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Fore Sam sh ” we va gta tedeat wae peasy ~ wer oe Tt ih ae le Ce Leereret’ yoeenst aperrwrntyn. T newer pape Tt eee wy 4 Lakes bens 9h sovbinet sje tpnigeit onus lene’ “ EOLOGY a u | m-™™\ 1m Se , GEOLOG Y LIBRARY Return this book on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for disciplinary action and may result in dismissal from the University. University of Illinois Library L161—O-1096 Digitized by the Internet Archive in 2010 with funding from University of Illinois Urbana-Champaign http://www.archive.org/details/panamericangeolo191897desm ¥ Fe % # eee OF THE UNIVERSITY of ILLINOIS, f aa aa » He, ee — = ae * . > sh A peg oe ele SO ee etn et ea a a ys ionA » Awa . % : ir THE AMERICAN GHOLOGIST A MONTHLY JOURNAL OF GEOLOGY \ AND ALLIED SCIENCES EDITORS AND PROPRIETORS FLORENCE Bascom, Bryn Mawr, Pa. CHARLEs E. BEECHER, New Haven, Conn. SAMUEL CALVIN, Jowa City, Iowa. Joun M. CLARKE, Albany, N. Y. PERSIFOR FRAZER, Philadelphia, Pa. Epwarp W. CLAYPoLE, Akron, Ohio. Unysses 8. GRANT, Minneapolis, Minn. JouHN EYERMAN, “aston, Pa. WARREN UPHAM, St. Paul, Minn. “MARSHMAN E. WapswortH, Houghton, Mich. IsRAEL C. WHITE, Morgantown, W. Va. Newton H. WINCHELL, Minneapolis, Minn. VOLUME XIX | JANUARY TO JUNE, 1897 Minnearouis, Minn. Ture GroLogicat PUBLISHING CoMPANY 1897 Tue FRANKLIN PRINTING Co., Printers f s .) af arg | a OVROM TOY the RRA AU 1 Le! 4 : 4 i A Se ; by ae z ‘ x - ha SNe nae J ; ab ax) yen , wa ” ‘ i 7, + hie. ‘ > " “4 a), «> a if “ "4 j a by 5 ‘ “ t My 23. ; \ n ; ‘ ’ CONTENTS: JANUARY NUMBER. PAGE Sketch of W. W. Mather. C. 4H. Hircucock. [Portrait.] 1 The Study of Natural Palimpsests. G. P. Grimstry....... 15 The Galena and Maquoketa Series. [II.] F. W. Sarpe- VGA. okt: ee ech 8 Pe SR we a 21 Rules and Misrules in Stratigraphic Classification. [I.] “SIDS WES 000) Teese Aca enlace aye 35 The Relation of the Streams in the Neighborhood of Philadelphia to the Bryn Mawr Gravel. Miss F. ARCOM ap LDR ME oc... -c.2-:scnens eevee eta ety een oe 50 Review of Recent Geological Literature.—The Underground Water of the Arkansas Valley in Eastern Colorado, G. K. Grrsert, 57.— On the Apical End of Endoceras, GERARD How, 60. —Faunas of the Paradoxides Beds in Eastern North America, ey F. MatrHew, 62.—The Disseminated Lead Ores of Southeastern Missouri, AR- THUR Winstow, 63.—Contributions to the Cretaceous Paleontol- ogy of the Pacific Coast: The Fauna of the Knoxville Beds, T. W. Stanton, 63.—Bibliography of Missouri Geology, C. R. Krys, 63. —The Eocene Deposits of the Middle Atlantic Slope, W. B. Ciark, 64.—The Cambrian Rocks of Pennsylvania, C. D. Waucort, 64.— Annual Report of the Inspector of Mines of Kentucky for 1895, C. J. Norwoop, 65. List of Recent Publications, 65. Correspondence.—The Age of the California Coast Ranges, F. LESLIE RANSOME, 66. Personal and Scientific News, 67. IV Contents. FEBRUARY NUMBER. Professor Ch. Fred Hartt, M. A.—A Tribute. FREDERICK Wy. Simons. |) | Portrants] Sse pe oe ere 69 The Galena and Maquoketa Series. [III.] F. W. Sarpe- son, [Plates IV. andi Vo jxe os file ee a Reaeeac be teas. 91 Rules and Misrules in Stratigraphic Classification. [II] ~ SG TAS MAR COU >. ca ee eee rae I ace cee tee 111 Rapidity of Weathering and Siem Erosion in Arctic attudes. R/S. “LanRa aeons ioe cee 131 Review of Recent Geological Literature.—Ueber cambrische und silu- rische Phosphoritfiihrende Gesteine aus Schweden, JoHan Gun- uasR AnpDERSSON, 137.—The Distribution of the Cambrian and the Silurian Formations in Siberia, Baron Tour, 138.—The Ancient Volcanic Rocks of South Mountain, Penn., FLorRENCE Bascom, 139. —The Relation of the Fauna of the Ithaca Group to the Faunas of the Portage and Chemung, Epwarp M. Kinpxp, 140. List of Recent Publications, 142. Personal and Scientific News.—Glaciation in the Puget Sound Region, 144.