASTROPHYSICS
G. E. Assousa, L. Brown, S. D'Odorico, J. W. Erkes, W. K. Ford, Jr., C. Petit jean,
K. C. Turner, M. A. Tuve, and C. M. Varsavsky
The astrophysics program this year
has included observations of the neutral
hydrogen around the Magellanic Clouds,
new observations of the velocities of emis-
sion regions in the Andromeda nebula,
considerable analysis of scattering data
from polarized protons, and foil excita-
tion spectrograms from the Van de Graaff
accelerator. Unfortunately, an intense
fire in the pressure tank of the Van de
Graaff accelerator did sufficient damage
to make the accelerator inoperative for
almost one year. However, the damage
has now been repaired and there is a
backlog of experiments waiting to be per-
formed.
Optical Astronomy
W. K. Ford, Jr., Vera C. Rubin, and
S. D'Odorico
Andromeda nebula. Spectra of 67 emis-
sion regions from 3 to 24 kpc from the
nucleus of M31 have been obtained with
the DTM image tube spectrograph at-
tached to the 72-inch telescope of the
Ohio State and Ohio Wesleyan Observa-
tories at Lowell Observatory, and the
82-inch telescope of Kitt Peak National
Observatory. At a dispersion of 135
A/mm radial velocities, principally from
Ha emission, have been determined with
an accuracy of ± 10 km/sec. No emission
regions have been identified from the
nucleus out to 3 kpc. However, spectro-
grams of the nucleus and the major and
minor axes out to 4 kpc show the [Nil]
A 6583 line in emission against the stellar
continuum, and velocities have been ob-
tained by measuring this line.
From the rotation curve for r < 24 kpc,
the following parameters for a disk model
of M31 are obtained. There is a dense
rapidly rotating nucleus of total mass
M = 5 X 109 9W0 Near r = 2 kpc the density
is very low and the rotational velocities
are very small. In the region 500 pc-
1400 pc, ionized gas is observed moving
out from the nucleus. Beyond r = 4 kpc,
the total mass of the galaxy increases
approximately linearly to about 14 kpc,
and more slowly thereafter. The circular
velocities are nearly constant in this re-
gion. The total mass in the disk of radius
of 24 kpc is 1.85±1011 Tie; one-half of
this mass is located in the disk interior
to r = 9 kpc. In contrast, the neutral
hydrogen mass calculated from 21 cm
DEPARTMENT OF TERRESTRIAL MAGNETISM
365
observations is 6.7xl09 9U?©; one-half of
it is contained in the disk interior to r =
13.4 kpc. There is no significant differ-
ence between the optical and 21-cm
circular velocities for M31. This is seen
in Fig. 1 where the optical observations
and the 21-cm rotation curve from
Burke, Turner, and Tuve (Year Book
63) are superimposed.
There is a remarkable similarity be-
tween the M31 rotation curve and that
adopted by Schmidt (1965) x for our gal-
axy. However, the rotation curve for
M31 has a slightly higher maximum
velocity, and decreases more slowly with
large distance from the nucleus, which
results in a 20% larger mass for M31
than for our galaxy (Burke, Turner,
and Tuve, Year Book 63, p. 341).
Infrared observations: An experi-
mental refrigerated RCA cascaded image
tube with an SI photocathode has been
used in the DTM image tube spectro-
graph to obtain spectra of stars and
galaxies in the region 6800A-11000A.
Much of this observing has been done
with the 36-inch NASA telescope at
Greenbelt, Maryland. Exposures as long
as 7 hours have been necessary. Never-
theless, highly useful infrared spectro-
grams of galaxies NGC 1068, 4151, and
M82 have been obtained ; all show strong
lines of [SIII] A 9069, A 9532 and He I
A 10830. The NASA telescope has also
been used to obtain photographs of M82
and several other galaxies through nar-
row-band interference filters.
Image tubes. Much of the work of the
Carnegie Image Tube Committee has in
the past years been carried out at the
Department of Terrestrial Magnetism.
This activity has included evaluating and
testing experimental image intensifiers,
24
400-
20
16
12
8
8
12
20
300
4? 200-
^ 100-
0-
S 100-
200
300
120 100 80 60 40 20 0 20 40 60
Distance to center (minutes of arc)
80
100
Kpc
1
1
1 1
" T — 1 1
\
i I l I
-
i+
Jk_
-
-
T
-'"^♦TTt-
"~ -
-
-
-
y
♦
Rubin and Ford HH regions
-
Curve: Burke, Turner, and
--*^.
^^
-i*^
Tuve 21-cm data
- sw
1
1
i i
i i i
i
NE
i i i i
-
Fig. 1. Rotational velocities in the plane of M31, as a function of distance from the center.
Black circles are velocities determined from optical spectra of H II regions; the solid line is
rotation curve determined by Burke, Turner, and Tuve from 21-cm radio observations.
366
CARNEGIE INSTITUTION
and more recently procuring, assembling,
and testing a number of image-tube sys-
tems that have been allocated to observa-
tories. The image tube program has been
supported by the National Science Foun-
dation and the Carnegie Institution of
Washington, and we wish to express our
thanks for this continuing support.
Radio Astronomy
J. W. Erkes, K. C. Turner, M. A. Tuve, and
C. M. Varsavsky
It has been a very active year in both
hemispheres for the radio astronomy
group. As in the past two years, the
major emphasis in the northern hemi-
sphere has been on equipment develop-
ment, and in the southern hemisphere on
observations. Dr. Tuve has obtained
many additional records of H-line emis-
sion with the 60-foot radio telescope at
Derwood, Maryland.
We wish to express our thanks to the
Office of Naval Research for the con-
tinuing loan, provided under contract
No. Nonr-3021 (00) , of 38 tons of pig
lead that serves as counterweights for
this instrument.
Equipment
J. W. Erkes and K. C. Turner
The major accomplishment this year
is certainly the completion of the elec-
tronics for the Derwood-Avery Road
interferometer in nearby Maryland. The
entire apparatus has successfully seen
"imitation fringes" from an artificial
radio source. A block diagram of the
system is shown in Fig. 2. Provision has
been made in the front-end switches of
the two telescopes, so that the Avery
Road instrument may be operated either
as an interferometer, or as a continuum
receiver for pointing and calibration
measurements, and the Derwood tele-
scope may be used either as an inter-
ferometer element or in our standard
hydrogen-line spectrometer mode. As of
this writing, the system is awaiting the
installation of the interferometer front-
end package on the Derwood telescope.
Modernization of our H-line spectrom-
eter continues. The latest improvement
is a digital timing system, which will
give increased flexibility in choosing in-
tegration times, and will eliminate a
variation of a few percent in the old
timing system.
Data Analysis
K. C. Turner
All data from the one degree spacing
survey of the region between the two
Magellanic Clouds have been reduced.
Figures 3 and 4 present some results. Fig-
ure 3 is a map of the total neutral hydro-
¥
\ Sky / }
1"°™ 1 |Movable feed |
T, r^n
^V
n
hHf^H
Avery Road
Derwood
10 5^sec
Delay line
Fig. 2. Block diagram of Derwood-Avery Road interferometer system.
-2
-4
i r
i r
t r
t 1 1 r
J L
J L
J L
20 18 16 14
12 10 8 €
X (Degrees of arc )
Fig. 3. Total neutral hydrogen between the Magellanic Clouds.
i 1 r
T r
J 0.1 J
Va> 60 km /sec
Contours are 10 M„/beom area:
J L
J L
J L
J L
20 18
16
12 10 8
X (Degrees of arc)
Fig. 4. High-velocity gas in the Magellanic Cloud system.
368
CAENEGIE INSTITUTION
gen observed, and Fig. 4 shows the distri-
bution of gas moving at high velocities
with respect to the Magellanic Cloud
system. Analysis of the very complex
structures observed here is continuing, in
an effort to understand something of the
history and dynamics of the Magellanic
Cloud system.
A Study of HB 21
J. W. Erkes
Observations of the distribution of
neutral hydrogen around the supernova
remnant HB 21 were begun, using the
60-foot Derwood dish and the 60-channel
H-line spectrometer. This supernova
remnant was chosen for analysis for two
reasons: its large angular size (nearly
two degrees) permitted the neutral hy-
drogen distribution near it to be mapped
in some detail; moreover, continuum ob-
servations show that HB 21 has been
seriously deformed, as if by a strong
interaction with the surrounding inter-
stellar material.
A preliminary contour map showing
the distribution of neutral hydrogen in
the velocity range from 0 to 10 km/sec
can be seen in Fig. 5. The broken line
shows the outermost extent of the super-
nova remnant as seen on high-resolution
continuum radio maps. The neutral hy-
drogen is arranged in a ringlike structure
whose diameter is roughly equal to that
of HB 21. A detailed analysis of these
observations is in progress.
Southern Hemisphere Observations
J. W. Erkes and K. C. Turner
Between October 14 and November 20,
1968, a survey of the Small Magellanic
Cloud was initiated. Observations were
made on a half-degree grid (at one beam-
width intervals). Observations at closer
spacing over the brighter regions were
then undertaken. Figure 6, a map of the
total amount of neutral hydrogen ob-
served, represents a preliminary result.
7.0
6.0 -
5.0 -
4.0-
3.0
92
91
91 89
Galactic longitude
88
Fig. 5. The neutral hydrogen near HB 21, in the velocity range 0-10 km/sec. The contour
interval is 4.56 X 1019 H atoms/cm2. The hatched areas are depressions.
DEPARTMENT OF TERRESTRIAL MAGNETISM
369
4 -
£ 0
o
-2
-4
0.5
o
X (Degrees of arc)
Fig. 6. Total neutral hydrogen near the Small Magellanic Cloud.
Previously published observations of
Hindman and Balnaves 2 at higher
spatial resolution lie approximately
within the 5 X 106 Wo contour. We esti-
mate that about 40% more points will
be necessary to complete the survey. The
Small Magellanic Cloud is of great in-
terest not only because it is one of our
nearest neighbor galaxies, but also be-
cause of its extremely complicated struc-
ture. Double-peaked hydrogen profiles
are the rule in the small cloud, and Hind-
man has suggested that several very
violent explosions took place there in
the past. Whether or not this is the case,
it seems clear that large-scale events
have occurred in the small cloud for
which we have no evidence in our own
galaxy.
Activities of the Instituto Argentino de
Radioastronomia
C. M. Varsavsky
During the period that extends be-
tween July 1, 1968, and June 30, 1969,
370
CARNEGIE INSTITUTION
the Instituto Argentino de Radioastro-
nomia-Carnegie Institution of Washing-
ton Radio Astronomy Station began to
materialize one of its basic aims, namely,
the training of young Latin American
astronomers. Three students completed
their Ph.D. thesis at the station: Dr.
Edemundo da Rocha Vieira, from the
University of Rio Grande do Sul, in
Brazil, and Drs. Silvia Garzoli and Este-
ban Bajaja, from the University of La
Plata, in Argentina. In addition, three
more students are currently writing their
Ph.D. theses at the station: Mr. Wolf-
gang Poppel, of the University of Buenos
Aires, and Miss Dora Goniadzki and Mr.
Raul F. Colomb, of the University of La
Plata. Two more, younger graduate stu-
dents, Mr. Fernandez, from the Uni-
versity of Buenos Aires, and Mr. Quiroga
from the University of La Plata, are be-
ginning to get their first research experi-
ence at the station while completing the
course requirements for their doctoral de-
grees. It is hoped that the flow of gradu-
ate students to the station will continue
at a rate of two to three new students
per year.
The progress of research activities at
the station showed itself at the last meet-
ing of the Argentine Astronomical So-
ciety, held at San Juan on October 10,
11, and 12, 1968. Members of the staff of
IAR presented ten papers, or one-fourth
of the total number of papers presented
at the meeting. This shows that the IAR-
CIW joint project has become a very
significant fraction of the total astro-
nomical effort in Argentina.
Most of the work is concerned with
the correlation of the gaseous and dust
components of interstellar matter and
with the general distribution of hydro-
gen, particularly outside the galactic
plane. It is expected that a brief sum-
mary of three years' work on these prob-
lems will be presented at a symposium
organized by the International Astro-
nomical Union on the "Spiral Structure
of the Galaxy," to be held August 1969.
Construction of the second 100-foot
steerable dish, which will be able to move
on rails up to a distance of 750 meters
from the first dish, has progressed con-
siderably and it is expected that it will
be completed in early 1970. The founda-
tions, the drive, and the dish proper
are practically finished; still to be done
are the rail system, pedestal, and the
final assembly.
Nuclear Physics
L. Brown and C. Petitjean
The force law for strong nuclear inter-
actions, still elusive after half a century
of study, has long been known to be de-
pendent on the relative orientation of the
intrinsic angular momenta (spins) and
orbital angular momentum with one an-
other and with the radius vectors con-
necting the particles. It is the strong
spin-dependence of nuclear forces that
has motivated the work that has com-
bined the Van de Graaff machine of the
Carnegie Institution with the polarized
ion source of the University of Basel.
The nucleon-nucleon force is fairly well
understood phenomenologically at non-
relativistic velocities, but it has proved
difficult to apply this force to describe
even slightly more complicated struc-
tures. Our collaborator, the theorist Dr.
R. G. Seyler, is now attempting to do
just that with our earlier measurements
of proton-deuteron scattering3 {Year
Book 66, pp. 64-66). At low energies,
the nuclear force is given for convenience
in terms of a potential function that now
has four terms for which there is ex-
perimental evidence: a central, a spin-
spin, a tensor, and a spin-orbit term. The
central potential depends on the magni-
tude of the separation of the particles,
which here are the target nucleus and
the incident nucleon; the spin-spin po-
DEPARTMENT OF TERRESTRIAL MAGNETISM
371
tential depends on the relative orienta-
tion of the spins of the particles; the
tensor potential depends on the relative
orientation of the spins and the radius
vector connecting them; the spin-orbit
potential depends on the relative orienta-
tion of the spins and orbital angular
momentum.
If one of the two particles has spin
zero, then only the central and spin-orbit
terms apply. This simplification lay be-
hind our earlier choice of 4He(p,p)4He,
12C(p,p)12C and 160(p,p)160 as reactions
for the study of scattering by polarized
protons. Scattering nucleons from me-
dium and heavy nuclei show strong ef-
fects of the central and spin-orbit terms
but little of the spin-spin or tensor
forces. This has made our analysis of
6Li(p,p)6Li especially appealing, since
the phase shifts derived from the mea-
surements show strong spin-spin effects
that can be examined independently of
the other force terms. Lithium-6 has
spin-one and protons spin-half.
The phase shift analysis of spin-half
particles on spin-one is discussed in Year
Book 66, pp. 64-66, and Year Book 67,
pp. 297-298, and Seyler recently pub-
lished a complete theoretical descrip-
tion.4 For low energies there are thirteen
states with orbital angular momentum 0,
1, and 2. Elastic scattering has a real
phase shift for each state, if inelastic
processes are excluded, and complex
phase shifts, if inelastic processes take
place, e.g., nuclear reactions. Mixing be-
tween states of the same angular mo-
mentum and parity, whereby particles
leave the interaction from a different
state than that by which they entered,
can also occur. Figure 7 shows the thir-
teen S, P, and D states that account for
26 parameters in 6Li(p,p)6Li; one must
add 7 mixing parameters, denoted by
arrows linking states that mix. This large
number of parameters caused us to fear
that the analysis might prove to be "too
easy" or, in other words, that we might
find many sets of parameters from which
good fits to the experimental data could
/z-\
f?
OUAO. "S3 4P.4P34P§ 4Dl\4D34D54D7
2 2 2 2 2\ 2 2 2
DOUB. 2Si
2
i_
t }
P.2P3
2 2
,1 t
Fig. 7. Parameters describing the states for
the elastic scattering of protons by 6Li. For
orbital angular momentum Lax = 2, there are
13 phase shifts associated with the 13 states.
Since inelastic channels are open, the phase
shifts are complex. The 7 arrows represent mix-
ing parameters coupling states of the same Jn.
If mixing parameters are real, a total of 33
parameters is needed to describe 6Li(p,p)6Li
for S-, P-, and D-waves.
be calculated. Nature has proved far
simpler than we expected, for only two
sets of phase shifts were found, and one
of these could be eliminated by straight-
forward reference to another experiment.
Figure 8 shows the phase shifts needed
to describe 6Li(p,p)6Li. Reference to
Fig. 7 discloses that phases for neither
the D states nor the 2P states are re-
quired; with these states absent, at least
insofar as the accuracy of our data al-
lows, no mixing can occur between them
and any other, hence all mixing param-
eters must be zero. This is not the place
for a review of our extended efforts to
find other sets of parameters, which are
described elsewhere in detail.5 Our phases
predict the results for scattering polar-
ized 6Li on hydrogen and may be sub-
jected to further experimental test in
the future, as two sources of polarized
lithium have been recently constructed.6'7
The splitting of the 2S and 4S phases is
noteworthy. This results from a spin-
spin interaction; the quadruplet state,
i.e., the 4S, has parallel spins and the
doublet state has spins which are anti-
parallel. The two phases are not identi-
cal, indicating that the potential for the
two orientations is different. What is
particularly striking and a bit puzzling
is that the doublet phase is larger in
372
CARNEGIE INSTITUTION
60
120
60'
60~ -
1 1 1 1 1 o I
* °-° °
*^ 4P -
•**
4 p
J.x^v3-oV*-^0J0.5/2-
• --© ^ ° o o w
/
• v" -
• *>
.' ox* K3/2
/ /
—
2 /
/
/
—
• / -
/
• ,x
X o
mm
/ x'
• o*
J s
* «'9
••\ ° o 0 *o -*o-0-0x- -xo- °/^
—
•'•>>*•
••*!•••
"8^ 9 ° o
-
^ °^ 0 - o oiv2 -
x^°xo-9-Tr-xo-o
1 1 1 1 1 .1-
0 2 Ep (MeV) 4 6
Fig. 8. Phase shifts as functions of energy. The points show the phase shifts that were obtained
as the best fit to the experimental data. A second, equally good set of phase shifts results if one
interchanges the 4P3/2 and the 4Pi/2 phases. The second set is eliminated by a previous identifica-
tion of the state near 5 MeV as 3/2".
DEPARTMENT OF TERRESTRIAL MAGNETISM
373
absolute value than the quadruplet; this
finding is the opposite of the effect that
we found in D(p,p)D and seems hard
to reconcile with the negligible values for
the 2P phases. Imaginary components of
the phases are not plotted in Fig. 8. They
are not particularly sensitive to the in-
elastic scattering data, which here is the
total cross section for 6Li(p,3He)4He.
The imaginary components were, there-
fore, inaccurately determined in this
analysis, but that inaccuracy is not
strongly reflected in the real components.
The 4P phases have strong splitting
effects attributable to the spin-orbit force
and showing two resonances: a 4P5/2 at
1.8 MeV and a 4P3/2 at 5 MeV. Inci-
dentally, our data and analyses are un-
able to distinguish between a 4P3/2 and a
4P1/2 resonance at 5 MeV, and we ob-
tained a second set of phases that is
identical to the one shown in Fig. 8 ex-
cept that these two phases are inter-
changed. An independent experiment had
previously determined the spin and par-
ity of the 5-MeV state, thereby eliminat-
ing the second set of phases.
Figure 9 presents the polarization in
6Li (p,p) 6Li in the form of a contour map.
The proton laboratory energy is plotted
along the abscissa, the laboratory scat-
tering angle is plotted along the ordinate,
and polarization efficiency is given by the
contours in units of 0.01. Our data are
distributed from 1.2 to 3.2 MeV over
scattering angles from 40° to 135°.
Fig. 9. Polarization contour map of 6Li(p,p)6Li. Analyzing efficiency contours of 0.05 spacing,
which are calculated from the smooth curves of the phase shifts in Fig. 8, are shown plotted on a
coordinate system of lab scattering angle against lab proton energy. Polarization data were
used in the phase shift analysis only up to 3.2 MeV, so this map may be unreliable above that
energy.
374
CARNEGIE INSTITUTION
Atomic Physics
G. E. Assousa, L. Brown, and W. K. Ford, Jr.
We had hoped to present the results
of extensive observations using foil ex-
citation spectroscopy in this report. A
new deflection magnet allowed us to use
beams of much heavier ions than had
been possible with the old magnet. Un-
fortunately, shortly after changing our
experimental program from nuclear
physics to atomic physics a terrible fire
burned the charging belt of the Van de
Graaff and did much damage to equip-
ment located within the pressure tank.
Fortunately, the machine was not seri-
ously damaged structurally and could be
repaired. The repairs cost us dearly in
time and removed the possibility of doing
experimental work until just recently.
The characteristic of our first work
with a beam of sodium ions (Year Book
67, 299-300) was a bewildering number
of lines that could not be matched in
wavelength to classified lines. We went to
lower beam energies with neon, 0.4 MeV
for Ne+, and found that a much more
normal spectrum results. Numerous un-
identified lines appeared as the energy
was raised, but only a few lines remained
at 2.5 MeV. From plates exposed to a
0.4 MeV beam excited by a self-support-
ing carbon foil 10 /xg/cm2 thick, we have
identified several transitions originating
in the 3p levels of Ne I and the 4f levels
of Ne II. There are several measurements
of the lifetimes of the Ne I levels from
other techniques which do not agree well
with one another, but none whatsoever of
Ne II. Our measurements agree suffi-
ciently well with the results of pulsed
electron beam excitation 8 to give us con-
fidence in the technique. An apparent
discrepancy, which troubled us for some
time, was removed when we learned that
a misalignment of the spectrograph slit
caused an attenuation of the observed
intensity of the beam along its length;
data for ascertaining the size of this
effect were present on plates exposed to
the gas-excited beam. We have re-
measured these lifetimes but have not
yet analyzed the plates.
BIOPHYSICS
E. T. Bolton, R. J. Britten, J. A. Chiscon, D. B. Cowie, L. J. Grady, B. H. Hoyer, D. E. Kohne,
N. J. Reed, and R. B. Roberts
Our interests, as in the past, have
centered on the nucleic acids of a variety
of organisms. Of particular interest have
been the large amounts of repeated DNA
sequences present in the genomes of
higher organisms, as well as the non-
repetitious (unique) DNA contained in
all living cells. A portion of this year's
report summarizes the major properties
of the repetitious DNA and serves as a
brief review of five years of intensive
research and as reference material for
our continuing interests in the DNAs
of many types of organisms. In addition
to this summary, the detailed reports of
our year's work with the DNAs of a
variety of organisms are presented.
Studies of the DNA of the calf demon-
strated that while the quantity of repe-
titious DNA is large, it is found in only
a few classes and that these classes con-
tained a high frequency of family mem-
bers which empirically are a collection
of polynucleotide chains found to be
similar in nucleotide sequences. On the
other hand, there is a scarcity of low-
frequency sequences. These results imply
saltatory replication rather than long-
term, gradual processes of growth of
families. Another series of interesting
experiments revealed that there is
marked interspersion of the repeated
nucleotide sequences among the non-
repetitive sequences within the bovine
genome.
Preliminary investigations of the repe-
titious DNA of the rat (and mouse)
indicate that the range of sequence di-
DEPARTMENT OF TERRESTRIAL MAGNETISM
375
vergence in a family appears to be ex-
tremely broad. Furthermore, the DNA
from families having the largest number
of members has the highest thermal
stability, implying lack of evolutionary
divergence.
Among the bacteria and the blue-green
algae the amount of repetitious DNA ap-
pears to be small and the frequency of
family members low. In the bacteria a
portion of the repeated nucleotide se-
quences has been identified with ribo-
somal DNA (Year Book 67, p. 310) . This
year another fraction of the DNA having
multiple copies was observed in E. coli.
The number of copies present is de-
pendent upon the growth state of the
cell. Such a correlation with the phase of
growth suggests that these multiple
copies are extrachromosomal and not un-
der the same control of replication as the
bacterial genome.
The DNA of the blue-green algae, and
of their viruses, has also been studied.
Taxonomic relationships among the blue-
green algae have been investigated by
measuring the amount of genetic ma-
terial held in common among the species
and by the thermal stability of their
DNA-DNA reaction products. Certain
blue-green algae, sensitive to the same
virus, were shown to be closely related;
others of the same family showed evolu-
tionary divergence from these virus-
sensitive algae, and in one case a family
member showed no indication of evolu-
tionary relationship. Furthermore, other
blue-green algae, taxonomically classi-
fied in other orders among the Cya-
nophyta, were shown to contain nucleo-
tide sequences common to the virus-
sensitive strains. It is evident that we
have just begun to decipher in an ob-
jective way a portion of the taxonomic
interrelationship among the blue-green
algae.
One important aspect of these investi-
gations was the discovery of a new blue-
green algae virus which appears to be
lysogenic to one strain, Oscillatoria
prolijera, and is virulent to several other
strains. This is the first example of
lysogeny to be reported outside of the
bacterial systems.
No genetic similarities, as measured
by DNA-DNA interactions, could be
detected between blue-green algae and
E. coli or some of the lysogenic viruses
of these bacteria. These studies will be
continued to search for an evolutionary
pathway coupling the blue-green algae to
other living organisms.
Most of the lysogenic bacteriophages
investigated thus far have been shown to
contain nucleotide sequences in common
(Year Book 67, p. 301). A defective
phage, obtained by inducing strains of
E. coli 15, appears to be an exception.
Studies investigating the nature of the
DNA of this virus, and of the relation-
ship of this viral DNA to that of its
bacterial host (and to nonlysogenic E.
coli strains) have been carried out. Pre-
liminary evidence suggests that the high
degree of reaction observed between the
viral DNA and the DNA of these E. coli
strains occurs because most of the DNA
of these viruses appears to reside in a
limited portion of the E. coli chromo-
somes and this viral DNA is preferen-
tially replicated a large number of times,
and packaged in a viral protein coat.
Finally, a new and very rapid method
for DNA extraction has been developed,
which makes use of hydroxyapatite to
bind native, sheared DNA. While the
method is very convenient, a greater
importance may lie in the potentially
more complete extraction of DNA with
the concomitant reduction in the risk of
missing minor components. DNA pre-
pared by the new method from the
fungus Neurospora shows a component
(25% of the total) which is almost
absent from DNA extracted by standard
methods. This component appears to re-
associate at the same rate as the principal
DNA. It is therefore not primarily re-
peated DNA. The reassociation of
Neurospora DNA measured spectropho-
tometrically exhibits the normal time
course expected for single-copy DNA
376
CARNEGIE INSTITUTION
with a small, rapid initial component.
Due to the presence of relatively large
quantities of mitochondrial DNA it is
not yet certain whether or not Neuro-
spora contains repeated sequences.
Observed Properties of Repeated DNA
Sequences (April 1969)
R. J. Britten
In the four years since the recogni-
tion of repeated sequences in DNA a
large number of observations of their
properties have been made. The general-
ity of their occurrence, their transcrip-
tion to form RNA, and the striking differ-
ences in transcription between different
cell types indicate that repeated se-
quences at present have a major role and
probably have had during much of evolu-
tion. Nevertheless their mode of origin
and function remains unknown. Table 1
lists the major observations that have
been made up to the present about re-
peated sequences. The following com-
ments on the items in the table are in-
tended to be a status report of current
knowledge.
1. Measurements of several kinds (hy-
droxyapatite, optical hypochromicity,
DNA agar) have shown that for the
more than 60 plant and animal species
examined so far a large fraction of the
DNA reassociates much more rapidly
than can be expected from the DNA con-
tent per cell. In bacteria, repetition of
ribosomal cistrons has been observed,
and a number of copies of episomal DNA
are present under certain conditions.
2. The DNA of a number of species
has been separated into repetitive and
nonrepetitive fractions on hydroxyapa-
tite after samples have been incubated
appropriately. These measurements give
the best available estimates of the quan-
tity of repeated sequences and the re-
sults vary from 20% for sea urchin DNA
to at least 80% for salmon and wheat
DNA under a standard criterion of pre-
cision (see 4, below). The boundary be-
tween repeated and nonrepeated se-
quences is somewhat arbitrary. The
amount of repeated DNA measured de-
pends on the length of the fragments as
well as the criterion of precision. Future
observations are likely to increase the
total quantity of repetitive DNA that
can be recognized.
3. The rates of reassociation of various
observed families of repeated sequences
range from 50 times that expected for
single copy DNA in Drosophila to 2,000,-
000 times the single copy rate in guinea
pig (see 7, below).
4. With several of the assay methods
it is possible to measure the thermal
stability of the reassociated DNA. A
wide range of thermal stability is ob-
served for reassociated repeated se-
quences including melting temperatures
TABLE 1. Observed Properties of Repeated DNA Sequences
1. Occurrence Observed in all tested species above the fungi.
2. Quantity From 20% to 80% of the total nuclear DNA.
3. Frequency From 50 to 2,000,000 related sequences per family.
4. Precision All degrees of thermal stability seen in reassociated re-
peated DNA.
5. Arrangement Scattered throughout the length of the genome.
6. Age Several hundred million years up to very recent.
7. Variety Patterns of frequency and precision vary widely even
among vertebrates.
8. Expression RNA complementary to some repeated DNA sequences
has been observed in every cell type examined.
9. Control of Different sets of repeated sequences are transcribed in
expression different tissues and stages of development.
DEPARTMENT OF TERRESTRIAL MAGNETISM
377
as low as 40° below that of perfectly-
matching reassociated DNA. A large
part of the reduction can be attributed
to imperfect matching of the strand pairs
and thus to divergence of some of the
sequences in a family from others in the
same family. A part may also be due to
the short length over which the homology
occurs in certain cases. A correlation
seems to exist between rate of reassocia-
tion and thermal stability (see p. 386 in
this report) indicating that the families
with the highest frequency (largest num-
ber of members) also have the highest
thermal stability and presumably have
originated most recently.
5. Long single strands of higher orga-
nism DNA (~107 daltons) form large
"network" particles when incubated so
that only repeated sequences reassociate.
All but 1-5% of calf DNA is included in
such particles and their formation is
specific; for example, calf and pea DNA
form separate particles when incubated
together. This observation indicates that
almost all fragments of moderately large
size contain somewhere in their length
a segment of repeated sequence. Many
fragments, of course, must contain more
than one. Recent experiments (described
on p. 378 of this report) have shown that
such interspersion occurs on an even finer
scale. Most fragments, about 1.5 million
daltons, appear to contain both repeated
sequences and nonrepeated sequences.
6. Two lines of evidence suggest the
great age of some families of repeated
sequences. One is the great difference in
nucleotide sequence among the members
of some families. The other is the exist-
ence of repeated sequences held in com-
mon between organisms such as fish and
mammals whose common ancestors ex-
isted hundreds of millions of years ago.
There are also families of repeated se-
quences which are not shared between
closely related species such as the mouse
and rat. These must have originated
relatively recently.
7. Each species appears to have a
distinct pattern of precision and fre-
quency of repeated sequences, and the
differences among them are not small.
Calf DNA, for example, has a frequency
spectrum dominated by a 66,000-copy
component making up one-third of the
DNA (described on p. 379 of this report) .
In the human, a component with about
this frequency does occur but it contains
much less DNA, while a moderate
amount of repeated DNA occurs with
about 1000 copies. In the calf no families
have been observed in the range of about
a thousand members. However, a 1000-
member family appears to dominate the
frequency spectrum of Xenopus laevis.
More observations are required for cor-
relations and systematic patterns to be
discerned. Nevertheless, from the pat-
terns of the few species that have been
examined it appears that only a rela-
tively small number of "families" of
repeated sequences are present in indi-
vidual species. It is not known whether
a "family" arises in an event in which a
segment of DNA is multiplied or a series
of events in which shorter segments are
multiplied to an approximately equal
extent.
8 and 9. Except for a few specifically
designed experiments (e.g., Year Book
67, p. 320), all of the large number of
measurements of RNA hybridization to
DNA of higher cells measure only se-
quence homologies of RNA to repeated
sequences of DNA. The results do not
indicate what part of a family of re-
peated sequences has been transcribed.
Measurements of the saturation of DNA
with RNA thus indicate the size of the
families of repeated sequences rather
than the "information content" or se-
quence length of the transcribed RNA.
After this realization, the observations
apparently must be described in new
terms. A role is suggested for repeated
sequences in gene expression, or its con-
trol. For example, more different re-
peated DNA sequences are represented
in RNA that never leaves the nucleus
than in that which reaches the cytoplasm
(mouse "L" cells, rabbit kidney cells and
378
CARNEGIE INSTITUTION
mouse liver cells). During embryonic de-
velopment of the African clawed toad,
Xenopus, the changes which occur in the
populations of RNA molecules are so
great that all of the families of repeated
DNA sequences which are observed to be
transcribed at some stages are apparently
distinct from all of those observed at
other stages of development. It is not
known that any of the transcribed re-
peated sequences are translated to yield
protein.
A Bovine Genome
R. J. Britten and Jean Smith
The general properties of the repeated
sequences of calf DNA have been previ-
ously reported (e.g., Year Book 66, Fig.
43) . The intensive study of the DNA of
this one species continues to be reward-
ing. In the following sections experi-
mental results are described which give
insight into three aspects of the organiza-
tion of this genome. The first aspect is
the scattering of interspersion of the re-
peated sequences throughout the DNA.
The second is a more detailed descrip-
tion of the major classes of repeated
DNA, including the identification of one
class making up about one-third of the
total DNA and present in 66,000
"copies." The third is the apparent ab-
sence of low frequency repetition such as
might be expected if much of the DNA
resulted from "gene amplification" by
means of copying DNA segments.
Interspersion of repeated and nonre-
peated sequences in the bovine genome.
Previous experiments (Year Book 64,
324-327) have indicated that for mam-
malian DNA almost all long fragments
(5-10 million daltons) contain segments
of repeated sequences. Since more than
half of the DNA is made up of nonre-
peated sequences a majority of these
long fragments must also contain non-
repeated sequences as well as repeated
sequences. The results shown in Fig. 10
indicate that this interspersion occurs on
an even finer scale.
In this series of measurements a rela-
S 40-
50k-SHEARED DNA
DOMINATING REACTION-
400 NUCLEOTIDES
LIGHTLY SHEARED TRACER
~ 4,000 NUCLEOTIDES
1.0
Cnt( MOLES
10
SECONDS
Fig. 10. The demonstration of fine-scale intermixing of repeated and nonrepeated sequences
in the calf genome. The upper curve shows the reassociation of calf DNA fragments sheared to
about 400 nucleotides. Incubation at 60°C in 0.12 M PB and hydroxyapatite assay under the
same conditions. The lower curve shows the reassociation of a small quantity of labeled
4000-nucleotide-long fragments with the majority of 400-nucleotide-long fragments. For the upper
curve, data have been included from a number of other measurements (all 50-k sheared) in order
to give a more complete picture of calf DNA reassociation kinetics.
DEPARTMENT OF TERRESTRIAL MAGNETISM
379
tively high concentration of DNA
sheared to short fragments (400 nucleo-
tides long) was mixed with a small
quantity of C14-labeled calf DNA which
had been sheared (blender at 7000 rpm)
to yield fragments 4000 nucleotides long.
This mixture was denatured and samples
were incubated for various times in 0.12
M PB at 60°C* and passed over hy-
droxyapatite. The reassociation of the
small fragments was assayed by the opti-
cal density of the bound DNA, and that
of the longer fragments by the bound
radioactivity.
Since the longer fragments were pres-
ent at a very low concentration, no
measurable amount of pairs was formed
between long fragments. Therefore, in
order for a labeled long fragment to bind,
a complementary strand pair had to be
formed with one of the short unlabeled
fragments. Nevertheless, at all times a
much greater proportion of the long DNA
fragments are bound than of the short
ones.
This result indicates that most of the
4000-nucleotide-long pieces contain non-
repeated as well as repeated DNA. It ap-
pears that at least two-thirds of the
nonrepeated DNA occurs adjacent to re-
peated sequences. In other words, most
stretches of nonrepeating DNA are inter-
rupted at least every 4000 nucleotides by
segments of repeated DNA.
Clearly, a great deal of interspersion
of the different sequences is present in
calf DNA. This test does not go so far
as to demonstrate that all repeated se-
quences are interspersed with the non-
repeated DNA. A minimum of 10-20%
of the repeated DNA scattered rather
evenly throughout the genome would
suffice. This evidence relates mostly to
* PB represents neutral phosphate buffer
made up of equal parts of Na2HP04 and
Na H2HPO4, pH = 6.8. Cot is an acronym for
the product of concentration and time (Mols
nucleotides X seconds per liter) . It is the param-
eter that controls the reassociation of DNA
when the temperature, salt concentration, and
fragment size are defined.
the intermediate rate fraction (66,000
copies) since the more rapidly reassociat-
ing DNA was partly removed from the
long tracer by a preparative hydroxyapa-
tite fractionation.
There are two major alternative ex-
planations for the interspersion, and fu-
ture measurements might make it pos-
sible to decide between them. First, there
could be a functional requirement for
distribution of repeated sequences
throughout the genome. For example, the
repeated sequences might be involved in
the regulation of transcription and ex-
pression of the adjacent regions of the
genome. Second, their interspersion might
simply be a measure of the extent to
which events of translocation have oc-
curred during evolution.
Resolution of the highly repetitive
fractions of bovine DNA. It is difficult to
identify the quantities and rates of re-
association of individual components of
the spectrum of repeated sequences from
a curve such as the upper one in Fig. 10.
However, the DNA can be fractionated
on hydroxyapatite after various degrees
of incubation. Study of the kinetics of
reassociation of individual fractions then
gives a more detailed view of the spec-
trum and may allow identification of
individual components.
Figure 11 shows diagrammatically the
steps of fractionation used in this analy-
sis. Three of the resulting fractions (un-
derlined on Fig. 11) were used for de-
tailed kinetic analysis with hydroxyapa-
tite. The results are shown in Figs. 12,
13, and 14.
Figure 12 shows the results for the
largest of the components, identified as
intermediate on Fig. 11. The curve drawn
on this figure is the time course of an
ideal second-order reassociation reaction
fitted to the data by a least-squares
method. The fit is obviously within error
and there is no sign of heterogeneity in
this component. Seventeen percent of the
DNA does not appear to reassociate and
this is due either to partial degradation
380
CARNEGIE INSTITUTION
100%
C0t = 48
41 %
-j
BOUND
9%
■->- FAST
'58 %
UNBOUND
23%
■-►-SLOW
36%
t
UNIQUE
32%
Cot = 3
----V INTERMEDIATE
UNTESTED
The percentages refer to the
original total DNA.
Fig. 11. Diagram of the steps of fractionation used in the study of the repeated sequences of calf
DNA. The boxes represent incubations and hydroxyapatite fractionations, done at 60°C in
0.12 M PB. The number in each box is the Cot used in the incubation. DNA which is unbound
and thus not reassociated moves to the right, while that which is reassociated moves downward.
Data on the reassociation of the three underlined fractions: "intermediate," "fast" and "slow"
are presented on the succeeding three figures. C14-thymidine labeled, primary culture, calf kidney
DNA prepared by the Marmur method was mixed with DNA extracted from calf brain tissue by
the new MUP method described on p. 400 of this report. In each fractionation step the quantity
of the two DNAs bound was equal within error (= ±3%).
20
uj 40
60
30
100
CALF DNA:
INTERMEDIATE FRACTION
0.0001 0.001 0.01 0.1
C0t(M0LES X SECONDS /LITER)
1.0
10.
Fig. 12. Reassociation of the "intermediate" fraction of calf DNA, measured with hydroxy-
apatite. CM labeled calf DNA was fractionated by partial reassociation and passage over
hydroxyapatite, as shown in Fig. 11. The fraction marked "intermediate" was then denatured and
samples incubated for various times, and passed over hydroxyapatite in 0.12 M PB at 60°C. The
percentage bound to hydroxyapatite is shown on the ordinate and the incubation Cot on a
logarithmic scale on the abscissa. The curve is the time course of an ideal second-order reaction
fitted to the data by a least-squares method using an IBM 1130 computer. RMS error is 1.5%.
DEPARTMENT OF TERRESTRIAL MAGNETISM
0
20
381
uj 40 -
Q.
<
>-
X
o
cc
Q 60
X
o
co 80
<
Q
100
—
1 1
1 1 1 1
-
CALF dna:
-
• — .
-
• *■»
^\ FAST FRACTION
-
-
>\^
-
-
\ #
_
-
t
^"X \
-
COMPONENTS OF Fll
J
[TED CURVE \ >v
\ \
i -~-j. i -— — i
-
i '
0.00001 0.0001 0.001 0.01 0.1
Cot(M0LES X SECONDS /LITER)
1.0
10.
Fig. 13. Reassociation of the "fast" fraction of calf DNA measured with hydroxyapatite. Condi-
tions were as described in caption of Fig. 12, except that two second-order reaction components
were used to derive the upper solid curve. RMS error is 2.2%. The individual components are
shown on the two lower curves. The slower component has the same rate constant within 15%
as the intermediate fraction of Fig. 12. The very fast component which appears to be half reacted
at Cot = 3 X 10"4 is probably a sequence 60 nucleotides long which is repeated 1 million times
in the calf genome. Little is yet known of the fraction which is bound at Cot = 10~5. It may
represent fragments that can form complementary regions by folding back on themselves.
of the DNA during extensive processing
or to imperfect fractionation.
The actual yield of this component is
about 30% of the DNA and it may be
estimated that it amounts to 37% of the
original total DNA. The rate constant
for this component is 60.6 Mx sec/liter,
while that for E. coli under identical con-
ditions is 0.25. The complexity or total
length of the DNA that is repeated
(Year Book 65, p. 89) is therefore about
17,000 nucleotide pairs. Since it makes
up 37% of the DNA there are about
66,000 copies present in the calf genome.
It is puzzling, even shocking, that more
than one-third of the calf genome should
be given over to a population of nucleo-
tide sequences with an apparently single
large frequency of repetition. This frac-
tion after reassociation exhibits the very
broad range of thermal stability often
observed for families of repeated DNA.
It should be noted that while the data
of Fig. 12 do not imply any heterogeneity
in this class of DNA some may never-
theless be present. A limited resolution
of different frequency components is set
simply by the time course of second-
order reactions. Thus, several families of
repeated sequences could be in this frac-
tion, differing from the mean by a factor
of 2 to 4 or even more for potential small
components.
What sort of mechanism could lead to
382
CARNEGIE INSTITUTION
20
40
60
100
-
1
•
1 1
•
1
CALF DNA:
slow fraction
/labeled
1
"
v
"
-
-
-
o
-Q
\»
-
"O— -.,
/
UNFRACTIONATED
■^ \
^ \
N \
\ \
CARRIER
V •
\o
\
\
\
\
>
v \ —
\ \
^ Y
1
1
1 "■---
1.0
10 100 1000 10,000
EQUIVALENT C0t (MOLES X SECONDS/ LITER )
Fig. 14. Reassociation of the "slow" fraction of calf DNA measured with hydroxyapatite.
Conditions were as described in the caption of Fig. 12, except for incubation in 0.6 M PB at 65° C.
A high concentration of unfractionated, unlabeled calf thymus DNA was added to accelerate the
reaction and serve as a reference. The two curves are ideal second-order reactions fitted by a
least-squares method, except the first point in each instance. They are half completed at Cot = 4050
for the upper curve (tracer; RMS = 3.3%) and CV = 4130 for the lower curve (carrier;
RMS = 1.3%). The abscissa is equivalent Cot as denned in the text.
the incorporation into the genome of
66,000 copies of a segment or segments
of DNA? Perhaps a single event was re-
sponsible, in which a length of DNA the
size of the genome of a small virus was
multiplied many times. Later the indi-
vidual copies might have diverged from
each other and fragments have been
scattered throughout the genome by
translocation. Another, but less likely,
possibility is that at various times small
fragments of DNA have been copied. For
reasons of structure or function in each
case about 66,000 copies would have been
incorporated into the genome.
The most rapidly reassociating DNA
of the calf. Measurements have been
made of the reassociation of the 9%
fraction identified on Fig. 11 as "fast."
The results are shown in Fig. 13. There
appear to be three major components
in this fraction. The slowest has a re-
association rate constant about equal to
that of the intermediate component (Fig.
12) . Some of the intermediate component
is expected as a "contaminant" in the
"fast" fraction since it partially reacts
at the C0t (4xl0~3) used in the frac-
tionation.
The faster component shown on Fig.
13 appears to be half reassociated at a
C0t of 3xl0-4. Due to the relatively
small amount of it there is a large po-
tential error in the estimate of its rate
of reaction and its quantity. However,
there is little doubt that it exists. This
component may be an analog of the
mouse "satellite," which consists of a
million copies of a sequence several
hundred nucleotides long. The sequence
DEPARTMENT OF TERRESTRIAL MAGNETISM
383
that has been repeated in the calf is
shorter, perhaps only 60 nucleotides long,
but there are apparently about a million
copies present. This component (or
family of repeated sequences) makes up
only 2 or 3% of a calf DNA but it could
be purified relatively easily. We have not
yet done so and thus do not have mea-
surements of its thermal stability or
composition. It is not known whether it
corresponds to the "dense satellite" that
is observed in CsCl density gradient
analysis of calf DNA.
About 25% of the DNA of the "fast"
fraction is bound at the earliest measure-
ment {C0t = 10-5). It appears that no
collisions are required between DNA
strands, i.e., no reassociation in the usual
sense, is required for the binding of this
fraction to hydroxyapatite. The binding
of this fraction of calf DNA may be
attributed to some specific characteristic
which makes it mimic the behavior of
double-stranded DNA, as far as its bind-
ing to hydroxyapatite. It seems likely
that an unusually high degree of local
complementary pairing can occur among
the bases of individual "single-stranded"
fragments.
The thermal stability and hyper-
chromicity observed when this fraction
is "melted" in the spectrophotometer give
further clues to its nature. The melting
occurs continuously over a broad range
of temperatures from 60 to 90 °C. There-
fore, this fraction probably is not cross-
linked in such a way that native-type
double-stranded secondary structure can
form. On melting, the hyperchromicity is
only about 10% of the optical density in
the denatured state. Thus, perhaps only
half, or less, of the bases are paired.
A large reduction in optical density
(8-10%) is observed when this fraction
is subsequently cooled even at very low
salt concentration (10-3M EDT). This
observation also indicates that collisions
between separate fragments are not
necessary for double-stranded type sec-
ondary structure to be formed in this
fraction.
Possibly these fragments are the result
of nucleotide sequence inversions and
thus contain complementary stretches of
bases which can "fold back" on them-
selves, as suggested by Peter Walker
originally for the mouse satellite as a
whole and later for a small fraction of it.
"Internal" base-pairing within a single
strand could consist of extended regions
of homology which, for example, permit a
"hairpin" to form. Many other patterns
can also be imagined, particularly since
there are only a few facts to go on. The
base sequence could contain a kind of
"intimate self-complementarity" such as
is present in the alternating "dAT" which
makes up 30% of the DNA of some
crabs. The sequences in this fraction of
the calf DNA cannot be quite as simple
as dAT since, in the reassociated state,
this DNA melts over a very broad range
of temperatures. Another possibility is
that there could be local clusters of bases
complementary to clusters elsewhere on
the fragment. The double-stranded re-
gions of sRNA might contain the requi-
site secondary structure for binding to
hydroxyapatite under our conditions.
Thus, the genes for sRNA might appear
in the "foldback" DNA fraction.
DNA with similar characteristics has
been observed in several creatures. The
first demonstration of such a "fold-back"
in mouse DNA was made jointly with
Peter Walker during his visit to this
laboratory in 1966. Only 1% of mouse
DNA is in this form compared to about
3% for calf. The African clawed toad
Xenopus laevis contains about 11%
while human DNA contains about 3%.
In some preparations a certain degree of
instability has been observed. That is,
the yield of this "foldback" fraction falls
during sequential steps of binding to
hydroxyapatite.
All of these estimates have been made
with DNA that had been sheared at
50,000 psi and has an average fragment
size of 400 or 500 nucleotides, single
stranded. One measurement, made with
calf DNA of a larger fragment size, sug-
384
CARNEGIE INSTITUTION
gests that a greater fraction of the DNA
can be bound to hydroxyapatite because
of "foldback." In preparation for the
experiment of Fig. 10, the labeled DNA
that had been sheared at 7000 rpm (frag-
ments about 4000 nucleotide pairs long)
was denatured, rapidly cooled to 60°C
and quickly passed over HAP in 0.12 M
PB. The effective C0t was about 10"4
and 31% of the DNA was bound. A part
of this binding was due to the rapidly
reassociating families of repeated se-
quences, but it is likely that the principal
binding was due to the "foldback." The
implication is, of course, that the "fold-
back" regions are also scattered through-
out the genome and are individually
fairly short, at least in comparison with
the long fragments used in this test. No
significant comment can yet be made on
the mechanism of origin or possible func-
tion of these "foldback" sequences. How-
ever, there is one bit of evidence suggest-
ing that they may be related to the
repetitive DNA. Apparently they occur
with relatively high frequency in mouse
satellite DNA9. About 20% of one of the
complementary strands prepared by
density gradient centrifugation binds to
hydroxyapatite at extremely low C0t.
Limit on low-frequency sequences. The
fraction labeled "slow" on Fig. 11 con-
tains sequences which had not reacted at
C0t = 4:8 but in a second incubation did
reassociate at Co£ = 2000. A large part of
this fraction is made up of nonrepeated
sequences, but in addition there would
be present in this fraction sequences re-
peated at a low frequency in the original
calf DNA if they existed. Their relative
concentration would be increased de-
pending on their frequency of repetition.
By calculation at least, those present in
about 10 copies would be increased four-
fold, while those with greater or less
numbers of copies would be less ampli-
fied.
In order to test sensitively for such
low repetition DNA, an excess of un-
labeled, unfractioned calf DNA was
added to the labeled "slow" fraction.
This added "carrier" DNA had been
sheared in the same way as the labeled
DNA (50,000 psi) so that it would have
the same rate of reassociation. The "car-
rier" DNA was present at a high con-
centration (3 mg/ml) and the salt con-
centration was also raised to 0.6 M PB
so that nonrepeated DNA would reasso-
ciate in a reasonable time (the last point
was taken at 8 days) . This mixture was
denatured and samples were incubated
for various times at 65 °C, diluted to
0.12 M PB and passed over hydroxyapa-
tite at 60 °C. Figure 14 shows the results
of the assay for the binding of both the
labeled "slow" fraction and the carrier
DNA.
The abscissa scale on Fig. 14 intro-
duces a new term, equivalent C0t, which
has become necessary as a result of the
use of high salt concentrations to ac-
celerate reactions of slowly reassociating
DNA. The effect of salt concentration
on the rate of the reaction is now rather
accurately known from the measure-
ments made by Wetmur and Davidson.10
In order to calculate equivalent C0t we
use the empirical formula given in Year
Book 67, which includes the following
term for the variation of rate with mono-
valent cation concentration (k) :
K(.24//c)-42
Unfortunately, in formula 16, pp. 333
and 334, Year Book 67, the upper ex-
ponent was omitted in printing. As this
equation is somewhat inconvenient,
Table 2 was prepared. Using the above
constants, it gives the rate of reassocia-
tion relative to that expected in 0.12 M
PB. Wetmur and Davidson's data, on
which this table is based, was obtained
in each case at the optimum temperature,
about 25 °C below the melting tempera-
ture at the particular salt concentration.
Observed rates will be less at other
temperatures.
There is no evidence from the curves
in Fig. 14 for any low repetition fre-
quency sequences. Clearly no large popu-
DEPARTMENT OF TERRESTRIAL MAGNETISM
385
TABLE 2. Rate of DNA Reassociation * versus Salt Concentration
Monovalent
Relative re-
Monovalent
Relative re-
cation con-
association
PBt
cation con-
association
PB
centration
rate
molarity
centration
rate
molarity
0.015
0.0000
0.01
0.465
3.8841
0.31
0.030
0.0016
0.02
0.480
4.0085
0.32
0.045
0.0133
0.03
0.495
4.1300
0.33
0.060
0.0453
0.04
0.510
42487
0.34
0.075
0.1021
0.05
0.525
4.3646
0.35
0.090
0.1831
0.06
0.540
4.4778
0.36
0.105
0.2858
0.07
0.555
4.5884
0.37
0.120
0.4063
0.08
0.570
4.6964
0.38
0.135
0.5410
0.09
0.585
4.8019
0.39
0.150
0.6867
0.10
0.600
4.9049
0.40
0.165
0.8404
0.11
0.615
5.0056
0.41
0.180
1.0000
0.12
0.630
5.1040
0.42
0.195
1.1633
0.13
0.645
5.2001
0.43
0.210
1.3288
0.14
0.660
52941
0.44
0.225
1.4954
0.15
0.675
5.3860
0.45
0240
1.6619
0.16
0.690
5.4758
0.46
0.255
1.8277
0.17
0.705
5.5636
0.47
0.270
1.9920
0.18
0.720
5.6495
0.48
0285
2.1544
0.19
0.735
5.7335
0.49
0.300
2.3146
0.20
0.750
5.8157
0.50
0.315
2.4722
021
0.825
62009
0.55
0.330
2.6271
0.22
0.900
6.5478
0.60
0.345
2.7791
0.23
0.975
6.8613
0.65
0.360
2.9280
0.24
0.050
7.1457
0.70
0.375
3.0739
0.25
1.125
7.4047
0.75
0.390
3.2167
026
1200
7.6413
0.80
0.405
3.3563
0.27
1.275
7.8582
0.85
0.420
3.4929
0.28
1.350
8.0575
0.90
0.435
3.6263
029
1.425
8.2412
0.95
0.450
3.7567
0.30
1.500
8.4110
1.00
* Calculatic
n based on an en
lpirical formula
(see text) fitted
to the data of
Wetmur and
Davidson.10 At optimum temperature, 25°C below melting temperature,
t Neutral phosphate buffer.
lation of such sequences is present in calf
DNA. What limits can be set from this
experiment? A component present in 10
copies and making up 2% of the original
DNA would make up 8% of a "slow"
fraction. It would very likely be recog-
nizable, but a smaller one might not be.
Suppose, for example, that half of the
slowly reassociating DNA was present in
two copies, the remainder being present
as single copies. In such a case the cal-
culated average rate of reaction of the
labeled "slow" DNA would be greater
than that of the carrier by only 7%,
which would be difficult to distinguish.
The two curves in Fig. 14 show the time
course of ideal second-order reactions
fitted to the data by a least-squares
method. (The earliest point at C0t = 0.8
was not included since some of the very
fast component remains.) There is no
sign of any systematic deviation of the
data points from these curves, and the
RMS errors are 3% for the tracer and
1% for the carrier. Half reaction for
these fitted curves occurs at C0t = 4050
for the tracer and at Co£ = 4130 for the
unfractionated carrier. Therefore, there
is no evidence at a moderate level of
sensitivity for sequences present in a
small number of copies.
This result is of general interest since
there are several lines of theoretical
argument which might suggest the exist-
ence of recognizable quantities of low
frequency repetition. First, it appears
386
CAENEGIE INSTITUTION
that gene duplication has often occurred
during evolution. Even though the result-
ing gene sequences undergo changes of
various sorts, the evidence of sequence
homology remains among the proteins
themselves, as, for example, in the well-
known case of vertebrate hemoglobins.
Second, there may have occurred events
of duplication at other levels of organiza-
tion during the evolution of the ungu-
lates. Specific chromosome duplications
would, under the proper conditions, leave
traces recognizable in this way. Third, it
has recently been proposed that during
the development of an individual many
or most genes are copied a number of
times to form "slave" genes 11* 12. It was
thought that the "slaves" would be the
DNA actually transcribed while "mas-
ter" copies were preserved for hereditary
service in the germinal line of cells with
less risk of damage. Finally, there is di-
rect evidence that certain genes are
"amplified"; that is, a number of copies
are made at given times or in specific
cell types. The best example is the set
of ribosomal genes which not only exist
in many copies in the DNA of every
cell, but are present in even larger
quantities in amphibian eggs and certain
other tissues. The negative evidence pre-
sented above of course does not rule out
such models, since only a few genes might
be amplified in particular tissues.
The failure to observe small numbers
of copies of DNA sequences implies that
repeated sequences originate in events
of large-scale multiplication (saltatory
replications) rather than from many
single duplications spread over a long
period of time. In the latter case one
would expect to observe a continuous
distribution of frequencies, rather than
what is actually observed in calf DNA:
relatively discrete large families with
many members and a paucity or absence
of low-frequency repetition.
Fractionation of Rat Repeated
Sequences According to Thermal
Stability
Nancy Reed
Families of repeated sequences, com-
monly characterized according to their
reassociation rates, may also be described
in terms of the thermal stability of the
reassociated products. Such an approach
can provide a roughly quantitative mea-
sure of the degree of sequence divergence
within a given family. Cross-reaction of
an isolated family with heterologous
DNA, furthermore, might furnish addi-
tional insights into the family's evolu-
tionary history. Results reported here
are preliminary explorations of such
questions, and deal with (1) the proper-
ties of isolated reassociated DNA frac-
tions of varying thermal stability and
(2) relationships among the fractions.
Studies have been performed with
mouse or rat DNA which had been
sheared at 50,000 psi, incubated to C0t =
100 at 50° or 60°C in 0.14 M phosphate
buffer, and applied to hydroxyapatite at
the incubation temperature. Following
elution of the adsorbed DNA at 5°C in-
tervals (Fig. 15), each fraction was re-
incubated at C0t = 10, again at 50° or
60 °C. Reassociated material was then
recovered from hydroxyapatite by elu-
tion at 0.4 M PB, 50°C. Thermal be-
havior of the fractions was similar to
that described by Britten and Kohne for
salmon DNA {Year Book 66). As with
salmon DNA, each fraction exhibits an
optical Tm within a few degrees of its
original HA elution temperature. The
hyperchromicity of a fraction was found
to vary directly with its thermal stabil-
ity: values ranged from about one-third
to more than three-fourths the hyper-
chromicity of native DNA for DNA frac-
tions eluting at 65 °C and at 90 °C, re-
spectively. However, while the fractions
exhibited specificity with respect to Tm
and hyperchromicity, their melting pro-
files, particularly among the low stabil-
DEPARTMENT OF TERRESTRIAL MAGNETISM
387
60
70 80 90
Temperature °C
100
Fig. 15. Thermal elution of the reassociated
repeated sequences of rat DNA. Rat DNA at
400 /tg/ml in 0.14 M PB was heated to 100°C
for 5 minutes, then incubated at 50 °C for 20
hours. About 40% of the DNA subsequently
bound to a hydroxyapatite column at 50°C
in 0.14 M PB. The bound material was eluted
at 5°C intervals.
ity fractions, exhibited considerable
overlap.
Since heterogeneity of a DNA sample
can be revealed in its reassociation pro-
file (see Year Book 65), reassociation
rates of the rat thermal fractions were
determined both optically and by HA
chromatography. Without exception it
was found that the higher the Tm of a
fraction of rat DNA, the higher was its
average reassociation rate. The rat 90 °C
fraction, for example, exhibited 50% re-
association at C0t = 7xl0~3 (HA assay
0.14 M PB) the 65°C fraction reached
50% reassociation at C0t s== 2 X 10_1.
Fractions of intermediate stability re-
vealed intermediate reassociation rates
(see Fig. 16) . Further, it was found that
while each fraction could be character-
ized by a unique reassociation profile, the
profiles in most cases were broader than
expected for a homogeneous sample.
Thus, each fraction appeared to contain
more than one component.
The possibility that there are se-
quences common to several (or many)
of the fractions was investigated through
the use of radioactive rat DNA. A
rat C14 — 90°C fraction, for example,
has been incubated with fiftyfold ex-
cesses of various nonradioactive frac-
tions. Considerable cross-reaction among
the fractions was observed. A majority
of the radioactive 90° or 80 °C fractions,
in fact, was found to be capable of re-
0
-
■ — — — °
A
20
-
x
V 70°. fraction
°40
3
XV
Q
:
90° fraction \
°\
5 60
\ \°
\ \°
80
\x \
^~~
0
100
,
t i
,
,
io-
10."
Equivalent C0t (mole sec/liter)
V
. t \
1 '
"~"r^sT"rvN
B
20
\ \
y-65° fraction
= 40
• \
V
o
"\
V
a 60
0)
80° fractior/V
\ *^*^
80
'X^
inn
•
10"
10'
10'
io-
10
Equivalent Cgt (mole sec/liter)
Fig. 16. Reassociation of thermal fractions of rat DNA. C14-DNA fractions (prepared as
described in text) were incubated in 0.14 M PB at 50°C at varying Cot values. Subsequent binding
of radioactivity to hydroxyapatite (0.14 M PB, 50°C) was measured.
388
CARNEGIE INSTITUTION
association with unlabeled 90°, 80°, 70°,
or 65 °C fractions. From the observed
rates of reaction, it has been possible to
estimate that about two-thirds of the
unlabeled 80 °C fraction and slightly less
than one-third of the unlabeled 65 °C
fraction may be homologous to material
in the C14-90°C fraction.
The presence of more than one com-
ponent in the 65 °C fraction was directly
demonstrated in a slightly different ex-
periment. A C14 — 65 °C fraction was in-
cubated with excess unlabeled 90 °C frac-
tion under conditions sufficient to allow
the reassociation of most of their com-
mon sequences. The remaining unreas-
sociated radioactive material was then
observed to be greatly reduced in its
ability to reassociate with a second
90°C fraction, but still capable of ex-
tensive reaction with a 70°C fraction.
Therefore, at least two classes of se-
quences are indicated in the C14 — 65°C
fraction. The precise number of families
in the rat genome is not yet known, but
these and other preliminary data are
consistent with a low value (less than
10). Several of the families may com-
prise a substantial fraction of the ge-
nome.
To summarize: the repeated sequences
in rat or mouse DNA can be fractionated
according to their thermal stability ; the
fractions exhibit specificity in thermal
behavior and reassociation rate. Cross-
reaction of the fractions, however, re-
veals the presence of sequences common
to many of them and indicates that the
range of sequence divergence within
families may be extremely broad.
DNA Sequences Present as Multiple
Copies in E. coli
J. A. Chiscon and D. E. Kohne
Reports of previous experiments {Year
Book 67, p. 310) describe methods for
the isolation and characterization of bac-
terial rR-cistrons, those nucleotide se-
quences coding for ribosomal RNA.
These experiments also demonstrate that
such cistrons represent small amounts of
repeated nucleotide sequences in the bac-
terial genome. A recent attempt has been
made to explore further the possibility
that additional repetitious DNA does
in fact exist in such prokaryotes as the
bacteria. Experimentation utilizing E.
coli has resulted in the isolation and
purification of a small DNA fraction
which exists as multiple copies within the
bacterial cell. The copy number is de-
pendent upon the growth stage of the
bacterial population.
E. coli BB P32-DNA from stationary
phase cells was isolated, sheared, de-
natured, and allowed to reassociate par-
tially during incubation {Year Book 67,
p. 311). This fraction was recovered
from hydroxyapatite, denatured, allowed
to reassociate partially, and the reacted
fraction again recovered. Conditions for
five such consecutive cycles were chosen
so that, from cycle to cycle, the amount
of nonrepetitive E. coli DNA able to re-
associate would decrease greatly. Re-
peated DNA sequences, however, would
react more rapidly and be conserved in
the reassociated fraction of each cycle.
Table 3 gives both expectations and ob-
served data which, at the conclusion of
the five cycles of purification, show the
percentage of reassociation expected of
nonrepeated E. coli BB P32-DNA to be
0.006%, and the actual percentage of re-
TABLE 3. Reassociation Rate Fractionation
of E. coli DNA
Calculated
Original
P32-DNA
input
expected
P32-DNA
P32-DNA
to be
Cycle
Cot
adsorbed, %
adsorbed, %
1
0.44
14.2
14.5
2
0.44
2.5
2.1
3
0.44
1.3
0.3
4
0.44
0.57
0.044
5
0.44
0.48
0.006
Note: Data showing the fraction of original
input P82-DNA from E. coli BB adsorbing to
hydroxyapatite when reacted with itself, and
the calculated fraction of nonrepetitive DNA
expected to adsorb to hydroxyapatite at the
given Cot values.
DEPARTMENT OF TERRESTRIAL MAGNETISM
389
association obtained, prior to removal of
rR-cistrons and their complementary
strands, to be 0.48%.
Following cycle 5, rR-cistrons were
removed from the recovered DNA by
incubating the solution with a large ali-
quot of R-RNA, Rnasing, passing the
solution through hydroxyapatite to trap
DNA-RNA hybrids, and passing the
nonreassociated DNA over Dowex-50 to
remove basic protein. DNA complemen-
tary to the rR-cistrons was then removed
by incubating the remaining DNA for
a time sufficient for almost complete re-
association {CQt = 0.3) of DNA for which
complementary strands were available.
The reassociated DNA, now amounting
to 0.3% of the bulk E. coli DNA, was
recovered from hydroxyapatite.
Figure 17 illustrates the time course
of reassociation of this final isolated
fraction of P32-DNA. The rapidly re-
associating fraction has a C0t for half
reaction of about 1.8 XlO-2, and the re-
action follows an ideal second-order re-
action curve with reasonable precision.
The Coii/2 suggests a DNA information
content of about 1.8 Xl07 daltons. Fig-
ure 18 shows the reassociation kinetics
of the isolated fraction of P32-DNA and
bulk E. coli DNA isolated separately
from both mid-log and stationary stages
of culture growth. The experimental
points for the bulk DNA from both
stages follow the ideal curve. The iso-
lated P32 fractions, incubated separately
with bulk DNA from each stage of
growth, differ both from the bulk DNA
and each other in time course of reasso-
ciation. The fraction incubated with mid-
log bulk DNA reassociated about two
times faster than the bulk DNA; the
fraction incubated with stationary bulk
DNA reassociated about seven times
faster. The multiple copies, then, may
represent as much as 4-5% of the total
0
0
i l 1
o
1 1
1
0.20
-
-
0.40
-
-
"a
o
|
o
0.60
0.8C
-
-
o
1 !
o
C0t (mole sec/liter)
Fig. 17. The kinetics of reassociation of an isolated fraction of E. coli BB P32-DNA. Each point
represents an aliquot taken from one of two incubation mixtures containing different DNA
concentrations. Following denaturation, the mixtures were incubated for the indicated Cot before
the aliquots were withdrawn, passed through hydroxyapatite, and the front and back peaks
monitored for radioactivity.
390
CARNEGIE INSTITUTION
0.20
0.40
0.60
0.80
1.00
1 1 1 1
I
\ \\
- \\\
-
\ \\
*x XA
\ \\
^A^
-
1 1 1 1
A«L
1
•
— a--
lO-2 I0"1 10° 10'
102
I03
C0t (mole sec/liter)
Fig. 18. The reassociation kinetics of an isolated fraction of E. coli BB P^-DNA incubated
separately with E. coli unlabeled bulk DNA isolated from mid-log and stationary stages of
culture growth. Open circles represent the reassociation of mid-log bulk DNA; open triangles,
stationary bulk DNA. Solid circles represent the reassociation of the small quantities of P32-DNA
incubated with the mid-log bulk DNA (1/1,800). Solid triangles refer to the P32-DNA incubated
with stationary phase bulk DNA. Each point represents an aliquot taken from one of four incuba-
tion mixtures containing different DNA concentrations. Following denaturation, the mixtures were
incubated for the indicated Cot before the aliquots were withdrawn, passed through hydroxy-
apatite, and the front and back peaks measured for optical density and monitored for radioactivity.
DNA of the stationary stage bacterial
cell. Further analysis of the data points
to possible heterogeneity of the isolated
fraction. At mid-log, two components
appear to be represented unequally as a
large fast fraction and a smaller slow
fraction, while in the stationary phase
the two appear to approach equality in
copy number.
The ability of the P32-DNA to hybrid-
ize with a mixture of 16S and 23S
R-RNA subunits was found to be low
(2.7%). In addition, although half of
the cold bulk DNA reassociated in each
of the experiments, the ability of the P32-
DNA to form duplexes with DNA from
salmon (0%), Salmonella typhimurium
(2.0%), Proteus mirabilis (3.5%) and
Enterobacter aerogenes (5.0%) was also
low.
It appears that, in addition to rR-
cistrons, other DNA nucleotide sequences
present as multiple copies within bac-
terial cells can be isolated from those
cells, utilizing the purification methods
outlined above. Differing degrees of
multiplicity during different stages of
culture growth suggest that this DNA is
not a part of the actual bacterial genome,
but is extrachromosomal in nature. The
possibility does exist that selective and
varying amplification of a small fraction
of the genome itself has been detected.
It is known, however, that certain extra-
DEPARTMENT OF TERRESTRIAL MAGNETISM
391
chromosomal elements escape normal
regulation and apparently form multiple
copies each time a bacterial chromosome
is replicated once. In addition, there must
be metabolic restriction of excessive
multiplication of these elements during
growth of the bacterial population. The
probability, then, is great that in this
case it is DNA from extrachromosomal
elements that has been studied. If this is
so, a relatively quick, simple, useful
method is available for isolation and
characterization of episomal and plasmid
DNA.
Cyanophyta and their Viruses
D. B. Cowie and Lillian K. Prager
Blue-green algae and bacteria are clas-
sified in a super-kingdom, the prokary-
otes, characterized as organisms lacking
well-defined nuclei. This distinction rep-
resents a basic difference from higher
cell types, the eukaryotes, in which true
nuclei exist bounded by nuclear en-
velopes. Our studies in this laboratory
of the nucleic acid composition of both
types of cells have shown another sig-
nificant distinction: the DNA of pro-
karyotes is nonrepetitive except for small
amounts of ribosomal or episomal DNAs,
while that of the eukaryotes consists of
large quantities of repeated DNA se-
quences as well as the nonrepetitive
DNA.
The investigation of genetic material
held in common among bacteria and
temperate bacteriophages has provided
some information concerning taxonomic
relationships as well as indicating prob-
able evolutionary patterns among these
organisms. These studies have been en-
larged to include the blue-green algae in
the hope that these organisms may serve
as an experimental system bridging the
apparent evolutionary discontinuity be-
tween the prokaryotic and eukaryotic
types of cells. Unlike the bacteria, the
blue-green algae share the property of an
oxygen- evolving photosynthesis with eu-
karyotic algae and higher plants.
Our first discovery was that the tax-
onomic classification of the blue-green
algae is often confusing and many refer-
ences are obscure or unattainable. As a
guide for experimentation and for discus-
sion, we have selected a classification of
Smith13 shown in Table 4.*
The discovery and isolation by Saffer-
man and Morris 15 of a virus (LPP-1)
capable of lysing certain species of the
three blue-green genera Lyngbya, Plecto-
nema and Phormidium suggested that
these organisms, all having a common
viral host-range specificity, might be
evolutionally related. It is of interest to
note that Lyngbya and Phormidium have
been classified in Suborder 1 as Oscil-
latorineae (Table 4) while Plectonema is
listed in Suborder 2, Family 2 under
Scytonemataceae.
Figure 19 demonstrates that nucleotide
sequence homologies exist among the
three blue-green algae sensitive to the
LPP-1 virus. Radioactive Plectonema
boryanum (597) DNA fragments were re-
acted with Lyngbya (488) and Phormid-
ium (485) DNA embedded in agar. The
degree of reassociation and the thermal
stability of the reaction products were
examined by means of the DNA-DNA-
agar thermal chromatography method.16
Since the blue-green alga Fremyella
diplosiphon (481) had been included by
Smith in the same family as Plectonema
boryanum (597) it was included in these
reaction tests with Plectonema DNA. No
reaction between these two DNAs was
observed, however, indicating that Fre-
myella (481) probably belongs in an-
other family of blue-green algae.
Figure 19 also shows that the thermal
stability of the reaction products formed
between Plectonema (597) DNA frag-
ments and the DNAs of Phormidium
(485) and Lyngbya (488) is almost as
high as that observed when the Plecto-
nema (597) DNA fragments are reacted
*A11 blue-green algae used are from the
Culture Collection of Algae at Indiana Uni-
versity14 unless otherwise identified.
392
CARNEGIE INSTITUTION
TABLE 4. Cyanophyta *
Order 1. CHROOCOCCALES Order 2. CHAMAEDIPHONALES Order 3. OSCILLATORIALES
Family 1. Chroococcaceae
Chroococcus
Gloeocapsa
Synechocystis
Aphanocapsa
Microcystis
Chondrocystis
Eucapsis
Synechococcus
Gloeothece
Chroothece
Bhabdoderma
Bacillosiphon
Dactylococcopsis
Aphanothece
Anacystis nidulans (625)
M erismopedia
Holopedium
C oelosphaerium
M arssoniella
Gomphosphaeria
Glaucocystis nostochinearum (64)
Gloeochaete
Family 2. Entophysalidaceae
Family 1. Pleurocapsaceae
Family 2. Dermocarpaceae
Family 3. Chamaesiphonaceae
Suborder 1. Oscillatorineae
Family 1. Oscillatoriaceae
Oscillatoria prolifera (1270)
Arthrospira
Borzia
Bomeria
Phormidium sp. (485)
Trichodesmium
Spirulina
Lyngbya sp. (488)
Lyngbya sp. (621)
Porphyrosiphon
Symploca
Microcoleus
Hydrocoleum
Schizothrix
Suborder 2. Nostochineae
Family 1. Nostocaceae
Anabaena
Aulosira
Anabaenopsis
Nostoc sp. (588)
Wollea
Aphanizomenon
Cylindrospermum
Nodularia
Family 2. Scytonemataceae
Scytonema
Tolypothrix
Plectonema boryanum
Plectonema boryanum (597)
Diplocolon
Desmonema
Fremyella diplosiphon (481)
Family 3. Stigonemataceae
Family 4. Rivulariaceae
* Condensed from Gilbert M. Smith, The Fresh-Water Algae oj the United States, McGraw-Hill
Book Company, Inc., New York, 1950.
TABLE 5. Reaction between Lyngbya (621)
DNA Fragments and the DNA of Other
Blue-Green Algae
Percentage
radioactivity
Radioactivity
bound relative
DNA in agar bound (c/m)
to control
Lyngbya (621)
6686
100
Phormidium (485)
1510
23
Plectonema (597)
981
15
Oscillatoria (1270)
4163
62
Anacystis (625)
2108
32
Note: Less than 0.01 /ig of Lyngbya (621)
DNA fragments were reacted with DNA-agar
each containing approximately 10 /xg embedded
algal DNA. Fifty-five percent of the Lyngbya
(621) DNA fragments reacted with the Lyngbya
(621) DNA in agar.
with Plectonema (597) DNA-agar. This
result indicates a high degree of precision
of base pairing among the reacting
nucleotide sequences. Table 5 shows that
compared to the reaction of the Plecto-
nema (597) DNA fragments with the
identical DNA in agar, 62% of the
Plectonema (597) fragments reacted
with the Lyngbya (488) and 51% with
the Phormidium (485) DNAs under the
experimental conditions employed (see
legend, Fig. 19).
The LPP-1 virus. The LPP-1 virus,
which is capable of infecting all of the
above blue-green algae except Fremyella
(481) has been isolated and some of the
characteristics of its DNA examined.
DEPARTMENT OF TERRESTRIAL MAGNETISM
393
700
=3
I 600
« 500
<
Q 400
o
^ 300
200
100
Plectonema (597) DNAfroaments
P/ectonemo (597) DNA-agar
Plectonema (597) DNA fragments
Lyngbya (488) DNA-agar
Plectonema (597) DNA fragments
Phormidium (485) D N A - agar
Temperature, °C
Fig. 19. Thermal elution profiles characteristic of the reaction of radioactive Plectonema (597)
DNA fragments with Plectonema (597) DNA-agar (circles and solid lines) ; with Lyngbya (488)
DNA-agar (crosses and broken lines) ; and with Phormidium (485) DNA-agar (solid circles and
solid lines). Two yug of the radioactive fragments were incubated overnight at 60°C with ap-
proximately 10 fig of the algae DNAs embedded in agar. The thermal elutions were carried out in
SSC/30 (SSC is 0.15 M NaCl to 0.015 M Na citrate).
Figure 20 shows the thermal elution pro-
file obtained from studies of the reaction
of LPP-1 DNA fragments with LPP-1
DNA-agar.
When LPP-1 DNA fragments ob-
tained from the infection of Plectonema
(597) are reacted with DNA-agar prep-
arations of Plectonema (597), Phormid-
ium (485), Lyngbya (488), or Fre-
myella (481), no DNA-DNA reactions
are observed. The lower curve shown in
Fig. 20 (solid circles) was obtained from
a study of LPP-1 DNA fragments after
incubation with Lyngbya (488) DNA-
394
CARNEGIE INSTITUTION
12,000
-5 10,000
8000
c
O
-O
«*-
o
>
o
o
'-a
D
6000
4000
2000
LPP-I Virus DNA fragments
LPP-I Virus DNA-agar
LPP-I Virus DNA fragments
Lyngbya DNA-agar
50 60 70 80
Temperature, °C
Fig. 20. Thermal elution profiles obtained from studies of the reaction of three different radio-
active preparations of LPP-1 DNA fragment preparations (circles with solid line; crosses; circles)
with 18 fig of LPP-1 DNA-agar, and with 7 ^g Lyngbya (488) DNA in agar (solid circles). More
than 35% of the LPP-1 DNA fragments reacted with the LPP-1 DNA agar, while less than 1%
reacted with the Lyngbya DNA after overnight incubation at 60°C. Less than 1 /xg of the
labeled LPP-1 DNA fragments were used for each test and the elution was carried out in SSC/30.
agar. Similar results were obtained when
the other blue-green algae DNAs were
tested. These results are in agreement
with those obtained by Luftig and
Haselkorn 17 who measured the degree
of hybridization of RNA synthesized in
vitro on an LPP-1 DNA template with
Plectonema (597) and LPP-1 DNAs; no
hybridization was observed with the
Plectonema (597) DNA and 18% hy-
bridization was obtained with the LPP-1
DNA. Thus this blue-green virus-host
system is similar to that obtained with
virulent, nonlysogenic bacteriophages
and their bacterial hosts {Year Book 67,
p. 309).
Similarly no reaction was observed
when the DNAs of several bacterio-
phages— A, 434 hy, <j> 80 and P22 — were
incubated with LPP-1 DNA. Thus, it ap-
DEPARTMENT OF TERRESTRIAL MAGNETISM
395
pears that genetic similarities do not
exist between these two types of the
prokaryotes tested, the blue-green algae
and the Enterobacteria, and some of
their viruses.
Lysogeny and the blue-green algae.
Several other blue-green algae viruses
have been recently described. SM-1, a
phycovirus isolated by Safferman and his
co-workers,18 which infects unicellular
blue-green algae, appears to be virulent
against Synechococcus elongatus and
Microcystis aeruginosa. Another virulent
virus Gin' isolated by Padan et al.19 and
having numerous similar features to
LPP-1 including the same host-range
sensitivity, appears to be quite similar or
identical to LPP-1.
While culturing various blue-green
algae by aeration in synthetic media, it
was noticed that a culture of Oscillatoria
prolifera (1270) appeared more foamy
than other strains of algae, suggesting
spontaneous lysis of a small portion of
the cells. A liter culture of this blue-green
algae was clarified by low-speed centri-
fugation for 10 minutes and the clear
supernatant recentrifuged (20,000 rpm
for 100 minutes) in a Spinco Model L
ultracentrifuge.
After ultracentrifugation, a small,
crystal-clear pellet was observed. Dr.
Russell L. Steere of the Plant Virology
Laboratory, U. S. Department of Agri-
culture, agreed to make an electron
microscopic examination of an aliquot of
the purified pellet. Particles were seen
strikingly different from the LPP-1 or
the SM-1 blue-green algal virus previ-
ously reported.*
The enthusiasm spontaneously gen-
erated at that time resulted in an agree-
ment to collaborate and to enlarge this
collaboration by the participation of Dr.
*It was at this time, in his laboratory, that
we were first informed by Dr. Steere of the
discovery and characterization of a second blue-
green algal virus, SM-1. (Safferman, Schneider,
Steere, Morris, and Diener.18)
Robert Safferman. f A sample of the
Oscillatoria (1270) virus was given to
Dr. Safferman to test for viral infectivity
among many of the numerous strains
of blue-green algae maintained at his
laboratory. Within a few weeks, Saffer-
man reported that our virus was capable
of infecting three blue-green algae,
Lyngbya (488), Plectonema (597) and
Phormidium (485). All others tested, in-
cluding several species of Oscillatoria,
were immune. In spite of our excitement,
there was the sobering apprehension that
a contamination of LPP-1 might have
crept into the virus sample given to Dr.
Safferman. This fear was allayed when
Safferman further reported that his strain
of Oscillatoria (1270), independently ob-
tained from Indiana University Algae
Culture Collection two years earlier, also
contained virus capable of infecting
Plectonema boryanum (597).
Lysogeny has been known to occur
only among bacteria. Hopefully suspect-
ing that the Oscillatoria virus seen in the
electron microscope might represent the
first known example of lysogeny other
than that among bacteria, an attempt
was made to induce the Oscillatoria algae
with mitomycin C (1 g/ml). The culture
lysed and the supernatant (after removal
of algal cells and cellular debris by low-
speed centrifugation) yielded a clear,
glassy pellet when ultracentrifuged.
At this time we can report that a virus
has been obtained which appears spon-
taneously in cultures of Oscillatoria
prolifera (1270) and has morphological
characteristics markedly different from
LPP-1; it is unable to lyse the Oscilla-
toria blue-green algae, and yet is capable
of infecting and lysing Lyngbya (488),
Plectonema (597) and Phormidium
(485). We are currently attempting to
ascertain whether the Oscillatoria (1270)
virus independently isolated by Dr. Saf-
ferman (1) has the same morphological
f Federal Water Pollution Control Admin-
istration, U. S. Dept. of Interior, Cincinnati,
Ohio.
396
CARNEGIE INSTITUTION
features characteristic of the virus iso-
lated in this laboratory and (2) whether
the virus's DNA shows any homology
with the DNA of the Oscillatoria (1270)
host.
The lysogenic virus obtained from
cultures of Oscillatoria (1270) appar-
ently has the same host range as the
virulent blue-green virus, LPP-1. Studies
were carried out to ascertain whether
the DNA of Oscillatoria (1270) con-
tained nucleotide sequences similar to
the DNA of the three blue-green algae
sensitive to the lysogenic virus.
Table 6 shows the results obtained
where radioactive Lyngbya (621) DNA
fragments were reacted with DNA-agars
of Lyngbya (621), Phormidium (485),
Plectonema (597) and Oscillatoria
(1270). Control DNA-agar containing
the DNA of Anacystis nidulans (625)
was used, as this blue-green alga is clas-
sified by Smith (Table 4) and by others
into an order different from that of the
other four algae used in this experiment.
The results were somewhat unexpected.
The Lyngbya (621) DNA did react with
the DNA of Phormidium (485) and
Plectonema (597) ; however, the reaction
was extremely low considering the reac-
tion observed when Plectonema (597)
fragments were tested against another
strain of Lyngbya (488) DNA-agar
(Fig. 19 and Table 5). In addition to
TABLE 6. Reaction between Plectonema
boryanum (597) DNA and the DNA of
Other Blue-green Algae
Percentage
radioactivity
Radioactivity bound relative
DNA in agar bound (c/m) to control
Plectonema (597)
control 15200 100
Lyngbya (488) 9460 62
Phormidium (485) 7762 51
Fremyella (481) 52 0.6
Note: 2.1 fig Plectonema (597) DNA frag-
ments were reacted with various DNA-agar
preparations each containing approximately
10 fig of embedded algal DNA. Thirty-four %
of the Plectonema (597) DNA fragments re-
acted with the Plectonema (597) DNA in agar.
giving a lower reaction, Lyngbya (621)
differs from Lyngbya (488) in being in-
sensitive to infection by the LPP-1 virus
(3). The suggestion is made that Lyng-
bya (621) is markedly different ge-
netically from the more closely related
group comprising Lyngbya (488), Phor-
midium (485) and Plectonema (597).
The data shown in Fig. 21 support this
conclusion. Thermal chromatograms ob-
tained from studies of the reaction of
Lyngbya (621) DNA fragments with the
DNA of other blue-green algae show that
the reaction products are less thermally
stable than those observed in the previ-
ous experiment (Fig. 19) . A large portion
of the bound radioactive Lyngbya (621)
fragments was eluted at temperatures
much lower than that observed for the
reaction of Lyngbya (621) fragments
with the identical DNA in agar. This
result implies imperfect base pair match-
ing among the reacting nucleotide se-
quences of the heterologous DNAs, and
evolutionary divergence. In part, how-
ever, some of the homologous segments
which elute at lower temperatures also
may reflect portions having a lower GC
content (with almost perfect base pair-
ing) than the overall GC content of
either of the reacting heterologous
DNAs.
Lyngbya (621) showed a high degree
of reaction, however, with Oscillatoria
(1270) and consequently could appro-
priately be classified in Order 3, the
Oscillatoriales (Table 4) .
Surprisingly, the Lyngbya (621) DNA
fragments reacted with the Anacystis
(625) DNA to a greater extent than that
of either the Phormidium (485) or
Plectonema (597) DNAs. Two references
subsequently located indicated that Ana-
cystis nidulans has probably been im-
properly classified as a member of the
Chroococcales. Silva 20 states: "The for-
mation of short but multicellular fila-
ments by the algae extensively cultured
and investigated under the name 'Ana-
cystis nidulans' indicates that this strain
should not be assigned to the Chroococ-
DEPARTMENT OF TERRESTRIAL MAGNETISM
397
400
1 1 1 1 1
Lynqbya (621) DNA fragments /
-
Oscillatoria (1270) DNA- agar */
300
Lvnabva (621) DNA fraqments / \ / 1
-
Plectonema (597) DNA- agar / \ \\ \
200
Lynobyo (62\) DNA fragments / \ 1 x
\r
Anacystis (625) DNA -agar / \ \\\
100
- j/\\'[
X^
/ -
X
f J \ / V / *
a / / V7 V y >
r \ T /x •' \l
i i i i i
/
/
V
30
40
50 60
Temperature, °C
70
Fig. 21. Elution profiles obtained from studies of the reaction of 0.01 ^ttg Lyngbya (621) DNA
fragments with DNA-agars containing approximately 10 fig blue-green algae DNAs. Circles with
solid lines, Oscillatoria (1270) DNA; crosses with broken lines, Plectonema (597) DNA; solid
circles with solid lines, Anacystis (625) DNA. Incubation and elution procedures as in Figs.
19 and 20.
cales. Drouet (personal communication)
has tentatively identified it as Phor-
midium mucicola (Nostocales) ."
Polyphyletic origins for members of
this group are suggested by the results of
Edelman, et al21 who found that six
members of the Order Chroococcales
examined had base compositions varying
from 35 to 71% GC. These authors ob-
served that "the genera placed in this
order are characterized by negative
rather than positive characteristics, and
form the residuum left after exclusion
of the strictly filamentous and regularly
endospore-forming Cyanophyta." Thus,
it appears that the reaction observed be-
tween the Lyngbya (621) DNA and the
Anacystis (625) DNA supports Drouet 's
suggestion22 that this Anacystis might
be identified as Phormidium mucicola
and should therefore not be classified as
a member of Order 1, the Chroococcales,
but probably among the Oscillatoriales.
DNA of the Defective Bacteriophage
of E. coli Strain 15
Leo J. Grady
The existence of common nucleotide
sequences has been observed among the
398
CAKNEGIE INSTITUTION
DNAs of genetically related bacteria and
some of these bacteria and their lysogenic
bacteriophages and finally among the
lysogenic viruses themselves. In the lat-
ter case even bacteriophages which at-
tack different bacterial species, such as a
A and P22, have been shown to contain
homologous DNA sequences (for review
see Year Book 67, p. 301). An exception
among the temperate phages previously
studied is the defective phage carried as
prophage by strain 15 of E. coli which,
while sharing common nucleotide se-
quences with its host, does not react with
any of the other phage DNAs studied.
Four other features distinguishing the 15
phage are: (1) While unable to undergo
a complete cycle of phage replication on
any strain of E. coli yet tested,23'24 the
15 phage can exert a bacteriostatic effect
somewhat reminiscent of that produced
by colicins and T2 or T4 phage "ghosts".
However, unlike colicins which have no
influence on the strain producing them,
the 15 phage only exhibits a bacterio-
static effect against E. coli 15, the same
strain from which it arises25'26. (2) The
15 phage appears to be unrelated sero-
logically to other E. coli bacteriophage
(A. Weisbach, personal communication).
(3) There is too much homology between
the DNA of E. coli and that of the 15
phage to be accounted for, as was done
by Cowie and McCarthy 27 in the case of
A, on the basis of the existence of one
phage genome per host chromosome. (4)
The presence of the 15 phage as prophage
appears to increase resistance of E. coli
15 to ionizing radiation.28 This is con-
trary to the results obtained by Marco-
vich using E. coli K12 (A).29
Several of the characteristics of the
E. coli 15 system are also manifested in
a case of defective lysogeny involving
B. subtilis, namely: (1) B. subtilis is not
normally sensitive to the phage, but un-
cured mutants can be isolated in which
a bacteriostatic effect is produced.30 (2)
An unusually high degree of homology
exists between phage and host DNA.30' 31
(3) The presence of the phage seems to
affect at least one response of B. subtilis
to ionizing radiation.32 In this instance,
part of the explanation appears to be
that no phage DNA is synthesized after
induction and, instead, B. subtilis DNA
is cut into fragments of appropriate
size and incorporated into phage pro-
tein.30' 31' 32 The host DNA contained in
the phages consists of some material syn-
thesized before induction and some made
afterwards.33 There is also evidence sug-
gesting that a limited portion of the B.
subtilis chromosome is preferentially
replicated a great many times.33
The possibility of a similar situation
existing in the E. coli 15 system was
initially investigated by resolving
whether any significant portion of the
DNA incorporated into phages had been
synthesized prior to induction. The thy-
mine-auxotroph E. coli 15 T- was
adapted to growth in a minimal medium
containing D20 and N15H4C1. Once suc-
cessfully adapted, the bacteria were
grown in the presence of thymine-l-14C
to an approximate titer of 3 X 108 cells/ml
and then transferred to a medium con-
taining H20, N14H4C1, thymine-2-14C and
mitomycin C at a concentration of 2
y/ml. Upon completion of lysis, the
phage were isolated and the DNA ex-
tracted. The composition of this DNA
was determined by comparing it with
appropriate heavy or light HMabeled
DNA markers in a CsCl gradient. The
results are shown in Fig. 22. All of the
DNA isolated from the phage banded
with the light marker, indicating that it
had been synthesized in the light medium
after induction. No evidence was found
for either heavy DNA, or for hybrid
DNA of intermediate density. This result
is not in agreement with the situation
existing in B. subtilis and suggests that
there is a difference between the two
systems. It does not, however, rule out
the possibility that some newly synthe-
sized bacterial DNA is incorporated into
phage particles.
A second set of experiments was un-
dertaken to establish the extent of ho-
DEPARTMENT OF TERRESTRIAL MAGNETISM
399
to
I
O
X
3
• Phage DNA
J L
J \wi I iZl^i
2 -
X I
a ^ Light control
« A
2 -
Heavy control
J I I A__L
A*- Phage
V. / V
j&Ai i v+
6
5
4
3
^2
I
10 20 30 40
«— p Fraction number
50
60
-Q
I
o
c
o
u
to
X
Fig. 22. Density in a CsCl gradient of DNA isolated from the defective 15 phage. Phages were
obtained from E. coli 15 T" which had been grown in a minimal medium containing Nib and D20,
and then shifted to a similar medium containing Nu and H20 and the time of induction with
Mitomycin C. Starting from the top, banding patterns are shown for: (1) phage DNA; (2) phage
DNA compared to a light, or normal density control; (3) a comparison of phage DNA with a
heavy marker. Centrifugation was for 72 hours at 30,000 rpm in a SW39L rotor and a Spinco
model L ultracentrifuge.
mology between 15 phage DNA and that
of E. coli strains 15 T", BB, and JG 151.
These strains are, respectively, lysogenic,
nonlysogenic (Year Book 64, p. 340),
and cured.34
The proportion of the phage DNA
homologous to the DNA of each strain
of E. coli was measured by incubating
a small amount of radioactive phage
DNA with a sample of the appropriate
DNA agar. In all three cases, at least
40% of the phage genome was capable
400
CARNEGIE INSTITUTION
of hybridizing with E. coli DNA. No
difference could be detected between
lysogenic and nonlysogenic strains.
Saturation experiments to measure the
amount of E. coli DNA homologous to
the DNA of the phage are currently in
progress. Preliminary results show that a
considerable portion of the bacterial DNA
is capable of hybridizing with the DNA
of the phage and also suggest that a dif-
ference may exist between the nonlyso-
genic strain on the one hand and the
lysogenic and cured strains on the other.
Certain anomalies in the data, however,
demand further work before these results
can be viewed with confidence.
A New Method for DNA Purification
R. J. Britten, M. Pavich, and Jean Smith
Passage of a crude cell lysate through
hydroxyapatite at room temperature in
the presence of 8 M urea and 0.14 M
phosphate buffer (PB) permits the DNA
to be absorbed while most other cell
constituents pass through. The DNA
may be recovered in a high degree of
purity simply by eluting from the hy-
droxyapatite with 0.4 M PB. Table 7
gives a detailed protocol for the method.
Milan Pavich, a summer student, had
made a series of exploratory measure-
ments of the effect of urea and of various
concentrations of PB on the binding of
DNA and RNA to hydroxyapatite. This
work led to a method for the separation
of RNA from DNA. The urea was origi-
nally added as a denaturating agent to
establish a reasonable criterion of pre-
cision for recognization of nucleic acid
strand pairs at room temperature. To
our surprise, experiments showed that
RNA was not bound under these con-
ditions. Therefore, tests were made to
see if DNA could be prepared directly
from tissues by this method. A sample of
calf kidney was ground in a blender in
the presence of sodium lauryl sulfate
(SLS) as a lytic agent and ethylene dia-
mine tetraacetate (EDT) to inhibit
nuclease action. When the mixture was
passed over HAP the RNA did indeed
pass through and a certain fraction of
the protein and other macromolecules
were bound. Very little of these other
cellular constituents are eluted under
the conditions which eluted the DNA
(0.4 M PB, 25 °C) . Tests with C14-valine
labeled mouse "L" cells indicated that
TABLE 7. DNA Extraction Procedure
Lysis (n) Suspend tissue in 8 M urea, 0.24 M PB, 1% SLS, .01 M
EDT(b>
Shear (c) Blender 10-20,000 rpm ; sealed, filled container.
Absorption (d) Pass over hydroxyapatite ; stir to prevent channeling.
Washing Several volumes of MUP: 8 M urea, 0.24 M PB.
Washing Several volumes of .014 M PB to remove urea.
Elution (e) With 0.4 M PB, after a final stir.
(a) For certain tissues a preliminary grinding in the presence of dry ice or
freeze-drying, increases yield by breaking down cell structure. All subsequent
operations at room temperature.
<b> PB is neutral phosphate buffer; SLS is sodium lauryl sulfate; EDT is
ethylene diamine tetraacetate. See footnote in text for an improved buffer.
<c) Frozen tissue lumps may be processed. Run twice for 1 min. Avoid
heating. Other methods such as a fine hypodermic syringe or a pressure
cell could be used.
(<1> Heavy loads of tissue may plug a column. It is possible to use a batch
method in a centrifuge, readjust the elutriant to MUP, absorb on a column
and elute in a relatively small volume, for a two-step purification.
<e) In the batch method the total HAP pellet volume may be taken as
diluent in adjusting the PB to .4 M for elution. A refractometer is con-
venient for adjusting salt concentrations and checking urea removal.
DEPARTMENT OF TERRESTRIAL MAGNETISM
401
less than 1/1000 of the cellular protein
was present in the DNA fraction. The
purity of the DNA has been checked in a
number of cases by "melting" in the
spectrophotometer. Typically, hyper-
chromicities of 25-28% of the optical
density at 98 °C are observed. In com-
parison, DNA of comparable purity (by
hyperchromicity test) prepared by
standard methods requires a lengthy pro-
cedure including successive stages of en-
zyme treatment deproteinization and
precipitation. Urea very likely acts to
denature many proteins, reducing the
danger of enzymatic activity. It may also
disrupt the cell and chromatin structure.
There is preliminary evidence that the
urea reduces the affinity of RNA for the
hydroxyapatite and unexpectedly in-
creases the affinity of native DNA for
the HAP.
The choice of this method * or the
standard method depends on the quan-
tity of tissue available, the quantity of
DNA required, and the fragment size
desired. This method is very convenient
for the preparation of DNA if the quan-
tity of tissue is small or even micro-
* Further development of this method is
likely to occur. At the time this section was
being • written Neltje Van de Velde and Bill
Hoyer tested it on plant materials as described
in Table 7 and failed to recover DNA. How-
ever, two modifications led to a good yield.
Molar sodium perchlorate was added to the
lysing mixture and the lysate was extracted
with an equal volume of chloroform (5%
octanol) centrifuged and the supernatant
passed over hydroxyapatite. Surprisingly, molar
NaClOi does not reduce the binding of DNA
under these conditions. At this moment it ap-
pears advisable to add these two features to
the protocol listed in Table 7, particularly in
difficult cases. In one test, 19 mg of DNA were
recovered on 20 ml of hydroxyapatite from 20 g
of human liver. In this case the DNA was con-
taminated with about 5% RNA and the hy-
droxyapatite capacity was greater than ex-
pected. In another trial Nancy Reed recovered
30 mg of DNA from 20 g of rat liver, using a
30 ml HAP column. No measurable quantity of
RNA was present with the DNA. Batch varia-
tion of the hydroxyapatite is indicated, and it
appears that for critical use tests must be made
on each batch of hydroxyapatite.
scopic, for example, with labeled tissue
culture cells. The avoidance of the
alcohol precipitation steps can increase
the recovery markedly. The MUP
method is limited by the capacity of the
hydroxyapatite to absorb DNA. The
capacity in turn depends on the surface
condition and thus the method of prepar-
ation or source of the hydroxyapatite
crystals. We customarily use a commer-
cial dry form (Bio-Rad HTP) for con-
venience. It is likely that an increase in
capacity could be achieved with finely
ground crystals. Under our conditions,
very large fragment size DNA cannot
be efficiently eluted. Since others have
chromatographed 60 million-dalton DNA
on HAP at room temperature, this is
probably not an insoluble problem.
Nevertheless it is our practice to shear
the tissue lysate in a blender at 10,000
or 20,000 rpm. This, of course, reduces
the DNA fragment size and improves re-
covery. It also is a convenient way to
disperse the tissue. Due to the presence of
the SLS and the released proteins, foam-
ing is severe if air is present during
blending. Therefore, a medium or small
sealable blender vessel is used and it is
filled with lysing solution.
Having a method which did not de-
pend on precipitation, it naturally oc-
curred to us that new minor fractions of
DNA might be recovered which differed
in molecular weight or state from the
principal part of the DNA. We were
nevertheless astonished to find that a
major component of Neurospora DNA
had been effectively discriminated
against in the standard Marmur proce-
dure. Figure 23 shows a melting curve for
DNA extracted by S. Dutta of Howard
University by this method. The low melt-
ing temperature fraction amounts to
about 25% of this DNA. A component
in this melting temperature range is
barely present or absent in DNA pre-
pared by the Marmur method or the
various modifications that have been
used to extract DNA from Neurospora.
It does not show up at all as a low
402
CARNEGIE INSTITUTION
60
100
-
1
• • • •-
•
•
>>
o 80
-
•
£
o
•
-C
o
te so
-
~
Cl
•
>>
JZ
«
£ 40
"
o
o
..-*
S 20
•
o
•
(5
•
•
0
•
•
•
70 80
Temperature, °C
i.o
- .90
-.85
Fig. 23. Neurospora DNA prepared by the MUP method-optical melting curve. Hyphae of
Neurospora crassa strain were freeze dried and suspended in the MUP lysing solution. The DNA
was extracted and purified on hydroxyapatite by the method described in Table 7. The low
melting component is barely observable in samples of DNA prepared by standard methods.
Melting curve done on the Gilford spectrophotometer in 0.12 M PB.
density component in any of the pub-
lished CsCl equilibrium measurements
for Neurospora DNA.
Up to this time DNA has been suc-
cessfully extracted from the following
species: calf, brachiopod, mouse, Neuro-
spora, iguana, human, E. coli, several
kinds of blue-green algae, chicken, Lacto-
bacillus, wheat, king crab, Amphioxus. In
the case of Fremyella it proved neces-
sary to grind the frozen tissue with dry
ice in a blender in order to make the ex-
traction reasonably efficient. The Neuro-
spora DNA was extracted from tissue
that had been freeze-dried. The extrac-
tion failed with Amoeba hystolytica, but
succeeded using a modification much like
the one described in the footnote.
Sensitive tests have been made for
calf and human DNA to assay any dif-
ference in the quantity and pattern of re-
peated sequences between DNAs ex-
tracted by this method and the standard
(modified Marmur) procedure. C14-
adenine HELA cell DNA prepared by
the standard method was mixed with
human liver DNA prepared with this
method. Both DNAs were sheared to
small fragments and the mixture was
denatured and incubated for various
periods in 0.12 M PB at 60°C. The single
strands and reassociated double strands
were separated by hydroxyapatite frac-
tionation and always had equal specific
radioactivity within error. Similar tests
were done with C14-thymidine calf kid-
ney DNA (standard extraction) and calf
brain DNA extracted with the new
method.
Brain
R. B. Roberts
The Biophysics Section continues to
maintain its interest in the mechanisms
of the brain and particularly in the bio-
chemical basis of long-term memory.
This is achieved for the most part by
continuing our collaboration with Drs.
Louis B. Flexner and Josefa B. Flexner
of the University of Pennsylvania. Dur-
ing the past year they have demonstrated
the long persistence of peptidyl puro-
mycin in the brain after injections of
puromycin sufficient to block memory.
Experimental work here has been sharply
curtailed after the departure of Dr.
DEPARTMENT OF TERRESTRIAL MAGNETISM
403
Adrian Rake. We maintain close con-
tact with his experimental program now
carried on at Pennsylvania State Uni-
versity. Our present activity is focused
on exploring the possibility that puro-
mycin acts by blocking receptor sites
for norepinephrine or epinephrine in the
central nervous system.
GEOPHYSICS
8. E. Forbush, S. R. Hart, I. S. Sacks, 7. S. Steinhart, L. T. Aldrich, M. A. Tuve, C. Brooks,
D. E. James, A. J. Erlank, A. T. Linde, G. Saa, S. Suyehiro, M. Casaverde, R. Salgueiro,
P. Aparicio, A. Rodriguez, D. Simoni, L. Tamayo, A. A. Giesecke, Jr., E. Deza, J. Frez,
E. Kausel, E. Gajardo, F. Volponi, J. Mendiguren, R. Cabre, L. Fernandez,
S. del Pozo, and J. Santa Cruz
In seismology this year the Andean
plateau has received special attention.
Both in obtaining new measurements of
its seismic properties and in interpreting
the old measurements, we have sought to
describe with increasing depth and pre-
cision the physical properties of this un-
usual part of the earth's crust. These
properties must be satisfied by any model
describing the process of continent for-
mation. Attempts to examine the process
itself were made in the Canadian shield
where isotope studies of ancient volcanic
rocks have placed bounds on any model
which describes the chemical association
of rubidium and strontium in the earth.
Another tool for studying the process, the
bore-hole strainmeter, has been tested
and perfected. The simplicity and sen-
sitivity of this device give promise of
increased availability both of strain
measurements in earthquake regions and
measurements of long-period (1 hour or
more) variations in the strain field due
to distant seismic events. These are
among the reports which follow.
GEOCHEMISTRY AND GEOCHRONOLOGY
S. R. Hart, T. E. Krogh, G. L. Davis, L. T. Aldrich, C. Brooks, and A. J. Erlank
Sea Floor Basalts
S. R. Hart
The hypothesis of sea-floor spreading
calls for the formation of an igneous crust
on the oceanic ridges and rises, followed
by lateral spreading and reassimilation
of the crust into the mantle along the
oceanic trenches. Dredging in the deep
oceans has provided many samples of
the upper oceanic crust; this material
with few exceptions appears to be a
tholeiitic or high-alumina basalt char-
acterized by unusually low (<0.5%)
potassium content. Unlike continental or
oceanic island basalts of similar composi-
tion, however, the dredge basalts are gen-
erally depleted in the large oxyphile trace
elements such as U, Th, Rb, Cs, and Ba,
and show high ratios of K/Rb, K/Cs and
Sr/Ba.
Considering the uniqueness in the trace
element composition of these submarine
basalts and the hostile nature of the en-
vironment in which the rocks must be
preserved, we have investigated the pos-
sible role of sea water alteration in pro-
ducing the anomalous trace element
characteristics. It has been noted that
the basalts tend to become increasingly
altered with distance from the median
valley (zone of origin) and that truly
fresh material is unusual beyond some
tens of kilometers from the median
valley. In part this effect is due to aging
in the sea water environment; in part it
may be due to variable degrees of burial
metamorphism, since the basalts which
occur on the flanks of the ridges may
only be exposed by fault uplift. Material
ranging from fresh glassy basalts from
the East Pacific Rise to relatively al-
tered basalts dredged at 7-km depth in
404
CARNEGIE INSTITUTION
the Puerto Rico Trench were obtained
through the cooperation of A. E. J. Engel,
Scripps Institution of Oceanography;
A. J. Nalwalk, University of Connecti-
cut; M. N. Bass, University of Cali-
fornia; and W. G. Melson, Smithsonian
Institution.
Since alteration of these basalts com-
monly proceeds inward from the surfaces
of pillows, joint blocks and flows, the
first test was to analyze the fresh interior
and compare it with the more altered
exterior or margin. We have done this for
the elements K, Rb, Cs, and Sr. We found
that for Sr the differences between in-
terior and margins are relatively slight
(maximum of 20%), whereas for the
alkalies the differences are veiy large.
In most samples the alteration causes an
enrichment of the alkalies; for several
altered basalt glasses the K and Rb were
depleted. For the six samples which
showed enrichments during alteration,
the average increase was a factor of
two for potassium, a factor of five for
rubidium, and a factor of twenty for
cesium. The results are shown in Fig. 24
in terms of K/Cs and K/Rb ratios as a
function of potassium content. In all
cases, the alteration drastically lowers
the K/Rb and K/Cs ratios; the trends
of the "alteration" lines joining the in-
terior-exterior pairs are generally simi-
lar, and of negative slope.
To explain these results in terms of
the simplest possible model, we propose
that the first effect of sea water altera-
tion will be to produce secondary min-
erals such as chlorites, zeolites, and clay
minerals. Then these minerals, in par-
ticular the clay minerals, will undergo
base-exchange reactions with sea water
and will absorb the alkalies preferen-
tially as a function of ionic radius. The
altered basalts might then be viewed as
mixtures of "fresh" basalt and a fully
exchanged clay mineral. If we assume a
typical clay mineral of 1.5% K, K/Rb =
250, K/Cs = 4700, then the mixing line
for fresh basalt plus clay mineral is as
shown in Fig. 24 (dashed line). Such a
mixing line provides an adequate repre-
sentation of the alteration data.
The alkalies in sea water are strongly
depleted in the heavier elements, as evi-
denced for example from calculated resi-
dence times: Na — 120 m.y.; K — 10 m.y.;
Rb — 4 m.y.; Cs — 0.6 m.y. This observed
depletion is in fact rather complementary
to the order of enrichment in these al-
tered basalts, with cesium being selec-
tively enriched during alteration. The
relative depletion of Cs and Rb in the
oceans is usually related to adsorption on
detrital clay minerals eroded from the
continents. Recently, however, it has
been suggested (Kharkar, Turekian, and
Bertine, 1968) 35 that these clays may
be saturated prior to reaching the ocean
and may act as a source of cations, not as
a sink. If this concept is true, sea-floor
basalt would provide a very convenient
sink for many elements, as it is being
continuously generated on the ridges and
is immediately accessible to sea water for
alteration. Control of sea-water chem-
istry by interaction with silicates has
received much attention recently. There
is the possibility that the sea-floor basalts
may play a very active role in this
process.
The difficulties for K-Ar dating of
dredge basalts which these alteration
studies imply are rather serious. Obvi-
ously the demonstration of a consistent
aging pattern for sea-floor basalts is an
important aspect of the hypothesis of
sea-floor spreading. However, as the
basalts move away from the ridges and
age, they also become increasingly al-
tered and more difficult to date. From our
results we would predict generally that
alteration will lead to increased potas-
sium contents which, coupled with pos-
sible loss of argon during the alteration
process, will lead to K-Ar ages that are
erroneously young. Separation of un-
altered minerals from these rocks for
dating is possible in many cases — for
example, plagioclase is quite common as
phenocrysts or xenocrysts. However, the
potassium levels in these minerals are
DEPARTMENT OF TERRESTRIAL MAGNETISM
2
405
200 500 1000
2000
5000
4000
'1 1 1 1 ' 1 | 1
^ H, sea water
25X ^
2^)23
1 1
1 1 1 1
I i_
2000
-
-
ce
* 1000
800
600
-
■
3 A
Legend x.
"Fresh" interiors
15
II A
aX \
< 20I2^
8
-
400
-
1-
"Altered" margins
-
▲
Fresh whole rocks
SX\ 14
A
Plagioclase from sample 7
~~^- ---.
__ __
o
Metabasalt and leached
200
residues
1 1 1 1 l 1 l l 1
! 1
1 1 ! 1
I 1
100
200
500
1000
2000
5000
Potassium content, ppm
Fig. 24. K/Rb and K/Cs versus K content of midoceanic ridge submarine basalts. The lines
connect analyses of interior and marginal portions of corresponding samples. Dashed curve
represents a mixing line for an average fresh basalt and a typical clay mineral. Open circles show
trend of a submarine metabasalt as a result of various leaching treatments.
very low (<0.01%) creating a difficult
analytical problem. In addition, the pres-
ence of excess argon in xenocrystic min-
erals may also be serious. We feel that
the prospects for accurate K-Ar dating
of sea-floor basalts are rather poor and
that other methods such as fission-track
dating may prove more promising.
In studying the oldest areas of oceanic
crust one naturally considers the oceanic
trenches, where the oceanic crust is pre-
sumably consumed some hundreds of
millions of years after formation. In col-
laboration with A. Nalwalk, we have
undertaken the study of selected trace
elements in a suite of basalts dredged
406
CARNEGIE INSTITUTION
from 7-km depth on the north wall of
the Puerto Rico Trench. Most of the
samples show some indication of sec-
ondary alteration, such as chloritization
of the olivines and pyroxenes, high ratios
of ferric to ferrous iron and high water
contents. The problem is to determine
whether this is an initial high-tempera-
ture deuteric type of alteration, a low-
temperature metamorphic alteration, a
sea-water alteration, or some combina-
tion of these.
Results of K, Rb, and Cs analyses on
these trench basalts are shown in Fig. 25.
8
-
1 '
i 1 i i
-v
I i ■
6
-
"Fresh"
Basalts --—
/
/
/
"e .*'£
BI3
-
4
1
1
S'" '
-
o
\
14"/
o
/
O 2
-
/-9
-
*
/
/
I04
/-5
—
8000
/ '
/
-
600C
/\
4000
I i
. i u
/ 2
III 1 II
1 1 1
1 1
200
500 1000 2000
5000
2000
1500
1000
800
£ 600
400
200
100
1 I I I II I
t — i p-m
r* B.I3 ~
"Fresh"
Basalts
/
/
/
/
I I I 1 I I I I I
J L
I I I
200
500
1000
2000
5000
Potassium content, ppm
Fig. 25. K/Rb and K/Cs versus K content of submarine basalts from Puerto Rico trench. The
dashed area is drawn to include the freshest midocean ridge basalts of Fig. 24.
DEPARTMENT OF TERRESTRIAL MAGNETISM
407
The alkali data define rather distinct
trends in terms both of K/Rb and K/Cs
ratios. However, these trends are dis-
tinctly different from those shown by
the fresher basalts of Fig. 24, shown here
as an outline area. There is in fact al-
most no overlap of the data for the trench
basalts and that for fresh ridge basalts.
There are other chemical parameters
of these trench basalts which show sig-
nificant interrelationships, and several
of these are shown in Fig. 26. Of par-
ticular interest is the CaO trend between
48% and 51% Si02 — essentially a pure
"calcium-loss" trend which would be
difficult to produce by any combination
of mineralogical effects during differen-
tiation. Leaching of calcium from glass
occurs very rapidly during aqueous al-
teration, and as many of the trench
basalts are rich in glass, we feel that
this CaO versus Si02 trend is a strong
indication of alteration in an aqueous
environment.
Because the strontium contents of
these basalts show rather large and con-
sistent variations relative to the other
elements (Fig. 26) , we have analyzed
selected samples for Sr87/Sr86. For sample
No. 6 (least altered by petrographic
K/Cs
75,000
50,000
25,000
0
2000
1500
K/Rb iooo
500
0
6000
K(ppm)4000
2000
^<
i* r 1
i — •
•_
I L
-
*'-
-
-
-*-'"
•
. 1 1
< * 1 1 1
Sr (ppm)
Fig. 26. Trends of K/Cs, K/Rb, K, Sr, and CaO versus Si02 for Puerto Rico trench basalts.
Solid line on CaO plot is calculated for pure Ca loss.
408
CARNEGIE INSTITUTION
criteria) the Sr87/Sr86 ratio is 0.7033;
for sample No. 2, 0.7047 and for sample
No. 11, 0.7061. A Sr87/Sr86 ratio of 0.7033
is very similar to that in average fresh
oceanic basalts ; on the other hand, ratios
as high as 0.706 are very unusual in
oceanic basalts. Because sea-water
strontium has a ratio of about 0.709,
we feel that the high ratios in sample
Nos. 2 and 11 probably represent partial
exchange with sea water. Furthermore,
as we have previously shown that the
alkali elements are affected by alteration
to a greater degree than strontium, we
infer that the K, K/Rb and K/Cs trends
of Figs. 25 and 26 are also related to
alteration by sea water. While the pres-
ent study leaves unanswered the question
of what the primary trace element char-
acteristics of the trench basalts were, it
does show that alteration processes can
produce high as well as low values of
K/Rb and K/Cs and that trace element
values for the alkali metals and alkaline
earths in sea-floor basalts must be viewed
with considerable caution.
Finally, having pointed out many of
the difficulties involved in dealing with
these basalts, we should also consider
what we have learned regarding their
primary trace element characteristics.
The unusually high K/Rb and K/Cs
ratios observed by Gast (1965) 36 are
substantiated. However, the general
trend of decreasing K/Rb with increas-
ing K content is probably the result of
chemical alteration. When we group our
freshest basalts geographically and con-
sider the variation of K/Rb ratio, we find
that this variation is largely independent
of potassium content. For example, three
of our freshest samples are from the East
Pacific Rise (sample Nos. 1, 5, and 21)
and they have K/Rb ratios of 700, 800,
and 740, though the potassium contents
vary by more than a factor of ten (from
430 ppm to 4600 ppm) . Samples from
the mid-Atlantic ridge show a larger
variation in K/Rb (980 to 1200) but
there again is no correlation with po-
tassium content.
The Grenville Front in the
Chibougamau-Surprise Lake Area
T. E. Krogh, C. Brooks, S. R. Hart, and
G. L. Davis
A metamorphic transition in the Sur-
prise Lake area near Chibougamau,
Quebec, was studied and described as a
transitional Grenville front by Deland
(1956). 37 A brief report of preliminary
results was included in Year Book 67.
The Rb-Sr ages of muscovites and bio-
tites from this metamorphic transition
are shown in Fig. 27. Figure 28 presents
the isotopic data for several whole-rock
samples.
