ii j
}
;
, ,
,
; F
: ‘
r Stat
hg
mr
4 “e
' ‘ j
i
Ja
!
a
ani Aa
i L
; penren ee
: F
:
:
;
aad r
‘
>
a
\
‘
wi
y
ORY.
=,
‘HIST
CROSBY
NATURAL
ILLIAM.
ETY 0
soc
W
$$
ON”
—
BOS’
OCCASIONAL PAPERS
OF THE
BOSTON SOCIETY OF NATURAL HISTORY.
LEE,
BOSTON:
Pos LEO. POR. THE. SOc LET Y¥:
1880.
Digitized by the Internet Archive
in 2011 with funding from
California Academy of Sciences Library
http://www.archive.org/details/occasionalpapers31880bost
CONTRIBUTIONS
TO THE
GEOLOGY
OF
HASTERN MASSACHUSETTS.
BY
WILLIAM -O. CROSBY
BOSTON:
BOSTON SOCIETY OF NATURAL HISTORY.
1880.
PUBLISHING COMMITTEE.
: Spire ScupDER, | . ALtpHEUs Hyatt,
| S. L. Aszor, M.D., J, AP tains
Epwarp BurRGEss.
Press of Rockwell and Churchill, 39 Arch Street, Boston.
TABLE OF CONTENTS.
Page
INTRODUCTION . 4 : F : : - : : Z 1
Topography and Gore Outlines . - : F : : ‘ : 8
Eozoic ForMATIONS ‘ , ‘ ‘ . ; é ; . F : 13
Naugus Head Series . ; F : ; ‘ - : : ; , 14
Huronian . : é : ; . ’ . : 2 = : 24
Granite ; ; ; ; ; ; ; : : ; j ‘ 27
Petrosilex . : ; : 45
Relations of the Dbieiites to the ete Gratn F : . 47
Details of the Petrosilex . : ph \ Ste , . : a 55
Petrosilex in Newbury . : : . j : ; ‘ 55
Concretionary Structure ‘ : 57
Petrosilex on Marblehead Neck tel the maihase ‘Taide : 63
Petrosilex of the Lynn and Medford Area . ‘ : ; 74
Petrosilex in Needham 5 ‘ : : i 79
Petrosilex in Dover, Medfield, aa Deibad: F : 80
Petrosilex in West Roxbury, Hyde Park, Milton, ae the
Blue Hill Region A é é 5 : 82
Petrosilex in Hingham and Pima 5 E . . : 91
Relations of the Petrosilex and Granite ; ? : i P 95
Diorite 3 3 Z - = is F 101
Hornblendic Gneiss, ie »— “Stratified ‘Geous ; : é : " 105
Limestone . F ; ;: : 5 é ; : 112
General Relations of the Pavenaas Rocks*. ; . . é : 116
Eozoic FoRMATIONS,—continued . : . : : ; : : , 123
Montalban : : ; : . : ; p : , , 123
Gneiss 3 : - F - x Z ‘ F , - 5 135
Mica Slate . 5 : . - : ‘ S p z : ; 136
Argillite . ; : . : : : . : : . : 137
Limestone . : : ; ; : ‘: 139
General Relations of the Wotiattan ieee : : : p ; 140
Stratigraphy of the Nashua and Merrimac Valleys . : . 154
General Relations of the Older Crystalline Formations of Eastern Wastes
chusetts : ° ee : : : : : 5 . : 161
Shawmut Group : : : : : : : : : 163
Details of the er ane : 5 , ; : é ; é 166
iii
1V TABLE OF CONTENTS.
Page
Shawmut Group in Newbury : : ; : : : 166
Shawmut Group in the Marblehead Repion : : : ; 167
Shawmut Group in the Lynn and Medford Region : : 169
Shawmut Group in Brighton, Newton, and Needham . . 170
Shawmut Group in Dedham, Hyde Park, Dorchester, and Milton, 174
Shawmut Group in the South Shore District : : : 5 175
General Relations of the Shawmut Group . ; - : - : 177
PALEOZOIC FoRMATIONS . - : ; : ; ° : : : . 181
Primordial : : : : : . , : . : ; : 183
Boston Basin . - ‘: “ A 4 183
Stratigraphy of ihe Boston aa : “ ‘ ; : 195
South Shore District . ; . : : : : : 197
Quincy and Milton : : - : 208
The Hyde Park, Mattapan, anid Bataabiira Belt : 4 : 216
The West Roxbury and Dorchester Synclinal : is j 223
The Brookline and Roxbury Conglomerate Belt . ‘ ° 229
The Upper Falls, Chestnut Hill, and Boston Slate Belt . : 235
The Conglomerate Bordering the Newton Lower Falls and
Brighton Band of Amygdaloid . : - ° 245
Conglomerate and Slate in Needham and South Natick : 250
The Broad Slate Belt, between the Boston & Albany Railroad
and the Crystallines of Waltham, Arlington, Medford, and
Malden. “ : : 5 ; ‘ : : : 253
Nahant : . : 5 : = . : . : 261
Marblehead Neck . : : : : : ; ° : 263
Volume of the Conglomerate and Slate 5 : - 265
Relations of the Conglomerate and Slate to the Ghillie: : 266
Basin of the River Parker . ; 5 : : j : ‘ - 267
Mineralogical Notes . : : : . 5 ° : . : 269
Pinite . : . ; A - : : - : : : 269
Kaolinite . : - : : : : ‘ : : 3 272
Devonian ? ; - ; : : 3 : : : ‘ : : 273
Carboniferous . : : : : : : : - : 275
Supplementary Note. : : i : : é 5 ; : : 276
PREFACE,
EaRLy in the summer of 1875 I began a systematic study
of the rocks in this vicinity, with the view of collecting such
data as, added to my previous knowledge, would enable me to
prepare a thesis for graduation in the department of Natural
History of the Massachusetts Institute of Technology, on the
‘¢ Geology of the Environs of Boston.” In the beginning of
the following winter I was charged by Prof. A. Hyatt, under
the direction of the Massachusetts Commission to the Centen-
nial Exhibition, with the task of preparing a geological map
of the State, for exhibition at Philadelphia. Opportunity was
afforded me by the Commission to visit all parts of the State.
The Boston Society of Natural History generously permitted
the use of my time as assistant in their Museum for this
purpose, and, as that winter was unusually favorable for ex-
ploration, I was in the field almost constantly. The Centen-
nial map and the report on the same were completed in the
following spring. The wider range of observation which this
work for the State had afforded seemed to justify me in ex-
(v)
vl PREFACE.
tending the scope of my thesis so as to include the whole of
Eastern Massachusetts, and it was accordingly finally written,
under the title of this paper. The thesis was accepted for
publication by this Society, and the Government of the Massa-
chusetts Institute of Technology made an appropriation to pay
for printing the map.
I resolved, however, partly on the suggestion of Prof.
Hyatt, to test my conclusions by another year of field work,
and various circumstances have conspired to extend this time
to nearly two years. By this means my original observations
have been doubled, anid, although the general plan of the paper
remains the same, it far exceeds its former limits, and many
of the geological boundaries on the map have been brought
nearer to an expression of the truth.
In deference to the view of Dr. T. Sterry Hunt, expressed
to me personally, and before this Society, I have given the
rocks, which in the original paper were designated as the
Norian system, a name having no chronological signification.
The Huronian petrosilex and felsite are no longer regarded as
synchronous with the breccias; but the latter rocks, together
with the amygdaloids, which appear to belong to the same
horizon, are set apart as a distinct formation under the name
of the Shawmut group. The conglomerates about Boston
have been found to underlie the slates, and hence are now
regarded as Primordial instead of Carboniferous.
For assistance received my acknowledgments are due, first
of all, to Prof. Alpheus Hyatt, who generously placed at my
disposal his original notes, sketches, and collection, represent-
ing observations made during several years on the geology
of Essex County; and I am also indebted to him for many
opportunities for investigation in the field and laboratory.
@
PREFACE. Vil
To Dr. T. Sterry Hunt I am indebted for much valuable
instruction, advice, and criticism, while a student in the Mas-
sachusetts Institute of Technology and since, without which the
performance of this work by me would have been impossible.
Though placed in a position most favorable to a thorough
acquaintance with Dr. Hunt’s views concerning the origin
of crystalline rocks and their relations to the more recent,
fossiliferous rocks, I entered the field with a general disbelief
in their applicability to the rocks of this region, which my first
observations only strengthened; and any conclusions in har-
mony with these views which may be found in this paper have
been reached in opposition to preconceived ideas wholly at
variance with them. |
For valuable data, freely contributed, my acknowledgments
are also due to Mr. L. S. Burbank, of Woburn; Mr.-f271.
Bouvé, President of the Boston Society of Natural History ;
Mr. F. W. Very, of Hyde Park; Prof. W. H. Niles, of the
Massachusetts Institute of Technology; Mr. W. W. Dodge,
of Cambridge, and others.
The chemical analyses recorded in this paper were made in
the Woman’s Laboratory of the Massachusetts Institute of
Technology, and for these I am under special obligations to
Mrs. Alice B. Crosby, Mrs. Ellen H. Richards, Miss E. M.
Walton, Miss H. A. Walker, and Miss Jennie M. Arms.
The President and Directors of the Eastern Railroad Com-
pany have assisted very materially in the exploration of Essex
County by granting free passes over their line.
Boston, August, 1878.
