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GEOLOGY 


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; THE 


AMERICAN (GEOLOGIST 


A MONTHLY JOURNAL OF GEOLOGY 


AND 


ALLIED SCIENCES 


EDITORS AND PROPRIETORS: 


SAMUEL Cavin, Jowa City, Towa. 
Epwarp W. CLAyYPoLe, Akron, Ohio. 
Francis W. Craain, Colorado Springs, Colo. 


JouNn EyERMAN, Haston, Pa. R. D. Santispury, Madison, Wis. 
PERSIFOR FRAZER, Philadelphia, Pu. ANDREW C. Lawson, Berkeley, Cal. 
Roperr T. Him1, Austin, Texas. JOSEPH B. TYRRELL, Ottawa, Ont. 


Epwarp O. Unricn, Newport, Ky. 
IsraEL C. Warren, Morgantown, West Va. 
Newton H. WincnHest, Minneapolis, Minn. 


VOLUME X. 


JuLY TO DECEMBER, 1892. 


MINNEAPOLIS, MINN. 
THE GEOLOGICAL PUBLISHING COMPANY 
1892. 


LL. KIMBALL PRINTING CO., PRINTERS. 


IIL 
y. (0 
CONTENTS. 
JULY NUMBER. 
A New Gigantic Placoderm from Ohio. aha K. 
W. GLAYPOLE. , 1 
The Stratigraphic Position of tie @eishice Mtarsietne Ene 
iii. GRANT +... 1. 4 
Notes on the Stratigraphy of a Portion of Genteal Appa 
lachian Virginia. N. H. Darron. me 10 
On the Significance of the White Clays of he Ohio Re- 
gion, FRANK LEVERETT. aes : 18 
The Relation of Secular Decay of Boake to Phe F ormation 
of Sediments. Ratpn S Tarr. tt) eo SERN SEES 1a on 5) 
Notes on Some Eeckdomiorplic from the "Dheonte Region. 
pillustratéd: |) W. H.-Hosgss...... : : 44 


On Some Basic Kruptive Rocks in the V conte of Lene: 
ton and Auburn, Androscoggin Co., Maine. [ Il- 
lustrated.| Grorcr P. MERRILL....... 49 


On the Occurrence of Typical Cheetetes in the Tiesotiani 
Strata at the Falls of the Ohio, and likewise in the 
Analogous Beds of the Kifel, in Germany. ee : 
EPALOG shy 1k MELOMING EXE, <>." \ chasms te. So. : 56 


Review of Recent Geological Literature —Tertiary Plants from Bolivia. 
N. L. Brrrron, 63.—Cuprocassiterite, a new Mineral. T. Mrexe, 
64—Bohemian Garnets. G. F. Kunz, 64.—Eleolite-syenite of 
Litchfield, Maine, and Hawes’ Hornblende-syenite from Red 
Hill, New Hampshire. W.S. Baytey, 64—The System of Min- 
eralogy of James Dwight Dana. E. 8. Dana, 64.—The Manning- 
ton Oil Field and the History of its Dev elopment. [. C. WHITE 
65.—Notes on the Geology of the Valley of the Middle Rio 
Grande. E. T. Dumsie, 65.—Revision and Monograph of the 
Genus Chonophyllum. Writ H. Suerzer, 66. 

Personal and Scientific News.—The Royal, Society of Canada; Annual 
Meeting, 66. 


AUGUST NUMBER. 
An Approximate Interglacial Chronometer. Pls. tv, v, 


Geer LE VV INOHML Lee fleet picks se eos 69 
Notes on Manganese in Canada. H. P. BruMELL...... 80 
Keokuk Group of the iene Valley. CHas. 8: 

BEACHLER . a SER ee 8S 


25 RTR 


IV Contents. 


New Lamellibranchiata. Pl. vir. E. O. Unricn......: 96 
The Geologic Evolution of the Non-Mountainous Topo- 
eraphy of the Texas Region. Ros. T. Hitn.... 105 
Notes on Earthquakes in Nicaragua, February 6, 1892. 
J. CRAWEHOR Dia. 056). 5 os + 2s peters Saudia ay aliens toh oan 


Review of Recent Geological Literature Tt He Barth aa its Inhabitants. 
Exiser Reexvs, 119—Bosquejo de una Carta Geologica de la 
Republica Mexicana. Pror. Antoyto Drv CastiLLo, 119—Bei- 
triige zur Geologie und Paleontologie des Republik Mexico. 
Dr. J. Fenix und Dr. H. Lenker, 120—The Geology and Paleon- 
tology of the Cretaceous Deposits of Mexico. ANGrLo Het.- 
PRIN, 121.—Correlation Papers—Cretaceous. C. A. Wurrr, 121.— 
Official Maps of the Republic of Mexico. Minister pr FoMENTO, 
121.—On the Clinton Iron Ore. C. H. Smyrue, 122—The Ortho- 
ceratidee of the Trenton Limestone of the W innipeg Basin. J. 
F. Wuarreaves, 124——The Geological and Natural History Sur- 
vey of Minnesota, Nineteenth Annual Report. N. H. WInNcHELL, 
124—The principal Mississippian Section. Cuiras. R. Knyzs, 125. 

Recent Publications —125. 

Correspondence —Termination of the Column of the Crinoid Hetero- 
crinus suberassus. Dr. D. T. D. Dyce, 180.—Glacial Strive in 
Kansas. lL. C. Wooster, 131—In the Texas Panhandle. Enpw. 
D. Corn, 131.—Dr. Wahnschaffe’s Work on the Drift Deposits of 
Germany. JoHN Bryson, 1382. 

Personal and Scientific News, 134. 


SEPTEMBER NUMBER. 
Description of two new Genera and eight Species of Cam- 
erate Crinoids from the Niagara Group.  CHAs. 
WacHsMUTH and FRANK SPRINGER............. 135 
Notes on a Collection of Fossils from the Lower Magnesian 


Limestone from Northeastern Lowa. 8. CALVIN.. 144 
The Scope of Paleontology and its Value to Geologists. 

BS: | Wal MBS och ieee eee aero reas eeee 148 
Some Problems of the Mesabi Iron Ore. N. H. WINCHELE. 169 


Editorial Comment.—The United States Geological Survey, 179. 

Review of Recent Geological Literature—The Montana Coal Fields. 
Watvrer Harvey Weep, 181—Summary Report of the Geologi- 
eal Survey of Canada for the year 1891. A. R.C. Senwyn, 182. 
—KEssayo Esladishio del Estado de Jalisco. Mariano BARcENo, 
182.—Paleeozoic Formations in Southeastern Minnesota. C. W. 
Haru and F. W. Sarprson, 182—Geology of the Taylorville Re- 
gion of California. J.S. Drezer, 183.—Jura and Trias at Tay- 
lorville, Cal. ALpreus Hyart, 188.—The Geological Map of the 
United States and the U. 8. Survey. JuLtes Marcov, 188. 

List of Recent Publications, 184. 

Correspondence.—Geology at the Meeting of the British Association at 
Edinburgh, 188. 

Personal and Scientific News—Notes on the Meeting of the Geologi al 
Society of America at Rochester; Notice of the Rochester 
Meeting of the A. A. A. 8.; The World’s Congress of Geologists ; 
New Discoveries of Manganese —193. 


Contents. Vv 


OCTOBER NUMBER. 
The Head of Dinichthys. [lllustrated.] E.W.Criayponrk 199 


Extra-Morainic Drift in New ae eY [Illustrated.] A. 
Ne, VV RAGHU No 335 cass Se OE Pah Ame 207 


Address of Prof. Charles Tiasaaeoh Eatote he Géoloateal 
Section of the British Association for the Advance- 


MCUMOn eetomue, PCM MER MSc ce ee 225 
Pleistocene Papers read at the late Beblogic sal Me -etings at 
TRGVELIPRSIT ETS er aaa Be A PANE 


Editorial Comment.—Geological Reminiscences of Rochester in 1892, 
242. Ward’s Natural Science Establishment, 245. 

Review of Recent Geological Literature—An Introduction to the Study 
of the Genera of Paleozoic Brachiopoda. James Hann, assisted 
by Joun M. Crarke, 251—Development of the Brachiopoda, and 
Classification of their Stages of Growth and Decline. CHARLES 
E. Brercuer, 253.—Annual Report of the Department of Mines 
and Agriculture, New South Wales, for 1891—Paleontology of 
the Cincinnati Group. Jos. F. JAMES s, 256—The Laramie, the 
Closing Stage of the Cretaceous. WuHrrman Cross, 256.—Thick- 
ness of the Devonian and Silurian in Western New York. C, 
S. Prosser, 257. 

Correspondence—Some Remarks on Professor Henry 8. Williams’ Ad- 
dress before Section E., A. A. A.S., at Rochester. Jutes Mar- 
COU, 257. 

Personal and Scientific News.—The Sixth Meeting of the International 
Congress of Geologists, August, 1894; The Next Annual Meet- 
ing of the American Association for the Advancement of 
Science; The Utilization of Lignite in Texas; The Age of Ko- 
zoon; Another Old Outlet of Lake Huron; Miscellany, 260. 


NOVEMBER NUMBER. 
New Lower Silurian Ostracoda. [Plate 1x.] KE. O. UL- 


III CIES. a" cho ORE ko ot oct SOM Res arene: 1o° 0 Fie tora ERE 203. 
Two New Lower Silurian Species of Lichas (Subgenus 

Hoplolichas). ([Illustrated.] E. O. Unricu..... 271 
The Platyceras Group of Paleozoic Gasteropods. C. R. 

Keys e.) 3); SEE Ee, Spc: ta ee ER Pal ips 
Classification of the acanieg of the Osiern of ean Ored 

Ramee hy creareuminins (33 258. Rey kes ee WUE. 
On the Formation of Oolite. A. RoTnupLetTz.......... 279 
The Immediate Work in Chemical Science. A. B. Pres- 

COT 4 5b ey RO BIO IE Lee ICHEN CLINE CARCI: Gite a bsid Dee nena 282 
Voleanie Dest eam Onaha Roa Je Oils. .!: 295 
New Discoveries at Baoussé Roussé, Near Mentone. Mar- 

QuIS pE NADAILLAC........ Sa 8 eee 296. 
The Shore-Lines of Ancient Glacier Lakes. J. KE. Topp. 298 


Editorial Comment—An Interglacial Chronometer, 3802.—A Mortuary 
Bittersweet, 303.—The Topographical Map of the United States, 
304. 


VI Contents. 


Review of Recent Geological Literature —Third Report of the Geologi- 
cal Survey of Texas. E. T. Dump, 311—Some new Species 
and new Structural Parts of Fossils. 8S. A. Miiurr, 316—Geo- 
logical Survey of Missouri. Arrniur Wixstow, State Geologist, 
The Higginsville Sheet in Lafayette County, 317.—Stratigraphy 
and Succession of the Rocks of the Sierra Nevada of California. 
James E. Miuts, 318—The Geology of the Crazy Mountains. J. 
E. Wourr, 319.—Geologie de l’ancienne Colombie, Bolivarienne, 
Venzuela, Nouvelle Grenada et Ecuador. Herman Karsten, 
321.—Report on the Geology of Seer Alabama and Ad- 
jacent Portions of Georgia and ‘Tennessee. CC. Wintarp Hayes, 
322.— Advance Sheets from the Eighteenth mhennel of the Geo- 
logical Survey of Indiana, Paleontology. $8. A. Minimr, 323.— 
The Mapping of Missouri. Arriur WiInsLow is as —Protolenus, 
a new Genus of Trilobites. G. F. Marrurw, 327.—The Round- 
ing of Sandstone Grains of the Trias, as Pen on the Divi- 
sions of the Bunter. T. Metiarp Rerapn, 324.—The Glacial 
Succession in Europe. JAMES Grikif, 327.—The Iron Deposits 
of Arkansas. R. A. F. PENRosE, 324.—Classification of the 
Cephalopoda; Penfieldite, a New Species; On Nepheline Rocks 
in Brazil, Part m. O. A. Derpy, 326.—Studies of the Muir Gla- 
cier, Alaska. H.F. Rerp, 326—Gibraltar. PaunL Cnorrat, 326. 

Correspondence-——-W. M. Harvey. R. T. Hron, 328.—On the Keokuk 
Group. C. H. Gorpon, 327. 

Personal and Scientific News scoveries at Mentone; Mesozoic 
Fossils from Central Himalaya; The Peary Greenland Expedi- 
tion; The Michigan Mining School.—829. 


DECEMBER NUMBER. 
A Preliminary Examination of So-Called Cannel Coal from 
the Kootanie of British Columbia. D. P. PENHAL- 


LOW. hte ee eens RNR Oa Dol 
Gondiinns of Segura era on Drumline " WARREN Up- 

2. 0 Pana Ui Mert a De boa UNS oy en ES fy biomass. 339 
The Geologic Structure of the Blue Ridge in Maryland 

and: Viroinia! CAR DE UR MK Une aeaeee ie mee eee 362 
On the Classification of the Dyas, Trias and Jura in 

Northwest Texas. Junzs M AROCOU Se rates ees 369 
The Areal Work of the United States aublogieall Survey. 

A Gator! iene oC oh OR Mo a ae NT eld emer BIT 
The Present Basal Line of Doings of pre ‘Jarbonifer- 

ous in Northeastern Missouri. C. R.. Krygs....... 380 


Editorial Comment.—The First Deead of Tie Gronoatsr, 384. 

Review of Recent Geological Literature—Man and the Glacial Period, 
G. F. Wriairr, 8387—Mammalia from Mongolia, R. LypEKkKer, 
389. 

List of Recent Publications, 389. 

Correspondence —The Third Texas Report, R. T. Hrru, 393.—Voleanic 
Dust in Kansas and Indian Territory, 8. W. Wi.utsron, 396.— 
Classification of the Cephalopoda, F. A. Barner, 396.—The 
Movements of Muir Glacier, G. Frepprick Wriant, 397. 

Personal and Scientific News, 398. 

Index, 399. 


The Amentcan Grotoatat, Vou. X, Prare I. 
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THE 


Pe KICAN GEOLOGIST 


Vou, X. JULY, 1892. No. 1 


[PaLaZONTOLOGICAL NOTES FROM THE LABORATORY OF BuUCHTEL COoL- 
LEGE.—NO. 1.] 


A NEW GIGANTIC PLACODERM FROM OHIO. 
E. W. CuayPpoie, Akron, O. 

To the two genera and species of gigantic placoderms from the 
Cleveland shale described some years ago by Dr. Newberry in the 
Paleontology of Ohio, and in the Monograph on the fossil fishes 
of North America, published by the U. 8. Geological Survey, has 
recently been added a third, equally formidable in its armour and 
scarcely less in size. This creature has been brought to light by 
the labors of Dr. Wm. Clark, of Berea, O., to whom geologists 
are also indebted for the material of great additions to our knowl- 
edge of some of the older forms of this remarkable ichthyic fauna. 
The new fish was found during the autumn of 1891, on the hori- 
zon and near the place which had yielded Dinichthys and Titan- 
ichthys. : 

Though resembling these, and especially the former, in general 
character, it yet exhibits at least one peculiar feature, in so far as 
yet known, which is sufficient at once to differentiate it from both 
its enormous contemporaries. 

It is not at present possible to give any adequate account of the 
whole animal, as only a portion of it has yet been found. This 
preliminary note will therefore be limited to a description of the 
lower jaw and the teeth, which have been completely extricated 


2 The American Geologist. July, 1892 


from the matrix, A great part of the rest of the head still re- 
mains broken and bedded in the stone, and much time and great 
labor must be expended before we shall be in a position to fully 
describe this. No part of the body has been discovered. 


GORCONICHTHYS CLARKI 


EXPLANATION OF FIGURE. 

Lower left mandible of Gorgonichthys clarki 25 inches long, showing 
groove worn by premaxillary, lateral process and denticles, and overlap 
of apparently two bones ankylosed together (mandibular and articular). 

Premaxillary tooth, broken, point only. 

Lateral tooth, fitting against lateral process of mandible. 

Rone, exact nature uncertain, apparently a second lateral tooth in up- 
per jaw. 

Gorgonichthys, g. n., Lower jaw or mandible. 

In general outline this resembles the corresponding bone of D/- 
nichthys, from the largest species of which also it does not much 
differ in length, being in this—the only specimen yet known—25 
inches long. There is the same upward curve at the hinder end, 
where also the bone thins away to a blade-like plate, the end of 
which was apparently received between two thin bony plates and 
afforded attachment for enormous muscles. The ankylosis of the 
two bones of which the jaw consists is firmer than in Dinichthys; 
that is to say, the jaw appears almost as if itconsisted of only a 
single bone. 

A little in front of the middle the mandible rises into a rounded 
tooth-like process an inch and a half high and occupying about 
four inches of its length. Hach slope of this process is set with 
a row of five or six denticles or rather denticular serrations of the 
bone, standing at right angles to the surface. The resemblance 
of the fish in this point to Dinichthys hertzeri of the so-called Hu- 


New Gigantic Placoderm.— Claypole. 3 


ron shale, is manifest. D. terrelli, however, of the Cleveland 
shale, has no such denticles. ‘ 

Sinking in front of this process to its average level, the jaw 
again rises so as to form at its extremity a strong pointed tooth, 
closely resembling that of Dinichthys, roundly triangular in out- 
line and having a total hight of five inches. The whole hight of 
this tooth from the lower edge of the jaw is nine inches. 

Upper jaw. 

Opposite to this tooth in the upper jaw is one correspon ling to 
the great ‘‘premaxillary” of Dinichthys as described by Newberry. 
The specimen is somewhat imperfect, as its base (or upper part) 
has been broken off. So far as preserved it appears rather rounder 
in section and smaller than the great premaxillary of Dinichthys. 
As in that genus, however, it fitted close against the outer and 
hinder face of the great mandibular tooth, already described. 
This is proved by the groove which it has worn, and in which it 
was lying when found. 

Behind this is the remarkable tooth which most perfectly char- 
acterizes the genus. Homologous to the cutting upper blade of 
the shears of Dinichthys, it evidently performed no similar func- 
tion in the animal. Neither on it nor on the tooth-like process in 
the lower jaw above mentioned is there the slightest sign of wear 
or rubbing, such as is always visible on the jaws of Dinichthys. 
This tooth, which measures nine inches from the front to the 
back by seven inches in a vertical direction, is totally different 
from the rounded upper blade of D/nichthys, and much heavier. 
It terminates downwards in two blunt processes, whereof the fore- 
most is the larger and the more prominent. Between these fitted 
the blunt projection of the lower jaw, though the signs of wear are 
not very conspicuous on either. Both show the usual hard, close 
and polished bony structure that marks the teeth of these fishes. 

The mode of attachment of the upper teeth to the head is, as 
in the case of Dinichthys, not yet known, but their position and 
their evident adaptation to the lower jaw leave no doubt of their 
relationship. The whole outfit constitutes the most formidable 
dentary weapon yet known from this or perhaps from any horizon 
excepting possibly “Carcharodon” of the Kocene. 

In addition to all the above there is another bone whose form, 
structure and position when found strongly indicate a close rela- 
tionship to them. This has been represented in the figure, not- 


4 The American Geologist. July, 1892 


withstanding the uncertainty resulting from our inability at pres- 
ent to pronounce on its exact position. The blunt tubercle on its 
lower side shows all the usual marks of having been a denticular 
process, and it almost certainly lay close behind the great tooth 
last deseribed. In default of certainty on this point, howeyer, I 
prefer merely to indicate its probabilities, and to leave its deter- 
mination for the future. 


Found in the Cleveland shale, near Berea, O., by Dr. W. Clark, and 
named for him in acknowledgement of his patience and perseverance in 
exhuming and extricating it.* 


THESTRATIGRAPHIC POSITION OF THE OGISHKE 
CONGLOMERATE OF NORTHEASTERN 
MINNESOTA.t+ 


By Uny 8S. Grant, Minneapolis. 

In the region of Ogishke Muncie or Kingfisher lake (T. 65-6, Lake 
Co., Minnesota) is a marked conglomerate of considerable extent. 
It is well known to lake Superior geologists as the Ogishke con- 
glomerate. It consists of pebbles of slates, graywackes and 
other clastic rocks, together with those of acid and basic erup- 
tives, all embedded in a matrix of varying composition. Fre- 
quently this matrix is a dark or light colored argillaceous slate; 
at other times it resembles graywacke, and again it acquires a 
greenish color and approaches the chloritic schist of this region. 
But perhaps the most characteristic facies of the matrix is an 
impure quartzyte with angular and rounded grains of quartz; 
fragments of feldspar and hornblende are also present. The 
pebbles are of all sizes up to those over a foot in diameter. They 
are usually well rounded and are sometimes elongated in the 
direction of the strike. The rock has been more or less meta- 
morphosed and in places the pebbles approach so near the matrix 
in character that the conglomeritic nature of the rock can be seen 
only on favorable weathered surfaces. The beds as a rule stand 
nearly vertical with a general northeasterly strike. However, 
it is often the case that no lamination can be discerned. The 
conglomerate, as far as known, fades off both along and across 
the strike, by simple loss of the pebbles, into the argillytes, green- 


*A short notice of this fossil was given at the meeting of the Geological 
Society of America at Columbus, O., in December, 1891, and the name 
was then first proposed. 

+Published with the permission of the State Geologist of Minnesota. 
Read before the Minnesota Academy of Natural Sciences, June 14, 1892. 


Ogishke Conglomerate.— Grant. 5 
stones and graywackes to the north, which have been described 
as belonging to the Keewatin series. The exact geographical 
extent of the conglomerate is not fully known; it covers an area 
of nearly fifteen miles inthe immediate vicinity of Ogishke Muncie 
lake, and has been seen to the north on the west shore of West Sea 
Gull lake and also in Ontario at the northwestern corner of 
Saganaga lake.* There has been no general agreement in regard 
to the relation of the Ogishke conglomerate to the surrounding 
rocks, and so it has seemed advisable, in the light of recently 
discovered facts bearing on this point, to give a brief outline of 
the opinions of the different geologists, who have worked in this 
region, concerning the position of the conglomerate; and also to 
state what is definitely known in regard to this question. 

The first notice and discription of this conglomerate was 
given by Prof. N. H. Winchel! in 1882.7 In that description he 
applied no particular name to it, but since then it has been 
universally known among lake Superior geologists as the 
Ogishke Muncie or Ogishke conglomerate. At first he regarded 
it as part of the series of black slates (Animike) occurring on 
Gunflint lake and also of the series represented by the slaty 
argillytes of the vicinity of Knife lake and westward (Keewatin).t 
On further study, however, the correlation with the latter series 
was entirely abandoned, and until 1887 he regarded this con- 
glomerate as the basal member of the Animike.? [See end of 
this paper, paragraph on the use of the term Ogishke conglom- 
erate.| In passing westward from the low dipping Animike of 
Gunflint lake to Ogishke Muncie lake, he says: ‘There is thus 
seen to be an undeniable gradation from the Animike into the 
[upper] conglomerate.’’|| ‘‘The formation of horizontal slates of 
the vicinity of Gunflint lake and the international boundary is the 
same as the highly tilted slate and quartzyte formation that 
passes into the slaty conglomerate of the region of Ogishke 
He regards the Ogishke conglomerate as separ- 


XE 


Muncie lake. 


*A, C. Lawson, Lake Superior Stratigraphy, AMER. GEOLOGIST, vol. 
VII, page 324, May, 1891. 


+Geol. and Nat. Hist. Survey of Minnesota, 10th (1881) Ann. Rept., p. 90. 
tIbid., pp. 94-95. 
§Ibid., 11th (1882) Ann. Rept., p. 170; 15th (1886) Ann. Rept., p. 381; 


16th (1887) ) Ann. Rept., pp. 91, 97- 98; Lith (1888) Ann. Rept., pp. 17, 20, 24, 
47; AMER. GEOLOGIST, vol. I, pp. ae 14, Jan., 1888. 


Geol. and Nat. Hist. Survey of Macaie 16th (1887) Ann. Rept., p. 91. 
**Tbid., 17th (1888) Ann. Rept., p. 17. 


So 


The American Geologist. July, 1892 


ated from the Keewatin by an overlap unconformity,* and in 
correlating it with rocks of other parts of the lake Superior region 
he makes it the Minnesota equivalent of the lower slate conglomerate 
of the original Huronian,t thus putting it as the basal member of 
the original Huronian group. 

Dr. Alexander Winchell, while admitting the possibility of the 
Ogishke conglomerate being part of the Animike,} still firmly 
believed it to be much older and an upper part of the Keewatin. 2 
“The prima facie evidence would make'it part of the Keewatin 
system, conformable in structure and consecutive in history. ”’|| 
‘‘Lithologically and stratigraphically, therefore, the identification 
[of the Ogishke conglomerate with the Keewatin] seems to be com- 
plete. * * * * * * Qn structural as well as lithological 
grounds the conglomerate seems to belong to the Keewatin series. '** 
“Of this, however, I feel authorized to testify—the range of rocks 
lying within the field of my explorations in Minnesota, represents 
but one system.’’tf Later he said that he regarded the Ogishke 
conglomerate as a basal conglomerate ;ii he probably meant the 
basal member of «a division of the Keewatin, as he certainly did 
not regard it as at the base of the Keewatin. 

Prof. R. D. Irving thought that the Animike slates of Gunflint 
lake were once continuous with the folded slates of the region of 
Knife and Ogishke Muncie lakes, and that these latter were part 
of the Vermilion lake series of slates (Keewatin).22 ‘:His (Mr. 
W. M. Chauvenet’s) work thus far, as also the results of our 
microscopic study of the sections gathered, has tended to show 
that the Knife lake schists are actually the Animike slates ina 
folded condition.”’|||| ‘‘The folded schists of Knife and King- 

*Ibid., p. 68. 


+The Animike black slates and quartzytes and the Ogishke conglom- 
erate of Minnesota, the equivalents of the “original Huronian,’ AMER. 
GEOLOGIST, vol. I, pp. 11-14, Jan., 1888. 


tGeol. and Nat. Hist. Survey of Minn., 16th, (1887) Ann. Rept., pp. 
349, 359. 

STbid., 15th (1886) Ann. Rept., pp. 179, 194-195; 16th (1887) Ann. Rept., 
pp. 844-350, 359-360; Proceedings of A. A. A. 8., XX XVIII, 1889. 

16th (1887) Ann. Rept., Minn. Survey, p. 347. 

**Tbid., p. 348. 

+tIbid., 15th (1886) Ann. Rept., p. 195. At this time he had not seen the 
Animike. 

ttTbid., 18th (1889) Ann. Rept., p. 215; foot note. 

SSU. S. Geol. Survey, 5th Ann. Rept., pp, 206-207. 

|| |Ibid., p. 207. 


‘ 


Ogishke Conglomerate.— Grant. ( 
fisher (Ogishke Muncie) lakes belong evidently to the Vermilion 
lake band.’* 

Prof. C. R. Van Hise agrees with professor Irving in plac- 
ing the Ogishke conglomerate as the equivalent of part of the 
Animike and in separating it from the Keewatin or that part 
of it which he terms the lower Vermilion, meaning by this the 
iron-bearing series of the Vermilion lake region.t He regards 
the conglomerate as a newer formation folded in with the older 
rocks of his lower Vermilion. ¢ 

Dr. A. C. Lawson was the first to show conclusively that the 
Ogishke conglomerate is much older than the Animike and 
is separated from it by an enormous structural and time 
break. @ 

The opinions of the more noted geologists, who have recently 
worked in this region, having been given in outline, we will now 
proceed to a brief consideration of the relations of the Ogishke 
conglomerate to the rocks above and below it. This will be 
given under three heads:—(1) Relation of the Animike to the 
Saganaga granite, (2) Relation of the Ogishke conglomerate to 
the Saganaga granite, (3) Relation of the Ogishke conglomerate 
to the Keewatin. 

Relation of the Animike to the Saganaga granite. On the 
north side of Gunflint lake the Animikeis seen in contact with an 
underlying series of schists and granite. This granite is known 
as the Saganaga granite from the fact that the lake of that name 
lies almost wholly within its limits. || Now the almost horizontal 
Animike beds rest, in a practically undisturbed condition, on the 
truncated edges of these schists, which stand nearly vertical. 
And they (the Animike strata) also lie upon the granite perfectly 
unconformable, fitting into the hollows of the eroded surface. 
This unconformity of the Animike on the schists and granite has 

*Tbid., p. 208. 

+An attempt to harmonize some apparently conflicting views of lake 


Superior stratigraphy, Amer. Jour. Sci., iii, vol. xii, pp. 117-187, Feb, 
1891. 


tIbid., pp. 122, 124. 
SLake Superior stratigraphy, AMER. GEOLOGIST, vol. VII, pp. 320-527, 
May, 1891; especially p. 324. 


|For a fuller account of this granite area see: 
A. Winchell, Geol. and Nat. Hist. Survey of Minn., 16th (1887) Ann. 
Rept., pp. 211-226, 330-334. H. V. Winchell, Geological age of the 
Saganaga syenite, Amer. Jour. Sci., iii, vol. x11, pp. 386-890, May, 1891. 


8 The American Geologist. July, 1892 


been described by N. H. Winchell,* Irving,t A. Winchell,} Van 
Hise? and Lawson,|| and no one has ever questioned it. It is 
not necessary in this connection to discuss the age of the above 
mentioned vertical schists, concerning which some question has 
been raised,** but it is sufficient for the present purpose to con- 
sider only the age of the granite. From all our knowledge of 
granite it is never known to have been formed in or to have pene- 
trated strata near the surface; we are thus forced to conclude 
that after this granite came into its present place and condition 
and before the Animike was deposited there must have been a 
jong period of erosion, during which all the overlying surface 
rocks were removed, Thus there is an enormous difference in 
age between the Animike and the granite, the former being 
separated from the latter by a great unconformity and as long a 
period of erosion as is known in lake Superior geology. 

Relation of the Ogishke conglomerate to the Saganaga granite. 
This granite has been traced in numerous exposures from Gun- 
flint lake to the western side of Saganaga lake, and there can be 
no doubt that the granite which comes in contact with the 
Keewatin near the western side of the latter lake is the same as that 
underlying the Animike on the north side of Gunflint lake. On the 
northwestern corner of Saganaga lake Lawson has found this 
granite in direct contact with the Ogishke conglomerate, where 
the granite cut the conglomerate and the Keewatin rocks in a 
truly irruptive manner.t+ Recently the writer has been enabled 
to supplement the observations of Lawson by finding another 
contact between the conglomerate and the granite near the south- 
western corner of the granite area. At this place the irruptive 
nature of the granite in the clastic rocks is clearly seen; it cuts 
across the strike of the conglomerate and has forced its way in 
between the different layers. The granite has also been found 


*Geol, and Nat Hist. Survey of Minn., 9th (1880) Ann. Rept, p. 82; 
10th (1881) Ann. Rept., p. 88; 16th (1887) Ann. Rept., pp. 67, 69. 

+Amer. Jour. Sci., iii, vol. xxxtv, p. 261, Oct , 1887; U.S. Geol. Survey, 
7th Ann. Rept., p. 421. 


tGeol. and Nat. Hist. Survey of Minn., 16th (1887) Ann. Rept., pp. 233-269, 
357; Amer. Jour. Sci., iii, vol. xxxrv, p. 314, Oct., 1887; AMER. GEOLOGIST, 
vol. 1, pp. 14-24, Jan., 1888; Bull. Geol. Soc. Amer., vol. 1, pp. 886-388. 


SU. 8. Geol. Survey, 10th Ann. Rept., pl. XL1. 
| AMER, GEOLOGIST, vol. vir, p. 824, May, 1891. 
**Bull, Geol. Soc. Amer., vol. 1, pp. 387-393. 
++AMER. GEOLOGIST, Vol. vII, p. 324, May, 1891. 


Ogishke Conglomerate.— Grant. 9 
near by in irruptive contact with undoubted Keewatin rocks.* In 
consideration of the above facts—the relation of the Saganaga 
granite to the Ogishke conglomerate and to the Animike— 
there can no longer be any doubt as to the relative ages 
of the two series; the latter is much younger than the 
former, being separated from it by a great unconformity 
and a long erosion interval. The same is also true of the 
Animike and the Keewatin, no matter what is the age 
of the vertical schists on which the Animike lies at Gunflint 
lake. 

Relation of the Ogishke conglomerate to the Keewatin. This is 
a subject which as yet cannot be regarded as definitely settled. 
Van Hise? considers the two as different formations separated by 
an unconformity. But thus far no entirely conclusive evidence 
on this point has been found. A. Winchell? thought that the 
two were one and were not separated by any interruption in 
deposition. And it must be admitted that in many cases the con- 
glomerate is seen to pass into schists and slates which, as 
far as the author knows, have not yet been separated from the 
Keewatin proper either lithologically or by any structural break. 
There is still need of more detailed observations on this point, 
but it can safely be said that all are agreed that the conglomerate 
is more recent than most of the Keewatin,—no matter whether it 
is considered as a part of the Keewatin or as an infolded younger 
series. For the present it is perhaps better to consider the con- 
glomerate as a part of the Keewatin. 

No attempt to parallelize the Ogishke conglomerate with other 
formations in the lake Superior region is here necessary, it being 
the only object of this article to present briefly the various opin- 
ions on the position of the conglomerate and to state its actual 
relations, so far as is known, to the rocks in its immediate vicin- 
ity. The terms Keewatin and Vermilion have been used in the 
sense employed by the Minnesota survey,—~. e., the former is the 
series of greenstones, graywackes, slates and earthy and semi- 
crystalline schists extending from Vermilion lake to and through 


*More detailed accounts of these contacts will appear in forthcon. ing 
reports of the Canadian and Minnesota surveys. 

tAmer. Jour. Sci., ili, vol. x1, pp. 117-137, Feb., 1891. 

{Geol. and Nat. Hist. Survey of Minn., 16th (1887) Ann. Rept., pp. 547, 
348. Proceedings A. A. A.S8., XXXVIII, 1889. 


10 The American Geologist. July, 1892 


Knife lake; the latter is the series of holocrystalline mica and 
hornblende schists that often occur both north and south of the 
former. 

The term ‘‘Ogishke conglomerate” has been used in this paper, 
as before stated, as referring to the conglomeritic terrane of nearly 
vertical dip, which lies on the shores of and to the north of 
Ogishke Muncie lake. This conglomerate has always been con- 
sidered as a single formation, but in 1888 N. H. Winchell* stated 
some evidence for the existence of two conglomerates near this 
place and separated them into an upper and a lower member, which 
he provisionally referred to the Animike and Keewatin respectively. 
However, the younger of these is largely seen to the southeast of 
Ogishke Muncie lake and has not been studied by other geologists. 
So in this paper the older of these two conglomerates is the one 
under consideration. 

Summary. The Animike and the Ogishke conglomerate can no 
longer be parallelized, as has often been done, for the former is 
separated from the latter by a great structural break and a long 
erosion interval. For the same reason the Animike can not be 
correlated with the Keewatin. The relation of the Ogishke con- 
glomerate to the Keewatin has not yet been conclusively estab- 
lished, but all agree that it is younger than most of the Keewatin, 
and for the present it seems best to consider it as part of the 
Keewatin. 

Petrographical Laboratory of the Johus Hopkins University, 
Baltimore, April, 1892. 


NOTES ON THE STRATIGRAPHY OF A PORTION 
OF CENTRAL APPALACHIAN VIRGINIA. 
By N. H. Darvon, U. 8. Geological Survey, Washington, D. C. 

Itis the purpose of these notes to describe the salient features 
of the stratigraphic column of the region, to assign definite names 
to certain of its members, and to call attention to a significant 
unconformity at or near the base of the Devonian. The field 
studies were made mainly in connection with the preparation of a 
detailed geologic map of Augusta, Highland, and portions of ad- 


*Geol and Nat. Hist. Survey of Minn., 17th (1887) Ann. Rept., pp. 97-98. 


Stratigraphy of Appalachian Virginia.—Darton. 11 


jacent counties covered by the ‘‘Staunton Sheet” of the U. 5. 
Geological Survey. This map will soon be published, together 
with sections and explanatory text, so that information regard- 
ing the distribution of the formations and their structure need 
not be given here. 

The principal geologic publications relating to the region are 
the reports* and notest of the State Survey by W. B. Rogers, 
and a paper by J. L. Campbell, ‘Silurian formations in Vir- 
ginia.”t Although Rogers’ observations were made over half a 
century ago, his reports, and especially the notes, give a remark- 
ably accurate and comprehensive account of the stratigraphy of 
Appalachian Virginia, but they are so brief that local features 
are not described. In the classification of the Paleozoics Rogers 
subdivided them into sixteen groups, to each of which a Roman 
numeral was assigned asa name. For the Carboniferous forma- 
tions descriptive or geographic names were also proposed. These 
numerals have been used to some extent by subsequent writers, 
but names from the New York series have gradually been intro- 
duced, and in the section on the Virginias in Macfarlane’s Geo- 
logical Railway Guide, Rogers employs New York names to- 
gether with his numerals, for the formations below the Lower 
Carboniferous. 

Campbell’s paper describes a section from Lexington to Warm 
Springs valley, and includes a table of the Silurian rocks ‘‘with 
their subdivisions compared with equivalent epochs of Dana’s 
Manual.”’ 

Although the greater number of groups of the Lower Paleozoic 
of New York extend through Pennsylvania, and are more or less 
distinctly represented in Virginia, many of their component 
formations lose their distinctive characters, and their stratigraphic 
range is not apparent in the Virginia sections. Owing to this 
lack of evidence as to the precise stratigraphic equivalency and 
range of the Virginia formations in terms of the New York series, 
the use of New York terms is misleading, In the application of 
the New York nomenclature for Virginia formations names were 


*Reports of Progress of the Geological Survey of the State of Vir- 
ginia, (1836-1841). 


2 +The Virginias, Vol. 3, p. 194; Vol. 4, pp. 12, 18, 23, 38, 39, 59, 60, 71, 
2, (1882-1883). 


tAm. Jour. Sci., 3d series, Vol. 18, pp. 16-29, 119-128. 


12 The American Geologist. July, 1892 


selected somewhat arbitrarily and applied to beds in most cases 
comprising a much greater stratigraphic range than the name im- 
plies, including deposits having codjrdinate names in New York, 
but not presenting typical characters in Virginia. The system 
of classification and nomenclature by which I was guided in 
mapping the formations in central Appalachian Virginia 1s the one 
adopted by the U. 8. Geological Survey and described in the 
Tenth Annual Report of the Director, pages 56 to 79. The fol- 
lowing quotations from this report are given in explanation: 


“The structural divisions shall be the units of cartography and shall 
be designated formations. Their discrimination shall be based upon the 
local sequence of rocks, lines of separation being drawn at points in 
the stratigraphic column where lithologic characters change. * * * 
In every case the definition should be that which best meets the prac- 
tical requirements of the geologist in the field and the prospective 
user of the map; that is to say, each formation should possess such 
characteristics that it may be recognized on the ground alike by the 
geologist and by the layman. 

“As each lithologic unit is the result of conditions of deposition that 
were local as well as temporary, it is to be assumed that each formation 
is limited in horizontal extent; the formation should be recognized and 
should be called by the same name as far as it can be traced and identi- 
fied by means of its lithologic characters, aided by its stratigraphic 
associations and its contained fossils. 

“The formations shall receive distinctive designations. The most de- 
sirable designations are binomial, the first member being geographic 
and the other lithologic. * * * Whenthe formation consists of beds 
differing in lithologic character, so that no single lithologic term is ap- 
plicable, the word “formation” shall be substituted for the lithologic 
term (e. g., Potomac Formation). 

“Tn the application of formation names, the laws of priority and pre- 
scription shall be observed; but in general the name previously given 
to a structural unit of unlike definition shall not be given to the newly 
defined formation.” 


As the Staunton sheet is to be the first published of the maps 
of Appalachian Virginia, it was necessary in its preparation to 
carefully consider a nomenclature for the stratigraphic units for 
the region, and to select names which involved no further cor- 
relation than was at present practicable. To this end a few 
names already known were adopted, together with several new 
names derived from prominent localities in the general region. 
These names are applicable for all of central Appalachian Vir- 
ginia, and in some cases for a wider area. They are given in the 


Stratigraphy of Appalachian Virginia.—Darton. 18 


following list in which are classified the strata from Silurian to 
Lower Carboniferous: 


| Names adopted by Rogers’ Other names which 


Group. | U.S. Geol. Survey. | number. have been used. Thickness. 
’ Greenbrier limestone XI 
c 5 (W. B. Rogers.) 
Carboniferous. | Pocono sandstone x Montgomery grits 600 to 800 ft. 
(2d Geol. Surv. of Pa.) (W. B. Rogers.) 
( Hampshire formati’n] TX in part.) Catskill (in part?) |1000 to 1400 ft. 
Devonian. - Jennings formation |VIII ‘ Chemung ‘* ‘* 2800 to 3200 ft. 
/ Romney shales VAT Hamilton “ * 500 to 900 ft. 
{ Monterey sandstone VII Oriskany 0 to 300 ft. 
Lewistown limestone VI Lower Helderberg 300 to 600 ft. 
(2d Geol. Surv. of Pa.) 
Silurian. | Massanuttensandst’n| ITV and V | Medina and Clinton 600 to 800 ft. 
Martinsburg shales Ill Hudson River 800 to 1400 ft. 
Shenandoah lime- II Valley limestones. 1500 ft. 
L stone Trenton, Chazy, Levis, 
Calciferous. 


The term ‘‘Shenandoah limestone” is thought to be very appro- 
priate, for the Shenandoah valley and river are well known 
features of its area. The formation comprises in the Staunton 
region a great mass of impure magnesian limestones below, grad- 
ing upwards through a series of cherty beds of no great thick- 
ness into several hundred feet of light-colored, heavily bedded, 
purer limestones. The lower beds were not found to be fossilifer- 
ous. Inthe cherty beds only a few middle Ordovician gasteropods 
were found. In these beds the distribution of cherts is irregular 
in amount, horizon and continuity. The upper member is spar- 
ingly fossiliferous at many localities with a middle to upper 
Ordovician fauna in which the forms Orthis occidentalis, O. 
testudinaria, Leptena alternata, and Chutetes Lycoperdon were pre- 
dominant. Pleurotomaria subconica, Conularia — trentonensis, 
Platynotus trentonensis and several others were also noted. 

In his reports and notes Rogers made no attempt to subdivide 
the great limestone series but fully recognized the charactertistics 
of its several members. In his contributions to Macfarlane’s 
xuide the upper beds are placed in the ‘Trenton,’ and this desig- 
nation has been generally applied to them. J. L. Campbell, in 
the paper above referred to, describes five subdivisions in the 
Lexington region, but in the Staunton region no lines of separation 
were found to be sufficient for areal distinction, 

The Martinsburg shales succeed the Shenandoah limestone with 
a thin series of alternating thin bedded limestones and slates at 


14 The American Geologist. July, 1892 


their base. The name is taken from Martinsburg, in the Shenan- 
doah valley in West Virginia, a region in which the formation is 
extensively and typically exposed. Its largest areas are in the 
great syncline of the Massanutten mountains, and the long nar- 
row area bordering the great valley on the west along the flanks 
of Little North mountain. The rocks are slates and shales, 
mainly of dark color; in the Massanutten syncline thin beds of 
sandstone are included, and occasional limestone beds or calear- 
eous streaks occur at other localities. The beds are fossiliferous 
at many points; graptolites are found in the basal beds, notably 
in some light colored weathered shales in cuts of the Chesa- 
peake & Ohio railway, two miles east of Staunton and further 
east; along the Little North mountain, and in the Warm Spring, 
Crab Bottom and other anticlinal valleys westward, remains of 
upper Ordovician brachiopoda are moderately abundant. The 
forms most frequently met with are Leptana sericea, Ll. alter- 
nata, Orthis testudinaria, O. pectinella, and Modiolopsis modio- 
laria. The precise equivalency of the formation is not known, 
but judging from its general relations and fauna it probably com- 
prises the Utica, Hudson River, and possibly small amounts of 
adjacent formations of the New York series. It is the No. III 
of Rogers’ reports and has generally been called ‘‘Hudson River.” 

The Massanutten sandstone receives its name from the promi- 
nent Massanutten mountains in which it is typically developed. 
It also constitutes the Little North mountain, and many other 
prominent ridges in Appalachian Virginia. 

The rocks of the formation vary in local characters, mainly in 
color, thickness of bedding and degree of silicification, but 
white and red quartzites prevail. In most sections the basal beds 
are alternating beds of dark sandstones and shales; these are 
succeeded by white and grey quartzites, which in turn give place 
to thinner bedded red and brown sandstones and shales. The 
formation was separated into two portions, numbers LV and \V, 
by Rogers, the lower part supposed to be equivalent to the Medina 
sandstone, and the upper shaly series to the Clinton, Niagara and 
Salina of the New York series; but while this subdivision may 
be practicable in some sections of the state, it would be most 
arbitrary and variable in the region to which these notes relate. 
The fossil ore horizon containing a Clinton fauna is not well 
developed in the region west of Staunton, and fossils are rare 


Stratigraphy of Appalachian Virginia.—Darton. 15 


in any portion of the Massanutten sandstone series. In the Goshen 
pass there are several beds bearing molluscan remains, and Scoli- 
thus (verticalis?) and plants are conspicuous at some localities. 

The Lewistown limestone is believed to be the southern ex- 
tension of the beds comprised under that name in south central 
Pennsylvania. The formation is a light colored, heavily bedded, 
relatively pure limestone, of very uniform character. The oc- 
currence of cherty beds in its upper portion is a characteristic 
feature, and it is also notably fossiliferous. The fauna is Lower 
Helderberg, but in its lower portion are also intermingled Orthis e/- 
egantula and Spirifera niagaraensis, representative Niagara forms. 
The more plentiful Lower Helderberg species are Zuphrent/s roe- 
meri, NStreptelasma stricta, Orthis oblata, O. perelegans, Strepto- 
rhynchus wolworthania, Strophomena rhomboidalis, Strophodonta 
headleyana, S. beckii, Cyrtia dalmani, Neucleospira ventricosa, 
Spirifera cyclopterus, S. concinnus, S. perlammellosus, S. macro- 
pleura, S. vanuceni, Rhyuchonella nobilis, R. formosa, R. ab- 
rupta, Eatonia medialis, Atyrpa reticularis, Pentamerus galeatus, 
and many others. The beds have been called Lower Helderberg 
by most writers, but they unquestionably represent a somewhat 
greater stratigraphic range, and the name used by the Second 
Geological Survey of Pennsylvania has been adopted for them. 

The formation is brought up very often in the anticlinals of 
central Appalachian Virginia, and it is a conspicuous and valua- 
ble member of the Paleozoic series. It thins gradually east- 
ward, and southwestward it disappears for some distance in the 
New River region, to reappear in the southwestern corner of the 
state. 

The Monterey sandstone is an arenaceous bed, everywhere 
closely associated with the Lewistown limestone from central Vir- 
ginia through Pennsylvania. It is acoarse grained, light colored 
sandstone or moderately silicified quartzite, usually friable in its 
weathered outcrops. It is number VII of Rogers, and has gen- 
erally been called Oriskany. Its abundant and varied fossils are 

mainly of Oriskany forms, but Lower Helderberg and Hamilton 
fossils are intermingled to a greater degree than in the New 
York Oriskany. The most distinctive Oriskany species recog- 
nized were Orthis hipparionyx, O. museulosa, Npiripfera AVenOSUS, 
SN. arectus, NS. pyxidatus, Batonia sinuata and Rensseliria ovides, 


but there are many others. 


16 The American Geologist. July, 1892 


The beds undoubtedly comprise not only the Oriskany, but in their 
upper portion the representatives of the several coordinate members 
of the Corniferous group. For this reason and the general uncer- 
tainty of precise correlation a new name has been adopted for the 
formation, This name is that of the county seat of Highland county, 
Virginia,a region in which the formation is extensively developed. 
Whether to class the Monterey sandstone in the Devonian or Silurian 
is a question which will have to be decided by the paleontologists. 

Between the Monterey sandstone and the slates of the next 
succeeding formation there is an unconformity by erosion which 
presents some interesting features. Its vertical extent is not 
great, and it is apparently confined to the more eastern series of 
exposures, but it appears to extend for some distance along the 
Appalachians. In the region west of Staunton the Monterey 
sandstone beds are eroded to a varying depth which reaches its 
maximum in an area northeast of Goshen, where the black slates 
of the Devonian lie on an irregular eroded surface of the cherty 
member of the Lewistown limestone, the Monterey sandstone 
having been entirely removed. The southern extension of the un- 
conformity has not been studied with care, but the abrupt break 
between the black slates and Monterey sandstone is frequently ob- 
served for many miles southward. The absence of the Monterey 
sandstone and Lewistown limestone in the New River region is 
probably due to this unconformity, the occasional masses of black 
chert occurring in their place being the remains of the detritus of 
the latter. In Pennsylvania similar relations have been described 
in some of the central counties, where the ‘‘Oriskany”’ and more 
or less of the associated formations have been locally removed. 

In central Virginia and also in Pennsylvania to a less extent 
there are iron ore deposits at the base of the Devonian shales, 
In Virginia these deposits have been extensively worked at Low 
Moor, Longdale, Victoria Mines, Ferrol, Pond Gap, and many 
other places, and their existence appears to be closely related to 
the unconformity, I have examined these deposits at several 
typical localities, and they appear to lie on the eroded surface, 
where they were probably deposited as bog ores in shallow basins 
of greater or less extent. They have since been buried under 
the great mass of Devonian and Carboniferous deposits, and more 
or less secondary arrangement has taken place. This secondary 
deposition would be necessary, perhaps, to account for the nature 


Stratigraphy of Appalachian Virginia. —Darton. 17 


of the ores and the impregnation of the surrounding rocks with 
more or less ferruginous material. 

The Devonian formations in central Appalachian Virginia com- 
prise from 5,000 to 6,000 feet of arenaceous and argillaceous 
deposits, separable into three series. The basal members are 
fissile shales, in greater part black or dark brown in color, con- 
taining occasional thin beds of sandstone and limestone. Their 
average thickness is about 600 feet. They give place to a series 
of light colored shales, in which olive, grey, and buff tints pre- 
vail, with interbedded light colored sandstones, averaging in all 
about 3,000 feet in thickness. The local sequence of beds in 
this series is variable, but the medial portion consists largely of 
arenaceous members. The upper series is characterized by thin 
bedded, relatively hard, more or less micaceous sandstones with 
shale intercalations, in greater part dull red, dark grey, and 
brown in color. Its average thickness is about 1,200 feet. 

These series intergrade through beds of passage often amount- 
ing to several hundred feet in thickness, but this amount is vari- 
able in different parts of the region. In his reports and notes 
Rogers classes the two lower series under his No. VIII, and sepa- 
rates the upper member, possibly more, as No. 1X. The three 
series have also been more or less generally known as Hamilton, 
Chemung and Catskill, but without any definition of their range. 
Notwithstanding the extensive intergrading, the series are so well 
characterized as wholes that it seemed best to separate them as 
formations. As in the case with most of the other formations, 
it was found that there were no names in existence which could 
be employed with any degree of definiteness, so new names were 
selected. The names adopted were Romney shales, from Rom- 
ney in West Virginia, for the basal series of dark shales, Jen- 
nings formation, from Jennings’ gap and Jennings’ branch in 
western Augusta county, Virginia, for the medial series of light 
colored shales and sandstones; and Hampshire formation from 
Hampshire county, West Virginia, for the uppermost series of 
dark sandstones. The Devonian formations are not fossiliferous 
at many horizons in the region west of Staunton. In the Rom- 
ney shales the following species are Corniferous: Discina lodensis, 
D. minuta, Orthis leucosia, Strophodonta demissa, Cyrtina hamil- 
tonensis, Spirifera mucronatus, S, granulifera, and Leiorhynchus 

limitaris. This isa Hamilton group fauna, but the stratigraphic 


( 


18 The American Geologist. July, 1892 


range of Hamilton group equivalents in the Romney shales is not 
apparent, and Hamilton deposits probably extend some distance 
above. 

In the Jennings formation very few beds are fossiliferous, and 
they are mainly in the medial beds where Chemung and Portage 
forms occur comprising Spirifera disjuncta, S. mesocostalis, Strep- 
torhynchus chemungensis, Chonetes scitula, and others, 

The Hampshire formation has yielded only a few plant remains 
which throw no light on the equivalency of the formation, but no 
doubt it comprises the representatives of the Catskill in their en- 
tirety or in greater part. 

The Pocono sandstone is apparently the southern extension of 
the beds which bear the name in Pennsylvania. It is the No. X 
of Rogers. Its basal beds are coarse grained, quartzite sand- 
stones, sometimes conglomeratic, massively bedded, usually light 
erey in color, and always constituting either a prominent ridge or 
protecting mountain cap. Higher members are thinner bedded 
and dark in color, and contain layers of slate with thin irregular 
coal beds. These coals have been worked at some localities but 
usually without profit, for the beds are thin, irregular and gen- 
erally much crushed. Lower Carboniferous plant remains occur 
in the coal-bearing slates but no molluscan remains were observed. 

On the Staunton sheet the Pocono sandstone caps Elliott’s knob 
and various other high summits, particularly along the Shenan- 
doah mountains, and it also constitutes the high, narrow ridge 
known as Narrow Back mountain. 

The Greenbrier limestone has been described with considerable 
detail by Rogers, and I have nothing to add to his descriptions. 


ON THE SIGNIFICANCE OF THE WHITE CLAYS OF 
THE OHIO REGION: 


By Frank LEVERETT. 

The fact has long been known that in southeastern Indiana and 
southwestern Ohio the southern portion of the glaciated district is 
covered to a depth of several feet by clays, distinctly different in 
color and structure from the underlying glacial beds, and from 
the surface portions of the glacial drift further north. In the In- 


*The work whose results appear in this paper was carried on under 
the supervision of Pres. T. ©. Chamberlin, with whose permission this 
paper is published in advance of the more detailed official report. 


White Clays of the Ohio Region.— Leverett. 19 


diana Survey Reports the tracts covered by these clays are spoken 
of as ‘‘slash land,” and in the Ohio Reports they are called the 
‘‘white clay districts.” It has also been known for some time 
that there are somewhat similar clay deposits in southern Ohio 
outside the glacial boundary. So far as [am aware these deposits 
outside the glacial boundary have never been correlated with the 
white clays that cover the southern portion of the glaciated dis- 
trict, nor has a common origin been ascribed to them. On the 
contrary, they have been attributed to quite distinct agencies and 
conditions in the one district from those which have been assigned 
in the other. The clays outside the glacial boundary have been 
quite generally attributed to a submergence caused by the hypo- 
thetical Cincinnati ice-dam, while those within the glacial bound- 
ary, being evidently incapable of explanation on this hypothesis, 
have been attributed to organic agencies such as plants, earth- 
worms, ants, beetles,etc.,which bring fine material to the surface. * 

It is the aim of this paper to show that these deposits are syn- 
chronous, that they have a common origin, that that origin was 
independent both of ice-dams and of organic agencies, and, fur- 
thermore, that they furnish important evidence concerning the 
sequence of events in this region during the glacial period. 

In the summer and autumn of 1889, I made an examination of 
the portion of the upper Ohio region in the vicinity of the sup- 
posed Cincinnati ice-dam, extending my observations up the river 
as far as the point where the glacial boundary bears away to the 
northeast. Careful comparison was made between the white clays, 
or silts, on Beech Flats and adjacent districts in Pike, Highland 
and Adams counties, Ohio, lying outside Wright’s glacial boundary, 


*The greater part of the literature, relating to these clays, and also that 
relating to the Cincinnati ice-dam, is comprised in the following refer- 
ences: 

E. Orton, Geology of Ohio, Vol 1, 1873, pp. 444-446. 

E. T. Cox (and associates), The Connty Reports of the Indiana Survey 
pertaining to the southeastern counties of Indiana. 

G. F. Wright, Amer. Journ. Sci., July, 1883; @lacial Boundary in Ohio, 
1884, pp. 73-76, 81-86; Ice Age in North America, 1889, pp. 326-350; Bull. 
No. 58, U. 8S. Geol. Survey, 1890, pp. 83-104. 

I. C. White, Proc. A. A. A. 8., 1883, pp. 212-213; Glacial Boundary in 
Ohio (Appendix) 1884, pp. 81-86; Amer. Jour. Sci., Vol. 34, 1887, pp. 374- 
881; Bull. Geol. Soc’y Amer., Vol. 1, 1890, pp. 477-479. 

J. P. Lesley, Penn. Second Geol. Survey (Z), 1884, pp. rx to xr. 

E. W. Claypole, The Lake Age in Ohio, Trans. Edin. Geol. Soc’y, 1887. 

T. C. Chamberlin, Bull. No. 58, U. 8. Geol. Survey, 1890, pp. 17-38; Bull. 
Geol. Soc’y Amer., 1890, Vol. 1, pp. 472-475, 478-479. 

F. Leverett, Proc. Boston Soc. Nat. Hist., Vol. xxiv, 1890, pp. 455-459. 


20 The American Geologist. July, 1892 


and attributed by him to a submergence occasioned by an ice-dam 
at Cincinnati, and those which cover the glacial drift further west. 
No essential difference of any kind could be detected. In both 
localities the clay has a depth of 2—5 feet,is nearly free from peb- 
bles and coarse grains, and is usually so compact as to be almost 
impervious to water; sandy pockets occur in it, and there are 
places where the clay seems to graduate into a sand or fine gravel , 
it also frequently exhibits indistinct lamination. Such pebbles as 
occur are either cherty or are of distant (mainly Canadian) deriva- 
tion, no limestones having been observed. The clay contains 
very little calcareous material. The absence of limestone pebbles 
and the small amount of calcareous material may, however, be 
due to removal by leaching subsequent to the deposition. Con- 
eretions of iron oxide are common and conspicuous features, 
occurring in the form of balls in all sizes from one-half inch or 
more in diameter down to barely discernible grains. | The follow- 
ing result of a chemical analysis of the clay confirms the evidence 
derived from an examination of the coarse particles of the deposit. 
The analysis was made by T. G. Wormley, a chemist of the Ohio 
Survey, and the specimen is from western Highland county which 
lies within the glaciated district. It appears in the Geology of 
Ohio (Volume 1, page 445): 


Water combined tenner Pla jeae nesses  MOLOe 
STlicieh acid a sceeecieeeeee see tret che Ais 3 62.60 
ATUIMINay en eee ro chotenarcteveveteiels eroneteieniers 18.90 
Sesquioxideroi arom yee ees eraciee = soo aly 
Manganese, .<.... aeserne cieereinse ayes 0.20 
Phosphate of lime ......... eG esol “OCS 
Carbonateiof elimiemancm crear ice a Ratca oot 
Carbonate of masmesiaermnriekicee err ile 1.82 
Potash and soda... ..-.-....---= 6 door RES 

(Moe Paes souGagdsacadcodgat oon .. 10010 


Specimens of the clays covering Beech Flats, in Pike county, 
Ohio, and of those covering the till in Highland county, 15-20 
miles back from Wright’s glacial boundary, have been submitted 
to Prof. R. D. Salisbury for microscopic examination. He finds 
no essential difference in the specimens. In both situations they 
consist mainly of quartz grains, among which are feldspar frag- 
ments, hornblende and possibly epidote and augite; there are also 
minute iron oxide concretions and coarse grains of chert. The 
material is largely angular, even when the grains are of sufficient 
size to have been liable to rounding under favorable conditions. 


White Clays of the Ohio Region.—Leverett. 21 


Not only are the clays of these two localities similar in macro- 
scopic and microscopic aspect, but they form a practically con- 
tinuous sheet extending from the Beech Flats and adjoining low- 
lands outside Wright’s glacial boundary westward onto the glacia- 
ted districts of southwestern Ohio, northern Kentucky and south- 
eastern Indiana, occupying the site of the hypothetical Cincinnati 
ice-dam and showing as strong development below (west of) the 
site of the supposed dam as they doabove it. The fact that these 
clays cover a part of the glaciated district proves that their dep- 
osition occurred subsequent to the time of maximum glaciation, 
and their distribution shows that the ice-sheet nowhere reached 
the Ohio river while they were being deposited. It is evident, 
therefore, that their deposition cannot be attributed to an ice-dam 
on the Ohio at Cincinnati or at any point below. 

A feature of much importance in connection with these white 
clays isa black soil with leached and highly oxidized subsoil 
which immediately underlies them. The structure of this soil 
corresponds with that of the underlying drift sheet and as a rule 
it appears to be inseparable from it, though the weathering and 
the addition of humus has given it an aspect somewhat different 
from the unweathered portion of the drift. It is of very com- 
mon occurrence and indicates the lapse of a considerable interval 
between the retreat of the ice-sheet and the deposition of the clays 
Its presence effectually disproves the current theory that the white 
clay was derived through organic agencies, from the underlying 
sheet of glacial drift. 

It has been suggested that the presence of the white clays if 
not explicable on the foregoing hypotheses, might be explained on 
a theory of general submergence due to a depression of the region 
to sea-level, the main objection urged against this theory having 
been that it involves a great change in altitude. The facts now 
ascertained, however, remove this objection by indicating the 
occurrence of a depression of several hundred feet, but at the 
same time raise other and more serious objections to the theory 
of general submergence. It is scarcely probable that a body of 
water of the magnitude indicated, involving as it must have done 
considerable time in its incursion and withdrawal, would leave 
no shore lines sufficiently marked to have attracted notice, but so 
far as I am aware none have been reported. Furthermore presi- 
dent Chamberlin informs me that he has personally examined 


29 The American Geologist. July, 1892 


portions of the states in which, on this theory, such shore lines 
should occur, and not only found none, but discovered no evi- 
dence of any kind to indicate the presence of such a body of 
water. It seems necessary therefore to look further for a solu- 
tion of the problem. 

Comparison has shown a marked similarity between the white 
clay deposit of the Ohio, and the great silt deposit of the upper 
Mississippi. All the phenomena of structure and distribution 
indicate that they originated under similar conditions. This being 
the case it is evident that a hypothesis which weuld account for 
the phenomena of the Mississippi region, would also account for 
those of the Ohio, so for a solution of the problem we need only 
apply, to the latter region, an explanation which has proved sat- 
isfactory in the former. A detailed study of the upper Missis- 
sippi region, particularly of that part of it which borders the 
driftless area, was made several years ago by Chamberlin and 
Salisbury, and led them to the conclusion that the distribution of 
the loess and associated silts and clays is best explained on a 
hypothesis of fluvio-lacustrine deposition.* Evidence was found 
that the altitude of the region was much below the present per- 
haps not far above sea-level, but instead of its being occupied 
by an inland sea, it is their conception that the valleys became 
silted up so that at the maximum of depression they were occu- 
pied by shallow, perhaps marshy, lake-like rivers many miles in 
width, whose waters moved slowly seaward from the edge of the 
melting ice-sheet. The constitution of these silts shows a direct 
derivation from glacial waters. The presence of shells of land 
mollusea in the silts, indicates that the region was subject to occa- 
sional or periodic overflow rather than to perpetual and deep sub- 
mergence. 

The applicability of this hypothesis to the Ohio region may 
be made more clear by a consideration of its application to a part 
of Illinois, where similar phenomena occur, but under more simple 
conditions. For nearly a hundred miles north from the extreme 
limit of glaciation in that state, and extending from the Missis- 
sippi river eastward to the hilly districts of southern Indiana, 
there is a generally flat surface on which there are few, if any, 


*“«The Driftless Area of the Upper Mississippi Valley.” By T. C. 
Chamberlin and R. D. Salisbury. Sixth Ann. Rept. U. 8. Geol. Survey 
pp. 211-216, 278-307. 


White Clays of the Ohio Region.—Leverett. 23 


morainic features, though there is a nearly continuous sheet of 
till. A large portion of this till sheet is covered by a white clay 
which we have correlated with the white clay of the Ohio region. 
It is similar to that deposit in structure and thickness, and over- 
lies an old land surface with soil and leached subsoil. It may 
prove to be connected with the Ohio clays by a practically con- 
tinuous sheet, the deposit having been traced across Indiana ex- 
cept in the driftless portion of the state which has not yet been 
examined, 

The north boundary of this deposit is determined by a moraine 
of which it is apparently a dependency.* Northward from this 
moraine are several later ones, which were also formed under con- 
ditions of low altitude and slack drainage, as is shown by silt 
aprons which fringe their outer border. These moraines appear 
to have been formed in relatively rapid succession, no soil having 
been found separating the silts in their aprons from the under- 
lying till, They are succceeded on the north by a series of 
moraines which were formed under conditions of high altitude 
and rapid drainage as is shown by gravel aprons and gravel terraces 
leading southward from them. 

Returning to the Ohio district we find that the present north 
boundary of the white clays of southeastern Indiana and south- 
western Ohio, is determined by a moraine, but evidently it is 
not the moraine with which the deposition was connected. That it 
belongs to a later period is shown by moraine headed terraces in 
neighboring valleys which contain gravel and sand, indicating 
clearly that they were formed under conditions of high altitude. 
How far the advance, marked by this moraine, extended beyond 
the one which produced the silts is not known. ‘Two instances 
have been found where silts similar to the white clay occur be- 
neath the till of the later invasion at points a few miles north of 
the moraine referred to. At Greensburg, Indiana, which lies 
perhaps five miles from the border of the white clay district, 
Pres. Chamberlin found good exposures of fossil-bearing silt or 
loess beneath the till of the later ice-invasion (See Third Annual 
Report of the U. 8. Geol. Survey, p. 333). At Wilmington, 
Ohio, which is also situated afew miles north from the north border 


*A line connecting the following cities will show approximately the 
distribution of this moraine: Litchfield, Hillsboro, Pana, Shelbyville, 
Mattoon, Charleston, Paris and Terra Haute, 


24 The American Geologist. July, 1892 


of the white clay district, the late Dr. L. B. Welch found in many 
wells, ata depth of about 30 feet and beneath the till of the newer 
drift,a loess-like loam containing fossils. As yet it is not certain 
that these overridden silts should be correlated with the white 
clays, but they are of much significance in showing that the ice in 
the later invasion encroached upon silt covered districts. 

The fact that the clay deposits become thinner toward the 
south and are gathered into the valleys, strengthens the view that 
the condition which obtained at the time of their deposition was 
one of overflow rather than of general submergence. In both 
Indiana and Ohio, the thickness at the border of the moraine is 
four or five feet, occasionally greater, and a gradual decrease is 
found in passing southward, the thickness on the interfluvial 
tracts in southern Ohio, 20-30 miles from the moraine, being 
little more than half as great. In Indiana I have made no exami- 
nations so far south of the moraine but am informed by Pres. 
Chamberlin, who has explored the drift covered region to some 
extent in the vicinity of the Ohio river, that there is scarcely any 
white clay on the interfluvial tracts for many miles north of the 
river, There is, however, loess-like silt, in small amount, along 
the Ohio below Louisville which he thinks may be correlated with 
these white clays. It is not improbable that the Kast White 
river carried a large amount of water from southeastern Indiana 
at the time the white clays were being deposited. The white 
clays have been traced down its valley to the point where it 
enters the driftless portion of southern Indiana, and they have 
there as strong a development as anywhere in that part of the 
State. 

From facts presented in the above discussion it appears that 
the white clays and the moraines with which they are associated 
have a distinct chronological position, being separated from the 
earliest glaciation by an interval during which the till sheet was 
undergoing oxidation and leaching, and from the last glaciation 
by an interval during which a marked change in altitude occurred. 
Equally strong evidence of the occurrence of these intervals is 
found in the character of the drainage and the degree of erosion 
As to the relative length of the intervals, we can at present offer 
no opinion, little being known as to the length of time involved 
in the changes by which they are denoted. 


bo 
Or 


HE RELATION OF SECULAR DECAY OF ROCKS 
TO THE FORMATION OF SEDIMENTS.* 


Rawpu S. Tarr, Ithaca, N. Y. 


CONTENTS. 
I. Secular Disintegration. (b) Derived by Surface Wash. 
(a) Conditions of Decay. (c) Derived by Wind Action. 
(b) Characteristics of Residual Soils. (d) Derived by Ice Action. 
(c) Distribution of Residual Soils. (e) Derived by River Action. 
II. Formation of Sediments. (f) Derived by the Sea direct. 
(a) General Statement. g) Summary. 


I. Secular Disintegration. 


(a) Conditions of Decay. 

Rocks are composed of minerals in greater or less variety both 
as to character and quantity, and the decay of rocks depends upon 
both the chemical and mechanical weakness of the material, 
The chief factors in rock disintegration are the mechanical ef- 
fects of heat, frost and organic life, and the chemical decay of 
minerals. 

(QJuartzose rocks decay with extreme slowness and their disin- 
tegration is chiefly mechanical. Limestone disappears rapidly, 
but soil accumulates slowly because of the solubility of the com- 
ponent minerals, the insoluble impuritiesalone remaining. Slates 
and other clay rocks, being themselves largely composed of resid- 
ual products, and hence not subject to extreme chemical altera- 
tion, produce soil slowly except by mechanical means. The rocks 
best fitted for rapid and extensive production of residual soils 
are the crystalline rocks both of igneous and metamorphic origin. 
This is particularly the case with those rich in the lime soda 
feldspar, hornblende and the like. These are broken up by decay 
into the less soluble silicates and the soluble protoxide bases. 
Since a given quantity of a very easily destroyed rock, such as lime- 
stone, disappears quickly, but leaves a small residuum, whereas the 
same quantity of a less soluble rock disappears more slowly but 
with greater residual product, the resulting amounts of residuum 
in the two cases, in a given time may not be widely different. 

The chemical decay of rocks goes on often to a very great 


*This essay was prepared for another purpose, and is in the main an 
abstract of the present knowledge on the subject. ‘The scattered state 
of the literature on Secular Disintegration, and the general interest of 
the subject, has prompted me to publish this summary where it will be 
accessible. 


26 The American Geologist. July, 1892 


depth, and in many regions a deep residual soil has been the 
result. The best conditions for the formation of such a soil are 
a moist climate anda region of abundant vegetation which sup- 
plies to the percolating water the necessary acids with which the 
chemical alteration of minerals is advanced. It seems also that 
secular decay proceeds more rapidly in warm than cold climates, 
though of this we have as yet no fair test, since the regions in 
the north so far studied have been recently glaciated and their 
residual soils removed. Theoretically this should be a factor of 
importance, for the abundance of decaying vegetation, the amount 
of rainfall, the duration of time when, through absence of frost, 
the water can percolate into the soil from the surface, and the 
greater temperature of the water in warm countries, are all in 
favor of the greater activity of rock decay in such regions. 


(b) Characteristics of Residual Soils. 

The ultimate result of secular decay is essentially a soil of un- 
iform character, whatever the nature of the rock may be. This 
is so because as the process continues chemical alteration proceeds 
to the last degree, the greater part of the soluble salts are re- 
moved, and only the insoluble parts remain, and these are quite 
uniform in character. Thus Caamberlain and Salisbury* state 
that in the driftless area of Wisconsin the residual soil on the 
sandstone differs but little from that on the limestone except that 
it is compact on the surface and more siliceous below. 

The ¢mmediate product of decay, however, depends largely 
upon the character of the source. According to professor Pum- 
pellyt granites, syenites, gneisses, diorites, etc., produce argil- 
laceous sand or sandy clay; porphyries, basalts, trachytic rocks, 
ete., produce ferruginous clays; impure limestones and dolomites 
undergo the greatest shrinkage leaving masses of sandy clay, 
often with chert; and calcareous sandstones and clays also leave 
sands and clays. 

A residuum from secular rock-disintegration consists, in its 
best development, of several zones, grading insensibly down- 
ward into the undecomposed rock. On _ the surface it is a clay, 
more or less siliceous, composed almost entirely of insoluble 
minerals in a very fine state of division. This zone extends as 


*Sixth Annual Rept. U. 8. Geol. Survey, pp. 240-58. 
tAm. J. Sci. 1879, xvir, pp. 183-144. 


Relation of Secular Decay of Rocks.— Tarr. 27 


far down as thorough decay has extended. — Below this the clay 
contains a greater percentage of soluble salts, is less finely divided 
and often contains undecayed masses of rock. Chert and pieces 
of quartz of moderate size are found in regions capable of sup- 
plying such substances, while in some of the soils derived from 
such igneous rocks as granite and basalt weathered and rounded 
boulders of disintegration, often fresh in the core, are common. 
This gradually passes into the quite thoroughly disintegrated but 
not completely decayed rock, where all the minerals are present 
in original form, if not in substance, and where the original 
structure may be plainly traced, although the rock is as easily 
torn to pieces as so much unconsolidated clay. When this occurs 
in rocksof metamorphic origin, the planes of schistosity are often 
as well defined as in the original unaltered rock. This by de- 
grees grades into the perfectly fresh unaltered rock. 


(c) Distribution of Residual Soils. 

Such soils as the above are found in various parts of the 
‘world. In northern Europe and northern America they are 
absent, having been swept from the surface by the continental 
ice sheets. In America, in the Hoosac mountains, in western 
Massachusetts, the rock was found, in the western end of the 
Hoosac tunnel, to be deeply disintegrated, though no residual 
soil was found. * 

At several points in southern Massachusetts, decay in the plu- 
tonic rocks is quite marked; and at Middlesex Fells, west of 
Cambridge, a diabase dike is deeply disintegrated, in places to a 
depth of twenty feet, to a gravel which can be easily worked 
with a shovel.+ Rounded boulders with an undecomposed core 
are present in this mass. Similar cases occur in the very much 
rifted granite of Essex and Cape Ann, Mass.,} and these cases 
are post glacial, the disintegration being the same in glacially 
transported boulders as in the bed rock. In the Middlesex Fells 
dike the roches moutonées surface of the decayed diabase still 
retain the glacial strie. These facts show how rapidly disinte- 
gration may proceed, even in a cold climate, in rocks of weak 
chemical composition. The process is not complete in these in- 


*Hunt, Am. J. Sci., 1883, xxvr, 190-213. 
+First noticed by Mr. J. B. Woodworth, of Harvard University. 


tShaler, Ninth Ann. Rept., U. S. Geol. Survey, p 567; Tarr, Am. J. Sci., 
April, 1891. 


28 The American Geologist. July, 1892 


stances, for so far it has gone no farther than mere disintegra- 
tion. The production of a residual soil is a much slower process. 

The case of the Hoosac mountains mentioned above, may be 
one in which a preglacially decayed rock has remained unre- 
moved through the entire period of ice erosion. Whether this 
be so or not we have in the driftless area of Wisconsin, a very 
remarkable instance of a pre or interglacial residual soil in a 
region which was surrounded by ice, though itself untouched by 
the ice.* In this area there is a widespread clay, quite unlike 
drift clays in that it is never stratified, and contains no angular 
fragments. It is an exceedingly tenacious clay, retaining mois- 
ture, and when it dries forming a ‘‘joint clay.”” The grains of 
silica are somewhat dissolved and etched by solution and weath- 
ering, the alkaline bases are entirely decomposed and the more 
soluble residues removed, while only soluble substances remain, 
From the decayed limestone and dolomite strata, the lime and 
magnesia, together with such alkalies as may have been present, 
are dissolved away, the mechanically included foreign materials 
alone remaining. The average depth of this residuary material 
over the driftless area is 7.08 feet. 

A more marked case of secular decay is found in the Atlantic 
coast states south of the glacial belt.t The mica schists of 
Pennsylvania and Maryland are often disintegrated to a depth of 
from fifteen to thirty feet, but the rock is merely disintegrated, 
not decayed, hence residual clay is not common. In Virginia 
and the Carolinas the rocks are often decayed to a depth of one 
hundred feet. Of this region, Dr. Hunt sayst that the rocks 
‘care often covered to a depth of a hundred feet or more, by the 
undisturbed products of their own decomposition, the protoxide 
bases having been removed by solution from the feldspars, the 
hornblende and the whole rock, with the exception of the quartz- 
ose layers, reduced to a clayey mass, still, however, showing in- 
clined planes of stratification. ”’ 

Other writers have described the same region. Russell? men- 
tions a dolerite dike in the Triassic sandstone of North Carolina, 


*Chamberlain and Salisbury. The Driftless Area. Sixth Ann, Rept. 
U.S. Geol. Survey, pp. 240-258. 
_ Russell. Subaerial Decay of Rocks, etc. Bull. No. 52, U. 8. Geol. 
Survey, 1889. 

{Chemical and Geological Essays, 1871-78, pp. 187, 250. 

§Bull. 52, U.S. Geol. Survey, p. 12. 


Relation of Secular Decay of Rocks.—Tarr. 29 


which, though originally so hard that it will ring under the ham- 
mer has been transformed to a yellowish clay that can be moulded 
like putty. Fresh sections toa depth of forty feet show this de- 
cay to the bottom, but the enclosing walls of sandstone show no 
alteration. The resulting product is essentially a kaolin with 
about seventeen per cent. of ferric oxide. * 

Among the other instances of secular rock decay in the United 
States might be mentioned that of the Ozark mountains of Mis- 
souri, described by Prof. Pumpelly.t Here the secular dissolving 
away of the limestones, which carry from two to nine per cent. of 
silica and clay, has left residuary products varying in thickness 
from twenty to one hundred and twenty feet. 

The best development of secularly decayed soil is in the trop. 
ics. In Nicaragua such decay has often reached to a depth of 
two hundred feet, according to Thomas Belt,who says that this 
kind of decay is common in the tropics and is chiefly confined to 
regions of forest. t 

The remarkable decay of the rocks in Brazil, which, with the 
associated phenomena, led Louis Agassiz to ascribe its accumula- 
tion to glacial action has been described by various writers. Dar- 
win states¢ that in the vicinity of Rio Janiero both the granitic 
(metamorphic?) rocks and talcose slates are decayed to a great 
depth. Every mineral exceptthe quartz is softened sometimes to 
a depth of one hundred feet, but the foliation of the rock remains. 
Appalled.by the vastness of the phenomenon, seemingly unlike any- 
thing at present in operation, he ascribed its formation to action 
beneath the sea. Of the same region Hartt says|| that the gneiss 
hills are covered with a coat of red soil, structureless and unar- 
ranged, varying in depth from a few feet to one hundred feet. 
Sometimes there are included in the clay angular fragments of 
quartz and rounded masses of diorite, generally quite decomposed 
except at the very core. The gneiss beneath is decomposed to a 
depth of from a few feet to one hundred feet, the feldspars hay- 
ing been altered to kaolin, the mica having parted with its iron, 
but the planes of stratification still remaining. 


*Insoluble alumina Al, O, and Fe, O, increase, but Si O,, CaO, Nas 
O, Fe O, etc., decrease by this decay. 


yAm. J. Sci , 1879, xvi, 133-44. 

{Naturalist in Nicaragua, 1888, p. 86. 

§Geological observations, p. 427. 

|Geology and Physical Geography of Brazil, 1870, pp. 23-26. 


30) The American Geologist. July, 1892 


In India there is a remarkable deposit of clay, called laterite, 
the origin of which the Indian geologists have not yet definitely 
determined.* It is a red, sometimes mottled, porous, argillaceous 
rock much impregnated with iron peroxide and sometimes resemb- 
ling jasper, but not so hard as a purely siliceous mineral. It is 
often traversed by tubes, sometimes vertical, sometimes horizon- 
tal, and sometimes irregular, which are filled with clay. The rock 
when first quarried is so soft that it can be cut out with a pick; 
but it hardens greatly on exposure. There are two kinds of lat- 
erite, the “‘high level” and ‘low level,’ which in places seem to 
grade into one another, but which in their extremes are quite dis- 
tinct, for the former is rarely stratified, while the latter is most 
commonly banded and bears evidence of marine origin. The low 
level laterite will be considered under the discussion of sediments 
derived from secular decay. 

The upper laterite often passes insensibly into the underlying 
rock, whether it is igneous, metamorphic or sedimentary, the 
transition form being called lithomarge. Sometimes, however, 
the dividing line between lithomarge and bed rock is quite marked. 
The laterite is quite indestructible and the region occupied by it 
is generally barren. Its thickness varies from fifty to two hundred 
feet. The high level laterite occurs as high as 4,700 feet above 
sea level and is found chiefly on the traps of the Deccan plateau, 
though it also occurs on the older rocks several hundred miles from 
any traps. It must formerly have beea much more extensive and 
perhaps formed a continuous sheet, though now very much dis- 
sected by erosion. 

As to its origin, no definite conclusion is arrived at by the atth- 
ors, though the low level laterite is believed to have been derived 
from the upper laterite partly by the action of the wind, partly by 
stream action. One suggestion in regard to the origin of the high 
level laterite is that it has been derived from the decay of a ba- 
salt sheet formerly more extensive. | Numerous obections are 
found to this theory, chiefly the difficulty of accounting for such 
a sheet in many places where laterite is found. Another sugges- 
tion is that it represents the decayed product of a vast sheet of 
volcanic ash deposited during the formation of the Deccan traps. 
This theory the authors seem to think the most probable one thus 


*Medlicott and Blanford, A Manual of the Geology of India, 1879, 
Vol. 1, p. 348. 


Relation of Secular Decay of Rocks.—Tarr. 31 
) Yo 


far offered, though it is confessedly offered merely in the effort to 
suggest something plausible and is quite without facts in its sup- 
port. 

Strangely enough, origin by secular disintegration is not dis- 
cussed, though it may have been considered and found inapplica- 
ble for reasons not set forth in the treatise. To offer an expla- 
nation of a phenomenon simply upon the basis of the description 
of the phenomenon by others is extremely hazardous, and it is 
with much hesitation that I make the suggestion that the laterite 
may be the product of secular disintegration. So far as the de- 
scription goes, it may well be of this nature. It is an indestruct- 
ible clay of nearly uniform character sometimes grading down- 
ward insensibly into the rock below. As has been stated, resid- 
ual soils differ but little according to the nature of the source 
from which they have been derived, and the uniform character of 
the laterite may thus be accounted for as well as its occurrence on 
both basalt and gneiss. The description tallies remarkably well 
with that of the residual soils of the southern states aud Brazil. 
By removal into basins and valleys through subsequent denuda- 
tion a stratified product might well result, and, when carried to sea 
and deposited, a rock like the low level laterite might be expected. 
This would account for the apparent gradation of the ‘‘low level” 
laterite into the ‘‘high level” form. 

Enough has been said of the occurrence of residual soils to show 
that they are extremely widespread. They occur wherever con- 
ditions have been favorable. Given a moist climate in a region 
of slight topographic diversity and the conditions for the accumu- 
lation of a residual soil are brought about; and, if time is allowed 
such a soil will accumulate. In a mountainous region of diverse 
topography, little soil can accumulate, for it is washed off as rap- 
idly as formed. _ In such regions the decay of rocks and the con- 
sequent production of sediments is probably more rapid than in a 
region whose rocks are protected from frost. and other sub-aerial 
agents by a blanket of residual soil. Also, in arid regions, resid- 
ual soils do not readily form, partly because of the general ab- 
sence of humidity and vegetation, and partly because the soils 
which do form are quickly removed, either by wind or water, on 
account of the absence of protective vegetation and the general 
aridity. 


Se) The American Geologist. July, 1892 


IT, Formation of Sediments. 
(a) General Statement. 

Products of rock disintegration and decay may aid in rock for- 
mation in either of six ways: Ist, they may remain in place and, 
unmoved, be buried beneath sediments,—such may be the 
fate of any of the residual soils at present exsting; 2d, they 
may be transported a short distance by ‘‘surface wash” or ‘‘ereep, ” 
as in arid regions; or, 3d, they may be removed by wind; or, 4th, 
by ice; or, 5th, by rivers; or, 6th, by the sea. These will be 
taken up for consideration in their order. The first needs no es- 
pecial mention, other than that already given it. One case where 
the products of disintegration have been buried in place, chiefly 
under their own overlying, decayed material, removed but a short 
distance, will be described in the latter part of the essay, under 
the discussion of sediments derived by the action of the sea di- 
rect. 

(b) By Surface Wash. 

Peculiar conditions exist in arid regions. Thorough rock de- 
cay is rarely if ever found in such places, for the reason that the 
essential elements of water and vegetable acids are not present in 
any considerable quantities. A certain amount of disintegration 
takes place, but there is little vegetation to hold the soil in place, 
and its almost constant dryness makes it an easy prey to the 
wind, by which the finer particles are blown hither and thither. 

The peculiarity of rainfall brings about another condition—the 
phenomenon of surface wash or creep. The rare rains which fall, 
generally come in copious downfalls, and, as they fall on a sur- 
face which is parched and dry, they are often very quickly ab- 
sorbed by the soil. Such desert regions are, as a rule, not occu- 
pied by well established drainage ways. The rains which are 
sufliciently copious to run off are rare, and the channels which 
they carve are often partially obliterated before another such rain 
occurs. There are broad tracts on which the rain finds no well 
established water-ways by which to escape. As it soaks into the 
parched, barren, and generally sandy soil, it tends to flow down 
the grade, and, in so doing, to carry some of the soil along with 
it; but often before the force of the accumulating waters is suffi- 
cient to carve distinct channels, the rains have ceased. Floods 
from violent cloudbursts in such places frequently become a moy- 
ing mass of mud at their lower course. 


Relation of Secular Decay of Rocks.—Tarr. 33 


The general effect of such conditions in arid regions of mod- 
erate slope is to produce great deposits of loose gravels extend- 
ing far out from the mountain bases. These are not properly 
talus deposits, nor are they of the cone delta type, but are inter- 
mediate between the two and with some of the characters of each. 
They are found in the arid regions of the west about the base of 
mountains, buttes and mesas and often merge into cone delta 
deposits. I have seen walls of recent construction partly buried 
beneath this wash in the mesa region of eastern New Mexico, 

Blanford* describes remarkable deposits of this character in 
Persia. Great gravel slopes in that country extend from the base 
of the mountains far out into the desert, often five or ten miles 
from their source. The foot hills are often quite buried beneath 
these gravels which bear some resemblance to lake deposits, but 
do not appear to be of this character. The angle of slope is from 
one degree to three degrees, there being sometimes a difference 
in elevation of from one to two thousand feet between the lower 
and upper ends. Much of the region is thus covered, and the 
thickness of the deposit is often several hundred feet. Near the 
source it is a coarse conglomerate, changing progressively down 
the slope to a gravel, and then to a sand, the latter covering the 
great desert flats and probably being in large measure trans- 
ported thither by the wind. Blanford explains the gravel slope 
as a surface wash, the result of the conditions of aridity, and 
rare, concentrated rains, in the manner described above, 

Similar deposits occur in India, and it is not impossible that 
the great gravel slopes of Patagonia ascribed by Darwint to ma- 
rine action may be in part of the same origin. The same condi- 
tions are imitated in a small way, in moist regions, on ploughed 
fields on hill sides. Instances of the downcreeping of the soil 
in these places are very common, and often the total result of a 
few years of such creeping is quite appreciable. 

By a change in climatic conditions, and the development of 
river systems in these desert regions, much prepared load ready 
for transportation, will be found in these deposits; and the en- 
croachment of the sea upon the gravel slopes would admit of a 
rapid deposition of extensive deposits by the working over of 


*Superficial Deposits in the Valleys and Deserts of Central Persia, 
Quart. J. Geol. Soc., 1873, xxrx, 493-503. 


+Darwin, Geological Observations. 


34 The American Geologist. July, 1892 


these. Some of the delta-like deposits of Tertiary age in the 
Himalaya mountains may be of this origin. 

Very similar to and grading into these deposits are the cone 
deltas or alluvial fans of arid regions. They result from the ina- 
bility of the streams to carry their load any farther. This is 
sometimes brought about by the absorption of the water by the 
soil, or by evaporation, when forms resembling gravel slopes are 
produced; but most commonly the decrease in carrying capacity 
is the direct result of the decrease in river slope. For this rea- 
son such deposits exist most commonly at the foot of mountains, 
opposite the ravines, forming a cone shaped delta. These alluvial 
fans often unite with one another by means of talus deposits, or 
by the surface wash, or even by actually meeting in their growth. * 
In the discussion of a paper on secular disintegrationt by profes- 
sor Pumpelly, Mr. Gilbert calls attention to these deposits in the 
arid regions of the west, particularly of the Great Basin, which 
are derived by processes chiefly mechanical and involving little 
rock decay. They accumulate in the valleys and at the foot of 
mountains, in alluvial cones needing only cementation to become an 
extensive conglomerate. 

Se (c) By Wind. 

Any one familiar with the conditions in the arid regions knows 
of the great importance of the wind as a transporting agent, 
Scarcely a day passes during which more or less sand and dust is 
not blown about; and very frequently great dust storms occur, 
during which much sand is transported, often to a great distance. 
Prof. Pumpelly states{ that ina simoon the driving dust and sand 
hides the country under a mantle of impenetrable darkness and 
penetrates every fabric. It often destroys life by suffocation, and 
in places leaves a deposit several feet deep. Such wind blown 
material may find its way to the sea direct, or into streams and 
thence to the sea; but more commonly it remains on the land. 
The importance of this means of transportation is not fully 
known, for the subject has never been carefully investigated; but 
when it is so studied, it will undoubtedly be found to be a very im- 
portant source of material for the formation of rocks. 


*For a complete discussion of these deposits [ refer to the following 
sources: Drew, Quart. J. Geol. Soc., 1873, xxrx, 441-471. Gilbert, Mon- 
ograph 1, U.S. Geol. Survey, 1890. 


TBull. Geol. Soc. Am. 1891, 11, 224. 
tSecular Rock Disintegration. Am, J. Sci., 1879, xv, 133-144. 


Relation of Secular Decay of Pocks.—Tarr. 35 


An important contribution to this subject has been made by 
Baron Richtofen,* who tries to explain loess in China by this 
process. The loess in that country and in other parts of the 
world has long been a puzzle to geologists, and various attempts 
have been made to account for its origin, though as yet no thor- 
oughly satisfactory general theory has been advanced. It is 
probable that loess is derived in a variety of ways, and the solu- 
tion of the problem of its origin has perhaps been delayed by 
the attempt to find a universally applicable hypothesis. 

In northern China the loess covers several hundred thousand 
square miles, often attaining a depth of two thousand feet. It 
is a calcareous loam, easily crushed to an almost impalpable pow- 
der, wholly unstratified and containing only land fossils. These 
facts seem to prove quite conclusively that it is not of marine ori- 
gin, and the fact that it is found in the loftiest passes, as high as 
8,000 feet above sea level, seems to prove that it is not lacustrine. 
It is found to contain innumerable vertical tubes which, it has 
been suggested, may be the casts of grass stems; so abundant 
are these that the rock cleaves vertically, and when, by the ero- 
sion of streams, through sapping or undermining, great blocks 
fall off, vertical cliffs remain. 

Richtofen believes that these vast deposits are wind blown in 
origin. A ‘‘central area’ is one in which evaporation exceeds 
precipitation. The in-blowing winds, aided by surface wasb, 
transport the finely divided materials into sucha region. The 
steppe vegetation characteristic of such a region would help to 
catch and hold the fine dust, and this grass, buried beneath the 
eolian deposits might leave by their casts such tubes as are 
found in the loess. Briefly this is Richtofen’s theory for the 
origin of loess in China. Professor Pumpelly accepts this theory 
and extends it to explain the loess of Missouri.+ In order 
to account for the great amount of material, which seems in 
excess of rock disintegration, he supposes that rivers charged 
with products of glacial attrition carried to the region material 
for the winds to transport. 

Professor Pumpelly calls attention to the fact that, while there 
is much secularly disintegrated material in southern Asia, the 
feldspathic rocks of northern China and central Asia are as free 

*China, 1877, 1, 56-189. 

Secular Rock Disintegration, Am. J. Sci., 1879, xv, 132-144. 


36 The American Geologist. July, 1892 


from it as are the rocks of New England, which have been swept 
clear of all such material by the recent ice advances. More- 
over the bare granite rock contains depressions seemingly due to 
erosion, without outlet, and varying in size from a few yards to 
several thousand feet,* and apparently the resalt of differences 
in rock texture. Such depressions would be expected to exist at 
the base of an area of secularly decayed material. From these 
facts the author argues that we may have here a source for the 
assumed veolian deposits of the loess. If it is assumed that 
China was exposed to the conditions which southern Asia has 
undergone, the country must at one time have been covered by 
a well marked residual soil. None now remains and it must have 
been swept away by some agent. Not by the sea, for there is no 
evidence of a marine incursion, nor by ice action, for evidences 
-of the existence of glaciers are entirely wanting. The agency of 
the wind alone appears to remain to account for this change. <A 
change in climatic conditions from moist to dry would set to 
work this powerful agent of transportation. 

By such a transformation a series of deposits are rendered pos- 
sible. The finest material driven great distances by the wind 
would finally settle and remain and accumulate under the protec- 
tion of the steppe grasses in the region intermediate between the 
arid interior and the moist coast climates, forming a deposit not 
unlike loess; the coarser sands would form the drifting desert 
sands; and the still coarser parts would remain behind and form 
the characteristic coarse stony steppes. ‘The conditions in China 
seem to suggest the plausibility of this explanation. 

Pumpelly offers a similar explanation for the loess of the trans- 
Mississippi regions. During early times the region of the Rocky 
mountains must have been the seat of secular disintegration, though 
now none of its products remain in place. The present aridity and 
prevailing west winds may account for its removal and for the 
presence of loess as far east as Kansas. The loess deposits of the 
Rhine and of the Central states may have been accumulated by 
reolian action, but in these cases the supply may more likely have 
been glacial flour which itself may have been derived by the gla- 


cier from secularly decayed soils. 


*Pumpelly, Geological Researches in China, etc., Smith’n Contr. 
Knowledge, xv, Art. 4, 26, 72, 73. 


Relation of Secular Decay of Rocks.—Tarr. 37 


Chamberlain and Salisbury, speaking of the loess of Wisconsin* 
describe it as neither a sand nor a clay, but intermediate between 
the two, being generally coarser than residuary earths. The par- 
ticles are, however, angular and irregular as in the case of resid- 
uary earths. Its depth in that region is from ten to fifteen feet 
over a wide area. 

These considerations are in the main theoretical, but the theory 
has much to commend it, since it accounts, apparently in a satis- 
factory manner, for a most puzzling series of deposits. 


(d) By Ice. 

The movement of a sheet of ice over a region which had been 
subjected to secular disintegration would result in the removal of 
the loose, decayed rock, which would furnish to the ice great 
quantities of sediment. During the melting of the ice, and at all 
times at its front the streams would be furnished with great bur- 
dens of sediment, which, either deposited in the valleys or car- 
ried to the sea, would aid greatly in rock formation. The final 
disappearance of the ice would leave the surface of the country 
littered with unstratified drift. 

Something of the same condition would result from the passage 
of an ice sheet over an undecayed rock, but the materials supplied 
would be less in amount. Ice cannot cut without tools. Leaving 
out of consideration valley glaciers,+ there are but two ways with 
which ice can be supplied with cutting tools, one by the loose ma- 
terial which it can pick up, the other by actually rending rocks 
asunder. The former supply ceases when the zone of disintegra- 
tion is passed and the latter soon follows. The erosive action of 
ice is to round, smooth and polish the surface over which it passes 
and thus to lessen the possibility of obtaining a supply of cutting 
tools. As the period of ice occupancy of a land continues, its 
power of erosion must diminish and finally become almost noth- 
ing. It will slide over rounded surfaces practically without any 
destructive effect and the streams will issue from its front with a 
very slight load of sediment. 

The great mass of detritus left by the ice of the glacial period 


*Driftless area of Wisconsin. Sixth Annual Rept. U. 8. Geol. Survey, 
278-307. 

tIn valley glaciers and in continental glaciers where mountain peaks 
project above the ice, detritus is furnished as a talus from the cliffs. 


38 The American Geologist. July, 1892 


has been a source of perplexity to many geologists and early led 
to a greatly exaggerated notion as to the amount of rock actually 
removed. Subsequent studies have shown that the pre-glacial to- 
pography remains with remarkable distinctness where not buried 
beneath glacial accumulations, and, consequently, that but little 
bed rock has been removed. Moreover, the case of the Hoosae 
mountains, described above, shows that in this place at least the 
original pre-glacially decomposed rock has not been all removed. 
If now it be assumed that in pre-glacial (or inter-glacial) times a 
considerable accumulation of secularly decayed rock existed upon 
the surface, the present accumulations may be accounted for 
without supposing a great deal of planing down of the rocks 
themselves. By this view the ice has acted more as a transporter 
of detritus already prepared than as a producer of such detritus. 

Moreover, this view of the glacial conditions also furnishes an 
explanation (in part at least) of that much discussed question of 
the origin of rock basins in glaciated regions. It yet remains to 
be proved that ice can, on a large scale, gouge out depressions. 
That under peculiar circumstances this is done is unquestioned, 
but that all or even a large per cent. of rock basins are the re- 
sult of this action is not yet satisfactorily demonstrated. In a 
region of secular disintegration the rock surface would necessarily 
be irregular and one containing numerous basins where rock of 
an easily disintegrated nature exists. 

Pumpelly* suggests this point and accounts for similar basins 
in China by the action of wind in removing secularly decayed ma- 
terials. Chalmers,t speaking of the rock basins of New Bruns- 
wick, says: ‘These Inke basins have evidently been formed by 
the sub-vrial decay of the rocks cn situ in Pre-Quaternary times, 
the softer limestones, graphitic schists and ferruginous rocks 
having been more deeply acted upon than the gneisses and fel- 
sites.”’ How far this idea can be extended by actual demonstra- 
tion is not at all certain for it has not been given the careful at- 
tention which it deserves. Secular decay undoubtedly produces 
just such forms, for it has regard chiefly for the chemical dura- 
bility of the rock. 

In their description of the driftless areat Chamberlain and Sal- 


*Am. J. Sci., 1879, xvi, 133-144. 
+Rept. Prog. Canada Geol. Survey, 1885, 1, 17 GG. 
tSixth Ann. Rept. U.S. Geol. Survey, 249. 


Relation of Secular Decay of Rocks.—Tarr. 39 


isbury make the point that the ‘glacial deposits of Wisconsin are 
not derived from a secularly decayed soil. They state that resid- 
uary products are almost completely robbed of alkalies, contain- 
ing chiefly quartz, undecomposable silicates and ferric oxide. 
Drift clays, on the other hand, are calcareous, and in some of 
these clays there is forty per cent. of magnesian limestone. ‘The 
drift clays are, in short, rock flour, and not, as are the residuary 
earths, the products of rock rot.”’ 

I think that this argument is not valid, for the reason that but 
a small part of secularly decayed rock consists of residual soil. 
Beneath the surface it becomes more and more like the rock from 
which it has been derived and finally passes insensibly into it. 
This last must have been the material with which the ice was work- 
ing in its last stages. Moreover, in places, perhaps over the 
greater part, the ice was then at work on the undecayed rock, 
and the churning up of this with the products of disintegration and 
secular decay might readily introduce a large element of calcare- 
ous matter. 

(ce) By Rivers. 

Residual soils can accumulate only where decay is in excess of 
denudation. Regions of considerable topographic diversity are 
generally free from accumulated soils and these soils are most lia- 
ble to form where the streams are not rapidly eroding. As an 
instance of this reference may be made to Mr. Russell’s paper* in 
which it is stated that where erosion is rapid, in the south- 
ern Piedmont region, owing to the more rapid solution of certain 
limestones, and the consequent standing out of other rocks, no 
residual soil remains. The presence of vegetation aids greatly in 
the retention of such soils, and this protective effect often allows 
the streams to run clear even when their flow is quite rapid. 

If, on the other hand, a region be elevated and new life be thus 
given to the streams, there is such rapid erosion thatthere is a tend- 
ency to strip off the accumulated soils. Such a revival or reju- 
vination of the streams seems to have taken place in China. The 
streams are yellow with silt derived from the loess, and the waters of 
the Chinese sea near the great rivers are yellow from this cause one 
hundred miles from the coast and for six hundred miles along the 
coast line. The muddiness of some of the rivers of the Mississippi 
system and of the Amazon are in large part due to the same cause. 


*Bull. No. 52, U. 8. Geol. Survey, 1889. 


40 The American Geologist. July, 1892 


Whatever the origin of the upper laterite of India (see above), 
the lower laterite has undoubtedly been derived from it in large 
measure by stream action. The most reasonable explanation of 
the change of conditions from a residual soil producing region (if 
this explanation be accepted for the upper laterite) to a region of 
denudation is that of elevation and consequently the giving of 
new powers to the streams. The lower laterite occurs generally 
near the shore and apparently extends out to sea beyond the pres- 
ent shore line. Its thickness is seldom greater than fifty feet, it 
is always sandy and sometimes contains rounded pebbles. Human 
implements found with the deposit prove it to be of recent origin. 
Medlicott and Blanford* believe it to have been subaerially de- 
rived from the upper laterite. In part, if not entirely, it has been 
formed beneath the sea having been transported thither by river 
action, and having been raised to its present position by a recent 
elevation. 

The importance of these suggestions in the explanation of cer- 
tain geological phenomena of the past may be very great. In the 
Carboniferous, for instance, numerous recurrent elevations and 
depressions are recorded and with them great quantities of sedi- 
ment were derived and deposited. In many regions great beds of 
clay were laid down, often having such a character as to admit of 
the explanation of residual origin. The remarkable development 
of blue, yellow, red and mottled clays in the Central Texas 
Carboniferoust may possibly be explained in this way. These 
deposits are often quite barren of fossils, indicating a very 
muddy sea. 

The Carboniferous time was one well adapted to the accumula- 
tion of a residual soil, being apparently one of considerable moist- 
ure, much vegetation, general warmth, and of low lying lands. 
The elevations and depressions so well recorded must have furn- 
ished the means of removal of any such soils, either by the 
actual encroachment of the sea, or by the erosion of the land 
by subaerial agents, or by both. Such an explanation makes it 
easier to understand the extensive accumulations of clays in these 
deposits. Similar deposits in other ages may have had a similar 
origin. On this subject Pumpelly writes? ‘‘the very fine marine 


*Geology of India, Vol. 1. 
+Tarr. First Ann. Rept. Texas Geol. Survey, 209-212. 
tAm. J. Sci., 1879, xvur, 133-144. 


Relation of Secular Decay of Rocks.—Tarr. 41 


sediments are probably for the greater part the rapidly removed 
products of long-continued, protected disintegration and decom- 
position. ”’ 

Changes in the amount of river load from the limpid stream of 
a low lying country, to the turbid stream flowing with rapid cur- 
rent over a recently elevated region covered with a residual soil, 
aside from the rapid accumulation of much fine sediment, must 
have an important effect upon the life of the region, which may 
be almost entirely exterminated by the incursion of the mud bear- 
ing waters. <A coral fringed coast would lose its character with 
such an incursion and an entire change of fauna result. How 
many times this has happened in the past it is entirely impossi- 
ble to tell at present, but a search among the geological records 
may very likely show many such changes which can be traced to 
this cause. 

(f) By the Sea. 

The depression beneath the sea of a country bearing a residual 
soil would produce similar though more widespread results. The 
fine sediments swept out to sea and the coarser remnants de- 
posited nearer the point of origin would rapidly produce exten- 
sive deposits, at the same time undoubtedly changing the charac- 
ter of the fauna. 

One recorded instance of this method of origin of sediments 
is all that has been found in the geological literature examined. 
It is so interesting that it is given here in some detail. For the 
complete account I refer to professor Pumpelly’s paper.* 

In the Hoosac mountains in western Massachusetts there is a 
central core of true granitoid gneiss characterized by a blue 
quartz. Above this and separating it from the overlying schists 
is a band of rock, which, though stratigraphically continuous, is 
widely different in its various parts. It wraps around the granit- 
oid core or island, and on the east is a quartzite, on the north a 
conglomerate, while on the west it is a white gneiss. By transi- 
tional beds these pass downward into the granitoid gneiss by 
direct stratigraphical conformity. The conglomerate contains, 
besides blue quartz pebbles, many pebbles of feldspar with an un- 
altered nucleus bordered by a kaolinized feldspar, which, since 
its production, has been altered to a secondary feldspar by meta- 


*The Relation of Secular Rock Disintegration to certain Transitional 
Crystalline Schists. Bull. Geol. Soc. Am., 1891, 11, 209-224. 


42 The American Geologist. July, 1892 


morphism. The feldspar cannot have been carried very far, other- 
wise it would have been destroyed. 

There is evidence that the pre-Cambrian surface was an eroded 
land surface. The chief evidence of this is found in the Stam- 
ford dike of Clarksburg mountain, near Williamstown, which was, 
in pre-Cambrian times, eroded out below the general level of the 
surface. Into this the over-lying Cambrian sags, and it contains 
fragments of weathered dike rock. 

Professor Pumpelly suggests that when the Cambrian sea en- 
croached on the land the country was covered by a deep secularly 
decayed covering. The residual soil and all the finer materials 
were quickly removed to a distance; but the deeper zone of semi- 
kaolinized material was only partly worked over and was deposited 
near at hand. Below this was the semi-disintegrated zone now 
represented by the transition beds of highly foliated granitoid 
gneiss. This, by its weakened condition, during the subsequent 
extensive folding, behaved like the worked over material above, 
and is therefore laminated. Hence the transition and apparent 
conformity between the schist and granitoid gneiss. It will be 
seen that this is a highly plausible theory which explains, so far 
as is at present known, all the peculiarities of this most puzzling 
region; and it seems to be the only theory which will explain the 
facts found in the field. 

These facts lead professor Pumpelly to suggest that most of 
the basal beds of sandstone, conglomerate and quartzite, marking 
the beginnings of geological periods, are produced in this way. 
Similar beds occur on the eastern edge of the Adirondacks where 
the feldspar pebbles, as in the case of the Hoosac mountains, 
have not been divested of their semi-disintegrated shell. 

Pre-Potsdam secular decay has been described by Newton from 
the Black Hills, by Peale inthe pre-Cambrian granite of the South 
Platte region in Colorado, and by ethers from various parts of 
the west. Pumpelly* has suggested a pre-Silurian disintegration 
of Pilot Knob, Missouri, and later explorations by mining have 
verified this suggestion by finding a deep zone of disintegration 
on the Silurian. In all these cases the transgression of the sea 
has in part worked over the materials of disintegration and buried 
the lower parts in large measure, beneath the sediment thus de- 


*Geol. Survey Missouri, 1873, 1, 12. 


Relation of Secular Decay of Rocks.—Tarr. 43 


rived. Plainly, a rapid encroachment of the sea on the land is 
necessary to admit of such a partial working over. The ordinary 
movements of the land are so slow that all such loose material 
would be removed. Cases where the secularly decayed soil is 
found buried in place, or only slightly removed from its place of 
origin must, therefore, be relatively rare. The evidence of the ex- 
istence of this kind of material during the periods of the past 
must, for the most part, be looked for in sediments removed some 
distance from their source. The mechanical and chemical con- 
stitution of such sediments ought to serve as a key to indicate 
their origin. 
(g) Summary. 

From what has been written it will be seen that secular disinte- 
gration may be an important source for the origin of sediments 
which may be derived from it in variousways. It may be trans- 
ported to its resting place in the process of rock building, by the 
wind, by ice, by running water or by the sea. A country chang- 
ing in climate from moist to dry is subject to erial action of 
considerable uniformity and intensity, and an accumulated resid- 
ual soil may thus be swept away ; the change from temperate to cold, 
the coming on of an ice period, brings about other conditions by 
which accumulated soils are removed. China seems to offer an 
instance of the former, New England of the latter. 

Changes in land elevation may admit of the accumulation of 
a residual soil or the removal of one already accumulated. A 
country long standing at a certain elevation is favorably situated 
for soil accumulation. The elevation of such a land gives to the 
streams new powers, and by this means the residual soils and dis- 
integrated materials may be removed. The same country de- 
pressed brings the soil within reach of the waves. 

Accompanying these changes there must be much destruction of 
life. The clear-water dwelling fauna of the shore, driven out by 
the appearance of mud-laden waters. is replaced by a different fauna. 
So there may have been alternations of faunas from this reason, as 
well as alternations of sedimentation, first rapid, then slow depo- 
sition, 

The importance of secular disintegration along the lines above 
suggested is not fully understood and seems to have been gener- 
ally overlooked by geologists. Secularly decayed soils exist at 
present and they must have existed in the past; lands have been 


44 The American Geologist. July, 1892 


raised and depressed and climates have changed; and such being 
the case it seems reasonably certain that sediments derived from 
secularly decayed soils must be abundant in the formations of the 
different ages. All the conditions for such accumulations have 
been present, and if the line of reasoning adopted in this essay is 
not fallaceous they must exist. The work of discovering evidence 
of them in the field yet remains to be done except in a very few 
CASES, 


NOTES ON SOME PSEUDOMORPHS FROM THE 
TACONIC REGION. 
By Wm. H. Hopss, Madison, Wis. 

(Published with the permission of the Director of the U. S. Geological Survey.) 

The pseudomorphs here considered occur in northeastern Con- 
necticut near the Massachusetts state line, within an area of 
crystalline rocks which are now being studied by members of the 
U. 8. Geological Survey. 


Tremolite Pseudomorphs after Salite. 

The crystalline dolomitic limestone of the vicinity of Canaan, 
Ct., has long been known to collectors asa locality for white 
pyroxene and tremolite. Well terminated crystals of the former 
are figured in Shepard’s Mineralogy. * 

In a recent paper Prof. G. H. Williams has described hemi- 
hedral pyroxene crystals from Canaan and mentioned an incipient 
uralitization of the mineral. f 

I have found pyroxene crystals to be abundant in the dolomitic 
limestone at numerous localities extending from Canaan north- 
ward «through the valley of the Konkapot river (Mill river), at 
Konkapot, Mill river, Hartsville, and Monterey. They are known 
to the quarrymen under the name, ‘‘Jason’s Teeth.” 

Their distribution seems to be confined to the region east of 
the Housatonic river. They are usually from one-half of an inch 
to an inch inlength and stoutly columnar, but they also attain di- 
mensions of several inches. Sometimes they are found in large 


*Vol. 11, p. 138, 1835, figures 3538 and 354. 
+Am. Journ. Science, xxxviul, p. 115 and Fig. 8, August, 1889. 


Pseudomorphs from the Taconic Region.—Hobbs. 45 


masses forming ridges which have been described as c¢a- 
naanite. * 

Tremolite from Canaan is mentioned in Cleaveland’s Mineralogy 
and is common in mineral collections. The best crystals come 
from the Maltby quarry about three-fourths of a mile north of Falls 
Village, where they are semi-translucent, attaining to a breadth of 
a quarter of an inch or more. They are usually white but some- 
times light green incolor. There is also a fine radial variety from 
this locality having a silky lustre. 

While making a reconnaissance of Canaan mountain in the 
summer of 1889, I came upon huge glacial boulders of impure 
limestone on the north flank of the mountain some distance above 
the exposures of limestone, and resting on a layer of till. ae 
locality is on the coaling road about one mile south of and 330 
feet vertically above the first road corner east of the junction i 
the Blackberry and Whiting rivers. These boulders were filled 
with nodules of coarse tremolite. Most of the nodules could be 
seen to have the form of pyroxene crystals, and several were dug ~ 
out on which all the planes of the prismatic zone were well de- 
veloped with the orthopinacoidal habit. In some cases the crys- 
tals show terminations by a pyramid which gives an angle of 
about 110° to the front, probably —2P. They attain to a length 
of two to three inches and a breadth of nearly twoinches. Very 
little of the pyroxene material remains owing to a paramorphic 
change to tremolite.+ The tremolite needles situated near the 
surface of the crystal usually le with their axes in the bounding 
planes or nearly so, and there is also a tendency on prismatic 
planes to parallel orientation with the pyroxene. The arrange- 
ment of the tremolite is usually quite irregular within the crystal. 

A portion of one of these pseudomorphs has been analyzed by 
Dr. W. F. Hillebrand in the laboratory of the U. 8. Geological 
Survey with the results given below under I. 


*This was first thought by Hitchcock to be scapolite (Geol. Rep. Mass 
2d ed., 1835, p. 315), afterwards nephrite or saussurite (Rep. Geol. Mass. 
1841, p. 569). On the basis of a faulty analysis by 8. L. Dana, it was 
thought to be a new mineral and named Canaanite (Alger’s Phillip’s 
Mineralogy, 1844, p. 89). Shepard at first thought it nephrite or saus- 
surite (Geol. Mass., 1841, p. 569), but afterwards “recognized it as pyrox- 
ene (Rep. Geol. Survey, ‘Conn., 1837, p. 134). In Dana’s System of Min- 
eralogy (5th ed., 1868, p. 803) an analysis by Burton is printed showing 
the mineral to be pyroxene. 


+(These specimens are No. 3186 of the U. S. Geological Survey collec- 
tion from the vicinity.) 


46 The American Geologist. July, 1892 


ie ae JOU We V. VI. 
sio, 57.97 60.98 60.10 59.05 51.80 58.64 
Al,O, 09 10 42 
Fe,0, tt 12 iu 
FeO 18 19 1.00 1.60 1.83 
CaO 15.05 14.64 12.738 31.35 20.21 20.25 
srO trace 
MgO 22.45 238 62 24.31 12.538 16.47 18.83 
MnO trace AT 
K,O 12 13 
Na,O 20 21 
H,O at 100° - 0B} ~ re 
H,0 above 100° 2.57 a og ae 
CO, 1.69 5.91 
F 78 


100.46 99.99 99.96 100.00 10v.88 100.00 


I. Tremolite pseudomorphs after salite, Canaan, Ct., Hille- 
brand. 

Il. The same recalculated with water removed and CO, re- 
moved as CaCO,,. 

III. White tremolite from Fahlun, Sweden (Dana's System of 
Mineralogy, 5th ed., 1868, p. 236). 

IV. Salite from Canaan, Ct., M. D. Munn (Ibid, 6th ed., 
1892, p. 356). 

V. Canaanite, Canaan, Ct., B. 8. Burton, (Ibid, 5th ed., p. 
803). 

VI. The same with CO, removed at CaCO,. 


These analyses show that the alteration of the salite of Canaan 
to tremolite is not true paramorphism, the change involving a 
loss of lime and againof magnesia. The specific gravity of the 
tremolite pseudomorphs is 2.9, that of salite analyzed by Mr. 
Munn was 3.35. 

It is quite possible that a portion of the tremolite contained in 
the dolomite at other localities near Canaan is derived in this 
way, but the manner of occurrence of much of the tremolite goes 
to show that it is formed directly from the recrystallization of 


the dolomite and its admixed quartz. 


Pseudomorphs after Feldspar from Norfolk Township, Ct. 

In the summer of 1889, I visited the Norfolk granite quarry, 
which is opened in Cambrian gneiss. There were noticed near 
the quarries blocks of much the same material, in which were 
well rounded nodules up to an inch and more in diameter. They 


Pseudomorphs from the Taconic Region.—Hobbs. 47 


appeared to be composed mainly of a colorless mica and feldspar 
mottled by grains of quartz. The mica is in scales lying along 
the cleavage planes of the feldspar. Sometimes no feldspar 
could be made out with certainty, but the direction of the mice 
scales indicated clearly two cleavages nearly perpendicular, corre- 
sponding with those of feldspar, and in many cases the nodule 
was seen to be made up of two individuals simply twinned ac- 
cording to the Carlsbad or albite law, dividing the nodule in 
halves. These twins are oftentimes very perfect, and closely 
resemble the simply twinned albite grains of Greylock mount- 


= hs 


A 


AS 
ete 
Ze 


Appearance of nodules in thin section. M Silvery Mica, Q Quartz, 
F Fibrolite. X 14. 


ain, except that they are larger and mainly composed of mica 
and quartz. 

Seen under the microscope in thin section, the nodules show as 
a background a network of colorless mica, possessing practically 
one orientation throughout the nodule (unless it is twinned), and 
inclosing quite uniformly distributed irregular areas of quartz. 
Penetrating the quartz and to some extent also the mica are 
numerous minute needles of fibrolite (See figure). No feldspar 
has been observed in section, yet many of the nodules doubtless 
contain some residue of feldspar. On separating the rock pow- 
der in the Thoulet solution a large part of the mica was removed 
when the solution had a specific gravity of 2.8. Owing, how- 
ever, to the difficulty of making a perfect separation of the 
different constituents into homogeneous grains, the material con- 
tinued to fall in the solution until the specific gravity was some- 
what below that of quartz. As the specific gravity of the quartz 


48. The American Geologist. July, 1892 


would be raised by the muscovite and sillimanite attached to it, 
the presence of a feldspar lighter than quartz is shown. 

A portion of one of these pseudomorphs has been analyzed 
quantitatively by Dr. W. F. Hillebrand in the laboratory of the 
U.S. Geological Survey, yielding the following proportions: 


SiO, 76.32 
ANOS 15.87 
Fe,O, 58 
FeO 36 
CaO .26 
K,O 4.55 
Na,O 124 
H,O at 100 .20 
H,O above 100 2.01 

100.34 


With traces of TiO,, SrO, Li,O and P,O,. 


In conversation with Prof. B. K. Emerson in 1891, he ex- 
pressed his opinion that the nodules were pebbles. I have since 
been convinced of this from examination of them. * 

The greater part of the quartz I look upon as original in the 
rock from which the feldspars were derived, and as essentially 
pegmatitic. The manner of occurrence of the quartz in areas 
quite regularly distributed in the mica, and the high acidity of 
the nodules seem to indicate this. The mica and fibrolite are 
regarded as due to a secondary alteration of a potash feldspar by 
dynamo-metamorphic agencies accompanied by a separation of 
quartz. The alteration of alkali feldspar into microscopic mus- 
covite and quartz is very common. 

During the summer of 1891, I visited the region northwest 
of the Norfolk quarry in company with Prof. Emerson. We 
succeeded in finding similar nodules in place in the Cam- 
brian gneiss of Tobey hill (about two miles northwest of the 
quarry), from which outcrops the blocks have probably been 
derived. 

University of Wisconsin, Madison, May 6, 1892. 


*Mr. J. E. Wolff has shown that the rounded porphyritic feldspars, 
which are characteristic of the “metamorphic conglomerate” and “albite 
schist” of Hoosac mountain and other localities in northern Berkshire, 
are of detrital origin. (Metamorphism of Clastic Feldspar in Con- 
glomerate Schist, Bull. Mus. Comp. Zool., Harv. Coll., xv1, No. 10, pp. 
173-183.) See also Pumpelly, The Relation of Secular Rock-Disintegra- 
tion to certain Transitional Crystalline Schists. Bull. Geol. Soc. Am., 
II, pp. 209-224. 


49 


ON SOME BASIC ERUPTIVE ROCKS IN THE VICIN- 
ITY OF LEWISTON AND AUBURN, ANDROS- 
COGGIN CO., MAINE. 

Puate II. 


By GeorcE P. Merrit, Washington, D. C., with analyses by R. L. PACKARD. 

The prevailing underlying rock in Androscoggin, as in ad- 
jacent portions of Cumberland, Oxford, Kennebec and Sagadahoc 
counties, is a coarse and variable micaceous or hornblendic gneiss 
often including considerable thicknesses of crystalline limestone, 
which is colored on Hitchcock’s map of the state as of Montalban 
age. Through this gneiss there has every where been injected a 
coarse highly feldspathic granite which forms the main mass of 
the more prominent hills or mountains of the vicinity. The so- 
called «‘David’s Mountain” near Baves College in Lewiston is a 
good example of this granite. Contact between the molten granite 
and the more calcareous portions of the gneiss has given rise fo 
various secondary minerals, including the vesuvianite and cinna- 
mon garnets which are found at various points within the coun- 
ties mentioned. Into numerous smali fissures in granite and 
gneiss alike have subsequently been intruded basic eruptives, some 
of which are of interest in the present stage of petrographical 
knowledge and none of which have as yet received the attention 
they deserve. 