—-Geological Society of America, 145. MARCH NUMBER. Origin of Pegmatite. W. O. Crosspy and M. L. FuLier. MPlates:. ViUL, VUE; Dae i eer ee eee 147 The Galena and Maquoketa Series. PartIV. F. W. Sunt TOSI} 0 eh See | LE etd! Rp ES Ea ae i EE? - 180 ’ Evidence of Glaciation in Labrador and Baffin Land. R. Saarr: | Plate Xie sedge RS tae Gy OE EL 191 Eskers Indicating Stages of Glacial Brcecsion in the Kansan Epoch in Northern Illinois. Oscar H. Her- paay. | [Plate XT. | soem ere sence et oan ree 197 Editorial Comment.—An Important Aid to the Investigator and General Student, 209. Review of Recent Geological Literature.—Sixteenth Annual Report of United States Geological Survey, C. D. Wautcorr, 210.—Geology of the Fox Islands, Maine: A Contribution to the Study of Old Voleanics, GEorGE Otis SmirH, 214.—Till fragen om fosforitla- grens upptridande och forekomst i de geologiska formationerna, HerMAN Hepstro6m, 219.—Tables for the Determination of Min- erals by Physical Properties Ascertainable with the aid of a few Field Instruments, PERstroR FRAZER, 221.—Geologic Atlas of the United States, Yellowstone National Park folio, 222. Correspondence.—An Explanation by Dr. Grimsley, 222. Personal and Scientific News, 223. APRIL NUMBER. Physiographie Geology of the Puget Sound Basin. James P.O KIMBaLy. \[ Plate XOUE cesar eee. ee ak 225 Contents. Vv Eskers Indicating Stages of Glacial Recession in the Kan- san Epoch in Northern Illinois, Concluded. Oscar 1 Cpe TCLS IS22 8p a eg EP SS, te Ae. rie Reag t 237 Hornblende-Basalt in Northern California. J. 8. Dinter 253 The Geology of a Typical Mining Camp in New Mexico. C.L. Herrick. [Plates XITI and XIV.].... Se 256 Valley Glaciers of the Upper Nugsuak ematain). Grae and on ADPe PARR. [| PlateckWelse 20.0 262 Lakes with More than One Outlet. Tuomas L. Watson... 267 Editorial Comment.—Synopsis of the Drift Deposits of Iowa, 270. Review of Recent Geological Literature.—The University Geological Survey of Kansas, 272.—Preliminary Report on Artesian Waters of a Portion of the Dakotas, N. H. Darron, 274.—Minéralogie de la France et de ses Colonies, A. Lacrorx, 276.—Ueber die Geolo- gischen Verhaltnisse des Cambrium von Tejrovic und Skrej in Bo- hemia, J. J, JAHN, 277.—-Elementary Geology, RateuH S. Tarr, 277.—Glaciers in North America. I. C. Russet, 278. Recent Publications, 279. The International Congress of Geologists. (Second Circular.] 283. Correspondence.—Moraines of Recession and their Significance in Gla- cial Theory, F. B. Tayior, 290. Personal and Scientific News, 291. MAY NUMBER. Changes of Level in the Bermuda Islands, Ratpo 8S. Tarr. Pelates MVa.; X VIL, XVIII. |}... 3 cee eysP Physiographic Geology of the Puen ‘Gouin eaein. Tons / PO Meese AtON LN. | ......:. 1 ee meeeee sls 304 A New Dinichthys—Dinichthys Kepleri. E. W. Cray- Bopreeetmame stout Me Keele... cs at eS Se SO On-the Genesis of Claystones. H.W. Nrewors.. 0... 324 Nomenclature of the Galena and Maquoketa Series. F. W. SARDESON. ........... ae alam mL teh The Age of the Ce iees of I North 4 Aunevien. ALEXAN- DER N. WINCHELL... oe 336 Relation of the Tiattiette or Ora eme Uplift of Nori America to Glaciation. Warren UPHAM..........000...... 339 Editorial Comment.—Natural Science, 343.—Seventh Session of the International Congress of Geologists, St. Petersburg, 344. Review of Recent Geological Literature.—The Geology of Minnesota, vol. rt, part 1, N. H. WincHect, State Geologist, 346.—A Sum- mary of Progress in Petrography in 1896, W. S. Baytery, 350.-—Bi- ennial Report of the State Geologist of Missouri, C. R. Keyes, 350. Recent Publications, 350 Correspondence.—Observations on the Cimarron Series, F. W. Cracin, 351. VI Contents. Personal and Scientific News, 364.—Lawsonite in Corsica; The Hayden Memorial Award; Death of Professors James and Cope; Missouri Geological Survey; St. Louis and California Academies of Science: Reception to Sir Archibald Geikie. JUNE NUMBER Evidenees of Current Action in the Ordovician of New York. R. Rurpemann. [| Plate Sagas eee 367 Lake Adirondack, B. F. Taytor.. s ba Nol oe What is the Olenellus Fauna? G. F oi ovis Ww. = S BOs Lakes with Two: Outlets in Northeastern Matmoaven: U. RGU NT 2c oe . 407 Rhythmic Recumulaaen of Moraines a Wenn tz 2e- Sheets. Warren UPHAM... Th ota or eam RR a SB Cae 411 Review of Recent Geological Literapone: Sith SbeiieneE of Copper Minerals in Hematite ore, Montana Mine, Soudan, Minn., J. H. Esy and C. P. Berkry, 417.