Ale
‘ae
; TORS AME tino hae te
4 tas pate 1
» ’ ‘
My % it
t i he ts tb voy :
) Le
k ‘ oe 4 Vit a) Bw hMity ry 7 Ly baa
i,
° : os es: eae e ‘Th Peedi ty 8 eo var TH
( ( ©
7 Hh f ney ‘ re he Pye eee
.
bs ‘ ayy ‘SU 4 ae f i 4 t aul 7 |
Md 1 j
y
‘ Pel iM ry £4 D any :
GLE OO LEP egrne CEP NTA ES Cae ey ‘ aaa
eS
ect | f F
3 F » EP CLR aae A <3 eter ty } Peg thy
.
Vy
ae? . \ & ;
Pigs, ee te iy i} ' is ;
1 r i 4
att 4 (tA F q Pee whe RA be
-
} ny r a), n
pA CN i Dd COHAN OMS bah oth EP Pe ecg
‘ H), }
\ 1 neq ed Fa
; ‘ y oA
4 he yi + AL : : id ad " | 4] call
; : , a eee Ay j ©) LON PY ah re ae Loa Many h
: 7 ny ¢ ‘a ‘ 4 ; f wit ‘
ta . hil ti Pye Ag Teregu ys ee hb ee
py 7 ae
’ ha es me ,
‘ Ley ‘ f Py , Nat si «
J oe ‘ ‘wie 1s ; vay POR g weld
. ' + i
, "ek Py ae “oe
bs Ce os eee nN Tae bee eyes 1.) Tee A ve
‘ ’
; : es Py A
te ba SHR ORL ieee
ri : : Ree aes nea me te i
. ¥
z : 7 ‘ et yh j Pah 4 #4) ih e P
. ‘ 1 f * a
i Re he WAS) Wie ift< :
‘
.
. iy pss
.
~
- LJ
*
a -
m
.
.
~ ‘ A ’
pn ge
om : ,
INTRODUCTION.
THE vast region extending from Long Island Sound, north-
easterly, and nearly insulated by the St. Lawrence, Richelieu,
and Hudson Rivers, and Lake Champlain, is well-marked
off, geographically, from the rest of the continent. Dr.
Ezekiel Holmes,! recognizing the geographic distinctness of
this most eastern member of the continent, and its almost com-
plete isolation by water, an isolation that appears to have been
perfect during the first part of the Paleozoic era, has correctly
termed it a peninsula. Newfoundland is a detached portion
of this geographic unit. In its geologic relations, also, the
region indicated is readily separable from the adjoining terri-
tory. The rocks are mainly crystallines, and, except in the
lower part of the valley of the Hudson, cannot be connected,
along their strikes, with the rocks of other regions. The
? Ann. Report on the Agriculture and Geology of Maine, 1861, p. 100.
* The Paleozoic sediments of this region, it is true, are continuous through the broad
interval between the Adirondacks and the Highlands of the Hudson, and were probably
connected, at one time, through the valley of the St. Lawrence, with the more exten-
sive deposits of the same age to the westward. Yet the crystallines are to so great an
extent the predominant rocks of this large territory, and, as the writer conceives, have
had, as a whole, an origin so vastly more remote than the most ancient of the uncrys-
talline sediments (these newer formations being regarded as merely superficial deposits,
often obscuring, but not essentially altering, the main structural features of the region),
as to warrant leaving the latter out of view in these general remarks.
OCCAS. PAPERS B. 8S. N. H.—III. 1
2
north-easterly strike prevalent north-east of a line extending,
in a general way, from Boston, via the White Mountains, to
the northern end of Lake Champlain, would, if continued
south-westerly, carry the crystallines of New England over
New York, and the Middle States generally. But beyond the
line indicated the formations bend to the south, and through-
out south-western New England are characterized by approxi-
mately north and south strikes, being cut off at right angles
by the waters of Long Island Sound. Along the New York
boundary, in southern Connecticut, however, the north-east
strike is resumed, and the rocks of that district sweep across
Manhattan Island and the Hudson. The breadth of New
England strata subjected to this westerly deflection is -prob-
ably not so great as at first sight appears. ‘The crystallines
of the Highlands of the Hudson are Laurentian, and are rec-
ognized by all geologists as older than those farther south, in
the vicinity of New York. It is the latter only that can be
traced easterly into New England, or that are here considered
as really belonging to this great geological province. The
Laurentian strata of the Highlands have a north-north-east
strike, varying toward north and south; and it is probable
that in their northerly extension, although soon dipping
beneath more recent formations, they sweep around to a
course parallel with the one hundred and fifty miles of newer
crystallines on the east, and reappear in Washington and
Saratoga Counties in New York; thus connecting the Lauren-
tian of the Highlands and New Jersey on the south with the
great Adirondack area on the north, and constituting at all
points a barrier against which abut the western edges of the
crystalline series proper to New England. The complete
absence, so far as has been definitely ascertained, of Lauren-
tian rocks from western New England corroborates this
view. In short, the crystalline formations of the northern
half of the Atlantic seaboard exhibit, in their strikes, a
grand double curve. Beginning in the north-east with a
trend parallel with the St. Lawrence and the Laurentide
3
Mountains, they bend to the south in southern New Eng-
land, and conform with the Laurentian barrier just pointed
out; while the remnant that is not cut off in the southern
extension, by the Atlantic, finally regains the former strike,
and spreads across southern New York and New Jersey.
This great Laurentian wall, which is doubtless continuous,
under the Paleozoic deposits, from Labrador to Virginia, or
beyond, formed the western shore of the ocean, in which the
newer crystallines of the Atlantic slope were deposited ; and,
subsequently, in its southern half, it became the eastern border
of the great Paleozoic sea. It has been a primary axis of
continental oscillations, a centre of disturbance — itself undis-
turbed. The importance of this ancient Laurentian axis, as a
structural feature of the continent, makes still clearer the
isolation and unity of what may be called the New England
or North-Eastern geological province. It is not intended to
deny the existence in New England of the older crystalline
formations, for Hitchcock has shown that they certainly occur
in the White Mountain region; but I may safely assert that
their occurrence in the western and central portions of this
province is always something exceptional. They are not
characteristic of any considerable areas.
This north-eastern province is naturally divisible, in a geo-
graphical sense, at least, into two parts, —a south-eastern and
a north-western. The division. is marked by a line of valleys
parallel with, but subordinate to and less distinct than, that
isolating the province on the north and west. ‘This axis of
depression follows the valley of the Connecticut, from Long
Island Sound, to near its source ; then, curving north-easterly,
and skirting the northern base of the White Mountains, it is
marked by the valley of Lake Umbagog, and the great lake
region of Northern Maine, passing to the northward of the
Katahdin Range. Entering New Brunswick, it is continued,
with the same trend, through the valley of the Restigouché
River and Bay of Chaleur, to the Gulf of St. Lawrence.
This secondary line of depression, like the first, is marked
+
throughout the greater part of its extent by considerable
deposits of uncrystalline sediments. These are, however,
almost wholly of early Paleozoic age, and show that these
valleys are of very great antiquity.
The rocks forming the subject of this paper occur wholly in
the more south-eastern of the two divisions, or sub-provinces,
above indicated. ‘This division embraces ‘that great deflection
of our Atlantic coast-line known as the Gulf of Maine. The
head of the Gulf of Maine is at Portland; and its apparently
but slightly contracted mouth is guarded by the two salient
angles, Cape Sable and Cape Cod; while the Provinces of
New Brunswick and Nova Scotia enclose its north-eastern end
as Eastern Massachusetts does its south-western. The line
joining the head of the Bay of Fundy and Plymouth, in
Massachusetts, may be regarded as the axis of the gulf, and is
about three hundred and. seventy-five miles long, with a trend
approximating north-east and south-west. This line is of
fundamental importance in the structure of this region, a base
line for both geography and geology. The maximum breadth
of the gulf at Portland is one-third of its length, or one
hundred and twenty-five miles. The prevailing and all but
universal line of strike throughout this entire region, from
Rhode Island to the Gulf of St. Lawrence, as already stated,
is north-east and south-west, — parallel with the axis of the
Gulf of Maine. The rocks which meet the water of this large
eulf are, for the most part, ancient crystallines ; and, where-
ever these are exposed to observation, the indications are plain
that the gulf is the product of erosion, — has been carved from
the ancient strata by which it is bordered, — and is not the result
of a synclinal or other depression of this portion of the earth’s
surface. The agent of erosion appears, at first sight, to have —
always been the waves of the Atlantic, and to have acted
uniformly from the east toward the west. A study of the true
contours of this body of water, however, brings to light facts
which seem to militate against this view. An examination of
a Coast Survey chart of this region shows that the water does
4)
not become constantly deeper as we proceed seaward from the
shore, anywhere between Portsmouth, N.H., and Eastport,
Maine; but, on the contrary, the water is usually as deep at
twenty to fifty miles from shore as at any greater distance less
than two hundred and fifty miles, beyond which the abysses
of the ocean begin, and the bottom falls away rapidly to
twelve hundred and fourteen hundred fathoms; and not un-
frequently the depth is actually greater at the lesser distance
from shore, so that the water shallows seaward. Thus, the
greatest depth recorded in the region of the Gulf of Maine,
one hundred and sixty fathoms, is only fifty miles from Ports-
mouth; and thirty-five miles from Mt. Desert gives us one
hundred and forty-five fathoms: while beyond this the water
shallows sensibly, and an equal depth is not found nearer than
one hundred and fifty miles from shore.