These dikes are all small,and neither their direction nor inclina- 
tion with the horizon is at all constant. Some of them are nearly 
vertical and run in a nearly east and west direction. Others are 
inclined at a very considerable angle. The original fractures 
through which the molten magma was protruded seem to have 
been very irregular, owing to the varying character of the rock 
masses traversed, and the material itself was too limited in amount 
to make its influence felt. 

The dikes with which this paper has principally to deal are 
situated to the southward and almost within the city limits of 
Lewiston and Auburn and therefore on both sides of the Andros- 
coggin river. The best exposures are on the Lewiston side in a 
quarry of limestone on the lower branch of the Maine Central 
railroad some 300 yards south of tie Androscoggin mill. 
(Locality (1) on sketch map.)* ‘here is here a considerable bluff 
of limestone facing the river, a part of which has been quarried 


*This is the locality described briefly by Hunt, Chemical and Geologi- 
cal Essays, p. 196. 


50 The American Geologist. July, 1892 


away for foundation material so that the dikes in the face of the 
quarry are easily accessible, but are visible nowhere else in the 
immediate vicinity, being covered by drift sands and clays. 
These dikes, of which there are nine exposed within a distance 
of 250 to 300 yards vary from fifteen inches to five feet in diam- 
eter, and have apparently a nearly east and west trend,though as 
they are here almost vertical and exposed only in the face of the 
quarry, this could not be told with certainty at the time of my 
visit. The rocks of the dikes are, as a rule, very fine grained, 
compact and nearly black in color, containing only olivines, an 
occasional augite, or rarely a feldspar in macroscopic forms. The 
olivines are in some of the dikes peculiarly large and abundant, 
comprising at times fully one-fourth the entire mass of the rock. 
In several instances on a surface five em. square not less than 
fifty olivines could be counted, varying in size from a pin’s head 
to five and even ten and fifteen mm. in diameter, all fresh and 
glassy,or with but a narrow well defined greenish white border of 
serpentine. Such large and fresh olivines are very rare except- 
ing in rocks of Tertiary or Post Tertiary age. The dikes are 
often beautifully banded parallel to their sides, the bands varying 
from two to five mm. in width and of light purplish gray and 
nearly black colors alternating. This feature is especially notice- 
able in the smaller and more compact dikes. On weathering the 
rock assumes a schistose structure cleaving parallel with the 
bandings, 7. ¢. with the walls of the dikes, into scales of all thick- 
nesses up to several inches, and often some feet in diameter. 
Submitted to microscopic examination the rocks from the vari- 
ous dikes present close textural and mineralogical resemblances, 


which may be generalized as follows:—A groundmass of stout 
acicular idiomorphic brown basaltic hornblendes, augites with a 
faint violet brown or purple tinge, elongated plagioclases and the 
usual scattering of iron ores, carrying abundant phenocrysts of 
olivine, more rarely of augite and still more rarely of plagioclase. 
A glassy base, though not identified beyond a reasonable doubt, 
is strongly suggested by almost amorphous interstitial areas filled 
with chloritic needles and ferruginous decomposition products. 
The olivines in some of the dikes are highly altered, but show 
beautifully perfect crystal outlines. In others, as above noted, 
they are almost as fresh and glassy as on the day of their erup- 
tion. The brown hornblendes occur throughout only in the 


Basie Eruptive Rocks.— Merrill. 51 


groundmass and in crystals of but one generation, the augites in 
two generations, the feldspars rarely in two, and the olivines in 
but one. The intratellural origin of these last is manifested by 
their presence in large numbers in blebs of considerable size in 
small offshoots from the main dikes, which are sometimes of not 
more than an inch in width and otherwise completely aphanitic. 
The olivines are not, however, equally conspicuous in all the dikes. 
In the first two met with going southward from the mill (the first 
about thirty and the second fifteen inches wide) olivine is scarcely 
evident to the unaided eye. In the third it is in certain parts of 
the dike very abundant; in the fourth scarcely evident again, and 
in the fifth and sixth extremely abundant and in large blebs, as 
mentioned above. That, however, the rocks are essentially the 
same and must be portions of the same magma, is evident from 
their similarity in mineral, as well as chemical composition. 

There are certain differences in the slides from different dikes 
that are worthy of note. The larger dikes, as would be expected, 
show as arule a more granular structure, though this is not a 
universal rule. In the second dike below the mill (28525)* the 
idiomorphic nature of the hornblendes and augites of the ground- 
mass is less distinctly marked than in the first. A sample from 
this dike yielded Prof. Packard 40.26% SiO,. The third dike 
(28526) is a typical camptonite, and excepting the numerous large 
olivines, is indistinguishable in the section from the original dia- 
base of dike No. 1, at Campton, New Hampshire, as described by 
Hawes.+ The fourth dike, three feet wide, (28527) is quite simi- 
lar, but the slides show in places a structure bordering upon 
ophitic. The fifth, 2 feet wide (28528), shows also a tendency 
toward an ophitic structure and there is a much less distinct sep- 
aration of the minerals into individuals of two generations. The 
olivine is here the only mineral porphyritically developed. The 
sixth dike, 24 feet wide (28529 and 39194), is the most striking 
of all, and the one to which owing to its richness in olivines my 
attention was first attracted. { 

In the hand specimen this is a dense dark gray aphanitic rock 


*The numbers given are those of the specimen as entered in the 
Museum catalogue. 


yAm. Jour. Sci., 3d, xvi, 1879, p. 147. 


{This is the rock referred to by Prof. Kemp in his paper “On the 


Dikes Near Kennebunkport, Maine.” Am. GeoLoatst, March, 1890, p. 
138. 


52 The American Geologist. July, 1892 


with abundant large (4 to 8 mm.) phenocrysts of augite, olivine 
and plagioclase, the olivines being most abundant. Like the true 
camptonites it shows under the microscope a dense groundmass 
of minute brown hornblendes, augites, plagioclase and iron ores, 
all in idiomorphic forms, throughout which are scattered the 
phenocrysts of olivine, augite, and plagioclase above noted. 

A search for similar dikes elsewhere in the vicinity resulted as 
follows :— 

At the Cedar street crossing of the lower branch of the M. C. 
R. R.—a few squares above the mill and to the northward— 
(locality (2) on sketch map) a dike 5 feet in width was found, 
consisting of a compact dull dark gray rock with an abundant 


sprinkling of small olivines. Under the microscope the mineral 
nature of the rock (28523) was found to be quite similar to the 
others mentioned, excepting that augites prevailed in excess of 
hornblendes in the groundmass. The structure was also quite 
variable in different sections, in some cases being decidedly por- 
phyritic, as in the camptonites, or again ophitic as in normal dia- 
base. An abundance of secondary calcite here, as in the other 
dikes, obscures everything. There is no doubt but that this be- 
longs to the same series of dikes. Still further northward, just 
below the Maine Central railroad bridge over the Androscoggin 
river, and running nearly parallel with the bridge is a dike some 
five feet in width of a dense dark greenish rock (28534) which 
under the microscope shows the ophitie structure of ordinary dia- 
base, and which yielded Prof. Packard 49.75% Si O,. This dike 
is covered by overlying rocks and soils on either shore and may 
be seen to advantage only in the river bed and at low water. 
{Locality (3) on map). This is presumably the dike mentioned by 
Jackson® as having a direction of N. 80 W., 8. 80 E., though the 
width as given by him is but 25 feet. 

Going southward on the Auburn side of the river the first dike 
encountered was on the property of L. Merrill, Lake street, above 
Fern. (Locality (4) on map). This was in granite and but three 
inches in width. The rock is dark gray, strongly banded parallel 
with the sides of the dike in gray and black colors and showing in 
the hand specimen simply a compact aphanitic ground without 
crystalline secretions of such size as to be determinable by the 
unaided eye or pocket lens. Under the microscope in thin sec- 


*Geol. of Maine, 3d Ann. Rep., 1889, p. 191. 


THe AMERICAN GEOLOGIST. Vou. X, PLATE II. 


(4) Sketch Map 


3 Showing 
~\ i 
Trap dikes tn Lewiston®Aubury 434 
2 
\ Approximate Seale ne 
€ / 
SS 
SSS HY 
=e : f 
, | 
Stationf/ nay h x 
ee | s 
etn Steg 
: ) Uf & 
e “ 
‘ s 
we Q 
. ation NX 
\e/ 
x 
= 
(5) Tic 
(Zine 
é 2 
< 
x 
ry 
4 
Q N x 
w 
% : > 
: =k 
S > 
& BS mn 
5 : i 
Y) S s 
s? i %, 
v 4 S} (1) 
y = 
LS 
|e R} — 
(6) 5 


Basic Eruptive Rocks.—Merrill. 53 


tions (28519) it shows a dense irresolvable base, the true nature of 
which is badly obscured by calcite and ferruginous decomposition 
products, but which was once evidently a glass. Throughout 
this base are thickly scattered abundant acicular plagioclases, iron 
ores in granular and gratelike forms and occasional larger rounded 
blebs of more or less serpentinized olivines. Hornblendes or 
augites if ever existing, have been obliterated by decomposition. 
This rock yielded Prof. Packard 39.40% Si O,. No other dikes, 
of which this might be considered an offshoot, were discovered in 
the vicinity. 

Going still farther south two small dikes, one 15 inches and one 
3 feet wide, were found exposed in the railroad cutting of the 
Lewiston and Auburn railroad on the west bank of the Little 
Androscoggin river nearly opposite the Barker cotton mill. 
(Locality (5) on map). These show a structure in every way 
identical with those first described south of the Androscoggin 
mill and from their position (nearly due west) there seem good 
reasons for assuming them to be a continuation of the Cedar 
street dike in Lewiston. A complete analysis of one of these 
rocks (28531) is given on p. 54. In a cutting of the Maine Cen- 
tral railroad, south of the Taylor Brook crossing, and about a 
mile below the city of Auburn occurs still another dike about 12 
inches in width (locality (6) on map). This rock (28532) in 
the thin section is indistinguishable from Hawes, dike 1, (diabase) 
at Campton Falls, New Hampshire.* It yielded Prof. Packard 
39.46% Si O, and is presumably a continuation of the dikes 
south of the Androscoggin mill on the Lewiston side of the river. 

Farther to the west, between the well known tourmaline and 
lepidolite locality, fancifully known as ‘‘Mount Tourmaline” and 
Stevens mill, is another dike five feet in diameter (28658) which 
shows also a camptonite structure and composition. It is to be 
noted, however, that slides in the Museum collection from other 
dikes having the same trend, but lying to the northwest, near 
Taylor pond, are normal diabases and ophitic in structure. 

The next dike met with, traveling south along the M.C. R. R., 
is found just before reaching Danville junction. This is a large 
dike of normal olivine diabase (35056) which yields some 46% 
BQ, 


*Dr. Hawes’ original specimens and thin sections are in possession of 
this department. 


54 The American Geologist. July, 1892 


Analyses of samples from the olivine rock, dike 6 below the 
Androscoggin mill in Lewiston (39199), and the 12 inch dike 
from the cutting in the Lewiston and Auburn railroad in Auburn 
(28531) yielded Prof. Packard results as below. For purposes of 
comparison are given (11) the analyses of dike No. 1, at Camp- 
ton, New Hampshire, as given by Hawes.* (iv) of the Montreal 
diorite as given by Harrington,t and (v) and (v1) camptonites 
from Proctor and Fairhaven, Vermont, as given by Kemp and 
Marsters. ¢ 


T. ILI ie IV. Vi Vi. 

Si O, 39.32 41.15 41.63 40.95 41.00 43.50 
Duos 1.70 1.60 3.95 3.39 
Al, O, 1448 13.51 18.26 16.45 21.56 17.02 
Fe, O, 2.01 2.32 3.19 13.47 13.44 13.68 
Fe O 18 8.63 9.92 
Mn O 0.71 1.28 27 0.33 
Ca O 8.30 8.75 8.86 10.53 10.40 8.15 
Mg O 11.11 10.09 7.31 6.10 3 85 6.84 
K, O 0.87 1.22 3.32 1.28 131 2.84 
Na, O 3.76 3.21 2.49 4.00 2.86 2.84 
PSO. 0.61 61 0.29 
CO, 5.25 5.04 5.20 
He 2.57 3.05 1.35 (Ign)3.84 5.00 4.35 

99.42 100.96 100.75 100.63 99.22 99.40 


From the above it appears that in the immediate vicinity of 
Lewiston and Auburn are two series of small and geologically 
speaking insignificant dikes, both having essentially the same 
trend (so nearly so that they were supposed at the time these 
observations were made, (1883), to belong undoubtedly to the 
same system) one of which is normal diabase while the other, in- 
cluding nine or more lying almost within the southern outskirts 
of the two cities, must be referred to the lamprophyrs, or if a 
specific name is demanded, may be called camptonites as the 
term is used by Rosenbusch. There are objections to this. In 
all of them augite occurs both as phenocrysts and asa constituent 
of the groundmass, and must be considered as of greater genetic 
importance than the hornblende. There is moreover an almost 
constant tendency toward an ophitic structure as displayed in 
basalts and diabases. 

Just how much weight in the matter of classification is to be 
attached to micro-structural features, it is perhaps as yet too 


*Am. Jour. Sci., 3d, xvi1, 1879, p. 147. 
tRep. Geol. Survey of Canada, 1877-78, p. 44 G. 
tTrans. New York Academy of Science, vol. x1, 1891. 


Basic Eruptive Rocks.— Merrill. 55: 


early to say. In the writer’s opinion neither these nor the fact 
that up to date such rocks may have been found occurring only 
in dikes is alone of sufficient importance to warrant the introduc- 
tion of new names into a branch of science already over-burdened. 
We must not, however, lose sight of the fact that in addition to 
the above characteristics (which may or may not prove constant) 
we have here a peculiarly basic magma standing intermediate be- 
tween the diabases and peridotites, and which, as a plutonic rock, 
can be relegated to none of the older groups. As a convenient 
temporary term the name camptonite as given by Prof. Rosen- 
busch is perhaps as good as any. The fact that the dikes so far 
described, are in all cases extremely narrow—from 3 inches 
to 5 feet—is, to say the least, interesting. That the structure 
of the rock is quite independent of the size of the dike is how- 
ever shown by the occurrence in the same vicinity of equally 
small dikes which are normal diabases in both composition and 
structure. 

It is to be noted that chemically the rocks might be considered 
as members of the monchiquite group, from which however they 
are excluded by the uniform presence of plagioclase feldspars.* 
The high percentage of magnesia, a necessary consequence of the 
abundant olivine, is also worthy of note as indicating a close 
chemical relationship with the peridotites. 

Thanks are due Mr. L. H. Merrill, chemist at the Maine ex- 
periment station, by whom many of the samples were collected 
and sections cut, as well as preliminary analyses made, 

National Museum, April, 1892. 


In his inaugural address, before the Royal Society of Canada, 
the President, Abbe J.C. K. Laflamme,of Laval University, Quebec, 
gave an extended account of the life and labors of the late Dr. T. 
Sterry Hunt,who had been one of the members of the society from 
its inception. 


*Compare analysis 11 above, with v as given by Prof. Rosenbusch in 
Min. u. Pet. Mittheilungen v1, Heft. x1, 1890, p. 464. 


56 The American Geologist. July, 1892 


ON THE OCCURRENCE OF TYPICAL CHAETETES 
IN THE DEVONIAN STRATA AT THE FALLS 
OF THE OHIO AND LIKEWISE IN THE 
ANALOGOUS BEDS OF THE 
EIFEL IN GERMANY. 


PiatEe III. 


By Dr. C. Romincer, Ann Arbor. 

The numerous forms formerly comprehended under the name 
Chetetes, by considering merely the general external resemblance 
of the fossils with the one described by Fischer under the name of 
Cheetetes radians, were found by more accurate microscopic ex- 
amination to exhibit many important differences in their structure. 

The majority of this mixed assembly could be placed under 
Monticulipora, a generic group proposed by D’Orbigny; another 
part was found to correspond with the forms described by Lons- 
dale under the name Stenopora; for still others the erection of 
new genera was deemed necessary, and only a very small number 
of them actually corresponded with Chetetes radians, the type 
of the genus. 

Chetetes so restricted, like Stenopora, was unknown in strata 
older than the Carboniferous period, but in the subjoined pages I 
am going to describe representatives of Chatetes from the 
Devonian at the Falls of the Ohio and from the contemporaneous 
beds of the Kifel in Germany. 

Before proceeding with the description it will be desirable, 
first, to define the characters distinguishing Chetetes from Monti- 
culipora, Stenopora and related genera, 

Common to all of these is the composition of their colonies of 
small elongated tubules which are in their whole extent inti- 
mately grown together; the channels of these tubules are inter- 
sected by more or less numerous transverse diaphragms, and 
are not in communication with the adjoining tubules by lateral 
pore channels as they occur in the favositoid tribe, whose gen- 
eral structure exhibits so many points of resemblance with 
Chetetes that even today some naturalists not only consider 
Chitetes as a subordinate member of the favositoid family, but 
have described characteristic Chetetes forms under the name 
Calamopora which is a synonym of Favosites. 

The above mentioned structural characters common to the 
various generic groups under consideration are subject to certain 


Chetetes in the Devonian Strata.—Rominger. 57 


modifications constituting the distinctive marks upon which the 
separation of Chtetes from Monticulipora, Stenopora, etc., is based. 
In Monticulipora and Stenopora the walls of the intimately united 
tubes are either distinctly double, exhibiting a central demarcating 
line between the contiguous walls, or this line is obliterated, but 
each of the tubes is in the immediate circumference of its orifice 
surrounded by concentric rings of darker shade than the lighter 
colored intermediate sclerenchymal mass, which plainly indicates 
the original independence of each of the anchylosed walls. 

In only a small subdivision of the Monticulipora group are the 
walls so thin that it is practically impossible to demonstrate 
their duplicity. 

Stenopora has double walls like Monticulipora, but among 
other differences the periodical swelling and contraction in the 
thickness of the walls constitutes its principal generic peculiarity. 
In Cheetetes the walls intervening between the tube channels are 
comparatively thick, but appear to be common to the contiguous 
channels; it differs further from the other generic groups by the 
development of irregularly disposed longitudinal crests within its 
tubes. Their number is variable; in some of the tubes no crests 
are observable, in others one, or two, or even three and four 
may be present which indentations cause considerable irregularity 
in the shape of the orifices. Another essential point of difference 
between Cheetetes and the other forms under comparison is said 
to be the multiplication of its tube channels during the progress 
of growth by a division of the older tubes, while in the other 
genera the tubes are multiplied by production of lateral gemme. 
This assertion is at least not fully correct; on the one hand I[ 
have before me sections of typical Chetetes in which a multiplica- 
tion of the tubes by gemmz, sprouting from the edges of the 
tube walls, is plainly exhibited; on the other hand an indubitable 
instance of a division of the older tube channels in two, or sey- 
eral, never occured to me, but not very rarely I have seen in 
transverse sections the longitudinal crests project so far into 
the lumen of the tubes that sometimes two opposite crests almost 
came in contact, which case might be apprehended as a not fully 
accomplished stadium of the division of a tube. 

The above mentioned want of differentiation in the walls of the 
adjoining tube channels, does not imply their perfect homogeneity ; 
in reality every tube orifice is bordered by a circle of nodules 


5 The American Geologist. July, 1892 


resembling in thin sections the cross cut acanthopores of a 
Monticulipora, but never showing a central perforation as they 
sometimes do. 

The size of these nodules differs considerably in the same circle; 
some three or four are larger than the other intermediate ones and 
constitute the upper termination of the, before described longitud- 
inal crests indenting the orifices; the other smaller ones cause no 
perceptible indentations of the tube channels, but they are per- 
ceptible as delicate longitudinal strive (Wandstraenge) on the 
faces of vertically cleft specimens, and better still in thin, longi- 
tudinal sections. The walls are actually composed of laterally 
anchylosed vertical columelles, which, counting the larger and 
smaller ones, amount to from ten to fifteen in each circumference 
of a tube. 

The specimens of Chitetes radians from Miatschkowa Govern. 
Moskau, which I have had occasion to examine, are of coarsely 
crystalline grain and do not allow of observing all the details of 
structure; much plainer are they exhibited by specimens of 
Chetetes milleporaceous from different localities in Indiana, Illi- 
nois and Kentucky, and in still greater distinctness all these 
structural particulars may be observed in the Devonian species 
found at the Falls of the Ohio and in the Eifel mountains. 

Noteworthy yet is the frequent development of morticules on 
the surface of Chetetes specimens, which are occupied by tube 
orifices of larger size than the rest. In addition to the other 
points of structural similarity, these monticules seem to me a con- 
firmation of the close relationship existing between Chtetes and 
Monticulipora. 

After these preliminary remarks I will enter on the special des- 
cription of the Devonian species of Chetetes. 

The specimens from the bed of the Ohio river I had colleeted a 
number of years past; on account of their external resemblance [ 
had identified them without closer exantination with a similar 
form abundantly found in the limestone formation of Sandusky 
and Kelley’s Island, and provisionally labelled them with the 
name C/etetes ponderosus. Later, Prof. Hall figured in one of 
his publications a form perfectly corresponding with the Sandusky 
specimens, and accordingly I adopted that name in place of the 
one given by me provisionally. 

Only recently, when I happened to look over these specimens, 


Chetetes in the Devonian Strata.—Rominger. 59 


I noticed that some differences existed between those from one 
locality and those from the other, and when I came to examine 
them microscopically, I found to my surprise more important 
differences in their structure than I had expected to find. 

The mode of growth in both is about the same, forming bulky 
convex masses or undulating thick tabular expansions, consisting 
of sub-parallel closely united tubules of about 4 of a millimeter in 
width; the surface exhibits low rounded monticules, on which or- 
ifices of somewhat larger size than the others present them- 
selves. 

In vertical fractures through such colonies is seen their compo- 
sition of a number of concentrically superimposed successive lay- 
ers, each of which represents a certain period in the growth, and 
a preceding and subsequent interruption of it. In this respect an 
obvious difference exists between the Sandusky and Louisville 
specimens. The concentric layers of the latter are merely indi- 
cated by an incrassation of the tube walls on that limit without an 
interruption in the continuity of their channels, while in the San- 
dusky form each concentric layer consists of an independent set 
of new tubes, which start with procumbent ends on the top of the 
orifices of a subjacent layer and soon after rise into an erect 
position. These procumbent basal ends of the new set of tubes 
frequently are consolidated into a continuous lamina, which under 
favorable circumstances allows a separation from the subjacent 
belt of tubules, presenting a wrinkled surface, very much like the 
laminar surfaces we can observe on splitting the double leaved 
expansions of a Ptilodictya or Stictopora. Suck periodical inter- 
ruptions in the growth occur at very variable intervals; in the same 
specimens the thickness of such a layer may »ot exceed two mill- 
imeters, subsequent ones may measure four and five millimeters, 
and some over an inch before a new disturbance in the growth 
commences. Qn cleaving such specimens vertically the tubules 
readily separate so as to present their angular outlines intact and 
the surface partly covered with wall substances which on its sides 
exhibits delicate transverse wrinkles of growth, besides stronger 
corrugations becoming most conspicuous in the angles of junction 
between the neighboring tube channels. The specimens from 
Louisville, in distinction from the Sandusky specimens, never 
exhibit such transverse rugosities; their tubes join under remark- 
ably straight edges, but on the other hand, they show a plain 


60 The American Geologist. July, 189% 


longitudinal striation, of which on the Sandusky form not a trace 
can be perceived. 

Comparing microscopical sections of the two forms, their struc- 
tural diversity is still more clearly exhibited. 

Transverse sections of the Sandusky specimens and of similar 
ones from the Helderberg group at Long lake near Alpena, 
present thin walled polygonal orifices 4 of one millimeter in di- 
ameter and somewhat larger ones crowded around the monticules. 
In the angles between the tubes a small number of triangular or 
quadrangular cell spaces may be noticed, which must be taken 
for the young ordinary tubes. Besides these, also acanthopores 
are observable in distantly scattered position. In every one of 
the successive layers the tubes are near their upper termination 
subject to a slight incrassation, which thickened portion exhibits 
under the microscope its diaphanous sclerenchymal mass dotted 
by numerous dark punctations disposed in a double row around 
the circumference of the orifices. If sections are not thin enough 
for good transparency, these densely crowded punctations could 
sometimes be mistaken for cross bars extending from one side of 
a wall to the other, or for the channels of connecting pores, but 
in sections, sufficiently thin, it becomes plain above all doubt, 
that these dark dots are isolated punctiform, and never trav- 
erse the entire thickness of the walls. This punctation of the 
substance of the tubewalls, noticeable in cross sections, is also in 
longitudinal sections dimly perceptible, but only the imcrassated 
wall portions show this dotted structure; the intersected thin- 
walled parts of the tubes do not. 

In all the examined specimens were found developed trans- 
verse diaphragms, unequally distributed and rather remote in po- 
sition, 

Summing up the points of the preceding description, this form 
(Hall's Chetetes tennis) corresponds in all particulars with 
Nicholson’s proposed subdivision of Monticulipora, termed Mono- 
trypa excepting in the presence of a few acanthopores, said to be 
missing in Monotrypa. But this arbitrary restriction of generic 
limits, which is not fully proved even with regard to the type 
form Monotrypa undulata, of which I have specimens exhibiting 
distantly scattered acanthopores, does not detain me from asso- 
ciating the described form with its nearest family relations and to 
introduce it under the name Monotrypa tennis Hall sp., since the 


Chetetes in the Devonian Strata.—Rominger. 61 


name Chetetes as now defined is no longer applicable in the case. 
As however the Louisville specimens, about to be described, fully 
correspond, in their structure with Chwtetes, my formerly used 
provisional designation Chetetes ponderosus can now be perma- 
nently settled upon them. 

Their externai mode of growth has already been mentioned. 
The width of the rounded polygonal tube orifices, is, as in the 
former, about one-third of a millimeter and of the larger ones, 
on the monticules, about half a millimeter; the intervening walls 
are stout, and not formed of a homogeneous mass of scleren- 
chyma,but obviously show their composition of a circle of solid 
vertical tissue columelles of alternately smaller and larger sizes. 
These columelles are intimately united with their side faces into 
closed channels with simple walls common to the contiguous cavi- 
ties. 

According to the different sizes of the tubes, from twelve to 
sixteen of such columelles may be counted in the circumference 
of an orifice. The larger columelles generally occupy the angles 
of the tubules, the smaller ones the intermediate part of the walls. 
Cross sections of the columelles under the microscope appear ex- 
actly like intersected acanthopores, as they present themselves in 
tangential sections of some Monticulipora species, but none show 
a central perforation like some of these doin Monticulipora. The 
entire thickness of the walls is occupied by these columelles, the 
larger of which cause a slight indentation of the margins, but in 
this species scarcely ever such strong crest-like projections occur 
as we observe them inthe tubes of Chetetes milleporaceus; other- 
wise, however, the longitudinal striation of the tube walls, corres- 
ponding with their columellar structure, is much more plainly vis- 
ible in thin sections, and even microscopically on cleavage faces 
of the Devonian form, than ever it occurs in specimens of Che- 
tetes milleporaceus. ‘ 

Transverse diaphragms, rather remote in position, are usually 
developed, but in some specimens I could not discover their pres- 
ence, 

From the Devonian limestones of the Eifel I have two different 
species. One of these I collected myself 50 years past in the vi- 
cinity of Gerolstein; it grows in strumose convex masses, and is 
preserved in a porous, granular limestone, with dull fracture. The 
fossil itself is likewise composed of a similar granular calcareous 


62 The American Geologist. July, 1892 


material, wherefore the more delicate structural details are some- 
what obscured. Still, in thin sections, the principal features of 
the species are sufficiently plain for recognition. Width of the 
tubes, one-third of a millimeter; shape of the orifices quite irreg- 
ular, somewhat rounded and longer in one direction than in 
the other, with conspicuous indentations of the cavities by two, 
three, or four of the larger vertical crests. The intermediate 
smaller columelles, though plainly recognizable in cross see- 
tions, do not cause indentations of the margins. In longitud- 
inal sections, the striated surface of the walls, the intersection of 
the tubules by moderately numerous transverse diaphragms, the 
concentric superposition of new layers without an interruption in 
the continuity of the tubules, and the multiplication by lateral or 
marginal gemmee, are all features readily observable. 

The material at my disposal is not sufficient to determine 
whether the second form, which I obtained from Prof. Schliiter 
in Bonn, is really a different species. It grows in thick, flat ex- 
pansions, which have been described and figured by Prof. 
Sehliiter under the name Calamopora piliformis. I refer to his 
own figures and explicit descriptions, from which the identity of 
his species with Chwtetes becomes evident before one subjects 
the fossil itself to a scrutinous examination. 

The margins of the irregularly polygonal, somewhat rounded 
orifices are indented by two or three, but not rarely by four and 
five, crest-like projections, and the intermediate portion of the 
margins shows the outlines of smaller columelles taking part in 
the formation of the walls. The tubules, one-third of a milli- 
meter wide, ascend almost parallel with each other from the base 
of the expansions to their upper surface without an obvious inter- 
ruption except by numerous transverse diaphragms, distant a little 
more than one tube diameter. Not a trace of lateral connecting 
pores can be discovered, and as Prof. Schliiter is fully aware of 
that fact, I feel somewhat surprised, that he unreservedly places 
this form under the genus Calamopora, a synonym of Favosites. 


EXPLANATION OF PLATE. 
Figs. 1-3, MonoTRYPA TENNIS Hall, sp. 
1. Small portion of tangential section, x 35, showing structure of 
walls and one of the acanthopores. 
2. Portion of vertical section, x 18, showing an acanthopore, the 
beaded structure of some of the walls, and several diaphragms. 


Vor, Pare Dnir 


THE AMERICAN GEOLOGIST. 


DEVONIAN AND CARBONIFEROUS CH42TETES. 


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Review of Recent Geological Literature. 63 


3. Another portion of a vertical section, x 18, showing the entire 
thickness of a narrow layer of tubes, and the minutely punctate charac- 
ter of their walls. 

Figs. 4-8, CHaTETES PONDEROSUS, N. sp. 

4. Tangential section, x 18, with part of a cluster of large cells. 

5. Portion of another section, « 28. 

6and7. Walls of two tubes, X 50, showing minute structure, the first 
with the wall thick, the second below the average in thickness. 

8. Vertical section, X 18, showing structure of walls of two tubes 
The constrictions of the walls are nearer each other than usual. 

Figs. 9-10, CHTETEs, sp. undet., from the Eifel of Germany. 

9and10, Vertical and transverse sections, x 18. 

Figs. 11-14, CHa TETES MILLEPORACEUS Ed & H. 

11,12and13. Small portions of three transverse sections, x 18, 
showing variations in wall-structure. 

14. Two tubes of a vertical section, x 18, showing wall-structure and 
arrangement of diaphragms. 

Figs. 15-16, Cia1rETESs PILIFORMIS Schiliiter, sp. 
15 and 16. Small portions of transverse and vertical sections, x 18. 


mi vibW Or RECHENT GHOLOGICAL 
LITERATURE. 


Tertiary Plants from Bolivia.—In the Trans. Amer. Ins. M. Es. (June, 
1892), Prof. N. L. Britton describes a number of Tertiary plants collected 
by Dr. A. F. Wendt at the silver mines of Potosi. The plants were found 
in a fine-grained sandstone which, according to Prof. Kemp, who made a 
microscopic examination of the rock, is undoubtedly volcanic glass and 
pumice. The fossils are very fragmentary, and the author is inclined to 
the opinion that some of the species represented are the same as living 
forms. Myrica banksivides Engelhardt, Cassia chrysocarpoides Engl., and 
C. ligustrinoides Engl., appear to bethe most common. Ten new species 
are described and seventy-nine figured, of which ten are undetermined. 


Geology of Maryland.—Johns Hopkins Univ. Cir. No. 95, pp. 37-39. 
Under the auspices of Drs. G. H. Williams and W. B. Clark, the univer- 
sity geologists made seven excursions in the vicinity of Baltimore, and a 
short notice of the results is given in the present paper. 

For geological work this university is perhaps more favorably situa- 
ted than any other institution. The state presents all the periods from 
the Archean to the Tertiary, and much of this is within a short journey 
of Baltimore. Perhaps the most interesting excursion from a paleonto- 
logical point of view was that to Fort Washington, on the Potomac river. 
A section is here most beautifully exposed and consists of Pleistocene 
8 ft., Eocene 12 ft., Cretaceous 20 ft., Potomac 55 ft. The first and last 
being at this point non-fossiliferous. No new evidence is given regard- 
ing the position of the Potomac group. 


64 The American Geologist. July, 1892 


OCuprocassitterite: A new mineral.—(Trans. A. 1. M. E. Feb. 1892). Mr. 
Tirus MEKE# describes an apparently new tin mineral, which he discov- 
ered at the Etta mine, Black Hills, 8. Dak. He gives the formula as 4 
SnO, + Cu, Sn (H O),, containing Sn 60 p.c.,. H,O 8p.c. Hardness 3, 
Sp. Gr. 5. Gives Sn and Cu reactions with soda. Dissolves in acids 
with separation of Sn O,. The author advances the opinion that the an- 
cients may have used this mineral, being of comparatively easy reduc- 
tion, in the manufacture of their bronze. 


Bohemian Garnets: Mr. Grorcr F, Kunz (Trans. A. I. M. E. Feb. 1892) 
gives the results of his visit to the garnet district of Bohemia, situated 
sixty kilometers northwest of Prague. The region is one of alluvium 
and diluvium resting upon the Cretaceous (Pliiner-kalk). Phonolite and 
basalt penetrate the strata. The garnets, which are of the pyrope va- 
riety, are found loose in the soil, in the diluvium, and embedded in the 
serpentine. The lower layer of the strata is cut away, the upper ones 
being thrown down, after which the stones are separated with water. A 
quantity of vertebrate remains bave been found in the diluvium by Dr. 
Parek. They are exhibited at Trebnitz, and comprise Hlephas, Rhinoce- 
ros, Antelodus, Rangifer, Cervus, Hquus, Bos, Ursus and Sus. From a 
financial point of view, Mr. Kunz mentions the fact that in 1890 these 
“ diggings” produced uncut garnets to the value of 80,000 guilders. The 
average daily pay of each worker is about 38 cents. 


Hleolite-Syentte of Litchfield, Maine, and Hawes’ Hornblende-Syenite from 
Red Hill, New Hampshire. By W.S. Baytey. Bulletin, G. 8. A., vol. iii, 
pp. 231-252, with a map and microscopic sections; June 4, 1892. Two 
varieties of eleolite-syenite are described in this paper, one of which 
the author names /dtchfieldite, from the township of Maine in which it is 
found. The second, which is a more nearly normal variety, comes from 
Red hill in Moultonboro, N. H., near the northwest end of lake Win- 
nipesaukee. 

The System of Mineralogy of James Dwight Dana, 1837-1868.— Descriptive 
Mineralogy. Sixth edition, by Epwarp Sauispury Dana. New York; 
I. Wiley & Sons, 1892, pp. 1134 + 58, figs. 1400. 

More than a score of years have passed since Prof. Dana, the elder, 
issued his fifth and last edition of his system of mineralogy. We are 
now glad to welcome this new edition, for the advance in this science, 
even in the past ten years, has been remarkable; still, his system in this 
country has not been abandoned. Besides many new additions, other 
changes of much importance have been incorporated in this sixth edi- 
tion. In the mathematical portion, the angles of the various species 
constitute an important feature. Many of these angles have been re- 
calculated and are now published in new form. Many new chemical 
analyses are given, adding much to the value of this great work. 

It is evident that professor Dana does not believe in an unnecessary 
increase in new species, aud it is also evident that his judgment in this 
respect is correct, for there are too many workers who are ready, at the 
least pretext, to create new species. This undoubtedly has arisen from 


Review of Recent Geological Literature. 65 


too hurried examination. If new names are absolutely necessary, let them 
be provisional until further investigations prove their right to become 
permanent. The learned author, much to his credit, is only able to rec- 
ognize between 800 and 900 species. We can agree with professor 
Dana in the statement that many apparently new species, if studied 
with sufficient care and comparison, would undoubtedly fall under some 
old species awd form varieties thereof, and of this the present work will 
be a constant reminder. 

The volume is a credit to American mineralogy, and the system of 
Dana will continue to be, as in the past, the chief guide and authority for 
English-speaking students, at least in America. 


The Mannington oil field and the history of its development. By I. C. 
Wuiter. Bulletin of the Geological Society of America, vol. iii, pp. 187- 
216, with map and sections; April 15, 1892. The district here described 
lies in Marion and Monongalia counties, W. Va., on the Monongahela 
river. In each of the three sections noted at Mount Morris, Mannington, 
and Fairview, the oil wells pass through the whole thickness (1,900 to 
2,000 feet) of the Carboniferous system, from the Permian or Dunkard 
Creek series to the “Big Injun” or Mount Morris oil sand, which be- 
longs to the horizon of the Pocono sandstone, the lowest of the Carboni- 
ferous strata. The paper contains also a very interesting history of the 
development, chiefly by Profs. White and Orton, of the “anticlinal theory” 
of reservoirs of oil and natural gas, and of its successful application to 
the discovery of new locations for oil wells in the Mannington district. 

Fossil plants from the Wichita or Permian beds of Texas. By I. C. 
Wuirr. Bulletin, G. S. A., vol. iii, pp. 217, 218; April 15, 1892. A 
collection of nineteen species of plants from the Wichita formation in 
Texas, which is regarded by Dr. C. A. White and Prof. E. D. Cope as 
certainly of Permian age on the evidence of its invertebrate and reptil- 
ian remains, is found to comprise eighteen species that occur in the 
Dunkard Creek series of West Virginia, southwestern Pennsylvania, 
and southern Ohio. The determinations of these plants were made by 
Prof. W. M. Fontaine, who, with the author of this short paper, referred 
these beds to the Permian, on the basis of their fossil flora, fourteen 
years ago. 


Notes on the Geology of the Valley of the middle Rio Grande. By E. T. 
DumBLe. Bulletin, G.S. A., vol. iii, pp. 219-230; April 22, 1892. The 
portion of the Rio Grande valley here described, from the mouth of San 
Felipe creek, near Del Rio, to Webb Bluff, near the south line of May- 
erick county, hasa length of about 80 miles. The elevation of Del Rio is 
973 feet, and the descent thence to Eagle Pass and Webb Bluff is about 
three feet per mile of direct distance, or approximately two feet per 
mile along the meandering course of the river. A slight southeastward 
dip, estimated to be about 100 feet per mile, brings successively newer 
beds into view as one travels down the valley, from the Arietina clays of 
Lower Cretaceous age at Del Rio to the Eocene beds of Webb Bluff. 
The thickness of the Upper Cretaceous strata appears to be about 7,800 


66 The American Geologist. July, 1892 


feet. Overlying the eroded surface of these formations are gravel 
deposits, often cemented by calcareous matter and passing into lime- 
stone, named the Reynosa beds, which contain fresh-water shells, as 
Bulimus alternatus Say, and are thought to be a phase of the Lafayette 
formation. 


A revision and monograph of the genus Chonophylium. By Wiiw H. 
SuEeRzER. Bulletin, G.S. A., vol. iii, pp. 253-282, with one plate; May 
24,1892. Twelve species of this genus of Paleozoic corals are recog- 
nized, two of them being described for the first time. Ten are North 
American, and two (including one of the new species) are European. 
The genus existed through the Upper Silurian era and the Corniferous 
and Hamilton divisions of the Devonian, its culmination being in the Up- 
per Helderberg epoch. 


PERSONAL AND SCIENTIFIC NEWS. 


THe Roya Socrery oF CANADA held its regular annual meet- 
ing in the Parliament Buildings at Ottawa, Ontario, from May 
31st to June 2d. 

The four sections adjourned to different apartments for the read- 
ing and discussion of papers. 

In Section II], Cuetmistry AND MineRALOGY, Professor EK. J. 
Chapman, of the University of Toronto, read the following two 
papers: On a New Form of Application-Goniometer. On the 
Mexican Type in the Crystallization of the Topaz, with some Remarks 
on Crystallographic Notation. 

In Section IV, GEoLocy AND Broutocy, Mr. G. F. Matthew, of 
St. John, N. B., delivered his Presidential Address ‘‘On the Dif- 
fusion and Sequence of the Cambrian Faunas.”’ 

In this address an attempt is made to distinguish the littoral 
and warm-water faunas of the Cambrian age from those which 
mark greater depths of the sea and cooler water. 

On the hypothesis that species capable of propagating their 
kind in the open sea would spread rapidly to all latitudes where 
the temperature of the sea was favorable, such forms as the grap- 
tolites are taken as fixed points in the successive faunas. The 
relation to the graptolites is noted of various species of other 
groups of animals, as they occur in different countries. It thus 
appears that several genera appeared first in America and after- 
wards spread to Europe. 

On the other hand a very close connection appears to have ex- 
isted between the Cambrian faunas of the north of Europe and 
those of the Atlantic coast of North America. Hence it is in- 
ferred that the temperature of the sea of these two coasts was 
similar, and the connection between them direct and unimpeded. 
Kqual temperatures in these different latitudes would be main- 


Personal and Scientific News. 6 


-J 


tained by a cold current flowing from the North European to the 
North Atlantic coast. The evidence available seems to point to a 
migration of the American species by a route to the west and north 
of the main part of the Atlantic basin. 

Mr. Matthew also contributed another paper entitled: J//ustra- 
tions of the Fauna of the St. John Group, No, VII. 

This is the final paper on this subject and treats chiefly of the 
fauna of the highest horizon in the group. It was accompanied 
by a list of all the species of the St. John group, showing the sev- 
eral horizons at which they have been found, 

There was an index to the whole series of the author’s papers 
on the species of this group; those of the Basal series which under- 
lies it, and those described by the author from the Cambrian rocks 
of Newfoundland. 

Besides the species from the highest horizon of the Bretonian 
Division (Div. 3) which formed the main subject of this paper, a 
few others from near the base of this division were described. 
Among these are a small Camarella and Strophomena, also small, 
which is perhaps the oldest known being from near the horizon of 
Parabolina spinulosa. 

From the highest horizon itself the species are of the age of those 
of the Levis shale, or thereabout, as shown by the graptolites 
found here. There are several orthids, some of which are identi- 
eal with, or are varieties of species of the Levis limestone de- 
scribed by Billings. The few trilobites known are of Cambrian 
types and include a Cyclognathus allied to C. micropygus and a 
Euloma. Several minute pteropods occur in these shales with the 
graptolites. 

The fossils of this horizon are known only from one locality, 
near the Suspension Bridge at the ‘‘ falls” of the St. John river, 
where they have escaped denudation owing to the complete over- 
turn which the St. John group has undergone at that point. 

Mr. J. F. WurreAves then presented a paper on The Fossils 
of the Hudson River Formation in Manitoba. 

The occurrence at the mouth of the Little Saskatchewan of 
rocks, which, on the evidence of a single fossil, were doubtfully 
referred to the Hudson River formation, is recorded by Dr. R. 
Bell in the Reportof Progress of the Geological Survey for 1874- 
75. The first definite recognition of that formation in Manitoba, 
however, is contained in tbe Report of Progress of the survey 
for 1878-79, on the evidence of a large series of characteristic 
Hudson River fossils collected at Stony mountain by Dr. Ells in 
1875 and by Dr. Bell in 1879, preliminary lists of which were 
given. An additional collection of fossils from this very prolific 
locality was made by Mr. Weston in 1884. In 1891 and ape 
Mr. D. B. Dowling found that Hudson River rocks occur also a 
Clarke’s Harbour, ten miles north of the Little Saskatchewan, a 


68 The American Geologist. July, 1892 


at an exposure six miles north of Clarke’s Harbour, at each of 
which localities a small series of fossils was obtained. 

The object of the paper was to give as complete a list as possible 
of the fossils of this formation in Manitoba. _ In the museum of 
the survey there are now as many as sixty species from Stony 
mountain alone. 

Pror. CuapmMAN contributed a paper On Paleozoic Corals. 
An attempt to simplify the determination of genera in the so- 
called Tabulated and Rugose corals of Paleozoic rocks. 

Str WittrAm Dawson then summarized in a very interesting 
manner his paper On the Correlation of Early Cretaceous Floras 
in Canada and the United States, and on some new plants of this 
period. 

The purpose of this paper was to illustrate the present state of 
our knowledge respecting the flora of Canada in the early Cre- 
taceous, and to notice some new plants from Anthracite, N. W. 
T., collected by Dr. Ami, and from Canmore, collected by Dr. 
Hayden. It was a continuation of the author’s paper on the Meso- 
zoiec Floras of the Rocky Mountain region of Canada in the 
Transactions of the Royal Society of Canada for 1885. 

Sir William Dawson then introduced a paper by Dr. Ami, of 
the Canadian Geological Survey, ‘‘On the Occurrence of Grapto- 
lites and other Fossils of Quebec age in the Black Slates of Little 
Metis, Quebec.” This paper contains notes and descriptions of 
Graptolites and other fossils from an interesting collection made 
by Sir William Dawson from rocks which have generally been 
assigned to the age of the Quebee group. 

Pror. L. W. Batney, of Frederickton, New Brunswick, in a 
paper entitled Observations on the Geology of Southwestern Nova 
Scotia, gives a review of the geological structure of Shelburne 
and Yarmouth counties, Nova Scotia, in the light of recent ex- 
plorations made by the author, with a sketch map of the form- 
ations. 

Section [IV elected the following officers for the ensuing year: 

President—J. F. WuHItTHAVES, F. G. 5S. 

Vice-president—PRor. J. MACOUN. 

Secretary—P ror. D. P. PENHALLOW. 

The whole society elected the following officers: 

President—J. G. Bourrnot, LL. D., etc. 

Vice-president -GEORGE M. Dawson, C. M. G., ete. 

Secretary—J. FLETCHER, F, L. 8S. 

Treasurer—A. R. C. S—uwyn, C. M. G., etc. 

Before adjourning the society extended a unanimous invitation 
to the Geological Society of America to hold their next winter 
meeting in Ottawa, Canada. 

Dr. Grorce M. Dawson, of the Geological Survey of Canada, 
has just had the honor of C. M. G. conferred on him by her Bri- 
tannic Majesty. 


THE 


AMERICAN GEOLOGIST 


Vou. X. AUGUST, 1892. No. 2 


AN APPROXIMATE INTERGLACIAL CHRONOM- 
ETER: 
N. H. WrncH et, Minneapolis. 
PLATES IV, V AND VI. 

In the present stage of the rapidly unfolding geology of the 
glacial and succeeding epochs every opportunity to cast light on 
that interesting drama should beimproved. The writer contrib- 
utes the following discussion to the subject with a hope that it 
may have some weight in determining one of the questions which 
yet remain unsettled.* The evidence here given that a consider- 
able interval of time, at least equalling that which has elapsed 
since the final withdrawal of the ice from the vicinity of the falls 
of St. Anthony, intervened between the first and second glacial 
epochs, is, perhaps, not conclusive proof, but in the opinion of 
the writer, it is far stronger than any evidence that has been ad- 
duced tending to reduce that interval to a mere recession and _ re- 


*A prev.ous paper by the writer, 7’he Geology of Hennepin County, 1892, 
a chapter in The History of Minne wpolis, | Atwater, contains the outlines 
of this discussion. 

The duration of interglacial time has also been indicated by Pres. T. C. 
Chamberlin: Som additional evidences be wing on the interval between the 
glacial epochs. Bul. Geol. Soc. Am, vol. 1, p. 459, 1890. The erosion of 
the trenches to which he alludes, as least so far as they lie within the 
drifted latitudes, seem3 to but very doub fully indicate the duration of in- 
terglacial time, since, as urged by James Geikie (On the glacial period 
and the earth movement hypothesis, pp. 18-19) such valleys may have 
been eroded in periods long anterior to the first glacial epoch, or even in 
pre-Cretaceous times. 


70 The American Geologist. August, 1892 


advance of the same glacial sheet, requiring a hundred, or two or 
three hundred, years; and as such if it should be accepted finally 
it will remove from the field of future controversy one of the ex- 
treme views of the shortness of that interval, and will open up a 
more clear, because more restricted, field for further investiga- 
tion. 

In the sixth annual report (1877) of the Minnesota survey (p. 
70) allusion was made to an old gorge in Ramsey county, in the 
following words: 


There is some appearance of the former extension of the valley of 
Rice creek much further southward, and it is no unreasonable sugges- 
tion that the great Mississippi itself may have once occupied this valley, 
entering the great gorge again where it becomes remarkably widened, 
at St. Paul; but the evidence is entirely topographical. Such as it is it 
ig perhaps overbalanced by a confusion of hills and high drift ridges 
north of St. Paul, which render it improbable that the Trenton is any- 
where entirely cut through from the Rice creek valley to St. Paul, as 
would have been the case if the Mississippi ever passed through there. 


Also, on p. 85 of the same report is the following statement: 


There is also a significant change in the direction [of the Mississippi], 
and one the more significant as it seems not to have been due tc any 
rock formation existing at St. Paul, but directly contrary to the rock 
sculpturing that exists there favorable to the continuance of the river in 
any pre-occupied valley running in the same direction. Allusion has 
been made to a possible ancient gorge through the Trenton north of St. 
Paul in describing the surface features of the county, but on the geologi- 
cal map of the county no such gorge is represented, because it never has 
actually been discovered, and its hypothetical location would perhaps be 
OL Morsenvice.: hanes aes 

These anomalous and significant facts can all be reasonably explained 
on the supposition that the Mississippi river was diverted from its 
ancient valley-gorge, north of St. Paul, by the ice and drift of the first 
glacial epoch, and that it was driven-into that which has been described 
in the report on Hennepin county, toward the west further, and joined 
the Minnesota valley at some point above Fort Snelling, but between 
that point and Shakopee, without passing over or through the Trenton 
limestone at all. Their united waters then formed the river which 
excavated the gorge between Fort Snelling and St. Paul (unless the 
Minnesota alone had already done it) between the first and second glacial 
epochs. 

Since that report was written several results have been attained 
which diminish the obstacles to the hypothesis which then existed. 
The extent and distribution of the moraines of the state have been 


established by more field work. The ancient discharge of the 


Interglacial Chronometer.— Winchell. {ai 


Minnesota river eastward through some valleys which lead to the 
Mississippi river at points south of St. Paul, thus possibly remov- 
ing the Minnesota river from the elements of the problem, has 
been described both by Mr. Upham and by the writer in reports 
on Martin, Blue Earth, Rice, Goodhue and Dakota counties. 
Some data from deep wells and from topographic levels have been 
obtained bearing upon the probability of a continuous old rock- 
cut valley extending from the mouth of Rice creek, near Fridley, 
to St. Paul. 

More recently the attention of the writer has been given again 
to this subject,* and he has attempted to illustrate on plates Iv 
and vy and yi some of the data on which the conclusions of this 
paper are based. That the valley of the upper Mississippi is 
very old is evident on a moment’s reflection.t That the main ar- 
tery of its drainage must always bave had a channel, more or less 
wrought in the rocky crust, is equally evident. It is also very 
plain that that old valley, and that old excavated channel, must 
have dated from the uprising of the rocks that formed the surface 
in the vicinity, from below the ocean’s level. Many changes, 
perhaps such as to cause the shifting of the actual line of erosion 
by such drainage from place to place, within certain limits, may 
have taken place since the Archean rocks of the central region of 
Minnesota first began to shed the continental waters. Some of 
these may have occurred since the Cambrian and Lower Silurian 
rocks, which are the only ones (with one non-important exception) 
which now exist in the region concerned later than the Archean, 
rose above the ocean and added their quota to the land area of 
the region. Allowing for all these shiftings, which are entirely 
hypothetical and have no claim to be allowed, in any exact state- 
ment, yet it will be at once admitted that there was sufficient of 
quiet in the interval from the Lower Silurian to the present, to 
permit the early Mississippi to excavate what might be styled a 
‘‘base-leveled” gorge through the rocks over which it flowed. We 
will not here enter upon the evidences that the present gorge is 
the oldest, dating from Silurian times, at least between St. Paul 
and the southern boundary of the state, but will simply call atten- 
tion to the fact that the immediate source and the mouth are most 


*Op. cit. The Geology of Hennepin County. 


TE. W. CiaypoLe. The Story of the Mississippi-Missouri. AMER. 
GEOLOGIST. Vol. 11., pp. 361-377. 


79 The American Geologist. August, 1892 


subject to change, the former by recurring glaciation, and the 
latter by oscillation of the coastal lands. — It is therefore obviously 
a non-sequitur to base any statements respecting the age of the 
upper Mississippi on facts and features that may be observed in 
the lower portion of the valley, and this will apply, with proper 
limitations, toa great many of the tributaries of the Mississippi. 

Such ‘‘base-leveled” channel, with steady slope and easy cur- 
rent, could have had no water-falls such as are produced by alterna- 
tions in the rock-strata with which streams come in contact in 
drift-covered latitudes. The occurrence of a water-fall in a river 
implies a comparatively recent change in the location of its bed. 
The same is true of rocky rapids. The drifted regions abound in 
water-falls. The non-drifted are without them; but vice-versa the 
drifted regions are scantily supplied with deep river-cut gorges, 
and the non-drifted are scored by deep gorges cut by the surface 
drainage. 

Such a valley is the gorge of the Mississippi, from St. Paul to 
the Iowa state line. Its depth is not measured by the hight of 
the present bluffs, for the excavation is found to extend several 
hundred feet below the present surface of the river. It has re- 
cently been partly refilled. Drift deposits (gravel and sand) lie 
upon the bottom of the rock-gorge and have a thickness of over 
two hundred feet. 

As the eroded valley is immensely deeper, within Minnesota, 
than the present bluffs, so it is also wider. The Trenton lime- 
stone which was its bed in Upper Silurian time and perhaps in Car- 
boniferous, now forms bluffs along each side some miles distant, 
having been wasted away more rapidly than the other, lower, lime- 
stone strata, through the disintegrating action of the erosible St. 
Peter sandstone immediately underlying it. (See plate v, fig. 3). 
These distant Trenton-St. Peter bluffs approach the river toward 
the north further, and at the falls of St. Anthony the Trenton 
again forms the bed of the river, being the barrier at the brink 
over which the water plunges. (See plate rv, fig. 2.) 

The study of the falls and the surrounding region has revealed 
some earlier history of the river, and has brought to light some of 
the abandoned gorges which the river formed in interglacial and 
pre-glacial times. The oldest valley seems to have been the most 
direct one, viz: that extending from the mouth of Rice creek 
above Minneapolis, to the mouth of Trout creek, at St. Paul. 


THE AMERICAN GEOLOGIST. Vou. X, Puate IV. 


Fig. 


Moratne 975 


Section at. Shingle Creek 
( Inter-Graectal Channer ) 


Moratne 950. 


Alluvial 


ou 


ee 5 St. Peter 
+.“ Pikst hoek at 265 Sandstone 
fv > =k Inthe cil ah 
Lakewood Cemetery well: 
Fig. 2 


Section at the Falls of St Anthony 


[Post Glaeiar SChanner) 


fa 


St. Peter Sandstone 


aine 1000 3 
4 : Peg. 3 Moratne 1000 
" Prat aren 


: 


Section Below the Falts 


(Post-Craci al Channet) 


St. Peter Sandstone 


Fg. 4 


Section at Fort Snélling 
[Post—Glaetar Gorge] 


Nt. Peter Sandstone Vertical Seale of Feet 
toe ____._309 _____3004 ___4qe@____goo 
| Horizontal Scale of Miles 
A 2 3 4 
_—_——_— — = = 


SECTIONS ACROSS THE MISSISSIPPI RIVER. 


| 


my 
{ 


}-41 
4 rs oi Star) - o ii > 
: Ps ‘ee Oy ya 
ihavy & A ; 
it 2 aes fs a hab it + 7 
J ; J i ‘ A , 
| 7 sg a - j i} 7 } 
‘ , : ‘ ie ies ‘ye 
al . ; f L, ‘ 
oi 4) x . . , re 
r 7; J 


rd 


“I 
is) 


Interglacial Chronometer.— Winchell. 


This is also the most frayed and smoothed off with age and surface 
disintegration, thus becoming wider and less distinct. 

In 1680, when father Hennepin, the discoverer of the falls of 
St. Anthony, taken by the Sioux Indians in the vicinity of La 
Crosse, was led in captivity to lake Mille Lacs, the source of 
the (then) St. Francois river, they left the Mississippi at St. Paul 
and apparently followed this route to avoid the rapids and falls of 
St. Anthony; for in this valley are several lakes and from them 
flows a canoeable stream to the Mississippi again, northward. 

There is a significant break-down and total lack of the Trenton 
limestone at St. Paul on the left bank, just above Dayton’s bluff, 
for a distance of nearly a mile. This break-down occurs on one 
side of the right angle which the river there makes, and directly 
where the course of the present river-channel below, if extended 
northwestward without the right-angled turn, would encounter the 
bluff. This fact alone is significant of changes in the course of 
the gorge of the Mississippi as occupied and eroded at different 
epochs in the past. On following up this intimation, the inquir- 
ing geologist ascertains that there is not orly no known existence 
nor any signof the Trenton limestone anywhere northwestwardly, 
and that the St. Peter sandstone a lower stratum occurs in out- 
crop in the low grounds intervening between the mouth of Trout 
brook and the mouth of Rice creek, but also that on either side, at 
a short distance, the Trenton still exists. On the southwest side 
it rises into a conspicuously hilly tract, and includes some of the 
highest beds belonging to this formation known in this part of 
the state. On the northeastern side it is less prominent, occur- 
ring so far as kaown, mostly as remnants of the outrunning fringe 
of the formation. But still further east, across a wider valley, a 
conspicuous spur of the higher beds of the Trenton shoots off 
northeastwardly, diverging from St. Paul and passing into Wash- 
ington county at Castle. This shows that at some former time 
there was a great valley northward from St. Paul, whose east and 
west sides diverged from the break-down in the Trenton which 
has been mentioned. One portion of this great valley, lower now 
than the rest, extends northwestwardly to the mouth of Rice’s 
creek and there encounters the present Mississippi river six miles 
above the falls of St. Anthony. In this portion of this valley lie 
McCarron, Bennett, Josephine, Johannah and Long lakes, con- 
nected with the Mississippi, either toward the north or toward the 


74 The American Geologist. August, 1892 


south and with each other, by Rice creek and Trout brook, con- 
stituting a marked valley which connects the Mississippi above 
the falls with the Mississippi below the falls by a nearly direct 
course. (Compare plate vI.) 

The writer, in former papers, has discussed the recession of 
the falls of St. Anthony,* and has deduced a time-measure for 
their recession from Fort Snelling to Minneapolis, and has shown 
that this also measures the time elapsed since the last glacial 
epoch. This result, approximately 7,800 years, has generally 
been accepted by glacialists, especially in America. It was 
shown that just prior to the last general glaciation the Mississippi 
river at Minneapolis occupied an old valley which diverges from 
the present channel within the limits of the city, at the mouth of 
Bassett’s creek, passed southward where now a series of lakes lie 
(Calhoun, Harriet, etc.) and joined the present Minnesota chan- 
nel at some point a short distance above Fort Snelling. There it 
turned to the northeast, at a right angle, and went on to St. Paul, 
and thence, with another right angle, as now, it finally took its 
undeviating course southward. The significance of the first of 
these right angles has been pointed out in that earlier discussion. 
It is the purpose of this paper to point out and discuss the sig- 
nificance of the second. 

In the light of what has been shown for the first it is a reason- 
able expectation to find a similar explanation of the second, 
should similar or identical conditions attend the second. 

Those conditions are: 

1. A great river seeking a channel of discharge, through a 
country uniform in its topography and geological structure, to the 
ocean. 

2. The derangement of the natural, direct and primary course 
of its erosion by the on coming of the conditions of a glacial 
epoch. 

3. The choking up of the (then) existing channel and the 
acceptance by the river on the retirement of the giacial conditions 
of another slightly different channel. 

4. Its entering again upon its old channel at a lower point, 
and the birth at that point of a new waterfall. 


*Fifth annual report of the Geological Survey of Minnesota, 1876, pp. 
156-189. Quart. Jour. Geol. Soc. Lond., Nov., 1878, pp. 885-902. Final 
report of the Geological and Natural History Survey of Minnesota, vol. 
I, pp. 318-341. 


oo *\ 


Tue AMERICAN GEOLOGIST. Vou. X, PLATE V. 


Fug.1 


Section of the Minnesota River 
1m. above Fort Snelling 
eter 


es 


Fig: 2 


Moraine 900° 
Tee toe Section at St. Paul 
Ke, 


c Inter Glacial Channer ] 


* St. Peter 


——— Lim stone : 


Fig. 3 


= West Bluff at Lake City 
St Peter — 


Shakonee ee eee ee 
Rithmond cia lal Dette oe: d Loa 


Ce ower Magnesian 
Cee ae imestone 


Pre-Giracriat 


Gor ge 


Horizontal Seale of Miles 


BF 


Herizental Scale of Mites( Fig.3 ) 


Vertical Scale of Feet 


oo oe oo 


SECTIONS ACROSS THE MISSISSIPPI RIVER. 


ee he = 


re Ae ee i eee ete 


yee Le hig iien Geer ey ae Serr 


: ag shear hae , ; 
weve di a a me 
. The a 


Ss Gh ee 


Sob Mar 


= ra 


Interglacial Chronometer.— Winchell. (5) 


5. The recession of this waterfall backward till it cut a gorge 
through the obstruction which it had been compelled to surmount 
rather than flow round. 

6. The greater depth, width and different direction of the old 
gorge from the gorge which the river excavated in the later stage 
of its history. 

7. The existence of another older valley from which the river 
might be presumed to have been expelled. 

8. The movement of the ice, in general, in that direction, 
about the falls of St. Anthony, which would tend to throw the 
river from its supposed older channel toward its supposed newer. 

These conditions all do exist, in connection with the second 
right angle, as plainly as they do in connection with the first. 
The map on the accompanying plate (v1) illustrates them. The 
difficulty which we encounter in attempting to handle the facts 
consists in the consciousness that they relate to a very old history. 
We have not often attempted to place time limits on geological 
data, and when we have ventured to do it we have confined our 
assays within post-glacial time. Our next step must be beyond 
the border that sets off post-glacial history as a unit of geological 
time amenable to our scrutiny, and leads into interglacial time. 
We reach the results inductively, just as we have for post-glacial 
time. Here are a set of facts. . They need reasonable interpreta- 
tion. That hypothesis which suited the other set of identical 
facts is naturally the first one invoked for this. Does it apply as 
well? 

The movement of the ice of the first glacial epoch has been 
stated to have been from the northeast in the vicinity of the falls 
of St. Anthony, that of the second from the northwest. This is 
based on the prevalent direction of transport shown by the nature 
of the drift materials when they are referred to their native places. 
The lower till—the copper-colored or red till—has a preponder- 
ance of rock debris from the region of lake Superior, and north- 
ern Wisconsin. The upper or gray till, which has a marked con- 
trast with the red, has a preponderance of rock debris from the 
direction of the Red river valley. ‘These tills come into contact 
about Minneapolis and St. Paul, and in all places where the two 
are seen in place,the gray overlies the red, but they are frequently 
separated by a layer of sand and gravel referable to the epoch of 
the red. When the glacier which deposited the red drift ap- 


T6 The American Geologist. August, 1892 


proached the region of Minneapolis it must have found the Mis- 
sissippi running in its most direct course southward, for it can 
only be supposed that the ordinary events of ordinary seasonal 
changes, and ordinary erosion of the surface of the country, prior 
to that event, would have acted to determine the location of the 
stream. Archzean highlands existed toward the east, in Wiscon- 
sin, and toward the west, in Minnesota. When the land rose 
from the Cretaceous baptism, those highlands must have shed 
their surface waters toward this valley. The resultant main 
stream, taking the easiest course toward the sea, excavated its 
channel first through the Cretaceous sediments and then into the 
Silurian or other strata, guided only by the accident of posé of 
the surface. If we know of no cause that could have diverted 
it, as we do not, we must suppose, « priort, that its course would 
be the most direct and shortest to reach sea level. We take no 
account here of the possible, and even probable, existence of a 
pre-Cretaceous river and hence a pre-Cretaceous gorge, for had 
‘such existed it would, in the first instance, have been governed in 
its location by the same influences. “We might add, that had 
such pre-Cretaceous gorge existed, its effect on the contours of 
the surface after the mantle of the Cretaceous sediments had been 
spread over the region, would have been favorable to the re-loca- 
tion of the stream, when the land became dry again, in the same 
gorge as it had excavated in pre-Cretaceous time, and hence that 
it matters but little whether we discuss here the pre-Cretaceous 
or the post-Cretaceous drainage. In either case the shortest, and 
the lowest line of drainage was chosen. <A glance at the map, 
and a knowledge of the geology of the region would at once indi- 
cate that the Mississippi, on the advent of the first glacial epoch, 
was probably running in the valley which has been referred to, 
from the mouth of Rice creek to the mouth of Trout creek, thus 
cutting out both of the right-angled turns that it now makes be- 
tween those points. This valley it must have occupied during 
Tertiary time at least, and probably since Lower Silurian time. 
Where was the Mississippi running on the withdrawal of the 
ice of the first glacial epoch? As has been stated, it was shown 
that when the second glacial epoch approached, the Mississippi was 
running in a channel excavated through the Trenton-St. Peter 
along the western suburbs of Minneapolis and reached the Minne- 
sota valley at some point above Fort Snelling, andit is fair to as- 


X, Priate VI. 


VoL. 


THE AMERICAN GEOLOGIST. 


OCASTLE 


we 


RBI 


Ani? 


ww! 


. 


Tan 


PO Faw’ 


rc a 
q Ko Ways 


N27 
aun WS NWN 
on 


UMN yng nnd WS 


Ss 


4inch 


Scale 4 Miles 


CONTOUR MAP OF THE VICINITY OF THE FALLS OF ST. ANTHONY. 


Interglacial Chronometer.— Winchell. ed 


sume that it was driven there by the events and forces of the first 
glacial epoch, and that it had occupied it during the time that in- 
tervened between the two glacial epochs. But that is an excavated 
river gorge, cut in rock in a manner sinilar to the present gorge, 
except that it is wider. Our problem is to measure the time re- 
quired for such excavation, for we are obliged to infer that the 
manner of its excavation was by the recession of an interglacial 
falls of St. Anthony. 

In this problem there are some elements identical with those 
which were employed in the calculation of the time required for 
the formation of the post-glacial gorge, and there are some which 
are somewhat different. 

Those which are the same are: 

1. The general slope of the country. 

2. The contact of the two formations which conspire to cause 
the water-fall. 

3. Uniform and horizontal position of the same rocks. 

4. Definite limit for the upper end of the eroded gorge. 

The elements which are different, or uncertain, are the follow- 
ing: 

1. The size of the river: 

2. The lower end of the excavated gorge, 7. e. whether the 
falls began at that point above Fort Snelling where the Mississippi 
at that time met with the Minnesota river, or at a point at St. 
Paul opposite Dayton’s bluff, where the lower right-angled turn 
takes place. 

As to the size of the river during interglacial time we have 
no definite data, except that we may infer that it was not so large 
but that it could flow in the gorge it excavated. We have no re- 
liable data by which to estimate the annual precipitation over the 
region which the river must have drained. It was a period in 
which some of the mountain ranges of the western country did not 
exist. The Rocky mountains did not extract and return to the 
Pacific ocean the moisture from the western winds quite so readily 
as they do now, and hence the contrast in annual rainfall between 
the plains and the eastern portions of North America was not so 
marked. Again there must have been active volcanoes in the 
western portion of the United States and perhaps some in Colo- 
rado, These must have disturbed the atmospheric conditions, 
causing at least in their near vicinity, copious rains, and these 


%8 The American Geologist. August, 1892 


centers of atmospheric disturbance were doubtless in some in- 
stances wafted far eastward, and even northward, shedding on 
the plains more moisture than they receive now. The present 
size of the interglacial gorge being somewhat larger than the post- 
glacial gorge, even after making allowances for some enlarge- 
ment by the disintegrating action of the last glacial epoch, and 
there being some reason to think the western country was wet in 
many places where now it is dry,* it is reasonable to infer that 
the river was permanently sustained at a higher stage by a greater 
precipitation. If this be allowed we shall have to admit that it 
would act more powerfully at the brink of a receding waterfall, 
and that the recession of such water-fall, for any given length of 
time, all other things being equal, would have been more rapid in 
interglacial time than it lias been in post-glacial time. his dif- 
ference may have amounted to twenty-five per centum of the post- 
glacial recession. 

In regard to the point of debouchure of the interglacial Missis- 
sippi into a pre-existing gorge, giving rise to a water-fall at the 
commencement of interglacial time, there are such uncertainties 
that it will not be possible to determine whether it was at St. Paul, 
opposite Dayton’s bluff, or at a point in the Minnesota valley a 
few miles above Fort Snelling. This all depends on how old that 
portion of the Minnesota (now the Mississippi) valley is, between 
St. Paul and the supposed point of junction above Fort Snelling. 
There is some reason to suppose that the Minnesota river did not 
always unite with the Mississippi where it does now, nor at any 
point in the vicinity. The Minnesota itself, at Mankato, has a 
significant right-angled elbow, and at other points further north it 
shows signs, especially in glacial and post-glacial time, of having 
taken a course to the Mississippi across Rice, Dakota and Good- 
hue counties. At earlier dates its waters may have found passage 
to the sea toward the southwest and the Missouri river, or through 
some of those deep rock-cut gorges which characterize the Undine 
region in Blue Earth county, thus having had some agency in the 
pre-glacial sculpturing of those canons in which lie the curious 
‘chains of lakes”? which Mr. Upham has described in Faribault 
county. 


*This difference is indicated by the existence of interglacial peat beds 
in southern Minnesota, and the discovery of many trees like cedars 
whose habitat is usually in swamps, in the upper till as well as in the 
peat beds. 


Interglacial Chronometer. — Winchell. 79 


Be all that as it may, there is one fact which tends rather in the 
opposite direction, and indicates that the Minnesota itself cut a 
gorge between St. Paul and Fort Snelling and also further up its 
valley even in pre-glacial time, and that the interglacial Missis- 
sippi found this gorge in existence when it was compelled to aban- 
don permanently its own pre-glacial gorge. That evidence consists 
in the depth of the gorge between St. Paul and Fort Snelling. 
This excavation has to be measured through the whole thickness 
of rock-strata which have been cut, regardless of the accidents of 
the present, for the spreading of the drift has obscured the history 
of the river preceding the ice age. This country became dry land, 
so far as can be judged from the latest marine formations (not 
considering the Cretaceous), at the close of the Lower Silurian. 
The whole of the Lower Silurian was probably deposited through- 
out the area incluled in this calculation, and at the present time 
there are preserved, in the hills to the south of St. Paul, as well 
as at St. Paul and toward the northwest and northeast, as already 
stated, some of the higher layers of the Trenton, even including 
some distinctively Galena characters. The thickness of all the 
Trenton beds (shales and thin limestones) is 114 feet. The St. 
Peter is exposed, above the river level, about 75 feet, and the 
gorge, as revealed by deep wells, is cut about 200 feet below the 
water level. The total excavation in the rock therefore is 389 feet. 
As this comports with the general depth of the Mississippi gorge 
below St. Paul, which must be referred to pre-glacial history, 
rather than with any excavation that can be referred to intergla- 
cial time, it points strongly to pre-glacial time for the excavation 
and hence also 


of the valley between St. Paul and Fort Snelling 
to the occupancy of the present valley in general by the Minnesota 
since pre-glacial time. 

At any rate, whether the interglacial falls began at St. Paul or 
not, the length of time required for their recession to the mouth 
of Bassett’s creek is sufficiently long forthe purpose of this paper. 
We will, therefore, assume the shorter recession, and calcu- 
late from the point above Fort Snelling on the Minnesota bluffs at 
which the Mississippi may be supposed to have leaped from the 
Trenton limestone to the river below when it was driven from its 
pre-glacial gorge. 

In a direct line the mouth of Nine-Mile creek in Bloomington 
township, which may most reasonably be taken as the point of 


80 The American Geologist. August, 1892 


commencement of the interglacial falls of St. Anthony, is distant 
from the mouth of Bassett’s creek where they stopped their reces- 
sion, twelve and a half miles, or about 50 per cent. further than 
the distance through which the post-glacial falls have receded, 
from Fort Snelling to Minneapolis. Taking the results of the 
calculation of the post-glacial recession as a measure of intergla- 
cial recession, we find they compare with the interglacial condi- 
tions as follows: 

Post-glacial recession 85 miles, in 7,800 years. 

Interglacial recession, 124 miles, at a vate perhaps 25 per cent, 
faster. 

The greater distance will more than compensate for the greater 
rate, and will allow us to add to the time required about 25 per 
cent. of the post-glacial time. This indicates 9,750 years for the 
lapse of time required for interglacial recession. 

Such an interval of time, if it occurred between the two glacial 
epochs, would allow for something more than the temporary re- 
treat and re-advance of the same ice sheet. It would give time 
for the weathering of the till of the first glacial epoch and the 
excavation of valleys in it by interglacial streams. It is time 
sufficient for the growth of forests and the accumulation of peats, 
for the development of a somewhat characteristic fauna and flora, 
and for the establishment of some human habitation as well as 
civilization. The whole Egyptian dynasty, and perhaps the dawn 
of the Chinese, might be compassed in such a period. 


NOTES ON MANGANESE IN CANADA. 


H. P. BruMELL, Ottawa. 
Assistant, Division of Mineral Statistics and Mines Geological Survey 
of Canada. 
(Communicated by permission of the Director.) 


In preparing the following brief sketch of the various impor- 
tant deposits of manganese in Canada, I have embodied the 
ereater part of tae article on that substance which I prepared for 
the annual report of the division of Mineral Statistics and Mines 
for 1890.* 

That the industry has not attained greater commercial promi- 
nence is due rather to its distance from market than to any in- 
sufficiency of supply; this applies, however, more especially to 


*Annual Report Geol. Surv., part 8, Vol. v, 1889-90. 


Manganese in Canada.— Brummell. 81 


the low grade or blast furnace ores than to the highly crystalline 
pyrolusite for which the market is restricted. Of the geographi- 
cal position of the ore deposits little need be said beyond the fact 
that the worked and, as faras is yet known, the workable deposits 
are allsituated within New Brunswick and Nova Scotia. Through- 
out these provinces are found many comparatively extensive de- 
posits of the crystalline and semi-crystalline ores, viz: pyrolus- 
ite, manganite and psilomelane, as well as large areas of wad or 
bog—manganese. The crystalline ores are, in the majority of 
cases, found in rocks of Lower Carboniferous age, while the bog 
ore deposits, being of recent formation, are found overlying rocks 
of any formation from the pre-Cambrian upwards. 

New Brunswick.—In New Brunswick the most important de- 
posit of the crystalline ores is that at Markhamville, Sussex, 
Kings Co., from the workings of which upwards of 20,000 tons 
have been shipped. The ore deposits are irregular beds, pockets 
and veins in a small area of Carboniferous limestone, on the 
northwest side of which are located the workings. Many of these 
ore bodies have attained large dimensions, one of them affording 
in the neighborhood of 4,000 tons of manganite with a consider- 
able proportion of pyrolusite. The discovery of manganese at 
this point was made in 1862, when it was worked by Mr. Wm. 
Davidson, of St. John, until 1865, after which the property 
passed into the hands of the Queen Manganese Co., by whom it 
was operated under the management of Major A. Markham until 
1889, when it again changed hands and was operated, still under 
Major Markham, by the Pope Manganese Co. Owing to the loca- 
tion of the deposits, in a valley cut through the softer limestones, 
no regular system of mining has been attempted, the operations 
being, until quite recently, altogether in the form of drifts and 
open cuts with which the hill on the north and west side of the 
property is literally honey-combed. During 1890, however, ex- 
plorations were being made by means of the diamond drill, with 
the result that two deep-seated deposits had been found and were 
being sunk upon. 


Of the ore shipped from this mine two distinct classes are ree- 
ognized, viz: ‘‘Blast furnace ore,” consisting almost entirely of 
manganite, and high grade or ‘grey ore,” consisting of pyrolu- 
site. The following analyses are of ‘‘high class manganese ore 

from Markhamville, New Brunswick” and are taken from «The 


82 The American Geologist. August, 1892 


a havin! 


Mineral Resources of the United States, calendar year 1888. 
Washington, 1890: 


IN@s il, INO; (2: No. 3. 
M wnganese binoxide 98.70 
peroxide 97.25 96 62 
Silica 0.55 
Tron 0.75 
Iron peroxide 0.85 0.78 
Barium trace 
Baryta and silica 0.95 0.85 
Water trace trace 
Loss 095 1.75 


Another important deposit of crystalline ore is that of Jordan 
mountain about five miles north of Sussex, Kings Co., and on the 
western side of the mountain. The ore bodies occur in a man- 
ganiferous limestone throughout which are scattered, in a manner 
similar to that at Markhamville, more or less extensive deposits 
of pyrolusite and manganite. Since its discovery in 1882, by 
the present owner, Mr. F. W. Stockton, of Sussex, but little has 
been done, further than a small amount of development work, 
consisting of stripping and an open cut of about eighty feet in 
length, in the bottom of which might be seen an interbedded len- 
ticular mass of ore, principally manganite. From this cutting 
about 400 tons of eighty to eighty-five per cent. ore had been 
extracted. 

Operations have been carried on for many years and by different 
companies at Quaco Head, a bold rocky promontory about one mile 
southwest of the village of St. Martins, Kings Co., unfortu- 
nately, however, with but slight success, owing to the low per- 
centage of ore contained in the rock mass. The deposit con- 
sists of a heavy bed of red calcareous shale highly charged with 
manganite and psilomelane, pyrolusite being of much rarer occur- 
rence than in the limestone deposits of the aforementioned local- 
ities. The property has been worked in a very desultory man- 
ner for many years, energetic operations not having been under- 
taken until its acquisition by the present company, who began 
work by driving a tunnel into the shales which show a bluff face 
of about 150 feet high. From this tunnel, which was driven about 
sixty feet, two cross-cuts were made in either direction for about 
twenty feet. In these workings several small pockets and con- 
siderable quantities of mill-rock were struck and the ore ex- 
tracted, though no shipments were made. In connection with the 
mine a well equipped mill was erected and a wharf built and 


Manganese in Canada. — Brunel. 83 


all facilities made for the easy handling of the ore. Owing to 
the position of the mine, ore could be run direct from the work- 
ings to the wharf and loading accomplished at one handling by 
means of self-dumping cars. 

Assays of the concentrated ore made by A. M. Cowly, Cam- 


bridge, Mass., gave the following result: 
Compact Porous 


variety. variety. 
Manganese dioxide 71.54 65.00 
Insoluble silicates 8.37 6.66 
Ferric oxide 2.19 1.75 
Ph: sphorus 0.02 0.04 
Calcium trace trace 
Metallic manganese 58.20 57.15 


A considerable proportion of lime is generally present in the 
concentrates, which will not, however, interfere with their fitness 
for use in the manufacture of steel for which purpose all the ore 
from this property will be most suitable. 

A peculiar occurrence of manganese is that which is to be seen 
on the north and northeast side of Gowland mountain, Elgin, 
Kings Co., where the ore, consisting principally of psilomelane, 
is found filling the interstices of a very much broken and partly 
decomposed granite of pre-Cambrian age. A small amount of 
development work was done on these deposits without, however, 
locating any other than small bunches of a very impure pyrolu- 
site and psilomelane. The following analysis made in 1885 by 
Mr. F. D. Adams, late assistant chemist to the Geological Survey, 
is that of a specimen of psilomelane from this property: 


Mangavese dioxide, available 50.21 per cent. 
Ferric oxide 3.06 & 
Insoluble residue 33.78 


The specimen also contained a very appreciable percentage of 
baryta. 

This property is peculiar in affording the only instance in New 
Brunswick where the crystalline ores of manganese are known 
to oceur in appreciable quantity outside of the Carboniferous 
areas. 

Other localities where manganese, in its crystalline forms, have 
been noted are, Upham, Waterford, near Petitcodiac, Springfield, 
Téte-a-Gauche Falls, and many points throughout Albert county. 
Of one of these, Shepody mountain, Dr. R. W. Ells, in his report 
to the Geological Survey for 1884, writes: ‘‘The rocks of the 
mountain (Shepody mountain) rest upon a small outlier of the 


S4 The American Geologist. August, 1892 


taleo-chloritic schists, which show on the road to the north, lead- 
ing to Curryville, and are flanked on the east by the grey sand- 
stones of the millstone-grit. On the northwest side a large de- 
posit of manganese was worked for some years, a tunnel being 
driven into the mountain along the contact with the underlying 
schists for nearly 1,000 feet, the ore, which consisted of pyrolu- 
site and psilomelane, occurring at the base of the conglomerate 
in irregular pockets. Operations have been suspended for some 
years, and the workings have all fallen in.” 

Of the deposits of wad in New Brunswick the most important 
are those at Dawson Settlement, Albert Co., where many acres of 
ore are found, the beds varying in extent and depth, and attain- 
ing in some places a thickness of over forty feet, to which point 
they have been proved. The deposits are covered throughout 
with peat and peaty matter, having a thickness of about twelve 
to twenty inches, the ore beneath this being found to be practically 
free from impurities. The mode of working is very simple, con- 
sisting of cross trenching, by which means the deposits are 
drained, after this the ore is excavated and dried in pans, the re- 
sult being a dry and almost impalpable powder. 

A partial analysis of the ore by Mr. W. F. Best, of St. John, 
gave: 


Manganese binoxide 0 
Iron oxide 18.0 
Vegetable matter 34.0 
Loss 1.0 
Copper trace 
Cobalt trace 

100.0 


Several analyses by Mr. John Burwash gave the following per- 
centages of manganese binoxide; 73.6, 35.5, 58.3, 57.6, 70.7, 
63.4, and an average specimen collected at various points and 
sampled gave 47.4. 

Nova Scotia.—As in New Brunswick extensive deposits of 
manganese are known to exist in Nova Scotia, where the ores and 
mode of occurrence are similar though differing in a great meas- 
ure in the matter of production, that of this province being much 
smaller than that of New Brunswick. In Nova Scotia, however, 
there is a very large proportion of pyrolusite or high grade 
ore. 

On the south shore of Minas Basin and midway between Noel 


Manganese in Canada.— Brumell. 85 


and Walton, is situated the best known and most important man- 
ganese mine in Nova Scotia, the Teny Cape mine, which, since 
its discovery in 1862, has been operated more or less continuously. 
Yhe ores, consisting mainly of pyrolusite and manganite, are 
found in the Carboniferous limestone which may be traced for 
many miles on the south shore of Minas Basin, the limestone im- 
mediately in connection with the ore deposits being highly man- 
ganiferous and interstratified with small beds and masses of 
manganiferous cale-shale, the whole being usually of a deep red 
color. The mode of occurrence is pockety, the ore being found 
in irregular masses and stringers which follow the bedding planes 
and fractures; some of these pockets are of considerable extent, 
one affording, it is said, upwards of 1,000 tons of high grade ore, 
principally pyrolusite. A very considerable proportion of all the 
ore extracted from this mine has been pyrolusite worth from $100 
to $125 per ton at the works, and containing from 85 to 95 per 
cent. of available binoxide. 


The following assays taken from an article entitled ‘‘ Notes on 
the Manganese ores of Nova Scotia,” by E. Gilpin, Jr., show 
the character of the ores obtained from Teny Cape and vicinity: 


Teny Cape (a) as (>) Douglas 


Manganese oxides 85.54 silt 84.62 
Iron peroxide 1.18 2.55 0.60 
Baryta 0.89 1.12 0.72 
Insoluble matter 8.27 2.80 1.73 
Phosphoric acid 0.34 1.038 
Water 8.54 2.05 5.29 
Oxygen 7.04 
99.76 99.70 100.00 


(a) Analyst, Dr. Howe. 
(b) es E. Gilpin, Jr. 
(¢) s§ H. Poole. 

Deposits similar to that at Teny Cape have been worked to a 
smaller extent at Cheverie, Walton, Noel and Shubenacadie, on 
the south shore of Minas Basin, while on the north shore no im- 
portant deposits of manganese have been noted, though some of 
the limonite and other iron ores of the neighborhood of London- 
derry are highly manganiferous; this is also the case with many 
of the iron ores of both Colchester and Pictou counties. 

The following assays, taken also from Mr. Gilpin’s article men- 
tioned above, show the character of some of these ores, the par- 


S6 The American Geologist. August, 1882 


ticular cases cited here being of two limonite ores from Spring- 
ville, Pictou county. 


Iron sesquioxide 10.848 48.223 
Manganese oxide 62.950 

“ peroxide 14.410 
Magnesium 1.630 
Lime 7.280 0.015 
Alumina 2.£80 Trace 
Baryta 0.670 
Sulphur 0.480 
Phosphorus 0.020 - 
Insoluble residue 2.731 25.130 
Water of composition eS 
Moisture 1.450 12.530 


90.439 100.808 


On Cape Breton island as well as on the main land of the 
province are found deposits of manganese, some of which attain 
considerable dimensions. Among the more important of these 
may be mentioned those situated near Loch Lomond, and of 
which Mr. Hugh Fletcher reports as follows: Geological Survey 
report, 1882-84: 

‘Large deposits of pyrolusite, which promise to be of great 
importance, have recently been discovered and developed by the 
Hon. E. T. Moseley, of Sydney, on the south side and near the 
head of Loch Lomond, in Cape Breton county. The ore is asso- 
ciated with lower Carboniferous rocks and has been worked in 
two places about three-quarters of a mile apart. At the most 
easterly of these, in a brook on the farm of Norman Morrison, a 
tunnel has been driven about thirty feet on a vein about seven 
inches thick, dipping N. 87° W. < 25° in fine red sandstone 
overlying reddish and greenish grit, with grains of quartz about 
the size of wheat and red marly sandstone. The ore is irregu- 
larly mixed with red and grey bituminous limestone, red and 
greenish shale conglomerate and other rocks blotched with cale- 
spar. It is in lenticular layers and also intimately mixed with 
the limestone, being probably of the same nature and origin as 
the hematite and forming at times a cement for the pebbles of the 
conglomerate * * * The mines were first worked in 1880. 
In 1881 about 70 tons, and in the following year 59 tons of ex- 
cellent ore were shipped to the United States, * * * An 
analysis of a sample from the Morrison mine atforded Mr, Adams 
91.84 per cent. of manganese dioxide, only .12 per cent. of fer- 
ric oxide and 2.91 per cent. of insoluble residue.” 


- 


Manganese in Canada.— Brumell. 87 


Many other deposits, both of crystalline ores and wad, are 
known to exist throughout the island. One of these on Boular- 
derie island is said to be quite extensive, and the character of the 
ore may he judged from the following assays: 


Te ne me 
Manganese per. xide 25.42 11.04 44.33 
Tron sesquioxide 12.49 35.50 
Insoluble matter 57.76 10.00 
Water 39.02 


I and II by G. C. Hoffmann, Chemist Geological Survey. III by E. 
Gilpin, Jr., Trans. Royal Society of Canada, Vol. 1, sec. Iv. 


Ontario and Quebec.—Outside of Nova Scotia and New Bruns- 
wick but little manganese is known to occur, and where noted is 
usually of low grade. In Quebec several small deposits of wad 
have been noted, the largest, perhaps, being that in Stanshead 
township, where on lot nine, range ten, the ore covers an area of 
about twenty acres, and has a thickness of about twelve inches. 
That this deposit has but slight commercial value is evidenced by 
the fact that the washed ore contains only 37% of peroxide. 
Another deposit, similar to the above, occurs on lot twenty, range 
twelve of Bolton, the ore there assaying 26%. Many similar 
deposits might be mentioned, though probably none as important 
as those noticed above. 

Manganese has also been noted as occurring on the Magdalen 
islands, a small group in the gulf of St. Lawrence. Of these. 
deposits Mr. Jas. Richardson in the report of the Geological Sur- 
vey 1879-80, writes: -‘Immediately under Demoiselle hill, on 
Amherst island, numerous blocks charged with peroxide of man- 
ganese, or pyrolusite, occur among the debris of the fallen cliffs. 
They are in pieces varying from one pound to ten or fifteen 
pounds in weight. There can be little doubt that they are de- 
rived from a deposit more or less regular in the hill side, but 
which is now completely concealed by the fallen debris. At a 
place bearing nearly due west from Cap aux Meules, at a distance 
of about a mile, and close to the English Mission church, similar 
pieces. to those above described are very frequently picked up. ” 
Assays of this ore, in the same volume, gave: 


Manganese dioxide 45.61 per cent. 
Water, hygroscopic 0.10 ts 


In Ontario manganese has been reported from Batchewaherung 
bay, lake Superior. The ore is manganite and is said to assay as 


CO 


8 The American Geologist. August, 1992 


high as 60% of peroxide; of the extent and exact situation of 
the deposit it is not possible to write. 

An interesting discovery of a manganiferous spothic iron ore 
is reported by Dr. R. Bell in the report of the Geological Sur- 
vey 1877-78, wherein he states that a band of about twenty feet 
of the ore, carrying 25% metallic iron and 24% carbonate of 
manganese, occurs in the Nastapoka islands, a group off the east 
coast of Hudson bay. The ore is easily accessible and will no 
doubt eventually prove of value, the high percentage of man- 
ganese contained making it eminently suitable for the manufacture 
of speigeleisen. 


KEOKUK GROUP OF THE MISSISSIPPI VALLEY. 
CHARLES 8. BEACHLER, Crawfordsville, Indiana. 
LITERATURE. 

The name Archimedes limestone was given by David Dale Owen, 1852, 
Geological Survey Wisconsin, lowa and Minnesota, to the forty feet of 
the heavy bedded, quarry, encrinital limestone, quarried in the bluff at 
Keokuk, Iowa. This bed in his table of the sub Carboniferous rocks of 
the Mississippi valley is placed as the uppermost member of the lower 
sub-Carboniferous; he terms the preceding rocks the Cherty limestone. 
The Archimedes limestone bed is succeeded by the lowest two members 
of the upper sub-Carboniferous which he named (a’) Geodife ous Bed, 
and (b’) Magnesian limestone. From the great number of fossil shells 
found in the lower part of the Archimedes limestone he uses a special 
name, that of Shell Beds, to distinguish it. 

These four beds form what has developed into the Keokuk group of 
the sub-Carboniferous period. 


(b') Magnesian limestone. 


(Keokuk) | Upper sub-Carboniferous (a') Geodiferous Bed. 


52.) ow " ‘ 
wee | (f) Archimedes limestone. 
Owen. | Lower sub-Carboniferous (e) Shell beds. 
| (d) Cherty limestone. 


8. C. Swallow, 1855, First and Second Annual Reports of the Geologi- 
cal Survey of Missouri, applies Owen’s name Archimedes limestone to 
all the rocks from the summit of the Encrinital series to the base of the 
Saint Louis series; from the description on page 183 it seems that the 
Cherty bed was regarded as the summit of the Encrinital limestone series. 
No other divisions were made. 


Saint Louis limestone. 
(Keokuk) 
1855. + Archimedes limestone. 
SWALLow. ( 


Encrinital limestone { Cherty beds. 


Keokuk Group, Mississippi Valley.— Beachler. 89 


James Hall, 1858, Geological Survey Iowa, volume 1, in arranging the 
sub-Carboniferous rocks of Iowa, places the Cherty and Archimedes 
limestone as two distinct beds under the division Aeokuk limestone, which 
term he uses instead of Owen’s name Archimedes limestone, dropping 
the term Shell beds; the Geode bed is made a transition bed, and the 
Magnesian limestone is termed the Warsaw limestone and placed under 


that division. 
Warsaw limestone. 


GEODE BED. 
(Keokuk) 
1858. Keokuk limestone. 
HALL. Cherty limestone. 


A. H. Worthen, 1866, Geological Survey of Illinois, volume 1, unites the 
whole section of Owen and Hall under the name KroKuUK Grovr, with 
the exception of the Magnesian or Warsaw limestone, which he seems to 
consider as a division of the Saint Louis, as seen by his referring the 
equivalents of the lowa Magnesian limestone, in Indiana at Blooming- 
ton and Spurgeon Hill to the St. Louis group. 


Warsaw LIMESTONE. 


Keokuk Group. ( Geode bed. 
WoRTHEN. + Keokuk limestone proper. 
1866. | Cherty limestone. 


Charles A. White, 1870, Geological Report of Iowa, volume 1, uses 
Hall’s names and divisions. 


Synonym—SILIcious GROUP. 

James M. Safford, 1869, Geology of Tennessee, proposes the name 
Silicious Group for rocks of the age of the “Highlands” of Middle Ten- 
nessee, and refers the 

Upper Silicious to the Warsaw and St. Louis. 
Lower Silicious to the Keokuk. 


GEOLOGY. 

The rocks of the Keokuk group occur in broad belts on both 
the eastern and western borders of the great Illinois coal field; in 
Indiana and Kentucky on the eastern border, extending into 
Tennessee and Alabama, and in Illinois and Iowa on the western 
border extending into Missouri, 

On the western border in Illinois and Iowa, where typical lo- 
calities are found, the rocks are exclusively of a caleareous char- 
acter attaining a maximum thickness of at least two hundred 
feet; in Missouri the uppermost member of the group, the Mag- 
nesian limestone, forms the principal representative and has un- 
dergone great local disturbances in the central part of the state. 
On the eastern border in Indiana and Kentucky the rocks occur 
as alternating beds of argillaceous sandstone, limestone and shale, 
thinning out toward the east and pass downwards into the Knob- 


August, 1852 


- 


Geologist. 


PECAN 


€ 


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heokuk Group, Mississippi Valley. — Beachler. ool 


stone,* attaining in Montgomery county, Indiana, a maximum 
thickness of about three hundred and fifty feet. In eastern Ken- 
tucky the rocks occur in the tops of the knobs resting upon the 
knobstone, in western part of state they thicken up reaching their 
maximum thickness in Hardin and southern part of Barren 
counties. Tennessee and Alabama the rocks assume a silicious 
character and are known as the Silicious group, attaining a max- 
imum thickness of not less than five hundred feet. 


a. The Cherty Bed, 

succeeds the Upper Burlington limestone and appears on the 
Iowa side at the ‘‘Cascade” south of the city of Burlington, 
where the extensive quarrying has developed a great number of 
fine transition forms of crinoids, from which the bed receives the 
name of transition bed by paleontologists; the bed consists of 
thin alternating layers of chert and encrinital limestone, and 
sometimes an intermixture of both. These beds next appear in 
the river bed above Keokuk forming the ‘‘rapids of the Missis- 
sippi river” where they attain a thickness of sixty to seventy feet. 
In Illinois this bed is seen along Hyde's creek three miles to 
Warsaw, thence to Nauvoo forming the lower part of the bluffs 
at Sagetown. In Indiana the only equivalent of the bed is found 
in eastern part of Montgomery county at New Ross where it loses 
its cherty character, the following section was observed: 


UI ey aaa fe Marcle, ce) visuals cuss sseice mi Deve SAE en pcel peed 0 tO,20uheet, 
PVE ACCOUS SANGSEON Clie. 2\s-cleis «52 ac 8 see seas 8 One 
Cmboidal limestone: 7. alessio esse hae ds Soest ato oi 
Binevarcillaccouslimestone......6.......0.-.. 2to4 © 
Ju) ESE TNS ass fs 0 A Ach ea ae lu to-— * 


In eastern Kentucky, geologists generally apply the name 
‘Keokuk’ to the shales and overlying knobstone, which rest upon 
the Genesee shales, and hold that the knobstone (Waverly) and 
Burlington groups are absent. At ‘*Button Mole knob” in Bul- 
litt county as well as in the knobs at the edge of the city of 
Lebanon, Marion county, the knobstone, which Owen pointed out 
so plainly in Indiana, is well developed, with the equivalent of 
the Lowa cherty bed with its characteristic brachiopods, resting 


on top. 


*Ohio and Kentucky authors use the Ohio term Waverly; according to 
the luw of vriority the name “Knobstone” has precedence as it was ap- 
plied by Owen in 1838 in his report of the Geological reconnassiance of 
Indiana made to the Legislature during that year. 


92 The American Geologist. August, 1892 


Cherty bed of the Kreolntilc. wrsnedtetieettoes ...-.Limestone. 
Knobstone of Ind. ) = 

Waveryo1 Olmert ile. 0s geese cecnee eee 
Chouteau of Mo. |) / Grey shales. 


ID Yeni OU C0 Seat ee Aen Bree HB pero etic ..... Genesee shale. 


Section of Knobs of Bullitt, Marion, and Boyle counties, 

Kentucky. 
b. The Keokuk Limestone, 

or Lower Archimedes limestone proper of Owen, is best exposed 
at Keokuk, overlying the cherty beds forming the rapids, and at- 
tains a thickness of forty feet. This bed gradually thins out 
toward the north and at its edges consists of alternationsof argil- 
laceous and arenaceous beds with subordinate beds of encrinital 
limestone. This character is seen to the extreme in the neigh- 
borhood of Mount Pleasant, Iowa, and at a less degree at Ap- 
panoose, Illinois. In Missouri the bed is exposed at Hannibal 
and at Boonville, cliffs of this limestone with its overlying equiv- 
alent of Magnesian division can be traced from the mouth of 
Riviére la Mine to below the town, forming a series of wave-iike 
antichnal axes. The following section was observed: 


Chert in irregular beds interstratified with beds of shaly limestone 
and calcareous clay, equivalent of the Magnesian limestone of Owen 
and the Warsaw of Hail—3 to 6 feet. 

Hard blue limestone, containing Productus magnus, P. semi-reticulatus, 
p. punctatus and Archimedes owenana. The Keokuk or Lower Archi- 
medes limestone proper—30 feet. 


In Hlinois this division of the Keokuk forms the heavy quarry 
rock at Hamilton, Nauvoo, Niota and Quincy, In Indiana the 
only equivalent is found on south branch of Walnut Fork in 
Montgomery county, the following is a section of the rocks: 


0) een nem nin sd aS Head veord Pee LOtoOrcOneet 
Blue shale—containing small poc kets of crinoids By 
Heavy quarry l.mestone, containing characteris- 

tic fossils—seen in the bottom of the creek...2to — « 


In Kentucky the writer has been unable to distinguish this 
division at any outcrops visited. 


ec. The Geode Bed. 
This may be found resting upon the Keokuk limestone proper 
at Keokuk, consisting of a bed of forty feet of calcareous shale 
or marl, containing numerous geodes of quartz and chalcedony 


Keokuk Group, Mississippi Valley.— Beachler. 93 


ranging from the size of a walnut to two feet in diameter, and 
cavities are usually filled with zinc blende, calcareous spar, ete. 
In Illinois the rocks have been recognized at Warsaw above the 
steamboat landing, on the branches of Otter creek, at Whitehall, 
Greene county, and on Little Sandy, Scott county. 

The great number of geodes lithologically characterizes this 
bed everywhere, in southern Indiana near Bono, Lawrence county, 
at Canton, Washington county, as well as in the top of the hills 
in Brown county, this bed may be seen, and the geodes line the 
sides of the roads. The rocks along Indian creek in southern 
part of Montgomery county are the exact equivalent of the Can- 
ton beds as they contain the same fossils but no geodes. 


The writer has also been unable to distinguish this bed in Ken- 

tucky. 

d. The Magnesian, 

or Second Archimedes limestone of Owen and the Warsaw of Hall, 
succeeds the ‘‘Geode Bed;” and to this succeed beds of shaly lime- 
stone, with partings of shale or marl rapidly disintegrating upon 
exposure; thickness forty feet. The section is seen above and 
below Keokuk, Lowa, but much better developed on the opposite 
‘side at Warsaw, Illinois. Tracing the formation north it appears 
at Mount Pleasant. 

In Missouri the rocks of this age are seen resting upon the 
Keokuk limestone proper at Boonville. In Indiana it occurs at 
Bloomington and Spurgeon Hill, as well as on Clear creek, Mon- 
roe county. In Kentucky it outcrops south of Glasgow and at 
Oil City, Barren county. 


ON THE RELATION OF THE CRAWFORDSVILLE, INDIANA BEDS 
WITH THE TYPICAL LOCALITY*. 

The Keokuk rocks form the surface of the whole of Mont- 
gomery county, with the exception of a narrow strip of later rocks 
extending into the western part, and are deeply covered with 
drift so that the only exposures are along the water-courses, 
The lamination is regular and generally thin, and the general dip 
is toward the southwest. 

The rocks seem to have been deposited and elevated at irregu- 
lar intervals, giving the same section, but a remarkable difference 


*Extract read before the Indiana Academy of Science, December 30, 
1891. 


Y4 The American Geologist. August, 1892 


in crinoidal life. The rocks cannot be divided into the three 
divisions lithologically as at the typical locality, and the only 
way the’ horizon of the different localities can be determined is by 
the comparison of the species of crinoids and their exact position 
in the strata, with species at the typical locality or with other 
localities whose horizon has been referred to the typical locality 
with absolute certainty. 
The rocks of the different horizons in the county always occur 

in the following order: 

d Argillaceous sandstone. 

c Blue shale. 


b Encrinital limestone. 
a Blue shale 


The lowest or Cherty bed outcrops gn Raccoon creek two miles 
southwest of New Roso, where the upper limestone (see section 
given under a, Cherty Beds) disintegrates in places, weathering 
out many crinoid remains, the types being characteristic of the 
Lower Keokuk; several specimens of Al/oprosel-ocrinus, which is 
characteristic of the Upper Keokuk, have been found at this 
locality as well as other localities that are equivalents of the 
lower beds. Bearing in mind that the rocks of this group in this 
county were deposited and elevated at irregular intervals, the 
next series of rocks in ascending order outcrops on the south 
branch of Walnut Fork four miles east of Crawfordsville, (see 
section under b Keokuk limestone). 

The limestone resembles very much that at Keokuk, Lowa; it is 
composed of enormous crinoid stems attaining a diameter of one 
inch and a length of several feet, associated with large specimens 
of Archimedes owenana Hall, Productus magnus M. & W. P. 
punctatus Sowerby, Platyceras equilatera Hall, P. infundibulum 
M.. & W. 

In the shale was found a small nest of crinoids containing a 
large Dorycrinus gould? Hall, and a very large Paryerinus proba- 
bly a new species. 

Again in ascending order the next series of rocks are those out- 
cropping on Indian creek about four miles above the mouth, 
where is exposed in the bottom of the stream blue shale, under- 
laid by encrinital limestone; the shale containing large nests of 
crinoids, several species being identical with those found at Can- 
ton, Ind., which is regarded as the Geode Bed:  Actinocrinws 


Keokuk Group, Mississippi Valley.— Beachler. 95 


lowei Hall, one of the most common species at Indian creek is 
found in numbers geodized at Canton. Several species have 
been found at Indian creek that are identical with those of Bono, 
Laurence Co., Ind., which also is equivalent of the Geode Bed. 

Tracing the Indian creek layers northwest seven miles they are 
found outcropping in the northeast part of Park county on Sugar 
creek where, together with the higher members of the sub-Car- 
boniferous, they are dovetailed into the Coal Measures. 

From the above facts we may consider the Indian creek locality 
as equivalent to the ‘‘Geode Bed.” Having established the hori- 
zon of the above localities which until 1889 were unknown as 
prolific erinoid localities, the most difficult question remains to 
be decided, 7. e. the determination of the ‘‘Crawfordsville beds,’ ° 
these beds heretofore have been regarded as Lower Keokuk as 
some of the crinoids resemble Burlington forms. 

In excavating at these beds in 1888 this fact was observed that 
the prevailing types of crinoids found ranging from the level of 
Sugar creek upward ten feet were the genera Cyathocrinus, Poterio- 
crinus and Barycrinus,; while above these occur the genera Ony- 
chocrinus, Forbesiocrinus, Gilbertsocrinus and Platycrinus; in 
Washington county these latter genera of crinoids are found over- 
lying the ‘‘Geode Bed” and are identical with those from upper 
layers at the ‘Crawfordsville beds.” 

One mile below the Crawfordsville beds may be seen a heavy 
layer of limestone containing large geodes about the sizeof a 
man’s head, and overlying is the equivalent of the ‘‘Crawfords- 
ville beds,” but diminished to a thickness of only a few feet. 
At Scott's Eagle Mills, in the northeast part of Park county, the 
writer has lately traced the Crawfordsville beds as overlying the 
Indian Creek beds. Poteriocrinus reaches its climax in size in 
the Crawfordsville beds, while the species of Barycrinus resem- 
ble very closely, if not identical with, the large species found on 
Walnut Fork. 

Alloprosallocrinus, an upper Keokuk species is also found at 
these beds. 

It will be seen by close study of the rocks on Sugar creek that 
the ‘‘Crawfordsville beds’’ occupy a position between the ‘‘Geode 
Bed” and the Magnesian limestone. 


PALEONTOLOGY. 
In the study of the life fauna, especially the crinoidea, of the 


96 The American Geologist. August, 1892 


Keokuk group, it is readily observed that this series of rocks 
forms the culminating period of a great crinoidal epoch; that its 
most ponderous forms occur at its summit, and its base contains 
the transition forms between this and the Burlington group; 
there exists a gradual development from the base to the sum- 
mit. 

In 1878 ina paperon ‘‘Transition forms in Crinoids,”” Proceed- 
ings Academy of Natural Sciences of Philadelphia, Messrs. 
Charles Wachsmuth and Frank Springer proposed the name of 
Crinoidal limestone for the Keokuk, and the Upper and Lower 
Burlington limestones, and clearly proved that these three lime- 
stones represent three successive grades of development; Froosts’ 
genus Agaricocrinus appears in the Lower Burlington with two 
arms to each ray, attains its maximum in the Upper Burlington, 
and becomes extinct at the close of the Keokuk, when it reaches 
its extravagance of form, and has been found with four arms to 
all the rays. Roemer’s genus Dorycrinus appears in the Lower 
Burlington with a single spine on the apex of the vault, species 
small, and disappears in the closing of the Keokuk with its ex- 
traordinary feature of spines on spines, as represented by Dory- 


erinus gouldi, 


NEW LAMELLIBRANCHIATA. 
Plate VII. 


By E. O. Uxtricu, Newport, Ky. 


No. 4. DESCRIPTIONS OF ONE NEW GENUS AND EIGHT NEW 
SPECIES. 

The greater part of the new forms that have been determined 
during the progress of my work on the Lower Silurian Lamelli- 
branchiata of the northwest for volume i of the final reports of 
the Geological and Natural History Survey of Minnesota, now 
going through the press, were recently published in the Nine- 
teenth Annual Report of that survey. In the last few months 
much new material has come into my hands, among it several 
species entirely new to me, and others that were too illy repre- 
sented in the original lot for description. In the present paper, 
and in another to follow, the more interesting of these additiona] 
new species are described, while the treatment of a few other 


New Lamellibranchiata.— Ulrich. 97 


forms, whose distinctness is not yet fully established, will be 
postponed till the appearance of the final volume. 


CLEIONYCHIA, 0. gen. 
(Cleio, I close, onyx, a claw.) 

Shell equivalve, subalate posteriorly; beaks terminal, more or 
less prominent, slightly incurved. Cardinal line straight, rather 
long, usually forming an angle of less than 90° with the anterior 
side. Ventral and posterior margins more or less rounded. 
Surface marked concentrically only, and sloping very gently to 
the posterior and hinge margins, and proportionately very rapidly 
on the anterior side. The latter, especially in casts of the in- 
terior, flattened or even concave. No byssal opening, the mar- 
gins closing tightly all around. Muscular impression situated in 
the postero-cardinal third, large, bilobed, the lower lobe much 
larger than the upper. Pallial line entire, extending from the 
muscular scar to the cavity of the beak. Hinge plate edentulous, 
excavated longitudinally for a linear ligament, with the inner 
edge thickened and bifurcate atthe posterior extremity. A small 
pit just beneath the beak. Upper part of anterior edge of shell 
thickened. 

Type: Ambonychia lamellosa Hall. 

This genus will include beside the type and the species next 
described, Ambonychia erecta and A, attenuata Hall, from the 
Trenton of Wisconsin, A. mytilioides Hall, from the Chazy of 
New York, Pterinea undata Emmons, and Ambonychia anyg- 
dalina Hall, from the Trenton of that state. Further, it is highly 
probable that A. nitida and superba, described by Billings from 
Anticosti, and one or two concentrically marked Upper Silurian 
species referred by Lindstré6m to Ambonychia, also should be 
placed under Cleionychia. 

As now understood the new genus is distinguished from Am- 
bonychia (1) by the absence of radiating plications or strive, (2) 
the absence of a byssal opening in the anterior end, (3) the less 
central position of the muscular scars, and (4) by the absence of 
distinct hinge teeth. 


CLEIONYCHIA RHOMBOIDEA, Nl. sp. 
Plate vi, Figs. 1 and 2. 
Shell, as seen in casts of the interior, of medium size, very 
oblique, rhomboidal in outline, the anterior and posterior and the 


98 The American Geologist. August, 1892 


dorsal and ventral margins subparallel. Dorsal edge nearly 
straight, likewise the posterior, the two lines meeting at an angle 
of about 120°. Postero-ventral angle sharply curved, the 
ventral side gently convex and rounding almost uniformly up 
into the anterior outline. Beaks terminal, small, projecting, 
slightly above the hinge line, scarcely incurved. Umbonal ridge 
strongly convex, extending toward the postero-ventral extremity 
in a slightly curved direction, so that the slopes on the anterior 
and ventral sides are more abrupt than on the opposite sides. 
Point of greatest convexity a little in front of and above the 
middle, 

Interior with the hinge plate rather wide and strong, and the 
anterior edge, for a short distance beneath the beaks, much 
thickened inwardly. Muscular sears large, situated about mid- 
way in the postero-cardinal half of the shell, the two lobes united 
by a narrow neck, the upper one oval in shape and about one- 
third as large as the more nearly circular lower one. 

The posterior extremity is more produced and more narrowly 
curved than in the other species referred to this genus. 

Formation and locality: Lower limestone of the Trenton 
formation at Minneapolis, Minnesota. A single specimen only. 
This was collected by Mr. J. C. Kassube, and by him donated to 
the museum of the Geological and Natural History Survey of 
Minnesota, where it is now to be found under the Mus. Reg. No. 
5526. 

CYPRICARDITES TERMINALIS, N. Sp. 
Plate vir, Figs. 8-10. 

Shell of medium size, moderately ventricose, extremely oblique, 
with the beaks terminal, rather small, strongly incurved,and pro- 
jecting but little above the hinge line. Umbo full, and the whole 
surface neatly rounded. Outline obliquely acuminate-ovoid, with 
the anterior end narrowly rounded and projecting scarcely, if at 
all, beyond the beaks, from which the margin slopes backward 
with a gentle curve into the base; posterior end broad, uniformly 
rounded; cardinal margin straight, about three-fifths as long as 
the diagonal length of the shell, rounding into the posterior mar- 
gin. Surface with faint wrinkles of growth and probably with 
finer concentric lines. Shell substance thin. Hinge plate rather 
narrow, with two long posterior and two or three short cardinal 
teeth in each valve. The latter are difficult to see because of the 


New Lamellibranchiata.— Ulrich. 99 


closely incurved beaks. Anterior mucular impression, as seen in 
casts of the interior, scarcely visible in a side view, being over- 
hung by the side of the umbo. In an end view they appear like 
two narrow vertical lobes tapering upward and placed just be- 
neath the free portion of the beaks. The surface of casts is full 
and rounded. 

If Vanuxemia Billings, is to be retained for species of this 
genus having the beaks subterminal, then not only the present 
but most of the associated species will have to go there. Of the 
latter C. rectirostris Hall, which is exceedingly like V. ‘nconstans 
Billings, is the most abundant and perhaps the nearest to C. 
terminalis, still, the two species are widely different, that one 
having a strong and thick shell, on the inner side of which there 
is, as in many other species of the genus, a ridge-like thickening 
that gives rise to the distinct sulcus and flattening of the beaks 
on internal casts. In C. terminalis on the contrary the shell is 
thin and without the internal ridge. The beaks are also more 
incurved than in C. rectirostris. 

Formation and locality: Lower limestone of the Trenton form- 
ation, at Minneapolis and Cannon Falls, Minnesota. Another 
specimen belonging to the Museum of the Geological Survey of 
Minnesota was found by Mr. Chas. Schuchert in the ‘Lower 
Blue beds” near Beloit, Wisconsin. 


CYPRICARDITES OVIFORMIS, 0. Sp. 
Plate vir, Figs. 3 and 4. 

Shell rather above the medium size, moderately convex, the 
outline almost regularly oval, with the posterior end a little the 
widest, and a slight straightening along the cardinal margin, 
Beaks small, situated between one-fourth and one-fifth of the 
length from the anterior extremity; erect, compressed, and not 
incurved in casts of the interior; in the shell projecting very little 
if at all above the hinge line. Umbonal ridge indistinct, with the 
point of greatest convexity a little above and in front of the mid- 
dle. In the casts there is a more or less sharply defined flattened 
strip running from the beaks downward. Hinge plate wide and 
strong, with two strong posterior lateral teeth in each valve, and 
sometimes a third small one above them, in the left valve. An- 
terior teeth consisting of one long tooth placed parallel with the 
margin of the shell in front of the beaks and five or six small 


100 The American Geologist. August, 1892 


unequal teeth running downward from the horizontal tooth. An- 
terior muscular scar distinct, elongate, vertically disposed, situ- 
ated immediately: beneath the cardinal teeth. Posterior scar illy 
defined. Shell substance thin except in the anterior and dorsal 
regions. 

The small vertically arranged anterior teeth, and the erect and 
strongly compressed beaks of casts of the interior, are the two 
principal peculiarities of the species. These and other equally 
obvious characters distinguish it from its perhaps nearest con- 
gener, C. obtusifrons Ulrich. C. glabellus Ulrich, from the 
shales, is wider in front and differently outlined posteriorly. 

Formation and locality: Two opposite valves were collected by 
Mr. Chas. Schuchert, at Janesville, Wisconsin, in the ‘‘Lower 
Blue limestone.” These are now in the museum of the Geologi- 
cal and Natural History Survey of Minnesota. 

Mus. Reg. No. 8324. 


CYPRICARDITES(?) MODESTUS, N. sp. 
Plate vu, Figs. 5-7. 

Shell-small, oblique, moderately ventricose, obliquely ovate in 
outline, known from casts of the interior only. In these the an- 
terior end is very small, sharply rounded, abruptly depressed be- 
neath the beaks, and almost entirely occupied by a subcircular 
muscular sear. Beaks small, only slightly incurved, appearing 
prominent from the front but not fromthe back. Umbonal ridge 
scarcely distinguishable, the cardinal slope faintly concave be- 
tween it and another low ridge-like swelling that forms the 
back of the cast. Along the hinge line there is a narrow im- 
pressed area. Shell thin; hinge-plate narrow; dentition undeter- 
mined, 

The generic position of this shell is doubtful, I having thus 
far failed in my efforts to make out the dentition of the hinge. 
From the narrowness of the hinge-plate I am satisfied that there 
cannot be more than a single posterior lateral tooth, if any. It 
is possible that the species isa Matheria with relations to the MW. 
rugosa, recently described by me from a lower horizon in the 
shales, in which the anterior muscular impression is as in the 
present species deeper than usual in that genus. It is clearly, I 
think, not a Modiolopsis, and until more is learned of its hinge it 
seems best to arrange the species as above. 


New Lamellibranchiata.— Ulrich. 101 


Formation and locality: Lower half of the Galena at Oshkosh, 
Wisconsin, and several localities in Goodhue county, Minnesota. 
Collectors, Chas. Schuchert, W. H. Scofield, E. O. Ulrich. 


TECHNOPHORUS SUBACUTUS, n. sp. 
Plate vii, Figs. 13 and 14. 
Shell small, rather ventricose, alated posteriorly, the hight and 


length respectively as two is to three. Cardinal margin nearly 
straight, anterior end uniformly rounded, ventral edge more gently 
curved, the posterior straight and sloping backward slightly to 
the acuminate extremity of the hinge line. 

In a cast of the interior the small beak is erect, projects prom- 
inently above the hinge line, and is situated about one-third of 
the entire length from the anterior extremity. Just in front of 
the beak there is a strong and deep impression, running almost 
vertically downward. On the anterior side this slit margins a 
rather large muscular scar. Extending backward from the beak 
the cast exhibits another, but in this case very obscure linear de- 
pression. Two curved folds, the posterior one the strongest, ex- 
tend from the postero-ventral angle toward the beaks, becoming 
indistinguishable, however, about midway between the two points. 
Surface markings and” hingement unknown. 

Length 11.5 mm., hight 6.8 mm., convexity of one valve about 
2.2 mm. 

This species is intermediate between 7. faberi 8. A. Miller, the 
type of the genus and 7. extenwatus, recently described by the 
author from the lower part of the Trenton shales of Minnesota. 
In the first the posterior end is shorter and produced below instead 
of above, in the second the shape is quite different and the pos- 
terior end more drawn out. <A nearer congener than either of 
these, but one that is as yet undescribed, occurs at Cincinnati, Ohio. 

Formation and locality. Upper part of the limestone of the 
Trenton formation at Minneapolis, Minn. 

Museum Geol. Nat. Hist. Sur. Minn.; Reg. No. 8338. 


TECHNOPHORUS FILISTRIATUS, Nl. sp. 
Plate vir, Figs. 11 and 12. 

Shell small, though large for the genus, compressed, with the 
greatest convexity in the anterior half, scarcely alate posteriorly, 
the hight and length as three is to five. Beaks small, projecting 
very little, slightly incurved, one-third of the entire length of 
shell from the anterior extremity. Anterior end much the widest, 


102 The American Geologist. August, 1892 


broadly and uniformly rounded except above where the curve 
turns rather sharply intothe hingeline. Ventral margin rounded 
in front, straight and sloping upward in the posterior half to the 
acute extremity. Posterior margin short, straight, sloping for- 
ward. Cardinal margin straight except for a slight prominence 
in the region of the beaks. Anterior half of surface marked with 
closely arranged, thread-like, concentric lines. These seem to be 
wanting in the posterior half, only a few obscure growth lines be- 
ing visible here. Posterior ridge sharp and strong, very gently 
curved in its course from the beak to the produced lower angle of 
the posterior extremity of the shell. Between this ridge anda 
line drawn vertically across the shell from the beaks the surface 
is depressed, forming a widening shallow sulcus and the straight- 
ening of the ventral margin. Postero-cardinal slope concave, 
narrow, descending rather rapidly. Interior unknown; shell sub- 
stance very thin. 

Length 21 mm., hight 12.5 mm., greatest convexity (of a left 
valve) 2.5 mm. 

Although the internal characters are as yet unknown, the data 
obtained point very strongly toward Miller’s Technophorus. Com- 
pared with 7. faberi Miller, the posterior end will be found to be 
longer and narrower, while there is only one posterior ridge where 
that species has two. 7. extenuatus Ulrich, another species from 
the Trenton shales of Minnesota, agrees closely in all respects ex- 
cept that it has the posterior end greatly produced. 