—Summary Report of the Geological Survey of Canada, 1896, G. M. Dawson, 417.—The Water Resources of Illinois, FRankK LEVERETT, 418. Recent Publications, 419. Correspondence.—A Complete Oil- Well Record, I. C. Wuirs, 422. Personal and Scientific News.—Glacial Lake Hamline, 423.—Sir Archi- bald Geikie’s visit to America, 424. Index, 427. 00 ee a 5 a beet: THE AMERICAN GEOLOGIST, Vol. XIX, Plate I. AMERICAN CEOLOCIST. Vou. XIX. JANUARY, 1897. No;, 1 SKETCH OF W. W. MATHER. By C. H. Hircucocr, LL. D., Hanover, N. H. [Portrait, Plate I.] William Williams Mather was born in Brooklyn, Connecti- cut, May 24,1804. The first of his ancestors to arrive in this country was the Rev. Richard Mather, who had emigrated from England in 1635 and settled in Massachusetts. The distinguished president of Harvard College, Increase, and his son Cotton, the eminent divine and author, belonged to the same stock. The maternal grandfather, Nathan Williams, was a soldier in the war of the Revolution. Young William became an adept in chemistry, and gradu- ated at the West Point Military Academy in 1828. In 1826 he corrected and amended the proofsheets of a treatise on chemistry prepared by J. W. Webster, who was afterwards executed upon the gallows for the murder of Dr. Parkman. Webster failed to acknowledge his indebtedness to Mr. Mather in his preface, thus showing his lack of courtesy. After graduation Mather remained for eight years in the army, partly on regular duty, partly acting as professor of mineral- ogy, geology and chemistry at West Point and Wesleyan University, and lastly as assistant geologist to G. W. Feather- stonhaugh in the exploration of Wisconsin Territory. 2 The American Geologist. January, 1897 In 1836 he was appointed geologist of the “first district” of the state of New York, taking the place of Edward Hitch- cock, who had resigned this position after about a month’s field-work. Prof. Mather made five annual and one final re- port on the geology of this district. From 1837 to 1840. he had in charge the first geological survey of Ohio, preparing two annual and one special report upon the collections gath- ered during the explorations. He was also employed to con- duct the geological reconnaissance of Kentucky in 1838, 1839, upon which he wrote a brief report. After the suspension of the Ohio survey, Prof. Mather pur- chased a tract of land in Jackson county, Ohio, and became a citizen of the state. Subsequently he taught natural science in the Ohio University, at Athens, and at Marietta College. His abilities as a geologist led to frequent employment as an expert in the examination of mineral lands upon lake Supe- rior, in Virginia, New York, Massachusetts, ete., during all the rest of his life. For several years he was connected with the Ohio State Board of Agriculture, either as secretary or chemist, and he was also the editor of the “Western Agricul- turist.” He died at Columbus, Ohio, Feb. 26, 1859. Prof. Mather had a vigorous constitution, and consequent large ability to engage in scientific explorations, with the ca- pacity to understand and describe natural phenomena and to speculate upon their causes. He possessed a gentle disposi- tion, was manly, self-reliant, just in his estimates of others, not dogmatic nor ostentatious, ready to give up any theory when convinced of its falsity, and he held firm religious prin- ciples. Through an active and laborious scientific career of thirty years no suggestion of censure ever assailed his integ- rity. His work was well and faithfully done, and his name will always hold a place of honor among the geologists.of his day. Farther special statements as to the official positions held, as to honorary degrees and membership in various societies, and a list of his various published reports, papers, and books are appended. These were furnished by his son, Mr. Richard Mather, of Ironton, Ohio. For further biographical details the reader is referred to the memorial sketch prepared by Hon. Ivers J. Austin in the annals of the New England His- Sketch of W. W. Mather.