Extending easterly from Cape Cod, for nearly two hundred
miles, is a broad expanse of shallow water, with depths rang-
ing from five to fifty fathoms, and including George’s Bank,
which reaches the surface one hundred and twenty miles from
land. A similar but less distinctly marked area of shallow
water stretches southward from Nova Scotia, with a breadth of
sixty miles, and a maximum depth of seventy fathoms. Sepa-
rating these two areas of moderate depths is a strait of deeper
water, eighty to one hundred and fifty-five fathoms. Following
the fifty-fathom line, this strait is, perhaps, fifty miles wide ;
while for the one-hundred-fathom line it is reduced to thirty-
five miles. It is plain that a broad submarine ridge or plateau
extends over nearly nine-tenths of the distance between Nova
Scotia and South-eastern Massachusetts, forming a nearly com-
plete barrier between the comparatively deep water of the Gulf
of Maine and the greater depths of the ocean beyond. If the
sea bottom were elevated fifty fathoms, the Gulf of Maine,
although still three hundred miles long, and having a maximum
depth of one hundred and ten fathoms, would be changed from
a broad-mouthed bay to an almost completely land-locked gulf.
The glaciating agent operated powerfully-to obliterate that
6
feature of the Gulf of Maine, upon which I am here insisting,
viz., its nearly continuous eastern rim; which, though no less
real than the western border of the gulf, escapes recognition
through its submergence beneath the waters of the Atlantic.
One of the most important effects of glacial action was the
transportation of immense quantities of detrital materials from
the north and north-west toward the south and south-east.
According to Prof. Hitchcock, the sheet of drift covering
South-eastern Massachusetts is at least three hundred feet
thick ; and any one familiar with the geology of this region,
who notes the characters of the pebbles and boulders which
this drift contains, cannot doubt that it has been largely
derived from the land to the northward; nor will it seem
improbable that Northern Massachusetts, and even New Hamp-
shire, may have contributed something to the result. We have
no reason to think the action of the ice-cap in this imstance
was anything exceptional ; it probably swept Northern as well
as Southern New England, and in even a more thorough
manner. Where now is the vast accumulation of debris that,
according to this supposition, must have been removed from
portions of Maine and New Hampshire? I believe it has been
shoved, in large part, beyond the present limits of the land,
and is now spread over the bottom of the Gulf of Maine;
contributing largely to the elevation of this bottom to the level
of the eastern rim, and thereby tending to obliterate the latter
as such. Jeffrey's Bank and Cashe’s Ledge, lying off the
mouths of the Kennebec and Penobscot Rivers, sixty to seventy
miles long, two-thirds as broad, rising from a depth of one
hundred and sixty fathoms, and approaching at many points
within five to fifty fathoms of the surface, should, apparently,
be regarded as a huge pile of glacial detritus, which, although
everywhere distinct from the eastern rim of the gulf, greatly
obscures its basin-like character. That the glacial action,
while tending to fill up the gulf, has contributed little or
nothing to the formation of the ridge or plateau constituting
its eastern border becomes sufficiently obvious when we note
7
the remoteness of this barrier from the land, and observe that
a considerable breadth of deep water intervenes at all points
between it and Jeffrey’s Bank. If, then, the debris were
removed from the bottom of the Gulf of Maine, it would
doubtless appear much more clearly than now to be a genuine
depression, or basin, shut off from the outside ocean by a broad
barrier ; which, whether we consider it to have been, at the
time when this gulf was eroded, above the sea, and backed,
may be, by an Atlantis, or as having been always submerged,
constitutes a serious objection to the view that the erosion of
the Gulf of Maine has been effected wholly or mainly by the
waves of the Atlantic. Without intending or desiring to raise
the question of the existence,in past geologic time of an Atlan-
tic continent, it will be shown in the sequel that there are other
reasons than those here advanced for believing that the Gulf
of Maine was, at least during the period of its formation, land-
bordered on the east as well as on the west; that it was.
eroded mainly, if not entirely, before the beginning of Pale-
zoic time; and that the rocks bordering this gulf, in Eastern
Massachusetts at least, are so disposed about the line which I
have denominated the axis of the gulf as to indicate that this
line is really the axis of a great anticlinal or series of anti-
clinals, the erosion of which, after the usual manner of anti-
clinal erosion, has, I conceive, produced the depression in
question.
It has long been known that the rocks bordering the Gulf -
of Maine exhibit a general uniformity along the strike. This
likeness is usually believed to extend not only to the Paleozoic
and more recent sediments and their relations to the crystal-
lines, but also to the crystallines themselves, which are con-
ceived to be arranged in broad irregular belts, parallel with the
axis of the Gulf of Maine, and each of which is, in a general
way, of the same age and composition throughout its extent.
Careful comparisons of the rocks, especially the crystallines,
of these various districts, have never been instituted; and the
prevalent opinion here alluded to, though probably correct, is
8
based upon general impressions gathered from hasty, bird’s-eye-
view surveys, rather than detailed and accurate knowledge.
During the last decade, various members of the Canadian
Geological Survey, and especially Mr. G. F. Matthew and
Prof. L. W. Bailey, have greatly extended our knowledge of
Acadian geology. Their labors, however, have been mainly
confined to New Brunswick; and Nova Scotia is yet, as
regards an accurate knowledge of the composition and relations
of the crystalline formations of the province, well-nigh an
unknown land. Our knowledge of the crystallines of Maine,
also, is wholly inadequate for the purposes of comparative
geographic study. In the study of the rocks of Eastern
Massachusetts presented here, a detailed comparison of this
region with those to the north-east has not been attempted ;
our knowledge, as just stated, not being considered ripe for
accurate generalization over so wide an area. Yet, although
the end kept steadily in view has been merely to advance in
some degree our knowledge of the character, distribution, and
relations of the various rocks occurring in a limited district,
it is hoped the way has been, in a measure, prepared for the
higher study hinted at.
TOPOGRAPHY AND GENERAL OUTLINES.
The extent of territory coming within the scope of this paper
is intended to be shown by the smaller of the two accompany-
ing maps. It includes in a general way all that part of the
State east of the north-south range of highlands of which Mt.
Wachusett is the culminating point, and north of the Rhode
Island boundary ; comprising the whole of Essex, Middlesex,
Norfolk, and Suffolk Counties, the eastern half of Worcester
County, and the northern portions of Bristol and Plymouth _
Counties. As shown by the map, the length and breadth of
the district are approximately equal, and the area is not far
from three thousand square miles, or about three-sevenths of the
State.
3
The topographic descriptions given us by the elder Hitchcock
and other writers, and the general evenness of the surface,
obviate the necessity for extended remarks under this head here ;
and, furthermore, the trends of the principal water-courses and
shore lines are sufficiently obvious on the map. I would call
attention, however, to the general relation of the topographic
features to the geologic structure, —a point likely to be over-
looked in a level and drift-covered region like this. The prevy-
alent line of strike in Massachusetts, as is well known, is
north and south, and in the western half of the State there are
no exceptions of importance to be noted. East of the Nashua
valley, however, a north-east and south-west strike prevails,
especially in Essex and Middlesex Counties ; a comparatively
limited area in the south-eastern part of Worcester County
and the adjacent portion of Rhode Island exhibits a strike at
right angles to this, or north-west and south-east ; while among
the Paleozoic strata a nearly east and west strike is most com-
mon. ‘That ‘‘ geology is revealed in topography ” is a trite
axiom of the science, which is well exemplified, even in this
extensively glaciated region. In a recent paper in the Ameri-
can Naturalist,! ‘‘On the Surface Geology of Eastern Massa-
chusetts,” I have discussed at some length the relations of the
topography of this district to the glaciating agent and to the
geologic structure. The general conclusion reached is, ‘‘ that,
comparatively speaking, the ice-cap rested lightly upon the
land, and that the topographic features having a skeleton or
framework of rock are, as a rule, of pre-glacial origin.” In
other words, to quote further, ‘‘ it appears probable that if the
present mantle of drift were entirely removed from the face of
the country, leaving a surface of naked rock, we should have in
all important respects a restoration of the" pre-glacial contours.
And this ancient topography having been, as I conceive,
fashioned mainly by agents more subtle than an ice-cap, and
hence taking a deeper hold on geologic structure, would, if thus
undisguised, reveal a closer correspondence with the structure
? Vol. x1., pp. 577, et seq.
10
lines of the subjacent rocks than we are able to detect in the
existing hills and valleys considered as a whole.” One of the
most remarkable facts in the distribution of glacial detritus, or
drift, in Massachusetts, as I have already observed, is the com-
paratively great depth to which it has been accumulated . over
the south-eastern portion of the State. There is a marked
paucity of rock outcrops in the southern half of Plymouth
County ; south of Plymouth and east of Middleborough they
are rarely met with; and Barnstable County is absolutely des-
titute of them. It is not improbable that the solid rocks in
this region are so deeply buried by the unconsolidated superficial
deposits, that, if the latter were removed, the whole of Barn-
stable County and a considerable part of Plymouth County
would be invaded and covered by the sea. Certainly here, if
anywhere, we may expect lake basins and river valleys to ex-
hibit in their forms and trends a complete independence of the
underlying rocks; and, as I have shown in the paper above
cited, this expectation is fully justified by the facts. In
Worcester County, and north of this region of excessive drift,
however, the dependence of the surface lineaments on the geo-
logic structure is very marked. This is especially noticeable in
‘the case of the larger features, such as the Blackstone, Nashua,
Merrimac, Parker, Ipswich, Charles, Neponset, and other
rivers; the Wachusett range of highlands; the parallel range
forming the eastern rim of the Nashua valley ; the somewhat
irregular belt of hills extending from Cape Ann to Beverly ; the
well-known range sweeping with bold front from Swampscott
to Waltham; and the Blue Hill range in Milton and Quincy.
The last three lines of hills, being principally composed of un-
stratified rocks, are less regular and distinct than the others ;
yet they no less clearly reveal the structure of the rocks com-
posing them ; for exotic rocks, being, in a certain sense, struc-
tureless, only conform with the general law in giving rise to
a systemless topography.