Formation and locality: . In beds regarded as equivalent to the 
‘‘Upper Buff limestone’ of the Wisconsin geologists and the 
Black River limestone of New York, six miles south of Cannon 
Falls, Minnesota. This horizon contains an interesting fauna, 
consisting chiefly of Lamellibranchiata, Gastropoda and Cepholo- 
poda. It follows layers filled with bifoliate Bryzoa and is suc- 
ceeded by soft shaly beds in which the predominant fossils are 
Phylloporina corticosa, Prasopora and numerous other Treposto- 
mata, and one of the so-called ‘‘branching fucoids. ” 


TECHNOPHORUS DIVARICATUS, Nn. Sp. 
Plate vit, Figs. 15 and 16. 

Shell small, moderately convex, elongate, the length a little 
more than twice the hight. Beaks small, incurved, projecting 
but little above the hinge line; situated about one-third of the en- 
tire length from the anterior extremity. Dorsal margin nearly 
straight, (faintly concave on each side of the beaks) about three- 


New Lamellibranchiata.— Ulrich. 103 


fourths as long as the shell, terminating abruptly where it joins 
the concave posterior edge, with the upper part of which it forms 
an angle little short of 90°. Anterior end a little the widest, 
strongly convex, especially above; below rounding neatly into the 
at first gently convex, then straight and finally concave basal line. 
Posterior ridge thin but very prominent, curving slightly in its 
course from the beak to the sharply produced postero-basal angle. 
Surface uniformly convex, and marked with fine, thread-like con- 
centric lines in the antero-basal three-fifths, beyond which it first de- 
scends into a sulcus and then ascends sharply into the ridge, drop- 
ping on the other side even more abruptly into the wing-like pos- 
tero-dorsal part of the shell. On each side of the posterior ridge 
there are distinct divaricating lines, twice as strong as the con- 
centric lines on the anterior part of the shell. They join each 
other on the ridge, and, those on the lower side of the latter, the 
concentric lines at angles of about 70°. Finally, there is another 
set of such lines along the dorsal edge, running parallel with the 
set on the lower side of the ridge. Internal characters unknown; 
shell substance very thin. 

Length 12.5 mm., hight at the beaks 5.8 mm., hight at posterior 
end of hinge 5.1 mm., greatest thickness of closed valves 4.1 mm. 

Casts of the interior would be distinguished by having the dor- 
sal and ventral margins more nearly parallel than is the case in 
any of the other species referred to the genus. With the shell in 
a good state of preservation the species is distinguished from all 
Silurian lamellibranchs by the peculiar surface ornamentation. 

Formation and locality: Near Cannon Falls, Minnesota, in the 
‘‘Phylloporina bed” of the Trenton shales. 


TELLINOMYA LONGA, 0. Sp. 

Plate vir, Figs. 17 and 18. 
Shellsmall, compressed, elongate, elliptical, the length equalling 
a little more than twice the greatest hight. Beaks small, situ- 
ated about one-fourth of the entire length from the anterior ex- 
tremity. Cardinal line, on the whole, very slightly convex, 
straight behind the beaks; anterior end short, semi-circular; 
ventral margin gently convex; posterior end a little narrower than 
the anterior, and more sharply rounded. Surface with obscure 
concentric lines; sloping rapidly at the cardinal margin but 
very gently to the ends and ventral edge. Hinge plate of mod- 
erate strength, bent a little beneath the beak, and with a thicken- 
ing on the lower side in frontof same. Posterior to the beak the 


104 The American Geologist. August, 1802 


plate is long, straight, and bears twenty or more small teeth, 
while on the anterior part only nine are to be counted. In the 
vicinity of the beak the teeth, especially those on the posterior 
side, ure very small. Anterior muscular impression deep, sit- 
uated immediately beneath the end of the hinge. Its posterior 
side is defined by a strong vertical thickening of the shell. Pos- 
terior scar distinct, but less sharply impressed than the anterior, 
situated at the end of the hinge just within the thin postero- 
cardinal border of the shell. 

Judging from the interior this shell, though more elongate, 
evidently belongs to the section of the genus of which 7. ventri- 
cosa Hall, 7. angela Billings, 7. contracta Salter, and 7. planodor- 
sata Ulrich, are typical members. In all of these the muscular 
sears are deep and large, excavating the shell under the ends of 
the hinge plate so that they are exceptionally prominent in casts 
of the interior. 

Formation and locality: In shaly strata, equivalent to the 
Black River limestone, at a point about eight miles south of Can- 
non Falls, Minnesota. 


EXPLANATION OF PLATE VII. 
Figs. 1 and 2, CLEIONYCHIA RHOMBOIDEA, D. Sp. 
Lateral and anterior views of a right valve. 
Figs. 3 and 4, CypRICARDITES OVIFORMIS, 0. sp. 
Anterior and lateral views of a cast of the interior of a left valve, the 
posterior outline restored. 
Figs. 5-7, CyYPRICARDITES (?) MODESTUS, N. Sp. 
5. Left side of a cast of the interior, x 3. 
6 and 7. Left side and anterior views of same, natural size. 
Figs. 8-10, CypRICARDITES TERMINALIS, 0. Sp. 
8. A left valve from the limestone at Minneapolis, natural size. No. 
5,100 of the Mus. Reg. of the Geol. and Nat. Hist. Surv. of Minnesota. 
9. A right valve from a similar position at Cannon Falls, Minnesota, 
10. Anterior view of these two valves. 
Figs. 11 and 12, TECHNOPHORUS FILISTRIATUS, 0. Sp. 
A left valve, natural size, and the antero-basal portion, * 3, to show 
concentric lines. ; 
Figs. 13 and 14, TECHNOPHORUS SUBACUTUS, 0. Sp. 
13. Cast of a left valve, natural size. 
14. The same, nearly 2.5, with the impression of the hinge and in- 
ternal ridge. 
Figs. 15 and 16, TECHNOPHORUS DIVARICATUS, 0. Sp. 
A left valve of the natural size and x 3. 
Figs. 17 and 18, TELLINOMYA LONGA, 0. sp. 
Interior views, of the natural size and X 3, of a right valve. 


THE AMERICAN GEOLOGIST. Vou. X, PuateE VII. 


43. 


NEW LAMELLIBRANCHIATA.—Ulrich. 


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105 


THE GEOLOGIC EVOLUTION OF THE NON- 
MOUNTAINOUS TOPOGRAPHY OF THE TEXAS 
REGION. AN INTRODUCTION TO THE 


STUDY OF THE GREAT PLAINS.* 
By Rost. T. Hitt, Austin, Texas. 


East of the Pecos river the topography of Texas is a vast 
series of plains and drainage valleys eroded into plains. It is 
characterized by a sub-horizontal structure of diverse terranes, 
the most extensive of which are of Neozoic, post Paleozoic age. 

Approached from the northwest the ‘‘Staked plains” are a con- 
tinuation of the Great Plains of central United States, which 
separate the Rocky mountain front from the Mississippi valley, 
and are composed of Miocene strata. In the eastern border of the 
state the plains are a continuation of the great coastal plain of 
the Atlantic and gulf region. Hach has its own topography, 
flora, fauna, and cultural conditions and, in general, a substruc- 
ture of horizontal strata void of mountain folds and corrugations. 

In the south of the state the great plains of Colorado meet and 
show their relation to the coastal plain of the Atlantic. 

Across the centre of Texas from the Rocky mountains at Las 
Vegas, New Mexico, to the coast at Galveston, a profile and sec- 
tion can be constructed which will reveal in detail the history of 
deposition and degradation of the region, including two great 
periods of eruptive activity. 

Portions of this section show for long distances a monotonous 
uniformity, but in the fifty miles on either side of the capital is 
revealed a comprehensive view of all the formations from the 
alleged Archean and Algonkian to the present time. 

The only formations immediately bearing upon the origin of 
the plains—both coastal and great—are of Neozoic origin, which, 
as a rule, may be considered the product of alternate subsidence 
and elevation accompanied by the invasion and recedence of the 
gulf of Mexico. 

During these time-intervals the processes of land degradation 
and coastal sedimentation together with changes of climate varied 
so as to produce the specific differences now existing in com- 
position of formations, residual soils, consequent drainage growth 
and resultant topography. Before giving the details of these 


processes of Neozoic time it may be proper to review our limited 
knowledge of the topographic features which existed at the close 


*This article is a continuation of my chapters on the Geography and 
Topography of the Texan Region, published in this magazine. 


106 The American Geologist. August, 1892 


of Paleozoic time; a period during which our continental outlines 
underwent their most radical changes and, for this region at least, 
the evolution of modern topography began. The eastern half or 
Appalachian outline of the continent was approximately defined 
east of the 97th meridian. Another but as yet obscurely de- 
fined land or islands existed in the region of the western Cor- 
dilleras (the Rocky mountain, Great Basin and Sierra regions). 
Between these main continental areas was the region which has 
since been evolved into the Great Plains, and is supposed to have 
been a vast enclosed basin extending far southward from the 
southwest corner of Appalachia. Through the heart of Texas 
was a long narrow isthmus or peninsula of post-Paleozoic land 
against whose western shore were laid down the vast ‘‘Red beds” 
formationof Permian, Triassic, and probably early Jurassic time. 
The rock structure of this strip of land was of Carboniferous and 
earlier age; it generally dipped westward or in a direction diamet- 
rically opposite to the great series of Neozoic sediments later 
deposited, from early Cretaceous to the present, which from their 
general dip to the gulf may be termed the coastward incline. 
The Paleozoic rocks of central Texas, although continuous in 
extent, are exposed as two distinct areas separated and covered 
by a remnantal mass of Mesozoic rocks, which now occupy the 
divide of the Brazos and Colorado rivers, and once continued en- 
tirely over them. The northern area, so far as exposed, consists 
of Carboniferous-Permian rocks. In the southern or Burnet area 
erosion has cut deeper into them, exposing successively lower 
rocks down to the Algonkian. There has been no permanent 
land area of Archean or Paleozoic rocks in this region since Meso- 
zoic time, for they were completely covered by subsequent sheets 
of deposition, and now occur in a valley of erosion surrounded 
on every side by the horizontal scarps of the Cretaceous, down 
which the drainage flows to the centre of the alleged Archean 
land. Thus are exposed the successive older rocks—Carbonifer- 


ous, Silurian, Upper Cambrian, —and in the lowest drainage valley 


the Algonkian is reached. If this had been a persistent land area 
it would not have been covered by Cretaceous sediments, and the 
drainage would flow outward from it instead of downward into it. 

This north and south strip of Paleozoic rocks, which is now 
becoming exposed across Texas, is an important factor in the 
evolution of the plains topography, for it has been influential in 
partially outlining the present surface features. 


Ewolution of the Mountainous Texas Region.—Hill.. 107 


After the close of the Carboniferous, and continuing through 
the undetermined period of the Red Beds epoch, this Paleozoic 
tongue was a land barrier extending south and east, an undefined 
distance; it drained westward into a great interior basin, now only 
indefinitely known by the extent of the Red Beds sediments 
which are in part derived from it. There is no trace of an east- 
ward flowing drainage, for the eastern projecting edges have been 
planed off by the numerous subsidences it has since undergone, 
and the sediments of the Red Beds epoch are not present. 

It is evident that this land barrier, which kept the marine waters 
of the gulf from the Great Plains region in Permo-Triassic time, 
was gradually degraded, and the great basin between it and the 
Rocky mountain area filled in, thus preparing the way for the 
free invasion of the Great Plains region by marine waters during 
the subsequent epochs of profound subsidence. 

At the beginning of Lower Cretaceous time, during the Weal- 
dan epoch, as is accurately determined by fossil plants, molluses 
and vertebrates, a profound subsidence began, during which, the 
narrow strip of land was completely base-leveled, and the marine 
waters of the gulf swept west and north over the entire state of 
Texas to the Cordilleran continent and the first marine invasion 
of at least a portion of the Great Plains occurred. It was during 
this epoch that the calcareous sediments of the Comanche series 
were deposited, which now form the most conspicuous feature 
in the topography and structure of the Texas Mexican region. 
During the deposition of these beds, the first half of Cretaceous 
time, the oceanic waters covered all of the Texan, West Indian 
and Mexican regions, and the northwest corner of South America. 
The shore line was around the southern front of the Colorado 
group of the Rocky mountain nucleus, extending eastward along 
the base of the Ouachita group of southern Indian Territory 
and Arkansas to the -end of the Appalachians, around which it 
deflected northward via Washington, coinciding with the known 
limits of the Potomac formations. 

At the close of the Comanche epoch another uplift of the con- 
tinent ensued, the ocean waters receded nearly to their present out- 
line, and the processes of land degradation were again accelerated. 

Once more the loading of the coastal plain began, aud the sedi- 
ments of another great formation were laid down. This was the 
Upper Cretaceous formation or the familiar Meek and Hayden 
section. Subsidence began again while the ocean receded interior- 


108 The American Geologist. August, 1892 


ward; the Texan and Great Plains regions, with much of the present 
Rocky mountain region, were covered with 2,000 feet of sediment. 

The remnantal outcrop of this great formation is shown upon 
the maps. Its sediments record the sequence of events as the 
Lower Cretaceous; that is (1) basement littoral beds of sand, (2) 
deeper beds of clay, calcareous in their upper portion, (5) a deepest 
stage of almost pure chalks, (4) beds shallowing towards the top. 

How much of the Comanche series was destroyed by base- 
leveling during this epoch can only be surmised. 

At the close of the Upper Cretaceous the most marked uplift 
of the Rocky mountain region took place, and the ocean’s waters 
again receded nearly to their present outline. Again land degra- 
dation and deposition began, resulting in the third loading down 
of the coastal plain, followed by the cycle of deposition and sub- 
sidence of the Eocene epoch. 

During the basal Eocene the central Texan region was covered; 
how far and to what extent is problematical, but another heavy 
load was added to the coastal plain. 

The great hiatus in the geologic history of the region is of 
Neo-Pliocene time, between the close of the Eocene and the 
beginning of the Appomattox. The present state of ignorance 
allows but little to be said of it. 

It is not known whether at the close of the Eocene there was 
any important event, such as the elevation or subsidence of the 
coastal plain. We have knowledge of only the basement history 
of the marine Eocene. Its upper contacts or gradation have 
never been studied or presented. 

It is known, however, that in Miocene or Pliocene time an- 
other shore line had developed along the Rocky mountain front, 
into which flowed the drainage of the Rocky mountain region, 
and all the vast region between the Rocky mountains and the 
coast was once more laden with sediments, and later these plains 
were elevated into the dry land which they have since remained; 
they present avast sheet of sediments upon much of which 
drainage channels have not yet been established, but so degraded 
and eroded upon its eastern edge, that their former extent in that 
direction has not been determined. No portion of the geologic 
record is more obscure than that of the conditions of the coastal 
region during this Mio-Pliocene epoch. Whether the Llano 
Estacado formation, which now covers and is co-extensive with 
the Great Plains region, was laid down at marine or lacustral base 


Evolution of the Mountainous Texas Region.—Hill. 109 


level is an important question; if at the former there should be 
some record in the coastal formations now remaining; if at the 
latter there should be structural or topographic evidence through 
the central Texan region of a land barrier which separated the 
lacustral from the gulf waters. After careful study the writer has 
so far been unable to find corroborative evidence of the lacustral 
theory while there is abundant evidence of the identity in origin 
of certain coast deposits with those of the Great Plains region. 

With the close of the unstudied Mio-Pliocene epoch history 
again becomes clear, and during late Pliocene, Pleistocene and 
recent times there is a remarkable continuation of alternations of 
loading down and degradation of the coastal plain, and the initia- 
tion and life history of the present topographic forms and drain- 
age system. 

At the close of or during the Llano Estacado or Mio-Pliocene 
epoch occurred an event which has given a peculiar configuration 
to southwestern Texas. Under the weight of the increasing and 
successive accumulations of coastal sediments, a great fault line 
developed extending nearly across the state from Austin to Del 
Rio, the down-throw being to the east. The scarp line thus 
evolved became the shore line for the subsequent Appomattox sea; 
erosion attacked it with increased activity, but, owing to condi- 
tions of aridity, with relatively small effect. 

During the Appomattox epoch, which is located by its dis- 
coverer, Mr. McGee, in late Pliocene, the long degraded land of 
earlier Miocene and Pliocene again subsided; but the shore line 
as delineated on the map extended across only one-third of the 
state, passing via Texarkana, Austin and San Antonio, west of 
Kagle Pass to the Rio Grande. 

Before this epoch two river systems had been developed, and they 
remained distinct features of the landscape. The older system 
included those streams which at the culmination of the Mio- 
Pliocene subsidence were mountain streams debouching near the 
present Rocky mountain front, and which under apparently very arid 
conditions extended their mouths seaward with the receding waters, 
across the Great Plains region; the Canadian and Pecos rivers 
are examples of this system. Thesystem, second in age, included 
those rivers originating in the uninterpreted interval between the 
close of the Great Plains epoch and the beginning of the Appo- 
mattox—the Colorado, Brazos, and Red belong here. 


110 The American Geologist. August, 1892 


During the culmination of the Appomattox a third and distinct 
system of drainage was evolved along the then low lying coastal 
plain, adjacent to and interior of its shore line. This group of 
rivers is easily traced upon the maps and includes the San Gabriel, 
Lampassas, Leon, the Bosques, Paluxies and Trinities. They 
are short streams not exceeding 100 miles in length, and drain 
the ancient structural or dip plain of the Grand Prairie, or Lower 
Cretaceous region. Their profile in relation to the plains which 
they drained are as shown upon the diagram, and they are rela- 
tively 500 feet higher at their heads than the adjacent and more 
deeply cut drainage of the first and second systems. The de- 
bouchement of these streams during Appomattox time is clearly 
marked upon the map by the great estuarian deposits, as shown 
by the river terraces especially of the Colorado where it emerges 
from the canons of the Grand Prairie (Appomattox land) into the 
Black Prairie (Columbian coastal plain). The sea receded and 
the submerged plain of Appomattox became dry land. The sea 
shore reached about one-half the distance between the present 
coast line and the ancient Appomattox shore. This was the 
Columbian epoch of Pleistocene time. Upon the new land, the 
present coast prairies, still a fourth system of coastal drainage, 
was initiated almost similar in extent and aspect to that of 
Appomattox time. The rivers of the third or Appomattox sys- 
tem were extended to the Columbian shore, while those of the 
second or Colorado, Brazos, pre-Appomattox type became long 
estuaries back to the Appomattox shore line; at the close of that 
period change in the direction of slope caused them to form a 
line of junction with some adjacent stream, ‘either with one of 
the older streams or with one another. These streams were ac- 
celerated by the elevation at the close of the Appomattox and 
Colorado, and have since cut deeper but proportionately less 
channels than the more voluminous streams of the older systems. 

Few of these streams have crossed by headwater erosion the 
great western scarp of the Grand Prairie; at present this portion 
of their development seems retarded for where they have crossed 
the western scarp line it has been by capture—by the laterals of 
. the older streams. 

The Columbian deposition plain, the present coastal prairie, in 
turn became dry land by the recedence of the gulf to its approx- 
imate present coast line; upon this recently submerged area was 


Evolution of the Mountainous Texas Region.—HMill. 111 


developed the latest and newest drainage system of the region, 
a fringe of small streams flowing directly into the gulf of Mex- 
ico, readily traced in the present Coastal Prairie region. 

At the close of the Columbia there was another upward move- 
ment of the continent. The streams of systems 1, 2, 3 and4 were 
again accelerated by an increased gradient and the prolongation 
of the coastal ends renewed. 

It may be well to review the present condition of the systems. 

Those of oldest or Miocene origin, for instance the Canadian 
and Pecos, in their youth drained the limited Rocky mountain 
and Plateau region, attained base level near the present front of 
the Rocky mountains, still receive their greatest drainage from 
the original receiving area and practically flow long distances 
without receiving any of the later developed drainage. In early 
Pliocene time their base level receded eastward with the shore line. 

With all the oscillations of elevations, invasions, and reced- 

-ences of the sea shore, these streams have continued to carry 
their loads of mountain sediments to the sea, until to-day they 
are merely long viaducts receiving most of their supply at their 
heads and draining little of the country through which they 
pass. 

At some yet undetermined time in history the Rio Grande, 
which was a great interior basin stream, cut its way across the 
continued axis of the Rocky mountain system and joined the 
Pecos; the writer inclines to think this was earlier than the Pleis- 
tocene and that through the water gap of the Rio Grande the 
great lakes of the basin region had a partial outlet to the sea. 

The rivers of the second system—the Red, Brazos, Colorado— 
have since their origin in the obscure epoch between Miocene and 
Pliocene time been at work upon the coastal plain developed 
at the close of the obscure Staked Plains or Mio-Pliocene epoch; 
their drainage with each succeeding event has degraded larger and 
larger areas. The coastward extension of these streams follow- 
ing the receding shore lines is also shown in the medial portions 
of their courses. In Appomattox time they received none of the 
new lateral drainage which flowed down the slopes coastward and 
parallel to them. With each oscillation of bave level their work 
has been retarded or accelerated until they have stripped vast 
regions in the active head-water areas and cut far below the level 
of the newer systems through Miocene, Kocene, Upper and 


112 The American Geologist. August, 1892 


Lower Cretaceous floors to the Algonkian or Archean, which the 
Colorado is now eroding. 

During the Appomattox the mouth of the Colorado was at 
Austin; during Columbia it reached base level at the same place, 
but continued a long estuary, like the Potomac, to the eastern 
coast; in post Columbian times it took a new channel from the 
Columbia to the present shore line; its old course is preserved as 
lakes and bayous; interior of that line it was twice superim- 
posed upon its old channel. 

Let us consider the drainage in relation to its task in denuding 
the land. In general, the divides of the Texas streams are flat- 
topped plateaus representing original deposition or consequent 
degradation plains over which head-water ramifications of the 
streams have not completely extended. In but one portion of one 
system does a state of completion exist, 7. e. the condition in 
which the head-waters of opposing streams have reached across 
the plateau and etched away the original deposition level. This 
area is the northern half of the central region, or the area in 
which the Paleozoic and Red Bed rocks are now exposed, to which 
in the author’s earliest paper upon Texas, the name Central De- 
nuded region was applied. Since the close of the Miocene Plains 
epoch, when the waters receded from the Rocky mountain front, 
it has remained an unsubmerged border-land, interior of Appo- 
mattox, Columbian, and present shore lines; degradation has 
been constantly at work upon it and erosion has cut through suc- 
cessive sheets of the Plains formation, the remnantal Upper and 
Lower Cretaceous and, in part, the Carboniferous to the alleged 
Archean. 

The Appomattox or Grand Prairie streams are approaching 
completion; and in a few places their headwaters have cut through 
the flat-top divides between them; they are rapidly approaching 
maturity as shown by the butte and mesa type of divides. 

The streams of the Columbian epoch are adolescent, but have 
done much work in the softer deposits of the Eocene area. 

The streams of the present epoch on the emerged Columbian 
deposition plain are nascent or just beginning their life work. 

‘xtended portions of the older systems, 7. e., those portions 
of the Rio Grande, Pecos, Red, Canadian, Brazos, and Colorado, 
whose mouths extend oceanward with the receding coastal line 
without draining the area through which they flow, are still doing 


Evolution of the Mountainous Texas Region.—Hill. 118 


their greatest work in their distant sources and merely cutting 
deeper channels in the areas through which they extend. 

Let us return to the part played by the ancient Paleozoic floor 
in this chapter of events. 

Extending across the heart of Texas from north to south as a 
low lying barrier between the gulf and the interior post-Paleozoic 
seas, it was so base leveled and degraded that when the profound 
Cretaceous subsidence began it was buried beneath thousands of 
feet of off-shore sediments, but of a softer, and more easily de- 
graded nature than the firm granitic, hard limestone and quartzite 
beds of the Paleozoic, which especially composed its lower part 
and southern end. 

In the great series of loading down the coastal plain coastward 
of it, and the consequent oscillation of elevation and subsidence 
of the vast plains region, it was natural that this solid core of 
Paleozoic rocks had greater resistance for the accompanying 
strains and stresses, and finally under continued loading the great 
balcones fault developed approximately along the coastal margin, 
leaving sharp projecting land adjacent to the Appomattox sea 
upon which degradation was facilitated; this has partially re- 
moved its Neozoic covering, and will ultimately degrade it to base 
level. 

The topography of the Texas plains is the product of the etch- 
ing of a series of sedimentation plains of post Eocene age by a 
series of consequent autogenetic drainage systems. The plains 
are the product of the oscillations of the Cordilleran continent, 
whereby the waters of the gulf and accompanying base leveling 
swept back and forth across the Texan region. These oscilla- 
tions began with the overcoming of the central Paleozoic barrier 
at the beginning of the Comanche or Lower Cretaceous epoch, 
attained their maximum in Upper Cretaceous time, as recorded in 
the Dakota base leveling, when the seaextended over much of the 
present Rocky mountain area. In Laramie-EKocene the oscilla- 
tion was almost as profound and far reaching, Following that 
epoch was decreasing intensity; the line of marine base level 
extended less and less inward during the invasions of Miocene, 
Pliocene, and Pleistonic time. 

Dependent upon conditions of deposition the rocks of these 
different periods are of different degrees of consolidation, and 
consequent resistance to denudation. 


114 The American Geologist. August, 1892 


In the Neozoic series, however, there are but three formations 
sufficiently consolidated to produce canoned or scarp topography 
—the iron ore beds of the Kocene, certain white rock beds of the 
Miocene or Llano Estacado, the Fayette beds, and the limestones 
of the Comanche series. 

The first two—the Eocene iron beds of east Texas and the 
Miocene beds of the Staked Plains—are thin horizontal beds of 
consolidated material underlaid by loose friable beds which rapidly 
disintegrate upon the removal of the cap sheet and produce mesas. 
These mesa prodycts are not greatly developed in Kast Texas 
because of the newness of the streams, but in the Llano Estacado 
are very marked. 


The great chalky limestone formation of the Comanche series 
has been the chief factor of resistance to sculpture in the Texas 
region, and the effects produced by erosion of its alternations of 
hard and soft beds are both beautiful and instructive. Along 
its eastern margin where it dips beneath the Upper Cretaceous its 
prevalent forms are dip plains and escarpments of stratification 
extending north and south; many streams flow along them in the 
same directions until they cut their way through the escarpment, 
when they again flow eastward to the sea. In the west central 
portion of the state headwater erosion of opposing streams has 
produced numerous buttes and mesas, which are often a hundred 
miles from the mother area of which they were a part. 

While the general coastward direction of the streams is the 
result of the prevalent slope, there are certain influential strue- 
tural features which in the aggregate produce the prevalent topo- 
graphic detail. 

First of these are joints and faults. 

The stratigraphic system of this region is broken by a system 
of complemental joints which have a major axis of west of south 
to east of north or sub-parallel to the coast line. In areas of 
unconsolidated chalks, sands, and clays, joints have no percepti- 
ble effect in deflecting streams, but where the material is consoli- 
dated streams adapt their courses to joint lines; this is shown by 
the Brazos in the Carboniferous rocks of Palo Pinto county, the 
Colorado in the Lower Cretaceous of Travis, and in other 
instances. 


Larthquakes in Nicaragua.— Crawford. 115 


In only two cases have great faults developed in the direction 
of these joint planes. One—the great Balcones fault from Austin 
to Del Rio—has a downthrow to the east and at right angles to 
the streams; except a slight deflection of the Colorado west of 
Austin, it has in no way affected the course of the streams. 

The other exceptional fault extending from Marietta, Chicka- 
saw nation to south of Texarkana has its downthrow interior- 
ward, and Red river follows its trough for many miles, and its 
direction is primarily influenced by it. 

The area is too vast to give details of many of the proposi- 
tions I have set forth, or to call attention to several minor topo- 
graphic processes. There are two agencies which cannot be 


passed, however, which play a more important factor in the Texan 
region than elsewhere in the United States, and these are wind 
and aqueous solution. Owing to aridity and lack of consolida- 
tion, the crumbling structure is readily transported by wind, dust 
and sand storms being of great frequence. In bluffs and canons, 
composed of alternating structure of consolidated and marly 
layers, the former are undermined by wind erosion. 

Over the vast and intensely heated limestone plateaus, solution 
plays a most important part, and there results a remarkable 
weathering of the limestones into miniature mountain ranges, and 
a corresponding deposition of that remarkable calcareous deposit 
’ known in Mexico as tepetate. 


NOTES ON EARTHQUAKES IN: NICARAGUA, 
FEB: 6G; lSo2- 
J. CRAwForD, Leon, Nicaragua. 

At10h.10 m., p. m., 6th February, 1892, occurred an ap- 
parently connected series of about 92 seconds total duration, of 
longitudinally oscillating, progressive, spherical, seismic waves 
Uy=a sin (Pt—nx)....] that passed northwestwardly and south- 
eastwardly in Nicaragua, parallel with, and along or near to, the 
volcanic masses which extend connectedly with but a few short 
interruptions, (as across the bay of Fonseca and lakes Managua 
and Nicaragua), between the volcanic groups in the states of SAL- 
vapor and Costa Rica. 


116 The American Geologist. August, 1892 


The facts obtained, in reference to this earthquake, to date— 
the sailing of the weekly Mail 8. ship from the port of Covinto— 
5 o'clock p. m., 9th February, 1892, are: 

Only one series of vibrations has occurred. The epicentrum 
was near the island of Zapatera at the west coast of lake Nicara- 
gua, distant about 14 miles east from the Pacific ocean and about 
28 miles southeast from the city of Granada. 

The focus has not yet been determined, but was more than 
15,500 feet (English) beneath a plane parallel with the sub-areal 
surface of the Pacific ocean. 

The co-seismal lines of emergence of the waves, at the earth’s 
surface, were elliptical, but converging at several places toward 
the longitudinal axis of the ellipsoid. 

The maximum of the horizontal element of the oscillations, or 
line of greatest disturbance at the earth’s surface was, on the 
northwestern side of the epicentrum, in lake Managua, about 65 
miles distant from the point of first emergence, 30 miles west- 
ward from the city of Managua, and about 36 miles southeast 
from the city of Leon. 

The rate of transit through the earth during the latter or vi- 
brating part was about 29 miles per minute. 

The greatest vibration, in the city of Leén, from a line per- 
pendicular to and at an altitude of 60 feet above the surface was 9° 
25’ about. 

Several adobe walls of houses in the cities of Granada, Mana- 
gua, and Ledén were slightly cracked, or, these walls (usually 24 
to 3 feet (English) thick and 14 to 18 feet high) were disconnected 
from similar ones connected at right angles, 7. e., those extend- 
ing north and south were slightly disconnected from those ex- 
tending east and west. 

The city of Managua being nearer the coseismal line of great- 
est force expressed at the surface than the other cities named 
felt this earthquake more severely. In the city of Ledén, the 
locality of the longest ordinates of the curvatures, or apex of 
elevation and depression, were easily discovered by finding the 
walls of houses that had been slightly displaced or cracked by 
the waves. 

During the first 60 seconds the oscillations were about one each 
six seconds 


causing a sensation as if they had originated from 
the impact against the hard floor of some deep seated cavern of 


Earthquakes in Nicaragua.— Crawford. Lat 


large masses of hard strata; there was felt a perceptible increase 
and decrease of the oscillations; then, for about 32 seconds were 
experienced more rapid or vibratory movements of short, high 
waves as if two large masses of rock had (at an interval of about 
15 seconds) suddenly separated from their places and fallen to 
the hard floor of a cavern, from a hight sufficient to cause a 
slight jar, each 90 miles distant, and converting the energy into 
elastic, longitudinally vibrating, progressive, spherical waves of 
force. 

No place has been discovered where permanent subsidence of 
the earth’s surface has resulted. 

This earthquake was not caused by volcanic forces such as the 
superior energy of high tension gases or aqueous vapors disar- 
ranging earth strata. 

The aqueous vapors arising from the cones of the nearly ex- 
hausted voleanoes on the line of force [Santa Clara, Momotomba, 
and Omatepa] have not increased nor diminished in apparent, 
quantity. 

No perceptible change has been observed in the amount or the 
temperature of large springs of water, issuing from fissures, near 
the base of some of the volcanic cones, on the line of force, in 
Nicaragua. 

The primary cause of this class of seismic disturbances in the 
earth’s crust in this region can be discussed hereafter when all 
the phenomena referable to this series have been studied. At 
present two theories—each with some good evidence—are pre- 
sented: First, —Motion from the interior friction of ‘the bodily 
tides” [Prof. G. Darwin, Philo. Transt. 1879, parts 1, 11, ] incident 
to the increased length of the siderial day and, probable, conse- 
quent elongation of the earth’s polar radius and increased pres- 
sure in equatorial latitudes. Second,—Contraction from secular 
cooling and the consequent increased tension in the narrow strip 


of land, between the line of volcanic masses in Nicaragua and 
the Pacific ocean, acquiring sufficient force to overcome the co- 
hesion and disconnect large masses of strata and precipitate them 
into adjoining caverns deeply located beneath the volcanic cones 
and masses of ejecta. This ‘‘sufficient force’ appears to have 
attained its maximum annually, or, at intervals of 10 to 14 
months during the past four years, as observed by the writer, in 


118 The American Geologist. August, 1892 


this part of Nicaragua, a short series of earthquakes having oc- 
curred annually, 

There has been a subsidence, occasioning plications or foldings 
of the strata, in western Nicaragua, between the Pacific ocean 
and the line of voleanic cones, (a strip of land 27 to 33 miles 
wide, ) whether paroxysmal and expressed in earthquakes or ¢on- 
tinuous—has not yet been determined. This subsidence is now 
in progress, and its phenomena are being studied by the under- 
signed. J. CRAWFORD. 

Leon, Nicaragua, 9th February, 1892. 


Postscriptum. Since mailing on 9th instant, “Notes on Earthquake 
phenomena in Nicaragua” on 6th instant, I learn, by telegraph, as fol- 
lows, in reference to the approximate length and width of the ellipsoid 
and the line of greatest disturbance at the earth’s surface: 

(a) The seismical force followed the volcanic belt southeastwardly 
into Costa Rica, and more severely south than north of the epicentrum, 
asif accummulating disturbing forces as it traversed the sub-terranean 
parts of the group of active and of “hot” volcanoes in that country. 

(b) The line of greatest disturbance curved irregularly in its southern 
course—first southwestwardly, between the city of Rivas and the Port of 
San Juan del Sur, in Nicaragua, thence southeastwardly near the Pue- 
blo of Philadelphia in northern Costa Rica and along the line of vol- 
canic masses to near the city of San José (quite severe), thence, (so far as 
[have information to date) southeastwardly into the Caribbean sea. 

(c) The length of the disturbance of this series of seismic waves has 
been traced for over 500 miles and the average width of their disturb- 
ance about 100 miles. 

(d) Electro-magnetic phenomena, to be described hereafter, were quite 
prominent. 

(e) The retardation of the waves in—and their greater disturbance of— 
some kinds of strata can be traced at several places, also, have been noted 
a few places where they were reflected from the strata and two or three 
places where, apparently, there was interference of waves and accum- 
ulation therefrom of force. 

(f) The focus was evidently a fissure, extending southeastwardly 
from Isla Zapatera in lake Nicaragua, for about 25 leagues into Costa 
Rica. J. CRAWFORD. 


February 14, 1892. 


119 


REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 


The Earth and Its Inhabitants. By E1skE Recuvus. Vol. 11, Mexico, 
Central America and West Indies. New York, D. Appleton & Co. 
1891. 8vo, 504 pp, 227 illustrations, 40 plates and maps. This is a geo- 
graphical description of Mexico, British Honduras, Central America, 
Panama, Gulf of Mexico and Caribean Sea, Cuba, Jamaica, San Dom- 
ingo and Hayti, Puesto Ruo, Virgin Islands, The Bahamas, Bermudas 
and the Lesser Antilles. A statistical appendix of population and areas 
is also given. For the first time we have collected ina single volume a 
clear and concise statement of the geographic and economic conditions 
of the southern half of North America. The work is a mast rly trea- 
tise from the pen of a scientific authority, and presents more solid in- 
formation concerning the orography, bypsometry, drainage, climate, 
floras, inhabitants, productivity and natural phenomena of the regions 
treated, than has hitherto been obtainable. The chapters on Mexico can 
be recommended as the most important reading to one who has a desire 
to become acquainted with that country. 

“Bosquejo de una Carta Geologica dela Republica. Mexicana,” compiled 
by a special commission, for the Secretary of Public Works, under the 
direction of PROFESSOR ANTONIO DEL CastiILLo, Director of the National 
School of Engineers. 

This map is a grand contribution to North American Geology, and a 
credit to the fellow scientists of our sister republic. It is handsowely 
printed on heavy plate paper, upon the scale of g jojo, and is so har- 
monious in color and void of irrelevant detail that its story is told with 
a plainness that is surprising, for here we have spread before our eyes 
the general features of Mexico, which every student of American areal 
geology has long desired to know. Three colors stand out in conspicu- 
ous boldness—yellow, green, and red—Quaternary, Cretaceous and 
eruptive, and these are the chief chapters of Mexican Geology—(1) A 
sedimentary floor of basa] Cretaceous (Comanche) rocks—the continua- 
tion of our Texan features, but broken into mountain blocks and plat- 
eaux; (2) Great sheets of Quaternary sediments—the basin structure 
of Utah and Arizona, and the whole more or less covered by eruptive 
sheets. The Cretaceous is to Mexico what the Cambro-Silurian is to the 
United States- its fundamental sedimentary rocks, and this map shows 
the youthfulness of that region compared to ours, and the apparent mi- 
gration southward of conditions, 7. ¢, the present basins, active vol- 
canoes of southern Mexico similar to those of late Quaternary time in 
the southwest United States. The utter absence of paleozoic rocks is 
indeed most important food for reflection. 

The critic might find cause for complaint in the absence of hypsome- 
tric data, but we must confess that in our opinion the chief virtue of the 
map is the omission of every possible line that would detract from its 
simplicity. 


120 The American Geologist. August, 1892 


Bertrage zur Geologie und Paleontologie der Republik Mexico; von DR. 
J. Fenix und Dr. H. LENKE, (of Leipsig). Part 1, Leipsig 1890. Part 
111, Stuttgart 1891, 4to, with numerous plates and maps. 

This work is the most important contribution to the geology of Mex- 
ico yet published, and by its excellent character and scientific composi- 
tion immediately assures the reader of the ability and intelligence of 
its authors. Space forbids, however, the enumeration of all the valua- 
ble contents, which shed so much light upon North American geology. 

Part 1, after a preface explanatory of the lack of previous knowledge 
of Mexico, and an introductory sketch of its salient features, is devoted 
to the “volcanic chain of central Mexico, including descriptions of 
Tuxtla, Popocatapetl, Ajisco, Nevada de Toluca, Jorulla, the peak of 
Tancitaro, Colima, Orizaba, Cofre de Perote, Malinche, Iztaccihuatl, San 
Andreas Ceboruco and Tepie. It is impossible to enumerate here the 
numerous and important results given, but every line is a much desired 
contribution to knowledge, especially that concerning the glaciers of 
Popocatapetl. . 

Part 11 is devoted to the valley of Mexico, and of itself is one of the 
most important contributions to the late Tertiary Geology of this conti- 
nent. Several pages are devoted to a careful topographic sketch full of 
important data. Chapter 2 describes the remarkable Pleistocene de- 
posits, showing a striking resemblance to the features of our own lake 
Bonneville as described by Gilbert. The earlier discoveries of a 
Pliocene vertebrate fauna by Cope are supplemented by newdata. This 
fauna, consisting of Equus, Elephas, Mastodon Glyptodon, Bison, etc., is 
similar to that of the Fayette beds of Texas and the Equus beds of the 
great basin region. 

The eruptive rocks of the valley were studied by Zirkel, and consist 
of amphibole andesites, hypersthene andesites of many kinds, and 
basalts. Finally a full table of altitudes is given. 

Part 11 contains two papers, the first by Drs. Felix and Lenke on the 
Geology of the State of Puebla, and the second by Dr. Felix on the Fos- 
sils of the Jurassic and Cretaceous formations of Mexico. In the part 
on Puebla the general geology is shown to consist of Cretaceous and 
Jurassic limestones, and the Pliocene Equus beds. Full notes are given 
on the fossil vertebrates of the latter formation. The Cretaceous is 
shown to consist of an upper horizon of limestones with Hippurites 
and Monopleura, which we believe analogous to the Monopleura and 
Caprina beds of the Glen Rose limestones of the Comanche series in 
Texas, while the lower division is very analogous to the Trinity forma- 
tion of the same region. The remarkable superficial formation known 
in Mexico as tepetate is described—an incrustation of carbonate of lime 
deposited over the valleys by the streams from tbe limestone mountains. 

The second part of Part 11 contains accurate descriptions and beauti- 
ful plates of the Neocomian and Jurassic fossils of Puebla. If any one 
still doubts the existence of the marine Jura in North America an ex- 
amination of these plates should convince him of his error. 


Review of Recent Geological Literature. 121 


The Geology and Paleontology of the Cretaceous Deposits of Mexico. By 
ANGELO HEILPRIN. (Proc. Phi. Acad Nat. Sci. 1890, extras, 1891.) 

It is unfortunate while so much of value has been recently published 
concerning Mexico, that an American should contribute such a mass of 
error as is contained in this brief paper. Prof. Heilprin from a brief 
visit to southern Mexico, concludes that the great Neocomian and Juras- 
sic formations so ably proven by Felix and Lenke are Upper Cretaceous, 
because they contain a hippurite fauna; as does the Upper Cretaceous 
of Europe. Although not much nearer Texas while in the City of 
Mexico than he was in Philadelphia, he devotes most of this paper to 
stating that assignment of the Comanche Series to the Lower Cre- 
taceous by Prof. Hill is wrong, and that that great formation with its 
Neocomian fossils, its Wealdan reptiles and plants, its 4,000 feet of sedi- 
ments stratigraphically below the Dakota sandstone of the Upper Cre- 
taceous, all belongs to the latter formation. We can only refer Prof. 
Heilprin to the rocks, the fossils—plants, vertebrates and mollusca,—the 
writings of Marcou, Roemer, Hill and White, to assure him of the error 
of his conclusions. 


Correlation Papers—Cretaceous. By C. A. Wuitr. (Bulletin U,. S. 
Geological Survey, Washington, 1891.) In this valuable compilation, 
many instructive pages are devoted to northern Mexico, especially con- 
cerning the development of the Comanche and Upper Cretaceous on the 
Rio Grande near Presudo del Norte, where the former rests on the Car- 
boniferous—the only place in Mexico, so far as known, where the Car- 
boniferous floor has been exposed. Interesting data are also given con- 
cerning the occurrence of the Laramie on the coastal slope near Lam- 
pazos.. A valuable bibliography of publications on Mexican paleontol- 
ogy is given, to which we may now add “Preliminary Notes on the Topo- 
graphy and Geology of Northern Mexico,” etc. By Robt. T. Hill, 
AMERICAN GEOLOGIST, September, 1891. 


Official Maps of the Republic of Mexico, published by the Minister de 
Fomento. Thirty beautiful sheets of the Republic of Mexico illustrat- 
ing the distribution of population, altitude, agriculture, soils, geology, 
railroads and mines, printed in a most artistic style, ame a revelation to 
us of what our friends beyond the Rio Grande are doing for science. 

In addition to these general maps there are several elegant contour 
maps Of limited areas giving the topography of the vicinity of Mexico, 
the volcanic peaks of Popocatapetl and Ixahuapetl. These contour 
maps in artistic appearance are only slightly inferior to those issued by 
the leading surveys of Europe and America. 

Part 1, treating the political geography, describes the boundaries of 
the state, and gives an extensive table showing all the cantons, depart- 
ments, municipalities and voting places, together with minute descrip- 
tions of the metes and bounds of the canton. A table is also given 
showing the population for the year 1885, and births and deaths. The 


122 The American Geologist. August, 1892 


total population of this small state was 1,159,541, and the births exceed 
the deaths by 7,257, showing the native civilization to be on the in- 
crease. The catalogue of settlements is quite extensive, and shows the 
existence of one capital (Guadalajara), 17 cities, 80 villages, 188 pueblos, 
70 congregations, 387 haciendas, and 3,847 ranches 

The chapters relating to geography, geology and botany are of chief 
interest however. The grand volcano of Coluna is described together 
with the other majestic peaks of this region. The valleys, canons and 
barancas, the basin plains, and every topographic feature are set forth 
clearly. 

The tables of altitude are so comprehensive that a contour map could 
be easily constructed from the data given. 

The third part, relating to geology, is of special interest. An excel- 
lent map is published. The oldest sedimentary rocks found are Cre- 
taceous, while eruptive and other igneous rocks predominate. The Ter- 
tiary history of the basins is of chief interest, showing as they do that 
most of the so-called Plateau region of Mexico is but the southern de- 
velopment of our own great basin region, with all of its wonderful his- 
tory of climatic changes and lacustral deposition. 

Part vi is devoted to the flora, especially its relation to altitude. A 
lengthy table gives the scientific and popular names of all the plants, 
their economic uses, and the geological formations which they inhabit. 
This part alone is one of the most intelligible contributions to plant 
distribution ever published on this continent. 


On the Clinton Iron Ore. C. SMYTH, JR. (Am. Jour. Sci., xii, 
1892, pp. 487-496) Perhaps more ieee facts, and more arguments 
to show the derivative origin of certain hematites from a change of lime- 
stone, have been drawn from the Clinton ore than from those of any 
other horizon. There seems to have been a widespread acceptance of 
that theory, at least for those ores, and the theory has been applied, per- 
haps without due circumspection to other formations. Pseudomorphous 
replacement of some carbonate, generally a limestone, but sometimes an 
iron carbonate, has been applied widely to explain the iron ores of the 
lake Superior region. More lately original oceanic deposition from 
chemical solution has been put forward for some of the lake Superior 
ores, on the ground that there is not sufficient evidence of the substitu- 
tion theory. Now Mr. Smyth proposes to remove from the substitution 
hypothesis its original cause and key, and to place the Clinton hema- 
tites in the category of original chemical deposits of date coeval with 
the enclosing strata. 

This result he bases on a careful and lengthy study of this ore at the 
typical locality, Clinton, N. Y.,and in detail the steps of the proof are 
somewhat as follows: 

1. The ore is not embraced in limestone, but in shales and sandstones, 
the latter so coarse sometimes as to be conglomerate. 

2. The beds are nearly or quite horizontal, and not so placed as to 
allow easy and rapid access of ferriferous waters. 


Review of Recent Geologrcal Literature. 123 


3. The ore is oolitic, and the oolyte has a concretionary structure, 
embracing in each lenticule, a rounded grain of quartz. 

4. The concentric layers of the lenticules consist of alternations of 
silica and hematite, which becomes evident on the removal of the latter 
by hydrochloric acid. The silica is sometimes amorphous, and some- 
times appears, under the microscope, to be chalcedony. 

5. This structure pervades the Clinton ore from Dodge county, Wis., 
from Rochester and Ontario, N. Y., from Tennessee, Georgia and Ala- 
bama; and even when the ore consists largely of the forms of Bryozoa 
such forms are permeated and coated with layers of ore, associated with 
silica, showing an intimate relation in the origination of the silica and 
the ore. : 

6. The shoal waters indicated by the character of the associated 
rocks at Clinton, were favorable for the formation of iron ore by sedi- 
mentation. 

. 7. If these lenticules were originally of calcite they must have been al- 
tered from the exterior inwardly, butin no case has there been found 
any remaining trace of such calcite. 

8. The strata are still horizontal, and percolating waters could not so 
uniformly reach and change a limestone layer, and especially to the 
neglect of other limestones overlying, situated even more favorably for 
such change. 

9. There seems to be a false chemical assumption in presuming that 
meteoric waters already surcharged with lime carbonate will also carry 
along iron salts and receive more lime in exchange for the iron at a cer- 
tain definite stratigraphic level. 

10, The lowest layer of iron ore is separated from that above it by a 
calcareous bed of shale. The substitution hypothesis requires that 
meteoric waters should pass through this shale leaving its 5 p. c. of lime 
unaffected and depositing no iron, but should abstract all of the lime in 
the lower layer where the ore is found—which seems to be gratuitous 
play of imagination. 

11. The bottom tier contains a lean ore, but its leanness is not due to 
an excess of remaining lime, but toa greater deposit of concretionary 
and fragmental silica. “It is in fact a ferruginous sandstone.” 

12. Instead of a removal of calcite by percolating waters the process 
has been the reverse and calcite is found to embrace the iron spherules 
some of which have been partially broken and exfoliated prior to such 
calcareous deposition. 

13. Wherever the spherules are found in patches and irregular 
groups throughout the rock, though not constituting a good ore, they 
are as completely formed of iron and silica as when they constitute ore. 
If they resulted from replacement they would naturally be only partially 
changed. 

14. Oolitic iron ores are being formed at the present day in conditions 
similar to those supposed for the Clinton shores and estuaries; such 
only need dehydration, which goes on at ordinary temperatures, to re- 
semble closely the Clinton ores. 


124 The American Geologist. August, 1892 


The foregoing facts and considerations have led Mr. Smyth to the con- 
clusion that the oolitic ores at Clinton are not of secondary origin but 
were deposited as hydrated peroxide of iron in intimate connection with 
cotemporary deposition of amorphous and chalcedonic silica. 


“The Orthoceratida of the Trenton Limestone of the Winnipeg Basin.” 
By J. F. Wurrraves. (Transactions of the Royal Society of Canada, 
Vol. rx, Section 4, pp. 77-90. Plates v-x1, both inclusive. 1891—dis- 
tributed in 1892.) 

This is one of the most important contributions to the history of the 
Cephalopoda of the Ordovician rocks which has appeared for a long 
time. The paper consists, as the author indicates, ‘of a critical and sys- 
tematic list of the Orthoceratide at present in the Museum of the Geo- 
logical Survey of Canada from the formation and region indicated in its 
title, with descriptions of such species as appear to be new.” Init Mr. 
Whiteaves considers the genera Actinoceras and Sactoceras as distinct 
from Orthoceras and Poterioceras from Gomphoceras. 

The following table shows at a glance the species, author and refer- 
ences of each form in the paper in question. 


» Species. Author. Reference. 

1. Endoceras annulatum, var. Hall. Plate Vy figs. 1 and Ja, p. 77. 

2: ge subannulatum, Waideld: Se 2 and 2a, p. 78. - 

3. oe crassisiphonatum, N. Sp. ‘¢ vi, figs. 1-4, Pl. vu, fig. 1, p. 79. 
4. Orthoceras simpsoni, Billings. “¢ VII, figs. 2,28 & 3, Pl. vit, fig. 1, p.80. 
5. semiplanatum, N. Sp. ss vill, ‘figs. 3& 3a, p. 81. 

6. eS selkirkense, N. Sp. « vit, figs. 2, 2a, 2b, p. 82. 

‘ig ss winnipegense, N. Sp. ae yun, figs. 4, 4a, 4b, p. 82. 

8. Actinoceras richardsoni, Stokes. “¢ 1x, figs. 1, 2 and 3a, p. 83. 

Gh sf bigsbyi, Bronn. Sai. hy 5 1-0 hee is 
10. ss allumettense, Billings. (x, figs. 3,\3a, p. 85. 

11. Sactoceras canadense, N. Sp. “*. X, figs. la-c, p. 85. 

12. Gonioceras lambii, N. Sp. “xt, figs. la-b, p. 86. 
13. Poterioceras nobile, Whiteaves. Not figured, p. 87. 

14. Yi apertuim, Whiteaves. |} ‘* x1, figs. 2 and3, p. 87. 
15. oe gracile, N. Sp. o XL figs. 4 and Ja, p. 87. 


The specimens from which the above species are enumerated were 
collected for the most part by officers of the Geological Survey of Can- 
ada during their explorations and surveys in Manitoba and Keewatin: 
Messrs. Dr. Bell, Dr. Selwyn, Weston, Tyrrell, Dowling, Lambe, and also 
by Messrs. Donald, Gunn and McCherles from the same district. They 
form a valuable addition to the National Museum of Canada at Ottawa. 


The Geological and Natural History Survey of Minnesota, Nineteenth an- 
nual report, for 1890. N. H. WINCHELL, State Geologist. 255 pages; 
with two plates, and 36 figures in the text. The first part of this report 
contains a translation of the treatise by Dr. Emanuel Boricky, “The Ele- 
ments of anew Method of Chemico microscopic Analysis of Rocks and 
Minerals,” 77 pages, with 40 figures of thin sections arranged on two 
plates. This work will be used in the study of the crystalline rocks of 
Minnesota, and will be welcomed by many petrographic students. 
Another translation presents a paper by the German geologist, Dr. J. H. 
Kloos, who made extensive observations in Minnesota before the begin- 
ming of the present survey. 


Recent Publications. 125 


The timber resources of Minnesota are discussed by Mr. H. B. Ayres, 

agent of the Forestry Division, U. S. Department of Agriculture. 
Though the average number of men employed in the state in preparing 
forest products for market reaches about 17,000, and the value of the an- 
nual product about $31,635,000, it is confidently affirmed that this indus- 
try and its supply need not soon decline, if the forest lands should 
receive legislative attention and proper care, as in some European coun- 
tries. : 
Other divisions of this report comprise a valuable catalogue of the 
meteorites in the State University collection, with references to litera- 
ture d-scribing them; notes on the petrography and geology of the 
Akeley lake region, in northeastern Minnesota, by W. S. Bayley; and 
descriptions of new Lower Silurian lamellibranchiata, chiefly from 
Minnesota rocks, by E. O. Ulrich, who describes and figures twenty- 
seven new species, referred to the genera Tellinomya, Technophorus, 
Cleidophorus, Modiolopsis, Orthodesma, Cypricardites, Matheria, Ischyro- 
donta, Whitella, Cuneamya, and a new genus named Plethocardia. 


The principal Mississippian section. By CuHarues R. Keyes. Bulletin, 
G.S. A., vol. iii, pp. 283-300, with one plate; June 3, 1892. The term 
Mississippian is used, in accordance with the suggestions of Profs. 
Alexander Winchell and H.S. Williams, as a substitute for “Lower Car- 
boniferous;” and the section here described in considerable detail, with 
careful correlations of the strata exposed at many localities, is seen in 
the bluffs of the Mississippi river from Burlington, Iowa, to Cape 
Girardeau, Missouri. The whole Mississippian series, as there observed, is 
divided into fuur groups, named in ascending order the Kinderhook, 
Osage, St. Louis, and Kaskaskia groups, which in turn comprise 
together fourteen recognized formations. 


ite Onn or Nt PUBLICATIONS. 


Papers in Scientific Journals. 

The School of Mines Quarterly, Vol. XIII, No. 1, Nov. 1891, contains: 
The Filling of Mineral Veins, by J. F. Kemp. 

- The National Geographic Magazine, Vol. IV, contains: Studies of 
Muir Glacier, Alaska, by H. F. Reid. 

The Canadian Record of Science, Vol. V, No. 1, contains: Additional 
Notes on Devonian Plants from Scotland, by D. P. Penhallow; On the 
Cherts and Dolomites of the Rocks of Thunder Bay, Lake Superior, by 
E. D. Ingall; Vol. V, No. 2, contains: Descriptions of some new Species 
of Fossils from the Cambro-Silurian Rocks of Quebec, by H. M. Ami; 
The Physical Features of the Environs of Kingston, Ont., and their Hist 
ory, by A. T. Drummond; Some Laurentian Rocks of the Thousand 
Islands, by Dr. A. P. Coleman; The Nickel Deposits of Scandinavia, by 
J. H. L. Vogt. 


126 The American Geologist. August, 1892 


Il. Proceedings of Scientific Sucieties. 

‘Trans. Wis. Acad. Sci. Arts and Letters, Vol. vir, 1888-1891, contains: 
Some Additional Evidences bearing on the Interval Between the Glacial 
Epochs, T. C. Chamberlin; On some Metamorphosed Eruptives in the 
Crystalline Rocks of Maryland, Wm. H. Hobbs; Notes on a little known 
Region of Northwestern Montana, G. E. Culver; On a new Occurrence 
of Olivine Diabase in Minnehaha County, South Dakota, G. E. Culver 
and Wm. H. Hobbs; Origin of the Iron Ores of the Lake Superior Re- 
gion, C. R. Van Hise; On the Correlation of Moraines with Raised 
Beaches of Lake Erie, Frank Leverett. 

Proc: Acad. Nat. Sci. Phil. (Jan. to Mar.) Remarks on the Quantity, 
Rate of Consumption, and Probable Duration of North American Coal, 
and the consequences to air-breathing animals of its entire combus- 
tion, Isaac J. Wistar; The development of the shell in the coiled stage 
of Baculites compressus Say, Amos P. Brown. 


ITT, Papers in Scientific Journals. 

Ottawa Naturalist, May. On Natural Phosphates. J.L. Willis. June. 
On the Sequence of Strata forming the Quebec group of Logan, with 
remarks on the fossil remains found therein. H. M. Ami. (Abstract.) 

School of Mines Quarterly, April. Topographical Survey of New 
York State, W. P. Trowbridge; Analysis of Chromite, Walter and 
Vulte; Fossil Forests of the Yellowstone, W. H. Weed. 

Nat. Geog. Mag., Vol. 1v, contains: Studies of Muir Glacier, Alaska, 
Harry Fielding Reid; Toe Mother Maps of the United States, Henry 
Gannett; An Expedition through the Yukon District, C. Willard Hayes, 
(to page 163). 2 

Geol. Mag. April. The Upper Trias of St. Cassian, Tyrol. Miss M. 
M. Ogilvie; On a new form of Discinocaris from Bohemia, Ottamar 
Novak; A new British phonolite, F. H. Hatch; Drift Coal in sandstone, 
G. W. Bulman; Onthe ash slates of the lake district, W. M. Hutchings; 
The age of the Himalayas, W. T. Blanford; Replies to various criticisms, 
J. F. Blake. 

May No. On a Neuropterous insect from the Lower Lias, H. Wood- 
ward; The lamprophyres of the north of England, Alfred Harker; How 
to take impressions of fossils, J. G. Goodchild; On the origin of earth- 
quake sounds, C. Davison; On the ash slates of the lake district, W. M. 
Hutchings. 

June No. Onthe Devonian rocks of south Devon, A. R. Hunt; Per- 
mian in Devonshire, W. A. E. Ussher; The mammoth and the glacial 
drift, H. H. Howorth; On Ammonites jurensis, 5,8. Buckman; The re- 
vised theory of glaciation, G. W. Bulman. 

Am. Jour. Sci., February No. Bear River formation, a series of strata 
hitherto known as Bear River Laramie, C. A. White; Stratigraphic posi- 
tion of the Bear River formation, T. W. Stanton; Iron ores of the Mar- 
quette district of Michigan, C. R. Van Hise; Illustration of the flexibil- 
ity of limestone, A. Winslow; Central Massachusetts moraine, Rees: 
Tarr; Proofs that the Holyoke and Deerfield Trap-sheets are contem- 
poraneous flows, and not later intrusions, B. K. Emerson. 


Recent Publications. rae 


March No. Mt. St. Elias and its glaciers, I. C. Russell; Hudson River 
fiord, A. M. Edwards; Contributions to mineralogy, No. 52, F. A. Genth; 
Tschermak’s theory of the chlorite group and its alternative, F. W. 
Clarke; Recent fossils near Boston, W. Upham; The highest old shore 
line on Mackinac Island, B. F. Taylor; Observations upon the structural 
relations of the upper Huronian, lower Huronian and basement com- 
plex on the north shore of lake Huron, R. Pumpelly and C. R. Van Hise; 
Preliminary report on observations at the deep well at Wheeling, West 
Virginia, W. Hallock; Mount Bob, Mount Ida or Snake Hill, T. W. Har- 
ris; Discovery of Cretaceous Mammalia, O. C. Marsh. 

April No. Melilite-bearing rock (Alonite) from St. Anne de Bellevue 
near Montreal, Canada, F. D. Adams; Azure-blue pyroxenic rock from 
the Middle Gila, New Mexico, G. P. Merrill and R. L. Packard; Correla- 
tion of moraines with raised beaches of lake Erie, F. Leverett; Plicated 
cleavage-foliation, T. N. Dale; ,Geological age of the Saganaga syenite, 
A. R. C. Selwyn; Third occurrence of peridolyte in central New York, 
C. H. Smyth, Jr.; Fulgurite from Waterville, Maine, W. S. Bayley; 
Mineralogical notes on brookite, octahedrite, quartz and ruby, G. F. 
Kunz; Recent polydactyle horses, O. C. Marsh. 

May No. Experiments upon the constitution of certain micas and 
chlorites, F. W. Clarke and E. A. Scheider; The age and origin of the 
Lafayette formation, E, W. Hilgard; Plattnerite and its occurrence near 
Mullan, Idaho, W.S. Yeates, with crystallographic notes by E. F. Ayres; 
Upper silurian strata near Penobscot bay, Maine, W. W. Dodge and C. 
E. Beecher; A meteorite from Pennsylvania, W. G. Owens; Two mete- 
oric irons, G. F. Kunz and E. Weinschenk; A new order of’ extinct 
Eocene mammals (Mesoductyla), O. C. Marsh; Notice of new reptiles 
from the Laramie formation, O. C. Marsh. 

June No. Sub-divisions in Archean history, J. D. Dana; Clinton iron 
ore, C. H. Smyth, Jr.; Josephinite,a new nickle-iron, W. H. Melville; 
Fibrous intergrowth of augite and plagioclase, resembling a reaction 
rim, in a Minnesota gabbro, W. 8. Bayley; Notes on Triassic Dinosauria, 
O. C. Marsh. 

July No. Polybasite and tennantite from the Mollie Gibson mine in 
Aspen, Col., 8. L. Penfield and S. R. Pearce; Post-Laramie deposits of 
Colorado, W. Cross; Fossils in the Archean rocks of central Piedmont, 
Va, N. H. Darton; Notes on the Cambrian rocks of Virginia and the 
southern Appalachians, C. D. Walcott; Synthesis of the minerals cro- 
coite and pheyicochroite, C. Ludeking; A hint with respect to the origin 
of terraces -in glaciated regions, R. S. Tarr; Occurrence of a quartz 
boulder in the Sharon coal of northeastern Ohio, E. Orton. 


IV. Excerpts and Individual Publications. 
Gordon’s Specimen Record. ©. H. Gordon, Evanston, Ill. 
Clays of the Hudson River Valley. H. Ries. Trans. N.Y; Acad: 
Sci., Vol. x1, p 33, 1891. 
The Geological Map of the United States and the United States Geo- 
logical Survey. Jules Marcou, Cambridge, 4to, 56 pp., 1892. 


128 The American Geologist. August, 1892 

A Review of Artesian Horizons, in southern New Jersey. Lewis 
Woolman. From the An. Rep., State Geologist, 1891. 

A Study in Geology. E. ©. Quereau,[a general description of the 
Alps.| From the report for 1891 of the Dept. of Nat. Hist. Northwestern 
University, Evanston. 

On a New Variety of Gaylussite from San Bernardino County. Henry 
G. Hanks. From Mining and Scientific Press, Mar. 26, 1892. 

Note on Leptoplastus. G. F. Matthew. Can. Rec. of Sci., Dec., 1891. 

List of Fossils Found in the Cambrian Rocks in, or near, St. John, N. 
B. G.F. Matthew. Bul. Nat. Hist. Soc. No. x. 

Rules of Nomenclature Adopted by the International Zodlogical Con- 
gress, Paris, 1889. Translated by Moritz Fischer. Am. Nat., May, 1892. 

The Paleontology of the Cretaceous Formation on Staten Island. 
Arthur Hollick. Trans. N. Y. Acad. Sci., Vol. tx, No. 5, 1892. 

Albirupean Studies. P. R. Uhler, Maryland Acad. Sci., 1892, pp. 189- 
200. 

On the Ore Deposits of Newman Hill, near Rico, Colorado. John B. 
Farish. Proc. Col. Sci. Soc., Apr. 4, 1892. 

The Terminal Moraine of the Continental Ice-sheet, and the Ice-age. 
Frank W. Very, Acad. Sci. Art, Pittsburgh, Oct., 1891. 

Suggestions for the Preparation of Manuscript and Illustrations for 
Publication by the U. 8. Geological Survey. W. A. Croffut. 

Elolite syenite near Beemerville, Sussex county, N. J. J. F. Kemp. 
Trans. N. Y. Acad. Sci., Vol. rx, p. 60, 1892. 

lllustrations of the Fauna of the St John Group, No. vi. G. F. Mat- 
thew. Trans. Roy. Soc. Canada. 4to, 32 pp., 2 plates, 1891. 

Three Deep Wells in Manitoba, J. B. Tyrrell. Trans. Roy. Soc. Can- 
ada, 4to, 14 pp., 1891. 

V. Foreign Publications. 

Mineralogy, F. H. Hatch, small 12mo., 123 pp. London, Whittaker 
& Co. 

A typical section, taken in detail, of the “Main coal” of the Moira, or 
western division of the Leicestershire and South Derbyshire coalfield, 
W.S. Gresley, Trans. Man. Geol. Soc., Part xvu, Vol. xxt. 

On the Glacial period, and the earth movement hypothesis, James 
Geikie. Read before the Victoria Institute, London; Supposed causes 
of the Glacial Period, (Edin. Geol. Soc. 18 Nov., 1891,) James Geikie. 

Trans. Edin, Geol. Soc. Sess. 1890-1891, contains: Landscape Geology; 
aplea for the study of geology by landscape painters, Hugh Miller; The 
southwest Mayo and northwest Galway silurian basin, with notes on the 
old or metamorphosed rocks of West Galway, G. H. Kinahan; Obituary 
notice of James Croll, J. Horne; An outlier or minor basin of Old Red 
sandstone, in Mid-Ross-shire, Wm. Morrison; The occurrence of plant 
remains in olivine basalt in the Bo’ness coalfield, Henry M. Cadell; On 
the more notable Scottish earthquakes which have occurred during the 
present century, Ralph Richardson; Homacanthus borealis Trag, a new 
selachian from the Lower Old Red of Caithness, W. T. Kinnear; Sup- 
posed causes of the glacial period, James Geikie. 


Recent Publications. 129 


Records of the Geological Survey of New South Wales, Vol. u, part 
4, 1892, contains: Onthe general geology of the south coast, with pet- 
rological notes on the intrusive granites and their associated rocks 
around moruya, Mount Dromedary and Cobargo, Wm. Anderson; De- 
scriptions of four Madreporaria rugosa species of the genera Phillipsas- 
trea, Heleophyllum, and Cyathophyllum, R. Etheridge; The cave shel- 
ters near Wollombi, in the Hunter river district, P. T. Hammond. 

Notice biographique sur Gustave Maillard, E. Renevier [Tiré du Bull. 
Soc. Vand. Se. Nat. xxvii, No. 106]. 

Bul. de la Soc. des Naturalistes de l’ouest de la France, Fome I, No. 4 
contains: Description des gneiss 4 pyroxene de Bretagne, et des cipolins 
quileur sont associés, A. La Croix; Terrain metamorphique et chim- 
ique de la ville-au-Vay, pres le Pellerin, avec liste de roches et des min- 
eraux que l’on y vencontre, Ch. Baret. 

Annales de la Soc. Geol. de Belgique, Tome xvitt, lve Liv., contains: 
Note sur les rapports des etages Tournaisien et Viseen de M. Dupont, 
avec son etage Waulsortien, C. de Vallee Poussin; Quelques particular- 
ites remarquables de la planchette de Herve, H. Forir; Etudes sur l’ 
Assise de Rouillon X. Stainier; L3 Poudingue de Naninne a Strud eta 
Dave, X. Stainier; Les Failles des Samson, X. Stainier; Le Terrain honil- 
ler 4 Salzinne-les-Moulins, X Stainier; Le Gres blanc de Maezeroul, X. 
Stainier; Sur les notations compliquées des cristaux de calcite, G. 
Cesaro; Surun terme nouveau du Quarternaire inférieur observé en 
Belgique, E. Delvaux; Etudes stratigraphique et paleontologique du 
Sous-sol de la Campine, E. Delvaux; Sur la significance des conglomer- 
ats 4 Noyaux Schisteux des Psammites du Condroz, Max Lohest; Les 
terrains Tertiaires superieurs du basin de la Mediterranée, Chas. de 
Stafani. 

Tome xrx, Liv. 1, contains: Sur un facies remarquable de |’ Assise de 
Herve, H. Forir; Etude sur les limons herbayens et les temps Qua- 
ternaires en Belgique, Alp. Briart; Description stratigraphique et pal- 
eontologique d’ une Assise de sables, inferieurs 4 |’ argile ypresienne, 
representant in Belgique les Old Havens beds du bassin de Londres, E. 
Delvaux. 

Eclogee geologic Helvetiz, Avril, 1892, contains: Note sur les corni- 
eules du Pays-d’ Enhaut, T. Rittener; Notice sur un affleurement d’ 
Aquitanien dans le Jura Vaudois, T. Rittener; Pleistocene du Nord de 
la Swisse et des parties limitrophes du Grand-Duche de Bade, G. Stein- 
man et L. du Pasquier; Etude stratigraphique sur les terrains Tertiaires 
du Jura Bernoes, L. Rollier. 

Foldlani Kozlony, March-April, 1892, contains: Dr. Carl Hofmann 
(with portrait), L. Roth v. Telegd; Ueber den grossen Freigoldfund aus 
der Umgebung von Brad, Aug. Franzenan. 

Bull. Soc. imp. Naturalistes de Moscou, No. 2 and 38, 1892, contains: 
Argiles de Speeton et leurs equivalents, A. Pavlow and G. W. Lamp- 
lugh; Qu’ est ce que c’ est que l’Hipparion, Marie Pavlow. 

Mittheilungen iiber das Glacialgebiet Nordamerikas; Die endmoriinen, 
Felix Wahnschaffe, |ab. Zeitschr. deut. geol. Gesell, 1892]. 


130 The American Geologist. August, 1892 


Ursachen der Deformationen und der Gebirgsbildung. Ed. Reyer, 
Leipzig, 1892. ; 

Ueber den gegenwiirtigen Standpunkt unserer Kentniss von dem 
vorkommen Fossiler Glacialpflanzen, A. G. Nathorst. [Bihang Svens. 
vet akadhandl. Bd 17, A’d 111 No. 5]. 

Die Nordamerikanischen Wiisten, J. Walther, [Verhand. Gesell. f. 
Erdkunde zu Berlin, xrx, 1892, No. 1]. 


VI. Laboratories and Museums. 


Bul. Lab. of Nat. Hist. State Univ. of lowa, Vol. 11, No: 2, contains: 
Report on some fossils collected in the Northwest Territory, Canada, by 
Naturalists from the University of lowa,S. Calvin; Two unique spirifers 
from the Devonian strata of Iowa, S. Calvin; A geological reconnoiss- 
ance in Buchanan County, lowa, S. Calvin; Notes on a collection of 
fossils from the Lower Magnesian limestone from northeastern Iowa, 8. 


Calvin. 


CORRESPONDENCE. 


’ Two or three years since, I concluded to find out, if I could, the char- 
acter of the termination of the column of the crinoid Heterocrinus sub- 
crassus, having a Lower Silurian slab showing about one hundred speci- 
mens of the calyx, and columns in a great profusion. 

I selected a column attached to its calyx, and followed it by uncover- 
ing, until I was rewarded by discovering the column diverging into well 
defined roots:—length of column from caly x 124 inches. 

At that time I believed that the genus Glyptocrinus were floaters, and 
devoid of bases or roots. 

About eighteen months ago, something caused me to doubt that idea, 
and I commenced the investigation of the t-rmination of their columns, 
aod now, after a great deal of work, and after many discouragements, 
I have been able to so far develop roots on the terminations of the col- 
umns of Glyptocrinus neali, Glypt. dyeri, and Glypt. baeri. I have a 
specimen of each species, showing the calyx, column, and roots intact, 
and one slab of Glypt. baeri having on its surface several specimens of 
that character. 

One character of the specimens surprised me:—the diversity in the 
length of the columns between calyx and roots in the specimens just 
mentioned. In Glypt. neali the length varies from two to four or five 
inches, Glypt. baeri from one-half inch to six or eight, and in Glypt. 
dyeri from one to four or five inches. 

I have also found a specimen of Heterocrinus simplex, showing calyx, 
column, and inverted saucer-like base, attached to another column. 

For further information in regard to above, address, 

Dr. D. TD. Dycuu: 


Lebanon, Ohio, July 22, 1892. 


_ Correspondence. 131 


GLACIAL Stria# IN Kansas. I have just measured (July 8, 1892) the 
‘direction of undoubted glacial strive in northern Kansas. The striated 
rock is a limestone covered with a stiff boulder-clay. The boulders are 
largely red quartzite, syenite, diorite, slate, and porphyry, the first pre- 
dominating. 

A fair moraine crosses the southern part of Nemaha county, where 
the drift is over 100 feet thick. Some of the deeper wells pass through 
a forest bed at the depth of 80 feet. Sticks and carbonaceous earth are 
brought up from about that depth in several localities. 

The striz run to the south, southwestward. More exactly they run in: 
Quarry No 1, Tn. 3, S., Sec. 17, R. 12, E., S. 24°, 36’ W. Quarry No. 2, 
30 rods south of No.1, S. 21°, 08’ W., both corrected for magnetic 
declination. 

I think that I am right in saying that these are the only strie that 
were formed during the first glacial epoch that have thus far been dis- 
covered in this state. Large slabs of the striated limestone have been 
taken from quarries in Nemaha county, and very many of the drift 
boulders are likewise beautifully grooved. L. C. WoosTER. 

Hureka, Kansas, July &, 1892. 


In THE TEXAS PANHANDLE. I have hada ride on a gray stallion of 
250 miles (from Big Spring, on the Texas Pacific railroad, almost due 
south of here) and am much the better for it in health. We have had all 
kinds of weather except rain, and this is a dry season even for this dry 
country. The weather has been alternately cold and hot, often present- 
ing a difference between day and night of thirty to forty degrees. Wind 
is almost constant, sometimes amounting to a gale or more, and the 
tendency is of course to keep us cool—sometimes too cool—when the 
wind has been from the north. On the other hand atemperature of 90° - 
100° Fah. does not feel hotter here than 75°-80° in Philadelphia. 
Our greatest difficulty has been bad water; in the last 60 miles before 
reaching here we had only one decent spring, and we had to dig to get 
that free from the pollution of cattle. The other waters were either 
rain-holes or strongly alkaline. 

Our party is in charge of W. F. Cummins of the state survey. Scien- 
tifically we have had a successful trip. Our line has been. along the 
eastern escarpment of the staked plains, with an occasional excursion on 
the plains and across its spurs. We have accessible Permian, Trias, 
Loup Fork, and Blanco beds. Lower down the country we had Creta- 
ceous-marine; all the beds here are lacustrine or estuary. The Blanco 
beds are above the Loup Fork, and contain a new vertebrate fauna, 
mostly mammals. We have so far fourteen species, of which ten are 
new to science, two of of them mastodons. The Loup Fork beds we 
have just discovered here, and the fossils are very numerous. We found 
a grave-yard of horses (three species), camels (two species) and masto- 
dons (one or two species). The ground was covered for acres with their 
bones, and in the bank we got out in a few hours six. nearly perfect 


ike The American Geologist. August, 1892 


skulls—all horses. So far no Carnixora, but we shall get them. The 

absence of rhinoceros is so far peculiar, but we shall get them I suppose. 

We got none inthe Blanco beds. This formation forms the entire sur- 

face of the Llano estacado awd is underlain by Trias and Permian. We 

found only the Loup Fork here, and how far it passes under the plains 

we have yet to know. Epw. D. Core. 
Clarendon, Texas, June 13, 1892. 


Dr. WAHNSCHAFFE’S WORK ON THE DrRiFTt Deposits OF GERMANY.— 
I was much interested in reading professor Salisbury’s review of the 
“Drifts of the North German Lowland,” in the May number of the 
AMERICAN GEOLOGIST. It was gratifying to find one German geologist, 
at least, who seemed to favor the aqueous origin of kettle-holes. 

In 1835 the writer published a small pamphlet on the drift formations 
of Long Island, in which the theory was advanced that the depressions 
connected with the terminal moraine were the result of sub-glacial 
streams. About this time, the late H. Carville Lewis had published a 
paper on “Marginal Kames,” and in it, he maintained that kettle-holes 
were not the result of natural erosion, and that they were in no way allied 
to ordinary valleys. I was confident, however, that future investigation 
would prove that he was in error, although I knew him to be a very close 
observer. It seems that their origin is still a disputed question. 

Professor Wright, in his recent work, the “Ice Age in North America,” 
adopts the view that their formation was due to dirt bands formed on the 
ice, although on page 54 he gives a picture of the Muir glacier where 
kettle-holes are in process of formation seemingly by the action of sub- 
glacial streams. 

I called his attention to this fact, and he admitted that in some cases 
kettle-holes owed their origin to sub-glacial streams. 

It seems from the review of Dr. Wahnschaffe’s work referred to, that 
Only one geologist—E. Geinitz—attributes them chiefly to the eddying 
action of waters during the melting of the ice. Dr. Wahnschaffe and 
others do not seem to favor this view, but insist that the waters arising 
from the melting of the last ice-sheet had no considerable influence in 
their formation. He argues that the depressions were already in exist- 
ence at the time of the deposition of the uppermost layer of till, which is 
doubtless true, but this need not weigh against their sub-glacial stream 
origin; as the channels may have been dried up, to some extent at least, 
before the final retreat of the glacier. The depressions in question are 
no chance formations but belong to a beautiful and wonderful system of 
glacial drainage. They are in reality sub-glacial valleys—the meeting 
place of the waters under the ice-sheet. Professor H. Carville Lewis 
argued that the rim of the basins was too perfect to admit of this, but 
when closely examined it will be found that the rim is generally 
more or less indented. The basin, of course, corresponds to the size of 
the streams that came together under the glacier. The small streams 
make the most perfect kettle-hole, while the larger rivers form the large 
ponds, swamps and peat-beds. I have studied this phenomenon for 


Correspondence. 133 


years along the whole extent of the terminal moraine on Long Island, 
and the longer J study the more I am convinced that these depressions 
are in some way related to sub-glacial or super-glacial drainage. 

The “ground moraine landscape” (= our terminal moraine) and the 
hills and ridges of sand and gravel, the German Durchragungszuge und 
kame, owe their modification to these glacial rivers, and I believe with 
professor Salisbury that they are closely associated in time of origin. 

I cannot think that pressure has had much to do with the formation of 
these moraine ridges on Long Island, as the material does not appear to 
be bulged up as intimated by Dr. Wahnschaffe, although there are a few 
writers who think they see evidence of pressure, and attribute the form- 
ation of some of the kame moraines, on the north side of the island, to 
lateral thrust. I cannot think so. 

It seems as if the debrzs had been carried along with, and in the ice- 
sheet, and as it fell from the grasp of the glacier much of it was assorted 
over by sub-glacial currents, and washed out from its terminal front, 
forming what is known asthe south side of Long Island (“overwash 
plains, whose surfaces show little relief”), yet the streams that issued 
from the front of the ice-sheet can be traced from the terminal moraine 
to the sea, and in places there are some conspicuous ridges which seem 
to run under the ocean, for Prof. Agassiz writing to Elie De Beaumont says, 
“the submarine dykes along our coast would be osars if they were ele- 
vated.” These professor Wright calls kame deltas while the hummocky 
ridges connected with our terminal moraine the late H. Carville Lewis 
would designate “marginal kames.” These marginal kames are always 
more prominent where the flood of waters was greatest, and are pushed 
further to the south, as may be seen near Fort Hamilton. Where the 
streams were not so powerful, the “ground moraine landscape,” our ter- 
minal moraine, ends more abruptly and the kettle-holes are more com- 
plete. Where the waters broke through, as at Hempstead, the terminal 
moraine disappears, and the plain becomes more extensive, and Far 
Rockaway point is the result. 

here is a slight difference of nomenclature among the glacialists of 
Europe and America, but the phenomena seem very much the same. I 
have never observed on Long Island anything that seems to answer to the 
Endmoriine of the Germans, nor such dykes as G. H. Kinahan describes 
as occurring in the counties of Wexford and Carlow, Ireland. and yet, in 
my last letter to the GroLoaist on Englacial Drifts, I spoke of a section 
in the Rockaway Railroad cut that would seem to combine the three sets 
of phenomena mentioned in the review of Dr. Wahnschaffe’s work, the 
Grundmoranenlandschaft, the Endmorane and Durehragungszuge und 
Kame. Usaid: “Inthe center of the bottom part of the drift is a mass 
of boulders in a sandy matrix, and over this is the hardpan, which is also 
full of erratics. Then comes the modified drift, and over all the engla- 
cial till which was probably laid down after the floods had subsided.” 

Thus we see that the same conclusions are being reached by independ- 
ent investigation. Joun Bryson. 

Eastport, L. L., July 6, 1892. 


134 The American Geologist. August, 1892 


PERSONAL AND SCIENTIFIC NEWS. 


THE GEOLOGICAL SociETY OF AMERICA meets in Rochester, N. 
Y., August 15 and 16, in conjunction with the American Asso- 
ciation for the Advancement of Science. <A joint letter from the 
Royal Society of Canada, and from the ‘‘Logan Club” at Ottawa, 
has been addressed to the president and secretary of the Geologi- 
eal Society of America, inviting them to meet next December, in 
Ottawa, the Canadian capital. Ottawa is the leading scientific 
centre in Canada now, and the fact that the Geological Survey 
staff and museum are there will be sufficient earnest of the likeli- 
hood of an enjoyable as well as of a profitable meeting. Several 
fellows have already expressed their willingness and desire to 
attend, and are in favor of Ottawa. The matter will come up for 
consideration before the Council of the Society at Rochester. 

PRESIDENT CHAMBERLIN, of the Wisconsin State University, 
has accepted the professorship of geology in Chicago University. 

Dr. CuaruEs K. BEECHER HAS BEEN APPOINTED assistant pro- 
fessor of paleontology at Yale University, New Haven. 

Mr. L. V. Prrsson, who has been studying the past two years 
in Heidelberg and Paris, will teach petrography at Yale Univer- 
sity during the coming year. 

Tur AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF 
Scrence, under the presidency of Prof. Jos. Le Conte, will meet 
at Rochester, N. Y., August 16. Provision has been made by 
the local committees for entertainment and numerous excursions. 

M. Aup. BRIART IN A RECENT REVIEW Of the ‘‘ Limons hesbay- 
ens” in Belgium, arrives at the conclusion that they are separable 
into two parts (at least) and that between them occurred an in- 
terglacial epoch of great length. This interglacial epoch he pro- 
nounces the ‘‘ veritable épogue quaternaire,” the ice incursions 
themselves being only episodes. 

The Geological Commission named by the law creating a Geo- 
logical Survey for lowa met on the 8th of July for the purpose 
of appointing a State Geologist. After considering the claims 
and recommendations of the various applicants they unanimously 
elected Prof. S. Calvin of the State University, notwithstanding 
the fact that he was not an applicant and had been doing all in 
his power to secure the election of another. 


AMERICAN GEOLOGIST 


Vou. X. SEPTEMBER, 1892. No. 3 


DESCRIPTION OF TWO NEW GENERA AND EIGHT 
SPECIES OF CAMERATE CRINOIDS FROM 
THE NIAGARA GROUP.* 
By CHARLES WACHSMUTH and FRANK SPRINGER, Burlington, Iowa. 
Iprocrinus W. and Sp. (noy. gen.) 
(IAIOy peculiar, KPINON a lily.) 
Infrabasals apparently 5, extremely small; placed at the bot- 
tom of a more or less deep concavity, and completely hidden by 
the column. Basals 5, very large; the posterior one truncated 
by the interbrachio-anal plate. Radials very large; four of 
them heptagonal; the two adjoining the anal side hexagonal. 
Costals 2, almost linear and considerably narrower than the radi- 


q 


als; the first quadrangular, and three or four times as wide as 
high; the second pentangular, the sides of its upper angle almost 
straight. Distichals 2 in the calyx; short. Interradial area on 
all sides composed of a single, large plate, which rises to the 
top of the dorsal cup. That of the anal side resting upon the 
basals, the four others upon the sloping upper faces of the 
radials. Ventral disk quite variable in form; covered by a large, 
undivided oral pyramid. The ambulacra tegminal, and in the 
typical species lined by small side-plates. Interambulacrals rep 


*The species will be finely illustrated in our forthcoming Monograph 
on the Crinoidea Camerata of North America. 


136 The American Geologist. September, 1892 


resented hy only one large, subtrigonal piece. Anus excentric. 
Structure of arms and column not known. 

Type: Idiocrinus elongatus. 

Distribution: So far as known, restricted to the Niagara group 
of America, 

Remarks. Differing from all other dicyclic Camerata in hay- 
ing a single plate in the anal area, in its central, undivided oral 
pyramid, and in having but one interambulacral plate to each side 
of the disk. 

IpIOCRINUS ELONGATUS W. and Sp. (nov. spec.) 

A small species. Calyx obconical; the ventral disk on a level 
with, or below, the upper margins of the dorsal cup; the cup 
deeply excavated at the bottom, the basals forming a large fun- 
nel-shaped pit. Plates without ornamentation and flat, except 
the radials, which are a little convex, and rise slightly above the 
plane of the cup. Suture lines not grooved. 

Infrabasals minute, constituting the bottom of the basal con- 
cavity. Basals extremely large and elongate, the lower end curv- 
ing abruptly inward, and forming a sharp edge around the bot- 
tom of the calyx; the exposed part of the plates rising to more 
than one-third the length of the dorsal cup. Radials once and a 
half as wide as high, distinctly angular at their lower faces; the 
two posterior plates hexagonal, being truncated by the interbra- 
chio-anal plate. Costals together less than half the size of the 
radials; the first linear; the second a very little higher, and its 
upper angles quite obtuse. JDistichals 2, somewhat higher and 
wider than the costals; the upper semi-free. Interbrachials 
one, those of the four regular sides resting upon the deeply slop- 
ing sides of the radials, the anal one upon the narrowly trun- 
cated basal; all extending to the upper end of the calyx, and all 
much higher than wide. 

The oral pyramid is somewhat weathered in the type, and the 
median part is imperfect, the apparent opening in the center being 
a mere break. The specimen, however, is interesting as showing 
indistinct traces of inter-oral sutures, which are obsolete in other 
specimens of this genus. The pyramid occupies nearly one-third 
the width of the disk, and its upper end, when perfect, formed a 
level with the distal faces of the second distichals. Interam- 
bulacral plates one, forming a triangular area lined by small side- 
pieces, which stand erect and form upon the surface well-defined 


Camerate Crinoids.— Wachsmuth and Springer. 187 


open grooves, of which the covering-pieces were not preserved. 
These grooves, as they pass out from the orals, bend at first 
slightly downward, but after bifurcating proceed upwards to the 
arms. Nothing is known of the structure of arms and column. 

Horizon and Locality: Upper part of Niagara group; St. Paul, 
Shelby Co., Ind. 

Type in the collection of Wachsmuth and Springer. 

IpiocRINUS VENTRICOsUS W. and Sp. (nov. spec. ) 

A very small species. Calyx nearly as wide as high; hight 
of dorsal cup about equal to that of the tegmen; the former 
bowl-shaped, the cup obtusely pyramidal. Plates smooth; the 
radials and costals somewhat longitudinally convex, causing a 
depression of the interbrachial spaces. Suture lines slightly 
grooved. 

Infrabasals extremely small and covered completely by the 
column; placed at the bottom of a narrow circular cavity, formed 
by the lower ends of the basals. Basals of moderate size, their 
lower ends incurving and forming the sides of the concavity, 
their upper angles slightly bending upwards. Radials once and 
a half as large as the two costals together, and twice as wide as. 
high; three of them heptagonal, the two posterior ones hexa- 
gonal. First costals quadrangular, much narrower thaa the radi- 
als, and three times as wide as high; the second of nearly the 
same width as the first but longer. Distichals narrower and 
shorter than the second costals. Interbrachials large, subellip- 
tical; that of the anal side a little wider, and truncating slightly 
the posterior basal. Oral pyramid convex, a very little tumid, 
extremely large for the size of the species, perfectly closed at the 
summit, and the interoral sutures obsolete. The outer face of 
the pyramid is covered with well defined radiating ridges, which 
proceed from the middle of the plate to the outer margins, in- 
creasing in hight and width as they pass outward. Ten of these: 
ridges are more prominent, and project outward around the cir- 
cumference, so as to give to the plate the aspect of a ten-rayed 
star. The inner floor is excavated centrally, and there are five 
deep grooves passing out in a radial direction. The interam- 
bulacral plates long, slender and cuneate, attached with their 
narrower upper ends to the inner margin of the orals. They 
project outward so as to form at their sides open spaces for the: 
reception of the ambulacra. Other parts unknown. 


138 The American Geologist. September, 1892 


Horizon and Locality: Upper part of Niagara group; near St 
Paul, Ind. 

Type in the collection of Wachsmuth and Springer. 

Remarks. The oral pyramid of this species, which is found 
occasionally detached from the body, was regarded by Miller, 
Benedict and ourselves to represent probably the ventral strue- 
ture of some Pisocrinus. This appeared the more plausible as it 
was expected from analogy that in P/socrinus, as in the allied 
Symbathocrinus and Haplocr/nus, the ventral disk consisted of 
orals only, and the plate fitted approximately upon the cup of one 
of the species, which occurs in the same bed. 

Hypriocrtnus W. and Sp. (nov. gen.) 
‘yHTIOS bending back, KPINON a lily.) 

Name applying to the character of the arms which hang down- 
ward. Calyx depressed, wheel-shaped. Infrabasals 5, small. 
Basals 5, four of them equal, angular at the upper end; the pos- 
terior one truncated by the anal plate. Radials comparatively 
small, all hexagonal. Costals 2. Fixed brachials rather large, 
except the first costals, which are quite short and quadrangular. 
First distichals one, the distal face broadly truncated; followed 
by several sharply cuneate pieces, which interlock, and of which 
the two or three proximal ones (in the type) take part in the 
calyx. Arms stout, probably biserial, and pendent, to judge from 
the arm openings, which are directed obliquely downward. First 
interbrachials of the regular sides very large; succeeded by sev- 
eral rows of smaller pieces. Anal plate touching the basals, and 
higher than the radials; supporting three much smaller plates in 
the next row, and others above. Ventral disk depressed; the 
posterior oral and the radial dome plates spinous; the anus ex- 
centric, and at the top of a large protuberance. 

Distribution: So far as known, restricted to the Niagara group 
of Indiana. 

Remarks. The genus has its closest relations with Thysanoc- 
vinus, from which it differs in the flatness of the calyx, in the 
pendent arms, and in the spine-bearing disk. 

Hypriocrinus typus W. and Sp. (nov. spec.) 

Specimens of medium size. Calyx wheel-shaped, nearly once 
and a half as wide as high. Dorsal cup broadly obconical to the 
top of the costals, then flanging outward and somewhat down- 
ward, Arm regions not lobed, but the upper margins of the in- 


Camerate Crinoids.— Wachsmuth and Springer. 189 


terradial..and interdistichal spaces formed into sharp edges by 
means of corresponding depressions in the dorsal cup and teg- 
men. Costals and distichals marked by rounded, longitudinal 
ridges, following the median line of the plates. Ventral disk a 
little higher than the dorsal cup, its lateral margins slightly bulg- 
ing, the lower end somewhat projecting over the upper margin of 
the dorsal cup. The plates flat, their surfaces in well preserved 
specimens densely covered by fine granules. 

Infrabasals small, hidden by the column; forming a flat, pen- 
tagonal disk. Basals rather large, about as wide as high, curv- 
ing abruptly upwards; the posterior one slightly truncated at the 
upper end; the interbasal suture lines distinctly grooved: Ra- 
dials twice as wide as high, their proximal ends distinctly an- 
gular. First costals much shorter and narrower than the radials, 
quadrangular. Second costals higher and a little wider than the 
first; their lateral faces short; the sloping upper faces placed at 
right angles. First distichals as large as the axillary costals, 
followed by two or three cuneate plates in the calyx, which 
slightly interlock. Structure of the arms not observed, but they 
were undoubtedly biserial and pendent. First. interbrachials of 
the regular sides the largest plates of the calyx; they reach up 
to the sides of the first distichals and are succeeded by two rows 
of two plates each. The anal plate a little higher than the radials, 
supporting three, two and two smaller plates. Interdistichals 
one, small. Posterior oral nearly central, large and extended 
into a heavy, short spine; the four other orals proportionally 
small and almost flat. Radial dome plates represented by plates 
of a first and second order, those of the latter by two or three 
plates to each division, alternately arranged; all large and spine- 
bearing. The spines near the outer margins of the disk directed 
obliquely outward, and visible in a dorsal aspect of the calyx. 
Interambulacral plates numerous, of the size of the smaller 
orals, and irregularly arranged. Anus excentric, placed at the 
top of a large ovate protuberance, which rises conspicuously 
above the general plane of the disk. 

Horizon and Locality: Niagara group; St. Paul, Shelby Co., 
Indiana. 

Type in the collection of Wachsmuth and Springer. 

EUCALYPTOCRINUS LINDAHLI W. and Sp. (nov. spec.) 

Above medium size. Most remarkable for its heavy, rounded 


140 The American Geologist. September, 1892 


arms, which to their full length are elevated prominently above 
the outer faces of the partition walls, so the latter are forming 
the bottom of a deep groove. Dorsal cup semi-globose, its lower 
concavity not larger than the width of the stem, and enclosing 
only the basals, which are hidden from view by the narrow, round 
stem. Plates not distinctly ornamented, merely showing a 
roughened surface. Suture lines slightly grooved. 

Radials rather large, as high as wide, rapidly sloping to the 
lower end; their lateral faces three times-as long as the slanting 
upper; the superior face concave. First costals quadrangular, 
smaller than the radials, a little wider than high. Second costals 
hexangular, wider and higher than the first; their sloping upper 
faces longer than any of the others; the upper angle slightly 
truncated by the interdistichal. First distichal smaller than the 
axillary costal, the second less than half the size of the first and 
subquadrangular. Palmars three in the calyx, transversely 
arranged, rounded on the back. First interbrachials ten-sided, 
as large as the radials, longer than wide, widest at the middle; 
the two of the second row nearly three times as long as wide, 
rising to the hight of the third palmars. The interdistichal a 
little shorter and narrower than the two upper interbrachials com- 
bined. The walls forming the compartments taper gradually 
to near the upper end, then widening rapidly and curving ab- 
ruptly inward, so as to form a flat surface at the summit ona 
level with the tips of the arms. Arms rather short, very heavy, 
almost cylindrical. They rise above the sides of the partitions 
much more conspicuously than is known to be the case in any 
other species, their tips being lifted out from between them al- 
most completely. 

Horizon and Locality: Niagara group, Wayne Co., Tenn. 

Type in the Illinois State Museum. The species is named in 
honor of Dr. Josua Lindahl, the eminent zoblogist and director 
of the state museum at Springfield. 

CALLICRINUS BEACHLERI W. and Sp. (nov. spec.) 

Closely resembling Hucalyptocrinus. The calyx has the form 
of a wine bottle, with long slender neck and a deep concavity 
at the bottom, but the partition walls, instead of forming closed 
compartments to the full length of the arms, rise only to a cer- 
tain hight, and are not closed from above. Hight of the calyx to 
the base of the tubular neck one-fourth greater than the width at the 


Camerate Crinoids.— Wachsmuth and Springer. 141 


topof the dorsal cup; the hight of the cup 11 millim., that of the ven- 
tral disk 16 millim., and the length of the partition walls 8 millim. 
Dorsal cup broadly truncated at the base; the sides almost straight, 
gradually expanding upwards. The radials and costals at their sur- 
faces sharply keel-shaped, especially the former, and the angu- 
larity continued upon the distichals, but not attaining the prom- 
inence as on the plates below; the first interbrachials slightly 
convex, with a small tubercle in the center. 

Basals small and nearly of the same size, forming a concavity, 
which is rather small and shallow for the genus. Radials near 
the upper end fully as wide as long, and twice as wide as at the 
lower part, which curves gently inward to meet the basals. First 
costals twice as wide as high; the second, which is higher and 
wider, rarely truncated by the interdistichals. First distichals 
twice as large as the second, and but little smaller than the ax- 
illary costals. The palmars small and pentangular. First inter- 
brachials longer than wide, a little smaller than the radials; the 
upper two together nearly twice as wide as the first, their 
upper ends rising to the hight of the second or third arm 
plates. Interdistichals but little smaller than the upper inter- 
brachials, and protruding upwards in a similar manner. Ven- 
tral disk conical, its sides convex. The ten plates which rest 
upon the interbrachials and interdistichals, respectively, and form 
the compartments for the reception of a pair of arms, are twice 
as high as the intervening ones, which rest against the sloping 
upper faces of the palmars. There are in all twenty partitions 
around the disk, and each arm occupies a separate compartment. 
The partition walls are moderately thick, and slightly grooved at 
their outer faces. The ten larger ones rise to a level with the 
upper end of the first ring of plates in the disk, of which they 
_ form wing-like extensions; they are sabre-shaped, and pointed at 
theirends. The second ring of the disk consists of four plates, 
which are much narrower at the top than at the bottom, and 
two of them are narrower than the others. The construction 
of the anal tube, its length, and the structure of the arms not 
known. 

Horizon and Locality: Niagara group, St. Paul, Ind. 

Type in the collection of Wachsmuth and Springer. 


142 The American Geologist. September, 1892 


Remarks. The unique specimen from which the above de- 
scription is made, was discovered by Mr. Charles Beachler, a very 
enthusiastic collector, in whose honor the species is named. 

MELOCRINUS ROEMERI W, and Sp. (nov. spec.) 

Syn. Cytocrinus levis Roemer; 1860, Silur. Fauna West. 
Tenns, "p: 46; (PI4, figs. 2'a.b, 

Syn. Ctenocrinus levis Shumard; 1866, Trans. Acad. Sci. 
St. Louis, p. 361. 

Syn. Melocrinus levis (not Goldf.) W. and Sp. (in part); 
1881, Revision, Pt. 1, p. 122. 

Calyx moderately small, turbinate, dorsal cup about as wide as 
high, gtadually spreading to the arm bases, which are formed 
into five very conspicuous lobes, giving to the calyx, as seen from 
above, a decidedly stellate outline. Plates without ornamen- 
tation, a little concave, except the median line of the radial 
plates, which is obtusely angular. The radial appendages, from 
which the arms are given off, composed of a single series of 
plates. 

Basals rather large, subequal, forming a shallow cup which is 
slightly truncate at the lower end. Radials twice as large as the 
first costals, hexagonal, about as wide as high; their upper slop- 
ing faces alittle larger than the corresponding lower ones. Second 
costals very small and curved like arm plates; their upper slop- 
ing faces unequal, that toward the outer side of the ray much 
longer and supporting a distichal, the inner one the first arm 
plate. The free rays, which consist of a single series of plates, 
give off the arms at intervals from alternate sides, not from 
opposite sides, as generally in this genus. Interbrachial spaces 
wide, the first plate large, succeeded by two rows of two and 
three plates respectively, which are followed by disk plates. The 
two outer plates of the upper row curve outward so as to form 
the sides of the lobes. At the anal side the first plate is larger; 
and followed by three plates in the second row, and four in the 
third. Ventral disk depressed, pentagonal; the ambulacral 
regions slightly raised above the general plane; the plates without 
ornamentation, almost flat, and the sutures difficult to see. The 
disk ambulacra are completely subtegminal; the orals apparently 
unrepresented, and the anus is placed at the-end of a large tube 
which bends to the posterior side. 


Camerate Crinoids.— Wachsmuth and Springer. 148 


Horizon and Locality: Niagara group; associated with Astrae- 
ospongia meniscus. Decatur Co., Tenn. 

Type in the collection of Wachsmuth and Springer. 

Remarks. Roemer described this species as Cytocrinus laevis, 
making it the type of a new genus. He supposed it had three 
basals, and he did not understand the arm structure, which is 
evidently that of Melocrinus. We refer the species to the latter © 
genus, but are compelled to change the specific name, as already 
Goldfuss in 1826 described a Melocrinus laevis from the Kifel, 
and replace it by Melocrinus Roemeri. Roemer originally in- 
cluded in this species two forms, the typical one from the Niagara 
group of Western Tennessee, and another from the same horizon 
of Louisville. The latter has been described by us as Melocrinus 
oblongus. The two species resemble each other in form, but J. 
oblongus is considerably larger, the calyx contains many more 
plates, and the tubular appendages giving off the arms are com- 
posed of two rows of brachials in place of one. 

MELOCRINUS OBLONGUS W. and Sp. (nov. spec.) 

A rather slender species of less than medium size. Dorsal cup 
obconical; the sides straight to the top of the second costals, 
whence the rays turn outward and form distinct lobes around the 
calyx, which give to the section a decidedly pentalobate outline. 
Plates convex, a little tumid, but without ornamentation. 

Basals small, subequal, notched at the sutures, the lower face 
but slightly truncate and very little excavated. Radials and first 
costals generally longer than wide, especially the former; the 
second costals often as wide as long. Distichals 2x10; the two 
upper axillary and separated by a smallinterdistichal. The tubu- 
lar appendages not preserved in the specimens, but,'as there are 
two distichals to each ray, they obviously were biserial. The 
first interbrachial as large as the first costal, succeeded by rows of 
two, three, three, and three plates, which meet the interambulac- 
rals. Anal interradius a little wider, with three plates in the 
second row, and four in the third. Ventral disk low, irregularly 
convex; the ambulacral spaces slightly elevated; the plates— 
almost of uniform size. Anus subcentral, at the 


orals included 
end of a tube. 

Horizon and Locality: Niagara group; near Louisville, Ky.. 
and St. Paul, Ind. 

Types in the collection of Wachsmuth and Springer. 


144 The American Geologist. September, 1892 


Remarks, This form was regarded by Roemer* as specifically 
identical with his Cytocrinus laevis, which comes from the same 
horizon in Tennessee, and resembles it in general form; but the 
appendages of that species are composed of single joints, and it 
has a smaller number of interbrachials. 

MELOCRINUS PARVUS W. and Sp. (nov. spec.) 

A small and very slender species of the type of Melocrinus 
Roemeri, having, like that species, five uniserial appendages giving 
off the arms. Dorsal cup ob-pyramidal, the interradial spaces 
deeply depressed, and the cross-section at the top of the costals 
distinctly pentalobate. The plates a little convex, and covered 
with obscure ridges. 

Basal cup almost cylindical, its upper end slightly wider, the 
lower face completely covered by the column; the plates as high 
as the radials, and the interbasal and basi-radial sutures dis- 
tinctly grooved. KRadials a little higher than wide. First costals 
of the same proportions as the radials. Second costals smaller, 
proportionally shorter, and irregularly axillary; one of their upper 
faces shorter and giving off an arm,the other forming the base of 
the free ray, which necessarily was uniserial. Interbrachials three 
at the regular sides, four at the anal side, the latter having three 
plates in the second row against two at the other sides. Ventral disk 
convex, the interambulacral spaces a little depressed; composed 
of moderately large, slightly convex plates. Anus excentric. 

Horizon and Locality: Niagara group, St. Paul, Ind. 

Type in the collection of Wachsmuth and Springer. 

Remarks. This species differs from M. roemeri in the nar- 
rower and less spreading base, in the proportions of the radials 
and costals, and in the convexity of the plates. 


NOTES ON A COLLECTION OF FOSSILS FROM THE 
LOWER MAGNESIAN LIMESTONE FROM 
NORTHEASTERN IOWA.+ 
By S. Carvin, Iowa City. 

Until recently we have been accustomed to regard the Lower 
Magnesian limestone of the Upper Mississippi valley as destitute 
of organic remains. Dr. White in his report on the Geology of 
Iowa, Vol. 1, pp. 173-174, says that ‘‘the only fossils that have 

*Silur. Fauna West. Tenn., 1860, p. 46. 

+From the Bulletin of the Laboratories of the State University of lowa. 


Fossils from Magnesian Limestone.— Calvin. 145 


been found in this formation in Iowa are, so far as known, a few 
traces of the stems of Crinoids found near McGregor.” Whit- 
ney in Hall’s Geology of Iowa, p. 337, speaking of indications of 
organic life in the Lower Magnesian limestone, says that ‘‘ip 
Iowa, indeed, we have observed nothing of the kind.” Owen 
seems to have been more fortunate than the other observers men- 
tioned, for in his report on the Geological Survey of Wisconsin, 
Iowa and Minnesota, p. 60, he enumerates a few genera that are 
represented in this formation, but does not cite localities. The 
Euomphalus and Ophileta which he mentions, may be from the 
horizon of the Lower Magnesian limestone of Iowa; the trilo- 
bites referred to are probably from the Upper Potsdam or St. 
Croix group as will be noted farther on. In the Geology of Wis- 
consin, Vol. tv, Whitfield describes a number of species from 
the Lower Magnesian limestone, but it is probable that the only 
species referable to the horizon of the formation in Iowa is his 
Euomphalus strongi which he says occurs in cherty beds in Rich- 
land county, Wisconsin. In the Geology of Minnesota, Final 
Report, Vol. 1, pp. 222-223, Prof. Winchell mentions the discov- 
ery of organic remains in limestone of the same age as our Lower 
Magnesian. The fossils occur only in cherty beds and embrace 
the genera Orthoceras, Ophileta and Pleurotomaria. 

In all discussions relating to the fauna of the Lower Magne- 
sian limestone of Wisconsin, lowa and Minnesota, it should be 
borne in mind that for many years geologists have confounded 
the St. Lawrence limestone, a member of the Potsdam or St. 
Croix series, with the Lower Magnesian. In the Geology of 
Minnesota, Final Report, Vol. 11, pp. 14 to 22, Prof. Winchell 
gives the results of the latest investigations on this subject and 
points out the true relations of the long misunderstood St. Law- 
rence limestone. It is possible that all the species of Diceloceph- 
alus, Conocephalites, Illenurus, and other forms associated 
with them, which have been credited to the Lower Magnesian 
limestone, have come from the St. Lawrence limestone and belong 
to a horizon below that of the Lower Magnesian. 

Within the past few years Mr. F. H. Luthe, an enthusiastic 
and intelligent amateur geologist, of McGregor, Iowa, has inves- 
tigated the fauna of the Lower Magnesian limestone of Clayton 
and Allamakee counties, and has brought to light an assemblage 
of forms of very great interest. Mr. Luthe has kindly placed 


146 The American Geologist. September, 1892 


his collection in my hands for examination. All the recognizable 
species belong either to the Gasteropoda or Cephalopoda. Indeed 
all the species belong to one or the other of the above groups ex- 
cept some amorphous, laminated, porous structures that recall 
certain forms of the Stromatoporoidea, 

The following species, all apparently confined to cherty layers 
of the formation, may be noted: 

Merorproma ALTA Whitfield. The collection contains speci- 
mens apparently identical with the species described and figured 
by Mr. R. P. Whitfield under the above name in his paper on 
Fossils from the Calciferous Sand-rock of Lake Champlain, Bul- 
letin of Am. Museum -of Natural History, Vol. 11, No. 2. The 
Iowa specimens referred to this spevies are larger than those from 
Lake Champlain. With the above occur two or three other species 
of Metoptoma. 

TRIBLIDIUM, sp. There are a few forms presenting the appear- 
ance of Capulus or Platyceras that probably belong to this genus. 

STRAPAROLLUS CLAYTONENSIS, n. sp. This is by far the most 
common species in the collection. It resembles Kwomphalus cal- 
ciferus Whitfield, Lake Champlain Fossils, p. 47, plate vin, figs. 
12 and 13. The volutions are four or more in number, circular 
in transverse section; umbilicus wide and deep; spire sometimes 
almost flat, usually slightly elevated. From F. calciferus W., 
this species will be distinguished by the fact that the volutions, in 
the cast, are not embracing, scarcely touching each other, and the 
volutions are not coiled in the same plane. ‘The two forms are 
about equally robust and the whorls expand at about the same 
rate. Straparollus claytonensis ditters from Huomphalus strongi 
Whitfield, in the greater number of less rapidly expanding volu- 
tions, the absence of caring or angles on the whorls and the pro- 
nounced difference between the umbilical and opposite sides. 

SPRAPAROLLUS PRISTINIFORMIS, n. sp. This is a smaller form 
than the preceding; volutions less robust, not embracing or 
slightly separated in the cast, coiled in the same plane so that 
the spire and umbilical sides are similar in appearance; whorls 
nearly circular in transverse section, upper surface of each marked 
by an obscure carina, with traces of another carina still more ob- 
scure half way between the middle of the whorl and the suture, 

RAPHISTOMA PEPINENSE Meek. The collection contains many 
specimens of this very beautiful species. The spire is depressed 


Fossils from Magnesian Limestone.— Calvin. 147 


and consists of about six volutions in specimens having a diam- 
eter of one inch. The periphery is sharply angulated and the 
umbilicus wide when compared with other species of the genus. 
Compare FR. trochiscum Meek, in U. $8. Exploration of the For- 
tieth Parallel, Vol. tv, p. 19. 

RAPHISTOMA MULTIVOLVATUM, n. sp. Shell moderately large, 
more than an inch and a quarter in diameter; spire depressed; 
whorls five or more in number, increasing gradually in size, each 
about one and a half times as large as the preceding; each whorl 
bears an obtuse angular carina near the suture; suture somewhat 
deeply impressed; upper surface of each whorl concave; outer 
margin marked by a sharp angle from which the convex lower 
surface of the last whorl slopes downward and inward to the 


angle that bounds the umbilicus. 
RAPHISTOMA PAUCIVOLVATUM, ne sp. This isa small lenticular 


species having from two to two and a half very rapidly expand- 
ing whorls. ; 

Hotopra turGipa Hall; There area number of specimens in- 
distinguishable from this species as it is described and figured by 
Hall, Billings and Whitfield. See Paleontology of N. Y., Vol. 
I, p. 12, plate m1, figs. 9 and 10; and Lake Champlain Fossils, 
by Whitfield, p. 50, plate rx, figs. 3-7. 

MuRCHISONIA, sp. ‘There are a few specimens referable to this 
genus. They are characterized by an elongate spire with many 
sharply angular volutions. 

ORTHOCERAS PRIMIGENIUM Vanuxem. This species is well repre- 
sented by two or three specimens, all showing the characteristics 
by which it may be readily distinguished. See works of Hall and 
Whitfield already cited. 

CYRTOCERAS LUTHEI, n. sp, Shell-rather small, elliptical in 
transverse section, only moderately curved; length of an aver- 
age specimen from two and a half to three inches, greatest diam- 
eter of body chamber three-fourths of an inch; septa very num- 
erous, ten chambers occupying the space of half an inch; septa 
oblique to the axis, rising highest on the convex side, the obliq- 
uity increasing as the septa approach the chamber of habitation; 
siphuncle large for the genus, situated close to the inner or con- 
cave margin, tapering more rapidly in proportion to size than the 
shell, and expanding toa trifling extent between the septa. Outer 
chamber long; margin of aperture and surface markings un- 


148 The American Geologist. September, 1892 


known. ‘This species will be readily recognized by its elliptical 
section, its oblique, closely crowded septa, and its large, internal, 
rapidly tapering siphuncle. 

The specific name is given in honor of Mr. F. H. Luthe, of 
McGregor, Lowa, to whose skill and enthusiasm science is in- 
debted for valuable additions to our knowledge of the fauna of the 
Lower Maznesian limestone in the valley of the Upper Mississippi. 

The collection contains fragments of other species that will 
sometime, we hope, be represented by identifiable specimens. 

In general aspect this fauna resembles that of the Calciferous 
sand-rock about lake Champlain. The identity of the species in 
some cases and the close resemblance in others, leaves little doubt 
as to the exact equivalency of the Lower Magnesian limestone 
of Iowa with the Calciferous series of northeastern New York. 

Geological Laboratory, University of Iowa, May 25, 1892. 


THE SCOPE OF PALEONTOLOGY AND ITS VALUE 
TO GEOLOGISTS. 


Address before Section E., A. A. A. S., Aug. 17, 1892, by H. S.WiLiraMs, 
New Haven, Conn. 


The scientific study of fossils is scarcely a century old. It 
was in 1796 that Cuvier for the first time ventured to say that 
certain fossil bones found in the Paris basin represented an ex- 
tinct species of elephant. 

About the year 1819, William Smith became famous by proy- 
ing that rock strata could be traced across the country by their 
fossils, that at each outcrop across miles of interval a stratum 
could be recognized by the identity of the fossil shells it contained, 

Previous to this, fossils had been regarded as curiosities. 
Cuvier and Smith made it clear that fossils tell us of organisms 
of whose existence or nature we should otherwise be ignorant, and 
that the kinds of organism are, somehow, related to the different 
strata of rocks. 

Deshayes who was a friend of Lamarck, and Lyell, and a little 
later, William Lonsdale were among the first to demonstrate the 
wide scope of paleontology and its inestimable importance in the 
interpretation of the problems of geology. 

Lyell tells us in his ‘‘Antiquity of Man,” (p. 3), of the method 
he employed in determining the subdivisions of the Tertiary: 
‘(When engaged in 1828” (he writes) ‘‘in preparing for the press 
the treatise on geology, above alluded to [the third volume of 


The Scope of Paleontology. — Williams. 149 


‘Principles of Geology’], I conceived the idea of classing the 
whole of this series of strata according to the different degrees 
of affinity which their fossil Testacea bore to the living forms. 
Having obtained information on this subject during my travels 
on the continent, I learned that M. Deshayes of Paris, already 
celebrated as a Conchologist, had been led independently, by — 
the study of a large collection of recent and fossil shells, to 
very similar views respecting the possibility of arranging the ter- 
tiary formations in chronological order, according to the propor- 
tional number of species of shells identical with living ones, which 
characterized each of the successive groups above mentioned.”’ 

The view of M. Deshayes may be given in the words of Robert 
Bakewell, as found in the 5th edition of his geology (p. 399, 
1838). He writes: 

‘‘M. Deshayes considers that the relative ages of different 
groups of strata or formations may be determined by their zoolog- 
ical characters alone; that is, by the species of shells they con- 
tain. He forms two grand divisions of stratified formations: 
1. Those which contain no species of shells analogous to exist- 
ing species [meaning identical species]. This division is stated 
to comprise all the secondary strata. 2. Strata which contain a 
greater or lesser number of species analogous to existing species. 
The last division comprises all the tertiary formations. Again 
he subdivided this division into three groups, according to the 
greater or lesser proportion of species of shells that they each 
contain analogous to living species.’’ (Bakewell’s Introduction 
to Geology, p. 399). 

The law here propounded is quite different from that announced 
by William Smith. ‘‘That each stratum contained organized 
fossils peculiar to itself, and might, in cases otherwise doubtful, 
be recognized and discriminated from others like it, but in a differ- 
ent part of the series, by examination of them.” (Phillips’ 
Memoirs of William Smith, p. 15.) 

Smith’s law considers only the significance of fossils as marks 
indicating the stratum to which they belong. Fossils studied 
and described on this basis, are at best but ‘‘Medals of Creation,” 
i. e., the classified signs by which geological formations may be 
recognized. This is the scope of the older paleontology. The 
higher or comparative paleontology as set forth by Deshayes, 
Lyell and Lonsdale considers the relationship which fossils bear 
to each other, to those which preceded them and to their succes- 


150 The American Geologist. ’ September, 1892 


sors. It deals with the history of organisms, and_ therefore is 
able to find in fossils themselves the evidence of the order of 
sequence of the rocks containing them. 

I quoted from Bakewell, because he considered Deshayes’ and 
Lyell’s methods as innovations. When, in 1833, he wrote the preface 
to the fourth edition of his geology, he expressed his contempt thus: 

“Great importance,” he says, ‘‘is attached to the study of fos- 
sil shells; but the character of the animals that inhabited them, 
of the power ‘they might possess of modifying the form of the 
shell under various circumstances, has scarcely been thought of. 
Some French conchologists are endeavoring to establish the doc- 
trine that fossil conchology, independent of the succession and 
stratification of rocks, is the only true basis of geology; anda 
trifling difference in the form of a shell, is deemed sufficient to 
constitute a new species, and to warrant the most important con- 
clusions respecting the age of the rock formations.’ 

This was sixty years ago, when the general belief was that 
species are immutable, and therefore that new creation was neces- 
sary to account for distinct species. The geologists recognized 
the importance of species as indication of the age to which the, 
containing rock belonged, and fossils were regarded as particularly 
valuable in classifying and identifying the stratified rocks, but the 
question was raised by Deshayes and Lyell—‘‘Is there not a natural 
sequence in the order of the successive species?” Lyell evidently 
did not for several years realize the full import of the question he 
propounded when he spoke of the relative affinity of the species. 

William Lonsdale, in 1839, made a_ still higher application of 
paleontology, in his determination of the fossils of South Devon- 
shire to be of intermediate age between the Carboniferous and 
Silurian systems, which led Sedgwick and Murchison in the same 
year to propose a Devonian system as of the same age as the Old 
Red system, though containing no fossils of the same species. 

The conditions were these: Murchison had recognized the “Car- 
boniferous limestones” and the following ‘‘Coal Measures” in 
northern England containing their characteristic fossils. In the 
Cheviot hills the ‘«‘Old Red sandstones’? were found below them, 
with their fish remains. 

In western England the ‘‘Silurian system” with its marine fos- 
sils was known to run upward into rocks with similar remains, 
considered to be the lower Old Red sandstone. 


The Scope of Paleontology.— Williams. A sad | 


And the order, (1) Silurian system, (2) Old Red system, (3) 
Carboniferous system, it was believed, expressed a continuous 
stratigraphical series. When certain fossils from the limestones 
of Newton, Bushel, and other localities in South Devonshire 
were given Lonsdale to describe, he determined them to be of the 
age of the Old Red sandstone, in the following way, (to use his 
own language): ‘‘It was therefore by combining together this evi- 
dence, the presence, in the same series of beds, of shells resem- 
bling or identical with Mountain limestone species, of Silurian 
corals, the Calceola Sandalina, and various distinct Testacea, that 
I was induced to suggest that the South Devon limestones are of 
an intermediate age between the Carboniferous and Silurian sys- 
tems, and consequently of the age of the Old Red sandstone:” 
(Notes on the age of the Limestones of South Devonshire by 
William Lonsdale, F. G. S. [read March 25, 1840] Trans. Geol. 
Soc. 2d Sec., Vol. v., p. 721.) 

Sedgwick and Murchison adopted Lonsdale’s conclusions without 
reserve, although they produced radical change in the classification 
they had already published, and on the strength of them they 
founded the Devonian System, and said: ‘This is undoubtedly 
the greatest change which has ever been attempted at one time in 
the classification of British rocks,” and further, <‘‘So far from . 
thinking ourselves rash and hasty in drawing the preceding con- 
clusions, we think we may rather be accused of being over-cau- 
tious and tardy in accepting evidence, however opposed to 
commonly received opinions. ”’ 

(Sedgwick and Murchison, ‘‘On the Physical Structure of 
Devonshire, etc., Pt. 11, on the Classification of the Older Strati- 
fied Rocks of Devonshire and Cornwall,” Trans. Geol. Soc., 2d 
Sec., Vol. v, p. 688.) 

This interpretation was not stratigraphical, nor was it a case of cor- 
relation by means of a common species of fossils,after the William 
Smith method of paleontology, but it was a case of determining 
the stratigraphical position of the Devonian fauna by a comparison 
of its species with those of other faunas from which it differed. It 
is a typical case of what I would call Comparative Paleontology, 

In both of the cases cited it will be noted that the fundamental 
fact underlying the determinations made, consists in the recog- 
nized natural order of sequence of species corresponding to the 
stratigraphic order of the rocks containing them. 