—Hitchcock. 3 toric and Genealogical Society, and to a similar notice in Appleton’s Popular Science Monthly for August, 1896. The accompanying portrait represents Prof. Mather as he appeared at the age of fifty-three, not long before his death, when in the maturity of his powers. The portrait in the Popular Sci- ence Monthly was taken in 1846, when forty years of age. The most important of Prof. Mather’s writings may be the “Geology of the First District of New York,” which afforded a larger list of formations than any of the other districts. It included—using the nomenclature of to-day—the Archean, Cambrian, Silurian, Devonian, Triassic, Cretaceous, Tertiary, and Quaternary. He must have been forward among his col- leagues in the establishment of the ‘New York System” and in the use of local names for the subordinate divisions. In his report for 1840 this system was said to consist of the Catskill, Helderberg, Shawangunk, and Hudson River. The first included the Chemung, the third was composed of rocks quite different from the Niagara, Clinton and Medina, of the Ontario division, and the Hudson: series embraced all the Lower Silurian, including the Potsdam. Two of the geolo- gists—Hall and Emmons—exeluded the Catskill from their enumeration, calling it simply “Old Red Sandstone.” The order of deseription was from above downwards in obedience to the general usage of the time. Mather had been commissioned by the American Associa- tion of Geologists in 1840 to present before them the subject of the “ Drift.” Not being in readiness to present his paper in 1841, and being absent from the next two meetings, he used the material, chiefly gathered in his own state. for his official report. This is unusually full and is one of the best presen- tations of the’subject in his time. The Quaternary is divided into three parts, Alluvium, Quaternary proper, and Drift. The description of the first relates to fluviatile, lacustrine, and marine alluviums, low-lying sands, bars, mud flats, peat, marl, bog iron, tufa, beaches, shoals, spits, dunes, together with full descriptions of all the fossils contained in these deposits, es- pecially the Infusoria | Diatoms]|. This topic also embraced springs, caves, transportation by floating ice, the disintegra- tion of rocks, and denudation. The second division related to the modified drift—river terraces, beaches bordering the great lakes, sand and gravel 4 The. American Geologist January, 1897 plains, the meadows and sands of Manhattan island, and the marine deposits along lake Champlain and Hudson river. Thirdly, came the subject of the Drift—erraties, hardpan, lists of striae, both for New York and other states. The de- scription of the distribution of boulders and till over Long island is very full and complete, and was used by the writer in the preparation of a paper presented to the Lyceum of Natural History in New York and the Long Island Historical Society in 1868, entitled “The Geological History of Long Island.” The facts of Mather’s report were employed to il- lustrate the theory that the backbone of Long island consti- tuted a part of the terminal moraine of the ice-sheet. Mr. Mather, however, followed his contemporaries in supposing that the dispersion of the boulders and the striation of the ledges resulted from floating ice in a time of general submer- gence. His objection to Agassiz’s glacial theory was the com- mon one of his day—that the flat lands of the middle western states did not offer a sufficient slope to produce motion in the ice-sheet. Owing to his connection with surveys in other states he says his conclusions were based upon what he had seen in over one hundred thousand miles of travel. The study of the formations of Long Island enabled Mather to recognize both the Tertiary and the Cretaceous, though he used a local name for the group. The outcrops of the Trias were rather limited, but he correlated the sand- stones with those of the Connecticut valley, and he suspected that the associated trap rocks might have been ejected in the Cretaceous. For the