The rocks of Eastern Massachusetts admit of a convenient,
and, it is believed, a chronologic, division into two great
11
groups, — the crystallines and the uncrystallines. The former
predominate, constituting the surface rocks over fully nine-
tenths of the area to which this paper particularly relates. The
chronologic distinctness of these groups will probably not pass
unquestioned. Yet it is true that, with the exception of the
argillites of the Nashua valley, which Prof. C. H. Hitchcock !
has correlated with the Primordial slates about Boston, none of
the crystallines of the eastern part of the State have, of late
years, been regarded as of Paleozoic or more recent age, by
any geologist familiar with the rocks of this region.
I have studied the relations of our Primordial strata to the
erystallines at every accessible point within my knowledge, and
in all cases, where the evidence is of a decisive nature, it affords
unequivocal support to the view, that between the crystallines
and the oldest uncrystallines there is a great chronologic break,
a ‘‘lost interval” of immense duration; for the unconform-
ability is perfect, and the imperfect lithologic resemblance
sometimes observable is due in every case to derivation or to
very local alteration. Furthermore, it will be shown in the
sequel, mainly on stratigraphic grounds, that the oldest rocks
in the State are on its eastern border, facing the Atlantic, and
that the various crystalline series appear to be so arranged
geographically as to become successively newer as we proceed
from Massachusetts Bay to the Berkshire Hills; so that, even
if there were crystallines of Paleozoic age in Massachusetts,
they would not probably be found in the eastern portion of the
State. I cannot but regard the distinctness of these two great
classes of rocks in this region as the most certain of all the
conclusions reached in this paper. Considering the Primordial
horizon as the base of the Paleozoic system, then it is true that,
in this region at least, the profound break between the crys-
tallines and the uncrystallines is coincident with that recognized
generally between the two grandest chronologic divisions, the
1 Geological Map of Massachusetts, in Walling’s Atlas, 1871. Subsequently, in the
final report upon the Geology of New Hampshire, Prof. Hitchcock has referred these
argillites to the ancient Huronian system.
12
Eozoic and the three succeeding eras, — Paleozoic, Mesozoic,
and Cenozoic, —for which, taken collectively, geologists have
failed to provide a name.
Several divisions have been established among the crystallines
of Eastern Massachusetts, based, for the most part, on litho-
logic and stratigraphic characters. The groups thus formed are
believed to have chronologic value, to be chronologically dis-
tinct. It is not without hesitation that, in describing these
series as both lithological and chronological, I raise the vexed
question of the value of purely physical characters as tests of
age among crystalline rocks; for I began my study of the
erystallines of this State with a wholesome distrust of the
value of lithological data in establishing chronological divisions,
and am not yet wholly prepared to apply this principle to wider
regions. Within my limited field of observation, however, I
am satisfied that its application is safe. It adapts itself so per-
fectly to all the facts, so far as I know them, that I do not hesitate
to assert that the lithological characters of the divisions which
have been worked out among the crystallines of Eastern Mas-
sachusetts — the chronological and geographical distinctness of
which can scarcely be doubted — are as unlike as the faune of
any two successive geological formations.
13
EOZOIC FORMATIONS.
The oldest of these crystalline series is the smallest in extent.
I propose to designate it, provisionally, as the Naugus Head
series, —in allusion to the promontory of this name on
the Marblehead shore, where the rocks of this series are best
developed and were first observed. Succeeding the Naugus
Head series, in the order stated, are the Huronian and Montal-
ban systems, and a series of semi-crystalline rocks, of very
dissimilar composition, but appearing to be identical in age and
geognostic relations, which, having their greatest development
in the vicinity of Boston, I have named collectively the Shaw-
mut group,— Shawmut being the ancient Indian name of
Boston.
In employing the names ‘‘ Huronian,” ‘‘ Montalban,” etc.,
terms having chronological signification, to designate the crys-
talline divisions of Eastern Massachusetts, I mean to assert
the general lithological and stratigraphical resemblance, but
not necessarily the chronological equivalence, of the groups
thus designated to the great and generally recognized Eozoic
divisions of other regions. My views on this subject cannot
be justly characterized as merely speculative ; for at all impor-
tant points they rest on the solid ground of facts. My position
with respect to our crystalline or Eozoic formations, briefly
stated, is this: There exists in Eastern Massachusetts a great
series of crystalline schists agreeing in all important respects
with the Montalban system as defined by Dr. T. Sterry Hunt.
Farther east is another vast crystalline formation, differing
widely from the first, and possessing all the essential char-
acters of the Huronian. ‘This second series is plainly older
than, and underlies, the first ; and it is underlaid in its turn by
a still more ancient-looking terrane which, consisting prin-
cipally of coarsely crystalline, and frequently exotic, basic
rocks, presents a general resemblance to the Upper Laurentian
or Norian series of the Canadian geologists. This, as above
. 14
stated, I have named, provisionally, the Naugus Head series.
In other words, the crystalline divisions of Eastern Massachu-
setts agree in composition and sequence with those established
in neighboring regions ; that this implies chronological equiva-
lence might fairly be questioned, and I do not assert it.
NAUGUS HEAD SERIES.
Several small areas of the rocks referred to this series have
been marked on the accompanying map.' Of these, two are
of especial importance; the first includes the city of Salem,
Salem Neck, the islands of Great Misery and Little Misery,
Baker’s Island, Naugus Head on the north end of Marblehead,
various small islands between Marblehead and Great Misery,
and several narrow strips along the Beverly shore; while the
second area embraces all but the seaward end of Large Nahant.
A glance at the map will show that these areas lie contiguous
to the sea-shore; and this fact — since these shores are for the
most part rocky —has enabled me to trace their boundaries
with considerable accuracy. In Salem and Peabody, however,
the rocks marked as belonging to this series seem to have
been more or less fluent, and are blended with the diorites of
the Huronian formation in inextricable confusion ; which, to-
gether with the absence of outcrops north of North river, has
rendered the determination of the western boundary of this
area difficult ; and the line as laid down on the map is partly
hypothetical.
The rocks of this series, though frequently stratified, appear
in general to have been somewhat fluent, and usually exhibit
more or less extravasation; but doubtless in some cases the
metamorphic action has stopped short of this extreme term,
though destroying all traces of bedding. In many places, as
notably on Winter Island and Great and Little Misery, the
entire formation seems to have been plastic, and the extravasa-
tion has been so extensive that the character of the rock
1 See post., pe 23.
15
changes at nearly every rod. One important fact should be noted
here, viz., nowhere in this region does the Naugus-Head
series appear to be cut by eruptives belonging to another for-
mation ; for all the exotic rocks of this group may be easily re-
ferred to, or shown to be derived from its stratified members.
The stratified rocks occur chiefly in Marblehead, and on the
Beverly shore west of Curtis Point. In Marblehead the strike
is E.-W., with a vertical dip; while on the Beverly shore
the strike varies from N.-S. to N.E.-S.W., and the dip
is thirty degrees to vertical to the N.W. The average strike
of the whole system is N. E.-S.W. More or less distinct
bedding has also been observed on the north side of Great
Misery, at several points on Salem Neck, on Coney Island, and
at one point on the north-east shore of Nahant.
The rocks of this series are composed chiefly of feldspar and
pyroxene. ‘These minerals occur mixed in very various pro-
portions. Perhaps the most characteristic rock is one composed
almost entirely of feldspar, containing little pyroxenic or
hornblendic material, and frequently destitute of it. It is
usually coarsely crystalline, this variety prodominating along
the Beverly shore east of Curtis Point; and the crystallization
is sometimes extremely coarse, as, notably, on the Beverly
shore, near the western end of West Beach, and in Marble-
head, especially about Dolliber’s Point. At the former locality
the rock is evidently exotic, and some of the feldspar crystals
are of immense size, ranging from three to six inches in length,
and one to two inches in breadth; but at Dolliber’s Point it is
distinctly bedded, and is interstratified with fine-grained pyrox-
enicrocks. Another, but less abundant, variety, is fine-grained,
presenting a very uniform texture and appearance, and ap-
proaching the compactness of felsite. This occurs at many
points, but is most largely developed on Baker’s Island, which
is principally formed of it. A dark, heavy, usually coarse-
grained diabase or norite, varying greatly in composition, and
frequently occurring as a nearly pure pyroxene rock, is the most
abundant rock of this series. It is the prevailing rock on
16
Nahant, where it is frequently very coarse and pyroxenic, with
a high specific gravity. A more feldspathic variety exhibits
traces of bedding on the north-east shore of this peninsula, as
already noticed. This stratified rock is about midway between
the Spouting Horn and Maolis Garden, and is of very limited
extent. The lines of bedding trend E.-W. for one hundred
feet or more, and then toward the west curve abruptly, but
smoothly, around to the south, forming a right angle.. Dip
vertical. This pyroxenic rock, in its several varieties, and the
feldspathic rock just noticed, occurring chiefly as eruptives,
underlie the city of Salem, and form the peninsula of Salem
Neck, and the islands of Great Misery, Little Misery, Pope’s
Head, and Eagle Island. The stratified rocks of this series
consist usually of interstratified, frequently alternating, pyrox-
enic and feldspathic beds. They are of all textures, from the
finest to the coarsest; the stratified pyroxenic rocks, however,
are generally fine-grained, schistose, and very distinctly bedded.
These last are well developed on Marblehead, west of Dolliber’s
Point, and especially about Naugus Head.