152 The American Geologist. September, 1892 


It is not probable that any of these early paleontologists under- 
stood the full meaning of this sequence, and we are hardly yet 
able to see how much the studies of the paleontologist have done 
to establish the derivative theory of evolution. But it is becom. 
ing every day more and more apparent that the reason for its great 
value to geology and for the grandness of the scope of paleontol- 
ogy is the fact that its subject matter is the records of the history 
of organisms. 

To the comparative paleontologist, fossils are hieroglyphics, 
which tell more fully than those of Egypt and Persia of the hab- 
its, customs, migrations and environments of the successive races 
from the beginning of the world. ‘Although the stratigraphic 
order is all important in reading them, when the clue to the story 
is found, the fossils are as much more important than the strati- 
graphy (to the correct interpretation of geology) as the meaning 
of a sentence is more important than the succession of the words 
on the page. 

But I speak here of the scope of the pure science. Before 
this audience I would call particular attention to the value of com- 
parative paleontology to the geologist, as a means of determining 
the structure and development of the earth. _ 

Lyell was the first to use paleontology as a means of classify. 
ing geological formations. In establishing the divisions of the 
Tertiary, 7. ¢., Eocene, Miocene and Pliocene, he made a numers 
ical comparison of the faunas themselves. This method has its 
imperfections, but the fundamental truth underlying its applica- 
tion is that there is a natural order of succession in the history of 
organisms whose remains are preserved in the strata. This order 
of succession is observable in respect of three different sets of 
characters : 

(1.) The parts or organs of which each individual organism is 
composed. 

(2.) The separate species existing at any particular time. 

(3.) The combination of species into faunas or floras which are 
associated with certain conditions of environment. 

In the first case we know how the organs arise, not ready made, 
but in each individual by gradual modification of the organless 
germ one after another the various parts and organs of the adult 
are perfected. The paleontologist has learned that in some gen- 
eral way, at least, the natural sequence of form of organs has 


The Scope of Paleontology.— Williams. 153 


followed the same law. As among vertebrates, the multirayed 
fin of the fish, the webbed paddle of the enaliosaur, the paw of the 
crawling reptile, the hand of man form a natural sequence of de- 
velopment, the later in each case presupposing the preceding stage. 

In the second case it is well known that there is a natural suc- 
cession of species. This succession points to genetic relationship 
between successive species, and it is an established law of this 
succession that species most like each other occur near together 
in the chronologic order, and species of the same genus, present- 
ing the greatest divergence from each other, are also the more 
widely separated in time. 

In the third case it ig known regarding living organisms that 
they present natural association with each other and in adaptation 
to the various conditions of environment. The law of this asso- 
ciation is expressed by the terms fauna and flora. Paleontology 
teaches that the faunas and floras change, and, as the law of Lyell 
illustrates, that this change is gradual and in a definite order. The 
individuality of a fauna can be recognized and can be followed 
out in its successive changes, and these changes are best ex- 
plained by the law of adjustment to environment. 

In the series of modified organs we see the law of organic de- 
velopment, in the series of successive species of a race, the law of 
hereditary evolution, and in the composition and changes of suc 
cessive faunas the law of adjustive adaptation to environment. 

It is an expression of these laws that the fossils become such 
delicate tests of the chronological order and the geological condi- 
tions of the past. 

In the interpretation of the divisions of the Tertiary, Lyell ob- 
served the law of succession of a single fauna, and, fora single 
continuous fauna, the gradual accession of new species and ex- 
tinction of old would express a normal law of succession. _ If, 
however, two faunas are compared, the number of common species 
would depend upon the likeness or difference of the environing 
conditions. 

To apply the Lyellian principle correctly, it is necessary to 
compare the successive faunas of the same province, and for the 
recognition of the province too, it is necessary to consider the 
possible change of climate, or the effect of theshifting of condi- 
tions by elevation or depression of the bottom, or change of re- 
lation of surface of sea to surface of the land, 


154 The American Geologist. September, 1892 


This principle involves the fact that each species has a limited 
life period, but it does not involve, in Lyell’s first usage of it, 
the fact that one species is necessarily descended from another, 

Before this latter law was accepted as a fact, the natural sequence 
of species, and of genera and orders was known. Lamarck had 
advanced the idea of the spontaneous origin and progressive de- 
velopment of the organisms of the earth, but it is interesting to 
note the fact that the natural sequence of different orders of be- 
ings was generally accepted before it was granted that natural 
descent was the explanation of the sequence. Deshayes maintained 
that the species of the Cretaceous were all extinct, and in this fact 
was found the ground for separating theeTertiary order of rocks 
from the Secondary, the former alone containing shells identical 
with those now living. 

The laws of geographical distribution, with resultant modifica- 
tions of those combinations of species called fauna and flora, and 
the modification of the species themselves in their adjustments to 
changed environment, are sufficient to explain the imperfections 
of the Lyellian principle of determining relative antiquity of for- 
mations by the mere numerical proportion of recent species they 
contain, but as a general principle it is satisfactory. The same 
principle of numerical comparison when applied to genera, fami- 
lies and orders furnished the basis for the classification of the geo- 
logical series into Cenozoic, Mesozoic and Paleozoic. 

The mere numerical comparison of faunas is incapable of very 
minute application in marking the chronological scale, for the 
reason that the life period or range of species is often equal to that 
of a geological period, and the life period of a genus may span 
two or three systems. In these particulars I refer specially to 
invertebrates. Land vertebrates express a much greater sensi- 
tiveness to changes of environment, but as a means of determin- 
ing the geological age of strata, they are of such rare occurrence 
as to be practically useless for the general geologist. Vertebrates 
when they are present, as well as plants, are of extreme value as 
time indicators. Thus it is evident that we owe to comparative 
paleontology, and not to stratigraphy or lithology, the primary 
classification of the geological scale, and the means of distinguish- 
ing the chronological position of each formation. 

A second invaluable service of paleontology to geology is found 
in the application of the law of succession of the great groups of 


The Scope of Pateontology.— Williams. 155 


organisms. In the history of vertebrates we are all familiar with 
the law of succession: (1) Fish, (2) Amphibians, (3) Reptiles, 
(4) Mammals, and in another line, (3) Reptiles, (4) Reptilian 
Birds, (5) Birds. 

The finding of remains of any one of these groups of animals 
is sufficient evidence that representatives of the lower type had 
previously existed. The abundance of reptilian remains is certain 
indication of later age than the Paleozoic; the abundance of 
mammals, of age later than Mesozoic. In the same way the trilo- 
bites are known to be an ancient type, and the decapods a more 
modern type of Crustacea. The Tetracoralla are older than the 
Hexacoralla. And a great number of similar instances can be 
named, where, in a particular class or order of organisms, there 
is a definite succession in the order of their dominance and theo- 
retically it is believed also, in their initiation. A third applica- 
tion of paleontology is made by the comparative study of species 
of a particular genus, or the genera of an order. In each genus 
there is observed to be a period of particular abundance before or 
after which there is more or less rapid diminution in the number 
of species found. Thus the brachiopods, so abundant all through 
the Paleozoic rocks, present a definite order of sequence in the 
genera and families, relative abundance of species of which, irre- 
spective of specific names, is a reliable indication of geological 
age. The Cambrian is indicated by the abundance of its Obolidz 
and other inarticulate genera, the lower Silurian by abundance of 
Orthide and Strophomenid, the upper Silurian by numerous 
genera of Strophomenidz, Pentameridz and Rhynchonellide, the 
Carboniferous by dominance of the Productide, the Mesozoic by 
dominance of Terebratulide and absence of the Paleozoic types. 
So, too, the Cephalopods furnish a scale of families which present 
a natural sequence, the Orthoceratide, the Goniatitida, the Cerat- 
itide, the Ammonitidz, and the dominance numerically of these 
several divisions at once testifies to the 1st half of Paleozoic, the 
2d half, the 1st half of Mesozoic, the second half of Mesozoic, 
and absence, or almost total absence of each, to the Tertiary and 
Recent. 

Less is known of the succession of species in continuous series 
as indicative of order of time. The famous ease of the classifi- 
cation of the beds of the Lias by its Ammonites is a characteristic 
example. Oppel, Wright, Buchman and others have studied the 


156 The American Geologist. September, 1892 


Ammonites peculiar to each stratum and classified and defined 
successive zones thereby. 

The name applied to each zone is the specific name of the Am- 
monite peculiar to the bed, as 

Zone of Ammonites (Aegoceras) planorbis, the planorbis bed. 

cry ae ee ot angulatus, angulatus bed. 

And so on, bucklandi, tuberculatus, obtusus, ete., beds. 

Although this is not the purely comparative method, but is 
rather an extension of William Smith’s principle of recognition of 
the beds by their fossils, the comparative element is seen in the 
succession of distinct species in succeeding comparatively thin 
beds. The studies of Branco and Hyatt expanded the investiga- 
tion to a comparative study of the series of Ammonites of a single 
genus, and brought out thereby the exact laws of succession of 
the several known representatives of the family and their relation 
to each other, showing unmistakable succession in series of forms, 
whose order can be accounted for only as genetic. 

Hilgendorf, in his famous study of the Planorbis of Steinheim 
and Waagen with the Ammonites, Neumayr with the Paludinas, 
Hornes in the case of the Cauncellaria, have traced elaborately the 
paleontological series of forms cf a single genus, illustrating this 
important principle. 

In the ease of the Pliocene Paludinas examined by Neumayr, a 
series from below upward was traced, which at the base exhibited 
anormal Paludina (P. neumayr?) and the latest of the series, (P. 
hoernesi) was not only regarded as specifically distinct, but as the 
type of a distinct genus, 7'u/otoma. (See Neumayr, p. 57.) 

Prof. Hyatt has elaborately traced out all the known species of 
the Arictidw in the same way, and arranged the different forms in 
series exhibiting their chronological mutations. Waagen applied 
this term ‘(Mutation to the modification of form observed on com- 
paring the successive representatives of such series, to distinguish 
it from the modifications which are exhibited contemporaneously, 
and are defined under the terms ‘‘variation” and ‘‘variety.” The 
series of fossil horses described by Marsh and Huxley is another 
vase in which the ‘‘mutations’’ reached a generic value. 

All through the field of paleontology may be found similar series 
of genera in which the succession is of such a nature as to suggest 
genetic relationship and to lead to the theoretical construction of 
phylogenetic lines of descent. 


The Scope of Paleontology.— Williams. 157 


Although it may be rightly objected that evidence is in most 
cases extremely imperfect, and in attempts to fill out paleontolog- 
ical series imagination has been freely used in filling the gaps, 
there can be no question as to the immense value to geology of 
the knowledge already acquired in this highly theoretical part of 
paleontology. 

It is the differences observed on comparing fossils coming from 
different horizons and different regions that are of value in these 
determinations, and not the numerical proportion of identical 
forms, as in the William Smith method of identifying strata. 

It is the direct interpretation of observed variation and muta- 
tion of organic forms into terms of the amount of geological time 
and the extent of change in environment. 

This comparative paleontology, to be accurately used, must 
deal with the finer details of form and structure, because the evi- 
dence of genetic affinity must be perfectly clear before the series 
can be depended upon as expressive of the true order of evolu- 
tion. 

A remark should be made here upon the limitations to the use 
of fossils as indicative of geological age. 

Granting the general proposition that the differences exhibited 
by different species of the same genus are variations and muta- 
tions in the descendants of a common stock, still it is not possi- 
ble to decide a priori what the rate of the modification may have 
been. Certain modifications are undergone in a season during 
the ontogenetic development of the individual from the germ cell 
to the adult. In the same way examination of a large number of 
cases in different groups of the Animal Kingdom, shows that in 
many cases there is in the early stage of the life history of a new 
genus, rapid expansion in specific modification, and later on each 
specific line appears to express only very gradual ‘‘mutation” in 
respect of certain characters in which at its early stage it was 
definitely variable. In other words, upon studying the life his- 
tories of species there appears good evidence of an /nitial stage 
in which the species present characters in a plastic state; later 
these characters became fixed in each genetic line, and the species 
appear, on this account, to be more distinct in their characters. 
Hence the amount of difference exhibited between two species 
will not arbitrarily indicate their distance apart in the genetic 
series. 


158 The American Geologist. September, 1892 


Also different genera exhibit different rates of mutation. It 
results therefore that the law of mutation must be studied sep- 
arately for each genus, and even then the accelerative effect of 
changed environment is not known, although it is within the 
reach of investigation. 

Another difficulty in the way of close application of these laws 
in determination of age is that prior’ it is impossible to tell 
whether the differences exhibited by two closely allied forms are 
varietal and associated with changed environment, or mutational 
and associated with the paleontological evolution of the race. 

The study of these problems must therefore be intimately asso- 
ciated with minute regard to stratigraphic sequence, just as in 
deciphering a manuscript, the succession of the words is essential 
to a correct interpretation of the writing. 

The way in which the paleontologic record supplements the 
stratigraphic evidence is seen in the fact that the paleontology is 
capable of showing gaps or omissions, the length and nature of 
which cannot be calculated from the strata themselves. 

Another mode of investigation has been employed in which 
the modifications of a particular part of an organism are made 
the subject of inquiry. 

The case of the toes of the ancestors of the horse, from the five- 
toed Kohippus to the one-toed modern horse, the camels, from the 
Poébrotherium of the Miocene to the Pliocene and recent Auch- 
enia, as shown in the bones and in the teeth, are examples, 

A typical illustration is the development of the sutures of the 
tetrabranchiate cephalopods. 

It will be remembered that the distinguishing feature of the 
cephalopod shell is its chambers, thus separating it from the 
shell of the gasetropod. The edges of the partitions forming the 
chambers where they meet the external walls of the shell, are 
technically called sutures. In the Nautilian shell, whether ex- 
hibiting a simple elongated cone as in Orthoceras, or a curved 
horn as in Gyroceras or Cyrtoceras, or a close coiled shell as in 
Nautilus, the sutures are simple. In other groups of chambered 
shells the suture line is wavy, forming lobes and saddles or vari- 
ously crimped, as in Goniatites or Ceratites. 

These suture lines form a regular series which both in time of 
initiation and in the period of dominance express a simple law of 
evolution. 


The Scope of Paleontology.— Willians. 159 


Every geologist is familiar with the more apparent features of 
the series as seen in the genera Nautilus, Goniatites, Ceratites 
and Ammonites. 

The various degrees and forms of lobes and saddles are the 
basis of elaborate classifications and systems of names proposed 
by Beyrich, the Sandbergers and others, but up to the present 
time I think we have not a published classification which recog- 
nizes the fundamental law of evolution expressed in the series, 

In analyzing the forms of suture, for my class in the History 
of Organisms, I found the following simple law to exist. 

The various suture lines of the chambered cephalopod shells 
can be distinguished by the differences in degree of complexity 
of the crimping of the edge of the septum. 

Viz: (a) In the Orthoceran and Nautilian type, the edge of the 
septum is straight, or the curving is not enough to produce more 
than a single oscillation of the suture line during its complete 
circumference. , 

(b) The Goniatite septum presents a lobed suture, but the edges 
of all the lobes and saddles are simple. 

(c) In the third type the lobes and saddles are variously crenu- 
lated. In the Ceratite the crenulation affects the base of the 
lobes, in Helictites the top of the saddles is crenulated, and in 
Mendlicottia the lobes, the saddles and the connecting parts of 
the suture are crenulated. 

(d) In the typical Ammounite, there is a tertiary crimping of 
the suture line, /. e., each of the archings of the line correspond- 
ing to the crenulations of Mendlicottia is again crenulated, form- 
ing a complexly foliate suture. 

(e) In the adult forms of Pinacoceras there is a_ still further 
elaboration of the crimping, the tertiary archings of the Ammon- 
ite are again crenulated, forming a quaternary stage of corruga- 
tion. 

The series presents a gradual elaboration of the crimping of 
the edge of the septum, forming a suture line, Ist, simple, 2d, 
primarily lobed, 3a, secondarily corrugated or the crenulated 
type, 4th, tertiarily corrugated or the foliate type, and 5th, the 
quaternary corrugations of Pinacoceras. 

In their historical bearings it may be said of this series that, 

Ist. It is the order in which the various types make their first 
appearance in the geological series. 


160 The American Geologist. September, 1892 


2d. It is the order in which the several types become domi- 
nant, 

3d. It is the order of elaboration in the ontogenetic growth 
of the individual. 

4th. It is the normal order of physical relation borne by the 
several types to each other; each type is a physical elaboration 
of the next preceding type. 

The convolutions of the suture are crimpings of the edge of a 
more or less flat disc—the septum——and these convolutions are 
the simplest mode of adjustment of the edge of such a disc, 
whose circumference increases more rapidly than its radius. 

Assuming this sutural featare to be the only difference in- 
volved in the comparison of the several types, it would be cor- 
rect to state that it would be physically impossible for the Am- 
monites, septum and suture to be formed without passing through 
the stages represented by the Nautilus, Goniatites and Ceratites. 
In other words the exhaustive analysis of this one element of 
structure of cephalopod shells shows us that the actual history 
of the organisms has been exactly that which a_ serial classifica- 
tion on the basis of differences of this part would suggest, but 
that no other classification or order of succession could take 
place by natural descent. It is unneccessary to speak of the 
value of such series for purely stratigraphical purposes. 

It is but one of a great many such mutations to be discovered 
in the study of comparative paleontology. The general law in- 
volved is this: in a series of genetically related forms in which 
the ,later representatives present a character which is but the 
physical elaboration of that found at a much earlier stage, there 
is implied the presence in the intermediate formations of species 
in which the character is in an intermediate stage of develop- 
ment, and of a continuous series connecting the extreme forms. 

I have thus far spoken of the general scope and application of 
comparative paleontology. I might cite many cases in which 
particular problems have been settled by the use of these methods, 
and refer to the works of Neumayr, Waagen, Kayser, Barrois, 
Gosselet, Frech, Tscherneyschew, and others in Europe, to the 
investigations of Hall, Whitfield, Whiteaves, White, Marsh, 
Cope, Walcott, Herrick, Hill, Prosser, Keyes, Clarke, and of 
Meek, who was one of the keenest of our earlier paleontologists. 
And there are many extremely valuable special investigations 


The Scope of Paleontology.— Williams. 161 


like those of Agassiz on the echinoids, Hyatt on the cephalopods 
and those of their followers, Jackson, Beecher and others. But 
at the present time it will be impossible to speak of them, even 
were Lable to do them justice. [I will, however, beg your attention 
toa series of paleontological investigations, with the details of 
which I am more familiar, and the steps of which are more or less 
related to each other, and have, collectively, resulted in throwing 
considerable light upon the geology and geography of the Devonian 
system. AsIhavealready said, the Devonian system was originally 
founded upon purely paleontological evidence. The question as 
to the lower limit of the Devonian in this country has been a 
purely paleontological problem, and the reason for including the 
Oriskany in the Devonian is because the fauna is more closely 
allied to that of the Looe and Cornwall slates, the Gedinnien and 
the Coblentzien formations of Europe, than to the Silurian faunas, 
and presents a larger proportion of species which connect it with 
the Corniferous faunas above than with the Helderberg below. 
(See Hall's list of species in 42d Annual Report of New York 
State Museum.) 

The correction of the ‘“‘Chemung” of lowa and Missouri and 
the adoption of de Verneuil’s earlier interpretations of the Car- 
boniferous age of the fauna as perpetuated in the Kinderhook 
group, was settled by the evidence of fossils. 

The Hercynian question of Europe was debated on paleontolog- 
ical, not stratigraphical grounds. 

In 1881 the minute study of Spirifera levis leading to the pre- 
diction that the character by which Davidson distinguished the 
lower Devonian Spirifera curvata from the Carboniferous Spir7- 
fera glabra would be found upon the higher form as well, which 
afterwards Davidson confirmed, was the first step toward dis- 
tinguishing the fauna of the upper Devonian of eastern America 
from the middle Devonian fauna as to its origin. 

The suggestive fact in this case was that this rare American 
upper Devonian spirifer was more closely allied morphologically 
to a common lower and middle European species than to any pre- 
ceding American form. This thought led to a thorough dissec- 
tion of the Devonian faunas of New York and neighboring states. 

The series of successive faunas along a common meridian were 
tabulated and compared, The sections were made parallel to each 
other and near enough together to make it possible to compare 


162 The American Geologist. September, 1892 


corresponding zones of the several series. By this method the 
law was established that the composition of a fossil fauna changes 
on passing geographically from one place to another. Upon 
tracing single species across these sections it was learned that the: 
mutation of the species, not only may be recognized on passing 
vertically upward through a continuous section, but that the more 
direct line of succession was often deflected laterally so that the 
immediate successor of a particular fauna of one section was 
found not directly above it in the same section, but at a higher 
horizon in a section ten or twenty miles distant. This shifting of 
faunas was taken as actual evidence of migration and was inter- 
preted as the result of oscillations of level. 

The examination of the remarkable fauna of High Point, at the 
southern end of Canandaigua lake (the locality of which was first 
shown me by Mr. J. M. Clarke), furnished me with still further 
clue to the solution of the origin of the faunas. I recognized, at 
once, upon seeing it, that it was related to the Lowa Devonian, and 
differed widely from the typical upper Devonian of New York, in 
the midst of which it lay. 

Further analysis of the fauna led to the discovery that the 
species peculiar to it apparently had their ancestors in the middle 
Devonian of Europe rather than in any middle Devonian of Amer- 
ica. With this stage of progress [ examined the fauna peculiar 
tothe Tully limestone. Much confusion had been thrown about 
it by the publication of a large number of species as ‘‘known” 
Tully fossils. Special search was made in original localities with 
the result of eliminating a large number of reported species which 
were found immediately below the true Tully limestone in the cal- 
careous termination of the Hamilton, where the typical Hamilton 
fauna is very abundant, and the true fauna which I described as 
the Cuboides fauna, was carefully compared with that of every 
locality in the world of which I could find report of its presence. 
The result showed that in eastern America where the Tully ap- 
pears, the fauna of the Cuboides zone begins abruptly, and from 
it upward, all through the upper Devonian, is a fauna closely re- 
lated in its species with the upper Devonian of Europe, Russia, 
Siberia, China and British America, and down as far as Lowa in 
the interior, the Nevada Devonian also showing close affinities 
with this type or fauna. 


The Scope of Paleontology.— Wilhams. 163 


But in Europe, where the statistics are abundant and clear, and 
‘so far as evidence bore upon the fact, also in Russia, Asia, and 
British America, the Cuboides fauna is the natural successor of 
the middle and lower Devonian of those regions. 

Mr. Whiteaves, in his recent studies of the British American 
Devonian along the McKenzie River valley, adds many points of 
confirmation of this view, as in some species like Str/ngocephalus 
Burtiné, which had not heretofore been known in America, but 
were characteristic of certain middle Devonian of Europe. 

These purely paleontological investigations had proved, with a 
high degree of certainty, that, relatively speaking, the Tully 
limestone marks a chronological point in the strata which within 
relatively small limits may be said to be chronologically and not 
merely taxonomically thesame as the Cuboides zone of Europe 
and Asia, and, second, that the upper Devonian faunas of these 
several regions are more closely allied than the typical upper De- 
vonian fauna of New York is to its typical middle Devonian fauna 
of the same area. : 

This is a very important conclusion, and the principle involved 
is of vast importance in further studies of comparative nature. It 
makes necessary the tracing of the geographical distribution of 
species in order to get accurate data for the interpretation of their 
geological succession. 

As confirmation, however, of the above conclusion, there has 
recently appeared a paper by Steinmanand Ulrich on the ‘*Devon- 
ian fossils of Bolivia,” in which we are shown the origin of the 
middle and lower fauna of New York and eastern America. 

By the comparison of the Devonian faunas of Bolivia, the 
Andes, Brazil, Falkland islands and South Africa, Ulrich reaches 
the conclusions as to their natural affinities with each other, and 
with the lower and middle Devonian faunas of eastern North 
America, and as remarkably distinct from the corresponding 
faunas of Europe and northern Asia. 

Not only does the presence of peculiar species link together 
these several regions and separate them from the northern set of 
regions, but some of the more characteristic species of the 
southern hemisphere type, as Vitulina and Leptocelia, are abun- 
dant and common to many localities and of higher range in the 
southern hemisphere and are rare or confined to lower horizon in 


164 The American Geologist. September, 1892: 


the Appalachian Devonian of North America, thus indicating 
their extra-limital range in the latter region. 

In the determination of the genetic affinities of the faunas of 
the southern hemisphere with those of the lower and middle 
Devonian in North America, just asin the tracing of the affinities 
of the Tully limestone fauna and upper Devonian, it is not the 
identity of species or the majority of species in contrasted regions 
that plays the greatest part, but it is the testimony of the some- 
what isolated forms, whose local distribution is traceable, and 
also by the breaks in successive lines of species which are asso- 
ciated together as races, though the species at each stage or in 
different regions may be described under different names. 

In the study of the Cuboides zone, it was such species as 
Orthis tulliensis, Strophodonta mucronata var, tulliensis, Rhyn- 
chonella venustula, which told the tale, each differing specifically 
from any European species, but belonging to races, which in 
Europe had representative species extending from the Silurian 
through the Devonian into the Carboniferous system, but in the 
Appalachian region lacked representatives in the middle Devon- 
ian, though well represented in the upper Devonian of New 
York, and were represented also throughout the Devonian deposits 
in the Nevada and Iowa areas. The continuance of the Kuro- 
pean type above this zone in the Appalachian region was also tes- 
tified to by such species as NSprrifera levis and Spirifera dis- 
juncta, Productus dissimilis of Hall (hallianus of Walcott), 
Orthis impressa, Rhynchonella puguus and others, which are well 
represented in the fauna above the Cuboides zone, but have no 
forerunners in the Appalachian higher than the lower Helderberg 
(in rare cases seen in the Corniferous), while in the Kuropean 
faunas there are connecting species all through the middle De- 
vonian, thus pointing to a change of fauna, not by extinction of 
the species, but by migration from one region to another. Just 
as the presence of the bones of Mylodon, Megalonyx, and the 
tapir in the United States, now extinct in North America, indi- 
cates a former extension of the South American living fauna of 
mammals into this continent. 

It was by a similar method that Dr. Ulrich traced the historical 
relations of the Hamilton fauna of the Appalachian province in 
eastern North America to the southern hemisphere. In his de- 
scription of the Bolivian fossils collected by professor Steinman, 


The Scope of Paleontology.— Williams. 165 


he made comparison not only with the species, but with the 
faunas of Brazil collected by Hartt, Derby and Rathbone, and 
of South African and Falkland islands’ faunas described by Salter 
and Sharpe. The most striking evidence of the affinity of these 
several faunas was derived from the study of three rather abun- 
dant genera of brachiopods; Leptocelia, Vitulina and Tropido- 
leptus, genera which I would describe as old type genera for this 
Devonian period, /. ¢., preserving the form and general charac- 
teristics of the lower Silurian Orthidae and Strophomenidae but 
assuming the later character of calcified brachial supports of the 
Terebratulas and Spiriferide. This is the case for at least the 
first two genera, and T’ropidoleptus possesses the punctate structure 
characteristic of the Terebratulas. 

Dr. Ulrich observes that Leptocelia is found in North America, 
particularly in the eastern part, in Bolivia, on the Falkland islands 
and in South Africa, but notasingle trace of it has been reported 
from the Devonian deposits of the other regions, Europe, Asia 
and Australia, and that the South African and South American 
species reach larger dimensions than those of North America 
(pp. 62, 63). 

A point bearing upon the general discussion, which Ulrich did 
not observe, is the fact that this Leptoccelia fauna extended 
northeastward as far as Quebec, Maine and Acadia, and in this 
region is the terminal marine fauna of the Devonian. There was 
evidently a barrier already separating the European sea from that 
of the Appalachian region, and the connection with the South 
American faunas was by the southwest. This in some measure 
may account for the conspicuous absence of characteristic Kuro- 
pean types in the Appalachian Hamilton faunas. 

In regard to the genus Vitulina, Dr. Ulrich remarks that it ap- 
pears in America, but is there a rare species in the later Hamil- 
ton, ‘‘While” he says, ‘‘it is in South America apparently present 
in each of the hitherto discovered Devonian regions,” viz., the 
province of Para in Brazil, as reported by Rathbone in Coati 
Island, Titicaca lake, according to Agassiz and Garman, the 
province of Sao Paulo, reported by Derby, Central Brazil by 
Smith, and in Bolivia, in several localities, by Steinman, South 
Africa, Schenk, (pp. 73, 74.) But it is entirely wanting in 
Europe, Asia and Australia. These facts show the type to be 
peculiarly a southern one, but it may still further be remarked 


166 The American Geologist. September, 1892 


that the Vitu/ina is in America isolated and above the horizon of 
Leptocelia, whereas in the Bolivian region it is not only associated 
with Leptocelia, but is common and appears also in other appar- 
ently higher zones in association with Trop/doleptus, which later 
in South America is not found associated with Leptocelia indicat- 
ing that the North American appearance of the type is extra- 
limital and later than its greatest dominance in South America. 

Tropidoleptus shows a different history. It is seen in Europe 
as well as North and South America and Africa, but in North 
America it is associated with a southern origin, for while it is 
particularly a Hamilton species and of the Appalachian province 
chiefly, it runs up into the upper Devonian of eastern New York, 
and is seen above the Cuboides zone. But it is wanting in the 
Mackenzie river basin fauna (Whiteaves, ‘“The Fossils of the Dey. 
Rocks, ete., 1891), which is the Devonian of Kuropean-Asia. In 
the European fauna it seems to be confined to a lower horizon, 
the Coblenzien of Kurope or the Looe slates, while in America it 
is more characteristic of the higher part of the Hamilton, and in 
Central New York is even a Chemung species. It is reported 
from Illinois and Iowa, but is evidently a rare form in those 
faunas, and in Nevada, where it is in the lower Devonian as it is 
in the European faunas. Thus its range in the Devonian deposits 
of the Appalachian region points to its association with the 
southern faunas and migration with them after their general 
separation from the European faunas, whose connection with 
North American areas was by way of Asia and across the Pacific 
basiu after the close of the Silurian, rather than by any connection 
across the Atlantic basin. 

The other species cited in Ulrich’s paper on ‘‘Fossils of Bolivia’ 
support the same conclusion that there was a close relationship 
existing between the Devonian faunas of South America and 
south Africa and the fauna in the Appalachian trough, reaching 
as high as the Hamilton formation, and that this general fauna 
was distinct from the Kuropean- Asiatic faunas of the same period. 
This differentiation of the lower from the upper Devonian faunas 
occurring in the Appalachian region, and tracing them to centres 
of geographical distribution in opposite hemispheres of the globe, 
throws light upon certain other important geological problems 
concerning the Devonian deposits of North America. 

As we follow the elaborate series of Devonian formations of 


The Scope of Paleontology.— Williams. 167 


New York southwestward across Pennsylvania, Ohio and Ken- ° 
tucky, we gradually lose the separate members, and black shales 
become conspicuous in their places, and in Tennessee there is but 
a thin black shale to represent this whole interval, and in northern 
Alabama scarcely anything separates the Silurian (in some cases 
lower Silurian), from the Carboniferous resting unconformably or 
even conformably upon it. Similar conditions are seen in north- 
ern Arkansas, where, about the Ozark uplift, the erosion of the 
Silurian terrane is such that at the corner of Illinois, Helderberg, 
Oriskany and even traces of Hamilton are left in place, while 
further west, the latest is Helderberg, or Niagara, or Trenton, 
and at extreme points magnesian limestone was the surface rock 
when the black shale was deposited, to be immediately followed 
by typical Carboniferous fossils. 

In Texas we find a similar cutting out of the Devonian, and 
more or less of the upper Silurian and the Carboniferous follow- 
ing the interval. 

These facts point to an elevation sufficient to occasion extensive 
erosion toward the southwest, followed by depression, which gave 
oceasion for the deposit of the black shale over extensive areas. 
If we are correct in tracing with Ulrich his Bolivian Devonian 
fauna to South Africa and recognizing it in the lower and middle 
Devonian faunas of the Appalachian area of North America, and 
in inferring, as I have suggested, that the change in fauna at the 
close of the Hamilton in New York was associated with the ar- 
rival of the Cuboides fauna into the Appalachian region, and thus 
that the upper Devonian is distinctly a Kuropean- Asiatic fauna 
and connected with it across the Pacific down the Mackenzie 
region, it is evident that the time of the change of these faunas 
corresponds with the time of the geologic events in the southern 
central part of the United States, above referred to. The eleva- 
tion which occasioned the erosion did not take place till the Ham- 
ilton period, and the depression and deposit of Black shales 
followed the incursion of the new fauna, or was, in part, contem- 
poraneous with it. 

The erosion ceased and the deposition began in the south later 
than in the north, as is indicated by the fuller representations of 
the separate deposits at the north than at the south, also by the 
smaller amount of the deposits, as indicated by the gradually 
thinning black shale on passing from Olio across Kentucky to 


168 The American Geologist. September, 1892 


Tennessee and Alabama. It was as early as the age of the Oris- 
kany that the separation of the typical southern from the typical 
northern faunas took place, and in the extreme northeastern ex- 
tension of the Appalachian region, the Acadian province of Maine 
and New Brunswick, we observe that this is the highest marine 
fauna reached in the Devonian. 

Elevation evidently shut out access to the sea for this region, 
It is from that time on that the faunas of the Appalachian region 
present their essential relation to the southern hemisphere faunas, 
and show the absence of the typical European fauna. We assume, 
therefore, that a barrier was raised that shut off connection with 
European regions during the lower Devonian. The elevation to 
the south took place somewhere near the close of the Hamilton, 
and the theory we propose is that an elevation such as to divert 
the currents, bringing in first the Cuboides fauna from the north- 
west and finally replacing entirely the Hamilton by the Chemung 
as far east as New York is the reasonable explanation of the 
facts. 

The interesting point is that the testimony of the migrating 
fauna chronologically agrees with the testimony of the oscillation, 
as recorded in the deposits. 

All along the southern limits of Devonian exposures in the 
United States there is indication of an oscillation upward and then 
downward between the Hamilton and the beginning of the Car- 
boniferous. 

The succession of faunas in New York indicates a change at 
the close of the Hamilton from a fauna whose closest affinities 
were with the South American faunas, to a fauna whose earlier 
stages were seen in Iowa, Nevada and the Mackenzie river, and 
whose affinities were with the Asiatic and European Devonian. 

In Arkansas and Tennessee the faunas of the Black Shale indi- 
cate that the first marine fauna to appear after the elevation and 
erosion are of an age as late as the Cleveland shale of Ohio, 7. e., 
the very terminal parts of the Devonian or beginning of the Car- 
boniferous. This event, it will be noticed, is associated with 
that general elevation of the continent, beginning in the northeast, 
which is expressed by the cessation of marine faunas, and ter- 
minating in the Coal Measures and the final elevation above the 
surface of the great mass of the continent east of the Mississippi 
river. 


Problems of Mesabi Iron Ore.— Winchell. 169 


This illustrates the general law of the close relationship between 
the fossil faunas and their environment. 

_ Just as the geologist knows how to interpret the fineness or 
coarseness of sediments into relative distances from a shore line, 
so the paleontologist is able to see in the shifting of faunas and 
the comparison of species evidences of elevation or depression of 
the marine bottom, which upon reaching sea level produced often 
the diversion of ocean currents and consequent modification of 
faunas. By the comparison of extinct faunas he learns to recog- 
nize the continuity or the discontinuity of the conditions of en- 
vironment such as mark geographical areas of distribution of 
living animals. The fossil faunas, their modifications and their 
migrations, as indicated by presence, absence, rarity, abundance, 
size, variation, or mutation of their species, are the sensitive evi- 
dences of changing geological conditions upon which the geolo- 
gist must depend for tying together his disconnected facts. 
Fossils have too often been regarded as only marks for distin- 
guishing the different geological formations, but the scope of the 
paleontology of to-day is far wider. The modern conception of 
the evolution of life has made paleontology the science of the 
History of Organisms. And it is because fossils exhibit in mor- 
phological characters the evidence of the ancestry through which 
they have arisen, and of the conditions of environment through 
which they have successfully struggled, that they are of such 
paramount value in all geological investigations in which the ele- 
ments of time or the order of sequence of events is concerned. 


SOME PROBLEMS OF THE MESABI IRON ORE.* 


N. H. WincuE LL, Minneapolis. 


CONTENTS. 
Theories of the origin of the ore already proposed. 
Some facts of its manner of occurrence, 
Extent of the range. 
Kinds of ore. 
The titanic ores excluded from this discussion. 
Difficulties in the way of acceptance of any of the proposed theories. 
Absence of limestone in the iron bearing horizon. 
Diffusion of iron through ferriferous schists rather than concentration. 
Why is such supposed concentration always at the same horizon ? 
Absence of dikes cutting tilted beds. 
Prevalence of pervious rather than impervious strata. 
Evident changes in the rock of the country, whether in the forms of breccia and 
gravel or in situ. 
Some NecEessary PostuLaTeEs. 
1. The ore has a definite position in the stratification. 
2. It is underlain by a porous quartzyte. 


*Read, August 22, 1892, before Section E, of the American Association 
for the Advancement of Science, Rochester, N. Y. 


170 The American Geologist. September, 1892 


3. It is overlain by or results from change in taconyte. 

4. It is at or near the horizon at which the great gabbro disturbance is believed 
to have occurred. 

5. It is associated with much kaolin or stratitied sedimentary kaolinic rock. 

6. At the same horizon is an important ore stratum the whole length of the range 
—at least 150 miles in Minnesota. ; 

7. Inthe near vicinity of the gabbro invasion the ore is hardened and largely con- 
verted to magnetite. 

8. It exists also as an important ore horizon further south, and beneath 480 feet of 
black slates, having been struck by diamond drill. Similar facts are reported 
from Menominee, Mich. 

9. The whole ore bed is sometimes an original breccia, and at times some of the 
associated rock strata consist of coarse breccias and of conglomerates. 

10. No theory yet proposed for this ore is wholly acceptable. 

11. If the assignment of the date of the gabbro to this horizon be fully established, 
it would furnish a causa vera for some of the physical features, and would sug- 
gest an intimate relation between the ore and the gabbro. 


Perhaps there is no more important or more interesting question, 
at present debated, relating to the iron oresof the Northwest, than 
that of their origin and their stratigraphic relations. | From an eco- 
nomic standpoint, no less than from a scientific, there could be no 
more important question, for it is not until the geological relations 
and origin of these ores are understood that proper methods of min- 
ing them can be entered upon, and with the least expense. It is 
because of recent studies in the field, adding some new facts to 
the solution of this problem, or complicating it by the injection 
of some new conditions, that the writer desires to review the ele- 
ments of the problem and to show the difficulties that yet lie in 
the way. It will be well to enumerate briefly the hypotheses that 
have been propounded recently, as an introduction to this discus- 
sion. There are five. 

1. Substitution for limestone. Mieroscopic examination re- 
vealed the existence of remnants of calcite, or dolomite, in some 
of the ‘‘cherts” accompanying these ores in some places, and after 
long research the late professor Irving arrived at the conclusion 
that the whole body of the ore horizon was originally in the form 
of a limestone essentially,a ‘‘cherty carbonate,” 
gin and essential characters, the black-band ores of the Carboni- 
ferous. This inferentially led to the idea of a great primordial 


simulating in ori- 


carboniferous age. 

2. Substitution for carbonate of tron. Owing to the frequency 
of such a change observed in nature, it was but a short step to 
suggest a carbonate of iron instead of a carbonate of lime. This 
would more readily supply the iron, which must be explained, 
than carbonate of lime, and at the same time would only require 
a slight change, if any, in the nature of the original rock, and in 
the conditions of its deposition. 4 


3. Concentration of tron oxide from the decay of ferriferous 


Problems of Mesabi Tron Ore.— Winchell. 7 


schists, or other yvock. When rocks decay, it makes but little 
difference what they are, they part with their contained iron. 
It may go off in solution, if the proper acids be present, and be 
gathered as oxide under ordinary natural drainage and weather- 
ing,in considerable quantities, on the evaporation of the solvent at 
some lower level. This process has been suggested as the possible 
cause of the accumulation of these ores at the stratigraphic hori- 
zon where they occur. 

4. Accumulation in troughs formed iy dykes cutting tilted strata 
at a somewhat uniform inclination, the iron itself being supposed 
to have been carried down and deposited by ferriferous waters, 
replacing a supposed ‘‘cherty carbonate.” This hypothesis in- 
volves the same conditions and processes as No. 1 above, but also 
gives explanation of the location of the supposed ore lenses. At 
the same time it involves the decay and concentration in a definite 
rock horizon which is demanded by No. 3. 

5. Deposition from oceanic solution at the time of — the 
formation of the rocks associuted. That the iron ores of the 
Keewatin age were deposited from solution, has been inferred from 
their association with rocks whose composition requires the 
cotemporaneous action of eruptive forces—but which are strati- 
fied by oceanic agency—such eruptive action causing chemical re- 
actions that would result in the precipitation of iron and silica. 
This hypothesis has been applied by the writer also to a portion 
of the Mesabi ores, viz., such as are embraced as somewhat ir- 
regular (wandering) strata in the lower portion of the formation. 
Such may be either hematite or magnetite. It may perhaps be 
extended farther than has been proposed. 


Some facts of the manner of occurrence. 

The Mesabi iron range extends, within the limits of Minnesota, 
a known distance of more than 150 miles, and it is iron-bearing 
through its whole extent. It commences at the west end of 
Gunflint lake, on the national boundary, and has been partially 
explored southwestwardly as far as the Mississippi river near the 
falls of Pokegama. The iron horizons do not fluctuate in their 
stratigraphic positions. The iron varies as the character of the 
accompanying rock varies. It is a duplex range and embraces 
ores of two distinct origins and kinds. 

The more southerly portion of the range, which is made up of 


br The American Geologist. September, 1892 


gabbro hills, contains large deposits of titanic magnetite, and 
this may be dismissed with the statement that this ore is at present 
not used, and of little economic concern. This discussion apper- 
tains wholly to the more northern belt where the recent remarkable 
developments have been made. This northern belt embraces non- 
titanic magnetite and hematite as well as limonite and gcethite, or 
‘yellow ochre,” as it is sometimes denominated by the miners. 
The magnetite thus far discovered is not of economic importance, 

compared with the hematite and geethite, but there are explora- 
tions now being made in some of the magnetites which promise 
to become perhaps equally valuable with the hematites. 

The non-titanic magnetite is found in the eastern portion of 
the range and ata lower horizon in the strata than the hema- 
tites, and when it is represented in considerable amount there is 
little or no hematite in commercial quantities. It is sometimes in 
close association with the gabbro containing titanic magnetite, 
and it is a reasonable hypothesis to refer the magnetic quality to 
the effect of the heated gabbro on the original ore, concentrating 
the iron by the expulsion of some of the oxygen. Still there isa 
trace of magnetic ore further west. It is there found in lean 
iron-bearing rock, and occupies belts of a few inches which pass 
through the rock in a rather peculiar zigzag or wandering fashion. 
But still further west the Pewabic quartzyte, which is the horizon 
which holds the magnetite in the eastern end of the range, is 
again regularly interstratified with magnetite in considerable 
amount, and as such it has been explored for commercial uses. 

Hard hematite is found in the Mesabi range, but it is rather as 
an accidental appendage of the soft hematite, and usually it 
grades into low-grade ore and is discarded. 

Hard limonite is found in larger quantities than hard hematite. 
It is apt to be impure, and it occurs in somewhat the same man- 
ner as the magnetite—7. ¢., it branches and permeates a rock bed 
irregularly, though frequently seen in distinct nodules and in- 
vugs when it is found to be a valuable ore. 

The hydrated oxide, however, in the form of gcethite is quite 
abundant. Some shipping mines will depend largely on this ore. 
The ore is in the form of ochre-yellow powder, or small masses 
easily reduced to powder. It is found only in the region of the 
recent new developments, in the western portion of the range. 

Soft hematite, however, is the ore for which the ‘‘Range” will 


Problems of Mesabi Iron Ove.— Winchell. 173 


be celebrated. This has recently been discovered in indefinite 
and almost incalculable amounts. It is generally amorphous, but 
in lumps, frequently as if a breccia of some sedimentary rock, 
easily crushed, and it also exists as a granular powder, finer than 
mustard seed, and can be mined by the simplest methods. The 
plans now being entered upon for excavating it only require a 
steam shovel and a railroad train. 


Stratigraphic relations. 

The horizon in which this ore occurs is that which has been 
identified as Taconic, or primordial. The strata have a gentle 
dip toward lake Superior, and a uniform strike from one end of 
the range to the other. The strata are as follows in descending 
order, omitting minor variations. 

1. Black slate with interbedded sheets of eruptive materials 
which are widespread and non-amygdaloidal. 

2. Gabbro out-break. ‘Titanic ore horizon. The line of this 
outbreak is found not to follow the present northern strike of the 
hematite ore horizon, but to encroach upon it, giving hard ores in 
the eastern end of the range, while toward the west its line of 
outbreak turns more southerly, passing the head of lake Superior 
at Duluth, but apparently forming a bed of conglomerate and 
breccia along the ore belt, noted at various places between Gun- 
flint lake and Pokegama falls. 

3. A peculiar siliceous rock, partly jasperoidal, partly of hard 
hematite, or hard limonite, sometimes conglomeritic and brec- 
ciated, cherty, flinty, usually gray, sometimes partly black or 
purple, and, toward the west, kaolinic, toward the east holding 
some magnetite. Altogether this is a non-descript rock, which 
sometimes is fifty feet in thickness, but so far as developed near 
the mines is less than twenty. It is a pretty constant rock and 
when the ore is absent it lies on or varies to the Pewabic quartzyte. 
This is the horizon of the hard hematite, hard limonite and of 
some of the non-titanic magnetite. In some way not yet fully 
determined it is associated with the next. It is not yet certain 
that all the soft ore is derived from a change of this rock to ore, 
but it is very certain that in some cases this rock is converted to 
ore. It overlies, apparently, the chief ore body of the range, or 
its lower portion is changed to ore. 

4. The chief horizon of soft hematite. The greatest thickness 
this bed has yet been found to exhibit is 105 feet. In the midst 


174 The American Geologist. September, 1892 


of this ore are found sometimes irregular masses of rock like No, 
3, as if remnants of that stratum not yet converted to ore, while 
some strata of soft ore are found also in the midst of No. 3. 
Not enough working has been done yet to reveal all the relations 
of the ore to No. 3. 

5. Pewabic quartzyte. In the near vicinity of the gabbro foci 
this is remarkably modified. Originally probably a chemical 
oceanic precipitate in its upper portion it is consolidated to a yit- 
reous quartzyte, but at more distant points it is composed of dis- 
tinct rounded grains. ‘The upper portion is in the form of chal- 
cedonic silica (so-called), a phase which extends westward, with 
modifications, so far as observed, at least to town 60-13. On 
the other hand this quartzyte becomes less siliceous, having a 
feldspathic element, and even an olivinitic constituent, and some- 
times large hornblende crystals embrace the quartz grains in a 
common matrix. When olivinitic it is also magnetitic and con- 
stitutes an important iron ore. In some places farther west, near 
the Mississippi river, is a quartzyte which is evidently the same, 
regularly interbedded with magnetite in thin alternations. 

6. Conglomerate. This is simply the base of the quartzyte, 
and takes on the character of the older underlying rock. When 
it lies on the greenstones its cementing matrix is green, when on 
the granite it is more siliceous and lighter. 

Northward from the strike of these strata extends the Archean 
complex, embracing the rocks and ores of the Vermilion range 
and the foregoing beds lie unconformably on the upturned 
edges of the older rocks where the two formations come into 
contact. But, wherever the highland spurs of the older rocks 
extend further southward, the primordial strata sweep about 
their bases, dipping in opposite directions on opposite sides 
of the spurs. They occupy no constant level, which might be 
considered an oceanic shore line, but they seem to exist where 
erosive agents have not been able to remove them. Hence they 
may have extended formerly much further north. It happens, 
however, that a range of granitic hills, the Giant’s range, occurs 
but a short distance to the north, and sometimes the strike of the 
Taconie is coincident for some miles with the southern base of 
this range. In other places a belt of ‘greenstone,’ which, how- 
ever, is itself rather rough and rises nearly as high as the granite 
hills, intervenes between the Taconic and the granite. 

It is evident that the present surface contour is but a poor 


Problems of Mesabi [ron Ore. — Winchell. 175. 
_ guide to the stratigraphist in attempting to determine the relative 
ages of these terranes, for the surface must have suffered a-pro- 
found degradation, The gabbro rock, which is by all conceded 
to be an irruptive rock, shows no sign of ever having outflowed 
at the surface of the earth. It is not bedded by amygdaloidal 
partings, nor has it, so far as known, any variable texture due to 
contacting with other older rocks. Yet it comes into contact 
_ with various older terranes, having crowded backward upon them 
while yet confined within the crust of the earth, without reaching 
the surface. It has been seen overlying the Pewabic quartzyte, 
the Keewatin greenstone and the granitic rocks of the Giant’s 
range, but maintaining everywhere a coarse and crystalline texture, 
It seems asif the irruptive movement must have been very slow, 
and that it progressed not forcibly, but as rapidly as the heating 
of the adjacent rocks rendered them more flexible. Subsequent 
to the molten invasion the surface degradation took place reveal- 
ing the deep-seated contacts which we see. It has been the 
writer’s opinion that this event of the irruption of the gabbro 
took place immediately after the deposition of the Pewabic 
quartzyte, based on the interbedding of that quartzyte with a 
rock resembling the gabbro, and on the observed immediate over- 
lie of the gabbro on an extensive area of the quartzyte. This 
observed overlie, however, loses its importance when it is learned 
that the gabbro also overlies the Keewatin and the crystalline 
granite of the Giant’s range, and the date of the disturbance will 
have to remain, as heretofore, not definitely established. 

In further considering, however, the Mesabi iron ore, certain 
problematic difficulties appear in the way of accepting any of the 
proposed theories for the origin of the ore. These may be 
enumerated ; 

1. There is no limestone known in the region, which could be 
considered the parent rock giving rise to this ore by a process of 
substitution, nor has there been any struck by any of the diamond 
drills that have recently been driven through the ore horizon. 

2. There is no known horizon of spathie iron which can be con- 
sidered to have been converted to oxide, 

3. There is no dissemination of carbonate of lime in the form 
of calcite, such as to indicate that the ore may have resulted from 
a substitution of iron for lime. The sparse mingling of minute 
fragments of calcite crystals, in microscopic sizes, with the silica 


176 The American Geologist. September, 1892 


of the chert, in some of the less ferruginous parts of the forma- 
tion, is hardly sufficient to account for such a vast deposit of iron 
ore. It seems like trifling with the problem to appeal to such a 
cause for the ore. 

4. As to concentration by decay of ferruginous schists——the 
process seems to have been the reverse, viz., from the ore has 
been diffused iron oxide through non-ferruginous schists, so that 
for several feet from the ore the surrounding rock is stained a ver- 
milion or brownish red. This has not only affected some of the 
green schists, but also some of the underlying quartzyte. And 
again, on the theory of ferruginous concentration from schists, or 
from any rock, it is necessary to explain the singular fact—singu- 
lar under that hypothesis—of the occurrence of the ore always at 
the same stratigraphic horizon in the same formation. Why 
should not this ore accumulate, at least sporadically, at some 
lower or slightly higher stratigraphic horizon? Here we find it, 
for 150 miles, maintaining its position in the series as constantly 
as any of the beds that are associated with it. 

d. The absence of dykes of irruptive rock. These have been 
supposed to have played an important role in the concentration of 
the hematites of the Penokee range, on the south side of lake 
Superior. Yet, on the north side but one such dyke has been 
discovered, and that is in the eastern extension of the iron range 
where, notwithstanding a year’s costly exploration in the vicinity, 
no hematite has yet been found in commercial quantities. At the 
western end of the range, where the recent discoveries have been 
made, not a single dyke has been discovered. Further, the strata 
that enclose the ore are not impervious, and could not form 
troughs, by any combination of dyke and dip, but the underlying 
rock is a loose white sandstone. It has sometimes become deeply 
stained by the downward percolation of surface waters carrying 
the ore mechanically amongst its rounded grains. 

6. There is an apparent extensive change in the rock of the coun- 
try. The details of this change cannot be given here. As one 
stands at the brink of one of the excavations and sees distinctly 
a sweep of plainly originally sedimentary layers, across the face 
of the cut, manifesting all the usual characters of sedimentation, 
and reflects that the strata which he now beholds consist of bes- 
semer hematite, slightly brecciated, soft, easily mashed, he is 
driven to one of two conclusions—either, first, that the ore was 
deposited as a constituent part of a sedimentary series, or second, 


Problems of Mesabi Iron Ore.— Winchell. LET 


that it is the result of some grand substitution process by which 
hematite has been made to take the place of the original sedi- 
ments. There are besides numerous minor evidences of some 
transition in the rock from its original composition to hematite, viz. : 

(a) Sometimes a gradual encroachment of a hematitic colora- 
tion from the outer portions of a block, or layer, upon a gray or 
blue central area, 

(b) Sudden cessation of a band of hematitic coloration at a 
fissure which evidently the waters producing the coloration could 
not pass, and the passage of the same waters, as shown by the 
narrow streak of hematite in the fissure, down the fissure away 
from the band before affected, leaving that portion on the 
other side of the fissure unstained—while at the same time the 
sedimentary banding of the whole rock sweeps unimpaired across 
the whole face, from one side of the fissure to the other. 

(c) There are larger areas where, as revealed by some of the 
shallow shafts on the western end of the Mesabi range, there is 
an abrupt change, borizontally, from rock to ore, the separating 
line being distinct for a perpendicular distance of at least two 
feet. In other places in the same shaft the ore and rock encroach 
irregularly upon each other. In these cases the ore is soft red 
hematite. If the process of substitution were now going on it 
would be reasonable to expect the oxide would be hydrated, es- 
pecially as such transition is within a few feet of the surface and 
easily accessible by atmospheric waters. 

(d) Not only is the rock changed in situ, but as breccias and 
gravels large deposits are found in which the pebbles, rounded as 
in a river current, or on an ocean beach, are converted to hema- 
tite. Such pebbles were rounded while still rock, and were sub- 
sequently converted to hematite. This is evinced by the varying 
texture, and concentric structure which change somewhat regu- 
larly from the surface to the centre, the outer crust being dense 
and the central portions being vesicular. Whether such pebbles 
appertain to the rocky strata, or are of the age of the drift, has 
not as yet been determined. 


Some necessary postulates. 
Notwithstanding it seems inadmissable to adopt any theory 
proposed thitherto for the origin of this ore, and that we are not 
qualified to propose a new one, there are some important facts 


178 The American Geologist. September, 1892 


which must be taken into account when the true explanation is 
discovered, These facts, which are based on observations made 
partly during the present season, may be set down severally as 
postulates on which some satisfactory theory may possibly be, in 
part, built at some future time. 

1. The ore has a definite position in the stratification. 


2. Itis underlain by a porous quartzyte. 


3. It is overlain by, or results from a change in a peculiar rock 
to which we have given the name taconyte. [To be described fully 
at a later date]. 

4. The whole ore bed is sometimes a breccia of some sedimen- 
tary rock, lying loose, and sometimes compact brecciated or even 
conglomeritic phases are common. Rarely a pebbly ore is found. 

5. Itis associated with much kaolinic, but water-stratified rock, 
and often the white kaolin, though embraced in the ore, is un- 
stained by it. 

6. It occurs at the same horizon the whole length of the Mesabi 
range. 

7. When the gabbro of the Mesabi range is adjacent this ore is 
found to be hard—either hematite or magnetite, but it is never 
affected by titanic acid—though it is by sulphur under such cir- 
cumstances. 

8. Apparently it rans southward with the dip of the formation, 
and by boring it is found under a large thickness of black slate 
about a mile south of the line of strike. 

“. The horizon of the ore is the same that has been assigned 
by the writer to the date of the disturbance of the gabbro flood 
But as that assignment is not sufficiently established it cannot be 
said that the ore has any relation of cause and effect to the gabbro. 


Conclusion. 

There are but two items in the conclusion to which we are driven: 

First. The Mesabi ore is not satisfactorily explained by any 
theory that has yet been proposed for it, or for its equivalent 
(Gogebie) ore on the south side of the great lake. There are 
some facts that favor all of the theories that have been proposed, 
but they meet with opposing facts of greater import. 

Second. There is but one known cause acting with sufficient 
force and on a geographic area sufficiently wide, to which we 
‘an appeal for the geographic and stratigraphic distribution of 


Editorial Comment. 179 


this ore 


and that is oceanic sedimentation. That there has been 
a profound change in the sediments since their origination is quite 
evident; but whether this change took place, in whole or in part, 
prior to consolidation or after it, is as yet unknown; and if after 
consolidation it is equally unknown whether it was accomplished in 
Taconic or in Recent time. There seems to have been something 
peculiar either in the nature of the sediments of this horizon or 
in the influences to which they have been subjected, and this 
peculiarity is expressed on both sides of the lake Superior basin. 


EDITORIAL COMMENT. 


THE UNITED STATES GEOLOGICAL SURVEY. 

The phenomenal development of the U. 8. Geological Survey 
has received its first serious check. Congress refused to vote the 
amount of money asked for by the director for its support during 
the current year, granting only about forty per cent. It became 
necessary at once to dismiss many of the employés, and even to 
abolish, or close temporarily, some of the lines of research on 
which the Survey was engaged. The annual cost of the survey 
has been for several years, between six and eight hundred thou- 
sand dollars, and the men who have been in commission or con- 
stant employ, have been about one hundred and fifty, not 
including laborers. 

We do not conceive that this check is indicative of any desire 
on the part of Congress to put an end to the Geoiogical Survey, 
although it is well known that a few legislators would welcome 
that result. We do not even suppose that Congress desired to 
injure the survey, or to impede it in the construction of the great 
geological map of the United States. In the hurry of the action 
taken by Congress in the closing hours of a long session, it is 
impossible to know what motives actuated the individual con- 
gressman, and it was manifestly impossible to express any form- 
ulated criticism or to enact any general plan for the future of the 
survey. The only feasible step was to reduce the annual fund 


and instruct a committee to report on the survey at its next ses- 
sion.. The action taken by congress will be construed by some, 
and especially by those who are affected by it officially, as a 
calamity to geological science. In some respects it will affect 
American geology unfavorably, but it isnot by any means certain 
that true geological science will in the end be retarded by it. The 


180 The American Geologist. September, 1892: 


survey may be curtailed in scope, but at the same time it may be 
given directness and individuality which will carry it triumphantly 
through future years to an end that will be ‘‘simple and entire.’’ 
Unfortunately, the United States Geological Survey never had 
any other organic act, nor any other duty assigned it more defi- 
nitely than to ‘‘construct a geological map of the United States.” 
It was left practically to the judgment of the director, who offi- 
cially reports to the Secretary of the Interior, although he is in no 
sense subject to his direction, to give significance and scope to 

that simple clause. It is manifest that there was open a wide 
door for difference of opinion, and for the expansion of the work 
of constructing a map, so as to include inquiries into the history 
and philosophy of geology, the physics of mountain structure, 

the causes of earthquakes, the laws of solids and fluids, the eco- 
nomic statistics of the rocks to be mapped, the description of the 
fossil contents, the microscopic delineation of the internal struc- 
tures and the chemical characters of the minerals in the strata’ 
concerned. All this, if entered upon, would requirea large library 
and numerous laboratories. It would mean the establishment of 
a scientific bureau which in its original research would be limited 
in its ultimate scope only by the bounds of human knowledge and 
the appropriations of money which Congress might grant. It is 
quite possible that the zeal of the director for American science in 
general has led him to take some such a view of the proper duty 
of the survey, and that under the head of geology he has been 
induced to include, practically, all that it covers theoretically, 

and has not sufficient warrant for it in the law ordering the con- 
struction of a geological map of the United States. However 
desirable such a bureau might be, whether as an agent for the ad- 
rancement of American science, or asa guide to other bureaus or 
to the state governments, in carrying forward allied investigations, 

it is open to doubt whether Congress intended to organize one 
when it created the geological survey. In the uncertainty which 
must exist on that point, it is plain that any parties or institu- 
tions which might become aggrieved, whether through fancied or 
actual wrong, or who might suppose their prerogatives were being 
usurped by the geological bureau, would not fail to point out the 
necessity of some change, and that their united voices, becoming 
voluminous, should finally find expression in adverse action by 
Congress. 

There are various minor causes that might be appealed to, to 


Review of Recent Geological Literature. 181 


explain the refusal of Congress to continue the survey on its pres- 
ent basis. Personal controversies, scientific jealousies, internal 
dissensions, however cloaked under social and official etiquette, 
local and state antagonisms, and the scientific ostracism which 
some have imputed to the survey against those who have criti- 
cised it and its work, these may have been, in some instances, 
the mainsprings which prompted individual opinion and advice, 
but we think we have compassed the whole opposition, so far as 
Congress could take cognizance of it, when we attribute the action 
to the conviction on the part of Congress that the survey had been 
expanded without warrant, so as to include much costly, original 
research which the law of the survey does not authorize. 

If, in the future, the work of the survey can be confined to a 
more limited field, so that the geological map may be constructed 
as rapidly as is consistent with thoroughness, and so that the 
science of geology may be relieved, financially, from the entangle- 
ments of other natural science, unless they be bound to it by stat- 
utory definition, we believe the progress of science in America will 
not be impeded by the adverse action of Congress; but that, on 
the contrary, numerous efficient laborers will spring up where now 
there is little encouragement for local effort, and these allied in- 
vestigations, relegated to independent institutions, scattered in 
all parts of the United States, will be carried on successfully and 
with a certain local pride, while the science of geology itself will 
pursue an unobstructed line of progress. 


REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 


Two Montana coal fields) By WALTER Harvey WEED. Bulletin, G. 
8. A., vol. iii, pp. 301-330, with 13 figures in the text; June 28, 1892. The 
Great Falls coal field, belonging to the Kootanie formation, of Lower 
Cretaceous age, is found to occupy a width of a few miles adjoining the 
northeast base of the easternmost range of the Rocky Mountains, and to 
extend from the sources of the Judith river in central Montana north- 
westerly at least 125 miles, and probably onward across the international 
boundary. Its thickest known coal seam is mined at Sand Coulée, 
twelve miles south of Great Falls, having a thickness of 31 to7 feet of 
excellent fuel coal. The Kootanie or Great Falls formation of sand- 
stones and shales, with gentle dips, reposes unconformably on the Car- 
boniferous rocks which form the foot-hills, succeeded westward in the 
mountain ranges by steeply upturned and folded strata ranging in age 


182 The American Geologist. September, 1892 


as determined by fossils, from Carboniferous to Cambrian. Above the 
Kootanie beds, whose identification here by their flora was first an- 
nounced by Newberry five years ago, the next recognizabie formation is 
the Ft. Benton, the intervening Dakota formation not being apparently 
represented The Kootanie flora has many species in common with the 
Potomac formation. 

A smaller coal field, allied by its fossil plants to the Ft. Union beds 
overlying the true Laramie, is mined at Red Lodge, situated near the 
south line of Montana ou the Rocky fork, tributary to Clarke’s fork and 
the Yellowstone. In this vicinity nineteen coal seams have been ex- 
amined; and six of them, which have been worked near Red Lodge, 
vary in thickness from 5 to 13 feet. The strata dip about 15° southward, 
terminating at the fault line that runs along the northern base of the 
Beartooth range which, though unexplored, is known to be glacier- 
crowned and is believed to include the highest peaks in Montana. 


Summary Report of the Geological Survey of Canada for the year 1891 
ALFRED R.C. SELWwyn, Director. Department of the interior, Ottawa. 
60 pages; price 5 cents. Among the many fields of work by this survey, 
all of which are here described, with concise statements of their princi- 
pal results, the observations of most economic importance relate to a 
very rich coal field of tae Kootanie formation in the southeast edge of 
British Columbia, about 200 miles northwest from Great Falls, Montana. 
Between the eastern summit of the Crow’s Nest pass, which crosses the 
most eastern ranges of the Rocky Mountain belt, and the valley of the 
Elk river at the mouth of Coal creek, which flows westward from this 
pass, Dr. Selwyn estimates an area of not less than 144 square miles, 
containing about 50,000,000 tons of coal in each square mile, of which 
probably half on an average is available for mining. Twenty coal seams 
were examined in the Crow’s Nest pass and westward, showing a total 
thickness of 132 feet of coal.. Three of these seams are respectively 30, 
20, and 15 feet thick. On the eastern side of the Elk river about seven 
miles below Coal creek, the series has twelve coal seams, three of which 
are each about 30 feet thick, with an aggregate of 148 feet. 


Essayo Esiadishio del Estado de Jalisco, por MARIANO BARCENO, Direc- 
tor del Observatorio Meteorologico Central. (Annales del Ministerode 
Fomento de la Republica de Mexico, Mexico, 1891. 8vo, pp. 729 ) 

Few, if any of the United States, possess such an excellent official 
and comprehensive description of their resources as professor Barceno 
has presented in this admirable monograph on Jalisco, one of the western 
central states of the republic. The neatly printed volume is divided 
into nine parts, treating of the geography, orography, geology, hydro- 
graphy, climatology, flora, agricultur>, horticulture, and the acclimatiza- 
tion of plants introduced into the state. . 


Paleozoic Formations in Southeastern Minnesota. By C. W. HAtu and F. 
W. Sarveson. Bulletin, G. 8. A., Vol. 111, pp. 331-368, with three plates, 
and seven figures in the text; June 23, 1892. The maximum total thick- 
ness of the Paleozoic strata in this district is about 2,400 feet, their 


Review of Recent Geological Literature. 183 


western limit being a line drawn from north to south not far west of 
Minneapolis and Mankato. The formations classed as Upper Cambrian 
attain a thickness of nearly 2,000 feet, while the Lower Silurian 
measures only about 450 feet. No Upper Silurian rocks are found; but 
a few feet of early Devonian beds occur in the south edge of the state. 
The Trenton and Galena limestones and shales are subdivided into ten 
beds, distinguished partly by lithologic but chiefly by paleontologic 
characters Lists of the fossils observed in each of these. beds, and in 
the other formations below and above the Trenton series, are noted. The 
authors extend the Cambrian upward to include the Lower Magnesian 
or Shakopee limestone, which is regarded by Walcott as the base of the. 
Silurian. 


Geology of the Taylorville Region of California. By J. S. Dinumr. 
Bulletin, G. 5S. A., Vol. 111, pp. 369-394, with nine figures of sections in 
the text; July 15,1892. The area here described is about twelve miles. 
long and six miles wide, lying in the northern part of the Sierra Nevada. 
mountain belt, immediately north of the fortieth parallel. Mt. Jura, 
near the center of this area, is so named because of its fossiliferous. 
Jurassic rocks. The exposed sedimentary series has a total thickness of 
24,500 feet; of which 17,500 feet are probably Paleozoic, and 7,000 feet 
are Mesozoic strata. The latter comprise at least three formations in 
the Trias, and five in the Jura, definitely recognized. by fossils. Erup- 
tive rocks are also present in great variety, their epochs of extravasa- 
tion being successively early Paleozoic, Triassic, at the close of the: 
Jurassic, and finally Neocene and Pleistocene. The region was covered 
by the sea during most of its history, until the end of the Jura period, 
when a great upheaval formed Jand along the present Sierra Nevada belt 


Jura and Trias at Taylorville, California. By Aupneus Hyarr. Bul- | 
letin, G. 5S. A., Vol. 111, pp. 395-412; July 15,1892. Professor Hyatt in 
this paper gives preliminary descriptions and discussion of the rich 
faunas, of early and middle Mesozoic age, which have been collected in. 
the strata of Mt. Jura and other parts of the area described by Mr. Dil- 
ler in the preceding paper. The Jurassic formations, in ascending 
order, are the Hargrave sandstone, referred to the Upper Lias of Europe;: 
the Thompson limestone and Mormon sandstone regarded as equivalent 
with the inferior Oolite; and the Bicknell sandstone and Hinchman tuff, 
respectively representing the Callovian and Corallian faunas of the 
European Upper Jura or Malm. The Jurassic system is more fully 
recognizable here than in any other known locality in the United States. 


The Geological Map of the United States, and the United States Geological 
Survey. JuLtus Marcov. Cambridge, Mass. April, 1892. 8vo, pp. 56, 

This is a caustic review and criticism of the United States Geological: 
Survey, its organization, work, personnel, and its relations to the pro- 
gress of geology in America. Mr. Marcou’s style of direct and severe: 
criticism isa marked characteristic of this pamphlet, and his well-known 
fearless manner of exposing what he is convinced is wrong, is apparent 
in every line. His life has been spent as an “independent geologist,” 


184 The American Geologist. September, 1892 


and very often his independence has been asserted at cost of his personal 
advantage. 

Mr. Marcou has radical and sometimes impractical views touching the 
U.S. Geological Survey, but some of his strictures have a basis of just 
criticism. He thinks the survey has been too costly, especially in pub- 
lication, and spread over too wide a field. He would have the field-work 
wholly completed in a district before the geologists publish any of 
the results, and he would have all reports confined strictly to descriptive 
facts, without entering into controversy. Precipitate publication en- 
tails contradiction and correction, and he would have the work of the 
survey above possible correction. He questions the capability and 
sometimes the candor of many of the leading collaborators on the survey, 
and would have every employé who may be responsible for any geolog- 
ical work, well informed on the geology of the original typical Euro- 
pean localities; and when such cannot be found in America, he would 
have European geologists employed, or would send American geologists 
to Europe to study for several months the rocks and fossils which first 
gave name and character to the formations which the separate geologists 
may be entrusted with in the United States. 

This document was freely distributed at Washington, and it was one 
of the factors to produce the late unfavorable action of congress in re- 
fusing the customary appropriation for the survey. 


List OF RECENE PUBLICATION: 


I. State and Government Reports. 


Geol. Surv. of Penn. The Summary Final Report, Vol. 1, describing 
the Laurentian, Huronian, Cambrian and Lower Silurian formations, 
pp. 719. Harrisburg, 1892. Atlas: Southern Anthracite Field: Parts 
tv B, v and vi, 1891. 

Geol. Surv. of N. J. Annual report of the State Geologist for 1891, 
pp. 270. Trenton, 1892. 

Geol. Surv. of Ala. Bulletin No. 2. Onthe Phosphates and Marls of 
Alabama, by E. A. Smith, State Geologist, pp. 82. Montgomery, 1892. 

Ken. Geol. Surv. Report on the Progress of the Survey for 1890 and 
1891, by John R. Proctor, pp. 26 with map. Frankfort, 1892. 

U. 8. Geol. Surv. Monographs, Vol. xvir. The Flora of the Dakota 
Group, by Leo Lesquereux, pp. 400. Washington, 1892. 4to. 

Eighth Annual Report of the State Geologist of N. Y. for 1888 con- 
tains: A classified list of the Paleozoic genera of Brachiopoda, by J. 
M. Clarke. A list of fossils in the Oriskany sandstone of Maryland, New 
York and Ontario, Canada, with an indication of their geological range, 
by Charles Schuchert; The Genus Bronteus in the Chemung rocks of 
New York, by James Hall; A list of the species constituting the known 
fauna and flora of the Marcellus epoch in New York state, by J. M. 
Clarke ; The Hercynian Question, by J. M. Clarke; On the locality of 


Recent Publications. 185 


flint implements in Wyoming county, N. Y., by I. P. Bishop; A cata- 
logue of the specimens arranged bv Prof. E. Emmons, as representatives 
of the Taconic System. 

Ninth Ann. Rep. of the State Geologist of N. Y. for 1889 contains: A 
notice by Prof. Hall of the slow publication of his paleontological 
work; On Syringothyris, Winchell, and its American species, by Chas. 
Schuchert; List of species of the American Paleozoic Orthis, Spirifera, 
Spiriferina, and Syringothyris, by Chas. Schuchert; New Forms of 
Dictyospongide from the rocks of the Chemung group, by James Hall. 

Tenth Annual Report of the State Geologist of N. Y. for 1890 contains: 
The genera of the Paleozoic Brachiopoda; Preliminary notice of a new 
Genus among the Brachiopoda, by James Hall; Quaternary Geology of 
the Hudson River valley, by Heinrich Ries, and the following by J. M. 
Clarke which were reviewed in the GEOLo«Ist for March, 1892: Notes 
on the Genus Acidaspis, Note on Coronura Aspectans, Conrad (sp.), 
Observations on the Terataspis Grandis, Hall. 

N. Y. St. Museum. Forty-third Annual Report of the Regents for 
1889, pp. 306. Albany, 1890. 

N.Y. St. Museum. Forty-fourth Annual Report of the Regents for 
1890, pp. 404. Albany, 1892. 

Geol. Surv. of N. Y. Paleeontology: Vol. vir. The Genera of Palo- 
zoic Brachiopoda, by James Hall, assisted by J. M. Clarke, pp. 367 with 
42 plates. 

Geol. Surv. of Tex. Bul. No.2. The Soils and Waters of the Upper 
Rio Grande and Pecos valleys, by H. H. Harrington, pp. 26, Austin, 1890. 

Geol. Surv. of Tex. Bul. No. 3. Reconnoissance of the Guadaloupe 
mountains, by R. 8. Tarr, pp. 42, Austin, 1892. 

Geol. Surv. of Tex. Second Report of Progress, by E. T. Dumble for 
1891, pp. 91. Austin, 1892. 

Geol. Surv. of Ala. Bul. No 8. The lower Gold Belt of Alabama, by 
Wm. B. Phillips, pp. 97, with map. Montgomery, 1892. 

Geol. and Nat. Hist. Surv. of Can. Contributions to Canadian 
Paleontology. Part iv, by Dr. D. Riist, pp. 10, with 3 plates. 

U. 8. Nat. Mus. Handbook for the Dept. of Geology. Part 1. 
Geognosy.—The Materials of the Earth’s Crust, by Geo. P. Merrill, pp. 
88, with 2 plates. Washington, 1892. 

Geol. Surv. of Ark. Ann. Rep. for 1890. Vol. mr. Whetstones and 
the Novaculites of Arkansas, by L. 8. Griswold, pp. 443, illustrated. 
Little Rock, 1892. 

IT. Proceedings of Scientific Societies. 

Bul. Phil. Soc. of Washington, Vol. x1, contains: On Some of the 
Greater Problems of Physical Geology, by C. E. Dutton; On the Crys- 
tallization of Igneous Rocks, by J. P. Iddings; The Mineral Composi- 
tion and Geological Occurrence of Certain Igneous Rocks in the Yellow- 
stone National Park, by J. P. Iddings; On Certain Peculiar Structural 
Features in the Foot-Hill Region of the Rocky Mts. near Denver, Colo., 
by G. H. Eldridge; Constitution and Origin of Spherulites in Acid 
‘Eruptive Rocks, by Whitman Cross; Mohawk Lake Beds, by H. W. 


186 The American Geologist. September, 1892 


Turner ; and Spherulitic Crystallization, by J. P. Iddings, which was re- 
viewed in the Grouoaisr for Dec., 1891. 

Trans. N. Y. Acad. Sci., Vol. x1, Nos. 3, 4,5; Dec., Jan., Feb., 1891-92. 

Bul. Am. Geog. Soc., Vol. xx1v, No. 2, June, 1892. 

Bul. Geol. Soc. Am., Vol. 111—Parts issued :— Paleozoic Formations of 
southeastern Minnesota, by C. W. Hall and F. W. Sardeson ; Geology of 
the Taylorville Region of California, by J. 8S. Diller; Jura and Trias at 
Taylorville, Cal., by Alpheus Hyatt; Stratigraphy and Succession of the 
Rocks of the Sierra Nevada, of California, by James E. Mills. 

Proc. Am. Acad. Arts & Sci., N.S., Vol. xvi, contains : The Pre-his- 
toric and Kiowa Co. Pallasites, by O. W. Huntington. 


III. Papers in Scientific Journals. 

Geol. Mag., July No., contains: On the Devonian Rocks of 8. Devon, 
by A. R. Hunt (Part 1m); Notes on the Coniston Limestone, by J. G. 
Goodchild; Formation of the Boulder-clay, by G.W. Bulman; Glacial 
Geology, by T. Mellard Reade; A Sand Pit at Hill Morton, near Rugby, 
by P. B. Brodie. 

Aug. No. contains : On the American Paleozoic Gasteropod Trematon- 
otus, by R. B. Newton; The Devonian Rocks of §. Devon, by A. R. 
Hunt (Part m1); An Irish Augitite, by Bernard Hobson ; Under-clays, A 
Preliminary Study, by G. W. Bulman; The Black Limestone of Malta, 
by J. H. Cooke; On Terebratulina substriata, by J. F. Walker ; Geology 
of the Lizard District, by A. Somervail. 

Am. Jour. Sci, Aug. No., contains : Gold Deposit at Pine Hill, Cal , by 
W. Lindgren; Great Shearzone near Avalanche lake in the Adiron- 
dacks, by J. F. Kemp; Development of the Brachiopoda (Part 11), by C. 
E. Beecher; Preliminary note of a new Meteorite from Kenton Co., 
Ken., by H. L. Preston; Additional Observations on the Jura-Trias trap 
of the New Haven Region, by J. D. Dana; Notes on Mesozoic Verte- 
brate Fossils, by O. C. Marsh. 

School of Mines Quart., July No., contains: Methods of Modern 
Petrography, by L. M. Luquer. 

Kansas University Quarterly, Vol. 1, No.1, July No., contains: Kansas 
Pterodactyls (Part 1), by 8S. W. Williston; Kansas Mosasaurs (Part 1), by 
S. W. Williston and E. C. Case. 

IV. Hecerpts and Individual Publications. 

On the Occurrence of Artesian and other Underground Waters in 
Texas, eastern New Mexico, and Indian Territory, by Robt. T. Hill. 
pp. 166. From Rep. Dept. Agr., Washington, 1892. 

On the Sponge-remains in the Lower Tertiary Strata, near Oamaru, 
Otago, New Zealand, by G. J. Hinde and W. M. Holmes. pp. 86, with 
plates. From Linnean Soc. Jour., Vol. xxrv, London, 1892. 

The Thickness of the Devonian and Silurian Rocks of western New 
York; approximately along the line of the Genesee river, by Chas. 8. 
Prosser. pp. 55, with map. From Proc. Rochester Acad. Sci., Vol. 2, 


Rochester, 1892. 
V. Foreign Publications. 


Annnal report of Dept. of Mines and Agriculture, New South Wales, 


Recent Publications. 187 


for 1891, 4to, pp. 322, with cuts and maps. Mainly devoted to 
Economics and Statistics. Sydney, 1892. 

The Physical Geology of Magnetic island, by A. Gibb Maitland, pp. 8. 
4to., with two maps and sections. Brisbane, Queensland. 

Bul. Soc. Imp. des Natur. de Moscow, No. 4, 1891, contains: Argiles 
de Speeton et leurs &quivalents, par A. Pavlow et G. W. Lamplugh. 

Verhand. Russ.-Kaiser. Mineral. Gesell. St. Petersburg. 2d Series. 
Vol. xxvii contains: Symmetrie der Figuren regelmiissiger Systeme 
von E. Fedorow; Ueber die Paramorphosen des Rutils nach Anatas ; 
Ueber die Gattung Stenopora Lonsdale und e’ne neue Art Stenopora 
Lahuseni, von G. Romanowsky; Petrographische Notizen, von M. 
Melnikow; Katalog der MeteoritenSammlung, von J. Simaschko; 
Geologishe Untersuchungen in dem Guberlinsk-Gebirge (vorliufiger 
Bericht) von F. Lewinson-Lessing; Ueber Pterichtys, von Dr. J. Victor 
Rohon; Kulibisit petrographische Skizze, von M. Melnikow; Kurze 
Skizze des geologischen Baues des transcaspischen Gebietes, von J. 
Mushketow; Astrachanit (Blédit, Simonyit) aus den Salzseen im 
Astrachanschen Gouvernement, von P. Jeremejew. 

Archiv des Vereins der Freunde der Natur. Mecklenburg. II Abtheil., 
1891, contains: Silur-Cephalop den der Diluvialgeschiehe, von H, 
Riidig-r; Foraminiferen und O-tracoden aus der Kreide von Moltzow. 
von G. Schacko; Sedimeniitrgeschiebe von Neubrandenburg, von A. 
Steusloff. 

Ueber den Gegenwiirtigen Standpunkt unserer Kenntniss von dem 
Vorkommen Fossiler Glacialpflanzen, von A. G. Nathorst. Bihang till K. 
Svenska Vet.-Akad. Handlingar, Stockholm, 1892. 

Norges Geologiske Underségelse. Om dornelse af jernmalmfore- 
komster, af J. H. L. Vogt, pp. 152, with map and cuts. Christiania, 1892. 

Norg. Geol. Und. Det nordlige Norges geologi, med bidrag af Dr. 
Tellef Dahll og O. A. Corneliussep, udgivet af Dr. Hans Reusch. pp. 
200, with large map and cuts. 

Norg. Geol. Und. Toromyrer inden Kartbladet “Sarpsborgs” Om- 
raade, af G. E. Stangeland. pp. 36, with map and cuts, Christiana, 1892. 

Sitzungsb. der. Physik-Medic. Soc. in Erlangen, Heft xxtv, 1892, con- 
tains: Das Marine Piiociin in Syrien, von A. Blanckhenhorn ; Beitrige 
zur Kenntnis der nutzbaren Mineralien des bayerischen Waldes mit 
specieller Berucksichtigupg des Silberges bei Bodenmais, von J. Thiel. 

Bul. Soc..Géol. de France, 3d Series, t. xx, 1891, No.1, contains: Etage 
mioctne et valeur stratigraphique de /’Ostrea crassissima au sud de |’Al- 
gérie et de la Tunisie, par P. Thomas; Sur l’existence Jurassique supér- 
ieur dans le massif du Grand-Galibier, par M. Kilian; Note sur lage de 
U Hippurites corbaricus des Pyrénées, par J. Roussel; Sur une carte des 
environs de Barcelone de M. J. Almera, par M. Collot. 

Verhand. des naturf. Vereines in Bruon. Band xxrx, 1890, contains: Das 
stidost-mahrische Eruptiv-Gebiet, von J. Klvana; Erster Nachtrag zur 
pleistociinen Conchylienfauna Mahrens, von A. Rzehak; Ueber die Bahn 
der am 1 Dec. 1889 bei cacak am Jeliza-Gebirge in Serbien gefallenen 
Meteoriten, von G. v. Niessl; Ueber die Periheldistanzen und andere 


4 


188 The American Geologist. September, 1892 


Bahnelement jener Meteoriten, deren Fallerscheinungen mit einiger 
Sicherheit beobachtet werden kounten, von G. v. Niessl. 

Die Hohlen des Harzes und ihre Ausfiillungen, von Dr. J. H. Kloos, 
pp. 24. From Abh.Ver. fiir erdk. Magdeburg, 1892. 

Note Geologische e Studio Chimico-Petrografico sulla regione Trach- 
itica di Roccastrada, by R. V. Matteucci, pp. 50, with plates. Roma, 1892. 

Memoire della R. Accad. delle Sci. dell’Istituto di Bologna, 5th series. 
Tomo vy contains: Zifioidi fossile e il Rostro di Dioplodonte della 
Farnesina presso Roma, by G. Capellini; Secondo contributo alla con- 
oscenza della microfauna terziaria italiana, by Carlo Fernasini; Nuove 
ricerche sulla melanoflogite della miniera Giona presso Racalmuto 
(Sicilia), by L. Bombicci. 


CORRESPONDENCE. 


GEOLOGY AT THE MEETING OF THE BRITISH ASSOCIATION AT EDIN- 
BURGH.—For the fourth time in its history the B. A. A. 8. has met in the 
northern capitol of the United Kingdom, this time under the presidency 
of the Director-General of the Geological Survey, Sir Archibald Geikie. 
The date was unusually early. Thus far the first half of September has 
been the time of holding this gathering,but an experiment was this year 
made of placing it one month earlier. Time will show if the experiment 
was successful or not. Probably the change is at least in part account- 
able for a rather smaller attendance than might have been expected at 
sO prominent a centre of wealth and learning. Many people at this time 
are out of town and cannot well alter their time of being absent. The 
numbers at the four Edinburgh meetings have been as follows: 

1834, 1,298. 
1850, 1,241. 
1871, 2,463. 
1892, 2,070. 

The smaller number present had of course the result of lessening the 
amount available in special grants, a matter always to be regretted as 
this is one of the most effective ways in which the B. A. A. 5S. aids the 
work of investigation. However, a total of £1,000 was distributed among 
workers in the various sections. In geology the following sums were 
allotted: 


Prof. Jagrestwich, Erratic Blo CKs}.c.<1- mae cieeane sioleieioicievierstelee £10 
Rev..‘LoWaltshire, Fossil (Phyllopodasiy c oamcle nies wa ceise Ge sie £5 
Prof. J. Geikie, Geological Photographs.:).... wecces ose cee nO 
Prof. E. Hull, Underground Waters .. MR. ......scceeccess £5 
Mr. J. Horne, Shell-deposits at Chapel-hall, &c............ £20 
Dr. R. H. Traquair, Eurypterids of the Pentlands............... £10 


Sir A. Geikie took for the subject of his address, “The Centenary of 
Hutton’s Theory of the Earth.” He showed inthe course of his remarks 
how much of our present geological systems was embodied in the “Theory” 
of this early writer, and how it has survived to the present day, after en- 
countering assault after assault from various quarters. 


Correspondence. 189 


“It was,” he said, “a special characteristic of this philosophical sys- 
tem that it sought in the changes now in progress on the earth’s surface 
an explanation of those which occurred in ancient times. Its founder 
refused to invent causes or modes of operation, for those with which he 
was familiar seemed to him adequate to solve the problems with which 
he attempted to deal. Nowhere was the profoundness of his insight 
more astonishing than in the clear, definite way in which he proclaimed 
and reiterated his doctrine that every part of the surface of the conti- 
nents, from mountain-top to sea-shore, is continually undergoing decay, 
and is thus slowly travelling to the sea. He saw that no sooner will the 
sea-floor be elevated into new land than it must necessarily become a 
prey to this universal and unceasing degradation. He perceived that as the 
transport of disintegrated material is carried on chiefly by running water, 
rivers must slowly dig out for themselves the channels in which they 
flow, and thus that a system of valleys radiating from the water-parting 
of acountry must necessarily result from the descent of the streams 
from the mountain crests to the sea. He discerned that this ceaseless 
and wide spreading decay would eventually lead to the entire demolition 
of the dry land, but he contended that from time to time this catastrophe 
is prevented by the operation of the underground forces, whereby new 
continents are upheaved from the bed of the ocean.” 

“But despite his firm grasp of general principles and his mastery of 
the minutest details, he had acquired a literary style which was singu- 
larly unattractive. Fortunately for his fame as well as for the cause of 
science, his devoted friend and disciple, Playfair, at once set himself to 
draw up an exposition of Hutton’s views. After five years of labor on 
this task, there appeared the classic ‘Illustrations of the Huttonian 
Theory,’ a work which for luminous treatment and graceful diction 
stands still without a rival in English geological literature.” 

Sir A. Geikie then rapidly reviewed the progress of these new opin- 
ions and sketched the various objections, scientific and theological, 
which they had met, passing on to the experimental work oi Sir James 
Hall, and the stratigraphical investigations of William Smith, the 
“father of British Stratigraphy,” and dwelling, as was seemly and cour- 
teous, on the great share that Edinburgh and Scotland had taken in the 
progress of the new science. Passing rapidly over the long and bitter 
conflict between the Plutonists and the Neptunists, which was mainly 
waged in the north, he proceeded to the discussion of what may be re- 
garded as the central scientific subject of his address—Uniformity versus 
Catastrophe. “Though,” he said, “ Hutton and Playfair believed in pe- 
riodical catastrophes, and indeed required these in order to renew and 
preserve the habitable condition of our planet, their successors gradu- 
ally came to view with repugnance any appeal to abnormal and espec- 
ially to violent manifestations of terrestrial vigor, and even persuaded 
themselves that such slow and comparatively gentle action as had been 
witnessed by man could alone be recognized inthe evidence from which 
geological history must be compiled. Well do I remember in my own 
boyhood what a cardinal article of faith this prepossession had become 


190 The American Geologist. September, 1892 


We were taught by our great and honored master, Lyell, to believe im- 
plicitly in gentle and uniform operations, extended over indefinite pe- 
riods of time, though possibly some with the zeal of partisans carried this 
belief to an extreme which Lyell himself did not approve. What the 
more extreme members of the uniformitarian school failed to perceive 
was the absence of all evidence that terrestrial catastrophes, even ona 
collossal scale, might not be a part of the present economy of this globe. 
Yet the admission that they have played apart in geological history 
may be freely made without impairing the real value of the Huttonian 
doctrine.” 

The speaker then quoted the Ice-Age as a strong case in point of the 
truth of his remark. “If,” he said, “any one had ventured sixty years 
ago to affirm that at no very distant date the snows and glaciers of the 
Arctic regions had descended southwards into France, he would have 
been treated as a visionary theorist. There cannot, however, be any 
doubt that after man had become a denizen of the earth a great physical 
change came over the northern hemisphere. The climate which had 
previously been so mild that evergreen trees flourished within ten or 
twelve degrees of the pole, became so severe that vast sheets of snow 
and ice covered the north of Europe and crept southward beyond the 
south coast of Ireland almost as far as the southern shore of England, 
and across the Baltic into France and Germany. Such a marvelous 
transformation in climate, in scenery, in vegetation and in inhabitants, 
within what wasafter all a brief portion of geological time, is surely en- 
titled to rank as a catastrophe in the history of the globe. And yet it ar- 
rived manifestly as a part of the great orderof nature. And thus taking 
a broad view of the whole subject, we recognize the catastrophe, while 
at the same time we see in its progress the operation of those same nat- 
ural causes which we know to be integral parts of the machinery where- 
by the surface of the earth is continually transformed.” 

Passing on then to another doctrine first clearly and definitely stated by 
Hutton, Sir A. Geikie sketched the views that prevail regarding geological 
time. ‘Some 6,000 years had previously been believed to comprise the 
whole life of the planet, and indeed of the entire universe. But the 
progress of research continually furnished additional evidence of the 
enormous duration of the ages that preceded the coming of man, while, 
as knowledge increased, periods that were thought to have followed each 
other consecutively were found to have been separated by prolonged in- 
tervals. Thus the idea arose and gained universal acceptance, that just 
as no boundary could be set to the astronomer in his free range through 
space, so the whole of by-gone eternity lay open to the requirements of 
the geologist. It was Lord Kelvin who first called attention to the 
fundamentally erroneous nature of these conceptions. He pointed out 
that from the high internal temperature of our globe, increasing inward 
as it does, and from the rate of loss of its heat, a limit may be fixed to 
the planet’s antiquity. He estimated that the surface of the globe could 
not have consolidated less than twenty million years ago nor more than 
four hundred million years ago, and he was inclined to believe that, 


Correspondence. ior 


from a review of all the evidence then available, some such period as 
one hundred million years would embrace the whole of geological his- 
tory.” 

“ Moralizing on these results,” the speaker added, “it is not pleasant 
to discover that a fortune, which one has unconcernedly believed to be 
ample, has somebow taken to itself wings and disappeared. When 
the geologist was suddenly awakened bythe energetic warning of the 
physicist it was but natural that he should think the accountant to be 
mistaken. But he consoled himself with tne reflection that, after all, 
one hundred million years was atolerably ample period of time, and 
might possibly have been quite sufficient for the long sequence of events 
recorded in the crust of the earth. But further considerations have led 
to sweeping reductions of the time allowabie for the evolution of the 
planet. Lord Kelvin is willing, I believe, to grant us some twenty mil- 
lion yea's, but Prof. Tait would have us content with less than tea mil- 
lions.” 

Discussing then the argument of the g-ologists from denudation of the 
land, he said that the rate of this process had in some cases been deter- 
mined, and found to vary between one foot in 730 years and «ne foot in 
6,800 years. Assuming the stratified masses to have at their greatest de- 
velopment a thickness of 100,000 feet, ‘they would require at the most 
rapid recorded rate of denudation a period of 73 million years, and at 
the slowest not less than 680 millions.” 

Alluding then to the biological evidence of great length of time, as 
shown by the changes which the life of the world has undergone, the 
speaker gave it as his opinion that the “ geological record furnishes a 
mass of evidence which no arguments from other departinents of Nature 
can explain away, in favor of an allowance of time much beyond the 
narrow limits which recent physical speculation would concede,” and 
concluded his address with an eloquent and picturesque sketch of the 
story revealed by geology concerning the region surrounding the ancient 
capital in which the meeting was held. 

Dr. C. Lapworth, the president of the geological section, being ill, his 
address was postponed and his place filled by various members. Prof: 
Rupert Jones supplied the vacancy on the first day. The papers were 
not of special interest, but included one on the Eurypterids of the Si- 
Jurian rocks, by Mr. Laurie; Prof. Jones’ report on fossil phyllopods; 
the exhibition of perhaps the oldest paleolith yet found, by Mr. Bell 
and Prof. Bonney; a note on the discovery of the bones of a sperm-whale 
in Scotland; one by Capt. Paterson; one by Dr. Johnston-Lavis on a 
pisolicic tuff in the Pentlands, and one by Mr. Watts on Java and ashes 
in the carboniferous rocks in Ireland. 

On Thursday morning, with Prof. Bonney in the chair, the report of 
the photographic committee was received, and a standard size and 
mount, to be determined later, resolved on. The report of the boulder 
committee followed, also that of the underground water committee. Two 
or three papers were also read on the Ice-age, which, however, contained 
no new matter, and are chiefly significant as indicating the extent to 


192 The American Geologist. September, 1802 


which the theory of Dr. Croll is losing ground, even in Scotland, the 
native land, and in Edinburgh the home of its distinguished author. 

On Friday the president was sufficiently recovered to be present. The 
only papers of more than local interest were one by Mr. B. N. Peach on 
a wide-spread radiolarian chert formation of Arenig age in the Southern 
Uplands of Scotland, indicating deep sea at the time of its deposit, and 
one by Mr. D. Bell on “Some alleged proofs of submergence in Scot- 
land during the Glacial Era.” 

On Saturday, with Prof. Lebour in the chair, prof. Hull gave an ac- 
count of a recent visit of exploration to Palestine, in which he men- 
tioned that terraces exist, showing that the Dead sea was once filled up 
to the level of the Mediterranean, now 1300 feet above it, and that in the 
glacial era, the Jordan formed a lake 200 miles long, while there existed 
at its northern extremity a volcano sending down streams of lava to the 
lake of Tiberias. 

Dr. Johnston-Lavis presented the annual report on Vesuvius, and one 
on the exploration of the Elbolton Cave completed the proceedings of 
the morning. 

In the afternoon 960 members of the Association took part in 16 excur- 
sions. One of these, tothe land of Scott, was rendered remarkable by 
a Visit to Gattenside House, where is now residing Lady Brewster, whose 
husband, Sir David Brewster, delivered the first annual address before 
the Association, 60 years ago. Other places of interest seen on this and 
different excursions were, Abbotsford, Melrose and Dryburgh Abbeys, 
Leith Docks and the Forth Bridge, Tantallon Castl>, N. Berwick cliffs, 
the Clyde shipbuilding yards at Glasgow, and the oil-works and mines, 
the Pentland Hills and collieries in their vicinity, and other spots espec- 
ially interesting to the botanists and zoologists. 

On Monday, with Sir A. Geikie in the chair, Prof. Lapworth delivered 
his address. He dealt mainly with the subject of the general form of 
the lithosphere, and likened the crust to a series of waves of different 
lengths and amplitudes, but it was of a nature that does not allow of 
condensation, and the papers that followed were chietly of local im- 
portance. 

The chief disappointment experienced was apparently caused by the 
unexplained absence of Prof.Garner and a promised paper on “The Lan- 
guage of Monkeys.” Possibly the author, as was the case at the A. A. 
A. 8. some years ago, failed to appear on account of insufficient ac- 
quaintance with his subject. 

Dr. Burdon Sanderson was appointed. president for the meeting at 
Nottingham in 1893, and the date was set for Wednesday, Sept. 13. It 
may be inferred from this action that the early date chosen this year has 
been found unsuitable. 

A deputation from Oxford presented an invitation, which was ac- 
cepted, to meet in that city in 1894. E. W. CLuAYPOLE. 

Akron, 0., Aug. 28, 1892. 


193 


PERSONAL AND SCIENTIFIC NEWS. 


THE GEOLOGICAL Society or AmeERIcA held its summer ses- 
sion at Rochester, N. Y., on Monday and Tuesday, Aug. 15 and 
16, 1892. The president, Mr. G. K. Gilbert, presided. The 
first paper, by Mr. Lawrence Johnson, treated of the phosphate 
beds of Florida and their geological history. In his opinion 
Florida began by the rise of a number of small islands of Eocene 
rocks in a shallow Miocene sea, and onthese rocky islands, guano 
was deposited by birds, while marl beds were at the same time 
formed in the narrow channels. He attributed the origin of the 
‘pebble phosphate” to the disintegration of these Miocene marl 
beds after elevation. After alluding to the vast erosion which these 
rocks have suffered, the author divided the phosphate beds into 
four groups, successively formed: 

(a) ‘*Compact Rock,” phosphate, 
(6) passing into ‘‘Laminated Rock,” 
(c) then into ‘‘Plate Rock,” and 

(d) lastly into ‘‘Soft-Phosphate.”’ 

In the absence of the author little discussion was possible, but 
some objection was raised against the origin attributed to the 
phosphates, inasmuch as the fossil remains indicate marine con- 
dition and exuviz rather than terrestrial. 

The next paper, Prof. E. W. Claypole’s, on the Dentition 
of Titanichthys and its allies, after paying a high tribute to the 
skill and pains of Dr. Newberry in so ably interpreting the first 
remains of the kind that came to light from the Ohio Devonian 
strata, and expressing the regret of the society that ill-health de- 
tained him from the meeting and from the prosecution of the 
work, described the detention of the Dinichthyidz as already 
known, pointing out the peculiarities of the teeth of the different 
genera, and then brought forward some recent discoveries by Dr. 
Clark of Berea, which led to the belief that at least two interman- 
dibular plates or teeth existed in some or in all the forms, and 
whose presence explained or removed several difficulties that pre- 
viously presented themselves. One intermaxillary, scalpri-form 
tooth was also present in the upper jaw, between the two great 
‘‘pre-maxillaries’” of Newberry, which apparently worked against 
the two already mentioned, in the lower jaw. These additions 
considerably simplify the mechanics of the jaws of these monsters. 

Prof. C. H. Hitchcock followed with a paper on the Connecti- 
cut valley glacier. He quoted several cases in which strize from 
the north crossed others previously made from 30° west of north, 
and stated that the latter, in such cases, occupied a slight hollow 
at the bottom of a basin or trough. He thought that this indi- 
cated a change in the direction of the ice and that during the 
greatest extension of the glacier, when drainage was almost im- 


194 The American Geologist September, 1892 


possible below it, the ice moved over the whole surface in one di- 
rection, scoring hill and valley alike, but that in the later stages 
where local conditions could in part control or influence 
the drainage, the course of the ice was also influenced 
thereby and it took its course along the valleys, scoring them in 
the direction of their length. He also showed a large map of the 
Connecticut valley elacier on which was represented the long 
eskar skirting the river and through which its channel has in some 
places been cut. The stones in the eskar have, he said, all come 
down the valley, and belong to the region. 

A paper by Prof. G. C. Broadhead was then read by Prof. 
Branner on the Ozark uplift and the history of the paleeozoie in 
Missouri. The author sketched what was, in his view, the course 
of events during palsozoic time in these mountains, narrating the 
story of their upheaval and subsidence in the paleeozoic sea. The 
paper was a summary of present knowledge on the subject rather 
than a contribution of new material. 

The paper that attracted most interest was by Prof. James Hall, 
of Albany, on the ‘‘Oneota Sandstone.’ He showed a section in 
which the relative position of this disputed layer and its associ- 
ated strata was set forth, and explained their relationships. The 
venerable and veteran American paleontologist stated as the re- 
sult of his long and repeated observations that the ‘‘Oneota Sand- 
stone” passed eastwardly into the lower Catskill and westwardly 
into the Portage. Over the latter lies the Chemung thickening 
and te the westward, with this thickening comes in a difference 
of composition, the ‘sandstones of the east giving place to the 
shales of the west. All these overlie immediately the Tully lime- 
stone where this latter exists. Dr. Hall continued his description 
of the Catskill, stating that no marine fossils existed in it, and 
that its almost sole bivalve shel! and its large fish indicated rather 
estuarian,or fresh water, than marine conditions of deposit. The 
merging of the Catskill, lithologically, in the Portage, to the 
Ww Sl is very sionificant in indicating that the Prete Gf a group 
depends not a little on biological conditions, which are second 
only to secular changes and extinction of species. 

A paper on dynamical geology by Mr. Becker was read in his 
absence by Prof. R. T. W Foodward. It dealt with the subject of 
strains produced by stresses, and insisted on the exact defini- 
tion of these and several other terms frequently employed with 
considerable laxity. The paper contained some new views of 
faulting which called forth a few remarks, but in the absence of 
the author a paper so mathematical in its treatment could not be 
fully discussed. 

Mr. Warren Upham had a lengthy paper onthe structure of the 
drumlins of Massachusetts. After alluding to similar objects in 
other parts of the country, he spoke of the different kinds of 
drift—englacial, subglacial and super-glacial, and maintained 


Personal and Scientific News. 195: 


that drumlins had been deposited very near the outer edge of 
the glacial sheet and were caused by acceleration of the upper 
layers of ice, causing, he said, deposition of material in the form 
of an oblong hillock atthat place. To the longer ridges or eskers. 
he assigned an origin in the beds of the super-glacial streams 
where gravel was dropped, and this, by gradual settling, at length 
came to rest on the bed of the glacier. 

Prof. G. F. Wright criticised some of the results published by 
Messrs. McGee and Salisbury from Pennsylvania, and summarized 
the indications of submergence during the Columbian era, in the 
Susquehanna valley mentioning terraces rising to a hight of 130 
feet above the river at Harrisburgh with others at a lower level. 
He went over the subject in detail tracing the ‘‘fringe,’’ as it has 
been called, into New Jersey, and maintaining that in some cases 
decomposed gneissoid rock had been mistaken for northern drift, 
especially as stones bearing the marks of creep-striz are abundant 
in several places. This paper called forth considerable contro- 
versy, the extreme views of some on the age of the early drift 
being actively contested by others. 

Some phases in the metamorphism of the schists in southeast- 
ern Berkshire, Massachusetts, was read by Mr. W. H. Hobbs and 
illustrated by photographs of microscopic sections. One by Mr. 
David White showed a new form of Tzeniopteris or an allied form 
from the Coal Measures, and illustrated the affinity of the genus, 
and Mr. A. §. Tiffany gave a few interesting facts regarding the ex- 
cavationof the palzeozoic strata in lowa by very ancient cataracts. 
Some of that may become of considerable importance in connec- 
tion with the subject of interglacial drainage. 

The council received a cordial invitation from the Royal Soci- 
ety of Canada and the Geological Survey to attend its winter meet- 
ing at Ottawa, which was accepted. 

AT THE LATE MEETING of the American Association for the 
Advancement of Science, Prof. Jos. LeConte, of California, pre- 
sided over the Association, and Prof. H. §. Williams, of Ithaca, 
N. Y., over Section EK. The meeting was attended by the usual 
excursions, receptions and other social diversions. About 500 
members attended. The next meeting will be at Madison, Wis. 
Following isa list of papers read in Sec. E. Mr. G. K. Gilbert 
also gave a public address under the auspices of the Rochester 
Academy of Sciences, on ‘‘Coon Butte and the theories of its ori- 
gin,” illustrated by lantern views. 

Terminal moraines in New England. By C. H. Hitchcock. 

A Passage in the History of the Cuyahoga river. By E. W. Claypole. 

Notes bearing upon the changes of the pre-glacial drainage of western 
Illinois and eastern Iowa. By Frank Leverett. 

Extra-morainic drift in New Jersey. By A. A, Wright. 

The volcanic craters of the United States. By Rob’t T. Hill. 

Recent geological explorations in Mexico. By Rob’t T. Hill. 


Paleobotany of the Yellow Gravel at Bridgeton, N. J. By Arthur 
Hollick. 


196 The American Geologist. September, 1892 


Presentation of samples from the salt mines of New York. ByS. A. 
Lattimore. 

The mining, metallurgical, geological and mineralogical exhibits to be 
shown at the World’s Columbian Exposition. By Geo. F. Kunz. 

Cerro-Viejo and its cones of volcanic ejecta and extrusion in Nicara- 
gua. By John Crawford. 

Paleobotany of the Yellow Gravel at Bridgeton, N.J. By Arthur 
Hollick. 

Pleistocene geography. By W.J. McGee. 

Distribution of the LaFayette formation. By W. J. McGee. 

Submarine valleys on Continental slopes. By Warren Upham. 

Cenozoic beds of the Staked Plains of Texas. By E. D. Cope. 

The Homotaxic relations of the North American Lower Cretaceous. 
By Robt. T. Hill. 

Exhibitions of Guelph fossils found in Rochester, N. Y. By Albert L. 
Arey. 

The American Mastodon in Florida. By John Kost. 

Some problems of the Mesabi iron ore. By N. H. Winchell. 

The mathematics of mountain sculpture. By Verplank Colvin. 

In Section H., Mr. W. J. McGee read a ‘valuable paper on 
‘“‘Comparative Chronology,” the principal points of which were to 
greatly lengthen the accepted period of geological history,particular- 
ly the later portion of it, but to shorten the period of human history. 
Mr. McGee objects decidedly to all supposed evidence of man in 
Tertiary time. It seems likely that the term ‘‘Tertiary”’ as applied to 
human remains in central Europe, has been misunderstood, and that 
the term is meant to designate, at least in some cases, simply the 
surface deposits which have more lately been denominated drift. 

Mr. W. H. Houmess, who presided over Section H., objects to 
the terms ‘‘paleolithic” and ‘‘neolithic,” as commonly employed to 
denote human implements of different dates and states of culture. 
He has found both in great abundance in the stone quarries of the 
ancients in Arkansas. The ‘‘paleolith” is the unworked ‘‘stock of 
the quarry,’ and as such was cached in quantities, or carried to 
great distances. The ‘‘neolith” was made at leisure, and as the 
occasion demanded, the same or similar ‘‘paleoliths’” being 
wrought sometimes into one tool and sometimes into another. 

AccorpINnG TO Pror. EH. D. Cops the ‘‘staked plains” of Texas 
are composed of Cenozoic strata, divisible into Kquus beds, Blanco 
Canon and Loup Fork, the last being lowest, confirming the de- 
terminations of Prof. Hill. They are underlain by Triassic. The 
Equus beds have a well-known vertebrate fauna. The same is 
true of the Loup Fork. Between these faunas, which are totally 
separate and distinct, existed a paleontologic blank, which has now 
been filled by the discovery of the Blanco Canon beds. There are 
no marine forms either in these beds of the staked plains, or in 
the Triassic or Permian below. He considers the Equus beds as 
probably of the age of the LaFayette, but that is based wholly on 
paleontologic evidenée. 

Prof. Cope obtained remains of Megalonyx in the Blanco Canon 
beds, and several species of Hquus in the Equus beds. He made 
a rich and varied collection of vertebrate remains. : 


Personal and Scientific News. 197 


A WorLD’s ConGRESS OF GEOLOGISTS will be held in Chicago, 
in the summer of 1893, in connection with the World’s Colum- 
bian Exposition. 

The excellent opportunity offered by this exposition for com- 
parative studies of the mineral resources of the various countries 
of the globe, cannot fail to act as an inducement for geologists 
to assemble on this occasion. It is also announced that many 
States in the Union, as well as countries in other parts of the 
world, have made liberal appropriations for their geological 
exhibits at the Columbian Exposition; and the exposition 
as a whole will surely attract great numbers of scientific vis- 
itors. 

The Congress will be held under the auspices of the World’s 
Congress Auxiliary of the World’s Columbian Exposition, which 
organization is recognized and supported by the United States’ 
government as one of a series of congresses in the course of the 
exposition season, all intended to show the moral, social and in- 
tellectual advancement of the world at the present time. 

The American Association for the Advancement of Science,on 
its 41st annual meeting, recently (Aug. 16th-22d) held in Roch- 
ester, N. Y., adopted resolutions cordially endorsing the con- 
gresses on the various branches of science within the scope of 
said association, and requested its various sections to appoint 
committees to cobperate with the respective local committees. 
Section HK. (geology) acting upon this request, appointed a com- 
mittee of the following geologists, viz.: Thomas C. Chamberlin 
(chairman), John C. Branner, Grove K. Gilbert, W J McGee, 
Rollin D. Salisbury, Eugene A. Smith, Charles D. Walcott, J. F. 
Whiteaves, Geo. H. Williams, H. L. Williams and N. H. Win- 
chell. The local committee consists of Josua Lindahl (chairman), 
Edmund Andrews (v. chairman), Victor C. Alderson, W. R. 
Head, Oliver Marcy and Charles W. Rolfe. 

The Directory will provide suitable places for meeting, and will 
extend to scientists in attendance all conveniences and courtesies 
consistent with the aims of the Auxiliary. 

It is expected that arrangements will be made to secure the pub- 
lication, in extenso, of the proceedings of the various congresses 
and the important papers to be presented at their sessions. These 
publications will be a memorial of the civilization of the Nine- 
teenth Century. 

We hope in the next number of the GkEOLOGIST to commuui- 
cate the,exact date of the opening of the Geological Congress. 
All communications should, until further notice, be addressed to 
Dr. Josua Lindahl, Geologist, Springfield, Illinois. 

Dr. I. C. WHITE HAS SEVERED his connection with the West 
Virginia University, Prof. 8. B. Brown, his" late assistant, suc- 
ceeding him in the chair of geology. Dr. White will hereafter 
devote his attention exclusively to his professional work in coal, 


198 The American Geologist. September, 1892 


oil and natural gas, and to his private business interests, which 
require much of his time. 

OWING TO THE REFUSAL OF CONGRESS to vote the usual appro- 
priation for the U. 8. Geological Survey, all field work has been 
suspended, and all the assistants, and many of the principal geol- 
ogists have been directed to close up their notes, putting them into 
condition for preservation or lateruse, as may be required. Many 
of the employés are discharged. The curtailment effects paleon- 
tology, petrography and chemistry most severely, and topography 
least. Messrs. Iddings, Penrose and Barus accompany Profs. 
Chamberlin and Salisbury to the University of Chicago. 

ON THE NEWLY ESTABLISHED IowA suRVEY, Mr. Charles R. 
Keyes is first assistant, and Prof. G. E. Patrick, of Ames, Iowa, 
is chemist. . 

TWO NEW DISCOVERIES OF MANGANESE ORE were reported by 
Mr. Edward Halse, at the recent meeting of the North of Eng- 
land Institute of Mining Engineers, one at Mulege, in Lower Cal- 
ifornia, and the other at Arenig, Wales. The first is on the west- 
ern shore of the Gulf of California. Here several outcrops of 
manganese ore veins are found crossing the trachyte which forms 
the bulk of the rock. The veins consist of psiomelane and gyp- 
sum and they vary in thickness from a fewinches to three or four 
feet. The prevalent direction is about northwest to southeast. 
The chief veins run in wavy lines, consisting of a succession of 
curves, each a few feet long. The best ore is found at La Trini- 
dad, where two veins intersect. 

That found in Wales is in the Lower Silurian formation in 
Eastern Merionethshire. There are deposits of trappean ash and 
feldspathic porphyry, accompanied with manganese ore. This 
ore consists chiefly of psiomelane and occurs in much the same 
manner as does that of Lower California. 

Pror. WriitiAmM P. TrowsrinGr, of Columbia College, died 
suddenly of heart failure, August 12, at his home in New Haven, 
Conn. In connection with the U. 8. Coast Survey, he made many 
valuable contributions to scientific knowledge, and for a time held 
the position of scientific secretary to the superintendent of the 
Survey. His loss will be felt by the Institution in whose Faculty 
he held an honored position, and by the many scientific societies 
of which he was a valued member. 


AMERICAN GEOLOGIST 


Vou. X. OCTOBER, 1892. No. 4 


[PALEONTOLOGICAL NoTES FROM THE LABORATORY OF BUCHTEL CoL- 
LEGE, No. 2.] 


THE HEAD OF DINICHTHYS. 
By E. W. Cuaypo eg, Akron, O. 

A specimen of the skull of Dinichthys intermedius recently 
found by Dr. W. Clark, of Berea, O., has supplied details pre- 
viously unknown regarding the plates of which it was composed. 
I propose in this note to give some account of these in connec- 
tion with a general description of the structure of the head of 
this species, all the main characters of which belong, doubtless, 
to the whole genus. 

In his admirable ‘‘Monograph of Fossil Fishes” Dr. Newberry 
has given (pl. Lit) a small outline sketch of what, in his opinion, 
was the general form of the head and of the individual plates of 
which it was built up. ‘This may be regarded as a condensed 
summary of what had then been discovered of Dinichthys. The 
recently found specimen, as might have been expected from the 
skill and acumen of this well known author, coincides to a very 
large extent with his figure and illustrates his familiarity with 
the structure both of the fossil and recent forms. _ 

The new specimen, however, corrects this diagram in a few 
points and adds others of some importance. 

In the annexed figure* I have represented the right side of the 


*The line of section through the orbital is placed (on the plate of 
the outside of the skull) about half an inch too far backward. 


200 The American Geologist. October, 1892 


cranium and shown the various plates, and to as great a degree as 
possible, the way and extent of their overlap and underlap, but 
in consequence of their co-ossification these are in a few places not 
exactly and positively determinable. The specimen figured meas- 
ures ten and a half inches from the tip of the nasal plate to the 
nuchal angle and the right side, which is scarcely displaced at all, 
is five and a half inches in breadth. 

The principal new details in the skull are in the forms of some 
of the plates and the over and underlap which has not previously 
been represented. 

Beside this, the structure of the upper jaw shows important 
additions, the principal of which will form the subject of a future 
Enote. 

THE PLATES OF THE HEAD. 

1.) The Supra-occipital occupies the middle part of the hind 
margin, and is very massive, being one inch and a quarter thick 
at the maximum, extending forward as shown and very slightly 
underlapping both the adjoining lateral plates. Its inner face 
carries three ridges, one running forward and the other two out- 
ward and backward along the margin. These latter are very 
thick and heavy,and their sutures with the ex-occipitals are nearly 
vertical, not underrunning the latter to any considerable extent. 

The sutures of the supra-occipital with both the parietal and 
ex-occipital or so nearly vertical that it is possible the overlap 
may be even the other way. This was certainly the case with 
D. minor whose supra-occipitals are often found separate. In 
these, the ex-occipital underlaps the supra-occipital, and the latter 
is considerably overlapped by the parietal. In direction they are 
nearly parallel with the axis of the head. 

At the junction of these three ridges and in the middle of the 
nuchal line is the well known double socket on the inner face so 
plainly shown in Dr. Newberry’s figures. (See pls. rv and sir of 
Monograph). The function of this socket is not exactly known, 
but it probably marks the place of insertion of some powerful 
muscle or ligament that connected the head with the rest of the 
body. 

2.) The Hx-oecipital plate forms most of the hind margin of 
the head outside of the supra-occipital and carries the socket of 
that singular lock-joint with the supra-scapula which character- 
izes the Arthrodira. On the inner side it moderately overlaps 


The Head of Dinichthys.— Claypole. 201 


SKULL o DINICHTHYS 
(Outside) 


202 The American Geologist. October, 1892 


Preorbstal 


Ue 


Post - orbstal 


SKULL of DIN ICHTHYS 
[inside / 


occ 
o-* = 
Swe-” 


wvtal 
‘ 
, 
cs 


The Head of Dinichthys.— Claypole. 203 


the supra-occipital and is in turn overlapped by the marginal (of 
Newb. and Traq.). In front it is overlapped by the concave edge 
of the parietal. It may be noted that this plate does not extend 
so far forward as was represented by Dr. Newberry. The space 
thus set free is taken up by the parietal. 

(3.) The Marginal (N. and T.) forms the outer and hinder 
margin of the head running to a blunt point at its termination. 
As said above it overlaps the ex-occipital. It also overlaps the 
parietal inwardly and underlaps the post-orbital in front. It is a 
massive plate folding inward and downward as shown in the figure 
(see section) so as to form part of the roof of the mouth and at 
the same time to serve as the front wall of a deep fossa receiv- 
ing the insertion of the muscle whose function was to lift the 
mandible (temporo-masseter). The hinder margin of this fossa 
is formed by the ridge of the supra-occipital mentioned above. 
These characters can be seen more or less plainly in the two 
figures above quoted (Monog. 1v and Li) but can be more dis- 
tinectly comprehended from the plan and sections given herewith. 

(4.) The Parietal plate occupies a post-median position in the 
skull and is large and important. Meeting on the median line for 
a short distance its fellow of the opposite side, its edge inclines 
backward and outward overlapping largely the supra-occipital and 
ex-occipital behind. It is in turn overlapped by the marginal 
and post-orbital and again overlaps the frontal. It is thick and 
heavy, projecting far on the inner face of the skull and forming 
the front wall of the fossa already mentioned. It appears to have 
been the solidifying element of the mid-skull, extending as a 
ridge from the marginal to the supra-occipital on the inner face. 

Judging from the conventional form which he has given to this 
plate in his restoration, its outlines cannot have been clearly de- 
fined in the specimen which Dr. Newberry studied. Instead of 
the small and elliptical area which he has assigned to it, it has a 
large size and an irregular outline and the insertion of this plate 
as above described makes a considerable difference in the post- 
median region of the skull. 

(5.) The Frontal plate, as the parietal, meets its fellow along 
the mid-line for an inch or more and forms but a very siaall part 
of the outer face, being largely concealed by the adjoining plates 
all of which it underlaps. These are the parietal, supra-occipital, 
pre-orbital, post-orbital and ethmoid. It is a thin plate which 


204 The American Geologist. October, 1892 


covered in the brain. This organ lay in the space between the 
supra-occipital behind and the parietals post-laterally. How 
much of this it actually occupied it is not possible exactly to de- 
termine. The cavity measures five inches from side to side, but 
if analogy is asafe guide, as it probably is, some of this was oc- 
cupied by the ear-capsules. It is probable that the brain proper 
was limited to the space within the forward projections of the 
parietal plates measuring about two and a half inches. This area 
is well outlined in Dr. Newberry’s figures where its boundaries are 
much more clearly marked than in the specimen now described. 

(6.) The Frontal plates, in consequence of their thinness, are 
usually, as in the present case, crushed down so that the brain- 
cavity is almost effaced. But the lateral spaces (ear-capsules) 
being protected by the massive post-orbitals are uninjured. 

(7.) The Post-orbital plate continues the outline of the head 
from the marginal behind to the pre-orbital in front,and the post- 
orbital process forms the hind margin of theorbit. Onthe upper 
face this plate overlaps the parietal, the frontal and the marginal, 
and is slightly overlapped by the pre-orbital. It ends backward 
in a blunt point. As the marginal it folds under and forming a 
forward continuation of the above-mentioned ridge that bounds 
the temporo-masseter fossa protects the ear-capsule and the lateral 
aspect of the brain. This ridge gradually sinks until it is lost or 
is merged in another on the inner surface of the pre-orbital plate. 

The natural strength of this plate due to its weight is largely 
increased by its form which may be seen by comparing the sec- 
tions with the figure of the skull. 