proper explanation of the distribution of the Trias in the Connecticut and Newark areas, with op- posite dips, Mather first states and rejects the fluviatile hy- pothesis of H. D. Rogers and then proposes a new theory based upon the courses of the equatorial or gulf stream and of the returning polar current. The first stream being direct- ed through the Connecticut valley would naturally deposit sediment upon an easterly slope, and the returning polar ecur- rent having a westerly tendency would drop its burdens upon the Palisade side of the Hudson. No part of this report has attracted more attention than his conclusions respecting the rocks east of the Hudson river. His colleague, Emmons, as is well known, had proposed an Sketch of W. W. Mather.—Hitchcock. 5 interpretation for certain formations in this district not ac- cepted by any other one of the board of geologists except in part by Vanuxem. These rocks consist of a series of great thickness, sandstone, limestone, and slate, to which Emmons gave the name of Taconic System, and supposed them to underlie the Potsdam sandstone, then esteemed as the base of the Silurian system. Inasmuch as these rocks did not oceur in the second district, Emmons could not legitimately des- eribe them in his official report except cursorily; nor could his views be properly illustrated upon the general geological map compiled from the reports of all the geologists. Hence he was compelled to state his views in a volume prepared later upon Agriculture, and to draw his illustrations largely from the adjoining states of Massachusettsand Vermont. This di- vergence of views led to the Taconic controversy—a discussion that became very bitter between its chief disputants—com- parable inintensity and duration to the similar conflict in England between Sedgwick and Murchison over the Cambrian and Silurian. In fact the principles involved were identical upon the two continents. Connected with the stratigraphical discussion arose the subject of metamorphism, which was unnecessarily controverted by Emmons and advocated by Mather. On these subjects Mather held: (1) The “ Taconic rocks are the same in age with those of the Champlain Division, but modified by metamorphic agency and the intrusion of plutonic rocks.” p..438. (2) The limestones that are frequently crystalline white and variegated marbles, talcose slates and quartz rocks of Dutchess, Putnam, Westchester, and New York counties are metamorphic rocks. They were originally “the rocks of the Champlain Division, but much more altered and modified by metamorphic agency than the Taconic rocks.” page 464. (3) The Primary [Archean] rocks are extensively developed in the highlands of the Hud- son, in New York, Westchester, Putnam, southern part of Dutchess. parts of Orange and Rockland counties, and Staten island. The kinds of ores and rocks correspond with those in the northwest part of the first district, in the Adirondack re- gion, The views of Mather on all these points would not essen- tially vary from those recently presented by professor James 6 The American Geologist. January, 1897 Hall and Mr. F. J. H. Merrill in their respective geological maps of the state. This statement, however, assumes that Mather would have accepted certain modifications of presen- - tation, such as the use of the terms Cambrian for the primor- dial fauna and the acceptance of the belief that the Granular quartz of Emmons is not the equivalent of the Potsdam but a much lower horizon. Mather’s name has been mentioned in connection with the suggestion that the State Geologists should meet for consul- tation, and with their co-workers form an association of ge- ologists. In November 1838, not being able to be present, at the meeting, he addressed a letter to the New York board of geologists, presented through professor Emmons, commencing as follows: “ Would it not be well to suggest the propriety of a meeting of the geologists and other scientific men of our country at some central point next fall, say in New York or Philadelphia. There are many questions in our geology that will receive new light from friendly discussion and the com- bined observations from various individuals who have noted them in various parts of our country. Such a meeting has been suggested by professor Hitehecock and to me it seems desirable,’ ete. From a letter of Mather to Hitehcock in 1849, it appears that professor Vanuxem made the motion before the Board to adopt the suggestion; and it is a well known fact in bis- tory that this vote led to the formation of the “American Asso- ciation of Geologists,’ followed several years later by the American Association for the Advancement of Science.