It is clear from the muscovite ages that
the metamorphic transition had occurred
and the region had cooled more than
2500 m.y. ago. Biotite Rb-Sr ages on
the other hand range from a minimum
value of about 900 m.y. in the southeast
part of the map area to 2100 m.y. in the
northwest. In cases where two biotites
were analysed, the coarser fraction al-
ways yielded an older age, and biotites
from the granites give older age values
than those from the metasediments. Bio-
tites have lost variable amounts of radio-
genic strontium by diffusion, probably
about 900 m.y. ago, whereas muscovites
have retained almost all of their radio-
genic strontium under the same condi-
tions.
The occurrence of this Archaean meta-
morphic transition near the thermal ef-
fect of the ~1 b.y. Grenville meta-
morphism may be simply a coincidence,
but an alternate explanation is possible.
A metamorphic gradient, developed verti-
cally 2500 m.y. ago, may have been ex-
posed in a lateral direction as a result
of later uplift, perhaps at 900 m.y. Min-
eral isograds exposed along the Grenville
front by this mechanism would pre-date
the front itself.
DEPARTMENT OF TERRESTRIAL MAGNETISM
409
LEGEND
['X'"| Granite
High grade
Lower grade
High grade
HI
Lower grade.
Metasediments
0 I 2 3 miles
i 1 1 I
Fig. 27. Generalized geologic map of Surprise Lake area, Quebec. Muscovite Rb-Sr ages (m)
are shown underlined; other ages are biotite Rb-Sr ages. In two cases both coarse- and fine-grain-
size fractions of biotite were analyzed, the coarse fraction giving the greater age in each case.
As the muscovites from the metasediments are metamorphic minerals, they establish minimum
ages for the metamorphic transition in this area.
1.5
Rb87/Sr86
2.0
2.5
Fig. 28. Rb-Sr isochron diagram for whole rock samples from Surprise Lake area, Quebec. Q23
samples are from an island in the eastern part of Surprise Lake. Q33 and Q38 are samples of
granitic gneiss located south of Surprise Lake.
410
CAENEGIE INSTITUTION
Isotopic analysis of whole-rock granite
samples from several locations does not
show any marked effect resulting from
the younger metamorphism. A poorly de-
fined isochron with an age of 2500 ±100
m.y. was obtained from several samples
from a single outcrop area. Samples from
other locations suggest a similar age but
with an anomalously high initial ratio.
Rb-Sr Relationships for Igneous
Rocks of the Corryong Province,
Victoria, Australia
C. Brooks
The Siluro-Devonian igneous rocks of
the Corryong District, Victoria, Aus-
tralia, have been the subject of an in-
tensive geochemical investigation.38 The
rocks consist of granites, dykes of varia-
ble composition, volcanics and leuco-
granites. The geochemical investigation
has revealed that the province is rela-
tively enriched in Rb, and consequently
the Sr87/Sr86 of any aging magma will
change considerably over short intervals
of time. In order to attempt a documen-
tation of this possibly changing isotopic
composition, and also to decipher the
complex chronology, a Rb-Sr investiga-
tion has been initiated in collaboration
with M. Leggo.
Isochrons have been determined for
the dominant "basement" granite (the
Corryong-Koetong batholith, Fig. 29),
muscovite dykes cutting the Corryong
granite (Fig. 30), the Mt. Mittamitite
leucogranite (Fig. 31), the Pine Moun-
tain leucogranite (Fig. 32) and for the
spatially associated Jemba rhyolites
(Fig. 33). Caution must be exercised in
0.78 -
0.76
CO
r^ 0.74
oo
CO
0.72-
0.70
Corryong / Koetong Granite
./To D 14
y^ Biotite
_
«/"*^14
A 23/
"A5
/^Dl9
^0.7164+ 0.0050
! ! 1
1
1 1
10
12
Rb87/Sr86
Fig. 29. Rb-Sr isochron diagram for total rock samples of the Corryong/Koetong granite
batholith (Victoria). Deleting the biotite (excluded by scale requirements) does not change the
age estimate but raises the isochron error to ± 97 m.y. at the 95% level of confidence.
DEPARTMENT OF TERRESTRIAL MAGNETISM
1.7
411
Muscovite dykes
A 68
BI6
K-feldspar
160
200
Rb87/Sr86
Fig. 30. Rb-Sr isochron diagram for total rock and mineral samples from muscovite dykes
which cut the Corryong/Koetong batholith. Both D12-13 muscovite and B16 muscovite plot on
the 423-m.y. isochron but are excluded by scale requirements.
0.77
0.76-
0.75
0.74
0.73-
0.72-
0.71
0.70
Mt. Mittamitite Leucogranite
A 12a
A9
A 10
TT-
AI2b
<- 0.7042 ±0.0009
I I
10
Rb87/Sr86
Fig. 31. Rb-Sr isochron diagram for total rocks of the Mt. Mittamitite leucogranite, Victoria.
The age and initial Sr^/Sr86 error estimates are given at the 95% level of confidence.
412
CARNEGIE INSTITUTION
5.0
Pine Mountain Leucogranitf
100
200
300 400
Rb87/Sr86
600
700
Fig. 32. Rb-Sr isochron diagram for total rocks of the Pine Mountain leucogranite, Victoria,
and associated dykes (B2, A27, PM 6, A28B) . Age error is at the 95% level of confidence.
00
</5
1. 10
1.00
0.90
0.80
0.70
Jemba Rhyolite
Rb87/Sr86
A 15
60
Fig. 33. Rb-Sr isochron diagram for total rocks of the Jemba rhyolite subsidence caldera,
Victoria. Error estimates are given at the 95% level of confidence.
DEPARTMENT OF TERRESTRIAL MAGNETISM
413
interpreting the isochron estimates given
in the figures because different linear
least-squares statistical models give dif-
ferent errors for the fits. Although work
is progressing to improve this situation,
it is not yet completed. However, the
data suggest that the period of igneous
activity lasted approximately 20 m.y.,
from the formation of the Corryong
granite at 427 m.y. to the extrusion of the
Jemba rhyolites at 409 m.y. The Jemba
rhyolite, which has an uncertain strati-
graphic relationship with the leuco-
granites, is apparently similar in age to
the leucogranites. The initial ratio data
is less informative due to the large
errors resulting from the lack of range in
Rb/Sr ratio. The preliminary data indi-
cate no significant difference between the
initial Sr87/Sr86 of the Corryong granite,
Jemba rhyolite or the muscovite dykes.
The initial ratio of the Mt. Mittamitite
leucogranite, however, is significantly
lower, which is somewhat contradictory
to the proposal that this leucogranite is
a later-stage product of the Corryong
batholith. Unfortunately, the Pine
Mountain leucogranite is too enriched in
Rb to provide an initial Sr87/Sr86 esti-
mate. Work is continuing in an effort to
determine more accurately the initial
Sr87/Sr86 ratios.
Discussion of the Use of Rb-Sr
Isochron Regression Treatments
C. Brooks and S. R. Hart
The publication of the new initial
Sr87/Sr86 value 39 for achondrites defines
a new level of precision of Sr isotope
measurement. Although it is highly un-
likely that any suite of terrestrial
samples will have been as perfectly
chemically closed throughout their his-
tory as the reported achondrite suite, this
improved level of precision requires a
detailed appraisal of isochron regression
treatments. These treatments, which are
used to estimate the Rb-Sr isochron pa-
rameters, are not in a satisfactory state,
since all proposed regression models in-
corporate certain shortcomings. An in-
vestigation of these models is being com-
pleted. Some aspects of the investigation,
however, have been finished.
Normality of error distribution. A
basic assumption in any application of
least-squares analysis is that all errors
affecting the fit of the regression line
are normally distributed. Qualitatively,
the more nonnormally distributed the
errors are, the less "certainty" one can
place on the errors calculated for the fit.
The degree of normality of the error
distribution function can be graphically
examined by calculating a cumulative
distribution analysis for replicate data
and testing for linearity on probability
paper. The only laboratory which has
published sufficient duplicate data for
such a treatment is the Department of
Geophysics and Geochemistry of the
Australian National University. The re-
sults for 100 total rocks, 52 feldspars,
and 50 micas are displayed in Fig. 34.
Inspection of this figure reveals that most
of the measurement errors for whole
rocks, feldspars, and biotites show some-
what sigmoidal trends. On plotting theo-
retical replicate error-data taken from
a known normal distribution, similar
trends were observed. This effect is ap-
parently a direct result of small-sample
statistics, and we conclude that the
A. N. U. error data are for the most part
normally distributed. It is clear that for
laboratories such as A. N. U., where
most of the data (>90%) is demon-
strably normal in error distribution, the
general least-squares analysis is applica-
ble with little reservation.
Correlation of errors. A recent least-
squares isochron regression development
has been published 40 in which the experi-
mental errors in X and Y are correlated.
For Rb/Sr isochrons, where the Sr iso-
tope ratios and concentration are meas-
ured together, correlation between the
Sr87/Sr86 and Rb87/Sr86 is obviously pos-
sible. This correlation is expressed as a
coefficient which varies from —1 to 0 to
+ 1. Minus 1 indicates perfect negative
correlation, i.e., a ( + 1%) error in X pro-
duces a ( — 1%) error in Y, zero indicates
414
CARNEGIE INSTITUTION
99%
907,
507c
10%
17c
• • A
H
\
&Sr
RbV,
d_L
99%
D
"-,
907c
\
\
50%
\
\
10%
1%
\
\,
-4 -3-2 -I 0+1 +2+3+4 -20 -10-05 0-05 HO -20
\"^—
99%
90%
50%
10%
1%
A
\
\-
J L
j_L
J_L
-15-10-5 0+5+10+15 -8-6-4-2 0+2+4+6+8 -40 -20-10 0+10+20+40
Percentage error between duplicates
Fig. 34. Probability plot displaying cumulative distribution analyses of the difference between
duplicates expressed as a percentage of their mean. The identification is as follows : A. Rb and Sr
for 100 total rocks. B. Unspiked Sr^/Sr86 for 15 feldspars. C. Calculated Sr87/Sr86 for 38 feldspars.
D. Rb^/Sr86 for 100 total rocks. E. Unspiked Sr^/Sr86 for 34 total rocks. F. Rb^/Sr86 for 50 micas
(biotites, muscovites). G. Rb^/Sr86 for 52 feldspars. H. Calculated Sr'YSr8* for 100 total rocks.
I. Calculated Sr^/Sr86 for 50 micas (biotites, muscovites).
no correlation at all, and +1 indicates
a ( + 1%) error in Y. To calculate a
value for the correlation coefficient (r),
the A. N. U. replicate data used in the
error distribution analysis has been
treated with a statistical package devel-
oped at the National Bureau of Stand-
ards, Washington, D. C. In this treat-
ment the paired X and Y errors are
plotted on conventional axes, and the re-
sulting trend or lack of trend fitted by
simple least-squares analysis. The pa-
rameters of the fitted line allow calcula-
tion of the correlation coefficient and the
error in the coefficient for that data.
Figures 35 and 36 display the trends for
total rocks, feldspars and micas. Con-
sideration of the sample correlation co-
efficients shown in Figs. 35 and 36 indi-
cate that (1) for total-rock data (Sr87/
Sr86<1.0), the correlation coefficient is
not significant at the 95% level of con-
fidence; (2) for the remaining data the
correlation coefficients are significant at
the 95% level and in the case of the
micas at the 99% level. Since most total-
DEPARTMENT OF TERRESTRIAL MAGNETISM
415
•
A
1 • 1
TOTAL ROCKS
r = 0.13 + 0.12
Sr87/Sr86<10
-3.01 -0.89 1.22
% Error in Rb /Sr
5.71
TOTAL ROCKS
r = 0.58 + 0.13
B
4.19
Sr87/Sr86> 1.0
-
2.67
-
•
-
1.15
_
•
*
• •
-0.36
•
-1.87
'
,.
, .
•1.11
1.51
% Error in Rb /Sr
b./l
■L 1 1
1 1 i-
c
2.96
'
-
.
0 22
.* i^JSati
.
-2.52
'
-
-5.27
-
TOTAL ROCKS
r = 0.44 + 0.08
-8.01
7 • 1 1
i i
-20.60 -11.7 -1.72 7.70 17.14 26.58
% Error in Rb87/Sr 86
Fig. 35. Plots of the errors between duplicate total rock data expressed as a percentage of the
mean value. The correlation coefficients (r) are given for each set of data, which are distinguished
by the mean Sr87/Sr86<1.0 (A), mean Sr^/Sr86 > 1 .0 (B) and all data (C). A plotted number
indicates the number of points coincident at that point.
rock regressions involve data whose Sr87/
Sr86 is less than 1.0, it is apparent that
the assumption of zero correlation be-
tween Sr87/Sr86 and Rb87/Sr86 is a valid
one. If regressions are to be made in-
volving micas or high Sr87/Sr86 total
rocks, a positive value of r should be
used. A reasonable estimate may be
adopted from the data of this investiga-
tion.
Some "nonstatistical" realities. Al-
though analysis of the degree of normal-
ity and correlation of data is part of a
detailed investigation of regression treat-
ments, we feel that there still remains the
need for human evaluation in the deci-
mal-point game of statistical argument;
the very nature of geological analysis
necessitates a degree of human evalua-
tion.
For example, minimization of Stu-
dent's t-multiplier by the analysis of ad-
ditional samples will produce smaller
values for the calculated isochron errors.
However, if these samples do not repre-
sent increased geological coverage of the
parent body, then this minimization of
the errors is artificial with respect to pre-
dictions about the parent body.
A second example involves the testing
of differences between ages and initial
Sr87/Sr86 ratios of isochrons. The increase
of the error estimates of the isochron fit
due to the raising of the levels of con-
fidence introduces the possibility that
statistics can be forced to support a pre-
416
CARNEGIE INSTITUTION
5.08
1
1
•
1 1
A
1.10
-
M
•
• •
•
• •
• - • ••
•
•
•
•
•
• •
• •
•
• •
•
2.86
•
6.83
-
•
-
10.81
•
BIOTITES, MUSCOVITES
r=0.76±0.0S
14.78
T
1
1
1
i "
-7.26 -2.19 2.88
% Error in Rb87/Sr 86
13.05
2.37
1
1
1
•
B
1.61
-
-
oo
CO
00
0.85
-
-
CO
•
2
o
0.09
•
•
•
•
•
•
•
• • •
• •
UJ
•
•
• «
<
•
•
•
•
•
-0.67
•
•
• •
FELDSPARS
r = 0.52 +0.12
-1.43
-
I*
• I
1
1
r
-3.33
1.92 -0.51 0.90
% Error in Rb87/Sr 86
2.31
3.72
Fig. 36. Plots of the errors between duplicate biotite/muscovite data (A) and feldspar data (B).
The correlation coefficients (r) are given.
DEPARTMENT OF TERRESTRIAL MAGNETISM
417
conceived idea. For example, consider
the following age estimates at the lo- level
of confidence for two six-data point
isochrons.
Isochron I 100 ±10 m.y.
Isochron II 200 ±10 m.y.
At all levels of confidence up to about
99.7%, the isochrons show distinctly dif-
ferent ages. At the 99.99% level, however,
there is no significant age difference. In
other words, statistical differences can
always be eliminated by unrealistic rais-
ing of confidence levels. This example
should properly be described as showing
a significant difference in age at all levels
of confidence less than 99.7%.
Some comment must also be made re-
garding the relative errors obtained from
a total-rock isochron as opposed to a
single very enriched sample from the
same body. An age error can be assigned
to this enriched sample (on the basis of
analytical precision and possible uncer-
tainty in the initial ratio) which may be
considerably smaller than the calculated
errors of the isochron. This age error for
the single sample, however, can in no
way be used to determine our confidence
level regarding the body as whole and as
a result cannot be used for testing for
differences between this body and any
other. In the same way, the single-sample
precision in Sr87/Sr86 cannot be applied
to a single low isochron point to predict
the initial ratio of the parent body. To
determine useful confidence limits for the
age and initial ratio estimates of a geo-
logic body, a sufficient number of samples
is required to overcome small-sample
limitations.
Perhaps nowhere in the application of
statistics to the field of geology is there
such inordinate extrapolation based on
so few observations. A recent published
example extrapolated an age and initial
Sr87/Sr86 from four hand specimens to at
least 1000 cubic miles of rock. The only
constructive suggestions that can be
made in this type of analysis are the
desirability of increasing the number of
samples analyzed, the need for adequate,
small-sample theory consideration, and
the realization that even carefully deter-
mined, precise isochron-parameters may
still misinterpret a geological state which
is not necessarily subject to statistical
laws of normal distribution.
Intelligent use of the available regres-
sion models even on closely controlled
statistical grounds will not completely
eliminate nonrealistic use, unless full ac-
count is taken of small-sample theory.
To make this clearly unambiguous, we
strongly suggest that isochron param-
eters be given with a stated level of con-
fidence, with stated assigned experi-
mental errors, and with a statement de-
fining the method and the number of
samples used in calculating these errors.
This will, we hope, minimize the isochron
"errors of ignorance," and lead to more
emphasis in the literature on the statisti-
cal concept of prediction about the par-
ent geological unit or body from isochron
regression results.
Potassium/Rubidium Ratio of Red Sea
Brines
S. R. Hart
Remarkable occurrences of hot brines
are found in at least three depressions
or closed basins on the floor of the Red
Sea. These brines, with temperatures up
to 56 °C and with salinities about eight
times higher than sea water, occur at
depths of about 2000 m along the median
rift zone of the Red Sea. A number of
theories have been proposed for their
origin: (1) extreme evaporation of the
entire Red Sea at some earlier stage, (2)
local solution of exposed salt deposits on
the sea floor, (3) evaporation in coastal
areas with later density flow to the deep
pockets, (4) leaching of evaporites in
underlying strata. A variation of the
last process has been proposed by Craig
(1966) 41 in which normal Red Sea water
enters the evaporite sequence comprising
the shallow sill separating the Red Sea
from the Gulf of Aden, undergoes geo-
418
CARNEGIE INSTITUTION
thermal heating as it is driven downward
by density flow, travels in fracture sys-
tems along the axis of the Red Sea finally
to emerge from beneath the sea floor into
the closed depressions, more than 400 km
north of where it started. Samples of the
56°C Atlantis brine, the 44°C Discovery
brine, and several of the intermediate
mixed layers separating the brines from
normal Red Sea water were analyzed
for K and Rb to see if the K/Rb ratio
could be used as an effective tracer for
investigating the origin of the brines.
Samples were made available by R.
Weiss and H. Craig of the Scripps Insti-
tution of Oceanography. Results of the
K/Rb analyses are shown in Fig. 37. The
two brines are quite similar in K and Rb
content (they have similar salinities as
well), with the small differences prob-
ably representing the analytical uncer-
tainties. Furthermore, the two inter-
mediate or mixed waters are on a perfect
mixing line between the brines and pres-
ent-day normal Red Sea water. This
strongly suggests that the mixing which
formed the intermediate waters has
taken place under present-day condi-
tions, since the salinity of the Red Sea
has probably varied widely in the past
because of climatic effects. The Red Sea
is at present open to the ocean at its
south end through a channel only 100
meters deep. Lowering of sea level during
glacial periods would have isolated the
Red Sea from the open ocean, and its
salinity would then be entirely controlled
by the local evaporation-precipitation
budget. The fit of points to the mixing
line suggests that at the time of mixing
the potassium content (and salinity) of
the Red Sea did not differ from the pres-
ent value by more than ±3-4%.
The K/Rb ratio of the brines is about
970, compared with 3200 for sea water
and about 200-400 for most igneous
rocks. Clearly the brines have not been
formed by simple evaporation of sea
water (this conclusion had also been
noted previously, based on consideration
3.00
2.00
1.00
Red Sea Samples
□ Error boxes ± 1%
in each concentration
500
1000
1500
K (ppm) — ►
2000
2500
Fig. 37. K and Rb contents of brines, intermediate mixed layers, and normal sea water from
the Red Sea. Mixing line for Red Sea samples is an approximate best-fit line to the data points.
Evaporation line is a line of constant K/Rb ratio equal to that in open ocean water (3160).
DEPAKTMENT OF TERRESTRIAL MAGNETISM
419
of the major-element chemistry of the
brines) . Furthermore, the K/Rb ratio is
unlike that in most crustal rocks, ruling
out possible origins related to bulk
weathering or leaching of common rock
types. From the equation of the mixing
line it is clear that, even if the brines
are not at original strength, the K/Rb
of the original source must have been
greater than 800 (since the K/Rb of the
mixing equation approaches 800 asymp-
totically for large K concentrations).
Ocean-floor basalts have K/Rb ratios
which are typically 800 and higher, and
since the Red Sea rift is a zone of genera-
tion of new oceanic basaltic crust, these
rocks would be a potential source for
alkalies with high K/Rb as well as a
source of heat. However, the oxygen and
hydrogen isotope data of Craig 41 clearly
shows that the water of the brines is re-
lated to normal southern Red Sea water,
and that most of the dissolved salts are
compatible with extraction from evapo-
rite sequences — rather than having any
relationship to magmatic water and
basaltic chemistry. Data on the K/Rb
ratios of typical evaporite deposits are
rather poor, but it does seem that certain
evaporite minerals such as sylvite will
have very high K/Rb ratios (2000-
10,000) , whereas other minerals such as
carnallite will have low K/Rb ratios
(100-200). Thus, depending on the par-
ticular mineralogy of a given evaporite
sequence it would be possible to obtain
brine solutions with K/Rb ratios as high
as those observed in the Red Sea brines.
The overall K/Rb of an evaporite se-
quence must ultimately trace back to the
drainage system which fed the original
salt lake. (Here it is interesting to note
that most fresh-water streams from a
variety of drainage basins contain dis-
solved alkalies with K/Rb ratios ~800-
1000.) The K/Rb data thus add some
positive support to the "evaporite-leach-
ing" theory of Craig 41 for the source of
the Red Sea brines.
Sr-Isotopic Evidence Bearing on the
Early Heterogeneity and Continuous
Differentiation of Earth's Mantle
The abundance of Sr87 has been in-
creasing since the time of nucleosynthesis
because of the natural radioactive decay
of Rb87. If we express this abundance as
a ratio with a nonradiogenic isotope such
as Sr86, then in every geological environ-
ment (such as Earth's mantle), the rate
of change of Sr87/Sr86 will be propor-
tional to the Rb/Sr ratio that existed in
that environment. This has important
implications concerning the evolution of
Earth, since the change of the Sr87/Sr86
ratio with time can be used as a "tracer"
in testing possible models for the chemi-
cal evolution in Rb and Sr in the mantle.
The use of the Sr87/Sr86 "tracer" in
this way depends entirely on the avail-
ability of rocks that have been directly
derived from Earth's mantle. To date,
most investigators concerned with rocks
derived from the mantle have confined
their efforts almost exclusively to the
modern volcanics for which no age cor-
rection is necessary. Almost no work has
been done on older volcanics or other
rocks of presumed mantle origin, conse-
quently our knowledge concerning the
development of Sr87 in the mantle with
time is severely limited.
Because of the lack of data, previous
workers have considered strontium de-
velopment in the mantle in terms of
"end-member" models, with one end-
member being the primordial strontium
ratio as defined by Rb-poor meteorites.
The other end-member is taken as mod-
ern volcanic strontium, and a linear
growth during mantle evolution is usu-
ally assumed. We have attempted to
close this gap in our knowledge of mantle
evolution by investigating volcanics from
the oldest accessible Precambrian ter-
rane in North America, the 2.7-b.y. Su-
perior Province in the Canadian Shield.
The metavolcanic belts sampled are
shown in Fig. 38.
The Archaean volcanic suites sampled
420
CARNEGIE INSTITUTION
Archaean Volcanic Belts
and
Sample Localities
Fig. 38. Generalized map showing location of principal metavolcanic belts in the Superior
Province, Canadian Shield. Solid circles show localities from which metavolcanic samples have
been obtained and analyzed for Rb, Sr, and SrVSr86.
range typically from basalt to rhyolite
with the basalts being similar in compo-
sition to modern subalkaline basalts
such as those dredged from the oceans.
Unlike their modern counterparts, how-
ever, the older rocks have been meta-
morphically upgraded to either zeolite,
greenschist or amphibolite facies. This
metamorphism provides a mechanism
whereby it may be argued that any
Sr87/Sr86 value measured in a Pre-
cambrian volcanic has been modified due
to movement of Sr and/or Rb during
the metamorphism. This possibility, to-
gether with such problems as the one
implied by the calcite content of the
metavolcanics, has been investigated in
detail. Our data provide strong evidence
that a considerably higher Sr87/Sr86
value existed in Earth's mantle 2.7 b.y.
ago than that predicted by a linear
growth from the "meteoritic" primordial
value. In addition, the Sr87/Sr86 data sug-
gests that the heterogeneity recorded for
the present-day mantle appears to have
existed also in the mantle 2.7 b.y. ago.
Various limiting cases for the evolution
of mantle Sr are considered. Several
models are found to be compatible with
our observations ; one of these is a simple
differentiation model with continuous
transport of Rb and Sr from the mantle.
Carbonate Contents and Sr87/Sr86 Ratios
of Calcites from Archaean Metavolcanics
C. Brooks, T. E. Krogh, S. R. Hart, and
G. L. Davis
Volcanic magmas crystallize into min-
eral assemblages that are highly sus-
DEPARTMENT OF TERRESTRIAL MAGNETISM
421
ceptible to alteration by weathering and
metamorphic events. Any proposed in-
vestigation of the initial Sr87/Sr86 in
total-rock samples of metavolcanics must
include consideration of the type and
degree of alteration. In the case of
Archaean greenstones, the most obvious
indication of alteration is ubiquitous
carbonate and silica.
We do not here attempt to relate the
formation of carbonate to any particular
time in the history of the metavolcanics.
If this alteration is associated with either
the parent vulcanism or the subsequent
metamorphism that led to formation of
the "greenstones," the problem of the
effect of alteration on the Rb/Sr isotope
parameters of the total rock is consider-
ably simplified. Any later open-system
behavior of the total rock or its altera-
tion products would prevent sensible Rb/
Sr chronology.
The carbonate component of the green-
stones was determined by means of gas
chromatography to a precision of ±2-
3%. A distinction was made between
vein and disseminated calcites; the for-
mer were separated from discrete veins,
while the latter were separated from
crushed rock that had been previously
hand-picked to exclude calcite veins.
Residues after preliminary 2N HC1
treatment indicated that the separates
were between 40% and 99% pure (the
contaminants were predominantly
quartz, with variable amounts of altered
plagioclase and composite calcite-clino-
zoisite grains).
The histogram of calcite contents
(Fig. 39) reveals that 52% of the
Archaean greenstones examined (Fig. 38)
contained less than 1% calcite, and 79%
contained less than 3% calcite. These
data are supported by a composite pre-
pared from 40 other greenstone samples
that gave a calcite content of 1.1%.
The histogram for the present-day
Sr87/Sr86 ratios of the calcites analyzed
(Fig. 40) shows that whereas the vein
calcites range from 0.701 to 0.718 in this
ratio
Colcile Content of Arctic
ZN=67
52% <l%
67% <2%
79% <3%
84% (5%
n n
Fig. 39. Histogram showing calcite contents
of 67 Archaean metavolcanics. Fifty-two per-
cent of the samples contain less than 1%
calcite; 79% contain less than 3% calcite.
nated calcite ratios form a mode at 0.702.
(The exception is a disseminated calcite
taken from a rock collected in close
proximity to the Grenville front.) The
surprisingly high Sr87/Sr86 ratios of some
of the calcites are worthy of considera-
tion especially since some of the values
observed are significantly higher than the
present-day Sr87/Sr86 of the host green-
stone. The isotopic distinction between
these "radiogenic" calcites, which gen-
erally have lower Rb/Sr ratios than the
host greenstones, implies that either (a)
the calcite strontium was introduced
under nonreactive conditions (ground-
water?) and did not reach isotopic
equilibrium with the host rock, or (b)
0-' o-' o-' o-' o-> o-1 o-1 o-1 o-1 o-1 ol
Present-day Sr87/Sr86
Fig. 40. Histogram showing measured SrVSr86
ratios of vein and disseminated calcites sepa-
Wlth one exception the dissemi-rated from Archaean metavolcanics.
422
CARNEGIE INSTITUTION
the calcite strontium was derived locally
by limited and selective leaching of only
the rubidium-enriched mineral phases.
Providing that the four disseminated
calcites measured are typical, then it is
apparent that the initial Sr87/Sr86 ratios
of greenstones will not be affected by
even as much as 10-20% of this calcite.
Vein calcites can have a measurable
effect on the Sr ratios of greenstones,
however. We conclude that careful field
sampling of Archaean greenstones, with
the exclusion of visible vein calcite, will
allow Rb-Sr isotope investigation in
which the measured isotopic parameters
have not been significantly affected by
alteration attributable to the calcite.
The Initial Sr87/Sr86 Ratios of the Upper
Metavolcanics, Ontario, Canada
and Lower Series, Michipicoten
C. Brooks, T. E. Krogh, S. R. Hart, and
G. L. Davis
The Michipicoten area has been the
subject of extensive geological investiga-
tion and our ground control is based upon
the excellent account given by Goodwin.42
He distinguishes lower, middle, and
upper series of metavolcanics in the
Michipicoten basin. Our sampling has
followed this internal division. Figure 41
displays Goodwin's geological relation-
ships and gives the location of our
sampling sites.
The Rb/Sr results for 22 metavolcanics
are displayed in the isochron diagram,
Fig. 42. Inspection of this figure reveals
that two separate lines must be fitted to
the data, one corresponding to the upper
series volcanics, one to the lower series.
Statistical analysis of the lower series
data indicates that there are sources of
"geological" scatter about the isochron.
Rejection of data (especially the higher
Rb87/Sr86 data points) to reduce this
scatter could not be supported on geo-
logical grounds, and hence the most
realistic isochron parameters are believed
to be those given in Fig. 42. The initial
Sr87/Sr86 ratio for the lower series meta-
Fig. 41. Geologic map of the Michipicoten metavolcanic basin, adapted from Goodwin.42
Sample localities shown as solid circles; numbers are sample reference numbers.
DEPARTMENT OF TERRESTRIAL MAGNETISM
423
0.720
0.715-
0.710
0.705 -
0.700
1.0
2.0
3.0
*/
0.82
1
1
V24^"-
^V32
" 0.78
^* VI9
0.74
>-*V43
/-^ V58
r^V33
yS Vz^yf/
0.70
V32
1
\/
V ttwf/
' y+ V23
-
V5I S
■ Upper volcanic series _
• Lower volcanic series
w la Experimental error limits
V57 /
V55 /
V50/ / y
' y4 V28
Upper series
Age(m.y.) Initial Sr87/Sr86
2550±I00 0.7028+0.0003
Lower series 2700+80 0.7012 + 0.0003
/ w/— V53
/[ \ V34
1 V35
V26R |
1
1 1 1
0.1
0.2
0.3
0.4
0.5
Rb87/Sr86
Fig. 42. Rb-Sr isochron diagram for Michipicoten metavolcanics. Inset shows samples from
the lower series which have high Rb/Sr ratios. Samples from the lower series and upper series
define distinctly different isochrons. Error limits are at 95% level of confidence.
volcanics remains constant despite the
deletion of high Rb/Sr data points.
Whereas some of the lower series data
reflect geological scatter, the upper series
of metavolcanics (with one exception)
fit an isochron exceedingly well. The ex-
ception (sample V53) is statistically dis-
tinct, and the isochron for the remaining
upper series data gives an age estimate
of 2550 ±100 m.y. and an initial Sr87/Sr86
ratio of 0.7028 ±0.0003.
Testing between the recommended iso-
chrons for the upper and lower series
data according to the Mclntyre et al.
procedure 43 indicates that the series are
distinctly different in initial Sr87/Sr86 esti-
mates at very high levels of confidence
( + 99.9%), and significantly different in
age estimates at any level of confidence
less than 98.5%. However, metavolcanics
are frequently found to record ages that
conform with times of regional meta-
morphism or plutonism. The 150-m.y.
age difference between the upper and
lower metavolcanic series, and the agree-
ment between the age of the upper series
and the average K/Ar mineral age re-
corded throughout the Superior Province
of the Canadian Shield, demands that the
possibility of metamorphic isochron ro-
tation during whole-rock redistribution
of strontium be considered for the upper
series volcanics.
There are variations in the meta-
morphic grade within the Michipicoten
basin. In the northeast it is low amphib-
olite facies (samples V32-V35) while
in the southwest it is low-to-middle green-
schist facies (samples V19-V27). The
upper volcanics (V50-V57) fall inter-
424
CARNEGIE INSTITUTION
mediate in metamorphic grade between
the lower volcanics from different parts
of the basin. To produce a metamorphic
isochron requires that a metamorphic
event distinguish the upper from the
lower series in a single volcanic pile. This
pulse would then be required to upgrade
both volcanic series while initiating iso-
topic redistribution in the upper series
only. The persistence of an excellent iso-
chron on which fall lower volcanics of
quite different metamorphic grades, e.g.,
V32 and V23, argues against meta-
morphic rotation of the isochron. In the
light of these considerations, we feel that
the initial Sr87/Sr86 ratios of the Michi-
picoten metavolcanics are not meta-
morphic or apparent values.
One method of attempting to eliminate
local mixing effects in the isotopic
composition produced by metamorphism
of volcanics is to analyze composites
consisting of numerous samples repre-
sentative of large exposures. Two com-
posites were collected (samples V27 and
V28) which together represent a sam-
pling volume of about 4 x 107 kilograms
of lower volcanics. These were found to
possess quite different Rb/Sr ratios, yet
each fell within experimental error on
the lower-series isochron, thereby adding
further weight to the primary nature
of that isochron.
Although metamorphic effects seem
inadequate to explain the difference in
the observed initial ratios, effects due
to crustal contamination, crustal or sub-
crustal magma aging, and remelting must
also be considered. The average value
of Rb for the lower-series section is cal-
culated to be 19 ppm, of Sr 217 ppm, and
of Rb/Sr 0.09. The average upper-series
section, which contains few felsic mem-
bers, is quite similar to the average lower
series section in these parameters (Rb =
14 ppm, Sr=194 ppm, Rb/Sr = 0.07).
It could be proposed that part of the
parent magma giving rise to the lower-
series volcanics aged in a molten or semi-
molten state for 150 m.y. and was then
extruded to form the upper volcanics.
To generate the observed Sr87/Sr86 dif-
ference in 150 m.y., the aging magma
would need a Rb/Sr of 0.27, a value con-
siderably higher than that observed in
either the average upper- or lower-series
members. Clearly this process is not con-
sistent with the observations. For the
same reason, remelting of the lower-
series volcanics after 150 m.y. will not
produce a magma with the observed
initial Sr87/Sr86. Preferential melting of
V24-type acidic lavas could fulfill the
Sr isotopic requirements, but is contra-
indicated by the lack of felsic volcanics
in the upper series (and the low Rb/Sr
ratio).
Crustal contamination has led to
variations in the initial Sr87/Sr86 of mod-
ern continental volcanics, and it could
be suggested that the upper- and lower-
series volcanics differ in Sr87/Sr86 due to
the incorporation (prior to extrusion) of
different amounts of contaminant. If we
take as the contaminant a sialic crust
500 m.y. older than the volcanics and
with a 'Rb/Sr ratio of 0.25, about 40%
of this would be required to produce the
observed difference in Sr87/Sr86. This de-
gree of contamination is inconsistent with
the Rb/Sr data and with the generally
mafic character of the upper volcanics.
In addition, it is doubtful that any sig-
nificant amount of crustal contaminant
was available at that time (Hart and
Davis, 1969). 44
The effect of sea-water contamination
on modern oceanic volcanics is con-
siderably greater than had been thought
before (see pp. 403^08 of this report).
Consequently interaction with an
Archaean sea could have caused modifi-
cation of the Sr isotopic composition.
Analysis of both an epidotized rim (sam-
ple V26R) and a core (sample V26C)
from a pillow indicates no difference in
the isotopic composition. While stron-
tium contamination has been observed in
modern oceanic volcanics, possible effects
during the Archaean will be greatly
minimized because of the similarity of
the sea-water strontium and volcanic
strontium at that time.
DEPARTMENT OF TERRESTRIAL MAGNETISM
425
Evaluation of the possible meta-
morphic processes, crustal contamina-
tion, magma aging, and magma regenera-
tion leads to the conclusion that the
initial ratios obtained for the Michipi-
coten metavolcanics are most probably
primary features of the volcanic mag-
mas. The initial ratio difference of 0.0016
(significant at the 99.9% level of con-
fidence) is taken to reflect a hetero-
geneity in the isotopic composition of
the Sr of the magma source regions prior
to 2.6-2.7 b.y. ago.
Initial Sr87/Sr86 Ratios of Regionally
Sampled Metavolcanics from the
Canadian Shield
C. Brooks, S. R. Hart, T. E. Krogh, and
G. L. Davis
A histogram for the initial Sr87/Sr86
ratios of 32 metavolcanics sampled on a
regional scale, the Michipicoten meta-
volcanics discussed above, and modern
oceanic volcanics is given in Fig. 43.
Whereas the ratios from the modern
oceanic volcanics are direct isotopic
measurements, the metavolcanic values
have been calculated from present-day
Sr87/Sr86 ratios assuming a 2.7-b.y.
growth period for radiogenic Sr. The ma-
jor error in any single projected ratio is
a combination of the estimated experi-
mental error in the measured Sr87/Sr86
ratio and the uncertainty in the age cor-
rection. For a ±100-m.y. value for the
latter, the combined limit of error for
over two-thirds of the projected initial
Sr87/Sr86 ratios is less than ±0.0005 at
the 95% level of confidence. For the few
samples with high Rb/Sr ratios (up to
0.14), the uncertainty in the corrected
initial ratio is a maximum of ±0.001.
The spread in the calculated initial
7
6
N 5
4
3
2
I
7
6
5
4
3
2
I
16
.
14
1 . Modern Oceanic Volcanics
(C)
12
10
-
8
6
|
4
2
1
Michipicoten Greenstones (B)
JZL
^d
LU
Regional Archaean Greenstones (A)
■ n . , . n
0.6990
0.7000 0.7010 0.7020 0.7030 0.7040
Initial Sr87/Sr86
0.7050
0.7060
Fig. 43. Histogram of initial Sr^/Sr86 ratios for (A) Archaean metavolcanics from the various
localities shown in Fig. 38; (B) metavolcanics from Michipicoten area, individually corrected for
age from Fig. 42; (C) modern oceanic volcanics, compiled from the literature. Also shown are
two Archaean metavolcanic composites: (1) 20 samples from Abajevis Hills, Quebec; (2) 70
samples from the various localities of Fig. 38.
426
CARNEGIE INSTITUTION
ratios of the regionally distributed
Archaean metavolcanics is considerably
larger than the maximum uncertainty in
any single ratio. This spread was not
found to correlate with either the geo-
graphical location of the samples, their
Rb content or Rb/Sr ratio. Individual
analyses of this type are prone to the in-
corporation of some spurious data; for
instance, the highest projected Sr87/Sr86
for the regional data was for a sample
taken from the Grenville front zone. If
the other three extreme values are simi-
larly spurious, the remaining spread
(from 0.7005 to 0.7035) is essentially the
same as that observed for the Michi-
picoten data. In considering the Michi-
picoten data we evaluated possible effects
due to metamorphic processes, crustal
contamination, magma aging, and
magma regeneration. We concluded that
the initial ratios and their range of
values are probably primary features of
the volcanic magmas. The similarity be-
tween the regional values and the Michi-
picoten data suggests, furthermore, that
these differences of initial ratio are re-
gional in scale and reflect heterogeneity
in the Archaean mantle on a broad scale.
In comparing the modern values and
the Archaean data (Fig. 43) , the present-
day isotopic heterogeneities in the oce-
anic mantle appear to be only somewhat
larger than the inferred Archaean mantle
values. Implications of this result are
discussed in a later section.
The mean value of the regionally se-
lected metavolcanics is 0.7020 ±0.0003,
and is compared with the calculated
ratios for the two composites shown in
Fig. 43. Composite 1 is composed of 20
samples from the Abajevis hills, Quebec,
and composite 2 is composed of 70 vol-
canics collected from the different areas
shown in Fig. 38. The projected Sr87/Sr86
values for the two composites are not
significantly different from the mean of
the 32 individual samples, thereby estab-
lishing the validity of the mean regional
value. This Archaean mean ratio is
clearly lower than the average value for
modern oceanic volcanics, and may be
used in evaluating models for the chemi-
cal evolution of Rb and Sr in the mantle.
Rb-Sr Mantle Evolution Models
S. R. Hart and C. Brooks
The Sr data which we wish to apply
toward interpretation of mantle evolu-
tion models are presented in Table 8.
For the present-day mantle we have
chosen average oceanic volcanic stron-
tium, since these volcanics appear to be
least affected by problems of magma
aging and contamination with sialic
crust. For the primordial strontium of
Earth we have chosen the strontium from
the Rb-poor achondrites. There is, of
course, no direct evidence that Earth
started with such strontium, and we must
bear in mind the evolutionary conse-
quences of a different primordial stron-
tium value. We use the average initial
TABLE 8. Initial Sr^/Sr86 Data Relating to Mantle Evolution
Rock type
Average initial
Sr^/Sr86
Age (m.y.)
Source of data
Oceanic volcanics
Archaean metavolcanics
0.7038 ± 0.0002
0.7018 ± 0.0002
Achondritic meteorites 0.6990 ± 0.0003
modern 63 basalts from Gast (1967)45
and 40 basalts from Bence
(1966)48
2600-2700 30 regional basic volcanics, 22
Michipicoten volcanics and
two composites of 70 and 20
samples each
4500 analyses of Gast (I960)47 and
isochron of Papanastassiou
et al, (1969)39
Note: Errors are estimated standard errors of each population in relation to a common value
for the E and A standard of 0.7082.
DEPARTMENT OF TERRESTRIAL MAGNETISM
427
strontium from the Archaean volcanics
discussed above as an intermediate time
point. This ancient volcanic association
is most similar to the orogenic basalt-
andesite-rhyolite association of the mod-
ern island arcs and should, strictly
speaking, not be compared to modern
oceanic volcanics, which may sample a
different type of mantle. However, Sr
analyses of modern calcalkaline island
arc volcanics are not abundant, and so
we are forced for now to use Archaean
and modern strontium data which are
derived from somewhat different types
of occurrences. Also, while the Sr evidence
from both the Archaean and modern vol-
canic data indicates a heterogeneous
mantle, our initial considerations will be
of an "averaged" mantle.
Figure 44 is an evolution diagram
showing the data of Table 8. As dis-
cussed earlier, the Archaean point falls
distinctly above a line (marked k = 0 in
the figure) joining "primordial" stron-
tium and modern mantle strontium. The
linear evolution model, k = 0, might be
termed an infinite reservoir model, as it
requires the Rb/Sr ratio of the regions
which we sample throughout time to be a
constant. While this model has been com-
monly used in the past to describe mantle
evolution (Hedge, 1966), 48 it is not in
accord with our Archaean data. Further-
more, both Gast (1968) 49 and Hurley
(1968) 50 have advanced strong argu-
ments showing that the mantle is not an
infinite reservoir with respect to supply-
ing crustal quantities of Rb and Sr. Their
data show that the mantle as a whole
cannot follow a simpler linear evolution
trend. However, it is possible that the
mantle is not well mixed on a large scale
and that the same mantle region is never
sampled twice. Thus each new generation
of magma could take place in a mantle
region which was a closed system until
that time, and the "apparent" evolution
curve would be linear. In view of the
Archaean data, however, it seems more
reasonable to consider various nonlinear
evolution models.
One approach to a nonlinear model
would be to consider a multistage evolu-
tion in which periodic extractions of ma-
/ fcHONDRITE
/ < EVOLUTION
/ lLINE
v;
^ ^^-^^
•o
00
s-
00
1.
CO
•O / jT
CV / /
o"/ X
"/ <Y
M */ n /
1/ J%%&
PRIMORDIAL
achondrite Sr87/Sr86
..1 ' i .L
i i i . i i _ ...
4.5
3.5
2.5 1.5
AGE (109 years)
0.5
0.705
0.704
0.703
0.702
0.701
0.700
0.699
0.698
Fig. 44. Rb-Sr evolution diagram. Curves connecting primordial strontium (Sr^/Sr86^: 0.6990)
and modern oceanic strontium (0.7038) are calculated for a continuous transport model. Values
of k are the transport parameters; other values are the initial Rb/Sr ratios required by the
model. Also shown is the evolution line of a typical chondritic meteorite with initial Rb/Sr ratio
of 025. Black circle at 2.6-b.y. age is our best average value for Archaean metavolcanics.
428
CARNEGIE INSTITUTION
terial from the mantle leave it succes-
sively depleted in Rb relative to Sr
(Hurley, 1968) . The three points of Fig.
44 can be fitted with an infinite number
of two-stage models, and there do not
exist enough data to adequately assess
a multistage evolution model. However,
the number of unconstrained parameters
can be reduced simply by approximating
a multistage process with a continuous
transport model. For example, assume
that both Rb and Sr are transported from
mantle to crust continuously, and at a
rate proportional to their instantaneous
concentration in the mantle. Thus,
d(Rb87)
dt
d(Sr86;
dt
d(8r8?]
dt
ARb87-yRbs
= -<xSrs
ARb87-ocSr8
where A is the radioactive decay constant
for Rb87, y is the transport coefficient for
Rb87, and a is the transport coefficient for
Sr86 and Sr87.
The solution may be written in the
form
/Sr87\
VSr86A~
/Sr87\
VSr8Vo
A (Rb87/Sr86)0 [l-er*+*»]
\ + k
where k is a combined transport coeffi-
ciently—a). We will assume Rb is
transported at a higher rate than Sr
(y>a).
We can also derive the fraction of Rb
and Sr left in the mantle as a function of
time,
(Rb87),/(Rb87)0 = e-<^<
(Sr86h/(Sr86)o = <ra'
and the time variation of the Rb/Sr
ratio,
(Rb87/Sr86) %l (Rb87/Sr86) 0 = e~^+k)t.
Similar models for uranium and lead
evolution have been discussed by Pat-
terson (1964), 51 Wasserburg (1966) ,52
and Gast (1967) .45
The obvious feature of this model is
that for every value of initial Rb/Sr
ratio, there is only one value of the com-
bined transport coefficient which will
satisfy the two Sr87/Sr86 end-points.
Figure 44 shows curves for this continu-
ous model for fc = 0, 2xl0-10, 3xl0"10,
and 1 X 10~9 yr_1, corresponding to initial
Rb/Sr ratios of 0.026, 0.040, 0.048 and
0.12. The Archaean data point is con-
sistent with a k value of 2-3 X 10~10 and
an initial Rb/Sr ratio of 0.04-0.05. This
k value then also sets limits on the extent
of transport of Rb and Sr from the
mantle. For the limiting case of no Sr
transport (oc = 0), we find that 65-80%
of the Rb has been removed from the
mantle. For a ratio of Rb and Sr trans-
port of y/oc *** 3, 75-90% of the mantle's
Rb and 40-55% of its Sr has been moved
into the crust. Hurley (1968) has esti-
mated the Rb/Sr ratio of the total crust
to be about 0.15. This value, coupled with
the initial value of about 0.05 for Earth
suggested by Fig. 44, leads to a value of
y/oc of about three.
It is interesting to note that, for
k~2-3 X 10-10, Rb and Sr are transported
to the crust almost linearly as a function
of time and if we equate this Rb and Sr
movement to the formation of conti-
nental crust, then the model requires a
relatively constant rate of continental
growth.
One of the main difficulties with this
model, at least as fitted to the Archaean
data, is its requirement of very extensive
removal of Rb from the mantle. Gast
(1968) has pointed out that it is unlikely
that Rb will be more extensively re-
moved from the mantle than radiogenic
argon, and that for an extreme case
where Earth starts with only 120 ppm K,
about 70% of its radiogenic argon (and
55% of its K) is now present in the crust
and atmosphere. This value is to be com-
pared with the estimate of 75-90% re-
moval of rubidium according to the con-
DEPARTMENT OF TERRESTRIAL MAGNETISM
429
tinuous transport model. To some extent
these comparisons are misleading, be-
cause the argon calculation refers to
Earth as a whole whereas the Rb-Sr evo-
lution model may in fact only relate to
the upper mantle regions from which
magmas have actually been derived
throughout geologic time. Hence, while
total Earth may be only 20-30% out-
gassed with respect to radiogenic argon
(assuming a more reasonable initial K
content of 300 ppm), the upper mantle
regions could be 100% outgassed. Fur-
thermore, the estimated uncertainties in
the data of Table 8 allow the fractional
removal of Rb to be as low as 40-50%.
The present-day Rb-Sr ratio of the
mantle, as determined by the k value of
2-3 xlO"10, would be 0.012-0.015, or
about one-third of its initial value. A
number of authors have commented on
the fact that submarine basalts have
Rb/Sr ratios which are too low to gen-
erate the observed Sr87/Sr86 ratios of the
basalts in 4.5 billion years, and they sug-
gest this rinding may indicate a deriva-
tion of basalt from a mantle region which
was recently depleted in Rb. Our model
for continuous Rb depletion in the mantle
is consistent with the submarine basalt
data, as the average Rb/Sr ratio of these
basalts (~0.01) is very similar to that
predicted by the continuous model for
the present-day mantle. The high K/Rb
ratio of these submarine basalts may
also be related to a continuous depletion
model in which the transport of Rb
would take place at a faster rate than the
transport of K, throughout geologic time,
leaving a residual mantle with a rela-
tively high K/Rb ratio.
Finally, we may consider what con-
straints the continuous evolution model
implies with regard to development of the
observed isotopic heterogeneities in the
mantle. There are two limiting ways in
which heterogeneities can be developed
in the mantle. (1) There can be a uni-
form initial Rb/Sr ratio throughout the
mantle, but with subsystems of different
values for the transport coefficients. Or
(2) there can be uniform transport co-
efficients throughout geologic time, but
with subsystems of different initial Rb/Sr
ratio.
Either way heterogeneities will de-
velop at a different rate, which may be
specified as the ratio of the range in
Sr87/Sr86 during Archaean times to that
at present. For (1), the Archaean range
will be 30% of the present range; for
(2), it will be about 55%. The actual ob-
served ranges, as derived from Fig. 43,
are almost the same for the Archaean
data and the modern data, and are thus
in contrast to the model prediction of a
range for the Archaean of one-third to
one-half of the present range. We suspect
that some of the Archaean variation may
be geological, related to the difficulty of
preserving primary initial ratios in vol-
canic rocks for long periods of time.
Moreover, the inherent precision of the
Archaean points is less than that of mod-
ern data because of the necessary time
correction. Clearly, a definitive test of
evolution models such as these requires
more analyses of better ultimate pre-
cision, not only for Archaean volcanics
but for volcanics of other ages.
The K, Rb, Cs, and Sr Geochemistry of
Archaean Metavolcanics
S. R. Hart, G. L. Davis, C. Brooks, and
T. E. Krogh
By comparing the trace element con-
tent of Archaean and modern volcanic
rocks, we may gain insight into the
changing nature of the mantle and of the
derivation processes which supply vol-
canic material to the surface. This ap-
proach is complementary to the studies
of strontium isotope abundances reported
in preceding sections.
The geologic setting and major element
chemistry of Archaean volcanics clearly
shows that they are similar to the modern
continental and island-arc calcalkali vol-
canic series (Wilson et al., 1965). 53 We
are unable, for lack of chemical data, to
assign rock names to the Archaean vol-
430
CARNEGIE INSTITUTION
canics which we have analyzed for trace
elements. However, Wilson et al. (1965)
suggest that typical Archaean volcanic
belts contain more basalts than andesites.
Baragar (1968) ,54 through systematic
sampling of two volcanic belts, showed
that basalts and andesites were more
nearly equal in abundance, with both
being more abundant than the more
siliceous rocks (dacites and rhyolites).
Basing our classification on Baragar's
work, we have simply divided our vol-
canics into two classes: K<0.6%, basic;
K>0.6%, siliceous. In this way we are
able to calculate trace element averages
for comparison with modern volcanic
types; Table 9 presents the averaged
data for the basic Archaean volcanics,
along with data for a basic composite
formed from 70 samples. The individual
values are also presented in Figs. 45 and
46. Many previous investigators have
noted the depletion of potassium in
Archaean volcanics relative to younger
volcanics ; our data show that this deple-
tion extends to the trace elements, Rb
and Sr, as well. In the Archaean vol-
canics, K, Rb, and Sr are depleted by
approximately equal amounts relative to
the young tholeiites, so that the K/Rb
and K/Sr ratios in the old and young
basic volcanics are essentially identical.
Looked at in terms of trace element
trends (Figs. 45 and 46) the data, though
scattered, appear to lie in areas some-
what separated from the trends of young
calcalkaline volcanic series such as those
in New Zealand. This divergence is espe-
cially pronounced in the more basic
Archaean rocks, since the New Zealand
trend does not extend very far into the
low potassium region. The data for the
siliceous Archaean volcanics is not
greatly different from the New Zealand
trend.
Is the depletion of K, Rb, and Sr in
Archaean volcanics a primary or sec-
ondary feature? Since all of these vol-
canics have undergone metamorphism to
some degree, it is natural to consider this
metamorphism as a possible cause for
depletion of K, Rb, and Sr. The data of
Fig. 45 are separated according to area,
and therefore may be considered in re-
spect to the overall metamorphic grade
of each area. The Abajevis-Clericy area,
generally zeolite-greenschist facies, has
a rather restricted range of K/Rb, with
15 out of 17 samples falling within the
range 230-400. The Surprise Lake area
shows a transition in metamorphic grade
(related to the Grenville front) from
greenschist to amphibolite facies and the
K/Rb ratios show a much larger scatter
than at Abajevis-Clericy. However, the
average K/Rb ratio is the same in both
the low grade and high grade areas. Simi-
larly, in the Michipicoten area, the vol-
canic series range in metamorphic grade
from low greenschist to low amphibolite
facies. Again there is no obvious correla-
tion of K/Rb with grade of meta-
morphism, though the scatter may be
somewhat larger in the higher grade
areas. There is some suggestion that
changes in K/Rb may occur in either
direction; volcanics which are siliceous
enough to form muscovite during meta-
morphism tend to have low K/Rb ratios,
whereas basic volcanics which form
amphibole during metamorphism tend to
have high ratios.
At extreme grades of metamorphism
it is likely that major changes in trace
TABLE 9. Comparison of K, Rb, and Sr Contents of Archaean and Modern
Basic Volcanics
Group
K,%
Rb,
ppm
Sr,
ppm
K/Rb
K/Sr
46 individual Archaean volcanics
Archaean composite, 70 samples
Orogenic andesites
Tholeiitic basalts
0.19
0.21
1.1
0.6
6.1
5.9
4.5
1.7
123
173
260
450
310
360
250
340
15.5
12.0
42.0
12.9
DEPARTMENT OF TERRESTRIAL MAGNETISM
431
2000
1500
1000
800
a 600
DC
* 400
200
100
1
1 1
1
1 1
1
III 1
LEGEND
-
A
□
O
x Abajevis-Clericy
° Michipicoten
A Surprise Lake
n Others
© Basic composite, 70 samples
_
o
o
O A A
•— New Zealand calcalkali series"
-
X
1
o
□
1 1
A
1
D A
X D
x og>
o
A
1 1
\
\
iD n
o *°
x xX
o
1
O
o o
X
III 1
100
1000
10,000
Potassium content (ppm)
Fig. 45. K/Rb versus K content of Archaean metavolcanics from the various localities of
Fig. 38. Solid line is the average trend line for samples from the modern island arc calcalkaline
series of New Zealand.
10,000 -
1000
10 100 1000
Sr (ppm)
Fig. 46. Logarithmic plot of K and Sr contents of Archaean metavolcanics. Strontium contents
show little variation compared with large variations in potassium content. Modern island-arc
volcanics from New Zealand shown for comparison.
432
CARNEGIE INSTITUTION
TABLE 10. Effect of Metamorphism on K, Rb, and Sr
Area
Facies
K,%
Rb,
ppm
Sr,
ppm
K/Rb
K/Sr
Emeryville
Colton
amphibolite
granulite
0.87
0.48
21.5
5.8
230
150
404
830
38
32
element chemistry can take place, as il-
lustrated by the data in Table 10. These
data were obtained on composites of a
major amphibolite unit which crosses
regional metamorphic gradients in the
classic Adirondack area of Engel and
Engel; samples were generously pro-
vided by A. E. J. Engel. The K, Rb, and
Sr contents of these amphibolite units
have been drastically reduced in the
high-grade granulite facies area. The
K/Sr ratio has remained relatively un-
changed, while the increased loss of Rb
relative to K has caused a doubling of
the K/Rb ratio. However, even these ex-
treme grades of metamorphism have not
depleted the potassium to the 0.2% level
observed in the Archaean volcanics,
strongly suggesting that this abnormally
low potassium content is a primary fea-
ture of Archaean basic lavas. In general,
while there may be a tendency toward
local redistribution of trace elements
during low grade metamorphism, we con-
sider gross changes throughout a thick
volcanic pile to be very unlikely. There
is certainly no obvious field or petro-
graphic evidence for large-scale migra-
tion of alkalies in metavolcanic se-
quences. A case of local redistribution
of major elements during burial meta-
morphism has been described (Smith,
1968) 55 and it is possible that the trace
elements will respond, on a local scale,
to this development of mineralogical
"patchiness." More extensive studies of
trace element behavior during meta-
morphism are clearly needed; however,
use of large representative samples and
sample composites may help to minimize
metamorphic effect.
If the K, Rb, and Sr depletions noted
for Archaean volcanics in Table 11 are
primary features, then what possible in-
terpretations can be formed regarding
the nature of the Archaean mantle?
While there are no young calcalkaline
orogenic volcanics with similar deple-
tions of K, Rb, and Sr, the submarine
basalts of the ocean floors have certain
characteristics which are similar to
Archaean volcanics. Average contents of
K, Rb, Cs, and Sr for these two volcanic
types are compared in Table 11. The sub-
marine basalts have low K and Sr con-
tents, similar to the Archaean volcanics;
however, Rb and Cs are further depleted
in the submarine basalts, leading to con-
siderably higher K/Rb and K/Cs ratios.
A preliminary model relating Archaean
and modern volcanism might be formu-
lated as follows. Submarine basalts are
formed in a region of high thermal
gradient (on the upwelling plume of
mobile mantle under the mid-ocean
ridges) , and probably represent products
of partial melting at shallow depths. We
suggest a similar low pressure mode of
TABLE 11. K, Rb, Cs, and Sr in Archaean and Submarine Basalts
Rock type
K,%
Rb,
ppm
Cs,
ppm
Sr,
ppm
K/Rb
K/Cs
K/Sr
Archaean volcanics
Submarine basalts
0.20
0.16
6.0
1.8
0.36
0.02
150
125
330
900
5500
80,000
13
13
DEPARTMENT OF TERRESTRIAL MAGNETISM
433
formation for Archaean volcanics, as it
is probable that geothermal gradients
were considerably higher during the
earlier periods of Earth history. Perhaps
partial melting at shallow depths is more
extensive than partial melting at high
pressure, leading to a magma with low
contents of K, Rb, Cs, and Sr. The simi-
larity of K and Sr contents in Archaean
and submarine basalts not only suggests
a similar mode of origin but suggests
that removal of K and Sr from the
mantle since Archaean times has not ex-
ceeded 20-30%. On the other hand, the
marked depletions of Rb and Cs in sub-
marine basalts may be explained by rela-
tively large removals of Rb and Cs from
the mantle since Archaean times. Thus a
transport model similar to that proposed
for the Sr isotopic evolution of the
mantle could be applied to these other
elements as well, with relative transport
coefficients in the order
Cs>Rb>K~Sr
Distribution of Potassium in Mafic
and ultramafic nodules
A. J. Erlank
Many workers have considered that
the mafic and ultramafic nodules and in-
clusions found in volcanic rocks, and
specifically those occurring in kimberlite,
may represent fragments of the upper
mantle. Recent studies on these materials
have paid particular attention to the
distribution of K and related elements
Rb, Cs, Ba, Sr, Th, U, and Pb, as well as
the Sr87/Sr86 ratio, in these nodules and
their component minerals, and these
abundances have been used to postulate
models for the composition and differen-
tiation history of the upper mantle. Two
questions are crucial to the interpreta-
tion of such data; both ultimately deal
with the possibility of modification of
the original composition of these rocks
and their minerals. In the first place,
where analysis of whole-rock samples is
concerned, secondary alteration and con-
tamination by crustal material is likely,
particularly for kimberlite nodules. In
this case it is difficult, if not impossible,
to evaluate the primary abundance pat-
terns. Several workers have analyzed
individual mineral separates of the pri-
mary phases to overcome this difficulty.
Apart from the question of whether it
is possible to obtain pure separates, this
raises the second question as to whether
the elemental composition now observed
is reflective of the composition of the
mineral at depth, i.e., whether or not the
composition of the minerals has changed
upon release of the high temperatures
and pressures under which they formed.
These questions can only be answered
by a thorough knowledge of the location
of the elements mentioned, i.e., the pre-
cise internal distribution as revealed by a
technique such as electron-probe analy-
sis. This study is concerned with the
distribution of K in a variety of possible
upper mantle materials. Of the elements
mentioned above, only potassium occurs
in high enough concentrations to be
amenable to electron-probe analysis. By
implication, however, the K abundances
to be discussed provide reliable informa-
tion concerning the distribution of these
associated elements.
During this work it has consistently
been possible to obtain a detection limit
on the order of 20 ppm K. Many of the
minerals analyzed have K contents at or
near the detection limit, and these re-
sults will consequently be imprecise. For
this reason particular care has been
taken in making corrections for back-
ground ; full details of the technique used
together with an assessment of accuracy
will be given elsewhere. In general, it
may be noted that the pure minerals are
considered to yield more reliable data
than the alteration products. For this
reason the values quoted for the altera-
tion products are best considered in a
relative manner by comparison with the
pure minerals. Analysis locations on the
434
CARNEGIE INSTITUTION
pure minerals were chosen by use of both
the reflected and transmitted light facili-
ties in those regions where the grains
were considered to be clear and fresh,
but it is considered likely that the elec-
tron-probe detects alteration, in the form
of high K abundances, that is not op-
tically visible.
Material examined comprises both
rock sections and mineral fractions and
is derived mostly from African kimber-
lite pipes. These include eclogites, garnet
peridotites, garnet pyroxenites and a
phlogopite nodule. For comparison a gar-
net pyroxenite from Salt Lake Crater,
Hawaii, and an eclogite from Kakanui,
New Zealand, have also been studied.
Secondary alteration. The possibility
of secondary contamination of nodules
and inclusions has been commented on
by several workers. Particularly relevant
to this work are the observations by
Gurney, Berg, and Ahrens (1966) 56 con-
cerning anomalously high Cs concentra-
tions in eclogites from the well-known
Roberts Victor Mine, and the subsequent
detailed account by Berg (1968) 57 con-
cerning the nature of the alteration pro-
cesses affecting these nodules.
All the kimberlite nodules studied
show, in varying degrees, evidence of
secondary alteration and contamination
processes, and it is clear that the distri-
bution of potassium is affected by these
processes. It has not yet been possible
to delineate the type and number of
alteration effects experienced by the
nodules, because (1) the alteration prod-
ucts are extremely variable in nature
even within small areas of the same pri-
mary mineral in single nodules, (2) the
type of secondary minerals found varies
from nodule to nodule, even for similar
rock types from the same pipe, and (3)
there is some dependence on geographical
distribution because garnet peridotites
from Lesotho (where the kimberlites are
found higher in the stratigraphic se-
quence intruding Karroo lavas) do not
appear to have such high K concentra-
tions associated with their alteration
products as do those from South Africa.
Likewise the type of secondary veining
observed in two eclogites from Tanzania
is different from that observed in eclo-
gites from the Roberts Victor Mine. How-
ever, much of the K contained in these
rocks, apart from that present in phlogo-
pite, is located in cracks, along grain
boundaries, secondary minerals, and al-
teration products. This is the essential
feature of significance if it be considered
that the alteration took place either dur-
ing transit and emplacement of the
kimberlite or during subsequent weather-
ing of the kimberlite, as both processes
would carry the imprint of the crustal
environment.
Berg (1968) 57 considers that the
Roberts Victor eclogites, which have
been especially severely affected, have
been subjected to two stages of altera-
tion, as suggested above, and this work
for the most part supports his contention.
The type of alteration which has affected
the garnets is dissimilar in composition
to that affecting the omphacites. The
latter type is important because of in-
terest in the K content of clinopyroxenes,
as discussed elsewhere in this report.
Plate 1 shows the fine-grained, turbid
alteration typical of Roberts Victor
omphacites. The electron beam scanning
photographs reveal a phase with a high
K concentration, which is also depleted
in Ca and Mg relative to unaltered
omphacite. Plate 1 (A) indicates the lo-
cation of two traverses, X and Y, which
are shown in Figs. 47 and 48. Berg
(1968) identified an analcime-type zeo-
lite as an alteration product of the
omphacite, but a study of Figs. 47 and 48
suggests that at least three phases are
chemically distinguishable, although op-
tically they are not. The relevant point
of interest concerns the presence of up
to 10% K in one of the phases, in com-
parison with ~0.12% K in the pure
omphacite. This, together with the fine-
grained nature of the alteration (note,
for example, that the K-rich phases are
often less than 10 /*m wide) causes con-
DEPARTMENT OF TERRESTRIAL MAGNETISM
435
GSFC 155 Eclogite, Roberts Victor Mine
!5kV, 0.02/ia, l/ibeam
Altered Omphacite
Fresh Omphacite
t\^\>^/^\^^
no
Fig. 47. Electron-probe traverses for Mg, Ca, and K along line X in Plate 1A showing variation
in composition between fresh and altered omphacite from Roberts Victor eclogite.
cern with respect to obtaining pure sepa- teration. One, which had been leached
rates of the fresh omphacite. Several with dilute HC1, still revealed the pres-
separates have been examined by elec- ence of up to 5% K in altered areas,
tron-probe analysis and all, to varying Hence, it would be desirable, when ana-
degrees, show the presence of K-rich al- lyzing omphacite separates, to monitor
GSFC 155 Eclogite, Roberts Victor Mine .
I5KV, 0.02 fia , l/ibeam
I I ifta sodium
100
10
150
>i«- fresh -a
>
~ 5
o
Microns
Fig. 48. Electron-probe traverse for Na, Ca, and K along line Y in Plate 1A showing variation
in composition between fresh and altered omphacite from Roberts Victor eclogite.
436
CARNEGIE INSTITUTION
the purity of the separates by comparing
the K content of these mineral fractions,
as determined, for example, by isotope
dilution analysis, with that obtained by
electron-probe analysis on pure material.
The type of alteration found in cracks
and surrounding the garnets from
Roberts Victor eclogites is presumably
related to the emplacement of the kim-
berlites. The term kelyphite has been
used to describe this alteration, but this
term is not considered appropriate for
these samples, as it seems clear that ex-
traneous material has been introduced.
Some of the material is phlogopite, and
some is related to phlogopite in having
high Mg and K contents (the latter often
up to 5%), but at the same time the
concentrations of other elements such
as Na and Ca are too high (locally up
to 9% Na and 7% Ca) to be pure phlo-
gopite. In several of the reaction rims
surrounding garnets, potash feldspar is
also present. It may be noted that these
semi-opaque alteration products (kely-
phite) are more readily identified by the
use of the reflected light than the trans-
mitted light facility. However, in many
cases these phases are too variable in
composition and too fine grained to be
identified. For ail Roberts Victor eclog-
ites, the amount of K located within the
reaction rims is far in excess of that
present in the fresh garnets, which in all
rocks analyzed have less than 20 ppm K.
As mentioned previously, the type of
alteration found in other eclogites differs
from that observed in the Roberts Victor
samples. Two eclogites from Tanzania
have virtually all their K located along
cracks and grain boundaries, and the
omphacite does not show the fine-
grained, turbid alteration characteristic
of the Roberts Victor omphacites. Plate 2
indicates the location of K in one of the
Tanzanian eclogites. This sample is con-
sidered to be the freshest kimberlite
eclogite available to the author. The
K-rich phase could not be identified, but
is not phlogopite. Elsewhere, along cracks
in the garnets, small 10-fx grains of
potash feldspar (~13.5% K) were ob-
served. The garnets and omphacites in
both samples have less than 30 ppm K.
A petrographic description and photo-
micrograph of the nodule shown in Plate
2, sample 501, is given by Williams
(1932, plate 82) ,58
The discussion above deals largely
with the Roberts Victor eclogites, as
recent workers have shown particular in-
terest in these nodules. However, many
of the comments regarding Roberts
Victor eclogites apply in a general way
to the other nodules found in kimberlite.
Plate 3 indicates the type of alteration
found in garnets from a garnet peridotite
nodule. The alteration is not phlogopite,
but again has phlogopite affinities in
having high K (-3.5-4.0%) and Mg
contents. This type of "kelyphitic" altera-
tion is common to all garnet pyroxenites
and peridotites examined, although those
from Lesotho apparently have suffered
less K metasomatism than those from
South Africa. The diopside in these
nodules is invariably veined with a fine
alteration product, although this does not
contain as much K as that observed for
the omphacite alteration product, the
highest concentration found being about
1.5% K. An unexpected feature is the
presence of local and erratic areas of
high K concentration in serpentine filling
olivine cracks, where K contents of ap-
proximately 4-6% K are encountered.
No separate mineral phase could be
identified. Sometimes, however, the ser-
pentine veining could be traced to a phlo-
gopite grain, and it could be shown that
the two minerals have reacted with evi-
dent leaching of the phlogopite ; this may
partly explain the redistribution of K
during the serpentinization process.
These features again demonstrate the
difficulty of obtaining pure mineral sepa-
rates. It should also be noted that the
examples shown in Plates 1, 2, and 3 have
been chosen to provide obvious and clear
demonstrations of the distribution of K
in the rocks examined. In many cases,
however, the K-rich alteration is not so
DEPARTMENT OF TERRESTRIAL MAGNETISM
437
clearly defined and not amenable to
analysis by the electron beam scanning
technique.
Preliminary work carried out on
nodules from other environments indi-
cates distributions similar to that re-
vealed above. A garnet pyroxenite from
Salt Lake Crater, Hawaii, contains less
than 35 ppm K in both pyroxenes and
in the garnet, while a K-rich phase con-
tained within a zeolite-carbonate vein
carries up to 3% K. An eclogite from the
Kakanui volcanic breccia, New Zealand,
has less than 30 ppm K in both clino-
pyroxene and garnet. Primary horn-
blende contains 1.2% K, but the highest
concentration of K in this rock up to
2.8% K, is in veinlike alteration along
cracks between the garnet and pyroxene.
Hence, even in these nodules it is likely
that whole-rock trace element work will
be of limited significance.
Potassium content of primary min-
erals. The features described above
demonstrate that high concentrations of
K are to be found in alteration products,
secondary minerals, veins, and cracks,
but no comment has yet been made re-
garding the contribution from such
phases towards the overall K content
of these rocks, nor of the role played
by phlogopite in this respect. Phlogopite
is a frequent constituent of the kimber-
lite nodules, and there has been some
controversy over its mode of origin.
While there is every indication that
phlogopite may be present in small
amounts in upper mantle material, it
appears that some of the nodules, notably
the Roberts Victor eclogites, contain such
large amounts that at least some of the
phlogopite is probably of secondary ori-
gin. Detailed modal analyses and whole-
rock analyses for K are required to re-
solve the question raised above, but the
available data indicates that, irrespec-
tive of the mode of origin of phlogopite
and of its contribution towards the K
content of the rock, much of the K in
these rocks is of secondary origin (Berg,
1968 ;57 Griffin, and Rama Murthy,
1968; 59 Allsopp, Nicolaysen, and Hahn-
Weinheimer, 1969) .60 At this stage it is
pertinent to discuss the K content of
the primary minerals of these nodules.
For reasons given above the role of
phlogopite will not be further considered,
and discussion will be limited to the oli-
vine, garnet and pyroxene phases in these
rocks. Only three olivines have been
analyzed in detail and, as expected, only
small amounts of K are present; all three
contain less than 20 ppm. Of 7 ortho-
pyroxenes studied, one has 35 ppm K,
and the remainder have on the order of
20 ppm or less. One orthopyroxene sepa-
rate analyzed by Griffin and Murthy
(1968) contained 170 ppm K. All the
above minerals are in peridotites and
pyroxenites.
Particular attention has been paid to
the K content of garnets from all types
of garnet bearing nodules, a total of 18
being examined. In most of these, three
separate measurements were made on
different grains. While occasional values
slightly above the detection limit were
recorded in single measurements, as
would be statistically expected, the in-
dividual average for all rocks is below
the detection limit, i.e., less than 20
ppm K. This contrasts sharply with
measurements made on mineral separates
from similar nodules. Griffin and Rama
Murthy (1968) report K contents rang-
ing from 30 to 490 ppm K in 6 garnets
from volcanic nodules, while Allsopp,
Nicolaysen, and Hahn-Weinheimer
(1969) found from 200 to 1340 ppm K
in garnets from 5 kimberlite nodules.
Taken together with the alteration fea-
tures previously described, this indicates
that it may not be possible to separate
garnet concentrates which are pure, at
least with respect to K.
The above observations show that
olivines, garnets, and orthopyroxenes are
not important in controlling the distribu-
tion of K in the upper mantle. There may
be some speculation regarding the pres-
ence of larger amounts of K in these
minerals at high temperatures and pres-
438
CARNEGIE INSTITUTION
sures but this is considered unlikely, as
work reported elsewhere in this report on
synthetic garnets in potassium-rich sys-
tems reveals that even at 70 kb and
1500 °C only trace amounts of K (<100
ppm) are able to enter the garnet struc-
ture.
The K content of clinopyroxenes is
larger and more variable, and hence im-
portant when considering the location
of K in upper mantle material. All data
obtained in this study are summarized
in Fig. 49. Measurements made on vol-
canic nodules other than those from
kimberlite, together with a few samples
from the Bushveld Igneous Complex, are
given in Fig. 49 (A) and show a maxi-
mum K content of 40 ppm. Figure 49 (B)
indicates the K content of 6 normal diop-
sides from nodules in kimberlite, with
a maximum value of 120 ppm being
found in a phlogopite nodule. Also shown
are two subcalcic diopsides, previously
analyzed by Boyd (1961) 61 and which
have the highest concentrations so far
observed for diopsides, namely, 280 and
340 ppm K.
Figure 49 (C) reveals that the distri-
bution of K in omphacite from eclogite
nodules in kimberlite is apparently bi-
DO 200
B
Diopside
Subcalcic diopside
IOO 300 500
Roberts Victor Mine
Other
Ml
n.n
mmn
100 300 500 700 900 1100 1300
Potassium, ppm
Fig. 49. Distribution of potassium in clino-
pyroxenes: (A) igneous clinopyroxenes other
than those from nodules in kimberlite, (B)
diopsides from nodules in kimberlite, (C)
omphacites from nodules in kimberlite.
modal. Seven samples (4 from the
Roberts Victor pipe) carry from less than
20 to 150 ppm K, while 8 others, all from
Roberts Victor, contain 800-1350 ppm K.
The first group obviously have concen-
trations similar to that observed for the
normal diopsides, but the second group
contain concentrations higher than ex-
pected from crystal-chemical observa-
tions. Similar variations have been ob-
served by other workers. Berg (1968),
Griffin and Murthy (1968) and Allsopp,
Nicolaysen, and Hahn-Weinheimer
(1969) report concentrations ranging
from 200 to 2100 ppm K in a variety of
omphacites from eclogite nodules in
kimberlite. It is not clear at this stage
how pure the mineral separates analyzed
by these workers are, but the electron-
probe measurements demonstrate the
existence of omphacites with 1000 ppm or
more K, and which are apparently fresh
and homogeneous at the 1-/* level. The
presence of a clinopyroxene with K con-
centrations of this order as a major upper
mantle phase has important implications
when considering the production of
basaltic magmas, and raises difficulties
for any differentiation scheme such as
proposed by O'Hara (1968). 62 However,
work described elsewhere in this report
on synthetic clinopyroxenes in potas-
sium-rich systems indicates that, at least
up to 32 kb and 1450 °C, the maximum
amount of K likely to enter the clino-
pyroxene structure is on the order of 150
ppm, in agreement with the concentra-
tions found in natural diopsides and the
low K omphacites. It is noteworthy that
a diopside inclusion from a diamond
analyzed by Boyd (1969), yields a K
content of less than 40 ppm.
Papike (1968) ,63 using single-crystal
X-ray techniques, has shown the pres-
ence of submicroscopic intergrowths of
amphibole in high-K Roberts Victor
omphacite, and this appears to be the
most likely explanation for these high K
concentrations. Possibly this may reflect
the presence of limited solid solution be-
tween clinopyroxene and amphibole at
DEPARTMENT OF TERRESTRIAL MAGNETISM
439
great depth. It is not considered that
these amphibole intergrowths are due to
the type of alteration process described
in the first section of this report, as one
of the samples examined (belonging to
the low-K group), which was chosen
because of the extreme alteration it had
undergone, still showed homogeneous K
concentrations (45 ppm) in small relict
areas of clear omphacite. It is possible
of course that the intergrowths reflect an
earlier, higher temperature alteration.
Recent research on kimberlite eclogites
has suggested the presence of at least
two types of eclogite nodule. Both Rick-
wood, Mathias, and Siebert (1968) 64 and
Macgregor and Carter (1969) 65 suggest
a classification in terms of Group I and
Group II eclogites (the former authors
also treat kyanite and corundum eclo-
gites as separate groups), and it appears
that both classifications may refer to the
same types of eclogites. Seven of the
samples analyzed by Rickwood, Mathias,
and Siebert have been analyzed in this
study, and for these all high-K ompha-
cites belong to Group I and all low-K
omphacites to Group II of their classifi-
cation. Hence this may reflect a different
mode or location of formation for the two
eclogite groups. It is considered unlikely
that the low-K types are differentiates of
the high-K eclogites, as this is contrary
to the known geochemical behavior of K.
It is clear that the high-K omphacites,
coupled with their high K/Rb and low
Sr87/Sr86 ratios (Allsopp, Nicolaysen, and
Hahn-Weinheimer, 1969) are of prime
importance in understanding upper
mantle differentiation processes. Other
compositional differences are also likely
to be important. Preliminary electron-
probe data show that the low-K ompha-
cites have distinctly higher Ca contents
than the high-K omphacites, and it seems
likely that other fundamental differences
also exist.
Potassium Contents of Synthetic
Pyroxenes at High Temperatures
and Pressures
A. J. Erlanh and I. Kushiro
Electron-probe analyses of presumed
upper mantle materials, in particular
kimberlite nodules, have revealed that
olivines, garnets, and orthopyroxenes in
general contain less than 30 ppm potas-
sium and hence do not play an important
role in the distribution of potassium in
the upper mantle. The K content of
clinopyroxenes is considerably larger and
is crucial when considering the produc-
tion of basaltic liquids with K contents
varying from 0.05 to 1.5%.
Garnet peridotites, such as those found
in kimberlites, are often assumed to be
the dominant rock type present in the
upper mantle. Chrome diopsides from
these nodules generally contain on the
order of 100 ppm K or less. The highest
concentrations measured to date by elec-
tron-probe analysis have been observed
in two subcalcic diopsides (Boyd, Year
Book 66, pp. 331-334) ; concentrations
of 280 ppm and 340 ppm K in these two
pyroxenes have been measured in this
study. Even allowing for 15% modal
abundance for diopsides in garnet peri-
dotite, the K content of the resultant
assemblage does not satisfactorily ac-
count for the high K contents of alkali
basalts, provided at least 1% direct
partial melting is involved in the pro-
duction of the basalt.
Potassium contents of eclogitic ompha-
cites from African kimberlites are more
difficult to interpret. Electron-probe
analyses given elsewhere in this report
demonstrate that the K distribution of
omphacites is apparently bimodal, with
some containing from 20 to 150 ppm K,
while others carry from 800 to 1400
ppm K. The comments expressed above
with respect to the diopsides obviously
apply to the low-K omphacites. How-
ever, the K content of the second group is
larger than expected and difficult to ex-
plain on crystal-chemical grounds. It is
440
CARNEGIE INSTITUTION
clear that the presence of clinopyroxene
with K contents of this order as an upper
mantle phase would be important for
controlling the distribution of K in
basaltic liquids. Hence, it appeared de-
sirable to seek confirmation of this
feature.
We have attempted to determine ex-
perimentally the amount of K which
could enter the clinopyroxene lattice un-
der upper mantle conditions by reacting
together, at high temperatures and pres-
sures, various clinopyroxenes and potas-
sium-rich phases and measuring the
potassium content of the resultant pyrox-
enes by electron-probe analysis.
The experiments were made in the
pressure range 15-32 kb with a piston-
cylinder apparatus similar to that de-
signed by Boyd and England (I960).66
Sealed Pt tubes were used for the hy-
drous runs. The starting materials are
mechanical mixtures of the following ma-
terials: synthetic pure diopside made by
Hytonen and Schairer; a mixture of
phlogopite composition consisting of
forsterite, quench forsterite, and glass;
a mixture crystallized at 1 atm from a
glass of composition anorthite 50 forster-
ite 50 (by mole) ; a natural omphacite
from Kaminaljuyu, Guatemala (origi-
nally described by Foshag, 1957) 67 which
has a composition close to diopside 45
jadeite 55 (by mole) (Clarke and Papike,
1968) ; 68 and a natural potassic richterite
from Wolgidee, Australia, which is simi-
lar in composition to that analyzed by
Wade and Prider (1940) 69 and is de-
scribed in this report, pp. 442-443.
In all of the hydrous runs, diopside
and omphacite were recrystallized to
euhedral~subhedral crystals even at
subsolidus temperatures. During the elec-
tron-probe analysis for K the other two
spectrometers were set for Ca and Mg,
and comparison of the starting materials
and reactants indicated the recrystalliza-
tion of the clinopyroxenes. Additional
measurements for Na also revealed the
nature of the pyroxenes formed. Phlogo-
pite occurs as hexagonal plates forming
thick books ; however, when glass is pres-
ent, it often appears as feathery crystals,
which are believed to be quench crystals.
Richterite which had been ground finely
was also recrystallized to relatively large,
euhedral~subhedral crystals. Because of
recrystallization in the presence of excess
vapor, equilibrium is believed to have
been attained in the hydrous runs. In
the anhydrous run made for the 1:1
mixture of diopside and phlogopite com-
position, the temperature was raised to
above the solidus to secure equilibrium.
A great deal of difficulty has been ex-
perienced in making the electron-probe
measurements. Partly this is due to the
small size of the reaction products, neces-
sitating the use of a l-2-/mi electron
beam and low sample current (0.025 fxa)
with resultant low intensity. The main
problem has, however, been caused by
the presence of minute inclusions and
intergrowths of these crystals with
K-rich phases (phlogopite and glass),
frequently resulting in anomalously high
K contents for apparently clear clino-
pyroxene grains. Consequently, several
runs have been discarded and we report
here only those measurements for which
a fair amount of consistency has been
established. Particular care has been
taken in making background measure-
ments, often by using the pure starting
materials which were always mounted
together with the reaction products. It is
to be noted that the results have only
been corrected for background and drift,
but it is believed that they are accurate
to within 10-20% of their true values;
this level of accuracy is adequate for
present purposes. A detailed account of
the technique used will be given on p. 443
of this report.
The assembled data are listed in Table
12. It is immediately apparent that re-
gardless of variation in mineral assem-
blage, temperature, pressure, and water
content, the amount of K which has
entered the clinopyroxene reaction prod-
ucts is small, less than 150 ppm. Even
where clinopyroxene has crystallized di-
DEPARTMENT OF TERRESTRIAL MAGNETISM
441
TABLE 12. Potassium Contents of Synthetic Clinopyroxenes and Garnets
Reactants
P,kb
T,°C
Dura-
tion,
hours
H20,%
Products
Ppm K in
clino-
pyroxene
Di + Anhy Phi (1:1)
15
30.5
32
21
1100
1150
1000
1450
4
3%
4
2y4
11.4
13.1
4.6
Di, Fo, Phi, Gl, gl
Di, Fo, Phi, Gl, gl
Di, Phi, gl
Di, Fo, Gl
140
90
70
140
Omph + Anhy Phi (1:1)
(2:1)
(1:1)
25
25
26.5
30
1000
1000
1050
1100
5y6
6
4
3
5.0
40.0
7.4
22.2
Omph, Phi
Cpx, Phi, Fo, gl
Cpx, Phi, Gl
Cpx, Fo, Phi, gl
110
50
<50
50
Rich + AniFoi(2:l)
Rich + Di (1:1)
20
24
1000
1000
3
2
4.7
10.4
Rich, Phi, Cpx
Rich, Cpx
120
<50
ppm K in
garnet
Anhy Phl + AnJEVh (1:4)
Phi*
30
70
1100
1500
3
%
12.6
Gt, Cpx, Phi
Gt, Phi, q-Phl, X
<50
<100
*Run prepared by Kushiro, Syono, Akimoto (1967) .70
Abbreviations: Di = diopside; Anhy Phi = anhydrous phlogopite composition; Phl = phlogo-
pite ; Fo == forsterite ; Gl = glass ; gl = glass balls considered to be quenched vapor ; Omph = ompha-
cite ; Cpx = clinopyroxene solid solution ; Rich — potassic richterite ; Gt = garnet ; AniFd +
crystalline mixture of anorthite and forsterite (1:1 by mole) = pyrope-grossular (2:1 by mole);
q-Phl = quench phlogopite; X= unknown phase.
rectly from liquid under anhydrous con-
ditions and in the absence of phlogopite,
nearly all the K has remained in the
liquid, as measured by the K content of
~13% in the glass. At this stage it is
not clear to what extent variations in
temperature, pressure, and sodium con-
tent affect the substitution of potassium.
These results seem in accord with the
natural diopsides and low-K omphacites
previously discussed, and we have found
no experimental evidence to explain the
presence of 1000-1500 ppm K in ompha-
cite. The most likely explanation appears
to be that these high-K contents are
due to the presence of submicroscopic
intergrowths of amphibole in the ompha-
cite structure, as suggested by Papike
(1968) 63 on the basis of X-ray studies.
This possibility has important implica-
tions regarding the genesis of eclogites
and basaltic lavas, and requires further
confirmation. In our runs with amphibole
and pyroxene, no reaction has occurred
between these minerals.
Also given in Table 12 are measure-
ments made on garnets produced in two
runs. Potassium was not detected in
either one. One of the runs had previ-
ously been analyzed with an electron
probe, and up to 5.8% K reported in the
garnets (Kushiro, Syono, and Akimoto,
1967) .70 The original electron-probe sec-
tion was available, and further study
showed that the earlier analysis was in
error. The discrepancy is most likely due
to the beam's overlapping high-K mica
in the original analysis. During the
analysis of this section, one of the break-
down products of phlogopite was found
to have a very high potassium content
(phase X in Table 12). Semiquantitative
analysis indicates that this phase has of
the order of 29% K20 and 32% MgO,
but with an anomalously low Si02 con-
tent of 1% or less. Unfortunately, the
fine-grained nature of this phase and
poor surface of the section prevented
proper analysis, and we are not able at
this stage to identify this phase. It seems
clear that clinopyroxenes and garnets
will not accept sufficient potassium in
their structures, even at high temperature
and pressures, to provide that required
to form basalt by simple partial melting.
In this case, the rocks which are parental
442
CARNEGIE INSTITUTION
to basalt must contain potassium-rich
phases such as phlogopite and/or K-rich
amphibole.
The Occurrence of Potassic Richter-
ite in a Mica Nodule from the
Wesselton Kimberlite, South Africa
A. J. Erlank and L. W. Finger
The presence of amphibole as a con-
stituent of the upper mantle has been
suggested by several workers, and cogent
geochemical and geophysical arguments
have been presented in support of this
contention (Oxburgh, 1964; 71 Ringwood,
1964; 72 Hart and Aldrich, 1967) .73
Amphibole, usually in the form of horn-
blende or pargasite, has frequently been
observed in rocks of possible upper
mantle origin, such as the amphibole
peridotites from St. Paul's rocks on the
mid-Atlantic Ridge, and as xenocrysts
and in xenoliths from basic volcanic
rocks and tuffs (Mason, 1968) ,74 but to
our knowledge has not been recorded as
a definite primary constituent of the
mafic and ultramafic nodules found in
Southern African kimberlite pipes.
During the course of electron-probe
analysis of a mica pyroxenite nodule
from the Wesselton kimberlite pipe,
South Africa, a mineral with an unusual
potassium content was encountered and
subsequently identified as the rare
amphibole, potassic richterite (magno-
phorite) . These nodules, also referred to
as phlogopite nodules, are distinctive in
that they consist almost entirely of
phlogopite (>90%) with minor amounts
of diopside. Garnet, olivine, and ortho-
TABLE 13. Electron Microprobe Analyses of Kimberlitic Potassic
Richterites and Diopside
Richterite
Diopside
Si02
j
1
2
3
>4.3
54.4
54.1
542
Ti02
"0.59
0.60
0.59
0.10
AI2O3
1.22
1.25
1.24
0.71
FeO*
4.36
4.34
4.22
5.07
MnO
0.07
0.07
0.07
0.17
MgO
20.9
21.4
21.2
16.0
CaO
7.06
7.14
7.15
20.7
Na20
3.19
3.20
3.34
1.50
K20
4.70
4.77
4.69
0.01
Cr203
Total
(
0.07
0.0
6
0.04
0.42
)6.5
97.2
96.6
98.8
Number of ions on
Numbers of ions on the basis of
the basis of
23 oxygens
6 oxygens
1
2
3
Si
52} »™
7.751
021 - 8.00
0.04 J
7.761
Si 2.010
Al
0.21
> 8.00
Ti 0.003^
Ti
0.03.
Al 0.031
Al
6. oh
Ca 0.820
Ti
0.06
0.02"
0.03]
Cr 0.012
Mg
Cr
4.46
0.01
- 5.00
4.55
0.01
v 5.00
4.52
0.01
* 5.00
Fe 0.157
Mn 0.005
> 2.018
Fe
0.46,
0.42 <
0.44.
Ca 0.820
Fe
0.05
0.101
0.07
Mg 0.881
Mn
0.01
► 2.00
0.01
- 2.00
0.01
► 2.00
Na 0.108
K 0.001 J
Ca
1.09
1.09
l'.io
Na
0.84
0.80
0.82,
Na
K
0.05'
0.86,
► 0.91
0.08 1
0.87.
\- 0.95
0.111
0.86.
> 0.97
* Total Fe expressed as FeO.
DEPARTMENT OF TERRESTRIAL MAGNETISM
443
pyroxene are absent. A petrographic de-
scription and chemical analysis of the
nodule in question, WESS 156, are given
by Williams (1932) ,58 pp. 347, 350.
The potassic richterite found in this
nodule is present in the form of small
subhedral grains, usually about 100 /mi
in length, contained within the diopside,
and appears to be of primary origin.
Optical characteristics are consistent
with those available for other richterites.
Three of these grains together with the
associated diopside, have been analyzed
by electron-probe analysis, while a
fourth identified by probe analysis in a
grain mount of separated diopside grains
has been partially isolated and analyzed
by single-crystal X-ray diffraction.
Relevant chemical data are presented
in Table 13. Multiple measurements
show each grain to be homogeneous with
very little, if any, variation between
grains. Compared with the type analysis
for potassic richterite (Wade and Prider,
1940) ,69 the Wesselton richterite has
slightly differing FeO and K20 contents,
but the most striking difference is the
lower Ti02 content of the Wesselton
potassic richterite (0.6% Ti02) com-
pared with the value of 3.5% Ti02 given
by Wade and Prider. The significance
of this feature and its possible depen-
dence on pressure is discussed on p. 000
of this report. The average of the three
analyses expressed in the amphibole for-
mula, is (K 86Na.08) (Na.82Ca1.o9 Mn,01
Fe07) (Fe.45Mg4.BiTi.04Cr.01) (Si7.77Al.21
Ti.02) 022 (OH)2.
The composition of the enclosing di-
opside is given for comparison purposes.
It has a lower chrome content than diop-
sides that occur in the peridotite nodules,
and is similar to a diopside inclusion
from a diamond studied by Boyd {Year
Book 67, pp. 133-135).
The Wesselton potassic richterite grain
examined by single crystal techniques
was only partially separated from the
enclosing diopside because of difficulties
in handling small grains. The interfering
diffraction pattern handicapped the ori-
entation of the grain but the following
cell data were obtained from precession
photographs: a, 10.00 A; b, 18.00 A; c,
5.26A; p, 104.8°; V, 917 A3. The cell
data of the diopside at 23°C were mea-
sured from back-reflection Weissenburg
photographs and yielded the following
results: a, 9.734 ±0.002 A; 6, 8.9135 +
0.0005 A; c, 5.261 ±0.006 A; ft 106.06 ±
0.03°; V, 438.6 ±0.6 A3.
It is difficult at this stage to assess
the importance of the occurrence of
potassic richterite in the mica nodule.
Certainly it appears to be of primary
origin, and work described by Kushiro
and Erlank in "Stability of Potassic
Richterite," p. 231 of this report, shows
that in the absence of phases other than
diopside it is stable to higher tempera-
tures and pressures than any other
amphibole so far examined. Hence, al-
though it occurs only as a trace con-
stituent in the nodule examined, it may
indicate the type of amphibole likely to
occur in the upper mantle. However, pre-
liminary work described elsewhere in this
report indicates that it may not be stable
in the presence of nonpotassic aluminous
phases such as garnet. Nevertheless, if
one percent of potassic richterite of the
type analyzed occurs in upper mantle
material, the resulting K content of 400
ppm is sufficient, when such material is
subjected to partial melting and frac-
tionation along the lines suggested by
O'Hara (1968), to account for the K
content of most basaltic lavas. This
would also apply to other elements re-
lated to K, specifically Rb and Ba, and
hence it would be of some interest to
determine the trace element content of
potassic richterites.
Stability of Potassic Richterite
I. Kushiro and A. J. Erlank
This report may be found in the annual
report of the Geophysical Laboratory
{Year Book 68, pp. 231-233) .
444
CARNEGIE INSTITUTION
Strontium Isotope Abundances in
Layered Ultramafic Rocks
A. J. Erlank
The continental crust has been in-
truded by a number of ultramafic layered
complexes during its geologic history,
and these are generally believed to origi-
nate in the upper mantle. Hence they
can provide information on the isotopic
characteristics of the liquids from which
they crystallized, and, by implication,
on the source areas of these bodies at the
time of intrusion. The South African
continent has been intruded by several
pre-Cambrian layered complexes, and
preliminary Sr isotopic work on two of
these is here described.
The well-known Bushveld Igneous
Complex has been adequately described
in the literature and hardly requires fur-
ther description. The related but smaller
Losberg Complex, also located in Trans-
vaal, South Africa, has recently been
comprehensively described by Abbott
and Ferguson (1965) 75 and Danchin and
Ferguson (1969) .76 Of special interest to
this study are the different K/Rb ratios
reported for equivalent rock types from
these two complexes (Erlank, Danchin,
and Fullard, 1968; 77 Danchin, 1968 78).
Sr isotope analyses have been made on
some of the mafic and ultramafic rock
types analyzed by these authors and the
results are shown in the Rb-Sr isochron
plot of Fig. 50. (Analysis of the standard
Eimer and Amend SrC03 during this
period yielded a value of 0.7085 ± 0.0003.)
For convenience, the Losberg data are
considered first. Least-squares analysis
of the data indicates an age of 1918 ±
350 m.y. and an initial Sr87/Sr86 ratio of
0.7061 ±0.0027 (95% confidence limits).
The uncertainties in these values are
0.730-
0.725 -
0.720 -
CO
«L 0.715
CO
0.710 -
0.705
0.700
Bushveld
Diorite
Anorthosite
Norite
Pyroxenite
— I r
Losberg
Quartz gobbro
Quartz norite
Harzburgite
J L
J L
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Rb87/Sr86
Fig. 50. Rb-Sr relationships in rocks from the Bushveld and Losberg igneous complexes.
DEPARTMENT OF TERRESTRIAL MAGNETISM
445
certainly partly because of the narrow
spread of the Rb/Sr ratios, consistent
with the overall range of magmatic dif-
ferentiation observed, and partly because
of the fact that the Rb and Sr concen-
trations have only been determined by
X-ray fluorescence. However, it is be-
lieved that the spread shown on the iso-
chron is also influenced by geological
processes. Electron-probe analysis of a
few of the rocks indicates that some re-
distribution of alkalies has occurred.
For example, the Harzburgites in the
Losberg are characterized by the pres-
ence of traces of biotite (^1-2%), a
feature not characteristic of the Bush-
veld rocks. The electron-probe studies
show clearly that the mica has been
"leached" by subsequent serpentinization
processes and the question naturally
arises as to the extent of the redistribu-
tion. More detailed work is required to
resolve this question; nevertheless it is
clear that the Losberg rocks define an
isochron which is not significantly differ-
ent in age from that previously estab-
lished for the acid rocks from the Bush-
veld Igneous Complex, i.e., 1970 ± 70 m.y.
(Nicolaysen, de Villiers, Burger, and
Strelow, 1958 79), but which is younger
than that found for rocks from the re-
lated Great Dyke in Rhodesia, i.e.,
2530 + 30 m.y. (Allsopp, 1965). 80
The Bushveld mafic and ultramafic
rocks have an insufficient spread in
Rb/Sr ratio to establish a reliable age
and, in fact, have such low ratios that the
measured Sr87/Sr86 ratios effectively yield
the initial isotope ratios. The single dio-
rite analysis is difficult to interpret, as
the genesis of these rocks is not clearly
established. If it is considered that this
rock is an iron-rich differentiate of the
basic suite, and if the initial ratio of the
basic rocks is taken as Sr87/Sr86 = 0.7065,
the age of this rock is 2125 m.y. This is
not significantly different in age from the
Losberg rocks, but the possibility exists
that the mafic rocks from the Bushveld
are slightly older than those from the
Losberg. However, the simplest interpre-
tation of the available data suggests that
both complexes were emplaced during the
same period of magmatic activity and
may in fact be cogenetic in origin, the
Losberg rocks being more differentiated
than those from the Bushveld.
The initial Sr isotope ratios of the two
complexes are not in agreement with
those inferred from other studies for the
upper mantle at that time. The initial
Sr87/Sr86 ratios for these complexes are
clearly within the range 0.7060-0.7065
and are significantly higher than the
ratio of 0.7025 for rocks of the Great
Dyke (Allsopp, 1965) and the ratios
given elsewhere in this report for 2700-
m.y. metavolcanics from the Canadian
Shield.
If the Bushveld and Losberg rocks
reflect the initial Sr isotope compositions
of their source areas, this could imply an
origin either in the upper mantle or lower
crust. The latter possibility is generally
considered unlikely on petrological
grounds, but is quite feasible from the
point of view of Rb-Sr abundance rela-
tionships. Derivation from the upper
mantle necessitates that the latter be
inhomogeneous in nature, with regions of
high radiogenic Sr87 content. The low
Rb/Sr and high K/Rb ratios of the
Bushveld rocks would further restrict the
composition of the source areas, if these
ratios are in any way reflective of these
regions.
It is perhaps more likely that the rocks
studied do not reflect the Sr isotope
compositions of their source areas, i.e.,
the upper mantle, and have been modi-
fied or contaminated during or after em-
placement. If so, such processes must
account for the similarity of the Sr87/Sr86
ratios in both complexes, and yet also
be consistent with the different Rb/Sr
and K/Rb ratios observed. Bulk assimi-
lation of crustal material could explain
these relationships in the Losberg rocks,
but the high K/Rb and low Rb/Sr ratios
of the Bushveld rocks are not easily ac-
counted for by this process unless ex-
tensive differentiation occurred subse-
446
CARNEGIE INSTITUTION
quent to contamination. Previous work
(Erlank, Danchin, and Fullard, 1968)
has already suggested that the Bushveld
mafic rocks are depleted in Rb because
of mineralogical effects.
It is also possible that selective dif-
fusion of radiogenic Sr87 into the magmas
of these rocks has occurred, without the
K/Rb and Rb/Sr ratios being signifi-
cantly changed. It is difficult to see how
such a process would affect both com-
plexes equally, unless a common magma
chamber is assumed. The same type of
comment would apply to a subsequent Sr
homogenization process.
The data presented in this study are in
agreement with data reported for other
ultramafic layered complexes and conti-
nental tholeiites in that high initial
Sr87/Sr86 ratios are observed, and it is
clear that such ratios are more common
than previously supposed.
COSMIC-RAY RESEARCH
S. E. Forbush
The variation in the cosmic-ray di-
urnal anisotropy with a period of two
sunspot cycles. Two preceding annual re-
ports described the statistical analyses
which led to the discovery of a well-
determined variation with a period of
two solar cycles in the cosmic-ray di-
urnal anisotropy recorded by Carnegie
Institution of Washington cosmic-ray
ionization chambers. Figure 3 in Year
Book 66 (p. 12) showed that the yearly
means of the diurnal anisotropy in the
asymptotic direction 128° E of the sun,
after removing the effects associated with
magnetic activity, were well fitted by a
20-year wave. This 20-year wave, twice
the sunspot period of 10 years for the
interval 1937-1965, passed through a
zero near the end of 1958 close to the
time when, as shown by Babcock from
measurements at the Mt. Wilson Ob-
servatory, the sun's poloidal magnetic
field reversed.
It is well known that the period of the
sunspot cycle varies from about 10 to
13 years with an average near 11 years.
Consequently, the interval between suc-
cessive reversals of the sun's poloidal
magnetic field is expected to vary from
about 10 to 13 years (period 20 to 26
years). If when such variation in re-
versals occur they correspond with those
in the reversal of sign in the asymptotic
component 128° E of the sun in the
cosmic-ray diurnal anisotropy this would
provide additional strong evidence that
reversal of the sun's general magnetic
field is responsible.
In addition to results shown for the
years 1937-1965 in Fig. 1, Year Book 66,
p. 10, Fig. 51 of this report includes re-
sults, shown by triangles, for the four
years 1936, 1966, 1967 and 1968. The
20-year wave in Fig. 51 (this report)
passes through a zero near the end of
1968. The yearly mean diurnal aniso-
tropy component for 1968 lies signifi-
cantly above the dashed curve (with a
period of 20 years). Analysis of solar
magnetograms made at Mt. Wilson Ob-
servatory gives no indication of any
tendency for reversal in the sun's poloidal
field as late as March 1969 which would
accord with the cosmic-ray result for
1968 in Fig. 51. Valuable additional evi-
dence concerning a causal relation be-
tween the two phenomena should be
available in the next few years.
In collaboration with Pomerantz and
Duggal of the Bartol Research Founda-
tion, a study based on Simpson's neu-
tron-monitor data from Huancayo was
made of the magnitude of the variation,
with a period of 20 years, in the asymp-
totic component of the diurnal anisotropy
128° E of the sun and of that in the
component 90° E of the sun (20-year
variation removed) . Both of these varia-
tions were found in agreement with those
from the ionization chambers during the
interval 1953 to 1966 for which the
neutron-monitor data were available.
Cosmic-ray ionization chamber for
Christchurch, New Zealand. The Car-
negie Institution of Washington cosmic-
ray ionization chamber No. C-4 was
DEPARTMENT OF TERRESTRIAL MAGNETISM
447
-10
1940
1950
I960
1970
Fig. 51. Twenty-year wave in the amplitude of the component of the diurnal anisotropy in
the asymptotic direction 128° east of the sun corrected for variations due to magnetic activity Uo.
installed in Christchurch in March 1969.
The Geophysical Observatory in Christ-
church constructed housing within a large
building used for storing equipment and
supplies for research projects in Ant-
arctica. The Geophysical Observatory
has kindly arranged for one of its tech-
nicians to carry out operation of the
meter and its routine maintenance.
Most of the measurements from the
ionization chamber records will be made
promptly by the Geophysical Observa-
tory at Christchurch in order to provide
data to correct radiation measurements
for the variable cosmic-ray background.
These radiation measurements by the
National Radiation Laboratory are made
by special detectors mounted within the
Carnegie Institution of Washington
ionization chamber which was operated
in Christchurch from 1937 to 1961.
Publication of cosmic-ray results. The
manuscript and tables for Carnegie Insti-
tution of Washington Publication No.
175, vol. XXII, have been turned over
to the Institution's editorial office which
anticipates that this volume will be
available late in 1969. This publication
will contain results for January 1960
through December 1968 from Huancayo
and Fredericksburg, for the period 1959
to 1961 from Christchurch, and for 1951
to 1953 from Godhavn.
Observations and reduction of data.
Cosmic-ray ionization chambers were
operated throughout the report year at
Huancayo, Peru, and at Fredericksburg,
Virginia. Scalings and reduction of
records have been maintained on a cur-
rent basis for both stations. The reduc-
tions have been greatly facilitated by the
use of the IBM 1130 computer. Registra-
tion from the cosmic-ray meter at Christ-
church commenced near the end of March
1969.
Cooperation in operation of cosmic-
ray meters. Grateful appreciation is ex-
pressed to the U. S. Coast and Geodetic
Survey and the staff of its magnetic ob-
servatory at Fredericksburg for efficient
operation of the meters during the past
report year, and to the Government of
448
CARNEGIE INSTITUTION
Peru and to the Director and staff of the
Instituto Geofisico del Peru for making
cosmic-ray records from Huancayo
available.
Grateful appreciation is expressed to
the Director and staff of the Geophysical
Observatory at Christchurch, New Zea-
land, for providing housing for the
ionization chamber and for greatly as-
sisting in the installation of the equip-
ment as well as its reception through
customs. We are also grateful to the
National Science Foundation for having
shipped the equipment and for providing
air transportation for Dr. Forbush from
Washington to New Zealand on an Air
Force Deep Freeze plane.
SEISMOLOGY
A Sensitive Borehole Strain-rate
Meter
/. S. Sacks and D. W. Evertson
The measurement of strain changes
in the earth is fundamentally important
to the understanding of earthquakes.
The amplitude of the change in the strain
field in the vicinity of an earthquake
decreases as the square of the distance
from the hypocenter, and therefore in-
struments of high sensitivity are required
to detect and measure these changes for
smaller earthquakes, and for those at
longer distances.
A borehole strain-meter has been de-
veloped jointly by the Department of
6 in. o.d.
CAPILLARY
BYPASS
0.004 in. i.d
xlin. LONG
CERAMIC
CALIBRATOR
(STEP VOLUME
CHANGE)
ALL
MATERIAL:
316 STAINLESS WATER
CHLOROFORM
LEAD BALLAST SATURATED
Fig. 52. Prototype of the borehole strain-rate meter. The first instrument was installed in a
borehole 150 feet deep on the DTM campus. Solid rock was intersected at a depth of 70 feet. The
water in the instrument is saturated with chloroform to inhibit microbial growth.
DEPARTMENT OF TERRESTRIAL MAGNETISM
449
Terrestrial Magnetism and the Applied
Research Laboratory of the University
of Texas at Austin. In essence, it con-
sists of a water-filled resilient tube in
intimate contact with the walls of a bore-
hole. As the strain in the surrounding
rock changes, the tube is deformed, forc-
ing liquid through a flow sensor into
an air space. A drawing of the instru-
ment is shown in Fig. 52. All metallic
parts are fabricated from 316 stainless
steel, because of its corrosion resistance.
It is, of course, imperative that the tube
faithfully follow the minute distortions
(down to 10~7 microns) of the hole. This
is ensured by prestressing the % -inch-
thick steel tube with an expanding
cement which bonds the strain-meter to
the rock. After curing for about one
month, the cement expansion is such as to
cause a prestress on the tube of about
7psi.
The flow sensor used is a linear solion
(Larkam, 1965) 81 developed by ARL.
This is a device in which the current flow-
ing between an anode and a cathode is
modulated by the pumping of the electro-
lyte (in this case due to the deformation of
the steel tube) through a porous cathode.
Two such cathodes are arranged in a
push-pull system (Fig. 53). Flow in the
direction of the arrow would cause the
current in cathode 1 to increase and the
current in cathode 2 to decrease.
Cathode 1
Cathode 2
Anode
Insulation
Diaphragms
Fig. 53. Schematic drawing of the solion flow
velocity sensor. The cathodes are made from
very fine platinum basket weave. The electro-
lyte is potassium iodide and free iodine, and the
solion body is made of Kel-F. The two half
cells have a bias voltage of about 0.5 volts
applied; the current in each cathode is a
measure of the flow velocity of the electrolyte
through the cathodes.
Solion noise measurements (by D. W.
Evertson), gave a noise current of 10-8
amperes, dominantly in the period range
20-100 seconds. The noise of the two
cathodes was coherent, however, sug-
gesting fluid pumping, and the actual
noise is probably substantially less than
10~8 amperes. Typical flow sensitivity of
this type of solion is 40 amps/cc/sec;
therefore, the threshold sensitivity is
0.4 xlO-10 cc/sec. The velocity sensitiv-
ity is flat down to 20-sec period; then
the sensitivity gradually decreases to-
wards shorter periods. The volume of
water in the steel tube is 30 liters, giving
a volume strain-rate threshold sensitivity
of 1.2 X 10~14/sec. The frequency response
of the strain-meter as installed in the
DTM campus is shown in Fig. 54. The
departure from a velocity law at periods
longer than one day is due to the capil-
lary bypass (Fig. 52). The purpose of
this bypass is to avoid permanent defor-
mation of the solion diaphragms caused
by tube deformation due to concrete pre-
stress, temperature changes during in-
stallation, and any long-term volume
changes of the immediate environment of
the strain-meter.
Results after the concrete had cured
(less than 3 months) showed that the site
noise was well above the internal noise
of the instrument. In the period range
covered by this instrument, the earth
noise is dominated by microseisms in the
6-20 sec range with strain rarely less
than 10~10 and occasionally an order of
magnitude higher. The earth tide (due to
the attraction of the moon) is about
4 x 10~8 at this latitude. The noise in the
period range between the microseisms
(~8 seconds) and about one hour has
been found to be locally generated by
small atmospheric pressure fluctuations
which typically seem to be about 30 mi-
crobars. If one considers the effect of very
long wavelength disturbances, where
wavelength A/4 is significantly greater
than the depth of the strain-meter, there
is no attenuation, and the strain c, is given
by e=P/E where P is the pressure and E
450
CARNEGIE INSTITUTION
10"
Noise ccused by atmospheric pressure fluctuations
IOO,OCO
10,000
1000
1.0
Period (seconds)
Fig. 54. Frequency response of the prototype strain-meter. The response below 100,000-second
period falls off at 12 db/octave due to the capillary bypass (Fig. 52). The response at short
periods is modified by electronic double integration to reduce the sensitivity in the microseism
range, 6-20 second period.
is Young's modulus for the rock. Assuming
pressure fluctuations of 30 microbars and
E for rock of 107 psi, the resulting strain
(vertical component) would be 4.5 X
10-11. Because this was the level of strain
noise actually found (see Fig. 55) , a
microbarograph with matched frequency
response was installed. Figure 56 shows
the correlation between the microbaro-
graph and the strain-meter. The low pass
filter which has been applied to both in-
struments cuts the sensitivity at a rate
of 6 db/octave at periods shorter than
200 seconds. The correlation is extremely
high at all times (except of course during
large earthquakes). It would appear
from this very high correlation that the
earth noise in the period range one hour
to three minutes must be at least one
order of magnitude less than the at-
mosphere-induced noise, i.e., less than
10~12. The wavelengths of the atmos-
pheric disturbances are relatively short,
since this noise seems to be associated
mainly with weather fronts which travel
at velocities as low as 15/km/hour.
Therefore, the wavelength of a one-
minute period disturbance is only 250
meters. It is found that the close wave-
form correlation that exists at periods
longer than about 3 minutes deteriorates
towards the shorter periods, i.e., down to
30 sec. Figures 55 and 57 show typical
records. Figure 55 is the recording of a
New Guinea earthquake.
Setting up a network of similar instru-
DEPARTMENT OF TERRESTRIAL MAGNETISM
451
001 . OS
452
CARNEGIE INSTITUTION
30 fi bars forM
Fig. 56. Comparison of microbarograph and strain-meter records. The microbarograph trace
has been broken into three sections and displaced vertically to compensate for the large low-
frequency excursion on the strain-meter record due to the earth tide. The close correlation of
the two traces at periods of less than 1 hour suggests that most of the noise on the strain-meter is
caused by atmospheric pressure fluctuations.
ments of high sensitivity and relatively
low cost might be a practical way to
learn the behavior of the stresses and
strains in earthquake regions of the
earth.
Time Anomalies and Structure
Beneath the Andes
/. S. Sacks, G. Saa, and P. Aparicio
The Carnegie Analysis Center was set
up in Lima, Peru, in 1965. One of the
subsidiary goals of the Center was the
collection of data to see what, if any,
correlation existed between surface ex-
pression and what lies beneath — for ex-
ample, the Andes Mountains, and anom-
alous velocities in the upper mantle.
Otsuka made a few preliminary deter-
minations using near-vertically incident
PKP waves {Year Book 65) ; and Prof.
Volponi in San Juan, Argentina, has been
engaged in a similar project in west
central Argentina for a number of years.
The study reported here covered the re-
gion between 12° S and 24° S. The earth-
quake waves used in this investigation
are shown in Fig. 58.
P waves. The compressional waves in
the distance range 30°-90° travel wholly
in the mantle and have angles of in-
cidence ranging from 40° to 20°. The
earthquake regions within this distance
range were divided into twelve 30° sec-
tors as shown in Fig. 59. Each sector was
treated independently. The group of sta-
tions available (see Plate 4) were treated
as a wide-spaced array. A discussion of
the statistical approach follows.
Arrival time at reference stations:
te + U (A)+A£r=£
(1)
where te is the origin time, or location,
error, expressed as time; tt(A) is the
theoretical travel time (Jeffreys-Bullen)
if there were no location errors or station
DEPARTMENT OF TERRESTRIAL MAGNETISM
453
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o
bJD
454
CARNEGIE INSTITUTION
Seismograph
station
Fig. 58. Seismic wave paths used for de-
termination of seismograph station time resid-
uals. The time residual is defined as the differ-
ence between the actual phase arrival time and
the theoretical arrival time calculated from
the Jeffreys-Bullen 1958 travel-time tables. The
asterisks indicate earthquakes.
residuals; tr is an arrival time reading
error at the seismograph station; r{6) is
the station residual (as a function of azi-
muth 6) to be determined (6 has been di-
vided into 30° independent sectors in
this study).
If a sufficient number of earthquakes
are studied in each sector, the reading
error tr will be much reduced, as well as
the nonsystematic part of te. In some
sectors the earthquakes occupy a small
region, e. g., in sector F dominated by the
South Sandwich Island events, whereas
Earthquakes for P-wave residuals
Fig. 59. Earthquakes used for the P-wave study. The earthquake epicentral region
into 12 sectors which were analyzed independently.
was divided
DEPARTMENT OF TERRESTRIAL MAGNETISM
455
in others, e. g., in sector K, they are well
dispersed. In sector F, the systematic
part of te may be substantial and must
remain unknown. There may also be
deviations from the travel-time tables
used in this particular region of the earth.
Distances greater than 30° were used
to minimize this error — at distances less
than 20°, these deviations are known to
be large (James and Sacks, Year Book
67). Residuals were calculated as above
for some "reference" stations which, as
a part of the worldwide network of
standardized stations, were also used by
other investigators. Table 14 shows the
mean residuals (each sector being given
equal weight) of some stations compared
with those determined by Herrin and
Taggart (1968) .82 The agreement is good.