Just behind the post-orbital process, and on the lower face,is a 
small and shallow notch (indicated in the figure) for the reception 
of one of the angles of the sub-orbital plate. 

On its lower and inner margin is a strong, stout and cylindrical 
process an inch and a quarter long which evidently joined by a 
suture some one of the plates that formed the roof of the mouth. 
It slants downward and inward at a low angle (about 15° with the 
horizontal) so as to meet a plate that must in some way have cor- 
responded in position and function to the vomer or the presphenoid 
of arecent fish. But no trace of any such plate remains in the spec- 
imen here described, though the two processes approached at their 
distal ends within half an inch of each other on the median line. 

(8.) The Pre-orbital plate is large and outlines the orbit in 


THE AMERICAN GEOLOGIST. Vou. X, Pate VIII. 


JAWS of DINICHTHYS 


Subhorbrilal 


<=>" 


JShear-looth 


SKULL of DINICHTHYS 


JSecaon acres, 


\ Occipital Beqror 


J"arress Orhs tals% | 


JStclion across Frontal \. 
EMC ae 


FARt wee 


oy 


i ; , pe Lady wth 2 
| nad 


ass 7 ; ; van ' sa 


be Sabie 3 : - J 
ihe a eel “Ta . é 
: relia eoewnrir sen Ween Feet ew —— base a ) 
Wee 


EE er og = = 
pes hOSTS.°: 4 ial S| Bs 
. - . j 
Paes - a way va isVe BH = =F 
Wags 7, 
ae 
- Pew : 
¥ 4 : 
ey = i . 
2 : 
_ # 
i 
i 
j j 
— 
3 F f 
tat 
= 
\ 
’ 
ame THe 
1 
¥ 1 


| a 
al 1 
3 ie ‘ SS i ee ¢ 
At f= 
a wh 


The Head of Dinichthys.—C laypole. 205 


front. Its pre-orbital process is slenderer than the post-orbital 
and meets the front end of the sub-orbital at or near its junc- 
tion with the premaxillary, thus completing the enclosure of the 
orbit. The pre-orbital overlaps the post-orbital, the ethmoid and 
the nasal. Its front edge runs from the nasal to the point of the 
pre-orbital process. It is strengthened on its inner face by a 
sharp, low ridge beginning at the point of the process and thick- 
ening inwardly as it rises for about one inch, after which it again 
sinks, until at length it merges in.the low, flat end of the temporo- 
masseter and capsular ridge already described. This re-enforce- 
meut of the pre-orbital plate is connected with the insertion of 
the premaxillary tooth which was carried in part at least on its 
front edge, the remainder being borne by another plate to be men- 
tioned later. 

The nasal openings, or what were apparently such, were situated 
on the front edge of the nasal plate and extended in part on the 
inner front edge of the adjoining pre-orbital. In the specimen 
described they are on the very margin, but this is owing to the 
loss of the plate to be mentioned below. (No. 12.) 

(9.) The Ethmoid plate is missing from this specimen, but it 
is so well known from other examples, and its size and relations 
are so clearly marked on the adjoining plates, that no difficulty is 
found in tracing it. It overlaps the hinder end of the nasal and 
a large area of the inner edge of the frontal, and underlaps the 
pre-orbital along its inner face. It resembles a spear-head in 
form with the point behind. On its inner face is seen the deep 
fontanelle, regarded as a place of lodgment for the extension of 
the pineal gland to a probable pineal eye. The fontanelle usually 
and perhaps normally, reaches the outer surface by a very small 
aperture, but was apparently in some specimens altogether closed. 

10.) The Nasa/ plate is trapezoidal in outline and completes 
the front of the head on the median line. It underlaps the pre- 
orbital and the ethmoid and overlaps to a very small extent, at 
its outer edge, the premaxillary plate, to be mentioned immedi- 
ately. (No. 12.) 

(11.) The Sub-orbital plate is a thin bladeof bone four inches 
long, with thickened front and lower margins, passing at its lower 
front angle into a narrow but thicker projecting arm two and a 
half inches in length and extending forward. On the lower edge 
of this arm is a long, thin, crescentic plate which serves as a but- 


206 The American Geologist. October, 1892 


tress or support externally for the great ‘‘shear-tooth” so charac- 
teristic of the genus. On its inner face this arm also carries an 
upwardly concave, horizontal plate which formed the floor of the 
orbit, enclosing, with the pre- and post-orbitals, the cavity for 
the eye. In front the sub-orbital formed a sutural connec- 
tion with 

(12.) The Premaxillary. This plate, which has been hith- 
erto unknown, is not found in the specimen here described, but 
its presence has been established from others. A complete de- 
scription of it will be given in a later note, as its relation to the 
teeth would require the introduction of the subject of the denti- 
tion. For the present it must suttice to say that it completed 
the outline of the fore-part of the head, enclosing the nasal open- 
ings and filling up the recess observable between the nasal and 
the pre-orbital plates. 

The great shear-tooth set in the upper jaw on the lower face of 
the sub-orbital is shown in the diagram, but it has been so fully 
-and clearly described and figured by Dr. Newberry that nothing 
further need be added here concerning it. 

(13.) The Post-marginal plate, figured by Dr. Newberry in his 
diagram, is not found in the present specimen, nor are its rela- 
tionships yet clearly known. It apparently formed one of several 
thin blades of bone whose office was the connection of the lower 
jaw with the head and which are usually found in so broken and 
confused a condition that their interpretation and re-construction 
have not hitherto been possible. 

The principal ‘‘slime-canals” have been indicated. These are 
four in number. ‘Three of them arise nearly together, about the 
meeting point of the supra-occipital, parietal and frontal plates, 
Of these, one which may be called the pre-orbital canal, runs 
almost straight to the anterior edge of the skull. It has not yet 
been traced on to the premaxillary plate. Another, which de- 
serves the name of pre-orbital, runs to the central region of the 
plate of the same name where, slightly curving, it passes to the 
margin and is continued on to the sub-orbital plate to meet the 
sub-orbital canal. This runs from the hinder and lower angle of 
that plate forward to its junction with the premaxillary plate and 
will doubtless be found continuous there with another when that 
plate is better known. The occipital canal starts nearly, with the 
first and second and runs outward and backward to the lock-joint 


Extra-Morainic Drift in New Sersey.— Wright. 207 
Y Y 


of the supra-scapula, where it sends off a branch, the supra-scap- 
ular, which continues over that plate nearly ina straight line 
through its middle. Turning sharply, almost at a right angle, 
outward and forward, the occipital canal continues till it meets 
the marginal canal. This skirts the outer edge of the head from 
the hinder angle of the marginal plate to the post-orbital canal 
which it meets nearly in the centre of the plate of that name. 

Besides these, there are indications of another, beginning in the 
angle between the pre-orbital and post-orbital canals and running 
forward and outward along the line of external suture of these 
plates. Turning sharply outward, after a short course, it termi- 
nates at the edge of the hinder partof the orbit. This is less dis- 
tinct than the others in consequence of a possible confusion with 
the almost coincident pre-post-orbital suture. 


EXTRA-MORAINIC DRIFT IN NEW JERSEY. 
A. A. Wrieut, Oberlin, O. 


There is a snare in the words ‘‘terminal moraine” as applied 
to the great ice sheet of the Glacial Epoch. On the one hand 
there is not one terminal moraine, but many; a dozen perhaps, in 
retreating order, as urged by Mr. Upham for Minnesota, and as 
shown by the recent work of Mr. Leverett, in Ohio, and as illus- 
trated everywhere within the glaciated area. On the other hand, 
the terminal terminal moraine, that is to say, the southernmost, 
is not terminal for the ice sheet, in the sense of accurately mark- 
ing at every point the utmost extension of the landice. Another 
expression, based upon a different geological conception, is 
needed for this line; and the words ‘‘glacial boundary” have been 
widely used and accepted. The terminal moraine cannot go 
south of the glacial boundary, but the glacial boundary may, and 
does often, lie many miles to the south of the terminal moraine. 
The area between the two lines, where they do not coincide, is 
marked with true signs of glaciation, and is covered with a thin- 
ner or thicker layer of transported material, which represents the 
work of the lobe of ice which once extended over it, but which 
was withdrawn before it had formed a definite boundary moraine. 
When we reflect that the Laurentide glacier was a fan-shaped 
sheet, radiating from a northern center, and not like the Swiss 


208 The American Geologist. October, 1892 


glaciers, gathered from a wide amphitheater to terminate below 
in an apex in a narrow valley, we can see that there is room for a 
wide variety in the terminal deposits. 

The distinction between the terminal moraine aml the true 
glacial boundary, was, as a matter of history, not so clearly in 
the minds of geologists when the task of tracing the terminal 
moraine acros, the continent was begun as it is now. Shortly 
after Mr. Upham had described the moraine as it exists on Long 
island, the official geologists of the New Jersey survey, profes- 
sors Cook and Smock, traced the moraine across that state from 
Perth Amboy to Belvidere. Their annual reports for 1877 and 
‘78 contain the details of the location and structure of this mo- 
raine. Professors Lewis and G. F. Wright then took up the 
work for the Pennsylvania survey; and their experience, especi- 
ally in western Pennsylvania, convinced them of the importance 
of giving attention to the extra-morainic glacial deposits. Al- 
though it was assumed, both in the New Jersey and the Pennsyl- 
vania reports, that the terminal moraine rested essentially upon 
the glacial boundary, yet professor Lewis, in closing the report 
upon Pennsylvania, stated that a study of the extra morainic de- 
posits would form the subject of a special report in the future. 
His untimely death, however, prevented him from completing the 
work. 

The boundary line was carried through Ohio, Kentucky, In- 
diana and Illinois by professor G. F. Wright, and it will be noticed, 
both in his reports and in his maps, that he distinctly abandoned 
the purpose of tracing a continuous moraine, and pursued that of 
tracing the glacial boundary. 

This frequent non-coincidence of the glacial boundary, and the 
terminal moraine, is the key by which are to be explained many 
of the observations to which I am about to allude. 

During the present summer, I had the welcome opportunity of 
doing some field work in New Jersey, part of the time in com- 
pany with professor G. F. Wright, whose wide experience in 
glacial geology will give to our joint observations a value which 
they could not possess if made by myself alone. 

Attention has recently been drawn to the extra-morainic drift 
of New Jersey by professor Salisbury in two papers; the first being 
given at the Washington meeting of the Geological Society, one 
year ago; the second being published in the last annual report of 


Fixtra-Morainic Drift in New Sersey.— Wright. 209 


the State survey.* In these papers many localities are given 
where glacial, or probably glacial,deposits have been found, south 
of the terminal moraine traced by professors Cook and Smock. 
Detailed descriptions of some of the deposits are given, and their 
origin’ is explained. I am indebted to these papers of professor 
Salisbury fora list of localities, many of which I have visited, 
and it is a pleasure to confirm the accuracy of the descriptions in 
most essential points. I shall only attempt to add some details, 
which it is hoped may throw additional light upon the nature of 
the deposits, and perhaps to show, that a somewhat different in- 
terpretation of their origin may be fairly entertained. 

It would seem, as a result of our investigations, that the de- 
posits at localities described as showing extra-morainie glaciation, 
extending from Belvidere and Oxford Furnace on the north, to 
the vicinity of Trenton and Monmouth Junction on the south, 
may all be comprehended under three groups. 

1. Prue Glacial Deposits, laid down by the same ice sheet that 
deposited the moraine, and nearly contemporaneous with the moraine 
in their origin. The northern localities belong to this group. 

2. Water Deposits,whether of currentor delta formation, or 
carried by floating ice. The southernmost localities belong to 
this group. 

3. Local Deposits, which have the anomalous aspect of being 
glacial deposits in an unglaciated area. These, when better un- 
derstood, are likely to be thrown back into the first group, or else 
be explained by agencies which are non-glacial. The two lo- 
calities belonging to this group are High Bridge and Pattenburg. 

The region containing the first group of deposits is in the 
southwestern Highlands of New Jersey. Three parallel moun- 
tain ridges run southwesterly through it; the Musconetcong, the 
Pohatcong and Scott’s mountain. The ridges are of Archean 
gneiss, and carry extensive deposits of iron ore. The interven- 
ing valleys are of magnesian limestone and Hudson River shale. — 
The moraine runs eastwardly across these ridges, from Belvidere 
on the Delaware river through or near Butzville, Pequest Furnace, 
Townsbury, Hackettstown and Budds lake; rising from 300 feet 
above tide at Belvidere to 960 feet at Budds lake. 

In this triangular area, between the moraine on the north, and 


*Bull. Geol Soc. Am. Vol. 3, pp. 178-182. 
Geol. Surv. N. J., Annual Report for 1891. 


210 The American Geologist. October, 1892 


Musconetcong mountain on the south, it is possible to trace a 
well connected series of glacial deposits, embracing all those 
which I would refer to the first group. This covers the localities 
of Oxford Furnace, Oxford church, Little York, Brass Castle, 
Washington, Pleasant Valley, probably Mt. Bethel, though this 
place was not visited, Roxburgh, Harmony, Lower Harmony, the 
country northeast and east of Phillipsburg, and also southeast 


tS 


a) —_— 
y 
ey 


ob 


of ZAtrvas. Shale ¥ Sandst 
CT Oneida ved Sandst | | Elevations 
MIIDHR Shale ¥ Slate refer To 
[IL Situr Limestones tide water 
Hoss Gneissoid Rocks Al 


to Springtown, Hughesville and Musconetcong mountain at a 
point two miles south of Bloomsbury. 

Avoiding as far as possible the stream valleys, the higher 
divides were explored. These deposits were found at the follow- 


ing levels: 


Oxford Furnace......)....:520 ft. Tittle pV ork arteries 850 ft. 
BrassiCastlemmeymemectemitt LOD Washington 2.3005 .esecosoU0: 
Harmony, .sia0 ee See OO UN. Phillipsburg, N. E...375 to 460 “ 


Musconetcong mountain, for a distance of three miles, at 700 
to 760 feet. 


Exxtra-Morainic Drift in New Jersey.— Wright. 211 


On Scott’s mountain, commencing three miles south of Rox- 
burgh, for a distance of one mile, at 720 feet. 

The water in the Delaware river has an elevation at Belvidere 
of 229 feet; at Phillipsburg and Easton 156 feet; at Riegelsville, 
at the lower end of Musconetcong mountain, 129 feet. 

These figures are sufficient to show that the deposits in ques- 
tion cannot be attributed to the agency of streams, flowing from 
the glaciated regions lying northward, but on the contrary, must 
be due, as has been urged, to an ice-sheet upon the land. 

The lithological and stratigraphical composition of the deposits, 
especially, proves them to be glacial. 1 scarcely know where to 
point for finer examples of genuine glacial deposits, than to those 
at Little York, Oxford Furnace, and the two cuts north of Wash- 
ington, the latter of which are five miles south of the moraine. 
At Oxford Furnace, for example, where the exposure is from ten 
to twenty feet thick, there is the greatest variety of pebbles and 
bowlders, drawn from every source, and of various sizes and 
shapes, imbedded heterogeneously in a matrix of sand and clay. 
The predominating bowlders are of gneiss from the hills close at 
hand. All of these are angular in shape. Some of them show 
wavy, green epidotic stripes; some have rusty, ferruginous 
stripes; while others carry free quartz containing tourmaline 
crystals, like specimens quarried from the Oxford tynnel. Mag- 
nesian limestone also crops out, in place, here; and fragments of 
it, completely scored on every side, were imbedded in the till. 
There were also fragments of limonite ore; black flint, probably 
from the limestone; angular fragments of shale and slate, both 
striated and unstriated. But besides these elements, of local 
origin, one is able in a few moments, to take samples of many 
other rocks from far away, such as coarse granite, with large, 
pink orthoclase crystals; milky quartz, perhaps from the slate 
regions to the north; Medina sandstones or quartzites from the 
north, the dark gray, red and purplish varieties, as well as the 
more characteristic whitish variety, whose surface tans to such a 
beautiful, smooth leather color; Oneida conglomerate, a bowlder 
2x2x6 feet, brought all the way from Kittatinny mountain, at 
least, its corners well rounded, as is the case with most of the 
northern material. Fragments of leached and spongy sandstone, 
perhaps feldspathic, are also found, while all are mixed in the 
fine confusion that demonstrates their deposition by an ice sheet. 


212 The American Geologist. October, 1892 


The surface of the country all around is strewn with gneiss, and 
also with quartzite bowlders, which were traced continously from 
the moraine at Butzville southward to Washington. It is amatter 
of surprise that such pronounced glacial deposits should ever 
have been relegated to an unglaciated area. They are of the 
same nature as many of those which are made to do duty as por- 
tions of the terminal moraine. Although it was constantly in 
our minds, we were unable to see any chemical basis for separat- 
ing these deposits from those of the moraine, such as superior 
oxidation or ferrugination. It should be noted that the gneiss 
which somewhat dominates the deposits at Oxford Furnace is 
often hornblendic and is seamed with iron ore. 

Evidence of glaciation in several other parts of the triangle re- 
ferred to was observed, though surface features had to be relied 
upon, as cuts and excavations were commonly wanting. Fora 
distance of eight miles northeast of Phillipsburg, the high ground 
of Scott’s mountain was explored upon two different roads. 
Everywhere there was found at least a thin scattering of foreign 
bowlders—conglomerates and quartzites predominating—while at 
several points there were notable accumulations of these, as at 
Harmony, a mile and a half east of Harmony, and two miles 
south of Lower Harmony. Southeast of Phillipsburg also 
they are generally distributed, with special accumulations 
on the pass between Springtown and Hughesville at an 
altitude of 320 feet, a mile east of Carpentersville at 250 
feet, and for a distance of three miles on the north slope of 
Musconetcong mountain, south of Hughesville and Bloomsbury, 
at altitudes from 700 to 760 feet. Above this altitude, on the 
summits rising to 900 feet and more, only the local gneiss bowl- 
ders occur. This is the only locality where the ice-sheet is known 
to have reached Musconetcong mountain, though there are 
northern bowlders in the valley a mile or two west of New Hamp- 
ton Junction at an elevation of 450 feet. These latter bowlders, 
however, were not traced into connection with the deposits north- 
ward at Washington, and it is possible that they have suffered 
some water transportation since the retreat of the ice. 

So far as is yet known, the ice did not flow over any of the 
passes on Musconetcong mountain and down its southern slope. 
A little stream has carried some of the Kittatinny mountain 
quartzites down the south slope to Little York in Hunterdon 


Extra-Morainic Drift in New Jersey.— Wright. 218 


county, from the 700 feet level just described. But it is most in- 
structive to observe that, aside from this stream, the region about 
Little York is absolutely free, not only from northern bowlders, 
but from the gneissoid rocks of the overhanging mountain as well. 

From the preceding account, therefore, it would appear that in 
western New Jersey the terminal moraine did not mark the true 
glacial boundary, but that the ice sheet must, for a certain period, 
have extended at least five miles further towards Washington, 
and at least 14 miles south of Belvidere upon the flanks of the 
musconetcong mountain. 

The second group of reported glacial deposits south of the 
moraine are the southern ones, such as those at Monmouth Junc- 
tion, N. J., and at Fallsington, Pa., three miles west of Trenton.* 

As one approaches Monmouth Junction on the Pennsylvania 
railroad from Trenton, it is noticed that as soonas the city limits 
are left behind, the cuts are all in a red gravel, which I assume 
to be the Columbia formation. It is a flood deposit from the 
Delaware river, with a very uniform level of from 80 to 100 feet 
above tide. It continues the entire 15 miles to Monmouth Junc- 
tion, and several miles beyond. At the Junction there is a cut 
15 feet deep in a uniformly stratified gravel, characterized by 
white and yellow pebbles, mostly less than an inch in diameter. 
With infinite labor, one faintly, but really, striated, water-worn 
pebble was found, but there is no evidence that it was left in its 


*At the meeting of the A, A. A.S., at which this paper was presented, 
professor Salisbury disclaimed the intention of asserting that an ice-sheet 
had existed as far south as Trenton, or over the center of Hunterdon 
county. The language, which I am sorry to have misinterpreted, is as 
follows: “The points in New Jersey and Pennsylvania mentioned above, 
however, [Oxford Furnace, High Bridge, Pattenburg, New Brunswick, 
Bethlehem, etc.], are not the southernmost localities where glaciated ma- 
terial is known to occur. Striated bowlders have been found both by Mr. 
Chas. E. Peet and the writer at and near Monmouth Junction, nearly 
twenty miles from the moraine at its nearest point, and fully forty miles 
south of the moraine on the same meridian. Glaciated material has also 
been found at Kingston, about half way between New Brunswick and 
Trenton. It has been found in Pennsylvania, about three miles west of 
Trenton, near Falsington. The similarity of the surface material of this 
locality to glacial drift (till) was first recognized by professor Smock. 
Striated material has also been found at Bridgeport (opposite Norris- 
town), Pa., by Mr. Peet and the writer, at least ten miles south of the 
parallel of Trenton. As at Falsington, the striated material-is here im- 
bedded in clay of such character that were the locality known to have 
been covered with ice, its reference to till would be fully warranted.” 
Bull. Geol. Soc. Am. Vol. 8, pp. 179-180. 

. Also: “In its southern extension the ice reached the region of the ‘yel- 
low gravel’ formation.” Ann. Report, State Geologist, p. 107. 


214 The American Geologist October, 1892 


present position by ice. A mile or two further on the cuts are 
shallower, and an admixture of coarser material is observed, 
though the red gravel continues. Angular fragments of eruptive 
diabase from immediately beneath, form a rough floor; well- 
rounded and polished northern quartzites, Oneida and Triassic 
conglomerates, and Triassic red sandstones up to a foot or more 
in diameter are imbedded in the gravel, while the surface for miles 
around is well supplied with these, and with larger, less rounded 
quartzites and conglomerates, up to two and three feet in diame- 
ter. Striated pebbles are very rare, and the whole can be ac- 
counted for, at this low level of 100 feet, by water and floating 
ice, without invoking the aid of an ice sheet. 

In the third category I have placed the two deposits at High 
Bridge and Pattenburg, both at the foot of the southeastern 
slope of Musconetcong mountain; one, where the Jersey Central 
railroad comes across, and the other where the Lehigh Valley 
road comes out of its tunnel. In several particulars they are 
very different from the more northerly deposits, and they well 
merit the special descriptions and emphasis which professor Salis- 
bury has bestowed upon them in his annual report. Whilst they 
are partly stratified and partly unstratified, containing material 
ranging from clay and sand up to bowlders of three and even 
seven feet in diameter, and are plentifully supplied with shale 
fragments with clean and sharp striations, still, on the other hand, 
it is to be noted: 

1. That the material of the deposits is exclusively local. No 
northern rocks could be found. At High Bridge the deposit 
rests in a cradle of gneiss rock in place, and the hard bowlders 
are all gneissic or granitic, not rounded, and may have been 
gathered from the slope which rises 450 feet above, At Patten- 
burg the floor is Triassic shale and conglomerate, but the bowl- 
ders are gneissic, like those that. are to-day creeping down the 
mountain slope on the north. The Hudson River shale and flinty 
limestones must be counted as local rock, even though no outcrop 
was detected in close proximity to the deposits. * 

*The High Bridge deposit was visited before I had seen the true drift 
material to the north of it. The entire absence of any northern element 
cannot therefore be stated quite so confidently for High Bridge as for 
Pattenburg. While the discovery of a single well-identitied northern 
pebble at either place would be of great significance, it could not alter 


the fact that these deposits are in radical contrast with the more north- 
erly ones in the proportion of local material which they contain. 


Extra-Morainic Drift in New Sersey.— Wright. 215 


2. Inthe country round about these deposits, and especially 
on the high land to the northward, no signs of glaciation could be 
discovered. From High Bridge northward four miles to White- 
hall, and thence southwesterly towards Glen Gardner, no signs of 
northern drift or ice-work were detected. Similar search north 
and south of Pattenburg gave the same results, as did also the 
study of adjoining railroad cuts, east and west on both roads; 
so that we are apparently presented with the spectacle of glacial 
deposits, ina region never invaded by an ice sheet; a matter 
which cannot fail to provoke further investigation. Were it not 
for the emphatic and convincing striation, both of the shale and 
gneissoid bowlders, we might turn with more hopefulness to an 
investigation of the possibilities concealed in landslides, and the 
secular creeping of plastic soil containing rock fragments, upon 
slopes of sufficient inclination in order to account, both for the 
striations of the rocks and the heterogeneous structure of the 
deposit. In the absence or meagerness of knowledge, however, 
upon this subject, and in view of the evidence that farther south 
upon this mountain, the ice-sheet abutted at a level of 760 feet, 
it may be more rational to suppose that over some passes, not yet 
discovered, some fingers of the ice-sheet may have extended for 
a sufficient time to form these limited and sharply isolated de- 
posits. 

Great relative antiquity as compared with the moraine to the 
north has been thought to attach to the deposit at High Bridge, 
as evinced by the extreme oxidation, leaching and ferrugination 
of its elements. The facts already stated will perhaps show why 
it possesses these characters. Its materials have never been sub- 
jected to the washing and scouring of a long glacial journey. 
The results of ancient oxidation and kaolinic decomposition are 
still visible in its elements just as they are inthe rotting Archean 
gneiss at its side, which still remains in place. It is also the case 
that the stratified portion of the deposit has been cemented into a 
veritable conglomerate, so tough that blasting was necessary in 
its excavation, by a highly ferruginous cement, whose origin is 
not far to seek. For here, as at Oxford Furnace, the gneiss con- 
tains a considerable proportion of ferruginous minerals, and at 
the High Bridge mines close by, it may be seen graduating into 
a large-grained hornblende schist, lying close to the layers of 
iron ore. The drainage water from such rocks as these w ill in- 


216 The American Geologist. October, 1892 


evitably supply an abundant quantity of ferruginous material to 
the deposits at its base. 

The interpretation given to these extra-morainic deposits must 
of necessity have its bearing upon the question as to the exist- 
ence of an earlier ice-sheet which once covered the state of New 
Jersey as far south as Trenton and the line of the yellow gravels. 
So far as the deposits which we have discussed can be referred to 
the later ice-sheet, or to water transportation or to any other sim- 
pler and sufficient causes so far, of course, they must fail to give 
support to the theory of an earlier ice-sheet. 

While not wishing to enter fully at the present time upon a 
discussion of the existence of such an ice-sheet in the past, I 
will, in closing, mention two points, which while negative, would 
still seem to have something more than a negative bearing against 
such a supposition. 

The first is, that no such ice-sheet has done duty in depositing 
northern material over the large Triassic area of Hunterdon county. 
Nota northern pebble could I find upon the high plateau west of 
Flemington, in the region about Cherryville, Quakertown, Croton 
and Little York, where the elevation is from 500 to 650 feet. Nor 
are there any on the low ground at Flemington and southward and 
eastward, where the elevation is from 125 to 250 feet. At hundreds 
of places the entire thickness of the soil is exposed down to the 
rock in place, and the complete identity of the soil with the un- 
derlying rock, without any foreign admixture, is perfectly clear. 

Finally there may be added one critical test, of the same sort, 
to which this supposed ice-sheet has failed to respond. It has 
failed to disturb the fragments of trap rock that lie upon the sum- 
mit of Sourland mountain, where they have been exposed to the 
weather presumably since the close of the Jurassic age. Sour- 
land mountain is a low swell, reaching an altitude of about 500 
feet and extending from Neshanic, southwestwardly to the Dela- 
ware river at Lambertville. The center line is trap while this is 
flanked on both sides by indurated Triassic shales. I have crossed 
this mountain at three different places, at Buttonwood Corners, at 
a point two miles west of Rocktown and at Lambertville, and at 
no point do these diabase bowlders appear to have been carried 
over upon the borders of the Triassic, by any force whatever, not 
even by gravity. It is difficult to see how an ice-sheet could 
have passed over without transporting some of these fragments. 


PLEISTOCENE. PAPERS AT THE ROCHESTER 
. MEETINGS. 

During the sessions of the Geological Society of America, 
August 15 and 16, and of Section E (Geology and Geography) 
of the American Association for the Advancement of Science, 
August 17-22, 1892, in Rochester, N. Y., a considerable number 
of papers, which are here briefly noticed, related to the Pleisto- 
cene period. 

GEOLOGICAL SOCIETY OF AMERICA, 

Studies of the Connecticut Valley Glacier. By C. H. Hrren- 
cock. The portion of the Connecticut river valley described in 
this paper extends from Lyme and Hanover south to Claremont, 
N. H. On each side of the valley the enclosing hills and uplands 
rise within a few miles to a hight of 500 feet or more above the 
river. Glacial strive on these highlands bear somewhat uniformly 
about 8. 30° E., while in the valley their prevailing direction is 
to the south or slighly west of south, conforming with the course 
of this depression. Bowlders and other drift materials have been 
transported in these diverse directions, southeastward on the higher 
country and southward in the valley. But oceasionally striz of an 
earlier southeastward glaciation are also found in the valley, pre- 
served in hollows or on sheltered parts of the rock surface and sur- 
rounded by the marks of the southward ice-flow. Either the cur- 
rents of the ice-sheet were here deflected southward during a late 
stage of the general glaciation, or a local glacier lingered in this 
valley after the ice on the higher land was melted, the latter being 
regarded by the author as the more probable explanation, 

In the ensuing discussion, Mr. WARREN UpHam spoke of the 
Connecticut valley esker (called a kame in the Geology of New 
Hampshire, vol. iii), which was traced twenty-four miles along 
the axis of this portion of the valley from Lyme, N. H., south 
to Windsor, Vt. When the receding border of the ice-sheet had 
become thinned by ablation, its surface here descended from each 
side toward the superglacial river by which the esker was being 
formed, and there was probably an indentation or embayment of 
the glacial boundary at the river’s mouth. The glacial currents 
which had before passed southeastward even in the bottom of the 
valley appear to have then turned to the south and west of south, 
being deflected perpendicularly toward the indented edge of the 
waning ice-sheet. 


218 The American Geologist. October, 1892 


Profs. E. W. CuaypoLe and W. H. Nixes doubted that an 
embayment of the ice-border could be formed in the Connecticut 
valley, and referred to the valley glaciers of alpine districts as 
suggestive that local glaciers might continue in valleys for some 
time after the departure of the ice-sheet from the adjoining high- 
lands. 

Mr. G. K. GiLtBert spoke of the question whether the abla- 
tion of the departing ice-sheet caused its portion south of the 
White mountains and southeast of the Green mountain range to 
be at last divided by these highlands from the ice farther north, 
so that its pressure by a great thickness of ice in Canada ceased, 
leaving the southern portion to take new courses of outflow de- 
pendent only on its own mass and the contour of the land. 

Conditions of accumulation of drumlins. By WARREN UP- 
HAM. Descriptions of the various forms of these hills of glacial 
drift or till, and of their known distribution in the United States 
and Canada, were followed by discussion of the evidences that 
they were accumulated rapidly beneath the thinned and receding 
border of the ice-sheet, being probably in large part built up by 
lodgment of previously englacial drift. In becoming lodged on 
the drumlins or on other and low deposits of subglacial till, 
bowlders and pebbles of drift that had been englacial would be 
considerably striated and planed; but the drift which fell loosely 
on the surface from an englacial or superglacial position when the 
ice disappeared would be mostly angular, not being thus sub- 
jected to attrition. At a great distance from the edge of the ice- 
sheet and within all its central area, the currents of its upper and 
lower portions probably moved outward with nearly equal rates, 
the upper movement being somewhat faster than at the base, 
Upon a belt extending many miles back from the margin, how- 
ever, where the slope of the ice-surface had more descent, the 
upper currents of the ice, unsupported on the outer side, would 
move several times faster than its lower currents, which were im- 
peded by friction on the land. There would be accordingly 
within this belt a strong tendency of the ice to flow outward with 
curved currents, tending first to carry drift upward into the ice- 
sheet and later to bear it downward and deposit it partly beneath 
the edge of the ice and partly along the ice boundary. The 
author believed the drumlins to be submarginal drift accumula- 
tions chiefly so deposited inside the course of contemporaneous 


Pleistocene Papers at the Rochester Meetings. 219 


terminal moraines, or often formed during the glacial recession 
while no halt or re-advance of the receding ice-margin permitted 
the formation of moraines. But the irregular distribution and 
grouping of the drumlins, their absence upon many large areas 
thickly covered by drift, and the occasional occurrence of lone 
drumlins, remain to be explained and seem to present the most 
difficult problem relating to the action of the ice-sheet. 

In discussion, Prof. R. D. SALIsBuRY thought the accumula- 
tion of drumlins easy to understand, but could not account for 
their occurrence in limited belts and groups or singly, while ad- 
joining large tracts have none. The term englacial drift he would 
restrict to the drift carried long distances in the upper part of the 
ice without intermingling with the more plentiful drift in the basal 
part of the ice-sheet. Much of the drift transportation he be- 
lieves to have taken piace by dragging under the ice. 

The extra-morainic drift of the Susquehanna valley. By G. 
FREDERICK WRIGHT. The extreme advance of the ice-sheet is 
held to be marked in the Susquehanna region by a thin mantle of 
drift with plentiful bowlders, extending to a distance of several 
miles in front of the conspicuous belt of hilly drift denominated 
the terminal moraine. In tracing the moraine through Pennsyl- 
vania, the author, with the late Prof. Henry Carvill Lewis, named 
this extra-morainic drift a ‘‘fringe,’* believing its deposition to 
have been nearly contemporaneous with the accumulation of the 
morainic hills. Terraces of stratified drift deposits, with infre- 
quent bowlders, occurring farther south along the Susquehanna, 
which have been regarded by McGee as evidence of a marine 
submergence changing the valley to an estuary, are thought in- 
stead to be of fluvial origin, belonging to a time when the land 
there was slightly depressed, but not to the sea level, near the 
close of the Glacial period. 

In discussion, Mr. W J McGee defended his interpretation of 
the terraces; and Prof. R. PD. SAtisspury objected to the term 
‘‘fringe,”’ because this extra-morainic drift is referred by him, as 
also by McGee and others, to an earlier epoch of glaciation, ap- 
parently several times as long ago as the last glacial epoch when 
the moraine was formed, 


SECTION E, AMERICAN ASSOCIATION. 
Terminal moraines in New England. By C. H. Hircncock. 


220 The American Geologist. October, 1892 


After referring to the outer moraines which were traced fifteen 
years ago on Long Island, Martha’s Vineyard, Nantucket, the 
Elizabeth Islands, and Cape Cod, and the moraine in northern 
Massachusetts recently reported by Mr. Ralph 8. Tarr as reach- 
ing from Cape Ann westerly to the Connecticut river, the author 
described morainic belts which he has observed in New Hamp- 
shire and Vermont, characterized by drift hills and knolls of very 
irregular and broken contour, with abundant bowlders, and en- 
closing many ponds in depressions of the drift. One of these 
belts extends from the south side of Squam lake northeasterly to 
the vicinity of Conway, N. H. Another is traceable from near 
Burlington, Vt., eastward to Umbagog lake and the Rangely 
lakes in the west edge of Maine. 

A passage in the history of the Cuyahoga river. By BE. W. 
CLAYPoLE. This river of northern Ohio flows in a preglacial 
valley along nearly all its course from Akron to its mouth at 
Cleveland. In one place, however, the river flows in a rocky 
gorge on the west side of the old valley, which there had become 
filled with drift to a hight somewhat above its enclosing rock-wall. 
The postglacial erosion of this gorge and of the drift filling the 
valley seems capable of affording, with further study, a measure 
of the time since the recession of the ice-sheet from that area. 

Notes bearing upon the changes of the preglacial drainage of 
western Illinois and eastern Towa. By FRANK LEVERETT. Deep 
wells indicate that a drift-filled valley extends from the Missis- 
sippi river near its most eastern portion on the boundary of Lowa, 
above the Rock Island rapids, southeasterly to the Illinois river. 
It seems therefore worthy of inquiry whether this may have been 
the preglacial course of the Mississippi, since the rock gorges of 
the Rock Island and Des Moines rapids show that between south- 
eastern Iowa and Illinois it has cut a new channel after being 
turned from an earlier valley by the ice-sheet. In preglacial and 
interglacial times, however, a largeriver ran in the present course 
of the Mississippi below Keokuk, and the drift-filled valley of 
this river was traced by Gen. G. K. Warren past the Des Moines 
rapids on their west side. 

Extra-morainic drift in New Jersey. By A. A. Wrieur. In 
the west part of northern New Jersey a general sheet of till 
covers the country southward from the terminal moraine at Bel- 
videre for a distance of a dozen miles, across Scott’s and Pohat- 


Pleistocene Papers at the Rochester Meeting. 221 


cong mountains to the Musconetcong range. ‘This drift sheet 
encloses plentiful bowlders and smaller rock fragments from 
formations lying north of the terminal moraine, and _ it is be- 
lieved by the author and by Prof. G. F. Wright that it belongs 
to the same epoch of glaciation as the moraine itself. Close 
south of the Musconetcong mountain isolated deposits of till are 
found at Pattenburgh and High Bridge, which contain chiefly or 
only stones derived from adjacent formations, having none from 
the sandstone of the Kittatinny range, although that sandstone is 
plentiful in the drift between the terminal moraine and the Mus- 
conetcong mountain. The Pattenburgh and High Bridge de- 
posits seem therefore referable to local glaciers, probably con- 
temporaneous with the maximum extension of the general ice- 
sheet. 

In discussion of this paper, Prof. R. D. Sanispury and W J 
McGEE attributed the extra-morainic drift of this district to a 
far more ancient glaciation than that which formed the terminal 
moraine at the farthest limit attained by the last ice-sheet. If 
the antiquity of the moraine be expressed by unity, that of the 
drift reaching thence southward, as shown by the progress of 
subaérial erosion and by the oxidation of the drift and the decay 
of its bowlders and pebbles, appears to require surely two figures 
for its expression. ‘This drift beyond the moraine has been es- 
timated variously to be from ten to fifty times as old as the mo- 
raine and the drift sheet that extends thence northward. 

Paleobotany of the Yellow Gravel at Bridgeton, N. J. By 
ArtTHUR Houiick. Leaves of about twenty-five species of plants, 
representing nearly twenty genera, among which are Magnolia, 
Asimina, Diospyros, and Persea, have been collected from the 
vellow gravel, sand, and loam at Bridgeton, in southern New 
Jersey, the only locality where fossils of any kind have been 
found in that formation. All these species are still living in 
the flora of the southern states, but none of them range north 
of New Jersey. It is the most completely recent collection of 
plants ever found in a fossilized condition. 

Mr. McGeg, in discussion, doubted that this deposit could be 
referred to either the Lafayette or Columbia formations, and sug- 
gested that more probably it had been eroded and re-deposited 
during the postglacial epoch, then receiving its fossil leaves. 

Mr. Lester F. Warp, having examined the locality, believed 


992, The American Geologist. October, 1892 


that the stratum containing the leaves is a part of the Lafayette 
formation, having not been disturbed since its original deposition, 
On this evidence the Lafayette epoch would belong in the Pleis- 
tocene period, instead of the Pliocene, to which it has been pro- 
visionally referred. 

Submarine valleys on continental slopes. By WARREN UPHAM. 
The submarine fjord of the Hudson river, whose bottom is 2,844 
feet below the sea level, and the similar valleys discovered by 
Prof. George Davidson off the coast of California, one of which 
sinks to the depth of 3,120 feet where it crosses the submarine 
contour line of 600 feet on the continental slope, are surpassed 
by the submerged canon of the river Congo. This canon, of 
which a description and map are given by Mr. J. Y. Buchanan, 
in the Scottish Geographical Magazine for May, 1887, extends 
about a hundred miles out to sea from the mouth of the Congo, 
and descends to a depth of more than 6,000 feet beneath the sea 
level. Along its last twenty miles before it enters the ocean, the 
Congo has a depth of 600 to 1,450 feet. At the mouth of the 
river the width of this gully, as Mr. Buchanan calls it, is three 
miles, and its depth is 2,000 feet. Thirty-five miles out to sea, 
the width of the gullied submarine valley or canon is six miles, 
and its depth 3,440 feet. At the distance of seventy miles off 
shore the general slope has fallen off to the depth of 3,000 feet, 
and below this the cafion has an additional depth of 3,000 feet 
more, thesounding to its bottom being 6,000 feet. Several other 
very remarkable submarine valleys are found on this western 
coast of Africa near the equator. 

Though Mr. Buchanan attributes these submerged canons to 
the action of marine currents setting in landward under the lighter 
fresh water of the river, while the land, according to his belief, 
has held its present relation to the sea level, geologists who have 
studied the submarine valleys of the eastern and western coasts 
of North America will confidently refer their origin in Africa, as 
on our own continental borders, to a formerly greater altitude of 
the land when it stood higher than now by as great an amount as 
the depths of the canons below the ocean’s surface. 

That the Congo submarine valley is not yet filled with the al- 
luvial silt of the river, which discolors the surface water to the 
distance of many miles off shore, proves that the subsidence of 
the land from its former altitude was geologically recent. These 


Pleistocene Papers at the Rochester Meeting. 223 


great epeirogenic movements of the plateau forming the southern 
half of Africa, like the oscillations shown by submerged valleys 
and fjords of North America and Europe, ranging in depth to 
4,080 feet in the Sogne fjord of Norway, took place doubtless no 
longer ago than during the Pleistocene or Glacial period, and the 
closing stage of the preceding Tertiary era, It seems also cer- 
tain that these earth movements had an intimate relationship with 
the origin of the great lakes of Africa and with the accumula- 
tion and departure of the North American and European ice- 
sheets. 

In discussion, Prof. JosEpH LEConrTE directed attention to the 
occurrence of submarine valleys on the California coast where no 
rivers now enter the sea. Not only a great uplift and subsequent 
depression of the continental plateau, but also vast outflows of 
lava and the formation of mountain ranges by which river courses 
have been changed, are there referable to late Tertiary and 
Quaternary time. 

Pleistocene Geography. By W J McGerr. A series of several 
maps was displayed and described, showing the extent of ive- 
sheets in North America during the first, second, and third glacial 
epochs which are recognized by the author, the extent of coastal 
submergence by the sea during these epochs, and the areas of 
the Pleistocene lakes Bonneville, Lahontan, and others, in the 
arid Great Basin of interior drainage. The deposition of the 
loess in the upper Missouri region was attributed to lakes and 
broad river floods, more or less obstructed by the ice-sheets. At 
present no sufficient data have been obtained for a correlation of 
the epochs of glaciation east of the Rocky mountains with those 
of the Cordilleran mountain belt and the Pacific coast. 

Distribution of the Lafayette formation. By W J McGerr. 
The gravel, sand, and loam beds formerly called the Appomattox 
formation, for which the name Lafayette is now substituted, oc- 
cupy the coastal plain from New Jersey soutliward to northern 
Florida and westward through the gulf states into Mexico. An 
area of 100,000 square miles has this formation at its surface; 
upon an equal area the Lafayette beds are thinly covered by the 
similar but considerably later Columbia formation; and from still 
another area of the same extent the Lafayette formation has been 
removed by stream erosion. Its original extent was therefore 
not less than 300,000 square miles. It is believed to have been 


294 The American Geologist. October, 1892 


deposited while this low plain was covered by the sea, but the 
Appalachian mountain belt appears to have then stood somewhat 
above its present hight. Between the coastal submergences to 
which the Lafayette and Columbia beds are referred, this plain 
was elevated higher than now and the Chesapeake and Delaware 
bays were formed by the erosion of the Susquehanna and Dela- 
ware rivers. If time since the recession of the latest ice-sheet 
has been 7,000 years, as is shown to be probable by the studies 
of N. H. Winchell, Gilbert, Wright, and others, the amount of 
erosion since the Columbia and Lafayette epochs indicates that 
they were respectively some 200,000 years and 10,000,000 years 
ago, the Lafayette being apparently fifty times as long ago as the 
Columbia, and the latter thirty times older than the last glacial 
epoch. 

In discussion, Mr. UpHAm questioned whether a simpler view 
of the epeirogenic movements producing the Lafayette formation 
might not be found in ascribing these beds to deposition by flooded 
rivers descending from the Appalachian mountain region and 
from the Mississippi basin, as shown by Hilgard, spreading the 
gravel, sand and loam over the coastal plain during the early 
part of a time of continental elevation. As this elevation in- 
creased, the rivers would attain steeper slopes and finally erode 
much of the deposits which they had previously made. During 
the culmination of the uplift, Chesapeake and Delaware bays 
were excavated, and erosion was in progress at a far more rapid 
rate than with the present low altitude of this region. The time 
ratios assigned to the Lafayette and Columbia formations in com- 
parison with the last glacial epoch may therefore be greatly ex- 
aggerated, and. they may belong wholly to the Pleistocene or 
Glacial period. 

Pror. E. D. Coprt doubted that the physical characters of 
the Lafayette beds could be produced by fluvial sedimenta- 
tion. 

Pres. T. C. CHAMBERLIN considered the question whether the 
Lafayette formation was mainly of marine or of fluvial origin 
undecided, but in New Jersey, at least, according to the studies 
of Prof. Salisbury, the latter view appears the more prob- 


able. 


225 


BRITISH ASSOCIATION FOR THE ADVANCEMENT 
OF SCIENCE.—EDINBURGH MEETING. 


Opening address by Pror. C. Lapwortn, LL, D., F. R.S., F. G. 8., President 
of the Section of Geology. 

It has, I believe, been the rule for the man who has been honored by 
election to the chair of President of the Geological Section of the Brit- 
ish Association to address its members upon the recent advances made 
in that branch of geology in which he has himself been most immedi- 
ately interested. It is not my intention upon the present occasion to de- 
part from this time-honored custom; for it has both the merit of sim- 
plicity and the advantage’of utility to recommend it. In this way each 
branch of our science, as it becomes in turn represented, not only sub- 
mits to the workers in other departments a report of its own progress, 
but presents by implication a broad sketch of the entire geological land- 
scape, seen through the colored glasses, it may be, of divisional preju- 
dice, but at any rate instructive and corrective to the workers in other 
departments, as being taken from what is to them a novel and an un- 
familiar point of view. 

Now every tyro in geology is well aware of the fact that the very 
backbone of geological science is constituted by what is known as strati- 
graphical geology, or the study of the geological formations. These 
formations, stratified and unstratified, build up all that part of the vis- 
ible earth-crust which is accessible to the investigator. Their outcrop- 
ping edges constitute the visible exterior of our globe, the surface of 
which forms the physical geography of the present day, and their .in- 
ternal characters and inter-relationships afford us our only clues to the 
physical geographies of bygone ages. Within them lies enshrined all 
that we may ever hope to discover of the history and the development 
of the habitable world of the past. 

These formations are to the stratigraphical geologist what species are 
to the biologist, or what the heavenly bodies are to the astronomer. It 
was the discovery of these formations which first elevated geology to 
the rank of a science. In the working out of their characters, their re- 
lationships, their development, and their origin, geology finds its means, 
its aims, and its justification. Whatever fresh material our science may 
yield to man’s full conception of nature, organic and inorganic, must of 
necessity be grouped around these special and peculiar objects of its 
contemplation. 

When the great Werner first taught that our earth-crust was made up 
of superimposed rock-sheets or formations arranged in determinable or- 
der, the value of his conclusions from an economic point of view soon 
le] to their enthusiastic and careful study; and his crude theory of their 
successive precipitation from a universal chaotic ocean disarmed the 
suspicions of the many until the facts themselves had gained such a 
wide acceptance that denial was no longer possible. But when the 
greater Hutton asserted that each of these rock formations was in reality 
nothing more nor less than the recemented ruins of an earlier world, the 


226 The American Geologist. October, 1892 


prejudices of mankind at large were loosed at asingle stroke. Like 
Galileo’s assertion of the movement of the globe, this demanded such a 
simple and apparently undignified mode of creation that there is no 
wonder that, even down to the present day, there still exist some to 
whom this is a hard saying, to be taken, if taken at all, in homceopathic 
doses and with undisguised reluctance. © 

Hutton, as regards his philosophy, was, as we know, far in advance of 
his time. With all the boldness of conviction he unflinchingly followed 
out these ideas to their legitimate results. He claimed that as the 
stratified formations were composed of similar materials—sands, clays, 
limestones, and muds—to those now being laid down in the seas around 
our present coasts they must, like them, have’ been the products of or- 
dinary natural agencies—of rain, rivers and sea waters, internal heat and 
external cold—acting precisely as they act now. And further as these 
formations lie one below the other, in apparently endless downward 
succession, and are all formed more or less of these fragmentary mate- 
rials, so the present order of natural phenomena must have existed for 
untold ages. Indeed, to the commencement of this order he frankly ad- 
mits, “I see no trace of a beginning or sign of an end.” 

The history of the slow acceptance of Hutton’s doctrines, even among 
geologists, is, of course, perfectly familiar to us all. William Smith re- 
duced the disputed formations to order, and showed that not only was 
each composed of the ruins of a vanished land, but that each contained 
in its fossils the proof that it was deposited in a vanished sea inhabited 
by special life creation. Cuvier followed, and placed it beyond ques- 
tion that the fossilized relics of these departed beings were such as 
made it absolutely unquestionable that these creatures might well have 
inhabited the earth at the present day. Lyell completed the cycle by 
demonstrating stage by stage the efliciency of present natural agencies 
to do all the work required for the degradation and rebuilding of the 
formations. Since his day the students of stratigraphical geology have 
universally acknowledged that in the study of present geographical 
causes lies the key to the geological formations and the inorganic world 
of the past. 

In this way the road was paved for Darwin andthe doctrine of de- 
scent. The aid which had been so ungrudgingly afforded by biology to 
geology was repaid by one of the noblest presents ever made by one 
science toanother. Forthe purposes of geology, the science of biology had 
practically completed a double demonstration: first, that the extinct life 
discernible in the geological formations was linked inseparably with the 
organic life of the present; and, second, that every fossil recognized by 
the geologist was the relic of acreature that might well have existed upon 
the surface of the earth at the presenttime. Geology repaid its obligation 
to biology by the still greater two-fold demonstration: first, that in the 
economy of nature the most insignificant causes are competent to the 
grandest effects, if only a sufficiency of time be granted them; and, sec- 
ond, that in the geological formations we have the evidences of the ac- 
tual existence of those mighty eons in which such work might: be done. 


British Association, Edinburgh Meeting—Lapworth. 227 


The doctrine of organic evolution would always have remained a 
metaphysical dream had geology not given the time in which the evolu- 
tion could be accomplished. The ability of present causes to bring 
about slow and cumulative changes in the species is, to all intents and 
purposes, a biologicalapplication of Hutton’s ideas with respect to the 
origin of the geological formations. Darwin was a biological evolution- 
ist, because he was first a uniformitarian geologist. Biology is pre- 
eminent to-day among the natural sciences, because its younger sister, 
Geology, gave it the means. 

But the inevitable consequence of the work of Darwin and his col- 
leagues was that the centre of gravity, so to speak, of popular regard and 
public controversy was suddenly shifted from stratigraphical geology to 
biology. Since that day stratigraphical geology, to its great comfort and 
advantage, has gone quietly on its way unchallenged,,and all its more 
recent results have, at least by the majority of the wonder-loving public, 
been practically ignored. 

Indeed, to the outside observer it would seem as if stratigraphical ge- 
ology for the last thirty years had been practically at a standstill. The 
startling discoveries and speculations of the brilliant stratigraphists of 
the end of the last century and first half of the present forced the ge- 
ology of their day into the very front rank of the natural sciences, and 
made it perhaps the most conspicuous of them all in the eyes of the 
world at large. Since that time, however, their successors have been 
mainly occupied in completing the work of the great pioneers. The 
stratigraphical geologists themselves have been almost, wholly occupied 
in laying down upon our maps the superficial outlines of the great 
formations, and working out their inter-relationships and subdivisions. 
At the present day the young stratigraphical student soon learns that all 
the limits of our great formations have been laid down with accuracy 
and clearness, and finds but little to add to the accepted nomenclature 
of the time. ° 

Our paleontologists also have equally busied themselves in working 
out the rich store of the organic remains of the geological formations, 
and the youthful investigator soon discovers that almost every fossil he 
is able to detect in the field has already been named, figured, and de- 
scribed, and its place in the geological record more or less accurately 
fixed. 

In France, in Germany, in Norway, Sweden, and elsewhere, in Canada 
and in the United States, work as thorough and as satisfactory has been 
accomplished, and the local development of the great stratified forma- ° 
tions and their fossils laid down with detail and clearness. 

Many an unfledged, but aspiring geologist, alive to these facts, and 
contrasting the well-mapped ground of the present time with the virgin 
lands of the days of the great pioneers, finds it hard to stifle a feeling of 
keen regret that there are nowadays no new geological worlds to con- 
quer, no new systems to discover and name, and no strange and unex- 
pected faunas to unearth and bring forth to the astonished light of day, 
The youth of stratigraphical geology, with all its wonder and freshness, 


228 The American Geologist. October, 1892 


seems to have departed, and all that remains is to accept, to commemor- 
ate, and to round off the glorious victories of the dead heroes of our 
science. 

But to the patient stratigraphical veteran, who has kept his eyes open 
to discoveries new and old, this lu]l in the war of geological controversy 
presents itself rather as a grateful breathing time; the more grateful as 
he sees looming rapidly upin front the vague outlines of those oncoming 
problems which it will be the duty and the joy of the rising race of young 
geologists to grapple with and to conquer, as their fathers met and van- 
quished the problems of the past. He knows perfectly well that Geol- 
ogy is yet in her merest youth, and that to justify even her very exist- 
ence there can be no rest until the whole earth-crust and all its phenom- 
ena, past, present, and to come, have been subjected to the domain of 
human thought and comprehension. There can be no more finality in 
Geology than in any other science; the discovery of to-day is merely the 
stepping-stone to the discovery of to-morrow; the living theory of to- 
morrow is nourished by the relics of its parent theory of to-day. 

Now if we ask what are these formations which constitute the objects 
of study of the stratigraphical geologist, I am afraid that, as in the case 
of the species of the biologist, no two authorities would agree in framing 
precisely the same definition. The original use of the term formation 
was of necessity lithological, and even now the name is most naturally 
applied to any great sheet of rock which forms a component member of 
the earth-crust; whether the term be used specifically for a thin homo- 
geneous sheet of rock like the Stonesfield slate, ranging overafew square 
miles; or generically, for a compound sheet of rock, like the Old Red 
Sandstone,many thousands of feet in thickness, but whose collective lith- 
ological characteristics give it an individuality recognizable over the 
breadth of an entire continent. 

When Werner originally discovered that the “formations” of Saxony 
followed each other in a certain recognizable order, a second character- 
istic of a formation became superposed upon the original lithological 
conception—namely, that of determinate “relative position.” And 
when William Smith proved that each of the formations of the English 
Midlands was distinguished by an assemblage of organic remains pecul- 
iar to itself, there became added yet a third criterion—that of the posses- 
sion of “characteristic fossils.” 

But thesa later superposed conceptions of time-succession and life-type 
are far better expressed by dividing the geological formations into zoo- 
logical zones, on the one hand, and grouping them together, on the other 
hand, into chronological systems. For in the experience of every geolo- 
gist he finds his mind instinctively harking back to the bare lithological 
application of the word “formation,” and I do not see that any real ad- 
vantage is gained by departing from the primitive use of the term. 

A zone, which may be regarded as the wnit of paleontological succession, 
is marked by the presence of a special fossil, and may include one or 
many subordinate formations. A system, which is, broadly speaking, the 
unit of geological succession, includes many “zones,” and often, but not al- 


British Association, Kdinburgh Meeting—Lapworth. 229 


ways, many “formations.” <A formation, which is the unit of geological 
stratigraphy, is a rock sheet composed of many strata possessing com- 
mon lithological characters. The formation may be simple, like the 
Chalk, or compound, like the New Red sandst ne; but, simple or com- 
pound, local or regional, it must be always recognizable, geographically 
and geologically, as a lithological individual. 

As regards the natural grouping of these lithological individuals as 
such, fair progress has been made of late years, and our information is 
growing apace. We know that there are at any rate three main groups: 
1st, the stratified formations due to the action of moving water above 
the earth-crust; 2d, the igneous formations which are derived from be- 
low the earth-crust; 3d, the metamorphic formations which have un- 
dergone change within the earth-crust itself. We know also that of 
these three the only group which has hitherto proved itself available for 
the purpose of reading the past history of the globe is that of the strati- 
fied formations. 

Studying these stratified formations therefore in greater detail, we 
find that they fall naturally in their turn into two sets—viz., a mechanical 
set of pebble beds, sandstones and clays formed of rock fragments 
washed off the land into the waters, and an organic set of limestones, 
chalk, &c., formed of the shells and exuvie of marine organisms. 

But when we attempt a further division of these two sets, our classifi- 
cation soon begins to lose its definiteness. We infer that some forma- 
tions, such as the Old Red and the Triassic, were the comparatively 
rapid deposits of lakes and inland seas; that others, like the Coal Meas- 
ures, London clay, &c., were the less rapid deposits of lagoons, river 
valleys, deltas, and the like; that others, like our finely laminated shales 
and clays of the Silurian and Jurassic, were the slower deposits of the 
broader seas; and finally, that others, like our Chalk and Greensand, 
were possibly the extremely slow deposits of the more oceanic deeps. 

Nevertheless, after looking at the formations collectively, there re- 
mains no doubt whatever ia the mind of the geologist that their me- 
chanical members are the results of the aqueous degradation of vanished 
lands, and that their organic members are the accumulated relics of the 
stony secretions of what once were living beings. Neither is there any 
possibility of escape from the conclusion that they have all been depos- 
ited by water in the superficial hollows of the sea-bottoms and ocean 
floors of the earth-crust of their time. ; 

In the life of every individual stratified formation of the mechanical type 
we can always distinguish three stages: first, the stage of erosion and 
transportation, in which the rock fragments were worn off the rocks of 
the higher ground and washed down by rain and rivers to the sea; sec- 
ond, astage of deposition and consolidation below the surface of the 
quiet waters; and third, a final stage in which the completed rock for- 
mation was bent and upheaved, in part at least, into solid land. In the 
formations of the organic type three corresponding stages are equally 
discernible: first, the period of mineral secretion by organized beings; 
second, the period of deposition and consolidation; and third, the final 


230 The American Geologist. October, 1892 


period of local elevation in mass. But one and all, mechanical and or- 
ganic alike, they bear in their composition, in their arrangement, and in 
their fossils, abundant and irresistible evidences that they were the pro- 
ducts, and that now they are the memorials of the physical geography of 
their time. 

Guided by the principles of Hutton and Lyell, geologists have worked 
out with great care and completeness the effects of those agencies which 
rule in the first of these three life-stages in the history of a mechanical 
formation. No present geological processes are better known to the 
young geologist than those of denudation, erosion, and transportation, so 
familiar to us in the eloquent works of our president. They form to- 
gether the subject matter of that most wonderfully fascinating chapter 
in geology, which, from its modest opening among the quiet Norfolk 
sandhillsssweeps upwards and onwards without a break to its magnificent 
close on the brink of the gorge of the Colorado. But our knowledge 
of the detailed processes of deposition and consolidation which rule in 
the second stage is still exceedingly imperfect, although a flood of light 
has been thrown upon the subject by the brilliant results of the Challen- 
ger expedition. And we are compelled to admit that our knowledge of 
the operations of those agencies which rule in the processes of upheaval 
and depression isas yet almost nil; and what little we have already 
learnt of the effects of those agencies is the prey of hosts of conflicting 
theories that merely serve to annoy and bewilder the working student 
of the science. 

But not one of the formative triad of detrition, deposition, and eleva- 
tion can exist without the others. No detrition is p»ssible without the 
previous upheaval of th3 rock-sheet from which material can be re- 
moved; no deposition is possible without the previous depression of the 
rock-sheet which forms the basin in which the fragmentary material 
can be laid down. 

Our knowledge, therefore, of the origin and meaning of any geologi- 
cal formation whatever, can at most be only fragmentary until this third 

chapter in the life-history of the geological formation has been attacked 
in earnest. 

Now all the rich store of knowledge that we possess respecting the 
first stage in the life of a geological formation has been derived froma 
comparison of certain phenomena which the stratigraphical geologist 
finds in the rock formations of the past, with correspondent phenomena 
which the physical geographer discovers on the surface of the earth of 
the present. And all that we know of the second stage again has been 
obtained in precisely the same way. Surely analogy and common sense 
both teach us that all which is likely to be of permanent value to us as 
regards the final stage of elevation and depression must first be sought 
for in the same direction. 

Within the last twenty years or so many interesting and vital discov- 
eries have been made in the stratigraphy of the rock formations, which 
bear largely upon this obscure chapter of elevation and depression. And 
I propose on this occasion that we try to summarize a few of these new 


British Association, Edinburgh Meeting—Lapworth. 231 


facts, and then, reading them in conjunction with what we actually 
know of the physical geography of the present day, try to ascertain how 
such mutual agreement as we can discover may serve to aid the strati- 
graphical geologist in his interpretation of the true meaning of the geolog- 
ical formations themselves. We may not hope for many years to come 
to read the whole of this geological chapter, but we may perhaps mod- 
estly essay an interpretation of one or two of the opening paragraphs. 

In the physical geography of the present day we find the exterior of 
our terraqueous globe divided between the two elements land and water. 
We know that the solid geological formations exist everywhere beneath 
the visible surface of the lands, but of their existence under the present 
ocean floor we have as yet no absolute certainty. We know both the 
form of the surface and the composition of the outer layers of the conti- 
nental parts of the lithosphere; we only know as yet even in outline the 
form of the surface of its oceanic portions. The surface of each of our 
great continental masses of land resembles that of a long and broad 
arch-like form, of which we see the simplest type in the New World. 
The surface of the North American arch is sagged downwards in the 
middle into a central depression which lies between two long marginal 
plateaux, and these plateaux are finally crowned by the wrinkled crests 
which form its modern mountain systems. The surface of each of our 
ocean floors exactly resembles that of a continent turned upside down. 
Taking the Atlantic as our simplest type, we may say that the surface of 
an ocean basin resembles that of a mighty trough or syncline,buckled up 
more or less centrally into a medial ridge, which is bounded by two long 
and deep marginal hollows, in the cores of which still deeper grooves 
sink to the profoundest depths. This complementary relationship de- 
scends even to the minor features of the two. Where the great conti- 
nental sag sinks below the ocean level, we have our gulfs and our Med- 
iterraneans, seen in our type continent as the Mexican gulf and Hudson 
bay. Where the central oceanic buckle attains the water line, we have 
our oceanic islands, seen in our type ocean as St. Helena and the Azores. 
Although these apparent crust-waves are neither equal in size nor sym- 
metrical in form, this complementary relationship between them is al- 
ways discernible. The broad Pacific depression seems to answer to the 
broad elevation of the Old World—the narrow trough of the Atlantic to 
the narrow continent of America. 

Every primary wave of the earth’s surface is broken up into minor 
waves,in each of which the ridge and its complementary trough are always 
recognizable. Thecompound ridge of the Alps answers to the compound 
Mediterranean trough; the continuous western mountain chains of the 
Americas to the continuous hollow of the eastern wacific which bounds 
them; the sweep of the crest of the Himalaya to the curve of the Indo- 
Gangetic depression. Even where the surface waves of the lithosphere 
lie more or less buried beneath the waters of the ocean and the seas, the 
same rule always obtains. The island chains of the Antilles answer to 
the several Caribbean abysses, those of the Hgean archipelago answer 
to the Levantine deeps. 


232 The American Geologist. October, 1892 


Draw a section of the surface of the lithosphere along a great circle in 
any direction, the rule remains always the same;crest and trough, hight 
and hollow, succeed each other in endless sequence, of every gradation 
of size, of every degree of complexity. Sometimes the ridges are conti- 
nental, like those of the Americas; sometimes orographic, like those of 
the Himalaya; sometimes they are local, like those of the English Weald. 
But so long as we do not descend to minor details we find that every line 
drawno across the earth’s surface at the present day rises and falls like 
the imaginary line drawn across the surface of the waves of the ocean. 
No rise of that line occurs without its complementary depression; the 
two always go together, and must, of necessity, be considered together. 
Each pair constitutes one of those geographical units of form of which 
every continuous direct line carried over the surface of the lithosphere 
of our globe is made up. This unit is always. made up of an arch-like 
rise and a treugh-like depression, which shade into each other along a 
middle line of contrary curvature. It resembles the letter S or Ho- 
garth’s line of beauty, and is clearly similar in form to the typical wave 
of the physicist. Here, then, we reach a very simple and natural con- 
clusion, viz.: the surface of the earth-crust of the present day resembles 
that of a series of crust-waves of different lengths and different ampli- 
tudes, more or less irregular and complex, it is true, but everywhere 
alternately rising and falling in symmetrical halves like the waves of 
the sea. ; 

Now this rolling wave-like earth-surface is formed of the outcropping 
edges of the rock formations which are the special objects of study of 
the stratigraphical geologist. If, therefore, the physiognomy of the face 
of our globe is any real index of the character of the personality of the 
earth-crust beneath it, these collective geographical features should be 
precisely those which answer to the collective structural characters of 
the geological formations. 

In the earlier days of geology one of the first points recognized by 
our stratigraphists was the fact that the formations were successive 
lithological sheets, whose truncated outcropping edges formed the pres- 
ent surface of the land, and that these sheets lay inclined at an angle 
one over the other, or as William Smith quaintly expressed it, like a 
tilted “pile of slices of bread and butter.” But as discovery progressed 
the explanation of this arrangement soon became evident. The forma- 
tions revealed themselves as a series of what had originally been de- 
posited as horizontal sheets, lying in regular order one over the other, 
but which had been subsequently bent up into alternating arches and 
troughs (¢. e. the anticlines and synclines of the geologist). Their vis- 
ible parts, which now constitute the surface of our habitable lands, were 
simply those parts of the formations which are cut by the irregular 
plane of the present earth’s surface. All those parts of the great arches 
and troughs formerly occurring above that plane have been removed by 
denudation; all those parts below that plane lie buried still, out of sight 
within the solid earth-crust. 

Although in every geological section of sufficient extent it was seen 


British Association, Edinburgh Meeting—Lapworth. 233 


that the anticline or arch never occurred without the syncline or trough 
—in other words, that there was never a rise without a corresponding 
fall of the stratum—yet it isonly of late years that the stratigraphical 
geologist has come clearly to recognize the fact that the anticline and 
syncline must be considered together, and must be united as a single 
crust-wave. For the arch is never present without its complementary 
trough, and the two together constitute the tectonic, structural, or oro- 
graphic unit, namely, The Fold, the study of which, so brilliantly in- 
augurated by Heim in his “Mechanismus der Gebirgsbildung,” is des- 
tined, I believe, in time, to give us the clue to the laws which rule in 
the local elevation and depression of the earth-crust, and furnish us with 
the means of discovery of the occult causes which lie at the source of 
those superficial irregularities which give to the face of our globe its 
variety, its beauty, and its habitability. 

We have said already that this wave or fold of the geologist resembles 
that of the wave of the physicist. Now we may regard such a wave as 
formed of two parts, the arch-like part above and the trough-like part 
below. The length of the wave is naturally the length of the axial line 
joining the outer extremities of the arch and trough, and passing 
through the centre, node, or point of origin of the wave itself, which bi- 
sects the line of contrary curvature. The amplitude of the wave is the 
hight of the arch added to the depth of the trough. The arch part of 
such a wave, if perfectly symmetrical, may clearly be regarded as be- 
longing either to a wave traveling to the right, in which case the com- 
plementary trough is the one in that direction, or it may be regarded as 
belonging to a wave traveling to the left, in which case its trough must 
be the one in that direction. But as in the case of the shore wave, the 
advancing slope of the wave is always the steeper, and the real centre of 
the wave must lie half-way down this steeper slope; so there is no diffi- 
culty in recognizing the centre of a geological fold and fixing the real 
direction of movement. 

The fold of the geologist differs from the ordinary wave of the physi- 
cist essentially in the fact that even in its most elementary conception, 
as that of a plate bent by a pressure applied from opposite sides, it nec- 
essarily includes the element of thickness. And this being the case, 
the rock sheet which is being folded and curved has different layers of 
its thickness affected differently. In the arch of the fold the upper 
layers of the rock sheet are extended, while its lower layers are com- 
pressed. On the contrary in the trough of the fold the upper layers are 
compressed and the lower layers are extended. But in arch and trough 
alike there exists a central layer, which, beyond taking up the common 
wave-like form, remains practically unaffected. 

But the geological fold has in addition to length and thickness, the 
further element of breadth, and this fact greatly complicates the phe- 
nomena. 

Many of the movements which take place in a rock sheet which is 
being folded, or in other words those produced by the bending of a 
compound sheet composed of many leaves, can be fairly well studied in 


234 The American Geologist. October, 1892 


avery simple experiment. Take an ordinary large note-book, say an 
inch in thickness, with flexible covers. Rule carefully a series of paral- 
lel lines across the edges of the leaves at the top of the book, about 
1% of an inch apart, and exactly at right angles to the plane of 
the cover. Then, holding the front edges loosely, press the book 
slowly from back and front into an S-like form until it can be pressed 
no further. As the wave grows, it will be noticed that the cross lines 
which have been drawn on the upperedge of the book remain fairly 
parallel throughout the whole of the folding process, except in the cen- 
tral third of the book, where they arrange themselves into a beautiful 
sheath-like form, showing how much the leaves of the book have 
sheared or slidden over each other in this central portion. It will also 
be seen when the Sis complete that the book has been forced into a 
third of its former breadth. Itis clear that the wave which the book 
now forms must be regarded as made up of three sections, viz.: a sec- 
tion forming the outside of the trough on the one side, and a section 
forming the outside of the arch on the other, and a central or common sec- 
tion, which may be regarded either as uniting or dividing the other two. 

As this experiment gives us a fair representation of what takes place 
in a geological fold, we see at a glance that the geologist is forced to di- 
vide his fold into three parts—an arch limb, a trough limb, and a mid- 
dle limb—which last we may call the copula or the septum, according as 
we regard it as connecting or dividing the other two. Our note-book 
experiment shows us also that in the trough limb and the arch limb the 
leaves or layers undergo scarcely any change of position beyond taking 
on the growing curvature of the wave. But the layers in the central 
part, or septum, undergo sliding and shearing. It will be found also, by 
gripping the unbound parts of the book firmly and practicing the fold- 
ing in different ways, that this septum is also a region of warping and 
twisting. This simple experiment should be practiced again and again 
until all these points are apparent, and the various stages of ‘he folding 
process become clear; the surface of the book being forced first into a 
gentle arch-like rise with a corresponding trough-like fall; then stage 
by stage the arch should be pushed over onto the trough until the sur- 
faces of the two are in contact and the book can be folded no further. 

In the structure of our modern mountain ranges we discover the most 
beautiful illustrations of the bending and folding of the rocky forma- 
tions of the earth-crust. The early results of Rogers among the Alle- 
ghanies, of Lory and Favre in the western Alps, have been greatly ex- 
tended of late years by the discoveries of Heim and Baltzer in the cen- 
tral Alps, of Bertrand in Provence, of Margerie in Languedoc, of Dutton 
and his colleagues in the western ranges of America, and of Peach and 
Horne and others in the older rocks of Britain. The light these re- 
searches throw upon the phenomena of mountain structure will be 
found admirably summarized and discussed in the works of Leconte, of 
Dana, of Daubree, of Reade, of Heim, and finally in the magnificent 
work of Suess, the “Antlitz der Erde,” of which only the first two vol- 
umes have yet appeared. 


British Association, Edinburgh Meeting—Lapworth. 235 


Looking first at the mountain fold in its simplest form as that ofa 
bent rock-plate, composed of many layers which have been forced into 
two similar arc-like forms, the convexities of which are turned, the one 
upwards and the other downwards, we find in the present mountain 
ranges of the globe every kind represented. We commence with one in 
which the arch is represented merely bya gentle swell of the rock-sheet, 
and the trough by an answering shallow depression, the two shading into 
each other in an area of contrary flexure. From this type we pass in- 
sensibly to others in which we see that the sides of the common limb or 
septum are practically perpendicular. From these we pass to folds in 
which the twisted common limb or septum overhangs the vertical, and 
so on to that final extreme, where the arch limb has been pushed com- 
pletely over on to the trough limb, and all three members, as in our note- 
book experiment, are practically welded into one conformable solid 
mass. 5 

Although the movements of these mountain folds are slow and insen- 
sible,and only effected in the course of ages,so that little or no evidence 
of the actual movement cf any single one of them has been detected 
since they were first studied, yet it is perfectly plain that when we re- 
gard them collectively, we have here crust folds in every stage of their 
existence. Each example in itself represents some one single stage in 
the lifetime of a single fold. They are simply crust folds of different 
ages. Some are, as it were, just born; others are in their earliest youth. 
Some have attained their majority, some are in the prime of life, and 
some are in the decrepit stages of old age. Finally, those in which all 

_three members—arch limb, trough limb, and septum—are crushed to- 
gether into a conformable mass, are dead. Their life of individual 
movement is over. If the earth pressure increases, the material which 
they have packed together may of course form a passive part of a later 
fold, but they themselves can move no more. 

In many cases, due partly to the action of longitudinal pressures, 
tho septum becomes reduced to a plane of contrary motion, namely—the 
over-fault, or thrust-plane, and the arch limb and the trough limb slide 
past each other as two solid masses, But here we have no longer a fold, 
but a fault. 

We see that every mountain fold commences first asa gentle alter- 
nate elevation and depression of one-or more of the component sheets of 
the geological formations which make up the earth-crust. This move- 
ment is due apparently to the tangential thrusts set up by the creeping 
together, as it were, of those neighboring and more resistant parts 
of the earth-crust which lie in front of and behind the moving wave. 
Yielding slowly to these lateral thrusts the crest of the fold rises higher 
and higher, the trough sinks lower and lower, the central common limb 
or septum grows more and more vertical and becomes more and more 
strained, sheared and twisted. As this middle limb yields, the rising 
arch part of the fold is forced gradually over on tothe sinking trough, 
until at last all three members come into conformable contact and fur- 
ther folding as such is impossible. Movement ceases, the fold is dead. 


236 The American Geologist. October, 1892 


We see also from our note-book experiment tbat the final result of the 
completion of the fold is clearly to strengthen up and consolidate that 
part of the crust plate to the local weakness of which it actually owed 
its origin and position. The fold has by its life-action theoretically 
trebled the thickness of that part of the earth-plate in which its dead re- 
mains now lie. If the lateral pressure goes on increasing and the layers 
of the earth-crust again begin to fold in the same region, the inert re- 
mains of the first fold can only move as a passive part of a newer fold: 
either as a part of the new arch-limb, the new trough-limb, or the new 
septum. As each younger and younger fold formed in this way neces- 
sarily includes a more resis ant, and therefore a thicker, broader, and 
deeper sheet of the earth-crust, we have here the phylogenetic evolution 
of a whole family of crust folds, each successive member of which is of 
a higher grade than its immediate predecessor. 

But it very rarely happens that the continuous plate in which any 
fold is imbedded is able to resist the crust creep until the death of the 
first fold. Usually, long before the first simple fold is completed, a new 
and parallel one rises in front of it on the side of the trough limb, and 
the two grow, as it were, henceforward side by side. But the younger 
fold, being due toa greater pressure than the older, must of necessity be 
of a higher specific grade, and the two together form a generic fold in 
common. 

Our present mountain systems are all constituted of several families 
of folds, all formed in this way, of different gradations of size, of differ- 
ent dates of origin, and of different stages of life evolution; and in each 
family group the members are related to each other by this natural gen- 
etic aftinity. 

Sometimes the new folds are formed in successive order on one side 
of the first fold, and then we have our unilateral (or so-called unsym- 
metrical) mountain groups, like those of the Jura and the Bavarian Alps. 
Sometimes they are formed on both sides of the original fold, and then 
we have our bilateral (or so-called symmetrical) ranges, like the Central 
Alps. In both cases the septa of the aged or dead folds are of necessity 
all directed inwards towards the primary fold. If, therefore, they orig- 
inate only on one side of the fold, our mountain group looks unsym- 
metrical, with a very steep side opposed to a gently sloping side. If 
they grow on both sides of the original fold, we have the well-known 
“fan structure” of mountain ranges. In this case the whole complex 
range is seen at a glance to be a vast compound arch of the upper layers 
of the earth-crust, keyed up by the material of the dead or dying folds, 
which by the necessities of the case constitute mighty wedges whose 
apices are directed inwards towards the centre of the system. Buta 
complete arch of this kind is in reality not a single fold, but a double 
one, with a septum on both sides of it; and it requires two troughs, one 
on each side of it, as its natural. complement. The so-called unsym- 
metrical ranges, therefore, which are constituted merely of arch limb, 
trough limb, and septum, are locally the more natural and the more 
common. 


British Association, Edinburgh Meeting—Lapworth. 237 


It is clear that in the lifetime of any single fold its period of greatest 
energy and most rapid movement must be that of middle life. In early 
youth the lateral pressure is applied at a very small angle, and the tan- 
gential forces act therefore under the most disadvantageous circum- 
stances. Inthe middle life of the fold the arch limb and the trough 
limb stand at right angles to the septum, and the work of deformation is 
then accomplished under the most favorable mechanical conditions and 
with the greatest rapidity. That is to say, the activity of the fold and 
the rate of movement of the septum, like the speed of the storm wind, 
vary directly as the gradient. 

In our note-book experiment we observed that little or no change took 
place in the arch limb and trough limb, while the septum became re- 
markably sheared and twisted. The same is the case in nature, but here 
we have to recollect that these moving mountain folds are of enormous 
size, indeed actual mountains in themselves. These great arches, scores 
of miles in length, thousands of feet in hight and thickness, must of 
necessity be of enormous weight, capable of crushing to powder the 
hardest rocks over which they move, while the thrust which drives them 
forward is practically irresistible. It is plain, therefore, that while the 
great arch limb and the trough limb of one of these mighty folds move 
over and under each other from opposite directions, they form together 
an enormous machine, composed of two mighty rollers, or millstones, 
which mangle, roll, tear, squeeze, and twist the rocky material of the 
middle limb or septum, which lies jammed in between them, into a 
laminated mass. This deformed material, which is the characteristic 
product of the mountain-making forces, is, of course, made up of the 
stuff of the original middle limb of the fold; and whether we call it 
breccia, mylonite, phyllite, or schist, although it may be composed of 
sedimentary stuff, it is certainly no longer a strutdfied rock ; and though 
it may have been originally purely igneous material, it is certainly no 
longer volcanic. It is now a manufactured article, made in the great 
earth mill. 

These mountain folds, however, are merely the types of folds and 
wrinkles of all dimensions which affect the rock formations of the earth- 
crust. Within the mountain chains themselves we can follow them fold 
within fold, first down to formations, then to strata, then to lamin, till 
they disappear at last in microscopic minuteness beyond the limits of 
ordinary vision. Leaving these, however, for the moment, let us travel 
rather in the opposite direction, for these mountain folds are by no 
means the largest known to the stratigrapbical geologist. Look at any 
geological section crossing the continent of North America, and it will 
be found that the whole of the Rocky Mountain range on its western 
side and the Alleghany range onthe east are really two mighty compound 
geological anticlines, while the broad sag of the Mississippi basin is actu- 
ally acompound geological syncline made up of the whole pile of the 
geological formations. That is to say, the continent of North America is 
composed of apair of geological folds, the two arches of which are repre- 
sented by the Rockies on the one side and the Alleghanies on the other, 


238 The American Geologist. October, 1892 


while the intermediate Mississippi syncline is the common property of 
both. Here, then, we reach a much higher grade of fold than the oro- 
graphic or mountain-making fold, viz., the plateau-making fold or the 
semi-continental fold, which, because of its enormous breadth, must 
include a very much thicker portion of the earth-crust than the ordinary 
orographic fold itself. 

But where must be the real middle limbs of these two American folds 
—those septal areas where most work is being done and the motion is 
greatest? 

Taught by what we have already learned of the mountain wave the 
answer is immediate and certain. They must be on the steeper sides of 
each of the two folds, namely, those which face the ocean. How per- 
fectly this agrees with the geological facts goes without saying. It is on 
the steep Pacific side of the western fold that the crushing and crump- 
ling of its rocks are the greatest. It is on the Atlantic side of the eastern 
fold that the contortion and the metamorphism of its rocks are at their 
maximum, while in the common and gently sloping trough of both folds, 
namely, the intermediate Mississippi valley, the entire geological 
sequence remains practically unmoditied throughout. 

Again, which of these two American folds should be the more active at 
the present day? Taught by our study of the mountain wave the answer 
again is immediate and conclusive. It must be that fold whose septum 
has the steeper gradient. Geology and geography flash at once into 
combination. The steeper Pacific septum of the western fold from Cape 
Horn almost to Alaska is ablaze with volcanoes, or creeping with earth- 
quakes, while the gently inclined Atlantic septum of the eastern fold 
from Greenland to Magellan straits shows none, except on the outer edge 
of the Antilles, in the very region where the slope of the surface is the 
steepest. We see ata glance that the vigor of these two great continental 
folds, like those of our mountain waves, varies directly as the surface 
gradient of the septum. 

Bat the geographical surface of North America, considered asa whole, 
is in reality that of a double arch, with a sag or common trough inthe 
middle. We have seen already that this double arch must be regarded 
as the natural complement of the equally double Atlantic trough. Here, 
then, if the path of analogy we have hitherto so triumphantly followed 
up to this point is still to guide us, the basin of the Atlantic must be, not 
only in appearance, but in actuality, formed of two long minor folds of 
the same grade as the two that form the framework of America, but with 
their members arranged in reverse order. If so, their submarine septa 
ought also to b3 lines of movement and of volcanic action. And this is 
again the case. The volcanic islands of the Azores and St. Helena lie 
not exactly onthe longitudinal crests of the mid-oceanic Challenger ridge, 
but upon its bounding flanks. 

But we have not yet, however, finished with our simple fold. If we 
draw a line completely round the globe, crossing the Atlantic basin at 
its shallowest, between cape Verde and cape St. Roque, and continue it 
in the direction of Japan, where the Pacific is at its deepest, as the trace 


British Association, Edinburgh Meeting—Lapworth. 239 


of a great circle, we find that we have before us a crust fold of the very 
grandest order. We have one mighty continental arch stretching from 
Japan to Chile, broken submedially by the sag of the Atlantic trough; 
and this great terrestrial arch stands directly opposed to its natural com- 
plement, the great trough of the Pacific, which is bent up in the middle 
by the mightiest of all the submarine buckles of the earth-crust, on 
which stand the oceanic islands of the central Pacific. 

But if this be true, then the septum of all septa on our present earth- 
crust must cross our grandest earth fold where the very steepest gradi- 
ent occurs along this line, and it must constitute the centre-point of the 
moving earth fold, and of greatest present volcanic activity. And where 
is this most sudden of all depressions? Taught once more by our geo- 
logical fold, the answer is instantaneous and incontrovertible. It is on 
the shores of Japan, the region of the mightiest and most active of all 
the living and moving volcanic localities on the face of our globe. 

But the course of the line which we indicated as forming our grandest 
terrestrial fold returns upon itself. It is an endless fold, an endless 
band, the common possession of two sciences. It is geological in origin, 
geographical in effect. It is the wedding-ring of geology and geography, 
uniting them at once and for ever in indissoluble union. 

Such an endless fold, again, must have an endless septum, which, in 
the nature of things, must crossit twice. Need I point out to the merest 
tyro in these wedded sciences that if we unite the Old and New Worlds 
and Australia, with their intermediate sags of the Antarctic and Indian 
oceans, as one imperial earth arch, and regard the unbroken watery ex- 
panse of the Pacific as its complementary depression, then the circular 
coastal band of contrary surface flexure between them should constitute 
the moving master septum of the earth crust. This is the “Volcanic 
girdle of the Pacitic,” our “Terrestrial Ring of Fire.” 

Or, finally, if we rather regard the compact arch of the Old World 
itself as the natural complement of the broken Indo-Pacific depression, 
then the most active and continuous septal band of the present day should 
divide them. Again our law asserts itself triumphantly. It is the great 
volcanic and earthquake band on which are struog the Festoon islands 
of western Asia, the band of mount St. Elias, the Aleutians, Kamtchatka, 
the Kuriles, the band of Fusijama, Krakatoa, and Sangir. The rate of 
movement of the earth’s surface doubtl ss everywhere varies directly as 
the gradient. 

We find, therefore, that even if we restrict our observations to the most 
simple and elementary conception of the rock fold as being made up of 
arch-limb, trough-limb, and twisting but still continuous septum, we are 
able to connect, in one unbroken chain, the minutest wrinkle of the finest 
lamina of a geological formation with the grandest geographical phe- 
nomena on the face of our globe. 

We find, precisely as we anticipated, that the wave-like surface of the 
earth of the present day reflects in its entirety the wave-like arrange- 
ment of the geological formations below. On the land we find that the 
surface arches and troughs answer precisely to the grander regional an- 


240 The American Geologist. October, 1892 


ticlines and synclines of the subterranean sedimentary sequence; and it 
may I believe, be regarded as certain that the submarine undulations have 
a similar or complementary relationship. We find in the new geology, as 
Hutton found in the old, that geography and geology are one. We find, 
as we suspected, that the physiognomy of the face of our globe is an un- 
erring index of the solid personality beneath. It bears in its lineaments 
the characteristic family features and the common traits of its long line 
of geological ancestors. 

Such, it seems to me, is an imperfect account of the introductory para- 
graphs of that great chapter in the new geology now in course of in- 
terpretation by geologists of the present day; and we have translated 
them exactly in the old way by the aid of the only living geological lan- 
guage, the language of present natural phenomena, and | doubt not 
that sooner or later the rest of this great chapter will be read by the 
same simple means. 

I have confined myself to-day to the discussion of the character- 
istics of the simple geological fold as reduced to its most elementary 
terms of arch, trough and unbroken septum; for this being clearly un- 
derstood, the rest naturally follows. But this twisted plate is really the 
key which opens the entire treasure-house of the new geology in which 
lie spread around in bewildering confusion facts, problems, and conclu- 
sions enough to keep the young geologist and other scientific men busi- 
ly at work for many a long year to come. 

Into this treasure-house I often wander myself, in the few leisure 
hours that I can steal from a very busy professional life; and out of it I 
bring now and again heresies that sometimes amuse and sometimes hor- 
rify my geological friends. As you have so patiently listened to what I 
have already said, perhaps you will permit me in a few final sentences to 
indicate in brief some of those novelties which I see already more or 
less clearly, and a few of those less novel points on which it appears to 
me that more light is wanted. My excuse is two-fold—first, to furnish 
material for work and controversy to the young geologists; and second, 
to obtain aid for myself from workers in other walks of science. 

The account of the simple rock-fold I have already given you is of 
the mostelementary kind. It presupposes merely the yielding to tan- 
gential pressure from front and back, combined with effectual resistance 
tosliding. But in the layers of the earth-crust there is always, in addi- 
tion, a set of tangential pressures theoretically at right angles to this. 
The simple fold becomes a folded fold, and the compound septum twists 
not only vertically but lateraliy. On the surface of the globe this 
double set of longitudinal and transverse waves is everywhere apparent. 
They account for the detailed disposition of our lands and our waters, 
for our present coastal forms, for the direction, length, and disposition 
of our mountain-ranges, our seas, our plains, and lakes. The compound 
arch becomes a dome, its complementary trough becomes a basin. The 
elevations and depressions, major and minor, are usually twinned, 
like the twins of the mineralogist, the complementary parts being often 
inverted, and turned through 180° (compare Italy with the Po-Adriatic 


British Association, Edinburgh Meeting—Lapworth. 241 


depression). Every upward swirl and eddy has its answering downward 
swirl. The whole surface of our globe is thus broken up into fairly 
continuous and paired masses, divided from each other by moving 
areas and lines of mountain making and crust movement, so that the 
surface of the earth of the present day seems to stand midway in its 
structure and appearance between those of the sun and the moon, its 
eddies wanting the mobility of those of the one and the symmetry of 
those of the other. In the geology of the earth-crust, also, the inter- 
crossing of the two sets of folds, theoretically at right-angles to each 
other, gives rise to effects equally startling. It lies at the origin of the 
thrust-plane or over-fault, where the septal region of contrary motion 
in the fold becomes reduced to, or is represented by, a plane of contrary 
motion. It allows us to connect together under one set of homologies 
folds and faults. The downthrow side of the fault answers to the 
trough, the upthrow side to the arch, of our longitudinal fold; while the 
fault-plane itself represents the septal area reduced to zero. The node 
of the fault, and the alternation and alteration of throw, are due to the 
effects of the transverse folding. 

These transverse folds of different grades, which affect different layers 
of the earth-crust differentially, account also for the formation of lacco- 
lites, of granitic cores, and of petroiogical provinces ; and they enable us 
also to understand many of the phenomena of metamorphism. 

Of the folds of the third order I shall here say nothing ; but I must 
frankly admit that the primal cause of all this tangential movement and 
folding stress is still as mysterious to me asever. I incline to think 
that it is due to many causes—tidal action, sedimentation, and many 
others. I cannot deny, however, that it may he mainly the result of the 
contraction in diameter of our earth, due to the loss of its original heat 
into outer space.’ For everywhere we find evidences of symmetrical 
crushing of the earth-crust by tangential stresses. Everywhere we find 
proofs that different layers of that crust have been affected differentially, 
and the outer layers have been folded the most. We seem to be dealing 
not so much with a solid globe as with a globular shell composed of 
many layers. 

Is it not just possible after all that,as others have suggested, our earth 
is such a hollow shell, or series of concentric shells, on the surface of 
which gravity is at a maximum, and in whose deepest interior it is non- 
existent? May this not be so also in the case of the sun, through whose 
spot-eddies we possibly look into a hollow interior? If so, perhaps our 
present nebul may also be hollow shells formed of meteorites; on the 
surfaces of these shells the fiery spirals we see would be the swirls which 
answer to the many twisting crustal septa of the earth. Our comets, too, 
in this case might be elongated ellipsoids, whose visible parts would be 
merely interference phenomena or sheets of differential movement. 

In this case we have represented before us to-day all the past of our 
earth as well as its present. Uniformity and evolution are one. 

Thus from the microscopic septa of the laminz of the geological for- 
mations we pass outwards zn fact to these moving septa of our globe, 


9492 The American Geologist. October, 1892 


marked on land by our new mountain-chains, and on our shores by our 
active volcanoes. Thence we sweep, 71 imagination, to the fiery eddies 
of the sun, and thence to the glowing swirls of the nebulie ; and so out- 
wards and upwards to that most glorious septum of all the visible crea- 
tion, the radient ring of the Milky Way. 

Prof. George Darwin, in his address to the section of mathematical 
and physical science at the meeting of the British Association at Birm- 
ingham in 1886, with all the courage of genius, and the authority of one 
of the sons of the prophets, acknowledged that it seems as likely that 
“meteorology and geology will pass the word of command to cosmical 
physics as the converse.” Behind this generous admission I shelter 
myself. But I feel absolutely confident that long after the physicists 
may have swept away these provisional astronomical suggestions as 
“the baseless fabric of a vision,’ there will still remain in the treas- 
ure-house of the geological fold a wealth of abundant material for the 
use of the mathematician, the physicist, the chemist, the mineralogist, 
and the astronomer, of the deepest interest and of the highest value. 


EDITORIAL COMMENT. 


GEOLOGICAL REMINISCENCES OF ROCHESTER IN 1892. 


a—Geology at Rochester. 
b—Excursion to the “Pinnacles”. 


c— i “« “ Niagara Quarries. 

(= “ “« “ Gorge of the Genessee. 

e_ “6 “ Niagara Falls. 

— ee “* the Salt-well at Livonia. 

g— a “ Trondequoit Bay and Lake Ontario. 


Apart from the papers and discussion the recent gathering of 
geologists at Rochester was noteworthy. Though Rochester is 
one of the large and old established cities of the Empire state, yet 
the American Association for the Advancement of Science had 
never before met there, and the recent gathering and its success 
are in great part due to the judgment and activity of Prof. Fair- 
child, of the university, aided by the local committee. 

The region around Rochester is one of considerable geological 
interest and several of the special points were visited by members 
of the Society and of the Section during their stay. This part of 
the annual gathering seems to be assuming more and more prom- 
inence—a fact searcely to be regretted. To most of the visitors 
as much advantage may be gained by seeing a new locality as by 
spending their time within four walls. Geology is an outdoor 


Editorial Comment. 243 


science and its successful propagation is likely to be successful 
in proportion as its study is prosecuted in the field. Possibly 
short excursions in the neighborhood of the place of meeting, 
preceded and accompanied with careful description and explana- 
tion,may form in time a regular part of the program both of the 
Geological Society and of the Section. Such excursions would be 
specially adapted to interest the younger members and to bring 
them into active work. 

Be this as it may, however, the excursions were interesting and 
profitable partsof the Rochester meeting. One afternoon a party 
with Mr. G. K. Gilbert, a native of Rochester, as guide, went to 
the Pinnacle hills, about two miles from the city, and examined 
their structure as it was shown in a large gravel pit. Here could 
be seen stratified sand overlain by gravel and shingle—true 
northern drift—and this again by till laden with large and small 
stones, many of them smooth and striated. Great irregularity 
was seen in one place where the bedded material had been dis- 
turbed apparently soon after its deposition. Several slight faults 
with small downthrow to the northeast were visible at various 
points and at the northeast end all signs of stratification ceased 
and the hill consisted of a confused mass of gravel and sand 
overlain by till. Numerous large and unworn blocks of Niagars 
limestone were scattered through the hill and had been brought 
from the outcrop of the same stone at a much lower level a few 
miles off. 

The visit formed the topic of an interesting discussion next 
morning, though some objection was raised by a few to this in- 
terruption of the program. Probably the objection can in future 
be obviated in such a case without causing difficulty. 

Another excursion was made to the quarries in the western.part 
of the city under the leadership of Prof. Arey of the high school, 
who has apparently collected more Niagara fossils from the region 
than any one else in the city who took part inthe meeting. These 
quarries cover many acres of ground and the stone has been ex- 
cavated to the depth of twenty feetor more. The Niagara is here 
a dark grey limestone yielding few fossils among which Stroma- 
topora concentrica is by far the most abundant. All are in a bad 
state of preservation, existing as casts alone. The characteristic 
minerals were found in plenty or bought from the boys; such as 
dolomite, selenite and other forms of gypsum, blende, ete. 


244 The American Geologist. October, 1892 


The excursion to Portage and Mt. Morris proved exceedipgly 
pleasant and instructive. Running alongside of the beautifnl 
gorge of the Genessee the geologists could not fail to be struck 
with the immense work that had been done by the river during 
post-glacial time. Miles of canyon, hundreds of feet in depth, 
passed in review as the country rapidly rose toward the higher 
table land of central New York. At the head of the gorge was 
seen the cutting-engine at work under the Erie viaduct in the 
form of the Upper Fall, which is continuing the task of excaya- 
tion to the southward. <A few miles lower down the Middle Fall, 
as a second cutter, is following suit and deepening the groove 
while the Lower Fall, hidden in the forest and accessible only 
with difficulty, is slowly coming up stream in the wake of the 
other two, and completing the work. Below these three follows 
arun of comparative peace until the river reaches Rochester and 
throws itself over the great Silurian escarpment where another 
series of falls exists and another consequent canyon is in course 
of excavation. 

The party were received and hospitably entertained by the citi- 
zens of Mt. Morris at dinner, after which carriages were in wait- 
ing which took them to the winding and most picturesque part of 
the gorge about two miles from the town. Here a very fine view 
was obtained over the country. The Genessee has cut since the 
Ice-Age a serpentine groove through the shale several miles long 
where the cataracts once existed which have now receded up stream 
to Portage. The river here flows several miles to accomplish 
what in a straight line is only a short distance. At a point just 
above Mt. Morris it is proposed to erect a solid dam of masonry 
130 feet high across the river and pond, back the water for eleven 
miles, forming instead of a canyon a winding narrow lake 150 
feet deep at its lower end and gradually shoaling upward. The 
plan is intended to equalize the flow of the Genessee, holding 
back the water in floods and supplying more effective and constant 
water power to Rochester and other towns along its course. Its 
effect on the scenery of the valley may not be improving but in 
this utilitarian age few stop to consider this aspect of the under- 
taking. A hasty stop at the salt-works concluded the day’s ex- 
cursion. 

Another party and a large one spent the day at Niagara chiefly 
y and the change. Here also they were well 


y 
d 


to enjoy the scener 


Editorial Comment. 945 


entertained, and the visit was highly appreciated, but the ground 
is very familiar to nearly all and any description would be super- 
fluous for geologists. 

The other Saturday excursions were intended chiefly for botan- 
ists and pleasure seekers. We need not say that they were well 
attended and enjoyed. 

A special party, led by Prof. H. T. Fuller, afterwards made an 
excursion to the new shaft drilled for salt at Livonia. In spite 
of the extraordinarily low price at which salt is now sold there is 
apparently a profit in its manufacture as the works are being en- 
larged and extended in every direction. 

Irondequoit bay and its preglacial valley and the beaches of 
lake Ontario were visited and investigated by special parties who 
chiefly made their own arrangements. Nothing but a visit can 
give adequate ideas of this monument of the Ice-Age standing in 
bold relief on the very edge of the Ontarian basin, and to glacial- 
ists few excursions could be more useful or interesting. Buta 
lengthy description would be of little use and might even become 
tedious. The general features are familiar. The ‘‘ridge road” 
occupies the old sand beach under which lies a lower one of 
coarse shingle chiefly composed of Medina sandstone mingled 
however with northern drift. Below the last and entirely con- 
cealed by glacial deposits is the ancient buried cliff, of hight un- 
known, which once formed the southern bluff of the Ontarian 
valley before the lake existed. Heavy deposits of silt and of 
morainic matter fill the inlets up to the level of the ancient 
outflow point where the waters of the lake escaped when the 
present channel of the St. Lawrence was blocked. These facts 
and the lessons which they can teach of the varying hight of the 
water and possibly also of the land lent great interest to the va- 
rious lake excursions and were to geologists exceedingly instruc- 
tive. All, whether geologists or not, fully appreciated the kind- 
ness of their Rochester entertainers, and the aid kindly given 
them by several of the railway companies whose lines run to 
Rochester. 

Warp’s NATuRAL ScrencE ESTABLISHMENT. 

Not the least among the attractions of Rochester to the geolo- 
gists belonging to the Association was the establishment of Prof. 
Henry A. Ward. From a small beginning, thirty years ago, this 
museum factory has grown to immense size. The earliest collec- 


246 The American Geologist. October, 1892 


tion made by its founder was purchased about twenty-eight years 
ago by the University of Rochester and now adorns its cases and 
supplies magnificent material for illustration. In few places can 
be found finer or larger specimens of some of the minerals there 
exhibited. Enumeration would be tedious, but the eye of even 
the cursory visitor, whether geologist or not, must be arrested by 
the splendid crystals of Cornish fluorite, Cinghalese graphite, 
blende and hematite from the north of England, and septaria of 
large size, cut and polished for ornamental purposes, from the 
upper Mesozoic beds of the coast of the English channel and from 
Mt. Morris, N. Y., while almost unique in its singularity and 
beauty is a large specimen of crystalline (?) anthracitein the form 
of curved blades of cone-in-cone from South Wales. 

On the paleontological side of the collection may be seen one of 
the finest sets of Kuropean Ammonites on this continent, with 
large suites of fossils from various countries and from many dif- 
ferent horizons, which are of immense value to the student for 
purposes of comparison. 

At the time of the purchase little had been done in American 
geology outside of New York state. The treasures of the great 
West were unknown and the East was almost unexplored. Hence 
this collection and most of those made at a similar date were 
composed, in great part, of foreign material. But additions have 
since been made and are being made as the department grows, 
and American paleontology has now a fair representation. The 
whole collection has recently been rearranged by Prof. Fairchild, 
and is in excellent condition. 

It was the gathering of the specimens now in the museum at 
the University of Rochester that started Prof. Ward on his career. 
From that day onward he has been engaged in the task of collect- 
ing. No labor, pains or expense has been spared in reason, and, 
we fancy, sometimes out of it, to increase the value of his stores, 
and now his museum and laboratories are unequalled in America 
and searcely, if at all, surpassed in scale in the world. It is dif- 
ficult to ask for specimens, excepting, perhaps, unique or almost 
inaccessible forms, without having them at once laid before you. 
The writer has tried, and speaks from experience. Prof. Ward 
has visited almost every part of the world in search of material 
and is often somewhere in foreign parts seeking what he may ob- 
tain by purchase or exchange. His aim is to get all material 


Editorial Comment. Q47 


from the typical localities so as to insure authenticity. He visits 
these places and secures collectors whenever possible, often men 
who are poor in money but enthusiastic in their work. From 
these he receives consignments year after year, thus keeping up 
the intercourse and the engagement. In some cases he finds it 
necessary to advance the funds for an expedition in search of 
the material wanted, and it is pleasant to learn that very rarely 
has the confidence been betrayed. 

Prof. Ward returned from a long tour of this kind during the 
meeting of the A. A. A. §S., bringing with him or sending on great 
quantities (over 200 cases) of minerals and other supplies. Here 
was stibnite from a rich Japanese locality, only discovered lately, 
luxulyanite (schorlaceous granite) from the typical region at Lux- 
ulyn cove, Cornwall, and polished serpentine from the classic 
Lizard Head, slabs of flexible sandstone (itacolumite) from Bra- 
zil, large blocks of ripple-marked sandstone from the quarries at 
Berea, O., basaltic columns from the Giant’s causeway, and 
large calcites from the old but seemingly almost exhausted beds 
of Iceland. 

Add to these syenite from the original Egyptian quarries at 
Assouan, dolomite from the Tyrol, liparite from the Lipari isles 
and hundreds of slabs of polished marbles from most of the well 
known marble quarries of the old and new worlds. 

All these, when received, are carefully studied, determined and 
mounted. Labels are printed for the minerals showing the name 
and locality, with formula of composition, crystalline system and 
the number assigned in Dana’s ‘‘Mineralogy.’’ It is needless to 
point out how much, by this care, the teaching value of the spec- 
imens is increased. 

In this connection should be noticed a school collection contain- 
ing 120 specimens, which is amply sufficient for elementary work 
in the hands of a good and competent teacher. Such a collection 
should be in every school in the country, above the lowest 
grade. 

Prof. Ward’s personal pet at present is his collection of meteor- 
ites of which he now has about 164 ‘‘falls.” One of these from 
Queensland had cost, he said,$1,020,and another that fell in Can- 
ada, only weighing a few ounces, was destined for the Royal- 
imperial museum at Vienna, where Dr. A. Brezina wanted it as a 
type of a kind not yet possessed by that immense collection. 


248 The American Geologist. October, 1892 


Money is evidently not the first consideration at Vienna in secur- 
ing objects of scientific value. 

The worth of a meteorite, Prof. Ward explained, is often in 
inverse proportion to its size, because, if large, there is abund- 
ance of the material for all, whereas if small it must be used eco- 
nomically. Large meteorites are usually sliced for purposes of 
study, anda small set of gang saws was slowly cutting its way 
through one of these bedded in plaster, in an adjoining workshop, 
at the rate of one-eighth of an inch a day. 

Not a few of the most interesting meteorites have been modeled 
and are on sale together with imitations-of many of the great and 
famous but unique gems of the world. These latter are mostly of 
glass and are exceedingly beautiful, while for purposes of illustra- 
tion and of teaching they are, to all intents,as useful as real gems. 

Another important element is a large collection of working ma- 
terial, which is sold by the pound for the use of students and 
chemists. This is sufficient to illustrate the chemical properties 
of the minerals; while for the optical and other physical proper- 
ties other sets are kept in stock. These are purchasable at prices 
that render it possible to use them for class purposes. Ores, also, 
of all the common kinds are kept for the same uses. 

One very important and interesting department which has been 
conceded to Prof. Ward by the U. 8. Geological Survey, is the 
construction of models of many interesting and important regions, 
such as the Gorge of the Colorado, AXitna, Vesuvius, the Cliff- 
dwellings of New Mexico, ete. An excellent model of the Serp- 
ent mound in Ohio was constructed during the meeting for the 
illustration of an address by Prof. Putnam before the Section of 
Anthropology. 

The value of this kind of work is not at all appreciated at pres- 
ent by teachers at large. Only the few can see its helpfulness. 
But we hope the day is not very far distant when geography as a 
science will take its proper place in education—when the teach- 
ing of this subject will cease to be a mere burlesque, a memory 
task of names and details, and become, as it can be and should 
be, one of the most interesting and useful of all our youthful 
studies. Then will our educators awaken to the value, or rather, 
the necessity of such helps as these, and relief maps and globes 
will be as much things of course in the school-room as they are 
in the schools of Switzerland and of Germany. 


Editorial Comment. 249 


But time would fail to tell of the many objects of interest that 
can be found in this museum, and we must limit ourselves to 

things geological. 

One peculiar feature in this collection, original with Prof. 
Ward, who himself once held the professorship of natural sci- 
ence in Rochester University, is the collection illustrating geo- 
logical phenomena, many fine specimens of which may be seen in 
the University Museum. Mud-cracks, ‘stylolites, cone-in-cone, 
fulgurites or lightning tubes formed in sand, lavasof many kinds, 
dendrites, volcanic bombs, folded gneiss, etc., are all illustrated 
by abundant and excellent specimens. Add to these the collec- 
tion of lithological specimens from the original localities, well 
labeled and showing on the back the geological section from which 
they each came, and its exact horizon in the section, and it is 
easy to see the great labor that has been spent in the preparation 
and elaboration of the material and its adaptation to the purpose 
of instruction. 

Prof. Ward is naturally full of experiences. No man could go 
about the world so far and so often as he-has been and on such 
an errand, without meeting with these. A mass of ‘‘grés lustré’’ 
was snatched from the bank of the Uruguay during a momentary 
stop of the river steamer, hauled on board and saved, to the as- 
tonishment of the fellow-passengers who came to the usual con- 
clusion in regard to this ‘‘crank.”’ The pumice gatherers of the 
Lipari isles laughed with undisguised contempt at the ‘‘fool’’ who 
drove down tothe shore mules laden with obsidian, ‘‘worthless 
stuff” and neglected the commercially salable pumice. 

Many of the museums of this country have been enriched by 
the labors of Prof. Ward, notably the museum of Comparative 
Zoology at Cambridge, where are several almost unique skeletons 
of the gigantic fossil mammalia, especially those from the wide 
pampas of Argentina, whose Tertiary gravels have yielded so 
many huge fossil sloths, etc., since the time when Darwin visited 
that country and made the world aware of the wonderful treas- 
ures that it contained. The Cambridge museum possesses My/o- 
don, Glyptodon, Lestodon, Skelidotherium and Toxodon, the last 
secured for Agassiz by a costly, urgent telegram sent by Prof. 
Ward from Buenos Ayres; $5,000 purchased the treasure in spite 
of the law against the exportation of these fossils, which was 
engineered through the Argentine Legislature by the well known 


250 » The American Geologist. October, 1892 


geologist, Burmeister, then curator of the museum at Buenos 
Ayres. Forgetting the cosmopolitan generosity that should char- 
acterize science, he descended into the field of politics and - 
attempted to exclude the students of other nations from the ad- 
vantages which South America possessed, but could only imper- 
fectly use. Fortunately, this selfish law never was, and perhaps 
could not be enforced. In the wholesale exportation of bones that 
was continuously going on for the manufacture of phosphates it 
was not to be expected that the custom-house officials could dis- 
tinguish those of Megatherium and Skelidotherium from the more 
common place bones of bos and Hquus or perhaps of Homo, even 
had they wished so to do, 

It is a treat to go through the museum with the professor when 
he is, as now and then happens, disengaged fora short time and to 
listen to the reminiscences suggested by this or that specimen. <A 
fine piece of crokidolite elicited the story of a visit to Griqua- 
land, the only known locality for the mineral, and a prowling ex- 
cursion to the stone kraals of the natives with hammer in hand. 
Selecting those that contained the mineral as discovered by strik- 
ing off a chip, the naturalist (what the Griquas call him is of no 
consequence here) pulled down the fence, took out the slab of 
crokidolite and either built up the wall again or left it for the 
owner to restore, as seemed to him advisable in regard to the 
future. 

A portion of a basaltic column recalled a visit to the cele- 
brated Giant’s causeway, where in the chalk underlying the basalt, 
some magnificent specimens of Ventriculites (paramoudras) were 
secured by sending a man with a wagon through the country to 
beg or to buy them, as the case might be, from the country-folk, 
by whom they are used as posts or ornamental stones and for a 
variety of other purposes. One of these stood eight feet high in 
the chalk pit where it was found, and another now in Rochester 
and almost perfect, measures three feet. 

Not the least debt which the geologist or the naturalist in gen- 
eral owes to Prof. Ward is one for the generosity with which he 
is willing to allow students to consult his specimens for purposes 
of comparison and of work. In few places can a better oppor- 
tunity be found because the specimens are not usually mounted 
and set for purposes of show so that they cannot be handled, but 
they arein the rough, natural condition. Ask for one and ina 


Review of Recent Geological Literature. 251 


minute the creature lies before you and you can examine almost 
every part of its structure inside and outside. In this way in- 
valuable assistance may often be obtained by a worker who is 
unable to buy or perhaps, in consequence of their size, unable to 
keep the bulky specimens which he nevertheless desires to con- 
sult or to compare. 

All this fails to give more than a scanty account of the treas- 
ures that the geologist can see at Rochester, and no mention has 
been made of other lines of study in which equally rich stores of 
material are kept. Ornithology, ichthyology and all the branches 
of zodlogy including human anatomy are comprehensively repre- 
sented, and from a whale to a lancelet, from a humming-bird to 
an eagle, the museum is able to meet at once almost any call that 
may be made upon it. Ward’s Natural Science Establishment is 
the Mecca for the American geologist and naturalist and a pil- 
grimage there is a sure profit and a joy. 


REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 


An Introduction to the study of the Genera of Paleozoie Brachiopoda. 
Part 1. By JAmEs HAtt, assisted by Joun M. CLarkE, Albany, New York, 
1892. The work before us is the first part of Vol. vir, Paleontology of 
New York. In this and the succeeding volume, which will be part two 
of Vol. vim, Paleontology of New York, the veteran paleontologist of 
America designs to set before the student the present knowledge of the 
genera of that most common and most interesting group of fossils, the 
Brachiopoda. Necessarily the discussions and illustrations of these 
volumes are limited to Paleozoic brachiopods. As usual, the class 
Brachiopoda is divided into two orders, and for these the author uses the 
simple and convenient terms proposed by professor Huxley, the Jnarticu- 
lata and the Articulata. To the definition and general discussion of the 
genera of the Znarticuluata the author devotes 183 pages; while 13 plates 
are occupied by generic illustrations of the same group. The remaining 
portions of the volume, about 170 pages and 29 plates, are given to the 
forms usually referred to the three closely related families, Orthida, 
Strophomenide and Productide. The spire-bearing brachiopods, the 
Rhynchonellide, Pentameride aud Terebratuloid forms, will be discussed 
in the second part of the volume. No attempt is made to arrange the 
genera either of the Articulata or Inarticulata in groups having the 
rank of zoological families. 

The manner in which the author treats the genus Orthzs will illustrate 


252 The American Geologist. October, 1892 


the method of the work in general. We have first, in chronological 
order, references to publications, particularly those of American authors, 
in which the genus is recognized. As a bibliography this feature of the 
work will prove of great value to students. Following the bibliography 
isa diagnosis of the genus. Variations in the external and internal 
characters of forms heretofore referred to the genus are discussed. The 
original type is considered, O. callactis and O. calligramma being selected 
from the species cited by Dalman as the only available types of the 
genus. The most common American form of the same type is 0. tricen- 
aria. Limiting the genus Orthzs to such forms, there remains a vast 
assemblage of heterogeneous species, that have been referred to Orthis 
by various authors, to be disposed of in some other way. These are dis- 
tributed among a number of genera, for a large proportion of which 
new names are proposed. For example we have Plectorthis to include 
the group of O. plicatella, Dinorthis for the group of O. pectinella, Plastomys 
for the group of O. subquadrata, Hebertella for the O. sinuata group, 
Orthostrophia of which O. strophomenoides is the type, Platystrophia for 
the group including O. biforuta, Heterorthis to include O. clytie and its 
relatives, Bilobites for O. biloba, Dalmanella for the group resembling 0. 
testudinaria, Rhipidomella for the group resembling O. méchelini, Schizo- 
phoria for the group of O. resupinata, Orthotichia for O. ? morganiana, 
and Hnteletes to include the species best known in America as Syntriel- 
asma hemiplicata, After some further general discussion of this group 
we find a list of species that should be included under each of the 
generic names. There is also a tabular arrangement showing the geo- 
logical range of each of the generic subdivisions. Only a few of the old 
genera afford opportunity for such extensive subdivision as Orthés. 

The genus Strophomena is limited to the forms agreeing in structure 
with that recognized by de Blainville and Defrance as the S. rugosa of 
Rafinesque. As so limited it would include such concavo-convex species 
as have been, in recent paleontological literature, referred to Strepto- 
rhynchus planumbona, 8. filiterta, etc.; while the Strophomena alternata, 
that usual!y holds an honored place among the earliest possessions of 
the embryonic paleontologist, is not a Stroph mena at all, but must here- 
after be paraded under the new generic name of Rafinesquina. The rigid 
spplication of the rules of nomenclature doubtless requires such changes, 
but the unsettling of long established terms is something always to be 
deplored. It would certainly be of great advantage to the taxonomic 
sciences, if aname, once in use and generally recognized as having-a 
definite application, could be retained by the action of some “statute of 
limitation,” notwithstanding the fact that indiscreet enthusiasts, rum- 
maging in the dusty corners of oblivion, may bring to light some long 
forgotten name that had once been applied to the same thing. 

For Strophodonta the present work revives the original and more cor- 
rect form of Stropheodonta. The generic name, Mimulus, proposed by 
Barrande in 1879, and used on page 272 of the present volume, is inad- 
missible according to strict rules of nomenclature, since Mzmulus has 
long been employed to desiguate a genus of labiate plants. 


Review of Recent Geological Literature. 253 


*. The work before us represents an inconceivable amount of pains-tak- 
ing labor. The determination of the internal characters of the multitud- 
jnous species of Paleozoic bravhiopods is something from which persons 
less enthusiastic and less gifted than the eminent author might. well 
shrink. The work has been in hand more or less continuously for more 
than twenty years. That it is at last practically completed is something 
‘for which professor Hall deserves to receive the thanks and congratu- 
lations of paleontologic students. 

The fulness with which each genus is illustrated adds incalculably to 
the value of the volume. 


Development of the Brachiopoda. Part I. Introduction. (Am. Jour. 
Sci., vol. x1, 1891, pp. 348-357, one plate.) Part 11. Classification of the 
‘Stages of Growth and Decline. (Ibid. vol. xxiv, 1892, pp. 183-135, one 
plate.) By Cares E. BEECHER. 

The object of these papers is to apply to the Brachiopoda “the law of 
morphogenesis as defined by Hyatt.” Noone of the classifications hereto- 
fore proposed is established upon fundamental principles but all are based 
on one set of secondary characters for certain groups and another set for 
other sections. The Brachiopoda, until 1883, had only been divided into 
two sections, the Lyopomata and Arthropomata of Owen, or the Inarticu- 
lata and Articulata of Huxley. When we consider that there are about 
5,000 known species of brachiopods, arranged in over 270 genera, occur- 
ing in the oldest uudoubted fossiliferous rocks and down to the present 
time, it certainly seems as if the class should be capable of further 
separation into large groups or orders besides those based upon the 
presence or absence of an articulating process. In that year, Dr 
Waagen in his great work on the Brachiopoda of the Salt Range of 
India, further divided each section into three suborders. While this 
classification brought together, more or less correctly, families having 
relations to each other, yet no far reaching attempt was made to show 
the genesis of the class in the application of the principles of phylogeny 
and ontogeny. In the above mentioned papers Dr. Beecher has applied 
the “principles of growth; acceleration of development; mechanical 
genesis and geologic sequence of genera and species.” The develop- 
ment of ancient species in their adult condition represents nealogic 
(youthful) or nepionic (young) stages of later forms. 

The first or embryonic shell is alike in all Brachipoda, except where 

. modified by accelerated development, it having been observed by the 
author in about forty genera, representing nearly all the leading fami- 
lies of the class. This, the first shell stage, he has termed the “ proteg- 
ulum” and is homologous with the “ protoconch” of Owen in cephalo- 
pods and gastropods, and the prodissoconch of Jackson in pelecypods. 
The protegulum is “corneous and imperforate, semi-circular or semi- 
elliptical in outline, with a straight or arcuate hinge line, and no hinge 
area.” The “prototype preserving throughout the development the 
main features of the protegulum, and showing no separate or distinct 
stages of growth” is found in the early primordial Obolus labradoricus 


254 The American Geologist. October, 1892 


Billings, which has been referred to KAutorgina by authors. This 
species is shown to be generically distinct from Autorgina cingulata, 
and for shells of that type the term Puterina is proposed. The proteg- 
ulum is usually “paterina-shaped,” yet in Orbiculotdea and Discinisca it 
is modified by accelerated growth “becoming more circular, and with 
shorter and more arcuate hinge in the ventral valve.” 

The author then explains in a clear and concise manner the “ modifi- 
cations from acceleration; differences in the valves and genesis of form” 
all of which is of the greatest importance to biologists and paleontolo- 
gists. The “types of pedicle openings” are then considered, of which 
there are four, and these are shown to be of general application to all 
brachiopods. Lyopomata and Arthropomata are each divided into two 
orders. The first into Atremata, in which the pedicle “in all stages of 
growth emerges freely between the two valves, the opening being more or 
less shared by both,” and Meotremata, where the pedicle is “more or less 
surrounded by progressive nealogic growth posterior to the initial hinge.” 
The Atremata contain Obolella, Trimerella, Lingula, etc., while the Neo- 
tremata have such genera as Discina, Acrotreta, Trematis, Orania, ete. 
The Arthropomata are divided into Protremata and Telotremata. The 
pedicle in the former “is enclosed in early nepionic stages by shell 
growth; posterior covering (pseudo-deltidium) retained at maturity, or 
resorbed or abraded in nealogic stages, so that the pedicle protrudes be- 
tween the two valves.” Types of this order are Orthisina, Strophomena, 
Productus, Orthis, Pentamerus, etc. The Telotremata are distinguished 
in that the “pedicle opening [is] shared by both valves in nepionic 
Stages, usually confined to one valve in later stages, and becoming more 
or less limited by two deltidial plates in ephebolic stages.” This order 
contains the Rhynchonellide, Spiriferide and Terebratulide. These 
four orders are again divisible into natural suborders, and to these the 
majority of the names proposed by Waagen will be applicable. 

Part IT. treats of the “classification of the stages of growth and de- 
cline.” The author gives in a condensed manner all the known embry- 
onic and larvel stages of brachiopods from the ovum to the first shell 
stage. Of these there are six for which he adopts the terminology of 
Hyatt, and gives of each one or more illustrations. For comparison with 
the brachiopode four figures of embryonic stages of Spdrorbis borealis are 
added, but the author says “it is not intended by this to indicate a close 
relationship with the chzetopods, fur the writer is inclined to accept the 
opinion of Joubin, that the brachiopods constitute a distinct and inde- 
pendent class.” 

The larval and later stages of Thecidium, as given by Kovalevski, are 
shown by Dr. Beecher to be genetically related to the Strophomenide 
rather than with the Terebratulide, to which the family Thecidiide is 
usually referred. Heretofore the Protremata, or strophomenoids, have 
been regarded as extinct with the close of the paleozoic age, but now 
this order is known to have lived from its inception uv to the present 
time. 