* The Geological Survey of Ohio was carried on during the years 1837 and 1838. Greater help was obtained from assis- tants than in the New York survey. As the result of these two years of labor Prof. Mather was enabled to establish the column of formations, whose accuracy was certified to by the later works of Dr. J.S. Newberry. The basal rock is the * Blue limestone” or Lower Silurian, followed by the “Cliff limestone,” which has been identified with the Upper Silurian *The correspondence relating to this subject is given in the Tenth Annual Report of the Regents of the University on the State Cabinet of Natural History, page 23. It seems that Hitchcock wrote on this subject to Mather in 1837 and 1838. Sketch of W. W. Mather.—Hitchcock. Z and Lower Devonian. The succeeding “ Black slates” are Upper Devonian. The ‘“ Waverly sandstone” finally proves to be the lowest Carboniferous, though referred to the Portage and Chemung groups in 1842 by professor Hall. The two latest members are the Conglomerate or Millstone grit and the Coal Measures. He found the beds of coal to be of great value, and interested himself in his later life by investing in these lands and laboring earnestly for their development. The great industries located in Ohio, dependent upon coal and iron, amply confirm the correctness of the judgment of Prof. Mather in those early days of their great value. Mr. Mather received the degree of M. A. from Wesleyan University, Middletown, in 1834, and that of LL. D. from Brown University in 1855. He was a member or corresponding member of numerous scientific societies, among which may be named: Yale Natural History Society, New Haven, 1836. -Lyceum of Natural History, New York, 1837. Academy of Natural Sciences, Philadelphia, 1838. Association of American Geologists, 1840. Association of American Geologists and Naturalists, 1841. National Institute, Washington, D. C., 1842. American Association for the Advancement of Science, 1847. He was also a member of various philosophical and histor- ical societies, viz. : Ohio Philosophical and Historical Society. Connecticut Historical Society. Historical and Geological Society of Norwalk, O. Minnesota Historical Society. He was trustee of Granville College, O., from 1840 to 1855, and a life member and director in many religious organiza- tions. List of Official and Professional Positions held by W. W. Mather. 1828. Brevet Second Lieutenant, U. S. Army, July Ist, 1828. Acting Assistant Instructor of Artillery at West Point during the en- campment, June. July and August, 1828. Assigned to duty with 6th Regiment Infantry at Jefferson Barracks School of Practice, 1828. Promoted to Second Lieutenant, 7th Infantry, July Ist, 1828. ROC Ordered to 7th Regiment at Fort Jousue April, 1829. Ordered to West Point as Acting Assistant Professor of Chemistry, Mineralogy and Geology, June 29th, 1829, and remained on duty there until June, 1835. 8 The American Geologist. January, 1897 1833. Acting Professor of Chemistry, Mineralogy and Geology at the Wes- leyan University at Middletown, Conn., during the recess of his course of instruction at West Point, by permission of the Secretary of War. 1835. On topographical duty, June to December, 1835, as Assistant Geolo- gist to G. W. Featherstonhaugh, making a geological examination of the country from Green bay to Coteau des Prairies; and Mr. Mather made a report and a topographical map of the St. Peter’s river valley of Min- nesota. Ordered to Regiment at Fort Gibson, November, 1835, and marched into Choctaw country May, 1836, in command of Company D, 7th Infy. 1836. Resigned from the Army, August 23d, 1836. Appointed Professor of Chemistry, Min. and Geology in the Univer- sity of Louisiana. 