If one treats the network of stations in
South America as an array, and deter-
mines residuals relative to reference sta-
tions, the major uncertainties in equa-
tion 1 disappear, as follows:
te + tt (A) +r(6)1=t1 reference station
minus
te + tt (A2)1 + r(0)2 = t2 of another
station
isr(6)1-r(6)2 = t1-t2.
Because time comparisons with a refer-
ence station are generally made over
small distances (<3°), the error tt (A2)
will be small. To the extent that r($)1 is
known from equation 1, and bearing in
mind the limitations [te, 0, tt (Aj], the
TABLE 14. Mean Residuals for Reference
Stations *
Herrin
Sacks, Saa,
and
and
Station
Taggart
Aparicio
ANT, Antofagasta, Chile
—0.52
-0.7
ARE, Arequipa, Peru
+0.54
0.0
LPB, LaPaz, Bolivia
+0.38
+0.4
PNS, Penas, Bolivia
+0.7
HUA, Huancavo, Peru
+1.58
+1.2
NNA, Nana, Peru
—0.09
—0.55
* Comparison of residuals determined in this
study with those determined by Herrin and
Taggart ( 1968) ,82
absolute residual r(e)2 = t2 — t1-\-r(9)1
may be calculated for all stations and all
sectors. Some sectors (C, D, G, J, L) had
too few earthquakes to allow reliability
tests, and residuals determined for these
sectors are given lowest weight in the
results shown in Fig. 60.
A similar study was undertaken using
PKP waves at distances greater than
145°. At shorter distances, the GH
branch is the first arrival and the emer-
gent nature and low amplitudes of this
phase make the arrival time hard to de-
termine with good precision. Between
145 and 155 there is dominant, impulsive
arrival between the DF and AB branches.
Travel times for this phase were de-
termined (Fig. 61) and were used as well
as DF for the residual study. Earthquake
epicenters were divided into 12 regions in
the same manner as for the P-wave re-
siduals. The residuals in certain sectors
could be determined with greater accu-
racy than those in others for the same
reasons given in the P-wave case. Region
H, which is dominated by Banda Sea
earthquakes, is particularly well deter-
mined. These earthquakes have very
sharp onsets, are numerous, and their
arrival times can be read with great ac-
curacy. Figure 63 shows the residuals for
the H direction, together with the stand-
ard deviations of the residual deter-
minations. The residuals are plotted as a
function of the elevation of the station.
The mean (M) residual, which was de-
termined by giving each sector equal
weight, is also plotted on Fig. 63. It will
be seen that the difference between mean
residuals in direction H is always less
than the standard deviation. This is not
too surprising because these PKP waves
have angles of incidence of about 7°
for DF, and 11° for the BC branch so
that the cone covered by the various sec-
tors is only 14° for DF or 22° for BC,
and the waves are effectively normally
incident. In contrast, the P-waves from
the various sectors cover a cone of about
80°.
Some system of comparison has to be
456
CARNEGIE INSTITUTION
dual
,cuz
p -«_ med
sparse
PKPX
N
P deep o
E W
p- wave residuals , Ci
P-wove residuols , TRJ
Fig. 60. P-wave residuals as a function of azimuth for some South American seismographs.
The results of the following four stations are displayed: AYE, (Ayanquera, coastal station,
southern Peru) ; CUZ, (Cuzco, Andean station, southern Peru) ; CCH, (Cochabamba, eastern
flank of the eastern cordillera, Bolivia) ; TRJ, (Tarija, eastern flank of the Cordillera de Mochara,
southern Bolivia). The geographical location of these stations and the relationship of the time
residuals to the position of the mountain chains is shown in Fig. 64.
adopted to assess the normalcy of these
results. If one makes the usual assump-
tion that the various topographic features
are in isostatic equilibrium, a compari-
son criterion can be developed. This as-
sumption implies that the weight of any
column, with excess mass above sea level
(which may represent the mountain re-
gion) is supported by a lower density
root, i. e., that the crust is thicker under
the mountain so that the excess mass of
the mountain is supported. Unfortu-
nately, to date, neither the seismic veloci-
ties nor the gravity in this area have been
DEPARTMENT OF TERRESTRIAL MAGNETISM
457
IU
w
9
—
.-
f 8
S
-
•
•
•
-° 7
u.
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ee
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£ °
•
*
'•-2
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•
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0
1 1 1 1 1 1 1 1 ! 1 1
146
Fig. 61.
dominant
147
148
149
150 151 152
Distance (degrees)
153
154
155
156
157
158
Travel-time difference between the BC and DF branches of PKP. The BC branch is
in the distance range 145-155 degrees.
determined very fully. The figures
adopted for seismic velocities and den-
sity above and below the Moho are sug-
gested to some extent by the work that
has been done. (See the following article
in this report, Explosion Studies in the
Altiplano.) However, these figures are
to be used only for comparison of the
residuals and are not to be taken as de-
termined models. The expected residuals,
plotted as a function of elevation and
based on an isostatic model, are shown
in Fig. 62. Some features are suggested
from the comparison of the "isostatic
line" (Fig. 62) and the actual observa-
tions. The results from the bulk of the
stations from sea level up to about 4-km
elevation fall fairly close to the isostatic
line. There is, however, a cluster of sta-
tions at elevation between 3 and 4 km
which have arrival-time residuals well
in excess of the "isostatic" line, and also
some stations up to an elevation of more
than 5 km at which the arrivals are
slightly early. Figure 63 is a schematic
section through the topography, showing
the position of stations having PKP ar-
rival-time residuals which are late, early,
or as expected. A certain pattern is seen
to obtain: stations on the west, i.e., on
the Pacific Ocean side of the divide of
the mountain ranges, are somewhat early,
whereas those to the east of center are
substantially late. Stations on the coast,
or on the flanks, and surprisingly enough
on the altiplane, show no anomaly.
It became apparent as the study pro-
gressed that various groups of stations
track together, i.e., that the variation of
the residuals of one station, for azimuth
and angle of incidence, was similar to
the variation for other stations of the
same group. The coastal group (AYE,
ATI, SGP, etc.), the mountain group
(HUA, CUZ, PUN) and the altiplano
group, (LPB, PNS, SCS, DSG) all
had residuals which behaved coherently.
Plate 5 shows the azimuthal results from
the P-wave studies plotted on a topo-
graphical map. It can be seen on the
coastal station, AYE, that the F-wave
residuals are greater for paths along and
below the Andes, i.e., when the waves
approach from the northwest. This is
also true for the mountain station Cuzco.
Cuzco also has large residuals when the
waves approach from the northeast, i.e.,
up the eastern flank of the mountain. The
TRJ station has large residuals when
waves approach from either the north-
west or the south. This once again follows
the line of the Andes. The station on the
west of the Andes, CCH, has rather small
azimuthal effects; the waves are slightly
delayed from the northwest.
One qualitative model which explains
458
CARNEGIE INSTITUTION
+ 2.0
+ 1.0
M = mean of all directions
"elevation" correction: 4.5Km/sec
"isostatic" correction:/^ =2.8,V,=6.5km/sec
/>2S3.3,V2 =8. 1 km/sec
0.0
-1.0
1000
3000
5000
Elevation (meters)
Fig. 62. Time residuals for PKP waves. The standard deviation, determined for the H direction,
is shown by the length of the bars. M indicates the mean residual which has been calculated from
the results of all sectors, giving each sector equal weight. Since the residuals of other sectors are
not as well determined as those of the H direction, the uncertainty of the M residuals may
be greater than those of the H direction. Note that the residuals of CUZ, HUA, and PUN are
significantly greater than predicted by the isostatic model.
2km
sea level
20 km
100
Vp =6.5 km/sec
P = 2.8
V =8.1 km/sec
p = 3.3
200
300km
\
Lower
velocity,
mean Vp contrast to
surrounding mantle
is O.I7km/sec down
* to depth of 400 km
early
late
\
Fig. 63. Crust and upper mantle model that explains the residuals in Figs. 63 and 65. 0, E, and L
indicate relative positions of the groups of seismograph stations whose arrivals are on time,
early, or late, respectively. The earthquake activity is generally east of the low velocity tongue
and also dips away from the west coast.
DEPARTMENT OF TERRESTRIAL MAGNETISM
459
the data is shown in Fig. 63. It will be
seen that it departs from an isostatic
model in that there is a low-velocity
tongue dipping down below the mountain
away from the ocean. The mean velocity
discontinuity across the tongue must be
about 0.2 km per sec if the tongue per-
sists to a depth of 400 km. It should be
noted that the earthquake activity is
generally to the west of the tongue, i.e.,
towards the Pacific Ocean side.
It was, of course, of considerable in-
terest to know that the residuals would
be on the eastern side of the Andes, i.e.,
on the western edge of the Brazilian
shield. A station was installed at Riber-
alta in the northern Bolivian jungle, to
determine this residual. This proved to
be a rather difficult area in which to
operate a seismograph, and only a few
results were obtained during one year of
operation. They did indicate, however,
that the residual on the edge of the
Brazilian shield is about the same as
those of the coastal stations on the west
coast. The Riberalta (RIB) mean resid-
ual is plotted in Fig. 62.
The following conclusions may be
drawn from this study about the upper-
most mantle under western South
America. (1) The Andes mountain chain
has a root of lower-velocity material
which dips away from the west coast.
The width of the root is about 100 km,
and the velocity difference between the
root and the surrounding mantle is about
0.2 km/sec if the length (down dip) of
the root is 400 km. If the root is shal-
lower, the velocity contrast will prove to
be greater. (2) The earthquake activity,
which also dips away from the west
coast, reaching a depth of 600 km, lies
on the west side of the low-velocity
tongue. (3) Apart from the low-velocity
tongue, there does not seem to be a sub-
stantial change in the mean velocity of
the uppermost mantle between the west
coast and the low-elevation pampas of
western Brazil. (4) The high plateau
(the altiplano) between two mountain
ranges, which probably has some tens
of thousands of feet of sediments, seems
to have a relatively normal delay for
near-vertical arrivals.
The data obtained from this study
resulted from the observations of a num-
ber of short-period vertical seismom-
eters. The NSF supported the construc-
tion and operation of many of these
stations.
Explosion Studies in the Altiplano
DTM Staff: collaborators from the University
of Wisconsin, the Southwest Center for Ad-
vanced Studies, the Instituto Geofisico Boli-
viano, the Instituto Geofisico del Peru, and the
Instituto Geofisico, Universidad Nacional de
San Agustin
As part of the Department's contri-
butions to the activities of the Inter-
national Geophysical Year, studies of
the crustal properties in southern Peru
and eastern Bolivia were made using
explosions in copper mines. In Year Book
57 the results of these efforts were re-
ported in detail. In summary, a normal
refraction profile was found along the
western flank of the Andes with seismic
arrivals refracted from both crustal and
mantle layers in the earth. Attempts to
find similar arrivals for paths into the
altiplano were frustrating. No waves re-
fracted from the mantle were observed.
The crustal structure determined from
the 1957 observations is given in Table
15.
It was decided more than two years
ago that another attempt to determine
these elusive seismic parameters of the
crust should be made. This decision was
based on several factors, among which
TABLE 15. Andean Crustal Models
Layer thickness, km
Velocity
km/sec
Peru,
1957
Bolivia,
1968
5.0 1.5 10
6.0 8.0 15
6.6 30.0 35
8.0
Crustal thickness, km 39.5 60
460
CARNEGIE INSTITUTION
were (1) the technological improvements
in our seismic equipment, which gave
more sensitivity at lower frequencies;
(2) the existence of many very sensitive,
semipermanent seismic stations in Peru
and Bolivia in the region to be studied;
(3) the growing competence of collabora-
tors in Peru and Bolivia; and (4) the
opportunity to participate in studies di-
rectly related to the upper mantle pro-
gram agreed to by the geophysics com-
munity in South America. The extensive
official arrangements in the two coun-
tries were ably accomplished by the
Instituto Geofisico del Peru, Ing. A. A.
Giesecke, Jr., executive director; and by
the Instituto Geofisico Boliviano, R.
Cabre, S. J., coordinator. We are in-
debted to these institutions, as well as to
the members of the staff of the Geophysi-
cal Institute, University of San Agustin,
Arequipa, Peru, A. Rodriguez B., di-
rector; and of the Observatorio San
Calixto, La Paz, Bolivia, R. Cabre, di-
rector. These are representative of a
large group of interested scientists and
officials of both countries whose efforts
made these observations possible. The
participation of our colleagues at the
University of Wisconsin and the South-
west Center for Advanced Studies was
supported in part by grants from the
Harry Oscar Wood fund.
The experiment was designed to pro-
vide 5 one-ton chemical explosions in
each of two lakes, one in southern Peru
and the other in southern Bolivia, sepa-
rated by about 850 km as shown in Fig.
64. It was anticipated that seismic energy
from each lake might be detected up to a
distance of 600 km, and that possibly a
complete reverse profile between the
two lakes would be obtained. For the
first events we therefore concentrated our
observations in the middle 250 km of the
line. No seismic arrivals from explosions
in either lake were observed in this
region. Subsequent explosions provided
arrivals shown in Fig. 65.
It is seen that the data are not suffi-
Lima
15S
20 S
Line of portable seismic stations (I968)
Line of portable seismic stations (I957)
Semipermanent seismic stations (I968)
®
Cities
Fig.
80W 75W 70W
64. Locations of explosion studies in the altiplano region.
DEPARTMENT OF TERRESTRIAL MAGNETISM
461
+3
~ +2
o
1 0
-1
... ,,.... , ,
... , .
— i
I 1
l
! 1
1
1 ■"
A
-
©
■
+ n
o
+
+
+ +
o
o
o
o
+
-
oS
t i i
i
!
1 1
1
1 !
1
i
0 20
60
100
140
180
220
260
A (KM)
+3
+2
o
LU
<
+1
0
-1
1—
-2
-3
-4
i i i i i
] i I
i i i
i ' i
i i
B
s
s
"■^"--^ .
• X
X. •
-
y
y
y
y
y
y
y
^--^•»
-
-
-
~
-
-
I I i I i
i I f
I, i i
i
1 1 ..
i i
-
0 20 60 100 140 180 220 260 300 340
A (KM)
Fig. 65. (A) Travel-time curve, 1968 Peruvian explosions; (B) travel-time curve, 1968 Bolivian
explosions.
cient in either country to provide a com-
plete crustal model. It is also apparent
that no seismic energy from the mantle
could be identified as such in Peru. To
estimate the crustal thickness in Bolivia,
the dashed lines of Fig. 65b were drawn
to approximate the near-shot data in
Peru. For the travel-time curve indi-
cated, we may calculate the results of
Table 15. In Bolivia, the data for the
first layer are nonexistent. The cross-
over between arrivals attributed to a
layer of velocity of 6 km/sec and arrivals
due to a layer of velocity of 6.6 km/sec
is sketchily observed, as is the crossover
between arrivals from the 6.6-km layer
and the 8.0-km mantle. The crustal
model obtained agrees reasonably well
with that estimated by other techniques.
It may be pointed out that 10-12 tons
of explosives are needed to complete a
reverse profile which would define the
crustal velocities and structure of the
Bolivian altiplano. It is not probable
462
CARNEGIE INSTITUTION
that any reasonable amount of explosive
material would provide needed data in
Peru.
A comparison of the two results of
Table 15 is of some interest. If one as-
sumes that the mantle velocity of 8 km/
sec persists to 60 km, the time difference
of the two models, for waves having
vertical incidence to the crust at this
depth, is 1.2 seconds and is not sufficient
to explain even half the variation found
between coastline and altiplano stations
discussed in the report of Sacks and Saa.
These newest efforts to define a crustal
model of the altiplano have again shown
a region of anomalously high absorp-
tion of seismic energy in southern Peru
and have given preliminary results which
demonstrate the possibility of measuring
completely the seismic parameters of the
crust in the central Bolivian region of
this unusual tectonic province.
Model Seismology
D. E. James
To facilitate analysis of seismic waves,
seismologists have traditionally parti-
tioned the earth into radially homogene-
ous spherical shells. In the early studies
of the earth this simplification was not
especially restrictive within the limits of
the available data and, until recently,
was not regarded as a serious obstacle
to interpretation of structure within the
earth.
The past several years, however, have
been almost revolutionary in seismology.
More abundant and sophisticated seismic
data which demonstrate widespread
lateral inhomogeneities have led to the
recognition that spherically homogeneous
layers can no longer be considered viable
approximations to the earth. Given these
conditions, it is clearly time to admit
that the earth is inhomogeneous, non-
linear, and anisotropic, and to proceed
toward a quantitative evaluation of the
heterogeneity.
Before it is possible to attempt such
an evaluation, however, it is necessary to
understand something of wave propaga-
tion through inhomogeneous media of
the kind likely to exist in the earth. At
least two approaches to the problem are
possible — theoretical studies and model
studies. Several groups are engaged in
theoretical treatment of some of the
problems; however, it seems to us that
the necessary assumptions are too re-
strictive for direct application to the
earth. We have therefore undertaken
two-dimensional model seismology as a
means of studying wave propagation
under conditions analogous to those we
believe exist in the earth. Our progress
in this past year suggests that it will be
possible to fabricate two-dimensional
models incorporating velocity gradients.
Before reporting our preliminary results
it is appropriate to review briefly the
justifications and limitations of thin
sheets as cross-sectional models of the
earth.
Two -dimensional models. A rather ex-
tensive discussion of the advantages of
two-dimensional models over three-
dimensional models can be found in a
classic paper by Oliver, et al. (1954), 83
in which they introduce the concepts of
two-dimensional modeling. There are,
however, a few assumptions and limita-
tions that we shall examine further
before proceeding. The most important
of these is the relationship between plate
dilatational velocity, wavelength, and
sheet thickness. Specifically, a funda-
mental assumption made in two-dimen-
sional modeling is that the wavelength
is long relative to plate thickness, so that
the plate dilatational velocity goes to a
limiting value for infinitely thin sheets.
We examine this problem in more de-
tail by considering dispersion in plates.
The details of the mathematical devel-
opment leading to the period equation
for plates has been presented elsewhere
(see Tolstoy and Usdin, 1953,84 for
derivation and earlier references) and
will not be repeated here.
The dispersion curves for the first two-
symmetric modes and the first anti-
DEPARTMENT OF TERRESTRIAL MAGNETISM
463
symmetric mode in %6-inch plexiglas,
and the first symmetric mode in %2-mcn
aluminum are shown in Fig. 66.
Three records were obtained for %6-
inch plexiglas and bandpassed, one be-
tween 20 khz and 160 khz, one between
80 khz and 320 khz, and the third be-
tween 160 khz and 640 khz. These records
were digitized and analyzed using a
multiple filtering technique described by
Dziewonski, et al. (1969) .85 The authors
kindly provided us with their computer
program which we have modified slightly.
The analysis of the 80-320 khz record
is shown in Fig. 67. The numbers are
linear amplitudes normalized to a maxi-
mum value of 99 and printed as a func-
tion of group velocity and period. The
minus signs denote local maxima along
a column. ALPHA and BAND are filter
parameters defined by Dziewonski, et al.,
and were chosen to maximize resolution.
The solid line is a fit by eye to the
maxima indicated for each period and
represents the dispersion curve for %6-
inch plexiglas. The light dashed lines
indicate the approximate limits of un-
certainty. The values of the group veloc-
ity indicated by the minus signs at the
display periods for the three analyzed
records are shown in Fig. 66A for com-
parison with the theoretical dispersion
curve for plexiglas. It can be seen that
the shape of the two curves matches ex-
tremely well ; it is not surprising that the
observed dispersion curve indicates lower
velocities in view of the fact that veloci-
ties are normally calculated for the first
break and the main energy packet ar-
rives slightly later.
It is important to observe that the
plate dilatational velocity, which we
shall take to be our compressional veloc-
ity in the model studies, is significantly
dispersive even in %6-inch plexiglas.
Ideally, we should prefer that the plate
dilatational waves be non-dispersive and
that they behave as much like genuine
body waves as possible. We consider a
dispersion of <10% in velocity over the
entire range of observed frequencies to be
acceptable. In general, this requires sheet
thicknesses of ~1 mm or less.
The plate wave dispersion affects the
apparent value of the specific attenua-
tion factor, Q. The value of Q in non-
metallic modeling materials is signifi-
cantly lower than in the earth and is
the one important parameter that does
not scale in model experiments. In addi-
tion to the value of Q being intrinsically
lower in the plastics commonly used in
modeling, the dispersion of the dilata-
tional waves results in a further decrease
in effective Q. This effect is quite sig-
nificant and studies are now in progress
to determine quantitatively the decrease
in apparent Q due to dispersion.
Modeling techniques. The apparatus
employed in our experiments is quite
similar to that used elsewhere and is
shown in Fig. 68. The pulses are pro-
duced by thyratron pulsers and have rise
times of <0.2 fxsec and tails of a few
microseconds.
Our efforts have been aimed princi-
pally at producing thin sheets of various
velocities with the use of polyester resins
and various kinds of filler. Depending
upon the composition and amount of the
filler used, the velocities of the cast
sheets can be increased over the velocity
of pure cast polyester by at least 25%.
Thus far, the most successful results for
increasing velocity (and Q) have been
obtained using powdered limestone and
powdered aluminum as filler. Polyester
mixtures with a volume ratio of one part
resin to one part aluminum or limestone
are comparatively nonviscous and can be
easily cast into large sheets 1 mm thick.
A list of a few velocity measurements
in cast sheets is given in Table 16.
Radiation patterns and free surface
amplitudes. In the model studies that are
anticipated, we shall in general wish to
measure amplitudes of waves arriving at
the free surface from a source located
either on the free surface or in the in-
terior of the model. As a preliminary to
any study involving amplitudes, it is
necessary to establish radiation patterns
464
CARNEGIE INSTITUTION
3.0
o
_o
CD
>
2.0
1.0
Plate thickness =1.6 mm
Compressional vel. = 2.680
Shear vel. = 1.370
Poisson's ratio - 0.323
• Observed dispersion values
12
200
400 600 800
Frequency (KHZ)
1000
6.0-
£ 5.5
o
>
a.
5.0
1
l i 1
l i i i I i 1
1
-B
Parameters:
Vp= 6.68 mm //i SEC
-
-
Vs ? 3.03 mm//i SEC
Plate thickness *0.8mm
-
-
Poisson's Ratio =0.370
-
-
cn
—
-
"""" ^_ JJn ~~ *
-
-
-
-
i
i i i
1 1 1 1 1 1 1
1
100
300
500
700
900
1100
Frequency (KHZ)
Fig. 66. Dispersion curves for plexiglas and aluminum. Observed dispersion as measured using
multiple filtering is shown for the first symmetric mode in plexiglas. Notation: U denotes group
velocity, c phase velocity, and the subscripting follows Tolstoy and Usdin (1953)8*.
DEPARTMENT OF TERRESTRIAL MAGNETISM
465
o
0)
>
O
o
2.40
~ 0
0
1 2
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16 30
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60 67 61 53 5B 7l| 55 30
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79 82 71 57 63 79
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82 85 72 57 64 80
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86 87 74 58 64 82
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30 37 32 19 36 80
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27 34 29 17 34 78
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17 24 22 12 29 72
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9
8
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15 22 20 11 27 70
70 29
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** 0 •
u
IVO
8
7
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7
13 20 18 10 26 69
69 29
12
7 3
2
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1 9
6
6
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12 18 16 9 25 67
68 28
0
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2
If 9
J 8
5
4
5
4
12 1
12 1
6
5
10 17 15 8 24 65
9 15 14 7 22 64
67 27
66 27
Alpha :
: .19.69
0
0
0
0
2
2
1 7
7
3
3
3
3
12 2
12 3
4
4
8 13 12 6 21 62
7 12 11 5 20 60
65 26
63 25
Band =
0.40
2.00
0
0
0
0
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-2
1 6
5
2
2
2-
2
■12 3
12 4
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3
6 11 10 4 19 58
5 10 9 4 18 56
62 25
61 24-
Dig. rate
= 2
sample At sec
0
0
0
0
2
2
5
4
2
2
12 4
12 4
3
3
4 9 8 3 18 55
4 8 7 3 17 53
60 23
58 23
Analyzed record2
512 pts.
0
0
2
3
2
12 4
3
3 7 6 2 16 51.57 22
b
0
2
•3
2
12 -4
3
3 6 5 2 15 49 56 21
0
0
2
2
-2
12 4
3
2 6 5 2 14 47154 21
1.95
- o
L,
0
1
1
.. 1
2
__I
11 4
_. .1
3
2 5 4 1 14 46|53 20
1 Mil
I ...
1
1
1
6 7 8
Period
9 10
[fi sec)
20
30 40 50
Fig. 67. Group velocities for i/ie-inch plexiglas sheet determined by multiple filtering technique.
Minus signs denote local maxima along the various columns. The numbers in each column give
spectral amplitudes on a linear scale. The dispersion curve is traced by following the maximum
from column to column. The maxima circled are plotted as observed dispersion values in plexiglas
in Fig. 66. The solid line gives the preferred dispersion curve, and the light dashed lines indicate
estimated limits of reliability. The heavy dashed vertical lines denote filter cuts.
for P- and £-waves from the transducers
and to measure free surface displace-
ments as a function of incident angle and
wave type. By reciprocity (Gupta,
1965) ,86 it is comparatively straight-
forward to demonstrate that for plane
waves the vertical displacement due to
incident P- or #-waves yields an angle-
dependent pattern of displacements
identical in shape and relative magnitude
466
CARNEGIE INSTITUTION
Brass-backed
PZT-5 receiver
transducer
Fig. 68. Experimental apparatus.
TABLE 16. Properties of Polyester Sheets with Various Fillers
Plate
Resin
Filler
thick-
vP,
v„
Pseudo-
(type and
(composition and
ness,
mm/
mm/
Poisson's
Temp.,
volume)
dry volume)
mm
jxsec
/isec
ratio
°C
MR-480;
1.5 liters
none
1.5
2.01
1.16
0.251
23.5
MR-480;
1 .4 liters
Al powder; 0.4 liters (1 lb.)
1.55
221
128
0242
23.6
MR-480;
1.3 liters
Al powder; 12 liters (3 lbs.)
1.6
2.46
1.42
0250
22.5
MR-480;
1.3 liters
Pulverized limestone; 1.1 liters
1.6
2.56
1.48
0.248
232
to the radiation patterns for P- and
S-waves resulting from a vertical dis-
placement at the free surface. Fig. 69
shows the angles and our notation for
incident and reflected waves at the free
surface. A and B are directly propor-
tional to the amplitudes of the incident
P and SV waves, respectively.
Although the problem of determining
free surface displacements has been
treated numerous times in the literature
(Jeffreys, 1926; 87 Knott, 1899; 88 Guten-
berg, 1944; 89 Nuttli, 1961 ;90 Gupta,
1965 86), the results are not in a par-
ticularly useful form for our purposes.
The following, therefore, is a brief de-
velopment, following Jeffreys' notation,
of vertical displacements and energy
partitioning at a free boundary.
Case I: Incident P-wave. If A, A1} and
Free surface
Incident P-wave
Incident S-wave
Fig. 69. Illustration giving notation and angular relations for incident and reflected waves at a
free surface.
DEPARTMENT OF TERRESTRIAL MAGNETISM
467
B1 are as shown in Fig. 69, then for any-
choice of velocities we have
where the exponent term has been
dropped.
where F=
B±=A
AX=A
2 VI
4tane [{1 + F) tan2e + l]
2Ftanetan/+[(l+^) tan2e + l] (tan2/-l)
4Ftanetan/-[(l + ff) tan2e + l] (tan2/-l)
{VI-2VD
ity, and Vp = plate dilatational velocity.
To use Ax and Bx as initial amplitudes of
waves now traveling to the opposite free
surface (as in the single-layer case de-
scribed below), it is necessary to con-
serve energy, so that
A2=B\ ^L+Al (Ewing, et al, 1957,
tan 6
p. 29) 91 and the amplitude of reflected
SV:
2Ftanetan/+[(l + F) tan2e + l] (tan2/-i;
V* = shear veloc-
k = wave number = w/c
B
/tan A*
\tan e J
and that of P — Ax.
The vertical displacement at the free
surface is given by
w = iK[tane {A—A1)-\-B1\
where to = angular frequency, c = appar-
ent velocity of wave in the x direction
along the surface, and i=V — 1. Replac-
ing k by w/c, and tan e by [c2/VD — l]1
(Ewing, et al, 1957, p. 26), we have
w
{(--?)'
(A
A1)+^-Bl
where V v — plate dilatational velocity and
7p/c=[l(tan2e + l)]'.
This equation gives the vertical free
surface displacement due to an incident
P-wave with amplitude coefficient, A.
The angular displacement pattern also
gives the radiation pattern of P for a
vertical displacement at the free surface.
This pattern, together with that for in-
cident SV, is shown in Fig. 70.
Vertical displacement
transducer
(Free surface)
2.0
Radiation Pattern
for P-waves
(Poisson's ratio=0.25)
• Measured amplitudes
up B
1
Vertical displacement
m j^- transducer (Free surface)
1.0
\
- \
\
? n
Radiation Pattern
for S- waves
(Poisson's ratio = 0.25)
--•--Measured amplitudes
Fig. 70. Radiation patterns for P and S due to a vertical displacement at the surface.
468
CARNEGIE INSTITUTION
Case II: Incident SV wave. Again, fol-
lowing the notation given in Fig. 69, we
have
tudes of P and SV are correct for a dis-
placement at the surface.
The discrepancy for £-waves between
R _B 2Ptanetan/+((l+P) tan2e + l) (1-tan2/)
1_ 2Ptanetan/-((l+P) tan2e + l) (1-tan2/)
AX = B
2Ptan/ (1-tan2/)
2 F tan e tan/- ((1+P) tan2e + l) (1-tan2/)
where F is given above and B is directly
proportional to the amplitude of the
incident SV wave.
By partitioning of energy at the bound-
ary, we have
B2 = A2^e+B2
tan/
so that the reflected P-wave amplitude
is equal to Ax (tan e/tan /)*.
The vertical amplitude due to an inci-
dent SV wave with amplitude coeffi-
cient = B is given by:
w—xk [{B + Bi) —tan e At].
Replacing k by w/c and tan e by (c2/
Vp — 1)§, we have
measured and theoretical results in Fig.
70b may be due largely to interference
effects that have made precise measure-
ments of S amplitudes difficult. We do
not believe the differences to be signifi-
cant. Use of a bender bimorph as de-
scribed by Chowdhury and Dehlinger
(1963) 92 should provide more reliable
measurements. The amplitude measure-
ments described below for PP and PS
phases give a more precise indication of
the general applicability of plane-wave
theory to the radiation patterns of verti-
cal motion transducers over typical
model dimensions.
Propagation and amplitudes in a single
layer. As a test of the applicability of
w
=ifpf (B + B.)-(l-- J)^] [(90° -/)>*„]
where the variables are as given above.
0C= critical angle of SV greater than
which no P-wave is reflected and SV is
totally reflected and phase shifted.
The free surface displacement pattern
for incident SV is given in Fig. 70B. It
should be noted that for both P and SV
an incident wave of unit amplitude has
been assumed so that the relative ampli-
plane-wave free surface reflection theory,
a single-layer model was investigated.
A series of record tracings (Fig. 71) are
shown for the various phases diagrammed
in Fig. 72. These results are virtually
identical to those reported by Press,
et al. (1954) ,93 The only phase of par-
ticular interest is the refracted SPS
phase. It is not especially prominent on
20 cm
40 cm— MjV
44
48
52
56
PS | SPS f
PSPS
100/i.sec
\ v \ \ \ \
Fig. 71. Record tracings showing the various phases diagrammed in Fig. 72.
DEPARTMENT OF TERRESTRIAL MAGNETISM
469
\Nv P,S,R *
e v^C
' t
Vv\p
\\s \
s\\ "X
p/ /
P
^j
V
9.80cm
1
Fig. 72. Ray paths for the various phases shown in Fig. 77. Bc is the critical angle for /S-waves.
Note the large amplitude of PS (SP) and PSPS (SPSP).
the records shown in Fig. 71 because of
the relatively high frequency pass band.
The SPS pulse has very large amplitude
at low frequencies, a fact which may
indicate that it is produced by curvature
of incident S at the free surface.
Amplitudes for a fixed frequency have
been computed for the PP and PS (SP)
phases using the radiation patterns and
vertical displacement expressions given
above. To obtain amplitudes which can
be compared to amplitudes measured ex-
perimentally, geometric spreading and at-
tenuation must be taken into considera-
tion sO that over any path length between
the free surfaces we have
Ad = A0exp
(nFi
where A0 = initial amplitude of wave
Ad = amplitude of wave at dis-
tance d from source
j— frequency
T— travel time over path
length = d/Vp.
It should be noted that this expression
must be calculated for each path sepa-
rately between the free surfaces.
Geometric spreading can be calculated
on the basis of total path length, and in
sheets is:
®
A0
where r0 is an arbitrary normalizing path
length, A0 is initial amplitude, A is final
amplitude, and rx is the path length
traveled by the ray in question.
The amplitudes for the plexiglas layer
have been computed and are shown to-
gether with experimental values in Fig.
73. For the purpose of amplitude calcula-
tions, plexiglas was a poor choice because
of the low and highly temperature-sensi-
tive Q value. Thus the theoretical ampli-
tude curves shown depend not so much
on the reflection and conversion coeffi-
cients at the free surfaces as they do
on Q. In this case, and those following,
the relative positions of the theoretical
amplitude curves of PP and PS are as
predicted by the radiation or vertical
displacement patterns shown in Fig. 70.
These curves have not been shifted rela-
tive to one another to provide a better
fit to the individual curves. We have
assumed in all cases that the amplitude
of PS is equal to that of SP. This as-
sumption is correct if the relative radia-
tion patterns of P and S for the source
and pickup transducer are the same.
Because of the dominating effect of Q
on amplitudes in plexiglas, amplitudes
were measured in a single-layer sheet of
Ys 2 -inch soft aluminum. Aluminum has
an extremely high Q, variously measured
between about 1000 and 200,000 (Knop-
off, 1964) ,94 and therefore attenuation
plays little role in the amplitude result
(provided the sheet is thin enough that
no significant dispersion takes place).
Measured amplitudes should depend only
on free surface reflection and conversion
coefficients. Results for two different fre-
quency pass bands are shown in Fig. 74.
The slope of PS appears to agree very
well with theory as does the relative
position of the PS and PP curves. It is
clear, however, that the slope of PP does
not provide an ideal fit to the experi-
470
CARNEGIE INSTITUTION
IOOO
500-
100
Q.
E
<
10
1.0
i r
1 i 1 :
Porometers:
Vp = 2.36m m//i SEC; Qp=45.0
Vs = L37mm//iSEC; Qs= 35.0
Sheet thickness = 1.6mm
Layer thickness =9.80cm
Pass bend =240 KHZ
• Observed PS amplitudes
o Observed PP amplitudes
— ■ Theoretical amplitude curves
10
20
30
40
50
60
Distance (cm)
Fig. 73. Amplitudes for PP and PS (SP) in plexiglas. It has been assumed that the amplitude
of PS is equal to that of SP by reciprocity. Solid lines are theoretical curves assuming the
parameters given in the figure. Effects due to Q and geometric spreading have been taken into
account.
mental data, particularly at 320 khz, al-
though the discrepancy is not especially
large. The fit for both PS and PP appears
to be everywhere better than about 25%
and over most of the curves less than
15%. The different values of Q used in
the two sets of calculations do not change
significantly either the slopes or the rela-
tive positions of the two curves.
The interference effect suggested by
the sigmoidal shape of the PS measured
amplitudes may be due in part to the
effect of PPPP. Within the range 38-55
cm, PPPP has approximately the same
arrival time as PS. Within this range,
however, its amplitude is more than an
order of magnitude less than that of PS
and does not appear to be sufficient to ac-
count for all the effects observed in the
PS amplitudes.
It is clear from the results described
above that plane-wave theory provides a
DEPARTMENT OF TERRESTRIAL MAGNETISM
471
~ 1,000
Vp=5.38
Vs = 3.03
Qp=2000
Qs = 1000
Sheet thickness = 0.8mm
Layer thickness = 12.08c
Pass band =320 KHZ
Observed
Theoretic
_
1 1 1 1 1
1
_
5,000
-
B
-
1,000
r
\ ^^-
\
~
-
-
"\
"
"
X
"
100
*
-
Par
a meters:
o
5.35
:
Vs
Qp
3.03
20,000
10,000
-
Sh
La
er thickness = 12.08cm
-
in
Pas
O £
5 band = 480 KHZ
Observed amplitudes
Theoretical amplitude curves
1 1 1 1 1
1
20 30 40 50
Distance (cm)
Distance (cm)
Fig. 74. Amplitudes in %2-inch aluminum layer for different pass bands.
good approximation to the measured
vertical displacements at a free surface
over dimensions and wavelengths appro-
priate for model studies. For future ex-
periments, the problem in general will be
one of calculating the amplitude of the
incoming wave from the measured dis-
placement at the surface.
Change in Earthquake Spectrum Be-
fore and After the Matsushiro Swarm
Shigeji Suyehiro
The Matsushiro Earthquake Swarm
started on August 3, 1965. Its region was
limited to a small area of about 10x10
km. The Worldwide Standard Seismo-
graph of short period (Vmax: 100,000)
at the Matsushiro Seismological Ob-
servatory in the swarm region recorded
663,142 earthquakes from the swarm
through August 1967, and 61,005 of these
were perceptible at the Observatory. This
swarm was accompanied by tremendous
land deformations. In October 1966 a
horizontal extension of 116 cm was ob-
served in the swarm region over a dis-
tance of about 3 km, corresponding to a
linear strain of 3.8 Xl0~4 (see Fig. 75).
This enormous amount of strain cannot
be explained merely by pure elastic de-
formation, but nonelastic deformations
such as fractures or creep must have
taken place.
As many fractures have developed in
the swarm region since the start, the
transmission of high-frequency energy
through this fractured region must be
affected by scattering. Many fractures
were seen at the surface and many others
must exist under the ground.
Prior to the start of the swarm, ob-
servations of local earthquakes had been
made at the Observatory, and informa-
tion was obtained pertaining to the trans-
mission of high-frequency energy before
the swarm. To study changes in the pre-
dominance of high-frequency energy, ob-
servations were repeated in January 1967
at the same spot and with the same in-
strumentation, which has a recording
response of up to 250 cps. These observa-
472
CARNEGIE INSTITUTION
EPICENTER REGION OF
EARTHQUAKES STUDIED
SWARM REGION
Fig. 75. Matsushiro swarm region, epicenter region of earthquakes studied, and geodimeter
base line which showed a linear strain of 3.8 X 10~*.
tions were compared with the pre-swarm
observations of December 1963 and
January 1964 for earthquakes occurring
in the same area outside the swarm re-
gion with a similar depth of 3-10 km (see
Fig. 75).
Data. Toward the end of 1966, the
swarm had been restricted to within 5 km
of the Observatory. From January 1967
the swarm activity started diffusing into
the surrounding area, and a series of
earthquakes occurred about 15 km south-
west of the Observatory with depth
ranging from 3 to 10 km. During the
pre-swarm observation, earthquakes oc-
curred also in this region with the same
depth range. Fortunately, in that period,
observations were made at the Matsu-
shiro Observatory with a tripartite net
and hypocenters were estimated solely
from these observations. To eliminate as
many uncontrollable elements as possi-
ble, the same source region, order of
magnitude, instrumentation, and receiv-
ing point were used to compare the
transmission of high-frequency energy
through the swarm region before and
toward the end of the swarm.
The selected earthquakes which satis-
fied the conditions were replayed from
magnetic tape through a varying band-
pass filter of one-third octave from 2.0-
2.5 cps to 200-250 cps, and the maximum
amplitude was measured within 0.6 sec
from the onset at each different band-
pass. Examples of filtered seismograms
DEPARTMENT OF TERRESTRIAL MAGNETISM
473
100 63 40 25 16
(till
80 50 31.5 20 12.5
BANDPASS FREQUENCIES
Fig. 76. Relation between relative trace
amplitude and band-pass frequency.
are shown in Plate 6. Figures 76, 77, and
78 show three examples of the relation
between relative trace amplitude and
band-pass frequency. Spectra of seismo-
grams of earthquakes which differ only
in the time of occurrence, namely before
and toward the end of the swarm, are
compared in Plate 6 and Figs. 76, 77,
and 78.
Figures 75-78 show the high-frequency
energy, which was more abundantly re-
corded for the 1964 earthquakes than for
the 1967 earthquakes. Many earthquakes
in the present category have been ex-
amined, and in no case is there conflict
with the statement made above. What
caused this variation? No change has
taken place in the instrumentation or in
the receiving station. The magnitude of
-^ "\ S ^s
,«'"* y£-~<~~~* n^
/ \ \
\ \
/ S-P : 2.2 sec
41 \ \ ~
\ \
/ TRACE AMPLITUDE ,
/ JAN. 16, '67
/ 13h20m37'
/ S-P : 1.9 sec
^
/ TRACE AMPLITUDE : 60
1 1 1 ! 1 1 1 1 1 1 1 1 I I I 1 I
250 160 100 63 40 25 16 10 6.3
200 125 80 50 31.5 20 12.5 8 5 cps
BANDPASS FREQUENCIES
Fig. 77. Relation between relative trace
implitude and band-pass frequency.
1.0
0.8
0.6
§ 0.4
S
< 0.2
<
" 0.1
£0.08
< 0.06
S 0.04
•
S 'V
\
JAN. 23, 64 / \
"*-y>—
\
S-P : 2.1 sec /
TRACE /
AMPLITUDE : 70 /
V
/ N*J
/
/ JAN. 15, '67
/ 16l,42m
• * S-P : 2.2 sec
TRACE AMPLITUDE :
229
0.01
1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 I !
250
160
100 63 40 25
16
10
6.3
200
125
80 50 31.5 20
BANDPASS FREQUENCIES
12.5
8
5 cps
Fig. 78. Relation between relative trace
amplitude and band-pass frequency.
earthquakes analyzed and their path of
propagation remain the same. Therefore,
only changes in the source spectrum or
in the nature of the crust along the path
of propagation, or in both, could cause
such a difference. For the following rea-
sons, the nature of the path is inferred
to have changed rather than the source of
the spectrum.
1. The source used in this study was
outside the swarm region and had shown
no extraordinary activity until January
1967 when the seismicity in that area in-
creased. Even in the swarm region, no
volcanic activity was found and no in-
crease of underground temperature could
be deduced from geomagnetic observa-
tions. It is difficult to assume any sub-
stantial change in the elastic constants
of material in the source region which
could have affected the source spectrum
of earthquakes of the same order of
magnitude.
2. Earthquakes that took place closer
to the Observatory in the swarm region
in 1967 were analyzed to determine
whether the source still produced high-
frequency energy. In Fig. 79 the trace
amplitude 125-100 cps/trace amplitude
of 63-50 cps, most of which are for 1967
earthquakes, is plotted against S—P
time, that is, the epicentral distance; if
earthquakes are close enough to the re-
ceiving station, high-frequency waves are
observable. This proves that the source
still produces high-frequency waves, but
474
CARNEGIE INSTITUTION
Ul
>
ff-.0
o
o
\
z
o
2
W o
I-
<
•
J •
•
•
•
• • •
•
•
»
•
•
•
•
•
• •
■
•
•
•
/
o o e0 ° o
o
o
o
o
o
0.5
1.0
1.5
2.5
Fig. 79. Relation between S
S-P
(0-1964, ©-I967)
P time and attenuation of trace amplitude over one octave.
the medium along the path was not so
conductive for the high frequencies in
January 1967 as it had been before the
swarm.
3. Very large ground deformations
have been observed in the swarm region,
especially in the north-south direction.
A strain of 3.8 X 10~4 was observed from
October 1965 to September 1966. This
deformation could not have been caused
by elastic strain alone, but is probably
the result of considerable Assuring, some
of which was observed on the surface.
It is very likely that the crust under the
swarm region has been highly fractured
as a result of an extremely large number
of earthquakes. The reduction of high-
frequency waves in January 1967, as
compared with those which existed be-
fore the swarm, must be attributed to the
medium along the path.
4. If the high-frequency energy is at-
JAN. 22, '64 23h46m43»
JAN. 22. '64 1 9ho6m24s
JAN. 23, '64 |2h22mIS*
UJ
JAN. 17. '67 Oeh54m079
JAN. 16, '67 I3h20m378
•
\
JAN 15. '67 lSh42m
< .
a
* \
\
\
\
-I K
LlI (0
or 5
\
\
\
\
X
§5
\
GRADIENT. -1.87 \
\.
GRADIENT --2.5 \
\
GRADIENT- -2.62 \
\
1 1 1 1 1
\
\
1 III 1
A
\
l ill
30 50 100 200 5
30 50 100
FREQUENCY
30 50 100
Fig. 80. Relative amplitude ratio of earthquake of 1967 to earthquake of 1964, amplitude
67(f) /amplitude 64(f).
DEPARTMENT OF TERRESTRIAL MAGNETISM
475
tenuated in the medium during propaga-
tion, what type of attenuation is con-
ceivable? Is it due to absorption or
scattering? As stated previously, it is diffi-
cult to assume any substantial change in
the physical or chemical nature of the
medium which might change the Q-value
to that extent. To study the dependency
of attenuation on frequency, the ampli-
tude ratio of 1967 and 1964 earthquakes
was plotted against frequency. Three ex-
amples are shown in Fig. 80. As seen
from the figure, the amplitude ratio is
proportional to the nearly inverse cube
of the frequency for high frequencies.
Such a high dependency on frequency
strongly suggests that the attenuation is
due to scattering.
5. From Fig. 80, it is seen that the
frequency dependency becomes apprecia-
ble from about 20 cps. Assuming the
velocity of a P wave in the region is
5 km/sec, the wavelength at 20 cps is
250 m. Again assuming that log E = 11A
+ 1.5 M and the maximum strain energy
stored in a unit volume is 3 X 103 erg/cm3
(strain energy: 0.5 eX2\ e: elastic
const.^xlO^lO12 c.g.s.; X=l~2x
10-4), the magnitude of an earthquake
released by breaking rock volume of
250x250x250 m will be 3.5. Such earth-
quakes are perceptible in a small region.
The present swarm consists of many
small earthquakes without any outstand-
ing one. The magnitude of the larger, per-
ceptible, earthquakes which occur fre-
quently, is 3.5-3.0.
The size of fissures, which may be
produced by those larger earthquakes in
the swarm, agrees with the wavelength
with which the scattering effect becomes
appreciable.
6. In Plate 6, the amplitude decays
after P arrival in the frequency range
of 50 cps more rapidly in the pre-swarm
earthquakes than in the earthquakes of
1967. This difference in the seismogram
can also be explained by the increased
scattering effect after the swarm.
From the present study, it is concluded
that the swarm region has been highly
fractured. The magnitude of the largest
swarming earthquakes agrees well with
the frequency of seismic waves with
which the scattering becomes effective.
It seems likely that the highly hetero-
geneous region was under strain, started
breaking by many fractures, and was
eventually released from the strain, as
experiments suggested.
Difference in the Relationship of
Magnitude to Frequency of Occur-
rence between Aftershocks and Fore-
shocks for an Earthquake of
Magnitude 5.1 in Central Japan
S. Suyehiro
An earthquake of magnitude 5.1 oc-
curred in central Japan in September
1967 in almost the same place where the
event of 1964 took place with different
"b" values for foreshocks and after-
shocks. The 1967 sequence was com-
pletely recorded by a set of comprehen-
sive magnetic tape seismographs of broad
frequency band and large dynamic
range; b values of 0.59 and 0.89 were
found for foreshocks and aftershocks as
compared with 0.35 and 0.76 found for
the 1964 sequence.
The main points of difference between
the events of 1964 and 1967, which
shared the same epicenter region and the
same pattern in sequence, are the magni-
tude of main shocks and the background
seismic activity. The magnitude of the
main shock was 3.3 in 1964 and 5.1 in
1967. The background activity was very
quiet in 1964, while in 1967 the Matsu-
shiro swarm had grown outward to in-
clude the present region where the activ-
ity was already high. If similarities are
assumed in larger and smaller earth-
quakes, the difference in the combination
of b values for foreshocks and after-
shocks must be attributed to the differ-
ence in the background activities rather
than the magnitudes of main shocks. Ac-
cordingly, the larger b value of 0.59 for
foreshocks in 1967, as compared with the
1964 event, was interpreted as result-
ing from the superposition of high back-
ground activity of 6 = 1 and pure fore-
shock activity with the same b value of
476
CARNEGIE INSTITUTION
0.35 as in 1964. A slight difference of b
value in the two aftershock sequences can
also be explained in the same way. With-
out the high background activity in 1967,
6 values of foreshocks and aftershocks in
the same region should have been as they
were in 1964.
Introduction
On January 22, 1964, a perceptible
earthquake of magnitude 3.3 occurred
about 16 km to the southwest of the
Matsushiro Seismological Observatory.
Twenty-five foreshocks and 173 after-
shocks associated with this earthquake
were recorded at the Observatory. From
the analysis of these records, a con-
siderable difference in the relationship of
magnitude to frequency of occurrence
was found between the foreshocks and
aftershocks, i. e., the coefficient b in the
Gutenberg-Richter formula was only
0.35 for the foreshocks as compared with
0.76 in the aftershocks (S. Suyehiro, T.
Asada, and M. Ohtake, 1964). 95 The
same difference was also observed in the
foreshocks and aftershocks of the Great
Chilean Earthquake of 1960 (S. Suye-
hiro, 1966) .96
In August 1965 a large swarm of earth-
SAKAI-MURA
. EPICENTER REGION OF
" EARTHQUAKES STUDIED
'//////,, : PRINCIPAL SWARM REGION
C.'D ': extended swarm region
Fig. 81. Area of earthquake swarm near
Matsushiro Seismological Observatory.
quakes started near the Matsushiro Seis-
mological Observatory (Earthquake Re-
search Institute, 1966 and 1967) .97 For
about one and a half years this swarm
was limited to a region of 10 km X 10 km,
but later the swarm region grew outward
to include the region where the sequence
of January 1964 took place (Fig. 81).
The activity in this region continued
with the form of swarm until September
1967 when a strong earthquake of magni-
tude 5.1 occurred with many foreshocks
and aftershocks. The earthquake was
much larger than preceding and follow-
ing earthquakes, which indicated that the
present sequence is of the fore-, main-,
and aftershock type rather than being
one of the rises in a swarm activity. Fur-
thermore, the origin of the main shock
was only 2 km from that of the main
shock of January 1964.
Naturally, a question was raised as to
whether the present sequence manifested
the same character as was found in De-
cember 1964, in which different b values
were assigned to foreshocks and after-
shocks.
Fortunately, two months before this
event, a set of seismographs of large dy-
namic range and of broad frequency
band, developed by I. S. Sacks, was in-
stalled in the Matsushiro Seismological
Observatory (I. S. Sacks, 1966) ,98 and
the whole sequence was recorded from
the level of background noise up to the
main shock adequately without satura-
tion. The results of the analysis and re-
lated discussions are reported in this
section.
Instrumentation
The present multichannel recording
system has velocity and displacement re-
sponses in a frequency range of %o~
30 cps, and its dynamic range covers
background noise from an assumed
quietest site to earthquake motions of
intensity IV or more (JMA scale). The
specially designed pendulum of low dis-
tortion is housed in vacuum, and its
operational period is 15 sec for the hori-
zontal component and 5 sec for the
DEPARTMENT OF TERRESTRIAL MAGNETISM
477
vertical component. Accordingly, the
present pendulum of comparatively long
period is free from distortion in the
short-period vibration field, which is not
true of most types of seismographs now
in operation. The output of the trans-
ducers is fed into a system of chopper
amplifiers and filters and recorded in
three levels for displacement response
and in two levels for velocity response
on slow-speed magnetic tape of 0.17 mm/
sec by the direct recording method.
With this system, all shocks from fore-
shocks or aftershocks of small magnitude
barely above the background noise up to
the main shock of magnitude 5.1, which
gave the intensity IV at the site of ob-
servation, were properly recorded by the
same frequency response without satura-
tion. Such an instrumental set-up is very
valuable for studies of magnitude and
frequency of occurrence, and for com-
parison of spectra of large and small
earthquakes.
Material
Seismogram. The magnetic tape of
about 40 hours in real time before and
after the main shock, namely, from 08
hours on September 13, 1967, to 11 hours
on September 16, 1967, was replayed and
recorded on ink-writing paper by a spe-
cially designed read-out system at the
Department. Examples are shown in Fig.
82 in which earthquakes with large dif-
ferences in magnitude are well covered
by a large dynamic range.
Earthquakes of S — P time from 1.4 sec
to 2.2 sec were all considered as fore-
shocks or aftershocks for the following
reasons. (1) The activity in the principal
swarm region had already calmed down,
AFTERSHOCKS
J SEP. 14, 1967
2lh09m J.S.T.
SPMV- L
v^VVi^Vvw^w
REL. MAGNIF* I
SPMV - H
REL. MAGNIFx 8
SPHV-H
REL MAGNIF: 300
SPHV-L
REL. MAGNIF* 40
^Mft^
Fig. 82. Seismograms showing that earthquakes with large differences in magnitude are well
recorded by a large dynamic range.
478
CARNEGIE INSTITUTION
and earthquakes of the same S — P range
in different azimuth were very small in
number. (2) The frequency of occurrence
of earthquakes of the said S — P time
rose abruptly about 40 hours before the
main shock. (3) Nearly all earthquakes
of magnitude larger than 1.8 gave a clear
initial motion, and the azimuth was
checked from the direction of the initial
motion. (4) Even if some foreign shocks
from different azimuths had leaked in,
they would have increased the frequency
of occurrence slightly in the magnitude
range of the first or second shock, which
could not have distorted the statistics.
Such a distortion, furthermore, could not
favor the present conclusion of a smaller
6 value for foreshocks, but would work
toward the opposite conclusion. For
aftershocks of much higher frequency of
occurrence, such a distortion is incon-
ceivable.
Magnitude Determination. Earth-
quakes corresponding to the above cri-
teria occurring within 40 hours before
and after the main shock were read from
the ink-writing records. Amplitudes
measured from the middle- or low-sensi-
tivity channel were all reduced to what
should have been recorded by the high-
sensitivity channel. Since the trace
amplitude of the background noise is
about 1 mm, earthquakes of maximum
trace amplitude of less than 3 mm were
all eliminated from the statistics. Magni-
TABLE 17. Magnitude and Frequency of
Occurrence of Foreshocks and Aftershocks
Trace
amplitude,
mm
Magnitude
Frequency of
occurrence
Fore-
After-
1000
300
100
o
LL1
£ 10
FORESHOCKS
V
\.
^"sJ ^
•
#
'"
2.0 3.0
MAGNITUDE
4.0
Fig. 83. Relation between frequency of oc-
currence and magnitude for foreshocks.
tudes were assigned on the following as-
sumptions.
1. The epicentral distance from the
Observatory is nearly the same, and the
difference of magnitudes of two earth-
quakes is equal to the difference of
logarithms of maximum trace amplitudes
of two earthquakes (A M12 = log Ax —
logii,).
2. The magnitude of the main shock,
5.1, and that of one foreshock, 4.1, deter-
mined by JMA, were used to reduce the
relative magnitude scale by 1 to the scale
in common use.
3. Frequency of occurrence and magni-
1000
300
100
y 30
shocks
shocks
O
3.0-5.9
1.0
59
316
6.0-11.9
1.3
37
212
12.0-23.9
1.6
31
151
24.0-47.9
1.9
21
110
48.0-95.9
2.2
7
44
96.0-191.9
2.5
6
24
192.0-383.9
2.8
5
6
384.0-767.9
3.1
4
5
768.0-1535.9
3.4
0
7
1536.0-3071.9
3.7
0
1
3072.0-6143.9
4.0
1
0
c.\
AFTERSHOCKS
Xj
•
1.0
2.0 3.0
MAGNITUDE
4.0
Fig. 84. Relation between frequency of oc-
currence and magnitude for aftershocks.
DEPARTMENT OF TERRESTRIAL MAGNETISM
479
tude were considered. Class interval in
trace amplitude and frequency of occur-
rence and corresponding magnitude for
foreshocks and aftershocks are listed in
Table 17. Figure 83 shows the relation
between frequency of occurrence and
magnitude for foreshocks, and Fig. 84
shows that relation for the aftershocks.
4. Frequency distribution of S — P
times. Frequency distribution of S—P
times for foreshocks and aftershocks is
shown in Fig. 85.
5. Background activity in the region
of the event. The swarm region started
growing, and the NE-SW diameter
reached 20 km as of August 1966, but
the present region was not yet included.
On January 16 and February 3, 1967,
earthquakes of intensity V took place in
the present region, called Sakai-mura
Village, and this region became active.
Table 18 shows the frequency of occur-
rence of perceptible earthquakes and in-
tensity observed at the village office of
TABLE 18. Perceptible Earthquakes in the
Sakai-mura Region from January to
August 1967
220
200
180
160
140
5-
U
Z 120
LU
O
uj 100
80
60
40
20
FORESHOCKS
Intensity
I
II
III
IV
V
(Mag.
(Mag.
(Mag.
(Mag.
(Mag.
2.5)
3.0)
3.5)
4.0)
4.5)
January 60
18
3
3
3
February 155
62
11
2
1
March 55
16
1
0
0
April 44
6
5
2
0
May 90
29
2
2
0
June 29
8
4
1
0
July 17
3
1
0
0
August 13
9
3
0
0
Total 463
151
30
10
4
Sakai-mura from January 1967 to August
1967, just before the present event. All
earthquakes originating in other regions
but perceptible at Sakai-mura village
were eliminated. Magnitudes were as-
signed on the basis of instrumental de-
terminations, and also according to the
relation of magnitude to intensity, (M =
y2I + const., for local shocks of nearly
constant epicentral distance).
AFTERSHOCKS
1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2SEC
S-P TIME
Fig. 85. Distribution oi S — P times.
1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 SEC
S-P TIME
480
CARNEGIE INSTITUTION
This activity is considered as the back-
ground activity in the region when the
present event took place, and the relation
between frequency of occurrence and
magnitude is shown in Fig. 86.
Discussion
1. b values. In the event of 1964, b =
0.76 ±0.02 for aftershocks and b = 0.35 ±
0.01 for foreshocks while in the present
event, b = 0.89 ±0.02 for aftershocks and
b = 0.59 ±0.03 for foreshocks. In both
cases, a smaller b value was found for
foreshocks and a larger value for after-
shocks. The difference between b values
for foreshocks and aftershocks, however,
is not so large for the present event as
it was for the event of 1964. The two
events took place in almost the same re-
gion, so why were b values not similar
for each?
Two points of difference can be raised
between the events of 1964 and 1967. One
is that the magnitude of the main shock
was 5.1 in 1967 as against 3.3 in 1964,
and the other is that the 1964 event took
place when the regional background ac-
tivity was very quiet, while the 1967
1000
300
100
>-
I 30
O
LU
OS
10
3
\
BACKGROUND ACTIVITY
\.»
V 6
'^
\. •
1 1 1 l l
2.5 30 3.5 4.0 4.5
MAGNITUDE
Fig. 88. Relation between frequency of oc-
currence and magnitude for background ac-
tivity.
event occurred when the regional activity
was already high and of swarm type (see
Table 18 and Fig. 86) . Since many simi-
larities have been found between large
and small earthquakes, especially in the
relation of frequency of occurrence to
magnitude, the first point alone scarcely
counts. The second point can most likely
be attributed to the fact that some rela-
tive difference in b values existed, par-
ticularly for foreshocks, in the events of
1967 and 1964, although a smaller 6 for
foreshocks was retained.
2. Superposition of two activities of
different b value. Let us first consider
the two foreshock sequences, which gave
a comparatively large difference in 6
value. It is assumed that the foreshock
activity for the main shock of September
1967 had the same b value of 0.35 as the
foreshock activity of 1964. With this
value superposed on the already existing
swarming background activity the super-
position of two activities was observed.
The well-known formula, which repre-
sents the relationship of frequency of
occurrence to magnitude, log N = a—bM,
does not follow the law of superposition.
In Fig. 87, two straight lines,
log N± = - 0.35 M and log N2=-l .00 M,
are drawn, having the same frequency of
occurrence at a relative magnitude of 0;
and log (N1 + N2) is also given as a
function of M. Evidently, log {Nx +
N2)=zf{M) can no longer be expressed
by a straight line, but is a convex curve
downward. However, the observable
magnitude range is usually not large
enough to see the curvature, and the
fraction which is observed would be con-
sidered a straight line. In a region where
one activity overwhelms the other, the
existence of minor activity has practi-
cally no effect on the major activity.
Only in a region where two activities
have comparable frequency of occurrence
does the resultant "apparent 6" have an
intermediate value of two 6's.
It is assumed that the frequency dis-
tribution for the present foreshock ac-
DEPARTMENT OF TERRESTRIAL MAGNETISM
481
s
—
"~^\^v, ,
^JV;
^
\
RELATIVE MAGNITUDE
Fig. 87. Superposition of two activities of different b's.
tivity shown in Fig. 85 is actually a part
of the resultant curve. The mean fre-
quency of occurrence of M = 3 earth-
quakes in pure background activity is
calculated to be 0.022/hour (Fig. 86) ,
while that of M = 3 earthquakes in super-
posed activity is 0.097/hour (Fig. 83).
Accordingly, the same value for pure
foreshock activity must be 0.097 —
0.022 = 0.075, which is 3.4 times larger
than the value of pure background activ-
ity. The magnitude range 1-4 in Fig. 83
corresponds to the magnitude range —1.2
to 1.8 in Fig. 87 if a difference of 3.4
times between 6 = 0.35 pure foreshock
activity, and 6 = 1.00 pure background
activity, at magnitude 3, is applied. If
the curve, log (N1 + N2), between M —
-1.2 and M = 1.8 in Fig. 87 is approx-
imated by a straight line, its b value is
log (tfx+tfa)-1.2-log (N1+N2)lm8/
M.1.2-M1.8}
which is calculated to be 0.62.
The observed value, 0.59, and the cal-
culated value, 0.62, on the above assump-
tion show good agreement. Thus, the
difference in b values for the foreshocks
of 1964 and 1967 can be interpreted as
being caused by the superposition of pure
foreshock activity and pure background
activity. The aftershock activity of a
higher frequency of occurrence is much
less influenced by the background activ-
ity than the foreshock activity. However,
if the same consideration is applied to
the aftershock activity, assuming that
the pure aftershocks have a b value of
0.76 as in 1964, the resultant b should
be 0.80. Again, this value has a fair
agreement with the observed value of
0.89.
3. Foreshocks and aftershock region.
Figure 85 shows the frequency distribu-
tion of S—P time of foreshocks and
aftershocks. Considering that the differ-
ence between the upper and lower limits
oi S—P time is 0.8 sec and that the wave
velocity of an imaginary S — P wave is
7.0 km/sec, the linear dimension of the
region becomes 5.6 km. From the Utsu-
Seki formula of log A = 1.02 M0-4.0
(M0: magnitude of the main shock, A:
area of aftershock region in km2), using
M0 = 5.1, a linear dimension of 4.0 km
is obtained, which is in good agreement
482
CARNEGIE INSTITUTION
with the observed value. Similar agree-
ment was found in 1964.
Conclusion
The difference in b values for fore-
shock and aftershock activities in 1964
and 1967 can be interpreted as being
caused by the superposition of high
background seismic activity and pure
foreshock activity. The same order of
difference in b values for foreshocks and
aftershocks seems to be characteristic of
earthquakes of fore-, main-, and after-
shock type which take place in the pres-
ent region near the Matsushiro Seismo-
logical Observatory.
REFERENCES CITED
1. Schmidt, M., Galactic Structure, A. Blaauw
and M. Schmidt, eds., Chicago: Univ. of
Chicago Press, p. 513, 1965.
2. Hindman, J. V., and K. M. Balnaves,
Australian J. Phys., Astrophysical Supple-
ment, No. 4, 1967.
3. Trachslin, W., L. Brown, T. B. Clegg, and
R. G. Seyler, Phys. Letters, 25B, 585, 1967.
4. Seyler, R. G., Nucl. Phys., A124, 253, 1969.
5. Petitjean, C, L. Brown, and R. G. Seyler,
Nucl. Phys., 129, 209, 1969.
6. Ebbinghaus, H., U. Holm, H. U. Klapdor,
and H. Neuert, Z. Phys., 199, 68, 1967.
7. Miers, R. E., and L. W. Anderson, Rev.
Sci. Instr., 39, 336, 1968.
8. Klose, J. Z., Beam-Foil Spectroscopy, S.
Bashkin, ed., Gordon and Breach Pub-
lishers, New York, 1968.
9. Flamm, W. G., P. M. Walker, and M.
McCallum, J. Mol. Biol, 40, 423, 1969.
10. Wetmur, J. G., and N. Davidson, J. Mol.
Biol, 81, 349, 1968.
11. Callan, H. G., J. Cell Sci., 2, 1, 1967.
12. Whitehouse, H. L. K, J. Cell. Sci., 2, 9,
1967.
13. Smith, M., in The Fresh-Water Algae of
the United States, McGraw-Hill Book Co.,
New York, 1950.
14. Starr, R. C., Am. J. Botany, 51, 1013, 1964.
15. Safferman, R. S., and M. E. Morris, Science,
140, 679, 1963.
16. Cowie, D. B., and P. Szafranski, Biophys.
J., 7, 567, 1967.
17. Luftig, R., and R. Haselkorn, Virology, 1,
344, 1966.
18. Safferman, R. S., I. R. Schneider, R. L.
Steere, M. E. Morris, and T. O. Diener,
Virology, 37, 386, 1969.
19. Padan, E., and M. Shilo, Virology, 82, 234,
1967.
20. Silva, P. C, in Physiology and Biochem-
istry of Algae, p. 827. Academic Press, New
York and London, 1962.
21. Edelman, M., D. Swinton, J. A. Schiff,
H. T. Epstein, and B. Zeldin, Bacteriol
Rev., 31, 315, 1967.
22. Drouet, F., Proc. Acad. Nat. Sci. Phila., 115,
261, 1963.
23. Frampton, E. W., and B. R. Brinkley, J.
Bacteriol, 90, 446, 1965.
24. Sandoval, H. K, H. C. Reilly, and B.
Tandler, Nature, 205, 522, 1965.
25. Ryan, F. J., P. Fried, and F. Mukai, Bio-
chim., Biophys. Acta, 18, 131, 1955.
26. Endo, H., K. Ayabe, K. Amako, K. Takeya,
Virology, 25, 469, 1965.
27. Cowie, D. B., and B. J. McCarthy, Proc.
Natl Acad. Sci. U. S., 50, 537, 1963.
28. Grady, L. J., and E. C. Pollard, Radiation
Res., 86, 68, 1968.
29. Marcovich, H., Ann. Inst. Pasteur, 90, 303,
1956.
30. Seaman, E., E. Tarmy, and J. Marmur,
Biochemistry, 8, 607, 1964.
31. Okamoto, K., J. A. Mudd, J. Mangan,
W. M. Huang, T. V. Subbaiah, and J. Mar-
mur, /. Mol. Biol, 84, 413, 1968.
32. Grady, L. J., and E. C. Pollard, Biochim.
Biophys. Acta, 145, 836, 1967.
33. Haas, M., and H. Yoshikawa, Virology, 3,
248, 1969.
34. Ishibashi, M., and Y. Hirota, J. Bacteriol,
90, 1496, 1965.
35. Kharkar, D. P., K. K Turekian, and K. K.
Bertine, Stream supply of dissolved silver,
molybdenum, antimony, selenium, chrom-
ium, cobalt, rubidium and cesium to the
oceans. Geochim. Cosmochim. Acta, 32,
285, 1968.
DEPARTMENT OF TERRESTRIAL MAGNETISM
483
36. Gast, P. W., Terrestrial ratio of potassium
to rubidium and the composition of earth's
mantle. Science, 147, 858, 1965.
37. Deland, A. N., The boundary between the
Timiskaming and the Grenville Sub-
province in the Surprise Lake area, Quebec.
Proc. Geol. Assoc. Can., 8, 127-141, 1956.
38. Leggo, M., Unpublished Ph.D. thesis,
Australian National University, Canberra,
Australia, 1968.
39. Papanastassiou, D. A., and G. J. Wasser-
burg, Initial Sr isotopic abundances and
the resolution of small time differences in
the formation of planetary objects. Earth
Planet. Sci. Letters, 5, 361-376, 1969.
40. York, D., Least-squares fitting of a
straight line with correlated error. Earth
Planet. Sci. Letters, 5, 320-324, 1969.
41. Craig, H., Isotopic composition and origin
of the Red Sea and Salton Sea geothermal
brines, Science, 154, 1544-1548, 1966.
42. Goodwin, A. M., Structure, stratigraphy,
and origin of iron formations, Michipicoten
area, Algoma District, Ontario, Canada.
Geol. Soc. Am. Bull., 73, 561-586, 1962.
43. Mclntyre, G. A., C. Brooks, W. Compston,
and A. Turek, The statistical assessment
of Rb-Sr isochrons. J. Geophys. Res., 71,
5459-5468, 1966.
44. Hart, S. R., and G. L. Davis, Zircon U-Pb
and whole-rock Rb-Sr ages and early
crustal development near Rainy Lake,
Ontario. Geol. Soc. Am. Bull, 80, 595-616,
1969.
45. Gast, P. W., Isotope geochemistry of vol-
canic rocks, in Basalts, 325-358, Intersci-
ence Publishers, New York, 1967.
46. Bence, A. E., The differentiation history of
the earth by rubidium-strontium isotopic
relationships. Ph.D. thesis, M. I. T., 1966.
47. Gast, P. W., Limitations on the composi-
tion of the upper mantle. /. Geophys. Res.,
65, 1287-1297, 1960.
48. Hedge, C. E., Variations in radiogenic
strontium found in volcanic rocks. J. Geo-
phys. Res., 71, 6119-6128, 1966.
49. Gast, P. W., Upper mantle chemistry and
evolution of the earth's crust, in The
History of the Earth's Crust, R. A. Phin-
ney, ed., Princeton Univ. Press, 1968.
50. Hurley, P. M., Correction to: Absolute
abundance and distribution of Rb, K
and Sr in the earth. Geochim. Cosmochim.
Acta, 32, 1025-1030, 1968.
51. Patterson, C. C, Characteristics of lead
isotope evolution on a continental scale in
the earth, in Isotopic and Cosmic Chem-
istry, 244-268, North Holland Publ., Am-
sterdam, 1964.
52. Wasserburg, G. J., Geochronology and iso-
topic data bearing on development of the
continental crust, in Advances in Earth
Science, 431-459, M. I. T. Press, Boston,
1966.
53. Wilson, H. D. B., P. Andrews, R. L.
Moxham, and K. Ramlal, Can. J. Earth
Sci., 2, 161-175, 1965.
54. Baragar, W. R. A., Can. J. Earth Sci., 5,
773-790, 1968.
55. Smith, R. E., J. Petrol, 9, 191-219, 1968.
56. Gurney, J. J., G. W. Berg, and L. H.
Ahrens, Observations on caesium enrich-
ment and the potassium/rubidium/caesium
relationship in eclogites from the Roberts
Victor Mine, South Africa. Nature, 210,
1025-1027, 1966.
57. Berg, G. W., Secondary alteration in ec-
logites from kimberlite pipes. Am. Min-
eralogist, 53, 1336-1346, 1968.
58. Williams, A. F., The Genesis of the Dia-
mond, 2 vols., E. Benn, Ltd., London,
1932.
59. Griffin, W. L., and V. Rama Murthy,
Abundances of K, Rb, Sr and Ba in some
ultramafic rocks and minerals. Earth
Planet. Sci. Letters, 4, 497-501, 1968.
60. Allsopp, H. L., L. O. Nicolaysen, and P.
Hahn-Weinheimer, Rb/K ratios and Sr-
isotopic compositions of minerals in ec-
logitic and peridotitic rocks. Earth Planet.
Sci. Letters, 5, 231-244, 1969.
61. Boyd, F. R., Electron-probe study of di-
opside inclusions from kimberlite. Am. J.
Sci., 267 -A, 50-69, 1969.
62. O'Hara, M. J., The bearing of phase
equilibria studies in synthetic and natural
systems on the origin and evolution of basic
and ultrabasic rocks. Earth Sci. Revs., 4>
69-133, 1968.
63. Papike, J. J., personal communication, 1968.
64. Rickwood, P. C, M. Mathias, and J. C.
Siebert, A study of garnets from eclogite
and peridotite xenoliths found in kimber-
lite. Contrib. Mineral Petrol, 19, 271-301,
65. Macgregor, I. D., and J. L. Carter, The
genesis of eclogite xenoliths from the
Roberts Victor kimberlite pipe, South
Africa. Trans. Am. Geophys. Union, 60,
342, 1969.
484
CARNEGIE INSTITUTION
66. Boyd, F. R., and J. L. England, Apparatus
for phase-equilibrium measurements at
pressures up to 50 kb and temperatures up
to 1750° C. J. Geophys. Res., 65, 741-748,
1960.
67. Foshag, W. F., Mineralogical studies on
Guatemalan jade. Smithsonian Misc. Col-
lections, 135, No. 5, Publ. 4307, 60 pp., 1957.
68. Clarke, J. R., and J. J. Papike, Crystal-
chemical characterization of omphacites.
Am. Mineralogist, 53, 840-868, 1968.
69. Wade, A., and R. T. Prider, The leucite-
bearing rocks of the West Kimberley Area,
Western Australia. Quart. J. Geol. Soc,
London, 96, 39-98, 1940.
70. Kushiro, I., Y. Syono, and S. Akimoto, Sta-
bility of phlogopite at high pressures and
possible presence of phlogopite in the
earth's upper mantle. Earth Planet. Sci.
Letters, 3, 197-203, 1967.
71. Oxburgh, E. R., Petrological evidence for
the presence of amphibole in the upper
mantle and its petrogenetic and geophysical
implications. Geol. Mag., 101, 1-19, 1964.
72. Ringwood, A. E., Mineralogy of the
Mantle, in Advances in Earth Science,
P. M. Hurley, ed., M. I. T. Press, 357-399,
1964.
73. Hart, S. R., and L. T. Aldrich, Fractiona-
tion of potassium/rubidium by amphiboles :
Implications regarding mantle composition.
Science, 155, 325-327, 1967.
74. Mason, B., Kaersutite from San Carlos,
Arizona, with comments on the paragenesis
of this mineral. Mineral. Mag., 36, 997-
1002, 1968.
75. Abbott, D., and J. Ferguson, The Losberg
intrusion, Fochville, Transvaal. Geol. Soc.
S. Africa Trans., 68, 31, 1965.
76. Danchin, R. V., and J. Ferguson, Differ-
entiation trends in the Bushveld and Los-
berg intrusions. Geol. Soc. S. Africa Trans.
(Willemse Volume), in press, 1969.
77. Erlank, A. J., R. V. Danchin, and C. C.
Fullard, High K/Rb ratios in rocks from
the Bushveld Igneous Complex, South
Africa. Earth Planet. Sci. Letters, 4, 22-29,
1968.
78. Danchin, R. V., K and Rb in the Losberg
intrusion, Transvaal, South Africa. Earth
Planet. Sci. Letters, 5, 41^44, 1968.
79. Nicolaysen, L. O., J. W. L. de Villiers, A. J.
Burger, and F. W. E. Strelow, New meas-
urements relating to the absolute age of the
Transvaal system and the Bushveld Igneous
Complex. Geol. Soc. S. Africa Trans., 61,
137-173, 1958.
80. Allsopp, H. L., Rb-Sr and K-Ar measure-
ments on the Great Dyke of Southern
Rhodesia. J. Geophys. Res., 70, 977-984,
1965.
81. Larkam, C. W., Theoretical analysis of the
solion polarized cathode acoustic linear
transducer. J. Acoust. Soc. Am., 37, 664-678,
1965.
82. Herrin, E., and J. Taggart, Regional varia-
tions in P travel times. Bull. Seis. Soc. Am.,
58, 1325-1337, 1968.
83. Oliver, J., F. Press, and M. Ewing, Two-
dimensional model seismology. Geophysics,
19, 202-219, 1954.
84. Tolstoy, I., and E. Usdin, Dispersive prop-
erties of stratified elastic and liquid media :
A ray theory, Geophysics, 18, 844-870,
1953.
85. Dziewonski, A., S. Block, and M. Landis-
man, A technique for the analysis of
transient seismic signals. Bull. Seis. Soc.
Am., 59, 427-444, 1969.
86. Gupta, I., Note on the use of reciprocity
theorem for obtaining radiation patterns.
Bull. Seis. Soc. Am., 55, 277-281, 1965.
87. Jeffreys, H., The reflection and refraction
of elastic waves. Monthly Notices Roy.
Astron. Soc, Geophys. Suppl., 1, 321-334,
1926.
88. Knott, C. G., Reflexion and refraction of
elastic waves with seismological applica-
tions. Phil Mag., 48, 64-97, 1899.
89. Gutenberg, B., Energy ratio of reflected
and refracted seismic waves. Bull. Seis. Soc.
Am., 34, 85-102, 1944.
90. Nuttli, O., The effect of the earth's surface
on the S-wave particle motion. Bull. Seis.
Soc. Am., 51, 237-246, 1961.
91. Ewing, M., W. Jardetzky, and F. Press,
Elastic Waves in Layered Media, McGraw-
Hill, New York, 1957.
92. Chowdhury, D. K., and P. Dehlinger,
Elastic wave propagation along layers in
two-dimensional models. Bull. Seis. Soc.
Am., 53, 593-618, 1963.
93. Press, F., J. Oliver, and M. Ewing, Seismic
model study of refraction from a layer of
finite thickness. Geophysics, 19, 388-401,
1954.
94. Knopoff, L., Q. Revs. Geophys., 2, 625-660,
1964.
95. Suyehiro, S., T. Asada, and M. Ohtake,
Foreshocks and aftershocks accompanying
a perceptible earthquake in central Japan.
Papers Meteorol. Geophys. (Tokyo), 15,
71-87, 1964.
DEPARTMENT OF TERRESTRIAL MAGNETISM
485
96. Suyehiro, S., Difference between after-
shocks and foreshocks in the relationship
of magnitude to frequency of occurrence
for the great Chilean earthquake of 1960.
Bull. Seis. Soc. Am., 56, 185-200, 1966.
97. The Party for Seismographic Observation
of Matsushiro Earthquakes and the Seis-
mometrical Section, 1966 and 1967: Mat-
sushiro Earthquakes Observed with a
Temporary Seismographic Network. Parts
1-4, Bull. Earthquake Res. Inst., Tokyo
Univ., 45, 67-90; 45, 197-223; 45, 887-917.
98. Sacks, I. S., A broad-band large dynamic
range seismograph. Geophys. Mono. 10,
Am. Geophys. Union, 543-553, 1966.
BIBLIOGRAPHY
Assousa, G. E., L. Brown, and W. K. Ford, Jr.,
Lifetimes of excited states in Ne I and Ne II
(abstract) . Bull. Am. Phys. Soc., 14, 485, 1969.
Baum, W. A., J. S. Hall, L. L. Marton, and
M. A. Tuve, Annual Report of the Com-
mittee on Image Tubes for Telescopes. Car-
negie Inst. Wash. Year Book 67, 389-391,
1967-1968.
Bolton, E. T., The evolution of polynucleotide
sequences in DNA, in Mendel Centenary:
Genetics, Development and Evolution, pp.
76-85, R. M. Nardone, ed., Wash, D. C,
Catholic Univ. of America Press, 1968.
Brandt, W., see Brown, L.
Britten, R. J, and D. E. Kohne, Repeated
sequences in DNA. Science, 161, 529-540,
1968.
Brooks, C, and S. R. Hart, On the realistic use
of Rb-Sr isochron regression treatments (ab-
stract). Joint Annual Meeting Geol. and
Mineral. Associations of Canada, with sum-
mer meeting of the Mineral. Soc. Am,
Montreal, Canada, Univ. of Montreal, June
5, 6, 7, 1969, General Programme and Ab-
stracts of Papers, pp. 5-6.
Brooks, C, S. R. Hart, and T. Krogh, Implica-
tions about the mantle from K, Rb, Sr con-
centrations and Sr87/Sr86 ratios of Archean
volcanic rocks (abstract). Geol. Soc. Am.
Program, 81st Ann. Meeting, Mexico City,
Mexico, p. 39, Nov. 11-13, 1968.
Brooks, C, S. R. Hart, T. E. Krogh, and G. L.
Davis, Carbonate contents and 87Sr/86Sr ratios
of calcites from Archaean metavolcanics.
Earth and Planetary Sci. Letters, 6, 35-38,
1969.
Brooks, C, S. R. Hart, T. E. Krogh, and G. L.
Davis, The initial S^/Sr88 of Michipicoten
greenstones and its bearing on the develop-
ment of the mantle (abstract). Joint Annual
Meeting Geol. and Mineral. Associations of
Canada, with summer meeting of the Mineral.
Soc. Am, Montreal, Canada, Univ. of
Montreal, June 5, 6, 7, 1969, General Pro-
gramme and Abstracts of Papers, p. 6.
Brown, L, W. K. Ford, Jr., Vera Rubin, W.
Trachslin, and W. Brandt, Foil- and gas-
excitation of sodium spectra, in Beam-Foil
Spectroscopy, I, pp. 45-77, S. Bashkin, ed,
N.Y, Gordon and Breach, 1968.
Brown, L, and C. Petitjean, 6Li(p, 3He)*He re-
action with polarized protons from 0.4 to 3.2
MeV. Nucl. Phys., A117, 343-352, 1968.
Brown, L, see also Assousa, G. E., and Petit-
jean, C.
Cowie, D. B, see Falkow, S.
Davis, G. L, S. R. Hart, and G. R. Tilton,
Some effects of contact metamorphism on
zircon ages. Earth and Planetary Sci. Letters,
5, 27-34, 1968.
Davis, G. L, see also Brooks, C, and Hart,
S.R.
De La Haba, G, see Flexner, L. B.
Duggal, S. P, see Forbush, S. E.
Erlank, A. J., Microprobe investigation of
potassium distribution in mafic and ultra-
mafic nodules (abstract). Trans. Am. Geo-
phys. Union, 50, 343, 1969.
Falkow, S, and D. B. Cowie, Intramolecular
heterogeneity of the deoxyribonucleic acid
of temperate bacteriophages. J. Bacteriol.,
96, 777-784, 1968.
Fischer, G. von, W. Schreyer, G. Troll, G. Voll,
and S. R. Hart, Hornblendealter aus dem
ostbayerischen Grundgebirge. Neues Jahrb.
Mineral. Monatsh., 11, 385-404, 1968.
Flexner, J. B., see Flexner, L. B.
Flexner, L. B, J. B. Flexner, G. De La Haba.
and R. B. Roberts, Loss of memory as related
to inhibition of cerebral protein synthesis.
J. Neurochem., 12, 535-541, 1965.
Forbush, S. E., Variation with a period of two
solar cycles in the cosmic-ray diurnal an-
isotropy and the superposed variations cor-
related with magnetic activity. /. Geophys.
Res., 74, 3451-3468, 1969.
Forbush, S. E, S. P. Duggal, and M. A. Pomer-
antz, Monte Carlo experiment to determine
486
CARNEGIE INSTITUTION
the statistical uncertainty for the average
24-hour wave derived from filtered and un-
filtered data. Can. J. Phys., 46, S985-S989,
196S.
Ford, W. K., Jr., Electronic image intensifica-
tion. Ann. Rev. Astron. Astrophys., 6, 1—12,
L. Goldberg, ed., Palo Alto, Calif., Annual
Reviews, Inc., 1968.
Ford, W. K, Jr., A. T. Purgathofer, and Vera C.
Rubin, Optical spectra near 1 micron: the
Seyfert galaxy NGC 4151 and the planetary
nebula NGC 6543. Astrophys. J., 158, L39-
L40, 1968.
Ford, W. K., Jr., and Vera C. Rubin, Spectra of
emission regions in M31 (abstract). Bull.
Am. Astron. Soc, 1, 188, 1969.
Ford, W. K., Jr., and Vera C. Rubin, The
spectrum of the 1968 supernova in NGC 2713.
Publ. Astron. Soc. Pacific, 80, 466-469, 1968.
Ford, W. K., Jr., see also Assousa, G. E., Brown,
L., and Rubin, Vera C.
Hall, J. S.,seeBaum, W. A.
Hart, S. R., Discussion of 'K/Rb in amphiboles
and amphibolites from northeastern Min-
nesota'. Earth Planet. Sci. Letters, 4, 30-31,
1968.
Hart, S. R., K, Rb, and Cs concentrations in
fresh and altered abyssal tholeiites (abstract).
Geol. Soc. Am. Program, 81st Ann. Meeting,
Mexico City, Mexico, p. 128, Nov. 11-13,
1968.
Hart, S. R., and G. L. Davis, Zircon U-Pb and
whole-rock Rb-Sr ages and early crustal de-
velopment near Rainy Lake, Ontario. Geol.
Soc. Am. Bull., 80, 595-616, 1969.
Hart, S. R., G. L. Davis, R. H. Steiger, and
G. R. Tilton, A comparison of the isotopic
mineral age variations and petrologic changes
induced by contact metamorphism, in Radio-
metric Dating for Geologists, pp. 73-110. E. I.
Hamilton and R. M. Farquhar, eds., N. Y.
Interscience Pubis., 1968.
Hart, S. R., see also Brooks, C, Davis, G. L.,
Fischer, G. von, and Steinhart, J. S.
James, D. E., and I. S. Sacks, Instabilities in
locating hypocenters using a small number
of stations — a discussion and a solution (ab-
stract). Earthquake Notes, Eastern Section
Seis. Soc. Am., 89, 9, 1968.
James, D. E., I. S. Sacks, E. Lazo L., and P.
Aparicio G., On locating local earthquakes
using small networks. Bull. Seis. Soc. Am., 59,
1201-1212, 1969.
Kohne, D. E., Isolation and characterization
of bacterial ribosomal RNA cistrons. Biophys.
J., 8, 1104-1118, 1968.
Kohne, D. E., Taxonomic applications of DNA
hybridization techniques, in Chemotaxonomy
and Serotaxonomy, 2, 117-130, J. G. Hawkes,
ed., N. Y. Academic Press, Inc., 1968.
Kohne, D. E., see also Britten, R. J.
Krogh, T., see Brooks, C.
Marton, L. L., see Baum, W. A.
Petitjean, C, L. Brown, and R. Seyler, Polar-
ization and phase shifts in 6Li(p,p)6Li from
0.5 to 5.6 MeV (abstract). Bull. Am. Phys.
Soc, 13, 1448, 1968.
Petitjean, C, L. Brown, and R. Seyler, Polariza-
tion and phase shifts in 6Li (p,p)°Li from 0.5
to 5.6 MeV. Nucl. Phys., A 129, 209-219, 1969.
Petitjean, C, see also Brown, L.
Pomerantz, M. A., see Forbush, S. E.
Purgathofer, A. T., see Ford, W. K., Jr.
Roberts, R. B., et al., A Report on National
Uses and Needs for Separated Stable Iso-
topes, Wash., D. C, National Academy of
Sciences-National Research Council, 37 pp.,
July 29, 1968.
Roberts, R. B., see also Flexner, L. B.
Rubin, Vera C, and W. K. Ford, Jr., Spectro-
graph^ study of the Seyfert galaxy NGC
3227. Astrophys. J., 154, 431-445, 1968.
Rubin, Vera C, see also Brown, L. and Ford,
W. K., Jr.
Saa, G., and I. S. Sacks, The effect of elevation
and region on the P and S waves of some
South American seismograph stations (ab-
stract). Trans. Am. Geophys. Union, 50, 237,
1969.
Sacks, I. S., see James, D. E. and Saa, G.
Schreyer, W., see Fischer, G. von.
Seyler, R., see Petitjean, C.
Steiger, R. H., see Hart, S. R.
Steinhart, J. S., and S. R. Hart, Calibration
curves for thermistors. Deep-Sea Res., 15,
497-503, 1968.
Stueber, A. M., Abundances of K, Rb, Sr and
Sr isotopes in ultramafic rocks and minerals
from western North Carolina. Geochim.
Cosmochim. Acta, 33, 543-553, 1969.
Tilton, G. R., see Davis, G. L., and Hart, S. R.
Tnichslin, W., see Brown, L.
Troll, G., see Fischer, G. von.
DEPARTMENT OF TERRESTRIAL MAGNETISM
487
Turner, K. C, Dynamics of the galaxy-Magel-
lanic Cloud system (abstract). Astron. J., 78,
S121, 1968.
Tuve, M. A., Letters: An Open Forum, Re:
Solid-earth geophysics after the termination
of the Upper Mantle Project. Trans. Am.
Geophys. Union, 49, 448-449, 1968.
Tuve, M. A., Odd Dahl at the Carnegie Insti-
tution, 1926-1936, in Festskrijt til Odd Dahl,
Fra Venner Og Kolleger, pp. 40-46, Bergen,
A. S. John Griegs Boktrykkeri, 1968.
Tuve, M. A., see also Baum, W. A.
Varsavsky, C. M., Dust and atomic hydrogen
in interstellar space. Astrophys. J., 153, 627-
632, 1968.
Voll, G., see Fischer, G. von.
PERSONNEL
Director
Ellis T. Bolton
Associate Director
L. Thomas Aldrich
Roy J. Britten
Louis Brown
Dean B. Cowie
Scott E. Forbush x
W. Kent Ford, Jr.
Stanley R. Hart
Staff Members
Bill H. Hoyer 2
Richard B. Roberts
I. Selwyn Sacks
John S. Steinhart 3
Kenneth C. Turner
Staff Associates
David E. James 4 David E. Kohne
Vera C. Rubin
Distinguished Service Member of Carnegie Institution
M. A. Tuve
Section Chairmen
Astrophysics: W. Kent Ford, Jr. Biophysics: Dean B. Cowie
Geophysics: L. Thomas Aldrich
Fellows
George E. Assousa, Florida State University,
Tallahassee, Florida
Willy Z. Barreda R., Universidad National
de San Agustin, Arequipa, Peru 5
Christopher Brooks, Australian National Uni-
versity, Canberra, Australia 6
J. Alfred Chiscon, Purdue University, Lafay-
ette, Indiana 7
Sandro D'Odorico, Osservatorio Astrofisico,
Asiago, Italy 8
Joseph W. Erkes
Urbana, Illinois 9
University of Illinois,
1 Retired June 30, 1969.
2 From November 1, 1968.
3 On leave of absence from October 7, 1968,
resigned June 30, 1969.
4 From September 1, 1968.
5 From June 1, 1969.
6 Through November 30, 1968.
7 Through May 31, 1969.
8 From January 1, 1969.
9 From September 1, 1968.
488
CARNEGIE INSTITUTION
Anthony J. Erlank, University of Cape Town,
Rondebosch, South Africa10
Leo J. Grady, Pennsylvania State University,
University Park, Pennsylvania X1
Jaime Guzman, Observatorio San Calixto,
La Paz, Bolivia 12
Kyoichi Ishizaka, Kyoto University, Kyoto,
Japan 13
David E. James, Stanford University, Stan-
ford, California 14
Alan T. Linde, University of Queensland,
Brisbane, Australia 15
Claude Petitjean, University of Basel, Basel,
Switzerland 16
Adrian V. Rake, University of British Col-
umbia, Vancouver, British Columbia 17
Nancy J. Reed, Fellow of the National In-
stitute of General Medical Sciences, Be-
thesda, Maryland 18
German Saa, S. J., LTniversidad del Norte,
Antofagasta, Chile
Erich Steiner, University of Basel, Basel,
Switzerland 19
Research Associates
Mateo Casaverde, Instituto Geofisico del
Peru, Lima, Peru
Reynaldo Salgueiro, Instituto Geofisico Boli-
viano, La Paz, Bolivia
Shigeji Suyehiro, Meteorological Research
Institute, Tokyo, Japan
Collaborators and Visiting Investigators
Pablo Aparicio, Y.P.F.B., La Paz, Bolivia.
John Bannister, Universidad de Chile, San-
tiago, Chile
Francesco Bertola, Osservatorio Astrofisico,
Asiago, Italy
Don J. Brenner, Walter Reed Army Institute
of Research, Washington, D. C.
Ramon Cabre, S. J., Observatorio San
Calixto, La Paz, Bolivia
Dorothy Canter, George Washington Uni-
versity, Washington, D. C.
Eric H. Davidson, Rockefeller University,
New York, New York
Salvador del Pozo, Instituto Geofisico Boli-
viano, La Paz, Bolivia
David Denham, Geophysical Laboratory,
Port Moresby, Papua and New Guinea
Ernesto Deza, Instituto Geofisico del Peru,
Lima, Peru
S. Dutta, Howard University, Washington,
D.C.
Dale Evertson, Applied Research Labora-
tory, University of Texas, Austin, Texas
Stanley Falkow, Georgetown University,
Washington, D. C.
Luis Fernandez, S. J., Observatorio San
Calixto, La Paz, Bolivia
Louis B. Flexner, University of Pennsylvania,
Philadelphia, Pennsylvania
Josef a B. Flexner, University of Pennsyl-
vania, Philadelphia, Pennsylvania
Jose Frez, Universidad de Chile-Zona Norte,
Antofagasta, Chile
Enrique Gajardo, Centro Regional de Sis-
mologia Para America del Sur, Lima, Peru
Albert Gelderman, National Institutes of
Health, Bethesda, Maryland
Alberto A. Giesecke, Instituto Geofisico del
Peru, Lima, Peru
Daniel Haapala, Georgetown University,
Washington, D. C.
Anton L. Hales, Southwest Center for Ad-
vanced Studies, Dallas, Texas
Pembroke J. Hart, National Academy of
Sciences, Washington, D. C.
Edgar Kausel, Universidad de Chile, San-
tiago, Chile
Roman Laubert, New York University, New
York, New York
Eduardo Lazo, Universidad Nacional de
San Agustin, Arequipa, Peru
Alfred Marshak, Tulane University, New
Orleans, Louisiana
10 From July 1, 1968.
11 From September 1, 1968.
12 From September 1, 1968 through October
31, 1968.
13 Through August 31, 1968.
14 Through August 31, 1968.
15 From January 1, 1969.
18 Through September 30, 1968.
"Through August 31, 1968.
18 From November 11, 1968.
1,1 From June 1, 1969.
DEPARTMENT OF TERRESTRIAL MAGNETISM
489
Martin F. McCarthy, S. J., Observatorio
Astronomico, Specola Vaticana, Italy
Jorge Mendiguren, Universidad Nacional de
Cuyo, San Juan, Argentina
Robert P. Meyer, University of Wisconsin,
Madison, Wisconsin
Anthony Morse, Franklin and Marshall,
Philadelphia, Pennsylvania
A. J. Nalwalk, University of Connecticut,
Groton, Connecticut
Jose Oblitas, Observatorio San Calixto, La
Paz, Bolivia
Daniel Ochoa, Universidad Nacional de San
Agustin, Arequipa, Peru
Ricardo Olea, Universidad de Chile, San-
tiago, Chile
Alois Th. Purgathofer, Universitat Stern-
warte, Vienna, Austria
Anibal Rodriguez, Universidad Nacional de
San Agustin, Arequipa, Peru
Robert Safferman, U. S. Dept. of Interior,
Cincinnati, Ohio
Jaime Santa Cruz, Observatorio San Calixto,
La Paz, Bolivia
Richard G. Seyler, Ohio State University,
Columbus, Ohio
Robert Shleser, Purdue University, Lafay-
ette, Indiana
Diglio V. Simoni, Universidad Nacional de
San Agustin, Arequipa, Peru
Russell L. Steere, U. S. Dept. of Agriculture,
Beltsville, Maryland
Neil A. Straus, University of Toronto,
Toronto, Canada
Lupe Tamayo, Universidad Nacional de San
Agustin, Arequipa, Peru
Carlos Varsavsky, Instituto Argentino de
Radioastronomia, Villa Elisa, Argentina
Fernando Volponi, Universidad Nacional de
Cuyo, San Juan, Argentina
Robert F. Wing, Ohio State University,
Columbus, Ohio
Design Engineer
Everett T. Ecklund
Electronic Research Specialists
Kenneth D. Burrhus
John B. Doak
Charles A. Little
Glenn R. Poe
Laboratory Assistants
Liselotte Beach
Margaret E. Chamberlin 20
Lillian K. Prager 21
Jean F. Smith 22
Neltje W. van de Velde
Office
Chief, Fiscal Section: Helen E. Russell
Office Manager: William N. Dove
Assistant Fiscal Officer: Niels M. Pedersen
Librarian: Lelah J. Prothro (part time)
Secretary: Claudine C. Ator
Stenographers: Dorothy B. Dillin, E. Kath-
leen Hill
Typist: Mary T. Sheahan 23
Shop
Shop Manager and Electronics Research
Specialist: Paul A. Johnson
Instrumentation Research Specialist :
Michael Seemann
Instrument Makers: Robert Hoffmaster,
Carl M. Rinehart
Machinist: Francis J. Caherty
20 Through August 31, 1968.
21 From October 1,1968.
From November 4, 1968.
Through March 15, 1969.
490 CARNEGIE INSTITUTION
Buildings and Grounds
Carpenter and Maintenance Foreman: Leo Maintenance Assistant: Stanley Gawrys
J. Haber Caretakers: Bennie Harris, Willis Kilgore,
Assistant Maintenance Foreman: Elliott M. Jr.
Quade
Part-Time and Temporary Employees
George F. Brigham, Jr. Jerome Roddy
Joseph A. Darr John Roddy
Allen Forsbacka Victor A. Scuderi
Kimberly A. Matthews Carl L. Shears
Stephen Nezezon Robert Tapscott
Milan Pavich
PLATES
Plate 1
Department of Terrestrial Magnetism
fcl PaSSttS
*f '!»<" M"frf -j;'^'
*i *• <mSmIPII''H
s,'*:."i'*'--"
'•V.VJP
$|
■;: 3v
B
300M
K
150M
Plate 1. Secondary alteration in Roberts Victor omphacite. (A) Photomicrograph showing
fresh (clear) and altered (turbid) omphacite. Boxed area indicates area covered in (B), (C),
and (D) which are electron beam scanning photographs for K, Ca, and Mg radiation re-
spectively.
Plate 2
Department oj Terrestrial Magnetism
B
•100M
inn
wmmwrnwi
rap*
K
50M-
Plate 2. Location of potassium along grain boundaries in an eclogite from Tanzania. (A)
Photomicrograph showing stubby garnet grains enclosed by omphacite. Boxed area indicates
area covered in (B) and (C) which are electron beam scanning photographs for K and Ca
radiation. Note concentration of K along cracks separating garnet and omphacite.
Plate 3. (A) Photomicrograph showing kelyphite type of alteration in garnet from a garnet
peridotite. Boxed area indicates area covered in (B) which shows K X-ray radiation from
an electron beam scanning photograph.
Plate 3
Department of Terrestrial Magnetism
Plate 4
Department of Terrestrial Magnetism
Plate 4. Seismograph stations used in this study. Most of the stations have DTM-type
drum recording seismographs with a broadly peaked response having maximum sensitivity
at 1.5 cps. The worldwide standard stations were used as reference stations.
Plate 5
Department of Terrestrial Magnetism
Plate 5. The relationship between azimuthal variation of P-wave residuals and mountain
chains. It was generally found that the P-wave arrivals were most delayed when the seismic
ray path lay along and beneath the Andes cordillera.
Plate 6
Department of Terrestrial Magnetism
NOT
FILTERED
JAN. 23, 1964
I2h22ml8s
S-P ■• 2.2 sec
TRACE AMPLITUDE : 70
_ H«^Mi^^
D JAN. 17, 1967
D 08h54m07s
S-P : 18 sec
TRACE AMPLITUDE ! 76
Ifffl
FILTERED
250-200 tt^0#^^^W,W#;i(4H^N
200-160 ri^|t||j^
160-125
^MlNl^^'l! M*4»i
1 1 1 1 n i j M H p
■i""*"! j »W4»i I'i I I !iii|n«4»)»».|»-K.fiiii»ii»ii
, n,,,,,,,! , , |[|. ilnhi >llltll|l| , ) | | ,| i | i ij H
125-too *^^W^^^MW^;(«|«^
*'"' ' ff »■> N»f»N PW «»»
100-80 -^J;;^**!*^^
.ruin *mi.i hi nmim LU"
80-63 H^fjj^
6 3 - 50 -wJ j ||^^iN^pt|^ TlwHffffm
^^^^lil^^Hl^Ml^l^X^
Before the swarm After the swarm
Plate 6
Department of Terrestrial Magnetism
B
4 0 - 31.5 «•** ■ ^l#^#f#H##«W^
*H^)W^
31.5-25 ^|^ r#||f™
I [ I ' Iti J
25-20 4?* M#f^
20-16 mil
16-12.5 iwfwfwfj iM/y^yvfr*MH«if^^
12.5-10
yywpwppiwi^
10-8 yA^^^
8-6.3
6.3-5
y»4444,444^"'f'
4^4iyW44#^
5.4 j44HV\j^it^H^p H't'i''*' fft1 ili*y'^V'V
4-3.15
NV
W^
If (ill!
>"
■IB
WfKWpl.ljJlffi*'
■Wfr*vN"fr*N^^4»^
3.15-2.5
444«H44,f,j >f ^ "^ t 'i iiH''iH*fH> j44f#>ff»^^
Before the swarm
After the swarm
Plate 6. Records of two earthquakes of the same region which represent the year of 1964
before the swarm (A) and the year of 1967 toward the end of the swarm (B).
Committee on Image Tubes
for Telescopes
Cooperative Project of Mount Wilson and Palomar Observatories,
Department of Terrestrial Magnetism, Lowell Observatory,
National Bureau of Standards, and United States
Naval Observatory
W. A. Baum
Lowell Observatory
John S. Hall (Chairman)
Director, Lowell Observatory
Flagstaff, Arizona
L. L. Marton
National Bureau of Standards
M. A. Tuve
Department of Terrestrial Magnetism
Carnegie Institution Year Book 68, 1968-1969
REPORT OF THE COMMITTEE
The Carnegie Image Tube Committee
was originally set up primarily to evalu-
ate various methods of electronic image
intensification. Many different ap-
proaches to the problem were investi-
gated. Several years ago various tests
indicated that the cascaded type of in-
tensifier could provide an appreciable
gain over unaided photography for many
sorts of astronomical observations. This
permanently scaled tube, which is similar
in some respects to an end-on photo-
multiplier, multiplies primary photoelec-
trons internally, and displays on a phos-
phor screen an intensified image that is
recorded photographically. Cascaded
tubes developed by RCA for the Com-
mittee were found in 1963 (Carnegie
Institution of Washington Year Book 64)
to provide gains in exposure time of 10
or more over conventional photographic
techniques.
Until 1963 the task of the Carnegie
Committee had been to evaluate experi-
mental tubes and to provide the manu-
facturers of tubes with a vigorous feed-
back of information and criticism of the
performance of their devices. The Com-
mittee's emphasis then shifted from this
evaluation and testing program to a
program of procuring, assembling, and
testing a number of image tube sys-
tems that could be fairly readily adapted
to observational problems. These com-
plete systems were made available to
observatories requesting them through
a joint NSF-Carnegie Allocations Com-
mittee. Since the inception of this activ-
ity in 1965, three dozen systems have
been provided to astronomical investiga-
tors at various observatories. Nearly a
third of these are outside of the United
States.
The allocations program has thus been
successful in introducing a powerful, new
technique in astronomical research. Re-
sults obtained with these Carnegie-RCA
devices appear regularly in the astro-
nomical literature. The rate of failure of
these allocated tubes due to breakage,
the slumping of cathodes, or the loss of
vacuum has been gratifyingly low. For-
tunately, tubes of high quality continue
to be available from RCA (Type
C33011).
During the past year or two, the
emphasis of the Carnegie Committee has
changed once again. With the completion
of the allocation program, more effort
has been put into improving the tech-
niques for using these tubes. In particu-
lar, Dr. I. S. Bowen * has designed sev-
eral spectrograph cameras that are espe-
cially suited to image intensifier work. A
contract for engineering services and a
purchase order for improved tubes with
high performance specifications are lead-
ing to the development at RCA of a
high-gain, low-distortion version of the
cascaded tube. Progress on this improved
tube has thus far been most encouraging,
leading us to hope that it will be com-
pleted during the coming year.
During this report year Dr. Bowen has
succeeded in designing two transfer op-
tical devices of high quality. The transfer
lens has long been the weakest link in
the cascaded-tube system, and we look
forward to exploiting the better image
quality that Dr. Bowen's new optics pro-
vide.
The development, procurement, and
distribution of image tubes have been
supported by the National Science Foun-
dation and the Carnegie Institution of
Washington, and the Committee wishes
to express its thanks for this continuing
support. We wish to acknowledge and
thank Dr. W. Kent Ford, Jr., for carrying
out so effectively the work on the image
tube systems at the Department of Ter-
restrial Magnetism. We are most fortu-
nate to have Dr. I. S. Bowen's continuing
interest and assistance in solving the
optical problems associated with image
intensifiers.
* Distinguished Service Member, Carnegie
Institution of Washington.
495
Department of Embryology
Baltimore, Maryland
James D. Ebert
Director
Carnegie Institution Year Book 68, 1968-1969
Contents
Introduction 501
Ribosomal RNA and its Genes during
Oogenesis and Development of
Xenopus laevis 505
The structure of rDNA 508
Transcription of rDNA in vitro . . . 506
Genes and Gene Products in Other
Animals 509
The DNA of Urechis caupo oocytes . 509
Differentiation of the silk gland in
Bombyx mori 509
Nucleic Acid Metabolism in Oocytes and
Embryos of Urechis cawpo ... 510
Histone Synthesis in Cleaving Embryos
of Xenopus laevis 513
Studies on Mitochondria from Xenopus
laevis: Their Composition, Func-
tions, and Biogenesis 514
Mitochondrial RNA 514
Protein synthesis in mitochondria from
ovaries of Xenopus laevis .... 515
Formation of mitochondria during em-
bryogenesis of Xenopus laevis . . 517
Cell Differentiation and Viral Suscepti-
bility 518
Do isolated myotubes synthesize DNA
after exposure to Rous sarcoma
virus? . 518
Effects of RSV in a relatively syn-
chronous mass muscle culture
system 519
Comparative studies on the hybridiza-
tion of RSV -RNA with DNA from
various sources 521
Homology between RSV -RNA,
RAV-RNA and DNA from vari-
ous species 522
Base ratio analyses of the segment
of RSV-RNA which hybridizes
with DNA from several sources. 522
Homology between RSV-RNA and
Adenovirus-DNA 524
Attempts to demonstrate natural hy-
brid formation between RSV-
RNA and cellular DNA ... 526
Hybridization of RSV-RNA with
DNA from Chinese hamster
chromosomes
Hybridization of RSV-RNA with
membrane-associated DNA . .
Initial Attempts to Determine the Bio-
logical Role of Cellular DNA
Homologous to RSV-RNA . . .
527
527
528
531
Trophic Effects of Nerve on Muscle . .
DNA and protein metabolism in de-
nervated rat diaphragm .... 532
Control of acetylcholine receptors in
muscle fiber membranes . . . 533
Characterization of Heart Cells of the
Chick Embryo 534
Epicardial investment, glycogen con-
tent and secretory activity of the
early myocardium 535
Characterization of 7-day heart cells
in vivo and in vitro 536
Potassium-inhibition of pacemaker ca-
pacity 538
Electron Microscopy of Cultured Cells . 540
Collagen Synthesis in Somatic Cell Hy-
brids between Lymphocytes and
Fibroblasts 542
The Mammalian Embryo in Relation to
Its Environment 546
The spacing of blastocysts .... 546
Anatomy and physiology of the pla-
centa 548
Baseline studies 548
Experimental production of hyper-
tension 550
Placenta extrachorialis in monkeys . 551
The Collection of Human Embryos . . 552
Development of the human heart at
seven postovulatory weeks . . . 552
Staff Activities 552
Bibliography 554
Personnel 555
INTRODUCTION
It was an eventful year in the Depart-
ment of Embryology. Although there
were no serious distractions, and the
work of the Department continued on an
even course, a decision was reached that
will affect the Department's program in
the years to come. Over the next two
years, the Department will undergo its
most extensive reorganization since the
realignment of its program after the Sec-
ond World War, and possibly the most
extensive in its history.
Almost since its beginning the Depart-
ment has fostered three separate lines of
research: human embryology, reproduc-
tive physiology (the mammalian embryo
and its environment), and experimental
embryology. Faithful readers of these re-
ports hardly need be told that over the
past decade more and more emphasis has
been placed on exploring mechanisms of
development at cellular and molecular
levels. Descriptive human embryology
and studies of maternal-fetal interac-
tions have diminished perceptibly in
quantity, although, happily, there has
not been a corresponding drop in the
quality of published work.
However, what were once three rela-
tively small fields of research, in which
the subject matter and techniques could
be mastered by one or two devoted,
energetic investigators, have become
three vast areas for exploration, requir-
ing a new depth and range of knowledge
and technical sophistication. The "criti-
cal mass" of investigators in each of
these areas is no longer one or two. Thus
the decision was made to focus the De-
partment's efforts almost entirely on
studies at cellular and molecular levels.
The programs in human embryology, in
the conventional descriptive sense, and
anatomic and physiologic studies of ma-
ternal-fetal interactions will gradually
be terminated.
Fields of research evolve. The Depart-
ment of Embryology was for over forty
years the leader in the field of human
embryology. Its Collection is by a con-
siderable margin the finest in the world.
Yet in the past decade its use has di-
minished. The intellectual climate of the
Department has shifted. The Collection
is no longer the focal point it once was —
and might still be, in a different setting.
The Department also played a key
role in the initiation and nurturing of
the field of reproductive physiology in
the primates. Now the field is expanding
rapidly, largely under the impetus and
leadership provided by the National In-
stitute of Child Health and Human De-
velopment.
These considerations enabled — in fact
required — that the Department's re-
sources be marshalled so as to permit
the exploration of the basic mechanisms
of determination and differentiation in
increasing depth.
What are the practical consequences of
this far-reaching decision? Some of them
will more properly be included in future
reports. However two steps of the long-
range program are firm enough to per-
mit their announcement at this time.
Dr. Douglas M. Fambrough, Carnegie
Fellow, and Dr. Ronald H. Reeder,
Helen Hay Whitney Fellow, joined the
research staff on July 1, 1969, thereby
further strengthening the Department's
competence in molecular biology.
In July 1971 or shortly thereafter, the
Carnegie Embryological Collection (in-
cluding the Bluntschli Collection) will be
transferred to Wayne State University,
where it will be housed in space spe-
cifically designed for it in the new Kresge
Eye Institute. It is understood that quali-
fied visiting scholars will continue to
have access to it. Professor Ronan
O'Rahilly, who has used the Collection
extensively in recent years (and who
is in residence at the Department of
501
502
CARNEGIE INSTITUTION
Embryology in 1969-1970), will be the
Director of Embryology in the Kresge
Institute, and Dr. Bent G. Boving will
move to Wayne State University in 1970
as Professor of Anatomy and Gynecol-
ogy-Obstetrics. It is expected that under
their leadership in its new location, the
Collection will be used more extensively
than it has been in recent years.
The history of embryology shows that
the problems of development exist on
many levels of complexity from the mo-
lecular to the evolutionary. They must
be approached on many levels; in addi-
tion, a variety of tools and viewpoints
are required, which can only be provided
by the interplay of various specialized
disciplines.
The most fruitful new generalizations
of the immediate future are likely to
emerge from the frame of perception
provided by molecular genetics: the
concept of levels of control, and their
interactions; the concept of regulation.
This is more than an expression of
faith. The approaches that are increas-
ingly characteristic of the field should
permit new ideas to be perceived and
new syntheses to be effected more read-
ily than ever before. A glimpse of the
possibilities that lie ahead is provided
by the progress reported by Brown,
Dawid, Reeder, and Wensink in their
continuing study of the genes coding for
ribosomal RNA. These genes are the first
to be isolated from an animal genome,
the ribosomal DNA and its products
having been analyzed in detail in Xeno-
pus laevis and other amphibians. In
Xenopus the ribosomal RNA sequences
are initially transcribed as a large 40S
precursor molecule, which is then cleaved
to give one 18S and one 28S rRNA mole-
cule. The 40S precursor contains few (if
any) sequences other than those for 18S
and 28S rRNA. Sequences for 40S rRNA
account for about half of the total length
of the isolated homogeneous DNA com-
ponent which has been designated as
ribosomal DNA (rDNA). The 40S se-
quences have an average deoxyguanylic-
deoxycytidylic acid (GC) content of
62%. The other half of the rDNA, called
"spacer," is interspersed with the 40S
sequences and has a GC content of about
77%. The spacer sequences are probably
not transcribed in vivo. The 40S and
spacer sequences alternate along the
length of the DNA, and the unit repeats
about 450 times at each nucleolar or-
ganizer in somatic cells of X. laevis. The
active and inactive lengths of DNA are
illustrated strikingly in electron micro-
graphs by Miller and Beatty of the Oak
Ridge National Laboratory. In primary
oocytes of X. laevis the rDNA is ampli-
fied so that an individual oocyte con-
tains about 4000 nuclear equivalents of
rDNA or 1000-fold more rDNA than
would be predicted from its tetraploid
complement of chromosomes.
In Year Book 67 (pp. 403-404) it was
reported that the somatic rDNA (present
at the nucleolar organizer of somatic
cells) and the extra replicas of this DNA
in oocytes differ from each other in
buoyant density, the buoyant density of
somatic RNA being lower by 6 mg/cm3
than that of the extra copies. Having ob-
tained both the somatic rDNA and extra
copies in oocytes in pure form, Brown
and his colleagues have been able to
show that the two DNAs differ in the
degree to which they are methylated, the
somatic rDNA containing about 4-5%
5-methyl deoxycytidylic acid (MeC) ,
while the extra copies contain less than
0.2% MeC. The presence of methyl
groups is known to lower the density of
DNA in cesium chloride and the content
of MeC in somatic rDNA is probably
sufficient to account for its lower buoyant
density.
However it is not sufficient to isolate
and describe these genes. That is only a
beginning. What we need to know is how
their activities are regulated. What is the
basis of differential gene expression?
Little is known about the way in which
cytoplasmic factors may impinge upon
the genome. It is known that in Xenopus,
rDNA functions during oogenesis and
DEPARTMENT OF EMBRYOLOGY
503
again after gastrulation, but not during
cleavage. K. Shiokawa and K. Yamana
of Kyushu University have described a
cytoplasmic factor obtained from cleav-
ing embryos which inhibits the formation
of rRNA when it is added to embryonic
cells at stages when the rDNA is known
to be otherwise active. However the evi-
dence presented does not permit one to
decide whether it is an inhibition of tran-
scription, i.e., synthesis of 40S rRNA, or
"processing" of 40S rRNA to the 28S and
18S components. The potential impor-
tance of the observation is clear; we
have few leads to the isolation of possible
repressors in embryonic cells. However,
it will be necessary to establish the level
of the inhibition.
To do so requires first that rDNA and
rRNA be isolated and characterized;
that has been accomplished. A further
step would be the development of a sys-
tem for the synthesis of the products of
rDNA in vitro. Brown, Reeder, and their
colleagues have searched for conditions
under which rDNA is transcribed with
high fidelity in vitro. Substantial prog-
ress is now reported (pp. 506-509) , using
a system in which Xenopus rDNA is
transcribed by E. coli RNA polymerase.
The assay developed measures how much
of each strand of the double-stranded
rDNA is transcribed, as well as the
amount and kind of RNA transcribed
from the spacer region. The technique
actually separates the heavy (H) strand,
which is transcribed in vivo, from the
light (L) strand. Studies of the comple-
mentary RNA synthesized using rDNA
as template shows that it contains both
rRNA and some RNA corresponding to
the spacer DNA. Chain initiation ap-
pears to be very accurate, but chain
termination less so, some polymerase
molecules apparently continuing to tran-
scribe beyond the 40S sequences into the
spacer region.