It has been suggested that some of the coarse feldspar, so
abundant in the rocks of this series, may be labradorite ; but
the analyses thus far made do not support such a view. Yet,
as only two specimens have been submitted to analysis, the
question cannot be regarded as settled. The first specimen
analyzed was taken from the very coarsely crystalline, stratified,
feldspar rock on Dolliber’s Point, Marblehead, and was placed
in the hands of Mrs. E. H. Richards, of the Massachusetts
Institute of Technology, who made the following report : —
BIO} «> ; 3 : : ; : : 7 66.639
ALO... : : : ; : : : : 19.375
KO): : ; : : ‘ : : ; 4.500
Na,O . : : : : : : 3 ; 10.011
CaO. . ; : ; : : : ‘ : traces
ie be Ge ; : : ; : : traces
100.525
ie
Such a chemical constitution belongs to no known species or
variety of feldspar, though coming very near orthoclase ; and,
fearing there had been an error in the first analysis, a second
was made from the same piece,—a clear, apparently un-
weathered specimen, — with a like result. A careful inspection
of a large number of specimens seemed to explain the anomaly,
by showing that the feldspar, although coarsely and perfectly
crystalline, is probably a mixture ; the crystals appearing to be
formed of thm interlaminated plates of at least two different
feldspars. This can be seen only on slightly weathered sur-
faces, one of the feldspars decomposing more readily than the
other. The constituent layers were not analyzed, as it seemed
impracticable to separate them. But if, as appearances indicate,
it is a mixture, and a mixture of two species only, they are
probably orthoclase, and albite or oligoclase, the former pre-
dominating. ‘The color of this feldspar is bluish-gray, weather-
ing white, and its sp. gr. varies from 2.55 to 2.60. Dissemi-
nated through it are numerous small crystalline grains of
magnetite. The coarse feldspar of the Beverly shore, similar
in physical characters to the preceding, was analyzed by Mrs.
Crosby, and found to have substantially the same chemical con-
stitution, containing one-half of one per cent. of calcium oxide.
The specimens just described, from the coarsely crystalline,
nearly pure, feldspar rock, are certainly not labradorite, and yet
that this species exists in some of the rocks of this series does not,
in my mind, admit of reasonable doubt. Much of the labradorite
in the norite of Essex County, New York, and probably of
other localities, is of a pale-green color and waxy lustre, and
seemingly compact. In the coarse pyroxenic rock of Nahant,
the feldspar is frequently physically identical with this, and
- yields by analysis a larger percentage of lime. The silica and
calcium oxide only were determined, with the following
result : —
SiO, CaO
Labradorite from Westport, N.Y. . - 54.60 4.85
Feldspar from Nahant E : ; (48.71 8.70
OCCAS. PAPERS B. 8S. N. H.—III. y)
18
The same feldspar, apparently, occurs on Salem Neck, and
at several other points in that region. In a formation so desti-
tute of free silica as the Naugus Head series, it were natural to
expect to find the feldspar mainly triclinic; and this expecta-
tion is fully realized, for, save in the very coarse feldspar rock
of the preceding paragraph, I have rarely failed to observe the
striz indicative of plagioclase ; and in not a few instances, judg-
ing by physical characters alone, this plagioclastic feldspar is
most probably labradorite. A triclinic feldspar from the west
end of Salem Neck, apparently little altered, afforded Mr.
Geo. H. Barton fifty-seven per cent. of silica.
Dark-colored mica, probably biotite, is common in the rocks
of this formation, though seldom abundant. Pyroxene appears
as a principal constituent, and hypersthene is believed to occur.
The massive, coarsely crystalline diabase, or norite, at Nahant
is often decidedly epidotic; and the epidote is particularly
abundant on the south shore, east of the steamboat wharf.
The most striking, and probably the most important minera-
logical character of this series of rocks is, that all members of
it are absolutely destitute of quartz. Lithologists will recognize,
in the complete absence of quartz from this formation, a strong
indication that the principal constituent, after feldspar, is
pyroxene, and not hornblende ; and it is probable that every
basic rock of this series may be properly classified, in a gen-
eral way at least, ‘as either diabase, norite, or pyroxenite.
The coarse feldspar rock, mentioned above, and consisting
mainly of orthoclase, is probably often a true syenite.
That this series of pyroxenic and feldspathic rocks, with its
associated minerals, — which is sometimes stratified, oftener
eruptive, frequently very coarsely crystalline, and always
quartzless, — is distinct from anything observed elsewhere in
Massachusetts, cannot be doubted. Lithologically at least, it
may be said to be sw? generis in Massachusetts geology. The
great disturbance which the Naugus Head series everywhere
exhibits, and its thoroughly crystalline appearance, stamp it as
older than the Huronian and Montalban formations ; and other
19
and more. important considerations confirm this view. ‘The
northern or Salem area of this series is bounded everywhere
either by the sea or by rocks belonging to the Huronian system.
On the north, in Beverly, we have coarse Huronian granite,
such as is quarried in Quincy and Rockport; while to the west
and south, in Peabody, Salem, and Marblehead, are dioriteand
fine-grained hornblendic granite, also Huronian. What, now,
are the geognostical relations of the Naugus Head series to
these Huronian terranes? It underlies them. Everywhere,
along the boundaries of the Naugus Head areas, we find the
various members of this series penetrating and cutting through
the Huronian rocks. But the converse of this is never ob-
served. Nowhere, so far as my observations extend, does the
Naugus Head series appear to be cut by the adjoining Huronian
rocks; nor by any member of the Huronian system; nor, in
fact, by any rocks not easily referable, as already stated, to the
stratified portions of this series itself. In short, the Naugus
Head series appears to be, as it were, at the bottom; and,
while it has been extravasated extensively through superjacent
formations, it is penetrated by nothing foreign to itself. The
relations of the Naugus Head series and the Huronian forma-
tion are best displayed in the cliffs along the shores of Beverly
and Manchester. Here the Huronian granite, already men-
tioned, is cut extensively by great dykes and eruptive masses of
rocks, both pyroxenic and feldspathic, clearly belonging to the
Naugus Head series; the feldspathic dykes appearing, usually,
to be older and larger than the pyroxenic. But this granite,
although it has evidently been more or less fluent, is never
found cutting any member of the Naugus Head series ; and we
are thus forced to the conclusion that this series is older than
the granite. |
~The Norian beds of Canada and Labrador were formerly
regarded as forming part of the Laurentian, bearing the name
‘¢ Upper Laurentian”; and, wherever their relations to the un-
derlying terranes have been observed, they lie directly upon the
Laurentian, never upon the Huronian or Montalban. The
20
Huronian, also, has heretofore, wherever its foundations could
be clearly made out, been found resting on a Laurentian floor.
The Norian and Huronian have never been observed under con-
ditions favorable for the accurate determination of their mutual
stratigraphic relations, and hence these are not positively known.
Prof. Bailey and Mr. Matthew, however (in the Geological
Survey of Canada, Report of Progress for 1870-71, p. 41),
report the occurrence, seven miles east of St. John’s, in the
Province of New Brunswick, of a small area of crystalline,
anorthic, and hypersthenic rocks, which are regarded as Norian
by Dr. T. Sterry Hunt, after an examination in setu; and
oencerning the geognostical relations of which they say, ‘* On
the north side these anortholite rocks are met by red gneiss and
granite, similar to the Laurentian gneiss at Indiantown, and
on the south are covered by conglomerates and diorites of the
Huronian series.”
This language is explicit, and indicates that here, at least,
the normal position of the Norian is be/ow the Huronian. Yet
it seems doubtful if this can be regarded as proved by the
facts observable at this place; for, according to Dr. Hunt,
these Norian rocks are, apparently, devoid of stratification, and
may belong to an extravasated mass; while the adjoining
Huronian beds are vertical. The mere occurrence, however, of
these Norian outcrops between ledges of Laurentian and
Huronian rocks, suggests that this is their normal position, and
if their geognostical relations to the Laurentian and Huronian
beds are regarded as due to the action of eruptive agencies, it
is hardly conceivable that they have come from any horizon
above the Huronian. Although conclusive proof that the Norian
system is older than the Huronian has not been afforded us by
a study of their relations at the only poimt where they are
known to occur together in s¢tu, yet the bulk of the evidence
points in that direction ; and the general facts, that the Norian
rocks are usually more crystalline, have in every respect a more
ancient aspect, and always exhibit less unconformability with
the Laurentian than the Huronian, increase the probability
21
that this is the true sequence of these oreat crystalline forma-
tions. This, it may be added, is the sequence deemed most
probable by Dr. Hunt, viz., Laurentian, Norian, Huronian.
The Naugus Head series is certainly distinct from, and (as
I have already shown) probably underlies, the Huronian ; and,
since it bears no likeness to the Laurentian system, we are
brought to the conclusion, that, if it is to be correlated with any
series already described, that series is the Norian. In short,
.the Naugus Head series does not resemble the Laurentian, and
is, stratigraphically, where we should expect to find the Norian ;
and these are, mainly, the considerations which led me to
designate this series as the “ Norian,” on the Centennial Geo-
logical Map of Massachusetts, and in my report on the same.
Having been informed, however, by so good an authority as
Dr. T. Sterry Hunt, whose opinion I had no opportunity to
obtain before the publication of the report above referred to,
that this series, chiefly on account of the supposed absence of
labradorite, cannot be regarded as of Norian age, I have em-
ployed here, and on the accompanying map, a provisional
designation ‘having no chronological signification. I am con-
strained to believe, however, that, save in not holding labra-
dorite as a principal constituent, if such proves to be the fact,
the Naugus Head series presents a fair agreement, lithologically,
with the essential characters of the Norian, as the latter has
been described by Dr. Hunt. It is proper to state, in this con-
nection, that Dr. Hunt, in 1869," identified, as belonging to the
Norian formation, a boulder found on Marblehead Neck, and
possibly derived from the Naugus Head areas to the northward.