1835. Declined. Geologist of the First District (S. E. quarter) of New York, contain- ing 21 counties, from July, 1836, to 1844. (Made five Annual Reports and one Final Geological Report.) 1837. Geologist superintending the Geological Survey of Ohio from 1837 to 1840. (Made two annual reports and one on the collections). 1838. Geologist making a Geological Reconnaissance of Kentucky, 1838 to 1839. (Made one report). 1842. Professor of Natural Science in the Ohio University, 1842-1845. 1845. Vice-President and Acting President, and Professor of Natural Sci- ence at the Ohio University, 1845. Geologist and Mining Engineer to various mining companies on Lake Superior in 1845, 1846 and 1847, and others in Virginia, New York, Mas- sachusetts, etc. 5 1846. Acting Professor of Chemistry, Mineralogy and Geology at the Mari- etta College, Ohio, January to March, 1846. Acting temporarily. Un- willing to accept the professorship in consequence of other arrange- ments. 1Saiee Vice-President and Professor of Natural Science in the Ohio Univer- sity, 1847 to December, 1850. 1850. Delegate of the Jackson County Agricultural Society to the State Agricultural Convention of Ohio, annually 1850, 1851, 1852, 1853, 1854, 1855, 1856 and 1858. 1850-4. Corresponding Secretary of the Ohio State Board of Agriculture 1850- 1854. (In charge of the office of the Board, conducting the correspond- Wy /@ My f: “ie ry, [ Sketch of W. W. Mather.—Hitchcock. 9 “Noy ence with the State Societies of other states, with foreign Agricultural Societies and individuals, and with the 80 County Agricultural Socie- ties subordinate to the Board. Also charged with preparing all the publications of the Board, the fairs in their details, and distribution of the awards.) Agricultural Chemist of Ohio for the State Board of Agriculture, analyzing soils, ores, coals, water, salines. etc., and making Agricul- tural and Geological surveys. (Vide reports in Reports of Ohio State Board of Agriculture.) 1851-2. Editor of the Western Agriculturist, Jan’y 1st, 1851, to July Ist, 1852. (First volume and one-half of second volume.) 1852. Delegate to the U.S. Agricultural Convention at Washington city for the Ohio State Board of Agriculture, June, 1852. 1853. Geologist of Lieut. Williams’ part of exploration for the Pacific rail- road across the Sierra Nevada, May, 1853. Declined. Disabled by a snake bite (supposed to be) and partial paralysis consequent, and am- putation necessary. Geological Engineer, making surveys of the available mineral re- sources of the Lexington and Big Sandy railroad in Kentucky . 1853-4. Member of the U.S. Board of Agriculture for Ohio. 1854. Appointed Lecturer on Agricultural Science in the Dennison Univer- sity, Ohio. Declined. 1855. Geological Engineer making the survey of the available mineral re- sources on the line of the Pittsburg, Maysville and Cincinnati railroad in Ohio. Member of the Board of Visitors appointed by the president to attend the examination of cadets of the U.S. Military Academy at West Point, New York, and report to the Secretary of War. 1856-7. Manager to build and put in operation Oak Ridge furnace, in Law- rence county, April 30th, 1856, to December 14th, 1857, when the fur- nace was in full operation from August 5th, 1856, to December 14th, 1857, Directer in said Furnace Co. from August, 1857. Writings of W. W. Mather. 1828. On the non-conducting power of water with regard to heat. Ameri- can Journal of Science and Arts, vol. xm, p. 368. 1830. Report on the analysis of the Lycoming Iron ores, (to Geo. Carpen- ter). Vide Mather’s manuscript, ‘‘Chemical Researches,’ March, 1830, page 37. a rrag i g 10 The American Geologist. January, 1897 On the crystalline form of Iodine. Am. Jour. Science, xviit, p. 184. On the crystalline form of Xanthite. Am. Jour. Science, xvut, p. 359. 1831. On the production of Aluminum and Magnesium. Am. Jour.-Sci- ence, xx, p. 408. 