An analogous approach is being taken
by Dawid and his colleague, R. F. Swan-
son, a Fellow of the U. S. Public Health
Service. Dawid has continued to center
his attention on mitochondrial DNA and
its immediate RNA products in Xenopus.
He has now offered additional evidence
that the 21S and 13S RNAs of mito-
chondria clearly differ from the 28S and
18S ribosomal RNAs. Moreover, pre-
liminary hybridization experiments sug-
gest that the 21S and 13S RNAs do not
share sequence homologies. It seems
likely, therefore, that different parts of
the mitochondrial DNA act as templates
in their formation.
At the same time Swanson has made
substantial headway in studying protein
synthesis in mitochondria isolated from
ovaries of Xenopus laevis. It is known
that mitochondria have the ability to
synthesize proteins in vitro. However
little is known of the source of informa-
tional RNA, the products themselves, or
the details of the process. Swanson has
developed a system in which the poly-
nucleotides polyuridylic, polyadenylic
and polycytidylic acids are taken up by
isolated mitochondria. The transport of
polyuridylic acid (poly U) across the
mitochondrial membrane results in an
increase in the incorporation of phenyla-
line. The system appears to offer promise
of identifying the site of protein synthe-
sis within the mitochondrion.
Another striking example of the effec-
tiveness of interdisciplinary studies is
seen in the relationship between develop-
mental biology and virology. It was over
fifty years ago that Peyton Rous dis-
covered the tumorigenic virus that bears
his name. It is less appreciated, however,
that in those studies he used two tech-
niques later to be developed further and
exploited by students of development.
One was the technique of transplantation
of tissue fragments to the embryonic
membranes of the chick embryo later
used by several generations of embry-
ologists to study the ability of embry-
onic tissues to differentiate when isolated
in a favorable environment well removed
from their normal relations with other
tissues, and by students of developmental
immunology in elucidating the graft-
504
CARNEGIE INSTITUTION
versus-host reaction. The second was the
use of the enzyme trypsin to liberate cells
from clotted plasma on which they were
growing, the forerunner of today's tech-
niques of dissociating tissues into their
component cells, now widely employed
in studies of the manner in which embry-
onic cells interact in forming their char-
acteristic patterns of tissue architecture.
But if virology contributed those tech-
niques to the study of development, it
was an embryologist, Ross Harrison, who
provided the method that is widely rec-
ognized as one of the principal technical
cornerstones of virology, that of tissue
culture. Viruses may be now propagated
in clonal lines of cells from a variety of
sources, normal and abnormal; and clon-
ally derived cells provide the most con-
venient and reproducible material for
studies of the mechanisms of action of
viruses in destroying or transforming
cells.
Even now, several new developments
offer promise for the future. One arises
out of an idea discussed in previous Year
Books, namely that in order to trans-
form a cell, a tumor virus must first
stimulate the synthesis of the cell's DNA.
During the year, Yoshikawa-Fukada, a
Carnegie Fellow, and Ebert have con-
tinued to probe into the mechanism
whereby oncogenic viral infection ac-
tivates part of the cellular genome. Their
earlier studies {Year Book 67, p. 431)
showed that Rous sarcoma virus RNA
(RSV-RNA) contains base sequences
complementary to those of DNA from a
variety of sources. They now report fur-
ther progress in characterizing these se-
quences and are attempting to determine
their significance in oncogenesis. As
noted a year ago {Year Book 67, p. 436) ,
the portion of RSV-RNA which hybrid-
izes with DNA from chicken cells has
a high content of adenylic acid. Further
studies now reveal this to be a general
pattern, i.e., the segment of RSV-RNA
that is enriched in adenylate is also ob-
served in hybrids with piscine and mam-
malian DNAs. Is this specific segment
of RSV-RNA directly involved in the
transformation process? It is noteworthy
that DNAs of other oncogenic viruses,
e.g., adenoviruses and SV40 virus, also
have a high content of deoxyadenylate.
Moreover there is evidence that DNA
from oncogenic viruses is integrated into
the genome of the host cell.
These and other findings suggest that
there may be, so to speak, a "viral onco-
genic sequence," with, possibly, a cor-
responding sequence in the cellular ge-
nome. If such a "viral oncogenic
sequence" exists, it should be revealed in
viral homologies. As a first test of this
scheme, Yoshikawa-Fukada and Ebert
have studied the relations between RSV-
RNA and the DNAs of three adeno-
viruses, types 2, 4, and 12. This family
of adenoviruses is interesting in that
types 2 and 4 are not oncogenic, while
type 12 is highly oncogenic. The results
are striking. RSV-RNA hybridizes far
more extensively with DNA from type
12 (oncogenic) than with DNAs from
types 2 and 4; moreover, preliminary
analyses indicate that the RSV-RNA
combining with adenovirus 12-DNA
again has a high adenylate content. Ex-
periments are also in progress to further
characterize the part of the cellular DNA
involved and to determine its role. The
initial findings are recorded on pages
521-531. It is at this point that Yoshi-
kawa-Fukada's and Robert J. Hay's pro-
grams interact. Hay, also working in
consultation with Ebert, has continued to
search for the mechanism whereby DNA
synthesis is stimulated in myotubes by
Rous sarcoma virus.
Mention has already been made of
five Fellows and Assistant Investigators,
Fambrough, Hay, Reeder, Swanson, and
Yoshikawa-Fukada, whose programs are
discussed more fully in the body of the
Report. They are representative of a
larger group of visiting scientists who
have contributed impressively to the De-
partment's vitality and well-being.
In the final year of his stay as a Fellow
of Carnegie Institution, Dr. Hayden G.
DEPARTMENT OF EMBRYOLOGY
505
Coon's work ranged widely in exploring
possible applications of the technique of
virus-assisted cell hybridization he de-
veloped last year in cooperation with Dr.
Mary Weiss {Year Book 67, pp. 424-
427) . One of the systems being analyzed
is a cross between cells producing large
amounts of collagen and cells producing
little or none, e.g., myeloma cells. In this
work Coon was joined during part of the
year by Dr. Lewis N. Lukens, on leave
from Wesley an University. On Septem-
ber 1, 1969, Coon took up a new position
as Associate Professor of Zoology at
Indiana University.
Another Carnegie Fellow, Yoshiaki
Suzuki, formerly of the National Insti-
tute of Health, Tokyo, joined Brown in
an attempt to isolate the genes coding
for the messenger RNA that directs the
synthesis of the silk protein, fibroin, in
the silkworm, Bombyz mori. Their initial
observations are described briefly later
in the Report.
Dr. Francis J. Manasek, on leave from
the Children's Hospital Medical Center,
Boston, spent the year with R. L. De-
Haan, continuing his earlier electron
microscopic studies of the formation of
the epicardium. In addition, he and Coon
initiated an investigation of the fine
structure of cells differentiating in vitro.
In July 1969, Dr. Harold E. Kasinsky,
a Fellow of the U. S. Public Health
Service for the past two years, took up an
appointment as Assistant Professor of
Zoology in the University of British
Columbia.
Finally, special mention should be
made of Dr. Harold R. Misenhimer who
in his second year as a Carnegie Fellow
brought to his collaboration with Dr.
Elizabeth M. Ramsey not only intense
interest and uncommon technical abili-
ties, but a deep understanding of the
difficult problems that lie ahead in the
field of maternal-fetal interactions. Dr.
Ramsey's program has long enjoyed close
ties with the Johns Hopkins School of
Medicine by virtue of her continuing
association with M. W. Donner and S. I.
Margulies. Now through Dr. Misenhimer
there are new links to Baltimore City
Hospitals, thus further strengthening the
research base in the community.
During the year two students com-
pleted the requirements for the doctorate
at Johns Hopkins : Iris Polinger, who had
been working with DeHaan, has taken up
a post in New York University College
of Dentistry, and Merry C. Schwartz,
one of Brown's students, has become As-
sistant Professor of Biology at Morgan
State College. Other students whose con-
tributions are mentioned specifically in
the Report include Lynn Billingsley
(with Boving), John Chase (with
Dawid) , Criss Hartzell (in Fambrough's
laboratory) and Pieter Wensink (associ-
ated with Brown) .
RIBOSOMAL RNA AND ITS GENES DURING OOGENESIS
AND DEVELOPMENT OF XENOPUS LAEVIS
D. Brown, I. B. Dawid, R. H. Reeder, and P. Wensink
(with the technical assistance of E. Jordan and M. Rebbert)
The DNA coding for ribosomal RNA
is the first group of genes to be isolated
in pure form from an animal genome (see
Year Book 67, pp. 401-404) . This ribo-
somal DNA and its products have been
analyzed in detail in the amphibian
Xenopus laevis. In this species the ribo-
somal RNA (rRNA) sequences are ini-
tially transcribed as a large 40S pre-
cursor molecule, which is then cleaved
to give one 18S and one 28S rRNA mole-
cule. Several lines of evidence suggest
that the 40S precursor contains few, if
any, sequences other than those for 18S
and 28S rRNA. Sequences for 40S rRNA
account for about half of the total length
506
CARNEGIE INSTITUTION
of the isolated DNA component which we
have designated as ribosomal DNA
(rDNA). The 40S sequences have an
average deoxy guany lic-deoxy cytidy lie
acid (GC) content of 62%. The other
half of the rDNA, called "spacer," is
interspersed with the 40S sequences and
has a GC content of about 77%. The
spacer sequences are probably not tran-
scribed in vivo. The 40S and spacer se-
quences alternate along the length of
the DNA, and the unit repeats about 450
times at each nucleolar organizer in so-
matic cells of X. laevis. In primary
oocytes of X. laevis the rDNA is ampli-
fied so that an individual oocyte con-
tains about 4000 nucleolar equivalents
of rDNA or 1000-fold more rDNA than
would be predicted from its tetraploid
complement of chromosomes.
Two problems have concerned us dur-
ing the past year. First, we have ana-
lyzed some physical and chemical char-
acteristics of the rDNA which is present
at the nucleolar organizer of somatic
cells (somatic rDNA) as well as the
extra replicas of this DNA in oocyte
nuclei. Both the somatic rDNA and extra
copies in oocytes have been obtained in
pure form. Second, we have synthesized
RNA in vitro using the purified rDNA
as primer. The aim of these experiments
is to reestablish in vitro the conditions
which control both the kinds and
amounts of rDNA transcribed in vivo.
The Structure of rDNA
The somatic rDNA and the extra
copies in the oocyte differ from each
other in buoyant density (Year Book 67,
pp. 403-404). The buoyant density in
CsCl of somatic rDNA is lower by 6
mg/cm3 than that of the extra copies.
Two possible reasons for this difference
would be a difference in nucleotide se-
quence, or a secondary modification of
one of the DNAs, such as methylation. To
test these hypotheses, (32P)-rDNA was
prepared from cultured kidney cells
(somatic rDNA) and from the ovaries
of newly metamorphosed froglets (extra
copies). The DNAs were enzymatically
hydrolyzed to mononucleotides, the la-
beled nucleotides were separated by thin
layer chromatography and located by
radioautography (Plate 1). A single
qualitative difference was detected be-
tween the two hydrolysates. The hy-
drolysate of somatic rDNA contains a
spot identified as 5-methyl deoxycyti-
dylic acid (MeC) which is missing in
the hydrolysate of oocyte rDNA. Bulk
X. laevis DNA contains about 1.5% of
its total residues as MeC. Somatic rDNA
has about 4-5% of its residues as MeC,
while the extra copies do not contain any
detectable MeC (less than 0.2%). The
presence of methyl groups is known to
lower the density of DNA in CsCl, and
the content of MeC in somatic rDNA is
probably sufficient to account for its
lower buoyant density.
The two rDNAs have been compared
by other techniques. Both rDNAs exhibit
a two-part melting curve. The 40S se-
quences melt at a lower temperature than
the spacer sequences because of the dif-
ference in their GC content. Judging
from the relative hyperchromicity, the
ratio of spacer to 40S sequences is simi-
lar for both rDNAs.
Another comparison of the DNAs was
made by analyzing the RNA products
made with RNA polymerase in vitro.
Hereafter we shall refer to these RNAs
made in vitro as " complementary RNA"
(cRNA). The base compositions of the
cRNAs synthesized on the two rDNAs
are indistinguishable. At present, the
only detectable difference between the
somatic rDNA and extra rDNA of
oocytes is that the somatic rDNA con-
tains about 4-5% MeC, while the extra
copies contain less than 0.2% MeC.
Transcription of rDNA in vitro
In the living cell rDNA is transcribed
in a highly specific manner. Only one of
the two DNA strands is transcribed
(which we will hereafter call the heavy
DEPARTMENT OF EMBRYOLOGY
507
strand, H), and only the 40S sequences
are copied from this strand. As far as is
known at present the spacer sequences
and the other strand (light, L) are not
transcribed. We have searched for condi-
tions in vitro under which rDNA would
be transcribed with high fidelity, i.e., in
the same way as in the intact cell.
As a beginning we have used RNA
polymerase from E. coli and have de-
veloped an assay to measure fidelity of
transcription in vitro. This assay mea-
sures how much of each rDNA strand
is transcribed as well as the amount of
RNA transcribed from the spacer region.
For the strand selection assay approxi-
mately 1 ^g of rDNA is denatured, hy-
bridized in solution with a 200-fold ex-
cess of unlabeled 18S and 28S rRNA,
and then centrifuged to equilibrium in
a CsCl density gradient. The rRNA
hybridizes only with the strand which is
transcribed in vivo (H) and since the
resulting RNA-DNA hybrid is denser
than the unhybridized strand (L), the
two DNA strands separate in the CsCl
gradient. The gradient is divided into
15 fractions, each fraction is treated with
alkali to release bound RNA, and the
DNA from each fraction is trapped on a
separate nitrocellulose filter. One such
set of filters can be hydridized with
radioactive RNA synthesized in vitro to
test the RNA for its homology to the
strands.
The fact that this technique actually
separates the H and L strands of rDNA
is illustrated in Fig. 1. 3H-labeled rDNA
separated into two equal-sized peaks,
and 32P-labeled rRNA hybridized almost
exclusively with the denser of the two
peaks, i.e., the H strand.
The E. coli RNA polymerase used in
these experiments was purified by the
method of Burgess. Recently Burgess and
his colleagues have shown that E. coli
polymerase is composed of four different
subunits. One subunit is called the S
protein ; it affects the specificity of chain
initiation but not chain elongation. They
have also shown that the S protein is
x
to
B rDNA-\ |
400
-
*1
'< 1
1 1 1
200
rRNA-\i',l
-
i
n-O
A
-
200
& A
;/\v / \
'/ » / \
1 \ L
'/ \i A
1,000
1,000
0_
to
5 10
Fraction No.
Fig. 1. Strand separation of rDNA. (A)
3H-labeled rDNA was prehybridized in solution
at 60 °C with excess unlabeled rRNA, spun in a
CsCl gradient, and collected in fractions. Each
fraction was alkali treated to remove rRNA,
trapped on a nitrocellulose filter, and rehybrid-
ized with 82P rRNA. (B) Same as (A) except
that the mixture of rDNA and unlabeled rRNA
was added directly to CsCl without prehybrid-
izing at 60° C.
largely removed from the enzyme by
chromatography on phosphocellulose
(PC enzyme) . Other methods of enzyme
purification, such as centrifugation in
glycerol gradient (GG enzyme), leave
the S protein attached to the enzyme.
We have tested the complementary
RNA (cRNA) synthesized using rDNA
as template with both RNA polymerases,
i.e., with and without S protein. The
cRNA was made under identical condi-
tions with (3H)-CTP and (32P)-CTP
included in the reaction mixtures with
the GG enzyme and PC enzyme, respec-
tively. The purified cRNAs were mixed
and hybridized with a series of strand-
508
CARNEGIE INSTITUTION
separated filters (Fig. 2A) . E. coli RNA
polymerase purified on a glycerol gradi-
ent (GG enzyme) , and presumably con-
taining S protein, has better than 95%
specificity for reading the H strand of
native rDNA. Phosphocellulose purified
enzyme (PC enzyme) is less specific but
still prefers the H strand. Whether this
partial specificity of PC enzyme is due
to some residual S protein is not yet
known. Another sample of the same
mixture of cRNA was assayed for se-
quences complementary to the spacer
region by hybridization in the presence
of an excess of unlabeled 28S and 18S
RNA (Fig. 2b). The radioactivity re-
maining after competition represents
spacer transcription. In other experi-
ments it has been shown that this un-
competed RNA has a GC content of
about 77%, corresponding to that of the
spacer DNA. About 12% of the cRNA
which hybridized to the H strand is a
copy of the spacer region, suggesting that
while chain initiation with the GG en-
zyme is very accurate, chain termination
is less accurate. The PC enzyme product
resembles that of the GG enzyme in this
respect. Some polymerase molecules ap-
parently continue to transcribe beyond
the 40S sequence into the spacer region.
These experiments suggest that the
nucleotide sequence of initiation sites has
been conserved during evolution, since a
bacterial enzyme can identify them in
an animal DNA with considerable
fidelity.
Electron microscope techniques are
being developed to map the gene se-
quences of rDNA molecules. Several
methods are being investigated whose
common purpose is to distinguish single-
stranded from double-stranded regions
of the molecule. Because of the different
base compositions of the rDNA se-
quences, it is hoped that a "denatura-
tion" map may be constructed as has
been done by Inman with lambda phage
DNA. In this method the DNA is par-
tially melted and the denatured regions
400 -
± 200 -
X
to
- 800
400 2,
ro
10 15
10 15
Fraction No.
Fig. 2. Comparison of cRNAs transcribed from native rDNA by the phosphocellulose enzyme
(3H, solid circles, solid lines) and by the glycerol gradient enzyme (32P, open circles, broken lines) .
The two cRNAs were mixed and hybridized on niters containing strand-separated rDNA. (A)
Hybridization without competition. (B) Hybridization with excess unlabeled 18S and 28S rRNA
present.
DEPARTMENT OF EMBRYOLOGY
509
prevented from reassociating by reaction
with formaldehyde. A denatured region
is visualized as two thinner strands bi-
furcating from a thicker strand and then
rejoining it. We are attempting to melt
out the 40S sequences while leaving the
spacer DNA double-stranded. In a sec-
ond method single-stranded rDNA will
be hybridized with rRNA and examined
with the electron microscope. Hybrid
regions should be thicker than single-
stranded DNA. If this distinction can
be made, then a "hybridization" map of
DNA will be constructed.
GENES AND GENE PRODUCTS IN OTHER ANIMALS
/. B. Dawid, D. D. Brown and Y. Suzuki
The DNA of Urechis cawpo Oocytes
/. B. Dawid and D. D. Brown
Urechis oocytes can be obtained in
large numbers free of contaminating
somatic cells. Their DNA has been iso-
lated and characterized. The haploid
DNA complement of the Urechis genome
is 1 fifxg. The oocyte, which is "tetra-
ploid," contains about 10 /^g of DNA,
more than twice the complement pre-
dicted from its chromosome content (see
Schwartz, this Report, p. 511). About
60% of this DNA has been characterized
as mitochondrial DNA by its presence in
a mitochondrial pellet, its rapid re-
naturation, and the presence of circular
DNA in the preparation. Furthermore,
this DNA forms common networks dur-
ing joint renaturation with chick mito-
chondrial DNA. Circular molecules of
Urechis mitochondrial DNA have con-
tour lengths of 5.85/a; mitochondrial
DNA of X. laevis which was spread un-
der identical conditions had a closely
similar contour length (5.86[x).
The DNA of Urechis oocytes contains
excess copies of rDNA. This is of par-
ticular interest since the oocyte has only
a single nucleolus, a common feature of
oocytes from marine invertebrates. The
nuclear DNA of Urechis oocytes contains
about 6 times as much rDNA as does
sperm DNA; this corresponds to about
24 nucleolar equivalents per oocyte in-
stead of the four predicted for a tetra-
ploid cell. This observation extends the
generality of rDNA gene amplification
in oocytes to include not only amphib-
ians, fish, several orders of insects — but
now an echiuroid worm.
Differentiation of the Silk Gland in
Bombyx mori
Y . Suzuki and D. D. Brown
An analysis of genes and gene products
has been undertaken for the posterior
portion of the silk gland in the silkworm,
Bombyx mori. It is our hope to isolate in
pure form the genes which code for the
messenger RNA which in turn directs the
synthesis of the silk protein, fibroin. Al-
though ribosomal RNA genes have been
isolated from animal DNA, no purifica-
tion of a gene which codes for a specific
cellular protein has been successful. It is
the regulation of these latter genes which
best characterizes a differentiated cell.
During the fifth instar the posterior part
of the silk gland synthesizes most of its
protein as silk fibroin. This unusual pro-
tein contains alternating glycine residues
in the crystalline region and about 73%
of its total amino acids as glycine and
alanine. Of particular interest is the pre-
dicted nucleotide composition of its gene
which can be estimated from the codons
for glycine and alanine (GGX and GCY,
respectively) . The messenger RNA (and
gene) for fibroin should have a base
composition of between 62 and 82% GC
depending upon the identity of the termi-
nal nucleotide (X and Y above). Bulk
Bombyx DNA is 38% GC. This differ-
ence in base composition should help in
510
CARNEGIE INSTITUTION
the separation of the fibroin gene from
bulk DNA.
Work to date has involved learning
how to grow the animals and the isola-
tion and labeling methods for their DNA.
Of particular importance is the avail-
ability of an established cell line from
ovarian tissue of Bombyx which is now
growing in the laboratory. We have
benefited greatly in these initial experi-
ments by the advice and generosity of
Dr. J. L. Vaughn of the U. S. Agricultural
Research Service at Beltsville, Mary-
land, and Dr. M. Himeno of Kyoto Uni-
versity, Japan, both of whom are experts
in raising Bombyx.
NUCLEIC ACID METABOLISM IN OOCYTES AND
EMBRYOS OF URECHIS CAUPO
Merry C. Schwartz
The advantages of the echiuroid worm
Urechis caupo for the analysis of nucleic
acid metabolism during both gameto-
genesis and embryogenesis were discussed
in Year Book 67, pp. 413-417.
A survey of the nucleic acid content
of Urechis embryos throughout embryo-
genesis is summarized in Fig. 3. In the
mature fertilizable oocyte, 10% of the
total RNA is 4S RNA, with rRNA (i.e.,
18S and 28S ribosomal RNAs) account-
ing for about 90% of the total. Thus
there are 10 molecules of 4S RNA in
the oocyte for each ribosome present.
The 5S RNA, the third structural RNA
of the ribosome, represents approxi-
mately 1% of the total RNA, or about
one molecule per ribosome present. These
relative amounts of 4S RNA, 5S RNA,
and rRNA are similar to those found in
most adult somatic tissues.
The embryo's content of both total
RNA (reflecting primarily rRNA) and
4S RNA remain virtually unchanged
throughout embryogenesis. However, net
increases in minor RNA species, e.g.,
messenger RNAs or specific transfer
RNAs, would not be detected by these
methods. Such synthesis, although quan-
titatively relatively insignificant, could
be qualitatively very important for em-
bryogenesis.
The haploid DNA complement for
Urechis, as determined in sperm, is 1 pg.
A mature oocyte is tetraploid and con-
tains 10 pg of DNA, 4 pg of nuclear
DNA, and approximately 6 pg of mito-
chondrial DNA (see Dawid and Brown,
this Report, p. 509) . By the trochophore
stage the larva's DNA content has
increased to 1.8 m^g, corresponding to
900 diploid cells. Thus, with regard to
net nucleic acid synthesis, DNA is the
primary product of embryogenesis in
Urechis caupo.
Since the embryo's RNA content is
approximately constant, one would like
to know whether the maternal RNAs
stored in the oocyte are conserved or re-
placed during embryogenesis. There-
fore, the relative synthesis of RNA and
DNA was monitored at several embry-
onic stages. Embryos were incubated
with 32P-phosphate and the relative in-
corporation of radioactivity into various
nucleic acids reflects their relative rates
of synthesis. As shown in Fig. 4, DNA
synthesis predominates during embryo-
genesis up to and including the post-
gastrula stage. Since the amount of DNA
synthesized during embryogenesis (1.8
m/xg per embryo) is much less than the
total RNA content of the embryo (14
m/*g), and since the synthesis of DNA
greatly exceeds that of RNA throughout
this period, then only a small fraction
of the embryo's RNA could be synthe-
sized after fertilization. Other experi-
ments measured the total amount of
RNA synthesized and accumulated up to
the post-gastrula stage and demonstrated
that less than 9% of the 4S RNA and
3% of the rRNA present in the post-
DEPARTMENT OF EMBRYOLOGY
511
10.0 -
.a
E
=L
E
I .00
0.10 —
0.0 1
Hours After Fertilization
/
yr
<*>
/
Fig. 3. Nucleic acid content (^nig/embryo) of Urechis embryos. The 4S RNA, total RNA, and
DNA content per embryo are plotted as a function of time after fertilization. The equivalent cell
numbers (solid circles) were calculated from the DNA content per embryo using 2 pg as the
DNA content of each diploid cell.
512
CARNEGIE INSTITUTION
1.00 -
1.00 -
»500
1.50
-
Ciliated ft
1.0 0
Blostula
!00
.500
_
-
00
..A
lv
25,000
.400
rRNA
000
Trochophore
h
.200
500
DNA
I\\
\
jf\
50,000
Froction No.
Fig. 4. Nucleic acid synthesis in the mature oocyte, ciliated blastula, post-gastrula, and trocho-
phore larva of Urechis. Eggs and embryos were incubated in 32P-phosphate and the nucleic acids
were extracted and fractionated on a MAK column. No comparisons of the radioactivity
incorporated at different stages can be made because of variations in the number of embryos and
differences in the incubation conditions.
gastrula embryo could have been synthe-
sized after fertilization.
RNA synthesis is not totally absent
during embryogenesis : the synthesis of
rRNA, 4S RNA, 5S RNA, and hetero-
geneous RNA was observed. The meas-
urement of the relative rates of synthesis
of specific classes of RNA can provide
insights into the mechanisms which regu-
late RNA transcription during embryo-
genesis. During cleavage both 4S RNA
and heterogeneous, nonmethylated high
molecular weight RNAs are synthesized.
The rate of synthesis of 4S RNA per cell
remains virtually constant through cleav-
age, gastrula, and post-gastrula stages.
During this same period the synthesis of
rRNA, which is not detectable during
cleavage, increases at least 13-fold. The
dramatic increase in the synthesis of
rRNA relative to 4S RNA synthesis be-
tween ciliated blastula and post-gastrula
stages is shown in Fig. 5. Thus, during
embryogenesis, the synthesis of 4S RNA
is regulated independently of the synthe-
sis of rRNA.
Similarly, the relative synthesis of 4S
RNA and 5S RNA has been compared at
various developmental stages. The syn-
thesis of 5S RNA relative to 4S RNA is
much greater in the trochophore larva
than in the earlier stages of embryogene-
DEPARTMENT OF EMBRYOLOGY
513
sis or in the mature oocyte. By combin-
ing data of this type with the preceding
comparison of 4S RNA and rRNA syn-
thesis, it is seen that whereas the synthe-
sis of 4S RNA is independent of rRNA
synthesis, the regulation of 5S RNA is
coordinate with the synthesis of the other
two ribosomal RNAs.
These results obtained in a spirally
cleaving embryo can be compared with
the synthetic patterns observed in the
radially cleaving embryo of Xenopus
laevis. Two basic features are common
to both embryos: maternal RNAs are
conserved throughout embryogenesis and
must function significantly in protein
synthesis in the embryo; and, the syn-
thesis of the three RNAs of the ribosome
appears to be coordinate and regulated
independently of the synthesis of 4S
RNA. Thus, basic differences in nucleic
acid metabolism between mosaic and
regulative embryos, if indeed such dif-
ferences do exist, must be more subtle
than are the general patterns observed
in this investigation.
Ciliated Blastula
< l .00
Post-Gastrula
750 -
30 50
Fraction No.
Fig. 5. The methylation of nucleic acids in
ciliated blastulae and post-gastrulae of Urechis.
Two suspensions of sibling embryos were incu-
bated with 8H-methyl L-methionine at ciliated
blastula and post-gastrula stages. At the end of
the pulse the nucleic acids were extracted and
fractionated on MAK.
HISTONE SYNTHESIS IN CLEAVING EMBRYOS OF
XENOPUS LAEVIS
H. E. Kasinsky
In our studies of the role of protein
synthesis in early development (Year
Book 67, p. 417), we have concentrated
on following up an observation made by
Hallberg (Year Book 67, pp. 409-413) in
the course of his study of ribosomal pro-
tein synthesis in Xenopus laevis em-
bryos. Hallberg noted that about 8% of
the total protein synthesized by cleaving
embryos pulsed with 14C02 eluted as a
single peak from a carboxymethyl cellu-
lose column (see Fraction C, ibid., Fig.
9). Electrophoresis of this radioactive
protein on acrylamide gels showed the
presence of two radioactive bands which
were distinct from known ribosomal pro-
teins (Ibid., Plate 2). Furthermore, these
two proteins were accumulated by the
swimming tadpole to the extent that they
were visible as both stainable and radio-
active bands in both normal and anucleo-
late embryos (Ibid., Plate 3). Our ex-
periments now suggest that both
proteins are histones.
Nuclei were prepared from erythro-
cytes of adult Xenopus by lysing the cells
in distilled water. Chromatin was pre-
pared from these nuclei by the method of
Bonner et at. in Methods in Enzymology,
XII:B (1968). Nuclear sap and ribo-
somal proteins were extracted with
saline-EDTA and 0.05 M Tris buffer,
pH 8, respectively. The chromatin was
purified by centrifugation through a
sucrose gradient, the sucrose dialyzed
away and the histone extracted from the
514
CARNEGIE INSTITUTION
chromatin with 0.4 N H2S04. The his-
tones were pretreated with 50 rnM di-
thiothreitol and then electrophosed on
15% gels of polyacrylamide at pH 4.5
in urea. Gels were stained with amido
black, photographed, and the band pat-
tern traced in the Joyce-Loebl micro-
densitometer. In order to determine the
position of radioactive bands, the gels
were dried on filter paper and autoradio-
graphed according to the method of Fair-
banks et al. (Biochem. Biophys. Res.
Commun., 20, 393, 1965). Microdensi-
tometer tracings of the radioactive bands
exposed on X-ray film were recorded.
Figure 6 shows that two proteins in
Fraction C from embryos coelectro-
phorese with two of the three main bands
of Xenopus erythrocyte histones. Fur-
thermore, as seen in Plate 2, the position
of the fast-moving band in Fraction C co-
incides with arginine-rich histone IV
(Fambrough and Bonner, Biochemistry
5, 2563, 1966), which is known to have
almost the same amino acid sequence in
both pea and calf. (Pea histone IV was
generously donated to us by Douglas
Fambrough.) In Plate 2, the bands at
the top, close to the origin, are those of
bovine serum albumin used as a marker
in these experiments. In Fig. 6 we have
reproduced only the tracings of the
center portion of each gel and have
omitted the albumin bands. We con-
clude that the fast-moving band in Frac-
tion C from both cleaving embryos and
swimming tadpoles is probably histone
IV, the ubiquitous histone whose struc-
ture has been conserved almost com-
pletely during evolution.
The data from Hallberg's experiments
Erythrocyte
Fraction C
C + Erythrocyte
©
Fig. 6. Microdensitometer tracings of acryla-
mide gels after electrophoretic fractionation of
Xenopus erythrocyte histones and Fraction C
proteins from swimming tadpoles: solid lines,
amidoblack stain; broken lines, radioautogram.
suggest that these two proteins are syn-
thesized de novo during early Xenopus
development and represent a large frac-
tion of the protein made during cleavage.
If there are 5 major types of histone in
Xenopus, as has been described for other
eukaryotes, then as much as 20% of the
proteins synthesized before gastrulation
may be of this class of proteins.
STUDIES ON MITOCHONDRIA FROM XENOPUS LAEVIS:
THEIR COMPOSITION, FUNCTIONS, AND
BIOGENESIS
I. B. Dawid, R. F. Swanson, J. W. Chase, and M. Rebbert
Mitochondrial RNA
7. B. Dawid, with the assistance of
Martha Rebbert
Last year it was reported {Year Book
67, p. 418) that mitochondria from Xen-
opus laevis oocytes contain two unique
RNA species which behave in electro-
phoresis on polyacrylamide gels as is ex-
pected of 21S and 13S RNA. In addition,
these preparations contain 4S RNA and
DEPARTMENT OF EMBRYOLOGY
515
some 28S and 18S RNA (rRNA). The
28S and 18S RNAs are considered con-
taminants since they can be largely
eliminated by RNase treatment of intact
mitochondria, or by removing the outer
mitochondrial membrane with digitonin.
How and where do the two mito-
chondrial RNAs (M-RNAs) originate,
i.e., on which DNA templates are they
transcribed: nuclear or mitochondrial?
Hybridization experiments were carried
out in an attempt to answer this question.
32P-labeled RNA was prepared from
mitochondria obtained from cultured X.
laevis kidney cells that had been labeled
for several generations. Such prepara-
tions contained large amounts of rRNA
in addition to the 21S and 13S RNA
species. These contaminants did not in-
terfere in the hybridization experiments,
for the purified mitochondrial DNA
(M-DNA) employed had been exten-
sively characterized as being free of
contamination with nuclear DNA. DNA
and 4S RNA were removed from the
labeled RNA which was then tested for
its ability to hybridize with mitochon-
drial and with nuclear DNA (Table 1).
M-DNA hybridized well with this RNA
and the level of hybridization was not
reduced by the addition of excess non-
radioactive rRNA. Nuclear DNA hy-
bridized at a much lower level and
unlabeled rRNA competed in this hybrid-
ization. It appears likely that the mito-
chondrial components in the mixture
(21S and 13S RNAs) hybridized with
M-DNA, whereas the ribosomal com-
ponents (28S and 18S) hybridized with
TABLE 1. Hybridization of Partially Purified
Mitochondrial RNA
Unlabeled
rRNA
RNA in
Hybrid, cpm
M-DNA, 5 /ig
M-DNA, 5 Mg
N-DNA, 40 fig
N-DNA, 40 ng
0
50 Mg
0
50 ng
3960
4270
710
106
Note : The K2P-RNA was used at a concentra-
tion of 5 fig in 2 ml of 4 X SSC ; the preparation
contained about 65% rRNA (18S and 28S) and
35% mitochondrial RNA (13S and 21S).
N-DNA is nuclear DNA.
TABLE 2. Base Composition of Hybridized
32P-RNA
In Hybrid with In Hybrid with
Acid N-DNA M-DNA
Cytidylic
Guanylic
Adenylic
Uridylic
25
16
36
23
the nuclear DNA. This conclusion is
supported by determinations of the base
composition of the RNA hybridized with
nuclear or mitochondrial DNAs. It has
been shown earlier that M-RNA has a
base composition low in GC content
(45%) , whereas the GC content of rRNA
is much higher (62%). The results in
Table 2 show that RNA which hybrid-
ized with M-DNA has a much lower GC
content than that which hybridized with
nuclear DNA. Preliminary hybridiza-
tion experiments suggest that 21S and
13S RNAs do not share sequence homol-
ogies; therefore it is likely that differ-
ent portions of the M-DNA act as tem-
plates in the formation of these RNA
species.
The nature and function of the 21S
and 13S mitochondrial RNA is as yet
unknown. The 21S component is present
in about twice the concentration of the
13S component and, although their mo-
lecular weights are not known accu-
rately, it appears likely that the two
components are present in a stoichio-
metric ratio of one.
Protein Synthesis in Mitochondria
from Ovaries of Xenopus laevis.
R. F. Swanson
In recent years it has been shown that
mitochondria have the ability to synthe-
size proteins in vitro. While the fact
itself is well established, the nature of
the products, the source of the informa-
tional RNA, and the mechanism of syn-
thesis are not well understood. Ribo-
somelike particles have been isolated
from Neurospora and yeast mitochon-
dria, but a submitochondrial system of
protein synthesis has not been estab-
lished.
516
CARNEGIE INSTITUTION
Several aspects of protein synthesis
in mitochondria isolated from X. laevis
ovaries have now been investigated. Bac-
terial counts, energy requirements, sta-
bility to ribonuclease, inhibition by
chloramphenicol, and lack of inhibition
by cycloheximide suggest that the ob-
served protein synthesis is not due to
contamination of the mitochondrial sys-
tem by either bacteria or cytoplasmic
ribosomes.
Several characteristics of mitochon-
drial protein synthesis could be studied
by following up the observation that
polyuridylic acid (poly U) is able to en-
ter isolated mitochondria and subse-
quently direct polypeptide synthesis.
This observation also provides a possible
basis for a model system for the study
of the coding properties of nonmitochon-
drial RNA, both natural and synthetic,
in mitochondrial protein synthesis. In
addition to poly U, polyadenylic and
polycytidylic acids are taken up by iso-
lated mitochondria. Incorporation of
3H-polynucleotides was measured as in-
corporation of radioactivity into a form
which is no longer digested by pancreatic
ribonuclease. The reaction has an abso-
lute requirement for magnesium ions and
is greatly stimulated by mercaptoetha-
nol. Incorporation does not occur at 0°C.
Neither Xenopus RNA nor DNA, native
or denatured, was incorporated under
these conditions, nor was RNA from
bacteriophage MS 2. Mitochondrial in-
corporation of poly U was also followed
by measuring the stimulation of ribo-
nuclease-insensitive phenylalanine incor-
poration (Table 3). In the absence of
poly U, or when ribonuclease and poly U
are added simultaneously, the rate of
phenylalanine incorporation is very low.
Ribonuclease had no effect when added
after mitochondria were incubated with
poly U for a short period of time. These
results indicate that a mechanism exists
for the transport of "messenger RNA"
across the mitochondrial membrane.
In an attempt to identify the intra-
mitochondrial site of protein synthesis,
TABLE 3. Polyuridylic Acid Stimulation of
Phenylalanine Incorporation by
Xenopus Mitochondria
Radioactivity (cpm) incorporated
Complete system
Ribonuclease added
after poly U
Ribonuclease added
before poly U
Minus poly U
60 min
2700
2880
90
80
Note: Mitochondria were incubated with
poly U (500 Atg/ml) for 10 minutes at 22°C.
Ribonuclease (100 ^g/ml) was added either
before or after incubation of mitochondria with
poly U as indicated. Aliquots of mitochondria
were assayed in a second incubation period for
ability to incorporate 3H-phenylalanine into
hot TCA precipitable material.
mitochondria were incubated with a mix-
ture of 14C-amino acids or with poly XJ
and 3H-phenylalanine. The mitochondria
were disrupted with the nonionic deter-
gent NP40 and the distribution of acid
insoluble radioactivity was analyzed
after sedimentation through sucrose
gradients (Fig. 7) . In the absence of any
further treatment radioactivity was
spread throughout the gradient. How-
ever, when a small amount of ribo-
nuclease was added before centrifugation
there was an increase in the amount of
labeled material having a sedimentation
coefficient of 55S and a decrease in more
rapidly sedimenting radioactive ma-
terial. The UV-absorbing material sedi-
menting at 80S probably represents cyto-
plasmic ribosomes which contaminate
the mitochondrial preparation, since this
material is removed by incubation of
intact mitochondria with ribonuclease
and by other means (see above) which
do not affect mitochondrial protein syn-
thesis.
A possible interpretation of these re-
sults is that the 55S material represents
single mitochondrial "ribosomes," the
amount of which is increased as a result
of digestion of "polyribosomes" by ribo-
nuclease. If this suggestion were cor-
roborated, the mitochondrial ribosome
would be the smallest known.
DEPARTMENT OF EMBRYOLOGY
517
Tube No.
Fig. 7. Sedimentation of mitochondrial extracts. (A) Mitochondria were incubated with poly U
and then with 3H-phenylalanine. After disruption of the mitochondria with the detergent NP40,
debris were removed by centrifugation at 20,000 X Q and the supernatant was layered on buffered
15-30% sucrose gradients containing magnesium and potassium ions. After centrifugation the
distribution of hot TCA precipitable radioactive material was determined. No additions (open
circles). Ribonuclease (1 /tg/ml) added before centrifugation (solid circles). Solid line represents
O.D. 260. (B) Mitochondria were incubated with a mixture of 14C-amino acids. Detergent treat-
ment and sedimentation and sedimentation analysis were then carried out as described under (A) .
Formation of Mitochondria During
Embryogenesis of Xenopus laevis
J. W. Chase
During the past year we have begun
a study of mitochondrial biogenesis in
the embryonic development of Xenopus
laevis. The study is intended to deter-
mine the time course of the formation of
mitochondria and some mitochondrial
components during embryogenesis. Ini-
tially, we have determined the content
of total mitochondrial protein and the
amount of cytochrome oxidase activity
per embryo throughout development.
The content of mitochondrial protein in
the unfertilized egg is about 10 /xg and
does not change until just after hatching
(stages 37-39). It then increases, and
has doubled by stage 45 (feeding) . Cyto-
chrome oxidase activity is about 0.03
/xatom oxygen/min/egg in the unfertil-
518
CARNEGIE INSTITUTION
ized egg, remains constant until stages
37-39, and doubles by feeding. Thus, we
find no change in the specific activity
of cytochrome oxidase during early de-
velopment of Xenopus, contrary to the
earlier report of Weber and Boell. This
difference may be due to a different
method of preparation of the mitochon-
dria. Earlier work had been done with
particles washed by differential centrifu-
gation; used on frog eggs and embryos,
however, this technique yields prepara-
tions containing varying amounts of pig-
ment which contributes to the apparent
mitochondrial protein. In the present
work continuous sucrose and discontinu-
ous ficoll gradients were used to obtain
mitochondria. The sucrose technique in-
troduced a difficulty: since the particles
obtained were similar to osmotically
lysed mitochondria when examined with
the electron microscope, it appeared pos-
sible that we had lost most of the soluble
proteins during the purification, which
loss would result in inaccurate values for
total mitochondrial protein. However, we
have discounted this explanation of our
results on the basis of experiments which
show that the same proportion of soluble
protein can be extracted from the mito-
chondria from eggs and embryos pre-
pared by either differential centrifuga-
tion or by sucrose gradients, and that
glutamic dehydrogenase (a soluble mito-
chondrial enzyme) is localized only in
the mitochondrial band in sucrose
gradients.
We are now concentrating on mito-
chondrial nucleic acid synthesis during
development. The experiments on mito-
chondrial protein content were conducted
to determine the stage at which mito-
chandrial protein, and presumably the
mitochondrial population, increases.
Studies on the synthesis of mitochondrial
nucleic acids will be related to this time
course of the rise in mitochondrial pro-
tein.
CELL DIFFERENTIATION AND VIRAL
SUSCEPTIBILITY
R. J. Hay, M. Yoshikawa-Fukada, and J. D. Ebert
(assisted by D. Somerville and B. Smith)
Do Isolated Myotubes Synthesize
DNA After Exposure to Rous
Sarcoma Virus?
The observation that DNA synthesis
occurs in myotubes of muscle colonies in
culture after infection with Rous Sar-
coma Virus (RSV) raises several ques-
tions (Year Book 67, pp. 429-431). One
phase of our program this year involved
attempts to determine whether or not
isolated myotubes could be induced to
synthesize DNA after exposure to RSV.
Three methods for separating myotubes
and myoblasts were employed. The first
required exposure of clonal cultures to
vincoleucoblastine (VLB) as described
previously (Year Book 67, p. 431). Our
main objection to this method is the
possibility that VLB induces irreversible
changes in myotube metabolism not ap-
parent by morphological examination.
The second method of separation in-
volved subcultivation, at high dilution,
on collagen-coated culture dishes. Clonal
cultures were washed three times in suc-
cession with Hanks' BSS minus divalent
cations. Trypsin (Difco 1:250) at 0.01%,
which had been brought to 37°C, was
added. The solution was allowed to cover
the culture surface and was then re-
moved immediately. After incubation at
37°C for 5 minutes, a suspension of
fibroblasts, myoblasts, and myotubes
was prepared in medium F12 215 by
gentle mixing using a wide-bore pipette.
Aliquots of this suspension were then
added to culture vessels containing F12
215. Typical muscle syncytia (Plate 3A)
DEPARTMENT OF EMBRYOLOGY
519
could be located 15-24 hours after addi-
tion to the culture vessel. Individual
syncytia could be isolated physically
from myoblasts and fibroblasts by using
conventional porcelain penicylinders if a
suitable dilution factor had been used
initially.
We exposed myotubes, isolated by
either of these methods, to dilutions of
RSV ranging from 5 X 105 to 107 focus-
forming units per ml. The cultures were
then pulsed for 3 hours with tritiated
thymidine at 12, 24, 48, or 72 hours after
exposure to the virus. Despite repeated
attempts, varying the time between iso-
lation and infection as well as virus dose,
we could obtain no unequivocal evidence
for thymidine incorporation in syncytia
exposed to RSV. These negative findings
add support to the hypothesis that RSV
gains entry and exerts its effect on the
myotube by infecting the myoblast at
some time prior to fusion. Additional
support for this assumption derives from
work done with the third system for
separating myoblasts and myotubes,
using somewhat different culture condi-
tions, described below.
Effects of RSV in a Relatively
Synchronous Mass Muscle
Culture System
The formation of myotubes in clonal
culture is an asynchronous process in
which myoblast fusion takes place over
an interval of 7-9 days (Year Book 62,
p. 441). Myoblast fusion in mass muscle
culture is very synchronous in compari-
son. It seemed probable that in gaining
insight into the mode of action of RSV
on DNA synthesis in myotubes, a higher
degree of synchrony than that offered by
clonal cultures would be required, espe-
cially because of the role of the myoblast
suggested above. For this reason we de-
veloped a novel mass culture system for
muscle which we have used extensively
in more recent studies. The procedure
finally adopted consisted of the following
general steps.
Cell suspensions were prepared from
11-day embryonic chick leg muscle and
were seeded in F12 215 at high density
(4xl07 cells/9 cm plate). After 18-26
hours of incubation the monolayer was
washed three times with Hanks' BSS
minus divalent cations and was treated
briefly with 0.05% trypsin. The trypsin
was removed and the cells were sus-
pended in F12 215 warmed to 37°C. The
cell number was adjusted to 106/ml and
the suspension was added to 9 cm plates
(10 ml/plate). After incubation for 90
minutes to allow fibroblasts to adhere
preferentially, the cells still in suspen-
sion (predominantly myoblasts) were re-
moved. The adhering cells were washed
gently three times with medium and the
washes were added to the cell suspension
obtained. This differential adhesion
(DA) method for increasing the ratio of
myoblasts to fibroblasts gives a higher
cell yield, more reproducible results and
at least as high a ratio of myoblasts
(80% or more by clonal analysis) as does
the differential trypsinization method
used earlier [Year Book 64, p. 484).
Cell suspensions prepared by the DA
method were used to seed collagen-
coated, 35 mm Falcon plates (2.5-5 X 105
cells/plate) . By microscopic examination
at 16- and 8-hour alternating intervals,
it was found that myoblast fusion is
most extensive during the interval from
40 to 72 hours after DA cell seeding.
Although this period of active fusion
varies slightly among experiments, the
system is much more predictable than
that used previously.
Muscle cultures at the end of the ac-
tive fusion period were exposed to vari-
ous doses of RSV and were pulsed for
3 hours at 12, 24, 48, and 72 hours
after infection. No examples of thymi-
dine incorporation attributable to ex-
posure to RSV were ever noted. In addi-
tion, brief pretreatment of the cultures
with trypsin or with the polyanion
DEAE-dextran, known to enhance in-
fectivity of some RSV types, did not
520
CARNEGIE INSTITUTION
lead to DNA synthesis in myotubes after
exposure to the virus.
Time of infection and the effect of
RSV on DNA synthesis in myotubes. Our
attention now focused on the effects of
RSV following exposure at earlier times,
prior to myotube formation. The cul-
tures were pulse labeled after myotubes
had formed. Two very striking findings
emerged as a result of a long series of
experiments of this kind. First, early in-
fection of myoblasts prepared by the
DNA method yielded cultures with rela-
tively small and often abnormal-looking
myotubes by 60-72 hours after seeding.
Second, a high proportion of myotubes
in such cultures synthesized DNA. In
some experiments we have estimated that
20-30% of the myotubes were affected.
Typical examples are shown in Plate 3B
and C. The time of infection was critical.
The best results, in terms of proportion
of myotubes labeled, were obtained when
the myoblasts were infected within the
first 24 hours after preparation by the
DA method. The cultures were usually
pulse labeled for 3 hours 65-96 hours
after DA seeding. Myotubes in control
cultures showed virtually no DNA
synthesis.
It is interesting to speculate that the
requirement for early infection may be
associated with a wave of DNA synthesis
in the myoblast population. O'Neill and
Strohman, using somewhat different cul-
ture conditions, observed that there is an
early phase of DNA synthesis and cell
division prior to the onset of active myo-
blast fusion. This is probably a pre-
requisite for fixation of the transformed
state in myoblasts as is the case for
transformation of chick fibroblasts.
Infection of preformed myotubes by
infected myoblasts. Having developed a
reproducible method for induction of
DNA synthesis in myotubes using RSV,
we wanted to demonstrate unequivocally
that myotube nuclei can be derepressed.
Myoblasts prepared by the DA method
were exposed to high doses of RSV and
were incubated for 12^0 hours in
medium containing tritiated thymidine
(2-5 /xc/ml). Such infected and heavily
labeled myoblasts, after trypsinization
and removal of diffusible label, were
added to muscle cultures set up earlier.
We found, as has also been observed by
Bischoff and Holtzer, that the more
mature myoblasts have a greatly reduced
capacity to accept new myoblasts. Ac-
cordingly, we added the infected and
labeled myoblasts to muscle cultures at
late stages of the fusion process (72
hours or more after DA seeding). By
this time addition of RSV alone will not
induce DNA synthesis in the myotubes
present. We then pulsed such cultures
for 3 hours at about 6, 16, 24, 48, or
72 hours after addition of the infected
cells, using either tritiated thymidine
(0.5-1 /*c/ml) or 14C-thymidine (0.25
jttc/ml) .
At this writing no extensive secondary
labeling has been noted under any condi-
tions. The usual finding is that heavily
labeled nuclei are incorporated into myo-
tubes but DNA synthesis is not detected
in adjacent nuclei. It has been possible,
however, to obtain secondary labeling
in a few nuclei adjacent to heavily
labeled nuclei under certain specific con-
ditions. Two variables which seem to
be most important are the time interval
between infecting the myoblasts and
adding them to recipient cultures, and
the time between addition of the infected
myoblasts and pulsing of the recipient
cultures. The secondary labeling was ob-
served, at low frequency, after pulsing
with either label but recent results after
14C- and 3H-thymidine labeling are
shown in Plate 3D and E.
Detection of the secondary labeling
in myotube nuclei is consistent with the
hypothesis that infected myoblasts re-
lease derepressor molecules into the
muscle sarcoplasm, but other interpreta-
tions are still possible. The occurrence
of DNA synthesis in mature myotubes
in clonal culture {Year Book 66, p. 600),
although rare, also argues for this con-
cept.
DEPARTMENT OF EMBRYOLOGY
521
Our present working hypothesis is that
derepressor molecules are synthesized in
the myoblasts prior to fusion. The ability
of myoblasts to fuse is impaired once
active release of virus begins. This could
explain the apparent critical timing be-
tween infection and use of myoblasts to
challenge preformed myotubes. The low
incidence of DNA synthesis occurring
in large, mature myotubes can be ex-
plained partly on this basis, but also by
the observation that myotubes become
less able to accept new myoblasts as they
mature. We further suppose that the
hypothetical derepressor molecules are
unstable in the myotube and can act on
myotube nuclei for only a short period
after their release into the sarcoplasm.
Thus, in a synchronous system such as
we are using, DNA synthesis could only
be detected in recipient myotubes by
pulse labeling over a critical time in-
terval. This interval may indeed be
shorter than the usual S phase of a given
cell population, since only part of the
genome may be involved in DNA syn-
thesis in nuclei of affected myotubes
(Year Book 66, p. 600 and Plate 3B).
This could explain the difficulty of ob-
taining extensive secondary labeling us-
ing the system outlined above. An al-
ternative explanation might be that
treatment of the infected myoblast popu-
lation with trypsin causes premature
leakage of derepressor molecules.
Experiments designed to test aspects
of this hypothesis and improve the pro-
portion of secondary labeling are planned
or in progress. Very gentle techniques
for subcultivation of infected myoblasts
are being adopted to minimize damage
to the cell surface. Suspensions of myo-
blasts obtained by these new techniques
will be used to infect myotubes as usual.
We have been able to reduce the pro-
portion of mononucleated cells in mass
muscle cultures by adding excess thymi-
dine (2.5 millimolar) at 24 hours after
the DA seeding (Plate 3F and G) . Myo-
blasts so treated fuse and form muscle
normal by morphological criteria, but
secondary proliferation of myoblasts or
contaminating fibroblasts is eliminated
or at least markedly reduced. This cul-
ture system offers the advantage that
background labeling due to mononucle-
ated cells is minimal. It may even be
possible to quantitate DNA synthesis
induced in these myotube populations
after addition of infected myoblasts. At-
tempts to increase the incidence of fusion
of infected myoblasts with cultures of
mature myotubes through the use of
Sendai virus are also being made.
Comparative Studies on the Hybridiza-
tion of RSV-RNA with DNA from
Various Sources
Our earlier studies have shown that
RSV-RNA contains some base sequences
complementary to those of DNA from a
variety of avian and mammalian species
(Year Book 67, p. 431) . Particular atten-
tion has been directed this year towards
characterizing these sequences, and at-
tempts have been made to determine
their significance in oncogenesis.
Before presenting the results, a discus-
sion of reports from other laboratories
may be useful. Temin attempted to
demonstrate the existence of DNA com-
plementary to RSV-RNA in RSV-in-
fected chick cells using DNA-RNA hy-
bridization techniques. Although his
findings have been cited as evidence in
favor of the existence of a DNA "pro-
virus," the low levels of specific radio-
activity reported render this conclusion
doubtful. Nevertheless, the requirement
of DNA synthesis for cell transformation
and productive infection by RSV, as well
as by other oncogenic viruses, is also
consistent with this hypothesis.
However, contradictory findings were
reported by Harel et al. and by Wilson
and Bauer, who found that RSV and
the related avian myeloblastosis virus
(AMV) RNAs hybridized to the same
extent with DNA from infected and from
522
uninfected cells. Harel observed about
20% competition with cellular RNA,
while Wilson and Bauer obtained over
80% competition. The relatively high
saturation values (almost equivalent to
those of ribosomal RNA genes in animal
cells) and very different levels of compe-
tition could be due to contamination of
the RSV-RNA preparations with cellular
RNAs.
Because of the low specific activity of
labeled RSV-RNA, such negative find-
ings do not exclude the possibility that
one or more DNA molecules, homologous
to RSV-RNA, are present in infected
cells. However, the existence of viral
particles and of actively replicating
RSV-RNA in nonvirus producing (NP)
cell cultures makes it unnecessary to
postulate proviral DNA. Moreover,
within the framework of current molecu-
lar biology, the proviral DNA hypothesis
requires the production of a new kind of
enzyme — an RNA-dependent DNA poly-
merase— to synthesize proviral DNA
copies from RSV-RNA as template. Fur-
thermore, a proviral DNA or RSV-
RNA-dependent RNA polymerase would
be required to make progeny RSV-RNA
in infected cells. We assume that the con-
tent of DNA in a chick fibroblast is
about 2.4 x 1012 daltons and that one pro-
viral DNA molecule (1.2 xlO7 daltons
per single strand) exists in a nucleus. A
maximum of 0.0005 fig of RSV-RNA
hybridizes with 100 fig of DNA under
the best conditions. This figure corre-
sponds to about 5% of the avian genome
which hybridizes with RSV-RNA. If
50 fig of cellular DNA and 105 cpm/^g
of RSV-RNA are used for hybridization,
then we are speaking of having to detect
a difference of less than 25 cpm in 500
cpm; in other words, 0.00025 fig of DNA
in 0.005 fig. A difference of this low
magnitude, even if deemed statistically
significant, is not sufficient in itself to
justify the novel concepts we have just
outlined.
CARNEGIE INSTITUTION
Homology Between RSV-RNA, RAV-
RNA, and DNA from Various Species
The ability of RSV-RNA to hybridize
with DNA from various sources was
determined using the hybridization tech-
nique described in Year Book 67, p. 432.
It should be emphasized that the hy-
bridization experiments were done in
the presence of chick ribosomal RNA at
concentrations 100 to 300 times those
of RSV-RNA to avoid possible competi-
tion with cellular RNA.
The DNAs extracted from pea, Eu-
glena, salmon sperm, and Rana pipiens,
organisms which are not susceptible to
infection with RSV, hybridize with RSV-
RNA to about the same extent (Fig.
8A-D). The small radioactive peak as-
sociated with yeast DNA (Fig. -8E) is
thought to be nonspecific because of the
low ratio of radioactivity to optical
density. A similar peak was observed
with DNA from E. coli {Year Book 67,
p. 435). The DNAs from pea, Euglena,
Rana pipiens, and yeast were generously
provided by Dr. John Sinclair.
The Bryan high titer strain of RSV
used in these studies contains 4-10 times
more of the helper, Rous Associated
Virus (RAV), than of RSV itself. Pre-
liminary experiments comparing RAV
with RSV in terms of hybridization with
DNA from various sources have been
performed using the same techniques.
The highest specific activity obtained
thus far after 32P-labeling is 6 X 104 cpm/
fig of RAV-RNA. As shown in Fig. 9A
and B, RAV-RNA, like RSV-RNA,
hybridizes with mammalian DNA but
not with bacterial DNA. Similar satura-
tion levels are also obtained with various
DNAs when RSV-RNA and RAV-RNA
are compared (see Table 4) .
Base Ratio Analyses of the Segment of
RSV-RNA Which Hybridizes with
DNA from Several Sources
As noted earlier (Year Book 67,
p. 436) , that portion of RSV-RNA which
hybridizes with chick DNA has a higher
DEPARTMENT OF EMBRYOLOGY
523
(A) Pea
(B) Euglena
(C) Salmon sperm
500
000 a
500 £-'
Tube No.
Fig. 8. Hybridization of S3P-RSV-RNA with DNA from various organisms.
(A) Hamster liver
(B) M. lysodeikticus
^&Qdp&
0
Tube No.
Fig. 9. Hybridization of 32P-RAV-RNA with mammalian and bacterial DNAs
600
400 .E
£
- 200
524
CARNEGIE INSTITUTION
TABLE 4. Saturation Values of Hybridized
RSV-RNA and RAV-RNA with Various
DNAs
Source of DNA Amount of RNA Saturating
100 fig of DNA
RSV-RNA
Mg
RAV-RNA
Mg
Spafas chick
fibroblast 0.009-0.010 0.010
RSV-infected chick
fibroblast
(72 hr. pi.) 0.009-0.010 0.011
Calf thymus 0.004 0.005-0.006
Salmon sperm 0.008 0.007
Hamster liver 0.003*
Clone 2 0.003 *
Adeno 2 virus 0.003 * 0.003 *
Adeno 12 virus 0.04 *
Note : Figures marked with asterisk represent
the results of one experiment. Others are the
average of 3-4 experiments using several differ-
ent preparations of labeled RNA and DNA.
Filters contained various amounts of DNA,
and saturation values were standardized to
per 100 fig of DNA.
adenylate content than the average for
whole RSV-RNA. Similar analyses were
performed after hybridization of RSV-
RNA with DNA from several species.
About 200 fig of DNA were hybridized
with 32P-labeled RSV-RNA in the pres-
ence of 300 fig of chick ribosomal RNA.
The preparation was treated with RNase
and fractionated by CsCl centrifugation.
Material in tubes, corresponding to the
radioactive peak shown in Fig. 8, was
pooled, and the hybridized RNA was
precipitated by TCA with carrier yeast
RNA. It was hydrolyzed in KOH, and
the resulting nucleotides were separated
by two-dimensional paper chromatogra-
phy. Base ratio analyses are shown in
Table 5. Although small differences are
observed in the actual figures, the base
ratio of hybridized RSV-RNA is gen-
TABLE 5. Base Ratio of Hybridized RSV-
RNA with Various DNAs in the Presence of
Chick Ribosomal RNA
Source of DNA
U G
Spafas chick fibroblast
Calf thymus
Salmon sperm
30.7 11.9 38.6 18.8
30.1 102 41.0 18.7
29.6 11.0 40.6 18.8
Note: Figures are the average of 3 analyses.
erally characterized by high A and G,
and low U. This is true for both mam-
malian and avian DNAs.
These observations suggested the pos-
sibility that the specific segment of RSV-
RNA which hybridizes with cellular
DNA might be involved in the trans-
formation process. Findings consistent
with such a general hypothesis are avail-
able from work with oncogenic viruses
containing DNA, reported by others, and
can be outlined as follows. (1) The
DNAs of the oncogenic adenoviruses and
SV40 have more deoxyadenylate than
do those of nononcogenic adenoviruses.
(2) Considerable evidence suggests that
DNA from oncogenic viruses is inte-
grated into the host cell genome. (3)
RNA synthesized in vitro with DNA of
SV40 or Polyoma viruses as template
hybridizes with cellular DNA. With this
background information in mind, we are
attempting to answer the following ques-
tions. Does RSV-RNA hybridize with
DNA from oncogenic viruses? What is
the base composition of the segment of
RSV-RNA which hybridizes with this
DNA? How is this RSV-RNA fragment
distributed in the host cell, particularly
in the nucleus. And finally, what is the
biological significance of this hybridizing
portion of RSV-RNA?
Homology between RSV-RNA and
Adenovirus-DNA
Adenovirus (Adeno) types 2, 4, and
12 were chosen for study. On the one
hand, they are related viruses of the
same "family"; on the other, they show
clear differences in oncogenicity. The
first two are not oncogenic while the last
is highly oncogenic. Viral DNA was ex-
tracted after purification of the virus
particles by treatment with genetron 113
followed by two centrifugation steps
using CsCl of density 1.34. The initial
results have been striking. RSV-RNA
hybridizes much more extensively with
DNA from Adeno 12 (oncogenic) than
with that of Adeno 2 or 4 (Fig. 10A-C).
DEPARTMENT OF EMBRYOLOGY
525
4.
E
O
<0
CVJ
d
d
0.75
0.5 0
0.25
750
5 00 |
250
10
Tube no.
Fig. 10. Hybridization of ^P-RSV-RNA with Adenovirus DNAs.
The density of DNA from Adeno 2, 4,
12, and KB cells is 1.716, 1.717, 1.708,
and 1.699, respectively. Since there is no
detectable optical density peak at re-
fractive index 1.4000 in 2 x SSC, the viral
DNA preparations were not contained
with host cell DNA.
Preliminary analyses of the base ratios
of the segment of RSV-RNA which hy-
bridizes with Adeno 12-DNA indicate
a high A and low U content. The tech-
nique employed was similar to that de-
scribed for Table 5, but no ribosomal
RNA was added during hybridization.
Additional experiments to characterize
this segment of RSV-RNA are in
progress.
For saturation experiments, a Milli-
pore filter holding 50-100 fig of cellular
DNA or 10-30 fig of viral DNA was
incubated in 1 ml of 4xSSC containing
100 fig of chick ribosomal RNA (both
18S and 28S) and different amounts of
32P-labeled RSV-RNA (specific activity
varies between 4xl04 cpm and 4xl05
cpm per fig RNA from preparation to
preparation) at 62 °C for 12 hours with
constant shaking. The filters were washed
once with 4xSSC and were incubated
in 2xSSC with 50 /xg/ml RNase (pre-
treated at 80°C for 10 minutes) at 37°C
for 30 minutes. Each filter was then
washed thoroughly with 50 ml of 4 X SSC.
Release of DNA from filters during hy-
bridization was significant, as was ob-
served from the increase in counts and
optical density of blank filters when they
were incubated with DNA-filters. There-
fore, only one kind of DNA-filter was
incubated in each vial, and blank filters
for background determinations were in-
cubated in separate vials. The back-
ground for RSV-RNA was about 0.1%
of input RNA. This is about 10 times
higher than ribosomal RNAs incubated
and treated as described above. The ad-
dition of 0.1% SDS (purified by ethanol
crystallization twice), which had been
reported to be effective in decreasing
background counts of RNA synthesized
in vitro, did not decrease background
counts under the conditions described
above.
A typical saturation curve is shown in
Fig. 11. About 1-2 fig of RSV-RNA per
ml is necessary to saturate 50 fig of DNA
from either mammalian or avian source
material. The amounts of RSV-RNA re-
quired to saturate DNA from various
sources are indicated in Table 4. Al-
though the saturation value obtained
for Adeno 2-DNA is close to that ob-
tained for mammalian DNAs, it can be
shown that this must be due to non-
specific background labeling rather than
to specific hybridization. The molecular
weight of Adeno 2-DNA is reported to be
2.4x10.7. Therefore, the saturation fig-
ure 0.003% can correspond only to a
DNA fragment of molecular weight 720
(2 nucleotide pairs) in one Adeno-DNA
molecule. Niyogi and Thomas reported
526
CARNEGIE INSTITUTION
1000 -
nfected(5l/tg)
RSV-RNA Mg/ml 4 x SSC
Fig. 11. Saturation curve of T-RSV-RNA hybridized with chick embryo DNA. A filter holding
DNA from uninfected cells contains an average of 76 fxg DNA; filters prepared using material
from RSV-infected cells contain an average of 51 ^g DNA (72 hours postinfection). Each point
represents an average from 4 niters (2 filters/ml incubation mixture).
that eleven nucleotide pairs are the mini-
mum number detectable by current hy-
bridization techniques.
Attempts to Demonstrate Natural Hy-
brid Formation Between RSV-RNA
and Cellular DNA
The cytoplasmic and nuclear RNAs of
chicken fibroblasts infected with purified
3H-uridine and 32P-labeled RSV were
fractionated by sucrose density gradient
centrifugation. Between 3 and 6 hours
postinfection, about 80% of intracellular
radioactive RNA was found in the
nucleus and 20% in the cytoplasm. Both
RNAs have a molecular size similar to
that of the smaller component of RSV-
RNA (Fig. 12). The DNA of 32P-RSV-
infected chick fibroblasts 6 hours post-
infection was extracted gently in 2 x SSC
to keep hydrogen bonds intact. This
DNA was then treated with SDS, pre-
incubated with pronase, and fractionated
=1
e
o
CD
CO
Q
O
0.6
0.2
6000
4000 -r —
2000
< tr
-z.
o
tr
e
CO
o
o
a>
a.
u
o
ZJ
>%
-z. O
,— »
.— ■»
?
i
A
\
CO
->—
Tube No.
Fig. 12. Sucrose density gradient centrifugation of 32P-RSV-infected chick embryo RNA. Cyto-
plasmic and nuclear RNAs were extracted 72 hours postinfection and centrifuged on a sucrose
gradient of 5-20% at 24,000 rpm for 20 hours in SW 25.3 rotor.
DEPARTMENT OF EMBRYOLOGY
527
E
o
to
C\J
D
6
3.0 -
2.0
1.0
Fig. 13. CsCl centrifugation of DNA from
chick embryo cells infected with ^P-RSV.
32P-RSV was adsorbed for 2 hours and then re-
moved. The DNA was extracted after an addi-
tional 6 hours of incubation in growth medium.
by CsCl centrifugation (Fig. 13) . In spite
of repeated attempts, it was not possible
to obtain reproducible evidence for a
radioactive peak associated with cellular
DNA. Only at much later stages after
infection was a radioactive peak detected
with ribosomal RNA and with DNA
from cells infected with 32P- or 3H-uri-
dine-labeled RSV. Thus, in vivo hy-
bridization of RSV-RNA with a cellular
DNA has not yet been proved.
These results suggest, however, that
most of the RSV-RNA moves into the
nucleus soon after infection. In addition,
the possibility that degradation products
from labeled RSV-RNA may be in-
corporated into DNA and thus obscure
the presence of a natural hybrid cannot
yet be excluded.
Hybridization of RSV-RNA with DNA
from Chinese Hamster Chromosomes
A Chinese hamster cell line, provided
initially by Dr. M. M. Elkind, was par-
tially synchronized by thymidine block
and the chromosomes were isolated from
the cells at metaphase. The chromosomes
were separated into 3 size-groups, com-
parable to those described by Mendel-
sohn et al., by slight modifications of
established methods. RSV-RNA was
hybridized as usual with DNA prepared
from the three chromosome fractions
(Table 6). Although the actual amount
hybridized varied from preparation to
preparation, there was so significant dif-
ference between the three fractions of
different size. Furthermore, the sum of
amounts of RSV-RNA which hybridize
at saturation with DNA from the three
fractions is very close to the value de-
termined for mammalian DNA. This
suggests that DNA homologous to RSV-
RNA is not located on any one chromo-
some or in any one size-group, but that
these genes are dispersed among the
chromosomes in all three size-groups.
Hybridization of RSV-RNA with
Membrane- Associated DNA
The preparation and some character-
istics of a DNA fraction associated with
nuclear membranelike lipid has recently
been reported for calf thymus chromatin
source materials. Experiments using the
same general technique were designed
to compare the hybridization of RSV-
RNA with membrane-associated DNA
TABLE 6. Comparison of 3 Classes of Chinese Hamster Chromosomes
Experiment
Number (dif-
ferent prepara-
tions of
chromosomes)
RSV-RNA (cpm/Mg DNA) Hybridized with
Chromosomes of 3 Size-Groups
Large Medium Small
I
II-l
II-2
III-l
III-2
IV (saturation)
338/65
1710/27
1390/24
640/60
649/65
0.004 Atg/100 fig
231/52
2458/71
2495/75
450/66
433/50
0.006 Mg/100 fig
332/70
1789/30
1319/29
692/66
501/50
0.004 fig/100 M
528
versus nonassociated DNA. The possibil-
ity that RSV-RNA might hybridize more
extensively with membrane-associated
DNA was suggested from the following
observations: (1) RSV can induce DNA
synthesis in myotubes and in contact-
inhibited cells; (2) the initiation of DNA
replication in bacterial and in mam-
malian cells is generally supposed to in-
volve an interaction between membranes
and DNA; and (3) the DNA homologous
to RSV-RNA is apparently dispersed
among the chromosomes of the Chinese
hamster cell (Table 6) .
DNA extracted from the precipitate
fraction of calf thymus chromatin
sheared under conditions of low ionic
strength, showed a higher level of hy-
bridization with RSV-RNA than did
DNA from the supernatant fraction. In-
terestingly, a much more striking differ-
ence was observed between similar frac-
tions prepared from Chinese hamster
cells collected in S-phase (Table 7).
Chinese hamster cells were partially
synchronized by thymidine block (2.5
mM. It is estimated that above 30%
of the cells were in synchrony after re-
lease of the thymidine block. They were
harvested in S-phase and fractionated
into cytoplasm and nuclei by homogeniz-
ing in "lysis buffer" (10 mM KC1, 10
mM Tris pH 7.5, 1.5 mM MgCl2) . Nuclei
were suspended in 20-fold diluted lysis
buffer and sonicated in a Branson Soni-
fier at power 4 for 90 seconds. The super-
natant obtained after centrifugation at
10,000 Xg for 20 minutes was referred
TABLE 7. Comparison of Soluble Chromatin
and Membrane-Associated DNAs
Hybridized RNA of
Different Experiments
Source of DNA
(cpm/100 fig
DNA)
Calf thymus
soluble chromatin
3316
4217
membrane-associated
3877
4663
Chinese hamster
soluble fraction
676
820
membrane-associated
1810
1630
Note: Each figure is the average of four
filters.
CARNEGIE INSTITUTION
to as the soluble fraction. The precipi-
tate, collected after one wash under the
same conditions, was called the mem-
brane-associated fraction. DNA ex-
tracted from both fractions was used
for hybridization (Table 7) .
Initial Attempts to Determine the
Biological Role of Cellular DNA
Homologous to RSV-RNA
Studies to define more fully the proper-
ties of the above-mentioned DNA frac-
tions were undertaken using HeLa cells
as source material. These were preferred
to Chinese hamster cells since they were
much more susceptible to synchroniza-
tion by excess thymidine.
The cytoplasmic fraction of HeLa cells
in S phase (90% synchronized) was
prepared as described above and after
centrifugation at 10,000 xg for 20
minutes, the supernatant was dialyzed
against DNA polymerase-buffer (2.5 mM
EDTA, mM 2-mercaptoethanol, 50 mM"
phosphate-buffer pH 7.5) and used as
cytoplasmic extract. It contains less than
0.2% cellular DNA. Isolated nuclei were
suspended in 20-fold diluted lysis-buffer
and sonicated in the Branson Sonifier at
power 4 for 30, 90, 180, and 300 seconds
followed by centrifugation at 10,000 xg
for 20 minutes. The washed sediment was
dialyzed against DNA polymerase buffer
and referred to as the membrane-associ-
ated fraction. The same precipitate frac-
tion of the nuclear sonicate that was used
for DNA extraction (Table 7) has the
ability to incorporate 3H-TTP into the
acid-soluble fraction in the absence of
added primer DNA. In the case of the
90-second sonicate, 90% of its incorpora-
tion is dXTP-dependent (Table 8) .
Cytoplasmic extracts, of course, need
template DNA to incorporate 3H-TTP
into the acid-insoluble fraction and about
80% is dXTP-dependent. There is a lag
of 10 minutes in the initial time course
of 3H-TTP incorporation. This lag dis-
appeared, however, when the cytoplasmic
extract and DNA were preincubated at
DEPARTMENT OF EMBRYOLOGY
529
TABLE 8.
DNA Synthesis in vitro
Source of Enzyme
TCA-Insoluble Radioactivity (cpm)
Complete - DNA - dXTP
(1) Cytoplasmic extract
31335
(2) Cytoplasmic extract
4423
(3) Membrane-associated fraction
sonicated for
30 seconds
3509
90 seconds
4871
180 seconds
1702
300 seconds
1222
1284
1125
188
552
617
142
Note: Complete system (0.25 ml) for (1) and (2) consists of 20 //.moles
Tris pH 7.8, 2 /imoles MgCl2, 1 /miole 2-mercaptoethanol, dXTP each 50
m/tmoles, 3H-TTP (2 /tc/imxmoles) 1 fie, heat-denatured calf thymus DNA
30 fig and 100 fig of protein. Extract (1) is a fresh preparation and extract
(2) was stored at 4°C for 2 weeks. Complete system for (3) is the same as
for (1) and (2), except calf thymus DNA.
4°C or 37°C for 10 minutes (Fig. 14).
This suggests that free DNA polymerase
first forms an active complex with tem-
plate DNA to start DNA synthesis.
As shown in Fig. 15, in the case of the
membrane-associated fraction, no time
lag was detected in the initial incorpora-
tion, and in 10-15 minutes the incorpora-
tion reached a plateau. Addition of cyto-
plasmic extract did not induce any
marked increase of DNA synthesis, but
the addition of heat-denatured DNA
<D 3000
o
2000
1000
37 C, lOmin
preincubate with
DNA
4° C, 10 min.
preincubate
with DNA
Heat denatured
DNA u
cytoplasmic
- sup
4 C
'■ 37°C«
fdXTP
IH-TTP
_l I
20 -10 0 10
Reaction time (min.)
Fig. 14. Time course of 8H-TTP incorporation by cytoplasmic extracts.
20
530
CARNEGIE INSTITUTION
2000
-
1500
Heat-denotured CT-DNA *y
100 0
1 .X---,
▲
9~* *° ~ */
500
~1 Cytoplasmic sup
tiii
10 20 30
Reaction time
40 50
(min.)
Fig. 15. Time course of 8H-TTP incorpora-
tion by membrane-associated fractions.
caused incorporation at a rate similar to
that observed with the cytoplasmic ex-
tract and heat-denatured DNA. These
results indicate that in the membrane-
associated fraction DNA-polymerase
and DNA exist forming an active com-
plex. Hence DNA synthesis starts im-
mediately if substrates are supplied.
However, once DNA polymerase finishes
reading the membrane-associated tem-
plate DNA, which is probably double-
stranded, it is released from DNA as free
enzyme. As such, it could not form an
active complex, and would be unable,
therefore, to read native DNA efficiently.
After the initial incorporation reaches a
maximum upon the addition of single-
stranded DNA to the membrane-associ-
ated fraction, released free DNA poly-
merase will react with the added DNA
and start synthesis in the same way as
in the cytoplasmic extracts.
The nature of DNA synthesized in
vitro with the membrane-associated frac-
tion was studied by alkaline sucrose
gradient (Fig. 16) and alkaline CsCl
centrifugation (Fig. 17). Dispersed
radioactive peaks from 10S to 2S, com-
parable to the values obtained by sedi-
mentation equilibrium with original
DNA from the membrane-associated
fraction, were observed. A sharp peak of
about 2S would represent the minimum
▲
3000
-
2000
-
in
O
1000
_on
1 1 1
* p
1.412
f
1.408 ^
1.404
10
Tube No.
20
Fig. 16. Alkaline sucrose density gradient
centrifugation of DNA synthesized in vitro
with membrane-associated fractions. The mem-
brane-associated fraction sonicated for 90 sec-
onds was used for DNA synthesis. DNA syn-
thesis was stopped after 45 minutes by adding
NaOH and EDTA with final concentrations of
0.1 N and 0.01 N, respectively. The supernatant,
after low-speed centrifugation, was layered on
a 5-20% gradient and centrifuged at 50,000
rpm for 15 hours at 5°C in SW 65 rotor.
unit. The centrifugation pattern in alka-
line CsCl suggests (although peaks are
not clear) that the two strands will be
separable because of their heterogeneous
base sequences. Thus the possibility for
isolation and further characterization of
this DNA appears promising.
Westphal and Dulbecco found an
homology between RNA (synthesized in
vitro) complementary to DNA of poly-
oma or SV40 viruses and cellular DNA
from 3T3 or BHK cells. In their experi-
ments DNA-filters trapping 160 ^g cel-
lular DNA were incubated with various
amounts of RNA complementary to viral
DNA (0.04-0.1 fig) . From 0.0001 fig to
0.0003 fig of RNA hybridized with 100 fig
of normal cellular DNA, with a linear
increase of hybridization according to
input RNA. There was no difference ob-
served between the complementary
RNAs to polyoma and SV40 DNAs. The
saturation values were not reported, but
a low ratio of input RNA to DNA was
used, RNA being added at about one-
tenth of an estimated saturation value.
(One fig of RNA was necessary to satu-
rate 10-4 fig of polyoma DNA. We as-
sume that the DNA of one nucleus con-
DEPARTMENT OF EMBRYOLOGY
531
T 3.0
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2~
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-
=L
6S ft /
E 2.0
O
~
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Nr
-
CD
-° ^
\
C\J
^ /
\
Q I.O'
\\
r 1
-
o*
^\
v:
V-°
•7 ' * -m^—^ ,
i
600 ~
400 .E
E
200 O
10
Tube No.
20
Fig. 17. Alkaline CsCl centrifugation of DNA synthesized in vitro with the membrane-associated
fraction. The sample was prepared as described for Fig. 16. After centrifugation each fraction
was neutralized, adjusted to 4 X SSC and trapped on a Millipore filter.
tains at least one region homologous to
a molecule of viral DNA. The ratio of
the weight of DNA in a virus particle to
the weight of DNA per cell is 5 XlO-7.
We can calculate, therefore, that 200 fig
of cellular DNA will be saturated by 1 /xg
RNA in the system described.) The re-
gion on mammalian DNA which is
homologous to RNA complementary to
polyoma and SV40 viruses may be the
same gene that is homologous to RSV-
RNA. Adeno 12-DNA could also contain
this gene.
About 0.04% of Adeno 12-DNA (m.w.
2.3 XlO7) is homologous to RSV-RNA.
Therefore, a segment of 9000 daltons
corresponding to 27 nucleotides in one
Adeno-DNA molecule hybridizes with
RSV-RNA. Since an eleven-nucleotide
base sequence is the minimum detectable
by hybridization, 9000 daltons will repre-
sent one unit of the homologous region.
With a given saturation value of 0.004%
(Table 4) and knowing that a mam-
malian nucleus contains about 5xl012
daltons of DNA, we can calculate that
2 x 10s daltons (which correspond to
2 XlO4 units) exist in the nucleus. If we
assume that this homologous unit is a
recognizing site of DNA polymerase or
an initiating site of replication, there are
2 X 104 initiating points for DNA replica-
tion in a mammalian nucleus and the
average replicating unit is 2.5 XlO8
daltons. It is interesting to note that di-
rect measurements with the electron
microscope by Taylor, Huberman, and
Riggs indicate that the average replicat-
ing unit in Chinese hamster cells ranges
from 1.2 to 7.6 XlO8 daltons.
TROPHIC EFFECTS OF NERVE ON MUSCLE
Douglas Fambrough, Criss Hartzell, and Arlyne Musselman
Motor neurons and the muscle fibers release of a chemical transmitter, acetyl-
they innervate interact in several ways, choline, from the nerve terminals. The
Most obviously, the action potentials con- acetylcholine interacts with the muscle
ducted by the motor nerves trigger the fiber membranes to initiate a change in
532
CARNEGIE INSTITUTION
permeability which leads indirectly to
contraction of the muscle. This func-
tional interaction is comparatively well
understood. More subtle interactions be-
tween nerve and muscle are inferred from
observations concerning both the forma-
tion of neuromuscular connections in the
embryo and the behavior of adult nerve
and muscle when they are disconnected.
These subtle interactions are collectively
termed "trophic interactions."
Besides being interesting in their own
right, trophic interactions between nerve
and muscle are relevant to the broader
questions concerning the molecular basis
of interactions between different cell
types and the mechanisms controlling
the surface properties of cells. In par-
ticular, the nerve-muscle system may
serve as a model for interactions between
functionally connected neurons in the
brain.
Our research during the past year has
focused upon the morphological, bio-
chemical, and physiological changes in
rat skeletal muscle following denerva-
tion. Most experiments have been done
on the left hemidiaphragm. It has long
been known that, following denervation,
this muscle undergoes a marked transient
hypertrophy involving greatly increased
DNA and protein synthesis. It is also
well known that denervated diaphragm
is typical of denervated muscle in becom-
ing supersensitive to acetylcholine. Un-
derstanding the molecular details of
these changes is prerequisite to under-
standing the mechanisms by which these
changes are prevented by the presence
of functioning motor nerves.
DNA and Protein Metabolism in
Denervated Rat Diaphragm
The rate of DNA synthesis in adult
rat diaphragm is very low. Following de-
nervation the rate of DNA synthesis in-
creases dramatically. We have deter-
mined the time course of this increase by
excising and culturing diaphragms de-
nervated for varying lengths of time in
vitro for 1 hour in a balanced salt solu-
tion with glucose and 3H-thymidine and
then either processing them for auto-
radiography or precipitating the DNA
and counting it in a liquid scintillation
counter. The results are shown in Table 9.
A significant increase in the rate of DNA
synthesis is apparent 12 hours after de-
nervation and the rate is maximal at two
to three days. By the sixth day the rate
has returned to the control level. These
data are in excellent agreement with the
data of Zak et al. obtained by measuring
the in vivo incorporation of ^-thy-
midine into DNA in denervated rat
diaphragm. Our autoradiographic studies
correlate well with the incorporation
data.
The mechanism responsible for the
increased rate of DNA synthesis in de-
nervated muscle is unknown. While
muscle fibers constitute the overwhelm-
ing bulk of muscle tissue, there are other
TABLE 9.
Incorporation of 3H-Thymidine into DNA* of Rat Diaphragms
Denervated for Varying Lengths of Time
Days
Number of
Cpm/nig
Denervated
Animals
Protein
S.E.
% Control
0 (control)
4
915
531
100
0.5
4
3,407
800
370
1
4
7,870
1205
860
1.5
4
11,937
645
1300
2
4
13,920
334
1520
3
4
5,232
202
570
4
5
4,198
109
460
5
5
1,238
199
135
6
3
924
76
101
7
5
919
175
100
10% TCA precipitable, 0.3 N NaOH (37°C, 18 hr) stable counts.
DEPARTMENT OF EMBRYOLOGY
533
cell types present. Before the mechanism
can be understood, we must identify the
cell types involved. Unfortunately, the
resolution of light microscope autoradio-
graphic techniques is not adequate to
determine whether the labeled nuclei are
subsarcolemmal or extramuscular. The
majority of the labeled nuclei are closely
apposed to the muscle fibers but not
visibly beneath the basement of the indi-
vidual fibers. Due to reports that satellite
cells are more abundant in denervated
gastrocnemius (Lee) and are the only
cells in regenerating (Resnik) or neo-
natal (Moss) rat muscle to incorporate
3H-thymidine, it is tempting to speculate
that the labeled nuclei of denervated
muscle belong to satellite cells. The pos-
sibility that denervated muscle tissue is
invaded by dividing, exogenous cells is
disfavored because cells labeled with
3H-thymidine by a series of injections
prior to denervation do not appear later
in denervated muscle.
To determine whether the frequency of
nuclear division as well as the rate of
DNA synthesis is increased by denerva-
tion, denervated diaphragms were cul-
tured 5 hours in vitro in the presence of
a mitotic inhibitor, vincristine sulfate.
In control muscle there were no mitoses
in a typical longitudinal section (except
in some connective tissue cells) , whereas
in comparable sections of three-day de-
nervated muscle there were three to eight
mitotic figures. Experiments are now un-
derway in which rats are being injected
with 3H-thymidine followed by injec-
tions of vincristine sulfate to determine
whether labeled cells undergo a subse-
quent mitosis. This in vivo technique
should eliminate any possible enhance-
ment of the frequency of mitosis caused
by in vitro conditions. If labeled mitoses
are found, electron microscopic study
should provide a rapid identification of
the cell types responsible for DNA syn-
thesis in denervated muscle.
We have investigated the increase in
rate of protein synthesis and of in-
corporation of glucosamine into glyco-
proteins in denervated muscle. The time
courses of these rate changes are similar
to that for DNA synthesis (see Table 9) .
The increased rate of protein synthesis in
denervated rat diaphragm represents an
increased synthesis of all the major types
of muscle tissue proteins. This was de-
termined by labeling control and de-
nervated muscle proteins with 3H-leucine
and 14C-leucine and then fractionating
the combined proteins by differential
centrifugation and by disc electro-
phoresis. Similarly the threefold increase
in the rate of glucosamine incorporation
into glycoproteins was found to repre-
sent increased incorporation into the
major glycoprotein fractions.
We have no evidence for the synthesis
of a new species of protein in denervated
muscles or for an exceptionally large
increase in the rate of synthesis of any
individual protein. However, our studies
of the changes in muscle membrane prop-
erties following denervation suggest that
such changes in protein metabolism may
indeed occur.
Control of Acetylcholine Receptors
in Muscle Fiber Membranes
Each muscle fiber is functionally con-
nected to its controlling motor neuron
through a single neuromuscular junction.
Acetylcholine (ACh) released from a
nerve terminal interacts with receptors
in the muscle fiber membrane to trigger
excitation of the muscle fiber. The ACh
receptors are concentrated in an area of
about 1000 fi2 at each nerve-muscle junc-
tion, while the surface of an entire muscle
fiber may exceed 5xl05/x2- There is no
effect upon the resting potential of a
muscle fiber when ACh is applied to the
fiber surface at a distance from the
neuromuscular junction. When the nerve-
muscle connection is interrupted, how-
ever, the entire muscle fiber membrane
becomes very sensitive to applied ACh.
Standard electrophysiological methods
developed by Nastuk, del Castillo and
Katz, and Miledi are used to measure
534
CARNEGIE INSTITUTION
ACh sensitivity. A recording microelec-
trode is positioned for intracellular re-
cording, a second electrode containing
3 M ACh is positioned just outside the
muscle fiber, and minute, metered pulses
of ACh are liberated from this second
pipette by iontophoresis. The change in
the transmembrane potential, caused by
the ACh, is amplified and displayed on
an oscilloscope. Photographic records of
the oscilloscope traces are analyzed and
the ACh sensitivity of the muscle mem-
brane is calculated as millivolts de-
polarization per nanocoulomb of current
passed through the ACh pipette. The
lower limit of detectable ACh sensitivity
is about 0.001 mV/nC. Ten-day de-
nervated rat diaphragm fibers have a
uniform ACh sensitivity of about 100-
200 mV/nC.
In order to study the development of
ACh sensitivity in denervated rat dia-
phragm, we have developed a method for
maintaining pieces of adult rat dia-
phragm in organ culture. Such pieces will
still contract when electrically stimulated
after two to three weeks in culture. ACh
supersensitivity develops in these cul-
tured muscles at about the same rate as
that of muscles denervated in vivo. Two
days after denervation, the ACh sensi-
tivity outside the endplate region is still
less than 0.001 mV/nC. After three days
postdenervation, fibers show a uniform
ACh sensitivity of 2-20 mV/nC, and
after 5 days in culture the sensitivity al-
ways exceeds 10 mV/nC. Actinomycin
D (1 /Kg/ml), an inhibitor of RNA syn-
thesis, or puromycin (10 /xg/ml), an in-
hibitor of protein synthesis, added to cul-
tures of denervated diaphragm will
totally inhibit the development of ACh
supersensitivity at any point in time.
However, neither actinomycin D nor
puromycin nor cycloheximide, at concen-
trations which inhibit virtually all RNA
or protein synthesis, will abolish ACh
supersensitivity which has already de-
veloped. Cultured diaphragm will not
tolerate these agents indefinitely but can
survive 48-hour incubations with no
diminution in ACh sensitivity. These re-
sults support the hypothesis that ACh
receptors are at least part protein and
that their construction requires normal
RNA and protein synthesis. The RNA
must have a short half-life since actino-
mycin D can halt the development of
supersensitivity. The positioned receptors
appear to be very stable.
Some factor secreted from the motor
nerve terminals may act as a regulator
of ACh receptor production. This hy-
pothesis is strengthened by the results
of an experiment in which fragments of
diaphragm devoid of nerve terminals
were maintained in organ culture. These
became ACh supersensitive more rapidly
than whole denervated fibers (in which
the nerve endings remain active for a
limited time) and had an ACh super-
sensitivity of up to 3 mV/nC after two
days. We have added homogenates and
extracts of sciatic nerve to diaphragm
cultures as single doses or by replace-
ment of the medium every day, but have
achieved no striking repression of the de-
velopment of ACh supersensitivity.
Likewise, various doses of ACh or of
ACh and eserine sulfate (a cholinester-
ase inhibitor) have had no marked effect.
CHARACTERIZATION OF HEART CELLS OF THE
CHICK EMBRYO
R. L. DeHaan, F. J. Manasek, I. S. Polinger and E. W. Schaejer, with the assistance of
K. A. Magness
During the past year we have focused of properties which characterize the cell
most of our attention on defining a set types of embryonic heart in vivo, and
DEPARTMENT OF EMBRYOLOGY
535
on comparing these with characteristics
of cells isolated from the heart in tissue
culture.
Epicardial Investment, Glycogen
Content, and Secretory Activity
of the Early Myocardium
Although most of the gross anatomic
changes occurring during cardiac organo-
genesis have been described, develop-
mental events at the cell and tissue level
remain relatively poorly understood.
F. J. Manasek's major efforts over the
past few years have been devoted to
elucidating events at this level, largely
with the use of the electron microscope.
It is anticipated that these descriptive
studies will provide the groundwork for
further experimental approaches.
The epicardium, the tissue layer in-
vesting the myocardium, was previously
thought to arise in situ from the develop-
ing myocardial wall. Consequently this
structure was called the "epimyocard-
ium." An earlier study by Manasek
showed that the wall of the tubular heart
contains only myocytes ; it is not covered
by an epicardium and does not contain
undifferentiated cells that could give rise
to the epicardium. During the past year
he completed a light and electron micro-
scopic study of epicardium formation
showing that the epicardium arises from
an extramyocardial source. The epicar-
dium is initially a single sheet of flattened
cells, first seen in the chick embryo at
stage 17 + , partially covering the myo-
cardium. The epicardium eventually
spreads over the entire myocardial sur-
face. Later, a subepicardial connective
tissue layer is formed. Since the epi-
cardium is not formed from the outer
myocardial cell layer, it is suggested that
the term "epimyocardium" be abandoned
in favor of the more accurate and simple
"developing myocardium." This work is
currently being extended in collaboration
with DeHaan. Serial sections of pertinent
stages are being reconstructed and the
pattern of epicardial migration over the
myocardium will be described.
An electron microscopic and histo-
chemical analysis of glycogen distribu-
tion in the intact early embryonic heart
showed that large pools of this poly-
saccharide are only present in cardiac
myocytes. Glycogen therefore provides a
convenient marker for the identification
of muscle cells at the light microscopic
level (Plates 4, 5). Polinger demon-
strated that this relationship also holds
true in vitro (described below) and that
glycogen is a stable marker. Preliminary
experiments with organ-cultured hearts
suggest that the stored intracellular
glycogen may not be available to the
cells as an energy source until late in
embryonic life.
Embryonic myocardial glycogen also
appears to be resistant to breakdown by
phagocytes. In an electron microscopic
study of normal myocardial cell death,
Manasek showed that even after phago-
cytes have ingested dead muscle cells
and digested most of their organelles,
glycogen particles are still recognizable.
Experiments are now being planned to
determine whether embryonic myo-
cardial glycogen is truly present in a
metabolically unavailable form.
Unlike other striated muscle, embry-
onic cardiac muscle contains a large
fenestrated Golgi system throughout
most of embryonic life. Beginning at
about the 4th day of development in the
chick, dense granules can be seen within
Golgi lamellae, suggesting a specific
myocardial secretory function. In the
chick, unlike mammals, these dense gran-
ules are present in ventricular (Plates
4, 5) as well as atrial myocytes. The
composition of these granules remains
unknown, but experiments performed
earlier this year suggest they are not
lipid soluble. Manasek and D. M. Fam-
brough, working in collaboration, are
attempting to isolate, purify, and char-
acterize these granules.
536
CARNEGIE INSTITUTION
Characterization of 7-Day Heart
Cells In Vivo and In Vitro
This year Iris Polinger completed her
analysis of the ultrastructure and be-
havioral properties of 7-day heart cells.
Her problem was twofold: To develop
criteria for identifying cell types in order
to determine if myocardiallike (M) and
fibroblastlike (F) cells in culture repre-
sent two distinct populations, or are
merely different manifestations of a
single cell type; and to compare M- and
F-cells in vitro with the cell types present
in the heart in vivo, using criteria other
than gross morphology.
In her recently submitted doctoral dis-
sertation, she employed seven criteria
for characterizing heart cells: (1) spon-
taneous activity, (2) nucleolar number,
(3) glycogen content, (4) myofibrillar
content, (5) adhesiveness to the plastic
culture substratum, (6) growth rate, and
(7) DNA synthesis.
Extending the observations of Mana-
sek, Polinger has confirmed that glyco-
gen is present in the 7-day chick heart
only in cardiac muscle cells, not in
epicardium, endocardium, or fibrous cell
types. Since, as noted above, particulate
glycogen is retained for extended periods
in culture, this substance could act as a
marker for heart muscle cells at this
stage. She has, in fact, found that after
the heart is dissociated, those cells which
contain glycogen "always and without ex-
ception contain myofibrils with Z-bands."
(Polinger, Doctoral Dissertation, p. 39,
Johns Hopkins University, 1969).
Clearly the correlation between myo-
fibrils and glycogen in heart muscle cells
is retained after dissociation with tryp-
sin. From counts on over 150 glycogen-
containing cells, removed from such cul-
ture plates and examined with the
electron microscope, she has also demon-
strated that the same correlation still
exists after 24 hours in vitro.
With these facts in mind, it was pos-
sible to correlate cells categorized live
in culture as M or F on the basis of their
morphology, with the presence or absence
of glycogen. For this study cultures were
grown by standard techniques in medium
629. Thirty-seven microscopic fields in-
cluding 538 cells were photographed live
with phase optics on Polaroid film. Each
cell was scored as a beating or quiescent
M- or F-cell. The plates were fixed and
stained for glycogen and RNA, the pho-
tographed fields were relocated and the
same cells were examined for glycogen.
The results were striking. Every cell
categorized as an M-cell, beating or not,
contained glycogen, as did that small
group of cells (3.7%) scored as beating
F-cells. Among the quiescent F-cells,
85% were completely devoid of glycogen.
Since glycogen is always correlated
in these cells with myofibrils, it may be
concluded that all cells categorized in
culture as M or "beating F," and a frac-
tion (as high as 15%) of quiescent
F-cells, are in fact myocardial muscle
cells. The glycogen-free cells are presum-
ably derived from epicardium, endo-
cardium, and fibrous tissues. Moreover,
inasmuch as the beating F category nor-
mally represents no more than 0.5% of
the total cells in a culture, and F-cells
usually constitute 25-30%, the error in
assaying M- and F-cells in a culture may
be calculated as only about 5% (0.5% +
15%X30%). This is a satisfactory level
of accuracy for an assay based upon
morphological criteria.
The observation that F-cells are well
spread, while M-cells remain rounded on
the culture plate for at least the first day
or two, prompted experiments to deter-
mine if this difference in spreading re-
flected a difference in adhesiveness of the
two cell types, and if such a difference
could be exploited to separate M- and
F-cells. As mentioned in Year Book 67
(and described in detail in her disserta-
tion) Polinger has devised a separation
technique which depends upon the dif-
ferential rate of attachment of M- and
F-cells to Falcon plastic dishes. With this
method she has obtained cultures con-
taining over 85% of either cell type.
DEPARTMENT OF EMBRYOLOGY
537
The separation technique may be de-
scribed briefly. Each of a series of plastic
culture dishes is inoculated with a
suspension of cells. After swirling the
medium the supernatant is removed from
one dish immediately, and at varying
intervals after inoculation from the repli-
cate plates. Each supernatant is trans-
ferred to another culture dish. These
latter dishes, referred to as supernatant
(S) dishes, contain those cells which
have not yet attached to the original
dishes. The original or residual (R)
plates then contain those cells which have
been able to attach to the substratum in
the time between inoculation and re-
moval of the supernatant.
Whereas control cultures (23-hour R
plates) contain 63% M-cells, these are
enriched to a maximum of 88% in 2-hour
S plates. In contrast in 1-hour R plates,
M-cells constitute only about 20% of
the population. Figure 18 shows the rate
of attachment of total cells and M- and
F-cells in the residual plates. By 1 hour
after seeding, 34% of the cells that will
ever attach in the R plates have already
done so. By 6 hours, 100% of the cells
that will attach have done so.
The initial rate of attachment of
F-cells is rapid (Fig. 18). By y2 hour
42% of the total F-cell population, but
only 7.7% of the total M-cell population,
have attached. Thus, the high rate of at-
tachment of cells during the first half
hour is due almost entirely to the attach-
ment of F-cells. After 1 hour in culture,
the rate of attachment of M-cells (Fig.
18) increases while the rate of attach-
ment of F-cells levels off. By 4 hours
after seeding, when 92% of attachable
cells have attached, 100% of the F-cells
and 82% of the M-cells have attached.
By 6 hours, all the cells that will ever
attach have done so. This value repre-
sents 32% of the inoculum in these
experiments.
When the percentage of M-cells in
residual culture plates was determined
using phase optics, and the plates were
stained with periodic acid-Schiff and
azure B (for glycogen and RNA), the
percentage of M-cells was again found
to be directly correlated with the per-
centage of cells containing glycogen.
o
i— H
X
Q>
JO
Q.
C
7-
6;
5-
4
3
2-
1-
7/ ,*
* ..— ... • . -...^/ L..,.
Total Cells
M-Cells
— - F-Cells
i h
12 3 4 5 6 7 8
Time supernatant removed (hours)
Fig. 18. Rate of attachment of M- and F-cells in residual plates.
— l
23
538
CARNEGIE INSTITUTION
A further difference between M- and
F- (glycogen and nonglycogen) cells in-
vestigated by Polinger is their strikingly
different rates of mitotic activity. Dur-
ing the first two days in growth medium
the majority of cells which incorporate
3H-thymidine into DNA are rapidly
dividing glycogen-free cells. Even at
day 1, the percentage of these cells which
become labeled is significantly greater
than that of cells containing glycogen.
On the other hand, this difference in
labeling index is not reflected in the in-
tact chick heart. When 7-day embryonic
hearts are labeled in vivo by injecting
3H-thymidine through the amnion, the
labeling index of glycogen-rich muscle
cells in the ventricular myocardial wall
is found to be similar to that of epi-
cardial and endocardial cells, which are
devoid of glycogen.
Potassium-Inhibition of Pacemaker
Capacity
In previous reports (Year Book 66,
67) and other publications DeHaan and
Gottlieb defined a pacemaker heart cell
in culture as any single isolated cell seen
to beat rhythmically. A potent regulator
of pacemaker function was shown to be
potassium. Employing dissociation pro-
cedures and media tested to yield maxi-
mal numbers of active cells, DeHaan
found that the number of pacemaker
M-cells which manifest their capacity
for spontaneous contraction at any given
moment was a function of the concen-
tration of potassium in the medium
(K+)0. At low levels of potassium
(1 ml), 70-80% of the M-cells derived
from a 7-day heart beat spontaneously.
As K0 is raised progressively by small
incremental injections of KC1 into the
culture medium, a fraction of the cells
become quiescent ("switch off") at each
steplike rise in K0. At normal serum
potassium concentration (4-5 mi¥) only
about 40% of latent pacemakers beat.
In high-potassium media, no more than
10-20% continue spontaneous activity.
This result is reversible, at least over a
short period, in that if the high-K
medium is removed from these cells and
replaced by one containing 1 ml K0,
70-80% of the M-cells begin beating
again. Some cells switch off at a given
K0 while others remain active, which
suggests the possibility that each pace-
maker cell may have an individual
threshold of K-inhibition.
To test this possibility, DeHaan and
E. W. Schaefer, an undergraduate stu-
dent at Johns Hopkins, designed an ex-
periment to answer the following ques-
tions :
1. Do the cells which are beating at a
given K0 remain on for extended periods
(hours), or does the %BC counted at a
particular time represent the statistical
average of a larger number of pacemaker
cells which are intermittently on and off?
2. Does each heart cell in a culture
exhibit its own threshold of K-inhibition?
3. To what extent does this threshold
remain constant with time?
Cultures of isolated 7-day heart cells,
prepared by techniques described previ-
ously by DeHaan and Gottlieb, were
incubated in medium containing 1.3 m/lf
K for 22-27 hours. Care was taken to
maintain pH, C02-level, and osmolarity
constant during all phases of the experi-
ment. Microscopic fields in a culture,
including about 30 actively beating pace-
maker cells, were photographed on Po-
laroid film at the beginning of an experi-
ment, and each beating cell was then
numbered on the photographs. A small
aliquot of 0.25 M KC1 saline was in-
jected into the culture dish. After a
5-minute equilibration period the num-
bered cells were reexamined and those
which had stopped were identified on the
photographs. A second aliquot of KC1
was added; the cells were again ex-
amined. A third injection brought the
K0-level to 9.6 mM. After recording
which of the 30 original cells had switched
off and which ones were still beating,
the plate was flushed twice with pre-
warmed, pregassed 1.3 mM K medium,
DEPARTMENT OF EMBRYOLOGY
539
TABLE 10. Spontaneous Pacemaker Activity of Identified Isolated Single Heart Cells
Observed Through Two Cycles of K0-Increase
Experi-
Experimental
Control
mental
(2)
(7)
(i)
Total
(3)
(5)
(6)
Total
(8)
(10)
Ko
pm
Pm
(4)
%
Ko
pm
Pm
(9)
% on
(ml)
counted
on
% on
S.E.
(mlf)
counted
on
% on
norm.*
1.3
267
267
100
1.3
59
59
100
100
Cycle
3.8
266
198
75.2
2.6
1.3
59
58
98.4
76.8
I
7.0
266
116
43.8
5.1
1.3
59
57
96.5
47.3
9.6
265
71
26.6
5.0
13
59
54
91.4
35.4
1.3
246
190
772
2.9
1.3
56
47
84.2
93.2
Cycle
3.8
243
147
61.0
2.7
1.3
55
46
84.0
7.0
II
7.0
234
100
42.7
5.9
1.3
50
42
842
58.7
9.6
189
60
31.0
4.6
13
50
42
84.2
47.7
* % on norm. = The percentage of active pacemaker cells normalized to discount control
decrement with time; z=z % onexp. + (100 — % onCOntr.).
restoring the culture to its original con-
dition. The culture was allowed to equili-
brate for 1.5-2.0 hours, and the cycle
of three injections was repeated, with
observations on the same population of
30 cells after each increment of K0. This
experiment was repeated nine times,
yielding a total of 267 cells observed
(903 observations). Two control experi-
ments were performed (total 58 cells) in
which plates were treated in an identical
way except that the injected aliquots of
solution were free of potassium and
therefore produced no increase in K0-
level.
Cells were counted as either beating
or quiescent at each K0-level. Each cell
either beating ( + + ) or not beating
( ) at a particular level of K0 in both
was then scored as "same" (S) if it was
cycles of K-injections.
The data from preliminary studies
completed in recent months are pre-
sented in Table 10 in terms of the per-
centage of the original pacemaker popu-
lation which remained active ("on") at
each potassium concentration through
the two cycles. The dramatic potassium-
inhibition effect, previously reported, is
illustrated in column 4. In column 9 the
decrement in pacemaker activity with
time is shown among control cells. The
experimental data, normalized to dis-
count this time decrement, are provided
in column 10. In Table 11 the behavior
of individual cells is compared during the
two cycles. The symbols shown in
columns 3 to 6 indicate that cells were
spontaneously active at a given K0 dur-
ing both cycles ( + + ) , quiescent during
both cycles ( ) , active during cycle
I but not during cycle II ( + — ) , or "off"
TABLE
11. Constancy
of Pacemaker Activity of
Identified
Isolated
Single Heart Cells
Observed Through Two Cya
es of Ko-Increase
Experimental
Control
(2)
(7)
(1)
Total
% same
(8)
(9)
Ko
pm
(3)
(4)
(5)
(6)
+ +
Ko
Total
(10)
(ml)
counted
+ +
+ -
- +
(ml)
pm
% same
1.3
267
248
0
19
0
92.9
1.3
56
842
3.8
266
191
48
13
14
89.8
1.3
55
85.6
7.0
266
125
109
1
31
88.0
1.3
50
85.5
9.6
265
85
129
9
42
80.8
1.3
50
90.6
Mean
87.9
86.5
540
CARNEGIE INSTITUTION
during cycle I but "on" during cycle
H(-+).
Tentative answers to the three ques-
tions raised above are provided by these
results. Control cells examined once, and
again two to three hours later (Table 11,
column 10) , appear in these experiments
to be remarkably constant. Although
there was some effect of the manipulation
of the culture (transfer of the culture
plate from incubator to microscope warm
stage, injection of control medium, me-
chanical agitation, etc.) and especially
of the time intervening between observa-
tions, more than 85% of the cells ex-
hibited the same behavior over a period
of 2-3 hours. Moreover, when pace-
makers were shifted from one level of
K0 to another, and the results were cor-
rected for the predictable decrement with
time, 87.9% of the cells exhibited an
individual threshold for potassium-inhi-
bition, which remained constant over the
same 2- to 3-hour period.
This estimate of constancy can be
shown to be a conservative one, as a re-
sult of an arbitrary convention employed
in scoring cell behavior. At the beginning
of an experiment, all the cells counted
were isolated singlets, beating independ-
ently. During the course of an experi-
ment lasting up to four hours, occasional
cells became conjoint with beating neigh-
bors. Since, in these cases, it became im-
possible to determine whether each cell
was acting as its own pacemaker or re-
sponding to a stimulus from its conjoint
partner, such cells were eliminated from
consideration after contact was observed.
This is the reason for the decline in total
number of pacemakers counted (columns
2 and 7, Table 10) throughout an ex-
periment.
It can be concluded, therefore, that at
least 88% of pacemaker cells derived
from a 7-day embryonic heart exhibit
individual thresholds for K-inhibition
which remain constant for several hours
in culture under the conditions described.
Other experiments now being con-
ducted by DeHaan appear to indicate
that the potassium-inhibition threshold
relationship of cells from hearts earlier
than 7 days are quite different than from
older hearts, suggesting that after the
heart forms and begins to beat, dramatic
changes occur in the transmembrane
Na-K ratios and, presumably, in ionic
fluxes. Techniques of culture and electro-
physiology previously reported are now
being modified for application to cells
from 2-day hearts, at the time the organ
begins beating, to study the differentia-
tive changes presumed to take place in
the pacemaker membranes during this
critical time.
Electron Microscopy of Cultured
Cells
Hayden G. Coon and Francis J. Manasek
Active cilia have been found on some
of the cells of the established line of
Xenopus laevis kidney originated by Dr.
Keen Rafferty of the Department of
Anatomy of the Johns Hopkins Uni-
versity School of Medicine. During the
three years this line has been carried it
has retained its predominantly epithelial
nature as well as a tendency toward for-
mation in crowded cultures of vesicles
reminiscent of kidney tubules. In the
course of producing a somatic hybrid cell
strain between this amphibian cell line
and the established mouse fibroblast LM
(TK~) CI 1 D (propagating mononucle-
ate hybrids apparently are possible and
will be the subject of a future com-
munication), we observed that patches
of cells possessed active cilia in cultures
grown for 3 weeks or more in our stan-
dard culture medium (F12 with doubled
concentrations of amino acids and pyru-
vate, supplemented with 15 /^g/ml
ascorbic acid and 5% fetal calf serum,
the whole diluted with water by 10%
for amphibian culture). To the best of
our knowledge, this is the first time that
cilia have been reported in continuously
propagated cell cultures. These organelles
DEPARTMENT OF EMBRYOLOGY
541
have been studied previously in explants
of tissue maintained for short times in
vitro as "organ cultures." The occurrence
of the ciliated cells in small patches sug-
gested a clonal origin, and we are at-
tempting to clone cell lines with high and
low probabilities of expressing the cili-
ated phenotype. This observation also
prompts us to reexamine cell cultures
from the more familiar ciliated tissues
such as lung and oviduct of mammalian
embryos. The relationships among the
centriolar apparatus and the basal bodies
during cell division and the action of
cilia under varied conditions of cell
fusion will be investigated.
The ultrastructure of the cilium is
characteristic and also serves as a defini-
tive demonstration. Consequently, Coon
joined forces with Manasek in studying
these and other cultured cells with the
electron microscope. Plate 6 shows the
typical cilia found in regions where visi-
ble ciliary activity was identified before
preparation for the electron microscope.
The logical way to cut sections of cells
showing cilia is in the plane normal to
the substrate — in this case, normal to
the plastic petri dish. Manasek has dis-
covered that it is possible to section the
epon , embedding medium containing the
cells and the polystyrene petri dish at
the same time. The result has produced
the series of unusual micrographs shown
in Plates 6-9. Previously it was standard
practice to separate the embedding
plastic from the culture dish, and usually
sections were taken in the plane parallel
to the freed surface. We believe that this
new method of examining the interface
between cells and their substrate will
yield valuable information on the ad-
hesion of cells to neighboring substances
and the modifications of the basal sur-
faces of cells induced by a variety of
substrates. The whole dimension of ultra-
structural comparisons between cells in
vivo and their counterparts in cell cul-
ture is still virtually unexplored.
Because of the novelty of this method
we include some details here. The cul-
tures were first rinsed in cold Hanks'
balanced salt solution and then fixed for
10 minutes at room temperature in cold
2G fixative: 2.5% glutaric dialdehyde
and sodium cacodylate buffer (0.025 M)
in Hanks' solution. They were rinsed with
fresh Hanks' solution and then postfixed
with 1% 0s04 in 0.1 M cacodylate buffer,
pH 7.6. Cultures were then dehydrated
with a graded ethanol series. Some cul-
tures were given a final rinse with a weak
solution of uranyl acetate in absolute
alcohol. Following absolute alcohol, the
cultures were embedded directly in epon.
After polymerization, small pieces were
sawed out and sectioned normal to the
culture dish on glass or diamond knives.
The plastic dish was not removed from
the epon and no difficulty was experi-
enced in sectioning the block, half of
which was polystyrene culture dish and
the other half epon. Sections were
mounted on uncoated copper grids,
stained with lead citrate and examined
in an Hitachi HU-11E microscope
operated at 50 kV.
Plates 7 and 8 illustrate an alteration
which we have found in each of the three
different epithelial cells in culture which
we have examined. The Xenopus kidney
line, kidney cells of the Chinese hamster,
and rat liver cells have shown a spe-
cialization of the basal cell surface simi-
lar in appearance to the terminal web
which is commonly seen at the apical
surface of many epithelia in vivo. A de-
tailed view of this "basal web" of fila-
mentous material is shown in Plate 8. It
is present on both the basal and apical
surfaces of many of these cultured
epithelial cells. It seems unlikely that
this basal web is merely a specialized
portion of a cell cortex, since the latter
feature is generally absent in these cul-
tured cells. The confusion of cellular
polarity which results when this kind of
specialization is present may signifi-
cantly change the function and behavior
of cells in culture. The discovery of struc-
tural alterations of these cultured cells
suggests experiments to be done in order
542
CARNEGIE INSTITUTION
to determine the change, if any, of this
region of contact as the substrate is
changed. We are beginning by asking
whether the same basal cytoplasmic
specializations are produced when these
cells are cultured on coatings of collagen,
fibrin clot, agar, cellophane, or other
types of plastic.
Plate 9 shows some new features of
cultures of rat liver cells (see Year Book
67) revealed by electron microscopy. In
regions where the cells of the typical
"monolayer" or epithelial sheet are
packed closely together, we were sur-
prised to find that they overlap one an-
other much more than could be detected
with phase optics. No typical junctional
complexes were found despite the epi-
thelial growth pattern of these liver
cells. In these old cultures (the rat liver
cell population had been maintained in
the same petri dish for ten weeks after
the sheet had reached confluence) a large
amount of material had accumulated
between the cells and the plastic culture
dish. The presence of a fibrous-appearing
material similar to the "reticular fibers"
of normal liver had been seen with phase
microscopy {Year Book 67). We had be-
lieved that this material was mostly
collagen because of its digestion in puri-
fied collagenese (Worthington CLSPA)
and because of the incorporation into
protein of large amounts of hydroxypro-
line from 3H-proline precursor. However,
we have found by electron microscopy an
amorphous material more like elastin
or basement membrane collagen in ap-
pearance, and we have found no evidence
of the typical banded pattern of mature
connective tissue collagen. Parallel align-
ments of electron-dense material were
also present (Plate 9C). Possibly it is
this material which contains the col-
lagenlike hydroxyproline synthesized by
these cells. We plan further studies of
these secretion products by the technique
of combining electron microscopy and
autoradiography of cultures which have
been pulsed with 3H-proline and "chased"
with cold proline. Further characteriza-
tion of this product will be attempted
by chromatographic analysis of proto-
collagen and its constituent polypeptide
chains. It seems possible that this epi-
thelial cell produces either a portion of
the collagen molecule or an imperfectly
aligned polymer. It is tempting to specu-
late that because of the clonal isolation
of a purified line of epithelial cells, an
intermediate or a deficient product has
accumulated. The addition of mesenchy-
mal cells or fibroblasts might result in
the final elaboration of a product more
like that formed in the normal tissues.