I know by personal observation that the Naugus Head rocks are
scattered as erratics all over the town of Marblehead, including
the Neck. Prof. A. Hyatt long ago recognized the rocks about
the city of Salem as probably older than the petrosilex of Mar-
blehead Neck ; but he did not separate them from the Huronian
diorites of Salem, Swampscott, and Marblehead.
1 Amer. Jour. Sci. (2) xirx., 183, 398.
22
The only rocks in Massachusetts that have been observed
passing below the Huronian system, or cutting through its lower
members, are those composing the Naugus Head series; and
this, together with its crystalline character and immense dis-
turbance, convinces me that this series is the oldest in the State.
In the light of our present knowledge the conclusion cannot be
avoided, that the Naugus Head series is the real base of the
geological column of Massachusetts.
The coarse-grained, readily disintegrating exotic diabase, so
extensively quarried in Medford, —and also occurring in Somer-
ville, Brookline, and, probably, other places, — bears a strong
resemblance to certain members of the Naugus Head series, es-
pecially to the coarse pyroxenic rock of Nahant and Salem
Neck; and the idea is natural that they are extruded portions
of this series, which may, I think, be regarded as the probable
seat of many of the eruptive masses cutting the newer formations
of this region.
For the accurate identification of these exotics in Medford,
Somerville, Brighton, Brookline, etc., we are indebted to Mr.
M. E. Wadsworth.'! This observer has found that the principal
dark constituent of these rocks, in the unaltered condition, is
always pyroxene, never hornblende; a fact which accords well
with the general conclusion already stated with respect to the
composition of the basic rocks of the Naugus Head series. The
forms and general relations of these masses will be more fully
described in connection with the uncrystallines which they
intersect.
The small area of basic exotics exposed near the head of
Washington avenue, in Chelsea, has been doubtfully referred to
the Naugus Head series. North of Wenuchus Lake, in Lynn,
is a hill composed of a nearly pure feldspar rock, — a
coarse, whitish fieldspar, apparently the same as that so well
developed on the Beverly shore. The rock is massive, having
the aspect of an exotic; and around the base of the hill it can
1) Prod. .B..S3) IN. yek Xa
23
be seen penetrating the Huronian diorite. It is undoubtedly
safe to regard this as an outlier of the series in question. In
what precedes I have described all the areas of the Naugus Head
series marked on the map; but recent observations have con-
vinced me that others exist. The hills immediately north of
Wadsworth’s Station on the New York and New England Rail-
road, in Franklin, appear to be entirely composed of a rock very
similar to the prevailing type on Salem Neck, — quite destitute
of quartz, and consisting chiefly of a coarse, triclinic feldspar, of
bluish and grayish colors, with some mica, dark-colored, and
often bronze-like, a green mineral that may be hypersthene, and a
very little hornblende or pyroxene. No stratification is visible ;
and the boundaries of this area are entirely unknown, save that
it does not appear to extend much, if any, south of the railroad.
The high hills in Sharon, near Sharon Centre, and on either
side of the Boston and Providence: Railroad, appear to afford
another area of these rocks. These hills are near the centre of
the large area marked on the map as Huronian diorite ; and some
observations made by Mr. F. W. Very, in Foxboro’, in connec-
tion with my own, lead me to suspect that, on the geological
map of the future, the Naugus Head series will demand a con-
siderable portion of the territory here assigned to a newer for-
mation. Among the rocks occurring here I have recognized the
most of those found in the Salem and Beverly areas. They are
of all textures, and some varieties hold abundant grains of
magnetite or menaccanite. In passing over the road leading
north-easterly from Reading Village, and about one mile from
the Boston and Maine Railroad, I have observed several ledges
of a coarse, apparently exotic, dioritic rock, the chief constitu-
ent of which is a coarsely crystalline plagioclase, which I am
strongly inclined to believe is labradorite; the rock, in that
event, probably being a norite. It is in a region where out-
crops are few and far between, and I could learn nothing of
its extent.
24
HURONIAN.
The rocks that may be referred to this system in Massachu-
setts, like those of the Naugus Head series, are believed to
occur only in the eastern portion of the State. They cover a
wide area; and, except where the Naugus Head series, Shaw-
mut group, and rocks of Paleozoic age face the Atlantic, they
form the seashore from the New Hampshire line to Plymouth.
This formation is bounded on the north and north-west by a line
running south-westerly from Salisbury through Essex and Mid-
dlesex Counties to Concord. Here, after giving off a long and
narrow deflection, which continues nearly twenty miles farther
to the south-west, the line bends to the south, and continues
through Framingham, Holliston, Medway, and Bellingham, to
the north-east corner of Rhode Island. On the south, it is met
mainly by the carboniferous rocks of Bristol and Plymouth
Counties.
The Huronian area has an extreme length, measured from the
New Hampshire line in Salisltury to Manomet Hill in Plymouth,
of sixty-five miles ; and a maximum breadth of forty miles across
the southern end, not counting the narrow band stretching from
Concord to Westborough. It is almost completely divided near
the middle by the Primordial, and, possibly, more recent rocks,
which lie about the shores of Boston Harbor, extending westerly
to Natick, and south-westerly to Rhode Island. On the accom-
panying maps the Huronian series comprises the areas marked
as ‘* syenite,” ‘* porphyry,” and ‘‘ hornblende slate,” on the geo-
logical map of Massachusetts, prepared by Professor Edward
Hitchcock.!
The existence in Eastern Massachusetts of rocks of Huro-
nian age was first announced by Dr. T. Sterry Hunt, in 1871.
In a paper on ‘* Granites and Granitic Vein-stones”? he speaks
of the « felsites” and «< felsite porphyries,” or ‘‘ orthophyres,” oc-
* Ihave marked the Huronian boundary on the map with a heavy line, for the sake
of greater distinctness.
* Chemical and Geological Essays, p. 187.
25
curring in Lynn, Saugus, Marblehead, and Newbury ; and says
in thisconnection, ‘‘ These rocks are, throughout this region, dis-
tinctly stratified, and are closely associated with dioritic, chlo-
ritic, and epidotic strata. They appear to belong, like these,
to the great Huronian system.” Dr. Hunt has included here all
the rocks which it is proposed to refer, in this paper, to the
Huronian series, save the binary and hornblendic granites
(which are so characteristic of Kastern Massachusetts) and the
limestones. In consequence of finding the Hozoon canadense
in the serpentinic limestone of Meakin, Dr. Hunt, in 1870,
referred this limestone and the associated rocks, as well as the
more crystalline and ‘less serpentinic limestones of Chelmsford
and Bolton, and the gneiss in which they are included, to the
Laurentian system. He made no mention, in this connection, of
the serpentinic limestone in Lynnfield, which is probably of the
same age as the Newbury deposit, since the associated rocks
appear to be the same. Prof. C. H. Hitchcock, also, in 1871,?
referred to the Triassic period, certain diorites in the vicinity of
Salem and Boston, which are here referred in part to the Nau-
gus Head series, and in part regarded as of Huronian age.
And more recently, in his late report (1875) on the geology of
New Hampshire, he has applied the term ‘‘ Labrador” to this
broad Huronian area, although these rocks have scarcely a
single character in common with the Labrador or Norian series
as defined by Dr. T. Sterry Hunt and the Canadian Geological
Survey.? It will be shown in the sequel, however, that all the
rocks within the area described probably belong to one and the
same lithological and stratigraphical series, the general characters
of which stamp it as Huronian.
A glance at the maps will show that the attempt to delineate
this formation lithologically, 7. e., to show the distribution of
its various lithological members, has been attended by moderate
1 Amer. Jour. Sci. (2), xurx., 75.
2 Geological Map in Walling’s Atlas.
8 Still later, in the atlas of the New Hampshire Survey (1878), Prof. Hitchcock
recognizes the existence of several limited Huronian areas in Essex County.
26
success. More might have been accomplished with a longer
time for exploration; yet much must ever remain undone, on
account of the great extent to which the rocks are, in some dis-
tricts, concealed by superficial deposits. A special color has
been used to represent the general Huronian formation wherever
the particular lithological representative is not knewn; but the
probabilities are great that the rock, whatever it is, belongs to
this age.! .
The Huronian system in this region, like the Naugus Head
series, though in a somewhat less degree, exhibits great disturb-
ance. Distinctly bedded rocks are the exception ; and, although
many apparently structureless rocks are probably really strati-
fied, it is undoubtedly true that a large part, perhaps the greater
part, of the formation has been more or less fluent, and ex-
travasation may be set down as a characteristic structural
feature. The extent to which some of the rocks of this series,
in Eastern Massachusetts, are characterized by a condition ap-
proaching chaos, can be fully appreciated only by those’who
have studied them somewhat in detail in the field. The strati-
fied portions of this series have usually a N. E.-S. W., vary-
ing to HK.—W., strike ; and the areas of unstratified and extrava-
sated rocks generally exhibit in their trends a tendency to
parallelism with the strike of the stratified rocks. The latter
usually dip steeply to the north-west.
The Huronian series of Eastern Massachusetts is principally
composed of the following rocks, or, rather, groups of rocks : —
1. Granite (hornblendic and binary).
2. Petrosilex (passing into felsite and quartzite).
3. Diorite (unstratified and largely exotic).
4. Hornblendic Gneiss, Stratified Diorite, etc.
5. Limestone.
1 In adopting the plan, wherever practicable, throughout this work, of mapping the
various formations lithologically rather than geologically, I have done much to keep
my facts and theories separate.