Much value, heretofore, was not placed on the nature of the covering 


Review of Recent Geological Literature. 255 


to the pedicle opening, or delthyrium, as it has recently been termed by 
Prof. Hall, whether it is of one piece, the “deltidium,” or composed of 
two pieces, the “deltidial plates.” It is here shown “that the deltidium 
in all species possessing it (the Protremata) is an embryological, or ne- 
pionic feature, which may or may not continue to the ephebolic period; 
while the deltidial plates in other brachiopods (the Telotremata) appear 
later during the nealogic and ephebolic period, or may never be devel- 
oped.” The deltidium “is a shell growth from the dorsal side of the 
body [in the typeembryo stage] which afterwards becomes attached to the 
ventral valve, and is then considered as belonging to it,” while the delti- 
dial plates first commence to grow out from each side of the delthyrium 
during nealogic growth, and are secreted by the ventral mantel lobe; a 
fundamental difference. 

The presence of a dorsal anal opening in the Lyopomata and its absence 
in recent Arthropomata the author admits is difficult to explain, its so- 
lution depending “upon whether the class is to be considered as pro- 
gressive or degraded.” In Silurian, Devonian and Carboniferous deposits 
forms occur belonging to the Protremata and Telotremata in which there 
has been observed a dorsal foramen, the “visceral foramen” of authors. 
“This character,” he says, “is evidently in no way connected with the 
pedicle opening, but points to the existence, in the early articulate 
genera of an anal opening dorsal to the axial line, as in the recent Crania. 
* * * ‘In reference to this character and the obsolescence of the eves 
the class must be viewed as retrogressive since paleozoic time. * * * 
Progressive in concentration of posterior elements, expansion of anterior 
elements, and limitation of pedicle opening to one valve.” 

The post-embryonic stages are then defined, also giving examples and 
figures of the “nepionic [young], nealogic [youthful], ephebolic [mature], 
and geratologic [old age] periods.” 

“Another aspect of growth and decline is manifest when the size of 
individuals and the chronological history of the groups are taken into con- 
sideration. Each genus and family began with small representatives, 
and rapidly developed the more radical varieties of structure. Then 
came the culmination and final reduction in size, with abundance of 
geratologous and pathologic forms. * * * The culmination of gera- 
tologous growth results in the reversion of the animal to its own nepionic 
period and is called the nostologic stage.” Among clinologic and nosto- 
logic genera are mentioned Cistella, Gwynia, Atretia and Platydia, which 
have lost many of their adult progressive ancestral features and, there- 
fore, represent early stages of growth in other modern species, 


Annual Report of the Department of Mines and Agriculture, New South 
Wales, for the year 1891. This report presents, in a very admirable way, 
the results of mining operations in New South Wales for the annual 
period it covers. Inthe case of some of the valuable minerals there 
are comparative tables giving the annual output year by year from 1865 
to 1891. The value of the yearly product of minerals by the colony is 
between six and seven millions sterling. The total value of minerals 


356 The American Geologist. October, 1892 


produced to the close of 1891 exceeds ninety-three and a half millions. 
The. value of silver and silver ores produced in 1891, exceeds three and 
a half millions, a value greater than all the rest of the minerals together. 
Coal comes next in importance, its value for the year being about one 
and three-fourths millions. Tin was produced to the value of £271,412, 
while of iron the value amounted only to £36,101. Bituminous and 
kerosene shales have a value in the colony and are mined and utilized to 
the amount of more than 40,000 tons. Indeed some of the coals, if we 
may judge from the analyses, are little better than the product known 
as shales. Of the coal, however, which is all of Mesozoic age, more 
than 4,000,000 tons were raised during the year covered by the report. 

There are detailed reports on the several mines and mining districts. 
There are tables showing number of men employed in mining, and 
number of accidents that occurred during the year. Besides the sub- 
jects usually found in mining reports we find a Water Conservation Re- 
port, which refers to public watering places established on the main 
stock routes of the colony for the convenience of traveling stock. All 
the watering places, with afew exceptions, are under the direction of 
caretakers who collect fees for the privilege of watering animals at so 
much a head. Some of these places are leased; in the case of those not 
leased, the fees are forwarded to the treasury. There are also reports 
from the Superintendent of Caves, a public office unknown in America. 

In an article in the fifteenth volume of the Journal of the Cincinnati 
Society of Natural History, Mr. J. F. James continues his summary of 
the Paleontology of the Cincinnati Group, enumerating and reprinting 
descriptions of the species of Stromatopara, Stromatocerium and Beat- 
ricea, also those of Columnaria among the Actinozoa.. The paper will be 
continued. 

The same writer also discusses the preservation of plants as fossils, 
showing how the mere impression of a leaf or other organ may in some 
cases be preserved, though not a vestige of the actual substance may 
remain to be fossilized. 


Mr. Whitman Cross, in the American Journal of Science (July, 1892), 
describes a series of strata in Colorado which fill a part of the gap exist- 
ing between the top of the Laramie (Cretaceous) and the lowest recog- 
nized Eocene beds. ‘The facts of stratigraphy and lithology show that 
in Colorado the great conformable series of Cretaceous formations ended 
with the coal-bearing Laramie strata. Deposition plainly ceased in this 
region because continental elevation, which had long been in progress, 
finally caused the retreat of the Laramie seas.” ‘ When sedimentation 
again began it was in comparatively small lakes or seas. In the pebbles 
of the Arapahoe beds is the record of the slow erosion of 14,000 feet of 
strata, from the Laramie down to the red beds of the Trias.” 

Then followed volcanic outbursts over a large area, not however nec- 
essarily requiring a very long era for their occurrence. The thickness 
of the Middle Park beds, the lower half of which is ia great part vol- 


— Correspondence. 257. 


canic, is 6,000 feet, indicating considerable subsidence during their for- 
mation. 

The author then discusses the evidence for the age of the beds that 
he has described, and says that the arguments drawn from the fossil ver- 
tebrates are not conclusive in either direction, because the age of the 
beds in which the types were found has not itself been decided. Hence, 
to employ them as a test of the age of other strata elsewhere, is in fact 
reasoning in a circle. 


Mr. C. S. Prosser contributes to the Proceedings of the Rochester Acad- 
emy of Science a paper on the thickness of the Devonian and Silurian 
strata of Western New York, along the line of the Genessee river, which 
is of present interest as relating tothe ground of the meeting of the 
American Association. He briefly sums up the various attempts in the 
early days of American geology to correlate the strata and to determine 
their thickness, and then from a careful comparison of four well kept 
borehole records, deduces the mean and actual thickness of the rocks. 
“Taking”, he says, “the sum of these maximum estimates, we have a 
series of rocks 6,810 feet in thickness between the base of the Olean con- 
glomerate and the top of the Archiean(?). The same section compiled 
from a series of well-records gives a thickness of 7,100 feet. At Roch- 
ester the thickness from the top of the Medina to the top of the Trenton 
is 1,756 feet, and at Wolcott 1,720 feet. Leaving out of consideration all 
well-records, a conservative estimate of the thickness of this series of 
rocks at Rochester, based on published data, would be from 1,250 feet to- 
1,500 feet. 


CORRESPONDENCE. 


SomME REMARKS ON PROFESSOR HENRY S. WILLIAMS’ ADDREss BE- 
FORE Section E., A. A. A.S., av RocuEster, N. Y., Auaust, 1892; on 
“THE SCoPE OF PALAZONTOLOGY AND ITS VALUE TO GEOLOGISTS,” IN THE 
AMERICAN GEOLOGIST FOR SEPTEMBER, p. 148.—In a letter printed in 
the AMERICAN GEOLOGIST for January, 1889, p. 61, I have given facts at 
variance with professor Williams’ expressed opinions on nomenclature 
and classification of the American Devonian; which have been accepted 
and made use of, by him, in his paper, entitled ‘Correlation Papers— 
Devonian and Carboniferous” (Bull. U.S. Geol. Surv., No. 80, 1891); and 
now I hope he will receive, as fairly, some important facts touching the 
real history of the discovery and use of paleontology in geological sci- 
ence, which are in a measure overlooked in his paper before the Ameri- 
can Association for the Advancement of Science. 

After the first paper of Cuvier, read before the Institut National, of 
France, the 1st pluviose an tv of the Republic, and published in 1800, in 
which he spoke for the first time of the existence of an entire fauna, 
anterior to the existing one, stratigraphy was begun in earnest round 


258 The American Geologist. October, 1892 


Paris by Cuvier himself, associated with Alexander Brongniart. In his 
autobiography, Cuvier says, “From 1804 to 1808, the singularity of the 
animals, of which I have discovered the bones at Montmartie, made me 
desire to know with more details the geology of the environs of Paris. 
My friend Brongniart joined me in this work. I discovered [after many 
combinations and comparisons of sections of quarries and butts] the uni- 
formity of our strata; and it was I who discovered also, in the forest of 
Fontainebleau, the immense layers of fresh water deposits intercalated 
between marine beds. We published the résumé of our researches in 
the spring of 1808.” The title of that important memoir is: Hssa¢ sur 
la géographie minéralogique des environs de Paris. 

A contemporary and the author of the first geological map of France, 
the celebrated geologist, d’Omalius d’Halloy, says of this work: “As 
regards geology, it is the most important of the century, because it con- 
tains the first record of the revolution which has created the present stat- 
utes of that science; that is to say, it first applied paleontology to the 
study of the crust of the earth.” 

In 1810 Alexander Brongniart and Cuvier published a second and 
most important edition of their memoir, in which is found, for the first 
time, lists of fossil remains special to each bed or group of strata. 

William Smith, after many years of researches, published, in June, 
1816, his masterly work for English geology of: Strata Identified by Or- 
ganized Fossils; followed next year by: Stratigraphical System of Organ- 
dzed fossils—explaining their use in identifying the British strata. Strata 
Smith, as he was nicknamed by his contemporaries in England, seems to 
have discovered, as far back as 1795, that each stratum was characterized 
by special fossil remains; and there is no doubt, that in 1799, he wrote a 
tabular view showing the order of the strata and their imbedded organic 

remains in the vicinity of Bath. Unfortunately it remained unpublished 
until his nephew, John Phillips, published his Memozrs of Wilton 
in 1844; so it cannot be used in a question of priority. 

At that time England and France were involved in constant wars, and 
Cuvier, Brongniart and Smith made their discoveries, completely in ig- 
norance of one another’s works and researches. Smith, in his 4to volume 
of 1817, quotes at p. rv of the introduction, among the works that he has 
consulted: Cuvier—Geographie Minéralogique des environs de Paris; but 
maintained that “The first written account of this discovery was circu- 
lated in 1799.” 

But if the discovery was simultaneous in England and in France, its 
great value and full importance was shown through Cuvier and Brongni- 
art’s published works on Comparative Anatomy; Recherches sur les osse- 
nents fossiles, and the géographte mineralogique des environs des Paris, from 
1800 to 1812; years before any of William Smith’s publications. 

Until 1819 nothing was attempted in the way of synchronism and as- 
similation of formations of strata at great distances, in using fossil re- 
mains only; when Alexander Brongniart read a report before the Acad- 
emy of Science, showing remarkabla similarity in each formation or 
terrain “dans les pays les plus éloignés, sous les latitudes et sous les 


Correspondence. 259 


méridiens les plus différentes.” But, as he says, it was only a first draft, 
too imperfect for publication; and it was only in 1821 that he publishéd 
in the Annales des Mines, his masterly paper: Sur les caracteres zoologiques 
des formations. From that day, Comparative paleontology was founded; 
and the first application of the principles and methods developed in the 
Memoir was on the celebrated fossil localities of the ‘‘Montague des 
Fiz vallée de Servoz,” Savoie, at the foot of the Mont Blanc, and “La 
Teste du Rhone,” near Geneva, where Brongniart recognized by the fos- 
sil remains the identity of these formations with the Glauconie crayeuse 
of Paris basin and the Gault and Green Sand of England. 

I have enjoyed the privilege of knowing personally and meeting often 
Alexander Brongniart during the two last years of his life, in 1846 and 
1847. He kept all his enthusiasm for parallelism and synchronism of 
formations at great distances by means of fossil remains, and followed 
with close attention all the work done in that direction by the younger 
generation of geologists, who then began to be divided into two branches, 
the geologist without any other qualification and the stratigraphic pale- 
ontologist. Brongniart saw the exaggeration of some in too great gener- 
alization of his principles, and was adverse to it. Alcide d’Orbigny 
more specially frightened him with his great number of successive cre- 
ations of faunas; and I must add that he was far from accepting the many 
great universal cataclysms insisted upon by Elie de Beaumont. Brong- 
niart was more in harmony with the views of Deshayes, who truly estab- 
lished the three great divisions of the Tertiary strata, according to the 
faunas, in working out his great and most important publication: De- 
scription des coquilles fossiles des environs de Paris, 1824-31. 

Lye}l did not work out the Tertiary fossils, he only used Deshayes’ 
researches and applied to the result arrived at a good nomenclature, 
calling the Tertiary formations: Eocene, Miocene and Pliocene. When 
Lyell came to Paris, in 1823, he knew next to nothing of the Tertiary 
strata, and it was there and then that Constant Prévost showed him all 
the divisions and classification, by great groups, and bed by bed, as they 
have been established by the joint efforts and discoveries of Cuvier, 
Brongniart, Deshayes and Prévost himself. 

There is no doubt that the school of paleontologists, which contained 
such great observers as de Buch, Agassiz, d’Obigny, Quenstedt, etc., did 
go too far in their generalization. Deshaves never accepted their extreme 
ideas, and always maintained passage of forms and even sometimes of 
species from one formation to another. 

I shall not refer to many points of geographical zoology and evolution 
of forms, more or less appreciated in professor Williams’ paper, but shall 
only say that speaking of “The scope of paleontology and its value to 
geologists” without quoting the magnificent and grand discoveries and 
papers of Barrande, seems a very extraordinary forgetfulness, and equally 
so is a complete absence of reference to the discoverer of the msthod and 

principle, Alexander Brongniart. Even reference to the works of those 
who have made use,with great success, of Brongniart’s methods in Amer- 
ica, is very incomplete and partial, for some of the first and best investi- 


260 The American Geologist. October, 1892 


gators of the United States, as: Dr. Samuel Morton, Vanuxem, Conrad, 
Emmons and Leidy, are entirely passed over, in Mr. Williams’ address. 
The use of paleontology for assimilation, synchronism and classifica- 
tion in geology, requires special talent, good judgment and an amount of 
practical knowledge which are seldom combined in one man; and this 
explains why so many observers fail to give good correlation and exact 
classification, notwithstanding their long and patient researches in pale- 
ontology. JULES MARCOU. 
Cambridge, Muss., Sept. 22, 1892. 


PERSONAL AND SCIENTIFIC NEWS. 


THE SrxtH INTERNATIONAL CONGRESS OF GEOLOGISTS is to be 
held at Zurich in August, 1894. <A preliminary circular, signed 
by professous Renevier, Heim and Golliez, has already been issued, 
together with a brief Proces-verbal of the meeting held on the 
3d of August, 1891, at Salzburg, which was concerned with cer- 
tain European maps. Considering the nature of their country the 
Swiss geologists are arranging two kinds of excursions, some 
across the Jura and the Alps for ‘those accustomed to long 
walks’ and others for the less sturdy, during which steamboats, 
railways and other conveniences will be utilized. Full particulars 
will be furnished later. The meetings will be held at Zurich, but 
the excursionists will reassemble at Lugano for the final meeting 
of the session. 

THE ANNUAL ReEpoRT oF THE LAUSANNE NATURAL HISTORY 
Museum, of which Prof. Renevier is keeper, shows the important 
accession of a large collection of Triassic fossils made by the pro- 
fessor himself at Hallstadt. Prof. Renevier, as may be seen 
above, is one of the committee on the next International Congress 
of Geologists. 

THE PROFESSORSHIP OF GEOLOGY AND MINERALOGY, AT BREs- 
LAU, left vacant by the death of the late professor F. A. Roemer, 
will be divided. The Professor Ordinarius will occupy the chair. 
of Petrology and the Professor Extraordinarius will have charge 
of the department of paleontology. It is considered probable 
that Dr. Fritz Frech of Halle, one of the leaders of the younger 
school of German geologists, will receive the latter. Dr. Frech 
is well known as the monographer of the Triassic Corals and as a 
writer on past zodlogical distribution. 

Mr. F. A. BATHER CONTRIBUTES A PAPER to the last report of 
the ‘“Museums Association” on the fossil crinoids in the British 
Museum, in which he describes his attempt to put into practice 
modern ideas of museum arrangement. He accepts as his rule 


Personal and Scientific News. ° 261 


the American maxim that a museumisa collection of labels illus- 
trated by specimens. The paper consists mainly of a reprint of 
the thoughtfully prepared labels which he has attached to his col- 
lection and will serve as an admirable model for educational 
museums. 

A SPECIAL ROOM 80 FEET By 40, to be termed the ‘‘Barran- 
deum” has been appropriated in the New Royal Bohemian Museum 
for the exhibition of the collection of fossils made by the late 
Dr. J. Barrande, illustrating his ‘‘Systéme Silurien de la Bo- 
héme;”’ and we learn that the ‘‘Barrande Fund” founded by Dr. 
Anton Fritsch for the further encouragement of the work that 
ceased at Barrande’s death, has now reached the sum of 10,000 
florins. The interest on this fund, which has been raised by 
voluntary contributions, will be available next year for the endow- 
ment of research in the Silurian formation in Bohemia, and it is 
hoped that some paleontologist will be thereby induced to study 
the smaller organisms of the system. 

THE TEXAS STATE GEOLOGICAL SURVEY HAS RECENTLY ADDED 
to its working force, as chemist, Dr. W. H. Melville, who has 
been for ten years connected with the United States geological 
survey; and, in the department of paleontology, Mr. G. D. Har- 
ris, late assistant in Tertiary invertebrate paleontology on the 
same survey. Prof. Cragin’s engagement with the Texas survey 
has recently been extended to February, 1893, his work including 
chiefly vertebrate and Cretaceous invertebrate paleontology. 

Dr. GEORGE A. Kania, of the University of Pennsylvania, has 
been appointed professor of chemistry at the Michigan Mining 
school, Houghton. 

THe Next AnNUAL MEETING of the A. A. A. 8. will be held 
in August, 1893, at Madison, Wis. Prof. William Harkness, of 
Washington, D. ©., was elected president; Prof. F. W. Putnam, 
of Cambridge, Mass., permanent secretary; T. H. Norton, of Cin- 
cinnati, general secretary, and H. L. Fairchild, of Rochester, 
secretary of the council. It was announced that an anthropo- 
logical congress would be held at the Columbian Exposition dur- 
ing the week following the next annual meeting of the A. A. A. 
S., with representatives of every American tribe, from Terra del 
Fuego to the Esquimaux of the Arctic zone. As an outgrowth of 
this congress, it is meant to found a museum of ethnology at Chi- 
cago, materials for which are now being collected by the ship 
load in Yucatan, Ecuador, Peru, Chile and elsewhere. A com- 
mittee was appointed to secure rooms for the various sections of 
the A. A. A. 8. to be used as headquarters during the entire pe- 
riod of the exposition, each room to be in the building the con- 
tents of which are most closely allied to the branch of science 
represented. 

CHARLES 8. PROSSER, LATE OF THE NATIONAL Museum, Wash- 
ington, has been elected to the professorship of natural history 


262 The American Geologist... October, 1892 


in Washburn College, Topeka, Kas., left vacant by Prof. Cragin. 
The work of the chair will be developed principally along the line 
of geology, and will embrace an examination of the stratigraphy 
and paleontology of the Upper Carboniferous about Topeka, ex- 
tending finally over a considerable part of eastern Kansas. 

THE PEERLESS CoAL Company, oF Daas, TEexas, has pur- 
chased the Calvert Bluff lignite, or brown coal, deposits, near Cal- 
vert, Texas, and will begin the briquetting of brown coal immedi- 
ately. This is one of the direct and practical results from the 
investigation, by state geologist Dumble, of Huropean methods 
of the utilization of brown coal,and from his attempts to initiate 
such utilization of brown coals in America. The term ‘‘lignite,” 
as generally used in this country, is erroneously applied, most of 
the varieties of coal so called being either brown coals, pitch coals, 
or glance coals; the term /iguite being properly applicable to the 
charcoal-Jike varieties which retain more or less perfectly the 
woody structure. 

THe AGE or THE Kozoon.  ‘‘It is well to note here that if the 
EKozoon is really animal in origin, the ‘Laurentian’ rocks of 

Janada, in which it oceurs, must be Huronian, or the later of 
Archeean terranes.” J. D. Dana, Amer. Jour. Sci., June, 1892, 
p. 462. 

ANOTHER OLD OUTLET OF LAKE Huron. In he Nation for 
September 22, Prof. G. F. Wright describes an old channel 
which connects lake Nipissing with Trout lake. The former is 
tributary to lake Huron, about 70 feet lower, by way of French 
river, and the latter flows by way of the Mattawan river into the 
Ottawa river. A subsidence amounting to only a trifle more than 
a hundred feet, would turn the current from lake Huron through 
lake Nipissing into the Mattawan and thence into the Ottawa, 
thus robbing Niagara of most of its glory. The subsidence 
which came with the close of the Glacial epoch was more than 
ample to produce this change, and the great lakes seem to have 
had discharge there for thousands of years before they acquired 
that by way of Niagara. This discovery confirms, in the opinion 
of Prof. Wright, the surmise of Mr. G. K. Gilbert, who reason- 
ing from a known differential northerly subsidence had suggested 
some time ago that the great lakes may formerly have had a dis- 
charge by way of the Ottawa river. The duration of this dis- 
charge must be added to the usually accepted length of post- 
glacial time, so far as it is based on a computation of the reces- 
sion of Niagara falls, since the Niagara recession must have be- 
gun after this channel was closed. 


THE AMERICAN GEOLOGIST. Vou. X, PLatE IX. 


NEW LOWER SILURIAN OSTRACODA. 


THE 


AMERICAN GEOLOGIST 


Vou, X. NOVEMBER, 1892. No. 5 


NEW LOWER SILURIAN OSTRACODA, NO. 1. 
By E. O. Uxtricu, Newport, Ky. 
PLATE IX. 

This is the first of a series of papers upon these fossils that I 
hope to issue in the near future. Hach part will be accompanied 
by at least one plate, and the rate of publication will depend very 
largely upon the leisure time at my disposal. 

My aim is to advance the subject to a point where it will be pos- 
sible to treat it monographically. The first essential for that 
condition is, obviously, a knowledge as complete as possible of 
the forms to be worked upon and classified. I propose, therefore, 
to publish descriptions and figures of all the new forms now in 
my hands, with occasional notes upon previously known species. 
I may add that these papers are to be regarded as ina great 
measure preliminary. Many of the species, all of those occurring 
in the Nortwestern states, will be reworked, I trust, more fully, 
and republished in Vol. ur of the final reports of the Geological 
and Natural History Survey of Minnesota. 

The systematic classification of these, mostly minute, paleozoic 
fossils, is attended with unusual difficulties. This fact must be- 
come apparent to anyone taking the trouble to enter into critical 
comparisons between the British, German and American works on 
the subject. It is not thata particular style of treatment pertains 
to each of these nations. No, no. It is, rather, that the num- 
ber of styles is limited only by the number of authors. The 


264 The American Geologist. November, 1892 


greatest trouble seems always to have been experienced in draw- 
ing the lines between the various genera constituting the large 
family Leperditiide, some authors claiming the existence of a 
complete chain of links connecting the simplest Primitia-aye, 
even Leperditia—with the most complex types of Beyrichia and 
Strepula. Now, while this is probably true, it seems to me that 
but too often these chains contain closely approximated links that 
in reality illustrate mere resemblances rather than genetic relation- 
ship. 

It is the determination of the genealogical affinities that is the 
prime necessity in building up a permanent classification. With 
nothing but the shells to guide us, can we hope to reach satisfac- 
tory conclusions respecting the paleozoic, especially the lower 
paleozoic, Ostracoda? We can try. 

In the accompanying plate several forms are illustrated of 
which it is really difficult to decide whether they should be called 
species or varieties. One thing, however, seems to be certain, 
and that is that, within reasonable limitations, each form is con- 
stant and, therefore, distinguishable from the others. That they 
represent recognizable stages in the developmental history of the 
Leperditiide is all that [ claim, it being quite immaterial to me 
what rank in classification the proposed names may ultimately 
hold, 


Leperditia tumida, n. sp. 
PrArH ix: BIGSseto 3: 

Length of a large right valve, 2.6 mm.; hight, 1.82 mm.; thickness, 
0.75 mim. 

Valves ovate, rather short, the posterior end much the widest, 
tumid, the convexity of the surface, except for a slight flattening 
and lengthening of the dorsal and anterior slopes, nearly 
uniform. Surface obscurely punctate, otherwise smooth, there 
being no external signs of either the eye-tubercle or muscle spot. 

This species compares with LZ. nana Jones, about as closely as 
with any other Lower Silurian form described, but being without 
an eye-tubercle and of more rounded shape, it is readily distin- 
guished. The Carboniferous species LZ. okeni Minster, LZ. car- 
bonaria Hall, and others of that type, agree very closely in nearly 
every respect. All these species differ from typical Leperditia 
in the method of closing the valves, the latter having them merely 
to overlap, while in the species under consideration the ventral 


New Lower Silurian Ostracoda.— Ulrich. 265 


edge of the right valve fits into a groove in the edge of the left. 
(See Figs. 7 and 12 of plate 1x.) 

Formation and locality: This species is very abundant (associated 
with Bryozoa) in the shaly part of the Birdseye limestone at High Bridge, 
Kentucky. These layers are here nearly ona level with the bridge. The 
species also occurs at Frankfort, in the same beds. 


Leperditia mundula, n. sp. 
PLATE Ix, Fias. 4 to 8. 

Length of en ire carapace, 2.6 mm.; hight, 1.64 mm.; thickness, 1.4 mm. 

This species differs from L. tum/da in being less high, causing 
the outline to be more elongate. In an end view the convexity 
of the valves is also more uniform. <A very faintly defined ovate 
area is distinguishable, by depression of the surrounding surface, 
just a trifle in front of the center of the dorsal slope. 


Formation and locality: This form occurred in considerable number 
in asmall package of soft shale obtained from the Birdseye (? Chazy). 
limestone, near the bottom of the Kentucky river gorge at High Bridge, 
Ky. This bed, which furnished also LZ. equilatera and L. germana, is at 
least two hundred and sixty feet beneath the Z. twmida horizon. 


Leperditia equilatera, n. sp. 
PiaTh ax, Pies: Stow. 

Length of entire carapace, 1.7 mm.; hight, 1.03 mm.; thickness, 0.8 mm. 

Carapace rather elongate, with the ends rounded, sub-equal, 
the back straight, the ventral edge gently convex and nearly par- 
allel with the dorsal. Surface of valves smooth, almost uniformly 
convex, there being only a very slight and quite undefined mesial 
depression in the dorsal slope. 

Distinguished from LZ. mundula in having the ends of nearly 
equal size and curvature, and the outline in a ventral view more 
uniformly convex, so that the point of greatest thickness is very 
near the middle of the valves. 

Formation and locality: Same as the last. About forty specimens. 


Leperditia inflata, n. sp. 
PrAp mix. Kies, 12° toxl5. 

Length of average left valve, 1.9 mm.; hight, 1.22 mm.; thickness, 
0.54 mm. 

Valves ventricose, the outline usually very much as in LZ. egui- 
latera, only the posterior end is somewhat wider and inflated, so 
that this half of the dorsal region projects more or less beyond or 
above the hinge line. The postero-dorsal angle, also, is more 


266 The American Geologist. November, 1892 


pronounced. Groove in ventral edge:of left valve sharply defined. 
Surface with a broad, undefined mesial depression in the dorsal 
slope. This depression is as much stronger than the one in Z. 
wquilatera as it is weaker than the one in L. sulcata. 


Formation and locality: Same as the last One hundred specimens, or 
more. 


Leperditia germana, 2. sp. 
PLATE 1X, Figs. 16 to 18. 

Length of averags left valve, 2.17 mm.; hight, 1.4 mm.; greatest thick- 
ness, 0.67 mm. 

This form is very closely related to LZ. mundula—perhaps it is 
merely a local variety of that species. It differs in having the 
ends more equal, the surface more convex in the dorsal half, and 
in having a very narrow rim or marginal channel, visible in a side 
view only, at the ends. Again, instead of a slight elevation sur- 
rounded by correspondingly gentle depressions, we have in L. 
germana only a sulcus. This is about as strong as the one in 
L. inflata, which species the present form resembles rather closely 
also in the outline. The basal line, however, is usually more con- 
vex and with the most prominent point nearer the center. But 
the most important difference lies in the lesser inflation of the 
posterior half of the dorsal region. (Compare Figs. 14 and 17, 
1240 ips<5) 

Formation and locality: Associated with Schmidtella crassimarginata 
Ulrich, at Mineral Point, Wisconsin, where it occurs abundantly in some 
of the thin layers of the Birdseye or “Lower Blue” limestone. 


Leperditia suleata, n. sp., and var. ventricornis, 0. var. 
PLatE 1X, Kies. 19 to 23. 

Length of an average right valve, 2.1 mm.; hight, 1.388 mm.; thickness, 
in anterior half, 0.48 mm., in posterior half, 0.58 mm. 

Valves sub-ovate, ends nearly equal, the posterior a little the 
widest; back straight for about three-fifths of the entire length; 
ventral edge gently convex, the most prominent part a little be- 
hind the center. Surface rising abruptly from all the edges ex- 
cept the dorsal which is occupied by the expanded terminus of a 
broad suleus which, though shallow and of undefined limits, is, 
nevertheless, always a conspicuous feature of the valves. In a 
ventral view the profile is highest a short distance within the ends, 
while the central portion is at least straight and in most cases 
decidedly concave. Closure of valves as in L. inflata. 

This form may be regarded by some authors as nearer Primitia 


New Lower Silurian Ostracoda. — U trich. 267 


than Leperditia, but I have satisfied myself fully that it, like the 
following species (. dorsicornis), is an extreme development of 
the type begun in the stock that produced the L. equilatera, in- 
flata, and germana of this paper. From these species it is suf- 
ficiently distinguished by the more abrupt end and _ ventral 
slopes, and the greater development of the sulcus. 

Of the form that I propose, provisionally, to name as var. 
ventricornis | have seen only the right valve illustrated. So far 
as I can see, the only difference between it and the typical form 
of the species is found in the obtuse and retrorsely directed 
ventral prominence. 


Formation and locwlity: Associated with, but less abundant than, L. 
tumida, in the Bird:eye limestone at High Bridge, Ky. 


Leperditia (? Primitia) dorsicornis, 0. sp. 
PLATE 1x, Fias. 24 to 26. 

Length of aright valve, 1.72 mm.; hight, 1.1 mm.; greatest thickness 
(center of posterior half) 0.54 mm 

Valves subelliptical, slightly oblique, the ends subequal, the 
back straight nearly tothe posterior extremity; the latter is gently 
convex and almost vertical in the upper two-thirds, while in the 
lower third the outline merges rapidly into the uniformly convex 
basal margin; anterior end uniformly curved. Surface much the 
highest in the posterior half, with a part prolonged dorsally into 
a short and obtusely pointed prominence that bends down close 
to the hinge line and projects somewhat beyond it. This promi- 
nence gives definition to the posterior side of a distinct sulcus, 
extending almost half across the valve from the central part of 
the dorsal edge, and forward along the latter. 

This species ought, perhaps, to be called a Primitia but for the 
reason given under L. sulcata I have chosen to designate it as 
above. Of the species believed to belong to the same line of de- 
velopment, L. inflata seems to be the nearest. They are, however, 
readily distinguished by the concentration of the dorsal promi- 
nence and the greater definition of the sulcus in L. dorsicornis. 


Formation and locality: The only specimen seen was found in the 
Hudson River rocks at Savannah, Illinois. 


Leperditia granilabiata, n. sp. 
PrATESTS, HIGS,..oL to-33. 
Length, of right valve, 2.1 mm.; hight 1.52 mm.; greatest thickness 
0.6 mm. 


268 The American Geologist. November, 1892 


Valves broadly subelliptical, scarcely oblique, the ends strongly 
rounded, nearly equal, the ventral margin uniformly and more 
than usually convex. Free edges, except in the cardinal regions, 
set with small but prominent papille. Surface minutely punctate, 
ventricose in the lower half, flattened in the upper; with point of 
ereatest convexity much beneath the middle. <A faint smooth 
(non-punctate) spot occurs just in front and above the center. 

This species might with others described in this paper be placed 
with Aparchites, Jones, but there is something so peculiar about 
Prof. Jones’ type of the genus and one or two undoubtedly con- 
generic species, that I hesitate to enlarge the limits of the genus 
beyond them. 


Formation and locality: Rare in the upper part of the Trenton shales 
(Phylloporina beds) at St. Paul, Minn. 


Leperditia millepunctata, n. sp. 
PLATE Ix, Fies. 37 to 39. 

Length, of a right valve, 1.57 mm.; hight 1.0 mm.; greatest thickness 
0.45 mm. 

This species is very similar to 1. wquilatera of this paper, but 
I have no doubt of their specific distinctness. There is a«slight 
channel and rim about the free edges wanting in that species, 
while the surface also is very finely punctate, and more uni- 
formly convex, the profiles of the two forms being different. The 
present species again is a little higher. 

It is possible that this species should be placed with Jsochilina 
rather than Leperditia, but as near as can be determined from the 
material at hand it appears that the valves overlap slightly, the 
left over the right, along the ventral border. 

Formation and loc dity: Trenton shales, one mile east of Fountain, 
Minnesota. Rare. 


Leperditia fimbriata, n. sp. 
PLATE Ix, Fies. 34 to 36. 
Length, of a right valve, (excluding spines) 1.88 mm.; hight 1.23 mm.; 
thickness 0.44 mm. Length of dorsal edge 1.2 mm. 
Valves suboval, moderately and almost uniformly convex, the 


ends nearly equally rounded, the posterior a little the wider. 
Extremities of dorsal edge angular, the posterior somewhat prom- 
inent. Point of greatest convexity slightly below the center. 
The entire ventral border and the ends, excepting the upper third 
on each side, with a fringe consisting of long, almost paliform, 


New Lower Silurian Ostracoda.— Ulrich. 269 


processes. At the ends the intervals between these processes is 
about 0.1 mm., but in the central part of the ventral edge they 
are shorter, and the projections themselves probably not*so long. 
The peculiar fringe distinguishes this species from all the others 
now referred to Leperditia., 
Formation und locality: Only one valve of this species is known. It 


was collected by the author in the upper beds of the Cincinnati or Hud- 
son River group, near Spring Valley, Minnesota. 


Schmidtella, n. gen. 

Carapace small, rounded, moderately convex. Valves inflated 
in the dorsal region so that this part projects shoulder-like over 
and out from the nearly straight hinge line. Right valve slightly 
the larger, its ventral edge overlapping that of the left. No 


sulcus nor tubercles. 
Type: Schmidtella crassimarginata, 0. sp. 


Tam somewhat in doubt respecting the systematic position of 
this genus, but provisionally would place it near Apuarchites, 
Jones, among the Leperditiidw. Nor am 1 satisfied that the de- 
scription should not be modified so as to include several smaller, 
as yet undescribed, species which agree in all other respects except 
in having an obscure subcentral impression, 

The name is given in recognition of the valuable services 
rendered to Silurian paleontology by Dr. F. Schmidt, of St. 
Petersburg, Russia. 


Schmidtella crassimarginata, n. sp. 
Plate 1x, Figs. 27 to 30. 

Length, of an average right valve, 1.25 mm.; hight 1.0 mm.; greatest 
thickness 0.4 mm. 

Valves broad-oval, very slightly oblique, the ends almost equal, 
the lower half with the ventral margin curved to form somewhat 
fess than a semicircle. Dorsal region flattened, slightly convex in 
aside view, rising very abruptly from and projecting slightly over 
the nearly straight hinge line. Pointof greatest convexity above 
the center. An undefined but rather conspicuous broad furrow 
around the ends and ventral margin, least distinct posteriorly, 
produces the thick border that has suggested the specific 
name, 

The obscurely defined, heavy and wide margin, and the flat 


270 The American Geologist. November, 1892 


dorsum are peculiarities that will distinguish this species at once 
from all described Silurian Ostracoda. 


Formation and locality: Very abundant on thin slabs of “Lower Blue” 
or Birdseye limestone collected at Mineral Point, Wisconsin. 


EXPLANATION OF PLATE IX. 


Figs. 1 to 8, LEPERDITIA TUMIDA, n. sp. p. 264. 

1. Right valve, of the usual form, x 10; 2, posterior, and 3, dorsal view 
of same, in outline. 

Figs. 4to 8, LEPERDITIA MUNDULA, 0. Sp. p, 265. 

4. Left side of entire carapace, < 10; 5, ventral,6, anterior view of same 
in Outline. 

7. Interior of a left valve, x 10, showing groove into which the ventral 
edge of the right valve is inserted when the valves are closed. 

8. Diagrammatic sectional view of the ventral portion of the carapace. 

Figs. 9 to 11, LEPERDITIA AQUILATERA, D. Sp. p. 265. 
9. Right side, 10, anterior, and 11,ventral view of an entire carapace, x 10. 
Figs 12 to 15, LEPERDITIA INFLATA, 0. sp. p. 265. 

12. Interior of full grown left valve; 13, dorsal view of same, < 10. 

14, Outline anterior view of closed carapace. 

15. A smaller left valve, approaching L. wquilatera in outline, x 10 

Figs. 16 to 18, LEPERDITIA GERMANA, 0. Sp. p. 266. 

16,17 and 18. Three outline views, side, anterior and ventral, of a left 
valve of this species from Mineral Point, Wis., x 10. 

Figs. 19 to 21, LEPERDITIA SULCATA, n. sp. p. 266. 

19, 20 and 21. Aright valve, x 10, with outline anterior and ventral 
views of same. 

Figs. 22 and 23, LEPERDITIA SULCATA, Var. VENTRICORNIS, 0. var p. 266. 

22, A left valve, x 10; 23, outline of same in a ventral view. 

Figs. 24 to 26, LEPERDITIA (? PRIMITIA) DORSICORNIS, 0. Sp. p. 267. 

24. A left valve, x 10; 25 and 26, outlines of same in anterior and ven- 
tral views. 

Figs. 27 to 30, SCHMIDTELLA CRASSIMARGINATA, D. gen. et sp. p. 269. 

27. Interior of right valve, x 10; 28, exterior of another right valve, 
equally magnified; 29 and 30, anterior and ventral views. 

Figs. 31 to 38, LEPERDITIA GRANILABIATA, 0. 8p. p. 267. 

31, 32 and 33. Three outline views, side, posterior and ventral, of a right 
valve, x 15. The puncte of a small part of the surface are shown in 
31. 

Figs. 34 to 86, LEPERDITIA FIMBRIATA, 0. sp. p. 268. 

Three outline views of a right valve, < 10. 

Figs. 37 to 39, LEPERDITIA MILLEPUNCTATA, n. sp. p. 268. 

Three outline views, and a small portion of the punctate surface, of a 
right valve, x 15. 


271 


TWO NEW LOWER SILURIAN SPECIES OF LICHAS 
(SUBGENUS HOPLOLICHAS),. 
By E. O. Uxricu, Newport, Ky. 
Lichas (Hoplolichas) robbinsi, n. sp. 


N 


Fig. 1. «,imperfect glabella of the natural size; }. profile of same. 
Specimen wanting the free cheeks and defective at the inner edge and 
at the center of the occipital ring. 

Glabella, including frontal prolongation, with the length equal- 


ling one and one-half times the greatest width. Without the 
frontal process the width is greater than the length. Frontal 
lobe very gently convex and with parallel margins in the posterior 
half, then expanding, the anterior half grows tumid and finally is 
produced forward into a single strong baculate process. Lateral 
lobes undivided, with margins almost parallel, the width and length 
about as one is to two and one-half, very little convex except in 
front where they bend outward and downward to the frontal mar- 
gin. Furrows between the central and lateral lobes very narrow; 
likewise the occipital furrow. Occipital ring rather narrow at the 
ends, nearly twice as wide in the middle where it probably sup- 
ported one or two central spines. Facial sutures apparently 
normal. Fixed cheeks of the form shown in the drawings, slightly 
depressed and with a linear curved impression immediately behind 
the eyes. Surface covered with papillz just visible to the naked 
eye. At intervals of one or two mm. there is a larger one. Free 
cheeks, eyes and thorax not observed. 

Since these two species, excepting the doubtful L. hy/@us Hall, 
are the first to be described from American rocks haying the 
characters of the subgenus Hoplolichas, Dames, they are not likely 


272 The Anne PICAN Gee log ist. November, 1892 


to be confounded with any of our known species of Lichas, None 
of the European forms known to me are very closely related. 

The specific name is given in honor of Dr. C,H. Robbins, of Wykoff, 
Minnesota, an indefatigable collector and student of the fossils of 
the Lower Silurian localities in southern Minnesota. The Galena 
limestones especially, have been made to furnish an abundance of 
their rich stores of interesting forms through his endeavors. 

Formation and locality: Inthe middle beds of the Galena (Trenton) 
limestone near Wykoff, Minnesota. 


Lichas ( Hoplolichas ) bicornis, 1.sp. 


Fig. 2. a, imperfect cephalic shield, natural size; ), profile of same. 

In this species the form of the lobes of the glabella (excluding 
the frontal prolongations), the fixed cheeks and the occipital ring 
are so much like these parts of the preceding species that it is 
not necessary to describe them. I shall therefore merely point out 
the most striking differences between the two species. 

In the first place the anterior part of the central lobe of the 
glabella is not drawn out into a single baculate prolongation, but 
supports two much smaller diverging horn-like processes, each 
1.5 mm. in diameter and probably less than 10 mm. in length. 
The dorsal surfaces of the three longitudinal lobes of the glabella 
are more convex transversely, and the lateral ones a little more 
elongate (the length is scarcely greater than twice the width). 
Finally there is a slight difference in the papillose marking of the 
test. the large set of papillae being more prominent in L. b/cornts. 

The two frontal horn-like processes will distinguish this species 
at once from all known American species of Liéchas. 

Formation and locality: Upper beds of the Cincinnati group near 
Spring Valley, Minnesota. 


273 


THE PLATYCERAS GROUP OF PALEOZOIC GAS- 
TEROPODS. 
By Cuarvies Roxiiin Keyes, Des Moines. 

It has been shown recently* that there are no good grounds for 
separating, generically, the recent forms of Capulus from the more 
typical Platycerata. Even if it were desirable to distinguish be- 
tween the modern and ancient sections, Conrad's familiar title 
could not stand. For, aside from being synonymous with Mont- 
fort's genus, Platyceras had been preoccupied as a generic term 
‘for more than three-quarters of a century. The name was used 
by Geoffrey? as early as 1746, for a genus of Coleoptera: and again 
by Latreillet in 1796. Nor can (Bhlert’s% recent revival of Phil- 
lip’s Acroculia be sustained, since the typical species are also true 
Capuli. 

Besides the two genera already mentioned, the shells of this 
group have been variously assigned to Pileopsis of Lamarck," 
Actita of Fisher von Waldheim, ** Acroculia of Phillips,++ Orthon- 
ychia of Hall,ii and some others. The relatiye merits of these 
names, as generic titles, have been fully discussed elsewhere. 

There has long been considerable difficulty in attempting to 
separate certain members of the group in question, on the one 
hand from some forms of Platystoma, especially from those spe- 
cies in which there is a greater or less tendency for the shells to 
uncoil; and, on the other nand, from various genera of patelloid 
shells. As might be expected in a group of gasteropods present- 
ing so few constant characters, which can be satisfactorily relied 
upon as classificatory criteria, it is often almost impossible to 
clearly distinguish between certain of these species. Many struc- 
tural features heretofore considered important in identification 
have been shown, recently, to possess very little, if any, specific 
value, owing to their great variability. It therefore becomes nec- 
essary to regard as of the utmost significance the basing of species 


*AMERICAN GEOLOGIST, Vol. VI, p. 6. 

+Hist. abrégée des Insectes, (1764). 

tPrécis des charact@res des Insectes, (1796). 

§Bul. Soc. Géol., France, (3), t. x1, p. 602. 

“ Anim. sans Vertebr., t. vi, p.16. (1822.) 

**Mem. Soc. imp. Nat. Moscau, t. vi, p. 234. (1823.) 
++Pal. Foss. Cornwall, p. 93. (1840.) 

tftRep. 4th Dist, New York, p. 172. (1843.) 
§$Proc. Acad. Nat. Sci., Phila, p. 150-181. (1890.) 


274 The American Geologist. November, 1892 


upon general resemblances rather than upon unimportant, varient 
characters arising from diverse conditions of environment imposed 
by a more or less extensive geographic distribution. Thus, in 
choosing for classification purposes the characters of any group, 
it is evident that only those features exhibiting the least tendency 
to modification are available. Even the most constant structures 
appear to lose much of their stability at some period during the 
existence of the group—-whether specific, generic or family; while 
other characters, more or less varient in the early stages of 
development, later become less liable to change. At some time 
or other these features blend and thus arise the transitional forms. 
It may be assumed then, that in many groups of the same 
genetic origin some varieties will present features that have 
remained for a long time practically unmodified; while others ex- 
hibit the same characters in a highly specialized, but ever chang- 
ing, condition. And it is of great interest to note in this 
connection that the latter—those having greatly exaggerated feat- 
ures—are the farms whose existence is of comparatively short 
duration; and that with these intensified structures the develop- 
ment is rather rapid, while their culmination is soon followed by 
a great diminution of the group's vitality, or more commonly its 
extinction, 
Under Conrad's generic name upwards of three hundred species 
of gasteropods have been proposed. In such a group of shells 
having so few salient characters for classification and a great range 
of variation, itis not hard to foresee some of the difficulties to be 
encountered in attempting to arrange satisfactorily the many dif- 
ferent forms. The placing of Platyceras, Orthonychia, etc., as 
‘sub-genera under Capulus, as has been done by Zittel* and others, 
manifestly does not meet the requirements, especially as regards 
the American members. Moreover, the group has been made te 
embrace a great variety of species, some of which are clearly not 
at all closely related genetically. Of these a few forms have been 
referred lately to the places to which they more properly belong- 
But there are still a considerable number of these shells which are 
evidently not members of the group, yet whose generic affinities 
cannot be determined at present, with exactness. 
In the recently issued synopsist of the Calyptraeide occurring 


*Handb. der Pal., 11 Band, p. 216. 
+Proc. Acad. Nat. Sci., Phila., pp. 150-181. (1890.) 


Platyceras Group of Paleozoic Gasteropods.—heyes. 275 
in the upper Paleozoic of America, the co-extension of Platyceras 
and Capulus was fully recognized and all the Carboniferous species 
hitherto referred to the former genus placed under the latter. At 
the same time considerable doubt was expressed as to the advisa- 
bility of associating all the forms mentioned under asingle generic 
title. When it comes to extending the examination to all the 
species usually embraced in Conrad's group, a very heterogeneous 
assemblage of shells is encountered. Hall, Meek and others have 
repeatedly called attention to the difficulties in the arrangement 
of the Platycerata. The first named author has even proposed 
two generic terms to include some of the more aberrant forms. 

In reviewing all the described species of the group under con- 
sideration, three more or less well defined and generally easily 
recognizable sections may be made out. The three are distin- 
guished readily from one another by their general shape; but there 
are other features equally distinctive. One section is character- 
ized by having a small, closely coiled spire, more or less contigu- 
ous with a large campanulate body whorl. Another group 
includes those shells having very small apices, usually arched but 
seldom closely coiled, the last volution very much elongated ver- 
tically, and often spiral. The third assemblage embraces the 
straight conical forms with little or no convolution of apical 
parts. To the first of the three groups, Monfort’s generic title, 
Capulus, applies; for the second and third it seems proper to re- 
vive Hall’s names, Orthonychia and Igoceras. Ina few cases 
these groups along certain lines seem to merge somewhat and 
their present limits eventually may require some modifications. 
On the whole, however, they appear to satisfy the requirements 
much better than any of the commonly accepted arrangements 
previously used. 

The American Platycerata now assigned to each of the three 
groups may be enumerated as follows: 


CAPULUS. 

argo Hall. . auriculatus Hall. 
billingst Hall. bisertalis Hall. 
bisinuatus Hall. buceulentus Hall. 
calantica Hall. carinatus Hall. 
elavatus Hall. crassus Hall. 
cymbium Hall. dilatatus Hall. 
dumosus Conrad. echinatus Hall. 


equilateralis Hall. erectus Hall. 


276 The American Geologist. 


fornicatus Hall. 
gibbosus Hall. 
intermedius Wall. 
lodiensis Meek. 
multisinuatus Hall. 
newberryt Wall. 
nodosus Conrad. 
occidens Walcott. 
paralius White and W. 
pentalobus Hall. 
platystomus Hall. 
reflexus Hall. 

rictus Hall. 
spinigerus Worthen. 
subsinuosus Worthen. 
sulcoplicatus Hall. 
thetis Hall. 

undatus Hall. 
ventricosus Conrad. 


conicum Hall. 
fissurellum Hall. 
perplecum Hall. 
pyramidatum Hall. 


subplicatum Meek & W. 


acutirostre Hall. 
arcuatum Hall. 


chesterense Meek and W. 


cornuforme Winchell. 
cyrtolites McChesney. 
formosum Keyes. 
lamellosum Hall. 
subrectum Hall. 
tubiforme Hall. 


gebhardi Conrad. 
haliotoides M. & W. 
latus Keyes. 
magnificus Hall. 
multispinosus Meek. 
niagarensis, Hall. 
obliquus Keyes. 
ovalis Stevens. 
parous Swallow. 
perplicatus Hall. 
plicatilis Hall. 
retrorsus Hall. 
stnuatus Hall. 
subrectus Hall. 
suicatus Conrad. 
symmetricus Hall. 
tribulosus White. 
undulostriatus Hall. 


IGOCERAS. 


capulus Hall. 
pabulocrinus Owen. 
plicatum Conrad. 
quincyense McChesney. 


ORTHONYCHIA. 


agreste Hall. 
attenuatum Hall. 
concavum Hall. 
curvirostrum Hall. 
dentalium Hall. 
éncile Hall. 
sptrale Hall. 
tortuosum Hall. 
unguiforme Hall. 


November, 1892 


Some of the forms included in the above are undoubtedly 


synonymous, but they cannot be eliminated until more satisfac- 


tory material has been examined. 


By transferring certain appar- 


ently anomalous species to other genera, the arrangement of the 


entire group seems to be much more in accordance with the 


observed affinities and differences of the various species than any 


other yet suggested, 


And in a treatment, soon to be issued, of 


the leading forms occurring in the Mississippi basin the plan here 


proposed has been followed. 


The great range of variation, even in a single species, together 


Theories of the Origin of Iron Ores.— Winchell. 277 


with some of the causes tending to produce these rapid changes, 
has been fully discussed in another place, making it unnecessary 
to take up again the habits of these organisms, detected even in 
the fossils by the intimate association of the gasteropods with 
crinoids. Concerning this phase of the question much might be 
said. The conclusions reached may be briefly summed up as follows: 

(1.) The gasteropod shell invariably lies over the anal opening 
of the crinoid. 

(2.) The mollusk remained in this position for a considerable 
period, probably for the greater part of life, as is shown by the 
shells on highly ornamented calyces and after the removal of them 
by the concentric grooves made on the ventral plates. 

(3.) The growing shell followed closely the inequalities of the 
surface upon which it rested—depressions giving rise to furrows 
and protuberances to folds or nodes. 

(4.) Shells lying simply on flat surfaces are much more de- 
pressed and proportionally broader than those clinging to the 
vertical or inclined portions of calyces in which the anal opening 
is situated laterally. 

The third of these statements is perhaps best illustrated by 
crinoids having low interradial areas and elevated radial regions, 
and is the probable explanation of the frequent occurrence of the 
more or less distinctly five-lobed calyptreean shells. Until very lately 
this phenomenon has admitted of no direct causal interpreta- 
tion. 

Since the appearance of the recent papers on the habits of the 
ancient calyptreans it has been inferred that these gasteropods 
were parasitic in their manner of living. This was not the case. 
For in no instance did the mollusks probably interfere at all with 
the nourishment of the crinoids, but merely fed, in part at least. 
upon refuse matter. 


CLASsSIElICATION OF THE FREORIES OF THE 
ORIGIN OF IRON ORES. 


By H. V. WiIncHELL, Minneapolis. 
A. MECHANICAL. 


a. Extra-terrestrial or cosmical. 
1. Meteorie fall:  [1.]* 
b. Terrestrial. 


‘* Figures in brackets refer to the theories as numbered and discussed 
in “The Iron Ores of Minnesota,” Bulletin No. 6, Minn. Geol. Sur. 


. 


The American Geologist. November, 1892 


bo 
I 
A 


1. Subterranean — eruption in dykes or accompanying basal- 
tic flows. [2.] 
2. Superficial action. 
a. Violent abrasion and transport. [13. 
Gane tinea erosion! 1; COR CEM BAG of on sands. [1 4. ] 
2. Oceanic sedimentation. [8. } 
B. CHEMICAL. 
a. Changes in situ. 
1. Change in the kind or quantity of iron already present in 
the rocks. 
a. Alteration of diffused ferric oxide into ferrous carbon- 
ate. [10.] 
4. Metamorphism of bog ore. [11]. | 
c. Metamorphism of lake ore.  [12.] 
d. Alteration of ferrous carbonate or sulphide into ferric 
oxide. [8 in part. | 
Change in the kind or quantity of other minerals. 
a, Substitution of iron oxide for some non-ferriferous 


iS 


mineral. [17. | 
4. Concentration, by removal of the other constituents. 
[4.] Similar to B a1. 
c. Electro-tellurie action. [16. } 
b. Removal by chemical action and subsequent deposition. 
1. By action of heat — sublimation.  [3. | 
2. By action of water. 
1. Oceanic precipitation. [8 in p’t. | 
(a. Secondary product of the 
decomposition of basic 
rocks. [18. ] 
| b. Secondary product from 
the decomposition of py- 
rite: Quire 
1. Saturation of porous strata.  [5. | 
2. Infiltration into cavities. [6, 15. | 
c. Deposit by springs. [9. ] 


| 
a. In drainage basins. 
| 


2. 


L. In the rocks. 


Mr. W.J. McGee, in ‘‘ The Pleistocene History of Northeastern 
lowa,’’ revives the use of the term geest, applied by DeLue in 
1816, and afterward by Eaton and Beck, in America, to ‘‘the 
immediate products of rock decay in situ.” P. 279, Hlerenth 
Annual Report of the Director U.S. Geol, Survey. 


bo 
=~] 
Ro 


ON THE FORMATION OF OOLITE.* 


By Dr. A. Rovupietz, of Munich. 

On the low shore of the Great Salt lake in Utah, there lie be- 
tween the pebbles and sand-grains, in great multitudes, snow- 
white calcareous corpuscles. They are thrown on the smooth 
strand by the waves of the lake and form a substantial part of 
the beach-sand. Where they still lie in the water, we usually 
see them partly covered with a bluish-green alga-mass. 

I could take with me last fall only dry material of this alga ; 
but that sufficed perfectly to recognize that the algoid bodies con- 
sisted of colonies of Glwocapsa and Gleothece cells, which richly 
secrete carbonate of lime. 

The cells of the Glawocapsa are 2 » in diameter and spherical, 
those of Glawothece 2—3 » thick and 4—5 yp long. 

They are invested with a clear, transparent, jelly-like mem- 
brane, which exceeds the cells in thickness. There are often 
several cells in one membrane, and the more or less spherical 
membranes are always pressed closely together, creating nearly 
the appearance of a uniform mass of jelly. 

The lime is enclosed in the alga-body in the form of rounded 
tubercles which often mass themselves together into larger, irreg- 
ular tubercular bodies. It is a fine-grained aggregate of calcite 
which always incloses numerous dead alga-cells that have already 
lost their greenish coloring. 

The snow-white and partly silver-gray calcareous bodies of the 
strand are of three-fold form: first, there are irregular tubercular 
bodies attaining several millimeters in diameter, second, spherical 
or oval forms for the most part one-third of a millimeter in diam- 
eter, and, third, long, thin rods about one-half a millimeter long 
and one-tenth of a millimeter broad. 

If we dissolve these bodies in dilute acid, the dead and shriv- 
eled fission-algze become free in quite the same way as by dissolv- 
ing the lime of the living alge. The snow-white, calcareous 
bodies may, therefore, be understood as dead alga-bodies,. 

The rounded to oval forms are, indeed, both by their external 
form and by the microscopic arrangement of the calcite, true 
odlites. Around an inner nucleus of irregularly granular lime, 
are laid concentric shells with, at the same time, radial arrange- 


* From the Botanisches Centralblatt, Nr. 35,1892. Translated by I. W. 
Cragin. 


Li. 


280 The American Geologist. November, 1892 


ment of the calcite crystals. But even in quite delicate sections 
the calcareous substance, both of the nucleus and of the shells, 
is interrupted by scattered, minute granules. If we dissolve the 
section cautiously and slowly in very dilute acid, the granules 
remain behind exactly in their original position, and we recognize 
in them the dead and crumpled G'la@ocapsa cells. 

The odlites of the Great Salt lake are, therefore, indubitably 
the product of lime-secreting fission-algve, and their formation is 
proceeding day by day. The rods and tubercles are of like con- 
stitution, save that in the latter the regular concentric structure 
of the lime is lacking. Furthermore, the little rods appear to be 
richer in alga-cells than the odlites. It must be left to the Amer- 
ican botanists to accurately trace this process of o@Glite-forming 
in place, or at least in living material. 

But even now the observations communicated suffice for find- 
ing an explanation of the origin of a few other already long 
known o@lites. 

A few years since, Joh. Walther (14 w. 16. Bd. Abh. siichs. 
Ges. Wissensch. 1888 und 1891) described and indicated as a re- 
cent formation, odlites from the strand of the Red sea. A prin- 
cipal role is ascribed to decayed animals. Last year I likewise 
investigated these odlites in place and found that they are a very 
widely distributed phenomenon along the west coast of the Sinai 
peninsula and usually decrease in frequency toward the interior 
of the land, although they still may be met with many kilome- 
ters, even day's marches, distant from the shore. But they also 
occur in older deposits which belong to the Quaternary period 
and build up the subaérially formed low coastal tracts in the fur- 
ther environs of Suez, whence Bauerman described them very 
well in 1868. They are there frequently consolidated into a hard, 
oblitic limestone. : 

These oblites are distinguished from those of the Great Salt 
lake chiefly in the fact that their nucleus always consists of a for- 
eign sand-grain, ‘The concentric shell-structure is very conspic- 
uously less developed than the radial. Then there are always 
to be noticed in the shells, peculiar vermiform and, not rarely, 
dichotomously branching canals that are filled up with calcite, 
which, however, in its orientation is quite independent of that of 
the calcite in the concentric shells, and has a much coarser grain. 

If we dissolve the lime with acid, there remain here also minute 


Formation of Oolite.—Rothpletz. 281 
grains which cohere in thin pellicles, and have quite the aspect 
of the fission-algze, as they occur in the Utah oilites. 

I have made the attempt to prove the plant-nature of these 
surviving pellicles by treatment with sulphuric acid and _ iodine 
solution, as well as with chloriodide of zinc, and thereby gained 
the knowledge that no blue coloring, but, indeed, a yellowish 
brown coloring, took place. Thus, however, behaved the fission- 
alg of the Salt lake and, to my astonishment, it was quite im- 
possible for me to color, in this way, the cell-membranes of a 
Halimeda which I had collected in the Red sea. 

It appears thus that the incapacity of cellulose to be stained 
blue, occurs not only in the Fungi but also in the lower Algz. 

The odlites of the Quaternary deposits and those of the drift- 
sand are all, without exception, porcelain-white. Among those, 
on the contrary, which I have collected at Suez, on the strand ac- 
cessible only at ebb tide, | found a smaller number which have a 
silver-gray to greenish-blue color and are not easily to be dis- 
tinguished from the silver-gray odlites of the Salt lake, if there 
were not the inner foreign sand-grain. 

The explanation of the inner vermiform canals, the study of 
the fresh-water fission-algze furnished me. Where these live in 
great abundance in damp places, springs, or pools, there lime- 
secreting Chrodcocci are accustomed to grow ina forest of thread- 
like fission-algz. So also may the case be in the sea. The 
thread-like algee may then become encased by the lime-crusts, 
their room may later be filled up with lime, and thus they con- 
tinue to preserve their external form. I suppose, therefore, in 
the vermiform structures of the Sinai odlites certain thread-like 
alge which were of course not themselves immediately concerned 
in the odlite-formation, but by the company in which they lived 
were imprisoned with it. It will be the task of future dredging 
investigations to bring to light the living oblite-maker from the 
depths of the Red sea. 

Hight years ago I found in the Lias of the Vilser Alps (in the 
so-called ‘* Aechsele”’ in the Reichenbacher valley) a gray lime- 
stone in a thickness of several meters, deposited between brachio- 
pod-bearing white and coral-bearing limestone. The same was 
quite filled with little, longish corpuscles which, owing to their form, 
I regarded as organisms, They are rods + mm.thick and up io 1 
mm.long,rounded off at both ends. In section,we recognize an in- 


282 The American Geologist. November, 1892 


ner nucleus of irregular granular calcite which repeats the form of 
the rods only onasmaller scale; therearound is laid a shell of un- 
usually regular zonal and radial structure, exactly: after the fashion 
of the true odlites. A foreign inner nucleus is never present, and 
the rather long, as well as always uniform shape of these prodig- 
iously abundant bodies confirmed me in the belief that they are 
organic forms, despite the fact that the structure of the shell af- 
forded me no point of support for it. Now, my supposition of 
that time gains much in probability because the agreement with 
the odlite rods of the Salt lake is one quite remarkable. 

But structures analogous to the irregularly granular alga-lime- 
stones of the Salt lake also seem to occur in older formations. — I 
refer especially in this statement to the so-called ‘‘ great obdlite 
structure” of the Wettersteinkalk. 

The structure of certain calcareous oblites which Wethered and 
most recently also Bleicher (May, 1892) have investigated seems 
to me to have great resemblance to that of the Sinai olite and 
is, perhaps, to be explained in the same manner, 

In the highest degree remarkable are the 12 » long rodlets which 
Bleicher has rendered visible in the iron odlites by treatment with 
aqua regia. He regards them, if possible, as bacteria (Comptes 
Rendus Acad. Science. Paris, March, 1892). If their plant- 
nature be established, they might also be claimed as fission-algze. 

According to the present stage of my researches, I am inclined 
to believe that at least the majority of the marine calcareous 
odlites with regular zonal and radial structure are of plant ori- 
gin: the product of microscopically small alge of very low rank, 
capable of secreting lime. 

8 Juli, 1892. 


THE IMMEDIATE WORK IN CHEMICAL SCIENCE.* 


ALBERT B. PRescorr, Ann Arbor. 

A division of science has a work of its own to do, a work that 
well might be done for its own sake, and still more must be done 
in payment of what is due to the other divisions. Hach section 
of our Association has its just task, and fidelity to this is an obli- 
gation to all the sections. Those engaged in any labor of science 
owe a debt to the world at large, and can be called to give an ac- 


*Retiring address as President of the American Association for the 
Advancement of Science, August, 1892. 


Chemical Science.—Prescott. 283 


count of what they are doing, and what they have to do, that the 
truth may be shown on all sides. 

If it be in my. power to make the annual address of this meet- 
ing of any service at all to you who hear it—in your loyalty to the 
Association—I would bring before you some account of the work 
that is wanted in the science of chemistry. Of what the chemists 
have done in the past the arts of industry speak more plainly 
than the words of any address. Of what chemists may do in the 
future it would be quite in vain that I should venture to predict. 
But of the nature of the work that is waiting in the chemical 
world at the present time I desire to say what [ can, and I desire 
to speak in the interests of science in general. The interests of 
science, I am well assured, cannot be held indifferent to the inter- 
ests of the public at large. 

It is not a small task to find out how the matter of the universe is 
made. The task is hard,not because of the great quantity in which 
matter exists, nor by reason of the multiplicity of the kinds and 
compounds of matter, but rather from the obscurity under which the 
actual composition of matter is hidden from man. The physicists 
reach a conclusion that matter is an array of molecules, little things, 
not so large as a millionth of a millimeter in size,and the forma- 
tion of these they leave to the work of the chemists. The smallest 
objects dealt with in science, their most distinct activities become 
known only by the widest exercise of inductive reason. 

The realm of chemical action,the world within the molecules of 
matter, the abode of the chemical atoms, is indeed a new world and 
but little known. | The speculative atoms of the ancients, mere me- 
chanical divisions, although prefiguring the molecules of modern 
science yet gave no sign of the chemical atoms of this century, 
nor any account of what happens in a chemical change. A new 
field of knowledge was opened in 1774 by the discovery of oxy- 
gen, and entered upon in 1804 by the publications of Dalton, a 
region more remote and more difficult of access than was the un- 
known continent toward which Christopher Columbus set his sails 
three. centuries earlier. The world within molecules has been 
open for only a hundred years. The sixteenth century was not 
long enough for an exploration of the continent of America, and 
the nineteenth has not been long enough for the undertaking of 
the chemists. When four centuries of search shall have been 
made in the world of chemical formation, then science should be 


284. The American Geologist. November, 1892 


ready to meet a congress of nations, to rejoice with the chemist 
upon the issue of his task. 

It is well known that chemical labor has not been barren of re- 
turns. The products of chemical action, numbering thousands of 
thousands, have been sifted and measured and weighed. If you 
ask what happens in a common chemical change you can obtain 
direct answers. When coal burns in the air, how much oxygen 
is used up can be stated with a degree of exactness true to the 
first decimal of mass, perhaps to the second, yet questionable in 
the third. How much carbonic acid is made can be told in weight 
and in volume with approaching exactness. How much heat this 
chemical action is worth, how much light, how much electro-mo- 
tive force, what train-load of cars it can carry, how long it can 
make certain wheels go round,— for these questions chemists and 
physicists are ready. With how many metals carbonic acid will 
unite, how many others it can make into carbonates, into what 
classes of molecules a certain larger fragment of carbonic acid can 
be formed, the incomplete records of these things already run 
through a great many volumes. These carboxylic bodies are open 
to productive studies, stimulated by various sorts of inquiry and 
demands of life. Such have been the gatherings of research. 
They have been slowly drawn into order, more slowly interpreted 
in meaning. The advance has been constant, deliberate, some- 
times in doubt, always persisting and gradually gaining. firmer 
ground. So chemistry has reached the period of definition. Its 
guiding theory has come to be realized. 

+The atomic theory” has more and more plainly appeared to 
be the central and vital truth of chemical science. As a working 
hypothesis it has directed abstruse research through difficult ways 
to open accomplishment in vivid reality. As a system of knowl- 
edge, it has more than kept pace with the rate of invention.. As: 
philosophy, it is in touch with profound truth in physics, in the 
mineral kingdom, and in the functions of living bodies. Asalan- 
guage it has been a necessity of man in dealing with chemical 
events. Something might have been done, no doubt, without it, 
had it been possible to keep it out of the chemical mind. But 
with a knowledge of the primary elements of matter, as held at 
the beginning of this century, some theory of chemical atoms was 
inevitable. And whatever theory might have been adapted, its 
use in investigation would have drawn it with a certainty into the 


Chemical Science. — Prescott. 285 


essential features of the theory now established. It states the 
constitution of matter in terms that stand for things as they are 
made. The mathematician may choose the ratio of numerical 
notation, whether the ratio of ten or some other. But the chemist 
must find existing ratios of atomic and molecular mass, with such 
degree of exactness as he can attain. Chemical notation, the in- 
dex of the atomic system, is imperfect, as science is incomplete. 
However defective, it is the resultant of a multitude of facts. 
The atomic theory has come to be more than facile language, more 
than lucid classification, more than working hypothesis, it is the 
definition of the known truth in the existence of matter. 

The chemical atom is known, however, for what it does, rather 
than for what it is. It is known asa center of action, a factor of 
influence, an agent of power. It is identified by its responses, 
and measured by its energies. Concealed as it is, each atom has 
given proof of its own part in the structure of a molecule. Proofs 
of position, not in space but in action, as related to other atoms, 
have been obtained by a multitude of workers with the greatest 
advantage. The arrangement of the atoms in space, however, is 
another and later question, not involved in the general studies of 
structure. But even this question has arisen upon its own chem- 
ical evidences, for certain bodies, so that ‘‘the configuration” of 
the molecule has become an object of active research. 

Known for what it does, the atom is not clearly known for what 
it is. Chemists, at any rate, are concerned mainly with what can 
be made out of atoms, not with what atoms can be made of. 
Whatever they are, and by whatever force or motion it is that they 
unite with each other, we define them by their effects. Through 
their effects they are classified in the rank and file of the periodic 
system. The physicists, however, do not stop short of the phil- 
osophical study of the atom itself. Asa vibratory body its move- 
ments have been under mathematical calculations; as a vortex 
ring its pulsations have been assumed to agree with its combining 
power. As an operating magnet its interaction with other like mag- 
nets has been predicated as the method of valence. There are, 
as IL am directly assured, physicists of penetration and prudence 
now looking with confidence to studies of the magnetic relations 
of atoms to each other.* Moreover, another company of workers, 


*“The results of molecular physics point unmistakably to the atom as 
a magnet, in its chemical activities.”’"—A. E. Dolbear, in a personal com- 
munication. 


286 The American Geologist. November, 1892 


the chemists of geometric isomerism, assume a configuration of 
the atoms, in accord with that of the molecule. 

The stimulating truth of the atomic constitution of the molecule, 
a great truth in elastic touch with all science, excites numerous 
hypotheses, which, however profitable they may be, are to be 
stoutly held at a distance from the truth itself. Such are the hy- 
potheses of molecular aggregation into crystals and other mineral 
forms. Such are the biological theories of molecules polymerizing 
into cells, and of vitality as a chemical property of the molecule. 
Such are the questions of the nature of atoms, and the genesis of 
the elements as they are now known, questions on the border of 
metaphysics. Let all these be held distinct from the primary 
law of the atomic constitution of simple molecules in gaseous 
bodies, an essential principle in an exact science. The chemist 
should have the comfortable assurance, every day, as he plies his 
balance of precision, that the atom-made molecules are there, in 
their several ratios of quantity, however many unsettled questions 
may lie around about them. Knowledge of molecular structure 
makes chemistry a science, nourishing to the reason, giving 
dominion over matter, for beneficence to life. 

Every chemical pursuit receives strength from every advance 
in the knowledge of the molecule. And to this knowledge, none 
the less, every chemical pursuit contributes. The analysis of a 
mineral, whether done for economic ends or not, may furnish a 
distinct contribution toward atomic valence. The further exami- 
nation of steel in the cables of a suspension bridge is liable to 
lead to unexpected evidence upon polymeric unions. Rothamsted 
farm, where ten years is not a long time for the holding of an 
experiment, yields to us a classic history of the behavior of nitro- 
gen, a history from which we correct our theories. The analysis 
of butter for its substitutes has done something to set us right 
upon the structure of the glycerides. Clinical inspection of the 
functions of the living body fain finds a record of molecular 
transformations too difficult for the laboratory. The efforts of 
pharmaceutical manufacture stimulate new orders of chemical 
combination. The revision of the pharmacopoeia every ten years 
points out a humiliating number of scattered errors in the pub- 
lished constants on which science depends. ‘The duty of the 
engineer, in his scrutiny of the quality of lubricating oils, brings 
a more critical inquiry into the laws of molecular movement. 


Chemical Science. — Prescott. 287 


There is not time to mention the many professions and pursuits 
of men who contribute toward the principles of chemistry and hold 
a share therein. If it be the part of pure science to find the law 
of action in nature, it is the part of applied science both to con- 
tribute facts and to put theory to the larger proof. In the words 
of one who has placed industry in the greatest of its debts to 
philosophic research, W. H. Perkin, ‘‘There is no chasm between 
pure and applied science, they do not even stand side by side, 
but are linked together.” So in all branches of chemistry, 
whether it be termed applied or not, the best workers are the most 
strongly bound as one, in their dependence upon what is known 
of the structure of the molecule. 

Studies of structure were never before so inviting. In this 
direction and in that especial opportunities appear. Moreover 
the actual worker here and there breaks into unexpected paths of 
promise. Certainly the sugar group is presenting to the chem- 
ist an open way from simple alcohols on through to the cell sub- 
stances of the vegetable world. And nothing anywhere could be 
more suggestive than the extremely simple unions of nitrogen 
lately discovered. They are likely to elucidate linkings of this 
element in great classes of carbon compounds, all significant in 
general chemistry. Then certain comparative studies have new 
attractions. As halogens have been upon trial side by side with 
each other, so for instance, silicon must be put through its paces 
with carbon, and phosphorus with nitrogen. Presently, also, the 
limits of molecular mass, in polymers and in unions with water, 
are to be nearer approached from the chemical side, as well as 
from the side of physics, in that attractive but perplexing border 
ground between affinity and the states of aggregation. 

Such is the extent and such the diversity of chemical labor at 
present that every man must put limits to the range of his study. 
The members of a society or section of chemistry, coming to- 
gether to hear each other’s researches, are better able, for the 
most part, to listen for instruction than for criticism. Still less 
prepared for hasty judgment are those who do not come together 
in societies atall. Evenmen of eminent learning must omit large 
parts of the subject, if it be permitted to speak of chemistry as 
a single subject. These considerations admonish us to be liberal. 
When metallurgical chemistry cultivates skepticism as to the 
work upon atomic closed chains, it is a culture not the most lib- 


288 The American Geologist. November, 1892 


eral. When a devotee of organic synthesis puts alow value upon 
analytic work, he takes a very narrow view of chemical studies. 
When the chemist who is in educational service disparages inves- 
tigations done in industrial service, he exercises a pitiful brevity 
of wisdom. 

The pride of pure science is justified in this, that its truth is 
for the nurture of man. And the ambition of industrial art is 
honored in this, its skill gives strength to man. It is the obliga- 
tion of science to bring the resources of the earth, its vegetation 
and its animal life, into the full service of man, making the 
knowledge of creation a rich portion of his inheritance, in mind 
and estate, in reason and in conduct, for life present and _ life to 
come. To know creation is to be taught of God. 

I have spoken of the century of beginning chemical labor, and 
have referred to the divisions and specialties of chemical study. 
What can I say of the means of uniting the earlier and later years 
of the past, as well as the separated pursuits of the present, in 
one mobile working force? Societies of science are among these 
means, and it becomes us to magnify their office. For them, 
however, all that we can do is worth more than all we can say. 
And there are other means, even more effective than associations. 
Most necessary of all the means of unification in science is the 
use of its literature. 

It is by published communication that the worker is enabled 
to begin, not where the first investigation began, but where the 
last one left off. The enthusiast who lacks the patience to con- 
sult books, presuming to start anew all by himself in science, has 
need to get on faster than Antoine L. Lavoisier did when he began, 
an associate of the French Academy in 1768. He of immortal 
memory, after fifteen eventful years of momentous labor, reached 
only such a combustion of hydrogen as makes a very simple class 
experiment at present. But, however early in chemical discov- 
ery, Lavoisier availed himself of contemporaries. They found 
oxygen, he learned oxidation ; one great man was not enough, in 
L774, both to reveal this element and show what part it takes in 
the formation of matter. The honor of Lavoisier is by no means 
the less that he used the results of others, it might have been the 
more had he given their results a more explicit mention. Men 
of the largest original power make the most of the results of 
other men. Discoverers do not neglect previous achievement, 


Chemical Science.— Prescott. 289 
however it may appear in biography. The masters of science 
are under the limitations of their age. Had Joseph Priestley 
lived in the seventeenth century he had not discovered oxygen. 
Had August Kekulé worked in the period of Berzelius, some 
other man would have set forth the closed chain of carbon com- 
bination, and Kekulé, we may be sure, would have done some- 
thing else to clarify chemistry. Such being the limitations of 
the masters, what contributions can be expected in this age from 
a worker who is without the literature of his subject ? 

In many a town some solitary thinker is toiling intensely over 
some self-imposed problem, devoting to it such sincerity and 
strength as should be of real service, while still he obtains no 
recognition. Working without books, unaware of memoirs on 
the theme he loves, he tries the task of many with the ‘strength 
of one. Suchas he sometimes send communications to this asso- 
ciation. An earnest worker, his utter isolation is quite enough to 
convert him intoacrank. Toevery solitary investigator I should 
desire to say, get to a library of your subject, learn how to use its 
literature, and possess yourself of what there is on the theme of , 
your choice, or else determine to give it up altogether. You 
may get on very well without college laboratories, you can sur- 
vive it if unable to reach the meetings of men of learning, you 
can do without the counsel of an authority, but you can hardly be 
a contributor in science except you gain the use of its literature. 

First in importance to the investigator are the original memoirs 
of previous investigators. The chemical determinations of the 
century have been reported by their authors in the periodicals. 
The serials of the years, the continuous living repositories of all 
chemistry, at once the oldest and the latest of its publications, 
these must be accessible to the worker who would add to this 
science. <A library for research is voluminous, and portions of 
it are said to be scarce, nevertheless it ought to be largely sup- 
plied. The laboratory itself is not more important than the 
library of science. In the public libraries of our cities, in all 
colleges now being established, the original literature of science 
ought to be planted. It is a wholesome literature, at once a stim- 
wlant and a corrective of that impulse to discovery that is fre- 
quent among the people of this country. That a good deal of it 
is in foreign languages is hardly a disadvantage ; there ouglit to be 
some exercise for the modern tongues that even the public high 


290 The American Geologist. November, 1892 


schools are teaching. That the sets of standard journals are get- 
ting out of print is a somewhat infirm objection. They have no 
right to be out of print in these days when they give us twenty 
pages of blanket newspaper at breakfast, and offer us Scott’s 
novels in full for less than the cost of a day’s entertainment. As 
for the limited editions of the old sets, until reproduced by new 
types, they may be multiplied through photographic methods. 
When there is a due demand for the original literature of chem- 
istry, a demand in accord with the prospective need for its use, 
the supply will come, let us believe, more nearly within the 
means of those who require it than it now does. 

What I have said of the literature of one science can be said, 
in the main, of the titerature of the other sciences. And other 
things ought to be said, of what is wanted to make the literature 
of science more accessible to consulting readers. A great deal 
of indexing is wanted, Systematic bibliography, both of pre- 
vious and of current literature, would add a third to the pro- 
ductive power of a large number of workers. It would promote 
common acquaintance with the original communications of re- 
search, and a general demand for the serial sets. Topical bibli- 
ographies are of great service. In this regard I desire to ask 
attention to the annual reports of the committee on Indexing 
Chemical Literature, in this association for nine years past, as 
well to recent systematic undertakings in geology, and like move- 
ments in zoology and other sciences. Also to the Index Medicus, 
as a continuous bibliography of current professional literature. 

Societies and institutions of science may well act as patrons to 
the bibliography of research, the importance of which has been 
recognized by the fathers of this Association. In 1855, Joseph 
Henry, then a past president of this body, memorialized the Brit- 
ish Association for codperation in bibliography, offering that aid 
of the Smithsonian Institution which has so often been afforded 
to publications of special service. The British Association ap- 
pointed a committee, who reported in 1857, after which the under- 
taking was proposed to the Royal Society. The Royal Society 
made an appeal to her Majesty’s government, and obtained the 
necessary stipend. Such was the inception of the Royal Society 
Catalogue of scientific papers of this century, in eight quarto 
volumes, as issued in 1867 and 1877. Seriously curtailed from 
the generous plan of the committee who proposed it, limited to 


Chemical Science.— Prescott. 291 


the single feature of an index of authors, it is nevertheless of 
great help in literary search. Before any list of papers, how- 
ever, we must place a list of the serials that contain them, as 
registered by an active member of this Association, an instance 
of industry and critical judgment. I refer to the well-known 
catalogue of scientific and technical periodicals, of about five 
thousand numbers, in publication from 1665 to 1882, together 
with the catalogue of chemical periodicals by the same author. * 

Allied to the much needed service in bibliography, is the service 
in compilation of the Constants of Nature. In the preface of 
his dictionary of solubilities, in 1856, Professor Storer said ‘that 
chemical science itself might gain many advantages if all known 
facts regarding solubility were gathered from their widely scat- 
tered original sources into one special comprehensive work.” 
That the time of the philosophical study of solution was near at 
hand has been verified by recent extended monographs on this 
subject. In like manner Thomas Carnelley in England, and early 
and repeatedly our own Professor Clarke in the United States, + 
bringing multitudes of scattered results into codrdination, have 
augmented the powers of chemical service. 

What bibliography does for research, the Handwoérterbuch does 
for education, and for technology. It makes science wieldy to 
the student, the teacher and the artisan. The chief dictionaries 
of science, those of encyclopedic scope, ought to be provided 
generally in public libraries, as well as in the libraries of all high 
schools.{ The science classes in preparatory schools should make 
an acquaintance with scientific literature in this form. If schol- 
ars be assigned exercises which compel reference reading, they 


Bolton’s Catalogue of Scientific and Technical Periodicals (1885: 
Smithsonian) omits the serials of the societies, as these are the subject 
of Scudder’s Catalogue of Scientific Serials (1879: Harvard Univ.) On 
the contrary Bolton’s Catalogue of Chemical Periodicals (1885: N. Y. 
Acad. Sci ) includes the publications of societies as well as other serials. 
Chemical technology is also represented in the last named work. 


+ The service of compilation of this character is again indicated by 
this extract from Clarke’s introduction to the first edition of his ‘* Con- 
stants” (1873): “ While engaged upon the study of some interesting 
points in theoretical chemistry, the compiler of the following tables bad 
occasion to make frequent reference to the then existing lists of specific 
gravities. None of these, however, were complete enough. : 


{The statistics of school libraries in the United States are very mea- 
gre, the expenditures for them being included with that for apparatus. 
For libraries and apparatus of all common schools, both primary and 
secondary, the annual expenditures is set at $987,048, which is about 
seven-tenths of one per cent. of the total expenditure for these schools. 


299 The American Geologist. November, 1892 


will gain a beginning of that accomplishment too often neglected, 
even in college, how to use books. 

The library is a necessity of the laboratory. Indeed, there is 
much in common between what is called the laboratory method, 
and what might be called the library method, in college training. 
The educational laboratory was instituted by chemistry, first tak- 
ing form under Liebig at Giessen only about fifty years ago. 
Experimental study has been adopted in one subject after an- 
other until, now, the ‘‘laboratory method” is advocated in lan- 
guage and literature, in philosophy and law. It is to be hoped 
that chemistry will not fall behind in the later applications of 
‘‘the new education” in which she took so early a part. 

The advancement of chemical science is not confined to discov- 
ery, nor to education, nor to économic use. All of those interests 
it should embrace. To disparage one of them is injurious to the 
others. Indeed, they ought to have equal support. It would be 
idle to inquire into their respective advantages. This much, how- 
ever, is evident enough, chemical work is extensive and there is 
immediate want of it. 

Various other branches of science are held back by the delay 
of chemistry. Many of the material resources of the world wait 
upon its progress. Inthe century just before us the demands 
upon the chemist are to be much greater than they have been, 
All the interests of life are calling for better chemical informa- 
tion. Men are wanting the truth. The biologist on the one 
hand, and the geologist on the other, are shaming us with inter- 
rogatories that ought to be answered. Philosophy lingers for the 
results of molecular inquiry. Moreover the people are asking 
direct questions about the food they are to eat,or not to eat,asking 
more in a day than the analyst is able to answer ina month. The 
nutritive sources of bodily power are not safe, in the midst of 
the reckless activity of commerce, unless a chemical safeguard be 
kept, a guard who must the better prepare himself for his duty. 

Now if the people at large can but gain a more true estimation 
of the bearing of chemical knowledge, and of the extent of the 
chemical undertaking, they will more liberally supply the sinews 
of thorough-going toil. It must be more widely understood that 
achievements of science, such as have already multiplied the 
hands of industry, do not come by chances of invention, nor by 
surprises of genius. It must be learned of these things that they 


Chemical Science.—Prescott. 293 


come by breadth of study, by patience in experiment, and by the 
slow accumulations of numberless workers. And it must be 
made to appear that the downright labor of science actually de- 
pends upon means of daily subsistence. It must be brought 
home to men of affairs, that laboratories of seclusion with deli- 
cate apparatus, that libraries, such as bring all workers together 
in effect, that these really cost something in the same dollars by 
which the products of industrial science are measured. Statistics 
of chemical industry are often used to give point to the claims of 
science. For instance it can be said that this country, not mak- 
ing enough chemical wood pulp, has paid over a million dollars a 
year for its importation. That Great Britain pays twelve millions 
dollars a year for artificial fertilizers, from without. That coal tar is 
no longer counted a by-product, having risen in its value to a par 
with coal gas. But these instances, as striking as numerous others, 
still tend to divert attention from the more general service of chem- 
istry as it should be known in al! the economies of civilization. 

It is not for me to say what supplies are wanted for the work 
of chemists. These wants are stated,in quite definite terms, by : 
sufficient number of those who can speak for themselves. But if 
my voice could reach those who hold the supplies, | would plead 
a most considerate hearing of all chemical requisitions,and that a 
strong and generous policy may in all cases prevail in their behalf. 

If any event of the year is able to compel the attention of the 
world to the interests of research, it must be the notable close of 
that life of fifty years of enlarged chemical labor, announced 
from Berlin a few months ago. When thirty years of age, August 
Wilhelm von Hofmann, a native of Giessen and a pupil of Liebig, 
was called to work in London. Taking hold of the organic de- 
rivatives of ammonia, and presently adopting the new discoveries 
of Wurtz, he began those masterly contributions that appear to 
have been so many distinct steps toward a chemistry of nitrogen, 
such as industry and agriculture and medicine have thriven upon. 
In 1850 he opened a memoir in the philosophical transactions 
with these words ‘‘the light now begins to dawn upon the chaos 


) 


of collected facts.” Since that time the coal tar industry has 
risen and matured, medicine has learned to measure the treatment 
of disease, and agriculture to estimate the fertility of the earth. 
It seems impossible that so late as March of the present year, he 
was still sending his papers to the journals. If we could say 


something of what he has done we could say nothing of what he 


294 The American Geologist. November, 1892 


has caused others to do. And yet, let it be heard in these United 
States, without such a generous policy of expenditure for science 
as gave to Dr. Hofmann his training in Giessen, or brought him 
to London in 1848, or built for him laboratories in Bonn and Ber- 
lin, without such provision by the State, the fruits of his service 
would have been lost to the world. Aye, and for want of a like 
broad and prudent provision for research with higher education, 
in this country, other men of great love for science and great 
power of investigation every year fail of their rightful career for 
the service of mankind. 

For the prosecution of research, in the larger questions now be- 
fore us, no training within the limitations of human life can be 
too broad or too. deep. No provision of revenue, so far as of 
real use.to science, can be too liberal. The truest investigation 
is the most prudent expenditure that can be made. 

In respect to the support that is wanted for work in science, I 
have reason for speaking with confidence. If I go beyond the 
subject with which I began I do not go beyond the warrant of 
the Association. This body has lately defined what its members 
may say, by creating a committee to receive endowments for the 
support of research. 

There are men and women who have been so far rewarded, that 
ereat means of progress are in their hands, to be vigorously held 
for the best advantage. Strength is required to use large means, 
as well as to accumulate them. It is inevitable to wealth, that it 
shall be put to some sort of use, for without investment it dies. 
By scattered investment wealth loses personal force. The Amer- 
ican Association, in the conservative interests of learning, pro- 
poses certain effective investments in science. If it be not given 
to every plodding worker to be a promoter of discovery, such at 
all events is the privilege of wealth, under the authority of this 
Association. If it be not the good fortune of every investigator 
to reach knowledge that is new, there are, every year, in every 
section of this body, workers of whom it is clear that they would 
reach some discovery of merit, if only the means of work could 
be granted them. Whosoever supplies the means fairly deserves 
and will receive a share in the results. It is quite with justice 
that the name of Elizabeth Thompson, the first of the patrons, 
has been associated with some twenty-one modest determinations 
of merit recognized by this Association. 


“To procure for the labors of scientific men increased facilities” 


Volcanic Dust from Omaha, Neb.—Todd. 295 


is one of the constitutional objects of this body. It is time for 
effectiveness towards this object. The association has estab- 
lished its character for sound judgment, for good working organ- 
ization, and for representative public interest. It has earned its 
responsibility as the American trustee of undertakings tn sctence, 

Eo give a swonger ) 92 -Jimpulsev... =: to scientific 
research” is another declaration of what we ought to do. To this 
end larger endowments are necessary. And it will be strange if 
some clear-seeing man or woman does not put ten thousand 
dollars, or some multiple of it, into the charge of this body for 
some searching experimental inquiry now waiting for the material 
aid, The committee upon endowment is ready for consultation 
upon all required details. 

“To give . . . more systematic direction to scientific re- 
search” is likewise stated as one of our objects. To this intent 
the organization of sections affords opportunities not surpassed. 
The discussions upon scientific papers give rise to a concord of 
competent opinions as to the direction of immediate work. And 
arrangements providing in advance for the discussion of vital 
questions, as formally moved at the last meeting, will in one way 
or another point out to suitable persons such lines of labor as 
will indeed give systematic direction to research. 

In conclusion | may mention another, the most happy of the 
duties of the American Association. It is to give the hand of 
hospitable fellowship to the several societies who year by year 
eather with us upon the same ground. Comrades in labor and in 
refreshment, their etforts reinforce us, their faces brighten our 
~way. May they join us more and more in the companionship 
that sweetens the severity of art. A meeting of good workers is’ 
a remembrance of pleasure, giving its zest to the aims of the 


year. 


VOLCANIC DUST FROM OMAHA, NEBRASKA.* 


By J. E. Topp, Vermillion, S Dak. , 
This material was from a stratum of whitish aspect, about 18 


inches in thickness, found in the bluffs facing the Missouri river 
about 7} miles north of Omaha. It has the same general char- 
acteristics as the voleanic dust which has been found in quantity 
along the Republican, in southern Nebraska, also in Knox, Cum- 


*Proceedings of the lowa Academy of Science, 1891. 


296 The American Geologist. November, 1892 


ming and Seward counties in the same state. This statement is 
made on the authority of J. S. Diller,of the United States Geolog- 
ical survey, who has examined samples from all these localities 
microscopically. This differs in being stained with oxide of iron, 
and the sharp angular grains are coated with carbonate of lime. 
Like the rest it contains with the finely pulverized glass, a few 
rounded grains of quartz and angular grains of feldspar less than 
.02 of a millimeter in diameter. The dust is such as is carried 
through the air from voleanoes, The sand grains and occasional 
diatoms indicate its deposition in still water. 

The following isa section of the bluff containing the volcanic 
dust stratum : 

Twenty-five to thirty feet—Loess, exposed as much more on 
slope above. 

Seven feet—Stratified yellow clayey loam, with many calcare- 
ous concretions. 

One and one-half feet—Voleanic dust, stained with iron oxide. 

Five feet—Yellow clayey loam, slightly stratified. 

One-half foot—Fine gray sand. 

Twenty feet—Coarse sand and pebbles obliquely stratified. 

Fifteen feet—Unknown, probably in part blue till. Level of 
the Missouri river. 

This lozality is the most eastern exposure of the volcanic dust 
stratum which is found scattered over most of Nebraska, — Dili- 
gent search has as yet failed to discover it on the Lowa side of 
the Missouri. 


NEW DISCOVERIES AT BAOUSSE ROUSSE, NEAR 
MENTONE. 


By the Marquis De NapatILiac. 

| know of no discovery touching pre-historic times more re- 
markable than those made in the caves of Baoussé Roussé, be- 
tween Mentone and Ventimiglia, on the borders of France and 
Italy. These caves were first discovered in 1872 by Mr. Riviere. 
Since that time this learned gentleman has vigorously prosecuted 
his excavations,* and they have yielded numerous human skele- 
tons, all belonging to the celebrated Cro-Magnon race, who at the 
end of the Quaternary period, or perhaps at the beginning of 


*They are related at length in “L’Antiquité de ’!homme dans les Alpes 
maritimes.” Paris, I. B. Baillitre et fils, 1887. 


Discoveries at Baoussé Roussé.——Nadaillae. 297 


neolithic times, ruled not only the south of France, but also all 
the Mediterranean shores. It is these same men we meet with 
under the names of Iberians, Ligurians, Sicanians, perhaps also 
under those of Pelasgians and Berbers. It is their bones that 
the brothers Siret found in the south of Spain, professor Sergi in 
Italy, and Mr. Riviére at Baoussé Roussé. 

All the bones, wherever found, show a great similitude. They 
are robust, and bespeak an athletic constitution and a large mus- 
cular power. The men were remarkably tall, the crania are doli- 
chocephalic, the tibias platyenemic, but since Dr. Manouvrier’s 
observations, we cannot see there an inferior character. The 
cranium of the first skeleton found (an old man) measured 1,590 
cubic centimeters. The cranium of the woman found next to 
him 1,450 cubic centimeters; but this last measurement is not 
quite accurate, on account of the decomposed state of the bones. 

The man had upon his head a net of small shells (Massa neritec), 
and bracelets of shells round his arms and legs. Near him Mr. 
Riviére collected more than 150 stone implements, and also num- 
erous bones of mammals, birds, and fishes, evidently the food of 
these people. 

New discoveries quickly followed the first ones, and we always 
find a particular mode of inhumation, which, I believe, still ex- 
ists, or lately existed, in some Indian tribes. The bones of all 
the adults, after the total decomposition of the flesh, were painted 
in red with the help of peroxide of manganese or other sub- 
stances frequently met with in the different caverns. 

The last excavations took place in February, 1892, in one of 
these caves, named Barma Grande. A communication made to 
the Academie des Inscriptions, March 4, 1892, informed us of 
the discovery, at 8 metres below the levelof the ground, of three 
new skeletons, a man, a woman, and a young subject whose dentes 
sapientiz had not yet evolved. They had been buried on a bed 
of cinders, broken fragments of charcoal, remains of all sorts, 
evidently the hearth on which the family cooked their victuals, 
The boy wore a necklace formed of two rows of the vertebrie of 
a fish and one row of small shells. At different points hung 
pendants cut out of the canine teeth of stags, decorated with 
parallel striz. The man had also a necklace of fourteen canines 
of the stag, also striated. With the skeletons were found a cer- 
tain number of stone instruments, some of them finely worked, 


298 The American Geologist. November, 1892 


but none of them polished, and some bone implements of very 
gross fabrication. 

The man was very tall, and, if we judge by the length of the 
thigh-bone (545 millimeters), his hight must have exceeded two 
metres (6 feet 6 inches). The boy, who had not yet attained his 
manhood, measured 1.63 metres (5 feet 8 inches). We must also 
remark the extreme wear of the teeth, very apparent already in 
the boy, and which in the man extended to their very root. I 
have already said that the caves of Baoussé Roussé yielded numer- 
ous bones of mammals, but none of them belonged to the extinct 
species, not even to the reindeer which is found in the south of 
Franee even at a late period. On the other hand, no polished 
stone implement was ever found in these caves. We can there- 
fore give these men a pretty accurate date, and place their exist- 
ence, as I have said, at the end of the Quaternary or the begin- 
ning of the neolithic times. One cave remains as yet unexcavated. 
It belongs to the Prince of Monaco. Orders are given that the 
excavations shall begin next spring. If they produce anything 
of interest, I will not fail to report them to the readers of Sevence. 


Rougemont, Sept. 2. — Science, Sept. 23. 


THE SHORE-LINES OF ANCIENT GLACIAL LAKES.* 
By J. E. Topp, Vermillion, 8. Dak. 

As most are aware, there are areas of drift external to any ter- 
ininal moraines, the origin of which is still in dispute. On 
general principles, it would be expected that numerous lakes 
would have frequently occurred during the Ice Age. As the ice 
advanced, streams would frequently be dammed, and their chan- 
nels more or less changed, and the weight of the ice, with its 
chilling effect, in level areas would not infrequently produce a 
subsidence toward the ice, which would often become filled with 
the floods escaping from the ice. 

Geike, in his ‘Tee Age,” last edition, draws a graphic picture 
of such lakes in central North America. Inferences derived from 
the Merjelen sea, and similar lakes in the Alps, Greenland and 
the Himalayas, strongly urge the probability of much larger ones 
of the same kind during ancient times. Such have been found in 


*Proceedings of the lowa Academy of Science, 1891. 


Shore Lines of Ancient Glacial Lakes.— Todd. 299 


side moraines upon the more recent drift. Lake Agassiz,and the 
lake of the Blue Earth region in Minnesota, and lake Dakota and 
James lake in Dakota, readily come to mind in this connection. But 
can similar lakes be recognized in the much eroded and fragment- 
ary deposits external to the great terminal moraines? Some, as 
one with whom I was talking a few years ago, when discussing 
Prof. Wright's hypothesis of lake Ohio, said, ‘Glacial lakes are 
a delusion and a snare,”’ yet the same person has mapped such a 
lake in central Wisconsin. Others would refer most of the extra- 
morainic drift to this cause. 

One difficulty, and one which some consider insuperable, is the 
absence of distinct barriers and shore-lines and old water levels. 
The beaches of lake Agassiz have been readily traced, but where 
are there any such traceable about lake Ohio or lake Missouri, or 
anywhere upon what has been called the older drift? The even, 
flat topography impresses one with lacustrine character in trav- 
ersing the Blue Earth region, or that between Scotland and 
Mitchell, 8. D.; but we can readily see that if a lake has been of 
transitory duration it would fail of producing a plain. 

Before dwelling on a few recent observations, which it is the 
main purpose of this paper to present, let us consider briefly a few 
reasons for the common obscurity of the shore-lines of old glacial 
lakes. 

1. The surface of such lakes would usually be very inconstant. 
The ice would have been a very uncertain barrier. The chance of 
depositing a beach or cutting a cliff would, therefore, have been 
small. 

2. The accumulation of shore deposits would not only be 
slight, but being made largely by floating ice would be quite un- 
equally distributed, especially in wide and shallow lakes. Preva- 
lent winds would drive the drift-laden ice to certain shores much 
more than to others. If the lakes contained islands, the more 
remote shores might receive no erratics, 

3. The difference in the ease of erosion between glacio-natant 
drift clays and the formations bordering them, may produce 
marked changes in topography and drainage. The regions of 
Dakota and Nebraska illustrate this well. Loose sands and easily 
eroded clays border the western edge of the compact and often 
boulder clad drift clays. While the latter are little affeeted by 
rains and streamlets, the former are rapidly removed. Moreover. 


300 The American Geologist. November, 1892 


the former are peculiarly subject to sliding and slushing out at 
base. The amount of erosion which has taken place since the 
occupation of the earlier glacial lakes may be more perfectly real- 
ized when we learn that the prominent high terrace found along 
the Missouri. White and Cheyenne rivers is more than 300 feet 
above their present water level. This terrace dates from the 
time of the second moraine, or possibly of the first of the ‘see- 


ond glacial epoch.” And this terrace is much more recent than 
the lakes under consideration. An erosion, which has excavated 


these valleys to sucha depth, must certainly have greatly changed 
the surface along the old lake borders. 

4. Yetanother influence may have frequently done much to mask 
lacustrine features, viz.,orographic changes. Gilbert has recognized 
this as prominent in the cases of lakes Bonneville and Ontario. 
Chamberlin finds an elevation of Champlain deposits, of 330 
feet in eastern Wisconsin, and of 5-600 feet in northwestern part 
of the same state. And this has been in a much less time than 
has elapsed since lake Missouri was filled with loess. 

So much on general principle. As may be remembered the 
writer has held that the extra-morainic drift of the Missouri val- 
ley is probably of sub-aqueous origin, that lake Missouri which 
deposited the loess, at an earlier stage was partly filled with sand, 
gravel and boulder clay; that a similar lake occupied the Red 
Lake region, from the Bijou hills to the big bend. Also that a 
similar one covered a wide scope of country from near the mouth 
of the Moreau northward. Hitherto, I have found rather scanty 
evidence of an old water level in the distribution of boulders 
about the Bijou hills, 590 above the Missouri or 1,900 above 
the sea, and a patch of bouldery gravel and clay 510 feet above 
the Missouri, covering an acre or so, south of the mouth of 
White river. 

In 1888 Prof. G. F. Wright reported the finding of something 
like a moraine along the divide south of the Moreau river. (See 
ProchwAs WALSH AGaS = mL Soon) 

It has been my privilege the past season (1890) to traverse the 
course of Prof. Wright, with the same companion, Rev. T. L. 
Riggs, and to spend a few days in the examination of this feature. 

[ found Fox ridge a high sandy plateau, forming the divide 
between the Moreau and Big Cheyenne rivers. Upon it, and on 
its south slope, | foundno northern erratics. Its summit, twenty 


Shore Lines of Ancient Glacial Lakes.— Todd. 301 


miles west of the Missouri, is about 2,400 feet above the sea. 
Along its northern slope is a peculiar flat-topped, butte-like ridge 
running east and west for 15-20 miles, its top being nearly hori- 
zontal and about 50 feet lower than the summit of Fox ridge. 

This was determined not only by several barometic readings, 
but by distant views from both north and south. The ridge is 
well covered with granite boulders, and drift 2-5 feet thick, but 
strange to say, no northern drift was found south of the ridge, 
except where its presence could be accounted for by recent trans- 
portation. The land just south of the ridge is frequently 50 feet 
lower than its top. This ridge is not strictly continuous. There 
is a wide gap, particularly, where it is crossed by the Virgin creek. 

The margin of the drift I had not time to trace fully, but was 
informed by Mr. Riggs, who knows the region well, that it crosses 
the Moreau 25-30 miles west of its mouth and runs northward at 
about the same distance from the Missouri for an indefinite dis- 
tance. Inside this margin the land nowhere rises higher than the 
margin, and it is here and there sprinkled with northern bould- 
ers, often in patches, especially on the higher levels. The divide 
between the Moreau and Grand rivers has an altitude of about 
2.300 feet. Most of the surface is of Cretaceous clays, and is 
much eroded, the alternating layers of hard and soft material, 
producing an interesting topography, studded here and there with 
high, flat-topped buttes. Z 

The course of the marginal ridge south of the Moreau is in 
line with some high clay buttes on the east side of the Missouri, 
just above the mouth of the Little Cheyenne, which are known as 
Welland ,buttes. They are strewn with a thin layer of boulders, 
and are the west end of a high divide separating the Little Chey- 
enne and Swan Lake creek. Crossing this divide is a well pre- 
served ancient channel, more than 400 feet above the Missouri, 
and there are traces of an old terrace along the Missouri, near the 
Welland buttes, at about the same level. 

Putting these things together, we come with some confidence to 
this conclusion: Fox ridge, with its eastern extension, the Wel- 
land buttes and the high land southwest of Bowdle and west of 
“aulkton, once formed the divide between the Cheyenne and 
Moreau rivers, when they flowed through to the James river val- 
ley. When the great ice sheet came down the latter valley dur- 
ing the glacial period, and occupied the outermost terminal mo- 


502 The American Geologist. November, 1892 


raine, there was for a time a great lake formed north of this Fox 
ridge divide. It was deep enough to float ice-floes and probably 
bergs from the edge of the ice sheet further north. These 
formed a bouldery beach along the margin, particularly along the 
southern side. Of the two outlets indicated, the western one 
cut down more rapidly, and formed part of the course of the 
Missouri. As erosion proceeded the bouldery margin beeame a 
ridge, because it yielded less rapidly to degradation than the soft 
clays and loose sands adjacent. 

For this glacial lake we propose the name lake Arikaree, after 
the Indian tribe whose home formerly occupied a considerable 
portion of its area. 


EDITORIAL COMMENT. 


AN INTERGLACIAL CHRONOMETER; A CORRECTION, 

In an article in the August number of the GkoLoGIsT (1892), 
entitled ‘‘An Approximate Interglacial Chronometer,” is an ob- 
vious error, It is plain to anyone who carefully studies the 
map given on plate vi that the ‘interglacial gorge” which is 
represented to extend from the mouth of Bassett’s creek, on the 
west side of the river, to the mouth of Nine-mile creek, should 
be continued, and actually was continued, further northward, and 
to the mouth of Rice creek, where the ‘‘pre-glacial gorge” is 
represented to begin. If the interglacial erosion began because 
the first glacial epoch displaced the river from any portion of its 
bed, the gorge that was the result of such interglacial erosion 
must have begun where the displacement began. The displace- 
ment began at the mouth of Rice creek, at that time, and not at 
the mouth of Bassett’s creek. This will make the interglacial gorge 
extend,as the Trenton limestone is known on each side of the river 
to extend, to near the mouth of Rice creek, increasing the result 
that expresses interglacial time to about fifteen thousand years. 

It was an oversight in the calculation, due to the use of an old 
map showing the gorge through the western limits of Minneapo- 
lis made in discussing the post-glacial recession of the falls of 
St. Anthony. The reader should understand the dotted lines 
that outline the interglacial gorge to be continued northward to 
the point where the pre-glacial gorge begins, and should substi- 


e 


tute 15,000 years for 9,750. 


Liditorial Comment. 303 


A Mortuary BirrErR-SWEETt. 

It is gathered from a recent obituary memoir that its subject 
in his youth was a good boy at school; neat and tidy ; that he 
had a handsome forehead, lips well proportioned, and was crowned 
with fine hair; that he had a natural and very modest demeanor ; 
that he was born to be a naturalist ; that loyalty to truth and in- 
genuousness were shining features of his nature (sic); that he had 
the rare experience of living nearly sixty-eight years without 
making an enemy ; that he proved himself an eligible candidate 
for a professorial chair; that he was elected ‘‘ without compe- 
tition” to the chair of president of an institution of Natural 
Sciences, which his biographer had held for a number of years 
before ; and that at a meeting held after his death ‘‘ample testi- 
mony was adduced that he had attained distinetion.”’ This is the 
bright side of the picture, and all of it, except that which the 
writer puts in quotation marks as cited from other sources. But 
oh! how different it is with the other side! We learn that in 
youth he was distinguished for disobedience of his parents and 
playing truant; his early medical career was soon closed on ac- 
count of neglect of duty and medical incompetency. It is fur- 
ther distinetly inferred, although not absolutely stated, that the 
pristine glory of the professorship of anatomy in the institution in 
which he filled that oftice was dimmed by his appointment. Even his 
father thought a good sign painter was spoiled to make a poor 
doctor. Hewas honored by being appointed a delegate of his uni- 
versity at two national meetings, without accomplishing anything 
for the credit of the institution. He delivered lectures to students 
on scientific subjects, seldom giving them the means of making 
useful application of his teachings in surgery and medicine; and 
he lectured and wrought for his university as a means of self 
maintenance,and because it was the principal source of his liveli- 
hood. He was a member of an important committee and a trus- 
tee of an important fund without attending to his duties. 

A lady of social influence made him a lion and he had the temer- 
ity to resemble some of the paintings of his biographer’s Saviour. 
At the age of sixty-five work and conviviality had abated his phys- 
ical and mental powers, and he even wrote a line from which the 
interpretation could be extorted that he believed in the possession 
of an unknown power by a suspected charlatan. His works are 
principally anatomical and of little interest to others than votaries 


O04 The American Geologist. November, 1892 


of vatural history, owing to their lack of applicability to indus- 
trial use. Though deeply interested in botany, Prof. Porter did 
not think his knowledge profound, and in fact a determination of 
a species by the subject of the sketch was promptly shown to be 
fallacious and corrected bya lady at Bar Harbor. Though deeply 
interested in mineralogy from boyhood he was more than once 
taken in by dealers in minerals who wished to test his knowledge. 

His head was small and his brain-weight below the average, 
which deficiency he probably compensated by good digestive ap- 
paratus. He called poetry ‘‘rhyming stuff,” and adopted the 
ethics of John Fiske. One attribute of genius he shared with 
it—/. ¢., sterility. No student of natural history was ever more 
assisted. After his death, representatives of his university solic- 
ited an immedtate contribution of $50,000 as an endowment fund, 
first to his widow and ultimately to revert to his university, but 
it is probable from the failure of the effort that the public has 
not judged the endowment urgent. * * * x 

The reader will naturally ask of whom this gloomy account is 
given. Was he Prof. Webster the murderer of Parkman? On 
what stage did this evidently overvalued person perform ? Above 
all, did he come to a good end? for with the natural perversity 
which his biographer pictures it is to be feared that he did not. 

In answer let it be said that this singularly severe eulogy or 
friendly cacology is entitled, «*A sketch of the life of Joseph 
Leidy, M. D., LL. D.,by W.8.W. Ruschenberger, M. D.,” and from 
the fact that its author has much experience and unquestioned 
success in preparing sketches of this kind (for which his indefati- 
gable industry in the bibhography of his subject fits him),it is an 
example of the kind of history which one man can write of an- 
other who is his opposite in character and attributes ; even when 
that writer is prepared by long service in a Philoso-Necrological 
Society. It is like a photograph of a bright landscape in mono- 
chromatic light; still, only for those few who are distinguished 
enough to invite the danger does it add a new terror to death. 


THe TopoGRAPHICAL MAP OF THE UNITED STATES. 

The subject of the proper adjustment of the scientific surveys 
of the territories was submitted by Congress to the National 
Academy of Sciences in 1878. The Academy was requested to 
“take under consideration the methods and expenses of conduct- 


kditorial Comment. 505 


ing all surveys of a scientific character under the War or Interior 
Departments, and the surveys of the Land Office, and to report 
to Congress, as soon thereafter as may be practicable, a plan for 
surveying and mapping the territories of the United States, on 
such general system as will, in their judgment, secure the best 
results at the least possible cost.’ 

A committee of the Academy reported recommending two dis- 
tinct bureaus or departments, under separate heads, one for. sur- 
veys of mensuration, to include the Coast and Geodetic survey 
and the topographical work of the Land Survey office, and one 
for the determination of all questions relating to the geologic 
structure and natural resources of the public domain. 

The sphere and duties of the latter were more fully defined: 
~-The best interests of the public domain require, for the pur- 
poses of intelligent administration, a thorough knowledge of its 
geological structure, natural resources and products. The domain 
embraces vast mineral wealth in its soils, metals, salines, stones, 
clays, ete. To meet the requirements of existing laws in the dis- 
position of the agricultural, mineral, pastoral, timber, desert and 
swamp lands, a thorough investigation and classification of the 
acreage of the public domain is imperatively demanded. The 
committee therefore recommend that Congress establish, under 
the Department of the Interior, an independent organization, to 
be known as the United States geological survey, to be charged 
with the study of the geological structure and economic resources 
‘of the public domain; such a survey to be placed under a director, 
who shall be appointed by the president and who shall report 
directly to the Secretary of the Interior.” 

This report was favorably received, and the act of Congress 
which established the U. 8. Geological survey (March 3, 1879), 
included in an act making appropriations for ‘‘sundry civil ex- 
penses” has the following words: <:For the salary of the director 


‘of the geological survey, which office is hereby established, under 
the Interior Department, who shall be appointed by the president 
by and with the advice and consent of the Senate, six thousand 
dollars; Provided, That this officer shall have the direction of the 
- geological survey, and the classification of the public lands, and 
the examination of the geological structure, mineral resources 


and products of the national domain, and that the director and 


members of the geological survey shall have no personal or 


B06 The American Geologist. November, 1892 


private interests in the lands or mineral wealth of the region un- 
der survey, and shall execute no surveys or examinations for 
private parties or corporations; and the Geological and Geographi- 
cal survey of the Territories, and the Geological and Geographi- 
cal survey of the Rocky mountain region, under the Department 
of the Interior, and the Geographical surveys west of the 100th 
meridian, under the War Department, are hereby discontinued. 
to take effect on the thirtieth day of June, eighteen hundred 
and seventy-nine, and all collections of rocks, minerals, soils. 
fossils and objects of natural history, archeology and ethnology. 
made by the Coast and Interior survey, the Geological survey. or 
by any other parties for the Government of the United States. 
when no longer needed for investigations in progress, shall be 
deposited in the national museum. 

‘‘For the expenses of the Geological survey, and the classifica- 
tion of the public lands and examination of the geological struc- 
ture; mineral resources and products of the national domain, to be 
expended under the direction of the Secretary of the Interior, one 
hundred thousand dollars. 


* oe * tt tt % 


‘The publications of the Geological survey shall consist of the 
annual report of operations, geological and economic maps. illus- 
trating the resources and classification of the lands and reports 
upon general and economic geology and paleontology. The an- 
nual report of operations of the Geological survey shall accom- 
pany the annual report of the Secretary of the Interior; all special 
memoirs and reports of said survey shall be issued in uniform 
quarto series if deemed necessary by the director, but otherwise 
in ordinary octavos. Three thousand copies of each shall be 
published for scientific exchanges and for sale at the price of 
publication; and all literary and cartographic materials received 
in exchange shall be the property of the United States, and form 
a part of the library of the organization; and the money resulting 
from the sale of such publications shall be covered into the 
treasury of the United States, under the direction of the Secre- 
tary of the Interior.” 

Mr. Clarence King, the first director, immediately took steps 
to extend the operations of the survey over the states as well as 
the territories. This was opposed strenuously, and failed in Con- 


egress on one or two occasions. But by changing the phraseology de- 


kditorial Comment. D307 


fining the purpose of the appropriation in the «Sundry Civil” 
bill, substituting ‘* United States” for ‘+ national domain,” the 
investigations of the Geological survey were authorized in 1883, 
to be carried on in the whole area of the United States. In lieu, 
however, of the previous definition of the duties of the survey the 
phraseology reads: +o continue the preparation of a geological 
map of the United States.” There was no new act. The old 
duties were not abrogated, but something, not before authorized, 
is ordered to be ‘continued. Under this appropriation, thus 
illy and unwittingly introduced into the expenses of the Govern- 
ment, the U. &. Geological survey entered upon a vast undertak- 
ing. Not to be limited to the strictly geological duties that had 
been defined in the original law, the survey now organized a corps 
of topographic surveyors and engineers and began a rapid semi- 
geodetic survey for topographical mapping of the United States, as 
a basis for the contemplated geological map of its domains. — For 
this work a large amount of the annual appropriation by Congress 
for the +:geological map of the United States” has been expended. 
From year to year, for the past ten years the appropriation for a 
‘geological map of the United States” has been taken to mean a 
continuance of all the original obligations and functions of the 
survey, and the conduet of a network of triangulation in various 
seattered areas in the country for later topographical mapping. 
This triangulation work has been filled in in several places, and 
maps have been constructed for geological purposes. Such maps 
are said to have cost sometimes one dollar, sometimes two dollars, 
and occasionally three or four dollars per square mile of the area 
mapped. 

Congress took no action concerning the establishment of a 
mensuration survey, under the recommendation of the Academy 
of Natural Sciences. Prof. J. EK. Hilgard, then superintendent 
of the Coast and Geodetic survey, seems not to have fully and 
fairly appreciated the situation. He neither took advantage of 
the favorable recommendation of the Academy of Sciences, in 
1878, nor in 1884, when the subject was again being investigated, 
did he adequately represent the functions and the duties, present 
and prospective, of the Coast and Geodetic survey. Partly from 
necessity and partly from inclination, therefore, the topographical 
work of the U. 8. Geological survey took on the characters and 


began the mapping which were the special prerogative and 


BOs The American Geologist. November, 1892: 


expected duty of the older survey. It is plain that the appro- 
priations committee expected to make further recommendations. 
intended to carry out the plan of the Academy of Sciences, be- 
cause in the clause relating to the collections made by the various 
surveys they designated the Coast and Geodetie survey ‘the 
Coast and Interior survey,” in keeping with a change proposed 
by the Academy's committee, 

Soon came murmurs of duplication and clashing of official 
functions between the two surveys. This became so loud and so: 
patent that Congress created a *‘joint commission” to examine: 
into the scientific work of the government more widely. This 
commission was appointel July 7, 1884, and continued its inves- 
tigation until 1886. It again consulted the National Academy of 
Science, and that body recommended the creation of a govern- 
mental ‘+ Department of Science,” to coordinate and include the 
Coast and Geodetic survey, the Geological survey, and the me- 
teorological work of the Weather bureau. Such recommenda- 
tion, however, was not received cordially, and never went into: 
effect. Since then the Weather bureau has been transferred from 
the War Department and given in charge, as a civilian bureau, to: 
the new Department of Agriculture ; the Geological survey has 
continued to ‘‘make preparations for a geological map of the: 
United States,” and the Coast and Geodetic survey, besides its 
transcontinental triangulation, has cooperated with various States 
in the construction of topographical maps, and has done its usual 
coastwise work, There was no coordination of the work of the: 
two surveys. The duplication is as flagrant as is possible under 
the courteous handling of two intelligent chiefs. 

It is time, however, that such waste of treasure and of energy 
he stopped. There are two series of independent triangulation 
being spread over the United States, each designed to prepare for 
topographical mapping. They are not bound to articulate with 
each other, nor to agree with each other. If they are both car- 
ried to completion there will be two sets of topographical maps. 
It is true that the area is so large within which they can operate 
that they do not yet violently impinge on each other. The States 
that elect to cooperate with the Coast and Geodetic survey in the: 
construction of their topographical maps, now some fifteen or 
twenty in number, are, for the most part, let alone, in this regard, 
hy the U. S$. Geological survey, while those which have attempted 


kditorial Comment. 309 


to use the topographical sheets of the U. 8. Geological survey 
have been compelled, in some instances, to abandon the attempt 
and to construct new sheets from independent triangulation — or 
at least from different data 
without extensive topographic data. 


or they have made geological maps 


We do not hesitate to say that it was a serious and far-reaching 
mistake when the U. 8. Geological survey, contrary to the recom- 
mendation of the National Academy of Science, and in addi- 
tion to the great work it had on hand in the examination of the 
geological structure and the natural mineral resources of the 
country, entered upon the geodetic and topographical surveying 
of the national domain. I[n_ brief, our reasons for this opinion 
are : 

1. There was already in existence fully equipped an_ efti- 
cient organization engaged in such work. It only needed re- 
enforcement and authorization, to have performed this topo- 
graphical work for the whole country with correctness and dis- 
patch. 

2. The duties of the Geological survey, as defined in the con- 
gressional acts relating to it, are ample for the functions of one 
bureau. 

3. We know of no precedent for it; but so far as example 
goes its influence would be opposed to it. The topographical 
mapping done by the early territorial surveys was discontinued 
by act of Congress, and no state survey had, at that time, entered 
upon topographical mapping under a law ordering simply a geo- 
logical survey. The British Geological survey does no topograph- 
ical mapping, but receives such maps from the Ordance Depart- 
ment. 

4. The country demands more accurate work in geodetic 
measurements and more exact mapping than the Geological sur- 
vey professedly aims to perform. A good topographical may, 
such as those constructed by the Coast and Geodetic survey, 
while costing perhaps ten dollars per square mile,is what the coun- 
try needs and must have, and would answer many other purposes 
than for the mere delineation of the geological structure. It 
would be of service in the Post Office Department, the Land 
Office, the Weather bureau, and especially in the War Depart- 
ment. <All economic and industrial, not to say educational affairs 
would be aided by such amap. On the contrary the topographical 


310 The American Geologist. November, 1892 


maps now being constructed by the Geological survey, are not 
claimed to be suited for anything else than geological purposes, 
and are not distributed as topographical maps. They would not 
do eredit to the country should they be distributed as such; and 
it may not be too much to say that ultimately they will be dis- 
carded even for geological purposes, and the geological structure 
will have to be delineated again on more accurate maps. 