COLLAGEN SYNTHESIS IN SOMATIC CELL HYBRIDS
BETWEEN LYMPHOCYTES AND FIBROBLASTS
Hayden G. Coon and Lewis N. Lukens in collaboration with Phillip Periman, National
Institutes of Health
(with the technical assistance of Mrs. Isabelle Williams and Mrs. Virginia Hicks)
Hybrid cells between a pigmented
hamster melanoma and a nonpigmented
mouse fibroblast have been found by
Davidson, Ephrussi, and Yamamoto not
to express pigmentation. These hybrid
cells have also been shown not to possess
the activity of DOPA-oxidase, a key
enzyme in the pathway for melanin bio-
synthesis. Earlier work by Green,
Ephrussi, Yoshida, and Hamerman had
established that hybrid cells between two
collagen producing fibroblast strains did
produce collagen and that the level of
collagen production by these hybrids was
approximately intermediate between that
of the two parental strains. These two
results have been cited by Davidson,
Ephrussi, and Yamamoto as suggesting
DEPARTMENT OF EMBRYOLOGY
543
that "differentiated" or specialized syn-
thesis by vertebrate cells is under "nega-
tive control/' i.e., in the hybrids the
negative control function of the non-
pigmented fibroblast was dominant to
the pigment synthesizing control mecha-
nism of the melanoma. It was hypothe-
sized that the control mechanism which
prevents or represses pigment synthesis
in the fibroblast is also able to prevent
pigment production by the melanoma.
While it is not yet clear which char-
acteristics will be found to exhibit nega-
tive control in hybrid cells and which
ones will not, the working hypothesis
proposed by Richard Davidson is that
parental cells showing the same differ-
entiated function will continue to exhibit
that function as a cellular hybrid,
whereas parental strains with dissimilar
differentiated functions will produce hy-
brids which exhibit negative control or
failure of expression of either specialized
function. We find evidence from the hy-
brids between rat liver (which cell
strains synthesize serum antigens) and
the mouse fibroblast "L" cells (which do
not) that the hybrids do not form any
serum antigens, neither those of the rat
nor those of the mouse (see Year Book
67, and the Wistar Symposium No. 9,
1969). This result is consistent with the
notion of negative control of differenti-
ated syntheses in hybrid cells.
Because collagen synthesis represents
the best example of persistent production
of a specialized molecule in hybrid cells,
and because of Dr. Lukens' experience in
the field of collagen biosynthesis, we de-
cided to continue the inquiry into the
control of collagen biosynthesis by hy-
brid cells. Specifically, we wanted to
know whether hybrid cells were also cap-
able of exhibiting negative control for
collagen synthesis. While comparative
studies are not complete, most cells of
the adult body do synthesize some col-
lagen, and certainly the cells from most
adult organs do so in cell culture. Cer-
tain cells of the blood and lymphoid
system, however, are known not to syn-
thesize collagen. Collagens are well
adapted for this kind of study because
they are very sensitively detected by
their large amount (about 9%) of a
virtually unique amino acid, hydroxy-
proline. We have decided to study hybrid
cells between lymphocytes which have
been shown by Green, Goldberg, and
Todaro not to produce collagen, and the
established mouse fibroblast "L" cell,
CI 1 D, which does synthesize collagen.
This fibroblast cell line characteristically
produces only small amounts of collagen,
but it has the advantage that it can be
selectively killed in tissue culture, which
greatly simplifies isolation of hybrid cell
strains. If the hybrids were to be capable
of exhibiting negative control of collagen
synthesis, then we would expect no col-
lagen to be synthesized by the lympho-
cyte X fibroblast hybrid cells. If collagen
were made by these hybrids, then we
would possibly have found evidence of
a counter example to the current general-
ization.
We have isolated 10 independently
derived rat lymphocyte (RLy)x mouse
fibroblast (CI 1 D) hybrid cell strains.
These hybrids were produced by a modi-
fication of the inactivated Sendai virus
procedure previously described (see Year
Book 67) . We have found, as did Henry
Harris and his collaborators, that the
thoracic duct lymphocyte is especially
difficult to fuse with other cells. We be-
lieve that our method will be of sufficient
interest that some details should be pre-
sented here.
CI 1 D cells were first plated in petri
dishes at 4xl06/100 mm dish. Four
hours later, after the cells had attached,
the dishes were rinsed with Hanks' saline
and drained nearly dry. The dishes were
kept cool by placing them on a metal
plate resting in a tray of crushed ice. A
few drops of /?-propiolactone-inactivated
Sendai virus (300 HAU/ml) were placed
in the center of each dish and were al-
lowed to spread uniformly to the edges
of the dish. Meanwhile, washed suspen-
sions of rat lymphocytes (prepared by
544
CARNEGIE INSTITUTION
thoracic duct cannulation and purified
by overnight incubation at 37°C in cell
culture medium generously supplied by
Dr. S. Strober of the NIH) were sus-
pended in the same concentration of cold
/?PL-inactivated Sendai virus so as to
yield 108 viable lymphocytes/ml. A few
drops (0.2 ml) of the lymphocyte-virus
suspensions were added to the center of
each of the cold dishes. As these drops
spread to the edges of the dishes, lympho-
cytes became stuck to the CI 1 D cells
already attached to the dish. After ten
minutes in the cold, the dishes were
gently transferred to a moist 37°C incu-
bator for about 90 minutes before stan-
dard culture medium was added. After
48 hours, the medium was changed to
selective medium HAT and renewed
twice weekly thereafter. An average of
34 macroscopic hybrid colonies per dish
appeared after three weeks of incuba-
tion. Only colonies from separate dishes
were considered certainly of independ-
ent origin. Since the selective medium
HAT killed all CI 1 D cells, and this
culture regime did not yield any rat cell
colonies (lymphocytes died and were ef-
fectively washed away by medium
changes) the system is a fully selected
method for the production of hybrid
colonies. Only hybrids which possessed
the fibroblast parent's characteristic at-
tachment to the plastic culture surface
were preserved by this method. However,
in one series the floating cells harvested
with the exhausted medium were col-
lected and cultured separately. None of
these cultures yielded a viable hybrid.
It may be concluded that a nonadhering
lymphocytelike hybrid is relatively rare.
Our first results from this study are
presented in Table 12. As is conven-
tionally done, we have taken incorpora-
tion of radioactivity into hydroxyproline
found in the protein from the cells and
medium after incubation in 3H-proline
as evidence of collagen production. The
ratio of the radioactivity of hydroxy-
proline in protein to the radioactivity of
proline in protein is a measure of the
quantity of collagen synthesized relative
to other cellular proteins. All five of the
independently isolated hybrid cell strains
between rat lymphocytes and CI 1 D
(RLy X CI 1 D) which we have tested
were found to be synthesizing collagen.
Furthermore, the hybrids are synthesiz-
ing collagen at a rate equal to, or in 4
cases greater than, that of the CI 1 D
parent! Negative control of collagen syn-
TABLE 12. Collagen Synthesizing Ability of Parental and Hybrid Cell Strains
[Disintegrations per minute (DPM) 3H-proline and sH-hydroxyproline (after purification to
constant specific activity) 15- to 24-hour incubations]
No. of
Replicate
Plates
Pooled
DPM
Hydroxy-
proline
Total DPM
in Acid
Hydrolysate
DPM
Hydroxy-
proline
X 100
Total
DPM
Cells/
Plate
X 108
DPM Hydroxy-
proline
Cell Strain
108
cud
cud
RLy X CI 1 D #3
RLy X CI 1 D #6
RLy X CI 1 D #7
RLy X CI 1 D #9
RLy X CI ID #10
1
2
2
6
2
2
3
67,200
71,900
41,200
387,500
33,850
21,300
194,000
8,040,000
10,160,000
5,450,000
29,200,000
2,635,000
1,950,000
14,550,000
0.84
0.71
0.76
1.33
1.29
1.09
1.33
13
13
3.5
9
1
0.86
15
5,160*
2,760f
5,900*
7,180f
16,900*
12,500*
4,3001
BRL 3C4
BRL 3C4
BRL 62
1
1
2
82,600
81,800
105,000
825,500
711,900
4,145,000
10.0
11.5
2.54
2.55
3.02
3
32,300f
27,300t
17,500*
Note : These measurements of rat liver strains were cited in the section with Dr. Manasek ; they
are included here as examples of high collagen producing cell strains. Note that the clonal strain
BRL 62 produces relatively less collagen than the separate clonal strain BRL 3C4. This may be
accounted for in part by the fact that 62 cells were in log phase of growth, whereas the 3C4 cells
were in older stationary cultures. * = 150 /u,C/plate/10 ml; t = 100 /tC/plate/10 ml.
DEPARTMENT OF EMBRYOLOGY
545
thesis does not appear to operate in
these hybrids.
This result does not, however, mean
that we have completely ruled out nega-
tive control for collagen biosynthesis.
There are two considerations which make
that strong a conclusion premature. In
Sendai virus to increase the probability
of hybrid strain formation, the absolute
rate of hybridization or the mating rate
was low (the calculated hybridization
frequency was about Y105 in these ex-
periments). The first objection to such a
conclusion, then, is that the hybrids
could have arisen from a minor con-
taminant of the lymphocyte population.
If the supposed contaminants came from
the vascular system, then they might
be expected to be capable of synthesizing
collagen and our result would still be
substantially in agreement with that of
Green, Ephrussi, Yoshida, and Hamer-
man. We believe that this possibility is
remote and that our examination of 5
separately derived hybrids effectively in-
creases the probability that at least one
of these 5 came from the great majority
of lymphocytes in the parental cell popu-
lation. A second and even more difficult
problem is posed by the fact that most
of the cells in these strains had "segre-
gated" or lost as many as one half of the
distinguishable rat marker chromosomes
by the time that the hybrids were suffi-
ciently numerous to be tested (about 25
cell generations) . If the postulated nega-
tive control of collagen synthesis depends
on the presence of a specific rat chromo-
some, it is possible that each of these
hybrid strains had lost that chromosome.
Again, the more hybrid cell strains we
examine, the less likely that a specific
chromosome is missing in each of them.
If, however, several chromosomes from
the rat lymphocyte must be present at
the same time in order to achieve nega-
tive control of collagen synthesis in the
hybrid, then it may prove very difficult
ever to obtain the desired evidence. Our
overall conclusion at this point must
be that we cannot be sure, but that it is
very possible that collagen synthesis is
not subject to the same kind of negative
control as melanin synthesis or serum
antigen synthesis. We shall have to study
many more independently derived lym-
phocyte X fibroblast hybrids to have an
answer to our original question. Fortu-
nately, improved technology has made
the production of these hybrids highly
efficient.
The possibility of hybrids having been
formed by a "contaminant" cell type is
removed if a cloned culture line is used
as the original parent. We have chosen as
one of these parents the mouse myeloma
cell line MOPC-315B originated by Dr.
Michael Potter at the NIH and adapted
to cell culture and cloned by his associ-
ate, Dr. Phillip Periman. Dr. Periman
has collaborated with us in producing
hybrid cell lines between two of his cul-
ture adapted, functional myeloma cell
lines and the selectable "L" cells, CI 1 D
and A9. These fascinating hybrid cells
will be studied in great detail because of
the parent myeloma cells' plasma cell-
like ability to synthesize specific immu-
noglobulins. Our results indicate that
these myeloma cells, like normal plasma
cells, do not synthesize collagen. In addi-
tion to these mouse myeloma cells, we
have produced hybrid cell strains from
human lymphocytes (supplied courtesy
of Dr. Periman) which have been ex-
tensively purified by passage through
glass columns and an interval in cell
culture. These fresh human lymphocytes
and still another culture cell line (HL-G)
derived from human lymphocytes have
been used as parents in further hybridi-
zations with CI 1 D. Neither the lympho-
cytoid cell line, HL-G, nor the fresh
human lymphocyte population produces
collagen. We have not yet assayed the
hybrids for collagen production.
If we assume that these hybrids will
show the same collagen synthesizing
ability that we have found in all five rat
lymphocyte x CI 1 D hybrids tested, then
another very interesting variation of the
basic "control of synthesis" experiment
546
CARNEGIE INSTITUTION
can be done. Because of species differ-
ences recently discovered between the
polypeptide cc2 chains of rats, mice, and
men, these peptides can be separated and
individually quantitated. Now the ques-
tion can be posed: are the polypeptides
characteristic of both species produced,
or is the collagen produced by the hy-
brid only an augmented synthesis of the
CI 1 D parent? Is a hybrid molecule of
a specialized structural protein like col-
lagen produced in these cells as was
found for the ubiquitous metabolic en-
zyme LDH by Weiss and Ephrussi in
1966? Can a "tribrid" be made in which
the chromosomes of three separate spe-
cies, combined in a single multiply hy-
brid cell, conspire to produce a trebly
hybridized collagen triple helix? The
separation and analysis of the different
collagen polypeptides is being done in
collaboration with Dr. George Martin at
the NIH. It would be especially exciting
if we were able to find evidence for the
"turn on" of a previously repressed spe-
cific cell function by observing the syn-
thesis of human collagen in the human
lymphocyte X CI 1 D hybrids.
THE MAMMALIAN EMBRYO IN RELATION TO ITS
ENVIRONMENT
The Spacing of Blastocysts
B. G. Boving and L. M. Billingsley
Rabbit blastocysts become approxi-
mately equidistantly spaced along the
uterine horn containing them. Their
spacing is a consequence of their being
pushed apart by waves of contraction
that arise from each end of the uterus
and from wherever the uterus is dis-
tended by a blastocyst within.
The first and older conclusion {Year
Book 55) derived from measurements of
distances between conceptuses, summa-
rized by dividing the standard deviation
by the mean. The mean of such coeffi-
cients of variation (one for each horn) is
not significantly different from the mean
of randomized models at 3, 4, and 5 days
after mating, but it becomes increasingly
and significantly more nearly even at
6 and 7 days after mating — indicating
the time to look for the spacing mecha-
nism at work. An indication of where to
look and what to look for is provided by
the fact that spacing occurs with blasto-
cysts well separated from each other.
This suggests that the uterus conducts
whatever activity it is that separates
blastocysts from each other and from the
ends of the horn after waves of contrac-
tion have arisen and spread from those
points where it is distended by a blasto-
cyst. Accordingly, at 6 to 7 days after
mating, rabbits were opened under anes-
thesia. The uterus was exposed but kept
warm and moist by a specially devised
fanned steam generator and, for fine con-
trol, a thermistor controlled heat lamp.
With the benefit of the previously de-
scribed ring light {Year Book 66),
uterine motion was photographed at 4
frames per second for subsequent study
at 6 times normal speed.
The second and newer conclusion
derives from the following observations.
(1) Waves of uterine contraction arise
from each end of the horn and from
wherever it is distended by a blastocyst
within. (2) They are propagated along
the uterine horn. (3) Such propagated
uterine contraction waves, usually called
"peristalsis," differ from peristalsis by
moving equally in both directions from
the point of distention and by not pro-
pelling the distending object. (4) Similar
contraction waves are stimulated by
beads of blastocyst size inserted into the
uterus. (5) Similar contraction waves are
able to move beads the size of unattached
blastocysts, but (6) they are unable to
move attached blastocysts or beads the
size of attached blastocysts. Formally,
preimplantation conceptus spacing by
DEPARTMENT OF EMBRYOLOGY
547
the rabbit may be explained in terms of
stimulus (distention + spontaneous move-
ment) , effector (uterine muscle) , action
(propagated contraction) and result
(equidistant spacing), giving some as-
surance that no major aspect of the
mechanism has been overlooked.
With conceptus spacing worked out for
one species, the rabbit, comparative
study was next. The rat was chosen, be-
cause it has repeatedly been claimed to
have even spacing, yet its blastocysts
do not exhibit the remarkable expansion
{Year Book 67) characteristic of the
rabbit's. Thus, it might have the poten-
tial to reveal a different spacing mecha-
nism. On the other hand, the "even spac-
ing" claimed for rat conceptuses has not
been supported by distance measure-
ments but by counts showing tubal and
cervical halves of uterine horns to con-
tain approximately equal numbers. Such
equal filling might have occurred with
conceptuses spaced randomly and pre-
sumably passively, whereas equidistant
spacing is statistically discriminated
from random spacing and may imply that
the uterus was stimulated by each con-
ceptus individually and exerted a spac-
ing reaction appropriate to the number
of conceptuses in the particular horn.
That implication of interaction applies
if the conceptuses do not touch each
other, but it does not apply in a string-
of-beads situation where equidistant
spacing may have resulted from nothing
more than the equality in size of the
abutting conceptuses. The first situation
was usually found at 5.5 days after esti-
mated time of mating, which is near the
time of implantation (Plate 10B), but
the second situation might develop as
early as 6.5 days after mating if there
were many conceptuses (Plate IOC).
With fewer conceptuses, it tended to
occur later (Plate 10D) . If some infor-
mation on locations of placental scars
observed postnatally may be borrowed
from the literature and added to the
present prenatal data, it may be inferred
that, as conceptuses grow, spacing by
abutting continues to equalize the dis-
tances between their centers slightly
and gradually until term (Fig. 19). By
that time, rat spacing is as equidistant as
rabbit spacing at the time of implanta-
tion. At implantation time, however,
while significantly more even than ran-
dom, rat spacing is significantly less
regular than rabbit spacing (Fig. 19).
Exploring the rat's less accurate and
distention-free preimplantation spacing
mechanism requires a determination of
when it operates. Accordingly, earlier
data are now being sought. External ex-
amination for swellings and inspection
after clearing are unreliable below the
5.5 day stage (Plate 10B). But if rat
uterine horns are dissected open, some of
the conceptuses are likely to be missed
because they are so small. At 4.5 days
after mating, it has been found possible
to take advantage of increased capillary
permeability at presumptive implanta-
tion sites, which lets them be marked by
intravenous injection with 5% Evans
blue in 0.8% NaCl solution (Plate 10A).
More such preparations are needed be-
fore the spacing typical of 4.5 days can
be measured and expressed quantita-
tively. To estimate the spacing typical
of 3.5 days, it will probably be necessary
to employ histological methods, which
are more troublesome but also less sub-
ject to the occasional doubt in diagnosing
an implantation site by the dye marking
method.
The comparative study, in addition to
pointing to the need for earlier rat data,
has suggested the desirability of later
data for rabbits to see if their nearly
equidistant spacing achieved by implan-
tation time is made even more regular
by conceptuses abutting when numerous
enough and big enough. More philo-
sophically, the rat-rabbit comparison
provides another example of more or less
closely related mammals accomplishing
a superficially similar result by at least
partly different mechanisms.
548
CARNEGIE INSTITUTION
1.00
.90
.80
.70
.60
.50
.40
.30
.20
JO
.00
RANDOM
-- EVEN
i i
1 r
\ \
i — r
t — i — r
15
20
DAYS AFTER MATING
Fig. 19. The spacing of rabbit and rat conceptuses in the uterine horn at various times after
mating is compared by coefficients of variation (standard deviation divided by mean distance
between centers). Perfectly equidistant spacing is reflected by zero; large samples with random
spacing tend to an average of unity. Vertical bars extend ± 2 S.E. Rabbit spacing is significantly
more regular than rat spacing when implantation begins (rat 5.5 days; rabbit 7.0 days).
Anatomy and Physiology of the
Placenta
E. M. Ramsey, H. R. Misenhimer, M. W.
Donner, S. I. Margulies, and C. B. Martin, Jr.
Baseline Studies
Because of the rapidity with which
the rhesus monkey has gained popularity
as an experimental model for reproduc-
tive physiology, plans for investigative
procedures have far outdistanced the
body of information on such funda-
mental matters as normal blood pressure,
blood constituents, etc., in both the
mother and the fetus. The sparse data
which are available have usually been
assembled as control values from the
point of view of some specific research
plan and hence have only limited gen-
eral usefulness. Data on the subhuman
primates are almost entirely lacking.
This situation has presented an in-
creasingly serious obstacle in our own
work as our studies have come to deal
more and more with physiology rather
than anatomy. It is obvious that results
obtained under experimental conditions
which modify basal body functions can
only be evaluated in comparison with
the normal values for the given functions.
Perhaps less apparent but of funda-
mental importance is the fact that many
of the surgical and pharmacological pro-
cedures which form necessary prelimi-
naries to experimental manipulations are
in themselves factors which modify nor-
mal conditions. For example, most of
the experiments which deal with utero-
placental circulation require the ad-
ministration of an anesthetic prior to
experimental manipulation. Bonica has
shown in humans that anesthesia may
DEPARTMENT OF EMBRYOLOGY
549
produce profound changes in blood pres-
sure, blood gases, etc. and that these
changes are variable and dependent upon
several factors including the agent being
employed.
It may be recalled {Year Book 67,
p. 460) that previously, in collaboration
with Bonica, we commenced an investi-
gation of the effect of anesthesia on the
uteroplacental circulation in the rhesus
monkey. We compared the effects of in-
travenous pentobarbital sodium and
nitrous oxide-oxygen anesthesia and
found the effects to be essentially the
same. We did not, however, analyze the
effect of the anesthetic agent per se on
the various parameters which might in-
fluence uteroplacental circulation, largely
because baseline data for these critical
parameters were not available.
For some years we have realized that
"someday" we would have to take time
from the forward progress of our pro-
gram to establish certain of these requi-
site baseline values. Such an experimen-
tal parenthesis duplicates the experience
of an earlier period in the work when
Ramsey and Corner devoted several
years to the establishment of normal
myometrial activity patterns in pregnant
rhesus monkeys, as a baseline for sub-
sequent radiologic studies (see Year
Books 56-60) . The results of that exercise
in self-discipline have been extremely
useful not only in our own work but in
that of other reproductive physiologists
who employ rhesus monkeys.
In attempting to collect data upon
those vital functions which form the focal
points of our current interest a first
hurdle lies in the fact that the monkey
must be anesthetized for most procedures,
including those which are easily and
quite comfortably carried out in con-
scious, cooperative human patients. The
second obstacle is presented by the
monkey's ability to remove chronically
implanted catheters, probes and the like,
an ability which most other laboratory
animals do not have. These difficulties
have been largely overcome by utilizing
a primate restraining chair into which
the animal is placed after the initial
anesthetic and surgery and where she is
allowed to recover to a normal, awake
state. Most animals tolerate such a re-
straining chair for protracted periods of
time, during which continuous monitor-
ing can be carried out without interfer-
ence from the animal.
Employing these devices we have made
continuous recordings of both maternal
and fetal systemic blood pressure and
pulse rate and have been able to obtain
arterial blood samples from both the
mother and fetus for simultaneous blood
gas studies. These measurements have
been made via plastic catheters inserted
into the femoral artery of both the
mother and the fetus. Values for ma-
ternal blood pressure obtained by simul-
taneous ausculation, employing a pre-
mature infant blood pressure cuff, were
found to be unreliable and actually mis-
leading because of the high values
registered. Technically no satisfactory
cuff could be obtained or devised and
psychologically the animal reacted to in-
flation of the cuff, and indeed to the mere
presence of the investigator, with an
agitation which greatly increased the
peripheral blood pressure while minimal
effect was noted on the central pressure.
The direct recordings, made hour after
hour in a quiet, isolated room, were
dependable and reproducible.
Our results thus far indicate a broad
range of maternal mean blood pressure
(diastolic pressure +% pulse pressure)
from 81.5 to 126.5 mm Hg with an aver-
age value of 104.6 (S.D. = 15.6) and a
similarly wide variation in maternal
pulse rate from 129 to 214 beats per
minute with an average of 178 (S.D.=
21.6). Maternal pH and blood gases have
also been studied and show a more con-
sistent pattern, except for p02 which is
quite variable and does not always follow
the trends of the other gases or of pH.
The mean values for these parameters
are as follows :
550
CARNEGIE INSTITUTION
Maternal arterial pH
Maternal arterial p02
Maternal arterial pC02
Maternal arterial HCO3
The data on blood pressure, pulse rate,
and blood gases have been collected from
pregnant animals in which the gesta-
tional age ranged from 101 to 156 days.
An insufficient number of observations
has yet been made to determine whether
or not the individual variations are re-
lated to gestational age; they do not
appear to be influenced by the weight
of the animal. Additional data are being
collected to expand this body of informa-
tion so that these factors and other
pertinent variables can be evaluated with
greater statistical validity.
An inadequate number of observations
of these parameters has been made on
fetuses to permit the calculation of
means and standard deviations.
The effect of anesthesia on maternal
and fetal blood pressure, pulse rate, and
arterial pH is illustrated in Figure 20,
which is a graphic analysis of a typical
study. The prompt and transient de-
crease in both maternal and fetal mean
blood pressure is a consistent observa-
tion. In approximately half of the ani-
mals studied the maternal hypotension
has been followed by a period of hyper-
tension which usually exceeds the limit
of two standard deviations above the
mean and persists for 2^ hours. This
observation warrants further study.
The arterial pH of both the mother
and the fetus decreases after intravenous
pentobarbital anesthesia. The magnitude
of this decrease appears to be dependent
upon the dose of pentobarbital and its
duration upon the route of administra-
tion, being most persistent when part of
the agent is given intramuscularly. Even
though a decrease in arterial pH is a
consistent finding following this anes-
thetic technique, it is seldom more than
2 S.D. below the mean. This trend toward
acidosis probably reflects the depressing
effect of pentobarbital on the respiratory
7.40 (S.D. = 0.06)
103.7 (S.D. = 13.8) mmHg
26.5 (S.D. = 2.1) mmHg
18.5 (S.D. = 1.7)
center of the brain, as has been reported
by other investigators. In general the
blood gas values tend to support this
observation by a concomitant drop in
p02 and HCO3 and a rise in pC02. How-
ever, the latter parameters are subject to
erratic variations that are sometimes
unassociated with the clinical condition
and are considered less reliable than
arterial pH in reflecting the well-being
of the mother or the fetus.
Another of the vital functions which
forms a focal point of our current inter-
est is the normal uterine artery blood
flow. Study of this, using an electromag-
netic flow meter, is in progress.
An additional experimental modality
which may affect the vital parameters
is the contrast medium employed for the
radioangiographic studies. It is con-
sidered nontoxic in the usual clinical
doses, but its effect upon mother and
fetus in our studies is being investigated.
Although we do not feel that our study
of baselines is by any means complete,
we believe that enough basic data are
now in hand to permit us to evaluate
experimental findings with some degree
of assurance.
Experimental Production of
Hypertension
All of the monkeys upon whose uterine
arteries Drs. Hodari and Hodgkinson
placed constricting bands in 1967 (Year
Book 67, p. 461) have now been preg-
nant, some of them twice, since the band-
ing. Clinical and laboratory data are
being carefully collected and collated.
Each pregnant animal is subjected to
radioangiography close to term and
fetuses and placentas are weighed and
examined. The study is being continued
in the expectation that some tentative
conclusions may be formulated following
one or two more breeding seasons.
DEPARTMENT OF EMBRYOLOGY
551
FETAL
pH
FETAL
PULSE RATE
FETAL
MEAN B.P.
MATERNAL
PH
MATERNAL
PULSE RATE
MATERNAL
MEAN B.P.
7.50 -
7.36
7.22
220
200
180 -
[
Nembutal
I50mg I. A.
-V*s~
50
45
40
7.54
7.42
7.30
I 80
I 70
I 60
J-~-v*vV--
!i . _^__^
1 — ^^—
1-
i> ei
HOUR OF STUDY
Fig. 20. Graphic analysis of a typical study showing the effect of anesthesia upon maternal
and fetal blood pressure, pulse rate, and arterial pH. The broken line in each instance represents
the mean, and the solid black bar at the left, two standard deviations. Monkey 67-97, 135 days
pregnant. Study CP14.
Placenta Extrachorialis in Monkeys
G. M. Harbert, C. B. Martin, Jr., and
E. M. Ramsey
Circumvallate or extrachorial placenta
is an infrequent anomaly of human preg-
nancy, though not altogether rare. It has
not previously been recorded in the
rhesus monkey and this fact has been
noted as bearing possible relevance to
the pathogenesis of the condition, since
monkey implantation is of the superficial
type and human implantation is inter-
stitial.
Occurrence of three single disc circum-
vallate placentas in rhesus monkeys
within a single year, all associated with
normal term gestations, was of striking
interest. Two of the cases occurred
among members of the Carnegie colony
and one in the colony of the University
of Virginia School of Medicine. Dr.
Harbert of the Department of Obstetrics
and Gynecology at the University of
Virginia made an intensive study of the
specimens which conformed both grossly
and microscopically to the pattern char-
552
CARNEGIE INSTITUTION
acteristic of human cases. The usual oc-
currence of a single disc placenta (80%
bidiscoid in the Carnegie monkey col-
ony) added a further element which Dr.
Harbert considered in his study. Since
all three specimens came from term preg-
nancies, no inferences could be drawn
about the original depth of implantation
though some weight was given to the fact
that the trophoblast, always less invasive
in the monkey than in the human, dis-
played no augmented invasiveness.
The cases are being recorded in the
literature as contributory evidence which
must be considered by all students of hu-
man placenta circumvallata in attempt-
ing to evolve a concept of the condition's
pathogenesis.
THE COLLECTION OF HUMAN EMBRYOS
B. G. Boving and E. M. Ramsey
With the assistance of Lynn Billings-
ley, Boving is rearranging the serial sec-
tions of human embryos so that they will
be in one continuous developmental se-
quence running through Streeter's Hori-
zons and then by millimeters of crown-
rump length.
Those interested in the early human
embryo will be glad to hear of an excel-
lent embryo in Horizon IX in the posses-
sion of Dr. J. E. Jirasek, Chief of the
Embryological Laboratory of the Insti-
tute for the Care of Mother and Child,
in Prague. This embryo, which Boving
was privileged to examine, is important,
because Horizon IX is represented by
only 2 specimens in the Carnegie collec-
tion plus drawings and photographs of a
third. More specifically, this specimen
was obtained at surgery and is well pre-
served. Thus, its freedom of the sharp
dorsal flexion present in some degree in
the other specimens suggests that the
flexion is not characteristic of the stage,
as had been suspected.
The Development of the Human
Heart at Seven Postovulatory Weeks
M. H. Cooper and R. O'Rahilly
Serial sections at stages 19, 20, and 21
(approximately 17-23 mm, C.-R.) were
studied in detail. At stage 19, most of
the features characteristic of the heart
were present, with the exception of the
septum secundum, which was seen during
stage 20. Moreover, the interventricular
foramen, which was patent at stage 19,
was closed at stage 20. A significant
growth in thickness of the myocardium
of both the atria and the ventricles oc-
curred from stage 19 to stage 21. This
was particularly noticeable in the portion
of the atria that would develop into the
musculi pectinati. The embryonic con-
nective tissue at the atrioventricular
sulcus was evident at stage 19 and, at
stage 21, it was seen descending along the
external surface of the ventricles.
STAFF ACTIVITIES
Among the symposia and conferences
in which various members of the staff
participated during the past year were
the following:
Sixth International Congress of Em-
bryology (Paris) ; Symposium on Cellu-
lar Senescence in vitro (Zinkovy, Czech-
oslovakia) ; Second Congress of the
National Academy of Medicine of Mexico
(Mexico City) ; Twenty-fourth Inter-
national Congress of Physiological Sci-
ences (Washington, D. C.) ; Park City
International Symposium on RNA in
Development (Park City, Utah) ; Sym-
posium on Fetal Growth and Develop-
ment (San Diego) ; Symposium in Ob-
DEPARTMENT OF EMBRYOLOGY
553
stetrics and Gynecology (San Francisco) ;
Conference on Reproductive Physiology
(Seattle) ; Fifteenth Cancer Retreat
(University of Michigan) ; Symposium
on Heterospecific Genome Interactions
(Philadelphia) ; Symposium on Com-
parative Physiology of the Heart (Han-
over, New Hampshire) ; Conference on
Conduction Development (Bethesda,
Maryland) ; Second Conference on Stud-
ies of Cellular Aging (Belmont, Mary-
land) .
Lectures were presented at a number
of campuses, including Emory Uni-
versity, Goucher College, Illinois Insti-
tute of Technology, Indiana University,
Morgan State College, Reed College,
State University of New York (Bing-
hamton) , the Universities of British Co-
lumbia, California (San Francisco),
Chicago, Connecticut, Florida, Illinois,
Massachusetts, Miami (Florida), Ore-
gon, Toledo, Washington, and Wiscon-
sin, and Wayne State University. Mem-
bers of the staff also spoke at a number
of hospitals and research centers, includ-
ing Baltimore City Hospitals, Beth Israel
Medical Center (New York) , and Wor-
cester Foundation for Experimental Bi-
ology.
Special presentations included the
Janet Baldwin Memorial Lecture at
Cornell University Medical School; the
First Victor E. Hall Annual Lecture at
the University of California (Los
Angeles) ; a lecture before La Sociedad
Venezolana de Puericultura y Pediatria
and El Departamento de Clinica Pedia-
tria y Puericultura of the Central Uni-
versity of Venezuela in Caracas; one
at the Centennial Program of Dalhousie
University Faculty of Medicine; the
Keynote Address at the Junior Sciences
and Humanities Symposium (Balti-
more) ; and a lecture at the dedication of
new facilities for the health sciences at
the University of Vermont.
Members of the group took part in
meetings of a number of learned socie-
ties, including, in addition to those al-
ready mentioned, the American Associa-
tion of Anatomists, American Chemical
Society, American College of Obsetri-
cians and Gynecologists, American Philo-
sophical Society, American Society of
Biological Chemists, American Society
for Cell Biology, Federation of American
Societies for Experimental Biology, Na-
tional Academy of Sciences, National
Society for Medical Research, Society
for Experimental Biology and Medicine,
and Society for Gynecologic Investiga-
tion.
Advisory and consultative services in-
cluded membership on the editorial
boards of Anales del Desarrollo, Devel-
opmental Biology, International Journal
of Cancer, Journal of Cell Biology, Jour-
nal of Embryology and Experimental
Morphology, Excerpta Medica (section
on Human Developmental Biology),
Current Topics in Developmental Biol-
ogy, and Quarterly Review of Biology.
Members of the staff continued to
serve on the University Science Develop-
ment Advisory Panel, National Science
Foundation; and the Visiting Commit-
tees of the Departments of Biology of
Harvard University, Massachusetts In-
stitute of Technology, State University
of New York (Buffalo), University of
Oregon, and University of Toledo. In
addition, service was rendered on Ad-
visory Committees of the Center for
Oral Health Research (University of
Pennsylvania) and the International In-
stitute for the Study of Human Repro-
duction (Columbia University).
Members of the staff also acted in
these capacities: Member of the Board
of Scientific Overseers, Jackson Labora-
tory ; Trustee, Marine Biological Labora-
tory ; Member of the Board of Scientific
Counselors, National Cancer Institute;
and Member of the Board of Directors,
Oak Ridge Associated Universities.
Other posts occupied by members of
the Department include the following:
in the American Association for the Ad-
vancement of Science, Committee on Sci-
ence in the Promotion of Human Welfare
and Newcomb Cleveland Prize Com-
554
CARNEGIE INSTITUTION
mittee; in the American Association of
Anatomists, Representative to Division
of Medical Sciences of the National
Research Council and Representative to
the National Society for Medical Re-
search; in the American Institute of Bio-
logical Sciences, Chairman of the Com-
mittee on Laboratory Animal Care,
Member, Public Responsibilities Com-
mittee and Council of Past Presidents;
in the American Society of Zoologists,
President-elect; and in the Society for
Developmental Biology, Member of
Executive Committee.
Formal teaching has been largely con-
fined to the Johns Hopkins Department
of Biology, but during the year lectures
were offered in other departments of the
University as well, among them Anat-
omy, Obstetrics and Gynecology, Patho-
biology and Pediatrics.
Other activities directed largely to-
ward teaching included the participation
of members of the Department in lectures
offered at high schools and junior high
schools, e.g. Dunbar High School (Balti-
more) and the Baltimore City-County
Science Seminars; and in the Embryol-
ogy Course at the Bermuda Biological
Station.
The Carnegie motion picture Utero-
placental Circulation in the Rhesus Mon-
key was shown to 22 audiences during
the period from November 1, 1967,
through June 30, 1969.
Seminars. The roster of speakers at
the seminars organized by the Depart-
ment to serve all those working in
developmental biology in the region
included David Epel (Stanford Univer-
sity) ; Chandler Fulton (Brandeis Uni-
versity) ; Joel Huberman (Stanford Uni-
versity) ; Tom Humphreys (University
of California, San Diego) ; Thomas Lentz
(Yale University) ; K. Marushige (Uni-
versity of British Columbia) ; Bruce
Nicklas (Duke University) ; Y. Nishi-
zuka (Kyoto University) ; A. Paes de
Carvalho (University of Rio de Janeiro) ;
Gordon Sato (Brandeis University) ;
Lauri Saxen (University of Helsinki) ;
Richard Sidman (Harvard Medical
School) ; J. E. Till (Ontario Cancer In-
stitute) ; and David Wolstenholme
(Kansas State University).
BIBLIOGRAPHY
Billingsley, L. M., see Boving, B. G.
Boving, B. G., Review of Ultrastructure of
Fertilization, by C. R. Austin. Science, 163,
1187-1188, 1969.
Boving, B. G., and Billingsley, L. M., Rat con-
ceptus spacing. Anat. Record, 163, 158, 1969.
Brown, D. D., see Green, H., Reeder, R. H.
Coon, H. G., and M. C. Weiss, A quantitative
comparison of spontaneous and virus-pro-
duced viable hybrids. Proc. Natl. Acad. Sci.,
62, 852-859, 1969.
Cooper, M. H., and R. O'Rahilly, The develop-
ment of the human heart at seven postovula-
tory weeks. Anat. Record, 163, 172, 1969.
Dawid, I. B., Cytoplasmic DNA in differentia-
tion and development. J. Animal Sci., 27,
Suppl. I, 61-69, 1968.
Dawid, I. B., and D. R. Wolstenholme, The
structure of frog oocyte mitochondrial DNA.
In Biochemical Aspects of the Biogenesis of
Mitochondria, E. C. Slater, J. M. Tager, S.
Papa, and E. Quagliariello, eds., Adriatica
Editrice, Bari, pp. 83-90, 1968.
Dawid, I. B., and D. R. Wolstenholme, Re-
naturation and hybridization studies with
mitochondrial DNA. Ibid., pp. 283-297.
Dawid, I. B., see also Wolstenholme, D. R.
DeHaan, R. L., Emergence of form and func-
tion in the embryonic heart. Develop. Biol.,
Suppl., 2, 208-250, 1968.
DeHaan, R. L., Guest Editorial — Congenital
heart disease: A plea for an experimental ap-
proach. New Engl. J. Med., 279, 44-45, 1968.
DeHaan, R. L., Review of Epithelial-Mesen-
chymal Interactions. Science, 162, 784, 1969.
DeHaan, R. L., and S. H. Gottlieb, The elec-
trical activity of embryonic chick heart cells
isolated in tissue culture singly or in inter-
connected cell sheets. J. Gen. Physiol., 52,
643-665, 1968.
DeHaan, R. L., see also Stalsberg, H.
Ebert, J. D., Preface I. In Dynamics of De-
velopment: Experiments and Inferences, by
Paul A. Weiss, Academic Press, New York,
pp. v-vi, 1968.
DEPARTMENT OF EMBRYOLOGY
555
Ebert, J. D., Discussion. In Symposium on
Molecular Aspects of Differentiation, J. Cell
Physiol., 72 (Suppl. 1), pp. 222-223; 227, 1968.
Ebert, J. D., Levels of control: A useful frame
of perception? In Current Topics in Develop-
mental Biology, vol. 3, A. A. Moscona and
A. Monroy, eds., Academic Press, New York,
xv-xxv, 1968.
Ebert, J. D., The Public Information Com-
mittee of the Jackson Laboratory: An Edi-
torial. J AX, 16, (4), 14-15, 1969.
Ebert, J. D., Review of Immunologic Defi-
ciency Diseases in Man, R. Good, ed., Medi-
cal Tribune, February 24, 1969.
Ebert, J. D., Review of Lymphocyte Stimula-
tion, by N. R. Ling. BioScience, 19, 376-377,
1969.
Ebert, J. D., Review of Cellular Aspects of
Developmental Pathology, by R. P. Bolande.
Quart. Rev. Biol, 44, 110, 1969.
Goldberg, B., see Green, H.
Gottlieb, S. H., see DeHaan, R. L.
Green, H., B. Goldberg, M. Schwartz, and
D. D. Brown, The synthesis of collagen dur-
ing the development of Xenopus laevis. De-
velop. Biol, 18, 391-400, 1968.
Harbert, G. M., C. B. Martin, Jr., and E. M.
Ramsey, Placenta extrachorialis in rhesus
monkeys. Anat. Record, 163, 195, 1969.
Kaltreider, D. F., see Misenhimer, H. R.
Manasek, F. J., Myocardial cell death in the
embryonic chick ventricle. J. Embryol. Exp.
Morphol, 21, 271-284, 1969.
Martin, C. B., Jr., see Harbert, G. M.
Misenhimer, H. R., and D. F. Kaltreider,
Preterm delivery of patients with decreased
glucose tolerance. Obstet. Gynecol., S3, 642-
646, 1969.
O'Rahilly, R., see Cooper, M. H.
Ramsey, E. M., Radioangiography of the pla-
centa. In Fetal Homeostasis, vol. III. Ralph
M. Wynn, ed., Appleton-Century -Crofts, New
York, N. Y., pp. 151-170, 1968.
Ramsey, E. M., Review of Reproduction in the
Female Mammal, G. E. Lamming and E. C.
Amoroso, eds., Plenum, New York; Butter-
worths, London, 1967 and Biology of Gesta-
tion, vol. I, The Maternal Organism. N. S.
Assali, ed., Academic Press, New York, 1968.
Science, 162, 447-448, 1968.
Ramsey, E. M., see also Harbert, G. M.
Reeder, R. H., and D. D. Brown, An assay for
the control of ribosomal RNA gene transcrip-
tion in vitro. Federation Proc, 28, 349, 1969.
Ristow, H., see Wolstenholme, D. R.
Schwartz, M. C, see Green, H.
Stalsberg, H., The origin of heart asymmetry:
right and left contributions to the early
chick embryo heart. Develop. Biol., 19, 109-
127, 1969.
Stalsberg, H., and R. L. DeHaan, Endodermal
movements during foregut formation in the
chick embryo. Develop. Biol., 18, 198-215,
1968.
Stalsberg, H., and R. L. DeHaan, The pre-
cardiac areas and formation of the tubular
heart in the chick embryo. Develop. Biol.,
19, 128-159, 1969.
Wolstenholme, D. R., and I. B. Dawid, A size
difference between the mitochondrial DNA
molecules of urodele and anuran Amphibia.
/. Cell Biol., 39, 222-228, 1968.
Wolstenholme, D. R., I. B. Dawid, and H.
Ristow, An electron microscope study of
DNA molecules from Chironomus tentans
and Chironomus thummi. Genetics, 60, 759-
770, 1968.
Wolstenholme, D. R., see also Dawid, I. B.
PERSONNEL
Year Ended June 30, 1969
(including those whose services began or ended during the year)
Research Staff
Bent G. Boving, Physiology
Donald D. Brown, Biochemistry
Igor B. Dawid, Biochemistry
Robert L. DeHaan, Experimental Em-
bryology
James D. Ebert, Director
Elizabeth M. Ramsey, Placentology and
Pathology
Assistant Investigator
Robert J. Hay
Research Associates (extramural)
Louis B. Flexner, Philadelphia, Pa.
Arthur T. Hertig, Boston, Mass.
Irwin R. Konigsberg, Charlottesville, Va.
Samuel R. M. Reynolds, Chicago, 111.
Fellows
Hay den G. Coon, Fellow of Carnegie In-
stitution
Douglas M. Fambrough,1 Fellow of Car-
negie Institution
1 Appointed Staff Member beginning July 1,
1969.
556
CARNEGIE INSTITUTION
Masako Fukada, Fellow of Carnegie In-
stitution
Harold Kasinsky, Fellow of U. S. Public
Health Service
Harold R. Misenhimer, Fellow of Carnegie
Institution
Ronan O'Rahilly, Fellow of Carnegie Insti-
tution
Kenjiro Ozato,2 Fellow of Carnegie Institu-
tion
Ronald H. Reeder,1 Fellow of the Helen
Hay Whitney Foundation
Yoshiaki Suzuki, Fellow of Carnegie Insti-
tution
Ronald F. Swanson, Fellow of U. S. Public
Health Service
Students
John Chase, Graduate, Biology, Johns
Hopkins University
John 0. Dunning, Graduate, Biology,
Johns Hopkins University
L. D. Frye, Graduate, Johns Hopkins Uni-
versity
H. Criss Hartzell, Jr., Graduate, Johns
Hopkins University
G. B. Pogoriler, Graduate, Johns Hopkins
University
Iris S. Polinger, Graduate, Biology, Johns
Hopkins University
M. C. Rechsteiner, Graduate, Johns Hop-
kins University
E. W. Schaefer, Undergraduate, Biology,
Johns Hopkins University
Merry C. Schwartz, Predoctoral Fellow,
National Science Foundation, Johns
Hopkins University
R. Stern, Graduate, Johns Hopkins Uni-
versity
Thomas G. Storch, Johns Hopkins Medical
School
Pieter C. Wensink, Graduate, Johns Hop-
kins University
Visiting Investigators
John Bonica, Seattle, Wash.
Louis E. DeLanney, Ithaca, N. Y.
Martin W. Donner, Baltimore, Md.
Marlene Eng, Seattle, Wash.
Raymond F. Gasser, New Orleans, La.
Daniel Goor, New York, N. Y.
Peter Gruenwald, Philadelphia, Pa.
1 Appointed Staff Member beginning July 1,
1969.
G. M. Harbert, Charlottesville, Va.
Alberto Hodari, Detroit, Mich.
Paul Hodgkinson, Detroit, Mich.
J. E. Jirasek, Prague, Czechoslovakia
Maurice Lambiotte, Bellevue, France
Lewis N. Lukens, Middletown, Conn.
F. J. Manasek, Boston, Mass.
S. I. Margulies, Baltimore, Md.
C. B. Martin, Jr., Augusta, Ga.
Dorcas H. Padget, Baltimore, Md.
Fernando Porturas, Lima, Peru
Glenn C. Rosenquist, Baltimore, Md.
Clerical and Technical Staff
James E. Abbott, Recorder
Grace M. Andrews, Secretary-Receptionist
Mary N. Barton, Librarian (part time)
James Blackwell, Custodian
William J. Cleary, Recorder
Diane M. Dombrowski, Technician
William H. Duncan, Senior Technician
Ernestine V. Flemmings, Laboratory
Helper
Richard D. Grill, Photographer
Ernest Harper, Chief Custodian
Virginia Hicks, Laboratory Helper
Eddie Jordan, Technician
Elizabeth Legum, Technician
Edna G. Lichtenstein, Secretary
Alice H. Mabin, Laboratory Helper
Kathleen Magness, Technician
Thomas F. Malooly, Business Manager
Juanita Mandy, Laboratory Helper
Arlyne Musselman, Senior Technician
John Pazdernik, Building Engineer
Betty Lou Phebus, Bookkeeper-Clerk
Conrad Pott, Custodian
Margaret J. Proctor, Secretary
Martha Rebbert, Technician
Arthur G. Rever,3 Fiscal Officer
Bessie Smith, Laboratory Helper
Delores Somerville, Technician
SuatLu Toh, Technician
Isabelle P. Williams, Technician
Leroy Williams, Custodian
David Wilmoth, Assistant Recorder
John L. Wiser, Machinist
Student Assistants
Lynn Billingsley, University of Maryland
Jeff Sollins, Drew University
Roberta M. Truitt, Morgan State College
2 Resigned after only four months because of
family illness.
3 Retired, June 30, 1969.
PLATES
Plate 1 Department oj Embryology
•
w
•
Plate 1. Autoradiogram of a two-dimensional chromatogram of the 5'-(3-P)-deoxyribonucleo-
tides isolated from hydrolysates of the somatic rDNA (left) and the extra copies of rDNA in
oocytes (right). The lack of complementarity seen in the nucleotides from extra rDNA is
due to unequal pool sizes during labeling and does not give an exact base composition of
the DNA. A, deoxyadenylic acid; G, deoxyguanylic acid; T, deoxythymidylic acid; C, deoxy-
cytidylic acid; M, 5-methyl deoxycytidylic acid.
Plate
Department oj Embryology
A B
Plate 2. Coelectrophoresis of Xenopus Fraction C proteins with arginine-rich histone IV
from pea. (A) Pea histone IV (B) Fraction C (C) Pea IV + Fraction C. Bands near the
top of gel are bovine serum albumin protein which was added as a marker.
Plate 3. (A) Myotube isolated as described in text. Fixed with glutaraldehyde 16 hours after
isolation. Phase contrast, X 250. (B) Myotube of a culture infected with 5 X 105 FFU of RSV
immediately after DA seeding. Pulsed beginning 67 hours after infection. Note apparently
more dense labeling in the mononucleated cells. Phase contrast, X 250. (C) Sister culture to B.
Phase contrast, X 250. (D) Myoblasts, which had been infected with RSV 45 hours earlier,
were added to DA muscle cultures 96 hours after seeding. They were pulsed with 14C-thymidine
beginning at 22 hours after addition of infected myoblasts. Note that the grains due to "C
are not localized as is the case with 3H labeling. Phase contrast, X 250. (E) Sister culture to D.
In this case the infected myoblasts were labeled, as described in the text, with 3H-thymidine
before being added to the muscle culture. Note secondary labeling in nuclei adjacent to
heavily labeled nuclei from infected myoblast cultures (arrow) . Phase contrast, X 250.
(F) Muscle culture to which excess thymidine was added 24 hours after DA seeding. The
culture was fixed with glutaraldehyde 56 hours later. Phase contrast, X 100. (G) Sister culture
to F, fixed after an additional 72 hours (a total of 152 hours after DA seeding). Phase
contrast, X 100.
Plate 3
Department of Embryology
-*<•
Plate 4
Department, of Embryology
: f.
■\
.-.«
• * *
Plato 4. A portion of a ventricular myocyte from the heart of an 8-day-old chick embryo
is shown in this electron micrograph. A large part of the cytoplasm is filled with glycogen
granules and cardiac muscle cells of this age embryo characteristically contain large pools of
this polysaccharide. In this cell, myofibrils do not appear to be packed in an orderly fashion.
Several fibrils are tangcntially sectioned, whereas two small bundles (F) are cut in cross section.
The Golgi region is prominent and the arrows mark two of the many putative secretory
granules seen in this cell. X 28,600.
Plate 5
Plate 5. Ventricular myocytes of newly hatched chicks still demonstrate large amounts
of glycogen, especially within the sarcoplasmic core, a portion of which is shown in this electron
micrograph. Mitochondria and lipid (L) droplets abound in this region. Two electron-dense,
membrane-bound granules are seen (arrows) within the Golgi system (G). A developing inter-
calated disc is seen in the upper left. X 29,700.
Plate 6
Department oj Embryology
/■
#
Plate 6. Typical cilia are seen projecting from the apical surface of a small percentage of
cultured Xenopus kidney cells. A prominent ciliary rootlet is present (arrow) and both
members of a diplosome are visible near the bottom of the plate. In this electron micrograph
portions of two cells are visible and a prominent space separates their lateral surfaces. X 46,000.
Plati
Department oj Embryology
Plate 7. Portions of several cultured Xenopus kidney cells are seen in this low magnification
(X 27,000) electron micrograph. The monolayer of low columnar epithelial cells are joined
near their apical surfaces by typical apical junctional complexes (arrow). Numerous microvilli
project into the large intercellular spaces between the lateral cell boundaries. The basal surface
is in close contact with the plastic culture dish (P) . These cells contain electron-dense inclu-
sions and their cytoplasmic matrix consists largely of ribosomes, both free and membrane
bound. Scattered mitochondria are present and a large Golgi system (G) is seen to the right
of the nucleus. The electron microscope does not reveal the presence of an extracellular matrix.
Plate 8
Department of Embryology
J
>.
/ f
W, *
* v
« 0
*? n. < • * * v '- i -
::_•-...
Plate 8. (A) At higher magnification the apical microvilli demonstrate a filamentous material
similar in appearance to antennulae microvillares. Similar projections are seen along the entire
apical surface. The microvilli along the lateral surface (see Plate 7) are devoid of this
substance, suggesting a functional difference. X 71,000. (B) The basal surfaces of cultured
Xenopus kidney cells are separated from the plastic culture substrate (P) by a narrow space.
Occasionally small amounts of material can be demonstrated in this space (arrows). Wherever
the cells demonstrate this close relationship to the plastic substrate they appear to develop
a cytoplasmic specialization characterized by parallel filaments. In many respects this basal
web (BW) appears similar to the terminal web of many epithelia. These cultured cells do not
generally contain a well-defined cortex, and the basal web may be a specific response to the
culture substratum. No specialized attachments to the substrate have ever been seen in these
cells. X 90,000.
Plate 9
Department of Embryology
o
Plate 9. (A) Cultured Buffalo rat liver cells form an epithelial sheet that is often several cells
thick. The apical surface has numerous microvilli, and the basal surface is widely separated
from the plastic substrate of the culture dish by a layer of extracellular material (ecm) . X 9,250.
(B) Under higher magnification (X 31,000) most of the extracellular material between the
culture dish (P) and the cell layer appears amorphous (AM). Occasional clumps of electron-
dense material are also present. In addition, a flocculent material, similar in appearance to
the material comprising basal laminae can also be demonstrated (arrows). Note the prominent
granular endoplasmic reticulum and the large glycogen accumulations (G) within the cells.
(C) Under higher magnification (X 150,000) the extremely dense extracellular ^ material is.
resolved into parallel repeating subunits with a separation of approximately 45 A,
Plate 10
Department oj Embryology
f.,r:;X£
B
Plate 10. (A) Rat uterus with presumptive implantation sites marked by intravenously
injected Evans blue; 4.5 days after mating. (B) Rat uterus with positions of conceptuses
marked by slight swellings. Spacing is more even than random; 5.5 days after mating. (C) Rat
uterus with conceptuses very obvious as swellings and translucent regions. With numerous
conceptuses, there may be little or no spacing between them after they reach this size. Spacing
approaches equidistance; 7.5 days after mating. (D) Rat uterus with pronounced swellings
from conceptuses. With few (upper horn) there may still be space between them and no
spacing by crowding. With more conceptuses (lower horn) the spacing by crowding begins
where the crowding is most severe; 13.5 days after mating.
Department of Plant Biology
Stanford, California
C. Stacy French
Director
Contents
Introduction 561
Biochemical Investigations 566
Studies on fractions of chlorophyll complexes from a variety of plants .... 566
Absorption and fluorescence of chlorophyllide a in vivo 570
Photosystem 1 and 2 particles from leaves of diverse ages 572
An action spectrum for methyl viologen reduction by fractionated spinach
chloroplasts 574
The forms of chlorophyll a in fractions of chloroplasts from different sources . . 578
A comparative study of the light-induced carotenoid change and fluorescence in
the chIorophyll-6-less alga Botrydiopsis alpina (Xanthophyceae) .... 587
The effect of ultraviolet irradiation on the carotenoid change, electron transport,
and photosynthesis of Botrydiopsis alpina 595
Electron transport and degradation of chloroplasts by hydrolytic enzymes and
ultraviolet irradiation . 598
Effects of A'-methylphenazonium methosulfate and pyocyanine on delayed light
emission in Chlorella cells and spinach chloroplasts 603
A test of fiber optics for fluorescence spectroscopy 607
Use of the ACME computer for analysis of real-time data 608
Experimental Taxonomy Investigations 609
The Mimulus investigations 609
Growth, photosynthetic, and biochemical responses of contrasting Mimulus clones
to light intensity and temperature 614
Comparative studies of Atriplex species with and without /3-carboxylation photo-
synthesis and their first-generation hybrid 620
Leaf factors affecting the rate of light-saturated photosynthesis in ecotypes of
Solarium dulcamara 633
Application of a new 02 sensing device to measurements of higher plant photo-
synthesis 636
Intercontinental crosses in Solidago 640
Vegetation of the Harvey Monroe Hall Natural Area 643
Staff Activities 644
Bibliography 645
Speeches 646
Personnel 648
Carnegie Institution Year Book 68, 1968^1969
INTRODUCTION
In recent years photosynthesis in-
vestigations have centered on the kinetic
relations between the substances that
make possible the flow of electrons from
water to those carbon compounds whose
reduction is the significant function of
the whole process. These oxido-reduction
reactions are coupled to phosphorylation
systems that also store chemical energy
as adenosine triphosphate. Thus by a
linked series of complex reactions carbon
dioxide is turned into the required or-
ganic components of living matter, and
power for their further interconversion
is provided in usable form.
The main tide of scientific effort in the
study of photosynthesis flows increas-
ingly toward the more precise refinement
of a theoretical picture describing the
interrelations between the pigments, en-
zymes, and intermediate compounds that
make up the photosynthetic system. The
drawing power of this tide had for some
years left an ebb in the field of knowledge
from which the main tide originated.
This was the descriptive and comparative
type of plant physiology through which
the general significance and biological
function of photosynthesis became ap-
parent over a century ago. Such types of
investigation have now been revived by
many vigorous groups.
Experimental taxonomy. One aspect
of the work of the Experimental Taxon-
omy Group of the Department might
now be described as an effort to bring the
advances in the detailed understanding
of the mechanisms of photosynthesis to
bear on explanations for the diverse
physiology of contrasting kinds of plants.
To apply effectively the relevant parts of
the vast body of intricate concepts about
photosynthesis to broader biological
problems — such as a determination of
the physiological basis of adaptation and
of natural selection and evolution in
plants — almost requires that investiga-
tors themselves be active contributors
to the main body of theoretical progress
as well as users of that new information
for the clarification of fundamental
ecological questions. A strong collabora-
tive effort on these lines has been de-
veloped by Drs. Bjorkman, Hiesey, and
Nobs with several members of the Stan-
ford faculty and their graduate students.
In the Experimental Taxonomy Sec-
tion, this year's activities include con-
tinuing studies at the altitudinal trans-
plant stations at Stanford, Mather, and
Timberline as well as intensive labora-
tory investigations directed toward fur-
ther penetration into unknown mecha-
nisms underlying natural selection and
plant evolution.
In 1947 the Experimental Taxonomy
Group met with university colleagues
having similar interests at the Depart-
ment Laboratory and at the mountain
stations. The purpose of this conference
was to select the type of plant material
best suited for long-term studies of the
adaptation mechanisms of plants to con-
trasting environments. The resulting
choice, the Erythranthe group of Mimu-
lus (monkey flower), has amply proved
its anticipated value as an experimental
group of species for such investigations.
Cross-fertilization experiments have been
combined with studies of growth char-
acteristics both at the Department's
three field stations and in controlled en-
vironments. Field work has been cor-
related to laboratory measurements of
the photosynthetic characteristics of
first-, second-, and third-generation
progeny. Each generation was studied
for several years.
A strong correlation was found be-
tween the inheritance of certain morpho-
logical characters and the ability to
survive in specific environments. The
action of combinations of genes caused
nearly all of the significant characters to
561
562
CARNEGIE INSTITUTION
be inherited in groups, that is, a purely
random assortment of characters did not
take place. Hybrid vigor was found to
depend as much upon the environment in
which it was tested as upon the genetic
inheritance of the plants. The genetic re-
combinations of some of the various steps
of the photosynthetic process suggest the
mechanisms underlying the ability of
hybrids to flourish in contrasting en-
vironments.
This long series of studies on the basic
question of biological quality, as de-
termined by the interplay of genetic and
of environmental influences, is being pre-
pared for publication as an Institution
monograph. This fifth volume in the
series Experimental Studies on the
Nature of Species appropriately marks
Dr. William M. Hiesey's retirement after
forty-four years devoted to basic re-
search on this problem of the compara-
tive influences of environment and of
heredity on the performance of an indi-
vidual.
Many of the questions arising from the
work of the Experimental Taxonomy
Group under Dr. Clausen's and Dr.
Hiesey's leadership can now be investi-
gated in a more definitive manner than
was possible at the time their significance
was first perceived. As Dr. Bjorkman
now has assumed responsibility for ex-
perimental taxonomy work at the De-
partment, the biochemical basis for
physiological characteristics of plant
adaptation to contrasting environments
is receiving greater emphasis. Thus there
is an increasing amount of collaboration,
and of similarity in the experimental
techniques, of the two groups in the De-
partment, although their objectives re-
main distinct.
Recently Dr. Bjorkman and Mr.
Eckard Gauhl, an Institution Research
Fellow from Professor Egle's laboratory
at Frankfurt, have been able to measure
simultaneously with high precision not
only the rates of carbon dioxide uptake
and water vapor release, but also the rate
of oxygen evolution during photosynthe-
sis in higher plants. Such measurements
are made possible by the development
of new equipment and are of special
value in the current comparative studies
of contrasting ecological races and
species.
In the growing field of comparative
studies of photosynthesis in plants from
ecologically diverse environments, recent
developments have revealed that photo-
synthetic differentiation in higher plants
is not limited only to differences in the
capacities of component steps of photo-
synthesis, but that differences in the
biochemical pathways of the process also
exist. During the past few years it has
been established that certain grass spe-
cies, whose main distribution is in tropi-
cal regions, possess a different pathway
for photosynthetic carbon dioxide fixa-
tion than do plants from temperate re-
gions. Members of at least three di-
cotyledonous families have also been
found to possess this newly discovered
pathway. In the saltbush genus Atriplex
some members have this pathway,
whereas others do not.
The discovery of different C02-fixation
pathways in photosynthesis has opened
up an exciting field of investigation for
those concerned with the biochemical and
physiological basis of adaptation. Dr.
Bjorkman and Mr. Gauhl have under-
taken a comparative study of two Atri-
plex species of differing C02-fixation
pathways. Their work is an integral
part of a broad study of mechanisms of
photosynthetic adaptation to environ-
mental factors, particularly with regard
to temperature. One of these Atriplex
species, A. patula, which occurs mainly
in cool coastal areas, fixes C02 by the
normal reductive pentose phosphate
pathway, whereas the other species, A.
rosea, which grows primarily in hot,
semiarid habitats, fixes C02 by the more
recently discovered C4-dicarboxylic acid
pathway. The two species differ with
regard to certain key photosynthetic en-
zymes, and they have profoundly differ-
ent photosynthetic characteristics. For
DEPARTMENT OF PLANT BIOLOGY
563
example, the strong inhibitory effect of
oxygen on photosynthetic C02 fixation in
normal air, which appears to be a wide-
spread phenomenon among higher plants
from temperate climates, is present in
A. patula but absent in A. rosea. The two
species also differ markedly in their in-
ternal leaf structure. Other investigators
have linked these combinations of differ-
ences to contrasts in plants of tropical
and temperate climates, and these char-
acteristics are thought to represent
fundamental differences in evolutionary
steps.
That these differences occur within
a single genus makes possible compara-
tive studies of functional adaptability
that are more pertinent than would be
the case if they occurred only in widely
separated taxa. Still more important,
however, the inheritance of the function,
and biochemistry of the various com-
ponents by which the two species differ,
may now be studied. Recently, Dr. Nobs
has been able to hybridize these two
species of Atriplex. First-generation hy-
brids are now being analyzed by Dr.
Bjorkman with regard to their photo-
synthetic and biochemical character-
istics. Dr. John Boynton, an Institution
Research Fellow from Duke University,
is making a study of cell and chloroplast
fine structure of the Fi-hybrid compared
with that of the parental species. It is
hoped that second-generation progeny
can also be obtained, a development that
would open up new opportunities for
genetic studies of the molecular and
physiological basis of natural selection
and speciation.
Mr. Gauhl has also completed a two-
year study on contrasting ecological races
of the European bittersweet, Solarium
dulcamara, in which distinct inherited
differences in photosynthetic character-
istics were demonstrated.
The relationships between certain
North American and European species of
goldenrod {Solidago) have long been a
subject of speculation among botanists.
The physiological studies on sun and
shade races of European forms of Soli-
dago virgaurea by Drs. Bjorkman and
Holmgren have created new interest in
ascertaining these relationships. Results
from hybridizations, most of which were
made by Dr. Nobs, now clearly demon-
strate that the European members and
the North American counterparts (re-
ferable to jS. multiradiata) are forms
which have evolved moderate genetic
barriers to intercrossing. Within either
group, highly diverse ecological races are
completely interfertile.
Biochemical investigations. The Bio-
chemical Investigations Group continues
to center most of its interest on the func-
tional relationships between photosyn-
thetic pigments and their associated en-
zymes in the two photosy stems. Each of
these systems contains a mixture of pig-
ments and enzymes in the form of par-
ticles. Many laboratories are trying to
improve techniques for the separation of
the two photosystems of chloroplasts.
Thorough resolution of the two requires
both adequate disintegration methods
and sharp separation procedures. The
primary test for successful fractionation
of chloroplasts into the two groups of
particles involved in system 1 and sys-
tem 2 is the ratio of the rates of two
chemical reactions, which are specific for
one or the other system. The pigment
composition of the systems is also differ-
ent. In general there is more chlorophyll
b and more of a "Ca 670" form of chloro-
phyll a in system 2 than in system 1.
In system 1 a "Ca 680" form of chloro-
phyll a predominates, and system 1 also
contains some of the forms of chloro-
phyll that have still longer wavelength
absorption maxima.
We are trying to analyze the absorp-
tion spectra of chloroplast fractions in
order to identify the specific chlorophyll
a complexes associated with each system.
Different species of algae have greatly
varying relative proportions of the dif-
ferent forms of chlorophyll. Furthermore,
the system-1 and system-2 fractions of
many chloroplasts show striking con-
564
CARNEGIE INSTITUTION
trasts in their absorption spectra. Dr.
Brown has separated fractions of chloro-
phyll-containing particles from a variety
of plants and has measured both their
absorption and fluorescence spectra at
low temperature. The collection and in-
terpretation of these data, and of data re-
sulting from older lines of investigation,
are still in progress. It is expected that
comparisons of a comprehensive series of
spectra resolved by digital computer
methods will show whether the spectra
for the different individual forms of
chlorophyll are alike or different in the
corresponding fractions of all species.
In determining whether all the chloro-
phyll in one fraction is actually a func-
tional part of that system, it is essential
to compare the absorption spectra of
both fractions with the action spectra for
the two chemical reactions of each frac-
tion. Action spectra, the relative effec-
tiveness of different wavelengths in caus-
ing a specific chemical effect, match the
absorption spectra of only the photo-
chemically active pigments in the mix-
ture. Absorption spectra, however, show
all the pigments present, even though
some of them may not be functional
for the systems tested. It is therefore very
important to learn how to measure action
spectra with high precision for system-1
and system-2 activity of fractions of
disintegrated chloroplasts.
Action spectra for oxygen exchange
in whole cells have been measured for
some time with adequate accuracy, and
the results can be plotted automatically,
like absorption spectra, with moderately
satisfactory results. However, for the
partial reactions associated with the
separate steps of photosynthesis in
chloroplast fractions, the precision so far
attainable is lamentable, and the band
widths of the monochromatic light for
action spectroscopy are about ten times
the routine width for absorption spectros-
copy.
In an effort to improve this situation
Dr. Eckhard Loos, an Institution Re-
search Fellow from Munich, has made
a study of ways to improve measure-
ments of action spectra for chloroplast
fractions. So far his work has been on
photosystem 1 as determined by the pho-
tochemical reduction of the dye methyl
viologen. Initially attempts were made to
introduce a controlled oxygen leak into
the system in such a way as to balance
the reduction of the dye by the photo-
chemical reaction. The intensities needed
at different wavelengths to maintain a
constant concentration of reduced dye
would reflect the relative photochemical
action of each wavelength. Such an ar-
rangement would have made automatic
plotting possible. There were, however,
difficulties with the oxygen leak sufficient
to make this approach impractical at
the present time.
The same dye reduction system was
therefore used in a sealed vessel for
point-by-point measurements. The opti-
mum concentrations of the critical com-
ponents of the reaction mixture were
determined. The system as worked out
gives easily measurable rates at low light
intensities. With a high pressure mercury
lamp, monochromator slits giving a half-
band width of 1.5 nm can be used. The
reproducibility of rate determinations,
however, is still inadequate. The pre-
liminary results of Dr. Loos' work have
shown close agreement between the ac-
tion and absorption spectra of system-1
particles from spinach chloroplasts.
Dr. Zdenak Sestak, a Visiting In-
vestigator from Prague, followed the
changes in the relative amounts of sys-
tem- 1 and system-2 pigments in develop-
ing leaves. In young radish leaves he
found about 25 percent of the chlorophyll
to be in system-1 particles while in older
leaves only 15 percent was in system 1.
Young leaves are therefore preferable
for preparation of system-1 fractions.
Several mild treatments, such as gentle
heating, ultraviolet exposure, and incuba-
tion with enzymes, disrupt the "Ca 680"
form of chlorophyll responsible for sys-
tem-1 photochemistry and change it to a
form with a shorter wavelength peak.
DEPARTMENT OF PLANT BIOLOGY
565
Similar treatments that reduce the pho-
tochemical activity of system 2 in spin-
ach chloroplasts have been investigated
by Dr. Kenneth Mantai, a Carnegie
Corporation Fellow who came to us from
Professor Bishop's laboratory at Oregon
State University. The common basis for
the effects of ultraviolet radiation and
the effects of treatments by destructive
enzymes is believed to be the disruption
of the structural unit comprising the pig-
ment-enzyme complex that is specific for
the functioning of system 2 in the chloro-
plasts.
The energy of a light quantum ab-
sorbed by a chlorophyll molecule is not
immediately used for making chemical
changes but instead is passed on through
many chlorophyll molecules until it ar-
rives at a particular reaction center. All
the chlorophyll molecules, acting to-
gether as an antenna to catch light
quanta for one reaction center, consti-
tute a photosynthetic unit. Emerson and
Arnold originally determined the size of
this unit by dividing the number of
chlorophyll molecules in a sample of
algae by the number of oxygen molecules
the algae could produce from a single
flash of bright light.
The same concept can be applied to
groups of photosynthetic units whose
products may depend on a single enzyme
for further processing. Thus each pig-
ment system can be thought of as a small
group of chlorophyll molecules feeding
energy to a particular reaction center,
while the products from several such cen-
ters are serviced by a single enzyme
molecule, which action defines a larger
composite unit. The size of this larger
unit can be determined by testing
whether the action of a single molecule
of an enzyme poison can render the en-
zyme molecule ineffective.
A somewhat similar experiment was
done this year by Dr. Lars Olof Bjorn,
a Visiting Investigator from Lund, who
calculated a photosynthetic unit of about
105 chlorophyll molecules. This result
was obtained from the stimulating effect
of phenazine methosulfate on the slow
emission of delayed light from cells fol-
lowing the activation of photosystem 1
by far-red light. The size of the func-
tional unit so measured is approximately
that of the morphological unit called a
thylacoid that is recognizable in electron-
microscope photographs of chloroplasts.
The connections to two large com-
puters at Stanford, described last year by
Dr. David Fork, have been used exten-
sively, and a Dataphone line to the IBM
360/67 Computer has been added. The
effective use of these facilities has been
made possible by a grant from the Na-
tional Science Foundation (No. GB 8630)
for "Pigment-Enzyme Interactions in the
Electron-Transport Mechanism of Pho-
tosynthesis." This grant gives our work
on the subject far greater scope than
could be managed on the Department
budget alone. In fact, the application of
computer analysis to a wide variety of
comparable chlorophyll spectra is the
essential difference between one aspect
of the present project and the somewhat
similar, but very limited, approach to the
problem that we have made in the past.
Our experience in applying for this grant
has, however, made clear the extreme im-
portance of flexible funds that can be
appropriated without delay. Without the
interim support of the Institution to pay
for computer use during the grant pro-
cessing period, a severe loss of momen-
tum and of investigators' time would
have occurred. In addition to serving
their computational purposes, the com-
puters have been a means of reducing the
secretarial work of manuscript revision
and of handling our reprint distribution
list.
The rate of publication on photosyn-
thesis, like the rate of publication in all
fields of science, has increased so much
that each scientist must continually nar-
row and redefine the limits of his spe-
cialty. Because of the quantity of pub-
lished work, the value of good review
articles is now far greater than that of
all but a very few original "contribu-
566
CARNEGIE INSTITUTION
tions" to the subject. The important pub-
lic service of the Kettering Laboratory
and of a Japanese group in preparing and
circulating lists of titles of papers on
photosynthesis and related matters has
made it possible at least to be aware of
work relevant to one's current enter-
prises. Reading even a reasonable frac-
tion of the important papers is already
impossible. There are no longer any ex-
perts on the whole subject of photo-
synthesis.
In 1965 we started a cooperative card-
file system to list papers of particular
interest under 75 subject headings. Each
card is punched for needle selection by
several subject headings, by author, and
by laboratory. The designation of papers
for card listing requires only a few
cryptic symbols on the journal or on the
reprint itself made by the interested
scientist. The whole operation is handled
by the Department secretary. This ap-
parently adequate and simple system has
in four years produced so many cards
that the selection of those in a desired
category is approaching the limit of
practicality.
We see no satisfactory solution to the
problem of literature listing and search-
ing that can be carried out efficiently
by a small group of research workers,
even with complete secretarial support.
Cost and programming problems seem to
make computer use for literature search-
ing an unrealistic approach for a single
laboratory. Some sort of a centralized
computer selection and listing system
serving the entire community of photo-
synthesis workers seems to be an eventual
necessity. However, the practical prob-
lems of interlaboratory agreement on
organization of the system and on meth-
ods for its efficient use are serious even
for the literature of photosynthesis. A
greater difficulty than incomplete listing
will be the danger of swamping the in-
terrogator with information only par-
tially relevant to his immediate concerns.
The purpose of a useful literature
search system is to go beyond the title
or abstract in order to retrieve buried
information about specific findings and
experimental techniques. A central com-
puter could perhaps answer an inquiry
by searching its internally stored library
and reporting only a reference and page
listing of the desired information that
would already be in the worker's own
library. Presumably we will have to wait
until such systems have been developed
for other types of scientific work before
it would be reasonable to attempt their
use for our subject. It would, of course,
be useful if some group of enterprising
computerized-library specialists could be
induced to use the publications on photo-
synthesis for developing a system to
search scientific literature.
BIOCHEMICAL INVESTIGATIONS
Studies on Fractions of Chlorophyll
Complexes from a Variety of Plants
J. S. Brown
In order to study the various forms of
chlorophyll, the forms should first be
separated. Detergents have been used for
this purpose for several years, but in
using them there is the disadvantage that
the detergent may adhere to the chloro-
phyll-lipoprotein complexes, modify the
spectra of the material, and complicate
further analysis. Therefore the nondeter-
gent, physical method of fractionation
devised last year by J.-M. and M.-R.
Michel is especially valuable (Year Book
67, p. 508). Briefly, the procedure con-
sists of disintegrating the chloroplasts or
algae suspended in a KCl-Tricine buffer
with the French press, layering the
broken material on a sucrose density-
gradient, and centrifuging the layered
material for 30-60 minutes to separate
the two kinds of chlorophyll-containing
particles.
DEPARTMENT OF PLANT BIOLOGY
567
The light fraction-1 particles are simi-
lar to the system- 1 particles separated by
detergent fractionation procedures. They
show relatively more long wavelength
absorption and fluorescence and have a
lower fluorescence yield per chlorophyll
than the denser particles in fraction 2.
These two kinds of particles were ob-
tained from several higher plants and
algae (Year Book 67, p. 516).
This year further experiments have
been performed to study some parameters
of the procedure itself: to fractionate
non-green algae, including the red alga
Porphyridium, the diatom Phaeodacty-
lum, and three blue-green algae, Ana-
cystis, Anabaena and Plectonema; and
to compare the absorption and fluores-
cence of the various pigmented particles.
The effect of mild heating and of trypsin
or porcine pancreatic lipase digestion on
the absorption of spinach particles was
also investigated.
The way in which the algae were grown
and harvested, and the way the chloro-
plasts were prepared, apparently had
little or no effect upon the subsequent
fractionation. A buffer of 0.05 M K2
HPO4-KH0PO4 at pB. 8 has proved to
be as suitable as the Tris or Tricine used
previously.
For the experiments reported here the
algae were suspended in 0.3 M KC1, 0.05
M Tricine, pH 8, and forced through the
needle valve three or more times. Since
the amount of breakage by the needle
valve was low with certain algae, we
tried the Braun "MSK" mechanical cell
homogenizer. Rapid shaking of a dense
algal suspension in the same buffer as
above with glass beads 0.25-0.30 mm in
diameter for 2 minutes was sufficient to
break practically all of the cells. We
have not yet standardized this breaking
method completely, but if conditions such
as the ratio of cells to beads and the
temperature during shaking are optimal,
this homogenate, after spinning in the
sucrose gradient, will yield the same frac-
tions as the material broken by the
needle valve. Cells of Scenedesmus, Por-
phyridium, and Anacystis have been
successfully fractionated after disinte-
gration by the MSK homogenizer.
Whether the bands in the sucrose
gradient contain different kinds of
chlorophyll particles has been deter-
mined by at least one of the following
spectroscopic criteria : low-temperature
absorption or fluorescence-emission spec-
tra, and relative fluorescence yields of the
chlorophyll.
Table 1 shows the relative fluorescence
yields of chlorophyll a in fractions of
chloroplasts and algae studied since those
listed in Table 9, Year Book 67, p. 518.
These yields were determined by the
same method as before, except that the
concentration of chlorophyll a alone has
been used in the current calculations in
order to compare algae that lack chloro-
phyll b.
TABLE 1. Relative Fluorescence Yield of Chlorophyll a in Fractions 1
and 2 at 20 °C and the Long- Wavelength Emission Maximum of
Fraction 1 at — 196°C
Fluorescence
Plant Material
Fluorescence Yield
Peak
Fraction 1
Fraction 2
Position, nm
Spinach
22
7.1
734
Atriplex semibaccata
0.72
2.2
735
Chlamydomonas rheinhardii
2.9
5.9
711
Scenedesmus obliquus
5.0
9.2
720
Botrydiopsis alpina
1.4
2.5
715
Phaeodactylum tricornutum
1.9
9.6
No peak
Anacystis nidulans
0.54
715
Anabaena cylindrica
0.91
726
Plectonema boryanum
024
728
568
CARNEGIE INSTITUTION
Low-temperature absorption and fluo-
rescence spectra in Fig. 1 of Chlamy-
domonas and Scenedesmus illustrate
typical separations in which fraction 2
has proportionately more chlorophyll b,
absorbing at 650 nm, and less long wave-
length absorption than fraction 1. Frac-
tion 1 has greater emission at longer
wavelengths than fraction 2 relative to
the peak near 680 nm. The small absorp-
tion band near 700 nm was first observed
in Scenedesmus by Butler, 1960, and
called C-705. Butler, 1966, suggested that
C-705 may be the same form of chloro-
phyll as Ca 695 in Euglena, and that it
is also the fluorescence-excitation band
seen in all the green plants that were
examined. However, we have not de-
tected this band in spectra of other algae
closely related to Scenedesmus.
600
650
700 650
Wavelength, nm
700
750
Fig. 1. Absorption and fluorescence spectra of fractions 1 and 2 from Chlamydomonas,
Scenedesmus and Porphyridium recorded at — 196°C. Excitation at 435 nm.
DEPARTMENT OF PLANT BIOLOGY
569
The fluorescence yields of fractions
from Porphyridium were not measured,
but differences in the absorption and
emission spectra can be seen in Fig. 1 and
do indicate that two kinds of chlorophyll
fractions were obtained. Most of the
phycoerythrin remained at the top of the
sucrose after centrifugation.
Attempts to fractionate the three spe-
cies of blue-green algae were originally
made by initially breaking the cells in
the needle valve. Since disruption was
incomplete, only a relatively small
amount of chlorophyll-containing par-
ticles were dispersed through the sucrose
gradient. Spectroscopic tests of samples
from various levels in the centrifuge tube
revealed no differences. More recently,
Anacystis was thoroughly broken by
shaking with glass beads in the MSK
homogenizer. Centrifugation of this ho-
mogenate in sucrose produced a layering
of phycocyanin at the top of the tube
and two well-separated green bands be-
low. However, these bands had very
similar absorption and emission spectra.
Since we have so far failed to find
two chlorophyll fractions from the blue-
green algae, we must consider the pos-
sibility that the separation of phyco-
cyanin from the denser fraction 2 type
of chlorophyll, with which it is thought
to function, may have altered the whole
particle. The particles of blue-green algae
all had the relatively low fluorescence
yields characteristic of fraction 1.
Fig. 2 shows low-temperature absorp-
tion and emission spectra of particles
from three species of blue-green algae.
The differences in the relative propor-
tions of the biological forms of chloro-
phyll are striking. All the spectra were
measured with submicroscopic particles
of about the same density and chloro-
phyll concentration. A positive correla-
tion is evident between the amount of
absorption at 710 nm and the height
of the long-wavelength (relative to the
short-wavelength) fluorescence band.
The question of which chlorophyll ab-
sorption band is the source of the long-
wavelength fluorescence band, enhanced
in fraction 1 at low temperature, has
often been asked. Different experimenters
have reported widely different peak posi-
tions for the long-wavelength emission
band in different kinds of plants. Since
a part of this variation might have been
due to errors inherent in different spec-
trofluorimeters and to the measurement
600
/ \ Extracts of Anacystis -
ff\ \ Anabaena-
// \
i i i — i — i — r
Plectonema-
Wavelength.nr
Fig. 2. Absorption and fluorescence spectra of particles of Anacystis, Anabaena and Plectonema
recorded at — 196°C. Excitation at 435 nm.
570
CARNEGIE INSTITUTION
of samples with too much chlorophyll,
we compared the fluorescence emission
spectra, measured in the same way, of
very dilute fraction-1 particles from a
number of species. The peak positions,
listed in Table 1, varied from 711 to
735 nm and showed no apparent correla-
tion with a particular absorption band
except for the case of the blue-green
algae mentioned above. The source of
this emission band still remains largely
unexplained.
An investigation of the stability of the
chlorophyll-lipoprotein binding that may
determine the characteristic absorption
spectra of the biological forms of chloro-
phyll was attempted. With spinach, heat-
ing the homogenate to 40 °C for 10
minutes, or storing it at 4°C for 2 days,
had no effect upon its subsequent ability
to fractionate in the sucrose gradient or
upon the absorption spectra of the frac-
tions. This is in contrast to broken cells
of some algae such as Tribonema and
Botrydiopsis, in which a considerable
transformation of the lcCa 680" chloro-
phyll peak to about 670 nm occurs within
a day of storage at 4°C.
Both fractions 1 and 2 from spinach
were incubated at 25 °C with trypsin
and in separate experiments with porcine
lipase for several hours. No change ap-
peared in the low-temperature chloro-
phyll absorption spectra of the treated
particles even though the fraction-2 par-
ticles clumped after 15 minutes.
In contrast to this lack of an enzyme
effect, Michel-Wolwertz {Year Book 67,
p. 505) observed that a protease (from
Streptomyces griseus) caused shifts in
the proportions of chlorophyll forms in
particles of Euglena and Chlorella.
Wheat lipase also changed the absorp-
tion of Chlorella particles. Either these
enzymes from different sources act dif-
ferently, or the chlorophyll complexes in
spinach are more resistant to their ac-
tion. However, treatment with trypsin
and porcine lipase, more than sufficient
to inhibit DCIP reduction completely
(see Mantai, this Year Book, p. 601),
need not be reflected in any detectable
change in chlorophyll absorption.
References
Butler, W. L., Biochem. Biophys. Res. Com-
mun., 3, 685, 1960.
Butler, W. L. in The Chlorophylls, Leo P.
Vernon and Gilbert R. Seely, eds., Aca-
demic Press, N. Y., p. 343, 1966.
Absorption and Fluorescence op
Chlorophyllide a in vivo
J. S. Brown
The accumulation of chlorophyllide a
(chlorophyll a without phytol) in a
Chlorella mutant "SCA" makes it pos-
sible to measure the absorption and fluo-
rescence spectra of that pigment in vivo.
Ellsworth and Aronoff, 1968, determined
that chlorophyllide a is the major por-
phyrin in this mutant, but that it is
easily converted in part to pheophorbide
a (chlorophyllide minus Mg) by ex-
posure of the cells to strong light or dur-
ing extraction by organic solvents. Dr.
Ellsworth kindly supplied us with a cul-
ture of the "SCA" mutant induced by
ultraviolet irradiation.
The absorption peaks of ethyl chloro-
phyllide and of chlorophyll a in ether
are both near 660 nm. The two major
biological forms of chlorophyll a absorb
between 670 and 683 nm. The absorp-
tion maximum of chlorophyllide a in
Chlorella is here reported at 690 nm.
This long wavelength peak position of
chlorophyllide in vivo shows that the
wavelength shift caused by the arrange-
ment of chlorophyll molecules on a car-
rier is not dependent on the presence of
the phytol tail.
The cells were grown on a glucose-agar
medium in darkness for 6 days. Absorp-
tion and fluorescence spectra of both the
intact cells and their homogenates were
measured near the temperature of liquid
N2 (Fig. 3). The homogenates were pre-
pared by passing the cells, suspended in
a 0.15 M KC1, 0.05 M Tricine buffer at
DEPARTMENT OF PLANT BIOLOGY
571
_Q
<
600
i 1 r
-I96°C
\ FO I
/
Absn
v-\ — r i i i i — i — h-v-h — i — i — h
Buffer homogenafe / \
F02
Fl
J L
650 700
Wavelength, nm
750
Fig. 3. Absorption and emission spectra measured at — 196°C of Chlorella mutant "SCA" cells
and their homogenate. Excitation at 435 nm.
pH 8, through the needle valve several
times and centrifuging at 3000 g for
10 minutes to remove the larger particles.
An approximate check on the pigment
content of the homogenate was made by
extracting these pigments with 80%
acetone in water and measuring the ab-
sorption spectrum. Characteristic ab-
sorption maxima of pheophorbide a at
410 and 535 nm indicated that some of
this porphyrin was indeed present in the
homogenates.
The absorption spectrum shows the in
vivo absorption maximum of chloro-
phyllide a at 690 nm. The shoulder be-
tween 670 and 680 nm that is more
prominent in the homogenate than in the
cells is probably due to pheophorbide a
because this pigment is known to be
formed from chlorophyllide by extrac-
572
CARNEGIE INSTITUTION
tion. The pigment causing the small band
near 710 nm is unknown. A form of pheo-
phorbide a absorbing at 710 nm has been
observed in aged Euglena {Year Book 61,
p. 352) and in Ginkgo leaves by Kunieda
and Takamiya, 1965. However, the main
peak in damaged Ochromonas (Brown,
1968) and in acid-treated chloroplasts
was found at 671 nm. Whether Ochro-
monas contained pheophorbide or pheo-
phytin was not determined, but the two
porphyrins have very similar spectral
characteristics.
The peak positions in the emission
spectra are difficult to explain unless we
assume that chlorophyllide a in vivo does
not fluoresce, and that the emission band
near 680 nm is from the pheophorbide.
This is reasonable since the pheophorbide
in Ochromonas fluoresced at 683 nm. The
emission peak at 713 nm is from a second,
unknown pigment form that is destroyed
by breaking the cells. The diatom Phaeo-
dactylum also has a similarly labile emis-
sion band at 714 nm (Year Book 65,
p. 486) .
References
Brown, J. S., Biochim. Biophys. Acta, 153,
901-902, 1968.
Ellsworth, R. K., and S. Aronoff, Arch. Bio-
chem. Biophys., 125, 35-39, 1968.
Kunieda, R., and A. Takamiya, Plant and
Cell Physiol, 6, 431-439, 1965.
photosystem 1 and 2 particles from
Leaves of Diverse Ages
Z„ Sestdk
During the development of a leaf from
unfolding to abscission its photosyn-
thetic rate displays characteristic
changes. The rate increases to the phase
of photosynthetic maturity followed by
a steady decline that may go below the
compensation point. Although changes of
chlorophyll content have a similar char-
acter, the slower decline of chlorophyll is
reflected in a gradual lowering of as-
similation numbers with the aging of
leaves. This was already observed in
1918 by Willstatter and Stoll (for review
see Sestak and Catsky, 1967) . One of the
reasons for these ontogenetic changes in
assimilation numbers may be an inter-
conversion of the forms of chlorophyll in
vivo and/or a changed ratio of photo-
systems 1 and 2.
To test this possibility the fractiona-
tion method of Michel and Michel-
Wolwertz {Year Book 67, pp. 508-514)
was employed to separate chloroplast
fractions enriched in photosystem 1 or 2.
In experiments with young, middle-aged,
and old spinach and radish leaves pur-
chased at the local market, the method
was used with only one minor modifica-
tion: besides linear gradients, step gradi-
ents (5 ml, 12.5% sucrose solution; 20
ml, 30% ; 5 ml, 50%) were used. Centrif-
ugation times of 30 or 35 minutes were
chosen for radish and 40 or 45 minutes
for spinach. The standard procedure was
found unsuitable for glass-house plants
of Mimulus cardinalis whose chloroplasts
and photosystems were probably too
heavily damaged by the procedure.
With linear gradients the method af-
fords a reasonable separation of three
bands. In step gradients band 2 often
appears only as an elongated tail of band
1 or in front of band 3, while band 3
is usually located at the boundary of the
last two sucrose concentrations. This re-
sults in irregularities in the flow-cuvette
evaluation of the results (see bands of
photosystem 2 in Fig. 4).
The disadvantage of the method is
that in various steps of the chloroplast
isolation procedure a great deal of
chlorophyll-containing material is re-
jected. Consequently the chloroplasts
thus fractionated may represent only a
specific fraction of the total plant tissue
initially used, i.e., the mature chloro-
plasts, chloroplasts with resistant mem-
branes, small chloroplasts, etc.
Absorption spectra of particles in
bands 1 and 3 (containing particles en-
riched in photosystems 1 and 2, respec-
tively) measured both at room tempera-
DEPARTMENT OF PLANT BIOLOGY
573
Photosystem I
Sucrose concentration
I2.5<st>_[ 30% V~ t0%
5 10 15 20 25
Volume of sample as measured
from top of the tube, ml
30
Fig.
4. The distribution of chloroplast par-
ticles from young and old radish leaves frac-
tionated by step-gradient centrifugation in
sucrose. The absorbance at 678 nm is plotted
against the quantity of sample withdrawn, as
measured from the top of the tube.
ture and at liquid nitrogen temperature
agreed with those given by Michel and
Michel- Wolwertz. No obvious difference
in the spectral characteristic other than
that corresponding to a different chloro-
phyll a/b ratio was found between par-
ticles from young and from old leaves.
On the other hand, visual inspection
of centrifuged sucrose gradients indicated
a different distribution of particles from
young and old leaf chloroplasts into the
individual bands. To test this the spec-
trophotometric system for light-scatter-
ing samples described by French and
Lawrence (Year Book 66, pp. 175-177)
was adapted for flowing the contents of
the centrifuge tube through the cuvette.
(The cuvette was modified by Mr. R. W.
Hart.) Starting with the bottom layer,
the gradient flowed through the cuvette
by gravity only. The resulting nonlinear
flow speed (see abscissa in Fig. 4) in-
duces difficulties in the quantitative
evaluation of the records and needs to be
improved by slow pumping of the gradi-
ent through the cuvette. The accuracy
was, however, found suitable (values
always within the limits of ±10%) by
comparing centrifuge tubes with different
amounts of broken chloroplasts put on
its top (Table 2).
The records (e.g., Fig. 4) confirmed
that chloroplasts from young leaves con-
tained more photosystem-1 and less pho-
tosystem-2 particles than chloroplasts
from old leaves. Thus, for example, band
1 from young radish leaf chloroplasts
included approximately 25% of the total
chlorophyll in the original homogenate,
whereas the same band from old leaves
had only about 15% of the total chloro-
phyll.
Particles of both photosystems from
young leaf chloroplasts had a signifi-
cantly lower ratio of chlorophylls a/b
and a 20-30% higher fluorescence at 683
nm per chlorophyll (a + b) than those
from old leaves. This difference was more
clearly pronounced by calculation per
chlorophyll a only in photosystem 2
which has a lower chlorophyll a/b ratio.
With the aging of the dialyzed separated
particles, these differences in fluorescence
yield between preparations from young
and old leaves diminished. This may be
due to a more rapid decay of the photo-
TABLE 2. An Accuracy Test for the Estima-
tion of Relative Chlorophyll Contents of
Different Fractions of the Homogenate of an
Old Radish Leaf*
Amount of
Sample
Band Area
Applied,
ml
Entire
Sample
100
150
207
Bandl
100
141
211
Bands
2 and 3
100
150
200
100
159
210
* The absorbance of a sucrose step-gradient
was measured in a flow-through cuvette at
678 nm. The area under the curves were com-
puted giving that for the lowest concentration
a value of 100.
574
CARNEGIE INSTITUTION
systems after isolation from young
leaves.
Although the results have to be con-
firmed on a large number of plant species
by analyses either of individual leaves on
a plant or of one leaf during its whole
life cycle, they suggest that with the
maturation and aging of leaves the
amount of photosystem-1 particles in iso-
lated chloroplasts declines in relation to
photosystem-2 particles. At the same
time their photoactivity relative to
amount of chlorophyll falls. Because par-
ticles of the (middle) band 2 were found
by Michel and Michel- Wolwertz to dis-
play photosystem-2 activity (their ab-
sorption spectra are also similar to those
of photosystem-2 particles) , it seems that
there is a surplus of photosystem-2 par-
ticles in chloroplasts, and, therefore, the
amount of photosystem-1 particles and
the amount of chlorophyll in them may
limit the photosynthetic rate.
Reference
Sestak, Z., and J. Catsky, in Le chloroplaste,
croissance et vieillissement, C. Sironval, ed.,
Masson et Cie., Paris, pp. 213-262, 1967.
An Action Spectrum for Methyl
Viologen Reduction by Fractionated
Spinach Chloroplasts
Eckhard Loos
In the last few years chloroplast frag-
ments have become available which are
enriched in one or the other of the two
photosy stems (systems 1 and 2) operat-
ing in photosynthesis of algae and higher
plants. To obtain better insight into these
two systems, especially with regard to
their pigment composition, one should
have them separated as cleanly as pos-
sible. An important criterion for the
completeness of a fractionation is the
degree of coincidence of the absorption
spectrum of a fraction with the action
spectrum for a reaction specific for sys-
tem 1 or 2.
Several absorption spectra of sub-
chloroplast particles containing predomi-
nantly photosystem-1 or photosystem-2
pigments have been published (Board-
man and Anderson, 1964; Anderson and
Boardman, 1966; Ogawa et al., 1966;
Vernon et al., 1966; Briantais, 1967;
Michel and Michel-Wolwertz, 1969; Bril
et al., 1969) . There are also a number of
action spectra for system- 1 and system-2
activity (Muller et al, 1963; Kelly and
Sauer, 1965; Vidaver, 1966; Joliot et al,
1968; Ludlow and Park, 1969) . However,
they were measured with whole chloro-
plasts or algal cells, which are known
to have flattened absorption and action
spectra. In the present study an attempt
was made to obtain an action spectrum
with fractionated chloroplasts. It was
hoped to gain in this way more exact
knowledge of the pigments sensitizing a
partial reaction of photosynthesis and to
be able to estimate the degree of separa-
tion of the two photosystems. Because
system-2 enriched particles are quite
labile and tricky to experiment with, the
attempt was made first with system-1
particles. Methyl viologen reduction was
chosen as a system-1 reaction (Arnon,
1963; Kok et al, 1965) using an artificial
electron donor and DCMU to block any
activity from system 2.
Material and Methods
About 180 g spinach leaves were ho-
mogenized for 10 seconds in the Waring
blendor with 65 ml of buffer "A" (Jensen
and Bassham, 1966) from which NaN03
and Na-isoascorbate were omitted. The
resulting brei was filtered through 8
layers of cheesecloth and the filtrate
centrifuged for 2.5 minutes at 3000 Xg.
The pellet was resuspended in 5-10 ml
0.05 M Tricine (pH 7.9), 0.15 M KC1
and forced twice through a needle valve.
Unbroken chloroplasts were then re-
moved by centrifuging for 5 minutes at
3000 X^. From the homogenate so ob-
tained, 2 ml (equivalent to 500-1500 jug
chlorophyll) were layered on 30 ml of a
linear sucrose gradient (10-50%) con-
DEPARTMENT OF PLANT BIOLOGY
575
taining 0.15 M KC1 and 0.05 M Tricine
pH 7.9. After 45 minutes' centrifugation
at 65,000 X g, system-1 enriched particles
were withdrawn from the green top band
in the centrifuge tube and, henceforth in
this report, are called fraction 1.
Unless otherwise indicated, the reac-
tion mixture used contained in moles/
liter: Tricine, 0.05 (pH 7.8-8.0) ; KC1,
0.15 ; NH4C1, lO"3 ; cysteine, 0.04 ; DCPIP,
2xl0~5; DCMU, 10~5; methyl viologen
2X10-4. The chlorophyll concentration
was 2.5 pg ml-1. To make this mixture
anaerobic, 1-ml plexiglas cuvettes were
filled, bubbled for 1 minute with N2, and
closed with a screw cover.
Methyl viologen reduction was fol-
lowed spectrophotometrically by record-
ing the increase of absorption at 386 nm,
a secondary peak of the reduced form of
methyl viologen. The measuring light
was isolated with an interference filter
(10-nm half bandwidth) and after pas-
sage through the sample detected by an
RCA photomultiplier (type IP 22),
which was protected from stray actinic
light by two Corning filters, No. 9782 and
No. 5543. The measuring beam and the
actinic light were at right angles to each
other, the path-lengths being 7.9 and
4.8 mm respectively. In action spectra
measurements the cuvette was backed
with an aluminum foil for a more even
illumination of the sample. Actinic light
was obtained from a 2000-w high pres-
sure mercury lamp used in conjunction
with a monochromator, and was filtered
through 4 cm water, a Balzers Calfiex
heat-reflecting filter and for the wave-
lengths 600-660 nm, through Corning
filter No. 2404, for 645-680 nm, through
Corning filter No. 2408 and, for 680 nm
and longer, through Schott filter RG5.
In experiments not dealing with action
spectra, actinic light was provided by a
ribbon filament lamp and a 680-nm in-
terference filter (10-nm half bandwidth)
plus a Calfiex filter. Light intensity was
monitored continuously by deflecting
part of the beam onto a calibrated sili-
con cell whose output was amplified and
integrated over the time interval of the
exposure. Absorption spectra were mea-
sured with a spectrophotometer specially
suited for light scattering samples
(French and Lawrence, 1968).
Results
A. Methyl viologen reduction using
cysteine-DCPIP as electron donor
The cysteine-DCPIP couple was used
as electron donor because with ascorbate-
DCPIP no activity was detected, con-
firming the results of Arnon (1963).
Kinetics. Two types of kinetics were
encountered. The first one, illustrated in
Fig. 5A, is characterized by a rapid in-
crease of absorption upon the onset of il-
lumination, after which the rate tapers
off to a constant value in the course of
several seconds; shutting off the light
causes a sudden decrease of absorption
followed by a more or less sloping back
rate.
The second kind lacks the transients
(Fig. 5B) . The reason for the two kinetic
u I
h-
1
A
1 i
•toff1 ' '
On /
Y
B
Off
On /
I.I.I
4 6 8
Time.min
10
12
Fig. 5. Kinetics of methyl viologen reduction.
In the experiment for Fig. 5A the DCPIP con-
centration was 1.4 X 10-4 M and the cysteine
concentration was 5 X 10~3 M. Upward trace
corresponds to a decrease of absorption. Wave-
length of light was 696 nm for part A of the
figure and 680 nm for part B, nonsaturating
light intensities.
576
CARNEGIE INSTITUTION
types is not yet clear. It may be a
seasonal variability in the spinach leaves,
for the kinetics with the transients were
observed from December through March
and could not be reproduced in the sum-
mer time.
The rate of the back reaction in-
creased during the course of an experi-
ment after many alternating light and
dark periods, apparently concurrently
with the accumulation of reduced dye
(Fig. 6) . The steady-state rate of methyl
viologen reduction in the following ex-
periments was corrected for the back re-
action, using the average of the steady
rates before and after a light exposure.
Optimizing the reaction conditions.
The concentration of some components
of the reaction mixture was varied to
find optimum conditions, to be able to
use the relatively weak light intensities
available with a narrow spectral band-
width of the actinic light.
A schedule of 5.5 minutes dark alter-
nating with 5.7 minutes light was em-
ployed. The light intensity was about
3000 ergs cm-2 sec-1, and the wavelength,
680 nm. Each point represents the aver-
age of at least two measurements.
The influence of DCPIP concentra-
tion. Table 3 shows the dependence of
the rate of methyl viologen reduction on
the DCPIP-concentration. The optimum
is around 3 x 10"5 M DCPIP, the decline
TABLE 3. Rate of Methyl Viologen Reduction
at Different DCPIP-Concentrations *
Rate of Methyl
Concentration of
Viologen
DCPIP, M
Reduction, Rel.
3 X lO"4
10.5
1 x io-*
48
3 X lO"5
125
1 x io-5
100
3 X 10"6
58.5
1 x io-6
25
* The cysteine concentration was 5 X 10"3 M.
in activity being sharper towards the
higher concentrations than towards the
lower ones. For all further experiments a
DCPIP concentration of 2 x 10-5 M was
chosen.
The influence of cysteine concentra-
tion. The concentration of cysteine,
which keeps the DCPIP reduced, may
affect considerably the rate of methyl
viologen reduction, as is illustrated in
Table 4. The optimum rates were ob-
served only in the relatively small con-
centration range between 0.04 and 0.08
TABLE 4. Rate of Methyl Viologen Reduction
at Different Cysteine Concentrations
Concentration of
Cysteine, M
Rate of Methyl
Viologen
Reduction, Rel.
4 X IO'8
8 X 10"3
1.6 X IO'2
4 X IO"2
8 X IO"2
3.7
12.7
17.2
25.6
25.0
IOO 200
Time.min
Fig. 6. Accumulation of reduced methyl viologen (line through crosses) and rates of re-
oxidation during the dark periods (points). Periods of 7-8 minutes light alternated with 4-5
minutes dark. Nonsaturating light intensities; chlorophyll concentration 1.3 g ml'1. Data are
taken from an action spectrum experiment.
DEPARTMENT OF PLANT BIOLOGY
577
TABLE 5. Rate of Methyl Viologen Reduction
at Different Methyl Viologen Concentrations
Concentration of
Rate of Methyl
Methyl
Viologen
Viologen, M
Reduction, Rel.
lO"5
11.6
5 X lO"5
11.9
2 X 10"4
13.4
5 X lO"4
11.1
1 x io~3
12.9
M . With the highest concentration tested
(0.08 M) in some cases the rate declined
with time. The reason for the relatively
low rates at weaker cysteine concen-
trations may be a too slow re-reduction
of DCPIP, which becomes oxidized in
the light by the chloroplast fragments.
The influence of methyl viologen con-
centration. One experiment was carried
out varying the concentration of methyl
viologen; it did not seem to be critical
under the chosen conditions (Table 5).
Dependence of the rate of methyl
viologen reduction on light intensity. A
four minutes light to four minutes dark
schedule was used for these experiments.
In general the light intensity curves were
S-shaped (Fig. 7) and only in a few
2000
Light intensity, ergs cm
Fig. 7. The dependence of rate of methyl
viologen reduction on light intensity, wave-
length 680 nm.
cases was a linear relationship found.
The slopes of the curves attained their
greatest steepness at rates which
amounted to 10% or less of the light-
saturated value. The reason for the non-
linearity in the lower intensity range is
not yet known. One explanation is a
limited cyclic electron transport, prefer-
entially driven at low light intensities.
B. Action spectrum for methyl viologen
reduction
To minimize errors due to the non-
linear intensity-versus-rate curves, two
measurements were taken :
1. The light intensities at a certain
wavelength and at a reference wave-
length were so adjusted as to yield ap-
proximately equal rates.
2. The measurements were made in
the linear portion of the light intensity
curve. In order to compare also some-
what differing rates obtained with dif-
ferent wavelengths, all rates were cor-
rected by adding the value of the
intercept, which is produced on the rate
coordinate at zero intensity by an exten-
sion of the linear part of the light curve.
This correction usually amounted to 30-
80% of the measured rates. Points for
light intensity curves were measured at
the beginning and in the middle or at
the end of an experiment.
Each wavelength was given for 3-4
minutes and immediately followed or
preceded by an exposure to a reference
wavelength, which was 680 nm in the
range 645-700 nm and 625 nm for the
region between 600 and 660 nm. The
dark periods lasted for 3-5 minutes.
Fig. 8 shows the points of an action
spectrum obtained in six experiments
involving five preparations of fraction 1.
For measurements between 645 and
700 nm (points in Fig. 8) a half band-
width of 1.5 nm was used; the chloro-
phyll concentration was about 1.3 /xg
ml-1 corresponding to an optical density
of about 0.05 at 680 nm. Two experi-
ments for points between 600 and 660 nm
(crosses in Fig. 8), however, were car-
578
CARNEGIE INSTITUTION
ried out with 2.5 and 1.5 nm half-band-
width and chlorophyll concentrations of
approximately 6 and 2.5 [xg ml-1. These
points were obtained using 625 nm as a
reference wavelength. They were joined
to the other points with 680 nm as refer-
ence by two wavelengths (645 and 650
nm) in the overlapping region, and the
average values were calculated from sets
of points. The factor was determined
by which the average of the 645-nm
points from the one set (625 nm as refer-
ence) differed from the corresponding
645-nm average of the other set (680 nm
as reference). Similarly such a factor
was obtained for the 650-nm values. The
average of those two factors was finally
used to multiply all points of the one set
(625 nm as reference) and so connect to
the other set.
As can be seen in Fig. 8 the absorption
spectrum (solid line) fits closely the
measurements for the relative action.
The divergence in the part between 670
and 680 nm is considered to be in-
significant, for it was not evident in two
other experiments which showed more
scatter.
Discussion
The data in Fig. 8 suggest that the
absorption spectrum of fraction 1 repre-
sents also the spectrum of the pigments
active in light reaction 1. However, the
action spectrum measurements are not
accurate enough to establish firmly
slight disagreements with the absorption
spectrum ; for instance no evaluation can
be made of the degree of activity of
chlorophyll 6. For a more precise action
spectrum, therefore, another way to
measure system 1 activity must be
sought.
The action spectrum from fractionated
chloroplasts is less flattened than the
action spectrum for methyl viologen re-
duction in whole spinach chloroplasts
obtained by Joliot et al. (1968) (the
broken line and circles in Fig. 8). This
underlines the necessity to use as finely
dispersed chloroplast material as pos-
sible for further action spectra.
References
Anderson, J. M., and N. K. Boardman, Bio-
chim. Biophys. Acta, 112, 403-421, 1966.
Arnon, D. I., Photosynthetic Mechanisms of
Green Plants, Publ. 1145 N.A.S.-N.R.C.
Washington, D. C, pp. 195-212, 1963.
Boardman, N. K, and J. M. Anderson,
Nature, 203, 166-167, 1964.
Briantais, J. M., Photochem. PhotobioL, 6,
155-162, 1967.
Bril, C, D. J. Van der Horst, S. R. Poort, and
J. B. Thomas, Biochim. Biophys. Acta,
172, 345-348, 1969.
Butler, W. L., Arch. Biochem. Biophys., 93,
413-422, 1961.
French, C. S., and M. Lawrence, Carnegie
Institution Year Book 66, pp. 175-177,
1968.
Jensen, R. G., and J. A. Bassham, Proc. Natl.
Acad. Sci., 56, 1095-1101, 1966.
Joliot, P., A. Joliot, and B. Kok, Biochim.
Biophys. Acta, 153, 635-652, 1968.
Kelly, J., and K. Sauer, Biochemistry, 4,
2798-2802, 1965.
Kok, B., H. J. Rurainski, and O. von H.
Owens, Biochim. Biophys. Acta, 109, 347-
356, 1965.
Ludlow, C. J., and R. B. Park, Plant Physiol.,
44, 540-543, 1969.
Michel, J., and M. Michel-Wolwertz, Carnegie
Institution Year Book 67, pp. 508-514,
1969.
Muller, A, D. C. Fork, and H. T. Witt, Z.
Naturfschg., 18b, 142-145, 1963.
Ogawa, T., F. Obata, and K. Shibata, Bio-
chim. Biophys. Acta, 112, 223-234, 1966.
Vernon, L. P., E. R. Shaw, and B. Ke,
J. Biol. Chem., 17, 4101-4107, 1966.
Vidaver, W., Plant Physiol, 41, 87-89, 1966.
The Forms of Chlorophyll a in Frac-
tions of Chloroplasts from
Different Sources
C. S. French
The previously reported attempts to
resolve the complicated absorption spec-
tra of chlorophyll complexes into spe-
DEPARTMENT OF PLANT BIOLOGY
579
cific components representing the differ-
ent natural forms of chlorophyll have
been continued. This year's work repre-
sents a level of approximation that has
served more to clarify the limits of use-
fulness of the curve analysis procedure
than to define the spectra of specific
chlorophyll components. Rather than
reporting in detail on the extensive but
still unsatisfactory curve analyses car-
ried out this year, we will present, on
identical scales, some of the spectra of
different investigators that illustrate the
complex nature and the range of varia-
tion within the red region of the spec-
trum which is caused by the presence of
different forms of chlorophyll a.
The spectra of normally green cells
or of whole chloroplasts cannot truly
represent the sums of the spectra of the
component forms because of the well-
known flattening effect due to the high
optical density of the particles them-
selves. Therefore, our recent curve
analyses have been mainly restricted
to spectra of small particles of broken
or fractionated chloroplasts.
Methods for separating chloroplasts
into two fractions corresponding roughly
to the pigments of photosystem 1 and
photosystem 2 are being intensively in-
vestigated in many laboratories. Previ-
ously we found the longer-wavelength
form of the two major chlorophyll a
components, Ca 680, to have a much
narrower bandwidth in the system-2 frac-
tions than in the system-1 fractions. Dr.
Brown's recent measurements with frac-
tions from numerous species of plants
have amply confirmed the generality of
this situation. Since the absorption bands
near 680 nm in the spectra of the two
fractions differ in half -width, it is obvi-
ous that spectra of whole chloroplasts,
or of their unfractionated homogenates,
are more complex than was expected
from the old assumption that they
were both made up of a small number of
forms of chlorophyll a similar in shape
and differed only in their proportions
in the two fractions.
The spectra of separated chloroplast
fractions, therefore, appear to offer the
greatest promise for resolution into the
spectra of the individual components,
and most of the recent work has been
on such material. Because the spectra
are sharper at liquid nitrogen tempera-
ture, most of the curve analyses have
been done with low-temperature data.
The extreme sharpness of the Ca 680
peak in fraction 2 is consistent with the
previously discussed idea that its shape
may be greatly influenced by refractive
index changes of the pigment near its ab-
sorption band. Devising methods for the
routine measurement of such wavelength
dependent scattering in a way that can
lead to a calculation of the true ab-
sorbance is of great importance. Various
possible methods have been considered
although we have not yet attempted to
make experimental tests of possible pro-
cedures. The main difficulty is to devise
a measurement system that would be
usable at liquid N2 temperature as well
as for suspensions at room temperature.
Theories. A basic question is whether
the spectra for different chloroplast
preparations are made up of identical
chlorophyll components in different pro-
portions or whether the wavelength
maxima and the widths of the com-
ponents themselves are different in the
various preparations of corresponding
chloroplast fractions. We hope to answer
this question by curve analysis.
To account for the variations in ob-
served spectra and yet to maintain the
simplest realistic concept of the mini-
mum number of chlorophyll forms that
must exist, we wish to distinguish be-
tween the three alternative hypotheses
illustrated in Table 6. According to the
constant components concept, the basic
major bands are assumed to correspond
to actual forms of chlorophyll that al-
ways have the same peak position and
width. Since variation in the proportions
of these components can give peaks or
shoulders at many different wavelength
positions, the observed variation in
580
CARNEGIE INSTITUTION
TABLE 6. Three Alternative Concepts to Account for the Observed Band Positions of
Chlorophyll a Types
Constant Components
Concept
The components have peaks
of constant wavelength and
width while the observed
variety of spectra is due to
differences in the propor-
tions of these forms.
Extra Components
Concept
The major components have
peaks of constant position
and width, extra bands may
or may not be present.
Variable Components
Concept
The major components have
peak positions and/or widths
that vary from one sample
to another within a specific
range for each type.
Name of
component
Ca665
Ca6702
Ca 680 s
Range of pos-
sible peak po-
sition due to
mixtures of
these compon-
ents 1
665-670
670-680
680-695
Universal
forms
Extra
forms
Approximate wavelength, nm
665
Range of variation for each
type of component
662-667
670
Ca 695 1
695-700
Ca 700 )
700-705
Ca 705 |
705-710
Ca710 1
Ca715 J
710-715
675
685
688
695
700
705
710
715
668-673 :
678-683
684-689
690-696
697-702
703-708
709-713
714-718
xThe presence of other components can modify the peak position for the sum of any pair
of components.
2 Predominant in system 2.
3 Predominant in system 1 .
wavelength position need not signify the
existence of a large number of different
chlorophyll forms.
Curve analyses of spectra for a single
sample or for a small number of samples
no matter how precise, cannot distinguish
between basic components and the
broader bands with intermediate peak
positions that are the sums of several
basic components. If the constant com-
ponent idea is correct, we should be able
to find the minimum number of invariant
components that when added with ap-
propriate height factors, will fit all
spectra.
The concept of extra components, by
contrast with that of constant com-
ponents, posits that there are two major
and universal forms in each system with
constant peaks at about 670 and 680 nm.
In addition, however, there may also be
any of a number of other invariant forms
also present in any particular sample.
The probable peak positions of some of
these less common extra forms are given
in Table 6. The two ideas should be dis-
tinguishable by comparison of the results
of many curve analyses. For the one,
identical components should fit all spec-
tra, while the other requires extra com-
DEPARTMENT OF PLANT BIOLOGY
581
ponents which also would always be at
specific wavelengths.
A third hypothesis, that of variable
components, unlike the other two, pre-
sumes that the chlorophyll a forms of
any one type are not constant but may
vary in their peak positions over a range
of about ±3 nm and possibly also in
their widths. If this is actually true, then
an almost unlimited number of com-
ponents would result from an extensive
series of curve analyses.
Curve analysis with Gaussian com-
ponents. During the past year we have
attempted to resolve various absorption
spectra of chloroplast fractions most of
which were prepared by Dr. Brown from
a variety of algae and leaves. We have
also analyzed spectra of some purified
chlorophyll-protein complexes prepared
by Dr. J. Philip Thornber of the Brook-
haven National Laboratory. One pro-
cedure used in analyzing these spectra
has been to match the experimental
curves by adding together simpler curves,
usually Gaussian probability functions.
The reason for doing so is that the Gaus-
sian curves thus obtained may represent
the individual bands of the different
chlorophyll forms and, therefore, serve
as a means for specifying their wave-
length, peaks and their widths at half-
height. Neither of these parameters of a
single band is directly identifiable in a
composite absorption spectrum. There is
no reason to expect Gaussian curves
necessarily to fit even a single isolated
band over its entire extent. Nevertheless,
that shape has been found to be adequate
for use with chlorophyll spectra except
at the long wavelength tails. Lorentzian
(Cauchy) curves are far less useful.
Each of the major forms of chloro-
phyll a that we wish to identify has a
main peak in the 660-700 nm region, a
wider and lower band near 620-640 nm,
and a still wider and lower band with
a maximum somewhere near 580 nm.
So far we have not been able to dis-
tinguish between the bands of the differ-
ent forms of chlorophyll a in the 570-
640 nm region. The long wavelength
tails of 620-640 nm bands do overlap
the main peaks and hence have some
small effect on the apparent shape of the
main peak. This overlap of unidentifiable
low and broad bands has been a source
of some uncertainty in determining the
height and, to a smaller extent, the half-
width of the major bands.