27
Although so connected lithologically and stratigraphically as
to be clearly members of one great series, yet these various
groups are, on the whole, well separated, occurring mainly in
large masses. The stratigraphic distinctness would be much
more striking but for the wide-spread extravasation which some
of the divisions have experienced. Their general separateness
implies that they are, for the most part, of different ages,
—are chronologically distinct; and may each be regarded
as a sort of sub-formation. | Whence it follows that, in all
their more special relations, they admit of separate description ;
and that is the plan adopted here. The different groups will be
taken up in regular order, beginning with the oldest. The true
sequence, excluding some of the limestone, is expressed in the
foregoing classification.
GRANITE.
The typical granite of this region, as shown at the quarries
in Quincy and other places, is a coarsely crystalline aggregate
of orthoclase, quartz, and hornblende. Orthoclase is the pre-
dominant mineral, and in its abundance constitutes the leading
character of the rock; this is pre-eminently a feldspathic gran-
ite. The hornblende is usually small in amount, and the rock
frequently passes, through the disappearance of hornblende, into
binary granite. All the Huronian granites of this region, and
especially this typical variety, are remarkably firm and coherent,
being strongly contrasted, in this respect, with the most of the
granite of the Montalban and newer formations. In Topsfield,
in and near the village, the granite is locally rather loose and
friable ; but this is the only instance of the kind within my
knowledge which is not clearly the result of atmospheric action.
And it may be said that these granites, as a rule, resist chemi-
cal quite as well as mechanical forces. The colors of the gran-
ite are mainly due to the feldspar, the hornblende seldom being
sufficiently abundant to sensibly darken the tint of the aggre-
gate. The feldspar is usually grayish or bluish, though differ-
28
ent shades of red and pink are very common, and green and
other tints are frequently met with. Feldspars of several dis-
tinct colors are sometimes commingled in the same hand speci-
men. * os Pe
ee oe ee
= v
77
purple. It rarely holds pebbles, and might be described as de-
void of all traces of sedimentary structure but for the limited
patches of banded petrosilex above described, which occur in it,
and differ from it only in being banded. We have no reason
to doubt that this rock is mainly petrosilex. A characteristic
brownish-red specimen from Lynn contains 73.9 per cent. of
silica. Towards the north, in Lynn, the rock varies much, is
frequently of a gray or drab color; and near the reservoir, on
the road to Dungeon Rock, it holds grains of quartz as well as
feldspar. Where the tongue of granite penetrates the petro-
silex on the west side of Wenuchus Lake, these two rocks
appear to have reacted upon each other, producing mutual
modifications, so that the contact is now marked by a zone of
debatable ground, in which one seems to find all sorts of transi-
tions between petrosilex and granite; and it is clear that one,
perhaps both, of these rocks must have been fluent.
Of the same general character — frequently quite compact,
and never very porphyritic —is the most of the petrosilex in
the north-west corner of Saugus and the adjacent portions of
Wakefield and Melrose; also in Medford, north of the Naugus
Head diorite, where it shows frequent local approximations to
granite ; in short, this is the prevailing, the characteristic va-
riety of petrosilex for the entire Lynn and Medford area. A
grayish, non-porphyritic specimen from Maplewood gave 72.6.
per cent. of silica. At many points in North Saugus, between
Main Street and Saugus River, the rock is more than usually
porphyritic, yet it holds numerous pebbles, and may possibly
belong with the breccia; this, however, is improbable, since
the undoubted breccia contains pebbles of this pebble-bearing
petrosilex. Are there two breccias here? I think not, although
the appearances are not wholly inconsistent with that view.
Along Fulton Street in Medford, between Salem Street and
the granite on the north, there is a large area of a dioritic rock
which appears to alternate between granite and felsite. It
is composed mainly of pinkish and greenish feldspar, with some
hornblendic material which, inconspicuous and slaty-looking, as
78
a rule, occasionally assumes the form of slender crystals half an
inch long. Grains of quartz are rare, and usually wanting.
Some of the feldspar, at least, is triclinic ; and, although marked
on the map as petrosilicious, this rock, in the vicinity of Fulton
Street, is more properly a diorite. To the eastward, how-
ever, its physical characters change; and near the line between
Medford and Melrose it appears through the Shawmut brec-
cia as a compact gray base, holding conspicuous crystals of
plagioclastic feldspar and slender needles of hornblende. Thus
it is clear that we here have a felsite passing into diorite. A
somewhat similar, but more porphyritic, rock is found still far-
ther east, beyond the Boston and Maine Railroad. This closely
resembles the crystalline layers in the stratified felsite at Dun-
geon Rock in Lynn, and, like that, it has the composition of a
true felsite, the percentage of silica being not quite 63. It car-
ries a few pebbles, however, and hence I am obliged to regard
it as possibly a recomposed rock, related to the diorite only by
derivation. Near the northern boundary of Melrose it appears
again, decidedly crystalline and free from pebbles; and on the
west side of the railroad at Greenwood Station there is an im-
mense exposure of a light-colored, feldspathic, crystalline rock
resembling that on Fulton Street in Medford, but finer grained,
which should be set down as diorite, though probably passing
into felsite. It is very basic, yielding only 57 per cent. of silica.
Indications are not wanting that all of these dioritic felsites in
Melrose and Wakefield may belong to the Shawmut group.
Granitoid petrosilex, such as occurs on the south-western end
of Marblehead Neck, has been observed at only two points in
the Lynn and Medford area, on the Newburyport turnpike in
Malden, and in North Saugus, near where Main street crosses
the Wakefield line. At both places the rock is very local, and —
yet its transition character is plain.
This extended area of petrosilicious rocks, although many
times larger than the Marblehead Neck region, and fully equal-
ling that limited area in structural complexity and the variety
of problems which it presents, has been the field of even fewer
ee —
79
observations; in an area where the student should traverse
nearly every square rod, there are almost whole square miles
which I have not seen. ‘The insufficiency of my observations
has necessitated the foregoing summary treatment of this
interesting region. Any other course would have involved me
in serious errors of commission as well as omission.
There are petrosilicious rocks in Reading and Woburn, inter-
stratified with quartzite, hornblendic gneiss, and other rocks ;
but since the amount is small and the close relations to the
associated rocks very evident, I will defer further mention of
them until that group is taken up. oi
Petrosilex in Needham. —Outcrops are very rare in the
narrow strip marked as petrosilex south of the Boston and
Albany Railroad, in the northern part of Needham, and hence
this area is largely conjectural. Near the station in Wellesley
the rock is reddish-brown, compact, and has a quartzose
appearance. It is probably continuous with the quartzite in
Natick, and appears to be everywhere closely associated with
the coarse granite.
Quite distinct from this is the petrosilex of the large area in
-the central and southern portions of Needham. The rock is
remarkably uniform over this entire area. It always presents
a compact, grayish or greenish-white base,porphyritic with feld-
spar crystals, and the most of the rock is elvanite, holding
grains of transparent quartz in addition to the crystalline
feldspar. The quartz grains are half a line to a line in diame-
ter, more conspicuous than the feldspar, and they seldom
assume the shape of crystals. Toward Newton Upper Falls,
and east of the Charles River, in Newton, the visible quartz is
wanting. So far as observed, the rock never holds pebbles
nor exhibits any traces of bedding; and yet very commonly it
presents a slaty appearance and yields to the knife, raising
doubts as to its Huronian age. The base is sometimes absent,
or nearly so, the rock being crystalline throughout, and ap-
proaching granite. A specimen from the railroad, one mile
south of Needham Station, afforded 75.45 per cent. of silica,
80
from which, and its great uniformity, I infer that this rock is
all petrosilex. The vertical joint planes in this rock frequently
intersect in such a manner as to develop a beautiful and perfect
columnar structure. The columns are not uncommonly hex-
agonal, four to eight inches in diameter, eight to twelve feet or
more in length, and as true and regular as any in basalt. Sey-
eral fine examples of this structure are exposed in the cuts on
the New York and New England Railroad, north-east of Charles-
River Village.
Petrosilex in Dover, Medfield, and Dedham. — The two
small patches of petrosilex along the railroad in Dover and
Medfield exhibit local transitions toward granite and diorite.
The rock is of greenish and grayish hues. My data from this
region are meagre, and further exploration would probably dis-
cover more of these small islands of petrosilex among the
granite and diorite. The petrosilex of the large area in Dover
and West Dedham presents many varieties. As a rule it
becomes more crystalline toward the west, appearing to pass
insensibly into the granites which border it in that direction.
On the other hand, we are as yet unable, as already stated, to
separate the petrosilex from the breccia on the south. The
difficulty here arises from the enclosure of pebbles in portions
of the petrosilex adjacent to the breccia; and the question is un-
settled as to whether the explanation found adequate on Marble-
head Neck will fit the similar phenomena in West Dedham.
The magnificent exposures in the former locality greatly facili-
tated the determination of the relations of the rocks. The
main body of the petrosilex in the vicinity of the breccia is of a
greenish hue, waxy lustre, usually not very hard, and, save when
holding pebbles or an occasional grain of quartz, quite compact.
It seems to have the composition of petrosilex, an average speci-
men from the hill west of the ‘‘ Oven Mouth,” on Main Street,
giving 72.35 per cent. of silica. Yet its inferior hardness,
usually yielding to the knife, suggests recomposition, though it
may mean simply decomposition. It does not differ in this
respect, however, from much of the elvanite in Needham.
81
What appears to be the same rock, minus the pebbles, and
sometimes more crystalline, covers a large area to the north
and west, being the prevailing variety in this region. The
pebbles are very rare, except in the immediate vicinity of the
breccia, and here they are never so numerous as to give the
rock a conglomerate aspect; ¢.e., as regards texture, there is
nothing like a transition from the petrosilex to the breccia.