5. The diversion of the funds provided for the geological sur- 
vey of the United States into the construction of a topographical 
map. It may be said, with a semblance of truth, that a correct 
geological map cannot be made without a previous topographical 
map. But the word correct here is susceptible of shades of 
meaning. Many ‘correct’? geological maps have been made 
without any previous topographical mapping. For the purposes 
for which the geological survey was created, very simple maps 
could be constructed, and, as defined in the original law, they 
would ‘illustrate the mineral resources and the classification of 
lands.” 

6. However necessary a topographical map may be to a geo- 
logical map of the United States, it was not contemplated in the 
act of Congress which established the Geological survey, nor in 
subsequent appropriations till 1886, when the appropriation was 
made after a lengthy investigation, when the affairs of the Coast 
and Geodetic survey were in avery unsettled condition; and when 
the Geological survey, under the impetuous lead of an energetic 
director, had secured from a committee of the National Academy 
of Seience a recommendation not to disturb the status quo of the 
survey. 

Both these surveys now are adequately manned, and we are 
confident that the plan of the National Academy of Science 
should be fully carried out by such legislation as would transfer 
the entire outfit and all the employés of the topographical branch 
of the Geological survey to the ‘‘Coast and Interior survey,” 
and the whole to the Department of the Interior. There should 
be such coordination that in no case would there be a duplication 
of the work. The Geological survey should follow the work of 
and 


the mensuration survey — so far as its mapping is concerned 
in the meantime it should concern itself with the investigation of 
such scientific and economic problems as the geology of the coun- 


try presents— and they are myriad. 


O11 


REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 


Third Annual Report of the Geological Survey of Texrus, 1891. E.'T. 
DuMBLE, State Geologist. Austin, 1892. 8vo, 410 pp. 

Besides the general administration report of Mr. Dumble, this volume 
embraces the following papers: 

Houston County, by W. Kennedy. 

Section from Terrell to Sabine Pass. W. Kennedy. 

Llano estacado or staked plains. W. F. Cummins. 

Notes on the geology of the country west of the plains. W. F. Cum- 
mins. 

Stratigraphy of the Triassic formation in Northwest Texas. N. F. 
Drake. 

Report on the paleontology of the vertebrata. E. D. Cope. 

Shells collected in a dry salt lake near Eddy, New Mexico, by Y. Sterki. 

Reports on the Cretaceous area north of the Colorado river. J. A. Taff. 

Trans-Pecos Texas. W. H. Von Streereewitz. 

Of these, the papers that possess the greatest general interest are 
those of Mr, Taff and Mr. Cummins. Mr. Cummins made the entire cir- 
cuit of the area of the “staked plains” and at their western bound he 
left them for a short trip into New Mexico, following the old route of 
travel where Mr. Jules Marcou passed in 18538 in the service of the 
United States in the survey of the line forthe Southern Transcontinental 
railroad. The age of the beds of Tucumcari has been a matter of dis- 
pute ever since the report of Mr. Marcou, who made them Jurassic. 
[See a review of the subject in the AMERICAN GEOLOGIST, Vol. iv, Sept., 
Oct., 1889.] Mr. Marcou’s determination has been sustained by Capt. C. 
E. Dutton, Prof. A. Hyatt and Prof. Robt. T. Hill, but opposed by Prof. 
James Hall and Dr. J. 8. Newberry. Mr. Cummins collected a great 
number of fossils from the vicinity, but they have not yet been thor- 
oughly studied. He, however, gives a list which have been identified 
with Cretaceous species. 

-The following is a list of fossils collected by him from the beds in 
dispute “in the vicinity of Tucumcari and Pyramid mountains:” 
Gryphew dilatata, var. tucumcart Marcou. 
Ostren marshit as determined by Marcou. 
Gryphoa ptichert Morton. 
Buogyra tevana Roemer. 
Ostreu quadriplicata Shumard. 
Trigonia emoryt Con. 
Curdium hillanum Sow. 
Cytherea leonensis Con. 
Turritella seriutim-granulata Roem. 
Pinna sp. 
Ammonites. 
Peceten. 


312 The American Geologist. November, 1992 


With the exception of the first two these have been referred repeat- 
edly to the Cretaceous (Washita and Fredericksburg divisions) in Texas. 

The discovery in the same strata of a fossil angiospermous plant, 
which Mr. Cummins’ figures and describes under the name Stereulia 
drakei is considered sufficient evidence of the Cretaceous age of the 
strata from which it came. 

The sections here compared and thought to belong to the Cretaceous 
are as follows 


Pyramid Mountain Tucumeari mountain 
by Mr. Marcov. by Mr. Cum™MiIns. 

1 White limestone....... Soc e eeu 1 White clayey limestone......... 20 feet 
2 Yellow limestone... Bee ee reciGis Gris 2 OL 2 Massive sandstone...........--. (Oy 
Be Ish) CN? on on cong cunabeddbioagD il) 3 Shale (blue clay? N. H. W.)..... 50) * 
4 White sandstoue................. 29 4 Massive yellowish sandstone... .235 ‘ 
5B Mellow sandstone..5..:2......... 80 S HRGOUSAMOStONG. 45. seen aoe cee eee La 
CUA ANTIC NAGI VKONAE), KRaogn oobeadoKe eles GYBltie lays. cre sce. cers ne eee er 
HiGrayishibluec Wiyeeasnees cece soe mee Mieburpilexclay... 3). cen oe neceeeie alone 
S VWarlewated amarlssof. occ. caccce as 000) SeATENICCOUS IClAViaccs seen eee aly 
i O BGs CLD sero < oe.-s ioe eee ree ea 
MO tala ee ictc oie aac aiacis ace UO OMe Ka BiG ky OW ReenneAsecdeeendsn WG oS 
liMibiehtmedyclays cs as.cceneree 3) ete 
12) Darkenpaliclay.-4 05> 3. 222 -ee ae oO eee 

MOT see oa ate aoe a, see OUlBneeL 


These sections are about ten miles apart, according to Mr. Cummins, 
but they are found in a region that embraces several other similar hills 
all of which are referred by both Cummins and Marcou to the same 
geologic horizon. If we understand, contrary to the statement of Mr. 
Cummins,* but apparently in harmony with his general argument, that 
the “blue clay” horizon (No. 3 above, of Marcou) is the stratigraphic 
equivalent of his “shale” horizon (No. 8, of his Tucumcari section), and 
not of his No. 6, and ignore the enormous thickening of Mr, Cummins’ 
No. 4 (his supposed ‘frinity sands), these sections present a reasonable 
degree of stratigraphic resemblance. We infer also, as argued by Mr. 
Cummins, that in Mr. Marcou’s section the word “limestone” in No. 2 is 
a misprint for sandstone. The thickening of the sandstones of Cum- 
mins’ No. 4, which may be considered the equivalent of Marcou’s Nos. 
4,5 and 6,is not an unwonted circumstance in the composition of 
coarsely fragmental formations. 

The settlement of the disagreement will have to depend on the fossils. 
In the light of the fossils named by Mr. Cummins, the beds seem to be- 
long to the lower Texas Cretaceous, but the question is not settled 
whether the lower. Texas Cretaceous, particularly the Trinity sands, is 
Cretaceous or Jurassic. Mr. Hill, who revolutionized the Cretaceous in 
Texas by adding to it the Comanche series including this member, has 
given a listof its molluscan fossils in his Arkansas report,} remarking 
that they bear “remarkable resemblance to forms from the upper Pur- 
beck and basal Neocomian or Wealden beds of Europe.” Mr. Marcou 
has reviewed this list of fossilst and made such changes in the identifi- 
cations that they are all made to appear Jurassic. In short, Mr. Marcou 


“The only blue clay bed in the vicinity is that in which the fossil zone of the Gry- 
phea dilatata var. tucumearé occurs.” p. 202. 

+Nvoozoic Geology of southwestern Arkansas. Chapter xiii. Annual report of the 
Geological Survey of Arkansas for 1888, Vol. rm, 1882. 


+ AMERICAN GEOLOGIST, Vol. 1v, Dec., 1889, pp. 857-357 


Review of Recent Geological Literature. 313 


affirms that the Trinity division of the Comanche of Hill, is the equiv- 
alent of the upper, and perhaps of nearly all of the European Jurassic. 
These Trinity sands being below the Tucumcari beds (7. e. below the 
blue clay containing the Gryphwo dilatata, var. tucumcuri Marcou), must 
belong to the Jura provided the Tucumcari beds belong there; and, 
per contra, the Tucumcari beds must fall into the Cretaceous if the 
Trinity sands belong there. Now Mr. Cummins refers his fossils to the 
“Tucumcari beds” as he has defined them, 7. e. to some sandstones that 
are actually above the horizon of Gryphewa dilatata, var. tucumecri, and 
he paralletizes them with higher portions of the Comanche, viz., with 
the Washita and Fredericksburg divisions. It seems quite likely that 
Mr. Cummins is correct in assigning those upper strata to the Cretaceous 
but the chief point of contention of Mr. Marcou, touching the under- 
lying strata, viz., Mr. Marcou’s E, D, C,and B, or Mr. Cummins’ Nos. 4 
and 5, seems not exactly disproved, and these may still remain in the 
Jurassic, at least until Mr. Cummins defines more closely in what por- 
tions of his Tucumcari beds he found his fossils. 

Mr. Cummins’ report is a very valuable one, and bears strongly préimu 
fucte against the Jurassic in Pyramid mountain. 

Mr. Taff’s report on the Cretaceous area north of the Colorado river 
agrees with that of Mr. Cummins in placing the Trinity sands in the 
Cretaceous, and he gives a diagram (p. 292) illustrating the unconform- 
able position of Bosque Cretaceous upon the paleozoic, with the “Trinity 
phase” at the bottom. The Trinity sands proper he shows are not an in- 
dividual entity in the stratification, but are closely knit with the Glen Rose 
and Paluxy, these making a three-fold formation which he distinguishes 
as the Bosque division. Overlying the Bosque division are the Fred- 
ericksburg aud the Washita divisions. It is a noteworthy distinction that 
Mr. Taff only finds the Gryphwa pitcheri and the Exogyra terani, character- 
istic fossils of the Cretaceous, in the upper divisions (p. 281). “The lowest 
limit of these fossils marks the upper limit of the Bosque division.” 

In the Bosque division is a different fauna, but few members of 
which extend into the higher divisions. In addition to the Gryphuw 
dilutata, var. tucumcar? Marcou, which Mr. Cummins admits cannot be 
the same as the G. pitcheri of the Cretaceous, and which is a fossil char- 
acteristic of the European Jurassic, and the Ostrea murshi which Mr. * 
Cummins has-not had opportunity to compare with European fossils of 
that name, both of which may be referred to the Bosque division. Mr. 
Taff enumerates the following fossils from this division. 

1. In the Trinity sands; Trigonia, Ammonites, “Ostrea beds,” (p. 295); 
Ostrea franklini (pp. 297 and 310); Ostrea camelinis (Ms. of Cragin), 
pp. 303 and 307; Trunks of trees much silicified, also changed to Jig- 
nite, constituting veritable driftwood, (p. 310). 

2. In the Glen Rose member; Monopleura, Goniolina, Caprotina (Re- 
quienia) penguiuscula, Exogyra, Ostrea, Arca, Ostrea subquadrata (pp. 
297-299); “Arca and small Ammonites, allied to A. pedernales Roemer, 
and Nerinea occur abundantly in the marly line,” 7. ¢. in Glen Rose 
(p. 304); Ostrea camelinis Cragin (p. 307); O. franklini (p. 310); Cardium 


O14 The American Geologist. November, 1802 


mediale, Natica, Cyrena, Goniolina (p. 313); Anomia (p. 315); Turritella, 

Cardium mediale and C. hillanum, Pleurocera, Serpula, Trigonia crenu- 

lata (pp. 316, 317); Cardium mediale (p. 837). 

3. In the Puluxy member; no fossils are named from the Paluxy. 

These Trinity fossils can none of them be pronounced Cretaceous by 
reference to any undoubted standard of comparison. The genus Tri- 
gonia ranges from the Liasto the Chalk, Ammonites from the Oolite to 
the present. Ostrea franklini was placed in the Cretaceous by Coquand 
without any authority whatever, except a surmise by Mr. Marcou that it 
was obtained “somewhere near the locality of Gryphea pitcheri.” It 
was published in the Arkansas geological report of Owen by Mr. E. T. 
Cox, without any description, only the illustrated plates having been 
found after Owen’s death.* Ostrea camelinis, of the manuscripts of 
Prof. Cragin, being a new species has no authority as a guide to the age 
of the strata containing it. 

In the Glen Rose member, which by Prof. Hill was not associated with 
the Trinity but was retained in the Fredericksburg division, the reported 
species are more afliliated with the Cretaceous, but there is not yet 
sufficient volume of a distinctively Cretaceous fauna to carry its assign- 
ment to that age beyond the limit of doubt. A large fauna is given the 
Fredericksburg division by Prof. Hill, but it is uncertain what part of 
it belongs in the Glen Rose division, detached from the Fredericksburg 
by Mr. Taff and placed in the Bosque division, but it appears to be buta 
meager portion of it—probably that which Mr. Hill has embraced in his 
“basal beds” of the Fredericksburg division. However, Mr. Taff mentions: 
Monopleura, may be either in the “basal beds” or the Caprina lime- 

stone of Hill. 

Goniolina, in magnesian limestone, with bivalves and gasteropods. 

Cauprotinu (Requicnia) penguiuseula, apparently a fossil of the “lower 
beds” and of the Caprina limestone. The genus is found in the upper 
Greensand of France. 

Heogyra, in the basal, alternating beds. The genus also is found much 
higher, as well as in the Jurassic. 

Ostrea, ranges from the Jurassic upward. 

Arca, ranges from the Trinity sands to the Washita division. 

“ Ostrea subquadrata.” Thin bedded limestone. Not mentioned by Hill. 

Ammonites. Ranges from the Lias to the Chalk. Hill gives A. peder- 
nalis Von Buch, in the Comanche Peak chalk. 

Nerinea, is a Jurassic genus. 

Ostreaw cumelinés ms. of Cragin. From the Trinity to the Glen Rose. 

Ostrea frunklint Coq. is abundant in the Trinity. 

Curdium mediale. Is given by Hill only for the Comanche Peak lime- 
stone, which is next above the “lower beds,” but Mr. Taff found it im- 
mediately above the Trinity sands, and therefore at the base of the al- 
ternating or “basal beds.” 

Natiew. Ranges from the Devonian to the present time. 

Cyrenu. A fossil of the Wealden, ranging upward. 


*This is on the statement of Mr. Marcon, AMERICAN GEOLOGIST, vol. 1v, p. 359, 1889. 


Review of Recent Geological Literature. 515 


Anomiv, is a common fossil of the upper beds of the Jurassic. Mr. Hill 
gives only one species (ind.) in this uncertain horizon, and that is in 
the Trinity sands. 

Turritella. Isa good Cretaceous genus, and if correctly identified goes 
far to prove the Cretaceous age of these beds. Mr. Hill has it running 
from the “lower beds” of the Fredericksburg division to the Navarro 
beds in the upper Cretaceous. 

Curdium hillanum. Also ranges from the Jura to the Chalk. 

Pleurocera. Found also in the Trinity (Hill). May be a Cerithium or a 
Nerinea, both Jurassic genera (Marcou). 

Serpula. Basal beds. Not mentioned by Hill. 

Trigonia crenulata. According to Hill ranges from the “ basal beds” to 
the Comanche Peak chalk. 

The Glen Rose member is wedge-shaped and runs out toward the west 
allowing the Paluxy to lie directly on the Trinity, when the Paluxy is 
preserved. In other cases both the Glen Rose and the Paluxy are want- 
ing, and the “ Texana bed,” of the Fredericksburg division, then comes 
immediately into superposition on the Trinity of the Bosque division. 

Notwithstanding this break in the order of stratification, which, how- 
ever, Mr. Taff does not seem to consider an unconformity of the Freder- 
icksburg on the Bosque, but rather an incident of continuous sedimenta- 
tion, and notwithstanding the partial alliance of the fauna with the Jur- 
assic, and the non-characteristic features of the other fossils he has 
named, Mr. Taff assigns the Bosque to the Cretaceous on the following 
grounds: 

“That the Trinity sand is Cretaceous and represents the littoral depos- 
its of a part of the lower Cretaceous series, has evidence in the facts that 
its beds abut against the pre-Cretaceous continental contour; that its 
beds conform to and blend with the undoubted Cretaceous Glen Rose 
limestones ; that its component materials are local, and have their origin 
in the paleozoic as a strictly near-shore rock ; and further, that it con- 
tains fossil fauna and flora that range through superimposed beds of 
sand and limestone.” 

There is, however, room to question whether the Glen Rose is “un- 
doubted Cretaceous,” and whether all the other “facts” mentioned 
would not hold true of the Jura, in case the Jura were supposed to ex- 
tend to the summit of the Bosque division, or at least to the summit of 
the “lower beds” of Hill. 

We know nothing of this subject from studies in the field. We take 
the facts and all the evidences as they are given by others. We have 
endeavored to call attention to the principal point of difference between 
Mr. Marcou and Messrs. Cummins and Taff, and we are constrained to 
conclude that the question is still an open one. Mr. Cummins’ fossils 
seem to be from strata that lie above the actual Tucumcari stratum, 
although still embraced in beds which Mr. Marcou placed in the Juras- 
sic—-indeed Mr. Cummins admits that he “did not find the Cretaceous 
fossils below the Gryphiea [tucumcari] beds.” Therefore they were 
from strata above, and as some of them are identical with those which 


316 The American Geologist. November, 1892 


Mr. Taff finds in the Fredericksburg division, associated with Gryphaa 
pitchert, they have no bearing on the strata which Mr. Marcou claims 
have unimpeachable*evidence of Jurassic age. He did in his original 
paper represent the whole of Pyramid mountain as Jurassic, above his 
stratum E, but he has not claimed, so far as we have learned, that any 
strata containing the Fredericksburg or Washita fauna are of Jurassic 
age. In Pyramid mountain these upper strata afforded him no fossils, 
and his assignment of them to the Jurassic was based apparently largely 
on topographic considerations. Mr. Cummins’ argument can only apply 
to these upper strata, and he seems to have proved, by the aid of Mr. 
Taff, who has defined the position of his fossils more exactly, that they 
are not in the Jurassic. 

By this report, of which other chapters, though perhaps equally mer- 
jtorious, no special mention can be made here, it is seen that the Texas 
survey is making substantial and even rapid progress in the field-work, 
and is elucidating the geology of a large and interesting and difficult 
section of the union. The ensemble of the volume is very creditable, 
the illustrations and maps are excellent. We only notice occasionally 
in Mr. Cummins’ report, an ungrammatical use of the word “strata,” 
which cannot be wholly the fault of the proof-reader. 


- Some New Species and New Structural Parts of Fossils. By 8. A 
MintER and CHarLEs Faber. (Jour. Cin. Soc. Nat. Hist., Vol. xv, No 
2, July, 1892.) In this paper the authors describe as new eight paleozoic 
species of fossils under names and from rocks as follows: Modéolopsis 
corrugata, M. longa, M. suleata, Orthodesma mundwm, Protoscolez magnus, 
and Cyclocystoides cincinnatiensis, from the Hudson River group of 
Ohio, /olocystites ufiniés from the Niagara group of Indiana, and Avzeu- 
lopectcn germunus from the Coal Measures of Kentucky. Besides, the 
under side of a specimen believed to belong to Agellacrinus pileus is de- 
scribed and new details of structure are brought out. The paper is ac- 
companied by a plate containing eighteen figures. 

A critical examination into the merits of the new forms seems to show 
a too great confidence of the authors in the obviousness of the peculiar- 
ities of their species. We miss, namely, suflicient comparisons with re- 
lated species, a criticism that may justly be made on most of Mr. 
Miller’s really valuable previous productions. As a rule we regard it as 
not only good practice but almost a necessity for the author of a new 
species to supplement his description with full comparisons with related 
species, since these are a great aid in the always difficult task of identi- 
fication. For instance, it would have been most desirable to learn from 
the authors just in what respects their Wodiolopsis corrugata differs from 
the similarly marked WM. pholadiformis Hall, and MW. capax Miller. As it 
is, we must confess that we are strongly inclined to doubt that these 
three names stand for as many good species. 

MV. longa agrees ina general way with MW. oblonga and M. subparallela 
of Ulrich, but seems to be even more elongate and with the point of 
greatest convexity nearer the posterior end. On the other hand, there 


Review of Recent Geological Literature. B17 


are points in the description and figure that cause us to think it possible 
that their specimen is not a true Modzolopsis, but rather an Orthodesma. 

M. sulcata seems to be a sharply distinguished species, but the Ortho- 
desma mundum,as illustrated, has a general expression decidedly like 
Modiolopsis anadontoides, M. cincinnutiensts and other species of that 
type. The illustrations of these shells have evidently been drawn by 
one unaccustomed to do natural history work. The specific characters 
are rather indefinitely brought out, and reasonable restorations of out- 
line, perfectly justifiable, might have been attempted with profit. 

We fail to see any grounds whatever for separating Protoscolex mag- 
nus from Ulrich’s P. ornatus, since the claim that their species is larger 
than his rests upon a misapprehension. In all other respects they are 
identical, and Ulrich’s measurements indicate a size scarcely if at all 
inferior to those given for P. magnus. 

As to the merits of Cyclocystoides cinetnnatiensis and Llolocystites af- 
jints, little can be said, since they belong to genera of which very differ- 
ent opinions prevail respecting their specific variability. According to 
our experience, species of these genera are numerous enough, but indi- 
viduals of the species seem to be rare. 


Geological Survey of Missour’, ARTHUR WINSLOW, state geologist, The 
Higginsville sheet, in Lafayette county. 17 pp. folio, map and page of 
geological sections. Published by the Geological Survey, Jefferson City, 
April, 1892. 

This report and map, and the plat of sections, are based on good work, and 
they are finely executed, for thedr kind. But their kind is very bad. It has 
been, and is still, to some extent, the practice of state geological surveys 
to publish large maps, or large sheets of larger maps, which are enclosed 
in a roll, or in a case which is entirely separated from the descriptive re- 
port. The two get far separated, and generally the maps become lost, 
or at least greatly damaged by the difficulties of handling. Thus the 
value of the reports themselves is lessened or lost. We instance the late 
publications of New Hampshire, Ohio and Wisconsin. Prof. Winslow 
has endeavored to obviate this inevitable separation and damage by 
printing the report on the same sized page as the large map and issuing 
them together as one document. But in our opinion he has only in- 
creased the objections to the large folio (or sheet) size of publication 
They will of course not become separated, thus bound in one cover, 
but the common user of such reports will have the trouble of handling 
such a sheet many times increased. Common library shelves will not 
accommodate such a document, and yet it should be in as ready reach as 
a book on a library shelf. We like the plan of the Minnesota and Penn- 
sylvania surveys (2dsurvey) which is the converse of this, viz: The 
maps are planned to be the size of the book-page (large quarto) includ- 
ing only a county on each. These-are bound into the book and are in- 
separable from it, and are always handy to consult whenever the report 
is read, and being of ordinary size the maps and the text can always be 
kept in convenient place with other books; and the maps themselves 


318 The American Geologist. November, 1892 


when they are all made, can be bound together separately in form of an 
atlas with briefer accompanying descriptions, if desired. In other 
words we should make the county the unit of mapping, just as it is the 
civil and geographic unit, and if the scales differ it is of no moment, 
since generally, especially in all western states, the townships are cut 
by section lines which on the face of the map constitutes a seule of miles 
for every map. Thus the map is always handy and will last as long as 
the book itself. 


Stratigraphy and Succession of the Rocks of the Sierra Nevada of Cali- 
fornia. By James E. Mitts. Bulletin of the Geological Society of 
America, Vol. 111, pp. 413-444, with map; Aug. 8, 1892. This description 
of the northern portion of the Sierra Nevada between the North and 
Middle forks of Feather river isa summary of the author’s observations 
during many years as a mining engineer. The accompanying map 
shows the rock formations on the greater part of an area of six town- 
ships from east to west and four from north to south, lying in Plumas 
county, immediately southwest of the Taylorville district and Mt. Jura, 
which have been described in the same volume by Diller and Hyatt, as 
noticed in the September GEOLOGIST (p. 183). In this northern part of 
its extent the Sierra is double, consisting of eastern and wes'ern divis- 
ions, the latter being in the course of continuation of the axis of the 
Cascade range, to which it is nearly related by its geologic features. 
Barometric measurements in the district mapped give the hight of 
Grizzly ridge, in the eastern division, as 7,952 feet above the sea; of 
Spanish peak, the culminating point of the western division, 6,990 feet; 
and of an intermediate mountain called Claremont, 6,962 feet. ~Con- 
tiguous valleys are between 3,000 and 4,000 feet. The northern end of 
the Sierra Nevada rises thus only about half as high as Mt. Whitney and 
other peaks near its southern end. 

The present altitude of this mountain range is ascribed principally to 
Tertiary and Quaternary uplifts by faulting; but the axes of greatest 
uplifting coincide approximately with those of previous ranges within 
the same area. “Repeated orographic movements have taken place 
along the same axes, and recurring uplifts along these axes have fol- 
lowed recurring erosion. In this way a pre-Mesozoic range arose, carry- 
ing up both crystalline and metamorphosed sedimentary rocks, and par- 
tially disappeared through erosion and subsidence; then a Mesozoic 
range arose and its strata became uptilted, and it in turn was reduced 
by erosion and subsidence: to very small proportions (in its northern 
half, at least, nearly or quite to base-level of erosion); and then in Ter- 
tiary and Quaternary time has arisen the present range, which is now 
undergoing its erosion, but whether it is now rising or subsiding is not 
determined,” 

Granites form the greater part of the pre-Mesozoic rocks of the Sierra 
Nevada, making up the core of the range and of each of its two north- 
ern divisions; and they are overlain by metamorphic slates and quartz- 
ites, which may represent several Paleozoic periods. 


Review of Recent Geological Literature. 319 


The metamorphic Mesozoic rocks belong to the Jurassic and Creta- 
ceous periods and comprise an apparently conformable series of sedi- 
ments and lavas several miles thick. The sedimentary rocks are princi- 
pally slates, often altered to quartzites, with some limestones. In the 
lower part of this series the principal eruptives are diabase and green- 
stone, products of alteration of moderately basic lavas; and in the up- 
per part, where the lavas were very basic, they are more or less com- 
pletely altered to serpentines. 

The prevailing strikes are parallel to the general trend of the range 
and of the coast; and the dips are mainly between 60° and vertical. 
Mr. Mills has not observed curving folds,and therefore concludes that the 
strata at the time of their tilting experienced much shearing on approxi- 
mately horizontal planes of overthrust, and that the subsequent upheavals 
have been chiefly by the faulting of mountain blocks. Neither has he 
found any unconformity of dip and strike between the pre-Mesozoic 
and Mesozoic groups of metamorphic strata: but they were doubtless 
separated by along period of erosion and subsidence. Upper Cretaceous 
(Chico) and Tertiary beds at the western foot of the range dip westward 
at low angles, indicating that the greater part of the tilting and meta- 
morphism took place during some stage of the Cretaceous period, which 
Becker, from his study of the few fossiliferous horizons, believes to have 
been at the close of the Gault epoch. The tilting was attended with 
much fissuring and the formation of veins of gold-bearing quartz and 
pyrite. 


The Geology of the Crazy Mountains, Montana. By J. E. Wourr. Bul- 
letin, G.S. A., Vol. 1, pp. 445-452; August 8, 1892. The Crazy moun- 
tains, an isolated range 40 miles long from south to north with a width 
of 15 to 20 miles, lie about 30 miles east of the easterly border of the 
main range of the Rocky mountains, and attain an elevation of 11,000 
feet above the sea, the difference in level between theirsummit and base 
averaging perhaps 4,000 feet. They lie close north of the Yellowstone 
river, and are conspicuously seen from the Northern Pacific railroad 
for many miles eastward froin Livingston. In structure they are com- 
paratively simple but unique, being probably, as noted by Upham, the 
best known example of the type of mountain ranges which have not 
been made by any definite process of mountain-building but are simply 
remnants of extensive uplifted areas that have been deeply eroded. . 

Nearly horizontal Cretaceous rocks form the principal mass of the 
range and reach far eastward in the great plains and westward to the 
frontal line of the Rocky mountains, where sharp uplifts expose the 
older rocks. The strata of the Crazy mountains consist of sandstones 
and occasional conglomerates, interstratified with shales, and appear to 
be wholly referable to the latest Cretaceous or Laramie epoch. Erup- 
-tive dikes in wonderful profusion and variety cut these strata; and in- 
trusive lava sheets and laccolites, up to a thickness of 365 feet, are in- 
terbedded with them, but no evidence of surface flows has been found. 
The more enduring igneous rocks preserved this range, while denuda- 


320 The American Geologist. November, 1892 


tion to the vertical depth of nearly a mile reduced all the surrounding 
country to a base-level. 
_ The head stream of Shields river, a tributary of the Yellowstone, has 
cut a deep valley in the western side of the range, dividing it into 
southern and northern halves. The southern part, which is the higher, 
-has numerous sharp, jagged peaks, from which the streams flow radially 
outward to the west, south, and east. In advancing up any of the val- 
leys, it is found at first comparatively broad and bounded by high bluffs 
of nearly horizontal sandstones; on approaching the central peaks, the 
valley becomes narrow, and the stream descends from a higher level 400 
or 500 feet by cascades and falls; and beyond this the valley again 
widens somewhat with a more gentle slope to its head. The “fall-line” 
is found on all the radial streams, and is due to the local hardening of 
the sedimentary Laramie rocks by a central stock of coarsely crystalline 
diorite, which is irregularly oval in outline and about six miles wide at 
its greatest diameter. From their contact with this stock the Laramie 
strata, dipping gently outward, are hardened and metamorphosed toa 
distance of about amile. The central portion of the diorite is cut by 
masses of a light-colored, finer-grained granitite. 

“Tt is surprising,” writes Dr. Wolff, “to see the similarity between this 
Tertiary diorite and granite and the Paleozoic masses of similar rock 
found exposed on the old eroded surfaces of the Atlantic states, as, for 
instance, on the northern shore of Boston, In both cases the same 
black patches are seen in the granite, referable here to enclosed dioritic 
fragments, and the same alternations of basic and acid rock in streaks 
or ‘Schlieren’ with parallel flow structure. * * * * The diorite 
stock as well as the adjacent Cretaceous rocks are cut by later vertical 
dikes of diorite-porphyrite and allied rocks; these dikes swarm in the 
contact zone, accompanied by horizontal and oblique sheets of similar 
rock. Mr. J. P. Iddings, who visited this place in 1891, finds that the 
vertical dikes, both in the stock and in all this part of the range, have a 
general radial arrangement, with the diorite mass as an approximate 
center, repeating a fact observed by him in a smaller diorite stock in 
the Yellowstone mountains. These long radial dikes extend outward 
even into the benches at the southern base of the range.” 

In the northern half of the range and its outlying buttes, the most 
prominent of the eruptive rocks, first collected by Dr. Wolff in 1883, is 
“found to be composed of feldspar (in part triclinic), augite and nephe- 
line, with biotite, sodalite, magnetite, olivine, :girine, etc., accessory; 
as an abyssal intrusive rock with the mineral combination nepheline, 
soda-lime feidspar, it filled a gap in the classification of Professor Rosen- 
busch, and was called by him ‘theralite’, as the first undoubted represen- 
tative of this family.” 

In conclusion, the author speaks of these mountains as an easily ac- 
cessible and magnificent field for further geologic and petrographic in- 
vestigation. “From Livingston or adjoining stations on the Northern 
Pacific railroad it is an easy day’s drive to the foot of the range; the 
canyons of the larger streams on the east side are easily accessible by 


Review of Recent Geological Literature. 321 


horseback and at the entrance even by wagon, and it is possible to ride 
to the falls in the contact zone. The outlying theralite buttes can all be 
visited by wagon.” 


“Geologie de l’anctenne Colombie, Bolivarienne, Venezuela, Noisvelle 
Grenada et Ecuador” par HERMAN KARSTEN, Berlin, R. Friedlander & 
Son. 

We distinguish in the region studied (Columbia, Venezuela and 
Ecuador) five definite geological periods of which the Jurassic is the 
oldest and has only recently been recognized in a locality in Columbia. 
The next period, however, the Lower Cretaceous outcrops in the moun- 
tains of the whole region and is characterized by a great variety of 
cepholapods. The presence in the lower strata which are specially 
marly, of Belemnites, Ptychoceras humboldtianus Krst., Ammonites 
negeerathii Krst., Am. rothii Krst., Am. sawtapcinus d’Orb., Am. bous- 
singaultii d’Orb., Hamites arbolede Krst., might perhaps justify two 
subdivisions of this period. 

The third series, the Upper Cretaceous, characterized by large deposits 
of limestones, sandstones and siliceous beds, may be recognized paleon- 
tologically by a great quantity of Rudistes which appear toward the 
east, and the Polythalamias, abundant in the centre and in the west. 

The fourth period, the Tertiary, is characterized by the abundance of 
vertebrate remains and the presence of pebbles and thick conglomerates 
formed at the expense of the siliceux beds of the older periods. Also 
by the great extension of micaceous marls, trachytic cinders and lipiliz. 

The fifth period, the Quaternary, is represented by washings, gravels, 
beds of pebbles, and breccias with shells on the sea coast; the shells be- 
long to species living at the present time. 

Several cases of unconformity in the respective disposition of these 
five series, show that they also correspond to distinct epochs of eleva- 
tion, and the geographical distribution of the Quaternary proves, in the 
most convincing way, even in the absence of a clear unconformity with 
the Tertiary, that these two periods were elevated at different times. 
The unconformities observed in the neighborhood of San Pablo in the 
lower Magdalena river probably mark this historical break. 

The (Quaternary has slight extension, some portions of the coast, 
somewhat elevated, belong toit. The Tertiary period is more developed; 
almost the whole of the immense plains of the Orinoco and doubtless 
large part of those of the Amazonas, belong to it; the highest summits 
of the actual continent, date from this time also. 

The Cretaceous, in which investigations show several distinct epochs, 
formed elongated islands in the Tertiary sea, in lines toward the north- 
east. The eastern island was the present massive of Cumaria; another 
island of the eastern series represented the massive of Mérida, and the 
western island, surrounded to the south by an archipelago of small vol- 
canic islands, was traversed by mountain chains, rich in veins, bearing , 
gold and platinum. 

It is quite remarkable that the steeper slopes of the Cretaceous re- 


322 The American Geologist. November, 1892 


gion, which runs or extends itself in acizcular arch toward the northeast, 
are turned to the massive of Guayana, whose rounded domes of granitic 
rocks rise from the Tertiary plains, as islands out of the ocean, as far as 
is known. On the contrary, the Tertiary strata, wherever they have 
been elevated in massives, either cover the slopes of the mountain 
chains or form valleys (“vullée de fracture”) as the valleys of the Magda- 
lena and Canea rivers, and the section of the strata looks to the valley. 

The massive of Guayana appears to be the centre of the different 
mountains or Cordilleras belonging to Columbia, and upon which de- 
pends the direction of all of them. They rise to the west, in Columbia, 
and to the northin Venezuela, as the borders of a large circular crevasse, 
formed in the crust of the earth in the circumference of this primitive 
centre of elevation; crevasse which then was not recognizable by im- 
portant massives in its total extension, but which marked the direction 
of the contemporaneous and future eruptions. 

The elevating force which caused the formation of the crevasse 
around the granitic centre, appears to have worked from east to west, in 
the primitive times, and plutonic epoch; that is it began to the northeast, 
reached its highest development in the north, and diminished more and 
more to the south. On the contrary,the last elevation of importance, 
which took place during the Tertiary volcanic epoch, followed an oppo- 
site direction. 

In the north the plutonic chains bordering the ocean reached their 
actual hight almost at the first elevation; at the end of the Cretaceous 
and Tertiary, they were only re-elevated; while in the south, they stood 
in part under the water, and only reached their actual form and hight at 
the end of the Tertiary, by the eruption of trachytic masses and lavas, 
which were very violent there, but became milder and milder toward the 
north. 


Report on the geology of northeastern Alubama, and adjacent portions of 
Georgia and Tennessee. C. WinuARD Hayes. Bulletin No. 4, of the 
Geological Survey of Alabama. 8vo. pp. 86, Montgomery, 1892 One 
plate of topographic outlines, and one geological map. 

This is a plain statement of the geological structure as made out in the 
field, over a critical area in the Appalachians, and covers all the Pale- 
ozoic from the Archean to and including the lower Carboniferous, and 
some portion of the Coal Measures. The field work was done by Mr. 
Hayes as an assistant on the U.S. Geological survey, and was reported 
to the state survey in pursuance of a compact between the two surveys 
in a cooperative plan for the examination of a section embracing the 
lower end of Lookout mountain, near Gadsden. The report, however, 
and the accompanying report,embrace considerably more area, that 
mapped being about 87 miles east and west, and 72 miles north and 
south. 

Mr. Hayes describes the remarkable fact, illustrated by the Rome 
thrust fault, that the lower rocks may be, and have been, faulted and 
raised and thrust bodily over strata of much later date in that portion of 


Review of Recent Geological Literature. 323 


the Appalachians. In this case the Cambrian strata are found to lie 
upon the middle Carboniferous, and the distance through which the 
-older strata have been moved westward, over the younger, by this thrust, 
is between four and five miles, and there is reason to believe that the 
Cambrian rocks once extended several miles further westward than they 
are at present found. The entire structure, stratigraphy, drainage, topo- 
vraphy, are neatly and concisely described in this brief report. The 
map is based on the U. 8. survey topographical sheets, and is a con- 
-densed expression of six of them. 


Advance sheets from the eighteenth report of the Geological survey of In- 
diana. Paleontology. By S.A. MILLER. September, 1892. Indianapolis. 
Octavo, pp. 79, and 12 plates of fossils. 

This pamphlet contains descriptions of seventy-six new fossil forms— 
Receptaculites, Cystites, crinoids, brachiopods, and cephalopods. They 
are from all points of the central area of the United States, mainly In- 
diana and Missouri, ranging from the Lower Silurian to the Carbon- 
iferous. 


The Mapping of Missour?. ArtuuR Winstow. (Trans. Acad. Sci. St. 
Louis, Sept., 1892. pp. 57-99.) The author sketches the history of the 
successive attempts to make a map of Missouri, and iliustrates, on re- 
-duced scales, some of the early maps, beginning with that of Ptolomus, 
edited in Rome in 1508, and extending through the sixteenth and seven- 
teenth centuries when little or no progress was made, to the eighteenth 
-and nineteenth in which marked advance has been made in accuracy of 
mapping the region of the Mississippi valley in which Missouri shares 
a part. 

The United States Coast and Geodetic survey began triangulation 
operations in Missouri in 1871, and has carried a network of triangles 
entirely across the state. The Mississippi river commission has accur- 
ately mapped the entire extent of the Mississippi in the limits of Mis- 
souri, and the Missouri river commission has delineated the Missouri 
valley in a similar manner, these organizations having done very accur- 
-ate work, both in mensuration and topographical delineation. 

The U.S. Geol. survey began, in 1884, to spread its inferior topograph- 
ical work over the state of Missouri, and constructed 25 sheets, on a 
scale of abouttwo miles to the inch. This work ceased in 1889. 

The Missouri state survey is engaged in making topographical maps. 
Mr. Winslow enlarges the scale of the U.S. survey maps—reduces the 
vertical contour interval to 20 feet, adds township and county lines, rep- 
resents railroads, etc., and produces sheets (now ten in all) of the size of 
1634 inches by 203, inches—a quadrilateral of fifteen seconds in extent 
in latitude and longitude, or from 228 to 240 square miles. 

It is noteworthy that for the purposes of the state geological survey 
in this instance, the topographical sheets of the U.S. Geological survey 
are rejected as unsuited and inaccurate, and the state survey proceeds 
to re-map the sume areas from data supplied by the United States Coast 
and Geodetic survey, or by the river commissions. 


324 The American Geologist. November, 1892 


The rounding of sandstone grains of the Trias, as bearing on the divisions 
of the Bunter. T., Metiuarp Reape, F. G. 8., (Proc. Liverpool Geol. Soc., 
1891-2). The author arrives at the conclusion, after comparisons of 
Bunter sandstones from various localities, that the roundness of the 
quartz grains, greater or less at certain localities, and the occurrence of 
pebbly strata, neither one, is any reliable indication of the horizon in 
which they occur. “The Bunter sandstones are a great group in which, 
form whatever cause, there has been a large impregnation of ferric 
oxide and other impurities which have in a majority of cases interfered 
with the deposition of secondary silica. The grains have also been laid 
down in turbulent conditions of current, evincing long travel of an os- 
cillatory or tidal character.” The author does not attempt to assign a 
cause either for the “turbulent conditions,” or the presence of large 
amounts of ferric oxide. Could not marine volcanoes have produced 
both, cotemporaneously with the accumulation of the sands? Again, in 
case of copious deposition of secondary silica, as in the silica embracing 
the pebbles of the “Pebble beds,” which seems to have alternated, geo- 
graphically as well as stratigraphically with the copious formation of 
ferric oxide, could not the same cause have operated to precipitate 
silica from the waters of the Triassic ocean and thus embrace the ac- 
cumulating pebbles or quartz grains? It is a significant fact that these 
two elements, “secondary” silica and ferric oxide, are frequently 
associated in this way. 


The Iron Deposits of Arkansas TR. A. F. Penrose. Annual report for 
1892 of the Geological Survey of Arkansas, Vol. 1, Octavo, pp. 158. 
Little Robk, 1892. : 

The report states that prior to 1860 two small bloomaries for iron, one 
in the northeastern and the other in the northwestern portions of the 
state, were in operation, but that since they ceased no iron has been 
mined, nor made in the state. This is owing to the poor quality of the 
ore and to the easy introduction of iron made in other parts of the 
United States, particularly in Missouri, since the construction of railroads. 

Iron ore of rather low grade is found in the state distributed from the 
Lower Silurian to the Recent formations, except in the Cretaceous, and 
geographically it is spread over most of the state. The ore at Magnet 
cove is nat in suflicient quantity to be of value for iron manufacture. 
Most of these deposits are limonite. There is some spathic ore from 
the Carboniferous shales and Tertiary clays and sands, and limited 
quantities of magnetic ore. The last occurs in a residual clay derived 
from the decay of crystalline rock in Magnet cove, and is known as Ar- 
kansas lodestone. This is the only ore in the state containing an appre- 
clable amount of titanium. Generally all the Arkansas ores are non- 
bessemer. 

The ores in the northeastern part of the state are probably in the 
Lower Silurian but their exact stratigraphic position is not known. The 
evidence seems to indicate that they are below the Calciferous. The 


Review of Recent Geological Literature. 325 


rocks dip under the saccharoidal sandstone, and the Izard and St. Clair 
limestones which represent the upper members of the Lower Silurian 
system in the Batesville manganese region, to the south of the iron 
region. 

The ores in the northwestern part of the state are probably on the 
same geological horizon, or perhaps somewhat in the Boone chert of the 
Lower Carboniferous. 

The ores of the Arkansas valley are in the Carboniferous and Lower 
Carboniferous. 

The iron ores of the Ouchita mountains occur ina series of novac- 
ulytes, siliceous shales, quartzytes and sandstones, though most of the 
deposits are immediately associated with the novaculyte and the siliceous 
shales. These strata are regarded Lower Silurian. They have furnished 
a few graptolites which Dr. Gurley regards as of Trenton age, but “the 
exact stratigraphic relations of some of the graptolite shales to the 
novaculytes are as yet uncertain.” This is the same novaculyte series 
that contains the manganese deposits, and has a thickness, sometimes, 
of 450 feet, in other places thinning out altogether. The ore, the erup- 
tive associations, the novaculyte, the slates, the titanium in the Magnet 
cove magnetite, the non-fossiliferous nature of the strata and the man- 
ner of occurrence of these deposits furnish many parallels with the ores 
of the Mesabi iron range in Minnesota, and strongly suggest a proba- 
bility of equivalence of age. 

The iron ores of southern Arkansas are in the Eocene of the Tertiary, 
and mostly below the Claiborne horizon of that series. These are lim- 
onites and small quantities of carbonates. Of these the author enters 
into a careful consideration of their origin. He traces them through 
the following stages. 

(1) The derivation of the iron from the decay of the rocks in the 
drainage area of the sea which in Tertiary times occupied the position 
of the present gulf of Mexico. 

(2) The solution and transportation of the iron in the form of soluble 
organic and iaorganic salts. 

(3) The precipitation of the iron as oxide or carbonate in lagoons or 
bogs along the coast. 

(4) The segregation, as carbonate (clay ironstone) of the iron precipi- 
tated in the above forms. 

(5) The conversion of the carbonate into the hydrous sesquioxide of 
iron (limonite) after the lagoons on the coast of the Tertiary sea had 
been elevated into a land area. 

Although the iron ores of the state are at present commercially value- 
less, thisis a valuable report. It sets at rest the ardent expectations of 
some prospectors and deprives them of their wealth,so far as it could 
consist in imaginary stores of iron ore, but it will be found to conduce 
greatly to the wealth of the people at large. It will forestall future ill- 
directed expensive exploration throughout the regions described, and 
will allow the citizen to prosecute in quiet the peaceful pursuit of such 
industries as the state actually possesses. 


526 The American Geologist. November, 1892 


Studies of Muir Glucier, Alashu. Harry Frenpina Rep (Nat. Geog. 
Mag. tv, Mch. 21, 1892). Someof Mr, Reid’s conclusions disagree largely 
with previous studies upon the same glacier. He finds the greatest ad- 
vance to have been seven feet two inches daily, and the smallest four 
inches. Professor Wright’s greatest advance, as measured in 1886, was 
72 ft. (Ice Age in N. A. p. 50); however, if we assume both measurements as 
correct, a change of climatic conditions may account for the very great dif- 
ference. Theerosion is estimated at three quarters of an inch per an- 
num. 

Mr. Cushing, the geologist of the expedition, found the exposed rocks 
to consist of limestone, argillite, quartz-diorite and diorite; and Dr. 
Williams’ microscopic examinations revealed several diorites, porphyry, 
porphyrites, gabbro (troctolite not from the glacier) and diabase. Dr. Her_ 
rick contributes a “microscopical examination of wood from the buried 
forest,” pp. 75-78; Mr. Rowlee, alist of plantsand finally Mr. Reid, meteor- 
ological and magnetic observations and suggestions to future ob- 


servers. 


Gibraltar —par Pau Caorrat. (Bull. Soc. Géol. France.) This in- 
teresting contribution is chiefly a criticism of the report on the geology 
of Gibraltar made some time ago by Ramsay and Geikie, who, accord- 
ing to M. Choffat, were unable, on account of artificial obstruction, to 
view the best exposed portions of the rock, which are now inaccessible. 
These gentlemen obtained but afew specimens of a single species of 
Rhynchonella, which was determined by Messrs. Etheridge and David- 
son to be very near &. concinna Sow., thereby placing the rock in the 
same horizon as the Great Odlite and Cornbrash of England. 

M. Choffat then alludes to the excellent report upon this celebrated 
rock by Smith, made many years ago, in which these remains are de- 
scribed as R. tetredia Sow., Lias. M. Choffat has been able to examine 
this species and also those collected by Ramsay and Geikie and finds 
they are identical. As this species (tetrwdra) occurs in the Alpine Lias, 
and as the author has lately discovered the same in Portugal he sees no 
reason for changing the age, as proposed by the two English observers. 
He therefore contends that the age (Lias) proposed by Smith is the proper 
one, 


On Nepheline rocks in Brazil, Part 1. OrvintiuE A. DERBY. (Quart. 
Jour. Geol. Soc. May, 1891.) In this paper the author comes to the 
conclusion that the Tingua peak, in the midst of an area of gneiss, com- 
posed as it is of orthoclase-nepheline rocks some of which are fragmen- 
tal tuffs though hardly distinguishable from phonolite flows, is a paru- 
sitic or supertmposed mountain, according to the nomenclature of Von 
Richthofan. This is but one of a number of localities in which the 
same features and the same rocks occur. Its age is unknown, but later 
sedimentary rocks containing similar eruptive rocks are near, and in 
the vicinity are Carboniferous fossils. It would appear therefore that 
the peak may be a remnant of a voleanic cone left after the denudation 


Review of Recent Geological Literature. a2 
J 


of Carboniferous rocks in which it may originally have been embraced. 
It is comparable to the basic volcanic tuffs that form a marked feature of 
the Keewatin, of the Archean of the “Northwest,” in the United States. 


Classification of the Cephalopoda. In the May number of the Proc 
Geol. Assn. (London, 1892, x11) comparison tables were given of the 
various systems of classification. In the July number another list is 
given, designed to replace the former. Tabler is Hyatt’s classification 
1867-83; Tab. Ir is Fischer’s, 1882-3; Tab. 111, Zittel’s, 1884; Tab. 1v. 
Bather’s, 1888; Tab. v, Steinmann’s, 1890. Bather’s is the most remark- 
able mainly on account of its brevity, here showing Lipoprotoconchia, 
sub-ord. Nautiloidea. Sosiprotoconchia, sub-ord. Ammonoidea, sub- 
ord. Coleoidea (Osteophora, Chondrophora). 


Penfietdite, a new species. (Am. J. Sci. xiv, 261.) Associated with an- 
glesite and laurionite from Laurion, Greece, Dr. Geuth has discovered a 
new lead oxy-choride of the composition PbO. 2 PbCl, (Cl.—18.21, Pb— 
79.73 O—2.06). Hexagonal, white, vitreous to greasy. Named after 
Prof. S. L. Penfield. 


Handbuch der Mineralogie. The sixth part of this excellent work by 
Dr. Hintze has just been issued. It treats principally of the serpentines 
sodalite nephelite, kaolinite and associated minerals. 


Protolenus, a new Genus of trilobite. G.F.MarrHew. (Bulletin x, 
Natural History Society of New Brunswick, Sept., 1892. 

The new genus of which two species are described, Protolenus etegans 
and P. paradoxides, occurs in the beds of Band b, division 1, of the St. 
John group, at Hanford brook, New Brunswick. 


The Glacial Succession in Hurope. JAMES GEIKIE. (Trans. Roy. Soc. 
Edinburgh, Vol. xxxvi, Part 1, pp. 127-150.) 4to. with amap. This isa 
review of the evidence in Europe for the idea of three or more glacial 
epochs in Pleistocene time, and he concludes that at least four such 
epochs of cold can be established. He goes further, and extends alter- 
nating seasons of cold and warmth into Pliocene time, thus making five 
glacial and four interglacial epochs. 


CORRESPONDENCE. 


ON THE KeokuK Grovup.—The August No. of the GroLocrsr con- 
tained an interesting paper on this subject by C. S. Beachler. In giving 
the literature he has overlooked a paper by tbe writer published in the 
American Journal of Science for October, 1890, in which the conclusions 
were practically identical with those now brought out by Mr. Beachler. 
In this paper a detailed section was given of the beds at Keokuk, and a 
study made of the fossil forms in which it was showa tbat the Craw- 
fordsville crinoidal bed represents the thin sandy stratum sometimes 


328 The American Geologist. November, 1892 


found at Keokuk above the geode bed, and represented by No. 13 of the 
section. This conclusion had been announced previously in a paper be- 
fore the Iowa Academy of Scienee (Mar. 10, 1890).* Mr. Beachler has ar- 
rived at the same results independently from a study of the Indiana 
area. 

These studies tend to aseparation of beds hitherto considered identical 
though much additional work is needed to set at rest obvious ques- 
tions. 

The disposition of the chert or transition bed below and the Magnesian 
or Warsaw above is still an open question, though recent writers seem to 
favor Owen and Hall in including them with the Keokuk. The evidence 
seems to sustain the following arrangement, here given tentatively: 


KEOKUK. INDIANA. 
Magnesian or 
Warsaw beds. - - Spurgeon Hill beds. 
Blue Sandy bed. - Crawfordsville beds. 


6 inches—seldom seen. 
(No. 13 of my Section.) 


Urrern KEoKUK. 


Geode bed. - - Indian Creek shale. 
KEOKUK. 4 | Bono beds. 
| 
| { Limestone bed. - - Walnut Fork beds. 
| Lower KEokuK. 4 
| Chert bed. - - New Ross beds. 


This follows very closely Owen’s division, made in 1852. In a paper 
on the Mississippian Section (Lower Carboniferous) before the G. 8. A., 
C. R. Keyes has given a brief descri tion of the Keokuk group, in 
which he ignores the work of previous observers, and gives but an im- 
perfect exposition of this important group of rocks. 

Evanston, III. C. H. Gorpbon. 


W. M. Harvey.—Another quiet and earnest worker in the field has 
been called to rest. Mr. W. M. Harvey, of Glen Rose, Texas, was buried 
on the 12th inst. To most of the readers of this journal his name was 
unknown. He belonged to none of the scientific societies, and held no 
scientific position, yet he lived a life devoted to nature, and through his 
explorations, made in the intervals of leisure he was able to take from 
his occupation as a house carpenter, discovered important material, now 
in the hands of Prof. L. F. Ward, of the U.S. Geological Survey, and 
Prof. E. D. Cope, of most signal value in completing the determination 
of the great lower Cretaceous system of this country. Through his 
patience asa collector, many important results were secured, in the 
vicinity of Glen Rose, including a locality where marine mollusca of the 
Trinity formation, as figured in tha Arkansas reports, were associated 
with the Potomac flora of the north Atlantic states, and above all, with 
the first determinable fossil vertebrates from those beds, including croc- 
odile and fish remains. This discovery is important because, with the 
three fold evidence it affords. the age of the lowest fossil bearing beds 
of the Comanche series can now be fixed with certainty. Professor 


*Proc. I. A.S. 1887-9, p. 100. _ 


Personal and Scientific News. 329 


Harvey was a native of Cincinnati, and acquired his love of fossils from 
association with the old school of paleontologists who there enthused all 
who met them with a love of science. He migrated to Texas for health 
and fortune. It was the writer’s good fortune in 1889 to discover him in 
his cottage filled with a rare local collection of the beautiful fossils of 
the adjacent country, and, again, in October, last year, to take to his 
home Prof. Lester F. Ward, under whose direction he collected a most 
abundant and important flora of the Potomac (Trinity) beds, which has 
been studied by Prof. Fontaine, and is now ready for publication. Mr. 
Harvey was one of many local geologists whom the writer has met in 
out-of-the-way places, working for the love of science, enduring the op- 
probrium of scoffing environment, but who, when the final award of 
honor will be given, shall find equal credit with those who, surrounded 
by every opportunity and luxury, have often accomplished less. 
Jaye bod Bere 


PERSONAL AND SCIENTIFIC NEWS. 


New Discoveries at MEntTONE, France. The discovery of 
three skeletons in this celebrated cave was made last February ; 
they were unearthed at a depth of about five feet, which is about 
25 feet below the original floor of 1872. The remains indicate a 
man of perhaps more that seven feet in hight; perforated teeth, 
shells, etc., were also unearthed. Mr. Vaughan Jennings, F. G. 
S., who visited the spot in March,suggests (Nat. Sei. 1, 272) that 
from a study of the implements found with the remains, they 
may belong to the neolithic age, but the skulls indicate an even 
more ancient type; however, the author concludes that the fact 
that similar perforated teeth, etc., have been found in the Dor- 
dogne cave of the same age as the classic drawings on bone, of 
the mammoth and reindeer, strengthens very much, the argu- 
ment for the palaeolithic age of the Méntone man. 

Mesozoic FossiIns FROM CENTRAL HIMALAYA. (Nat. Sci. 1, 
447.) Fossils from India recently examined in Vienna are found 
to conform in a marvelous degree with eastern Alpine species. 
Dr. Diener has formed an exploring party to visit the Himalayas 
for the express purpose of studying the fauna thereof with a 
view to comparison with the Austrian-Alps fauna. 

THE GREENLAND ExpLorinc Exprpition: The relief expedi- 
tion sent out last summer has returned, bringing with it all the 
members of the first expedition, with the sad exception of the 
young geologist, John Verhoeff, who was lost while out alone on 
a geological expedition. To quote Mr. Peary, ‘‘I have traced 
the northern limit of the interior ice-cap of Greenland; I have 
settled in my own mind the northern limit of the mainland of 


330 The A MEPICAN Geologist. November, 1892 


Greenland, demonstrated the existence of enormous glaciers in 
all the northern fiords; | have completed surveys of Davis bay, 
Inglefield gulf and Whale sound, and finally T have had excep- 
tional facilities for studying that most unique tribe of about 250 
persons, the arctic highl: unders..’ 

We shall await with great interest Mr. Peary’s reports upon 
these obscure subjects. The Academy of Natural Sciences of 
Phila., has the credit of giving support to this most successful 
expedition, 

Tue Micuican Mininac Scuoont, at Houghton, Mick., has 
recently been endorsed and commended by a committee appointed 
by the Superintendent of Instruction, consisting of D. A. Ham- 
mond, Perry F. Powers and 8. EK. Whitney. They made two 
visits of inspection, and report: ‘‘The Michigan Mining School, 
we may say in closing, has come to stay; because it has demon- 
strated its fitness to live. Whatever may have been its weakness 
in the past, it is now doing valuable work. It is well equipped, 
has an able faculty, and a demand upon it greater than it can now 
supply. We see no reason why it should not be a very valuable 
auxiliary in the future development of the mining resources of 
the state.” 

CHANGES IN THE DEPARTMENT OF GEOLOGY AT THE KANSAS 
Srate University. Prof. 8. W. Williston, the former incum- 
bent of the chair of geology, retains paleontology and vertebrate 
anatomy. Mineralogy and physical geology have been created a 
new chair to which Prof. Erasmus Haworth, late of Oskaloosa, 
lowa, has been appointed as associate professor. 

Mr. J. FP. WirrEAVES COMMUNICATES to the Canadian Record of 
Ne“vence for October, a description of a new genus and species of 
phyllocarid Crustacea from the middle Cambrian of mount 
Stephen, B. C. Three genera of Phyllocarida are known from 
the Cambrian rocks of Europe and America. ‘The new genus, 
Anomalocaris, now described by Whiteaves, adds a fourth. 
Anomalocaris differs conspicuously from the other genera in the 
characteristics of the abdominal appendages and in the number 
and disposition of the caudal spines. The type specimen is 
named A. canadensis. 

Dr. FLOWER’S RECENT LITTLE BOOK, “The Horse,’ (New York, 
D. Appleton and Company,) though not primarily designed for 
specialists, will be found a very convenient aid to advanced stu- 
dents, not only in biology but in geology as well, since it presents 
a most excellent summary of the present state of scientific 
knowledge concerning an animal that figures prominently in both 
of these sciences. 

Dr. OromaR NOVAK WHO WAS CONTINUING THE RESEARCHES of 
Barrande into the Silurian faunas of Bohemia while filling the 
chair of geology at the University of Prague, died on July 29th, 
He was only 42 years of age. 


fue AMERICAN GEOLOGIST. Vor. X, Prats X- 


Bre. 2: 


MICROSCOPIC SECTIONS OF SO-CALLED CANNEL COAL. 


THE 


AMERICAN GEOLOGIST 


Vou. X. DECEMBER, 1892. No. 6 


A PRELIMINARY EXAMINATION OF SO-CALLED 
CANNEL COAL FROM THE KOOTANIE OF 


BRITISH COLUMBIA. 
By D. P. PENHALLow, F. R.S. C., F. R. M. 8., McGill College, Montreal. 


Prate X. 

During the past year anumber of specimens of a coaly mineral 
having the general properties of a cannel coal, and locally recog- 
nized as such, were obtained from the Kootanie and Lower Cre- 
taceous formations of British Columbia. Their peculiar physical 
constitution, and the great difficulty of ascertaining association 
with any of the materials ordinarily known to contribute to coal 
formation, made their examination a matter of more than ordi- 
nary interest. The specimens at first placed in my hands, con- 
sisted of a slide by Mr. Weston of the Geological Survey, to- 
gether with a small fragment taken from a characteristic hand 
specimen. They were submitted to me by Sir Wm. Dawson, who 
had received them from Dr. George Dawson of the Geological 
Survey. <A preliminary inspection satisfied me that a more ex- 
tended examination of the original material was desirable. Dr. 
Selwyn, of the Geological Survey, kindly supplied me with five 
characteristic hand specimens from as many different seams, some 
of them widely separated. These were submitted to a critical 
examination, and from some of them, a number of fresh slides 
were prepared. 

So far as their general characteristics are concerned, these 


coals are all of the same nature, differing chiefly in degree of 


332 The American Geologust. December, 1892 


consolidation under the influence of pressure. In all the more 
compact specimens the fracture is conchoidal and lustrous; a few 
show a coarse lamination while others do not. All agree in being 
made up of similar rod-like bodies which are more or less closely 
compressed. In one case the rods were loosely piled in a promis- 
cuous manner,in such a way as to exhibit their form and size very 
perfectly, being held together, apparently, by a partial fusion 
with one another, or by a cementing substance of a similar na- 
ture. In the most compact forms, it could be readily ascertained 
that the rods constituted the entire substance of the coal, their 
transverse and longitudinal fractures being sufficiently conchoidal 
and lustrous to distinguish them from oneanother. The rods are 
round and. straight, and closely resemble, in some of the less 
compact specimens, rods of amber of dark color. The least 
diameter found was 0.5 mm. From that they range upwards to 
2. mm., which, however, is not very common. Their length ap- 
pears to He between 5 mm. and 2.5 em. One specimen was 
characterized by a decided flakiness, the flakes being closely 
compressed and apparently composed of finer laminz of a sub- 
stance similar to that constituting the rods. 

Several sections were taken from the different hand specimens 
and prepared for microscopical examination, 

Section 2136 was prepared by Mr. Weston of the Geological 
Survey, from one of the least compact of the hand specimens. 
It shows the rods to be cut variously, but chiefly transverse and 
longitudinal. Lines of flow none; tissue or cell structure none. 
Granulations common and often disposed so as to form zones 
surrounding hyaline areas. Granules round or oblong and often 
spore-like,.1.9 » in diameter. Color, reddish amber.  I[rregu- 
lar lines of fracture often penetrate the rods at right angles for 
one-fourth their diameter; they usually show as shrinkage clefts 
or air tubes. 

A conspicuous feature of the rods is the presence in their in- 
terior of tubular, often branching, openings which are strongly 
suggestive of vegetable growth, and at first are apt to lead to the 
supposition that they are fungous mycelia. On account of their 
peculiar form, it may be well to refer to them as myceloid tubes 
large 


or ramuli. They may be roughly classed as of two kinds 
and small, 
The large tubes were found to be cut in all ways, precisely as 


Examination of So-called Cannel Coal.—Penhallow, 333 


long, tubular cells loosely and sinuously disposed would be, so 
that there were longitudinal and transverse, as well as oblique 
sectionsof them. Longitudinally they show an apparent cell wall 
and prominent central cavity. They are more or less vermicular 
and simple or irregularly branching. The cavity is often filled 
with a poorly defined granuiar substance, and they sometimes 
contain air. 

In transverse section the apparent wall appears prominently, 
and shows as what seems to be a rather thick wall with an outer 
and dark, limiting membrane. The tubes are usually about 39 
w broad, and the wall 14 » thick. 

The small myceloid ramuli are freely branching and some- 
what interlacing, and in many cases are filled with air. It is 
very common to find them occupying large areas of the rods, 
while less frequently they assume the form of stellate groups 
closely resemblings tufts of /ivularia. These groups are com- 
monly 109 » broad The separate tubes measure from 1.9 » to 
3.8 » and even 15 » in diameter. In the smaller forms where 
the radial disposition is most pronounced, these ramuli com- 
monly terminate in sub-spherical pockets. 

The substance lying between and apparently cementing the 
rods together, consists chiefly of a fine granular matter—the 
granules being very angular—which seems to have been derived 
from the same material as the rods through some pulverizing 
action, 

Section 1 was prepared at the Redpath Museum, as were all 
the following sections. In this the rods show frequent round 
air cavities measuring from 9.6 » to 105.6 » in diameter. Small 
lamine and angular fragments fill the spaces between the rods, 
apparently consisting of the same material. The rods themselves 
are wholly structureless and otherwise as in the preceding sec- 
tion. 

In section 2 the rods are cut longitudinally and transversely, 
Lines of flow and evidence of structure wholly wanting. The 
fine, myceloid ramuli are abundant and often contain large quan- 
tities of air. The large ramuli are not very abundant, but when 
present usually contain air. The interstitial substance forms a 
spongy cement—hbeing traversed by numerous round openings— 
consisting of minute, angular fragments of amber-like material 
imbedded in an amorphous substance of somewhat granular 


3354 The American Geologist. December, 1892 


character and possibly derived from cellular structure. ‘The whole 
forms a cementing substance which unites the amber-like rods. 

Section 3 is that of a flake taken from hand specimen number 
5. It is composed of a spongy mass, possibly the residue of 
cellular structure, in which are embedded small fragments of 
amber-like substance of angular form, the whole as in the inter- 
stitial substance of number 2. 

Section 4 was obtained from a single rod or filament 1 em. long 
by 1.25 mm. wide. Structure none. Round cavities similar to 
air bubbles, frequent, but not so conspicuous as in many other 
Cases. . 

The details thus outlined sufficiently express the characteristics 
of all the other sections examined, and the general results of the 
examination make certain facts prominent. i 
1. The total absence of structure. 

2. The presence of tubular ramuli of diverse dimensions. 
3. The presence of rounded cavities. 


- 


The presence in large quantity, of angular fragments of 
material of the same nature as the rods. 

5. The presence of an amorphous substance together with the 
last, either occurring as distinct flakes, or acting as a cement to 
unite the rod, 

It is desirable that these facts be considered somewhat in detail. 

The complete absence of structure throughout the numerous 
rods submitted to examination, is significant. Out of several 
hundred rods there was only one instance of an appearance which 
was at all suggestive of derivation from structure. In this case, 
a very limited area was occupied by a series of rather closely ar- 
ranged plates running transversely to the axis of the rod, but these 
are, I think, capable of reference without serious question, to the 
action of internal shrinkage. (Fig. 2.) Had normal structure at 
any time constituted a part of these rods, it is quite likely that 
out of one or two hundred, some evidence of this fact would 
have appeared. The total absence of such evidence lends strength 
to the view that the rods must have been derived from material 
originally structureless and, practically, of the same nature as 
now found. 

The presence of spore-like granulations is a feature more or less 
common to all organie structure which has passed into a fossil 
state, and is incident to the more or less complete breaking up of 


Kramination of So-called Cannel Coal.—Penhallow. 335 


the original organic matter with the elimination of the elements 
of water. When such changes occur, the modified parts acquire 
a darker color which eventually become black, assume a granular 
form and dispose themselves in accordance with the particular 
nature of the molecular changes in the material as a whole. This 
has elsewhere* been shown to produce very peculiar effects, as in 
modification of the structure of Nematophyton. In this it is 
possible to find a satisfactory explanation of the distribution of 
eranules about the surfaces of air tubes or internal fissures in 
such a way as to produce the appearance of a cell wall. 

The presence of tubular ramuli is a condition which, without 
critical examination, might seem to justify the opinion that my- 
celia had penetrated the body and become permanently preserved. 
This necessitates the supposition that (a) the material of the rods 
was once soft and that when in that condition it had flowed over 
and engulfed the associated fungi, or (b) that while plastic, it 
possessed nutritive properties and was readily penetrated by 
fungi. The total absence of lines of flow offers serious opposi- 
tion to the first hypothesis, and indicates that the rods were, 
from the first, of the form and general character now found. 
The second hypothesis is probably not admissible for reasons 
which will appear later, although it is undoubtedly true that the 
rods were originally composed of,a soft and even viscous sub- 
stance. 

It is furthermore found that the ramuli are not septate, but 
form continuous simple or branching tubes; their branching 
is irregular and not determined with that uniformity which is 
consistent with the growth of organic structure; the tubes are 
irregular and often contain side pockets such as no vegetable 
structure is known to have, but such as might readily be formed 
under certain conditions of contraction in the surrounding mass. 
Also, the remarkable disposition of these tubes is wholly incon- 
sistent with their character as possible vegetable structures. 

Precisely similar tubes may be formed under certain conditions, 
in any plastic material. It is a matter of common experience in 
the preparation of glycerine jelly mounts, that if a somewhat ex- 
cessive pressure be applied to the central area of the cover glass, 
the latter will be slightly bent down below the line of the margin. 
Upon removal of the pressure after the jelly has hardened, the 


*Trans. Royal Soc. Can. vit. ry. 24-25 AMERICAN GEOLOGIST, LX. p. 369. 


6 Lhe American Geologist. - December, 1892 


cover glass springs back to its normal position and in so doing 
tends to draw away from the jelly immediately below. The 
necessary consequence of this is the formation of a cavity which, 
owing to the peculiar consistency of the jelly, will assume the 
form of a series of irregularly branching ramuli often dispersed 
in astellate manner. The figures and tubes thus formed are in 
all essential respects the exact counterpart of the ramuli found 
in the rods of cannel coal now under consideration, and I think 
we mnay safely infer that the latter arise from the same general 
cause as the former. This would make them the result of inter- 
nal shrinkage caused by the gradual elimination of a volatile ele- 
ment, but as the loss of such a volatile constituent must always 
take place first at the surface, there would necessarily be formed 
an external layer of greater resistance which would tend to pre- 
serve the original form and promote a shrinkage through the 
central mass towards the firmer bounding layer. This view is also 
justified by the known occurrence of similar shrinkage cracks 
and pockets in amber and other forms of fossil resin. 

The material occupying the spaces between the rods and ap- 
parently cementing them together, consists of an amorphous and 
irregularly granular mass full of rounded holes, thereby giving it 
a spongy character. Within this matrix are imbedded numerous 


small, angular or rounded—sometimes laminve—fragments of 
material which, from its general aspects, appears to be the same 
as the rods, and in all probability is the material of rods which 
were broken up in various ways. The presence of such frag- 
ments and the curious way in which the rods are massed in thick 
seams, together with the absence of other material, would seem 
to indicate the agency of water. The source of the amorphous 
substance is not so clear. It has no apparent relationship with 
the rods and fragments, nor does it anywhere present any struct- 
ural aspects. so that we are left wholly in doubt as to its possi- 
ble nature. A hypothetical view might regard it as the debris of 
vegetable structure, but it does not appear so carbonaceous as 
material from such a source should be. 

These considerations render it fairly clear that the origin of 
these coals must be sought in some other direction than modified 
vegetable structure. From their character as determined by mi- 
croscopical examination, from their fracture and color in trans- 
mitted light, as well as from their combustible nature, we can 


Examination of So-called Cannel Coal.—Penhallow. 337 


only conclude that they represent some form of fossil resin. The 
possibility of their derivation from resin was first suggested by 
Dr. G. M. Dawson in his first letter transmitting the specimens. 
But certain difficulties seem to stand in the way of this hypothe- 
sis. Among these is the absence of any lines of flow. We may, 
however, conceive the resin to have been solidified in the resin 
passages of the tree, and this is certainly implied by the form and 
size of the rods as now found. 

Again, the enormous volume of these rods, sufficient to pro- 
duce thick and extensive coal beds, would almost seem to be in- 
compatible with their origin in the way suggested above, unless 
we suppose (a) that the resin bearing trees of that period were 
enormously abundant—far exceeding anything known in modern 
vegetation, and possibly of a species which has ceased to exist, 
or (b) that the trees produced resinin such enormous quantity 
that rapid and great accumulations were possible. 

The complete absence of any definite structure associated with 
the specimens, still further complicates the problem, though it is 
quite possible that the plant remains found in the surrounding 
strata may throw important light upon the subject, when oppor- 
tunity offers to systematically collect and study them. In the 
present state of our information, three possibilities suggest them- 
selves. (1) The resin was produced wholly in the bark. Upon 
decay of the trees the bark separated from the wood, the two 
floated independently and may have eventually reached the same 
or different places of deposit. The free bark while floating suffered 
sufficient disintegration to liberate the contained resin, which was 
sarried to a separate place of deposit. This hypothesis gains no 
support from modern vegetation, and is doubtless one which will fail 
to satisfactorily account for the great accumulations found, — (2) 
The occurrence of the resin in the wood or in both wood and bark, 
the structure of which decayed sufticiently to liberate itafter being 
hardened. In such case we might reasonably expect to find some 
remnant of the woody structure associated with the rods. Their 
purity, however, indicates a complete separation from the structure 
inwhich they had their origin,and, moreover,such separation must 
have taken place with great facility. Modern examples lend no 
support to this view. (3) The resin tubes may have been pro- 
duced in layers in such a way as to promote a rapid and complete 
breaking up of the organic structure in drying or decay, with 


338 The American Geologist. ° December, 1892 


consequent liberation of the indurated resin. The subsequent 
action of water would tend to separate the two completely, and 
thus establish the purity of the resin as now found. The only 
possibility of obtaining any support for this theory from modern 
vegetation, came to us at the close of my examination of these 
coals, in a report that certain spruce and tamarack trees now 
crowing in the Kootanie district do produce resin in large quan- 
tity and in such a way as to determine their speedy breaking up 
when subjected to desiccation or to maceration, and that from 
them might be derived data which would have an important bear- 
ing upon the nature of these coals. As it was important that evi- 
dence of so promising a nature should be examined, I asked Mr. 
D. A. Stewart, of Winnipeg, an engineer in the employ of the 
Canadian Pacific railway, if it would be possible to procure 
for us, specimens of the trees in question. This he very kindly 
consented to do, and we have since been placed under obligations 
to both Mr. Stewart and other officers of the Canadian Pacific, 
by the receipt of four fine specimens measuring about two and 
one-half feet long, and with diameters of upwards of a foot. 
Since then all of the specimens have been carefully examined and 
with wholly negative results. The details of this examination 
will appear later. It is sufficient for our present purpose to 
point out that the last hypothesis advanced to account for the 
origin of these coals receives no support from modern vegetation, 
and we can only hope, therefore, that in future examinations of 
these deposits, associated plant remains may be found which will 
throw light upon a now very obscure problem, 

A chemical examination of these coals has been made by Mr. 
G. C. Hoffmann, of the Geological Survey of Canada,* but as 
his results bear only upon their fuel value, they throw no light 
upon their origin. At my request, Dr. Harrington, of McGill 
College, has kindly undertaken to determine the soluble constitu- 
ents in order to bring them into comparison with certain fossil 
resins from Cedar Lake, which he had already examined.t The 
Cedar Lake resins show 21.01% soluble in absolute aleohol, and 
24.84% soluble in ether. The cannel coals in question show only 
4.6% soluble in chloroform, and 3.17% soluble in ether, the 
solution in each case being strongly fluorescent. It is, therefore, 


— 


*Rept. Geol. Surv. Can. 1v,7 R. 
tAmer. Jnl. Sei. xni1, 332. 


Accumulation of Drumlins.— Upham. 339. 


obvious that no direct comparison can be made, but while these 
results fail to show relationship between the amber or fossil 
resin and the cannel coal, they do not enable us to say that the 
latter did not have its origin in vegetable structure. It is quite 
possible that the greater degree of insolubility of the coal may 
be the result of a greater degree of alteration. 


EXPLANATION OF THE Figures. PLare X. 
1. Coal showing rods in longitudinal section, together with granular 
matter lying between, X 6. 
2. Filament of coal in longitudinal section showing a small area 
occupied by transverse shrinkage cracks, 70. 


CONDITIONS OF ACCUMULATION OF DRUMLINS.* 


By WarrEN Upnam, Somerville, Mass. 
CONTENTS. 

Page. 
Statement of the Problem...... BEN CHEE ASS + PARED DEMISE OIE Darr DORSET deme os! 
Definition and Varieties of Drumlins....................c secs veeeseeceeee ees BBO 
SSOCTAD NLC SD ISECIDUTION . o\</.tae chien ct e=/o nists sieveaae-e) -/ahe)e =e Se tee macnn ae ake 342 
Subglacial and Rapid Deposition shown by Structure................. 2-2... 346 
Questions concerning the Action of the Ice-sheet. ae eseterehes ene letataicwe eatateh sien wee 
Probable Accumulation of the Drumlins from Englaci: fl Dristes.30o 28 Vee 351 
WPIECHLONSTLOCOrMer TNEOLTIES. © asia sited nse cleeleleticela tie we sla e eatadeitevits © dersteTeein sy ale 351 
Transportation of Drift into the lower part of the Ice-sheet.................. 358 
Ablation causing Englacial Drift to become Superglacial . 354 

Stratum of Superglacial Drift made again Englacial by increased Snowfall 
and by Advance of the thicker portion of the Ice-sheet. are Senet eisai et tO 
Ice Currents massing the Englacial Stratum into Dremiling +00 ces nese OSB 
Review of Objections to this “Explanation ‘(ols aeposoiins isle jaik ciaiehss 3) eo Salsuateyaieieielata cjetaie 358 
Comparison with Terminal Moraines, Kames, and Eskers .... 0 .. 2.2.20. 0222 0000s 360 
Minwicrothedlcomreuas One: Glacial HpOCh.)c0 <cre des socisce at saci cleave coher smeees. O01 


STATEMENT OF THE PROBLEM. 

Definition and Varieties of Drumlins.—The drift hills called 
drumlins consist, at least superficially and in most cases through- 
out their entire mass, of till or boulder-clay, being unstratified 
clay, sand, gravel, and boulders, mingled indiscriminately to- 
gether, which therefore must be attributed to deposition by ice 
without modification by the assorting and stratifying action of 
currents of water. They have usually an oval form, with smoothly 


*This paper, in preliminary outlines, was presented before the Geo- 
logical Society of America, Aug. 16, 1892, at the meeting in Rochester, 
N. Y., as noted in the October Gro.oaisr (p. 218). Further study has 
since led to the opinions given here, that the englacial drift of which, 
under this view, the drumlins appear to have been chiefly formed, had 
become superglacial by ablation and was afterward enclosed as a 
stratum within the ice-sheet, being thence amassed in these hills ; 
and that, according to such explanation of the origin of the drumlins 
and their comparison with the terminal moraines, the Ice agejmay 
probably have comprised only a single glacial epoch. 


5340 The A MeCPiCan Geologist. December, 1892 


rounded top and steep slopes, especially at the sides, from which 
features Prof. C. H. Hitchcock in 1876 named them Jenticeular 
Aifls, the first distinctive term applied to these drift acecumula- 
tions in this country. Subsequently the name drwinlins, used by 
M. H. Close ten years earlier for similar hills and ridges of till 
in Ireland, has come also.into common use here. 

Oval or elliptical forms of drumlins prevail, with rare excep- 
tions, in New Hampshire, Massachusetts, and Connecticut. In 
some other districts, as in central New York, these hills vary from 
the oval type to prolonged ridges, running nearly straight several 
miles; and in eastern Wisconsin, as described by Chamberlin, they 
are prevailingly circular and dome-shaped on some areas, being 
therefore called inaimmillary hills, while in other localities they 
oecur mainly as long parallel ridges. Wherever drumlins are 
found, their longer axes trend in parallelism with the courses of 
the glacial strix and transportation of boulders, that is, with the 
current of the ice-sheet. Glacialists are agreed that this relation- 
ship and the very regular and smooth contour of the drumlins 
resulted from the moulding action of the overriding ice, to which 
masses thus elongated opposed the least resistance. 

In the areas of their greatest development the drumlins range in 
hight from 25 or 50 feet up to 200 feet or rarely more, and propor- 
tionately inlength from an eighth of amile to one mile, or, in tracts 
where they become long ridges, two to three miles or more. The 
slopes of their ends are gentle or moderately steep, having from 
5 to 20 feet of ascent in a distance of a hundred feet; but the 
steeper ascent of their sides varies usually from 15 to 30 feet in 
the same distance. Instead of amassing the till in such promi- 
nent accumulations, we should expect that the ice-sheet would 
tend constantly to wear away the hill tops and leave thick de- 
posits of subglacial drift only in depressions of the country and 
on low or nearly level land, 

That the drumlins are commonly till or boulder-clay from 
crest to base is shown by sections of wells and other excavations, 
and on the coast by wave erosion, as in Boston harbor and _ its 
vicinity, where a third or half of a drumlin innumerous instances 
has been washed away, leaving sea cliffs of till from 20 to 100 
feet high. Frequently, however, drumlins rest on moderate ele- 
vations of the bed rocks, which outcrop on portions of the lower 
slopes to a hight of perhaps 50 or 100 feet, forming a pedestal 


Acéumulation of Drumlins.— Upham. 341 


capped by the rounded mass of till for the upper half of the 
hill. 

Again, lenticular slopes of till, having the same smoothly flow- 
ing outlines as the drumlins, are sometimes accumulated on the 
lee side of hills of rock; the hill and the detritus sheltered behind 
it being known as ‘‘crag and tail.” A large number of such 
slopes were mapped by the writer in 1878 in New Hampshire, 
besides about half as many similar slopes of till lying upon the 
nortiern sides of rock hills, where they were most fully exposed 
to the ice-current. The knobs of rock in each case may be said 
to have combed the drift from the ice by which it was being borne 
forward. More rarely the slopes were gathered upon both north and 
south sides alike, blending together and assuming the form of a 
drumlin, but having outcrops of rock at the top. In Massachu- 
setts, however, though almost equally a region of plentiful rock 
hills, Mr. George H. Barton, in mapping the drumlins, finds very 
few of these till slopes. 

Most instructive variations from the usual constitution of the 
drumlins are presented where anticlinally stratified beds of gravel, 
sand, and clay or fine silt, form their inner part. reaching in a 
dome-shaped accumulation from the base upward to comprise 
sometimes the greater part of the section, with a deposit of till, 
which may be from a few feet to 25 feet or more in thickness, 
spread over these beds so as to form the entire surface. Among 
many sections of drumlins observed by me in New England, the 
only examples of this structure are Third and Fourth Cliffs, par- 
‘tially eroded drumlins in Scituate, Mass., on the shore of Massa- 
chusetts bay.* These rounded, low hills, rising respectively about 
70 and 60 feet above the sea, consist of till upon their whole sur- 
face and to a depth that varies from 15 to 25 feet and more, but 
below include beds of modified drift that attain in Third Cliff a 
thickness of at least 30 to 40 feet, reaching to the boulder-strewn 
shore, and in Fourth Cliff a thickness of 10 to 20 feet, being 
seen there to be underlain by till and to be also in part interbedded 
with it. 

In Madison, Wisconsin, and its vicinity, drumlins having thus 
an anticlinal nucleus of modified drift and surface of till are 
more frequent, as Tam informed by Prof. T. C. Chamberlin and 


*Proceedings of the Boston Society of Natural History, Vol. xxiv, 
pp. 228-242, with map and sections; April 17, 1889. 


342 The American Geologist, December, 1892 
Mr. I. M. Buell. The hill on which the state capitol is built be- 
longs to this class, as shown by the section of its artesian well.* 
Its hight is about 80 feet above the adjoining lakes, and the sec- 
tion passes through till for the first 8 feet, and through sand and 
gravel, enclosing occasional boulders, for the next 72 feet. 

Geographic Distribution. —Generally throughout drift-bearing 
areas the till, excepting where it is accumulated in the hills and 
knolls of the terminal moraines, has a comparatively low and 
level or moderately undulating surface. But on certain tracts a 
large part of the till is exceptionally amassed in the drumlins, 
which stand up very conspicuously as high hills, sometimes oc- 
curring plentifully with irregular arrangement in groups or belts 
which may extend 20 to 50 miles or more and often have their 
greatest length in parallelism with the course of the terminal mo- 
‘aines. Klsewhere drumlins are sparingly scattered here and 
there with intervals of several miles between them, this being often 
observed on the borders of their tracts of greatest abundance; and 
rarely a single typical drumlin,as Pigeon hill on Cape Ann,may be 
separated many miles from any other like accumulation of till. 

It would be expected that the abundance or absence of drum- 
lins must be determined, or at least influenced, by the varying 
contour and diversity in lithologic characters of the bed rocks; 
but I have been unable to discover this relation or dependence, if 
any exists. © In southern New Hampshire, and southward to the 
neighborhood of Boston, the drumlins are finely developed on 
some portions of the low land near the coast, being spread over 
areas which would otherwise be nearly level; but at many places 
inland they are equally abundant among high irregular hills of 
rock. They seem as likely to be found on one side as another of 
any mountain or prominent hill range; and the altitudes at which 
they occur vary from the level of the sea to 1,500 feet above it 
on the hight of land between the Merrimack and Connecticut 
rivers. Interspersed with the tracts of plentiful drumlins are 
other tracts which have none. If their distribution has been 
mainly independent of the differences in topography and the 
limits of various rock formations, as seems to be true, we are 
brought to the alternative that it probably resulted from move- 
ments of the ice-sheet and the conditions of its erosion, trans- 
portation, and deposition of the drift. 


“Geology of Wisconsin, vol. 11, 1877, p. 50. 


Accumulation of Dinmlins.— Upham. 343 


Besides the frequent arrangement of these hills and ridges of 
till in groups and somewhat definite belts, which are from a few 
miles to 10 or 20 miles wide, with intervening belts or irregular 
areas destitute of drumlins,a still more noteworthy feature of their 
geographic distribution is found in their occurring thus upon some 
extensive districts, while they are utterly wanting on larger portions 
of the great glaciated areas of North America and Kurope. On this 
continent it seems probable that the districts where they are found, 
ranging from southern New Brunswick and Maine to northwestern 
Manitoba, may have been uncovered contemporaneously from 
the ice-sheet during the same general stage of its final recession. 

‘Mr. Robert Chalmers has observed numerous drumlins on the 
east side of lake Utopia and between the Magaguadavic and St. 
Croix rivers in Charlotte, the most southwestern county of New 
-Brunswick.* Under the name ‘‘whalebacks,”’ Mr. G. F. Matthew 
describes these and other drumlins in the southern part of this 
province on an area extending from the St. Croix about 90 miles 
east to Upham township. tf 

Drumlins are reported in Maine by Prof. George H. Stone, the 
lenticular type prevailing in the western part of the state, while 
toward the east they also take the form of long ridges. In size 
and numbers, however, they are described as inferior to the drum- 
lins of New Hampshire, Massachusetts, and New York. ¢ 

The earliest mapping of drumlins in this country was done by 
the writer in 1878, under the direction of Prof. C. H. Hitchcock, 
for the Geological Survey of New Hampshire.@ Nearly 700 
drumlins were noted in the southern half of this state, besides 
about 175 lenticular slopes of till. Farther north in New Hamp- 
shire such accumulations are absent or very rare. Some 130 
drumlins in adjacent portions of northeastern Massachusetts and 
southwestern Maine were also noted on this map. The most im- 
portant feature of the distribution of the drumlins in New Hamp- 
shire is their occurrence chiefly upon three belts which vary from 
5 to 20 miles in width and extend 25 to 30 miles from northeast 


*Geol. and Nat. Hist. Survey of Canada, Annual Report, new series, 
vol. tv, for 1888-89, p. 23 N. 

+Geol. and Nat. Hist. Survey of Canada, Report of Progress for 1877- 
78, pp. 12-14 EE. 

¢Proceedings of the Boston Society of Natural History, vol. xx, 
1880, p. 484. Proceedings of the Portland Society of Natural History, 
March 11, and Nov. 21, 1881. 


§Geology of N. H., atlas and vol. 111, 1878, pp. 285-809, with heliotype. 


O44 The American Geologust. December, 189 


to southwest. These tracts are separated by others of equal or 
vreater width upon which searcely any drumlins are found. 

Profs. Shaler, Wright, Hitchcock, and Davis, and the present 
writer, have deseribed the drumlins of Boston and neighboring 
areas, Where they are admirably developed.* During the years 
1890 to 1892 the drumlins of the entire state of Massachusetts 
have been mapped and carefully studied by Mr. George H. Bar- 
ton, under the direction of Prof. N. 8. Shaler, for the United 
States Geological Survey. Their total number is found to be 
about 1,500, counting, as in New Hampshire, the separate rounded 
summits of compound drumlin aggregations, where two or three of 
these hills,or sometimes more,are merged together at their bases. 

From the vicinity of Spencer, Mass., a series of abundant 
drumlins, according to Davis, extends south to Pomfret in north- 
eastern Connecticut. They probably also occur plentifully in 
other parts of this state, reaching southward to Long Island 
sound; for Round hill in Orange, near New Haven, described by 
Prof. J. D. Dana, appears to be a drumlin. t 

New York has a magnificent area of drumlins, perhaps the 
most interesting in the United States, which stretches more than 
60 miles from Syracuse westward nearly to Rochester, lying be- 
tween lake Ontario and the ‘‘Finger lakes.” { These hills are well 
seen along the New York Central and West Shore railroads. 


*N.S. Shaler, “On the Parallel Ridges of Glacial Drift in eastern 
Massachusetts,” Proceedings, Boston Society of Natural History, vol. 
x11, 1870, pp. 196-204. Illustrations of the Earth’s Surface: Glaciers, 
1881, pp. 60-68. U.S. Geol. Survey, Seventh Annual Report, for 1886, 
pp. 321-2; Ninth Annual Report, for 1888, pp. 550-1. 

G. F. Wright, Proc., B. S. N. H., vol. xrx, 1876, p.58, and vol. xx, 1879, 
p. 217. The Ice Age in North America, 1889, chapter x1. 

C. H. Hiteheoek, “Lenticular Hills of Glacial Drift,’ Proc., B.S. N. 
H., vol. x1x, pp. 68-67. 

W. M. Davis, Illustrations of the Earth’s Surface: Glaciers, text de- 
scribing Plate xxiv. Proc., B. 8. N. H., vol. xx1r, 1882, pp. 34, 40-42. 
“Drumlins,”’ Science, vol. tv, pp. 418-420, with illustrations, Oct. 31, 
1884. “The Distribution and Origin of Drumlins,’ Am. Jour. Sei., I, 
vol. xxv1il, pp. 407-416, Dec., 1884. 

Warren Upham, “Glacial Drift in Boston and its Vicinity,’ Proc., B. 
S. N. H., vol. xx, 1879, pp. 220-234; “Marine Shells and Fragments of 
Shells in the Till near Boston,’ Proc., B. S$. N. H., vol. xxiv, 1888, pp. 
127-141, also in Am. Jour. Sei., III., vol. xxxvir, May,1889. “The Struct- 
ure of Drumlins,” Proc., B. 8. N. H., vol. xxtrv, 1889, pp. 228-242. 

tAm. Jour. Sei., ITI, vol. xxv1, 1883, pp. 357-361. 

tL. Johnson, “The Parallel Hills of western New York,’ Trans., N. 
Y. Acad. of Sci., vol. 1, 1882, pp. 78-80; Annals, do., vol. 11, pp. 249-266, 
with map. 

Db. F. Lineoln, “Glaciation in the Finger lake region of New York, 

\m. Jour. Sei., IIT, vol. xirv, pp. 290-801, Oct., 1892. 


ce 
me 
Or 


Accumulation of Drumlins.— Upham. 


Near Clyde and Lyons a considerable proportion of them are pro- 
longed in ridges which rise with steep sides to sharply narrow 
crests, having lengths of two, three, or Several miles from north 
to south in parallelism with the glaciation of the region. With 
these are many other drumlins having the typical lenticular con- 
tour, from which all gradations are seen to the prolonged sharp 
ridges. Another area of drumlins, occurring in less profusion 
and presenting only the lenticular form, lies between Adams and 
Carthage, in Jefferson county, between the east end of lake On- 
tario and the Adirondacks. * 

In the drift-covered northern part of New Jersey drumlins are 
probably infrequent, only two examples being mentioned by Prof. 
R. D. Salisbury in his recent preliminary paper on the Pleisto- 
cene formations of that state. + 

No drumlins have been found in Ohio, Indiana, and Illinois, 
by Mr. Frank Leverett, Prof. G. F. Wright, and others, who have 
thoroughly examined that area, mapping its terminal moraines 
and other drift deposits. 

Next northwestward, however, drumlins are again encountered in 
great abundance and variety inthe east part of Wisconsin. Professor 
Chamberlin, describing these and other till accumulations and the 
known areas of drumlins, in his address as vice president of Section 
E of the American Association in 1886, wrote as follows: 


Somewhat allied to the true moraines are the special forms of ag- 
gregation of the subglacial débris, or—interpretation aside—of the 
great sheets of till. They present a richness of variety and of inter- 
gradation that almost defy classification. The list of forms embraces 
(a) till tumuli; (6) mammillary and lenticular hills; (¢) elongated 
parallel ridges trending with the ice movement; () drift billows akin 
to the above but without individual symmetry or discernible paraltlel- 
ism of axes or definite arrangement, giving a smoothly undulatory 
contour to the surface; (¢).crag and tail; (f) precrag and combings ; 
(y) veneered hills, and a great residual congeries of irregular emboss- 
ments and unclassifiable till hills. The most remarkable are the 
mammillary, lenticular, and elongated ridges, now frequently included 
under the term drumlins, which have become subjects of special in- 
quiry. These have a fine development in southern New Hanipshire, 
central and eastern Massachusetts, northeastern Connecticut and 
Nova Scotia, in all of which the elliptical or lenticular varieties pre- 
rail. They have a still more remarkable development in central New 


*Bulletin, Geol. Soe. of America, vol. 111, 1892, p. 142. 
tGeol. Survey of N. J., Annual Report for 1891, p. 74. , 


546 The American Geologist. December, 1892 


York, where the elongated type predominates. They have an even 
more varied development in eastern Wisconsin, extending into the 
northern peninsula of Michigan, where all varieties, from till tumuli 
to the extremely elongated ridges, are abundantly developed, the 
number of individuals being probably not less than 5,000. About 
1,000 drumlins have been mapped in New Hampshire, about 1,200 in 
Wisconsin, and large numbers in Massachusetts and New York. The 
total number within areas already known probably aggregates 10,000. 
These are almost wholly confined to the area of later drift.* 

Throughout a large region farther northwest, comprising Minne- 
sota, northern and central Lowa, South and North Dakota, and 
southern Manitoba, Prof. N. H. Winchell’s and my own explora- 
tion and mapping of the drift and its terminal moraines have 
failed to discover any of the peculiarly moulded masses of till 
classed as drumlins. 

Beyond this region, drumlins have been reported only by Mr. 
J. B. Tyrrell in lake Winnipegosis, where they form groups. of 
lenticular and elongated low islands. t 

In Ireland, Scotland, and northern England, drumlins are very 
abundant or frequent on many tracts, as described by Kinahan, 
Close, James Geikie, and others. It seems probable that they 
will also be found to have a considerable development in northern 
Germany and northwestern Russia. On the north and west side 
of the Baltic Sea, however, in the region where the Kuropean ice- 
sheet was thickest, they are infrequent or altogether absent, ac- 
cording to Baron de Geer, who, in excursions with me a year ago 
to see the drumlins in the vicinity of Boston, stated that no sim- 
ilar hills of till have been observed by him in his extensive ex- 
amination of the drift formations of Seandinavia. 

Subglacial and Rapid Deposition shown by Structure.—The 
till forming the drumlins invariably exhibits the characteristic 
features of subglacial till or ground moraine, excepting its super- 
ficial portion which was englacial and superglacial when the ice- 
sheet melted away. Many boulders, which are commonly strown 
plentifully on the surface of the drumlins, appear to have fallen 
upon them from the receding ice-sheet, together with a stratum 


“Pro. As Ag Amey MOLL Soe MV. 204: 

tGeol. and Nat. Hist. Survey of Canada, Annual Report, new series, 
vol. rv, for 1888-89, p. 22 A. Bulletin, G. 8. A., vol. 1, 1890, p. 402. 

“Inequality of Distribution of the Englacial Drift,’ Bulletin, G. 
S. A., vol. m1, 1891, pp. 184-148. “Criteria of Englacial and Subglacial 
Drift,’ Am. GroLtocrsr, vol. vit, pp. 876-885, Dec., 1891. 


Accumulation of Drumlins.— Upham. B47 


of the till that varies from one foot to a few feet in depth near 
Boston, but is sometimes 10 to 15 feet thick on the tops and 
flanks of drumlins in New Hampshire. This upper part of the 
till is comparatively soft and easy to dig, while its main portion 
below is so compact that it must be picked and is far more expen- 
sive in excavating. The probable cause of the contrast in hard- 
ness was the pressure of the ice-sheet upon the lower till during 
its accumulation, while the upper till was contained in the ice and 
dropped loosely at its melting. Occasionally a thin layer of sand 
or gravel lies between the englacial and subglacial till, as on the 
top of the drumlin named Convent hill in Somerville, Mass., 
where the upper 3 feet of the till, forming the surface, are under- 
lain along an observed distance of several rods by a bed of sand 
from 1 to 3 feet thick. 

Subglacial till is further distinguished from that which was 
finally dropped from the departing ice by its smaller rock frag- 
ments, which are mostly less than two feet in diameter, and 
sometimes consist only of pebbles, cobbles, and small boulders 
not exceeding half this size, though often it also contains large 
boulders; by the glacially worn faces of many of these stones, 
which are frequently marked with striz; and by traces of a pe- 
culiarly bedded structure, in parallelism with the surface. The 
last feature is especially characteristic of the till in drumlins, 
excepting its upper few feet. Although boulders, gravel, sand 
and clay are thoroughly commingled, the deposit is imperfectly 
laminated and tends to separate and crumble into thin flakes. 
This is frequently noticeable in a fresh excavation, but is most 
distinctly seen after a few weeks of exposure. It shows that the 
ice in its passage added new material to the surface of the ground 
moraine, which generally lay undisturbed beneath. 

To a depth that commonly varies from 5 to 10 feet on low or 
moderately undulating tracts, butis often 15 to 20 feet or more on 
the drumlins, the color of the tillis yellowish gray or buff, while 
at greater depths it is a darker and bluish gray. This difference in 
color is due to progressive weathering, the influence of air and water 
upon the iron contained in the till having changed it in the upper 
part from protoxide combinations to the hydrous sesquioxide. On 
low tracts the weathering of the tillisoften limited to its compar- 
atively loose englacial portion, but it has generally extended be- 
yond into the subglacial till of the drumlins and lenticular slopes _ 


348 The American Geologist. December, 1892 


My observations of thesectionsof drumlins, before mentioned, 
forming Third and Fourth Cliffs in Scituate, Mass., and islands 
in Boston harbor, and the prevailing trends of the drumlins near 
Boston in parallelism with the latest deflected glacial currents, 
convince me that these hills were somewhat rapidly heaped up. 
beneath the retreating ice-sheet within a few miles back from its 
margin. Peculiar dark bands, evidently representing successive 
stages of deposition, were noted in the till of the northern part 
of Third Cliff. ‘Their number is seven or eight, each six to twelve 
inches thick, varying from one to three or four feet apart, continu- 
ing separate along an extent of about 200 feet, with no branching 
or inosculation. The portion of the till thus banded has a verti- 
eal width of 15 to 20 feet and a dip of about five degrees north- 
ward, being included between 20 and 45 feet above the sea. It 
is more inclined than the overlying surface of the drumlin, which 
is there about 60 to 55 feet above the sea, or than even the steep- 
est slope of the surface farther down. No stratified layers or 
seams of modified drift occur in the banded part of the till, which 
is nearly like the remainder of the extensive deposit of till in 
this section, excepting that it has somewhat more sandy and 
porous layers alternating with somewhat more clayey and there- 
fore impervious layers, the latter being noticeable because they 
retain the moisture more persistently and have a slightly darker 
color. But no definite line of demarcation separates these layers, 
there being instead a gradual change which occupies a thickness 
of several inches. Boulders and gravel are indiscriminately 
mingled through the whole mass, which is the ordinary boulder- 
clay or till; and these alternations inthe proportions of clay seem 
probably attributable to the slightly varying conditions of alter- 
nating summer and winter, affecting the rate of motion of the 
ice-sheet and its tendency to deposit its ground moraine on the 
surface of the drumlin. If this is the true explanation, the 
yearly addition of till to that part of the section averaged 2 or 
2! feet, and the accumulation of the entire drumlin of Third 
Cliff required probably not more than 25 or 30 years. 

Though such banded structure, approximately parallel with the 
surface, has not been found in the drumlins of New Hampshire 
and inland parts of Massachusetts, nor even of the vicinity of 
Boston, excepting within close proximity to the sea, it is yet fre- 
quently observable in the drumlins of the islands of Boston har- 


Accumulation of Drumlins.— Upham. b49 


bor. For example, it is finely developed in the cliff forming the 
northeast end of Peddock’s island, where five or six such bands 
are separated by intervals that vary from three to six feet; at the 
southwest end of Long island, where a single dark band about 
half way up the cliff, or 30 to 40 feet above the sea, extends 
fully 400 feet; and at the south end of Spectacle island, where 
two dark bands six or eight feet apart are distinctly seen along a 
distance of at least 150 feet at a similar elevation above the sea 
and below the top of the cliff as on Long island. In all these 
sections, as in Third Cliff, the dark bands have anticlinal dips, 
which are somewhat more inclined than the overlying arched 
surface. 

Very rapid accumulation of ground moraine is shown by Fourth 
Oliff, for that drumlin, soon after the beginning of its formation, 
received a wedge-shaped deposit of true subglacial till, increasing 
from nothing to six feet in thickness along its exposed extent of 
about 100 feet, laid down on the southern slope during a smalt 
part of the time, probably only one summer, if so long, in which 
the central portion of this hill was being formed by the subglacial 
deposition of 10 to 20 or 25 feet of stratified sand and gravel, 
which in their continuation southward enclose the wedge of till. 
Under all this modified drift, the base of the section at its center 
is a low dome-shaped deposit of till, which, like the thick arch 
of till forming the upper and outer part of the drumlin, is 
divided from the modified drift by a well defined line with which 
the obscure lamination of the till and the bedding of the sand 
and gravel are parallel. No evidence of erosion, nor of tumul- 
tuous pushing forward, was anywhere seen; but instead the whole 
section appears to represent continuous deposition. The very 
hard and compact condition of the till, and its characteristic 
flakiness, which | have spoken of as lamination, both below and 
above the modified drift and in the enclosed wedge, indicate that 
it was deposited as a ground moraine beneath the pressure of the 
ice-sheet, instead of as englacial till falling loosely from the ice 
when it melted. The conditions leading to the accumulation of 
the basal till were followed by such as caused the modified drift to 
be spread over it, the latter apparently requiring no longer time 
than a single summer or the portion of the year attended by 
abundant ice-melting; but on the southern slope the deposition of 
this sand and gravel was for a short time interrupted while the 


»y~ 


oo) The American Geologist. December, 1892 


wedge of till was being amassed. Subsequently the accumula- 
tion of till began again over all the dome of sand and gravel, and 
continued thenceforward until the formation of the hill was com- 
pleted and the overlying ice disappeared, 

In addition to the evidence in the structural features of the 
drumlins, indicating that they were accumulated rapidly during 
the closing stage of the Glacial period, a strong argument toward 
the same conclusion is afforded by the prevailing east-southeast 
trend of the longer axes of these hills about Boston, while the 
striation on the bed-rocks is mostly south-southeast, the difference 
between the two courses being forty-five degrees. Recent exam- 
ination of the glacial striz in the city of Somerville, however, 
lying next northwest of Boston, shows that, besides their com- 
mon south-southeast courses, they are in many localities deflected 
to the east-southeast and even sometimes to due east. Elsewhere 
in all the districts characterized by abundant drumlins in this 
country and the British Isles, their longer axes and the striz are 
parallel; and it seems sure that both were determined by the cur- 
rents of the ice-sheet. Their difference in direction in the neigh- 
borhood of Boston I believe to be due to a deflection of the mo- 
tion of the ice there during its final melting. Through the time 
of its maximum thickness and extent the ice-sheet moved south- 
southeastward across this area, and reached to the terminal mo 
raine of Long Island, Block Island, Martha’s Vineyard, and Nan- 
tucket; and onward the course of its border was probably east- 
northeast along the submarine plateaus of the Fishing Banks. 
But when a mild climate began to cause the glacial boundary to 
recede northward, the melting probably advanced faster upon the 
area of the gulf of Maine than upon southern New England, so 
that the ice-front became indented by a deep embayment east of 
Massachusetts, toward which the latest currents along the coast 
were deflected. The formation of the drumlins about Boston 
seems to have taken place wholly during the time of deflected 
glacial movements, the ground moraine being massed in these 
hills on account of inequalities in the force and direction of the 
overriding ice-sheet, when its receding border was probably only 
a few miles distant. Farther inland throughout Massachusetts, 
Mr. Barton finds the trends of the drumlins prevailingly parallel 
with the striation, but with occasional exceptions where the longer 
axes of drumlins vary much from this course, probably because 


Accumulation of Drumlins.— Upham. 351 


of small indentations in the glacial boundary and consequent 
divergence of the latest ice-motion from its previous direction. 

If the dark bands noted in the till of Third Cliff, Peddock’s 
island, and elsewhere, are marks of accumulation in successive 
years, which seems highly probable, the drumlins of Boston and 
vicinity received, at least in some instances, from one to six feet 
of till yearly deposited over their whole surface, so that the ac- 
cumulation of these hills to their hights of 50 to 150 or 200 feet 
required only from two or three decades to a century of years. 
Indeed, where they exhibit no such banding, I have thought that 
sometimes their eutire formation may have been more rapid, so 
that the most massive drumlins, like the largest esker ridges, were 
probably deposited in so short a time that their beginning, growth, 
and completion would occupy considerably less than a man’s life- 
time. The drumlins appear to have been heaped up beneath the 
ice-sheet within a few miles back from its margin, or perhaps oc- 
casionally withineven less than one mile, as seems to be suggested 
by Mr. Barton's observations. Wheretheyare scattered over any 
extensive area, probably they were not all in progress of deposi- 
tion contemporaneously, but were successively accumulated as the 
ice-margin retreated. 

Questions CONRECCIIULIG the Action of the Ice-sheet.—While some 
steps of progress seem to be gained by the foregoing observations 
and discussion, here abridged from my latest paper on this sub- 
ject three years ago, toward a knowledge of the manner and time 
of deposition of the drumlins, the questions as to how the ice- 
sheet could amass these hills, and why they are distributed in 
abundance upon some districts, but are absent or represented only 
by a few examples upon other large areas, remain to be answered. 
Their distribution, however, is to so large a degree independent 
of topographic features, and of the character of underlying rocks, 
that the explanation of their origin and grouping appears more 
likely to be found in variable conditions of the glacial movements 
resulting from secular climatic changes during the final melting 
of the ice. 


PROBABLE ACCUMULATION OF THE DRUMLINS FROM ENGLACIAL 
DRIFT. 


Objections to former Theories, 


Several theories of the way in 
which the ice-sheet produced the drumlins have been suggested. 


’ 


B02 The American Geologist. December, 1892 


The earliest was by Shaler in 1870, who supposed these hills in 
the vicinity of Boston to be remnants spared from the fluviatile 
and tidal erosion of a once continuous sheet of drift, which had 
been contained in aglacier that descended the Charles river valley. 
His later view is similar, but attributes the very thick drift sheet 
of this hypothesis to deposition during the earlier of two epochs 
of glaciation, and its erosion partly to sea and river action during 
an interglacial epoch, but mainly, for the peculiar sculpture of 
the drumlins, to excavation and removal of the drift from all the 
intervening areas by the later glaciation. To, accord with’ this 
view, however, the terminal moraines of the later ice-sheet must 
vastly exceed their very moderate observed volume. Another 
objection, pointed out by Salisbury, is that the drumlins appear 
to be composed wholly of the newer drift. 

Hitchcock and Wright have thought the drumlins to be perhaps 
the material of terminal moraines swept over and massed in these 
peculiar forms by subsequent farther advances of the ice-sheet. 
If this view were true, the till of the drumlins could not have its 
nearly uniform character, but would contain here and there re- 
markable aggregations of boulders, and frequent irregular en- 
closures of sand and gravel would be found, representing the 
kame deposits and lenticular beds of modified drift which so 
commonly make up considerable parts of the terminal moraines. 
Salisbury remarks that neither the distribution nor the composi- 
tion of the drumlins seems to favor this hypothesis, and he there- 
fore believes that they were built up beneath the ice, not being 
fashioned from hills overridden by it. 

Mr. Clarence King and Prof. J. D. Dana have conjectured that 
the drumlins, at least in some cases, were made by superglacial 
streams, charged with drift, pouring through crevasses or a moulin 
to the land surface, there depositing their drift, which afterward 
by the onflow of the ice would be subjected to its pressure and 
sculpturing. This explanation lies under similar objections with 
the last. 

Kinahan and Close in Ireland, Prof. James Geikie in Scotland, 
and Davis and Salisbury in this country, look on the drumlins as 
analogous to the sand bars of streams. Professor Davis writes: 


In view of the irregularity of the surface on which the ice-sheet 
moved, and of the greater weakness of some rocks than others, we 
must suppose an irregular velocity in the motion of the ice and an 


Accumulation of Drumlins.— Upham. 353 


unequal distribution of the rubbish beneath it. If the faster motion 
at one place causes an excess of erosion there, the slower motion at 
another place may bring about an excess of deposition. This differ- 
ence of action is known to prevail between the central and marginal 
parts of glaciated areas; and the local accumulation of drumlins in 
an intermediate region gives a smaller example of these two parts 
played by the ice. If the causes of the irregular motion of the ice 
lie in the general form of the country, the location of faster and 
slower currents will be relatively permanent; the districts of faster 
currents would be found where the greatest volume of ice is allowed 
to pass, and some of the points of retardation may be the seats of 
long continued drumlin growth.* 


For accordance with this theory, the areas bearing drumlins 
should be determined chiefly by the topography and rock forma- 
tions, which, however, seem to have exerted little influence. The 
rapid accumulation of the drumlins appears also inconsistent 
with the belief that they were mostly supphed from drift immedi- 
ately before eroded from the land surface and transported by sub- 
glacial dragging to its place in these drift hills. 

The origin of the drumlins may be better understood, or at 
least to the writer it seems more intelligible, if we inquire how 
the drift which had been englacial until the time of departure of 
the ice would be deposited. 

Transportation of Drift into the lower part of the Ice-sheet,— 
It is evident that the ice-sheet in its passage over a mountainous 
or hilly country must gather much drift into its lower part, to as 
great hight as the altitude of the mountains and hills, by grind- 
ing off and plucking away detritus and blocks of rock from these 
elevations, thence carrying them forward enclosed within the ice 
many hundreds of feet, and in the lee of the White, Green, and 
Adirondack mountains even thousands of feet, above the ground. 
But it has seemed to some geologists difficult to account for the 
transportation of much drift into the ice from moderately undu- 
lating or plain districts, such as make the greater part of the 
drift-bearing areas of our continent and of Europe. On these 
nearly flat lands, however, I find at localities in Minnesota and 
Manitoba good proofs, as they seem to me, that the thickness of 
the englacial drift was sometimes as much as forty feet near the 
ice- border where it was amassing prominent terminal moraines, 
and on lines or belts where confluent ice-currents met from broad 


*Am. Jour. Sci., III, vol. xxvii, p. 415. 


WY 


j4 The American Geologist. December, 1892 
’ 


regions on each side.* Similarly in England, according to the 
observations of Mr. G. W. Lamplugh, a confluent ice-sheet flow- 
ing from Seandinavia and Scotland was pushed up on the York- 
shire coast, bringing much englacial drift, with marine shells, 
which it had eroded and gathered up from the shallow and almost 
level basin occupied before the Ice age and again afterward by 
the North sea. + 

The manner in which the ice gathered drift into its basal por- 
tion from any plain tract seems to me explainable by a consid- 
eration of the currents of outflow toward its border. In the cen- 
tral area of the ice-sheet the currents of its upper and lower por- 
tions probably moved outward with nearly equal rates, the upper 
movement being slightly faster than at the base. Upon a belt 
extending many miles back from the margin, however, where the 
slope of the ice-surface had more descent, the upper currents of 
the ice, unsupported on the outer side, would move much faster 
than its lower currents which were impeded by friction on the 
land. There would be accordingly within this belt a strong 
tendency of the ice to flow outward with somewhat curved cur- 
rents, tending first to carry the onwardly moving drift gradually 
upward into the ice-sheet, and later to bear it downward and de- 
posit it partly beneath the edge of the ice and partly along the 
ice boundary. 

Ablation causing Englacial Drift to become Superglactal,— 
Whenever the warm climate terminating the Glacial period ex- 
tended unchecked through many years, the depth of the ablation 
or superficial melting of the outer part of the ice-sheet was 
probably not less than 15 to 25 feet each summer, as has been ob- 
served on the Muir glacier in Alaskat and on the Mer de Glace in 
Switzerland.% At such rates of melting any district enveloped 
by ice 2,000 to 4,000 feet thick, as was true of the central por- 
tions of New England and doubtless also of a broad belt thence 
west to the Laurentian lakes and to Minnesota and southern 


*Geol. and Nat. Hist. Survey of Minnesota, Ninth Annual Report, 
for 1880, pp. 322-326; Final Report, vol. 1, 1884, pp. 608, 604. Geol. and 
Nat. Hist. Survey of Canada, Annual Report, new series, vol. tv, for 
L888-89, pp. 38-40 E. 

+Quart. Jour. Geol. Society, London, vol. xtivit, 1891, pp. 384-431, 
With maps and sections. 

tH. F. Reid, in National Geographic Magazine, vol. tv, pp. 31, 38. 
March, 1892. 

§Prestwich’s Geology, vol. 1, p. 176. 


Accumulation of Drumlins.— Upham. 300 


Manitoba, would be uncovered in one or two centuries, and the 
recession of the glacial boundary would average probably a half 
mile or more yearly. 

During any long series of years when the ice-sheet was being 
thus rapidly melted, its outer portion to a distance of probably 
twenty miles from its boundary, being reduced by ablation to a 
thickness ranging from 100 feet and less upward to 1,000 feet, 
would bear on its surface, especially in the valleys and hydro- 
graphic basins of its melting, much drift which had been before 
contained in the higher part of the ice. Only scanty englacial 
drift, mainly consisting of boulders borne away from hills and 
mountains, appears to have existed at altitudes exceeding 1,000 
or 1,500 feet; but all the lower ice probably contained an increas- 
ing proportion of detritus and boulders which had been brought 
into it from below by the upward movements due to faster flow of 
the central and upper glacial currents than of those retarded by 
friction on the ground. The thinned borderof the ice-sheet upon 
the belt having a remaining thickness of less than 1,000 feet 
would therefore become covered with drift, as Russell has de- 
scribed the borders of the Malaspina glacier or ice-sheet, which 
stretches from the Mt. St. Elias range to the ocean. * 

Stratum of Superglacial Drift wade again Buglacial by in- 
creased Snowfall and by Advance of the thicker portion of the LIce- 
sheet, —At many times the general recession of the ice-sheet was 
temporarily interrupted. The return of a prevailingly cold cli- 
mate for several decades of years, or occasionally, as we may 
suppose, for a century or more, brought increased snowfall, which 
sufficed to hold the ice boundary nearly stationary, perhaps fre- 
quently first having pushed it again a considerable distance for- 
ward. The thick ice lying far back from the border may then 
have flowed over its previously thin and drift-covered outer belt, 
aiding with the new snowfall to envelope the once superglacial 
drift stratum within the ice-sheet. These halts or re-advances, if 
the front of the ice had a nearly constant position during several 
years, became marked by terminal moraines, of which I have 
mapped a series of eleven in consecutive order from south to 
north in Minnesota, North Dakota, and Manitoba, while Mr. 


*National Geographic Magazine, vol. 111, 1891, pp. 53-208, with 19 
plates and maps. Am. Jour. Sei., IIT, vol. xii, pp. 169-182, with map, 
March, 1892. Am. GroLoaist, vol. vir, p. 384, Dec., 1891. 


356 The American Geologist. December, 1592 


Leverett has traced a still larger number through Illinois, Indi- 
ana, and Ohio, With the increased thickness and steeper gradient 
of the outer belt of the ice-sheet while the recession of its 
boundary was slackened, wholly stopped, or changed to a re-ad- 
vance, due mainly to very abundant snowfalls, much drift which 
had been formerly exposed on the ice surface would become again 
englacial, so that a stratum of drift several feet thick might be 
enclosed in the ice at an altitude increasing inward from less than 
D0 feet to 500 feet or more, 

Tee Currents massing the Englacial Stratum (nto Drintins. —The 
upper current of the thickened ice above the englacial bed of drift 
would move faster. than that drift, which in like manner would 
outstrip the lower current of the ice in contact with the ground, 
Close to the glacial boundary, whether it halted and even re-ad- 
vanced or merely its retreat was much slackened but did not en- 
tirely cease, which last seems probably to’ have been the case 
with the drumlin areas of Massachusetts and New Hampshire, 
the upper part of the ice must have descended over the lower 
part. This ditferential and shearing movement, as I think, 
gathered the stratum of englacial drift into the great lenticular 
masses or sometimes longer ridges of the drumlins, thinly under- 
lain by ice and overridden by the upper ice flowing downward to 
the boundary and bringing withit the formerly higher part of the 
drift stratum to be added to these growing drift accemulations, 
The courses of the glacial currents and their convergences to the 
places occupied by the drumlins were apparently not determined 
somuch by the topography of the underlying land as by the con- 
tour of the ice surface, which under its ablation had become 
sculptured into valleys, hills, ridges, and peaks, the isolation of 
the elevations by deep intervening hollows being doubtless most 
conspicuous near the ice-margin. 

In New England, on account of the absence or extreme rare- 
ness of any beds of modified drift which give evidence of having 
been covered by a re-advance of the ice, the till of the drumlins, 
according to this view, appears to have been collected in its pres- 
ent masses in the basal part of the ice-sheet, while a moderate 
thickness, probably seldom more than 50 or 100 feet, of ice lay 
beneath. Over the drumlins a somewhat greater thickness, per- 
haps varying from 200 to 500 or 1,000 feet, of ice formed largely 
from the snowfalls of recent years or the immediately preceding 


BOT 


Accumulation of Drumlins.— Upham. 


century or more, with probably much addition from the thick, 
inner part of the ice-sheet, containing, from whichever source, 
little or no drift, passed and moulded these hills in their smoothly 
oval, or round, or elongated forms. 

It is thus readily seen why the amount of finally englacial drift 
upon the surface of drumlins is usually less than on intervening 
tracts of low ground and on those parts of the drift-bearing area 
from which the ice-sheet was more rapidly melted away. 

We can also understand why these accumulations are so fre- 
quently found capping the top of low hills of the bed-rocks, 
since these projected through the ice that lay beneath the super- 
glacial, and afterward again englacial drift stratum, and so were 
obstacles to favor an aggregation of that drift, either as a com- 
plete drumlin resting on the hill of rock,or as a lenticular slope of 
till, of which abundant examples are found in New Hampshire, 
collected on the stoss or the: lee side of the rock hill and ocea- 
sionally in slopes of this form, covering both these most exposed 
and most sheltered sides of the hill thickly and its intervening 
flanks thinly, with visible outcrop of the rock only at its summit. 