These curve analyses made with the
RESOL program have resulted in a
number of adequate matches of Gaus-
sian curves to the experimental spectra.
The interpretation of the results by at-
tributing particular Gaussian curves to
the absorption bands of specific chloro-
phyll complexes has not yet been very
successful. There are two difficulties in
the use of this method. One difficulty
can probably be greatly reduced by
program modifications that are being ex-
plored. That trouble is the sometimes
extreme modification by the program of
the wavelength peaks and half-widths
of the estimated input bands with which
the computation starts. When this hap-
pens the resulting fit may be excellent
even though the bands so determined
cannot possibly be considered as repre-
senting the absorption bands of chloro-
phyll complexes.
Dr. Tunnicliff has recently shown us
how to restrict the amount of wavelength
adjustment allowed for each iteration.
Mr. Lawrence is working on a modifica-
tion of the program using this principle.
The plan is to make a restriction for
both the peak wavelength change and
the width change per iteration inde-
pendently specifiable for each input
band. If these modifications can be
made to operate successfully, the pro-
gram will be much more useful for
complex spectra. For instance, the whole
curve for a known or suspected chloro-
phyll component describable as the sum
of several Gaussian or Lorentzian func-
tions can be entered and either rigidly
held or allowed minor adjustments while
the program determines the remaining
components of the system. In this way
582
CARNEGIE INSTITUTION
the difficulties that have caused so much
trouble in curve analysis this year may
be avoided. With these modifications it
should be possible to use enough input
bands to allow for the main peaks of the
minor components as well as for the side
bands of the major chlorophyll forms.
This has not yet been possible with the
present program lacking the restraints
on band adjustments.
Another and more serious difficulty
is that many of the spectra do not have
sharp enough characteristics to require
only a single combination of Gaussian
curves for a precise fit. With such spectra
we have to use some other method for
determining the band shapes. Character-
less curves are, however, valuable for
testing the reality of component spectra
that have been determined from other
data.
One partially successful attempt to
derive the separate chlorophyll spectra
in a two-component mixture is illustrated
in Fig. 9. This is the room-temperature
spectrum of Dr. Thornber's purified
system-2 pigments from spinach. This
spectrum is of particular interest because
it contains the highest proportion of
chlorophyll b of any fraction we have
seen. In this case the RESOL program
gave a very rough resolution of the 570-
640 nm region but reasonable bands for
the main 652 chlorophyll b and 671
chlorophyll a peaks. The larger of the
minor component bands at 632 nm, how-
ever, is probably too wide, too high, and
at too long a wavelength. Combining the
652-nm and 604-nm components with
a portion of the 575 band to represent
the spectrum of chlorophyll b in vivo
gives a completely objective, although
inadequate, solution to this curve resolu-
tion problem. The derived curves are
given in the upper part of Fig. 9. The
analogous addition of the 671-nm and
632-nm bands with part of that at 575
nm to represent the spectrum of Ca 670
of system 2 is also not satisfactory. How-
ever, this figure illustrates a method
10
c
o
o
<
1 1 1 1 1 1 1
1, ' 1 ' '
f
\
1
•\v
It
1
\
4
\
M
\m
/ f
\ '
o + . •/ T
\\
J^^
\\
\\
\>
1 1 1 1 1 1 1
\\
0
600
650
Wavelength, nm
700
c
o
u
0)
a
c
o
"a
u
O
CO
_Q
<
Fig. 8. Wavelength dependence of relative action for methyl viologen reduction by fraction 1
(points and crosses). Solid line: absorption spectrum of fraction 1. Broken line and circles: action
spectrum for methyl viologen reduction in whole chloroplasts ; adapted from Joliot et al. (1968).
DEPARTMENT OF PLANT BIOLOGY
583
0)
o
c
D
<
— i 1 , 1 1 1 1 1 —
Derived component spectra
Chyll a
671
r\
-M
J \
/ /
i */ \
/' A v
' '' \
/ N / <
Chyll b
650 /
V
\
\
-^
System 2 chyll protein
Thornber 23°C
C-44 A
600
650
Wavelength, mju
700
Fig. 9. The absorption at room temperature of Dr. Thornber's purified system-2 chlorophyll
protein matched with Gaussian curves. In the upper part the components have been added to
approximate very roughly the spectra of the chlorophyll b and chlorophyll a components.
that may be valuable in the future after
the curve analysis program is improved.
Comparison of spectra by subtraction.
One procedure occasionally useful for re-
lated pairs of characterless spectra is
nearly the same except for the relative
amounts of a common component. If
that requirement is more or less true,
then the difference spectra give a reason-
able approximation to the band shape of
584
CARNEGIE INSTITUTION
one component. This procedure, de-
scribed last year, has been applied to a
number of curve pairs and has frequently
shown that the spectra selected differ
by several unexpected bands. One of the
more significant of these calculations by
the DSPEC program came from two
spectra of a fraction from homogenized
Botrydiopsis that were prepared on suc-
cessive days. That from the fresh ho-
mogenate had a large Ca 680 band
while that from the same homogenate
stored overnight at 4°C had very little
of that component. Even this pair of
spectra showed an unexpected difference
near 665 nm as well as the major dif-
ference peak at 680 nm (French et at.,
1968).
This comparative procedure for deriv-
ing the spectra of component bands
eventually should have more utility if
enough appropriate pairs of spectra can
be found. The method has the advantage
over the approximation by Gaussian
components in that it gives the entire
spectrum of a component rather than
only the width and position of its main
band. So far, however, these difference
spectra have been more useful in empha-
sizing the presence of unsuspected com-
ponents than in finding the precise shape
of the components that are obviously
present.
To compare curves with each other we
have found it well worth the extra ex-
pense to have all spectra plotted on the
same scale with a peak height of 7.5
inches and a wavelength scale of 1 nm =
Y15 inch. Such a graph made by the
SPLOT program also serves to make any
errors of curve digitizing strikingly ap-
parent. An even greater convenience is
the file of 4 X 5 positive film photographs
of the standard-scale plots that are ac-
curately aligned with each other. Many
of these can be superimposed to com-
pare all spectra of a particular type. For
visual study they are held in a plastic
frame with slots. When arranged in
order of the increasing height of a par-
ticular band such a set of spectra gives
a three-dimensional view of the inter-
relations of several bands.
To search for the less obvious com-
ponents the spectra measured at — 196°C
are being compared within the following
groups of preparations:
(a) Particles prepared by sucrose-
gradient centrifugation of algae lacking
chlorophyll b, and purified chlorophyll-
protein preparations free of chlorophyll
6 (13 spectra).
(b) Fraction-1 particles from various
sources (6 spectra).
(c) Comparable fraction-2 particles
(6 spectra).
(d) Miscellaneous: unfractionated ho-
mogenates, (following centrifugation at
3000 g for 10 minutes to remove large
particles), and spectra of whole cells
that are pale enough to give compara-
tively undistorted spectra (9 spectra).
Some very revealing information about
the complexity of spectra appears when
two apparently similar spectra are super-
imposed, as shown in Fig. 10. In that
figure are absorption spectra kindly sup-
plied by Dr. Thornber for two of his
purified samples of chlorophyll protein
from the blue-green algae Tolypothrix
and Phormidium (Thornber, 1969).
Small bulges, caused by minor com-
ponents, are more clearly seen by com-
parison with a curve that is similar but
lacks these smaller bands. Figure 10
clearly shows that the Phormidium
preparation absorbs relatively more at
633, 665, 688, and 708 while the Toly-
pothrix material has proportionately
more absorption near 678 and 695 nm.
Both have a major component at about
672 nm with a secondary band at about
620-635 nm. It also seems that the Phor-
midium may have the peak of its second
largest component at 680 rather than
at 678 nm, its apparent position in the
Tolypothrix preparation. It is possible,
however, that the apparent difference
may be only in the relative proportions
of identical components. If, in fact, each
of the two spectra does consist of a mix-
ture of 665, 672, 678-680, 688, 695, and
DEPARTMENT OF PLANT BIOLOGY
Algae without chlorophyll b Fraction
585
Fraction 2
Botrydiopsis top
fractions C22
Old
WXWC2IFresh
CI9 Euglena -^
Tribonemo. top
fractions
C34
Stichococcus-^
C6 Spinach ^j
670/
C35
Stichococcus-^/
Chlorophyll proteins
Thornber
C38 Phormidium— »f
600
650
700
600 650 700
Wavelength, nm
600
650
700
Fig. 10. Some selected spectra at — 196°C showing various forms of chlorophyll. Comparisons
of similar spectra suggest the presence of small amounts of extra chlorophyll forms in addition
to those common forms giving the major peaks. The data was kindly provided by the following
workers: M.-R. Michel- Wolwertz, C6, C18, C19, C27, C28; J. S. Brown, C34, C35, C65, C68;
P. Thornber, C38, C39; L. Prager, C21, C22, C29, C30; D. C. Fork, U. Heber and M.-R. Michel-
Wolwertz, C36, C37.
708 components, each with a side band in
the 620-640 region, it is not surprising
that the RESOL resolution of the Toly-
pothrix spectrum into 6 Gaussian com-
ponents gave the oversimplified picture
shown in Fig. 11 with the indicated
errors of this match.
For the Phormidium spectrum, C38,
three widely different curve analyses
were obtained, all with about the same
error of fit. None of them gave inter-
pretable components. A visual compari-
son of selected spectra, as in Fig. 10,
gives a preference to the interpretation
that differences between comparable
fractions result from different propor-
586
CARNEGIE INSTITUTION
CO
o
c
C
_Q
l_
O
to
_Q
<
1
1
1
«, C39A
Points are data
\ -I96°C
Curve is sum of
components
670.0 /
\ \ 680.4
\ K 16.7
578.9 -*•— — -^
25.2 ^^628.8^:
^HjT 60.9
\ \ \ 693.2
\ \ V 8.8
^? /"
\A\V 703.3
Error x7.63
r*\
\ , /fN, ,/T^
a^ ~ / v_
1 1 1
600
650
Wavelength, nm
700
Fig. 11. A partial resolution of Dr. Thornber's spectrum at — 196°C for purified chlorophyll
protein from Tolypothrix. It is not yet possible to resolve the 600-640 nm region into its
components.
tions of similar components, provided
enough separate components are con-
sidered for each curve. Smaller amounts
of extra forms, however, may also exist
in some of these algae.
Considered from the point of view of
the constant component theory the spec-
tra for the sharpest and for the smooth-
est spectra of fractionated chloroplasts
of Fig. 10 show that if the Euglena
fractions 1 and 2 each contain a Ca 680
component as sharp as those in Stichococ-
cus, then there must be at least two
components in the 665-675 region of
Euglena that are low or absent in
Stichococcus. The 695-nm and 705-nm
components of Euglena show clearly in
this comparison.
Euglena must have a higher propor-
tion of components at about 665, 670,
and 675 nm than does Stichococcus. Fur-
thermore, Stichococcus has the highest
chlorophyll b peak and the sharpest
Ca 680 component of any alga so far
investigated. These two pairs of spectra
for fractions 1 and 2 of Stichococcus
and Euglena are the most difficult ones
to explain by the theory of constant
components. A better comparison is of
the same Stichococcus data with that for
spinach fractions. Here, apparently, an
increase in the amount of a 673-nm com-
ponent added to the Stichococcus curve
for either fraction could bring them up
to the spinach curves in that region. For
fraction 2 in addition to the other ob-
vious differences, a component near 685
nm appears to be larger in spinach than
in Stichococcus.
In brief, the results of the past year's
work have emphasized the presence in
most preparations of more forms of
chlorophyll than are evident unless some
sort of curve analysis is carried out.
Continuing improvements in the
methods of curve analysis applied to a
DEPARTMENT OF PLANT BIOLOGY
587
large collection of precisely measured
spectra from a wide variety of prepara-
tions from many diverse plant species
may eventually decide between the three
concepts here described.
The costs of computer use for this
work since March 15, 1969, have been
covered by NSF Grant No. GB 8630,
which has made it possible to increase
greatly the number of spectra investi-
gated. It is a pleasure to thank Mr. Mark
Lawrence for programming help, Mrs.
Helen Kennedy for digitizing the curves,
and various colleagues for their contribu-
tions of selected spectra.
References
Brown, J. S., submitted to Biophys. J., 1969.
French, C. S., and Lillian Prager in Progress
in Photosynthesis Research, H. Metzner,
ed., II, 11 pp., (in press), 1969.
French, C. S., M. R. Michel-Wolwertz, J. M.
Michel, J. S. Brown, and Lillian Prager in
Biochemical Society Symposia Number 28,
Porphyrins and Related Compounds, T. W.
Goodwin, ed., Academic Press, London and
New York, pp. 147-162, 1968.
Thornber, J. P., Biochim. Biophys. Acta, 172,
130-144, 1969.
A Comparative Study of the Light-
Induced Carotenoid Change and Fluo-
rescence IN THE CHLOROPHYLL-6-LESS
Alga Botrydiopsis alpina
(Xanthophyceae)
David C. Fork and Yaroslav de Kouchkovsky
Introduction
A number of absorbance changes hav-
ing similar kinetics were seen upon il-
lumination of the yellow-green alga
Botrydiopsis alpina that were apparently
produced by a transient shift to longer
wavelengths of the absorption bands of
a carotenoid pigment {Year Book 66,
p. 160; Year Book 67, p. 496). Action
spectra measurements reported last year
{Year Book 67, p. 496) demonstrated
that both photochemical systems caused
the shift in this particular, as yet un-
identified, carotenoid. Inhibition of sys-
tem 2 by DCMU permitted the observa-
tion that system 1 mediated a rapid shift
of the carotenoid absorption to longer
wavelengths which reversed again during
illumination. The subsequent addition
of the electron donor couple DAD and
ascorbate produced a sustained caro-
tenoid shift in the light, again sensitized
by system 1. System 2 was also shown
to be responsible for a sustained caro-
tenoid shift that was relatively slow at
the light intensities used.
We studied here the dependence of the
carotenoid shift and of chlorophyll fluo-
rescence upon treatments that would in-
fluence the primary photoreactions. A
number of treatments were investigated
in an attempt to obtain separately the
carotenoid shift produced by each of
the two photosystems. We have found
both the initial rise and decay of the
carotenoid shift follow first-order kinetics
and an indication for another, slower
first-order component.
It may be that the carotenoid pigment
showing these shifts, like chlorophyll b,
undergoes slight absorption changes
when its supporting membrane is dis-
turbed by electron transport. The carot-
enoid shift is discussed in relation to
the chlorophyll-6 change, electron trans-
port and a high-energy "intermediate"
produced during photophosphorylation.
Materials and Methods
Botrydiopsis alpina was cultured as
previously described (Fork, 1969).
Light-induced differences of absorbance
at 515 nm were used to follow the carot-
enoid changes. These measurements were
done as described earlier (de Kouch-
kovsky and Fork, 1964). The half-band-
width of the measuring beam was 2 nm.
The algae were diluted with culture
medium so that the final transmission of
the cell suspension was around 10% at
515 nm. The temperature was 20 °C
and the gas phase was air. Sometimes
the results were also compared, using
588
CARNEGIE INSTITUTION
wavelengths other than 515 nm (such
as 482 and 497 nm) where absorbance
changes typical of the carotenoid can
be seen.
Fluorescence was measured simul-
taneously with absorbance changes.
Actinic light to excite fluorescence and
the carotenoid shift was incident on the
top surface of the cell suspension, which
was contained in an open cuvette. The
photomultiplier, for monitoring fluo-
rescence, was located above and to one
side of this cuvette. The actinic light
used in all these experiments had a
wavelength of 652 nm and a half-band
of about 9 nm. The light produced by
using Schott RG 1, 3 mm in combination
with a Balzers heat-reflecting filter Cal-
flex C, a water filter (27 mm), and a
Baird- Atomic interference filter type
B-l. The intensity of this beam was
about 2.9 nanoeinstein cm-2 sec-1 (5.3 X
103 ergs cm-2 sec-1). A combination of
Schott RG 10 (3 nm) and Baird-Atomic
interference filters (742 nm, type B-l,
half-band, about 9 nm) transmitted fluo-
rescent light of this wavelength but ab-
sorbed 652 nm actinic light. Fluorescence
at 742 nm is very likely a "satellite" of
the main emission band at 685 nm, and
is, therefore, a reflection of the function-
ing of system 2 (compare the composite
fluorescence band in vitro which is nearly
an image of the absorption band and
the experiments made in vivo that were
reported by Lavorel, 1962) .
A schedule of 6 seconds light and 48
seconds dark was used.
Results
The top trace of Fig. 12 shows kinetics
typical for the absorbance change pro-
duced at 515 nm upon illumination of
Botrydiopsis alpina {Year Book 67, p.
496). The initial increase of absorbance
Control
//
.1 —
Off
\
V AA5I5
r
— i
On
Menadione
//
_|l
|l
0
ff
V AA5i5
\
1
"
AF742
AF742
On
f —
II
1 1
i
i I
I I
1 i !
DCMU
1
NH2OH
\
~~1
1
11
II
^
T
1 1
i i
AA=5xlO"3
f
i
1 1
i 1
i i
1 i 1
\
^2o2
Na2S204
11 '
\
'l —
1 1
1
1
1 1
— 1 //J
i
i I
_J //J
1
i i
0 14 6 80 14 6 8
Time, sec
Fig. 12. Kinetics of light-induced absorbance changes at 515 nm produced upon illumination of
Botrydiopsis alpina with red actinic light (described in the text) and the effect of DCMU,
H2O2, NH2OH, Na2S204 and menadione. The concentrations (M) used were: DCMU, 5 X 10"B M ;
H202, 5X10"8 M; NH2OH, 1 X 10~2 M; Na.S.O*, 5 X 10"3 M ; and menadione, 1.6 X 10"5 M.
Note that a faster recording was made for the "on" than for the "off" portions of the traces.
DEPARTMENT OF PLANT BIOLOGY
589
produced upon illumination is followed
by a much slower rise which was com-
pleted within about 6 seconds in the light
(the length of the exposures used for
Fig. 12). Darkening produced a rapid
decrease of absorbance to the former
dark baseline.
Fig. 13 reveals that both the initial
rise and the decay of the carotenoid shift
are caused by first-order reactions. The
decay curve was obtained by plotting
the absorbance change that still re-
mained at intervals after darkening the
cell suspension. The rise curve was ob-
tained by plotting the carotenoid that
remained unreacted at intervals after
the actinic light was given. The half
times (t1/2) and the rate constants (k)
for the rise and decay are similar in
both cases. The values for the rise are
ti/2 = 0.07 sec and k = 9.5 sec-1, and for the
decay, £i/2 = 0.09 sec and k = 7.9 sec-1. In
some cases it was possible to analyze
the decay as the sum of two first-order
reactions.
The absorbance change produced by
carotenoids, like those caused by chloro-
phyll b, are strongly dependent upon
the dark interval given between ex-
posures. This effect was described in
Year Book 63, p. 441 for the chloro-
phyll 6 change. In essence, the carot-
enoid change also increases up to a cer-
tain maximum with increasing dark
.04
^v, ' '
l > I
' -
.03
-
.02
"
.01
Rise N. <
"
.005
-
ck Decay
-
.0025
i ! .
1 , 1
0.1 0.2
Time, sec
0.3
Fig. 13. Semilogarithmic plot of the rise and
decay of the 515-nm absorbance change in B.
alpina measured as described in the text.
intervals between exposures. This in-
crease is not proportional to the dark
interval but varies in a complex way.
Therefore, in all experiments reported
here, a uniform dark interval (48 sec)
was given between successive exposures
until a reproducible response was ob-
tained.
Having determined conditions needed
to obtain reproducible results it was
then possible to investigate the effects on
the carotenoid change and on fluorescence
of substances which are known (or could
be expected) to exert strong effects on
the early reactions of photosynthesis.
Fig. 12 shows examples of the results
produced on the carotenoid change and
on fluorescence after addition of the in-
hibitors DCMU and NH2OH, of a
reductant, Na2S204, an oxidant, H202,
and of vitamin K3 (menadione). As
noted previously (Year Book 67, p. 498),
DCMU had only a partial inhibiting
effect on the carotenoid change. The
on-rate in DCMU (Vif measured as
shown in the insert of Fig. 14) was
unaffected but the initial deflection, Xi}
(see insert) was increased. DCMU al-
most completely inhibited the steady-
state part of the change, Xs, and greatly
depressed the off-rate, Vs. Illumination
in the presence of the oxidant, H202,
produced a large increase in the initial
deflection (Xi) but a decrease in the
on-rate, Vi} resulting in maximum de-
flection being reached at longer times
than in the control. The steady-state
deflection, Xs, and the off-rate, Vs, were
decreased in the presence of H202. Hy-
droxylamine at the concentration used
for Fig. 12 (10-2 M) had no effect on the
on-rate, increased the initial deflection
slightly but lowered the steady state
and off-rate. Hydrosulfite (10-2 M)
slowed down the decay of the 515-nm
change and at the same time produced
increased fluorescence. A transient de-
crease of fluorescence appeared after
about 0.5 sec of illumination.
Measurements of the parameters of
the 515-nm absorbance change and those
590
CARNEGIE INSTITUTION
200
A DCMU
Initial defln. (Xi)
<J
IC
-1
I0"6
10-5
o
c
c
NH
2OH
a
in
<
<3
200
100
0
Off
, 1 i
ratefV^^
Ste
ady
nitial defln.(Xj)
^£)On rate(Vj)
state (Xjl
T . i i i ii
B H2°2
D
Menadione
^ ^_^^lnitia
1 defln. (Xj)
^
fl
ratctV,)
^~"^\^ °\
, , , 1
Steady staMXs) ^*
< , , 1 , , , ,
Off rate(Vs)
o ft
I0"6 I0"5
Concentration. M
Fig. 14. The effect of concentration of DCMU, H202, NH2OH, and menadione on various
parameters of the absorbance change at 515 nm in B. alpina measured as shown in the insert.
I0"6 10-5
Concent re Hon, M
Fig. 15. The initial, Fi, and peak, Fp, fluorescence (measured as shown in the insert) as a
function of the concentrations of DCMU, H2O2, NEL-OH, and menadione. The measurements were
made simultaneously with those for absorbance changes given in Fig. 14.
DEPARTMENT OP PLANT BIOLOGY
591
of fluorescence (determined as shown in
the inserts) are given in Figs. 14 and 15
as a function of the concentration of
H202, DCMU, NH2OH, and menadione
(vitamin K) .
An increase in the DCMU concentra-
tion from 10-7 to 2xl0-5 M had little
effect on the on-rate of the 515-nm
change, but it gave rise to strong in-
hibition of the steady-state change as
well as to the off-rate (Fig. 14A). By
4 X 10-6 M the initial deflection was
doubled. As customarily observed, the
initial fluorescence, Fi} increased with
increasing DCMU concentrations (Fig.
15A). The maximum peak fluorescence,
Fp, was doubled already at a concentra-
tion somewhat below 10~6 M. (At about
this concentration and above, the initial
deflection of the 515-nm change was in-
creasing strongly.) It should be noted
that measurements of Ft are somewhat
difficult to make with certainty because
the response time of the recorder makes
possible an overestimation by including
in this measurement part of the fast rise
of variable fluorescence.
Hydrogen peroxide, at concentrations
higher than 5 X 10-4 M inhibited the on-
and off-rates as well as the steady state
515-nm deflection, but it dramatically
increased the initial deflection (Fig. 14,
part B). Both the initial and the maxi-
mum peak fluorescence were increased
by addition of up to about 5xl0~3 M
H202 (Fig. 15, part B). Further addition
of H202 did not change F4 but it de-
creased Fp.
A thousandfold variation in the con-
centration of hydroxylamine (from 10~4
to lQ-1 M) produced relatively little ef-
fect on the on-rate of the 515 change
(Fig. 14, part C). At concentrations
above 10~3 M, NH2OH produced a pro-
gressive inhibition of the steady state
and the off-rate of this change con-
comitantly with a large increase in the
initial deflection. Figure 15, part C,
shows NH2OH had only a slight effect on
the maximum of peak fluorescence. Ini-
tial fluorescence was increased more than
Fp at concentrations above 10~3 M. Since
the curves are plotted as percent of the
control and not as actual values of Ft or
Fp, the crossing over of the two curves
does not mean that Ft becomes larger
than Fp. Below 10~3 M, however, there
was little effect of NH2OH on either
Fp or Fi.
Menadione (Fig. 14, part D) below
10-5 M had a slightly stimulatory effect
on both the initial deflection and the
on-rate of the 515-nm change, but it
inhibited slightly the steady-state change
and the off-rate. Above 10~5 M, all
parameters measured for the 515-nm
change declined, the on-rate declining
most rapidly. The initial fluorescence
was not effected by menadione at con-
centrations up to about 2 x 10-5 M (Fig.
15, part D). Above this it produced a
strong inhibition of the initial fluores-
cence. By contrast, the peak fluorescence
began to be inhibited at concentrations
above about 10~6 M. The effect of mena-
dione on variable fluorescence (the dif-
ference between the peak and initial
fluorescence) is also shown in part D of
Fig. 15. The maximum effect of mena-
dione on variable fluorescence occurred
between concentrations of 10~6 and 10~5
M. At 10-5 M variable fluorescence was
reduced by 50 percent.
Figure 16 shows the effect on fluores-
cence and on the carotenoid change of
combined additions of DCMU + H2Oo,
NH2OH + H202, and DCMU + NH2OH.
As was seen earlier in Fig. 14, H202
alone gave a large stimulation of the
initial deflection of the 515 change. Fig.
16 shows, as described above for Fig. 12,
that the time needed to attain the maxi-
mum deflection t was increased by ad-
dition of 14 peroxide. Variable results
were sometimes obtained for fluorescence
(but not for the carotenoid change) when
using hydrogen peroxide. In the experi-
ments shown in Fig. 16, H202 (5xl0~3
M) decreased somewhat both Fi and Fp
while in the experiment shown in Fig. 14
the same concentration produced in-
creased fluorescence. However, H202 al-
592
CARNEGIE INSTITUTION
400
-5 300
i_
"c
0
0
'o
§ 200
i_
<u
a.
in
m
<
< 100
AA5I5
X
X; » vs
Xr
Vj __
On
t
Xj
vs
t
Off
X;
t
x
xs
■1»
Vj
00
t
Xs
00000
0
u
V
. Flu
F> F
Xs
orescence74
/i xs
>>
Fluorescence, percent of con-
0 0
D 0 0
Fj
»
fp
Fp
Fj
Fj
F7_
F
Fp
<>
Control DCMU
H?0?
NH2OH DCMU NH2OH DCMU
■HpOo
•HoO? +NH2OH
Fig. 16. The effect of DCMU, H202, NH20H, and DCMU plus H20a, NH20H plus H202, and
DCMU plus NH2OH measured simultaneously on the 515-nm absorbance change and fluorescence
(as shown in the inserts). The concentrations used are given in the legend for Fig. 12.
ways had an effect on the kinetics of the
FitoFprise (Fig. 12).
Interestingly, the combination of both
DCMU and H202 completely inhibited
the carotenoid change while at the same
time it produced the usual approximate
doubling of fluorescence.
The combination of hydroxylamine
plus hydrogen peroxide did not produce
the dramatic inhibiting effect shown by
the combination of DCMU and H202.
Although the values could not be de-
termined precisely, the initial deflection
of the 515 change was decreased slightly
and the time, t, needed to attain the
maximum deflection was increased thus
producing a decrease of the initial on-
rate. Fluorescence was almost unaffected
by this combination.
Hydroxylamine plus DCMU gave a
2.5-fold stimulation of the initial deflec-
tion of the 515 change in addition to in-
creasing the on-rate and, as a conse-
quence, the time needed to attain the
maximum initial deflection was shortened
to about 50% of the control. The steady-
state 515 absorbance change was com-
pletely inhibited. This combination also
produced a 2.5-fold increase of the initial
fluorescence and about half as much in-
crease in the peak height of fluorescence.
Discussion
Since DCMU apparently acts by pre-
venting reoxidation of reduced Q (Duy-
sens and Sweers, 1963), it leads to the
inactivation of the traps of system 2.
DEPARTMENT OF PLANT BIOLOGY
593
The carotenoid change produced by sys-
tem 2 is also inhibited with DCMU be-
cause the action spectrum for the change
persisting after treatment showed sys-
tem 1 sensitization {Year Book 67, p.
496) . DCMU had almost no effect on the
on-rate of this carotenoid change over
the range of concentrations tested (10~7
to 2 X 10"5 M ) suggesting that the change
produced by system 2 is slower than
that produced by system 1. Action spec-
tra for the slow change appearing after
a few seconds of illumination showed
system-2 activity. In these experiments
the addition of H202 gave rise to a large,
but slow, change (Fig. 12) . Since perox-
ide is a strong oxidant, it may act by
oxidizing a component near system 1
such as P700 (see Fig. 17). If the effect
of H202 is to allow only a system-2 ca-
rotenoid change to persist, then DCMU
would be expected to abolish the change.
This was what actually occurred when
H202 and DCMU were combined as
shown in Fig. 16. Inactivation by H202
of some component near system 1 would
then allow accumulation of intermediates
reduced by system 2 and produce in-
creased fluorescence. Such a result was
described in Fig. 15 for fluorescence. It
is not known what conditions are re-
quired with H202 to produce both a slow
carotenoid change and increased fluo-
rescence since H202 sometimes did not
stimulate fluorescence. In most cases,
however, this is what was seen.
Hydroxylamine apparently acts on
system 2 by blocking reactions near
water splitting (de Kouchkovsky, 1961;
Joliot, 1968) . This compound at lO"3 M
produced nearly complete inhibition of
oxygen evolution but had almost no
effect on the dark-decay of the 515-nm
change and on the fluorescence of
Chlorella (de Kouchkovsky, 1969). Ap-
parently, hydroxylamine (NH2OH) at
this concentration replaces water
(H-OH) as the electron donor giving rise
to strong inhibition of oxygen evolution
and little effect on fluorescence. Simi-
larly, in Botrydiopsis low concentrations
of hydroxylamine (lO^-K)-3 M) had al-
most no effect on fluorescence nor much
effect on the carotenoid change. At con-
centrations above 10-3 M, however, this
substance acted like DCMU by increas-
ing the initial deflection and the on-rate
but inhibiting the steady state and the
off-rate of the carotenoid change and at
the same time increasing fluorescence.
Thus hydroxylamine at concentrations
higher than a certain level may interact
additionally at another site by prevent-
ing the return of Y+ to the Y state (Fig.
17).
Menadione has been shown (Year
— -i V A
H202 Na2S204 r
Fig. 17. Generalized scheme showing the effect of various substances on the carotenoid
change in B. alpina. For details see the text.
594
Book 66, p. 165; Amesz and Fork, 1967)
to be an effective quencher of the varia-
ble fluorescence originating in system 2.
This quenching process is apparently
caused by a direct interaction of chloro-
phyll and quinone molecules and not by
a stimulation of electron transport. More
evidence that menadione acts close to
system 2 was provided by the observa-
tion that this substance inhibited the re-
duction of the /-type cytochrome in light
absorbed mainly by system 2. In these
experiments menadione inhibited the
slow phase of the change (steady state)
mediated by system 2. Concomitantly
with this, menadione was extremely ef-
fective in quenching variable fluores-
cence in Botrydiopsis. The concentra-
tion for 50% quenching was 10 fiM. By
comparison, Viva required a concentra-
tion of 50 fxM (Fork and Amesz, 1967) .
In contrast to this inhibiting effect
on the steady-state 515-nm change,
menadione produced a stimulation of the
initial deflection over more than a hun-
dredfold variation in concentration.
Menadione produced a decline in the on-
rate at concentrations greater than about
1.5 XlO-5 M and a decline of the steady
state. Interestingly, DCMU, also acting
close to system 2, did not have an effect
on the on-rate of the 515-nm change.
Quanta absorbed by system-2 traps in-
activated by DCMU may become avail-
able to system 1 by a "spill-over" type
of mechanism (Myers and Graham,
1963). Amesz et al. (1969) found in the
blue-green alga Anacystis nidulans that
light absorbed by system 2 could, in the
presence of DCMU, be used for such
system-1 reactions as the oxidation of
cytochrome or P700. Subsequent addi-
tion of 1,4-naphthoquinone, a close rela-
tive of menadione (2-methyl-l,4-naph-
thoquinone) and an effective quencher,
prevented this spill-over. Menadione is
apparently effective in quenching fluo-
rescence since it provides "artificial"
traps for quanta absorbed by system 2
(Amesz and Fork, 1967) . Thus it would
prevent spill-over of quanta to system 1
CARNEGIE INSTITUTION
and would decrease the on-rate of the
515-nm change mediated by system 1.
Under these conditions the initial deflec-
tion would not be much affected (Fig.
14) but would take longer to appear.
There is no evidence to date to indi-
cate that the carotenoid showing these
light-induced shifts participates as a
redox catalyst in the electron-transport
chain. Rather, it appears that the change
may reflect, as does the chlorophyll-6
change, a disturbance of the supporting
membrane as a result of electron trans-
port. Junge and Witt (1968) recently
postulated that the chlorophyll-6 change
(seen at 475, 515, and 650 nm in plants
containing this chlorophyll) is produced
by the formation of an electrical field
across the thylakoid membrane, which
in some unknown way, gives rise to a
change in the absorption of chlorophyll 6
and then a translocation of H+. The
chlorophyll-6 change was found (Junge
and Witt, 1968) to have a biphasic decay
after a short light flash that could be
decomposed into two first-order reac-
tions. Analysis made here of the rise and
decay of the carotenoid change showed
that both followed first-order kinetics,
and there is some indication for another,
slower, component also exhibiting first-
order kinetics. Junge and Witt observed
a linear relationship between the rate
of phosphorylation and the amplitude of
the slow phase of the chlorophyll-6
change in spinach chloroplasts. Condi-
tions producing phosphorylation acceler-
ated the decay of this change by the
same amount as electron transport.
In bacteria Amesz and Vredenberg
(1966) found a quantum yield of 3 for
the carotenoid shift, suggesting that these
changes are not produced by a chemical
reaction. More likely, electron transport
in the membrane causes a change in the
environment of the carotenoids resulting
in a small change in their absorption
spectrum. Baltscheffsky (1969) has sug-
gested that an energy-rich intermediate
of phosphorylation coupled to electron
transport produced a membrane con-
DEPARTMENT OF PLANT BIOLOGY
595
formation resulting in the carotenoid
shift in bacteria. Fleischman and Clay-
ton (1968) suggested, on the basis of
studies with inhibitors and uncouplers,
that the carotenoid shift in Rhodopseu-
domonas spheroides depends upon the
formation of an energy-rich intermedi-
ate of phosphorylation. It will be of in-
terest to determine whether the carot-
enoid shift that can be seen in algae and
higher plants can be related in a similar
manner to a membrane change and pho-
tophosphorylation.
References
Amesz, J., and D. C. Fork, Biochim. Biophys.
Acta, 143, 97-107, 1967.
Amesz, J., and W. J. Vredenberg, in Currents
of Photosynthesis, J. B. Thomas and J. C.
Goedheer, eds., Donker, Rotterdam, pp.
75-83,1966.
Amesz, J., W. Noteboom, and D. H. Spaar-
garen, in Progress in Photosynthesis Re-
search, H. Metzner, ed., Proc. Intern.
Congr. Photosynthesis Research, Freuden-
stadt, Germany, in press, 1969.
Baltscheffsky, M., Arch. Biochem. Biophys.,
130, 646-652, 1969.
Duysens, L. N. M., and H. E. Sweers, in
Studies on Microalgae and Photosynthetic
Bacteria, Special Issue of Plant and Cell
Physiol., Jap. Soc. of Plant Physiologists,
The Univ. of Tokyo Press, pp. 353-372,
1963.
Fleischman, D. E., and R. K. Clayton, Photo-
chem. Photobiol, 8, 287-298, 1968.
Fork, D. C, in Progress in Photosynthesis
Research, H. Metzner, ed., Proc. Intern.
Congr. Photosynthesis Research, Freuden-
stadt, Germany, in press, 1969.
Joliot, A., Thesis, Univ. of Paris (1968).
Junge, W., and H. T. Witt, Z. Naturforsch,
23b, 244-254, 1968.
de Kouchkovsky, Y., Comp. Rend. Acad. Sci.,
Fr., 252, 2026-2028.
de Kouchkovsky, Y., in Progress in Photo-
synthesis Research, H. Metzner, ed., Proc.
Intern. Congr. Photosynthesis Research,
Freudenstadt, Germany, in press, 1969.
de Kouchkovsky, Y., and D. C. Fork, Proc.
Natl. Acad. Sci. U. S., 52, 232-239, 1964.
Lavorel, J., Biochim. Biophys. Acta, 60, 510-
523, 1962.
Myers, J., and J. R. Graham, Plant Physiol.,
38, 105-116, 1963.
The Effect of Ultraviolet Irradiation
on the Carotenoid Change, Electron
Transport, and Photosynthesis of
Botrydiopsis alpina
David C. Fork and Kenneth E. Mantai
Many similarities exist between the
absorbance changes produced by chloro-
phyll b in green algae and higher plants
and those attributed to a long-wave-
length shift of a carotenoid in the yellow-
green alga Botrydiopsis alpina (cf. Fork,
1969, and elsewhere in this report). The
light-induced difference spectrum for the
carotenoid change in this alga has
maxima at 450, 482, and about 515 nm
(and minima at 466 and 497 nm). The
carotenoid change may be conveniently
followed at any of these peak wave-
lengths; for this study we have chosen
482 nm. The difference spectrum in an
alga with chlorophyll b such as Viva,
by contrast, has a positive maximum
around 515 nm and negative minima
near 475 and 650 nm (Fork et al, 1966) .
The kinetics of the chlorophyll b
change and the carotenoid change have
many features in common. Both show
upon illumination a rapid initial deflec-
tion followed by a slower and larger
change in the light. Darkening produces
a rapid decay to the former base line. An
example of the kinetics seen at 482 nm
is given in the trace on the left side of
Fig. 18. As explained in another section
of this report, these absorption changes
are dependent upon the dark interval
given between exposures. Therefore, for
the experiments reported here, an appro-
priate scheduling was used until repro-
ducible changes were attained.
Action spectra for the initial deflec-
tion have shown sensitization by system
1 for both the chlorophyll-6 change
596
CARNEGIE INSTITUTION
T
AA = lxlO"3
Off
-4
Time of UV treatment, min:
1
00
<
<
[
0
(\
3
f\
6
9
I
1
On
1
i i 1
Mil
i i
1 i i i 1
i i
Mm
t
1 i
M 1 i i i 1
T
8 0
ime.sec
Fig. 18. The effect of ultraviolet irradiation (253.8-nm mercury line) on the kinetics of light-
induced absorbance changes at 482 nm in Botrydiopsis alpina. A schedule of 3 seconds light and
6 seconds dark was used. Half-band width of the measuring beam was 2 nm. The red actinic light
was a broad band from 620 to about 800 nm and had an intensity of 12 X 105 ergs cm"2 sec"1.
(Fork et al., 1966) and the carotenoid
change {Year Book 67, p. 496; Fork,
1969) . The slow phase appearing after
several seconds of illumination is acti-
vated by system 2 in both cases. Earlier
studies with Scenedesmus have shown
(Mantai and Bishop, 1967) that the slow
phase of the chlorophyll-6 change is
more sensitive to ultraviolet irradiation
than is the rapid, initial deflection. Be-
cause of the similarities between the
changes described above, it was expected
that the slow phase of the carotenoid
change mediated by system 2 would be
more sensitive to ultraviolet irradiation
than would the initial deflection. Figure
18 shows that this actually was the case.
After 6 minutes of UV treatment the
slow phase was strongly affected. The
slow phase of the change was measured
as the maximum excursion of the trace
above the initial, rapid on-deflection. By
contrast, the height of the initial deflec-
tion of the 482-nm change was hardly
affected until longer times of irradiation
had passed. After this ultraviolet treat-
ment the cells produced a time course
having a large, transient negative change
upon darkening. Fig. 19A shows a semi-
logarithmic plot of the slow phase re-
maining after increasing times of ir-
radiation with UV. Since the absorbance
change observed consists of several com-
ponents, a strict measurement of the
fast and slow phases is difficult (see Fig.
18). As shown in Fig. 19A, there is an
initial lag period of about 5 minutes
during the ultraviolet treatment before
inhibition of the slow phase begins. This
suggests that some reaction other than
the one being inhibited by the UV ir-
radiation is rate limiting for the absorb-
ance change, and it is not until the
process affected by the irradiation itself
becomes rate limiting that a decrease in
the absorbance change occurs. After the
initial lag period, the decay of activity
with time follows first-order kinetics;
and back extrapolation of the linearly
decreasing part of the curve yields a half
time (t1/2) for decay of about 5 minutes.
This lag period was not always seen,
however. The absorbance changes shown
in Fig. 18 (obtained from a different
sample than that used for Fig. 19) did
not show this lag in the UV effect. Never-
theless, the slow phase, when measured
as described above, also decayed by first-
order kinetics and had a t1/2 of about 6
minutes. The decay of the chlorophyll-6
change in spinach chloroplasts after ir-
radiation was also found to be first order
(Mantai, unpublished) .
A study was made of the effect of UV
irradiation on the reaction centers of
system 2. For this we measured the
DEPARTMENT OF PLANT BIOLOGY
597
10 20
Irradiation time.min
Fig. 19. (A) The slow phase of the 482-nm
change in B. alpina as a function of increasing
times of UV irradiation. The slow part of the
change was measured as described in the text.
The actinic light was the same as described
in Fig. 18. The same culture of cells was used
for all the measurements shown in Fig. 19. (B)
Variable fluorescence in B. alpina treated with
DCMU (1 X 10"4 M) as a function of the time
of exposure to UV. Variable fluorescence was
measured as the difference in level between the
fluorescence produced immediately upon il-
lumination and the maximum level produced.
Dark interval between exposures, 30 seconds.
Measurements were made at 685 nm (half-band
amount of variable-yield fluorescence
remaining after increasing periods of
UV treatment. Duysens and Sweers
(1963) have shown that fluorescence
having a variable yield during illumina-
tion is controlled by the reduction state
of the system-2 reaction centers. When
these traps are reduced, fluorescence is
high; and when they are oxidized, the
traps serve as quenchers (Q) and de-
crease fluorescence. Fig. 19B shows that
the variable-yield fluorescence also de-
cayed by first-order kinetics, with a
half-time for inactivation similar to that
of the carotenoid change (4-5 minutes) .
Similar results have been reported earlier
for the effect of UV on variable fluo-
rescence in spinach chloroplasts (Mantai,
1968; Malkin and Jones, 1968).
Light-induced reactions of the /-type
cytochrome in Botrydiopsis were fol-
lowed by measuring absorbance changes
at 420 nm. This cytochrome has been
shown by many workers in many differ-
ent types of plants to be oxidized by
system 1 and reduced by system 2. This
effect was confirmed also for Botrydi-
opsis. Fig. 19C shows that the reduction
of the cytochrome was sensitive to UV
and decayed by first-order kinetics with a
t1/2 of about 6 minutes. In contrast to re-
15 nm) by using interference and colored glass
filters that transmitted fluorescent light but
absorbed the blue actinic light. The latter had
a peak near 420 nm, a half-band of 40 nm, and
an intensity of about 102 ergs cm"2 sec-1. (C)
Light-induced reactions of the /-type cyto-
chrome in B. alpina as a function of exposure
time to ultraviolet. Measurements were made
at 420 nm, half-band width 2 nm. The differ-
ence spectrum matched that of cytochrome /
and had a maximum at 403 nm, with a Soret
band near 419 nm. For each measurement the
rate of reduction upon darkening was measured
and was corrected for the endogenous cyto-
chrome reduction remaining after the cells were
poisoned with DCMU as described in (B). The
initial rate of absorbance increase (reduction)
divided by the steady-state level of oxidation
attained in the light (in DCMU) was plotted
as shown. Oxidation was taken as the light-
induced steady-state absorbance decrease pro-
duced in the presence of DCMU. Red actinic
light was as described for Fig. 18.
598
CARNEGIE INSTITUTION
duction, the oxidation of the cytochrome
(mediated by system 1) was unaffected
by irradiation times up to about 20
minutes. After this, oxidation was also
affected. It should be noted that all these
comparative measurements on the carot-
enoid change, variable fluorescence, cyto-
chrome reduction, and oxidation were
made with the same sample.
The data given above supports also
the hypothesis that the slow phase of
the carotenoid change is produced by
system 2. Since the kinetics and the
effects of UV on both the carotenoid
and chlorophyll-6 changes are very simi-
lar, it would appear that both of these
absorbance changes result from similar
reactions, although the compound re-
sponsible for the change in each case
may be quite different. If these changes
reflect some type of disturbance pro-
duced in their supporting membrane by
a process such as electron transport (for
example, by generation of an electric
field across a membrane as proposed by
Junge and Witt, 1968), then UV may
act by disrupting membranes in some
way. Other evidence (Mantai, 1968) has
also suggested that ultraviolet light
produces a disruption of lamellar mem-
branes.
References
Duysens, L. N. M., and H. E. Sweers, in
Studies on Microalgae and Photosynthetic
Bacteria, Special Issue of Plant and Cell
Physiol., Jap. Soc. of Plant Physiologists,
The Univ. of Tokyo Press, pp. 353-372,
1963.
Fork, D. C, J. Amesz, and J. M. Anderson,
in Energy Conversion by the Photosyn-
thetic Apparatus, Brookhaven Symp. in
Biol., 19, Brookhaven National Laboratory,
Upton, N. Y., pp. 81-94, 1967.
Fork, D. C, in Progress in Photosynthesis
Research, H. Metzner, ed., Proc. Intern.
Congr. Photosynthesis Research, Freuden-
stadt, Germany, in press, 1969.
Junge, W., and H. T. Witt, Z. Naturforsch.,
23b, 244-254, 1968.
Malkin, S., and L. W. Jones, Biochim. Bio-
phys. Acta, 162, 297-299, 1968.
Mantai, K. E., Thesis, Oregon State Univ.,
Corvallis, Oregon, 1968.
Mantai, K. E., and N. I. Bishop, Biochim.
Biophys. Acta, 131, 350-356, 1967.
Electron Transport and Degradation
of Chloroplasts by Hydrolytic
Enzymes and Ultraviolet
Irradiation
Kenneth E. Mantai
Recent development of the chemios-
motic hypothesis for the mechanism of
both oxidative and photosynthetic phos-
phorylation has led to increased interest
in membrane structure and integrity as
a vital factor in efficient operation of
the energy trapping reactions. Measure-
ment of various chloroplast reactions
after treatments which disrupt the mem-
brane structure could help to elucidate
the role that the structural integrity of
membranes plays in these reactions. Be-
cause chloroplast membranes consist of
about 50% lipid and 50% protein,
digestion of these substances with appro-
priate enzymes could provide informa-
tion on their importance in the mem-
brane structure. There is evidence that
the inhibition of photosynthesis by ultra-
violet irradiation is due to a structural
disruption of the chloroplast membranes.
The following report compares the ef-
fects of UV irradiation, pancreatic lipase
digestion, and trypsin digestion on elec-
tron transport as measured by DCIP
(2,6 dichlorophenolindophenol) reduc-
tion in spinach chloroplasts.
Both UV irradiation and lipase di-
gestion decrease the level of fluorescence
in chloroplasts (Kok, et al., 1967; Oka-
yama, 1964), suggesting that the photo-
chemistry itself is being affected by the
treatments. Fig. 20 shows the effects of
UV irradiation, pancreatic lipase, and
trypsin digestion on the relative quantum
yield of DCIP reduction. As seen in the
figure, all three treatments decreased
the quantum yield, confirming that the
DEPARTMENT OF PLANT BIOLOGY
599
10 20 30 40 50 60
Light intensity, ergs crrf2sec~' xlO"3
Fig. 20. Effects on relative quantum yield of
DCIP reduction after UV irradiation, pan-
creatic lipase digestion, or trypsin digestion.
Reaction mixtures consisted of: sucrose, 0.4 M ;
KC1, 15 ml; Tricine, 50 ml (pH 7.6) ; DCIP,
33 (jlM and chloroplasts containing about 40
fig chlorophyll, the exact amount varying
slightly from experiment to experiment. The
total volume was 3.0 ml. Enzyme digestions
were carried out at 25°C in 0.4 M sucrose, 15
ml KC1, and 50 mM Tricine (pH 7.6). UV
irradiation was performed as previously de-
scribed (Mantai and Bishop, 1967).
photochemistry was indeed being in-
hibited.
There is considerable evidence for
two pathways of electron transport in
chloroplasts, only one of which is coupled
to photophosphorylation. Therefore, the
possibility that there might be a differ-
ence in the sensitivity of these pathways
to the action of trypsin, lipase, or UV
irradiation was tested by treating the
chloroplasts and then measuring the rate
of DCIP reduction in the presence or ab-
sence of a chemical uncoupler (CCCP,
methylamine, NH4C1, atebrin, or grami-
cidin D).
Electron transport measurements made
after UV irradiation, Fig. 21, shows that
there was no difference in the rates at
which coupled or uncoupled electron
transport was inhibited (compare ir-
radiated and methylamine uncoupled
curves). CCCP uncoupled less effec-
tively, and finally inhibited slightly, as
the period of irradiation increased (see
also below). In this experiment, a high
concentration of CCCP (33 fiM) was
used. Reducing the CCCP concentration
to 3.3 ixM did not qualitatively change
the results. The rates shown in the figure
are under light saturating conditions.
It should be mentioned that in this type
of experiment if the two pathways have
initial steps in common (e.g., trapping
centers), and one of these steps is rate
limiting, any differences in sensitivity
between the rest of the two pathways
would not be detected.
A similar experiment measuring DCIP
reduction after digestion with pancreatic
lipase is shown in Fig. 22. In this case
300
200 -
20
0 3 6 9 12 15
Time of irradiation, min
Fig. 21. Effect of uncoupling agents on DCIP
reduction after UV irradiation. Conditions as in
Fig. 20 with uncouplers added to give the fol-
lowing concentrations: CCCP, 33 fiM and
methylamine, 20 mM.
600
CARNEGIE INSTITUTION
f- 320
240 r y. — ■
1 I 1
'
Additions to Lipase
o + CCCP
1
treated: -
\_
■ a
A + Atebrin
A + Gramicidin D
r s~
/
V
"~"N _
C+ Methylamm*
■ + NH.CL
"
"
L Lipase tr
eated (•) \
-
Control (x)
\t
— :
"
! ' 1
o
■
a o 2 4 6 8 10 12
Time of incubation, min
Fig. 22. Effect of uncoupling agents on DCIP
reduction after digestion with pancreatic lipase.
Reaction conditions as in Fig. 20 with mi-
couplers added to give the following concen-
trations: CCCP, 3.3 /xM; atebrin, 10 nM ;
NH4C1, 1 ml; methylamine, 20 mM and
Gramicidin D, 0.5 g ml-1. Solid line shows lipase
treated sample in absence of added uncouplers.
Dashed line shows control sample without
added uncouplers.
the lipase itself acts initially as an effi-
cient uncoupler as shown by the in-
creased electron flow. The zero-time
sample shows considerable uncoupling
because about 30 seconds elapsed be-
tween the time the enzyme was added
and a sample removed. The uncoupling
is complete after a short time, and addi-
tion of chemical uncouplers causes no
further stimulation of electron flow.
After continued digestion the total rate
of light-saturated DCIP reduction de-
creases.
Trypsin digestion also uncouples
chloroplasts (Fig. 23A) , although not as
effectively as lipase as seen by further
stimulation of electron transport after
addition of methylamine. Again, con-
tinued digestion led to a decrease in
photoreductive capacity. In the experi-
ment shown in Fig. 23B the uncoupler
CCCP was added to trypsin-treated
chloroplasts. Under these conditions
CCCP acted as a potent inhibitor of
electron transport. This inhibition ap-
pears to affect only the "extra" or coupled
electron transport pathway. The same
concentration of CCCP (3.3 /jM) caused
a doubling (Fig. 23B) of electron trans-
0 5 10 15
Time of incubation, min
Fig. 23. Effect of methylamine or CCCP on
DCIP reduction after trypsin digestion. Condi-
tions as in Figs. 20 and 21.
port in untreated chloroplasts and did
not inhibit either UV- or lipase-treated
samples. However, there did appear to be
a slight inhibitory effect in UV treated
chloroplasts as irradiation time increased
(Fig. 21) . CCCP has been reported to in-
hibit electron transport at relatively high
concentrations in untreated chloroplasts,
but, as shown in Table 7, the inhibition
was not concentration-dependent in
trypsin-treated chloroplasts. CCCP did
DEPARTMENT OF PLANT BIOLOGY
601
TABLE 7. The Effect of Various Concentrations of CCCP on the Rate of
DCIP Reduction * in Control and Trypsin Treated Spinach Chloroplasts
CCCP Concentration, /xM
Control
Trypsin treated
0.0
79.1
45.8
0.33
81.6
46.6
0.66
39.4
1.70
58.9
3.33
107.0
32.0
9.99
161.2
Expressed as /m moles red. mg. chl 1 hr \ Conditions as in Fig. 20.
not stimulate DCIP reduction at con-
centrations as low as 0.33 \xM in trypsin
digested chloroplasts nor did it inhibit
untreated chloroplasts at concentrations
as high as 10 \xM. Treatment of chloro-
plasts with papain, another proteolytic
enzyme, gave similar results.
Reports from Park's laboratory have
shown that glutaraldehyde-fixation of
chloroplasts stabilized system-2 activity
(Park, et al, 1966) . Although the initial
activity of these chloroplasts is low, the
rate of DCIP reduction is stimulated
by the uncoupler methylamine and in-
hibited by DCMU, suggesting that the
activity is the result of true photosyn-
thetic reactions and not of artifacts in
the fixation procedure. It has also been
shown that glutaraldehyde cross-links
proteins, both inter- and intramolecu-
larly, without greatly affecting their
conformation. In view of this, experi-
ments were performed to determine
whether fixation would provide protec-
tion against the action of trypsin, lipase,
or UV irradiation. In Fig. 24 the effects
of UV irradiation on DCIP reduction
in fixed and normal chloroplasts are
shown. The fixation procedure had no ef-
fect on the inhibition by UV irradiation.
Figure 25 shows the results of similar
experiments measuring the effects of
fixation on the inhibition by (A) pan-
creatic lipase and (B) trypsin. Glutaral-
dehyde-fixation afforded striking pro-
tection against the inhibitory effects of
these two enzymes. Measurement of the
fatty acids liberated after lipase diges-
tion did not reveal any great difference
between fixed and unfixed samples, in-
dicating that the lipase was still able to
attack the fixed chloroplasts. No attempt
was made to assay the activity of the
trypsin in fixed and unfixed samples.
The possibility thus remains that the
fixation procedure made the lamellar
proteins unavailable to the trypsin, per-
haps simply by steric hindrance. How-
ever, fixed chloroplasts exhibited partial
uncoupling by trypsin, suggesting that
the enzyme attacks the membrane.
Since glutaraldehyde-fixation protects
against the effects of lipase, it would ap-
pear that those lipids readily hydrolyzed
>^
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KT>
E
o
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c
o
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-a
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Time of irradiation, min
Fig. 24. Effect of UV irradiation on normal
and glutaraldehyde-fixed chloroplasts. Reac-
tion mixture consisted of phosphate buffer,
0.01 M (pK 7.3); DCIP, 33 fiM and chloro-
plasts containing about 40 /j.g chlorophyll.
602
CARNEGIE INSTITUTION
1
Lipase digested
A
200
100
_
_
80
-
\ Unfixed
-
60
-
-
T 40
_
_
_c
_
"€ 20
en
£
t-
\ °
Fixed
o
c
O
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3.
-
c
o
o
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u 80
ql
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Q
i
Trypsin digested
B
'o 40
~o
CC
i Unfixed
-
20
-
-
-— 4— _ °
\ o
Fixed
o
— — o
1 1 1
-
0 10 20 30
Time of incubation, min
Fig. 25. Effect of pancreatic lipase or trypsin
digestion on DCIP reduction in normal and
glutaraldehyde-fixed chloroplasts. Conditions as
in Fig. 24.
by pancreatic lipase are required only
as a "glue" and not as obligate com-
ponents for electron transport. The pro-
tection afforded by fixation against
trypsin is somewhat less easily explained.
Trypsin preferentially attacks peptide
bonds in which the carboxyl group is
donated by a basic amino acid residue,
usually arginine or lysine. Chloroplast
lamellar and structural protein is rather
low in both of these amino acids and
relatively few breaks in the protein
molecules would be expected. Glutaralde-
hyde, by cross-linking both inter- and
intramolecularly, may hold the protein
conformation in its original state in spite
of the breaks in the protein molecules
themselves.
UV irradiation inhibits in a manner
similar to trypsin and lipase, with some
striking exceptions. The most evident is
the lack of uncoupling by UV irradiation
(see Fig. 21). PMS-mediated cyclic pho-
tophosphorylation is inhibited by UV
irradiation at about the same rate as the
loss of Hill reaction activity, at least
with relatively low (although still satu-
rating for the Hill reaction) actinic light
intensities. However, lack of uncoupling
implies that the site of inhibition may
be in the electron transport chain rather
than in the phosphorylation mechanism.
As shown in Fig. 20, the relative quan-
tum yield of DCIP reduction decreases
after UV irradiation (as does the varia-
ble fluorescence) indicating that system
2 is being affected. Moreover, since cyclic
photophosphorylation is at least one
component removed from system 2
(DCMU blocks after the primary elec-
tron acceptor for system 2, but does not
inhibit cyclic photophosphorylation),
UV irradiation must either produce a
general effect on the membrane system
or inhibit at two separate sites. There is
no strong evidence that UV irradiation
destroys a specific component or com-
ponents of the electron transport chain.
Although plastoquinone and other qui-
nones are in fact destroyed by UV ir-
radiation, it does not appear that this is
the major cause of the inhibition
(Mantai and Bishop, 1967).
It seems reasonable to conclude that
the inhibition of electron transport by
pancreatic lipase, trypsin, and probably
UV irradiation as well, is caused by a
structural disruption of the lamellar
membranes rather than inactivation of a
specific component. The inhibition by
UV irradiation, however, appears to be
more specific and does not uncouple al-
though phosphorylation is inhibited.
DEPARTMENT OF PLANT BIOLOGY
603
References
Kok, B., et al, Energy Conversion by the Pho-
tosynthetic Apparatus, Brookhaven Symp.
in Biol. No. 19, Brookhaven National
Laboratory, Upton, New York, pp. 446-
458, 1967.
Mantai, K. E., and N. I. Bishop, Biochim.
Biophys. Acta, 131, 350-356, 1967.
Okayama, S., Plant and Cell Physiol., 5, 145-
156, 1964.
Park, R., et al., Proc. Natl. Acad. Sci., 55,
1056-1062, 1966.
Effects of JV-Methylphenazonium
Methosulfate and Pyocyanine on
Delayed Light Emission in Chlorella
Cells and Spinach Chloroplasts
L. 0. Bjbrn
In trying to understand the process
of photosynthesis it is useful to study the
reverse process, i.e., the delayed light
emission (afterglow) that comes from
plants even several minutes after they
have been transferred from light to dark-
ness.
That the light emission is closely re-
lated to photosynthesis is indicated by
the fact that many chemical agents
which influence the latter also change
the former. Thus the substances reported
below to change the pattern of light
emission are known to be efficient, al-
though artificial, catalysts of photo-
synthetic phosphorylation.
One aim of biological research is to
determine the minimum unit that can
perform a certain function and to iden-
tify this unit structurally. It has long
been known that the chlorophyll mole-
cules do not function separately in pho-
tosynthesis, but rather cooperate in
groups. The number of cooperating mole-
cules found in a group or "photosynthetic
unit" depends on the kind of experiment
by which it is measured. The unit for
the primary conversion of light into
chemical energy contains a few hundred
chlorophyll molecules, while several such
units might form a larger unit capable of
more complex functions. The experiments
described below indicate that a specific
kind of afterglow originates in units con-
taining about the same number of chloro-
phyll molecules as the structural unit
called a thylacoid.
In these experiments the plant sample
was first illuminated for 30 seconds. The
exciting light was then shut off and the
afterglow measured for a few minutes.
The exciting wavelength, isolated with
interference filters, was either 648 or
730 nm. The sample was either Chlorella
pyrenoidosa (Indiana Culture No. 252)
or spinach chloroplasts ("whole chloro-
plasts" in 0.34 M NaCl buffered to pH
7.7-7.8 with 0.05 M Tricine) . The light
emission was recorded from about one
second to a few minutes after the end of
excitation. Air had free access to the
samples, and the Chlorella were kept
suspended by a continuous stream of air
bubbles during irradiation and measure-
ment.
With intact cells the decay kinetics
vary with the wavelength used for excita-
tion. With 648 nm a monotonic decay is
obtained; but after excitation with
730-nm irradiation of sufficient intensity
and duration the light emission drops to
a minimum, rises again to a maximum
and finally slowly declines. This maxi-
mum at about 1 minute in the decay
curve was first described by Bertsch and
Azzi (1965). This so-called component V
(nomenclature of Shuvalov and Litvin,
1969) that is induced only by long-wave-
length light, differs from other kinds of
afterglow not only by its action spectrum
and time dependence, but also by the
emission spectrum (Litvin and Shuvalov,
1966) . It also has a different temperature
dependence (Bertsch and Azzi, 1965;
Shuvalov and Litvin, 1969), and is
strongly influenced by oxygen.
Among the more interesting results of
the current experiments are the effects
of Af-methylphenazonium methosulfate
(PMS) and its photooxidation product,
pyocyanine, on the afterglow. Both seem
to enter Chlorella rapidly. PMS accele-
604
CARNEGIE INSTITUTION
rates the emission of component V. The
effect can be detected with a PMS-con-
centration of only 10~9 M (Figures 26
and 27). The 648-nm-induced emission
is affected only by much higher concen-
trations. Pyocyanine gives the same ef-
fects as PMS, but a ten times higher con-
centration is required. The same effect of
pyocyanine has been described by Rubin
and Venediktov (1967) for Vallisneria,
but the concentration used in their in-
vestigation was very high (10-2 g 1_1 =
4.8xlO-5M).
The results in Figures 26 and 27 were
obtained with dilute suspensions of algal
cells, and in this case the effect of PMS
depends on its concentration but is inde-
pendent of the algal concentration. If
very dense suspensions are employed,
PMS is somewhat less effective on a con-
centration basis. However, when the
amount of PMS is expressed in relation
to the amount of Chlorella, the efficiency
is higher in dense suspensions. In one
series of experiments a suspension with
the following characteristics was used:
cell concentration, 1.0 xlO11 1_1; chloro-
phyll concentration, 1.77 mM (chl a
1.34 ml, chl b 0.43 ml) ; packed cell
250
1 1 1 1
1
1
I
\\ Concentration
1 > 1
of PMS:
1
I *\ 3x10-8 M
1 v*"
K/ v. io-
\ 3xlO"9M \\f
8M
— """v"
0
! 1 1 1
! i i
9M
1
>^~
1
f
0 50 100
Time after exposure, sec
Fig. 26. PMS accelerates the slow light emis-
sion, component V, in a suspension of Chlorella.
Concentration of chlorophylls a + b = 4.3 X
10"5 M , excitation by 30 seconds far red, 730 nm,
at about 4 X 10* erg cm"2 sec-1.
:♦= 200
--730nm.30sec;
dark 20sec
10-9 10-6 I0"7 I0-6 I0"5 I0'4
Concentration of PMS.M
Fig. 27. Effect of PMS on the afterglow from
Chlorella suspensions (concentration of chloro-
phylls a + b ranging from 6.6 X 10"6 to 6.8 X
10"4 M) excited by 30 seconds of either red
(648-nm) or far red (730-nm) light. The
abscissa indicates the concentration of PMS, the
ordinate the afterglow intensity 20 seconds or
70 seconds after end of exposure, as indicated
on the curves.
volume, 29% of suspension volume. Table
8 shows the effect of 1 X 10"8 M and 3 X
10-8 M PMS at this high cell concentra-
tion. It was found that, when a suffi-
ciently long time had elapsed after the
end of excitation, the luminescence in-
tensity with PMS declined to a certain
fraction of the intensity without PMS,
and that this fraction eventually reached
a fixed value. For 1 X 10~8 M PMS, this
limiting value was 0.62.
If we assume that there are "after-
glow units" of approximately uniform
size (perhaps related to the "photosyn-
thetic units"), the result of the above
experiment can be used to determine a
maximum concentration of these units
(corresponding to a minimum size). If
DEPARTMENT OF PLANT BIOLOGY
605
at any time the intensity of luminescence
with PMS is only the fraction x of that
without PMS, then at least the fraction
(1—x) of the luminescent units are in
some way affected. A unit which is af-
fected must be associated with at least
one molecule of PMS. Thus the molar
concentration of afterglow units cannot
exceed (molarity of PMS)/ (1 -x).
In the present case with [PMS] =
lXlO"8 M and x = 0.62, the maximum
molarity of afterglow units is (1 X 10~8)/
0.38 M = 2.63xl0-8 M. Since the con-
centration of chlorophyll is 1.77 X 10"3 M,
there are at least 6.7 xlO4 molecules of
chlorophyll per unit.
The unit estimated in this way is con-
siderably larger than the "classical"
photosynthetic unit. It may be identical
with the unit estimated by Junge and
Witt (1968) for the light-induced chloro-
phyll-6 change. They estimate a size of
about 105 chlorophyll molecules, and be-
lieve the unit to be one thylacoid.
This estimate of unit size applies of
course only to component V afterglow.
The other afterglow components may
emanate from units of different sizes.
Low concentrations of PMS only in-
crease the rate of emission but do not
change .the amount of light emitted. In
the experiment shown in Table 8, the
long-term emission was decreased to 62
and 39% by the two concentrations of
PMS, but the light integrated from 5 to
370 seconds after the end of excitation
was 105 and 102% of the value of the
1 I
\ PMS added/
' i i
, i
\ \ r i ,
\ \_ Control
i I i
_
0 40 80 120
Time after exposure, sec
Fig. 28. Afterglow from 2.5 ml Chlorella
suspension (concentration of chlorophylls a +
b = 1.6 X 10"* M ) excited by 30 seconds far red
(730-nm) light at about 4 X 10* erg cm"3 sec-1.
Forty seconds after the end of the exposure, ap-
proximately 0.5 ml of either water (dashed line)
or 10"5 M PMS (solid line) were injected.
control without PMS. However, with a
high concentration of PMS the total
amount of light is decreased.
The acceleration of emission by PMS
can also be demonstrated by injecting it
into the sample in the dark period after
excitation. In the experiment shown in
Figure 28 a large amount of PMS was
used, and it is readily seen that the total
amount of light emitted was decreased
by PMS.
Although leaves of many plants (in-
cluding spinach) were found to give
decay curves of essentially the same type
as Chlorella, isolated chloroplasts seem
to lack most of component V of the de-
layed light. With spinach chloroplasts
the decay curves appear very similar
(monotonic decline) whether the emis-
TABLE 8. Effect of PMS on the Afterglow from a Dense Chlorella
Suspension Excited for 30 sec at 730 nm, Average of Four Experiments
Time Course:
Ratio of
Dark Time,
Relative Intensity
Luminescence with PMS to
sec
without PMS
Luminescence
1 X 10"8 M
without PMS
3 X lO"8 M
860
PMS
PMS
20
1.21
1.87
70
1009
1.08
1.05
120
611
0.75
0.58
170
319
0.74
0.51
220
176
0.72
0.46
270
106
0.63
0.37
320
59
0.62
0.40
370
35
0.62
0.39
606
CARNEGIE INSTITUTION
sion is induced by 648 or 730 nm light.
A few differences between the effects of
the two wavelengths were observed:
1. Pyocyanine at a concentration of
3xl0"6 M slightly increases the 20-
second delayed light excited by 730 nm,
but decreases that excited by 648 nm
(Fig. 29). The effects are not as pro-
nounced as those found by Mayne (1967)
for delayed light in the millisecond
range.
2. Ascorbate (0.01 M) increases the
long-lived afterglow excited by 730 nm
(remnants of component VI) } but has no
effect on that excited by 648 nm (when
no other additions are made, see below
and Fig. 30).
3. The afterglow excited by weak
648-nm light is diminished by a previous
exposure to 730-nm light, but enhanced
by a previous exposure to strong 648-nm
light. This holds even when the dark time
after the first exposure is so long that
the afterglow induced by it has become
negligible. A similar effect was reported
by Litvin and Shuvalov (1966).
Although ascorbate alone has no effect
on the 648-nm-induced emission, it
IOO
1 1 1
No PMS
i
> •
*
50
\ I0-6M PMS
-
0
1 1 1
^ lO"4 3xlO-4 I0-3 3xl0-3
c
•oncentration of ascorbate, M
10-2
Fig. 30. Afterglow from spinach chloroplasts
(concentration of chlorophylls a -f b = 4.1 X
10"5 M) 20 seconds after the end of 30-second
excitation by red (648-nm) light at about
1.5 X 103 erg cm-2 sec-1. Afterglow intensity is
decreased by ascorbate only in the presence of
PMS.
50
6) 0
o 50
Additive : Pyocyanine
— I0"8
With ascorbate, IO"2M-^\
Additive:PMS
648nm
Without ascorbate
10-7 I0"6 I0"5
Concentration of additive, M
Fig. 29. Effect of PMS and pyocyanine on the
afterglow from spinach chloroplasts 20 seconds
after the end of 30-second excitation by either
red (648-nm) or far red (730-nm) light.
greatly enhances the effect of PMS,
probably because PMS is reduced by
ascorbate (Fig. 30). Ascorbate can be
replaced by isoascorbate. Bertsch et al.
(1969) found no effect of PMS alone on
the fast delayed light (1 — 20 msec) from
chloroplasts, while PMS (3xl0~5 M)
plus ascorbate (5xl0~3 M) produced
almost complete inhibition. In the pres-
ent experiments PMS alone inhibits at
a high concentration, but in the presence
of ascorbate the same effect is produced
by less than one tenth as much PMS.
In my experiments pyocyanine alone
had less effect than PMS alone. In this
respect the late delayed light differs from
that in the millisecond range investigated
by Bertsch et al. (1969). As expected,
ascorbate did not radically change the
effect of pyocyanine (which is not re-
duced by ascorbate). Ascorbate does
have an effect at very high concentra-
DEPARTMENT OF PLANT BIOLOGY
607
tions of pyocyanine, possibly due to
traces of PMS in the pyocyanine prepa-
ration.
References
Bertsch, W. F., and J. R. Azzi, Biochim. Bio-
phys. Acta, 94, 15-26, 1965.
Bertsch, W., J. West, and R. Hill, Biochim.
Biophys. Acta, 172, 525-538, 1969.
Junge, W., and H. T. Witt, Z. Naturforsch.,
23b, 244-254, 1968.
Litvin, F. F., and V. A. Shuvalov, Biokhimiya,
31, 1264-1275, 1966.
Mayne, B. C, Photochem. Photobiol, 6, 189-
197, 1967.
Rubin, A. B., and P. S. Venediktov, Fiziol.
rastenii 15, 34^40, 1967.
Shuvalov, V. A., and F. F. Litvin, Molekuly-
arnaya Biologiya, 3, 59-73, 1969.
A Test of Fiber Optics for
Fluorescence Spectroscopy
C. S. French, R. W. Hart, N. Murata, and
C. Wraight
The ideal geometry of a system for
exciting fluorescence and for collecting
the emitted light to give the minimum
distortion of the emission spectrum by
reabsorption of the fluorescent light
within the sample is to have both optical
axes perpendicular to the surface of
the sample. Collection of the emitted
light over a large solid angle with simul-
taneous perpendicular illumination is
difficult with lenses or mirrors.
However, the availability of glass fiber
optics in sheet form makes possible a
convenient fluorescence excitation and
light collection system for use in fluo-
rescence spectrophotometers with the
axes for both beams perpendicular to the
sample surface. With alternate sheets of
fibers for the incident and for the emitted
light nearly half the sample surface may
be exposed to the collector fibers.
The efficiency of light collection de-
pends on the acceptance angle of the
individual fibers and on the overlapping
of the cones of illuminated spaces with
the cones of the space seen by the collec-
tion fibers. The numerical aperture of
the fibers, 0.5 in air, corresponds to a
light cone of 60° for the ends in air and
to about 83° for the ends in water. For
a sample in immediate contact with the
ends of the fibers the overlapping is zero
at the surface but becomes high a short
distance below the surface of the sample.
The original recording fluorescence
spectrophotometer with automatic cor-
rection for variation in sensitivity of the
detector and of the monochromator's
transmission with wavelength (French,
1956) was modified to test the fiber
optics system as shown in Fig. 31. Al-
though the principle seems useful, the
system we developed was not satis-
factory.
The soft plastic backing of the 0.003-
inch diameter fibers was removed by
softening with chloroform and scraping
to avoid waste space in the bundle ends.
However, sheets of glass fibers parallel to
each other can be bought with the backing
material omitted from the ends (Fiber
Photics Inc., 2557 Soquel Drive, Santa
Cruz, California, 95060).
The width of each fiber optic sheet was
chosen to match the length of an image
of the exit slit of the monochromator
Fig. 31. An arrangement for measuring fluo-
rescence spectra with fiber optics.
608
CARNEGIE INSTITUTION
used for the excitation light. The width
of this image required the use of 12 sheets
in the bundles for the incident light. At
the sample position the sheets carrying
the excitation light alternate with the
collecting sheets, and one extra collecting
sheet was added outside the last excita-
tion sheet. The ends of each bundle of
sheets were coated with epoxy cement
and pressed into cavities of rectangular
cross section in plastic blocks for the
bundles going to the two monochroma-
tors. For the sample position an alumi-
num block was used. The ends of the
three bundles were ground and polished.
The aluminum block has a horizontal
surface so a solid sample may be laid on
it. A removable plastic sleeve fitted over
the round top of the block and sealed
with an O-ring, holds liquid samples.
A box with a light-tight cover and plastic
foam insulation supports the aluminum
sample block and can be filled with
liquid N2 or other liquid to hold the
desired temperature long enough for a
spectral measurement.
An aluminum cover can be used to de-
fine the thickness of a liquid sample and
to act as a reflector for increasing the
light collection efficiency with weakly ab-
sorbing solutions. Other aluminum in-
serts giving various sample depths are
used to check for distortion of the emis-
sion spectrum by internal reabsorption.
Spectra of identical shape for sample
depths differing by a factor of two pro-
vide adequate evidence for lack of such
distortion.
At the suggestion of Dr. Charles Weiss
we have also made curved focusing re-
flectors, as shown in the upper part of
Fig. 31, to increase the light collecting
efficiency for dilute liquid samples. In
these reflectors the space between the
reflector and the sample chamber is filled
with clear plastic. For highly scattering
samples, such as those with ice crystals,
black covers that do not reflect were
made.
The system we built, although pro-
viding a convenient method for handling
samples, gave 71% of the overall effi-
ciency of our previous lens system in-
stead of an anticipated gain. This test
was made on a fragment of fluorescent
Corning glass No. 3387 in a flat reflecting
aluminum holder. Some of the loss may
be attributed to the microscopically
visible chipping of some of the ends of
the glass fibers in the grinding process.
A more serious loss, however, occurs
from the fact that the angle of divergence
of the beam entering the monochromator
exceeds the f 2.5 cone of the collector
lens. An improvement of 20% was
achieved by adding a small field lens
inside the slit.
In testing the system, chlorophyll ad-
sorbed on the epoxy cement in which
the fibers were embedded. To remove the
contaminant the fibers and plastic were
cut back 0.02 inch and the space filled
with epoxy cement. A %6-inch lucite
plate was added to keep the sample from
sticking to the epoxy. These modifica-
tions led to disastrous light losses.
The fiber optics system with these
modifications was compared to the old
lens and mirror system. The lens and
mirror system was then about 30 times
more efficient than the modified fiber
optics system which has been, at least
temporarily, abandoned. The fiber optics
arrangement could probably be made to
give reasonably good performance if the
sample end of the fibers were covered
with a very thin layer of material to
which the sample did not adhere.
Reference
French, C. Stacy, in The Luminescence of
Biological Systems, Frank H. Johnson, ed.,
A.A.A.S., Wash. D. C, pp. 51-74, 1955.
Use of the ACME Computer for
Analysis of Real-Time Data
David C. Fork
We have developed several programs,
largely as the result of the competent
help of Linda Crouse of the ACME com-
DEPARTMENT OF PLANT BIOLOGY
609
putation center, that enable us to use the
computer to handle real-time data. (A
description of the ACME facility is
given in last year's report, Year Book
67, p. 534) .
As presently written, the programs
allow us to vary the rate at which the
analog signals will be sampled (up to
about 1000 points per second using an
IBM 1800 or up to about 20,000 points
per second with the IBM 270X inter-
face). Depending upon the needs of the
experiment, a variable number of time-
course curves can be analyzed. For each
of these curves, measurements of up to
ten differences of amplitude can be made.
The data can be returned as obtained
by the IBM 1800 or, to avoid a flood of
unwanted numbers, averaged over a par-
ticular region of interest.
In addition, a second channel of analog
input is reserved for data received from
a photocell that monitors the actinic
light. The program determines when the
light has been turned on and off and
measures its intensity. A value at any
point in time, along a curve, can be ob-
tained by entering in the program the
time the measurement is to be made in
relation to the time the light went on or
off.
The programs are also designed to
measure slopes over designated time in-
tervals. Thus, by entering appropriate
factors the quantum yields can readily
be determined.
EXPERIMENTAL TAXONOMY INVESTIGATIONS
The Mimulus Investigations
William M. Hiesey, Malcolm A. Nobs, and
Olle Bjorkman
A considerable part of the current
effort of the Experimental Taxonomy
Group has been directed towards bring-
ing to conclusion the long-term investiga-
tions on the Erythranthe section of
Mimulus. This group of species was se-
lected for combined cytotaxonomic,
transplant, and physiological investiga-
tion in a multiple-approach study aimed
at improving our understanding of the
many-sided biological question of how
differentiation between species and eco-
logical races within species is related to
mechanisms of inheritance, to major ex-
ternal factors of contrasting natural en-
vironments, and to internal physiological
functions. Plants are better suited than
animals for such studies primarily be-
cause plants can be cloned and manipu-
lated experimentally with much greater
freedom in cytogenetic, transplant, and
physiological investigations needed in
such an integrated program.
Earlier Year Books (50, 1951; and
53, 1954, to 67, 1969) have reported
progress on various aspects of the Mimu-
lus investigations. The results from these
and more recent researches are incorpo-
rated in a Carnegie Institution mono-
graph to appear as Volume V of the
series, Experimental Studies on the Na-
ture of Species. It seems appropriate to
review the major features of this mono-
graph.
Mimulus as an experimental object. In
searching for basic principles regarding
mechanisms of evolution in higher plants,
the choice of experimental materials is
of utmost importance. Earlier studies
by the Experimental Taxonomy Group
on various species-complexes such as
Potentilla glandulosa, Achillea mille-
folium, and the grass genus Poa pointed
to characteristics lacking in these groups
that would have been helpful for extend-
ing the earlier studies to include quanti-
tative physiological investigations. The
latter are needed to fill an important gap
in our knowledge relating to the genetic
structure of species and races, the en-
vironments in which they evolved, and
their internal functioning. The Eryth-
ranthe section of Mimulus was chosen
primarily as a vehicle to bridge this gap.
610
CARNEGIE INSTITUTION
The features of the Erythranthe sec-
tion that make this group particularly-
suitable for experimental investigations
include a unique combination of essen-
tial characteristics. The most important
are (1) all members are diploid with the
same chromosome number (n = 8) ; (2)
all of the five species that have been
brought into culture can be intercrossed
in any combination to produce vigorous
first-generation hybrids; (3) these Fx
hybrids range from completely fertile to
highly sterile, and reflect different de-
grees of genetic compatibility within the
section that clearly evolved from a com-
mon ancestral stock; (4) the species,
and often races within species, have dis-
tinct marker characters that can be fol-
lowed through successive generations in
genetic experiments; (5) the flower struc-
ture of all the members of the group
favors easily controlled pollinations, and
in interfertile combinations many seed-
ling progeny may be obtained from a
single flower; (6) species and ecological
races within the Erythranthe section
differ widely in their capacity to survive
in contrasting climates such as are found
at the Stanford, Mather, and Timberline
transplant stations; (7) all members of
the section can be readily propagated
vegetatively as clones to obtain geneti-
cally identical plants that can be used in
diverse kinds of transplant and physio-
logical experiments and (8) all members
have leaves and stems suitable for use in
quantitative physiological measurements
involving gas exchange on intact living
plants. Few plant groups meet all of
these requirements as well as this group
of Miinulus species.
Bio systematic relationships within the
Erythranthe section. As reported in Year
Book 64, pp. 427-429, there are two ma-
jor interfertile groups within the Eryth-
ranthe section, one composed of the two
most widely distributed species, M.
lewisii and M. cardinalis, and the other
of the three southernmost species, M.
verbenaceus, M. eastwoodiae, and M.
nelsonii. The species of either group
when intercrossed produce F± hybrids
that are partially sterile to varying de-
grees. One of the most sterile combina-
tions, M. lewisiixM. nelsonii, gave rise
to a fertile, vigorous, distinctive amphi-
ploid (see Year Book 65, pp. 468-471),
thus establishing the close ancestral re-
lationship between the genetically most
diverse members of the section. The
varying degrees of interfertility among
inter- and intra-specific combinations re-
veal in finer detail different stages of
genetic isolation that have evolved within
the section.
Recombinations of morphological char-
acters in hybrid populations. From an
experimental point of view it is a most
fortunate circumstance that M. lewisii
and M. cardinalis, the two species of
widest geographic distribution, are inter-
fertile and occur in distinct but comple-
mentary climates. Mimulus lewisii occurs
in more northernly areas and at higher
altitudes in contrast with M. cardinalis
of more southern distribution, mostly at
lower altitudes. First-generation hybrids
between ecologically extreme forms of
the two species are interfertile, and their
progeny provide a means for studying
the mode of inheritance of the distinctive
morphological characters differentiating
the two species in relation to their re-
sponses in the contrasting climates at
the Stanford, Mather, and Timberline
transplant stations.
The numerous morphological charac-
ters that distinguish the two species in-
clude flower color, flower structure, pat-
terns of pigment distribution in localized
areas in the corollas, and such vegeta-
tive characteristics as leaf shape and
number of dentations along leaf margins.
The segregation of 20 characters distin-
guishing M. lewisii and M. cardinalis
has been studied extensively in Fx, F2,
and F3 populations when cloned and
grown at Stanford and at the Mather
and Timberline transplant stations.
Inheritance of morphological markers
in relation to capacity for survival at
the transplant stations. Of the many
DEPARTMENT OF PLANT BIOLOGY
611
morphological characters studied, only
one distinguishing M. lewisii from M.
cardinalis has been found to be inherited
in a simple Mendelian manner. The pres-
ence or absence of yellow carotenoid pig-
ment in the upper epidermis of the
corollas is determined by a single gene.
Its presence in M. cardinalis in con-
junction with other pigments causes the
flowers of this species to have the bright
orange-red appearance. In M. lewisii this
pigment is absent, and the corollas are
pale pink or purple, depending on the
particular race. In the Fx hybrid the ex-
pression of the yellow carotenoid pig-
ment carried by M. cardinalis is sup-
pressed by a dominant gene carried by
M. lewisii. In F2 and F3 progeny this
character is inherited in the ratio of 3
without carotenoid pigment to one with
carotenoid pigment, its expression or lack
of it being superimposed upon a wide
array of independently inherited pigment
characters governed in inheritance by
complex gene systems. The resultant
number of phenotypic expressions of
flower color in F2 and F3 progeny is,
therefore, very large.
All other characters distinguishing M.
lewisii and M. cardinalis that we have
studied have a complex hereditary basis
that cannot be resolved in simple Men-
delian terms. An example is the inheri-
tance of leaf characteristics. Mimulus
lewisii has relatively narrow oblanceolate
leaves with nearly entire edges, as il-
lustrated in the top row in Fig. 32 at
the left. The array shown is typical of
that found in seedlings obtained by self-
pollinating the M. lewisii parent. Cor-
responding leaves of the M. cardinalis
parent used in crossing experiments are
shown in the same figure (top row at
the right) . As compared with M. lewisii,
the leaves of M. cardinalis are broader,
more obtuse at the tips, and have toothed
margins.
The leaves of Fx hybrids between M.
lewisii and M. cardinalis are clearly in-
termediate, but with variations over-
lapping both parental populations, as
shown in Fig. 32 (row next to the top).
In the second generation the assortment
of recombinations in leaf characters
covers the entire range from one parental
extreme to the other, with maximum
frequencies in intermediate classes that
fall within the range of the Fx progeny.
Third-generation progenies derived by
self-pollinating selected F2 individuals
possess leaf characters that may differ
appreciably from one another, depending
on the characteristics of the particular
F2 parent. The leaves from the series of
F3 population shown in Fig. 32 are ex-
amples. The first of this series, No. 7541,
was derived from a lewisii-like F2 indi-
vidual. The leaf types segregated in this
F3 population include the range of varia-
tion of the original M. lewisii parent plus
that found in Fx progeny. The flowers
produced by this same F3 population
ranged over various lewisii-like shades
of pink, all having short styles and
stamens, characters of M. lewisii. The
correlation in the inheritance of pre-
dominantly lewisii-like characters in this
population in both leaf and floral char-
acters is clearly evident on analysis.
In contrast, the F3 progeny derived
from a cardinalis-like F2 individual had
broad, obtuse leaves with toothed mar-
gins, as shown in Fig. 32 (culture No.
7565, bottom row). In this population
the range of variation in leaf characters
included that of the original M. car-
dinalis parental population and the Ft
progeny. The flowers of this same F3
population segregated into an array hav-
ing predominantly cardinalis-like char-
acters. The bias in segregation towards
M. cardinalis in this population is as
striking as in the previous F3 progeny
whose characters segregated strongly
towards M. lewisii.
Third-generation progenies derived
from F2 individuals in classes intermedi-
ate between those of the parental types
segregate over a considerably wider
range than in the two examples just men-
tioned. Examples are shown by the arrays
of leaves in Fig. 32 including the F3
612 CARNEGIE INSTITUTION
Lewisii Cardinalis
MMA
F3 Progenies
7541
♦ A 4 7545
tlHiiii <
«A 7566
Mllllti.
7543
ftftftft ft I* 1 « «
A A 1 7530
M ft t I M ♦ • 1
• 7526
it A ft ft I ft it
7565
• /ooo
♦ ft • ft M ft ft ft
Fig. 32. Differences in leaf characters between subalpine M. lewisii and coastal M. cardinalis,
their Fi hybrid, and ranges of segregation within F3 progenies derived from F2 individuals of
different genetic composition. See text.
DEPARTMENT OF PLANT BIOLOGY
613
populations 7545, 7566, 7543, 7530, and
7526. Some of these populations, notably
7545 and 7530, approach the diversity
found in F2 populations.
The responses of cloned transplants
at the altitudinal field stations at Stan-
ford, Mather, and Timberline of paren-
tal, Fi, F2, and F3 progenies which have
been studied over a long period of years
show definite correlations between the
morphological characters they inherit
and their capacity to survive in contrast-
ing climates. The plants shown in Plate
1A, photographed in the Timberline
garden in 1967, summarize the responses
of M. lewisii, M. cardinalis, and their Fx
hybrid at the subalpine station. The pho-
tograph was taken in early September
after the onset of early autumn frosts
and the season's first light snowfall and
shows the already matured and dormant
M. lewisii (left) with the withered re-
mains of its flowering stems. The spot
marked by the tape measure at the right
is where coastal M. cardinalis was re-
peatedly planted and died from winter-
kill. In the center is their F1 hybrid
showing marked vigor and the ability
to withstand the freezing weather to a
considerably higher degree than even the
M. lewisii parent native to the Timber-
line area.
Plate IB shows a small portion of the
Timberline garden in 1967 in which the
responses of three F3 progenies were
being tested. The row marked (1) is a
planting of the offspring of the lewisii-
like F2 plant 7111-16, row (2) the off-
spring of the Fi-like plant 7111-17, and
row (3) the offspring of the cardinalis-
like F2 plant 7135-35. Plate IB was
taken in 1967 two years after the cloned
propagules were planted in the garden.
At this time the F3 progeny of the lewisii-
like F2 plant shown in row 1 were nearly
all well established and vigorous, and
most of the plants flowered. The F3
progeny of the Fx-like F2 plant 7111-17
were highly variable, ranging from weak
to vigorous, with a high frequency of
nonsurvivors. The F3 progeny of the
cardinalis-like plant 7135-35 were uni-
form and at that time had mostly sur-
vived, but all were later in seasonal de-
velopment. Plate 1C was taken in the
same garden a year later (1968). Here
the plants in row 1, the offspring of the
lewisii-like F2 individual, are quite uni-
formly vigorous and starting to flower,
those in row 2 from the Fx-like F2 plant
show extreme variability due to segrega-
tion, with only a small proportion of
survivors, and those in row 3, the off-
spring of the cardinalis-like F2, have all
succumbed to winter-killing.
Genetic coherence. Earlier Year Books
{62, pp. 387-391 and 63, pp. 433^35)
have reported evidence for partial ge-
netic linkages between groups of marker
characters that distinguish such species
as M. lewisii and M. cardinalis. Such
combinations of characters are inherited
in second- and third-generation progenies
in recombination frequencies that indi-
cate that purely random assortment of
such characters does not occur; parental
combinations of characters tend to segre-
gate together with greater frequency than
would be predicted on the basis of free
random recombination. That such char-
acters also tend to be correlated with
the responses and survival of individual
plants at the transplant stations is now
also fully evident. Extensive data from
repeated crossings of both F2 and F3
progeny in Mimulus have been analyzed
statistically with the help of an IBM
360/67 computer and clearly reveal the
existence of such partial linkages. Al-
though the observed recombinations of
characters in the F2 are always striking
and spectacular, they are fewer than
would be predicted on the basis of free
random recombination. The expression
of hybrid vigor, or heterosis, in first- and
second-generation progeny in both inter-
and intra-specific combinations in re-
lation to the parental races is about as
dependent on the environment in which
it is observed (i.e., at the transplant sta-
tions) as upon the genetic constitution
of the parents.
614
CARNEGIE INSTITUTION
Physiological studies. The compara-
tive study of species, races, and hybrids
at the physiological and biochemical
level as a means of probing further into
mechanisms underlying natural selec-
tion requires the development of quite
different techniques from those employed
in the cytogenetic and transplant studies.
It is, however, of enormous advantage
to use the same cloned plant materials in
comparative quantitative physiological
studies from which a wealth of back-
ground information is available in order
that the data from the various ap-
proaches can be effectively integrated.
This does not, however, preclude the use
of other species that may be valuable as
reference points in comparative studies.
The physiological studies on Mimulus
have centered on the study of the photo-
synthetic performance under a variety of
controlled variables. These studies have
led to ramifications that involve basic
questions concerning the mechanism of
some of the various steps in the photo-
synthetic process itself and how altera-
tions in particular steps appear to affect
the resultant performance of genetically
distinct ecological races and species.
Earlier Year Books have reviewed these
developments, and current new findings
are reported in the following pages. In
the Mimulus monograph the physiologi-
cal work will be reviewed to date, to-
gether with a report of preliminary stud-
ies on the culture of excised tissues under
aseptic conditions as an aid in the com-
parative study of physiological and bio-
chemical characteristics of ecological
races and species.
Growth, Photosynthetic, and Bio-
chemical Responses of Contrasting
Mimulus Clones to Light Intensity
and Temperature
Olle Bjorkman, Malcolm A. Nobs, and
William M. Hiesey
In recent months we have concentrated
on a study of two contrasting clones of
Mimulus and their Ft progeny. The
parental clones, as shown by the trans-
plant and genetic investigations, are
among the most contrasting members of
the Erythranthe section with respect to
their growth and survival at the Stan-
ford, Mather, and Timberline transplant
stations, yet are genetically compatible
and differ in a large number of conspicu-
ous morphological characters. One clone,
7635-2, is a form of M. lewisii from
Logan Pass, Glacier National Park, at an
elevation of 2100 m, and the other is a
clone of M. cardinalis, 7211-4, originally
from the hot foothills of the Sierra
Nevada of California at Jacksonville at
an altitude of 250 m. The environments
of the two races represent temperature
extremes at which members of the
Erythranthe section naturally occur.
Responses when grown under different
light intensities. Figure 33 shows the
mean dry weight increases in growth of
the two clones over a 17-day experimen-
tal period when subjected to incident light
intensities of 18,000, 53,000, and 106,000
ergs cm-2 sec-1. In the experiment the
daylength was 16 hours, and temperature
was held constant at 21 °C. The C02 and
02 concentrations were those of normal
air. The plants were grown in Perlite in
plastic pots and were watered with Hoag-
c
0
a
u
CD
ft)
a
CO
O
u
en
o
<v
l_
$
JZ
>>
-*—
u
£
-o
o
u
CO
en
k
a
ft)
c
CJ>
c
o
ft)
2
0.8
0.4
Jacksonville .
(M. cardinalis)
7211-4
40
80
120
Light intensify, ergs cm"2 sec"1 xlO3
Fig. 33. Effect of light intensity on dry matter
increase in the Logan and Jacksonville clones
of Mimulus. Temperature was held constant at
20°C, and C02 concentration at 0.03%.
DEPARTMENT OF PLANT BIOLOGY
615
land's nutrient solution. The 17-day ex-
perimental period was considered long
enough to provide a good measure of
growth response to different light in-
tensities, and short enough for growth to
be exponential. As shown in Fig. 33 the
growth rates of the two clones under
these experimental conditions were di-
rectly proportional to the incident light
intensity. The growth rate increase for
M. lewisii with increasing light intensity
was somewhat greater than for M.
cardinalis.
The light-saturated photosynthetic
rates of both clones when measured at
20°C both at concentrations of 21.0%
and 1.5% of 02 are generally higher as
the light intensity during growth is in-
creased, as shown in the upper part of
Table 9. A significant difference between
the two clones is evident, however, in
their relative rates when grown under
the intermediate intensity of 53,000 ergs
cm-2 sec-1 as compared with the highest
at 106,000 ergs cm-2 sec-1. In Logan the
increase in photosynthetic rate at the
higher light intensity when measured in
21% 02 is much smaller than in Jackson-
ville. The differences are even greater
when the light-saturated photosynthetic
rates are measured in 1.5% 02. The rates
measured on this Logan clone are higher
than those observed on M. lewisii from
Timberline, clone 7405-4 {Year Book 65,
pp. 464-468). This suggests that con-
siderable diversity exists within M.
lewisii in light-saturated photosynthetic
rates when measured under 21% 02 pres-
ent in normal air.
Anatomical sections of leaves of the
two clones reveal parallel modifications
in leaf thickness and in number of cell
layers when grown under the three light
intensities. Leaf thickness of both clones
was approximately doubled when grown
under the highest light intensity as com-
pared with the lowest (i.e., at 106,000
versus 18,000 ergs cm-2 sec-1). At the
intermediate light intensity the leaves
were of intermediate thickness. The
leaves of the M. lewisii clone were about
25% thicker than those of M. cardinalis
under any given intensity. The increase
in leaf thickness as a result of increased
light intensity is attributable to a greater
number of cell layers in both the palisade
and spongy parenchyma as well as to
greater cell size.
It might be anticipated that the rate
of light-saturated photosynthesis on the
basis of leaf area should increase with
increasing leaf thickness if the compo-
sition of biochemical components inside
the leaves that determines the capacity
TABLE 9. Effect of Light Intensity During Growth on Subsequent Light-Saturated Rate of
Photosynthesis, Carboxydismutase Activity, and Contents of Chlorophyll and
Soluble Protein in the Leaves of Two Mimulus Clones
Logan 7635-2
Jacksonville 72
18 53
11-4
Light Intensity for Growth,
erg cm-2 sec-1 X 10*
18
53
106
106
Photosynthesis at 20°C
and 0.03% C02,
Atmole C02 dm"2 min"1
In 21% 02
In 1.5% Oa
6.6
8.8
11.0
17.9
12.4
172
4.1
5.6
8.8
13.0
12.9
18.7
Carboxydismutase Activity,1
jtmole CO2 (g fresh wt.)"1 min"1
4.7
10.0
11.3
4.4
7.9
13.5
Chlorophyll a + b,
mg (g fresh wt.)-1
1.33
1.53
1.70
1.44
1.25
1.87
Soluble protein,2
mg (g fresh wt.)"1
9.3
20.6
20.7
82
15.9
25.1
1 Assay conditions: 0.05 M NaHC03; 4 X 10"* M ribulose-l,5-diphosphate; pH 8.0, 30°C.
2 Protein was determined by the Folin-Lowry method.
616
CARNEGIE INSTITUTION
for light-saturated photosynthesis re-
mains constant. On the other hand, in
normal air where photosynthesis is par-
tially limited by C02 concentration, one
might predict that light-saturated photo-
synthesis would not increase proportion-
ally to leaf thickness because of the
greater diffusion resistance to C02 in the
thicker leaves. The actual experimental
data reveal that photosynthesis increases
faster as the leaves become thicker than
would even be predicted on the basis of
the first hypothesis. This result points
to a third possibility, namely, that bio-
chemical components inside the leaves
that limit light-saturated photosynthesis
have increased with increasing light in-
tensity when computed on a fresh-weight
or unit-volume basis.
The data presented in Table 9 support
this conclusion. In both clones carboxy-
dismutase activity is highly modified by
the light intensity during growth; the
higher activities occur in plants grown
under the higher light intensities. The
pattern of modification in the two con-
trasting clones differs in that Logan
shows little increase in the activity of
the enzyme when grown under the inter-
mediate as compared with the highest
light intensity, whereas the activity in
Jacksonville in this step is approximately
doubled. There is, thus, a good correla-
tion between rate of photosynthesis at
light saturation and the carboxydismut-
ase activity. This is in agreement with
the results obtained in this laboratory
with other species (Bjorkman, 1968, a,
b; Gauhl, this Year Book).
The chlorophyll content, expressed on
a fresh weight basis in the leaves of both
clones, generally increases with increas-
ing light intensity during growth, but
the increase is much smaller than that
for carboxydismutase activity. This re-
sult is not surprising since the content of
light-harvesting pigment would not be
expected to have much influence on the
rate of photosynthesis in the light-satu-
rated state. The content of soluble pro-
tein, on the other hand, closely parallels
the carboxydismutase activity and the
photosynthetic rate in both clones. This
suggests that the levels of enzymes other
than carboxydismutase may also be
modified in a similar manner by different
light intensities during growth.
Responses to differences in tempera-
ture. The differential effects of the two
temperatures, 10 °C as compared with
30°C, on the growth of the M. lewisii
clone 7635-2 (Logan) and the M. cardi-
nalis clone 7211-4 (Jacksonville) are il-
lustrated in Plate 2. The photographs
shown were taken one month after com-
parable cuttings of each clone were
placed in controlled cabinets and sub-
jected to a light intensity of 53,000 ergs
cm-2 sec-1 for 16-hour days, the tempera-
tures being held constant at 10, 20, and
30 °C day and night. The nonsurvival of
the Logan clone at 30 °C under these
conditions, as compared with good
growth and flowering of the Jackson-
ville clone, and, conversely, the more
active growth of Logan at 10 °C as com-
pared with Jacksonville during the 30-
day experimental period, is consistent
with the very divergent responses of
these two clones when grown at the
Stanford, Mather, and Timberline trans-
plant stations.
Propagules of the same two clones
were subjected to the same experimental
treatment and then harvested after a
15-day period before the Logan clone
had succumbed at 30°C. This clone had
then developed abortive precocious
flowering stems having small green
leaves. The average net increases in dry
weights of the clones during this period
are shown in Table 10. It can be seen
that the increase in growth of the Jack-
sonville clone was 2.4 times greater at
30 than at 10° C, whereas in Logan the
difference in increment of growth at these
contrasting temperatures was approxi-
mately the same with a ratio of 0.9.
In view of the marked hybrid vigor
observed at the altitudinal transplant
stations in F1 progeny between M. lewisii
and M. cardinalis described in the pre-
DEPARTMENT OF PLANT BIOLOGY
617
TABLE 10. Effect of Temperature on Growth
Net Mean Dry Weight Increase in 15 Days, mg
Clone
Logan 7635-2
Jacksonville 7211-4
Fi Logan 7635-2 X
Jacksonville 7211-4
Grown at
10°C
139
140
8.9*
7.0
232 ± 14.7
Grown at
30°C
126 ± 24.4
337 ± 32.2
277 ± 25.0
Ratio, Growth
at 30°C to
Growth at
10°C
0.9
2.4
12
* Standard error of the mean.
ceding section, an experiment was con-
ducted in which the growth of Ft seedling
progeny of the M. lewisii clone Logan
7635-2 and the M. cardinalis clone Jack-
sonville 7211-4 was compared with the
growth of rooted cuttings of the parents
at 10 and 30°C. The conditions of il-
lumination and C02 and 02 concentra-
tion were the same as in the preceding
temperature experiments. Although the
14 seedling Fx replicates grown at each
temperature were fairly variable, their
growth response at 30 °C was intermedi-
ate between the parents, as shown by the
mean net dry weight increases listed
in Table 10. Evidence of hybrid vigor
under the high temperatures is therefore
lacking, but at 10 °C the apparently
greater growth of the hybrid over that of
the parents may be significant.
Determinations of carboxydismutase
activity, of the content of soluble pro-
tein, and of chlorophyll in the leaves
were made on the Logan and Jackson-
ville clones grown at 10, 20, and 30°C.
All determinations were made during the
period when both clones were in active
growth at all three temperatures. The
results of these determinations are listed
in Table 11.
In both clones the soluble protein con-
tent of the leaves was higher at 10 than
at 20 or 30°C. This marked accumula-
tion of soluble protein at low tempera-
ture is a point of interest for which no
satisfactory explanation is at hand. In
the Jacksonville clone where this ac-
cumulation is particularly great, there is
no corresponding increase in carboxy-
dismutase level. The activity of this en-
zyme is about the same regardless of
whether the clone was grown at 10, 20,
or 30°C.
In the Logan clone the carboxydismut-
ase activity is about the same in leaves
that have been grown at 10 and 20°C.
TABLE 11. Effect of Temperature During Growth on Subsequent Levels of
Carboxydismutase, Chlorophyll and Soluble Protein in the
Leaves of Two Mimulus Clones
Logan 7635-2
Jacksonville 7211-4
Temperature During Growth
10°C 20°C 30°C 10°C 20°C
30°C
Carboxydismutase activity,1
Atmole C02 (g fresh
wt.)-1 min-1
10.6
10.0
3.62
5.2
7.9
6.5
Chlorophyll a + b, mg
(g fresh wt.)-1
1.62
1.53
0.78
1.21
1.25
1.00
Soluble protein,2 mg
(g fresh wt.)-1
262
20.0
13.9
39.9
15.9
16.3
1 Assay conditions: 0.05 M NaHC03; 10-<t M ribulose-l,5-diphosphate;
pH 8.0, 30°C.
2 Protein was determined by the Folin-Lowry method.
618
CARNEGIE INSTITUTION
The activity is considerably higher than
in the Jacksonville clone. However, in the
Logan clone growth at 30 °C results in a
very much reduced carboxydismutase
activity. Similarly, the chlorophyll con-
tent of the leaves was much reduced at
30° as compared with 20° and 10°C in
Logan whereas in Jacksonville the cor-
responding values were essentially the
same at the three different temperatures.
These results point to a breakdown of
the photosynthetic apparatus in the
Logan clone at 30 °C, whereas there is
no evidence of any detrimental effects of
high temperature in the Jacksonville
clone. We do not know whether the
detrimental effects of high temperature
in the Logan clone are primarily due to
an intrinsically low degree of tempera-
ture stability of its photosynthetic ap-
paratus, or whether processes responsible
for the continuous synthesis of its com-
ponents, such as photosynthetic pigments
and enzymes, are adversely affected by
high temperature so that the rate of their
synthesis does not keep up with the rate
of their breakdown.
Light-saturated photosynthesis in
Mimulus and in many other higher plants
as measured in air containing normal
CO* and Oo concentrations is often char-
acterized by a comparatively small de-
pendence on temperature in the range
15-30°C. This relatively weak effect of
temperature on light-saturated photo-
synthesis has been generally interpreted
to mean that photosynthesis is limited
mainly by physical barriers to C02 dif-
fusion since any process that is limited
by enzyme activity would be expected
to exhibit marked temperature depen-
dence.
Newer evidence now indicates that the
small effect of temperature on the photo-
synthetic rate as observed in normal air
is largely due to the inhibiting effect of
02 on photosynthetic C02 uptake. As
shown in Fig. 34, the temperature de-
pendence in both the Jacksonville and
Logan clones is much greater in 1.5%
than in 21.0%. These results are in close
agreement with those obtained by Joliffe
and Tregunna (1968) for wheat leaves,
and by us with Marchantia (Year Book
67, pp. 479-482) , but are at variance with
those previously reported by us for Mim-
ulus (Year Book 66, pp. 222-225).
In 1.5% 02 and 0.03% C02 the Ar-
rhenius equation is approximately valid
for both the Logan and Jacksonville
clones of Mimulus in the range 5-15 °C.
At the higher C02 concentration of
£ 20
_* E
_a -a
"a. jy
3 O
<m e
O =i
U
-
Logan
y*l.5%02^\
"
Jacksonville
"
-
X2I%0;
1.5% 02
8
^-^"21% 02
- *
-
20
30 10
Leaf temperature, °C
30
Fig. 34. Temperature dependence of light-saturated photosynthetic rate in the Logan and
Jacksonville clones of Mimulus under 1.5% and 21.0% 02. Measurements were made under saturat-
ing white light of 3.4 X 10B erg cm-2 sec-1 intensity (400-700 nm) from a 2.5 KW Xenon lamp
and a C02 concentration of 0.030%.
DEPARTMENT OF PLANT BIOLOGY
619
0.07% a linear relationship between the
logarithm of the photosynthetic rate and
the inverse of absolute temperature is
obtained up to at least 27°C (cf. this
Year Book, Fig. 51). Energies of activa-
tion calculated from Arrhenius plots
for the Mimulus clones yielded values
of approximately 16 to 19 Kcal mol-1
equivalent to Qi0 values of 2.7 to 3.3.
These are comparatively high values for
biological reactions.
It is of great interest that we have
obtained very similar values for C02
fixation in vitro with partially purified
preparations of carboxydismutase from
both Mimulus and Marchantia. The
close agreement between the activation
energies for photosynthesis and the
carboxylation reaction in vitro might,
of course, be coincidental. On the other
hand, it could reflect a causal relation-
ship. A close agreement between mea-
surements of the two processes would
be expected if the activation energies for
the carboxydismutase-catalyzed reaction
in vitro is approximately the same as in
vivo, and if the carboxylation reaction
is a major limiting step of light-saturated
photosynthetic rates at temperatures be-
low 15°C.
No marked differences in activation
energy for light-saturated photosynthe-
sis were found between the Logan and
the Jacksonville clones when both were
previously grown at 20 °C at a light in-
tensity of 53,000 erg cm-2 sec-1 (400-
700 nm). The main difference between
the two is that Logan exhibits a higher
rate of photosynthesis than Jacksonville
at all temperatures in the range 5-
30 °C. Another difference is that in Logan
the rate declines at temperatures above
approximately 25°C, whereas in Jack-
sonville such a decline is not apparent
until the temperature considerably ex-
ceeds 30 °C.
A question of great importance is to
what extent the temperature dependence
of photosynthesis may be affected by
the temperature under which the plants
are previously grown. This problem was
investigated on Marchantia last year
(Year Book 67, pp. 479-482) . The results
of similar experiments using the Jack-
sonville clone 7211-4 of Mimulus are
shown in Fig. 35. The dependence of the
light-saturated rate of C02 uptake on
temperature was determined on intact
attached leaves of plants previously
grown at 10, 20, and 30°C.
As is evident in Fig. 35, the rate of
photosynthesis at 15 °C and 1.5% 02 was
Grown at I0°C
1.5% 02
i.i.i,
Grown at 20 C
1.5% 02
/ ^-^""2I%02
Grown at 30 C jS* •
Xl.5%02 -
/ /^ 2I%02
10
Leaf
20 30
iperature,°C
Fig. 35. Effect of temperature during growth on subsequent temperature dependence of light-
saturated photosynthetic rates under 1.5% and 21.0% 02 in the Jacksonville clone of M. cardinalis.
Conditions for measurements were the same as in Fig. 34. The rate at 15°C in 1.5% 02 was set to
unity for each leaf.
620
CARNEGIE INSTITUTION
little affected by the temperature under
which the plants were grown. To facili-
tate direct comparisons of the tempera-
ture curves shown, the light-saturated
photosynthetic rate as measured at 15 °C
and under 1.5% 02 is plotted as equal
to unity for each of the three clone-
members previously grown at the three
temperatures.
The temperature dependence of photo-
synthesis when measured under both
1.5% and 21.0% 02 concentrations is
very similar for leaves previously grown
at 10 and 20° C. There is, however, a
slight shift of the optimum toward lower
temperatures in the clone-member grown
at 10 °C as compared with the one at
20°C. When grown at 30°C, a more pro-
nounced change in the shape of the tem-
perature curve takes place, with consider-
ably higher light-saturated photosyn-
thetic rates at the higher temperatures
than in the clone-members grown at 10 or
20 °C. This effect is evident in measure-
ments made both in 21.0% and 1.5% 02,
but it is more pronounced at the lower
02 concentration. This suggests that the
modification in temperature dependence
is not caused by changes in the rate of
the processes underlying the inhibiting
effect of 02 (photorespiration) . The ac-
tivation energy from photosynthesis in
the range 5-10 °C is, nevertheless, not
significantly affected by any of the three
temperatures under which the Jackson-
ville clone of M. cardinalis was grown.
Conclusions. At this stage of our still
incomplete understanding of the physio-
logical and biochemical mechanisms that
operate in higher plants, each increment
of new experimental information changes
our concepts of them. An example is
our current interpretation of temperature
dependence for light-saturated photo-
synthesis as a result of measurements
made under low as compared with high
02 concentration, discussed above.
It is evident that the two contrasting
clones of M. lewisii and M. cardinalis
differ markedly in both physiological
and biochemical characteristics when
studied under certain sets of controlled
conditions. At the same time they pos-
sess many characteristics in common
that are also shared by such unrelated
plants as the liverwort Marchantia. The
experimental techniques for exploring the
physiological and biochemical basis of
natural selection have now been de-
veloped to a point where new basic in-
formation is coming to light that needs
further exploration and analysis before
a satisfying understanding can be
achieved.
References
Bjorkman, O., Physiol. Plantarum, 21, 1-10,
1968a.
Bjorkman, O., Physiol. Plantarum, 21, 84^99,
1968b.
Joliffe, P. A. and E. B. Tregunna, Plant
Physiology, 43, 902-906, 1968.
Comparative Studies of Atriplex Spe-
cies WITH AND WITHOUT /J-CARBOXYLA-
tion Photosynthesis and their
First-Generation Hybrid
Olle Bjorkman, Eckard Gauhl, and
Malcolm A. Nobs
The recent discovery of a new C02
fixation pathway in photosynthetic or-
ganisms, first found to be operative in
sugar-cane (Kortschak et al., 1965;
Hatch and Slack, 1966), has stimulated
new interest in comparative studies of
photosynthesis among higher plants. Sev-
eral groups of investigators, particularly
in Australia, Canada, and the United
States, are currently studying the bio-
chemistry of the new carboxylation
pathway and its relation to photosyn-
thetic characteristics and leaf structure.
This pathway is commonly referred to
as the C4-dicarboxylic acid pathway
since oxaloacetate, malate and aspartate
are the first products of C02 fixation, or
as ^-carboxylation photosynthesis since
it involves /3-carboxylation of phos-
pho(enol) pyruvate. Members of at least
five different families of higher plants
DEPARTMENT OF PLANT BIOLOGY
621
belonging to both the monocotyledoneae
and the dicotyledoneae (Hatch et al.,
1967; Johnson and Hatch, 1968) have
been shown to possess this pathway.
Within each of four different genera, in-
cluding Atriplex, some species possess the
pathway while others do not.
Of particularly great interest to those
of us concerned with mechanisms of
adaptation and natural selection in
plants are the observations that (1) the
/?-carboxylation pathway seems to be
mainly limited to taxonomic groups
distributed mostly in tropical and sub-
tropical regions, and (2) that plants
which possess this pathway apparently
have profoundly different photosynthetic
characteristics than do plants in which
it is absent. In the plants possessing
/3-carboxylation the compensation point
for C02 exchange in air approaches zero,
and illuminated leaves do not release
C02 into C02-free air. Moreover, the
strong inhibiting effect of oxygen on the
rate of photosynthetic C02 uptake in
normal air, which is a very widespread
phenomenon among plants without the
/^-carboxylation pathway, is absent in
plants having this pathway.
The finding that differentiation in
carboxylation pathways exists among
species within the same genus provides
a unique opportunity for studying bio-
chemical and physiological mechanisms
of adaptation. Not only are such species
a more favorable material for compara-
tive work than plants of unrelated taxo-
nomic groups, but also they may permit
studies of the inheritance of the different
photosynthetic pathways if the species
have sufficient genetic compatibility to
allow hybridization between them. In
those cases where different carboxylation
pathways have been found among spe-
cies within a single genus heretofore, the
species belonged to different subgenera
and may not be sufficiently closely re-
lated to permit intercrossing.
In our own search for suitable experi-
mental plants, we chose two species of
the family Chenopodiaceae, Atriplex
patula ssp. hastata and A. rosea L., both
of which are very common in California.
In their biosystematic work on North
American species of Atriplex, Hall and
Clements (1923) wrote: 'The most
closely related species (to A. patula)
seem to be the rosea group. . . . There
is no direct connection with any other
group." Both species are annuals and are
diploid with nine pairs of chromosomes.
A. patula L. is a common species in
coastal marshes throughout North
America with the possible exception of
Mexico, and is widely distributed also
in Europe and Asia. There is great
morphological variation in this species,
and many subspecies have been recog-
nized; frequently these subspecies have
morphological variation in this species,
The A. patula material used in the
present work was collected in a coastal
salt marsh close to San Mateo Beach
State Park, Pescadero, California, and
was identified as ssp. hastata Hall and
Clem. (=var. hastata Gray). It is a
common plant in salt marshes along the
Pacific coast of California, Oregon, and
Washington.
A. rosea L. is a native of Eurasia with
its main distribution from central Asia
through southeastern Europe and the
Orient. It is also common in major
Mediterranean Islands as well as in
Morocco and Egypt. The species is
naturalized in western United States and
is very abundant in semiarid places in
the hot interior of the region, where it
often occurs together with A. semibac-
cata, a naturalized introduction from
Australia. In California A. rosea is a
common plant in the interior valleys,
but it occurs also in the southern part
of the San Francisco Bay area where the
present material was collected. Interest-
ingly, both A. patula ssp. hastata and
A. rosea are abundant in this area al-
though also here the latter species oc-
cupies much drier locations than does
the former.
Up to the present time species that
have been found to possess /?-carboxyla-
622
CARNEGIE INSTITUTION
tion photosynthesis also possess a spe-
cialized leaf anatomy characterized by
a layer of large chloroplast-containing
cells which surround the vascular bun-
dles. Whether or not this specialized leaf
anatomy is essential for the functioning
of /?-carboxylation photosynthesis has
not yet been established, but it is never-
theless a valuable characteristic in pre-
liminary screening of species. Moser
(1934) described almost 100 Atriplex
species, many of which, including A.
rosea, possess this specialized leaf struc-
ture, whereas others such as A. patula do
not. This characterization of A. rosea
and A. patula has recently been con-
firmed by Downton et al. (1969) and in
this laboratory for our own material.