Morover, the breccia holds pebbles of a petrosilex indistinguish-
able from that in question. The pebbles are usually petrosilex, |
but many granitic pebbles have been observed ; these are fine-
grained. The petrosilex pebbles are commonly pinkish, and
this is the color of many of the pebbles in the breccia. |
At the corner of Main and Pond Streets in West Dedham,
and quite near the breccia, there is ‘‘ flattened pebble” or schis-
tose petrosilex, identical, save that it has a reddish tinge, with
that studied on Marblehead Neck. It bears no resemblance
as regards either structure or component materials to the adjoin-
ing breccia. More or less distinctly banded petrosilex is known
to occur at several points in this Dedham and Dover area, but
always in small patches. On Dover Street, in Dover, it holds
rounded grains of quartz. Toward the east, on and near Fox
Hill, we have the most typical petrosilex which this area affords.
It is black, hard, and compact, except at one point where Mr.
Very has observed banding. The bands are distinct on the
weathered surface, but entirely wanting on the fresh fracture ;
and, since this petrosilex is very homogeneous throughout, we
conclude that it was probably all banded originally. This rock
has contributed many pebbles to the breccia. A specimen from
Fox Hillhas been found to contain 72.9 per cent. of silica, and
18.7 ‘per cent. of aluminum and iron sesquioxides. uw
THe HeLIQTYPE PRINTING Co
)
ema |
|
-—
(Z6 Pear. St, Boston
t
Occas papers, Bost. Soc. Naf. Hist. II. Plate . 3.
Ry ;
ton,
.
o ©
3
s
c i:
acai @)
& ~ SS
20 SS et.
<=
E SS z
a ;
yn ‘y
be
fi a
v G
ard Si
S c
U q
£ ra
oe
re o
3 a
aa =
3 &
*
= a
get
—
non Chi
pad ]
~ 6
© e
mu =
= a
r—
3 i]
E :
Lv pd
5 i
D
x 7 9
a 2 |
s 3 .
Zz, % 4
A °
4 & ne
OD « ca)
a S nv
: fh.
We
- *
Pig. 3. Merrimac Synclinal from Westford to Dunstable.
THe HevorvPe PRINTING Co
Occas. papers, Bost. Soc. Nat. Hist. II.
el LLL: ITED)
Fig. 2. North side of Hewitts Cove . SE |
ce
om Spas
pode BOE UN RNTE D709 DO RAVEY SY
ATS: aM ]/ EAE OL bf FOS I DAB SOR I+ x
gobs obanteusng AMM iter toe BDSS SER Sa eet
Fig 3. Bakers Hill, Himgham.NW. across synclinal.
3
é :
hig.4. Blacks Creek and Rock Island Cove anticlinal,
y nearly ¢m.W. of O.C.R.R.Quincy. &
“4 ;
A Fi
xy
G7 F020 98d
ay) if] rv) 90 Ono
bopo hg Upoe oy
89908 0 2 ahyoe?
Fi g. 5. Same as above 125rods farther west. 8
%
ii NS
Liv} ) §0
ous
AAO)
x
slate bandin Dorchester.
Horizontal seate of Pgs L 2,3, 40rd 3 = about JOO? to an rok;
and of Fig.6 = 1800 ftwon wxct.
Tinea olhexe pear
}HE MELIOTYPE + RINTING VO
Plate 5.
Occas. papers, Bost. Soc. Nat. Hist. II.
‘ jf ’ iy
;
‘ , 4 fo
Si mg OE,
1 4
vton Centre . Chestnut. Hill
f 406 06 ‘ ‘| in = ra
lp Dp) A 0 of vote Fis *fo%. ony yes)
ali from W @
: . : Refevences for Plates 4 and 5.
feral Gainite - Sw} Setrostter. FG Amyg dato . Fess) hegtonvenrate,
Occas, Papers. Boston Soc. Nat. Hist., Vol. Ill.
(ay linge
Take Boy
{
yEVIAAGE
i \3 ay
SCALE, 1 Mie to J Iven
Fy = 2
GeO LOGICAL M. \p
OF
EASTERN MASSACHUSETTS:
Se
Naugus Head Series
Hurontan
sor
NVonlatlban «
———$———_
I and of ——
==
were OF lh
FD all
: == nga
BY
H
W. O. CROSBY.
1877.
Explanation of Colors:
Grancle
Petrostlex
Diortle
Limestone
General Hurontan
Grantle
GNnetss
Mica State
/ Irgillile
Limestone
Hornblendictneiss kc. ==
L
[-
;
4
|
Shawn wt Group
| Breccia
| dmvgdaloid ft
; f { Conqlomerale
Primordtatl Ss
Slate
Devonian2 | |
Carboniferous ‘aoe “4
—,
Post Pliocene |
Shawmut Breccia and Amvyvgdaloid
are not distinguished on the small
Map. Primordval Slate and Conglom
erale ditto.
Niue
A Marigot (0h
Arrows and accompanying Cujures
whow dérection and umount of dip,
Parallel broken lines shaw directo
of glacial stria
ey
ry ey
Ln (SM Momaiowe
. :
cs
<
aS)
SS, yf : SCALE,
AW
(( (yy) i= \ = 5
——— >
ASUBY ng
Kosi sts
y//)
« =
Wachterett S
=e
=
UK LNG tks
=
Ped dojelk
rt Leak
(a
SHA Heit
Ns
Wand Se, i
{MOUTH
LANDING;
Tintves| PLATS,
ARS 2
a Grantle
~» 7p DaEeeeEEeen
Gnetss [ |
Mica Slate
Se
Post Pliocene ers
- Montalban « Shawmut Breccia and Amygdaloid
are not distinguished on the small
Map. Trimordiat Slate and Conglom.
erate ditto,
Argilile
__ SCALE, 1 Mix to 1 Ise Limestone
A Meriaal 110, Beacon
ey Salisbury Marsh
i) |
Arrows and accompanying figures
show direction and amount of dip.
Parallel broken lines show direction
of ylactal striae
“ sf
\
\\ Y YF \ \ =
=
> ASH BY
fm
= \ erreug un
=e
Wachusett
chunsete
va
2
a Bumsker
~ wie
SS
As if A =
y
% {
3 {
Es = : — == = = =F : Lebiagss 1 /;
= ; 5
5 = = oN
Heaconpote ® *
tra) | thestarie —
cork, Se 7X [) ie
as ttn eSB TD i XQ
Len “KST
Roe aa oN \ -BLACKST
==
=
7
0
A Mtum Pond
SoupRTL Serre re K
by,
a
°
>
SCALE, 5 Mires rol Ixcu
i
a
DUXBURY
‘
j if { glk ie , ;
“tt y Sih a7] a se rer tT a
Ri ; ) ; }
L Dron ww DO a
-
RE AS ie Oe I iy ODORS a vary tJ
; : ; iy wei SS
— — ~ a a — eich
ser eg Ne LA NT
-
a
r
+
-
“ed
4
‘ m hs c :
; : a |
is or 4 Py a 5 5
«- - ‘ , ¥ 4 =“ rs
; = 3" .
a AF 24 es }
wey e * P 4 ‘
: é ae i |
: be % ‘ j }
' 3
Vv ; eo ; a q
' “ eg
. a. j fe,
be : 3 ~ s
: J Se
. i 7 ‘ Z
\ > 4 |
. D ’ 4 7 , oa 7
; ; A ,
- ye 4) 7
7 +
Re, b 10S acs
) ‘ ba 2 1
- f teal 1 2 ia bs a
; et , eo ?
| ; ae ae
; mt 5g Fk eae ‘ "
iy
x ‘ | ‘ 7 :
eo ’ ‘. “et ~ i
; re : } Z : Wea
; “ + nO ew t ag
‘ ; Rea eet Tare
. \ - » — = e “Wy
; ; ae af ret
¥. \ : = ‘ >
; .
j at
f
- i 1
: ‘
% Sen, r a
|
4
Ke ,
4 . “h %
’
. i ud ‘ a
‘ » ae { i
’ me Ye y
7 \*
/" *- sean) oj ply om
; j 3 ‘ F : Mb ees -
y ‘ J s a }
~ - 5
- * ye . ¥
t Al Ps 5
ee
: . ; yt
4
re $
: j ;
j — ‘
‘ j
1 > ;
7 i ‘ «il
we “hes, ms —edayit yi 17
> dine te OI
3 ' ¢ % - ihe
' By ate ¢ 4 (tls eYES
~),
oat i ; a5 ee =
1 ty Pa PTE), Ma SI, pete
4.4 ry v PJ
’ \ > at e ‘
a Ae ee Re | , ~ : ;
oS ae Shs ae ; :
j
wt oy . : ’ i
3 r es ‘ i
- : 1 f (
: , :
q 4 : :
. és
, ; : ' } yw ‘
Ag I ” gl <
| 5 a Fe we a a ;
& ae : 4 , :
ears oR eS a es 9
' y Ny van, ee ? id - # 2 =
‘om a2 ae grin t i
+ ‘ : m3 aa? = " *! ss 9
- . 2
re, : . q ' : =
‘4 hae : . Tw 5 |
era a SS atl
PI) =n ‘ Z, , y a >: y) aS OS
: ; 5 ; as
: ; ‘a
: : oe
7 he ¢ 7
ee yh, Ree ; 4
- x y!
'
, a
3 ‘
‘/ re . €
rty
‘ S by hh
wy |S 4
‘ i
‘ J
‘ S ” -
.
‘
/
-
¢
4 . ‘
"
1 MAM sh
\ 5
, ‘ a ls ,
; * bata ah ‘ 7
. * i i .
‘ HH Lad
vey” wi 4
és e y
Tee
3 1853 10004 5