Powderhorn hill, in Chelsea, Mass., one of the largest drum- 
lins near Boston, rising about 200 feet above its base, which is 
near the sea level, and having an exceptionally elongated form, 
with the length of three-quarters of a mile and one-fourth as 
great width, affords evidence that a slight thickness of ice re- 
mained beneath it when it was accumulated. Extensive excava- 
tions, 20 to 40 feet deep, in each end of this drumlin consist 
wholly of till, with no trace of any bed or seam of stratified drift. 
In one of these sections, about 30 feet high, on the north side of 
its southeastern end, I observed a nearly vertical, irregular course 
of fracture, from one to six inches wide, filled with sand and fine 
gravel brought by percolating water, where this long hill had suf- 
fered a slight dislocation in sinking as the underlying ice melted. 
Such fractures, extending deeply into the hill, were also found in 
the construction of the reservoir on its top, which gave much 
trouble by leaking, until the bottom was made impervious with 
cement. The till where not so fractured is water-tight, and 
numerous reservoirs on other drumlins near Boston have been 
free from this difficulty. The narrowness of Powderhorn hill, in 
proportion to its length, probably caused it to sink more unequally 
than most of the drumlins in this district. 


358 The American Geologist. December, 1892 


On some other areas, and perhaps more commonly, drumlins 
may have been formed from the englacial stratum of drift during 
a time of re-advance of the ice-sheet, carrying the drift forward 
so that it would be accumulated on a land surface. This appears 
to have been the case in central New York, where Prof. W. M. 
Davis finds that the sections of drumlins frequently show strati- 
fied gravel and sand underlying the till, and that often the rela- 
tionship of these formations is suchas to prove that the stratified 
beds were somewhat eroded before the deposition of the till, But 
the absence of such sections in Massachusetts and generally in 
New England makes it probable, as stated, that here the recession 
of the ice was continued, though with a much diminished rate, 
while the drumlins were being amassed. 


Review of Objections to this Kaeplanation,—At first sight, this 
explanation of the accumulation of the drumlins appears to be 
opposed by two conspicuous objections, which must be answered. 
The first is the local derivation of much of their material. Where 
the peculiarities and restricted limits of the adjacent rock forma- 
tions on the north permit an approximate determination of the 
distances of transportation of the drift forming the drumlins, it is 
found that a large part, sometimes more than half, has been car- 
ried only a few miles. It seems surprising that local material 
should constitute so important an element of the drift contained 
within the ice at considerable hights, until we consider how fast 
it would be uplifted by even a very slight upward inclination of the 
basal current of the ice. If the drift eroded from any place was 
carried up with an average ascent of only one degree, it would 
rise, within one mile, to an altitude of 92 feet above the ground, 
and within two to three miles would be as high as the tops of the 
most prominent drumlins. Currents ascending at this rate, or 
even two or three degrees or more, may very probably have ex- 
isted in the lowest part of the ice-sheet, on account of the accel- 
eration of its upper currents, within distances from 20 to 50 miles 
or more back from its boundary. By these currents much drift 
eroded from the land surface would be gradually incorporated in 
the comparatively sluggish lower part of the ice, reaching alti- 
tudes 100 to 1,000 feet above the ground within a few miles from 
its sources. 

When the boundary receded, the upper currents of the outer 
belt of the ice, upon a width of probably ten miles, would pour 


Accumulation of Drumlins.—Uphan. 300 


down toward the open land, causing the deposition of much sub- 
glacial till; and whenever a stratum of the englacial drift became 
covered with much new ice, it would probably be aggregated en- 
glacially or altogether subglacially in drumlins. The drift that 
had been eroded and lifted into the lower part of the ice during 
many centuries might thus be rapidly accumulated in the drumlins 
during only a very small fraction of the time that had been required 
for its being stored up in the ice. Through such processes I can 
better understand the origin of these prominent drift hills, than 
by any method that I am able to imagine for nearly contempora- 
neous erosion, subglacial transportation, and deposition of their 
till. Moreover, I find great difficulty in forming a conception of 
convergent basal currents powerful enough, in spite of their fric- 
tion on the land, to amass these hills; but the inequalities of con- 
tour of the outer belt of the ice, as irregularly thinned by ablation, 
may well have produced upper and central currents of sufficient 
energy to sweep the englacial drift stratum into irregularly 
grouped and scattered or even solitary drumlins, when new ice 
and snowfields added a considerable depth over all the previous 
drift-covered surface of the ice sheet. 

The second objection alluded to arises from the abundance or 
frequency of glaciated stones and boulders in the till of the drum- 
lins and from its compactness, flaky lamination, and other features 
which prove it to be subglacial till or ground moraine. If this 
drift was englacial during a considerable time and became massed in 
these hills beneath only a few hundreds of feet of ice, could it pre- 
sent so impressive characteristics of subglacial accumulation under 
heavy pressure? ‘To this question we must reply that the stratum 
of englacial drift would be subjected to much wear of its bould- 
ers and smaller rock fragments as they were carried forward with 
shearing and sliding motion to the drumlin accumulations, and 
that in becoming lodged on the surface of the drumlins or on 
other and low deposits of subglacial till, they would be further 
striated and planed. The previously englacial drift in being so 
transported and deposited would acquire all the marks of ice- 
wear which the till of the drumlins exhibits, and the pressure of 
500 to 1,000 feet, more or less, of solid ice flowing downward 
across it would seem adequate to produce its very hard and com- 
pact condition. We are thus able, as [ believe, to account for all 
the differences between these deposits and the mostly unworn 


360 The American Geologist. December, 1892: 


drift which fell loosely on the surface from an englacial or super- 
glacial position when the ice disappeared, 


COMPARISON WITH TERMINAL MORAINES, KAMES, AND ESKERS. 

My study of the glacial lake Agassiz, under the direction of 
Prof. T. C. Chamberlin, for the United States Geological Survey 
and partly for that of Canada, shows that several large terminal 
moraines, marking pauses or re-advances interrupting the general 
glacial recession, were accumulated contemporaneously with the 
existence of that lake, while yet the whole duration of Lake Ag- 
assiz was apparently only about a thousand years.* The rapidity 
of formation of the moraines was thus similar with that of the 
drumlins, and both seem to have been made possible only by the 
large amount of the englacial drift. The fast retreat of the ice 
indicates that probably its melting border then had usually a more 
steeply sloping surface than in its time of greatest extent to the 
south, and that consequently the rate of motion of the outer part 
of the ice-sheet was commonly increased during its final melting. 
Any pause of the retreat for even a few years would therefore 
form a moraine, though the outer belt of the ice may have been 
generally too steep to expose much superglacial drift. But dur- 
ing some stages of the recession we may conclude that consider- 
able tracts of the ice-border were so thinned by ablation that 
much englacial drift became superglacial, with the result that 
when again a colder climate brought a temporary thickening of 
this marginal ice the previously superglacial stratum of drift was 
chiefly amassed in drumlins. The known drumlin areas of New 
Brunswick and New England, New York, Wisconsin, and Mani- 
toba, would therefore be expected to belong to the same stages of 
the closing part of the Ice age. This would imply what seems 
from other reasons not improbable, that the outermost moraines 
in the states east of Ohio and on the east side of the driftless 
area in Wisconsin correspord to some of the inner and late mo- 
raines in the greater part of the region of the Laurentian lakes 
and the upper Mississippi, as perhaps the exceptionally massive 
Leaf hills, Itasca, and Mesabi moraines, which are the ninth, 
tenth, and eleventh of the series in Minnesota. 


*Geol. and Nat. Hist. Survey of Canada, Annual Report, new series, 
vol. rv, for 1888-89, pp. 50, 51 E. Am. Grornoatst, vol. vi, pp. 224-6,. 
April, 1891. 


Accumulation of Drumlins.— Upham. 


Again, my studies of the very massive kame .deposits forming 
the greater part of the outermost terminal moraine on Long 
Island eastward from Roslyn, of the large kame called the Devil's 
Heart, rising in a somewhat conical hill 175 feet above the adjoin- 
ing country south of Devil’s lake in North Dakota, and of the 
esker named Bird’s hill, seven miles northeast of Winnipeg, 
seem to me to demonstrate, beyond all doubt, that their material, 
and probably likewise that of kames and eskers generally, was 
supplied by superglacial streams from the plentiful englacial drift, 
and could not have been brought from drift beneath the ice by 
subglacial drainage. 


View OF THE Ick AGE AS ONE GLACIAL Epocu. 

In conclusion, I deem it a duty to state that this reference of 
the drumlins, terminal moraines, kames, and eskers, to rapid a ¢ 
cumulation from previously englacial drift during the departure 
of the ice, seems to me better accordant with the view that the 
Ice age comprised only one great epoch of glaciation, attended by 
oscillations of the ice-border, than withythe alternative view which 
supposes the ice-sheets to have been at least once and perhaps 
several times almost entirely melted away, afterward being re- 
stored by recurrent glacial epochs. This belief in the unity of 
our glaciation [I held during my work on the New Hampshire 
Geological Survey in the years 1874 to 1878; but in my ensuing 
work on the survey of Minnesota, the peat and forest beds en- 
closed between deposits of till in that region led me to accept the 
duality or plurality of glacial epochs as taught by Croll, James 
Geikie, N. H. Winchell, Chamberlin, Shaler, McGee, Salisbury, 
and at present by most American glacialists. The recent state- 
ment by Prof. G. F. Wright of the evidences for the unity of 
Quaternary glaciation as the more probable view,* expresses a 
similar opinion with that to which I have been gradually return- 
ing, during the past year or longer, through the guidance of my 
investigations in this field. Moraines and drumlins are effects of 
secular vicissitudes of climate on the border of the departing ice- 
sheet, which I think to have owed its existence to great altitude 
of the land at the beginning of the Glacial period, to have been 
attended when at its maximum extension and volume by depres- 


*“Unity of the Glacial Epoch,’ Am. Jour. Sci., III, vol, XLIV, Pp. 
351-373, Nov., 1892. 


362 The American Geologist. December, 1892 


sion of the land on which it lay, and to have witnessed, during 
the retreat and removal of its load, a progressive re-elevation of 
the same area to its present hight. 

For Europe, also, after reading the recent very ably written 
article by Prof. James Geikie,* in which he argues for five dis- 
tinct epochs for glaciation, I think that there, as here, it is more 
reasonable to refer the whole of the glacial drift toa single glacial 
epoch, with moderate fluctuations in the extent of the ice-sheets and 
glaciers. In thus differing from this eminent glacialist and from 
Wahnschaffe in Germany, Penck in Austria, and DeGeer in 
Sweden, who are of the same opinion with Geikie, that there were 
long mild interglacial epochs in Europe, | come into agreement, 
on this question, with other distinguished European  glacialists, 
as Lamplugh in England, Falsan in France, and Holst in Sweden, 
who hold that the Quaternary reign of ice was essentially a unit. 
3ut this present state of our division under the two opinions surely 
calls for much further observation and candid study that ulti- 
mately the truth may be confidently known, on whichever side 
it may be. 


THE GEOLOGIC STRUCTURE OF THE BLUE RIDGE 
IN MARYLAND AND VIRGINIA. 


By Arruur Kerru, of the U. 8. Geological Survey, Washington, D.C. 

In the following pages there will be discussed the belt of rocks 
in Virginia and Maryland, lying between the Shenandoah and 
Cumberland yalleys and the Piedmont plain. Attention will 
be given chiefly to their structural relations as they have been 
brought out by recent discoveries of fossils. The topographic 
features of the belt arein brief (1) the great limestone valley on the 
west, (2) the Jura-Trias plain on the east, and (3) between them 
the mountain belt which consists of the South Mt.-Blue Ridge 
ehain and Catoetin-Bull Run Mt. chain enclosing a broad level 
valley, The topography is the direct result of differential erosion 
among hard and soft rocks, and accordingly is a key to their areal 
distribution. The mountains are formed by sandstones and the 
intermediate valley by granites and schists. In passing north- 
ward through Maryland the granite areas rapidly lessen and dis- 
appear, and the valley contracts to insignificant dimensions. 


*“On the Glacial Suecession in EKurope,’ Trans., Royal Society of 
Edinburgh, Vol. xxxvi, pp. 127-149, with map, May. 1892. 


Keith. 363 


Geologie Structure of the Blue Ridge. 


South Mt. and Blue Ridge have been the subjects of numerous 
discussions in previous years, and publications concerning them 
have been made by Rogers Bros., Hunt, Fontaine, Leslie, Frazer 
and Geiger and Keith. All of these discussions have been based 
on physical evidence alone and have scarcely brought out the com- 
plexity of the chain, 

In 1891 Lower Cambrian fossils were found in the Blue Ridge 
at Balcony Falls, Va., by Walcott, and in August, 1892, he found 
Lower Cambrian fossils at Mt. Holly at the north end of South 
mountain and in the rocks of York valley, in Pennsylvania, In 
the latter end of August the writer accompanied Walcott through 
the mountain belt in Maryland and Pennsylvania with the purpose 
of finding fossils, and establishing the age of the entire chain. 
Search was directed especially to the sandstones and shales form- 
ing the mountain ranges and was abundantly rewarded. One layer 
in particular, the topmost one, yielded fossils in greatest abund- 
ance wherever tested. (The fossils will be described by Mr. Wal- 
cott in the American Journal of Science for December.) Subse- 
quently the structure of the mountain belt was worked by the 
writer in this new light, from the Pennsylvania line southward to 
Thoroughfare Gap in Bull Run mountain and Front Royal along 
the Blue Ridge. Lower Cambrian fossils were found as far south 
as Manassas Gap in the Blue Ridge. 

The rocks of the mountain belt fall into two classes, sediment- 
ary and igneous, each with several divisions. The igneous rocks 
will be fully described in Am. J. Science for December, by Prof. 
G. H. Williams, and only briefly touched upon here. 

Broadly considered, the region is a broad anticline and succes- 
sively younger rocks appear east and west from the nucleus of 
igneous rocks. This arch is crumpled into several synclines and. 
broken by faults that follow the mountain lines quite closely. 
The resultant structure is quite complicated, and there are very 
few places in which a normal and complete section can be found. 

Five types of sedimentary rock occur: (1) the Siluro-Cambrian 
limestone of the great valley, (2) fine calcareous white sandstone, 
(3) greenish gray sandy shales with thin sandstone beds, (4) mass- 
ive white sandstone in places conglomeratic with streaks and 
bands of black, (5) shale, usually black and slaty. As pointed 
out by Geiger and Keith, these types occur in distinct bands fol- 
lowing the lines of structure. The fine sandstone caps a line of 


S64 The American Geologist. December, 1892 


knobs in asynclinal axis next the valley limestone; the massive 
sandstone follows the syncline of the main ridge; and between the 
two sandstones lies a slope or valley of shales. Southward from 
the Potomac the two sandstone types become very much alike; 
northward they diverge and their differences are accented. 

On structural grounds alone the two sandstones should be equal 
to each other in age as they occupy parallel synelines and the 
same shale passes under both. 

On this hypothesis, the massive bed would represent shore accu- 
mulations and the fine sandstone the off-shore deposit. | Kven then 

the narrow limits of the change render it very abrupt. 

Organic evidence, however, does not bear this out. As has 
been stated, fossils were very numerous in the fine sandstone 
and a few were found in the sandy shales. In the massive sand- 
stone and the black slaty shale beneath it none were discovered. 
This difference in organic contents is as marked and persistent as 
the textural difference between the beds, and could hardly have 
been possible in synchronous deposits a mile or less apart. 

The age of the massive bed of sandstone must be determined by 
structure in default of fossils. Over the fossiliferous beds lay 
the valley limestone, as determined by the sequence at York, Pa., 
and at Balcony Falls, Va. If, then, the limestone lay directly 
over the massive sandstones, the two sandstones must be the same 
in age; if no limestone rested on the sandstone the latter would 
presumably be older than the sandy shale. In the latter case 
sandy shales might be expected to occur above the sandstone at 
some point. Search was made for such places and several were 
found, two of them being indubitable. One was immediately 
northwest of Monterey, Pa.,on the Blue Ridge, near the Maryland 
line; the other was on the Blue Ridge, six miles northeast of Front 
Royal, in Virginia. In each of these cases a syncline of the 
massive quartzite was overlain by sandy shales for a few miles. 
A similar sequence extends along the east side of Catoctin mount- 
ain for about ten miles and appears to be complete west of Fred- 
erick, There all the sandstones and shales of the mountain dip 
east under the Frederick limestone. The resemblance between 
this section and the York section is striking, and each contains 
the same varieties of massive and slaty limestones and limestone 
conglomerates. The York limestone is largely Cambrian and the 
resemblances of structure and composition indicate that the Fred- 


Geologic Structure of the Blue Ridge.—Weith. — 365 


erick limestone is also Cambrian. North and south from this sec- 
tion the limestone is soon covered by the Jura-Trias sandstones, 
and its contact with the sandstones is not of sufficient extent to be 
free from doubt. As a corroboration of the sequence made out 
in other places it is good but not sufficient for independent proof. 

With the discovery of the sandy shales overlying the massive 
sandstone the sequence was established as follows: 


(1.) Blue banded and mottled limestone, with thin beds of slaty 
limestone, sandy shale, sandy limestone, and limestone 
conglomerate, Cambrian fossils. 

(2.) Fine grained, white sandstone,with beds of shale. Lower 
Get OTDLOSSULS: “=, S Si stsiay sth enshelela al oe syaveiotela ele, sts cafa's-<s revel die'eis 250 feet 

(3.) Gray sandy shales, with beds of sandstone abundant near 
the middle. Scolithus and Lower Cambrian fossils. 1,200 to 1,500 ft 

(4.) Massive white sandstone, with bluish-black bands, felds- 
pathic and in places conglomeratic...... ..... ....1,000 to 1,200 ft 

(oomcravmeand black Slaty Shales 7.0.22 1. cceccecess voces 0 to 400 ft 

(6.) Igneous rocks, 


With the above sequence it is necessary to assume several faults 
to account for the present attitudes of the rocks. The fine sand- 
stone only once dips under the limestone, and then for only half 
a mile; the massive sandstone rarely passes under the sandy shale; 
and the igneous rocks occasionally pass over the massive sand- 
stone. Thrust-faults, therefore, exist between the limestone and 
sandstone belts and between the two sandstone belts, by which 
the anticlines have been broken and thrust up till only the syn- 
clines remain. The faults along these two Jines reach over the 
whole extent of the Blue Ridge and South mountain that has been 
studied, and locally the sandstone is faulted under the igneous 
rocks, 

East of Front Royal the two faults run together, the sandstones 
disappear and the igneous rocks are faulted against the valley 
limestone. The limestone-sandstone, or western, fault, is made 
manifest in many places by breccias of sandstone with calcareous 
matter, notably northeast of Front Royal. The eastern or second 
main fault is for the most part inferred from the sequence, occa- 
sionally from the areal distribution of the rocks, as at.Monterey 
and Front Royal. 

On Catoctin mountain the structure is much simpler. The ap- 
parent normal sequence at Frederick is broken to the north and 


366 The American Geologist. December, 1802 


the strata bent into a syncline, with a probable fault at the east 
side. Later a post-Triassic fault occupied this line and brought 
the Frederick limestone down against the bottom beds of massive 
quartzite and black slate. Southward the synclinal axis emerges 
from the Jura-Trias sandstone near the Potomac for a few miles 
and in the middle part of Bull Run mountain in Virginia, Klse- 
where the sandstones have a monoclinal dip. 

While the structure of the sedimentary rocks is the first object 
of these pages, several facts of structure in the igneous rocks are 
worth stating here. These rocks are of three kinds when classed 
according to their original constitution, ¢. ¢., diabase, granite, 
and quartz-porphyry. Inextent the diabase is the most important 
and the quartz-porphyry the least. Roughly speaking, the are: 
between the Blue Ridge line and Catoctin line is underlain by dia- 
base, partly replaced by granite at the south, and by quartz- 
porphyry at the north. The granite areas occupy a triangular 
tract with a base of thirty miles east of Front Royal and its apex 
west of Frederick. The quartz-porphyry occupies two areas in 
the district examined by the writer, the smaller lying east and 
northeast of Front Royal, the larger beginning north of the lati- 
tude of Frederick and six miles north of the granite apex. Near 
Front Royal it occurs as a narrow strip between the diabase that 
forms the summit of the Blue Ridge and the Cambrian sand- 
stones. In Maryland it lies in the form of a rude elongated cross. 
In Pennsylvania, according to Prof. Williams, the quartz-por- 
phyry is as widespread as the diabase. 

Upon this group the Cambrian sandstones and slates were de- 
posited unconformably. ~ In places the sandstone lies upon gran- 
ite, in other places upon diabase, in others upon quartz-porphyry. 
In many localities widely scattered along the Blue Ridge, the 
sandstones and slates contain fragments of the igneous rocks, 
showing that the sandstones are later deposits. 

The relations of the igneous rocks to each other are not always 
plain. So far as known to the writer, the granite and quartz- 
porphyry do not come into contact. Between the granite and dia- 
base the contacts are common. The granite occurs in the form 
of large masses and eruptive tongues in the diabase and abundant 
evidence of its eruptive nature can be found in its irregular 
boundaries, offshooting tongues, and included fragments of dia- 
base. The boundaries of granite and diabase are exceedingly 


Geologic Structure of the Blue Ridge.—fheith. 367 


complex, and areas of massive granite merge into areas of massive 
diabase through a multitude of interbedded tongues. These 
tongues vary in thickness from a few inches up to two or three 
miles and attain a length of six miles. 

The relation of quartz-porphyry to diabase is not clear at first 
sight in the region under discussion. It can be inferred from 
several phenomena, however, with considerable surety. At sey- 
eral localities in Maryland are occurrences of tufaceous beds in 
the quartz-porphyry that indicate surface production. These 
beds are near the edges of the quartz-porphyry and are presumably 
the upper beds. Also there are frequent occurrences of banding 
and wavy flow structure common to surface lavas. From these 
facts it is probable that the quartz-porphyry was a surface flow. 
That being the case, the relation of diabase to quartz-porphyry is 
a simple one and not complex like the granite eruption. As there 
are only one diabase bed and one quartz-porphyry bed that can be 
differentiated, the diabase either follows or precedes the quartz- 
porphyry. 

For want of bedding planes in the quartz-prophyry it is difficult 
to determine any structure. It may be assumed for the present 
that the surface of so large a flow was approximately level and 
that the tufaceous beds mark that surface. The present dips of 
that surface, therefore, represent later plication. Its general 
position is along low ground and drainage lines, suggesting anti- 
clinal erosion of an underlying bed. Wherever steep slopes make 
the dips plain, the quartz-porphyry is the underlying bed and the 
tufaceous beds marking the top are next to the diabase. Several 
outliers of quartz-porphyry are only exposed by deep stream cuts, 
and several outliers of diabase cap summits in the quartz-porphyry 
area, The south ends of the quartz-porphyry visibly pass under 
the diabase. From all of these points there would seem to be no 
doubt that the quartz-porphyry underlies the diabase. 

If this relation is accepted as true, it follows that the diabase 
itself was a surface flow. Internal evidence of this is wanting, 
for no tufaceous beds or flow structures have been observed in the 
diabase. Negatively, the diabase is the topmost volcanic bed 
and shows no eruptive contacts. It reaches continuously from 
Maryland ten or more miles into Pennsylvania and over half way 
through Virginia, with an average width of twenty miles. This 
extent is commensurate with the large lava flows of the present 


268 The American Geologist. December, 1892 


surface and is an extreme for an eruptive mass. Finally, the 
diabase lies on the surface of a surface flow, hence it must be a 
surface flow itself. 

Compression has produced little change in the quartz-porphyry 
except the distortion of folding. Along two faults at the east 
base of South mountain and east of Froat Royal, the quartz- 
porphyry has been dragged out into a lustrous mica slate of very 
fine texture. In some places there has also been produced a small 
amount of schistosity. As a rule it has suffered no change when 
compared with the diabase, a difference to be attributed to its 
simpler chemical composition (nearly pure silica) and to its greater 
mechanical strength. 

The diabase has uniformly received a strong schistosity and 
rearrangement of minerals. Muscovite, biotite, chlorite, epidote, 
and quartz have been developed everywhere; and locally amygdu- 
loids occur with jasper, quartz and epidote. The epidote and 
quartz occur both in disseminated grains and in lenses attaining a 
thickness of four feet. Cases of unaltered diabase are very rare, 
but occasionally occur. 

In addition to these igneous rocks, a considerable number of 
small dikes belonging to the Jura-Trias system were seen. These 
occur throughout the mountain region, but are most frequent in 
the granite tract. 

To sum up, the sequence of the rocks in the mountain region is 
as follows: 


SILURO-CAMBRIAN......!....0...-.. Lamestone. 
CAMBRIAN LA eee etre: Sandstone. 
Saal RMR Aes che ts ties See Shale. 
RR Aer cs mith Aen Sandstone. 
See referee Baia ne Slate. 
Sy ae Mencyenoxe ene eu eeNs Granite. 
Evayek a tarne ciate nike a oe Diabase. 
Jeboso dodo odebac Quartz-porphyry. 


Their physical history is, in brief: 


Surface flow of quartz-porphyry followed after short interval 
by surface flow of diabase. Injection of granite into the 
diabase, presumably passing through the quartz-porphyry. 
Dynamic action and production of schistosity in diabase... Erosion. 
Submergence and deposition of Paleozoic strata. Dynamic 
action with folding, cleavage, and elevation................ Erosion. 
Submergence and Jura-Trias deposition. 


369 


ON THE CLASSIFICATION OF THE DYAS, TRIAS 
AND JURA IN NORTH-WEST TEXAS. 


By JuLEs Marcov, Cambridge, Mass. 


In the Second and Third Annual Reports of the Geological Sur- 
vey of Texas, Austin, 1891-1892, Mr. W. F. Cummins has given 
the following classification and nomenclature for the strata in 
north-west Texas. He begins with the Carboniferous or Coal 
Measures, divided into six great formations, which he calls: 
Bend, Millsap, Strawn, Canyon, Cisco and Albany divisions. [I 
shall make no remarks on the Bend, Millsap and Strawn divi- 
sions. 

The Canyon division, so-called on account of its development 
at Canyon, in the western part of Palo Pinto county, contains a 
fauna entirely Carboniferous. It is a well defined formation, and 
sasy to recognize in central and northern Texas. 

The Cisco division is well exposed at the town of Cisco, on 
the Texas and Pacific railway. The stratigraphy, lithology and 
paleontology differ so much from what exist in the.Canyon di- 
vision, that it seems as a first great group of another stratigraphic 
system, or at least a passage formation between the true Carbon- 
iferous and the Dyas (Permian). In it are found a certain num- 
ber of Dyassic forms, such as: Allorisma, Avicula, Aviculopecten, 
Nucula, ete. A eareful paleontologic investigation, as well as 
good and minute stratigraphic observations are much wanted. 
For the present I am inclined to regard it as the base of the 
Dyassic system, and related to the group which exists on the south 
side of the mouth of the Platte river, at Plattsmouth City (Ne- 
braska). 

The Albany division, named for the reason that in the vicinity 
of Albany, in Stackelford county, the strata are well developed, 
correspond exactly to the Dyas of Nebraska City (Nebraska); hav- 
ing the same fauna, lithology and stratigraphic position, 

In the Second Annual Report, Geol. Surv. Terus, at p. 398, 
there ‘‘is a complete list of fossils of the Coal Measures,” in 
which the fossils belonging to the Cisco and Albany divisions are: 
confounded with the fossils of the Canyon and Strawn divisions. 
That list needs to be revised, not only for the exact stratigraphic 


44 
wy 


“I 


i) The American Geologist. December, 1892 


position of each fossil, but even also in regard to the determina- 
tion of the species. 

The Wichita division, well developed along the Big Wichita 
river, is composed of red sandstone and red clay. Quite a large 
number of vertebrate fossils have been found by Mr. Cummins, and 
deseribed by professor KE. D. Cope. Some fishes, such as: Cerat- 
odus, Ctenodus, Otenacanthus. ete... ‘are Mesozoic forms well 
known in the Kuropean Dyas and Trias. Reptiles and Bachtra- 
chians collected in Wichita division, recall also Mesozoic forms. 
Until now not a single locality or a minute stratigraphic position, 
of all those Texan fossil vertebrates has been revealed; professor 
Cope saying only Texas,and Mr. Cummins being as much discreet ; 
so other geologists cannot control the exactness of the age of the 
strata, and the true value of Messrs. Cummins and Cope’s dis- 
coveries in comparison with the well known localities and strati- 
graphic positions of the fossil vertebrates of Kurope. The list 
given by professor Cope in the Second Ann. Rep. Geol. Sure. 
Texas, pp. 416-419, is absolutely useless. If Cuvier, Agassiz 
and others had been so reticent and had kept secret the localities 
from which came the fossils they described and named, the science 
of Comparative Paleontology, and the classification of strata 
would not have received the great help derived from their works. 
The tendency of a few American vertebrate paleontologists 
not to divulge the localities from which they get their specimens, 
and to say only Texas! Wyoming! ete., is anything but cred- 
itable. ; 

Mr. Cummins has collected a Dyassic flora in the upper portion 
of the Wichita division, at the head of Godwin creek, Baylor 
county. Professor T. C. White has recognized in it, two Sphen- 
ophylluin, an Odontopteris, a Callipteris, four Callipteridinm, 
eight Pecopteris, a Goniopteris, and more specially a Walehia, 
so characteristic of the Dyassic flora in Kurope. 

It is certain that the Wichita division belongs to the Dyas (Per- 
mian), and forms the upper part of that system in Texas. 

The next division, ‘‘Clear Fork beds,” contains in its lower 
part, strata which ought to be united with the Wichita division, 
Such are the localities called: Camp and Godwin creeks and Mili- 
tary crossing in Archer and Baylor counties; in which Mr. Cum- 
mins has found a certain number of fossil invertebrates. The list 
published, in the Second Ann. Rep. Geol. Surv. Texas, p. 415, 


The Dias, Trias and Jura in Teras.—Mareou. 371 


shows Mesozoic Cephalopoda such as: Medd/icotia and Popano- 
ceras, mixed with Dyassic forms such as: Arieulopecten, Gervilia, 
Clydophorus, ete. Tt isa fauna related with the Russian fauna 
of the Artinsk beds, and may be considered as the American rep- 
resentative of a part of the Russian Dyas (Permian). 

Some of the vertebrates determined by professor Cope have 
been found, according to Mr. Cummins, in the strata of the lower 
part ot the Clear Fork division, about a little above the horizon 
of the fossiliferous limestone, with Med/cottia of the Military 
crossing (Baylor county). So it will be best and more logical to 
separate from the Clear Fork division, about 300 feet of its 
lowest strata, which will reduce its whole thickness of 1,975 feet, 
as given by Mr. Cummins, to about 1,600 feet. Then the Clear 
Fork division, so reduced, is a formation above the Dyas, and 
represents the Lower Trias or Bunter sandstone of Kurope. Where 
I saw it, just north of the Wichita mountains, all along our road, 
by the 355th parallel, after passing the Cross Timbers to Rock 
Mary and the natural mounds, I did not find fossils; but on lith- 
ological and stratigraphic ground, T have no doubt that all the 
strata there are Lower Trias. In my reconnaissance of 1853, it 
was impossible to do more than to follow the road, with a few 
zig-zags, right and left, because it was a heavy marching with a 
military escort, with strict orders not to go outside and never to 

lose view of the main column. 

The Double Mountain division is remarkable on account of its 
heavy and important dolomitic limestone, its very thick beds or 
lenticular masses of white gypsum and its salty clays and shales. 
Mr. Cummins says that he saw among the dolomites many casts 
of fossils, but he does not give a single determination even of 
family, genus or species, so we are entirely ignorant of their na- 
ture. I did not find any trace of fossils, when T crossed that for- 
mation, except near. Epsom spring, before reaching Antelope 
hills, where I found a large fossil tree, beautifully silicified and 
transformed in jasper, which when polished resembles somewhat 
the Pranstes feuroti’ of the Trias of the Val d Ajolin the Vosges. 
I have considered that gypsum group as representing the Middle 
Trias or Muschelkalk of Germany; and I continue to do so, for 
nothing in it recalls in any way the Dyas of England, France and 
Saxony; it is a younger formation. 

The Dockum beds or division of Mr. Cummins, was deseribed 


372 The American Geologist. December, 1892 


by me as far back as 1853, as Triassic; and more, as representing 
the Keuper and Variagated marls of Europe. The difference 
between Mr. Cummins’ thickness of those strata, and what 
I saw from Antelope hills to Rocky Dell creek and Pyramid 
mount (Tucumeari area), is difficult to be explained. My estima- 
tion is about 1,500 feet, when Mr. Cummins gives only from 125 
feet to 400 feet, with an average of about 200 feet only. — It is 
possible that Mr. Cummins has referred one thousand feet of the 
strata, between Antelope hills and Rocky Dell creek, as Dyas 
(Permian); and has kept for his Trias the strata from the lowest 
part of Rocky Dell creek to the white and yellow sandstone of the 
Pyramid Mount section, which according to my estimate of thick- 
ness is about 500 feet. 

Now comes the Tucumeari stratigraphy, so admirably developed 
round the Great and Little Tucumcari mountains, Monte Reyuelto 
and Pyramid mount. In regard to Monte Revuelto, Mr. Cum- 
mins says: *‘This mountain was by mistake called Big Tucum- 
cari on the maps published by Mr. Marcou. The Monte Revuelto 
and not Rivuelto as it is wrongly spelled by Mr. Cummins, term- 
inates the great mesa of the Llano Estacado, just due south of 
Fossil creek. It is the most prominent peak and the best land- 
mark of the area, and it is not easy to make a mistake with. It 
was pointed out tous bysome Mexicans traveling with our party, 
and by some Indians of the Pueblo of San Felipe whom we met 
there. The Big Tucumeari, called now only Tucumeari mount, 
is isolated by denudation and erosion in the great valley, called 
Plaza Larga by the Mexicans, north of the Llano Kstacado. On 


a 
SD 


Mr. Cummins’ map, he took the Big Tucumcari mount for Monte 
Revuelto; and what he calls Big Tucumeari is truly the Little 
Tucumeari. Asto his Little Tucumeari, itis a very small isolated 
hill, marked on my map, south of the true Little Tucumeari, but 
without any name. My geological map and the topographical 
map of lieutenant A. W. Whipple, of the Pacitic Railroad ex- 
plorations, by the 35th parallel, both surveyed and constructed 
in 1853, are the only exact maps ever published on the Tucumeari 
area, except asmall sketch map, marked No. 4, in lieutenant J. H. 
Simpson's report of 1849, Washington, which gives also the exact 
position, of the Little and Big Tucumeari. The map of Mr. Cum- 
mins, in the Third Ann. Rep. Geol. Surv. Texas, is at variance 
with the three first maps published, and according to right of pry- 


The Dias, Trias and Jura in Teeas.—Marcou, 373 


rity cannot be used for geographical names of the Tucumeari 
area. 

In the Marnes /sisées (variegated marls) of Plaza Larga no fossils 
have been found, either by Mr. Cummins or myself; but farther 
south-eastward, in continuity of the strata, Mr. Cummins has col- 
lected fragments of Stegocephali, Crocodilia, Clepsysdurus and 
Zatomus. Above the variegated marls, so easy to follow bed by 
bed at the Pyramid mount section, we find a series of about 200 
feet of white and yellow sandstone, blue clay, calcareous sand- 
stone and at the top a white limestone. The fossils begin to be 
found in the blue clay, about 30 feet thick. A bed, two inches 
thick,of Gryphwa dilatata vay, tucumcari’, packed close together, 
is found at half a foot from the base; and more of those Gryphwa 
tucumcarii can be collected higher up, in the whole group of blue 
clay, with an Ostrea of the Ostrea marshii form. Those two 
fossils are characteristic Jurassic species, and indicate that the 
age of the blue clay is Oxfordian. 

Mr. Cummins accepts the Gryphau dilatata var. tueumcarit as 
a good species distinct of the Gryphwa pitcher’ of the Texas Neo- 
comian; but it is his only concession. Ina special chapter, en- 
titled: ‘‘Notes on the geology of the country west of the Plains 
—Tucumeari, New Mexico,” pp. 201-210, inthe Third Ann. Rep. 
Geol. Surv. Texus, Mr. Cummins contests the exactness of my 
conclusion in regard to the Jurassic age, and he refers the Tu- 
cumeari beds to the Cretaceous, and in that system to the Wash- 
ita division; that is to say, to the upper part of the Lower Cre- 
taceous, above the Trinity division, and even above the Com- 
manche Peak and Fredericksburg division. 

Lithology.—My. Cummins has a long and useless dissertation 
on lithology, saying that I committed an error, to call ‘‘Caleare- 
ous sandstone or sandy limestone” the strata above the blue clay 
with Gryphaa tucumcari’, which he calls, also, like me, ‘+ Calea- 
reous sandstone.” It is exactly the same definition, and even the 
same name. In my wood-cut section of Pyramid Mount (see 
THE AMERICAN GEOLOGIST, Oct. 1889, p. 162), for brevity of the 
table of explanation of the letters used to designate each bed, I 
used only :‘ Yellow limestone,” but in the description of the strata 
T call them ‘‘ Yellowish siliceous limestone,” and in Vol. 111, Pa- 
cific Railroad Explorations, ‘*Caleareous sandstone.” So there 
is no ground whatever for a discussion. I have called the beds 


BT4 The American Geologist. December, 1892 


in 1853, ‘*Caleareous sandstone,” and Mr. Cummins calls the 
same beds in 1891, also, ++ Calcareous sandstone.” 

Paulwoutology.—** The following is a list of the fossils collected 
by me (Mr. Cummins) from the Tucumeari beds in the vieinity of 
Tucumeari and Pyramid mountains :” 

Gryphwa dilatata var. tucumeari, Marcou, 

Ostrea marshir, as determined by Marcou. 

Gryphwa pitchers Morton. 

Ewvogyra texana Rom. 

Ostrea quadriplicata Shamard. 

Trigonia emoryt Con, 

Cardium hillanum Son. 

Cytherea leonensis Con, 

Turritella servatin granulata Rom. 

Pruna sp. 

Ammonites, 

ecten, 

Everyone who is familiar with assimilation of strata and par- 
allelism of formations, always takes special care to give proofs of 
identity of fossils, by means of good figures and deseriptions of 
species. Here not a single fossil pretended to be identical with 
fossils of the Washita division, is either figured or described. 
Mr. Curamins contents himself in saying: ‘+I believe if Marcou 
had seen the fossils | have collected he would not have hesitated 
to place the Tucnmeari beds in the Cretaceous.” T shall 
ask simply, why Mr. Cummins did not send me_ his fossils to 
look at? 

The Ammonites, which are always among the most important 
fossils for determination of age of the strata, are not even hinted 
at: simply saying Aieimonites, 

Professor A. Hyatt made an extended and very minute explor- 
ation of the Tucumeari area in 1889, He collected numerous 


and important series of a quantity of fossils—at least sixty spe- 
cies—and he asked me to look over his collection with him. I 
did not see in it a single Cretaceous fossil; no Gryphwa pitcheri, 
no Leogyra terana, ete. Professor Hyatt is justly considered as 
the best specialist, on this side of the Atlantic, for fossil ceph- 
alopods; and he has already worked out for the Geological Sur- 
vey of Texas, the +‘ Carboniferous cephalopods” published in the 
Second Aun, Rep., and is now engaged on the Nautilidee of Texas, 


The Dias. Trias and Jura in Tevas.—Mareou. 375 


also for the Geological Survey. Why did not Mr. Cummins send 
his collection to professor Hyatt, at Cambridge, to compare what 
he got with the fine specimens of Mr. Hyatt? 

As it is,the list of fossils published by Mr. Cummins cannot be 
used, Ishall only say, that it is simply impossible to find together in 
the same bed the Gryphwa dilatata vay. tuewmears, with the Gryphaa 
pitchers and the Bxogyra terana,  Kither the fossils determined 
by Mr. Cummins are incorrectly referred to species entirely ditfer- 
ent, or by some accident Mr. Cummins’ specimens have been care- 
lessly packed up and the labels have become somewhat mixed or 
changed from one packet to another. 

Mr. Cummins insists with great force on his discovery in the 
top bed of the Tucumeari mountain, of a fragmentary leaf of a 
dicotyledonous plant called Sterculia drake, which he describes 
and figures at p.210. Until now.he says,no angiospermous leaves 
have been found in older strata than the Cretaceous, and ‘‘a single 
specimen in certain cases is sufficient to definitely determine the 
age to which the strata belong.” 

Fossil leaves of Angiosperms have been found, some time ago, 
round Fredericksburg, Virginia, in strata called the Potomac 
formation, which is regarded by some geologists as belonging to 
the lowest beds of the Wealden, and by some others as old as the 
Purbeck formation or upper Jura of England. A leaf resembling 
in the outline a leaf of sassafras has been found in the Potomac 
formation of Virginia, similar to the leaf found at the Tucumeari. 
So there is nothing very new in the discovery of a leaf of 
dicotyledonous plant in the Jurassic bed of the Tucumeari 
mountain. 

I have showed before (THE AMERICAN GEOLOGIST, Dec., 1889; 
«Jura, Neocomian and Chalk of Arkansas,” pp. 357-367 ) that 
the Trinity beds of Arkansas contain a fauna entirely Jurassic, 
and that they belong to the Jura system. It seems, according to 
the observations of Mr. Robert T. Hill, that the upper part of 
the Tucumeari strata, above the horizon of the Gryphau tucumear(, 
is related and of the same age as the Trinity beds. 

In résume, the supposed Cretaceous age of the Tucumeari strata 
is an error; not so great as the one of Messrs. James Hall, Shu- 
mard, Meek and Newberry, who synchronized them with the 
Dakota division of the upper Cretaceous, but is no less a grave 
one, for it displaces a whole system of rocks from its position just 


376 The American Geologist. December, 1892 


above the Trias and below the true Cretaceous Neocomian of 
Texas, and puts it far up, as the upper portion of the Lower Cre- 
taceous, or Washita division. 

Another grave error is the reduction of the Texan Trias to the 
upper 200 feet of that system, which has truly in Texas a thick- 
ness of no less than 5,000 feet; and to refer to the Dyas or Per- 
mian, not only the Lower and Middle Texan Trias, but even two- 
thirds of the Upper Trias, reducing the great Texan Trias to an 
insignificant system; and at the same time giving to the Texas 
Dyas an importance absolutely imaginary, and out of all propor- 
tion to its value and position in American stratigraphy. Besides 
Mr. Cummins has increased also the already very great formation 
of the Coal Measures or Carboniferous, im placing in it the Lower 
Dyas of Nebraska City and Plattemouth, Nebraska, which he calls 
Albany and Cisco divisions of the Coal Measures. 

As the Geological Survey of Texas has begun to publish geo- 
logical maps of great area, in the Third Annual Report, it is im- 
portant to signalize to its director the difference of opinions held 
by other observers than his own assistants in the survey, on ques- 
tions which involve great scientific responsibilities, not only for 
Texas, but also for American geology. 

Here is the detailed table showing the order of succession and 
classification of northwest Texas, the Indian Territory and New 
Mexico by Mr. Cummins, in comparison with the classification L 
have given as far back as 1853, and which has been repeated in 
detail in Tie AMERICAN GEOLOGIST, September, 1889, pp. 
156-157. 


Mr. Cummins’ classification in North-west Mr. Marcou’s Classification. 
Texas and New Mexico, 1890-1891. 1853. = 


(Gryphea  pitcheri lime- 

| stone of Comet creek, or 

‘pb i ~ tq ’ 

CRETACEOUS. Neocomian. Thickness, 
L. 5 feet. 


Break. Unconformity. 


TertTiARY.—No. 2. White clayey limestone. sete c - 
20 feet.—G. { Section of Pyramid mount, Tucum- 


( Washita division, numbered 3, 4, 5 and 6, | ect ae Berane en 

' ered with letters G, F, E, D, C 

| and B. The divisions G and F 
belong to the Upper Jura: E rep- 
resents the Oxfordian.—19%5 feet. 


and corresponding to F, E, D, and C, 


JURASSIC 
SYSTEM. 


pes Marcou’s section, at the Tucumcari 


CRETACEOUS. 


area.—3/5 feet. 


Areal Work of the U. S. Geological Survey. —Mc Gee. 377 


{ Concordance of stratification. 


. { Concordance of stratification. 
TRIASSIC. 400 


| 
feet. | 


1 Dockum divisio 2 | Variegated marls.——500 feet. _ ; 
| a 
Di 3 
2 | Sandstone, dolomite and red clay; 
as extending from Antelope hills to 
Double Mountain division. = | Rocky Dell creek.—1000 feet. 
4 =, {Red marls inclosing gypsum, salt, 
Thickness, 2075 feet. Za<) clay and dolomite, extending from 
CA) Natural Mounds to Antelope hills. 
Dest —1500 feet. 
sexe bcadap tea See OE SY ae a, AEE Fy eR AS oa ge Lacs ees eee 
Clear Fork division.—1875 feet. | y {Vermilion marls and clays, inter- 
Zz Nota bene.—At the base of the divis- | 3 3 3 stratified with beds of red marly 
s iou—about the first 300 feet—inverte- et sandstone, with green spots; ex- 
=-  brate fossils have been found at Mil- a QA tending from Cross Timbers to 
& itary crossing and Godwin creek 4 Rock Mary and Natural Mounds. 
a (Baylor Co.), and at Camp creek | D —2000 feet. 
(Archer Co.). A few vertebrates — ------------------:-----------------------2-2eseeeeseeeeeeeeeeee - 
have been found also scattered at 
about the same lower horizon. ( Nota bene.—This formation embraces 
wee ae : the lower portion of the Clear Fork 
Wichita division.—1800 feet. _ division—about 300 feet—and the 
3 Wichita, Albany and Cisco divisions 
Nota bene.—In the upper part, atthe § of Mr. Grannies: . 
head of Godwin creek, a Dyassic flora © 
with Walchia has been found, with + 
vertebrate fossils such as: reptiles, ”) Red and blue clay with conglomerate ; 
batrachians and fishes. = | extending from Topofki creek to 
Sn eh a ee Cross Timbers, west of old Fort Ar- 
g [Albany division.—1180 feet, With the 3 | buckle or Beaversville.—1000 feet. 
a Dyassic fauna of Nebraska City. A 
7% | Cisco division.—846 feet. ed el Sa a dt 
s Dyassic mixed with Carboniferous | Break. Unconformity. 
st) fossils. 
2 | Canyon division.—930 feet. crore ( Limestone of Delaware 
5 CAREONIFEROUS | Ridge, with a Carbonif- 
With a Carboniferous fauna. eas { erous fauna. 


THE AREAL WORK OF THE U. S. GEOLOGICAL 
SURVEY :* 
By W. J. McGee, Washington. 

When the U. 8. Geological Survey began its work some 13 
years ago, only a small portion of the public domain was mapped 
out, so that the first thing to be done was to prepare a topographi- 
cal map. It was not considered then nor is it considered now, 
necessary to prepare a detailed map; all that was and is desired 
isa map giving the main landmarks and the contour lines, sur- 
veyed and drawn with just sufficient accuracy for the scale of the 
map and no more. It was at first decided to use the scale of four 
miles to the inch throughout most of the domain and employ the 
scales of two miles and one mile to the inch in more important 
centers. However, the methods of survey have been so much im- 
proved since then, and the cost per mile so much reduced in con- 


ss 


* Abstract of a paper read before the American Institute of Min- 
ing Engineers, at the Reading Meeting. 


= 
os 


The American Geologist. December, 1892 


sequence, that it has. been found consistent with economy to 
abandon the four-mile-to-the-inch scale, and subsequently the 
two-mile-to-the-inch scale was abandoned also, This adoption 
of the one-mile-to-the-inch scale was also rendered necessary, as 
it became evident that the requirements of geologists would not 
be met satisfactorily by the smaller scales. The total area sur- 
veyed topographically to date is 557,000 square miles, distributed 
over 42 states and territories. Four states, viz., Connecticut, 
Massachusetts, New Jersey and Rhode Island, together with the 
District of Columbia, have been completed. Each sheet of the 
maps is about 1518 in. and the side of the one-mile-to-the-inch 
map represents 15 minutes of latitude. The sheets are engraved 
on copper and are printed from stone transfers. Each sheet is 
printed from three plates, giving respectively the hydrography in 
blue, the altitudes between contour lines in shades of brown, and 
the topography in black. Altogether 615 sheets are now printed 
in the different scales out of the 694 sheets surveyed for. No 
legal provision has yet been made for the public sale of these 
maps. 

No system has ever yet been uniformly adopted among civilized 
countries for representing the geological structure and character- 
istics in maps. Most geological authorities at present adopt some 
arbitrary system of coloring according to their own taste and 
fancy, so that the art of geological mapping may be said to be only 
in an experimental stage as yet The system adopted by the U. 8. 
Geological Survey is novel, and is thought to meet the require- 
ments of engineers, miners, ete., ina better way than any other 
method yet proposed or tried. The system provides for the separ- 
ation of rock formations into four classes, viz.: 1. Fossiliferous 
or fragmental; 2, volcanic; 3, granitoidal and schistoidal, and 4, 
superficial. These classes of rocks are represented by ground 
colors and pattern overprints in such a manner that the entire 
range of available colors may be used for each. The fragmental 
rocks are represented by the primary colors in orderly arrange- 
ment, each color indicating an age-group (Carboniferous, Silurian, 
etc.). These colors are used as uniform ground tints, and over- 
prints in line patterns represent the distinct formations of which 
the group is made up. The voleanic rocks are represented by 
angular figures either on a white ground or over a ground tint 
representing an age-group. The crystalline rocks are similarly 


Areal Work of the U.S. Geological Survey.— McGee. 379 


represented by hachures disposed either irregularly or in such a 
manner as to indicate structure. The superficial deposits are 
represented by round figures in such a manner that they may be 
mapped in their normal relation, overlying the older rocks, on 
the sheets showing the underlying formations. The general sys- 
tem provides for the representation of the geology on the topo- 
graphical maps. The atlas sheets are colored in manuscript by 
the geologists in the field and the geological symbols are after- 
ward engraved on zinc. In order to make these sheets available for 
all uses, provision has been made for printing each sheet in portfolio 
form, supplemented by as many different impressions of the same 
map as may be required. Thus the portfolio will usually include a 
topographic sheet without geological symbols; a geological sheet 
showing only the age-groups and formations; a structure sheet in 
which sections drawn to scale are printed on a sheet showing the 
groups and formation boundaries; sometimes a sheet of columnar 
sections showing the structure in greater detail; in some cases a 
sheet showing the superficial deposits only; and when the occasion 
requires,a sheet of mineral resources, showing the location of mines, 
quarries, coke ovens,smelters and furnaces as well as mineral areas. 

These geological surveys consume much time. Moreover, a 
variety of circumstances have combined to delay the completion 
of the surveys except in special districts, such as the Lake 
Superior iron region, the quicksilver and gold regions of Cali- 
fornia, the phosphate belt of Florida, the Eureka and Virginia 
City districts in Nevada, and some mining areas in Colorado. 

Final geological surveys of greater or less extent have been 
executed in 32 states and territories. These surveys cover an 
area of 117,000 square miles, and are in part represented on 100 
regular atlas sheets and a large number of special maps. 

The cost of the topographical surveys has varied with the scale 
and other conditions from less than $1 to over $5 per square 
mile. The average cost of the survey, including drawing, has 
been $5 per square mile on the one-mile-to-the-inch scale and the 
total cost since the first has been about $4 per square mile. The 
cost of the geological survey has varied between much wider limits. 
In fairly representative districts the cost has averaged $5 to $6 
per square mile, The average cost from the beginning has aver- 
aged $8 per square mile, but this cost includes preliminary ex- 
penditure on instruments, books, laboratories, ete. 


20/ loa} . i abe 
380 The American Geologist. December, 1892 


THE PRESENT BASAL LINE OF DELIMITATION OF 
THE CARBONIFEROUS IN NORTHEASTERN 
MISSOURI.* 


By Cuarues Rouuin Keyes, Des Moines. 

Although for many years past the Kinderhook beds have been 
regarded as the basal part of the Lower Carboniferous, or Missis- 
sippian series, in the upper Mississippi valley a decided Devonian 
facies of the contained fossils has always been observed. This 
particular faunal aspect has occasioned much comment and has 
attracted wide notice. ; 

So much were some of the earlier geologists impressed with this 
character of the organic remains that they hesitated but little in 
referring the beds in question to the upper Devonian (Chemung). 

The best exposures of Kinderhook rocks are found along the 
Mississippi river at Burlington, Lowa, Kinderhook, Ill., Hannibal 
and Louisiana, Missouri. At all of these places the lithological 
characters are practically the same, except perhaps towards the 
more northern limit of their exposed range,where the upper part 
is changed somewhat and the lower portion does not rise above 
the water level. 

At Louisiana the exposures are perhaps more open to obserya- 
tion than elsewhere; though for seventy miles along the river the 
outcrop is practically continuous. 

The vertical section at the place just mentioned is as follows: 


Teittise tial 
16. Brown and white, compact, encrinital limestone thinly 
loyevoKokevels vale. Soames (CMV icascoc ood Sosodpodoswc cocc 5 
15. White, encrinital limestone very heavily bedded 12 
14. Coarse-grained encrinital limestone, very heavily 
bedded yer yea) Viren ates tatters meena sk ns lcis eres 20 
13. Massive, white encrinital limestone, coarse-grained ; 
with abundant white chert nodules and nodular 
Poa Severe te ee Recast ee MRAM eS etch alot ee uote 11 
12. Brown encrinital limestone, compact and heavily 
bedded, somewhat earthly in places .. . 15 
11. Compact, fine-g1 rained buff limestone with few or no 
partings SPAR ST CARL Ga Ui bine Beta Ae Sf NO PLB Oh NA cd et opegea 15 
10. Sandy shales, brownish, forming soft friable sandstone 
loe ally Lor ales cubsurerane sey ary chetore Dai stovelten aecals sie yoy) relia vet eg nels ; 12 
9) Greenish clave yusiiall Sia arca vie bi seieeielyeraayelens velar ts 70 
8. Thinly bedded, compact limestone, fine-grained, with 
conchoidal fracture, in layers 4 to 6 ine hes in thick- 
ness, like lithographic stone in texture and appear- 
DICE 7s Mavslioal Met eoaperepaane ease re eee shave atic e yc armelatemel evel 50 


*Published by permission of Mr. Arthur Winslow, director of zthe 
Geological Survey of Missouri, from work prosecuted during the years 
1891-2. 


Basal Line of the Carboniferous —leyes. 381 


fo paucay clay Shale (2 to 4 amches) 2.0 256 cee nee nee es 3 
HaOrabonercemish Clayey shale. 0.2.2.2 6.06 cus eee eos 2 
Eee Ma Chem lissTG Clay Stall! y\cis.s 2 ceo cicjcis <0 vie, tices + sae eye 1 
4. Buff, magnesian limestone, very heavily bedded...... 10 
POOL ASG WLS OOMUG alec ulejas oto iciicje ele «deve aie cise oe 5 
2. Blue clay-shale, with thin bands of impure limestone — 60 
1. Heavily bedded JMESTOME “EXPOSE be cievsyscr sc 1-5/0. 0/00 5 


No. 1 is the Trenton limestone; 2 the Hudson River shales; 5 
and 4 probably represent the Niagara limestone; the first increas- 
ing rapidly in thickness southward, and ina distance of 20 miles 
reaches a vertical measurement of 30 to 40 feet. 5 and 6 are 
probably Devonian, equivalent to the ‘“‘black shale’ of adjoining 


is a thin seam 2 to 4 inches in thickness and 


— 


states. Number 7 
highly fossiliferous. With few exceptions the ‘‘lithographic’ 
fossils come from this layer. It probably belongs more properly 
with beds 5 to 6. Apparently the organic remains are nearly all 
identical with forms from the Hamilton rocks farther northward, 
Should the union of this thin highly fossiliferous seam to the 
underlying shales be more in harmony with the real relation of 
the faunas of the respective beds, as now seems likely, than with 
the faunas above, it would remove to a great extent the present 
Devonian facies from the lithographic (Louisiana) limestone, 
8 is the Louisiana limestone,a compact, rather thinly bedded rock, 
breaking with a conchoidal fracture. It is very poor in fossils. 
Numbers 9 and 10 are the Hannibal shales. 11, the Chouteau 
limestone, with a few fossils. Number 12 is the Burlington 
limestone, with the characteristic basal faunas of the Burlington. 
13 is also the lower Burlington, carrying considerable chert, and 
containing the most prolific fauna in the section. 14, 15 and 16 
belong to the Burlington limestone; the upper portion containing 
the typical fauna distinctive of the upper division. 

Owen, who was the first to give attention to the geological de- 
tails of the rocks as exposed along the ‘‘Father of Waters” above 
the mouth of the Missouri, limited the term ‘‘Subcarboniferous, ’’ 
which hitherto has long been applied to all the strata below the 
Coal Measures as far down as the Hudson River shales,to what is 
now known as the Lower Carboniferous, or Mississippian series. 
The Louisiana or ‘‘Lithographie limestone” was not included; for 
his ‘‘Argillaceous Marlites’ seem to have been regarded as the 
basal member. 


*U.S. Geol. Sur. Wisconsin, Iowa, and Minnesota, p. 92. ( 1852.) 


382 Th eC American Geolog ist. December, 1892 


Swallow*, Hall¥,and White}, who are all well acquainted with the 
sections and their fossils, correlated the beds immediately below 
the Burlington limestone with the Chemung (Devonian). In 
northeastern Missouri and adjoining portions of Lowa and Illinois, 
the “Chemung” includes the Chouteau limestone, Vermicular 
shales and Lithographic limestone. 

Hall having studied more particularly in Iowa, erroneously re- 
garded certain sandy shales, or yellow sandstones, just below the 
great limestone at Burlington, identical in age with a lithologi- 
cally similar rock 50 miles to the northward, at the mouth of 
the Pine creek, Muscatine county. The latter has recently been 
shown by Calving to belong to the Hamilton group as known in 
Iowa. Consequently Hall having investigated the northern local- 
ity more thoroughly, perhaps, very naturally came to the conclu- 
sion that the entire formation under consideration, as he under- 
stood it, was actually Devonian. But, as already shown, the 
rocks of the two places are widely separated in point of time. 

Meek and Worthen||, who had considered chiefly the fossils in 
the upper part of the so-called “‘Chemung,” both at Burlington, 
Towa, and at Kinderhook, Illinois, a few miles from Hannibal, 
Missouri, regarded the fauna more closely related to the Carbon- 
iferous than to the Devonian. Since the publication of these 
views writers upon the subject have accepted them and they have 
been adopted in the geological reports of Illinois, Missouri and 


Towa. 

By reference to the vertical section already given it will be seen 
that the commonly known Kinderhook of this region is a three- 
fold division, the upper and lower being limestones and the 
median one a clayey or sandy shale. At Burlington the fossils 
heretofore noted have been found only in the upper portion of the 
formation, though recently an extensive and interesting fauna 
has been discovered in the clayey portion much lower down. 
Here the lower calcareous member is not exposed. At Louisiana 
and the vicinity the median member is practically unfossiliferous ; 
as is also the lower, except at the very base. 


*Geol. Sur. Missouri, Ann. Rep., p. 101. (1855.) 

tGeol. Iowa, Vol. 1, p. 90. (1858.) 

+Proc. Boston Soc. Nat. Hist., Vol. virz, p. 289. (1862.) 
§AMERICAN GEOLOGIST, Vol. 11, p. 25. (1889.) 

\|Am. Jour. Sei., (2), Vol. xxx11, p. 167. (1866.) 


Basal Line of the Carboniferous. — heyes. 383 


It will be recalled that Marion and Pike counties, Missouri, at 
Hannibal, Louisiana and Clarkesville principally, were the leading 
localities for a large proportion of the ‘‘Kinderhook” fossils 
originally described by Shumard, Hall, White and Winchell. And it 
has been noted that most of these fossils have a very decided 
Devonian aspect; that they give a peculiar tone to the fauna 
of these beds. ; 

Heretofore little mention has been made concerning the exact 
horizon of the fossils in question, since reference to the ‘‘litho- 
graphic” limestone or ‘‘Kinderhook” beds has been considered 
sufficient. Lately, however, extensive collections of fossils have 
been made at all three of these places just mentioned as well as. 
many intervening and neighboring exposures. Kverywhere the 
‘lithographic,’ or Louisiana, limestone has been found to be 
practically devoid of organic remains except an occasional form 
in the thin sand partings above the bottom layer which is less 
than one foot in thickness. 

At the very base of the limestone is a thin seam of butf, sandy 
shale seldom over three or four inches in thickness (number 7 of 
section). 

This seam is highly fossiliferous. It contains the Productella 
pyxidata (Hall), Cyrtina acutirostris (Shumard), Chonetes ornata 
(Shumard), Sprifera hannibalensis (Shumard), anda host of other 
forms, many indistinguishable from species occurring in undoubted 
beds of western Hamilton. The sandy seam is underlaid by six 
feet of dark argillaceous shale which has been regarded as part of 
the Devonian ‘‘black shale” of the Mississippi basin. This in 
turn rests upon 15 feet or more of buff, magnesian limestone and 
oolite of Niagara age probably. 

Lithologically the thin sandy layer is more closely related to 
the underlying shales than to the overlying limestone. Faunally 
it has very much closer affinities with the western Hamilton (De- 
vonian) than with the Kinderhook (lower Carboniferous). 

In Iowa the ‘‘Devonian aspect” of the Kinderhook fossils has 
disappeared largely, since Calvin's recent discovery that the 
“Chemung” sandstones of Pine creek, in Muscatine county, are 
in reality true Devonian. In Missouri the same Devonian facies 
of the fauna contained in the lowest member of the Carbonifer- 
ous is lost from view completely by eliminating the species found 
jn the thin sandy seam at the base of the Louisiana, or lithographic, 


384 The American Geologist. December, 1892 


limestone, Thus the faunas of the Devonian and Carbonifer- 
ous of the upper Mississippi valley become more sharply con- 
trasted than ever. And the apparent mingling of faunas from 
the two geological systems manifestly is due to erroneous as- 
sumptions rather than detailed field evidence. 

Depriving the ‘‘Lithographic” limestone, which attains a thick- 
ness of more than 60 feet at Louisiana, in Pike county, Missouri, 
almost entirely of the extensive fauna commonly ascribed to it, 
and which has been seen comes from a thin seam lying below the 
calcareous layers, its geologic age becomes a problem yet to be 
solved. The few fossils known from the limestone itself have 
been heretofore rarely met with. But until abundant evidence to 
this effect is found it seems advisable to still consider the 
Louisiana (lithographic) limestone in this region as the basal 
member of the Carboniferous. 

It appears very probable that a marked unconformity exists be- 
tween the Carboniferous and Devonian rocks of the area under 
consideration, instead of a regular sequence of strata as has been 
supposed usually. The proofs of this statement, however, are 
not such at present as to warrant a definite formulation of the 
evidence, yet many facts recently observed point strongly towards 
this conclusion; while the sharply contrasted faunal peculiarities 
are in themselves very suggestive, and very remarkable, 


EDITORIAL COMMENT. 


Tuk First Decap or THE GEOLOGIST. 

With this month closes the tenth volume of THE AMERICAN 
GEoLoGisr. It may not be unwholesome to revert briefly to the 
past five years. That time is too short an interval to warrant 
the expectation of great results, or to span any of the great 
epochs which mark revoiutions in science. There is of course in 
the history of every revolution, whether in politics or in science, 
a seeding time and a reaping time. The changes in geologic 
science, however, have always been so gradual, and spread over 
so many countries, that the participants have rarely realized 
whether they were sowing or reaping; and it has required the 
observer of a later generation, who could gather up the elements 


Editorial Comment. 385 


of the science of the past and analyze them, to point out the seed 
and the fruit it may have produced. While the science of geol- 
ogy can claim hardly more than a century, though it doubtless 
existed long in an embryonic state, it has witnessed some marked 
periods of progress. Epoch-marking men can be pointed out all 
through its history. Such were Hutton, Cuvier, Darwin and 
Louis Agassiz. Such were Amos Eaton, Ebenezer Emmons and 
Leo Lesquereux. Yet during their lives they were not known as 
such. They had their opponents and difficulties, and their fol- 
lowers only could fairly appreciate their labors. 

Tue AMERICAN GEOLOGIST cannot distinctively lay claim to the 
credit of sowing seed, nor reaping fruit. It doubtless shares, 
however, in both. No such publication can be said to exist with- 
out some influence. The future only will reveal what may be the 
effect of its influence on American geology. Inside of the cases 
of its ten tomes, which have been sent regularly to all parts of 
the world, are contained the thoughts of numerous American 
geologists, on many of the obtrusive problems of the science as 
they have come before students in America. Besides ‘the ‘‘Re- 
views, ‘‘Correspondence”’ and ‘‘Personal and Scientific News,” 
those volumes contain 246 contributed articles, not written by its 
editors, 108 editorial articles, and 56 articles of ‘‘editorial com- 
ment.’’ There have been described, within these ten volumes, 
25 new genera and 117 new species of fossil forms. Microscopic 
petrography and general paleontology and stratigraphy have been 
fully represented in its pages. While necessarily questions of 
general geology have had a large share in the pages of the GroL- 
oGist, yet the relations of geology to education and to ethical 
training, as well as to the operations of the miner and the sur- 
veyor have frequently been discussed. Astronomers, chemists 
and mineralogists have alike found information and valuable re- 
search by perusing its monthly issues. 

Notwithstanding this, the Groxoaist has not accomplished, in 
its full measure, as intended at the outset, and as foreshadowed 
in the «‘Introductory,” at the opening of volume 1, all that its 
editors have desired. It is natural for man to plan and adopt as 
nearly as possible a model design; it is, alas, also natural that 
its accomplishments should fall short of the perfect model. The 
editors of the GEOLOGIST are no exception to that order of nature, 
and they admit that their efforts have not been sufficient as yet 


386 The American Geologist. December, 1892 


to carry out all that was promised in the ‘‘Introductory.” — Per- 
haps they will be able to approach nearer to the achievement of 
their highest hopes during the next five years. 

Five years ago, in the midst of a general feeling of disquiet 
among the geologists of the country, seven men boldly took the 
initiative in the establishment of an American journal which 
should give expression as well to the ‘‘feeblest whispers’ as the 
‘loudest thunder” of geological thought in America. Six of these 
discharged all their promises, and, except for the intervention of 
the pale messenger, six of them would still be found steadfast in 
their places. This board conducted the GkoLoGist through two 
years. Five remain of that seven, but their burdens have been 
lightened by the addition of seven others to their ranks. 

On this accession to the editorial board, making twelve, it was 
planned, at first, that each editor should be responsible for the 
issue of one number, in alphabetical rotation. This has been in 
a measure carried out, but it was found shortly that the labors of 
the respective monthly editors would have to be mixed in the 
monthly issues. The editors are scattered from the Atlantic to 
the Pacific, and from the lakes to the gulf, and with all possible 
precaution and dispatch the timely succession of contributions 
could not be kept in orderly routine. Therefore there is no way 
of indicating the amount of work done by the individual editors, 
nor of establishing the authorship of the anonymous articles, ex- 
cept that each contributor knows his own. 

It has been the practice, from the first, to maintain an anony- 
mous editorial department, and also to print all reviews anony- 
mously. The unpleasant truth must sometimes be told, and it is 
more likely to be told and told correctly under the shield of an 
anonymous journal than when its relator is compelled to carry 
the brunt of all its consequences. Therefore the editors have had 
equal and untramelled freedom, as individual editors, to write 
whatever they chose. Sometimes they have found themselves at 
variance on views expressed, and they have had the privilege not 
only as individuals to disown what they did not approve, privately, 
whenever they have been disposed, but even to criticise the 
GroLoagist publicly in their own name, or to write counter edi- 
torials in rebuttal of other views. The Gkronoaist is therefore 
no ‘composite photograph” of twelve, without character and 
complexion, and destitute of all dominant traits, but is instead a 


Review of Recent Geological Literature. 


(Ss) 
On 
=| 


lively succession of single photographs each one of which shows 
its strong traits. The editors understand this and they wish the 
reader also to bear it in mind, While the GroLoaistr asa journal, 
is responsible for all that is said between its covers, the separate 
editors must be considered responsible in the first instance only 
for what they may contribute; but, secondly, they share in the 
joint responsibility of the anonymous articles. The former they 
cannot repudiate, but the latter they may disclaim in any way 
they choose. It is manifest that this secures for the journal the 
largest possible result from a composite editorship, and yet 
yields to every editor the right of such individual person- 
ality as he may choose to assert irrespective of his asso- 
ciates, 

The editors wish to take this opportunity to again express 
their obligations to the geologists of America. Without their 
co-operation it were vain to attempt to sustain such a magazine 
in America. The editors feel encouraged, and even flattered, by 
the cordiality and generosity with which the journal has been 
received. While it has not yet reached a self-sustaining finan- 
cial basis, it has come very near to it, and the editors are confi- 
dent that in the near future with a continuance of the favors of 
the past it will pass that mark. 


REVIEW OF RECENT GEOLOGICAL 
LATHE RA TURE: 


Man and the Glacial Period. By G. Frepertck Wricut. With an 
appendix on Tertiary Man, by Prof. Hexry W. Haynes, pp. 385, with 
three folded maps, and 108 figures in the text. New York: D. Appleton 
& Co. (No. 69, International Scientific series. ) 

This work is partly an abridgment and partly an extension of the 
author’s previous larger volume, “The Ice Age in North America.” 
Glaciers and ice-sheets now existing are described in the first three 
chapters, special attention being given to the Muir and Malaspina 
glaciers in Alaska and the ice-sheet and glaciers of Greenland. The 
next two chapters are devoted to the Pleistocene glaciation of North 
America, its strie, till, drumlins, terminal moraines, kames, and valley 


385 The American Geologist. December, 1892 


drift and terraces. The sixth chapter treats of the ancient glaciers 
of the Alps and other mountains in the eastern hemisphere and the 
ice-sheets and glacial drift of northwestern Europe, including a very 
interesting description of the drift in Great Britain by Mr. Perey F. 
Kendall, with an excellent contour map of the British Isles. 

In the seventh chapter the changes of drainage produced by the 
ice-sheets are described, with the formation of a glacial lake in the 
Ohio valley, of the much enlarged Laurentian lakes when the receding 
ice was a barrier preventing their present northeastward outflow, of 
lake Agassiz in the valley of the Red river of the North and basin of 
lake Winnipeg, and of the Quaternary lakes Bonneville and Lahontan 
in the arid Great Basin of interior drainage. For the parallel roads 
of Glen Roy in Scotland the old explanation is given, ascribing them 
to obstruction by a local glacier, instead of which Jamieson has shown 
that the glacial lake of Glen Roy was pent up by the departing 
Seottish ice-sheet. 

The evidences of man’s existence during the glacial period both in 
Europe and North America are the subject of the eighth chapter. 
For this continent the author should have added, besides the many 
localities which he cites where stone implements have been found in 
river gravels belonging to the ice age, the three discoveries showing 
man to have been contemporaneous with the great Pleistocene lakes, 
namely, the charred sticks, ashes and stones placed to form a rude 
hearth, found at a depth of about 18 feet under the ridge of beach 
gravel on the shore of the glacial lake, Iroquois, in Gaines township, N. 
Y., which Gilbert refers to the time of discharge of this lake through 
the Mohawk and Hudson rivers; the chipped fragments of quartzite 
found by Tyrrell ina beach of lake Agassiz; and the obsidian spear- 
head discovered by McGee in the sediment of lake Lahontan. 

Professor Wright discusses the cause and date of the glacial period 
in the two remaining chapters. Concerning the cause, he agrees 
with Upham and Le Conte that it was probably the great altitude to 
which the glaciated countries had been uplifted during the closing 
stage of the Tertiary era and beginning of the Quaternary, shown by 
fjords and submarine valleys to have been generally 3,000 feet or 
more above their present hight; and concerning the length of the 
Postglacial or Recent period, his observations accord with those of 
N. H. Winchell, Gilbert, Andrews, and others, that probably only 
about 7,000 to 10,000 years have elapsed since Canada and the north- 
ern United States were uncovered from their ice-sheet. The length of 
the Glacial period is believed, as by Prestwich, to have been probably 
no more than 30,000 or 40,000 years. Only one epoch of Pleistocene 
glaciation is admitted by the author; and the supposed interglacial 
forest beds and other fossiliferous beds between deposits of till are 
attributed to moderate recessions and re-advances of the ice-border, 
This interpretation and some others of the author’s conclusions, es- 
pecially those relating to the cause of the Ice age and its date and 
duration, will doubtless be topies of much further debate by glacial- 


Review of Recent Geological Literature. 389 


ists, as indeed they have been already during many years, before 
unanimity of opinions will be reached. 

Professor Haynes, in an appendix of ten pages, reviews the evidences 
which by some archeologists have been thought to indicate man’s 
existence in the Pliocene and Miocene periods, and concludes that 
they are wholly unreliable. The antiquity of our race, so far as it is 
demonstrated by geology, extends back, therefore, according to these 
authors, probably not much more than 20,000 or 380,000 years, for the 
earliest discovered traces of paleeolithic man seem referable to the 
time of maximum extension of the ice-sheets and their ensuing stages 
of retreat. 

Mammalia from Mongolia. By R. Lyprkker, Esq. Contributed to the 
Records of the Geological survey of India (vol. xxiv, pt. 4, pp. 207-11). 
Fourteen specimens representing several species (//yena Equus, 
Gazella) are described, and according to the author, great interest is 
attached to these species for the reason that they carry the Pliocene 
mammalian fauna to a more northern district of China, than has hith- 
erto been reported, and that they indicate two new Indian Siwalik 
species in Chinese territory. Three figures of teeth in the text. 


Pie Oor RECENT: PUBLICATIONS. 


I, Government and State Reports. 

Geological Survey of Texas, Bulletin No. 1. Artesian water on the 
Llano Estacado, Dr. Geo. G. Shumard; also Report and analyses of 
Texas Sumach (Rhus copallina), by George H. Kalteyer. Austin, 
1892; pp. 19. 

Sketch of the Geology of Alabama. E. A. Smith, state geologist, 
octavo, pp. 36. 

First Report of the Bureau of Mines, to the Legislature of Ontario, 
Archibald Blue, Toronto, 1892, pp. 258. One geological map. 

U.S. Dept. of Agriculture, Relations of Soil to Climate. E. W. 
Hilgard, Washington, 1892, pp. 59. 

U. 8. Geol. Survey, Mineral Resources of the United States, calen- 
dar years 1889 and 1890. David T. Day. Octavo, pp. 671. 

II. Proceedings of Scientific Societies. 

Acad. Nat. Scei., Philadelphia, Part wu, April-October, contains: 
Mineral localities of Philadelphia and vicinity, Rand, Jefferies and 
Cardeza; The Fauna of the Blanco beds of Texas, E. D. Cope; A 
revision of the North American Creodonta, with notes on some genera 
which have been referred to that group. W. B. Scott. 


890 The American (reologist. December, 1892’ 


Royal Society of Canada, Transactions, vol. 1x, Sec. rv, contains: 
Parka decipiens. Notes on specimens from the collections of James 
Reid, Sir Wm. Dawson and Prof. Penhallow [Reviewed in the Grono- 
Gist, vol, 1x, p. 841]; The gold-bearing rocks of New Brunswick, and 
the possible discovery of remunerative gold deposits in that province, 
L, W. Bailey ; Two species of trees from the Post-Glacial of Illinois, 
D. P. Penhallow; Illustrations of the fauna of the St. John group, No. 
vi, G. F. Matthew; On the geology of the St. Clair tunnel, Frank D. 
Adams; The Orthoceratidie of the Trenton limestone of the Winnipeg 
basin, J. F. Whiteaves, [Reviewed in the Gronoaisr, vol. x, p. 124]; 
Deep wells in Manitoba, J. B. Tyrrell; On the geology of part of the 
Province of Quebec, R. W. Ells; On the mode of occurrence of remains 
of land animals in erect trees at the South Joggins, Nova Scotia, J. W. 
Dawson. 

Annales de la Soe. Geol. de Belgique, Tome xrx, 2 me livraison, con- 
tains: Contribution a lV étude du frasnien, X. Stainier; Observations 
sur la correlation des diverses bandes considérées comme frasniennes 
par M. X. Stainer, par G. Dewalque ; Quelques observations relatives 
au devonien du bassin de Namur, G. Malaise; De la formation des 
dépots de phosphate de chaux dans la province de Liége, Cam. Gillet ; 
Sur une analogie de formation d’une variété de phosphate de chaux 
de Hesbaye et des phosphates de Curacao et de la Floride, M. Lohest ; 
Distribution @eau de Bruxelles, par Ed.-G. Detienne. 

Bulletin de la Soc. Geol. de France, t. x1x, No. 13, July, 1892, con- 
tains: Note sur la succession des zones du terrain erétacé du Beaus- 
set et sur leur comparaison avee celles des Martigues. A. Toucas ; Note 
sur la serie saumitre de Fuvean et de Rognac, Ph. Matheson; Note 
sur le gisement du Rouve et sur l’ dge des couches cretac¢ées sup¢rieures 
du Beausset, M. Peron; Note sur la bande d’ affraissements de Chi- 
bron, M. Bertrand; Sur I’ allure tourmentée des plis isoclinaux dans 
les montagues de la Savoie, M. Kilian; Observations sur Il’ age des 
plis de la Provence, M. Collot; Sur le Bajocian du Var, M. Kilian; 
Note sur les zones de plissements de Salernes et @Aups, M. Zurcher ; 
Observations sur les couches fluvio-la-custres 4’ Lychnus et I’ Urgo- 
aptien d@ Orgon (Bouches-du-Rhone), par Edm. Pellat. 

Jahres-Bericht d. Naturforsch, Gesell. Granbtindens, xxxv, (1890-91), 
Chur, 1892, contains: Geologische Bau des Rhiilikongebirges, Chr- 
Tarnutzer. 

Mittheilungen des Naturf. Gessell, in Bern, 1891 (1892), Nos. 1265- 
1278, contains: Beitriige zur interglacialzeit auf der Stidseite der 
Alpen, A. Baltzer; Der Loess des st, gallischen Rheinthals, A. Baltzer ; 
Zur herkunft der bernischen bunten Nagel-fluh, A. Baltzer. 

Annalend. K. K. Naturhist, Ilofmseums,Wien, 1892, Band vit, No. 1 
u.2, contains: Die Gastropoden des Schichten von St. Cassian der 
stidalpinen Trias, tr. Theil, Ernst Kittl. 

Abhand. d. Gross. Hess. Geol. Land-Anstalt, zu Darnnstadt, Band 
ir, Heft 2, comprises: Die alten Neckarbetten in der Rheinebene, von 
A. Mangold. 


Recent Publications. 391 


Ueber die basaltischen Kralerbildungen nOrdlich und nordo6stlich 
von Giessen, A. Streng, (xxrx, Ber. d. Oberhess. Gesseil, Nat. u. Heil- 
kunde, zu Giessen). Eine Reise in das Land der Mormonen, A. 


Strong (Iden). 
Geologische und geographische Experimente, von Ed. Reyer (Wein). 
Lu. I Hefte, Leipzig, 1892. 


ITI.—Papers in Scientific Journals. 

Can. Record of Science, Vol. vy, No. 3, contains: Thomas Sterry Hunt, 
J. W. Dawson, (with a portrait); The Utica terrane in Canada, H. M. 
Ami. 

No. 4 contains: Description of a new genus and species of phyllo- 
earid Crustacea from the middle Cambrian of Mt. Stephen, B. C., J. 
F. Whiteaves ; The Utica terrane in Canada, Henry M. Ami; Notes on 
Cambrian faunas, G. F. Matthew. 

Jour. Cin. Soc. Nat. Hist., Vol. xv, No. 2, contains: The preserva- 
tion of plants as fossils, Jos. F. James; Some new species and new 
structural parts of fossils, 8. A. Miller and Chas. Faber; Manual of 
the paleontology of the Cincinnati group, Jos. F. James. 

Geological Magazine, Sept.: Notes on Russian geology, W. F. Hume ; 
The mammoth and the glacial drift, H. H. Woworth; On rapid eleva- 
tion of submerged lands and the possible results, E. Hill; The so- 
ealled serpentines of Lleyn, Catherine A. Raisin. 

Oct.: Further additions to Australian fossil Echinoidea, J. W. Greg- 
ory; On Liassic sections near Bridport, J. Francis Walker; Further 
remarks on the Coniston limestone, J. E. Marr; Note ona granite 
junction in the Ross of Mull, J. G. Goodchild; The Malvern erystal- 
lines, A. Irving. 

Novem. Further contributions to the Devonian fish fauna of Can- 
ada, A. 8. Woodward; On porphyritiec quartz in basic igneous rocks, 
A. Harker; Lithophyse in obsidian, Lipari, H. J. Johnston-Lavis ; 
Faulting in drift, T. Mellard Reade; Glacial geology, Old and New, 
Perey F. Kendall; Selenology, 8. KE. Peal; The mammoth and the gla- 
cial drift, a reply to A. J. Jukes-Browne, H. H. Howorth. 

Am. Jour. Sci., Sept. The Gulf of Mexico, as a measure of Isostacy, 
W.J. McGee; Kelauea in April, 1892, S. E. Bishop; The Devonian 
system of eastern Pennsylvania, C. 8. Prosser; Relations of the Lau- 
rentian and Huronian on the north side of lake Huron, A. E. Barlow ; 
Note on the change of electric conductivity observed in rock magmas 
of different composition on passing from liquid to solid, Carl Barus 
and J. P. Iddings; Estimation and dehydration of silver oxide, M. 
Carey Lea. 

Oct. An ottrelite bearing phase of a metamorphic conglomerate in 
the Green Mountains, C. L. Whittle; Mica peridotite from Kentucky, 
J. 8. Diller; Glaciation in the finger-lake region of New York, D. F. 
Lincoln ; Crystallography of the Ceesium-mercuric halides, 8. L. Pen- 
field ; Restorations of Clavsaurus and Ceratosaurus, O. C. Marsh; Res- 
toration of Mastodon americanus Cuv., O. C. Marsh. 


392 The American Geologist. December, 1892 
. 

Novem. Unity of the glacial epoch, G. F. Wright; Contributions to 
mineralogy, No. 54, F. A. Genth, with crystallographic notes by 8. 
L. Penfield; Notes on the Farmington, Washington county, Kansas, 
meteorite, Hl. L. Preston; A note on the Cretaceous of northwestern 
Montana, IH. A. Wood; The deep artesian boring at Galveston, Texas, 
hk. T. Hill; Notice of a new Lower Oriskany fauna in Columbia county, 
New York, CG. E. Beecher, with an annotated list of fossils, by J. M. 
Clarke; Description of the Mt. Joy meteorite, EK. EK. Howell. 


IV. Eecerpts and Individual Publications. 

The post-Laramie beds of Middle Park, Colo. Whitman Cross, 
Proc. Col, Sen Soet, Oct, 1892: 

Notes on some eruptive rocks from Alaska. Geo. TH. Williams, Nat. 
Geog. Mag., Vol. rv. 

The Vailan or annular theory. Stephen Bowers, Ventura, Svo, pp. 
24, 1892. 

VW. Foreign Publications. 

Scientific Proceedings of the Royal Dublin Society, Vol. vir (n. s.), 
March, 1892, Part 3, contains: On the structure and origin of the 
Quartzite rocks in the neighborhood of Dublin. W. J. Sollas. 

The fossil Crinoidea in the British Museum (an attempt to put into 
practice modern ideas of museum arrangement), Ff. A. Bather. From 
the annual report of the Museums Association for 1891. 

On the discovery of mammoth and other remains in Endsleigh 
street (London). Henry Hicks. From the Quart. Jour. Geol. Soe., 
Vol. xLviit, p. 453, 1892. 

Soe. Geog.du Nord. Annales xrx,1891,contains: Notice preliminaire 
sur lanature et l’origine des phosphates de chaux de la craie. Renard 
et Cornet ; Observations au sujet de la note sur le terrain houiller du 
3oulonnais de M. Olry, par M. Gosselet; Composition de l’étage 
houiller en Bas-Boulonnais, par M. Ludovie Breton; Note sur la de- 
couverte d’une faune marine dans les sables landeniens par M. Gos- 
selet; Apercu sur les gites de phosphate de chaux de Hesbaye (apres 
les travaux de MM. Lohest, Schmitz et Forir, par M. Gosselet ; Sur les 
terrains phosphaté¢s de Picardie, par Henri Lasne; Observations sur 
le terrain Silurien des environs de Barcelone, par Charles Barrois; 
De quelques théories nouvelles, par M. Peroche; Les Insectes des 
couches triasiques de Fairplay, Colorado. Analyse d’ un travail de 
M.S. Scudder, par M. Charles Maurice; Sur I’ existence d’ un gise- 
ment de Blende et de Galéne dans le départment du Nord, par L. 
Cayeux; Etudes micrographiques du tuffeau a Cyprina planata du 
Nord de la France et de la Belgique; Du role Diatomées dans la 
formation de ce Tuffeau (notice préliminaire), par M. L. Cayeux; La 
Craie du Nord de la France et la boue 4 Globigérines (note prelimi- 
naire) par M. L. Cayeux; De lexistence des Diatomées dans l’yprésien 
du Nord, par M. L. Cayeux; Diffusion des trois formes distinctes de 
V oxyde de titane dans le Crétacé du Nord de la France, par L, Cayeux ; 
Memoire sur la faune du gr?és Amoricain, par Charles Barrois; La 


Correspondence. , 393 
* 

Craie du Nord est bien un dép6t terrigtne, par M. L. Cayeux; Sur un 
calcaire moderne concretionné avee diatomées de Saint-Nectaire-le- 
Bas, par M. L. Cayeux ; Composition min¢éralogique des Sables glau- 
conieux landeiens, par L. Cayeux; Note sur le Tertiaire du Boulon- 
nais, par H. Parent; Sepulture de I’ age de la Pierre polie 4’ Rouvroy 
(Aisne) pres Saint Quetin, par M. Rabelle; De l’existence de nom- 
breux Radiolaires dans le Jurassique et dans l’ Eocene du Nord de la 
France.—Origine probable de la silice de la Gaize et des Tuffeaux 
eocenes, par M. L. Cayeux; Sur la presence de vert¢ébrés dans Eocene 
inférieur du Nord de la France, par A. Malaquin; Observation au 
sujet du mode de formation du conglomerat 4 silex par M. Gosselet ; 
Du role de la geologie dans |’ enseignement de le gCographie et de 
P agriculture, par M. Gosselet ; Notes pour I étude du terrain quater- 
naire en Hesbaye au Mont de la Trinité et dans les collines de la 
Flandre, par M. Ladritre. 


CORRESPONDENCE. 


THe Tutrp TEXAS REPORT.—Permit me to correct a few errors of 
statement in the review of the Third Annual Report of the Geologi- 
cal Survey of Texas, published in your November number, inasmuch 
as they put on record Prof. Alpheus Hyatt and myself in a manner 
unauthorized by us. 

You state that Mr. Jules Marcou’s determination of the Jurassic 
age of the Tucumcari beds in New Mexico has been sustained by 
Capt. C. E. Dutton, Prof. A. Hyatt, and Prof. Robt. T. Hill, and op- 
posed by Prof. Jas. Hall and Dr. J. 8. Newberry. I am sure that 
neither Capt. Dutton, Prof. Hyatt nor myself has authorized this 
statement. Capt. Dutton has never published a line on the Tucum- 
eari region, and I think has never visited it. In his admirable mon- 
ograph on Mount Taylor and the Zuni Plateau, he does uphold Prof. 
Marcou’s determination of the Jurassic in New Mexico, but in an en- 
entirely different portion of the territory from Tucumeari. 

Prof. Hyatt and I have studied the region minutely; the former 
spent a whole field season in the vicinity, while I have made two 
special trips to this inaccessible locality. By agreement we have re- 
frained from publishing the lengthy papers either might have pre- 
pared, andl am positive Prof. Hyatt never recorded an opinion on 
Tucumeari, but is cautiously working up his material. 

I have expressed my opinions in the following five publications. 

1. Cireular, School of Geology of University of Texas, Austin, 1887. 

2. Geological Survey of Arkansas, Annual Report 1888, Vol. 1. 

3. The Comanche Series of the Texas-Arkansas Region. Bulletin 
of the Geological Society of America, Vol. rr, pp. 503-528, 1891. 

4. Notes on the Texas-New Mexican Region. Bull. Geolog. Soe. 
Am., Vol. ri, 1891. 


394 The American (reologist. December, 1892 


5. On the Occurrence of Artesian and Underground Waters in 
Texas, New Mexico, etc. Washington, April, 1892. 

In the earlier of these writings I said Mr. Marcou had not been 
properly understood, and his Grypheea dilatata and Ostrea marshii 
beds were Jurassic, as he was justified in affirming from the occur- 
rence of these species. But as a result of later investigations and 
the discovery of these species associated with Comanche faunas, this 
statement was corrected and in the report upon underground waters, 
above mentioned, p, 129, which was sent to the GroLoaist some months 
before, Mr. Cummins’ report was published, my conclusions upon the 
geology of Tucumeari were distinctly stated as follows: 


THE TRINITY SANDS AND RED BED REGIONS. 

“The writer has twice visited the Mesa Tucumeari and found ita 
most interesting geological remnant of the former area of the Llano 
Estacado. The table or summit described by Capt. Simpson is covered 
with the typical Llano Estacado formation, identical in composition 
and formerly continuous with the sheet which covers the Llano proper, 
some 20 miles distant. Below this is a vertical escarpment of 50 
feet or more of typical Dakota sandstone, resting upon loose sands and. 
clays, forming a slope identical in aspect and fossil remains with the 
Denison beds of the Washita Division, which have been eroded away 
from the 400 miles intervening between it and the main body of those 
beds at Denison, Tex. Beneath this is a large deposit of the typical 
Trinity sands country, of white pack-sands, thin clay seams, and 
flagstones, while the base is composed of the typical vermilion sandy 
clays of the Red Beds.” 

Since much of this Texas report was used without credit upon work 
done by myself or my assistants, including Mr. Taff, working under 
my direction [First Annual Report 1889, pp. Lxxxvitr and 106-141] the 
state geologist, with the above passage before him, might have spared 
himself the labor of disproving a theory I had long since publicly 
disowned. 

Concerning the age of the Trinity beds of my Trinity division, for 
which Mr. Taff, without statement of authority or reason, substitutes 
the name Bosque, I have always held that they present a Wealden 
fauna which both in Europe and in this country presents certain 
transitional Jura-Cretaceous features, but is by general agreement 
placed in the Cretaceous and so considered. If Messrs. Cummins and 
Taff can speak with positiveness on this subject, they are to be con- 
gratulated, for there are several geologists who have had much longer 
acquaintance with the occurrence and problems of the basal Creta- 
ceous in this country, who, after careful years of labor, are still con- 
servative in expression—among these are Profs. Ward, Fontaine, 
White, MeGee and myself. 

Your statement on p. 314, that the Glen Rose beds were not asso- 
ciated by me with the Trinity, but were retained in the Fredricksburg 
division, is a mistake. This was true in my earlier publications, but 


Correspondence. 395 


in my later papers, especially one upon the Comanche series of the 
Arkansas-Texas region, read before the Geological Society of America, 
in Washington 1891, and published bythe society, I separated the 
lower beds of the Comanche series from the Fredricksburg division, 
and placed the Trinity sands and Glen Rose beds in a distinct division, 
to which I gave the name of Trinity division. The state geologist of 
Texas participated in the discussion which followed the reading of 
this paper [See Bul. Geol. Soc. Amer. Vol. 11, p. 327] and inasmuch as 
the section there published is reproduced by Mr. Taff without a word 
of credit, except for horizons, I append it in parallel columns with his. 


Section and Nomenclature of the Com- Section and Nomenclature of the Com- 
anche Series as published by Hill in the anche Series as published by J. A. Taf, 
Bulletin of the Geological Society of Third Annual Report Geological Survey 


America, May, 1891. ‘of Texas, Sept. 1892. 
DEFINITION OF THE TERRANES. I, Lower CRETACEOUS. 
CONSTITUTION OF THE COMANCHE SERIES. Washita Division. 
C. The Washita, or Indian Territory m. Vola limestone (3). 
Division. 1. Arietina clay. 
11. The Denison Beds. k, Denison (3). 
10. The Fort Worth Limestone. J. Fort Worth (3). 
y. The Duck Creek Chalk. Fredericksburg Division (2). 
8. The Kiamitia Clays or Schloenbachia i. Kiamitia clay (3). 
Beds. h. Austin marble (38). 
B. The Fredericksburg or Comanche Peak g. Flag limestone (3). 
Division. f. Caprina limestone (1). 
7. The Goodland Limestone. e. Comanche Peak (1). 
6. The Caprina Limestone. d. Texana. 
5. The Comanche Peak Chalk. Bosque Division (5). 
4. The Gryphea Rock and Walnut c. Paluxy sand (3). 
Clays. b. Glen Rose (alternating) bed (3). 
3. The Paluxy Sands. a. Trinity sand (3).* 
ae gue peo Ben. : *(1) B. F. Shumard, (2) Dr. Ferd. Reemer 
2. The Glen Rose or alternating beds. (3) R.'T. Hill, 2 
1. The Trinity or Basal Sands. BN 


Why, after the general section had long been published, Mr. Taff, my 
former assistant, should publish the arrangement of this section and 
its description as original, with no other credit given than the nomen- 
clature of the above given horizons, may be attributed to the early 
attempt of an able young worker at publication, but his substitution 
of “Bosque” for my Trinity Division, [See Bull. Geol. Soc. Amer. 1891, 
pp. 503-5-28] and his accrediting to Dr. Ferd. Roemer my Fredericks- 
burg division is remarkable. 

I am always glad to correct any errors in my work, and I have some- 
times amended my nomenclature. Both of these privileges every 
worker, especially one in a progressive science, has, but it is doubtful if 
others can change an established nomenclature without explanation. 

In the nomenclature of the Comanche and Upper Cretaceous, in 
my later papers, I have sought to substitute geographic for paleon- 
tologic designations of beds, but have aimed to give credit to the 
humblest assistant. I ask that the readers of Messrs. Cummins’ and 
Taff’s papers compare them with my report in the First Annual Re- 


396 The American Geologist. December, 1892 


port of the Texas Geological Survey, pp. UXXXII-LXXXvitrand pp. 106- 
141; with the American Journal of Science, April, 1887, and other 
papers of mine referred to in this communication. 

The valuable writings of Dr. C. A. White, as well as those of Prof. 
Jules Mareou (who made the first correct determination of the Lower 
Cretaceous age of the beds of northern Texas), are likewise entirely 
ignored in this report.* 

There are also several erroneous statements in the review concern- 
ing the range of species, but these will be reserved for future com- 
ment. Rost, T. Har: 

Washington, D. C., Nov. 18. 1892. 


VoLcANIC pust IN Kansas AND InprIAN Terrrrory.—The peculiar 
voleanic dust or sand mentioned by professor Todd in the November 
GEOLOGIST occurs, as is Well known, in various places in western Kan- 
sas. I found it, as early as 1874, in Norton county, and professor St. 
John records it from several localities in the extreme southwestern 
part of the state. During the past year I have received specimens 
from the Indian Territory,south of Arkansas City, and from a few miles 
southwest of Galena, a locality considerably further east than Omaha. 
The sand in both these latter localities is rather more grayish in color 
than that from the northwest, but otherwise is identical. The gentle- 
man who gave me the specimen at Galena, stated that the deposit is 
many feet in thickness at this locality. S. W. WILLISTON. 

Lawrence, Kansas, Nov. 22, 1892. 


CLASSIFICATION OF THE CEPHALOPODA. The November number of 
the American GroLoactsr contains a note (p. 327) on the comparison 
Tables of Classification issued in the July number of Proc. Geol. Assoc. 
London,to illustrate the Presidential address. I do not wonder at 
your saying “Bather’s is the most remarkable mainly on account of 
its brevity.” As you have further reprinted the words that purport 
to represent my Classification, I should like to have the opportunity 
of saying that I am not responsible for that Table, and that it does 
not properly represent any views held by me now or formerly. 
Though no actual classification of the Cephalopoda was ever pub- 
lished by me, still the cancelled Table did represent the views held by 
me in 1888 and expressed in various papers about that date. The 
views to which I was led were largely influenced by the ideas of 
American writers, and I should be sorry to see a misleading account 
of those views disseminated, without correction, by an American pub- 
lication. Therefore I ask you to be good enough to print the accom- 
panying table. Not having been able to read all the recent literature 
on Cephalopoda, I cannot say that I regard these as the best possible 
views aut the present day ; but I regi arded them as the best views pos- 


an or a resumé of Mr. Marcou’s early SENSE of the Lower 
Cretaceous in the Texas region, see Bulletin 45, U. 8. Geological Sur- 
vey ; The E resent ( ‘ondition of Knowledge of the Geology of Texas. 
By Robt. T. Hill. 


= 
‘ 


Correspondence. 3S 


sible in 1888, and am not aware that any facts recently brought to 
light would greatly affect then. 
Faithfully yours, F. A. BATHER. 
Natural History Museum, 
London, 8. W., Nov. 18, 1892. 


CLASSIFICATION OF CEPHALOPODA. 


LIPOPROTOCONCHIA. SOSIPROTOCONCHIA. 
NAUTILOIDEA. Intermediate and AMMONOIDEA. COLEOIDEA. 
Orthoceratidae (s. str.) more ancestral Bactritidae Osteophora 
Gomphoceratidae forms— — Asellate Aulacoceratidae 
Poterioceratidae Endoceratidae Latisellate, and Xiphoteuthidae 
Ascoceratidae Actinoceratidae — Angustisellate Belemnitidae 
Cyrtoceratidae grades of Belopteridae 
Lituitidae Goniatites Spirulidae 
Trochoceratidae Families of Ammon- Sepiadae 
Nautilidae ites uncertain. Chondrophora 
(Myopsid) 
Beloteuthidae 
Teuthidae 
Belemnoteuthi dae 
Loligidae 
Sepiolidae 
(Oigopsid) 
Octopodidae 
Philonexidae 
Cirrhoteuthidae 


Tue Movements or Muir Griacier.—In accounting for the apparent 

discrepancy between Prof. Reid’s measurements of the movement of 
the Muir glacier and my own, in your notice of his important work, 
attention should have been called to one other point, namely, that we 
did not measure the same portions of the glacier. Professor Reid 
measured the motion only as far eut from the edges as he could plant 
stakes; but there was a quarter of a mile or more in the middle which 
he found it impossible to reach. The reason why he could not reach 
it was that that was the most rapidly moving part where conse- 
quently the crevasses were impassable. My base-line was on a level 
with the edge of the ice, so that we could recognize the pinnacles and 
domes and moraine-covered patches as they slowly moved past across 
the horizon. Mr. Baldwin and myself were very confident that we 
made no mistake in the recognition of these objects. Professor Reid’s 
base-line was several hundred feet higher up upon the mountain side 
than our line, so that in looking down upon the glacier he had not 
the same advantages for recognizing the pinnacles. Of course, a larger 
margin of error should be allowed for our observations than for his, 
since our angles were taken with a sextant and his with a theodolite. 
sut on points nearer the shore our results were very nearly the same 
as his. Professor Reid has just returned from another expedition to 
the Muir glacier, and reports great changes in the appearance of the 
front. This year the front has assumed almost exactly the shape 
which is shown in my photographs of six years ago, while two years 
ago the contour of the front was entirely different. Professor Reid 
has brought back a large amount of important information about the 
whole system, but it is too early yet to publish the result. 

Oberlin, O., Nov. 7, 1892. G. Freperick Wrenn. 


398 The American Geologist. December, 1892 


PERSONAL AND SCIENTIFIC NEWS. 


Dr. A. OSANN, for many years first assistant to Prof. Rosen- 
buseh in Heidelberg, and later extraordinary professor of miner- 
alogy and petrography in that University, has been appointed 
geologist on the Geological Survey of Texas aud will have charge 
of the petrographic work of the survey. He sailed from Germany 
about the middle of November. 

A Larae DiaAmonp.—The second largest diamond in the world 
is now undergoing the cutting process at Antwerp. Its weight is 
at present 474 carats, but it will lose no less than 274 carats be- 
fore it is ready for the market. Even then, however, it will be 
the second largest diamond in the world, standing between the 
280 carats of the Persian diamond ‘‘Great Mogul,’ whose exist- 
ence is considered very mythical to-day, and is said to weigh 193 
earats, and the Victoria, or Imperial, diamond, the property of 
the Nizam of Hyderabad, and the Russian ‘‘Orloff’ brilliant, 
The De Beers Yellow weighs 225 carats, recently sold to an In- 
dian rajah. Roughly speaking, the Antwerp stone will be ane 
the size of a pigeon’ sege. In its present state it measures 2.741 
inches by 1.767 inc hes. Its polished surface will measure .786 
inch each way. 

Curap ALumiINuM.—A French electro-metallurgical company, 
which employs the Herault-Kiliani aluminum process, asserts that 
it will be able to sell the aluminum at a price equivalent to less 
than 15 cents a pound, provided it is in a position to dispose of a 
yearly output of 3,000 tons of the metal. 

ALABAMA Brryi.—The range of metamorphic schists and coarse . 
granites that traverse Coosa county, Ala., yield some interesting 
minerals. Among them are tantalite, cassiterite and beryl. 
Some fine specimens of the latter have been cut for exhibition at 
the Alabama State Fair soon to be held in Birmingham. The 
better specimens are found near the old town of Rockford in the 
vicinity of Hissop P. O. 

The most striking geological feature of the district is the oceur- 
rence of heavy bands of a coarse schist in places heavily impreg- 
nated with graphite and pyrite and lying between extensive ledges 
of granite. Some large pieces of tantalite have been found 
near Rockford, the largest weighing 45 ounces, being now in the 
Museum of the Alabama Geological Survey. ‘Tin ore also occurs, 
but, so far, only surface fragments and crystals have been found. 

Tuk GRoLoGICAL Socrery or AMERICA will hold its fifth annual 
meeting at Ottawa, beginning Wednesday, Dec. 28, at 10 o'clock 
a.m. The invitation to this city was issued jointly by the Logan 
Club, the Canadian Geological Survey, and the Royal Society of 
Canada, and the sessions will be in the House of Commons build- 
ing. His Excellency, the Governor-General, will give an address 
of welcome. 


ENDER PO BOE. xs 


A 


Advance sheets from the eighteenth report, 
padi survey, Paleontology, Miller, 

Alabama, geology of northeastern, Hayes, 
522. 

Aluminum, 398. 

another old outletof lake Huron, Wright, 

Appalachian Virginia, N. H. Darton, 10; 
Keith, 362. 

Approximate interglacial chronometer, N. 
Hi. Winchell, 69,302. 

Annual report of the department of 
mines, New South Wales, 255. 

Areal work of the U. 8S. Geol. Surv., Me- 
Gee, 377. 

Arkansas, the iron deposits of, Penrose, 
324. 


B 

Bailey, L. W., 68. 

Basal line of delimitation of the Carbon- 
iferous, Keyes, 380. 

Basic eruptive rocks in Androscoggin Co., 
Maine, Geo. P. Merrill, 49. 

Bather, F. A., 260: 3%6. 

Baussé Roussé, new discoveries at, Nadail- 
lac, 296. 

Beecher, C. E., Development of the brach- 
iopoda, 253. 

Beachler, C.S., Keokuk group in the Mis- 
sissippi valley, 88. 
Beitrage zur Géol. u. 
Felix u. Lenke, 120. 
Blue Ridge in Maryland and Virginia, 

Keith, 362. 
British Association at Edinburgh, Clay- 
pole, 188; Address of Lapworth, 225. 
Benton, N. L., Tertiary plants from Bo- 
ivia, 63. 


Pal. de Mexico, 


Brumell, H. P., Notes on Manganese in 
Canada, 80. 

Bryson, John, Wahnschaffe’s work on the 
drift of Germany, 132. 


Cc 


Calvin, 8., Collection of fossils from the 
Lower Magnesian in Iowa, 144. 

Cambrian faunas, diffusion of, Matthew, 
66. 


Camerate crinoids from the Niagara, 
Wachsmuth and Springer, 135. 
Castillo, Antonio del, Carta geologica 


Mexicana, 119. 

Cannei coal from Kootanie, Penhallow,331. 

Chietetes in the Devonian at the falls of 
the Ohio, Rominger, 56. 

Chemical science, the immediate work in, 
Prescott, 283. 

Choffat, Paul, Gibraltar, 326. 

Chonophyllum, revision of, W. H. Sher- 
zer, 66. 

Clark, W. B. (and G. H. Williams), Geology 
of Maryland, 63. 

Classification of the theories of the origin 
of iron ores, H. V. Winchell, 277; of the 
cephalopoda, 327; 396. Of the Dyas, Trias 
and Jura in northwest Texas, Marcou, 
369. 

Claypole, E. W., Gigantic placoderm 
from Ohio, 1; Geology at the British 
Association at Edinburgh, 188; 193; Head 
of Diniehthys, 199. . 

Clinton iron ore, origin of C. H. Smyth, 
Jr., 122. 

Conditions of the accumulation of Drum- 
lins, Warren Upham, 339. 

Cope, E. D., In the Texas Panhandle, 151, 
196, 


400 


Correlation 
White, 121. 
CORRESPONDENCE. 
Attachment of Heterocrinus, D. T. D. 
Dyche, 180; Glacial strive in Kansas, 
L. C. Wooster, 131; In the Texas Pan- 
handle, E. D. Cope, 131; Wahnschaffe’s 
work on the drift deposits of Ger- 
many, J. Bryson, 182; Geology at the 
recent meeting of the British Associa- 
tion at Edinburgh, E. W. Claypole, 
188; Remarks on H. 8. Williams’ ad- 
dress at Rochester, Jules Marcon, 257; 
On the Keokuk group, C. H Gordon, 
327; W. M. Harvey, Robt. T. Hill, 328. 


papers—Cretaceous, C. A. 


why 
The Third Texas Report, R. T. Hill, 
393: Volcanic dust in Kansas, 8S. W. 
Williston, 396; Classification of the 
Cephalopoda, F. A. Bather; 396; Move- 
ments of Muir glacier,G. F.Wright,397. 
Crawford, J., Notes on earthquakes in 
Nicaragua, 115. 
Cretaceous in Mexico, A. Heilprin, 121. 
Cross, Whitman, Close of the Cretaceous, 
256. 
Cummins, W. F., Report on the Texas 
survey, 311. 


D 


Dana, E. S., Dana’ssystem of mineralogy, 
64. 

Darton, N. H., Notes on the Central Ap- 
palachian in Virginia, 10, 

Dawson, Sir William, Cretaceous floras,68. 

Decay of rocks and formation of sedi- 
ment, R. S. Tarr, 25. 

Derby, O. A., Nepheline rocks in Brazil, 
py] 


Diller, J. S., Vayloryille region of Califor- 
nia, 183. 

Drumlins, Conditions 
Upham, 339, 

Dumble, E. T., Geology of the middle Rio 
Grande, 65; Third annual report, Texas 
survey, 311. 

Dyche, D. T. D., Attachment of Hetero- 
crinus, 130. 

Dyas in northwest Texas, Marcon, 369. 


of accumulation, 


E 


Earth (The) and its inhabitants, Reclus, 
119. 
EDITORIAL COMMENT. 
The United States geological survey, 179. 
Geological Reminiscences of Rochester, 
in 1892, 242. 
Ward’s Natural Science establishment, 
245. 
An Interglacial chronometer; a correc- 
tion, 302. 
The Topographical map of the United 
States, 304. 
A mortuary Bittersweet, 303. 
The first decad of the GroLoats7, 254. 
Extra morainic drift in New Jersey, A. A. 
Wright, 207. 


F 


Felix, Dr. J., Map of Mexico, 120. 
First decad of the Grouoaist, 384. 
Formation of oolite, A. Rothpletz, 279. 
FOssILs. 
Gigantic placoderm from Ohio, 1; Chie- 
tetes in Devonian strata, 56; Tertiary 


4 


/ ii dew. 


plants from Bolivia, 63; Chonophyl- 
lum, Sherzer, 66; Of the Hudson River, 
in Manitoba, Whiteaves, 67; Cretaceous 
floras, Dawson, 68; New Lamelli- 
branchiata, Ulrich, 96; Orthoceratidee 
of the Winnipeg basin, Whiteaves, 124: 
Attachment of Heterocrinus, Dyche, 
130; New crinoids from the Niagara, 
Wachsmuth and Springer, 135; Krom 
the Lower Magnesian in Towa, Calvin, 
144; Dinichthys, Claypole, 199; Gen- 
era of paleozoic brachiopoda, Hall,251 : 
Development of brachiopoda, Beecher, ° 
253;"New ostracoda, Ulrich, 263: New 
species of Lichas, Ulrich, 271: New 
fossils, Miller, 316, 323; Classification 
of the cephalopoda, 327; 396. Protole- 
nus, anew genus, Matthew, 327. 


G 


Geikie, Sir A., Centenary of Hutton’s 
Theory of the Earth, 188. 

Geikie, James, Glacial succession in Eu- 
rope, 32%. 

Geologic evolution of the non-mountain- 
ous topography of Texas, R. T. Hill, 105- 

Geologic structure of the Blue ridge in 
Maryland and Virginia, A. Keith, 3&2. 

Geological society of America, 134, 193. 

Geologleal survey of Minnesota, 124; of 
Canada, 152; of the United States, 179, 
183, 198, 304: of Arkansas, 326; of Texas, 
261,311: of Missouri, 317; of Alabama, 
322: of Indiana, 323, 

Geology of Columbia, Bolivia, ete., Kar- 
sten, 321. 

Geology of Maryland, Williams and Clark, 
63: Of the Crazy mountains, Wolff, 319- 

Gigantic Placoderm from Ohio, Claypole,1. 

Gibraltar, P. Choffat, 326. 

Glacial strive in Kansas, Wooster, 131. 

Glacial succession in Europe, James 
Geikie, #27. 

Grant, Uly §8., Stratigraphic position of 
the Ogishke conglomerate in north- 
eastern Minnesota, 4. 

Greenland exploring expedition, 329. 


H 


Hall, C. W. (and Fz W. Sardeson), Paleo- 
zoic formations in southeastern Minne- 
sota, 182. 

Hall, James, Testimonial of the Inter- 
national Congress of Geologists, 1: 
Oneota sandstone, 194; An introduction 
to the study of the genera of paleozoic 
brachiopoda, 251. , 

Hayes, Willard C., Geology of northeast- 
ern Alabama, 322. 

Head of Dinichthys, Claypole, 199. 

Heilprin, A., Cretaceous in Mexico, 121. 

Hill, Robt. T., Non-mountainous topo- 
graphy of Texas, 105; W. M. Harvey, 329. 
The Third Texas Report, 393. 

Hitchcock, C. I1., Connecticut yalley gla- 
cier, 193. 

Hobbs, W. H., Notes on some pseudo- 
morphs from the Taconic region, 44: 
195. 

Hutton’s theory of the earth, A. 
188. 

Hyatt, A., Jura and Trias at Taylorville, 
California, 183. 


Geikie, 


Index. 


Immediate work in chemical science, A. 
B. Prescott, 283. 

Interglacial time, N. H. Winchell, 69; Alp. 
Briart, 134; 302. 

International congress of geologists, 260. 

Introduction to the study of the genera of 
Paleozoic brachiopoda, James Hall, 251. 

Tron deposits of Arkansas, R. A. F. Pen- 
rose, 324; Iron ores. classification of, H. 
VY. Winchell, 277. 


J 


James, Jos. F., 256. 

Jura and Trias at Taylorville, California, 
A. Hyatt, 183; In Texas, 311. 

Jura and Dyas and Trias in northwest 
Texas, Marcon, 369. 


K 


‘Karsten, H., Geology of Columbia, Bolivia, 
ete., 321. 

Keith, A., Geologic structure of the Blue 
ridge in Maryland and Virginia, 362. 

Keokuk group of the Mississippi valley, 
C.S. Beachler, 88. 

Keyes, C. R., The principal Mississippian 
section, 125; Platyceras group of paleo- 
zoic gasteropods, 273; Basal line of the 
Carboniferous in Missouri, 380. 


E 
Laflamme, Abbe, J. C. K., 55. 


Lamellibranchiata, new, E. O. Ulrich, 96. 

Lapworth, C., Address at the British As- 
sociation, 225. 

Lenke, Dr. H., Map of Mexico, 120. 

Leverett, Frank, White clays of the Ohio 
region, 18. 

Lichas, Two new Lower Silurian species, 
Ulrich, 271. 

Lignite, its utilization in Texas, 262. 

Lindahl, Josua, 197. 

Lydekker, R., 389, 


M 


Mammalia from Mongolia, Lydekker, 389, 
Man and the Glacial Period, Wright, 387. 
Mannington oil-tield, White, 65. 

Mapping of Missouri, H. Winslow, 323. 

Marcon, Jules, Geological map of the 
United States, 183; Some remarks on 
Prof. H. S. Williams’ address, 257; 
Classification of the Dyas, Trias and 
Jura in northwest Texas, 369. 

Mentone, New discoveries at, 329. 

Matthews, G. F., 66. 

McGee, W. J., Comparative Chronology, 
196; Areal work of the U.S. Geol. Sur., 
377. 

Merrill, Geo. P., Basic eruptive rocks in 
Androscoggin Co., Maine, 49. 

Michigan mining school, 330. 

Miller, S. A., New species and new struct- 
ural parts of fossils, 316. 

Mills, James E., Stratigraphy of the Sierra 
Nevada, 318. 

MINERALS. 

Cuprocassiterite, 64: Bohemian garnets, 
3: Manganese in Canada, 80: Mesabi 
iron ore, 169: Manganese ore, 198: Pen- 
tieldite, 327: Cannel coal from the Koo- 


401 


tanie, 331. Large diamond, 398; Beryl 
in Ala., 398. 
Movements of Muir glacier, Wright, 397. 


N 

Nadaillac, New discoveries 
Roussé, 296. 

New discoveries at Mentone, 329. 

New Lower Silurian Ostracoda, E. O. UI- 
rich, 263. 

New species and new structural parts of 
fossils, 8. A. Miller, 316. 

Non-mountainous topography of Texas, 
Hill, 105. 

Notes on earthquakes in Nicaraqua, J. 
Crawford, 115. 

Notes on fossils from the Lower Magne- 
sian in Lowa, Calvin, 144. 

Notes on manganese in Canada, H. P. 
Brumell, 80. 

Notes on the middle Rio Grande, E. T. 
Dumble. 65. 

Notes on the stratigraphy of the central 
Appalachians, Darton, 10. 

Novak, Otomar, 330, 


at Baoussé 


O 


Official maps of Mexico, 121. 

On the formation of Oolite, A. Rothpletz , 
279. 

Orthoceratidie of the 


Whiteaves, 124. 
Osann, Dr, A., 398. 


Winnipeg basin, 


Pp 


Packard, R. L., Rock analyses by, 54. 

Paleozoic formations in Southeastern Min- 
nesota, Hall and Sardeson, 182. 

Panhandle of Texas, E. D. Cope, 131. 

Penhallow, D. P., Cannel coal from the 
Kootanie, 331. 

Placoderm, gigantic, from 
pole, 1. 

Fane: The iron deposits of Arkansas, 
324. 

Platyceras group of paleozoic gasteropods, 
Keyes, 273. : 

Pleistocene papers at the Rochester meet- 
ings, 217. 

Principal Mississippian 
Keyes, 125. 

Prescott, A. B., The immediate work in 
chemical science, 282. 

Prosser, C. S., Thickness of the Devonian 
and Silurian, 257; 262. 

Pseudomorphs from the Taconie region, 
W.HL. Hobbs, 44. 


Ohio, Clay- 


section, C. K. 


R 


Recent Publications, 125; 184; 398. 

Reade, 'T. Mellard, The rounding of sand- 
stone grains, 324. 

Reclus Elisée, The Earth and its Inhabit- 
ants, 119. 

Reid H. F., Studies of Muir Glacier, 326. 

Rocks. 
Basic eruptive in Maine, Merrill, 49. 
Eleolite-syenite of Litchfield, Maine, 64. 
Nepheline rocks in Brazil, Derby, 326, 

Rominger,C.,Chivetetes in certain Devonian 
strata, 56. 


402 


Rothpletz, 


\., On the formation of oolite, 
279. 


S 


Sardeson, F. W. (and C. W. Hall), Paleo- 
zoic formations in Southeastern Minne- 
sota, 182. 

Scope of Paleontology, H. 
148. 

Sherzer, W. 
lum, 66. 

Shore- lines of ancient glacial lakes, J. E. 
Todd, 298. 

Sienificance of the white clays of the Ohio 
merion , Frank Leverett, 18. 

Smyth, ~ he, Jr. , Clinton iron ore, origin 
of, Be. 

Some problems of the Mesabi iron ore, N. 
H. Winchell, 169. 

Stratigraphy of Appalachian Virginia, N. 
H. Darton, 10; Of the Sierra Nevada, 
Mills, 318. 

Studies of Muir glacier, Reid, 826. 

System of mineralogy (Dana’ 8), 64. 


S. Williams, 


H,, Revision of Chonophyl- 


a 


Taconic region, some pseudomorphs trom, 
W. I. Hobbs. 44. 

Taff, J. A., Report on the Texas survey, 
311. 

Tarr, R. S., Secular decay of rocks and 
formation of sediment, 25. 

Taylorville region of California, J. S. Dil- 
ler, 183. 

Theories of the origin of iron ores, H. V. 
Winchell, 277. 
Tiffany, A. S., 195. 
The rounding of 

Reade, 324. 
Todd, J. E., Volcanic dust from Omaha, 
Neb. egos "Shore-lines of ancient glacial 
lakes, 298. 
Trias in northwest Texas, Marcon, 369. 
Trowbridge, W. P., 198. 
Two Montana coal ‘fields, W. H. Weed, 181. 


sandstone grains, T, M. 


Two new Lower Silurian spec ies of Lichas 
’ 


Ulrich, 271. 


In der. 


U 


United States geological survey, 179, 304, 
Olte 

Upham, Warren, Structure of drumlins of 

Mass., 194: Theconditions of accumula- 

tion of the drumlins, 339, 

Ulrich, E. 0., New Lamellibranchiata, 96; 
New Ostracoda, § 263; New species of 
Lichas, 271. 


Vv 


Volcanic dust from Omaha, Neb., J. E. 
Todd, 295. 


W 


Wachsmuth and Springer, New Niagara 
crinoids, 135. 

Weed, W. i. ; Two Montana coal fields,181. 

Whiteaves, By F,, Hudson River fossils in 
Manitoba, 67; Orthoceratide of the 
Winnipeg basin, 124; 380, 

White clays of the Ohio region, Leverett, 
18. 

White, I. C., The Mannington oil-field, 65; 
197. 

Williams, G. H., (and W. B. Clark), Geol- 
ogy of Maryland, 63. 

Williams, H.S., Scope of Paleontology ,148. 

Williston, S.W ., Volcanic dust in Kansas 
and Indian Territory, 393. 
Winchell, H. V., Classification of the 
theories of the origin of iron ores, 277. 
Winchell, N. TH. , Approximate interglacial 
chronometer, io: 302; Nineteenth Teport 
of the Minnesota survey, 124; Some 
problems of the Mesabi iron ore, 169, 
Winslow, Arthur, Geol. survey of Mis- 
souri, 317; Mapping of Missouri, 323. 
Wolff, J.E. , Geology of the Crazy moun- 
tains, 319. 

World's Congress of geologists, 196. 

Wooster, L. EC, Glacial strive ‘in Kansas, 
131. 

Wright, A. A., Extra morainic 
New Jersey, 207, 

Wright, G. F.,195, 262; Man and the Gla- 
cial Period, 387. 


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