During the past year comparative
studies of the two species' growth, as
well as their biochemical and photosyn-
thetic characteristics, have been made
and are reported below. Concurrently we
attempted to hybridize the two Atriplex
species. This led to success only recently
when Fj hybrids between A. rosea and
A. patula were obtained; some early re-
sults with these hybrids are included at
the end of this report.
The plant material used in the com-
parative studies on biochemical and pho-
tosynthetic characteristics was grown in
controlled growth cabinets under a light
intensity of 1.1 X 105 erg cm-2 sec-1 (400-
700 nm), a temperature of 25°C, and a
photoperiod of 16h/day, except in the
experiments summarized in Table 5
where the light intensity during growth
was half of that given above. Young,
mature leaves were used throughout the
investigation. All photosynthesis mea-
surements were made on single leaves
attached to intact plants.
Activities of carboxylation enzymes.
In plants with /3-carboxylation photo-
synthesis, oxaloacetate, malate, and as-
partate are the first products to be
labeled when 14C02 is fed to photo-
synthesizing leaves. There is strong evi-
dence that phospho(enol) pyruvate
(PEP) serves as substrate in the car-
boxylation reaction. This is further sup-
ported by the finding that plants with
/?-carboxylation photosynthesis have
very high activities of PEP carboxylase
whereas plants lacking this pathway
have low activity of this enzyme (Hatch
et al, 1967; Johnson and Hatch, 1968).
As shown in Table 12, A. rosea has about
50 times higher PEP carboxylase activ-
ity than A. patula. The values are in
excellent agreement with those reported
by Hatch and co-workers for other spe-
cies with and without /3-carboxylation
photosynthesis.
Although the activity of carboxy-
dismutase is considerably higher in A.
patula than in A. rosea, the values for
the latter species are very much higher
than those reported by Hatch and co-
workers for other species with ^-carbox-
ylation. A comparison of carboxydismut-
ase activity in species with ^-carboxyla-
tion and species that lack this pathway
revealed that the activity found in A.
rosea is not unusually high in compari-
son with other ^-carboxylation species;
neither was there consistently lower
TABLE 12. Activity of PEP Carboxylase and Carboxydismutase in
Extracts of A. patula and A. rosea*
Species
PEP Carboxylase Activity,
Atmol CO2 per min per
Carboxydismutase Activity,
/imol CO2 per min per
Soluble Chloro-
Fresh Protein, phyll,
Weight, g mg mg
Soluble Chloro-
Fresh Protein, phyll,
Weight, g mg mg
A. patula
A. rosea
0.6 0.03 0.44
26.8 1.54 14.41
11.52 0.590 8.41
4.60 0.265 2.47
* Enzyme activities were measured at 30 °C as described by Bjorkman
and Gauhl (1969).
DEPARTMENT OF PLANT BIOLOGY
623
carboxydismutase activity in the species
that have /3-carboxylation photosynthe-
sis as compared to those that lack it.
A. patula is outstanding in that it has
the highest activity of all species in-
vestigated. These results are summarized
in Table 13 and a full account of the
study is given elsewhere (Bjorkman and
Gauhl, 1969).
Fractionation of total soluble leaf pro-
tein on Sephadex G-200 (see pp. 636-637,
this Year Book) in two species with simi-
lar carboxydismutase activities and pro-
tein contents, one with /?-carboxylation
and one without, indicated that approxi-
mately half of the total soluble protein
was located in the "fraction 1" protein
peak in both species. Therefore, the pres-
ence of comparatively high carboxy-
dismutase activities for species with
/?-carboxylation is apparently indicative
of similarity high concentrations of this
enzyme. Other experiments showed that
it is unlikely that the great differences
between the carboxydismutase levels ob-
tained here and those reported by Hatch
and co-workers are caused by differences
in the light, or in the temperature regimes
under which the plants were grown.
Experiments in which different grind-
ing procedures were compared revealed
that, while nearly complete cell breakage
could readily be achieved with leaves of
A. patula and other species without
/?-carboxylation, breakage of the thick-
walled sheath cells surrounding the vascu-
lar bundles in A. rosea and other species
with /3-carboxylation proved quite diffi-
cult. Special measures were required to
break these cells. The mesophyll cells
of A. rosea leaves were, on the other
hand, very easy to break. High carboxy-
dismutase activity in leaf extracts of
species with /3-carboxylation was ob-
tained only when a high degree of break-
age of the bundle sheath cells had been
achieved. Further experiments in which
A. rosea leaves were subjected to pro-
gressively more vigorous grindings
showed that carboxydismutase activity
increased as an increasing fraction of
the protein was released from the bundle
sheath cells, indicating that the chloro-
plasts in these cells contain carboxy-
dismutase levels similar to those present
in the mesophyll cells of species without
/3-carboxylation photosynthesis. These
results strongly suggest that, in A. rosea
and other species with /3-carboxylation,
at least the bundle sheath cells are cap-
able of C02 fixation via the reductive
pentose-phosphate pathway.
PEP carboxylase activity in leaf ex-
tracts of A. rosea was, on the other hand,
high even when only a minor fraction
of the bundle sheath cells had been
broken, and the activity did not increase
with increased breakage of these cells.
These results provide evidence that high
PEP carboxylase levels are present in
the mesophyll cells of A. rosea. Ap-
parently, the bundle sheath cells con-
tain little or no PEP carboxylase. This
finding would indicate that the chloro-
plast-containing bundle sheath cells in
plants with /3-carboxylation photosyn-
TABLE 13. Carboxydismutase Activity in Species With and Without
/3-Carboxylation *
Carboxy-
Carboxy-
Species with
dismutase
Species without
dismutase
/3-carboxylation
Activity
3.6
/3-carboxylation
Activity
Distichlis spicata
Elymus mollis
4.1
Paspalum distichum
2.2
Mimulus cardinalis
5.2
Zea mays
2.3
Solarium dulcamara
3.7
Amnranthus edulis
2.0
Plantago lanceolata
3.0
Atriplex semibaccata
4.9
Solidago spathulata
4.5
A triplex rosea
2.5
Atriplex patula
8.4
* Assay conditions were as described by Bjorkman and Gauhl (1969).
Activity at 30° C is expressed in /*mole CO2 (mg chlorophyll)"1 (min)"1.
624
CARNEGIE INSTITUTION
thesis are not responsible for the /3-car-
boxylation of PEP. However, since PEP
carboxylase seems to be rather unstable
in crude enzyme preparations of A. rosea
leaves, the results cannot be taken as
conclusive evidence for the absence of
PEP-carboxylase in bundle sheath cells.
These results appear to be consistent
with the hypothesis that there are two
consecutive carboxylation reactions in
plants with /^-carboxylation photosyn-
thesis. In the first carboxylation, C02 re-
acts with PEP to form C4-dicarboxylic
acids, the reaction being catalyzed by
PEP carboxylase. This newly formed
carboxyl group might then be transferred
to ribulose-l,5-diphosphate to form
phosphoglyceric acid either by a "trans-
carboxylation," or the carboxyl group
may be first decarboxylated to C02,
which is then fixed in a conventional
Calvin cycle carboxylation, mediated
by carboxydismutase. If PEP carbox-
ylase is indeed absent in the bundle
sheath cells, then it seems likely that the
first carboxylation occurs in the meso-
phyll cells, and the second occurs pri-
marily in the bundle sheath cells.
Glycolate oxidase activity. There is
considerable evidence to support the hy-
pothesis that the inhibitory effect of 02
on photosynthetic C02 uptake in higher
plants without /^-carboxylation photo-
synthesis is caused primarily by a re-
oxidation of photosynthetic products
(that is, photorespiration) , and that
glycolate is a major component of the
evolution of C02 by illuminated leaves
in C02-free air. Previous studies in which
it was found that the activity of glyco-
late oxidase was very much lower in
species with /^-carboxylation than in spe-
cies lacking this pathway suggest that
this enzyme is responsible for the evolu-
tion of C02 in the light (Tregunna,
1966; Oeser et al, 1968). In later work
where species of the dicotyledonous
genera Amaranthus (Tolbert et al.,
1969) and Atriplex (Osmond, 1969) were
included, the differences in glycolate
oxidase activity between species with
and those without /^-carboxylation were
much less pronounced although still con-
siderable.
Table 14 shows the rates of 02 uptake
in leaf homogenates of A. patula and
A. rosea in the presence and in the ab-
sence of glycolate. Evidently, the ac-
tivity of glycolate oxidase in A. rosea is
about two-thirds as high as that found
in A. patula. The true values for A. rosea
may possibly be even higher than shown
here since the breakage of the vascular
bundle sheath cells was not quite com-
plete. As with carboxydismutase, high
activities of glycolate oxidase in A. rosea
extracts were obtained only when good
breakage of bundle sheath cells had been
achieved.
In view of the high glycolate oxidase
activity in A. rosea extracts, it appears
unlikely that the absence of an effect of
02 concentration on photosynthetic C02
uptake, and of other characteristics
commonly attributed to photorespira-
tion, can be explained by differences in
the activity of glycolate oxidase.
C02 compensation point for photo-
synthesis. The C02 compensation point
(the C02 concentration at which the
rates of C02 fixation and production are
equal) is known to be close to zero at 02
concentrations of less than one or two
percent, and to increase linearly with in-
creased 02 concentration in species with-
out ^-carboxylation photosynthesis. In
species with /^-carboxylation, however,
the C02 compensation point remains
very low regardless of the 02 concentra-
tion. As shown in Fig. 36, the response in
A. patula is typical of species without
TABLE 14. Glycolate Oxidase Activity at 21°C
and pH 8.0 in Leaf Homogenates of A. patula
and A. rosea *
Species
Addition
None
Glycolate
None
Glycolate
Oxygen Uptake
nmol min-1 (mg
chlorophyll)-1
Atriplex patula
Atriplex patula
Atriplex rosea
Atriplex rosea
30
200
40
150
Glycolate concentration was 0.01 M.
DEPARTMENT OF PLANT BIOLOGY
100 i 1 — ■ 1 1 7 1 ■' >■<■ '
625
10 20 30
Oxygen cone, percent
40
Fig. 36. Effect of 02 concentration on C02
compensation point for photosynthesis in 21%
02 in A. patula at three different leaf tempera-
tures. Light intensity was 1.0 X 105 erg cm"2
sec-1 (400-700 nm).
/?-carboxylation. The compensation point
is strongly dependent on temperature,
but at any given temperature the com-
pensation point is directly and linearly
related to 02 concentration. In A. rosea
the compensation point is less than a few
ppm C02 at all 02 concentrations in the
range 0-40%, a response characteristic
of species with /?-carboxylation photo-
synthesis.
The differential response between the
two Atriplex species with regard to the
C02 compensation point is further il-
lustrated in Fig. 37 where the compensa-
tion point in 21% 02 is plotted as a func-
tion of leaf temperature. In A. patula the
compensation point increases exponen-
tially with increasing leaf temperature,
whereas in A. rosea it remains very low
throughout the entire temperature range
from 5 to 36 °C. Incidentally, even
though the compensation point is not
in itself a rate, the data given in Fig. 37
for A. patula yield a nearly straight line
in an Arrhenius plot. The "activation
energy" derived from such a plot is equal
40
20
A. rosea
10 20 30
Leaf temperature, °C
Fig. 37. Temperature dependence of COa
compensation point for photosynthesis in 21%
02 in A. patula and A. rosea. Light intensity
was 1.0 X 105 erg cm"2 sec"1 (400-700 nm).
to approximately 7600 calories (Qio =
1.56).
Transient changes in photo synthetic
rate following changes in light intensity.
Fig. 38 illustrates the time-course of
photosynthetic C02 uptake by A. patula
and A. rosea leaves in response to a
sudden decrease in light intensity under
1% and 21% 02. In A. patula the steady-
state rates at both the higher and the
lower light intensities are about 50%
greater in 1% than in 21% 02, whereas
in A. rosea the rates are unaffected by 02
concentration. Under 21% 02 A. patula
leaves show a pronounced "undershoot"
in the rate of C02 uptake when light
intensity is suddenly decreased, a phe-
nomenon which is presumably closely
related to the "post-illuminative burst"
of C02 evolution that takes place in
higher plants without /?-carboxylation
photosynthesis. Under 1% 02 these ef-
fects are absent. In corn, a species with
/?-carboxylation, the transient effects are
absent under both 1% and 21% 02
{Year Book 66, pp. 224-227).
These results are consistent with the
hypothesis that the effects reflect the
temporary continuation of a process
leading to C02 production which occurs
in the previous steady-state, in plants
626
CARNEGIE INSTITUTION
9- 6
A.patula
21% 02
v-
A. rosea
21% 02
6 0 3
Time.min
Fig. 38. Time-course of photosynthetic C02 uptake in 1% and 21% 02 by A. patula and
A. rosea leaves following a sudden decrease in light intensity. Arrows indicate the time at which
light intensity was reduced from 2 X 105 to 5 X 104 erg cm"2 sec-1 (400-700 nm). Leaf temperature
was 25 °C, and C02 concentration 0.030-0.033%.
without /3-carboxylation photosynthesis.
However, as shown in Fig. 38, a complex
transient change in the rate of C02 up-
take occurs in A. rosea leaves after the
light intensity is suddenly reduced. This
effect is absent in corn, but a similar
effect was found to be present in another
species with /?-carboxylation, namely,
Amaranthus edulis (loc. cit.) . The
transient effect in A. rosea and Amar-
anthus is an interesting phenomenon for
which no explanation is at hand. Its
presence in both 1% 02 and 21% 02
suggests that it may be related to a
different process than the effect observed
in species without /?-carboxylation in
21% 02.
Effect of 02 concentration on the
light-saturated photosynthetic rate and
on the resistance to gas diffusion. At
constant temperature, C02 concentration
and C02 uptake decrease continuously
in A. patula with increasing 02 concen-
trations in the range of 1-21%, whereas
the rate is little affected in A. rosea (Fig.
39). It is of considerable importance to
know whether or not this higher rate of
light-saturated photosynthesis in A.
patula in low 02 concentration is ac-
companied by a lower resistance to C02
diffusion from the ambient atmosphere
into the leaf. If, as is often assumed, the
light-saturated rate of photosynthesis in
air of normal C02 and 02 concentration
1 1 1 1
A. rosea
C\J
6 O
_^
_o ^
RO
^^"°\
a
=>"S
6>
A.pa+ula — o_
u S
<-t— ,
o o
<Ji H-.
40
-
-
-+- C
O <y
u O
U &
-
~
Z a
0
i i i i
0
10 20
Oxygen cone, per cent
Fig. 39. Effect of 02 concentration on light-
saturated rate of photosynthetic C02 uptake in
A. patula and A. rosea. Light intensity was
4 X 105 and 6 X 105 erg cm"2 sec"1 (400-700 nm)
with A. patula and A. rosea, respectively. Leaf
temperature was 25°C, and C02 concentration
0.030-0.032%.
DEPARTMENT OF PLANT BIOLOGY
627
is limited mainly by physical resistance
to gas diffusion, then a marked increase
in the photosynthetic rate due to a de-
creased 02 concentration could not occur
without a concomitant decrease in diffu-
sion resistance.
Of the various component physical re-
sistances to gas diffusion, only the one
imposed by the stomata can be expected
to be influenced by changes in the gase-
ous composition of the atmosphere. Since
any changes in stomatal resistance that
would affect the diffusion of C02 would
also affect the rate of the diffusion of
water vapor from the leaf, the influence
of 02 concentration on resistance to C02
diffusion can be followed by measuring
the rate of transpiration. Simultaneous
measurements of C02 uptake and trans-
piration were therefore made at different
02 concentrations on A. patula and A.
rosea leaves. Some of the results of these
measurements are presented in Table 15.
A full account of this work is given else-
where (Gauhl and Bjorkman, 1969).
The results clearly show that resist-
ance to C02 diffusion in the gas phase is
not significantly influenced by 02 con-
centration in leaves of either A. patula or
A. rosea in spite of the fact that the
rate of light-saturated C02 uptake in
the former species is enhanced by ap-
proximately 50% when the 02 concen-
tration is reduced from the normal 21%
to 1.5%. It can be concluded, therefore,
that at least in A patula the rate of
light-saturated photosynthesis in normal
air is not limited primarily by physical
resistance to gas diffusion even at the
TABLE 15. Effect of 02 Concentration on the
Rates of C02 Uptake and Water Vapor Release
by A. patula and A. rosea Leaves*
Species
C02 Uptake,
(Umole
cm"2 min"1
Water Vapor
Release,
mg dm-2 min"1
A. patula
A. rosea
21% 02 1.5% 02
12.3 18.7
21.2 21.9
21% 02 1.5% 02
51.6 51.6
48.0 48.0
* Measurements were made under saturating
white light, and 0.031-0.032% C02 at 26°C.
comparatively high temperature of 25 °C
(see p. 634, this Year Book).
Other experiments in which the rate
of transpiration in the two Atriplex spe-
cies was measured at 6 different 02 con-
centrations gave no evidence of any ef-
fect of 02 concentration on stomatal
diffusion resistance. The resistance of the
stomata to water vapor transfer varied
from 1.0 to 1.4 sec cm-1 with A. patula
and from 1.1 to 1.3 sec cm-1 for A. rosea.
Thus, there is no significant difference
in resistance to water loss between the
two species when they are grown and
kept under conditions of ample water
supply. This does not, of course, pre-
clude the possibility that the two species
may differ in their transpiration rates
under water stress. Since under low 02
concentration the light-saturated rate of
photosynthesis is similar in the two Atri-
plex species, there is no intrinsic differ-
ence in the ratio of photosynthesis to
transpiration. However, because of the
strong inhibiting effect of 21% 02 on
photosynthesis in A. patula, but not in
A. rosea, the efficiency of photosynthesis
in normal air in terms of water loss is
greater in the latter species.
Temperature dependence of light-
saturated photosynthesis. There are sev-
eral reports that species which possess
/3-carboxylation photosynthesis have
higher optimum temperatures for photo-
synthesis in normal air than plants that
lack this pathway. Figs. 40 and 41 show
the temperature dependence for photo-
synthetic C02 uptake at a high light
intensity of 3.5 XlO5 erg cm-2 sec-1 (400-
700 nm) for A. patula and A. rosea, re-
spectively. This light is not fully satu-
rating for A. rosea at high temperatures
(Fig. 43). The curve for A. rosea was
determined in 21% 02, but since the rate
of photosynthesis in this species is un-
affected by 02 concentration in the range
from 6 to 38° C, the curve is also valid
for low 02 concentrations.
The temperature dependence of light-
saturated photosynthesis in A. patula is
markedly affected by 02. As was also
628
CARNEGIE INSTITUTION
10 20
Leaf temperature, °C
30
Fig. 40. Temperature dependence of the rate
of photosynthetic C02 uptake in 1.7% and 21%
Oa by an A. patula leaf. Light intensity was
3.5 X 105 erg cm"2 seer1 (400-700 nm) and C02
concentration 0.032-0.035%.
found with M. cardinalis (see p. 618,
this Year Book), the inhibitory effect of
02 increases with increasing temperature.
(It should be noted, however, that the
light-limited rate of C02 uptake in both
A. patula and Mimulus is markedly in-
hibited by 21% 02 at both high and
low temperatures; see Year Book 67, p.
482). A comparison of the rates of C02
uptake by the two Atriplex species in
strong light and normal air shows that
in A. rosea the rate is more temperature
dependent in the upper range. This is
consistent with previously reported dif-
ferences between unrelated species with
and without /?-carboxylation photosyn-
thesis. However, the temperature de-
pendence is remarkably similar in the
two Atriplex species when the 02 con-
centration is kept at a low level, par-
ticularly in the low temperature range
where the Arrhenius equation is ap-
proximately valid. In this range the ac-
tivation energy is high, and no signifi-
cant differences in activation energy are
10 20 30
Leaf temperature, °C
Fig. 41. Temperature dependence of the rate
of photosynthetic C02 uptake in 21% Oa by an
A. rosea leaf. Light intensity was 4.3 X 105 erg
cm-2 sec-1 (400-700 nm) and CO2 concentration
0.031-0.034%.
apparent between the two species.
These results fail to support the hy-
pothesis that the differences in photosyn-
thetic response to temperature between
species with and without /?-carboxyla-
tion are indicative of different tempera-
ture characteristics of the carboxylation
enzymes. They rather suggest that the
rate-limiting step is either the same in
the two species, or, if different steps are
limiting, these have approximately the
same energies of activation. It is tempt-
ing to speculate that carboxydismutase
may be a rate-limiting enzyme in both
species at low temperatures (cf. p. 619,
this Year Book).
C02 dependence of light- saturated
photosynthesis. The response of light-
saturated photosynthesis to C02 con-
centrations in the two Atriplex species
is of special interest in view of the pres-
ence of high PEP carboxylase activities
in A. rosea but not in A. patula. PEP
carboxylase has been reported to have
a much higher affinity for C02 {Km~
10-4 M) than carboxydismutase (Km~
10-2 M). If these different affinities in
vitro result in differences in C02 depend-
DEPARTMENT OF PLANT BIOLOGY
629
ence of photosynthesis between the two
species, then such differences should be
apparent under low 02. Comparisons of
the C02 dependence of photosynthesis in
the two species when in 21% 02 are
complicated by the inhibiting effect of
02, particularly since the degree of the
inhibition by 02 increased with decreas-
ing C02 concentration.
Figure 42 depicts the C02 dependence of
photosynthetic 02 evolution under 0.15%
02 in the two species. The measurements
were made as described on pages 637-
638. The response to C02 concentration
is very similar in A. patula and A. rosea,
with half of the maximum rate being
reached at approximately 0.02% C02 in
both species. The somewhat earlier satu-
ration in A. rosea in comparison with A.
patula may possibly be significant. How-
ever, at the light intensity used (4 x 105
erg cm-2 sec-1; 400-700 nm) photosyn-
thesis in A. patula is light saturated
under all C02 concentrations, but it is
not fully saturated at the highest C02
concentrations in A. rosea. This may
have resulted in a somewhat lower C02
saturation in the latter species. The re-
200 400 600
CO2 conc.ppm
Fig. 42. Dependence of C02 concentration on
the rate of photosynthetic 02 evolution by A.
patula and A. rosea leaves in 0.15% O2. CO2
concentration is given as the mean of the con-
centrations of the gas entering and that leaving
the leaf chamber. Light intensity was 3.7 X 105
erg cm-2 sec-1 (400-700 nm) and leaf tempera-
ture 26° C. Photosynthesis measurements were
made with the device described on pp. 636-640.
suits thus indicate that the two Atriplex
species do not differ markedly in their
photosynthetic response to C02 concen-
tration when reoxidation of photosyn-
thetic products in the light is suppressed
by keeping the leaves at a low 02 con-
centration.
The saturation of photosynthesis at
low C02 concentrations in A. patula ap-
pears to be inconsistent with the high
i£m-values that have been reported for
carboxydismutase. However, recent work
(Cooper et al., 1969) provides evidence
that carboxydismutase cannot utilize bi-
carbonate, and that only C02 itself can
serve as substrate for the enzyme. At the
pH used for the determination of the
Km, the concentration of C02 is only on
the order of one percent of the total
"C02" added to the reaction mixture.
If the Km is recalculated for C02, it be-
comes 100 times lower than the value
based on total "C02". The differences
in the i£m-values between PEP carbox-
ylase and carboxydismutase based on
total "C02" may, therefore, not be rele-
vant to photosynthetic C02 fixation.
Dependence of photosynthesis on light
intensity. It is well known that unusually
high light intensities are required to
saturate photosynthesis in corn and cer-
tain other species recently found to
possess /?-carboxylation photosynthesis.
As shown in Fig. 43 this is also true for
A. rosea. Complete light saturation is not
reached even at light intensities equal
to full sunlight (approximately 5xl05
erg cm-2 sec-1, 400-700 nm) in this spe-
cies whereas in A. patula light saturation
is essentially reached at about half this
intensity. In normal air (21% 02,
0.032% C02) the rate at high light in-
tensities is considerably higher in A.
rosea than in A. patula, but at low light
intensities the rates are approximately
equal.
Since the degree of enhancement of
photosynthesis that takes place in A.
patula when 02 concentration is lowered
is approximately the same at all light
intensities, and since no enhancement
630
CARNEGIE INSTITUTION
20
1.5% 02
^
^"^Z>- — o_~ —
(
T 15
_
^i<-— o
_
c °
E
A.patulo^o-^?'
/ /
e io
- / /
-
"O
,° /A. rosea
1 5
V
-
2L
l/
aT
1 °
21% 02
<M'
u l5
A. rosea /^
-
. 1
o
_-— o °
c
_£ 10
/>^;
patula
-
0
i_
_i_
1 5
"
0
/
0 12 3 4 5
Light intensity, ergs cm-2 sec"1 xlO5
Fig. 43. Effect of light intensity on the rate
of photosynthetic C02 uptake in 1.5% and 21%
02 by A. patula and A. rosea leaves. Leaf tem-
perature was 25° C and CO2 concentration
0.030-0.034%.
at all occurs in A. rosea, the former spe-
cies becomes more efficient in utilizing
light of low intensities than A. rosea
under 1.5% 02. These results suggest
that the quantum yield for C02 uptake
under low 02 is higher in A. patula than
in A. rosea.
Experiments in which light-limited
rates of C02 uptake of the two species
were measured in monochromatic light
(at 665 nm) provided further evidence
that this is indeed the case. As shown
in Fig. 44 the quantum requirement for
C02 uptake under low 02 concentration
is 35-40% higher in A. rosea than in A.
patula. This indicates that /?-carboxyla-
tion photosynthesis may be intrinsically
less efficient than conventional photo-
synthesis in terms of the amount of C02
reduced to carbohydrate per amount of
energy expended. This would be the case
if /3-carboxylation photosynthesis re-
quires more ATP or NADPH2 for each
C02 fixed.
If this is true the main advantage of
0.8
1 1 1 1 1 1 p '
Atriplex patula /
Atriplex rosea
* /
i
0.6
k. / /
/'
0.4
M / /
/ A*
/ / 0+
0.2
J /j?
vw // 0*
/ /
O
//
Jy
-O.I
X 1,1,1,
/ . 1 . 1 . 1
12
8
Light absorbed, nanoeinstein cm-2 sec
12
Fig. 44. Light-limited rate of photosynthesis of A. patula and A. rosea leaves in 1.2% and
21% Oa as a function of light intensity in nanoeinstein sec-1 absorbed by each cm2 leaf area.
Quantum requirement (0_1) is expressed in einstein per mole C02. C02 uptake was measured
at 665 nm (half -band width, 12 nm), 25°C, and 0.031-0.032% C02. Leaf absorptance (measured
in an Ulbricht integrating sphere) was 86% and 89'% at 665 nm for A. patula and A. rosea,
respectively.
DEPARTMENT OF PLANT BIOLOGY
631
jS-carboxylation photosynthesis appears
to be the conservation of carbon under
high levels of irradiance and high temper-
atures. Under saturating light intensities
the supply of chemical energy would not
be expected to be limiting and, therefore,
a higher ATP or NADPH2 requirement
than in conventional photosynthesis
would have no effect on the light-satu-
rated rate of C02 uptake. It should be
remembered, however, that photosynthe-
sis in species with /?-carboxylation is not
completely light-saturated even in full
sunlight, and consequently the rate of
C02 uptake in such plants in natural
habitats will always be partially de-
pendent on the supply of chemical
energy. Under low light intensities the
benefits gained by eliminating the in-
hibitory effect of 02 in plants with
/?-carboxylation photosynthesis would
be counteracted by the greater require-
ment for chemical energy. This is con-
sistent with the finding that the quantum
requirement for C02 uptake is approxi-
mately the same for the two Atriplex
species in normal air (Fig. 44). Com-
parative measurements of light-limited
rates of photosynthesis in other species
should reveal whether or not the higher
quantum requirement of A. rosea in
comparison with A. patula under low
02 concentration is indeed attributable
to /?-carboxylation photosynthesis per se.
Growth responses. Our comparative
studies on the photosynthetic character-
istics of the two Atriplex species demon-
strate that in normal air under condi-
tions of high light intensity and high
temperature A. rosea is capable of con-
siderably higher rates of photosynthetic
C02 uptake than A. patula. The differ-
ences between the two species decreased
with decreasing light intensity and de-
creasing temperature, and disappeared
at rate-limiting light intensities. A ques-
tion of considerable interest is whether
or not these differences in photosyn-
thetic performance are reflected in
growth.
Preliminary experiments in which the
two Atriplex species were grown at dif-
ferent light intensities indicate that A.
rosea requires higher light intensities
for maximum growth than A. patula.
Nevertheless, both species grow slowly
at low light intensity (1.5 X 104 erg cm-2
sec-1, 400-700 nm) and must be con-
sidered to be sun species.
When the two Atriplex species were
grown under a light intensity of 1.1 X 105
erg cm-2 sec-1, the optimum temperature
for growth was in the range 20-25 °C
for A. patula and 25-30°C for A. rosea.
The growth rate of A. rosea was much
greater at 30 than at 15 °C, whereas
there was no marked difference in growth
at these two temperatures with A.
patula. At 38 °C A. patula grew poorly,
whereas A. rosea grew considerably
better at this temperature than at 15°C.
The differences that exist between the
two Atriplex species in response of
growth to different light intensities and
temperatures thus seem consistent with
differences in photosynthetic character-
istics. Comparative growth experiments
at high temperatures and different oxy-
gen concentrations might provide fur-
ther information on the causal relation-
ship that appears to exist between
growth response and photosynthetic
characteristics that distinguish plants
with and without /3-carboxylation photo-
synthesis. Such growth experiments are
planned.
Characteristics of Ft hybrids: A. rosea
xA patula. As mentioned earlier, at-
tempts to hybridize the two Atriplex
species were successful only very re-
cently, and only by using A. rosea as
the female parent. The hybrid material
is currently being subjected to intensive
investigation with regard to biochem-
istry, leaf anatomy, and cytogenetics.
Some early results are reported here.
Like both of the parents, the Fx hy-
brids are diploid, and are highly uni-
form in appearance, having intermediate
morphology and growth habit. As shown
in Fig. 45, leaf shape and size are clearly
intermediate. This is also true of the
632
CARNEGIE INSTITUTION
« f m Ml
A. rosea
F, hybrid
A.pafula
Fig. 45. Comparison of the leaf shape of the Fi hybrid, A. rosea X A. patula, with the leaf
shape of the parents.
betacyanin content in the lower leaf epi-
dermis; in A. rosea the betacyanin is
very prominent, whereas it is absent in
A. patula.
Examination of leaf sections with the
light microscope revealed that the gen-
eral leaf anatomy of the Fx hybrid is also
roughly intermediate between the par-
ents. The mesophyll of the hybrid leaves
resembles that of A. patula, but the
palisade cells are less densely packed.
There is also a greater density of chloro-
plasts in cells around vascular bundles
in the hybrid than in A. patula, but the
large thick-walled bundle sheath cells,
characteristic of A. rosea and many
other species with /?-carboxylation pho-
tosynthesis, are absent. Cell and chloro-
plast ultrastructure of the hybrid in
comparison with the parental species is
now being studied in this laboratory by
Dr. John Boynton.
The data presented in Table 16 show
clearly that the ¥x hybrid is definitely
not intermediate between the parental
species with regard to photosynthetic
characteristics. Photosynthesis is strongly
affected by 02 concentration in the ¥x
hybrid, apparently even more so than in
A. patula, the male parent. The rate of
photosynthesis in the Fx hybrid is lower
than in either parent under 21% 02.
The activity of carboxydismutase in
the Fx hybrid is only about half of that
in A. patula, but higher than in A. rosea.
PEP carboxylase activity in the Fx hy-
brid is only about one-tenth of the ac-
tivity present in A. rosea, the female
parent, even though it may be slightly
higher than in A. patula. The chlorophyll
content of the leaves, which is about
the same in both parental species, is
about one-third lower in the hybrid.
These results demonstrate that, in
TABLE 16. Some Photosynthetic and Biochemical Characteristics of the
Fi-Hybrid Between A. rosea and A. patula in Comparison with the
Parental Species *
Species
Photosynthesis
Rate
Enhance- PEP
ment in Carbox- Carboxy-
1.5% O2, ylase dismutase
% Activity Activity
1.5% 02 21% 02
A. rosea 3.8
A. rosea X A. patula Fi 4.1
A. patula 6.0
3.8
2.4
4.1
0
69
48
14.7
1.4
0.8
3.4
5.1
9.6
* Photosynthetic rates as well as enzyme activities are expressed in ^mole
C02 min-1 (g fresh wt.)~\ Photosynthesis was measured in white light of an
intensity of 1 X 105 erg cm-2 sec"1 (400-700 nm), at a leaf temperature of
25° C, and a C02 concentration of 0.032-0.034%. Enzyme assays were made
at 30°C; other conditions were as described by Bjorkman and Gauhl
(1969). The plants were grown at a light intensity of 5.5 X 104 erg cm-2 sec-1
(400-700 nm).
DEPARTMENT OF PLANT BIOLOGY
633
Atriplex, photosynthetic and biochemi-
cal characteristics associated with (3-csly-
boxylation photosynthesis are not trans-
mitted simply by the plastids from the
female parent to the progeny. Instead,
inheritance of these characteristics ap-
pears to be predominantly under nuclear
control. The results further suggest that
the number of genes that govern the
processes underlying /?-carboxylation
photosynthesis, and the absence of an
inhibitory effect of oxygen on C02 up-
take, may be small.
Attempts are currently being made to
obtain second-generation progeny from
the Fi hybrids. If these attempts are
successful, it may be possible to find out
which of the several correlated char-
acteristics, physiological, biochemical,
and anatomical, are essential to photo-
synthetic function in plants with /?-car-
boxylation photosynthesis, as well as to
analyze genetically the inheritance of
these characteristics. This could greatly
enlighten our understanding of the
physiological and molecular mechanisms
of adaptive differentiation and natural
selection in plants.
References
Bjorkman, 0., and E. Gauhl, Planta, 88, 197-
203, 1969.
Cooper, T. G., D. Filmer, Marcia Wishnick,
and M. D. Lane, J. Biol. Chem., 244, 1081-
1083, 1969.
Downton, J., T. Bisalputra, and E. G.
Tregunna, Can. J. Botany, in press, 1969.
Gauhl, E., and 0. Bjorkman, Planta, 88,
187-191, 1969.
Hall, H. M., and F. E. Clements, The Phylo-
genetic Method in Taxonomy; The North
American Species of Artemisia, Chryso-
thamnus, and Atriplex, Carnegie Inst, of
Wash. Publ. 326, Washington, D. C, 1923.
Hatch, M. D., and C. R. Slack, Biochem. J.,
101, 103-111, 1966.
Hatch, M. D., C. R. Slack, and H. S. Johnson,
Biochem. J., 102, 417-422, 1967.
Johnson, H. S., and M. D. Hatch, Phyto-
chem., 7, 375-380, 1968.
Kortschak, H. P., C. E. Hartt, and G. O.
Burr, Plant Physiol, 40, 209-213, 1965.
Moser, H., Beih. Bot. Zentr., 52, 378-388,
1934.
Oeser, A., N. E. Tolbert, R. H. Hageman,
R. K. Yamazaki, and T. Kisaki, Plant
Physiol. Abstr., 5-12, 1968.
Osmond, C. B., Biochim. Biophys. Acta, 172,
144-149, 1969.
Tolbert, N. E., A. Oeser, R. K. Yamasaki,
R. H. Hageman, and T. Kisaki, Plant
Physiol, 44, 135-147, 1969.
Tregunna, E. B., Science, 151, 1239-1241,
1966.
Leaf Factors Affecting the Rate of
Light-Saturated Photosynthesis in
Ecotypes of Solanum dulcamara
Eckard Gauhl
As reported last year {Year Book 67,
pp. 482-488), clones of Solanum dulca-
mara L. from sunny and shaded habitats
show marked differences in their re-
sponse to light intensity during growth.
When propagules of clone Mb 1, origi-
nally from a densely shaded habitat in a
reed-grass marsh near Monchbruch, Ger-
many, were grown under a low light in-
tensity of 24xl03 erg cm-2 sec-1 (400-
700 nm) and subsequently exposed to a
high intensity of llxlO4 erg cm-2 sec-1,
the leaves showed evidence of photoin-
hibition. After a few days under the
higher light intensity the quantum effi-
ciency of photosynthesis was markedly
reduced. No such detrimental effect was
detected in leaves of clone Fe 2, which
originated from a sunny habitat on an
open sand dune on Fehmarn Island in the
Baltic Sea. Fully mature leaves of this
clone show a considerable increase in
light-saturated photosynthetic rate after
transfer to a high light intensity. More
recent work revealed that when leaves
of the clone from the shaded habitat are
subjected to prolonged exposure to high
light intensities, not only light-limited
rates but also the light-saturated rate
of photosynthesis is reduced, as shown
in Fig. 46.
634
CARNEGIE INSTITUTION
c
>^ _o
_° 0
o
_c
50 100 150
Light intensity, ergs cm"2sec"' xlO"3
Fig. 46. Rate of C02 uptake as a function of
light intensity for a leaf of Solarium dulcamara,
clone Mb 1, grown in weak light and after ex-
posure to strong light for 10 days.
The light-saturated rate of apparent
photosynthesis in normal air may be
limited by physical resistances to gas
diffusion as well as by the capacities of
enzymatic reactions. It is also affected
by the rate of reoxidation of photosyn-
thetic products with 02 (photorespira-
tion) . An attempt was made to determine
which of these factors are of great-
est importance in determining (1) the
decline in photosynthesis when leaves of
the shaded habitat clone are transferred
from a low to a high light intensity and,
conversely, (2) the increase in photo-
synthesis that takes place when leaves of
the sunny habitat clone are transferred
from a low to a high light intensity.
Diffusion resistance and 02 effect. To
determine whether the changes in the
rates of photosynthesis of the Solanum
ecotypes are caused simply by changes
in physical diffusion resistances, simul-
taneous measurements of C02 uptake
and transpiration were made with the
method described by Gauhl and Bjork-
man (1969). When the transpiration rate
is known, the resistance against the
transfer of water vapor from the surface
of the mesophyll cells to the ambient
atmosphere (Rw) can be calculated. This
resistance includes the resistance to gas
diffusion through the stomatal openings
and that of the external boundary layer.
Photosynthetic C02 uptake involves
these same resistances and an additional
resistance due to the diffusion of C02
in the liquid phase from the mesophyll
cell walls to the carboxylation sites in
the chloroplasts.
Of these three resistances, only the
stomatal diffusion resistance can be ex-
pected to be influenced by changes in
the gaseous composition of the ambient
atmosphere. Since it is well established
that the rate of C02 uptake of many
plants, including S. dulcamara, is en-
hanced when the oxygen concentration
surrounding the leaf is reduced from
21% to a lower level, photosynthesis and
transpiration were measured simultane-
ously under alternate 02 concentrations
of 21% and 1.5%, and a constant C02
concentration of 300 ppm. If physical
barriers to the diffusion of C02 into the
leaf are mainly limiting the rate of light-
saturated C02 uptake, enhancement of
photosynthesis due to the lower 02 con-
centration could not take place without
a decrease in the resistance Rw. The re-
sults summarized in Table 17 show that
the enhancement of the photosynthetic
rate in low 02 found in the leaves in-
vestigated is not accompanied by a de-
crease in Rw. The degree of enhance-
ment was about 50% in all leaves.
Carboxydismutase activity and pro-
tein content. There is strong evidence
that the activity of certain photosyn-
thetic enzymes, particularly carboxy-
dismutase, may be a major limiting fac-
tor determining the light-saturated rate
of photosynthesis in leaves (Bjorkman,
1968; Wareing et al, 1968). Parallel in-
creases in protein content and light-
saturated photosynthesis found in the
leaves of clone Fe 2 originally from a
sunny habitat after exposure to strong
light for 1 to 6 days suggested that syn-
thesis of one or several photosynthetic
enzymes could, at least in part, account
for the increased rate of C02 uptake.
The activity of carboxydismutase was,
DEPARTMENT OF PLANT BIOLOGY
635
TABLE 17. Resistance to Water Vapor Transfer, Rw and Rate of COa
Uptake in 21% and 1.5% Oxygen
21% 03
1.5% Oa
C02 Uptake,
C02 Uptake,
Rw, sec
yumole
Rw, sec
fimole
cm-1
dm"2 min"1
cm-1
dm"2 min-1
Clone Mb 1 grown
in weak light
1.74
7.07
1.78
10.35
After 12 days
in strong light
2.22
3.90
2.25
5.77
Clone Fe 2 grown
in weak light
1.95
5.07
1.95
7.35
After 6 days in
strong light
1.75
12.55
1.73
18.32
Note: The measurements were made under saturating light and a COa
concentration of 300 ppm.
therefore, determined in leaves of this
clone grown in weak light and again
after the leaves had been exposed to
strong light for 2, 4, and 6 days. Pro-
cedures used for the preparation of the
leaf extracts and for the enzyme assays
were as described by Bjorkman (1968).
The results of these determinations are
summarized in Table 18. The activity
of carboxydismutase increased when
computed on the basis of fresh weight
and chlorophyll, but the specific activity
remained constant. These data strongly
indicate that the increased protein syn-
thesis that takes place upon exposure
to strong light includes de novo synthesis
of carboxydismutase.
There is much evidence that car-
boxydismutase and fraction-1 protein of
leaves are the same protein entity. Frac-
tion-1 protein, which comprises a major
portion of the total soluble protein in
TABLE 18. Carboxydismutase Activity in Leaf
Extracts from Solarium dulcamara, Clone Fe 2,
Grown in Weak Light and Transferred to
Strong Light for 2, 4, and 6 Days
Days in
Strong
Light
Enzyme
; Activity, ,u,mole COa
per min
0
2
4
6
Per dm2
Leaf Area
6.21
8.41
11.44
13.92
Per mg
Chlorophyll
0.96
1.36
1.65
2.45
Per mg
Soluble
Protein
0.17
0.17
0.17
0.17
leaves, can readily be separated by gel-
filtration on Sephadex G-200. This tech-
nique was used in the present work to
follow changes in the amount of frac-
tion-1 protein in leaves of the clone Fe 2
grown in weak light and then transferred
to strong light for 2, 4, and 6 days.
Leaves with the major veins excluded
were homogenized in a buffer containing
0.1 M Tris-HCl, 0.01 M MgCl2, 2.5 X
10-4 M EDTA, 1 gl-1 isoascorbate and
5 ml DTT (dithiothreitol) . The final
pH was 7.95. The homogenate was spun
at 25,000 rpm for 20 minutes, the super-
natant treated on a Sephadex G-50
column (0.9x15 cm), and the protein-
containing portion of the eluate subse-
quently applied to a Sephadex G-200
column (2.5x40 cm). Both columns
were equilibrated with the same buffer
used for homogenization except that iso-
ascorbate and DTT were omitted. All
operations were carried out at 2°C. The
eluate from the Sephadex G-200 column
was collected in 2.5-ml fractions, and
the protein in each fraction precipitated
with CCI3COOH and determined with
the Folin-Lowry method. Fig. 47 shows
the elution pattern of the protein from
leaves grown in weak light and after
being placed for 4 days in strong light.
The prominent peak in these curves
represents fraction-1 protein. Table 19
lists the content of total soluble protein
and fraction-1 protein in leaves grown
636
CARNEGIE INSTITUTION
80 100
Eluate.ml
Fig. 47. Elution curves of protein separations
on Sephadex G-200 of leaf extracts of Solatium
dulcamara, clone Fe 2, grown in weak light
and after exposure to strong light for four
days. The same amount of leaf material (fresh
weight) was used for both separations.
in weak light and after exposure to
strong light for 2, 4, and 6 days. Both
total protein and fraction-1 protein in-
crease in a roughly parallel way during
the exposure to strong light.
Conclusions. A change in the 02 con-
centration surrounding the leaf from
21% to 1.5% did not have any effect on
the degree of stomatal opening. Photo-
synthesis was enhanced almost 50% in
all leaves tested regardless of origin or
preconditioning. This indicates that the
change in light-saturated photosynthesis
that takes place in the different ecotypes
as a result of short-term exposure to
high light intensities cannot be due to
changes in physical barriers to diffu-
TABLE 19. Soluble Protein and Fraction-1
Protein Content of Leaves of Solanum dulca-
mara, Clone Fe 2, Grown in Weak Light and
Transferred to Strong Light for 2, 4, and
6 Days
Days in
Strong
Light
0
2
4
6
Total Soluble
Protein, mg per
g Fresh
Weight
16.65
21.76
29.10
32.00
Fraction-1
Protein, mg
per g Fresh
Weight
7.63
8.28
10.13
1226
sions of C02, or in the rate of reoxida-
tion of photosynthesis in the light
(photorespiration) . The causes of the re-
duction in the light-saturated rate of C02
uptake in the shaded habitat clone upon
exposure to strong light are still un-
known. The parallel increase in photo-
synthesis, protein content and carboxy-
dismutase activity in leaves of the sunny
habitat clone as a result of exposure to
strong light suggests strongly that syn-
thesis of key photosynthetic enzymes
may be the major factor increasing the
rate of photosynthesis after transfer to
a higher light intensity.
Bjorkman, O.
1968.
References
Physiol. Plantarum,
1,
187-
Gauhl, E., and O. Bjorkman, Planta,
191, 1969.
Wareing, P. F., M. M. Khalifa, and K. J.
Treharne, Nature, 220, 453, 1968.
Application of a New 02 Sensing De-
vice to Measurements of Higher
Plant Photosynthesis
Olle Bjorkman and Eckard Gauhl
Until recently no technique for mea-
surements of photosynthetic 02 exchange
by leaves that combines the accuracy,
simplicity, and convenience in operation
of the infrared analyzer for measure-
ments of C02 was available. Almost all
information on photosynthetic 02 ex-
change by higher plants has been ob-
tained from mass spectrometric measure-
ments.
Polarographic measurements of 02 ex-
change have been widely used in studies
of algal photosynthesis for many years.
Last year we successfully adapted this
technique for measurements of photo-
synthesis by thalli of the liverwort Mar-
chantia polymorpha. Unfortunately,
however, the technique is unsuited for
use with higher plant leaves.
Very recently, a greatly improved
version of the paramagnetic 02 analyzer
DEPARTMENT OF PLANT BIOLOGY
637
was tested for use with higher plants
in Professor Egle's laboratory in Frank-
furt, Germany, with promising results
(Schaub et al., 1968). In addition to this
improved paramagnetic analyzer, an en-
tirely new 02 sensing device, exploiting
the high ionic conductivity to oxygen of
a newly developed ceramic, has become
commercially available. Because of its
very high sensitivity, it appeared to be
potentially useful for measurement of
photosynthetic 02 evolution and the
testing of the device for this purpose
was therefore undertaken in this labora-
tory. The sensor is manufactured by the
Westinghouse Electric Corporation, New
Products Division, Pittsburgh, Pa., and
is incorporated in Model 209 02 Monitor
of this company. Scientific Products,
Menlo Park, California, kindly made
one such instrument available for test-
ing.
The sensor consists of a nonporous
tube of a calcium stabilized zirconium
oxide ceramic to which porous electrodes
are attached. It is also equipped with a
furnace operating at 850 °C. This tem-
perature is kept constant with a solid-
state proportional controller.
The gas to be analyzed is admitted to
one side of the ceramic tube and the
reference gas to the other side. Oxygen
molecules on the side with the higher 02
pressure gain electrons to become ions,
while simultaneously on the other side,
oxygen molecules are formed by reverse
action. The potential of the cell is then
given by
V= (RT/nF) In (Ps/Pr)
(1)
where R is gas constant; T, absolute
temperature; F, Faraday; Ps, partial
pressure of 02 in the sample gas ; and Pr,
partial pressure reference gas (Burke,
1969). With the cell used in the present
study the open circuit potential (mV)
is given by
V = 55 log (Ps/Pr)
(2)
water vapor and carbon dioxide, but care
has to be taken not to introduce com-
bustible gases into the cell since at the
high operating temperature these will re-
act with oxygen and reduce its concen-
tration.
In measurements of photosynthesis
with an open flow system under rate-
limiting C02 concentrations it is usually
desirable that the uptake of C02 by the
leaf does not result in an excessive re-
duction of the C02 concentration in the
leaf chamber. In most cases a reduction
exceeding 25% would be undesirable.
Under a C02 concentration of normal
air this would amount to about 80 ppm.
Since the uptake of one mole of C02
can be expected to correspond to a
roughly equal amount of 02 being
evolved, the change in 02 concentration
also should not exceed this value. It is
therefore desirable that a concentra-
tion change of about 1 ppm be resolved
by the device.
Figure 48 shows the calculated rela-
+ 4
The cell voltage is unaffected by the
presence of noncombustible gases such as
Ps-Pr,ppm
Fig. 48. The open circuit voltage produced by
the zirconium-oxide ceramic cell as a function
of the difference in 02 concentration between
the sample and the reference gas, at different Oa
concentrations in the reference gas.
638
CARNEGIE INSTITUTION
tionship between the cell voltage and the
difference in 02 concentration between
the sample and the reference gas at vari-
ous 02 concentrations. From these data
it may be predicted that sufficient sensi-
tivity can be obtained at 02 concentra-
tions of less than 2000-10,000 ppm 02.
In the photosynthesis measurements re-
ported here the 02 concentration of the
gas entering the leaf chamber was kept
at 1500 ppm. At this concentration the
sensitivity of the device was sufficiently
high and there was no evidence of ad-
verse metabolic effects that might be
caused by anaerobic conditions. The 02
concentration in the leaf chamber was
kept in the range of 1500-1560 ppm. As
shown in Fig. 48, the relationship be-
tween the 02 concentration and the cell
voltage is very close to linear in this nar-
row range.
The output voltage of the 02 cell was
measured with a Keithley Model 150 B
Microvoltmeter and the amplified signal
displayed with a dual channel Hewlett-
Packard 7100 BM potentiometric re-
corder. The indicating circuitry and
other accessory components that are
integral parts of the Westinghouse Model
209 Monitor were either inadequate or
unnecessary for the present application.
With the exception of the 02 cell as-
sembly and the temperature controller,
all circuits in the Model 209 02 Monitor
were disconnected. An open system simi-
lar to that described by Bjorkman
(1966) was employed. All measurements
were made on single leaves, attached to
the plants.
With the 02 concentrations used in our
photosynthesis measurements the noise
level of the output voltage from the 02
cell was very low. The estimated signal-
to-noise ratio of the amplified and re-
corded signal was about 500 to 1. A
change in concentration of 0.2 ppm could
easily be detected when the 02 concen-
tration was kept at about 1500 ppm.
Under these same conditions the base
line drift was estimated to be 1% of full
scale deflection over a 10-hour period.
These data suggest that a considerably
higher amplification factor could be used
while a tolerable noise level could still
be maintained. As far as we are aware,
there is no other 02 sensing device pres-
ently available with as high a sensitivity
in this concentration range.
The instrument was completely un-
affected by vibrations from pumps and
other equipment that were mounted on
the same bench. It was also unaffected
by considerable changes (some ±5°C)
in the ambient temperature. Another at-
tractive feature is that no elaborate
calibrations are needed. The response of
the cell to changes in 02 concentration
can readily be predicted from equation
2. Experimental values obtained by
diluting pure 02 with N2 agreed with
these predicted values within the experi-
mental error of the calibration procedure.
This error was approximately ±3% and
that of the analyzer is presumably
smaller.
Figures 49-51 show typical results of
experiments in which the dependence of
photosynthesis on light intensity and
temperature was determined. Tracings
from the recorded charts presented in
Fig. 49 illustrate the time course of pho-
tosynthesis when the leaves were sub-
jected to changes in light intensity. The
rate of 02 evolution, calculated from the
predicted response of the 02 cell, was in
very close agreement with the rate of
C02 uptake in all cases where both rates
were measured. Results of determina-
tions of the dependence of photosynthetic
02 evolution on C02 concentration in
leaves of Atriplex patula and A. rosea,
using this new 02 sensing device, are
shown in another section of this Year
Book (p. 629, Fig. 42).
The response time of the 02 measur-
ing system is determined by the volume
of the leaf chamber and the gas con-
nections between it and the 02 cell, and
by the flow rate. The response time of
the 02 cell itself is, according to the
manufacturer, only one millisecond.
Because of its insufficient sensitivity
DEPARTMENT OF PLANT BIOLOGY
639
Light 111.4
1 f T"
41.7 13.5 Dark
ergs cm"2sec"
xlO3
12
10
20
Time.min
30
40
c
E
(M
E
-a
o
E
a
15
CM
o
o
Fig. 49. Recorder traces of the time courses of 02 evolution and C02 uptake in a Mimulus
verbenaceus leaf subjected to decreases in light intensity. The leaf temperature was 25 °C and
the C02 concentration in the leaf chamber was approx. 0.08%. White light was provided by a
2.5 kW high pressure Xenon lamp.
at high 02 concentrations, the device is
of limited usefulness in photosynthesis
measurements under field conditions and
0 50 100 150
Light intensity, ergs cm"2:
200
"' xlO3
250
Fig. 50. Effect of light intensity on the rates
of 02 evolution and C02 uptake in an M.
verbenaceus leaf. Conditions were as given
under Fig. 49.
in studies on the inhibitory effect of 02
on net photosynthesis (photorespira-
tion). It is, however, probably the best
instrument currently available for ki-
netic studies of higher plant photosyn-
thesis under low 02 concentrations where
reoxidation of photosynthetic products
in the light is inhibited.
A particularly valuable feature of the
02 cell is its complete insensitivity to
C02. This greatly simplifies measure-
ments of the dependence of photosyn-
thesis on C02 concentration, and of
photosynthetic responses under saturat-
ing C02 concentrations where the infra-
red C02 analyzer has a relatively poor
resolution. The 02 analyzer, described
here, provides an excellent supplement
to the infrared C02 analyzer in com-
parative studies of photosynthetic char-
acteristics in higher plants, and it has
640
CARNEGIE INSTITUTION
02 evolution
0.0340 0.0345 0.0350 0.0355
Inverse of absolute temperature, (°K)_I
Fig. 51. Arrhenius plots of the effect of leaf
temperature in the range 6-24° C on the rates
of 02 evolution and C02 uptake in an M.
verbenaceus leaf. Saturating white light of an
intensity of 2.5 X 105 erg cm-2 sec"1 (400-700
nm) was from a 2.5 kW high-pressure Xenon
lamp.
now been incorporated into our photo-
synthesis measuring system.
References
Bjorkman, 0. E., Physiol. Plantarum, 19,
618-633, 1966.
Burke, J. E., Science, 161, 1205-1212, 1968.
Schaub, H., W. Hilgenberg, and H. Fock,
Z. Pflanzenphysiol, 60, 64-71, 1968.
Intercontinental Crosses in
Solidago
Malcolm A. Nobs
The goldenrods of the sunflower family
(the genus Solidago) comprise about 100
species that are distributed mostly in
the Northern Hemisphere with only a
few representatives in South America.
The greatest diversity occurs in Eastern
North America with about 75 species.
On the Pacific Slope only about 12 spe-
cies are found, while in the vast continent
of Eurasia only a single widespread spe-
cies, Solidago virgaurea L., is considered
to be native.
Dr. Jean Beaudry and his co-workers
at the University of Montreal (Beaudry,
1963; Kapoor and Beaudry, 1966) are
making a comprehensive biosystematic
study of the North American members
of the genus. Results from comparative
physiological studies on contrasting eco-
types of Solidago virgaurea from north-
ern Europe by Bjorkman and Holmgren
interested us in the long-standing ques-
tion regarding the degree of relationship
between the Old World S. virgaurea and
Pacific Slope forms of the genus that
appeared to be ecological counterparts.
Crossings begun by us in 1965 (Year
Book 65, p. 471) and continued during
the last two years have yielded hybrids
that now provide information relating
to our original question.
Table 20 lists the species used in the
crossings, their origins, the pollen fertili-
ties and chromosomal pairing of both
parents, and of their F1 hybrids. The
crossings included, as far as possible,
combinations of pairs of races from simi-
lar ecological habitats in western Europe
and western North America. One pair
consists of arctic forms, a member of
S. virgaurea from northern Norway, and
a form of S. multiradiata from Umiat,
Alaska. Both are continental interior
forms from approximately 70° N. lati-
tude. Another pair consists of an alpine
form of S. virgaurea from the Sierra
Nevada of Spain at 3000 m elevation and
38° N. latitude and a form of S. multi-
radiata from the Sierra Nevada of Cali-
fornia at the same altitude and latitude.
A third pair of lowland counterparts
were crossed. These were a tall, branched
form of S. virgaurea from near Barce-
lona, Spain, and a coastal form of S.
spathulata D.C. from central California,
both from approximately 38° N. lati-
tude. Another North American repre-
sentative, S. spectabilis (D.C. Eat.)
Gray from Mono Lake, California, at
DEPARTMENT OF PLANT BIOLOGY
641
TABLE 20. Pollen Fertilities and Chromosome Pairing in Parental and Hybrid
Combinations of Solidago
Percent
Species or Hybrid
Culture
Origins
Normal
Meiotic Pairing
Combination
No.
(Elevations and Latitudes)
Pollen *
(Metaphase I)
Parental Species:
S. multiradiata Ait.
7654
Timberline, Sierra Nevada of
California, 3100 m, 38° N.
90
Regular, 9 pairs
S. multiradiata Ait.
7338
Umiat, Alaska, 100 m, 70° N.
78
Regular, 9 pairs
S. spectabilis (D.C.
Eat.) Gray
7657
Mono Lake, California,
2000 m, 38° N.
92
Regular, 9 pairs
S. spathulata D.C.
7659
Coastal Central California,
San Mateo Co., 50 m, 38° N.
87
Regular, 9 pairs
S. spathulata D.C.
7335
Coastal Central California
Ft. Ross, 20 m, 38° N.
90
Regular, 9 pairs
S. virgaurea L.
B039
Beskades, Norway,
600 m, 70° N.
80
Regular, 9 pairs
S. virgaurea L.
HV124
Hallands Vadero, S. Sweden,
50 m, 56° N.
90
Regular, 9 pairs
S. virgaurea L.
7612
Barcelona, Spain, 600 m,
41° N.
Sierra Nevada, Spain,
89
Regular, 9 pairs
S. virgaurea L.
7613
80
Regular, 9 pairs
3000 m, 38° N.
Hybrid Combinations:^
multiradiata X 'multi-
radiata
7592
Umiat X Timberline
82
Regular, 9 pairs
multiradiata X
spectabilis
7668
Timberline X Mono Lake
54
Moderately regu-
lar, 15% with
multiradiata X
univalents
spathulata
7672
Timberline X Coastal
San Mateo
51
Moderately regu-
lar, 12% with
multiradiata X
univalents
spathulata
7590
Timberline X Coastal Ft. Ross
60
Nearly regular, 6%
with univalents
virgaurea X virgaurea
7568
South Sweden X N. Norway
80
Nearly regular, 5%
with univalents
virgaurea X virgaurea
7692, 7693
South Sweden X Barcelona
and Reciprocal
78
Nearly regular, 6%
with univalents
virgaurea X multi-
radiata
7573
South Sweden X Timberline
15
Irregular, 7 pairs +
virgaurea X multi-
2 tetravalents
radiata
7678
Sierra Nevada (Spain) X
Timberline (California)
19
Irregular, 7 pairs -f-
2 tetravalents
virgaurea X
or univalents
spectabilis
7679, 7680
Barcelona (Spain) X Mono
23
Irregular, 7 pairs -f-
virgaurea X
Lake (California)
2 tetravalents
spathulata (2n)
7682-102
Sierra Nevada (Spain) X
Coastal California
13
Irregular, univa-
lents plus chains
virgaurea X
(San Mateo)
spathulata (4n)f
7682-111
Ditto
50
Multivalents plus
virgaurea X
univalents
spathulata
7684
Barcelona (Spain) X Coastal
California (San Mateo)
18
Irregular, 7 pairs +
2 tetravalents
virgaurea X
and univalents
spathulata
7690
Beskades (Norway) X
Coastal Central California
(San Mateo)
20
Irregular, 7 pairs +
2 tetravalents
virgaurea X
spectabilis
7691
Beskades (Norway) X Mono
Lake (California)
12
Irregular, 6 pairs +
2 tetravalents
and univalents
* Pollen stainable with lacto-phenol and cotton blue.
f Spontaneous tetraploid Fi hybrid.
642
CARNEGIE INSTITUTION
2000 m elevation has also been included.
As indicated in Table 20, the Fx
hybrids of all the combinations in-
dicate that there is a high degree
of homology between their chromo-
somes and those of the parental species.
Even the most highly irregular com-
binations as, for example, Fx hybrids
between different forms of S. virgaurea
and S. multiradiata, or between S. vir-
gaurea and S. spathulata, have about
80% chromosomal pairing. That some
structural repatterning of the chromo-
somes has taken place is, however, very
evident. These appear to be primarily
due to segmental interchange. The strong
sterility barriers, as indicated by the
high percentage of aborted pollen, also
suggests that accumulated gene differ-
ences as well as other small undetectable
structural rearrangements may have
taken place in the differentiation of the
North American and European counter-
parts. The combination 7683 (Table 20)
between Solidago virgaurea from the
Sierra Nevada in Spain and S. spathulata
from coastal Central California yielded
a spontaneous tetraploid with n = 18
chromosomes. The pollen of the tetra-
ploid is 50% normal as compared with
only 13% for the diploid hybrid plants,
suggesting that the tetraploid may have
considerably higher fertility than the
diploids. The extreme vigor of the tetra-
ploid in the Stanford garden as con-
trasted with the diploids further indicates
that it is an amphiploid, and implies
that a fairly high degree of genetic
divergence has taken place between the
parental species.
The very close homology between the
chromosomes of even the most contrast-
70°
50°-
40°-
30°-
20°-
10° -
Percent normal polle
50-60
Under 25
Fig. 52. Fertilities of first-generation hybrids between European and North American forms of
Solidago. The habit sketches of the parental forms are drawn to scale from plants grown in the
Stanford garden. See text.
DEPARTMENT OF PLANT BIOLOGY
643
ing ecological races of the European S.
virgaurea, and also between correspond-
ing North American forms of S. multi-
radiata, is evident from Table 20. That
parallel differentiation in the two spe-
cies has taken place in the two con-
tinents is now clear. It is equally clear
that the two species have been derived
from the same ancestral stock and are
closely enough related to have preserved
most of their chromosomal homology.
Figure 52 summarizes the relation-
ships between the North American and
European forms of Solidago in graphic
form and illustrates the major morpho-
logical differences between the parental
forms used in the crossings. The draw-
ings of the parental plants are made to
scale as the plants are observed in the
Stanford garden. It should be remem-
bered that such vegetative characters
as stem height may be strongly modified
in contrasting environments.
References
Beaudry, Jean R., Can. J. Genet. Cytol., 5,
150-174, 1963.
Kapoor, B. M. and J. R. Beaudry, Can. J.
Genet. Cytol, 8, 422-443, 1966.
Vegetation of the Harvey Monroe
Hall Natural Area
Jens Clausen
Occasioned by the XI th International
Botanical Congress meeting at the Uni-
versity of Washington, Seattle, August
24 to September 3, 1969, two major field
excursions are planned that include the
Institution's Department of Plant Biol-
ogy field stations and central laboratory.
The Mather and Timberline transplant
stations will be featured, the latter situ-
ated in the Harvey Monroe Hall Natural
Area. A list of plant species native to
this unique area that has been compiled
over a period of years is being printed
by the Institution in booklet form and
will be available to the visiting botanists.
In view of the wide biological interest
in the Harvey Monroe Hall Natural Area
a brief review of its history appears to be
appropriate. In his annual report {Year
Book 32, pp. 20-21) President John C.
Merriam discussed the establishment of
this Natural Reserve Area in connection
with future research on fundamental
problems in biology, such as environ-
ment and heredity. Dr. Herman A.
Spoehr, then Chairman of the Division
of Plant Biology, in his report the same
year (p. 180) discussed the significance
of the Area "combining an unusual com-
plex of environmental conditions and
biological materials."
Dr. Harvey M. Hall proposed the
establishment of such a "natural area."
He emphasized that "natural conditions
will be preserved virtually free from
disturbance excepting those necessary
for the conduct of scientific research."
Hall's proposal was unique in that it
would permit scientific research con-
sistent with the conservation of the na-
tive vegetation, animal life and other
natural features in essentially undis-
turbed form. Hall's very extensive first-
hand field knowledge of the entire flora
of California enabled him to perceive
the special value of having available
for basic experimental work such a
strategically located preserve. After
Hall's death, in 1932, a mutual contract
between the U. S. Forest Service and
the Carnegie Institution was drawn
setting up the area as Hall had proposed,
to be named in his honor.
The approximately 20-square-kilom-
eter area (about 7 square miles) in-
cludes diverse topographic features that
are truly representative of the high
Sierra Nevada of California. Included
are three valleys lying in an east-west
direction that touch the east rim of the
Sierra Nevada at 38° N. latitude. The
valleys lie at altitudes between 3000 and
4000 m (about 10,000-13,000 ft.), and
each has steep north- and south-facing
slopes that provide unusual ranges of
temperature, with cold night air collect-
644
CARNEGIE INSTITUTION
ing at the bottom of the valleys (Year
Book 64, pp. 431-435) .
The present-day vegetation includes
a total of 347 species-complexes and 4
interspecific hybrids, an unusually high
number of species for an area above
3000 m altitude. Within the Hall Area
are local edaphic niches that range from
bogs and moist meadows to dry screes,
rough, rocky talus and glacial moraines
that extend up to the still active Con-
ness Glacier. It appears the Sierra
Nevada was uplifted more than 1000 m
during the 1-2 million years since the
midglacial period. During the shifts in
altitude and climate the species, posses-
sing genetic flexibility, evolved new eco-
logical races as they were raised in alti-
tude with the mountains.
Within the Hall Area the present-day
vegetation consists of what appear to be
72 species that are members of circum-
polar to circumboreal complexes that
must have immigrated from the north
through the Cascade-Sierran mountain
ranges. About 68 species belong to com-
plexes that have related races and spe-
cies along the Pacific slope, some spilling
over to the east of the Sierras; related
to this group are 32 high-alpine, endemic
Sierra Nevada species that could have
occupied ice-free refuges during the
period of heaviest glaciation. The re-
maining 175 species appear to have their
relatives in the Great Basin-Rocky
Mountain region, and must have entered
the Hall Area over the dry mountain
ridges from the east, although many
spill over to the higher altitudes on to
the Sierran west slope. Of these, 14 reach
the Atlantic, and 31 occur in Alaska.
As the Sierras gradually rose, the I
aridity of the Great Basin increased,
providing habitats for the multiple forms
of sagebrushes and rabbitbrushes. The
Hall Area itself is geologically recent,
probably having been free of ice only
within the last 2000-6000 years, al-
though forms of hardier species may
have occupied refuges for longer periods.
STAFF ACTIVITIES
Dr. William M. Hiesey retired on
June 30, 1969. He joined the Institution
in 1926 and has led the Experimental
Taxonomy Group since 1956. Dr. Hiesey
plans to remain active for the completion
of an Institution monograph, Experi-
mental Studies on the Nature of Species,
Vol. V., Biosystematics, genetics, and
ecological physiology of the Erythranthe
section of Mimulus, by William M.
Hiesey, Malcolm A. Nobs, and Olle
Bjorkman.
Because of overlapping interests of
the Experimental Taxonomy Group and
of several Stanford professors, the ties
between the Institution and the Depart-
ment of Biological Sciences of Stanford
University have become closer. In addi-
tion to direct experimental collaboration
with Professors Harold Mooney, Peter
Ray, and Peter Raven, and their gradu-
ate students, a Stanford Seminar on
Plant Physiology and Ecology has met
weekly at our Department under Pro-
fessor Ray's direction. Plans are in
preparation for expansion of the col-
laborative work of Drs. Bjorkman and
Nobs with the Stanford group at the
mountain stations and at the laboratory.
Dr. Jens Clausen was invited to at-
tend the Vth Congress of EUCARPIA,
the European Association for Research
in Plant Breeding, meeting at Milan,
an international symposium in Denmark
of the Scandinavian Association of
Geneticists in honor of Professor C.
Syrach Larsen's retirement, and a meet-
ing of the Danish Botanical Society. His
talk on "Genecology and Breeding" will
be published in English and in Russian.
Dr. Clausen has prepared a description
of the Harvey Monroe Hall Natural
Area, with a check list of its plants
showing also their relatives in other
DEPARTMENT OF PLANT BIOLOGY
645
regions. This Institution publication
which developed from his talk at the
Danish Botanical Society is available
to two groups of botanists visiting the
mountain stations in connection with
the XI International Botanical Congress
held in Seattle in August, 1969.
Dr. Fork and Dr. Jan Amesz of
Leiden, a former Carnegie Corporation
Fellow, have collaborated on an article,
"Action spectra and energy transfer in
photosynthesis," for Annual Reviews of
Plant Physiology and have also con-
tributed a chapter, "Spectrophotometric
studies on photosynthesis," for a com-
prehensive text on photophysiology,
edited by Professor Giese of Stanford.
Dr. Norio Murata, an Institution Re-
search Fellow has been awarded the
prize for promotion of research by the
Japanese Biochemical Society for his ac-
complishments in the study of fluores-
cent pigments of photosynthesis.
Mr. Jan Kowalik was awarded the
Jurzykowski Award by the Alfred
Jurzykowski Foundation on January 24,
1969, in recognition of his outstanding
achievements in the field of bibliography.
Drs. Brown and Murata attended the
Gordon Conference on Photosynthesis at
Holderness, New Hampshire, June 29 to
July 4, 1969.
During the year the Institution's Bush
Cabin at Inverness, California was built
in a heavily wooded area close to the
Tomales Bay State Park and the Point
Reyes National Seashore. This was made
possible by Dr. Bush's gift to the Insti-
tution for staff recreation. The cabin
shell was built by a contractor while
completion of the roof, deck, interior
finish, wiring, and finish plumbing is
providing an abundance of recreational
challenge for the Department's Staff and
Fellows.
BIBLIOGRAPHY
449* Amesz, Jan, see Fork, David C.
453 Bjorkman, Olle, and Eckard Gauhl, Car-
boxydismutase activity in plants with
and without /3-carboxylation photosyn-
thesis. Planta, 88, 197-203, 1969.
458 Bjorkman, Olle, and Eckard Gauhl, Use of
the zirconium oxide cell for measure-
ments of photosynthetic oxygen evolu-
tion by intact leaves. Photosynthetica, in
press, 1969.
454 Bjorkman, Olle, see Gauhl, Eckard.
Bjorkman, Olle, Characteristics of the pho-
tosynthetic apparatus as revealed by
laboratory measurements. IBP/PP Tech-
nical Meeting, Trebon, Czechoslovakia,
Productivity of Photosynthetic Systems,
Models and Methods, Czechoslovakia
Academy of Science, ed., Preliminary
texts of invited papers, pp. 136-148,
April 10, 1969.
Brown, Jeanette S., Selective and reversible
absorption changes of chloroplast par-
ticles. Fifth Intern. Congr. Photobiol.,
Hanover, New Hampshire, Abstracts of
Congress, 5, p. 101, 1968.
* Department of Plant Biology publication
numbers.
Brown, Jeanette S., Fluorescence of frac-
tionated chloroplast particles (abstract).
Biophysical Journal, 9, A-124, 1969.
442 Brown, Jeanette S., see French, C. S.
449 Fork, David C, and Jan Amesz, Action
spectra and energy transfer in photo-
synthesis. Ann. Rev. Plant Physiol., 20,
Leonard Machlis, ed., Annual Reviews,
Palo Alto, Calif., pp. 305-328, 1969.
445 French, C. S., Biophysics of plastid pig-
ments. Closing Session Summary, Inter-
nal. Congr. of Photosynthesis Research,
Freudenstadt, June 4-8, 1969, Photo-
synthetica, 3(1), 94-96, 1969.
French, C. S., Absorption and fluorescence
spectra of forms of chlorophyll. Fifth
Intern. Congr. Photobiol, Hanover, New
Hampshire, Abstract of Congress, 5, 73,
1968.
French, C. S., Analysis of spectra of chloro-
plast fractions (abstract). Biophys. J., 9,
A-124, 1969.
French, C. S., The forms of chlorophyll a
in plants (abstract). Plant Physiol., 1$,
Suppl., S 20, 1968.
442 French, C. S., M. R. Michel-Wolwertz, J.
Michel, J. S. Brown, and L. Prager,
Naturally occurring chlorophyll types
646
CARNEGIE INSTITUTION
and their functions in photosynthesis.
Biochemical Society Symposia, 28, Por-
phyrins and Related Compounds, T. W.
Goodwin, ed., London, pp. 147-162, 1969.
454 Gauhl, Eckard, and Olle Bjorkman, Simul-
taneous measurements on the effect of
oxygen concentration on water vapor and
carbon dioxide exchange of leaves.
Planta, 88, 187-191, 1969.
Gauhl, Eckard, see Bjorkman, Olle.
446 Heber, Ulrich, Conformational changes of
chloroplasts induced by illumination of
leaves in vitro, Biochim. Biophys. Acta,
180, 302-319, 1969.
442 Michel, J. M., see French, C. S.
442 Michel- Wolwertz, M. R., see French, C. S.
442 Prager, L., see French, C. S.
SPEECHES
Bjorkman, Olle, Adaptive differentiation of
photosynthetic characteristics among species
and races of higher plants from ecologically
diverse habitats. Advanced Plant Physiology
and Biochemistry Seminar, MSU/AEC Plant
Research Laboratory, Michigan State Uni-
versity, East Lansing, Michigan, March 4,
1969.
Bjorkman, Olle, Comparative studies of photo-
synthesis and growth in species with different
pathways of carboxylation. Advanced Plant
Physiology and Biochemistry Seminar, MSU/
AEC Plant Research Laboratory, Michigan
State University, East Lansing, Michigan,
March 5, 1969.
Bjorkman, Olle, Ecological aspects of photo-
synthesis. Department of Botany Seminar,
University of California at Davis, Davis,
California, November 5, 1968.
Bjorkman, Olle, Oxygen inhibition of photo-
synthesis and growth, photorespiration,
/3-carboxylation photosynthesis, and related
matters. Stanford Plant Physiology Graduate
Seminar, Carnegie Institution, Stanford,
California, May 7, 1969.
Bjorn, Lars 0., Delayed light emission. Stanford
University Plant Physiology Graduate Semi-
nar, Carnegie Institution, Stanford, Cali-
fornia, April 23, 1969.
Brown, Jeanette S., Selective and reversible
absorption changes of chloroplast particles.
Fifth International Congress on Photobiol-
ogy, Hanover, New Hampshire, August 29,
1968.
Brown, Jeanette S., Fluorescence of fractionated
chloroplast particles. Biophysical Society, Los
Angeles, California, February 27, 1969.
Brown, Jeanette S., Biological forms of chloro-
phyll a. Stanford University Plant Physiology
Graduate Seminar, Carnegie Institution,
Stanford, California, October, 1968.
Brown, Jeanette S., Spectroscopic analysis of
different chlorophyll containing particles.
Gordon Research Conference, Holderness
School, Plymouth, New Hampshire, June 30,
1969.
Clausen, Jens, Genecology and breeding. Vth
Congress of Eucarpia, European Association
for Research in Plant Breeding, Milan, Italy,
October 2, 1968.
Clausen, Jens, Genecology and breeding.
Scandinavian Association of Geneticists
Symposium on Seed Orchards, in honor of
Dr. C. Syrach Larsen, Scandinavian Seminar
College, Holte, Denmark, October 7, 1968.
Clausen, Jens, Genecology and breeding.
Mendelian Society, Botanical Society, Lund,
Sweden, October 17, 1968.
Clausen, Jens, Populationsstudier over traeer i
en alpin-subalpin dal i Sierra Nevada, Cali-
fornia (Population studies on trees in an
alpine-subalpine valley in Sierra Nevada,
California). Danish Botanical Society, Bo-
tanical Laboratory, University of Copen-
hagen, Copenhagen, Denmark, October 23,
1968.
Fork, David C, Recent studies on inter-
mediates of electron transport in photosyn-
thesis. Biology Department Seminar, Uni-
versity of Chicago, Chicago, Illinois, May 23,
1969.
Fork, David C, Intermediates of photosyn-
thetic electron transport. Biology Depart-
ment Seminar, California Institute of Tech-
nology, Pasadena, California, June 2, 1969.
Fork, David C, Photosynthetic electron trans-
port. Stanford University Plant Physiology
Graduate Seminar, Stanford, California,
January 15, 1969.
French, C. S., Absorption and fluorescence
spectra of forms of chlorophyll. Fifth Inter-
national Congress on Photobiology, Hanover,
New Hampshire, August 28, 1968.
French, C. S., The forms of chlorophyll a in
plants. American Society of Plant Physi-
ologists, Amherst, Massachusetts, August 31,
1968.
DEPARTMENT OF PLANT BIOLOGY
647
French, C. S., Analysis of spectra of chloroplast
fractions. Biophysical Society, Los Angeles,
California, February 27, 1969.
Gauhl, Eckard, Photosynthetic differentiation
among Solatium dulcamara ecotypes from ex-
posed and shaded habitats. Stanford Uni-
versity Plant Physiology Graduate Seminar,
Carnegie Institution, Stanford, California,
December 4, 1968.
Hiesey, William M., Biosystematic and com-
parative physiological studies in Mimulus.
Stanford University Plant Physiology Gradu-
ate Seminar, Carnegie Institution, Stanford,
California, February 19, 1969.
Hiesey, William M., Experimental studies on
comparative plant physiology at the Carnegie
Institution Laboratory. Biology Department
Seminar, San Jose State College, San Jose,
California, May 7, 1969.
Mantai, Kenneth E., Effect of hydrolytic en-
zymes on photosystem 2. Stanford University
Plant Physiology Graduate Seminar, Car-
negie Institution, Stanford, California, Febru-
ary 12, 1969.
Mantai, Kenneth E., Effects of hydrolytic en-
zymes and UV irradiation on electron trans-
port in chloroplasts. Biology Department
Seminar, Oberlin College, Oberlin, Ohio,
April 28, 1969.
Nobs, Malcolm, Genetic diversity in Mimulus
species and races and their responses to con-
trasting climates. Biology Department Semi-
nar, University of Iowa, Iowa City, Iowa,
January 9, 1969.
648
CARNEGIE INSTITUTION
PERSONNEL
Biochemical Investigations
Staff: C. Stacy French, Director; Jeanette S.
Brown, David C. Fork; James H. C. Smith,
Emeritus
Carnegie Corporation Fellow: Kenneth E.
Mantai x
Institution Research Felloivs: Eckhard E.
Loos,2 Lars Olof Bjorn,3 Norio Murata,4
Colin Wraight 5
Visiting Investigators: Zdenek Sestak,6
Marcel Andre,7 Yaroslav de Kouchkovsky 8
Guest Investigator: Teruyo Murata9
Technical Assistants: Lillian Prager,10 Mary
Holzer,11 Helen Kennedy,12 Gregory S.
Martinelli 13
Experimental Taxonomy
Staff: Olle Bjorkman, William M. Hiesey,
Malcolm A. Nobs; Jens C. Clausen,
Emeritus
Institution Research Fellows: Eckard
Gauhl,14 John E. Boynton 15
Technical Assistant: Frank Nicholson
Gardener: Archibald H. Lawrence
Summer Research Assistants: Stephen G.
Wood,16 Peter G. Mika 17
Part Time Garden Helpers: Andrew Liber-
tone,18 Charles Wright II19
Clerical Assistant: Marylee Eldredge 20
Administrative Secretary-Accountant: Clara
K. Baker
General Department Secretary: Wilta M.
Stewart,21 Karen D. Roberts22
Mechanical Engineer: Richard W. Hart
Electrical Engineer: Mark C. Lawrence
Custodian: Jan Kowalik
Custodian Helper: Dietrich G. Seaman23
1 From September 5, 1968. From Oregon State
University, Corvallis, Oregon.
2 From January 6, 1968. From Institut fur
Angewandte Botanik, Technische Hochschule,
Munich, Germany.
3 From January 3, 1969. From University of
Lund, Lund, Sweden.
4 From June 3, 1969. From University of
Tokyo, Tokyo, Japan.
5 From June 23, 1969. From University of
Bristol, Bristol, England.
"From September 11, 1968, through October
20, 1968. From Czechoslovak Academy of Sci-
ences, Prague, Czechoslovakia.
7 From October 14, 1968, through November
21, 1968. From Commisariat a l'Energie
Atomique, Centre d'Etudes Nucleaires de
Cadarache., France.
8 From November 27, 1968, through Decem-
ber 22, 1968, from CNSR, Gif-sur-Yvette,
France.
9 From June 3, 1969. From University of
Tokyo, Tokyo, Japan.
10 From July 1, 1967, through August 2, 1968.
"From July 1, 1968, through February 7,
1969.
12 From February 3, 1969.
13 From June 19, 1969.
11 From April 11, 1967, through June 30, 1969.
From Botanisches Institut der Johann Wolf-
gang Goethe-Universitat, Frankfurt, Germany.
15 From June 9, 1969. From Duke University,
Durham, North Carolina.
18 From June 18, 1968, through September 3,
1968.
17 From June 16, 1969.
18 From October 3, 1967, through February 7,
1969.
19 From May 13, 1969.
20 From October 15, 1956, through February
15, 1969.
21 From November 3, 1967, through March 31,
1969.
22 From March 24, 1969.
23 From January 22, 1969, through February
15, 1969.
PLATES
Plate l(A-B)
Department of Plant Biology
Plate 1(A). Subalpine M. lewisii (left), the Fi hybrid between M. lewisiiy^M. cardinalis
(center), and the vacant position of the nonsurviving coastal M. cardinalis parent (right,
marked by tape) in the Timberline garden, September 1967, after an early autumn snowfall.
Plate 1(B). Three third-generation progenies from the above cross in the Timberline garden,
summer of 1967; row 1, F3 plants from the M. lewisii-like F2 plant, 7111-16; row 2, F3 plants
from the Fi-like F2 plant 7111-17; and row 3, plants from the M. cardinalis -like F2 plant
7135-35.
Plate 1(C)
Department of Plant Biology
Plate 1(C). The same scene in the summer of 1968,
eliminated bv winter-kill.
all plants in row 3 having been
Plate
Department of Plant Biology
Plate 2. The Logan and Jacksonville clones of Mimulus after a 30-day period at 10 and
30°C. The light intensity was maintained at 5.3 X 104 erg cm-2 seer1 (400-700 nm) during a
16-hour photoperiod, and the C02 concentration at 0.03%.
Genetics Research Unit
Cold Spring Harbor, New York
Alfred D. Hershey
Director
Carnegie Institution Year Book 68, 1968-1969
Contents
Genes and Hereditary Characteristics 655
Determination of phenotype 655
DNA phenotypes 661
Bibliography 668
Personnel 668
GENES AND HEREDITARY CHARACTERISTICS
Determination of Phenotype
Historically influential ideas have to
be simple. Since natural phenomena need
not be simple, we master them, if at all,
by formulating simple ideas and explor-
ing their limitations. The notion that
genes determine the characteristics of
biological individuals and species is ex-
ceptional among simple ideas: its limita-
tions have consistently diminished with
the passage of time. In these notes I con-
sider both the simplicity and the limita-
tions of our ideas about genetic determi-
nation.
The early students of heredity were
forced to distinguish between the genetic
constitution of an animal or plant (its
genotype) and the expression of its
genes in visible characters (its pheno-
type). The distinction is particularly
clear in a heterozygous individual that
received dissimilar genes from its two
parents: the dual genotype clearly gives
rise to a single phenotype. But even an
individual with a single set of genes ex-
hibits a phenotype that depends on stage
of development, environmental influ-
ences, and accidental factors.
The notion that genotype controls
phenotype is pure tautology in the typ-
ical breeding experiment in which geno-
type means differences between geno-
types, and phenotype means differences
between phenotypes. Mendel brought the
tautology to light by showing that in-
heritance depends on unit factors. The
generality of his discovery may be sum-
marized by saying that we know of no
biological characters, including develop-
mental patterns, that are immune to
gene mutations. The importance of his
discovery lay in showing that inheritance
could be analyzed: he initiated the col-
laboration between nature and scientists
that has characterized the study of in-
heritance to this day. Nevertheless, the
more general relation between genotype
and phenotype for many years seemed
infinitely complicated, as indeed it was
in the prechemical era of genetics.
In 1940 Beadle and Tatum redirected
attention to Mendel's unit factors when
they described their first experiments
with the bread mold Neurospora. This
organism was unique at the time in per-
mitting both genetic and nutritional ex-
periments. Thus Srb and Horowitz
(1944) could analyze fifteen Neurospora
mutants unable to synthesize the amino
acid arginine and show that each bio-
chemical step in the synthesis is, in gen-
eral, the province of a single gene func-
tioning in the synthesis of a single
enzyme. This result, epitomized in the
phrase "one gene-one enzyme," obviously
conflicted with what everybody knew:
that the relation between genotype and
phenotype was infinitely complicated.
Chiefly because of this conflict, and
partly too because the meaning of the
phrase was not precisely defined, the new
hypothesis met with strenuous opposi-
tion.
Actually, the hypothesis consisted of
two parts: only one gene functions
specifically in the synthesis of a single
enzyme, and one gene functions specifi-
cally in the synthesis of only one enzyme
(if any). Both parts were necessarily a
little vague, because the significance of
the word "specifically" was not clarified
for another decade or more. (We now
say that one gene determines the amino
acid sequence of one enzyme.)
I don't suppose it is possible to assign
a date to the eventual acceptance of the
one gene-one enzyme hypothesis, but I
remember clearly the Cold Spring Har-
bor Symposium of 1951 at which the
controversy reached its climax. At that
meeting Horowitz and Leupold presented
their paper entitled "Some recent studies
bearing on the one gene-one enzyme
hypothesis," a paper that would be better
655
656
CARNEGIE INSTITUTION
known today if it had been called "Con-
firmation of the one gene-one enzyme
hypothesis by the use of conditional
lethal mutations." In the stormy discus-
sion that followed I was unable to grasp
the issues, but it was clear to me that
nearly everyone was quarreling with
Beadle and Tatum, who were absent, and
ignoring the results just presented.
Horowitz and Leupold offered rather
subtle arguments in support of the hy-
pothesis that only one gene functions "in
a direct manner" in the synthesis of a
single enzyme. They also showed that
there are relatively few genes concerned
with functions common to synthesis of
proteins in general, and proposed that
the immediate precursors of proteins are
single amino acids or their derivatives,
not polypeptides. Their paper is historic
both for cogency of argument and be-
cause it describes the first systematic use
of temperature-sensitive mutants.
In the context of the one gene-one en-
zyme hypothesis, subsequent develop-
ments are mainly the discovery of two
smaller classes of genes: regulator genes
(Jacob and Monod), whose products in
the well-known examples are proteins in-
teracting directly with DNA to interfere
with the expression of other genes or
groups of genes (Gilbert, Ptashne) ; and
genes in which the structures of riboso-
mal and transfer RNA's are encoded
(Spiegelman). At the present time there
are no clear indications that additional
classes remain to be discovered, though
of course not all gene-determined pro-
teins are properly called enzymes.
It is well to keep in mind that classical
genetics was a perfected discipline some
time before chemical genetics was in-
vented: no real conflict between them
was possible. (Read, for example, Sewall
Wright's paper published in the Physio-
logical Reviews in 1941, then G. W.
Beadle's published in the Chemical Re-
views in 1945.) The initial aim of chem-
ical genetics called for elucidation of the
structural and functional basis of the
determination of phenotype by genotype.
This aim, as nearly everyone agrees, has
been achieved in large measure, and
largely through elucidation of the struc-
ture of DNA (1953). The chief element
of surprise, I think, was the simplicity of
the denouement, anticipated in part by
Beadle and Tatum.
If the overall plan is simple, one ought
to be able to put it into a few words,
which I attempt as follows.
First, the genotype resides in DNA —
more importantly, in the one-dimensional
sequence of the four nucleotides in single
DNA strands.
Second, nucleotide sequences in single
DNA strands represent a code transcrib-
able into complementary sequences ac-
cording to simple one-to-one rules: the
four bases form only two interstrand
pairs, guanine-cytosine and adenine-
thymine. This code is used for DNA
replication, gene transcription, and syn-
thesis of ribosomal and transfer RNA's.
It also regulates the structure of typical
double-strand DNA molecules.
Third, sequences in one of the two
complementary strands, transcribed into
messenger RNA, represent a second code
translatable into amino acid sequences
in proteins. This is a nonoverlapping
triplet code (three bases per amino acid)
usually called the genetic code.
Fourth, the phenotype, insofar as it is
understood at all, resides exclusively in
amino acid sequences. This can be seen
in several ways. For one thing, enzyme
activities, which depend on specific pro-
tein structures, constitute a large part of
the analyzable phenotype. For another
thing, the three-dimensional structures
of proteins are directly determined by
the one-dimensional sequences of their
constituent amino acids, as first sug-
gested by the reversible thermal inacti-
vation of enzymes, and currently being
proved by the artificial synthesis of en-
zymes.
Finally, gross structure can be di-
rectly determined by subunit structure,
as seen in the reconstitution of certain
virus particles from their molecular con-
GENETICS RESEARCH UNIT
657
stituents, and in the joining of phage
tails and heads to make viable phage
particles. These demonstrations that
specific three-dimensional structures can
arise spontaneously out of appropriate
one-dimensional structures did much to
resolve old biological puzzles quite inde-
pendently of the many detailed mecha-
nisms now being brought to light.
My summary is necessarily abstract.
Perhaps I should mention one concrete
fact. Rust and Sinsheimer have shown
that either complementary strand of
DNA from the phage called <£X can in-
fect bacterial cells to give rise to iden-
tical viral progeny. Therefore the two
strands contain the same genetic infor-
mation: they encode the same genotype.
If we could examine these two strands
in detail, we should find that they differ
from each other in a systematic way:
each adenine residue in one is matched
by a thymine residue at the correspond-
ing position in the other, and similarly
for the pair guanine and cytosine. We
are sure of this in spite of the fact that
we cannot read nucleotide sequence di-
rectly. How we know is fairly simple too,
but the evidence cannot be put into a
few words.
So far I have made what I consider to
be factual statements. Perhaps the best
way to assess my judgment in this mat-
ter is to look at the criticisms raised by
the few people who have made serious
efforts to challenge it.
Carl Lindegren, a perceptive man with
a brave disregard for the rules of debate,
once pointed out in Nature (1955) that
the city of Chicago existed for some time
before it became dependent on electric-
ity. He inferred that if DNA happened
to be a late-comer on the biological
scene, contemporary research would be
hard put to discover that fact. Linde-
gren's analogy is not very apt, since
towns do not acquire public utilities by
inheritance. Nevertheless, it is fair to ask
why biologists should believe in some-
thing not visible in the historical record.
The answer, to which molecular genetics
has contributed significantly, can be
given as follows.
If we assume kinship of living things,
we at once imagine an evolutionary
family tree stemming from an aboriginal
branch point that represents an event of
singular importance. That event, the in-
vention of hereditary differences, I take
to be conceptually equivalent to the ori-
gin of life. If we find DNA in both ab-
original branches, we conclude either
that DNA function antedates the origin
of life or that DNA was independently
created two or more times. In fact, bio-
chemists find a common genetic code
exploited in all members of a reasonable
sample of biological species. To most
people, the hypothesis of unique origin
provides the only economical explana-
tion.
The same issues are raised in extreme
form by those experimental evolutionists
who suggest that life is being continually
recreated. There are really two issues.
On the one hand, the unity of biology
suggests kinship of living things. On the
other hand, the complexity of the sim-
plest forms of life suggests an inordi-
nately low frequency of spontaneous
generation: at least once on earth to be
sure, but perhaps not at all in an un-
explored universe. I am aware that these
arguments are logically ambiguous. I am
also aware that they were advanced be-
fore the phrase molecular genetics was
coined. But I wish to make two less ob-
vious points. First, in spite of the sim-
plicity of the overall plan of inheritance,
recent advances in molecular genetics
serve only to augment, not diminish, our
appreciation of biological complexity.
For example, Peter Lengyel recently
added up 130 known macromolecular
components necessary just for the syn-
thesis of protein. Second, without evi-
dence for the unity of biochemistry, a
unity now clearly evident in the uni-
versality of the genetic code, the doctrine
of the unity of biology would be insecure
indeed, particularly with respect to the
simpler forms of life. In short, life exists
658
CARNEGIE INSTITUTION
and we infer that it had a beginning. To
find anything credible in either the fact
or the inference is to miss the point.
Barry Commoner has devoted more
thought to the search for weaknesses in
molecular biology than anyone else (ex-
cepting, of course, molecular biologists) .
His paper in Nature, October 26, 1968,
presumably reflects his maturest judg-
ment. In it he cites the discovery by
Speyer that mutations affecting Rom-
berg's DNA polymerase (an enzyme
concerned with DNA synthesis) can in-
fluence the rate of further mutation. This
fact shows, according to Commoner, that
heritable characteristics are determined
in part by nucleotide sequences in DNA,
in part by the properties of enzymes. He
has also remarked somewhere, presum-
ably to defend his inference against ob-
vious forms of attack, that it has not
been shown that information theory is
applicable to biological problems. Both
these statements strike me as irresponsi-
ble: they are not untrue, just obtuse and
misleading. Because Commoner has writ-
ten eloquently and at length, using such
phrases as "theoretical crisis," "illusory
successes of molecular biology," and
"collision course" to manufacture con-
flict between "two kinds of biology," it
seems worth while to try to straighten
out the technical basis of his argument.
(Quotations from Science and Survival,
Viking Press, 1967.)
Long before 1953 it was evident that
general mutation rates are themselves
gene determined. The early geneticists
described this situation as follows. The
heritable characteristics of organisms
are determined by genes received from
their parents and transmitted to their
progeny, genes that must, therefore, be
duplicated in each generation. But genes
are not perfectly stable, or are not du-
plicated with perfect fidelity, whence
arise the variations (mutations) that
serve evolutionary purposes. Thus it is
necessary to distinguish between a mech-
anism of duplication, on which inheri-
tance depends, and the occasional fail-
ures of that mechanism, which may give
rise to new lines of inheritance. The fre-
quency of failure depends on all sorts of
things — external radiation, exposure to
various chemicals, temperature, ionic
milieu, as well as genetic constitution it-
self— including, we now know, the gene-
determined structure of at least one en-
zyme. Thus information theory, insofar
as it is needed in this context, is just the
common sense of geneticists, who saw fit
to distinguish between speech and noise.
I am forced to conclude that Commoner
is quarreling with the principles of ge-
netics, and that he hasn't told us any-
thing about molecular biology.
To separate my counter-criticism from
the arbitrary meanings of words, I re-
peat it in a form that avoids loaded
phrases entirely. I noted above that fac-
tors external to the cell, such as ambient
temperature, affect mutation rates. Ac-
cording to Commoner's reasoning we
ought, on that account, to abandon our
notion that living cells can reproduce
themselves.
There are, I think, more interesting
limitations to current biological princi-
ples than anything pointed out by the
carpers. The discovery by early geneti-
cists that a unique set of genes determines
the characteristics of the individual at
once raised the question whether or not
heritable characteristics are determined
exclusively by those genes. This question
remains unanswered and is, in fact, diffi-
cult to phrase intelligibly. The demon-
stration by molecular biologists that a
linear genetic code can be translated into
three-dimensional structure, as in the as-
sembly of virus particles, showed that in
principle the known mechanisms of in-
heritance could be the only mechanisms.
(The example of the viruses is important
because there one can observe the re-
generation of quite different viral species
in the same cellular milieu, depending
only on the kind of DNA molecule intro-
duced at the start.) The inference that all
three-dimensional structure is encoded in
GENETICS RESEARCH UNIT
659
nucleotide sequences does not necessarily
follow, however. I shall call that infer-
ence the unwritten dogma, since it must
be shared at least by those biologists who
consider molecular biology all but
finished.
The problem is defined by beautiful
experiments with protozoa (see T. M.
Sonneborn, "Does preformed cell struc-
ture play an essential role in cell hered-
ity?" in The Nature of Biological Diver-
sity, McGraw-Hill, 1963; and Vance
Tartar, The Biology of Stentor, Per-
gamon Press, 1961). Experiments of
similar import with fertilized eggs of the
African toad have been reported by
A. S. G. Curtis (Endeavour, 1963) .
In the work cited, diverse sorts of
experiment bring to light a primordium
in the cell cortex that is indispensable to
development and, at least in Parame-
cium, persists through both sexual and
asexual reproduction. I propose to dis-
cuss this and related problems in a super-
ficial way, mainly to place my wager
that the status of the unwritten dogma
is likely to remain ambiguous for some
time.
First of all, what sort of problem is it
that the cell seems to have solved by
inventing its cortical primordium? The
important thing, it seems to me, is to
preserve by growth and division an ele-
ment that persists in the cell in only one
copy. This requirement is clear because
experimental duplication of the cortical
primordium produces a dual monster.
The same problem is presented by genes
and chromosomes themselves, and we
have no real idea how it is solved. In
bacteria, there is some evidence that
DNA replication too is controlled by a
cortical primordium.
How can this problem be solved in
principle? Perhaps by making use of
another obscure fact, that cellular differ-
entiation often appears to be irreversible.
If irreversible differentiation can occur
during the life of the individual, it could
have occurred in the remote history of
all living cells.
Given the fact that a cortical structure
forms part of the cellular inheritance,
how can we account for its persistence?
Suppose, as a minimum hypothesis, that
the cortical primordium is a molecular
structure composed of two typical gene
products that interact spontaneously
with each other in a characteristic
fashion. Suppose too that the functioning
of the pertinent genes is controlled in
such a way that the two reactants are
produced alternately, never appearing
free in the cytoplasm at the same time.
This is a necessary condition to avoid
production of supernumerary cortical
primordia, and a sufficient condition to
permit an inherited primordium to grow.
Then inheritance is assured by centering
the structure on the cleavage line at each
cell division. Of course this scheme, even
if it should prove correct, says nothing
about the reason for being of the cell
primordium. The scheme serves, there-
fore, merely to bring us to the conceptual
stage at which molecular principles cease
to help.
Throughout these notes, I have tried to
show that the contemporary phase of
molecular biology, while giving decisive
answers to genetic questions, did not alter
the framework of those questions, and
indeed could not have succeeded so well
if important alterations had proved
necessary. I wish now to comment briefly
on those aspects of cell biology to which
genetics, molecular or not, has contrib-
uted very little. In short, what are the
limitations of molecular biology?
The cell theory, dating from 1839 or
earlier, engenders lengthy discussions in
textbooks of biology, discussions that are
interesting but do not, I think, succeed
very well in stating a theory. The central
notions are: that living things come in
cellular form, that cells arise only from
pre-existing cells, and that all cells are
homologous. Without the last proviso,
it is not clear what the word "cell"
means, for the "typical" cell pictured in
schoolbooks is an abstract thing. Thus
the cell theory stands or falls in company
660
CARNEGIE INSTITUTION
-with the assertion that all cells share a
common ancestry, which is basically an
article of faith. Discussion of the theory
commonly ends with the statement that
the cell is "the structural unit of life,"
or even "life's minimum unit" (Life,
Simpson and Beck, 1969). Such state-
ments serve chiefly as a reminder that
scientific theories cannot be profitably
discussed outside their proper experi-
mental context.
According to Tartar (The Biology of
Stentor, 1961), the pertinent experiments
are nearly as venerable as the cell
theory. For instance, Gruber (1885),
pursuing earlier work, showed that a sin-
gle cell of the protozoan genus Stentor
could be cut into three parts, from each
of which a complete animal would regen-
erate. In subsequent experiments with
other ciliates, pieces as small as y80 of
the cell volume were found capable of
regeneration. Such experiments reveal,
of course, that cells of certain protozoan
species are multinucleate. More im-
portant to my purpose, they show that
the cell is a homeostatic unit of life, not
a minimum unit, and raise the question,
what is the minimum unit? By suppress-
ing this question, the cell theory in effect
keeps living things out of the laboratory.
The experiments with Stentor pene-
trate beyond the cortical primordium to
reveal what is usually called cell polar-
ity. Polarity might be defined for present
purposes as a vital principle not ac-
counted for by any useful hypothesis.
In Stentor, this principle seems to reside
in all parts of the cell cortex.
Stentor coeruleus is an aquatic one-
celled animal bearing feeding organs at
its head end and a hold-fast at its tail
end. The entire surface is marked by
longitudinal stripes of two kinds: clear
stripes carrying cilia, alternating with
granular stripes without cilia. During the
life of the animal, its cortical stripes
grow both in width and in number. The
splitting of old (wide) stripes into young
(narrow) ones occurs on the ventral sur-
face and proceeds asymmetrically, pro-
ducing a circumferential (leftr-right)
gradient of stripe widths meeting as a
visible boundary on the median ventral
surface.
At the start of normal cell division, or
during regeneration of decapitated ani-
mals, new mouth parts start to form in
the region of stripe multiplication on the
ventral surface. (The parts afterwards
migrate to their normal position.) These
observations define an oral primordium
site lying near the junction between wide
and narrow stripes. However, this site is
not itself a hereditary structure, because
the dorsal half of a longitudinally bi-
sected animal regenerates a new one,
which appears in a newly created junc-
tion between wide and narrow stripes.
Thus the oral primordium develops when
required at the poles of a left-right
gradient, and near the equator of a
longitudinal gradient.
Likewise the tail structure (hold-fast)
comes not from a specific hereditary
primordium but from the posterior pole
of a longitudinal gradient. Thus if the
hold-fast is tucked forward by surgical
means, a second one develops at the
newly created posterior pole. Animals
with two mouths and one tail, or with
two tails and one mouth, once created
by surgical interference, survive as he-
reditary biotypes with varying degrees
of stability.
A piece of cortex grafted in reverse
orientation into a normal animal may
rotate to restore normal polarities, may
degenerate and disappear, or may de-
velop its own mosaic stripe pattern.
Similarly, an animal bisected trans-
versely and reconstructed with the head
portion rotated 180° with respect to the
tail, may regain its normal stripe pat-
tern either by rotatory slippage of the
two halves with respect to each other or
by replacement of stripes in one of the
halves through outgrowth from the other.
These and other experiments show that
polarity resides in every part of the
cortex.
According to Tartar, Prowazek (1904,
GENETICS RESEARCH UNIT
661
1913) understood the situation about as
well as anybody. The cell nucleus can
only provide substances for growth and
differentiation. Neither the nucleus with
its arbitrary orientation nor the fluid
endoplasm can account for the evolution
of specific cell structures: that calls for
patterns hidden in a rigid ectoplasm.
In Stentor and certain other cells, all
reasonably large pieces of the cell cortex
are equipotent with respect to regenera-
tion of cortical patterns — patterns that
are, moreover, subject to metastable
variations. In bacteriophages, supramo-
lecular patterns do not persist as such
but recur, apparently residing exclu-
sively in the gene-determined structures
of individual molecules. Taken together,
these facts encourage us to see in cortical
polarity a historical invention that ought
to be analyzable in terms of structure
and process. They do not encourage us to
think that the task of molecular biology
is finished, even at the cellular level. In
Tartar's words, "our greatest lack and
most fruitful opportunity in biology lies
in conceiving and testing the nature and
capabilities of persistent supramolecular
patterns." To the ambitious young mo-
lecular biologist seeking prospects, I rec-
ommend, a careful reading of Tartar's
book.
DNA Phenotypes
Many years ago methylcytosine was
found as a minor constituent in wheat
germ DNA. However, no clue to the sig-
nificance of unusual bases in DNA ap-
peared until the discovery of glucosy-
lated hydroxymethylcytosine in phages
T2, T4, and T6. In these phages, the
replacement of cytosine by its hydroxy-
methyl derivative was found to be com-
plete (Wyatt and Cohen, 1953). The
glucosylation also proved to be massive,
but showed a distinctive pattern in each
of the three species (Volkin, 1954; Sins-
heimer, 1956; Lehman and Pratt, 1960;
Romberg, Zimmerman, and Romberg,
1961) . Since the three phage species were
known to be very similar in function, the
pattern of glucosylation could be recog-
nized at once as part of the phenotype. A
more general argument was clear too:
since diverse phage species can multiply
in cells of a single bacterial species,
many phages must use a common genetic
language. Therefore hydroxymethyl-
cytosine is equivalent to cytosine, and
uracil (found in some phage DNA's as
well as in RNA) is equivalent to thy-
mine, in the genetic dictionary. In
fact, experiments with Romberg's DNA
polymerase later showed that a dozen
or more bases, including artificial ones,
are equivalent to one or another of the
four kinds of which DNA is typically
composed. Thus the genetic message is a
specified sequence of four nonequivalent
units. Equivalent units are those ex-
pected and found to be interchangeable
in the base pairing rules of Watson and
Crick. The choice among equivalent
units generates optional phenotypes, op-
tional sometimes at the discretion of the
experimenter.
The notion that DNA, the bearer of
the genetic message, itself exhibits di-
verse phenotypes occasioned some sur-
prise, though the biological rationale was
clear enough. Speciation may be re-
garded as the acquisition of devices by
which living things compete (and some-
times cooperate) to preserve and dis-
seminate their genes. One might have
anticipated modification of DNA struc-
ture as a particularly direct means to
this end. Indeed, Seymour Cohen sug-
gested that hydroxymethylcytosine in
T2 DNA might serve to protect against
the action of degradative enzymes. His
suggestion has proved correct for the
glucosylated DNA.
The role of glucosylation as a species
marker in the DNA of phage T2 is par-
ticularly dramatic. When its DNA con-
tains glucose, this phage multiplies in
bacterial cells and destroys the nonglu-
cosylated DNA of the host. When the
DNA of the phage does not contain glu-
cose, it is rejected by the host, though it
662
CARNEGIE INSTITUTION
can function normally without gluco-
sylation under special conditions (Arber,
Annual Reviews of Microbiology, 1965).
The example of phages T2, T4, and T6
is rather special since few DNA's contain
glucose. However, similar purposes are
accomplished by more subtle chemical
means in other species. In Escherichia
coli and many of its phages, methylation
serves as a strain-specific marker. Here
the common features of several systems
are "modification" of DNA at a few spe-
cific sites by a bacterial methylating
enzyme, and "restriction" by a nuclease
that can cleave the DNA at the same
sites provided they have not been meth-
ylated previously. A number of such ge-
netic systems are known, each character-
istic of a different bacterial strain. Thus
in E. coli strain A, the DNA of phage A is
methylated (or cleaved) at just one
critical site lying between genes cu and
0. In E. coli strain B, A DNA is meth-
ylated or cleaved at two or more sites not
including the A-specific site. The terms
"modification" and "restriction" refer to
the biological consequences of methyla-
tion and cleavage: in general, phage par-
ticles cannot infect a given strain of E.
coli with high frequency unless they con-
tain DNA previously marked by the
methylating system of that strain. The
bacterial DNA is subject to the same
modifications and restrictions, which
therefore give to DNA itself a number of
alternative mating types (Arber and
Linn, Annual Reviews of Biochemistry,
1969).
It should be added that the DNA of
E. coli contains numerous methylated
adenine and cytosine residues that do
not play any known role as compatibility
factors, although their distribution in the
DNA is strain specific. Their significance
is unknown.
Diverse phenotypes are seen also in
gross structure of DNA. Thus the DNA
of phage 4>X comes in single-strand
rings, T2 DNA as circularly permuted
rods, T5 DNA with characteristic single-
strand cuts, several phage DNA's with
terminal repetitions, others with terminal
cohesive sites. The significance of these
variations is obscure but they probably
reflect modalities of DNA replication on
the one hand and, on the other, alterna-
tive means of getting the proper length
of DNA into phage particles. The varia-
tions repeat a common theme: exploita-
tion of the structural principle of com-
plementary base sequences to permit
cleavage and rejoining of DNA mole-
cules without loss of message content. As
expected according to this principle, one
cut in the single-strand ring of </>X DNA
appears to be biologically irreparable.
Idiosyncrasies of DNA structure have
been discussed in annual reports from
this laboratory for several years. Impor-
tant examples are reviewed by C. A.
Thomas, Jr. {Journal of Cellular Physi-
ology, Supplement 1, 1967).
The amount of DNA per cell is an-
other complex variable with phenotypic
aspects. The primary component of the
variation is the species-specific number
of genes per set, which varies from three
or four to a few hundred just among the
viruses. Since evolutionary specialization
often calls for new genes without making
old ones obsolete ("ontogeny recapitu-
lates phylogeny") , the maximum number
must be very large. The question of non-
genic DNA remains open and may prove
unanswerable since some genes probably
function only under special conditions,
during embryonic life for instance. Sev-
eral genes in T4 are dispensable or not,
depending on functions provided by the
host. Perhaps the proper way to phrase
the question about nongenic DNA is to
ask what functions of DNA remain to
be discovered.
Repetitious DNA is fairly common
(Britten and Kohne, Science, August 9,
1968) . It is of course an obligatory fea-
ture of DNA replication, especially dur-
ing phage growth where it probably
plays a physiological role in terms of
gene dosage. A more interesting example
has been analyzed by Brown and Dawid
GENETICS RESEARCH UNIT
663
(Science, April 19, 1968) . Oocytes of the
African toad contain large amounts of
DNA that consists mainly of sequences
matching those present in ribosomal
RNA. Apparently the repetitious DNA
is used for rapid synthesis of ribosomal
RNA during oogenesis.
The extreme case of variation in
amount of DNA is of quite another sort.
RNA viruses dispense with the DNA
phase of genetic determination entirely,
having invented one or two genes per-
mitting direct replication of RNA. What
once seemed a major historical puzzle
turns out to be a typical biological
quirk.
Britten and Kohne give evidence for
the existence of repeating sequences
within single gene sets. They detect such
sequences only in vertebrate species, but
their methods may not be applicable to
species with fewer genes. The striking
feature of the data is multiple repetition
of a few sequences, which cannot repre-
sent simply production of supernumerary
gene copies because the repeated se-
quences are not perfectly identical. Brit-
ten and Kohne interpret their data in
historical rather than functional terms,
but the possibility of special function
should be considered too. Current ideas
about the genetic origin of antibodies are
a case in point.
Adams, Jeppesen, Barrell, and Sanger
(Cold Spring Harbor Symposium, 1969)
have detected a complementary sequence
in the RNA of phage R17 (in DNA, the
equivalent structure would be called an
inverted repetition). These authors di-
rectly determined the sequence of 57
ribonucleotides found in a particular
fragment of the viral nucleic acid. The
sequence can be written in the form of a
hairpin cross linked by 19 out of 25
possible base pairs. Evidently such a
structure could be accounted for by a
series of historical accidents. More in-
teresting is the likelihood that specified
sequences affect secondary structure in
RNA to permit control of replication or
translation or both. The general implica-
tion seems to be that nucleotide se-
quences are subject to evolutionary con-
straints that have nothing to do with the
genetic message proper — an inevitable
correlate, perhaps, of the redundancy of
genetic language.
The arrangement of genes within
DNA molecules has subtle phenotypic
consequences (Stahl, Journal of Cellu-
lar Physiology, Supplement 1, 1967).
These are well illustrated by a single
example. In A prophage, nearly all phage
functions have to be repressed, and
the function of a single gene called C\
serves this purpose. Ptashne and Hop-
kins showed that the cT product is a
protein that attaches specifically at two
binding sites in the DNA bracketing the
genes cr and rex. Szybalski and Taylor
showed that in the absence of the Ci
product, transcription starting in the
vicinity of cT proceeds outward in both
directions. Evidently the repressor inter-
feres with transcription at two starting
points to meet the needs of the prophage
in a remarkably direct way. This scheme
of control depends on the arrangement of
two genes and two repressor binding sites
and, owing to the polarity of the genetic
message, on the orientation and control
mechanisms of outlying genes as well.
Thus a highly specified chromosomal
arrangement that serves functional needs
also links together several genetic ele-
ments whose shuffling by genetic recom-
bination has to be discouraged. The
example conforms nicely to the operon
model of Jacob and Monod, with special
features attributable to the fact that
lysogeny compresses the entire phage
genome into just two mutually exclusive
functions.
The A repressor system also illustrates
an evolutionary principle that is too
often ignored: biological adaptation al-
ways means coadaptation, ultimately
involving entire genomes, organisms, and
populations. This principle accounts in
part for the paradox that evolution uti-
lizes mutations that are individually
deleterious. The same principle suggests
664
CARNEGIE INSTITUTION
that attempts to distinguish between
adaptive variation and "non-Darwinian
evolution" through neutral mutation
(King and Jukes, Science, May 16,
1969) are doomed to failure. Lest my
remarks be construed as a defense of
Darwinism, I offer the following proposi-
tions. Only strong theories generate al-
ternatives. Darwinian theory is charac-
teristically weak.
Perhaps the most puzzling aspect of
DNA phenotypes has to do with the dis-
tribution of nucleotides within the mole-
cules. Since recent discussions of this sub-
ject (Skalka, Burgi, and Hershey, Jour-
nal of Molecular Biology, 1968; Year
Book 67, pp. 558-560) are already out of
date, I recapitulate here the main his-
torical facts before presenting some re-
cent results obtained by Yamagishi and
Skalka.
Perhaps the best way to state the
problem is to describe the methods of
study. Owing to the base-paired struc-
ture of DNA, the average composition of
a molecule or fragment can be expressed
by a single number, the molar fraction of
guanine plus cytosine (G+C), which is
equivalent to the fraction of guanine-
cytosine pairs. The remaining fraction,
if we neglect exceptional bases, repre-
sents adenine-thymine pairs.
The distribution of nucleotides within
molecules can be determined by breaking
them into fragments of known size,
separating the fragments into classes of
diverse composition, and measuring the
G + C content in each class. Since the
distribution is necessarily dependent on
size of fragments, the analysis has to be
repeated with fragments of various sizes.
This sort of analysis has now been car-
ried out for a few phage and bacterial
species.
The nature of the problem could be
seen only dimly in 1953, when interest
was first focused on base sequence as the
clue to the genetic message. The DNA
species known at that time contained
about 44% G + C, which seemed reason-
able in a way, since an efficient language
would use all letters with similar fre-
quency. This thought was short lived
because Lee, Wahl, and Barbu (1956)
and Belozersky and Spirin (1958) re-
ported a number of bacterial DNA spe-
cies whose G + C contents ranged from
26% to 74%. Thus it appeared that DNA
language, like human language, was not
designed primarily for efficient com-
munication.
The discovery that the buoyant den-
sity of DNA is strongly dependent on
composition (Rolfe and Meselson, 1959;
Sueoka, Marmur, and Doty, 1959)
yielded the first results concerning nu-
cleotide distribution in DNA. For in-
stance, Rolfe and Meselson found that
the standard deviation of G + C content
among fragments of E. coli DNA (frag-
ment length probably about 104 nucleo-
tide pairs) was less than ±3%, to be
compared with the 48% range covered
by variations among species. Thus di-
verse bacterial species, surely possessing
many functions in common, do not con-
tain many DNA segments of similar
composition. Rolfe and Meselson con-
cluded that the compositions of protein
and DNA could not be directly related
to each other by a universal code.
Sueoka (1961) studied directly the re-
lation between composition of DNA and
composition of protein by analyzing the
whole cellular protein of a number of
microbial species. He found that the
frequencies of the amino acids leucine,
valine, and threonine showed no correla-
tion with the G + C content of DNA.
However, glycine, alanine, and arginine
showed a weak positive correlation, and
lysine, glutamic acid, and isoleucine
showed a weak negative correlation.
Sueoka's results can now be interpreted
in terms of the degeneracy of the ge-
netic code, in which 61 codons specify
one or another of just 20 amino acids
(Crick, Cold Spring Harbor Symposia on
Quantitative Biology, 1966) . Thus there
are four valine triplets each containing
either one or two guanine or cytosine
residues, and the abundance of valine
GENETICS RESEARCH UNIT
665
could not be favored by either extreme
DNA composition. Alanine triplets con-
tain two or three guanine or cytosine
residues, and lysine triplets zero or one,
in agreement with Sueoka's results.
Sueoka's main conclusion, that composi-
tions of DNA and protein are not
strongly correlated, is also consistent
with the coding dictionary, which allows
a stretch of DNA specifying one each of
15 frequently occurring amino acids to
vary in G + C content between 29% and
67%. Furthermore, both mutational
study of individual proteins and compar-
ative analysis of homologous proteins
from different species show that func-
tional requirements do not impose severe
restrictions on the composition of protein.
Therefore the observed variations in
composition of DNA cannot signify di-
verse requirements with respect to the
composition or function of proteins.
Having reached the conclusion just
stated, Sueoka (1962) and Freese (1962)
proposed that the composition of DNA
was determined mainly by the geneti-
cally determined rates of mutational in-
terconversion between guanine-cytosine
pairs and adenine-thymine pairs. These
authors also assumed that DNA compo-
sition, as such had no functional signifi-
cance and therefore could not respond to
selective pressures. The latter assump-
tion was perhaps superfluous to their
main proposal because, however diver-
gence in composition of DNA among
different species may arise, one might
expect it to be accompanied by coadap-
tive variation in mutational habit.
If DNA composition in a given species
were determined primarily by muta-
tional habit, guanine-cytosine pairs
should be distributed at random among
DNA fragments of gene size or larger.
Recent analyses of several phage and
bacterial DNA's by Yamagishi and
Skalka show that the distributions are
never random (see below). One must
conclude either that DNA composition
does reflect specialized functional adap-
tations or that interspecific genetic re-
combination is frequent with respect to
the evolutionary time scale. Perhaps
both possibilities should be considered
likely. In any case, the hypothesis of
domination by mutational equilibria
loses its force.
Last year Yamagishi and Skalka pro-
posed that an asymmetric distribution of
G + C in bacterial DNA in the vicinity
of A prophage might be designed to favor
the types of genetic recombination that
give rise to transducing phage {Year
Book 67, pp. 558-560). They are no
longer enthusiastic about this hypothesis
for two reasons. First, it now appears
that the fo'o-transducing phage analyzed
last year is atypical, having picked up
bacterial DNA not proper to the bio re-
gion of E. coli. Its structure may not be
relevant to the hypothesis under test.
Second, the recognition that unselected
fragments of E. coli DNA are rather dis-
similar in composition neutralizes the
significance of departures from the aver-
age composition in the vicinity of pro-
phage insertion sites.
Miyazawa and Thomas (1965) first
demonstrated that the DNA of E. coli
contains segments of dissimilar compo-
sition. Yamagishi has carried the analy-
sis further, and some of his results are
presented in Fig. 1. The upper part of
the figure confirms previous work in
showing that large fragments of the
DNA are uniform in composition. The
lower part of the figure shows that frag-
ments of the order of size of individual
genes range in G + C content from 39%
to 56%. The distribution is asymmetri-
cal, with an average at 51%. The distri-
bution is nevertheless rather compact:
its standard deviation is ±3.8 percent-
age units in G+C content, as compared
with ±6.7 units for A DNA (Skalka,
Burgi, and Hershey, 1968) .
Yamagishi also examined E. coli DNA
fragments of other lengths. His results
show that stretches of the extreme com-
position 39% G + C range in length up to
about 35,000 nucleotide pairs and com-
prise 3% of the total DNA. The asym-
666
CARNEGIE INSTITUTION
<
Q
6^
O
E
c
CD
+-»
C
o
o
O
+
(J
Density
Fig. 1. Distribution of fragments of E. coli DNA with respect to guanine + cytosine content.
Upper part: fragments of molecular weight 70 million (about 105 nucleotide pairs). Lower part:
fragments of molecular weight 1.3 million (2000 nucleotide pairs). In both parts, distributions of
DNA with respect to buoyant density in Hg-Cs2S04 are shown by histograms, and the G + C
content of fractions by the curves. Single fractions, or pooled fractions indicated by horizontal
bars, were analyzed directly to get the points on the curves. For methods, see Skalka et al,
Journal of Molecular Biology, 84, 1-16, 1968.
GENETICS EESEARCH UNIT
667
metry of the distribution shown in Fig. 1
is characteristic, and signifies that long
stretches of low G + C content are more
numerous than long stretches of high
G + C content.
The DNA of Bacillus subtilis is gen-
erally similar to that of E. coli except
that its fragments range from 35% to
50% in G + C content, with an average
of 44%. In collaboration with I. Takaha-
shi of McMaster University, Yamagishi
could show by genetic tests that regions
of exceptional G + C content in B. subtilis
include typical bacterial genes. Therefore
local variations in composition do not
reflect merely temporary residents in the
bacterial chromosome such as prophages.
Yamagishi also analyzed several spe-
cific segments of E. coli DNA recovered
from various 080 transducing phage
lines. Here the content of bacterial genes
can be identified by genetic tests, and the
corresponding DNA can be recognized
by fractionation with respect to density
combined with hybridization tests to dis-
tinguish between components of phage
and bacterial origin. A segment contain-
ing the tryptophan operon consists of
DNA ranging in G + C content from
45% to 57%. A segment containing lac-
tose genes is more homogeneous, with an
average G + C content of 54%. Among
the various segments examined, only the
gal region contains DNA corresponding
to the average for the entire chromosome,
51% G + C (Yamagishi and Skalka, Year
Book 67, p. 559).
Skalka has examined a number of
phage DNA species by density analysis
of molecular halves and smaller frag-
ments (about 2000 nucleotide pairs). By
this method A DNA molecules are readily
shown to consist of dissimilar halves and
to be made up of four or more distinct
segments containing 37%, 43%, 48.5%,
and 57% G + C (Skalka, Burgi, and Her-
shey, 1968). The closely related phages
434, 82, and 21 are very similar to A
except that the 37% G + C section is
absent in phage 21. Phage $80, related
to A, and the unrelated phage 186 re-
semble each other in containing only two
distinct segments, the molecular halves,
measuring approximately 50% and 55%
G + C, respectively. The DNA of phage
P2 also contains dissimilar halves, and
resolves into three widely dissimilar seg-
ments. The DNA of phage P22 contains
at least two dissimilar segments. Mo-
lecular halves of this DNA have the
same composition, presumably because
the molecules come with circularly per-
muted nucleotide sequences. Unlike the
others, phages T5, T7, and PI contain
DNA's that are strikingly uniform in
composition, though not absolutely so
because small fragments exhibit asym-
metrical density distributions. Phage PI
contains 5% of DNA of only 37% G + C.
Two conclusions emerge. First, all
DNA's so far examined contain rela-
tively long segments that differ in com-
position. Second, the phage DNA's so
far examined fall into two classes. DNA
molecules from phages A, 186, P2, and
probably P22 are composed of a few long
segments of dissimilar composition. Since
the effect is to produce dissimilar halves,
these may be called asymmetric DNA's.
By contrast, phages T5, T7, and PI con-
tain DNA's of relatively uniform com-
position. The grouping suggests that
phage A may be taken as representative
of a class. If so, asymmetry of DNA
structure, clustering of genes of related
function in the genetic map, and propen-
sity toward interspecific genetic recom-
bination form a seemingly harmonious
set of class characteristics.
668
CARNEGIE INSTITUTION
BIBLIOGRAPHY
Bear, P. D., and A. Skalka, The molecular
origin of lambda prophage mRNA. Proc.
Natl. Acad. Sci. U.S., 62, 385-388, 1969.
Makover, S., A preferred origin for the replica-
tion of lambda DNA. Cold Spring Harbor
Symp. Quant. Biol, 33, 621-622, 1968.
Skalka, A., Nucleotide distribution and func-
tional orientation in the deoxyribonucleic
acid of phage <£80. J. Virology, 3, 150-156,
1969.
Skalka, A., see also Bear, P. D.
Yamagishi, H., Single strand interruptions in
PBS 1 bacteriophage DNA molecule. /. Mol.
Biol, 35, 623-633, 1968.
PERSONNEL
Year ended June 30, 1969
Elizabeth M. Bocskay, Chief Clerk
Elizabeth Burgi, Associate in Microbiology
Agnes C. Fisher, Secretary to Director;
Editor
Alfred D. Hershey, Director
Laura J. Ingraham, Research Assistant
Shraga Makover, Carnegie Institution Fellow
Barbara McClintock, Distinguished Service
Member
David H. Parma, National Science Founda-
tion Postdoctoral Fellow
Jennie S. Pope, Curator of Drosophila Stocks
Anna Marie Skalka, Carnegie Corporation
Fellow
Carole E. Thomason, Technical Assistant
Hideo Yamagishi, Carnegie Institution Fellow
Temporary
Robert A. Weisberg, Guest Investigator
Bibliography
July 1, 1968-June 30, 1969
PUBLICATIONS OF THE INSTITUTION
Carnegie Institution of Washington Year Book
67. Octavo, xii + 76 + 609 pages, 22 plates,
262 figures, Washington, D. C, January 1969.
PUBLICATIONS BY THE PRESIDENT
Caryl P. Haskins
Report of the President. Reprinted from
Carnegie Institution of Washington Year
Book 67, 86 pages, 2 plates, 6 figures, Janu-
ary 1969.
The way of the future (An address presented
at Queens College of the City University
of New York, March 28, 1968), Queens
College Press, Flushing, New York, 1968.
The humanities and the natural sciences:
partnership and paradigm. ACLS News-
letter, Vol. 20, No. 1, January-February
1969, pp. 20-37.
The inspiration of the amateur. Graduate
School Chronicle (University of Mary-
land), Spring 1969, pp. 1, 3-6.
The testament of the years between (The
Encyclopaedia Britannica Lecture, pre-
sented at the University of Edinburgh,
1968), Edinburgh University Press, 1969.
PUBLICATION BY THE EXECUTIVE
OFFICER
Edward A. Ackerman
Recursos Naturales y Desarrollo Industrial,
Provincia de Magallanes. With David F.
Bramhall and Orris C. Herfindahl. Pub-
lished for the Ford Foundation Urban and
Regional Development Advisory Program
in Chile, Santiago, Chile, 1968.
669
Administrative Reports
Report of the Executive Committee
To the Trustees of the Carnegie Institution of Washington
Gentlemen :
In accordance with the Provisions of the By-Laws, the Executive Committee submits
this report to the Annual Meeting of the Board of Trustees.
During the fiscal year ending June 30, 1969, the Executive Committee held four
meetings. Printed accounts of these meetings have been or will be mailed to each Trustee.
The estimate of expenditures for the fiscal year beginning July 1, 1969, has been
reviewed by the Executive Committee.
The terms of office of the Chairmen of all Committees of the Board expire on May 2,
1969. The terms of the following members of Committees also expire on May 2, 1969:
Executive Committee Nominating Committee
Carl J. Gilbert Carl J. Gilbert
Crawford H. Greenewalt
Richard S. Perkins
Finance Committee
Richard S. Perkins
Henry S. Morgan, Chairman
May 2, 1969
673
Report of Auditors
Lybrand, Ross Bros, c Montgomery
REPORT OP INDEPENDENT CERTIFIED PUBLIC ACCOUNTANTS
To the Auditing Committee of
Carnegie Institution of Washington:
We have examined the statement of assets and funds balances
of Carnegie Institution of Washington as of June 30, 1969, and the
related summary statement of changes in funds for the year then ended
and the supporting exhibits and schedules. Our examination was made
in accordance with generally accepted auditing standards, and accord-
ingly included confirmation from the custodian of investments held at
June 30, 1969 ^ and such tests of the accounting records and such other
auditing procedures as we considered necessary in the circumstances.
We previously examined and reported upon the financial statements of
the Institution for the year ended June 30., 1968.
These statements have been prepared on the general basis of
cash receipts and disbursements and, as a result, omit accrued income,
liabilities and provision for depreciation. Accordingly, they do .not
purport to present financial position or results of operations as they
would appear had generally accepted accrual basis accounting principles
been applied in their preparation.
In our opinion, the accompanying financial statements
and supporting exhibits and schedules (Pages 4-17) present fairly the
assets and funds balances of Carnegie Institution of Washington at
June 30j 1969 and 1 968, and the changes in funds for the year ended
June 30, 1969* on the basis indicated above consistently applied.
Washington^ D. C,
October 2, 1 969
675
STATEMENT A
ASSETS AND FUNDS
JUNE 30, 1969 and 1968
ASSETS
1969 1968
Cash $ 688,866.39 $ 273,715.58
Advances 38,410.02 44,265.83
Investments (cost)*, Schedule 2:
Governmental obligations 1,892,625.00 2,907,695.31
Nongovernmental bonds 39,123,254.31 41,176,949.69
Corporate stocks 37,711,702.61 34,539,849.64
Mortgage 13,983.06 16,397.31
Land (cost) 389,306.96 368,760.86
Buildings and equipment (cost) 6,748,789.29 6,497,273.68
Total assets $86,606,937.64 $85,824,907.90
FUNDS
Operating Fund, Exhibit 1 $ 2,318,156.83 $ 918,043.52
Restricted Grants, Exhibit 2 105,817.51 (5,893.90)
Endowment and Special Funds, Exhibit 3 77,044,867.05 78,046,723.74
Land, Buildings, and Equipment Fund, Exhibit 4 7,138,096.25 6,866,034.54
Total funds $86,606,937.64 $85,824,907.90
♦Approximate market value on June 30, 1969: $109,262,034.
676
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677
EXHIBIT 1
CHANGES IN OPERATING FUND
FOR THE YEAR ENDED JUNE 30, 1969
Balance, July 1, 1968 $ 918,043.52
Appropriations, Statement B :
Budget, July 1, 1968, to June 30, 1969— Exhibit 3 $4,697,212.00
Carnegie Southern Observatory 1,000,000.00
Employee benefits, special, Bush Gift 3,700.00 5,700,912.00
Total available for expenditures 6,618,955.52
Expenditures :
Salaries 2,205,623.72
Laboratory 365,788.18
Employee benefits, retirement contributions 276,077.39
Employee benefits, other 133,80657
Equipment 297,557.98
Fellowships 155,794.89
Building 181,157.51
Operating 138,456.43
Travel 94,243.81
Publications 84,097.99
Awards 76,930.16
Financial advisory services 74,016.26
Taxes 78,367.75
Consulting fees and insurance 77,620.94
Rent 24,606.09
Shop 18,309.70
Entertainment 9,708,59
Dormitory 8,634.43
Total expenditures 4,300,798.69
Balance, June 30, 1969 $2,318,156.83
678
EXHIBIT 2
CHANGES IN RESTRICTED GRANTS
FOR THE YEAR ENDED JUNE 30, 1969
Carnegie Corporation of
New York
Helen Hay Whitney
Foundation . . .
Jet Propulsion Laboratory
National Aeronautics &
Space Administration
National Science
Foundation
Office of Naval Research.
Public Health Service
University of Minnesota. .
Total
Expenditures
Balance Balance
July 1,1968 Grants Salaries Other June 30, 1969
$49,886.14 $ 80,000.00
583.37 8,500.00
351.18
$104,799.13 $ 25,087.01
8,458.37
48.20
625.00
302.98
(32,876.58) 182,272.00 $ 6,171.28 158,071.88 (14,847.74)
(12,445.02) 332,500.00 15,454.39 208,151.79 96,448.80
(9,119.39) 27,133.00 2,594.76 16,248.85 (830.00)
(3,662.18) 47,538.00 19,556.64 25,287.72 (968.54)
1,388.58 1,388.58
($5,893.90) $677,943.00 $43,777.07 $522,454.52 $105,817.51*
* Does not include grants to be received as follows :
National Aeronautics & Space Administration $105,211.00
National Science Foundation 254,023.05
Office of Naval Research 6,164.00
Public Health Service 4,650.00
$370,048.05
679
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SCHEDULE 2
INVESTMENTS, JUNE 30, 1969
Principal
Amount
Description
Approximate
Market
Maturity Book Value Value
Federal Agency Bonds
$ 400,000 Federal National Mortgage Association,
4%s
500,000 Federal National Mortgage Association,
5%s
1,000,000 Federal National Mortgage Association,
Part. Certificates, 5%s
j 1,900,000 Total
Foreign and International
Bank Bonds
$ 700,000 Alberta Government Telephone,
Commission Deb., 4%s
750,000 Alcan Aluminum Corporation,
Prom. Note, 4%s
489,000 Aluminium Co. of Canada, Ltd.,
S. F. Deb., 4%s
146,000 Australia (Commonwealth of),
4%s
114,000 Australia (Commonwealth of),
5s
466,000 Australia (Commonwealth of),
5%s
750,000 Bell Telephone Co. of Canada,
1st Mtg. Series X, 4%s
250,000 British Columbia Power Commission,
S. F. Deb. Series L, 4%s
750,000 Industrial Acceptance Corp. Ltd.,
Sec. Note Series Z, S^s
125,000 Intl. Bank for Reconstruction &
Development, 3s
125,000 Intl. Bank for Reconstruction &
Development, 3%s
250,000 Intl. Bank for Reconstruction &
Development, 41/£s
1970 $ 394,500.00 $ 390,248
1972 498,125.00 465.000
1973
1,000,000.00
932,500
$ 1,892,625.00 $ 1,787,748
1989
$ 700,000.00
$ 469,000
1984
750,000.00
575,625
1980
494,013.40
386,310
1971
143,810.00
136,145
1972
114,000.00
104,310
1982
467,843.20
391,440
1988
747,300.00
523,125
1987
245,000.00
170,000
1982
750,000.00
534,375
1976
125,000.00
100,000
1975
123,125.00
100,000
1977
250,000.00
205,000
683
INVESTMENTS— Continued
Principal
Amount
Description
Maturity Book Value
Approximate
Market
Value
Foreign and Industrial
Bank Bonds — Continued
751,000 Quebec Hydro-Electric Commission,
S. F. Deb., 5s
200,000 Shawinigan Water & Power Co., 1st Mtg.
& Collat. Tr. S. F. Series M, 3s
1,000,000 Shell Funding Corp., Collat. Tr.
Series B, 4%s
500,000 Toronto (Municipality of Metropolitan),
S. F. Deb., 5s
$ 7,366,000 Total
Public Utility Bonds
$ 750,000 Colonial Pipeline Co., Sec. Note
Series A, 4.829s
250,000 Columbia Gas System, Inc.,
Series F, 37/8s
237,000 Columbus & Southern Ohio Electric Co.,
1st Mtg., 31/4s
300,000 Consolidated Edison Co. of N.Y.,
1st & Ref. Mtg. Series N, 5s
4,000 Consumers Power Co.,
1st Mtg., 4%s
200,000 Minnesota Power & Light Co.,
1st Mtg., 3y8s
250,000 Niagara Mohawk Power Corp.,
Gen. Mtg., 3%s
400,000 Niagara Mohawk Power Corp.,
Gen. Mtg., 4%s
200,000 Pacific Gas & Electric Co.,
1st & Ref. Mtg. Series X, 3%s
250,000 Pacific Gas & Electric Co.,
1st & Ref. Mtg. Series BB, 5s
250,000 Pacific Power & Light Co.,
1st Mtg., 4%s
236,000 Potomac Electric Power Co.,
Deb., 4%s
200,000 Public Service Co. of Indiana,
1st Mtg. Series F, 3V8s
400,000 Public Service Co. of Indiana,
1st Mtg. Series L, 4%s
1988 737,857.50 510,680
1971 200,720.00 182,500
1985 1,000,000.00 800,000
1979 498,637.50 400,000
$ 7,347,306.60 $ 5,588,510
1990
$ 750,000.00
I 558,750
1981
245,937.50
177,500
1970
237,938.01
223,076
1987
301,406.52
229,500
1987
4,015.48
3,055
1975
200,935.77
158,750
1986
251,843.98
165,938
1987
402,098.79
310,500
1984
200,874.90
127,750
1989
251,209.26
192,500
1986
251,818.07
165,313
1982
239,125.84
171,985
1975
201,068.99
159,000
1987
400,000.00
277,000
684
INVESTMENTS— Continued
Principal
Amount
Description
Maturity Book Value
Approximate
Market
Value
Public Utility Bonds — Continued
500,000 Public Service Electric & Gas Co.,
1st & Ref. Mtg., 47/8s
250,000 Southern California Edison Co.,
1st & Ref. Mtg. Series H, 4%s
200,000 Southern California Edison Co.,
1st & Ref. Mtg. Series J, 4%s
300,000 Washington Water Power Co.,
1st Mtg., 4%s
S 5,177,000 Total
Communication Bonds
$ 400,000 Illinois Bell Telephone Co.,
1st Mtg. Series E, 41/4s
200,000 Mountain States Telephone &
Telegraph Co., Deb. 3%s
100,000 New York Telephone Co.,
Ref. Mtg. Series E, 3%s
200,000 Pacific Telephone & Telegraph Co.,
Deb, ZVis
250,000 Southern Bell Telephone &
Telegraph Co., Deb. 4s
300,000 Southwestern Bell Telephone Co,
Deb, 3y8s
S 1,450,000 Total
Railroad Bonds
$ 100,000 Chesapeake & Ohio Railway Co,
Gen. Mtg, 4%s
267,000 Fort Worth & Denver Railway Co,
1st Mtg, 4%s Guar
> 367,000 Total
Industrial and Miscellaneous Bonds
$ 1,000,000.00 Boeing Co., Notes,
6%s
550,000.00 CI.T. Financial Corp,
Deb, 4%s
960,000.00 Columbia Broadcasting System, Inc.,
Prom. Note, S^s
400,000.00 Commercial Credit Co,
Note, 3%s
700,000.00 Commercial Credit Co,
Note, 4%s
1987 502,888.77 388,125
1982 250,937.56 180,000
1982 201,130.17 150,500
1987
300,000.00
209,250
$ 5,193,229.61
$ 3,848,492
1988
$ 402,981.08
$ 283,500
1978
200,280.00
148,750
1978
100,394.47
73,500
1978
200,882.86
148,750
1983
250,601.26
181,563
1983
302,250.00
196,500
$ 1,457,389.67
$ 1,032,563
1992 $ 99,500.00 $ 68,500
1982 268,108.23 181,560
$ 367,608.23 $ 250,060
1986 $ 1,000,000.00 $ 855,000
1970 536,937.50 522,500
1991 960,000.00 794,400
1976 402,761.12 302,000
1982 700,000.00 500,500
685
INVESTMENTS— Continued
Principal
Amount
325,000.00
483,000.00
1,000,000.00
500,000.00
187,000.00
500,000.00
500,000.00
200,000.00
480,000.00
1,000,000.00
200,000.00
200,000.00
150,000,00
190,000.00
750,000.00
1,000,000.00
357,913.55
297,069.72
161,820.38
208,335.32
640,659.68
400,000.00
232,000.00
676,666.67
200,000.00
Description Maturity Book Value
Industrial and Miscellaneous Bonds — Continued
Crown Zellerbach Corp.,
Prom. Note, 4%s 1981 325,000.00
Erie Mining Company, 1st Mtg.
Series B, 4V2s 1983 468,935.04
First National City Bank,
Capital Conv. Notes, 4s 1990 1,075,715.00
FMC Corp., S. F. Deb.,
3.8s 1981 500,000.00
Four Corners Pipe Line Co.,
Sec. Note, 5s 1982 187,000.00
General Electric Credit Corp. (N.Y.),
Sub. Note, 4%s 1987 500,000.00
General Electric Credit Corp. (N.Y.),
Prom. Note, 5s 1975 500,000.00
General Motors Acceptance Corp.,
Deb., 3y2s 1972 200,000.00
General Motors Acceptance Corp.,
Deb., 4s 1979 435,037.50
General Motors Acceptance Corp.,
Deb., 478s 1987 990,000.00
General Motors Acceptance Corp.,
Deb., 5s 1977 195,000.00
General Motors Acceptance Corp.,
Deb., 5s 1981 199,000.00
General Portland Cement Co.,
Conv. Sub. Deb., 5s 1977 154,500.00
Grant W. T. Financial Corporation,
Promissory Note 1969 190,000.00
Household Finance Corp.,
Deb, 4%s 1993 746,250.00
Hystron Fibers, Inc.,
Notes, 5%s 1986 1,000,000.00
Instlcorp, Inc., Collat. Tr.
Notes, A-16 1991 345,957.98
Instlcorp, Inc., Collat. Tr.
Note Series A-19 1991 287,240.18
Instlcorp, Inc., Collat. Tr.
Note, A-21 1991 156,156.69
Instlcorp, Inc., Collat. Tr.
Note, A-23 1991 204,960.39
Instlcorp, Inc., Collat. Tr.
Note, A-36 1992 614,494.87
Intl. Harvester Credit Corp,
Deb, 4%s 1979 398,000.00
Kaiser Aluminum & Chemical Corp,
1st Mtg, 5%s 1987 232,000.00
Kresge (S. S.) Company,
Prom. Note, 47/8s 1983 676,666.67
Montgomery Ward Credit Corp,
Deb, 47/8s 1980 199,000.00
686
Approximate
Value
Market
268,125
326,025
975,000
355,000
159,418
318,750
422,500
177,500
355,200
743,750
168,500
162,500
117,000
190,000
517,500
842,500
290,804
240,626
130,670
168,751
501,316
300,000
182,120
512,574
138,000
INVESTMENTS— Continued
Approximate
Principal Market
Amount Description Maturity Book Value Value
Industrial and Miscellaneous Bonds — Continued
95,000.00 National Dairy Products Corp.,
Deb., 2%s 1970 94,654.50 88,825
700,000.00 Owens-Illinois, Inc.,
Notes, 5s 1991 700,000.00 514,500
1,871,000.00 Penney (J. C.) Company, Inc.,
Conv. Sub. Deb., 41/4s 1993 2,092,961.25 2,072,133
525,000.00 Sears Roebuck Acceptance Corp.,
Sub. Deb., 4%s 1977 511,505.00 425,250
1,000.000.00 Shell Oil Company,
Deb., 5s 1991 1,000,000.00 777,500
250,000.00 Spiegel, Inc.,
Deb., 5s 1987 250,000.00 175,625
456,000.00 Statewide Stations Inc.,
Sec. Note, 4%s 1994 456,000.00 318,060
215,000.00 Talcott (James) Inc.,
Senior Note, 5V2s 1980 212,850.00 179,525
700,000.00 Texas Gulf Sulphur Co.,
Prom. Note, 4.7s 1989 700,000.00 540,750
452,963.01 Trailer Train Co.,
4%s 1976 452,963.01 391,813
296,000.00 Tremarco Corporation, 1st Mtg.
Series E, 5s 1983 296,000.00 244,200
700,000.00 United Air Lines, Inc.,
Notes, 5s 1984 700,000.00 521,500
680,000.00 United Shoe Machinery Corporation,
S. F. Deb, 5%s 1992 678,300.00 567,800
542,500.00 U. S. Steel, S. F. Sub. Deb.,
4%s 1996 443,873.50 381,106
1,048,000.00 Westinghouse Electric Corp.,
Demand Note 1,048,000.00 1,048,000
250,000.00 Whirlpool Corporation,
S. F. Deb, 3V2s 1980 250,000.00 171,875
490,000.00 Woolworth (F. W.) Company,
Prom. Note, 5s 1982 490,000.00 344,225
$24,720,928.33 Total $24,757,720.20 $20,301,216
$40,980,928.33 Bonds, funds invested $41,015,879.31 $32,808,589
Mortgage
$ 13,983.06 Alfred D. Hershey and Harriet D.
Hershey, 5V2s 1974 $ 13,983.06 $ 13,983
687
INVESTMENTS— Continued
Number
of
Shares
Description
Book Value
Approximate
Market
Value
Common Stocks
23,110 American Electric Power Co., Inc $ 162,703.74 $ 768,408
65,868 American Smelting & Refining Co 1,360,609.98 2,083,076
42,352 American Telephone & Telegraph Company 1,161,275.59 2,297,596
32,000 Armstrong Cork Company 131,908.39 1,168,000
11,000 Avon Products, Inc 956,691.61 1,702,250
2,000 Burlington Industries, Inc 86,634.16 70,000
34,800 Caterpillar Tractor Co 601,472.84 1,757,400
24,000 Chesebrough-Pond's Inc 746,765.43 1,047,000
16,500 Chicago Pneumatic Tool Co 601,964.31 561,000
39,200 Coca-Cola Company (The) 628,984.09 2,724,400
36,000 Continental Oil Company (Del.) 146,960.65 1,255,500
2,500 Corning Glass Works 59,631.83 677,500
43,972 Eastman Kodak Company 443,434.12 3,297,900
24,000 Federated Department Stores, Inc 582,805.81 900,000
15,104 First National City Bank 348,278.77 979,872
19,400 Ford Motor Company 577,047.36 916,650
30,627 General Electric Company 767,899.37 2,756,430
13,800 General Foods Corp 1,210,911.44 1,124,700
35,419 General Motors Corporation 1,143,847.99 2,758,255
36,200 Gillette Company 1,239,112.08 1,905,025
83,424 Goodyear Tire & Rubber Company 1,702,971.74 2,450,580
40,012 Gulf Oil Corporation 154,333.51 1,530,459
31,668 International Business Machines Corp 851,09557 10,695,867
61,175 International Nickel Co. of Canada Ltd 1,296,074.87 2,240,534
57,000 International Paper Company 2,112,936.24 2,194,500
12,900 Johnson & Johnson 750,762.93 1,460,925
47,630 Kennecott Copper Corporation 1,308,403.57 1,952,830
15,000 Merck & Co., Inc 107,286.55 1,389,375
17,000 Minnesota Mining & Manufacturing Co 1,691,650.93 1,717,000
30,700 Mobil Oil Corporation 1,099,916.18 1,799,788
5,000 National Cash Register Company 720,712.50 639,375
33,600 Panhandle Eastern Pipe Line Co 1,067,554.69 1,033,200
9,000 Penn. Central Co 614,232.68 444,375
61,400 Philip Morris Incorporated 1,551,034.72 1,765,250
4,600 Sears, Roebuck and Co 207,078.03 318,550
32,800 Southern Co 878,283.72 885,600
23,561 Standard Oil Co. (New Jersey) 671,594.17 1,828,923
24,190 Texaco Inc 249,172.89 1,826,345
43,500 Texas Gulf Sulphur Co 1,257,455.80 1,103,813
44,000 TRW Inc 2,214,408.91 1,540,000
7,600 Texas Utilities Co 104,621.78 400,900
56,800 U. S. Plywood-Champion Papers Inc 697,928.16 1,874,400
35,999 Virginia Electric & Power Co 636,133.86 967,473
20,000 Whirlpool Corporation 943,953.26 1,100,000
26,100 Xerox Corp 1,863,165.49 2,528,438
1,372,511 Common stocks, funds invested $37,711,702.61 $ 76,439.462
Aggregate investments $78,741,564.98 $109,262,034
688
SUMMARY OF INVESTMENT TRANSACTIONS
FOR THE YEAR ENDED JUNE 30, 1969
Cash, July 1, 1968
($ 184,712 31)
Sales and Redemptions
Capital Capital
Gain Loss
Book
Value
Bonds
$ 127,466.65
1,081,000.03
$ 744,943.36
103,415.41
$ 9,262,253.15
2,414.25
4,950,804.21
Mortgage
Common Stocks
Realized capital gain,
net — Statement B
1,208,466.68
848,358.77
360,107.91
$1,208,466.68
14,215,471.61
360,107.91
$1,208,466.68
Total sales and redemptions
14,575,579.52
5,154.61
49,768.54
14,445,790.36
Income applied to amortization
Gifts
of bond premium
Total
Bonds
Acquisitions
6,198,642.07
8,122,657.18
14,321,299.25
$ 124 491 11
Cash, June 30, 1969
689
Abstract of Minutes
of the Seventy-First Meeting of the Board of Trustees
The annual meeting of the Board of Trustees was held in the Board Room of the
Administration Building on Friday, May 2, 1969. Chairman James N. White called the
meeting to order.
The following Trustees were present: Michael Ference, Jr., Crawford H. Greenewalt,
Caryl P. Haskins, Robert A. Lovett, Keith S. McHugh, Henry S. Morgan, William I.
Myers, Garrison Norton, Robert M. Pennoyer, Richard S. Perkins, William M. Roth,
William W. Rubey, Frank Stanton, Charles P. Taft, Charles H. Townes, Juan T. Trippe,
and James N. White.
The minutes of the Seventieth Meeting were approved.
William T. Golden was elected a member of the Board of Trustees.
The following were elected for one-year terms: Henry S. Morgan as Chairman of the
Executive Committee, Richard S. Perkins as Chairman of the Finance Committee, Garrison
Norton as Chairman of the Nominating Committee, Keith S. McHugh as Chairman of
the Auditing Committee, and Frank Stanton as Chairman of the Retirement Committee.
Vacancies in standing committees, with terms ending in 1972, were filled as follows:
Garrison Norton was elected a member of the Nominating Committee; Carl J. Gilbert,
Crawford H. Greenewalt, and Richard S. Perkins were elected members of the Executive
Committee; and Robert M. Pennoyer and Richard S. Perkins were elected members of
the Finance Committee.
The reports of the Executive Committee, the Finance Committee, the Retirement
Committee and the Auditing Committee were accepted. On the recommendation of the
latter it was resolved that Lybrand, Ross Bros, and Montgomery be appointed as public
accountants for the fiscal year beginning July 1, 1969.
The annual report of the President was accepted.
To provide for the operation of the Institution for the fiscal year beginning July 1, 1969,
and upon recommendation of the Executive Committee, the sum of $4,651,730 was
appropriated, the appropriation to be made specifically in the amount of $4,484,130 from
the Working Capital Fund, $10,110 from the Colburn Fund, $370 from the Hale Fund,
$450 from the Harkavy Fund, $290 from the Morgenroth Fund, $985 from the Teeple
Fund, $21,995 from the Wood Fund, and $133,400 from Restricted Grants.
691
Articles of Incorporation
JfijHtgjjijr Congress of % Irattb %Mts of America;
Begun and held at the City of Washington on Monday, the seventh day of December, one
thousand nine hundred and three.
.AN" ACT
To incorporate the Carnegie Institution of Washington.
Be it enacted by the Senate and House of Representatives of the United
States of America in Congress assembled, That the persons following, being persons
who are now trustees of the Carnegie Institution, namely, Alexander Agassiz,
John S. Billings, John L. Cadwalader, Cleveland H. Dodge, William K Frew,
Lyman J. Gage, Daniel C. Gilman, John Hay, Henry L. Higginson, William
Wirt Howe, Charles L. Hutchinson, Samuel P. Langley, William Lindsay, Seth
Low, Wayne MacVeagh, Darius 0. Mills, S. Weir Mitchell, William W. Morrow,
Ethan A. Hitchcock, Elihu Root, John C. Spooner, Andrew D. White, Charles
D. Walcott, Carroll D. Wright, their associates and successors, . duly chosen, are
hereby incorporated and declared to he a body corporate by the name of the
Carnegie Institution of Washington and by that name shall be known and have
perpetual succession, with the powers, limitations, and restrictions herein contained.
Sec. 2. That the objects of the corporation shall be to encourage, in the
broadest and most liberal manner, investigation, research, and discovery, and
the application of knowledge to the improvement of mankind; and in particular —
(a) To conduct, endow, and assist investigation in any department of
science, literature, or art, ..and to this end to cooperate with governments,
universities, colleges, technical schools, learned societies, and individuals.
(b) To appoint committees of experts to direct special lines of research.
(c) To publish and distribute documents.
(d) To conduct lectures, hold meetings, and acquire and maintain a library,
(e) To purchase such property, real or personal, and construct such building
or buildings as may be necessary to carry on the work of the corporation.
693
694 CARNEGIE INSTITUTION
(f) In general, to do and perform all things necessary to promote the
objects of the institution, with full power, however, to the trustees hereinafter
appointed and their successors from time to time to modify the conditions and
regulations under which the work shall he carried on, so as to secure the
application of the funds in the manner best adapted to the conditions of the time,
provided that the objects of the corporation shall at all times be among the
foregoing or kindred thereto.
Sec. 3. That the direction and management of the affairs of the corporation
and the control and disposal of its property and funds shall be vested in a board
of trustees, twenty-two in number, to be composed of the following individuals:
Alexander Agassiz, John S. Billings, John L. Cadwalader, Cleveland H. Dodge,
William N. Frew, Lyman J. Gage, Daniel C. Gilman, John Hay, Henry
L. Higginson, William Wirt Howe, Charles L. Hutchinson, Samuel P.
Langley, William Lindsay, Seth Low, Wayne MacVeagh, Darius 0. Mills,
S. Weir Mitchell, William W. Morrow, Ethan A. Hitchcock, Elihu Eoot,
John C. Spooner, Andrew D. White, Charles D. Walcott, Carroll D. Wright,
who shall constitute the first board of trustees. The board of trustees shall
have power from time to time to increase its membership to not more than
twenty-seven members. Vacancies occasioned by death, resignation, or otherwise
shall be filled by the remaining trustees in such manner as the by-laws shall
prescribe ; and the persons so elected shall thereupon become trustees and also
members of the said corporation. The principal place of business of the said
corporation shall be the city of Washington, in the District of Columbia.
Sec. 4. That such board of trustees shall be entitled to take, hold and
administer the securities, funds, and property so transferred by said Andrew
Carnegie to the trustees of the Carnegie Institution and such other funds or
property as may at any time be given, devised, or bequeathed to them, or to such
corporation, for the purposes of the trust; and with full power from time to time to
adopt a common seal, to appoint such officers, members of the board of trustees or
otherwise, and such employees as may be deemed necessary in carrying on the
business of the corporation, at such salaries or with such remuneration as they may
deem proper; and with full power to adopt by-laws from time to time and such rules
or regulations as may be necessary to secure the safe and convenient transaction
of the business of the corporation ; and with full power and discretion to deal
with and expend the income of the corporation in such manner as in their
judgment will best promote the objects herein set forth and in general to have
and use all powers and authority necessary to promote such objects and carry out
the purposes of the donor. The said trustees shall have further power from time
ARTICLES OF INCORPORATION 695
to time to hold as investments the securities hereinabove referred to so transferred
by Andrew Carnegie, and any property which has been or may be transferred
to them or such corporation by Andrew Carnegie or by any other person,
persons, or corporation, and to invest any sums or amounts from time to time
in such securities and in such form and manner as are permitted to trustees
or to charitable or literary corporations for investment, according to the laws
of the States of New York, Pennsylvania, or Massachusetts, or in such securities
as are authorized for investment by the said deed of trust so executed by Andrew
Carnegie, or by any deed of gift or last will and testament to be hereafter made
or executed.
Sec. 5. That the said corporation may take and hold any additional
donations, grants, devises, or bequests which may be made in further support of
the purposes of the said corporation, and may include in the expenses thereof
the personal expenses wThich the trustees may incur in attending meetings or
otherwise in carrying out the business of the trust, but the services of the
trustees as such shall be gratuitous.
Sec. 6. That as soon as may be possible after the passage of this Act a
meeting of the trustees hereinbefore named shall be called by Daniel C. Gilman,
John S. Billings, Charles D. Walcott, S. Weir Mitchell, John Hay, Elihu Root,
and Carroll D. Wright, or any four of them, at the city of Washington, in
the District of Columbia, by notice served in person or by mail addressed to
each trustee at his place of residence; and the said trustees, or a majority
thereof, being assembled, shall organize and proceed to adopt by-laws, to'elect
officers and appoint committees, and generally to organize the said corporation;
and said trustees herein named, on behalf of the corporation hereby incorporated,
shall thereupon receive, take over, and enter into possession, custody, and
management of all property, real or personal, of the corporation heretofore known
as the Carnegie Institution,' incorporated, as hereinbefore set forth under " An A.ct
to establish a Code of Law for the District of Columbia, January fourth, nineteen
hundred and two," and to all its rights, contracts, claims, and property of any
kind or nature ; and the several oflicers of such corporation, or any other person
having charge of any of the securities, funds, real or personal, books or property
thereof, shall, on demand, deliver the same to the said trustees appointed by this
Act or to the persons appointed by them to receive the same ; and the trustees
of the existing corporation and the trustees herein named shall and may take
such other steps as shall be necessary to carry out the purposes of this Act.
Sec. 7. That the rights of the creditors of the said existing corporation
known as the Carnegie Institution shall not in any manner be impaired by the
696
CARNEGIE INSTITUTION
passage of this Act, or the transfer of the property hereinbefore mentioned, nor
shall any liability or obligation for the payment of any sums due or to become
due, or any claim or demand, in any manner or for any cause existing against
the said existing corporation, be released or impaired; but such corporation hereby
incorporated is declared to succeed to the obligations and liabilities and to be held
liable to pay and discharge all of the debts, liabilities, and contracts of the said
corporation so existing to the same effect as if such new corporation had itself
incurred the obligation or liability to pay such debt or damages, and no such action
or proceeding before any court or tribunal shall be deemed to have abated or been
discontinued by reason of the passage of this Act.
Sec. 8. That Congress may from time to time alter, repeal, or modify this
Act of incorporation, but no contract or individual right made or acquired shall
thereby be divested or impaired.
Sec. 9. That this Act shall take effect immediately.
Speaker of the House of Representatives.
«e
President of the Senate pro tempore.
~^^~*g- — £^ —
t
By-Laws of the Institution
Adopted December 13, 1904. Amended December 13, 1910, December 13, 1912,
December 10 1937, December 15, 1939, December 13, 1940, December 18, 1942,
December 12, 1947, December 10, 1954, October 24, 1957, May 8, 1959, May 13, 1960,
May 10, 1963, May 15, 1964, March 6, 1967, and May 3, 1968.
ARTICLE I
The Trustees
1. The Board of Trustees shall consist of twenty-four members with power to increase
its membership to not more than twenty-seven members. The Trustees shall hold office
continuously and not for a stated term.
2. In case any Trustee shall fail to attend three successive annual meetings of the
Board he shall thereupon cease to be a Trustee.
3. No Trustee shall receive any compensation for his services as such.
4. All vacancies in the Board of Trustees shall be filled by the Trustees by ballot at an
annual meeting, but no person shall be declared elected unless he receives the votes of
two-thirds of the Trustees present.
5. If, at any time during an emergency period, there be no surviving Trustee capable
of acting, the President, the Director of each existing Department, and the Executive
Officer, or such of them as shall then be surviving and capable of acting, shall constitute
a Board of Trustees pro tern, with full powers under the provisions of the Articles of
Incorporation and these By-Laws. Should neither the President, nor any such Director,
nor the Executive Officer be capable of acting, the senior surviving Staff Member of each
existing Department shall be a Trustee pro tern with full powers of a Trustee under the
Articles of Incorporation and these By-Laws. It shall be incumbent on the Trustees
pro tern to reconstitute the Board with permanent members within a reasonable time
after the emergency has passed, at which time the Trustees pro tern shall cease to hold
office. A list of Staff Member seniority, as designated annually by the President, shall
be kept in the Institution's records.
ARTICLE II
Officers of the Board
1. The officers of the Board shall be a Chairman of the Board, a Vice-Chairman, and
a Secretary, who shall be elected by the Trustees, from the members of the Board, by
ballot to serve for a term of three years. All vacancies shall be filled by the Board for
the unexpired term; provided, however, that the Executive Committee shall have power
to fill a vacancy in the office of Secretary to serve until the next meeting of the Board of
Trustees.
2. The Chairman shall preside at all meetings and shall have the usual powers of a
presiding officer.
697
698 CARNEGIE INSTITUTION
3. The Vice-Chairman, in the absence or disability of the Chairman, shall perform the
duties of the Chairman.
4. The Secretary shall issue notices of meetings of the Board, record its transactions,
and conduct that part of the correspondence relating to the Board and to his duties.
ARTICLE III
Executive Administration
The President
1. There shall be a President who shall be elected by ballot by, and hold office during
the pleasure of, the Board, who shall be the chief executive officer of the Institution.
The President, subject to the control of the Board and the Executive Committee, shall
have general charge of all matters of administration and supervision of all arrangements
for research and other work undertaken by the Institution or with its funds. He shall
prepare and submit to the Board of Trustees and to the Executive Committee plans
and suggestions for the work of the Institution, shall conduct its general correspondence
and the correspondence with applicants for grants and with the special advisers of the
Committee, and shall present his recommendations in each case to the Executive Com-
mittee for decision. All proposals and requests for grants shall be referred to the President
for consideration and report. He shall have power to remove, appoint, and, within the
scope of funds made available by the Trustees, provide for compensation of subordinate
employees and to fix the compensation of such employees within the limits of a maximum
rate of compensation to be established from time to time by the Executive Committee.
He shall be ex officio a member of the Executive Committee.
2. He shall be the legal custodian of the seal and of all property of the Institution
whose custody is not otherwise provided for. He shall sign and execute on behalf of
the corporation all contracts and instruments necessary in authorized administrative and
research matters and affix the corporate seal thereto when necessary, and may delegate
the performance of such acts and other administrative duties in his absence to the
Executive Officer. He may execute all other contracts, deeds, and instruments on behalf
of the corporation and affix the seal thereto when expressly authorized by the Board of
Trustees or Executive Committee. He may, within the limits of his own authorization,
delegate to the Executive Officer authority to act as custodian of and affix the corporate
seal. He shall be responsible for the expenditure and disbursement of all funds of the
Institution in accordance with the directions of the Board and of the Executive Com-
mittee, and shall keep accurate accounts of all receipts and disbursements. Following
approval by the Executive Committee he shall transmit to the Board of Trustees before
its annual meeting a written report of the operations and business of the Institution
for the preceding fiscal year with his recommendations for work and appropriations for
the succeeding fiscal year.
3. He shall attend all meetings of the Board of Trustees.
4. There shall be an officer designated Executive Officer who shall be appointed by
and hold office at the pleasure of the President, subject to the approval of the Executive
Committee. His duties shall be to assist and act for the President as the latter may duly
authorize and direct.
5. The President shall retire from office at the end of the fiscal year in which he becomes
sixty-five years of age.
ARTICLE TV
Meetings and Voting
1. The annual meeting of the Board of Trustees shall be held in the City of Washington,
in the District of Columbia, in May of each year on a date fixed by the Executive
BY-LAWS 699
Committee, or at such other time or such other place as may be designated by the
Executive Committee, or if not so designated prior to May 1 of such year, by the
Chairman of the Board of Trustees, or if he is absent or is unable or refuses to act, by
any Trustee with the written consent of the majority of the Trustees then holding office.
2. Special meetings of the Board of Trustees may be called, and the time and place
of meeting designated, by the Chairman, or by the Executive Committee, or by any
Trustee with the written consent of the majority of the Trustees then holding office.
Upon the written request of seven members of the Board, the Chairman shall call a
special meeting.
3. Notices of meetings shall be given ten days prior to the date thereof. Notice may
be given to any Trustee personally, or by mail or by telegram sent to the usual address
of such Trustee. Notices of adjourned meetings need not be given except when the
adjournment is for ten days or more.
4. The presence of a majority of the Trustees holding office shall constitute a quorum
for the transaction of business at any meeting. An act of the majority of the Trustees
present at a meeting at which a quorum is present shall be the act of the Board except
as otherwise provided in these By-Laws. If, at a duly called meeting, less than a quorum
is present, a majority of those present may adjourn the meeting from time to time
until a quorum is present. Trustees present at a duly called or held meeting at which a
quorum is present may continue to do business until adjournment notwithstanding the
withdrawal of enough Trustees to leave less than a quorum.
5. The transactions of any meeting, however called and noticed, shall be as valid as
though carried out at a meeting duly held after regular call and notice, if a quorum is
present and if, either before or after the meeting, each of the Trustees not present
in person signs a written waiver of notice, or consent to the holding of such meeting, or
approval of the minutes thereof. All such waivers, consents, or approvals shall be filed
with the corporate records or made a part of the minutes of the meeting.
6. Any action which, under law or these By-Laws, is authorized to be taken at a
meeting of the Board of Trustees may be taken without a meeting if authorized in a
document or documents in writing signed by all the Trustees then holding office and
filed with the Secretary.
7. During an emergency period the term "Trustees holding office" shall, for purposes
of this Article, mean the surviving members of the Board who have not been rendered
incapable of acting for any reason including difficulty of transportation to a place of
meeting or of communication with other surviving members of the Board.
article v
Committees
1. There shall be the following Standing Committees, viz. an Executive Committee,
a Finance Committee, an Auditing Committee, a Nominating Committee, and a Retire-
ment Committee.
2. All vacancies in the Standing Committees shall be filled by the Board of Trustees
at the next annual meeting of the Board and may be filled at a special meeting of the
Board. A vacancy in the Executive Committee and, upon request of the remaining
members of any other Standing Committee, a vacancy in such other Committee may be
filled by the Executive Committee by temporary appointment to serve until the next
meeting of the Board.
3. The terms of all officers and of all members of Committees, as provided for herein,
shall continue until their successors are elected or appointed.
Executive Committee
4. The Executive Committee shall consist of the Chairman, Vice-Chairman, and
Secretary of the Board of Trustees, the President of the Institution ex officio, and, in
700 CARNEGIE INSTITUTION
addition, not less than five or more than eight Trustees to be elected by the Board by
ballot for a term of three years, who shall be eligible for re-election. Any member elected
to fill a vacancy shall serve for the remainder of his predecessor's term.
5. The Executive Committee shall, when the Board is not in session and has not given
specific directions, have general control of the administration of the affairs of the
corporation and general supervision of all arrangements for administration, research,
and other matters undertaken or promoted by the Institution. It shall also submit to the
Board of Trustees a printed or typewritten report of each of its meetings, and at the
annual meeting shall submit to the Board a report for publication.
6. The Executive Committee shall have power to authorize the purchase, sale, exchange,
or transfer of real estate.
Finance Committee
7. The Finance Committee shall consist of not less than five and not more than six
members to be elected by the Board of Trustees by ballot for a term of three years, who
shall be eligible for re-election.
8. The Finance Committee shall have custody of the securities of the corporation
and general charge of its investments and invested funds, including its investments and
invested funds as trustee of any retirement plan for the Institution's staff members and
employees, and shall care for and dispose of the same subject to the directions of the
Board of Trustees. It shall have power to authorize the purchase, sale, exchange, or
transfer of securities and to delegate this power. It shall consider and recommend to the
Board from time to time such measures as in its opinion will promote the financial interests
of the Institution and of the trust fund under any retirement plan for the Institution's
staff members and employees, and shall make a report at each meeting of the Board.
Auditing Committee
9. The Auditing Committee shall consist of three members to be elected by the Board
of Trustees by ballot for a term of three years.
10. Before each annual meeting of the Board of Trustees, the Auditing Committee
shall cause the accounts of the Institution for the preceding fiscal year to be audited
by public accountants. The accountants shall report to the Committee, and the Com-
mittee shall present said report at the ensuing annual meeting of the Board with such
recommendations as the Committee may deem appropriate.
Nominating Committee
11. The Nominating Committee shall consist of the Chairman of the Board of
Trustees ex officio and, in addition, three Trustees to be elected by the Board by ballot
for a term of three years, who shall not be eligible for re-election until after the lapse
of one year. Any member elected to fill a vacancy shall serve for the remainder of his
predecessor's term, provided that of the Nominating Committee first elected after
adoption of this By-Law one member shall serve for one year, one member shall serve
for two years, and one member shall serve for three years, the Committee to determine
the respective terms by lot.
12. Sixty days prior to an annual meeting of the Board the Nominating Committee
shall notify the Trustees by mail of the vacancies to be filled in membership of the Board.
Each Trustee may submit nominations for such vacancies. Nominations so submitted
shall be considered by the Nominating Committee, and ten days prior to the annual
meeting the Nominating Committee shall submit to members of the Board by mail a list
of the persons so nominated, with its recommendations for filling existing vacancies on
the Board and its Standing Committees. No other nominations shall be received by the
Board at the annual meeting except with the unanimous consent of the Trustees present.
BY-LAWS 701
Retirement Committee
13. The Retirement Committee shall consist of three members to be elected by the
Board of Trustees by ballot for a term of three years, who shall be eligible for re-election
and the Chairman of the Finance Committee ex officio. Any member elected to fill a
vacancy shall serve for the remainder of his predecessor's term.
14. The Retirement Committee shall, subject to the directions of the Board of Trustees,
be responsible for the maintenance of a retirement plan for staff members and
employees of the Institution and act for the Institution in its capacity as trustee
under any such plan, except that any matter relating to investments under any such
plan shall be the responsibility of the Finance Committee subject to the directions
of the Board of Trustees. The Committee shall submit a report to the Board at the
annual meeting of the Board.
ARTICLE VI
Financial Administration
1. No expenditure shall be authorized or made except in pursuance of a previous
appropriation by the Board of Trustees, or as provided in Article V, paragraph 8, hereof.
2. The fiscal year of the Institution shall commence on the first day of July in each
year.
3. The Executive Committee shall submit to the annual meeting of the Board a full
statement of the finances and work of the Institution for the preceding fiscal year and a
detailed estimate of the expenditures of the succeeding fiscal year.
4. The Board of Trustees, at the annual meeting in each year, shall make general
appropriations for the ensuing fiscal year; but nothing contained herein shall prevent
the Board of Trustees from making special appropriations at any meeting.
5. The Executive Committee shall have general charge and control of all appropria-
tions made by the Board. Following the annual meeting, the Executive Committee may
allocate these appropriations for the succeeding fiscal year. The Committee shall have full
authority to reallocate available funds, as needed, and to transfer balances.
6. The securities of the Institution and evidences of property, and funds invested and
to be invested, shall be deposited in such safe depository or in the custody of such trust
company and under such safeguards as the Finance Committee shall designate, subject
to directions of the Board of Trustees. Income of the Institution available for expenditure
shall be deposited in such banks or depositories as may from time to time be designated
by the Executive Committee.
7. Any trust company entrusted with the custody of securities by the Finance Com-
mittee may, by resolution of the Board of Trustees, be made Fiscal Agent of the
Institution, upon an agreed compensation, for the transaction of the business coming
within the authority of the Finance Committee.
8. The property of the Institution is irrevocably dedicated to charitable purposes,
and in the event of dissolution its property shall be used for and distributed to those
charitable purposes as are specified by the Congress of the United States in the Articles of
Incorporation, Public Law No. 260, approved April 28, 1904, as the same may be
amended from time to time.
ARTICLE VII
Amendment of By-Laws
1. These By-Laws may be amended at any annual or special meeting of the Board of
Trustees by a two-thirds vote of the members present, provided written notice of the
proposed amendment shall have been served personally upon, or mailed to the usual
address of, each member of the Board twenty days prior to the meeting.
Index
Abbott, D., 444, 484
Abell, George 0., 144
Abelson, Philip H., vii, 43, 50, 51, 93, 170, 343,
355
report of the Director, 165-356
studies, 297-303
Abt, Helmut, 155
Ackerman, Edward A., ix
publications, 669
Adams, Leason H., 92, 282
Adelman, Saul J., 120, 161
publications, 155
Adkins, John M., 105, 161
Adkison, Bruce, 155, 162
Agassiz, Alexander, xi, 693, 694
Ahrens, L. H., 434, 483
Ahrens, T. J., 339, 346
Akimoto, S., 218, 219, 229, 235, 245, 246, 247,
248, 333, 346, 351, 441, 484
Albers, W., 277, 353
Aldrich, L. Thomas, vii, 52, 320, 350, 359, 403,
442, 484, 487
Alexander, L. E., 291, 346
Aller, Lawrence, 144
Allmann, R., 344
Allsopp, H. L., 437, 438, 439, 445, 483, 484
Aly, M. K, 108
Amako, K., 482
Amesz, Jan, 594, 595, 598, 645
publications, 645
Amstutz, G. C, 334, 351
Anderko, K, 256, 350
Anderson, J. M., 574, 578, 598
Anderson, L. W., 482
Andre, Marcel, 648
Andrews, P., 483
Aoki, K., 193, 258, 317, 346, 348, 351
Aparicio, Pablo, 52, 55, 403, 452, 455, 488
Appleman, D. E., 292
Aramaki, S., 340, 346
Arnold, R. G., 259, 260, 261, 263, 264, 346
Arnon, D. I., 574, 575, 578
Aronoff, S., 570, 572
Arp, Halton C, vii, 113, 130, 134, 135, 142, 160,
244
publications, 155
Asada, T., 476, 484
Ashby, Eric, v
Assousa, George E., 79, 82, 364, 487
publication, 485
studies, 374
Ayabe, K., 482
Azzi, J. R., 603, 607
Baade, Walter, 9, 40, 103, 129, 130, 137
Babcock, Horace W., vii, 94, 97, 160
report of the Director, 97-163
Bahcall, John N., 108, 141, 155
Bailey, D. K., 194, 346
Bajaja, Esteban, 370
Baker, Dennis D., 161
Baker, I., 191, 333, 346
Baker, P. E., 346
Balchan, A. S., 170, 251, 253, 255, 346
Baldwin, George J., xi
Ballard, L. N., 334, 353
Balnaves, K. M., 369, 482
Baltitude, R. J., 241, 346
Baltscheffsky, M., 594, 595
Bannister, John, 488
Banno, S., 215, 318, 346
Bappu, M. K. Vainu, 116
Baragar, W. R. A., 430, 483
Barbon, Roberto, 155
Barbour, Thomas, xi
Barnes, V. E., 339, 346
Barreda R., Willy Z., 82, 487
Barth, Ruth, 281
Barth, T. F. W., 221, 278, 280, 281, 283, 349
Bartlett, F., 142
Baschek, Bodo, 155
Bass, M. N., 404
Bassett, W. A., 170, 250, 251, 252, 347, 351, 354
studies, 249-251, 251-253
Bassham, J. A., 574, 578
Baum, W. A., 486, 493
Beach, Liseiotte, 489
Beadle, G. W., 63, 655, 656
Bear, Phyllis D., 79, 668
Beatty, Barbara R., 68, 502
Beaudry, Jean, 640, 643
Beck, A. J., 660
Becker, W., 149
Beckers, J. M., 144
Becklin, E. E., 41, 113, 122, 123, 128, 139, 140,
141, 156
Bell, J. D., 342
Bell, James F., xi
Bell, Peter M., vii, 48, 173, 231, 254, 265, 277,
336, 341, 343, 353, 355
publications, 344
studies, 253-256, 276, 277-278, 336-339
Bence, A. E., 426, 483
Berg, G. W., 434, 437, 438, 483
Bergh, Sidney van den, 41, 129, 134, 135, 136,
142, 143, 160, 161
publications, 156
Bergman, W., 305
Berner, R. A., 335, 347
703
704
CARNEGIE INSTITUTION
Bertine, K. K, 404, 482
Bertola, F., 136, 144, 488
Bertsch, W. F., 603, 606, 607
Bhatnagar, Arvind, 77, 81, 107, 148, 161
Bickford, M. E., 307, 354
Biggar, G. M., 202, 206, 213, 347, 352
Billings, John S., xi, 693, 694, 695
Billingsley, Lynn M., 505, 556
publications, 554
studies, 546-548
Bird, M., 356
Birle, J. D., 291, 347
Bisalputra, T., 633
Bishop, N. I., 596, 598, 599, 602, 603
Bjorkman, Olle, viii, 72, 561, 562, 563, 616, 620,
622, 623, 627, 632, 633, 634, 636, 638, 640,
644, 646, 648
publications, 645, 646
studies, 609-614, 614-620, 620-633, 636-640
Bjorn, L. O., 74, 84, 565, 646, 648
Blackee, Lawrence E., 161
Bliss, Robert Woods, xi
Block, Stanley, 342, 484
Boardman, N. K., 574, 578
Boesgaard, Ann Merchant, 156
Bohlin, J. David, 143, 161
Bohm, K.-H., 104, 113
Boise, James W., ix
Boldt, E., 156
Bolton, Ellis T., vii, 56, 57, 374, 487
publication, 485
report of the Director, 359-490
Bolton, John G., 134, 145, 156
Bonatti, E., 334, 335, 347, 351
Bonica, John, 548, 549, 556
Boving, Bent G., viii, 71, 502, 505, 555
publications, 554
studies, 546-548, 552
Bowen, Ira S., vii, 42, 153, 160, 495
Bowen, N. L., 222, 223, 229, 231, 340, 347, 353
Bowen, V. T., 352
Bown, M. G., 328, 347
Boyd, Francis R., Jr., vii, 47, 169, 172, 186, 216,
217, 218, 219, 220, 221, 229, 233, 234, 240,
243, 246, 254, 255, 276, 319, 320, 321, 324,
325, 326, 327, 328, 329, 347, 348, 354, 355,
438, 439, 440, 443, 483, 484
publications, 344, 345
studies, 214-221, 315-320, 324-329
Boynton, John E, 84, 563, 632, 633, 648
Braccesi, Alessandro, 134, 145
Bradford, Amory H., v, vi
Bradford, Lindsay, xi
Bradley, Omar N., xi, 92
Bradt, H., 139, 156
Brandt, Willy, 485
Brenner, Don J., 488
Brian tais, J. M., 574, 578
Bridgman, P. W., 252, 276, 347
Bril, C., 574, 578
Brinkley, B. R., 482
Britten, Roy J., vii, 14, 57, 58, 59, 60, 61, 62, 374,
386, 487, 662, 663
publication, 485
studies, 376-378, 378-386, 400-402, 402-403
Brookings, Robert S., xi
Brookins, D. G., 317, 347
Brooks, Christopher, 52, 53, 54, 55, 79, 82, 315,
403, 483, 487
publications, 485
studies, 307-308, 313-315, 408-410, 410-413,
413-417, 420-422, 422-425, 425-426, 426-429,
429-433
Brooks, E. R., 311, 347
Brown, Donald D., viii, 67, 68, 502, 503, 505, 555,
662
publications, 554
studies, 505-509, 509-510
Brown, G. Malcolm, 77, 202, 213, 214, 227, 228,
229, 328, 342, 347
Brown, Jeanette S., viii, 74, 564, 572, 579, 581,
585, 587, 645, 646, 648
publications, 645
studies, 566-570, 570-572
Brown, Louis, vii, 364, 482, 487
publication, 485
studies, 370-373, 374
Brueckel, Frank J., 161
Bruman, Joseph R., 146
Bryan, Wilfred B., 46, 47, 77, 81, 170, 188, 191,
193, 195, 197, 199, 200, 347, 355
publication, 345
studies, 187-190, 190-194, 194-200
Buerger, M. J., 282
Bumba, V., 156
Bunch, T. E., 319, 347
Bundy, F. P., 253, 347
Burch, Philip, 20
Burd, Sylvia, 161
Burger, A. J., 445, 484
Burgi, Elizabeth, viii, 664, 667, 668
Burke, Bernard F., 365
Burke, J. E., 637, 640
Burnet, Sir Macfarlane, 21
Burnham, Charles W., 223, 261, 282, 283, 284,
345, 347
Burns, R. G., 254, 255, 256, 347, 348
Burr, G. O., 72
Burrhus, Kenneth D., 489
Bush, Vannevar, v
Bussey, J. J., 341
Butler, W. L., 568, 570, 578
Cabre, Ramon, 52, 403, 460, 488
Cadwalader, John L., xi, 693, 694
Caherty, Francis J., 489
Calder, Ritchie, 21
Callan, H. G„ 482
Campbell, William W., xi
Canter, Dorothy, 488
Carmichael, I. S. E, 194, 345, 348
Carpenter, R. H., 259, 348
Carter, J. L., 439, 483
INDEX
705
Carty, John J., xi
Casaverde, Mateo, x, 52, 403, 488
Catsky, J., 572, 574
Chamberlin, Margaret E., 489
Chao, E. T. C, 173, 336, 354, 356
studies, 336
Chapman, S., 108
Chase, John W., 505, 514, 556
studies, 517-518
Chase, Richard A., x
Chase, S., Ill
Chayes, Felix, vii, 46, 169, 170, 186, 187, 190,
193, 197, 221, 347, 348, 355
publications, 345
studies, 174-187, 200-201
Chelle, P., 11
Chevalier, R. A., 107
Chikashige, M., 258, 348
Chinner, G. A., 202, 203, 214, 220, 243, 348
Chiscon, J. Alfred, 57, 61, 79, 82, 374, 487
studies, 388-391
Chowdhury, D. K., 468, 484
Christensen, Clark G., 135, 161
Christy, R. F., 126
Clark, A. H., 259, 260, 261, 348
Clark, Joan R., 234, 292, 296, 328, 342, 347, 348,
352, 440, 484
Clark, L. A., 267, 348
Clark, Maynard K., 140, 161
Clark, S. P, 202, 215, 222, 223, 224, 247, 348
Clark, S. P., Jr., 254, 348
Clausen, Jens C, viii, 562, 644, 646, 648
studies, 643-644
Clayton, R. K., 595
Clegg, T. B., 482
Clements, F. E., 621, 633
Cohen, Judith G., 119, 156
Cohen, Seymour, 661
Cole, Whitefoord R., xi
Collins, W. H., 307, 311, 353
Colomb, Raul F., 370
Commoner, Barry, 658
Compston, W., 483
Conti, Peter S., 156
Coombs, D. S., 239, 353
Coon, Hayden G., 79, 83, 504, 541, 555
publications, 554
studies, 540-542, 542-546
Cooper, M. H., 555
publications, 554
studies, 552
Cooper, T. G., 629, 633
Corlett, M., 261, 348
Corliss, L. M., 282
Cotty, W., 316
Courtes, G., 145
Cowie, Dean B., vii, 57, 59, 374, 398, 482, 487
publication, 485
studies, 391-397
Cowley, John P., 161
Cragg, Thomas A., 105, 161
Craig, H., 417, 418, 419, 483
Craig, James R., 77
Crick, Francis, 4, 661, 664
Cromer, D. T., 285, 291, 348
Cronan, D. S., 335, 348
Crouse, Linda, 608
Crowther, J. G., 22, 23
Cuille, J., 11
Curtis, A. S. G., 659
Curtis, C. D., 254, 348
Czyzak, Stanley J., 144
Danchin, R. B., 444, 446, 484
Danziger, I. John, 127, 134, 145
Davidson, Eric H., 15, 61, 62, 488
Davidson, N., 384, 385, 482
Davidson, Richard, 542, 543
Davis, B. T. C, 173, 216, 217, 220, 221, 229,
345, 348
Davis, D. N., 156
Davis, Gordon L., vii, 53, 54, 55, 315, 326, 327,
345, 355, 403, 424, 483
publications, 485
studies, 307-308, 308-309, 309-313, 313-315,
408-410, 420-422, 422^25, 425-426, 429^33
Dawid, Igor B., viii, 67, 69, 502, 503, 505, 510,
555, 662
publications, 554
studies, 505-509, 509, 514-515
Day, Arthur L., 278, 279, 281
Day, Floyd E., 161
Deer, W. A., 188, 348
Degens, E. T., 299, 348
DeHaan, Robert L., viii, 505, 535, 538, 555
publications, 554
studies, 534-540
Dehlinger, P., 468, 484
De La Haba, G., 485
Deland, A. N., 313, 348, 408, 483
Delano, Frederic A., xi
DeLanney, Louis E., 556
Delbriick, Max, 93
Demarque, Pierre, 125, 156
Denham, David, 488
Dennison, Edwin W., vii, 42, 150, 160
Desborough, G. A., 259, 348
Destenay, D., 291, 348
Deutsch, Armin J., vii, 97, 119, 120, 121, 146, 160
publications, 155
DeVries, R. C, 203, 348
deWys, E. C, 202, 212, 355
publications, 345
Deza, Ernesto, 52, 403, 488
Dickens, Robert J., 77
Dickinson, R. G., 279, 349
Diener, T. O., 395, 482
Difley.JohnA., 154, 161
publication, 156
Doak, John B., 489
Dodd, W. W., 136
Dodge, Cleveland H., xi, 693, 694
D'Odorico, Sandro, 82, 364, 487
studies, 364-366
706
CARNEGIE INSTITUTION
Donnay, Gabrielle, vii, 173, 279, 281, 282, 293,
330, 343, 348, 355
publications, 345
studies, 278-283, 288-290, 292-296, 296-297
Donnay, J. D. H, 281, 282, 330, 356
Donner, Martin W., 505, 556
studies, 548-551
Doro, Stephen, 161
Downton, J., 622, 633
Doyle, R. W., 335, 348
Dreiling, Raymond, 161
Drickamer, H. G., 170, 251, 253, 254, 346, 348,
349, 355
Drouet, F., 397, 482
Duecker, H. C, 255, 351
Duggal, S. P., 446, 485
Dulbecco, R., 530
Dunning, John O., 556
DuPuy, David, 41, 142, 156
Durand, J. L., 291, 349
Dutta, S., 401, 488
Duysens, L. N. M, 592, 595, 597, 598
Dwornik, E. J., 352
Dziewonski, A., 463, 484
Ebbinghaus, H., 482
Ebert, James D., viii, 67, 69, 70, 94, 504
publications, 554, 555
report of the Director, 497-556
studies, 518-531
Ecklund, Everett T., 489
Edelman, M., 482
Edwards, G., 346
Eggen, Olin J., 104, 113, 114, 120, 125, 132, 140,
156
Egle, K., 562, 637
El Goresy, Ahmed, 77, 81, 254, 355
publications, 345
studies, 277-278
Elkind, M. M., 527
Elliott, C. J., 339, 340, 341, 349
Elliott, N„ 282
Elliott, R. P., 256, 349
Ellsworth, R. K., 570, 572
Endo, H., 482
Eng, Marlene, 556
Engel,A.E.J.,404,432
Engel, C. G., 432
England, Joseph L., vii, 217, 220, 221, 234, 240,
243, 254, 265, 276, 320, 347, 354, 355, 440,
484
publications, 277, 278
Epel, David, 554
Ephrussi, Boris, 542, 545, 546
Epstein, H. T., 482
Erd, R. C, 267, 268, 269, 349, 354
Eremenko, V. N., 270, 349
Erkes, Joseph W., 82, 364, 487
studies, 366, 368, 368-369
Erlank, Anthony J., 52, 55, 82, 171, 172, 173,
326, 344, 403, 443, 444, 446, 484, 488
publication, 485
studies, 231-233, 233-236, 307-308, 320-324,
433^39, 439-442, 442-443, 444-446
Ernst, W. G., 245, 349
Evans, Howard T., Jr., 267, 268, 269, 342, 349
Evans, J. W., 108
Evertson, Dale W., 56, 363, 449, 488
studies, 448-452
Ewing, M., 467, 484
Fair, Eugene B., 161
Falkow, Stanley, 488
publication, 485
Fambrough, Douglas M., viii, 80, 83, 501, 504,
505, 514, 535, 555
studies, 531-534
Feldman, U., 110
Fenner, Charles P., xi
Ference, Michael, Jr., v, 691
Ferguson, Homer L., xi
Ferguson, J., 444, 484
Fernandez, Luis, 52, 370, 403, 488
Fiala, J., 317, 349
Filmer, D., 633
Finger, Larry W., 55, 78, 81, 170, 173, 174, 186,
197, 221, 282, 287, 291, 345, 347, 349, 355
studies, 283-288, 290-292, 320-324, 442^43
Fink, K., 356
Fischer, K., 284, 287, 349
Fischer, G. von, 485
Fiske, R. S., 190, 349
Flamm, W. G., 482
Fleet, M. E., 266, 349
Fleischman, D. E., 595
Flexner, Josef a B., 402, 488
publication, 485
Flexner, Louis B., x, 402, 488, 555
publication, 485
Flexner, Simon, xi
Fock, H., 640
Foerstner, H., 349
Forbes, W. Cameron, xi
Forbush, Scott E., vii, 52, 93, 403, 448, 487
publications, 485
studies, 446-448
Ford, W. Kent, Jr., vii, 364, 487, 495
publications, 486
studies, 364-366, 374
Fork, David C, viii, 74, 565, 578, 585, 594, 595,
596, 598, 645, 646, 648
publications, 645
studies, 587-595, 595-598, 608-609
Forrestal, James, xi
Foshag, W. F., 234, 349, 440, 484
Foster, J., 352
Foster, M. D., 317, 318, 353
Foster, W. R., 202, 212, 355
Fournier, Charlotte, 161
Fox, P. J., 335, 349
Frampton, E. W., 482
INDEX
707
Frarey, M. J., 311
Frazier, Edward N., 106
Freeman, K. C, 40, 105, 131, 140
French, Bevan M., 50, 172
studies, 339-342
French, C. Stacy, viii, 71, 74, 573, 575, 578, 584,
587, 608, 646, 647, 648
publications, 645, 646
report of the Director, 558-648
studies, 578-587, 607-608
Frew, William N., xi, 693, 694
Frez, Jose, 52, 403, 488
Fried, P., 482
Friedmann, I., 346
Frogel, Jay A., 123, 124, 161
Frye, L. D., 555
Fujisawa, H., 229, 346
Fukao, Y., 254, 349
Fullard, C. C, 444, 446, 484
Fulton, Chandler, 554
Fung, S. C, 254, 349
Fiirst, U., 270, 349
Fyfe, W., 253, 348, 349
Gadjusek, D. Carlton, 12
Gage, Lyman J., xi, 693, 694
Gaines, R. V., 293, 345, 349
Gajardo, Enrique, 52, 403, 488
Garmire, G., 156
Garrison, Robert F., 146, 156
Garzoli, Silvia, 370
Gaskell, T. F., 176, 349
Gass, I. G., 188, 190, 346, 349
Gasser, Raymond F., 556
Gast, P. W., 241, 349, 408, 426, 427, 428, 483
Gauhl, E., 72, 80, 84, 562, 563, 616, 622, 623, 627,
632, 633, 634, 636, 647, 648
publications, 645, 646
studies, 620-633, 633-636, 636-640
Gay, Helen, viii
Gay, P., 328, 347
Gebbie, K., 108
Gelderman, Albert, 488
Geller, S., 291, 349
Georgen, Robert D., 161
Gheith, M. A., 331, 333, 349
Ghose, S., 284, 287, 349
Gibbs, V., 347
Giesecke, Alberto A., Jr., 52, 403, 460, 488
Gifford, Walter S., xi
Gilardi, R. D., 342
Gilbert, Carl J., v, vi, 673, 691
Gilbert, Cass, xi
Gilbert, M. Charles, 78, 81, 231, 245, 246, 277,
341, 353, 356
publications, 345
Gillett, Frederick H., xi
Gilluly, J., 190, 349
Gilman, Daniel C, xi, 693, 694, 695
Glass, B., 352
Gold, T., 41, 142
Goldberg, B., 543
publications, 555
Golden, William T., v, 93, 691
Goldreich, P., 41, 142
Goldschmidt, V. M., 280
Goniadzki, Dora, 370
Goodell, H. D., 332, 354
Goodwin, A. M., 422, 483
Goor, Daniel, 556
Gossner, B., 291, 349
Gottlieb, Sheldon H., 538, 554
publications, 555
Goudriaan, F., 273, 353
Grady, Leo J., 57, 82, 374, 482, 488
studies, 397-400
Graham, J. R., 594, 595
Green, D. H., 241, 245, 346, 349
Green, H., 542, 543, 545, 554
publications, 555
Greenewalt, Crawford H., v, vi, 673, 691
Greenstein, Jesse L., vii, 8, 41, 94, 97, 104, 113,
114, 116, 117, 119, 120, 136, 160
publications, 156, 157
Greenwood, H. J., 288, 349
Greig, J. W, 221, 340, 347, 349
Grevesse, N., 157
Griffin, R. F., 124
Griffin, W. L., 437, 438, 483
Grimaldi, F. S., 269, 354
Gr0nvold, F., 261, 350
Gruenwald, Peter, 556
Gunn, D. W., 334, 354
Gupta, I., 465, 466, 484
Gurdon, J. B., 19
Gurney, J. J., 434, 483
Gutenberg, B., 466, 484
Giiven, Necip, 78, 282
Guzman, Jaime, 82, 488
Haapala, Daniel, 488
Haas, M., 482
Habermehl, G., 342
Hadidiacos, C. G., 345
Hafner, S., 356
Hageman, R. H., 633
Haggerty, Stephen E., 45, 50, 78, 81, 171, 172,
247, 248, 249, 333, 346, 350, 355, 356
studies, 329-330, 330-332, 332-336
Hahn-Weinheimer, P., 437, 438, 439, 483
Hales, Anton L., 488
Hall, Donn M., 161
Hall, Harvey M., 621, 633, 643
Hall, H. T., 259, 260, 261, 264, 350, 355
Hall, J. S., 486, 493
Halla, F., 270, 349
Hallberg, R. L., 513, 514
Hamilton, W. C, 283, 285, 291, 350
Hansen, Edward C, 78, 81, 356
Hansen, M., 256, 350
Haraburda, Joseph M. S., ix
Haraldsen, H., 261, 264, 350
708
CARNEGIE INSTITUTION
Harbert, G. M., 552, 556
publications, 555
studies, 551-552
Hardorp, J., 117, 118, 157
Hare, P. Edgar, vii, 50, 51, 343, 355
studies, 297-303
Harris, Henry, 18, 543
Harris, J. W., 316, 328
Harris, P. G., 188, 190, 346, 349
Harrison, C. G. A., 332, 350
Harrison, Ross, 504
Hart, Pembroke J., 488
Hart, R. W., 573
studies, 607-608
Hart, Stanley R., vii, 52, 53, 54, 55, 315, 320,
345, 350, 403, 424, 442, 483, 484, 487
publications, 486
studies, 307-308, 313-315, 403-408, 408-410,
413-417, 417-420, 420-422, 422^25, 425^26,
426-429, 429-433
Hartt, C. E., 633
Hartwick, F. D. A., 157
Hartzell, H. Criss, Jr., 505, 556
studies, 531-534
Harvey, John W., 110
Harwood, H. F., 214, 354
Haselkorn, R., 394, 482
Haskins, Caryl P., v, vi, ix, 691
publications, 669
Report of the President, 1-94
Hastings, J. M., 282
Hatch, M. D., 72, 620, 621, 622, 623, 633
Haug, P. A., 304, 350
Hay, John, xi, 693, 694, 695
Hay, Robert J., 504, 555
studies, 518-531
Hays, J. D., 215, 352
Hazard, C, 135
Heber, Ulrich, 80, 585
publications, 646
Hedge, C. E., 427, 483
Heezen, B. C, 335, 349
Heintze, J. R. W., 157
Helden, R. van, 149
Hellner, E., 287, 349
Henard, Kenneth R., ix
Henderson, J. R., 350
Henderson, Marjorie A., 161
Hendricks, Sterling B., 281
Henry, Barklie McKee, xi
Henry, N. F. M., 231, 350
Henry, R. C, 118
Herrick, Myron T., xi
Herrin, E., 455, 484
Hershey, Alfred D., viii, 63, 64, 93, 664, 667, 668
report of the Director, 651-668
Hertig, Arthur T., 555
Hess, H. H., 229, 350
Hewish, Anthony, 8, 40
Hewitt, Abram S., xi
Hey, Max H, 289, 293, 345, 349
Hicks, Virginia, 542
Hiesey, William M., viii, 92, 93, 561, 562, 644,
647, 648
studies, 609-614, 614-620
Higginson, Henry L., xi, 693, 694
Hijikata, K., 215, 350
Hilgeman, Theodore, 123, 161
Hilgenberg, W., 640
Hill, R., 607
Hiltner, W. A., 157
Himeno, M., 510
Hindman, J. V., 369, 482
Hirota, Y., 482
Hitchcock, Ethan A., xi, 693, 694
Hitchcock, Henry, xi
Hodari, Alberto, 556
Hodgkinson, Paul, 556
Hoering, Thomas C., vii, 52, 171, 343, 355
studies, 303-307
Hoffmaster, Robert, 489
Holdgate, M. W., 188, 190, 349
Holm, U., 482
Holmberg, E. B., 134
Holmgren, K. Paul, 563, 640
Holzer, Mary, 648
Honea, R. M., 354
Hooper, Peter, 129
Hoover, Herbert, xi
Hornblower, Marshall, ix
Hornung, G., 317, 352
Howard, Robert F., vii, 105, 106, 107, 110, 144,
160
publications, 157
Howe, William Wirt, xi, 693, 694
Howie, R. A., 188, 348
Hoyer, Bill H., vii, 57, 374, 401, 487
Hsu, Joseph P., 161
Hubble, Edwin, 8, 9, 10
Huberman, Joel, 531, 554
Huckenholz, Hans, G., 78
publication, 345
Hudson, Hugh, 111, 141
Hughes, E. E., 128
Hulbe, C. W., 276, 353
Humphreys, Tom, 554
Hurley, P. M., 44, 307, 350, 427, 428, 483
Hutchinson, Charles L., xi, 693, 694
Hybl, Albert, 342
Hyland, Ardon R., 123, 124, 161
Hytonen, Kai, 222, 224, 225, 234, 440
Iben, Icko, 125
Idzinga, Fred, 161
Ingamells, CO., 290
Ingham, William, 111
Ingraham, Laura J., 668
Ingram, B., 352
Irvine, T. N., 318, 350
Ishibashi, M., 482
Ishizaka, Kyoichi, 79, 82, 488
Ito, T., 283, 284, 285, 350
Jackson, E. D., 319, 342
Jacob, Francois, 656, 663
INDEX
709
Jahns, R. H., 341, 351
James, David E., vii, 52, 79, 82, 403, 455, 487,
488
publication, 486
studies, 462-471
James, O.B., 336, 350, 356
Jamieson, J. C, 350
Jardetzky, W., 484
Jarosewich, E., 188, 352
Jeffes, J. H. E., 277, 353
Jeffreys, H., 466, 484
Jensen, R. G., 574, 578
Jessup, Walter A., xi
Jewett, Frank B., xi
Jirasek, J. E., 552, 556
Joensuu, D., 346
Johansson, K., 288, 350
Johnson, H. L., 114
Johnson, H. S., 621, 622, 633
Johnson, Hugh M., 146
Johnson, Melvin W., 161
Johnson, Paul A., 489
Johnson, Torrence V., 147, 161
Johnston, W. G. Q., 313, 350
Joliffe, P. A., 618, 620
Joliot, A., 578, 593, 595
Joliot, P., 574, 578
Jones, L. W., 597, 598
Jordan, E., 505
Joy, Alfred H., 161
Julian, William H., 41, 142, 161
publication, 157
Junge, W., 594, 595, 598, 605, 607
Kalb, Jon E, 78, 81, 356
Kaltreider, D. F, 555
Kapoor, B.M.,640, 643
Karle, Isabella L., 342
Karle, Louise I., 342
Kasinsky, Harold, 80, 83, 505, 556
studies, 513-514
Katem, Basil N., 161
publication, 157
Katsura, T., 229, 248, 346
Katz, L., 332, 350
Katz, Margaret, 161
Kausel, Edgar, 52, 403, 488
Ke, B., 578
Keen, M.J, 332, 350
Keenan, Philip C, 117, 121, 146, 157
Keil, K., 319, 347
Kelly, J, 574, 578
Kendall, M. G., 185, 350
Kennedy, G. C., 319, 340, 350
Kennedy, Helen, 587, 648
Kerr, M. H, 188, 325
Khalifa, M. M., 636
Kharkar, D. P., 404, 482
Kieffer, Hugh H., 161
King, K, 356
Kingston, G. A., 331, 350
Kisaki, T., 633
Klapdor, H. XL, 482
Klein, C, Jr., 288, 350
Klein, G, 18
Kleinman, D, 123
Klose, J. Z., 482
Knopoff, L, 469, 484
Knorring, O. von, 219, 317, 318, 325, 352
Knott, C. G, 466, 484
Kodaira, Keiichi, 117, 118, 119, 120, 161
publication, 157
Kohne, David E, vii, 57, 61, 374, 386, 487, 662,
663
publications, 486
studies, 388-391
Kok, B., 574, 578, 598, 603
Konigsberg, Irwin, x, 555
Konnert, J., 342
Kopecky, M, 157
Kortschak, H. P, 620, 633
Kouchkovsky, Yaroslav de, 593, 595, 648
studies, 587-595
Kowal, Charles T, 135, 136, 161
publications, 157
Kowalik, Jan, 94, 645, 648
Kozlovsky, Ben-Zion, 161
publication, 157
Kracek, F. C., 276, 281, 350
Kraft, Robert P, 116, 150, 157
Kristian, Jerome, vii, 9, 40, 77, 81, 103, 132, 137,
139, 140, 141, 149, 154, 160
publications, 157
Krogh, Thomas E., vii, 53, 54, 55, 173, 307,
315, 343, 350, 355, 403
publication, 486
studies, 307-308, 308-309, 309-313, 313-315,
408-410, 420-422, 422-425, 425^26, 429-433
Kruchinina, G. I., 270, 349
Krzeminski, Wojciech, 77
Ksanda, C. J., 280
Kuhn, T. S, 23
Kuklin, G. V, 157
Kullerud, Gunnar, vii, 48, 49, 173, 261, 263,
264, 265, 267, 269, 272, 278, 329, 343, 348, 350,
351, 355
publications, 345
studies, 256-259, 270-273, 273-276, 276, 277-
278
Kunieda, R., 572
Kuno, H., 231, 245, 351
Kushiro, Ikuo, 47, 48, 55, 78, 81, 171, 172, 199,
200, 202, 210, 218, 219, 224, 225, 235, 236,
242, 246, 247, 317, 318, 327, 333, 344, 346, 351,
355, 356, 441, 443, 484
publications, 345
studies, 222-226, 226-229, 231-233, 233-236,
240-245, 245-247, 439-442, 443
Kutina, J, 356
Kuznetsova, I. K, 219, 319, 354
LaBerge, G. L., 334, 351
Lackner, Dora R., 157
LaCroix, A., 188, 351
Lambert, David L., 107,
publications, 157
108, 118, 122, 161
710
CARNEGIE INSTITUTION
Lambert, I. B., 245, 247, 351
Lambiotte, Maurice, 556
Landisman, M., 484
Lane, M. D., 633
Langley, Samuel P., xi, 693, 694
Larkam, C. W., 449, 484
Larsen, C. Syrach, 644
Larson, E. E., 354
Laubert, Roman, 488
Lausen, C, 245, 351
Lavorel, J., 588, 595
Lawrence, Ernest 0., xi
Lawrence, Mark C, 573, 575, 578, 581, 587
Lazo, Eduardo, 488
Leckie, Wilfred H., 161
Lees, W. R., 356
Leggo, M., 410, 483
Leigh ton, Robert B., vii, 97, 127, 160
publication, 157
LeMaitre, R. W., 346
Lengyel, Peter, 657
Lentz, Thomas, 554
Lepp, H., 333, 351
Lewis, G. K, Jr., 254, 349
Li, C. T., 351
Linck, G., 339, 340, 351
Lindberg, M. L., 331, 351
Lindbergh, Charles A., xi
Linde, Alan T., 52, 82, 403, 488
Lindegren, Carl, 657
Lindemann, W., 288, 351
Lindsay, William, xi, 693, 694
Lindsley, Donald H, vii, 45, 172, 229, 231,
247, 333, 344, 351, 355
publications, 345
Lippincott, E. R., 255, 351, 355
Lipscomb, W. N., 332
Little, Charles A., 489
Litvin, F. F., 603, 606, 607
Locanthi, Dorothy D., 117, 161
Lodge, Henry Cabot, xi
Loomis, Alfred L., v, vi
Loos, E. E., 74, 80, 84, 564, 648
studies, 574-578
Lorenz, Ernest O., 161
Love, L. G., 334, 351
Love, Warner E., 342
Lovett, Robert A., v, 691
Low, F., 123
Low, Seth, xi, 693, 694
Lowe, Elias A., 92
Lowen, A. Louise, 161
Lowrance, John, 152
Luciano, Richard, 161
Ludlow, C. J, 574, 578
Luftig, R., 394, 482
Lukens, Lewis N., 505, 543, 556
studies, 542-546
Luria, Salvator, 93
Luth, W. C, 341, 351
Luyten, Willem J., 104, 141, 146, 147, 157
Lynden-Bell, D., 105, 114, 131, 132
Lynds, C. R., 103, 137, 141
Lynn, D. C, 335, 351
Macdonald, G. A., 191, 351
MacDonald, R., 194, 195, 346
MacFarlane, M., 157
MacGregor, I. D., 200, 229, 318, 351, 439, 483
MacKenzie, W. S., 194, 348, 354
MacVeagh, Wayne, xi, 693, 694
Magness, K. A., 534
Majumdar, A. J., 276, 353
Makover, Shraga, 79, 83, 668
Malkin, S., 397, 398
Mallia, E. A., 108, 157
Manasek, Francis J., 505, 535, 536, 541, 556
publications, 555
studies, 534-540, 540-542
Mangan, J., 482
Mann, J. B., 285, 348
Mansuri, Q. A., 351
Mantai, K. E., 74, 84, 565, 570, 596, 597, 598,
599, 602, 603, 647, 648
studies, 595-598, 598-603
Manwell, Tom, 157
Mao, Ho Kwang, 48, 81, 170, 173, 250, 251, 252
351, 354, 356
studies, 221-222, 249-251, 251-253, 253-256
Marcovich, H., 398, 482
Margulies, S. I., 505, 556
studies, 548-551
Marmur, J., 482, 664
Marshak, Alfred, 488
Martin, C. B., Jr., 556
publications, 555
studies, 548-551
Martin, George, 546
Martin, R., 339, 340, 352
Martin, William McC, Jr., v, vi
Martinelli, Gregory S., 648
Marton, L. L., 486, 493
Marushige, K., 554
Mason, B., 231, 320, 352, 442, 484
Mathias, M., 439, 483
Matson, Dennis L., 161
Matsuii, Y., 318, 346
Mayer, W., 139, 157
Mayne, B. C, 606, 607
McCallum, M., 482
McCarthy, Brian J., 398, 482
McCarthy, Martin F., 489
McClintock, Barbara, viii, 62, 668
McClure, Robert D., 41, 122, 134, 142, 157
McCord, T. B., 147
McGee, J. D., x
McGough, Sheila A., ix
McHugh, Keith S., v, vi, 691
Mclntyre, G. A., 423, 483
McKenzie, David, 111
McLaughlin, W. A., 346
McMahon, B. E., 354
McNamara, D. H., 147
Medaris, L. G., Jr., 230, 352
Meenakshi, V. R., 356
INDEX
711
Mellon, Andrew W., xi
Melson, W. G., 188, 245, 352, 404
Menard, H. W., 187, 200, 352
Mendiguren, Jorge, 52, 403, 489
Mercy, E. L. P., 215, 218, 219, 317, 318, 319,
352
Mero, J. L., 334, 352
Merriam, John C, 643
Meyer, Henry O. A., 50, 78, 82, 169, 172, 219,
254, 319, 320, 321, 322, 328, 339, 344, 352,
356
studies, 315-320
Meyer, Robert P., 489
Michel, Jean-Marie, 80, 566, 572, 573, 574, 578,
587
publications, 645, 646
Michel-Wolwertz, Marie-Rose, 80, 566, 570,
572, 578
publications, 645, 646
Miers, R. E., 482
Mihalas, Dimitri M., 118
Mika, Peter G., 648
Miller, Margaret Carnegie, xi
Miller, O. J., 18
Miller, O. L., Jr., 68, 502
Miller, Roswell, xi
Miller, William C., 125, 154, 161
Mills, Darius O., xi, 693, 694
Milton, C, 289, 352
Minkowski, Rudolf, 9, 40, 103, 136, 137
Misenhimer, Harold R., 80, 83, 505, 556
publications, 555
studies, 548-551, 551-552
Mitchell, S. Weir, xi, 693, 694, 695
Mitchell, Walter E., Jr., 147
Mitterer, Richard M., 78
Mizutani, H., 254, 349
Modell, D. I., 283, 284, 285, 354
Moh, G., 264, 356
Monod, Jacques, 656, 663
Montague, Andrew J., xi
Mooney, Harold, 644
Moore, P. B., 347
Morgan, Henry S., v, vi, 673, 691
Morgan, T. H., 63
Morimoto, N., 267, 282, 283, 284, 285, 350
Morris, M. E., 392, 395, 482
Morrow, William W., xi, 693, 694
Morse, Anthony, 489
Morse, S. A., 78, 82, 356
Moss, A. A., 339, 340, 341, 349
Moser, H., 622, 633
Moxham, R. L., 483
Mrose, M. E., 352
Mudd, J. A., 482
Mudd, Seeley G., xi
Mukai, F., 482
Muir, I. D., 190, 191, 192, 193, 352, 354
Muller, Hermann, 20, 574, 578
Munch, Guido, vii, 111, 112, 127, 153, 160
publication, 157
Munoz, James L., 78, 231, 341, 351
publication, 345
Murata, Norio, 84, 645, 648
studies, 607-608
Murata, Teruyo, 648
Murray, Bruce C., Ill, 161
Murray, C. A., 126
Murthy, V. Rama, 437, 438, 483
Musselman, Arlyne, 531
Myers, A. T., 317, 318, 353
Myers, J., 594, 595
Myers, William I., v, vi, 691
Nagata, T., 248, 346
Naldrett, Anthony J., 78
publication, 345
Nalwalk, A. J., 53, 404, 405, 489
Naranan, S., 157
Nather, R. E., 139, 157
Naylor, M. D. T., 157
Nayudu, Y., 334, 347
Neal, Clare, 106, 161
Neufville, John de, 202, 215, 222, 223, 224, 225
Neugebauer, Gerry, 41, 111, 113, 122, 123, 127,
128, 139, 140, 141, 161
publications, 158
Newell, E. B., 127, 158
Nicholls, G. D., 245
Nicholls, J., 345, 352
Nicholson, Frank, 648
Nicklas, Bruce, 554
Nicolaysen, L. O., 437, 438, 439, 445, 483, 484
Nishikawa, M., 240, 245, 345, 351
Nishikawa, Shoji, 279
Nishizuka, Y., 554
Nissen, H. XL, 296
Nixon, P. H., 172, 218, 219, 317, 318, 324, 325,
352
Nobs, Malcolm, A., viii, 72, 561, 563, 644, 647,
648
studies, 609-614, 614-620, 620-633, 640-643
Nordlie, B. E., 319, 350
Norton, Garrison, v, vi, 691
Nose, J, 258, 348
Noyes, A. A., 280
Nuttli, O., 466, 484
Obata, F., 578
Oblitas, Jose, 489
O'Brien, Peter N. S., 79
Ochoa, Daniel, 489
O'Connell, Robert W., 161
Oeser, A., 624, 633
Ogawa, T., 574, 578
Ogelman, H., 158
O'Hara, M. J., 202, 206, 213, 215, 218, 219, 244,
317, 318, 319, 324, 347, 352, 438, 443, 483
Ohtake, M., 476, 484
Oinas, Valdar, 161
publication, 158
Okamoto, K., 482
Okayama, S., 120, 603
Oke, J. B., vii, 41, 97, 117, 119, 122, 124, 133,
135, 139, 140, 141, 160
publications, 158
712
CARNEGIE INSTITUTION
Olea, Ricardo, 489
Olinger, B., 350
Oliver, J., 462, 484
Olsen, Edward T., 141, 319, 347
Olsiewski, Martin J., 161
O'Neil, Frederick G., 161
Onuma, K., 197, 355
Oort, Jan H., x, 114
Opdyke, N., 332, 335, 352
O'Rahilly, Ronan, 71, SO, 83, 401, 554, 556
publications, 555
studies, 552
Orrall, F. Q., 108
Osawa, A., 271, 352
Osborn, E. F., 203, 222, 348, 352
Osborn, William Church, xi
Osmer, Patrick S., 161
publication, 158
Osmond, C. B, 624, 633
Owens, 0. von H., 578
Oxburgh, E. R., 320, 352, 442, 484
Ozato, Kenjiro, 84, 556
Padan, E., 395, 482
Padget, Dorcas H., 556
Padlan, Eduardo A., 342
Paes de Carvalho, A., 554
Pagel, B.E.J., 158
Pankey, T., 335, 352
Papanastassiou, D. A., 426, 483
Papike, J. J., 234, 235, 288, 292, 347, 348, 438,
440, 441, 483, 484
Park, R.B., 574, 578,601,603
Parks, C. F., 329, 352
Parma, David H., 83, 668
Parmelee, James, xi
Parsons, William Barclay, xi
Paton, Stewart, xi
Patterson, C. C, 483
Pauling, Linus, 173, 279, 281, 293, 352
Pavich, Milan, 59, 60, 400
studies, 400-402
Pawson, David L., 282
studies, 296-297
Peach, John Vincent, 77, 158
Peacock, W. J., 281
Pederson, James D., 161
Pennoyer, Robert M., v, vi, 691
Pepper, George W., xi
Periman, Phillip, 545
studies, 542-546
Perkins, Richard S., v, vi, 673, 691
Pershing, John J., xi
Persson, Sven E., 161
Peterson, B. A., 141
Peterson, Deane M., 81, 120, 121, 161
Peterson, M. N. A., 332, 350
Petitjean, Claude, 79, 83, 364, 482, 488
publications, 486
studies, 370-373
Phemister, T. C, 307, 352
Phillipi, G. T., 303, 352
Philpotts, A. R., 330, 353
Pickett, James M., 80
Pilcher, Carl, 147
Pirie, N. W., 11, 12
Piatt, R. G., 356
Poe, Glenn R., 489
Pogoriler, G. B., 556
Polinger, Iris S., 505, 535, 536, 556
studies, 534-540
Pollard, E. C, 482
Pollock, Harry E. D., x
Pomerantz, M. A., 446, 486
Poort, S. R., 578
Poppel, Wolfgang, 370
Porturas, Fernando, 556
Posnjak, Eugene, 280, 281, 334, 354
Potter, Michael, 545
Powell, H. E., 334, 353
Pozo, Salvador del, 52, 403, 488
Prager, Lillian K., 59, 489, 585, 587, 648
publications, 645, 646
studies, 391-397
Prentis, Henning W., Jr., xi
Press, F., 468, 484
Preston, George W., Ill, vii, 104, 119, 160
publications, 158
Preston, Gerald, 161
Preston, H., 293, 248
studies, 288-290
Prewitt, C. T., 289, 295, 347, 354
Prider, R. T., 231, 234, 323, 324, 354, 440, 443,
484
Pritchett, Henry S., xi
Proskouriakoff, Tatiana, ix
Puchelt, Harold R, 78, 82, 356
Purgathofer, Alois Th., 489
publications, 486
Quirke, T. T., 307, 311, 353
Rabbitt, J. C, 353
Racine, Rene, 41, 77, 81, 115, 122, 129, 135,
142, 153, 161
publications, 158
Radoslavich, E. W., 282
Rake, Adrian V., 79, 82, 403, 488
Ramdohr, P., 334, 353
Ramlal, K, 483
Ramsey, Elizabeth M., viii, 94, 505, 549
publications, 555
studies, 548-551, 551-552, 552
Rand, J. R, 44
Raphael, John D., 161
Rapp, G. R., Jr., 173, 356
studies, 290-292
Rappaport, S., 139, 158
Raup, D. M., 296, 353
Raven, Peter, 644
Ray, Peter, 644
Reed, Nancy J., 57, 374, 401, 48S
studies, 386-388
INDEX
713
Rebbert, Martha
studies, 505-509, 514-515
Rechtsteiner, M. C., 556
Reeder, Ronald H., viii, 67, 68, 80, 84, 501,
502, 503, 504, 554, 556
publications, 555
studies, 505-509
Rees, M. J., 158
Rehnborg, Edward H., 161
Reid, Harry Fielding, 363, 561
Reilly, H. C, 482
Reinders, W., 273, 353
Rentschler, Gordon S., xi
Reynolds, Samuel R. M., 55
Ribbens, Rudolf E., 161
Richards, A. F., 190, 353
Richardson, F. D., 277, 353
Richardson, Stephen W., 78, 231, 277, 341, 353
publications, 345
Richter, H. D., 267, 268, 269, 349
Rickard, James J., 127, 153, 161
Rickwood, P. C, 439, 483
Riley, Malcolm S, 116, 161
Rinehart, Carl M., 489
Ringwood, A. E., 220, 247, 318, 320, 348, 353,
442, 484
Ristow, H.,
publications, 555
Ritz, Edward W., 161
Roberts, H. S., 353
Roberts, Richard B., vii, 57, 375, 487
publications, 486
Robie, R. A., 265, 353
Rockefeller, David, xi
Rodgers, A. W., 127, 158
Rodriguez, Anibal, 52, 403, 460, 489
Roedder, E., 236, 239, 353
Rogers, D. P., 329, 353
Romano, R., 194, 353
Rooke, J. M., 219, 317, 318, 325, 352
Root, Elihu, xi, 695
Root, Elihu, Jr., xi, 693, 694
Rooymans, C, 277, 353
Rosenberg, J. T., 339, 346
Rosenquist, Glenn C, 556
Rosenqvist, T., 271, 277, 353
Rosenwald, Julius, xi
Ross, C. S., 317, 318, 353
Ross, Harrison, 69
Ross, M., 288
Roth, William M., v, vi, 691
Roy, R., 276, 340, 346, 353
Roy, S., 334, 353
Rubey, William W, v, 691
Rubin, A. B., 604, 607
Rubin, Vera C, vii, 487
publications, 486
studies, 364-366
Rudnicki, Konrad, 158
Rule, Bruce H., vii, 42, 152, 153, 155, 160
Rurainski, H. J., 578
Rust, David Maurice, 77
Ryan, F. J., 482
Ryerson, Martin A., xi
Ryle, M., 140
Saa, German, 52, 55, 79, 83, 403, 455, 462, 488
publications, 486
studies, 452-459
Sachs, Howard G., 161
Sacks, I. Selwyn, vii, 52, 55, 363, 403, 455, 462,
476, 485, 487
publications, 486
studies, 448-452
Safferman, Robert S., 391, 395, 482, 489
Salgueiro, Reynaldo, x, 52, 403, 488
Sandage, Allan R., vii, 39, 40, 104, 105, 114,
115, 125, 126, 128, 129, 130, 131, 132, 140,
141, 149, 160
publications, 158
Sandoval, H. K., 482
Sanduleak, N., 159
Santa Cruz, Jaime, 52, 403, 489
Sargent, Anneila I., 120, 161
Sargent, Wallace L. W., vii, 120, 130, 132, 133,
134, 135, 160
publications, 159
Sato, Gordan, 554
Sato, M., 249, 353
Sauer, K., 574, 578
Saxen, Lauri, 554
Scargle, Jeffrey D., 147, 159
Schaefer, E. W., 538, 556
studies, 534-540
Schairer, J. Frank, vii, 172, 194, 203, 204, 210,
212, 213, 214, 215, 223, 224, 225, 229, 231,
234, 327, 340, 344, 346, 347, 348, 353, 354,
355, 440
studies, 202-214, 221-222, 222-226
Schaub, H., 637, 640
Schiff, J. A., 482
Schild, Rudolf E., 122, 124, 161
publications, 159
Schmidt, Karl-Heinz, 143, 159
Schmidt, Maarten, vii, 8, 140, 141, 145, 161, 365
publications, 159
Schmitt, John, 41, 142, 159
Schneider, I. R., 395, 482
Scholz, Michael, 117, 118, 121, 161
publications, 159
Schreyer, W., 345, 486
Schwartz, Merry C, 505, 556
publications, 555
studies, 510-513
Scoon, J. H., 191
Scott, William H., 78, 82, 356
Seaman, E., 482
Searle, Leonard T., 127, 132, 134, 160
publications, 159
Seemann, Michael, 489
Segnit, E. R., 202, 354
Seifert, Friedrich, 346, 356
Senftle, F., 335, 352
Sestak, Zdenak, 564, 574, 648
studies, 572-574
714
CARNEGIE INSTITUTION
Seyler, Richard G., 370, 371, 482, 489
publications, 486
Shannon, R. D., 289, 295, 354
Shand, S. J., 194, 354
Shankland, T. J., 255, 354
Shaw, E. R., 578
Shepley, Henry R., xi
Shibata, K, 578
Shilo, M., 482
Shima, H., 264, 354
Shinya3^ev, A., 356
Shiokawa, K., 68, 503
Shleser, Robert, 489
Shoemaker, E. M., 336, 354
Shuvalov, V. A., 603, 606, 607
Sibata, N., 271, 352, 354
Sidman, Richard, 554
Siebert, J. C, 439, 483
Silsburv, James H., 81
Silva, P. C, 396, 482
Simon, Michal, 107, 143, 161
publications, 159
Simoni, Diglio V., 52, 403, 489
Sinclair, John, 80, 522
Sitter-Koomans, C. de, 339, 340, 352
Sivaraman, K. R., 157
Skalka, Anna Marie, 65, 79, 83, 664, 665, 666,
667, 668
Skinner, B. J., 269, 276, 354
Slack, C. R., 620, 633
Smith, B.
studies, 518-531
Smith, Benny W., 162
Smith, Douglas, 82, 172, 344, 356
studies, 229-231
Smith, Gilbert M., 391, 392, 396, 482
Smith, G. S., 291, 346
Smith, James H. C, viii, 648
Smith, Jean F., 58, 59, 60, 489
studies, 378-386, 400-402
Smith, J. V., 282, 347
Smith, R. E., 432, 483
Smith, Sara F., 106
Smith, Theobald, xi
Snellen, Grant H., 9, 40, 103, 137, 139, 140,
154, 159
Snider, A., 43
Sollins, Jeff, 556
Somerville, D.
studies, 518-531
Spinrad, Hyron, 121, 125, 159
Spoehr, Herman A., 643
Spooner, John C, xi, 693, 694
Sobolev, N. V., Jr., 219, 319, 354
Sonneborn, T. M., 659
Sorem, R. K., 334, 354
Sosman, R. B., 280
Stalsberg, Helge, 80, 554
publications, 555
Stanton, Frank, v, vi, 691
Starr, R. C., 482
Steere, Russell L., 395, 482, 489
Steiger, R. H., 346, 486
Steiner, Erich, 83, 488
Steinhart, John S., vii, 52, 403, 487
publications, 486
Stenflo, Jan O., 107, 144, 148, 159
Stephenson, C. B., 159
Stepien, Kazimierz, 118, 119, 159
Stern, R., 556
Stewart, J. M., 293, 348
Stiles, Robert G., 162
Stoeckly, Robert, 159
Stokes, R. N., 40, 105, 131
Stook, P. W., 250, 251, 347
Storch, Thomas G., 556
Storey, William Benson, xi
Strangway, D. W., 334, 354
Straus, Neil A., 489
Strelow, F. W. E., 445, 484
Strittmatter, Peter, 118
Strober, S., 544
Strom, S. E., 120, 148
Strong, Richard P., xi
Strunz, H., 291, 349
Stueber, Alan M., 79, 486
Subbaiah, T. V., 482
Sugaki, A., 264, 354
Sutherland, L. J., 188
Suyehiro, Shigeji, x, 52, 403, 476, 484, 485, 488
studies, 471-475, 475-482
Suzuki, Yoshiaki, 84 505, 556
studies, 509-510
Swanson, Paula, 106, 161
Swanson, Ronald F., 69, 503, 504, 514, 556
studies, 515-517
Sweers, H. E., 592, 595, 597, 598
Swift, I. H., 252, 354
Swings, J. P., 159
Swinton, D., 482
Switzer, George, 316
Swope, Henrietta H., 161
Syono, Y., 218, 219, 235, 245, 246, 247, 351, 441,
484
Szafranski, P., 482
Tachibana, T., 18
Taft, Charles P., v, vi, 691
Taft, William H., xi
Taggart, J., 455, 484
Takahashi, I., 65, 667
Takahashi, T., 170, 250, 251, 252, 347, 351, 354
studies, 249-251, 251-253
Takamiya, A., 572
Takeuchi, Y., 271, 354
Takeya, K, 482
Tamayo, Lupe, 52, 403, 489
Tammann, G. A., 115, 129, 149, 159
Tandberg-Hanssen, E., 108
Tandler, B., 482
Tannenbaum, Andrew S., 106
Tarmy, E., 482
Tarrare, Irena, 159
Tartar, Vance, 64, 659, 660, 661
INDEX
715
Taylor, Benjamin J., 40, 103, 121, 125, 137, 159
Taylor, Lawrence A., 82, 173, 261, 263, 354, 356
studies, 259-269, 273-276
Terzan, Agop, 149, 159
Thackeray, A. D., 122
Thayer, William S., xi
Thomas, C. A., Jr., 662, 665
Thomas, J. B., 578
Thomas, Pamela W., ix
Thomas, R. N., 108
Thomason, Carole E., 668
Thompson, A. Gerald, ix
Thompson, David, 162
Thompson, G., 352
Thompson, R. N., 194, 354
Thompson, William, 162
Thornber, J. Phillip, 581, 582, 583, 584, 585, 586,
587
Tilajef, Eli A., 162
Till, J. E., 554
Tilley, C. E., 190, 191, 192, 193, 194, 202, 204,
213, 214, 245, 352, 354, 355
Tilton, G. R., 486
publications, 346
Tokes, L. G., 304, 354
Tolbert, N. E., 624, 633
Tolstoy, I., 462, 464, 484
Tooms, J. S., 348
Towe, K. N., 296, 354
Townes, Charles H., v, 10, 691
Trachslin, W., 482, 486
Tregunna, E. B., 618, 620, 624, 633
Treharne, K. J., 636
Trimble, Virginia, 159
Trippe, Juan T., v, vi, 691
Troll, G., 486
Truitt, Roberta M., 556
Tsuji, Takashi, 114, 121, 161
publication, 159
Tuft, Peter, 80
Tunell, George, 278, 281, 283, 334, 354
Turek, A., 483
Turekian, K. K., 404, 482
Turner, Kenneth C., vii, 364, 365, 487
publications, 487
studies, 366, 366-368, 368-369
Turnock, A. C, 356
Tuttle, O.F., 341,351
Tuve, Merle A., vii, 52, 364, 365, 366, 403, 483,
487
publications, 487
studies, 366
Tyndall, E. T. P., 252, 354
Usdin, E., 462, 464, 484
Utter, Merwyn G., 105, 161
Uyeda, S., 254, 349
Van der Horst, O. J., 578
Van Schmus, W. R., 307, 354
Van Valkenburg, A., 255, 355
Varsavsky, Carlos M., 364, 489
publications, 487
studies, 366, 369-370
Vaughan, Arthur H., Jr., vii, 127, 134, 152, 161
Vaughan, Virgal Z., 162
Vaughn, J. L., 510
Veblen, D., 356
Veeder, Glen, 110
Velde, Neltje W. van de, 174, 401, 489
Venediktov, P. S., 604, 607
Verhoogen, J., 199, 354
Vernon, L. P., 574, 578
Vess, Grace D., 161
Vidaver, W., 574, 578
Vieira, Edemundo da Rocha, 370
Villiers, J. W. L. de, 445, 484
Visvanathan, Natarajan, 77, 81, 103, 135, 139,
149, 150, 161
publication, 159
Voll, G., 487
Volponi, Fernando, 52, 403, 489
Vredenberg, W. J., 594, 595
Wade, A., 231, 234, 323, 324, 354, 440, 443, 484
Wade, C. M., 141
Wadsworth, James W., xi
Wager, L. R, 187, 354
Walburn, Marjorie H., ix
Walcott, Charles D., xi, 693, 694, 695
Walcott, Frederic C, xi
Walcott, Henry P., xi
Waldbaum, D. R., 265, 288, 350, 353
Walker, P. M., 393, 482
Wallerstein, George, 123, 150, 159
Wampler, E. J., 141
Wareing, P. F., 634, 636
Warner, B., 159
Warren, B. E., 283, 284, 285, 354
Washington, H. S., 194, 195, 354
Wasserburg, G. J., 483
Watkins, N. D., 249, 332, 333, 354, 355
Watson, James D., 4, 661
Weart, Spencer R., 108, 109, 110, 161
publications, 159
Weaver, J. S., 351
Weed, Lewis H., xi
Wegener, A., 43
Wehmiller, J. F., 356
Weir, C. E, 255, 355
Weisbach, A., 398
Weisberg, Robert A., 668
Weiss, Charles, 608
Weiss, Mary C, 80, 505, 546, 554
Weiss, Paul A., 554
Weiss, R., 418
Weistrop, Donna E., 161
Welch, William H., xi
Wensink, Pieter C, 67, 502, 505, 556
studies, 505-509
West, J., 607
716
CARNEGIE INSTITUTION
139, 140, 161
Westphal, James A., 9, 40, 103, 111, 112, 137,
publications, 159, 160
Westphal, 0., 530
Wetherill, G. W., 307, 354
Wetmur, J. G., 384, 385, 482
Whatley, L. S., 255, 351
Wheeler, E. P., II, 231, 355
White, Andrew D., xi, 693, 694
White, Edward D., xi
White, Henry, xi
White, James N., v, vi, 691
White, R. W., 245, 355
Whitehouse, H. L. K, 482
Whittaker, E. J. W., 283, 288, 355
Wickersham, George W., xi
Wier, Anthony, 129
Wiik, H. B., 191, 195, 199
Wilcox, John M., 106, 160
Wildey, Robert L., Ill
Williams, A. F., 323, 355, 436, 443, 483
Williams, Isabelle
studies, 542-546
Williams, K. L.
studies, 270-273
Williams, Madeline B., 162
Wilson, H. D. B., 429, 430, 483
Wilson, J. T., 190
Wilson, Olin C., vii, 97, 116, 121, 146, 161
publications, 160
Wilson, R. L., 248, 355
Wilson, Ralph W., 162
Wilson, Robert E., xi
Wing, Robert F., 489
Winston, R., 316
Wishnick, Marcia, 633
Witt, H. T., 578, 594, 595, 598, 605, 607
Wolf, R. A., 108
Wolff, Sidney Carne, 118, 160
Wolstenholme, David R., 554
publications, 555
Wood, Stephen G., 648
Woodward, Robert S., xi, 279
Woodworth. Felice, 162
Wones, D. R., 346
Worst, P., 18
WTraight, Colin, 84, 648
studies, 607-608
Wright, Carroll D, xi, 693, 694, 695
Wright, Sewall, 656
Wright, T. L., 249, 353
Wyckoff, Ralph W. G., 278, 279, 280, 281
Wyllie, P. J., 245, 247, 351
Yagi, K., 197, 215, 350, 355
Yaldwyn, J. C, 187
Yamagishi, Hideo, 65, 79, 83, 664, 665, 667, 668
Yamana, K., 68, 503
Yamasaki, R. K., 633
Yoder, Hatten S., Jr.. vii, 171, 172, 194, 204,
212, 213, 214, 215, 221, 222, 240, 244, 245,
246, 247, 255, 342, 344, 351, 352, 354, 355
publications, 346
studies, 202-214, 226-229, 236-240
York, D., 483
Yoshikawa, H., 482
Yoshikawa-Fukada, M., 69, 70, 80, 83, 504, 556
studies, 518-531
Younkin, Robert, 112
Yund, R. A., 259, 260, 261, 264, 272, 273, 350,
351, 355
Yuyama, Shuhei, 80
Zach, R., 110
Zachariasen, W. H., 293, 294, 355
Zahner, J. C, 254, 355
Zeldin, B., 482
Zemann, Josef, 78, 295, 355
Zies, E. G., 186, 194, 195, 199, 355
Zimmerman, Lorenz, 661
Zirin, Harold, vii, 107, 108, 109, 110, 111, 124,
161
publications, 160
Zussman, J., 188, 348
Zwicky, Fritz, 133, 135, 136, 161
publications, 160
Zwicky, M., 135
Zyuzin, N. I., 219, 319, 354
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