1832. Geological notes and Geological Section in Connecticut. Geological notes on the Highlands of New York. Am. Jour. Science, xxt, p. 94. 1833. Sulphurets of Bismuth, and formation of anew compound--the disul- phuret. Am. Jour. Science, xxtv, p. 189. On the principles involved in the reduction of Tron and of Silver ores, withasupplement on the principal silver mines of South America. Am. Jour. Science, xxiv, p. 213. ' Elements of Geology for the use of Schools. Published at Norwich, Conn., by William Lester. 1834. On Diluvion, for the use of the Cadets of the U. S. Military, West Pt. (part of the Geological Course). Lithographed by the U. 8S. Mili- tary Academy at the Academy Press. Geology and Mineralogy of Windham and New London Counties in Connecticut. Published at Norwich, Conn., by William Lester. Geological Map and sections of the above Counties on Lester’s Topo- graphical Map of Windham and New London Counties. Published at Norwich, Conn., by William Lester. Report on the Salisbury fron Ores and their reduction. Vide Math- er’s manuscript, ‘*‘ Chemical Researches,” vol. 1, page 85. Survey and Report to — Bacon on the Simsbury Copper Mines, and analysis of the ores. Vide Mather’s ‘‘ Chemical Researches,”’ vol. TI, page 57. 1835. Contributions to Chemical Science, viz: (1) On Chloride of Alumi- num and its analysis, and the atomic constitution of the chloride and oxide of aluminum. Am. Jour. Science, xxvit, p. 241. (2) A hydrated chloride of aluminum and its analysis, and its atomic constitution deduced. Am. Jour. Science, xxvit, p. 253-256. (3) Crystallized tin from solution (a new method). Am. Jour. Sci- ence, XXVII, p. 254-255. (4) GeorgiaGold. Analysis of the Georgia Gold Assayers. Am. Jour. Science, xxvii, p. 255-256. (5) Silver of Lane’s mine, Monroe, Conn. (Auriferous) Analysis of and remarks on other minerals of that mine. Am. Jour. Science, XXVII, p. 256-257. j (6) Potash Iodide of Platinum, its preparation, decomposition and atomic constitution. Am. Jour. Sci., vol. xxv, p. 257 (7) Cloriodide of Platinum, its preparation, decomposition and atomic constitution. Am. Jour. Sci., vol. xxvu, p. 258-262. Sketch of W. W. Mather.—Hitchcock. Tee (8) Crystallized Perchloride of Platinum, analysis and atomic con- stitution, (a hydrated perchloride). Am. Jour. Sci., vol. xxvit, p. 262-263. (9) Amalgam of Platinum. a new and easy method of preparation. Am. Jour. Sci., vol. xxvi1, p. 263. (10) Iodide of Mercury, solvents and properties. Am. Jour. Sci., vol. xxvit, p. 263. (11) Bitungstate of Ammonia, solubility in water determined, and re-agents for. Am. Jour. Sci., vol. xxyir, p. 264. (12) Disulphuret of Bismuth, with analysis and atomic constitution. Am. Jour. Sci., vol. xxvit. p. 264. Report on the Geological Reconnaisance between Green bay and the Coteau des Prairies, by Lt. W. W. Mather, on topographic duty, as as- sistant to G. W. Featherstonhaugh. Manuscript report sent from the Arsenal, near St. Louis, Mo., in November or December, 1835, to Lt. Col. J. J. Abert, of Topographical Bureau, Washington. Returned to the author in 1851, at his request. Topographical sketch of the valley and meanderings of the St. Peter’s river, accompanied the above report, from plotting courses and dist- ances. Sent with the above report, but not returned with the report to 1836. Report on the Martinsburgh Lead Mines and Ores. Instrument proposed for measuring accurately the expansion of solid bodies, and which may be used as a thermometer, and is also adapted for testing standards of length, and for Geodetical operations, Am. Jour. Sci. and Arts, xxx, p. 324. 1837. First Annual Report on the Geological Survey of the First, or S. E. District of New York, made December, 1836. State Assembly Doc. No. 161, p. 63-97, 1837. Report on Gold Mines of North Carolina. [To McIntire, Gregory & Co.] Second Annual Geological Report of the First District, N.Y. As- sembly Doc., 200 of 1838, p. 121-184. Report on a reputed coal tract in Pennsylvania. 1838. Geology for use of schools and academies. Revised, enlarged and stereotyped. Published and stereotyped in New York by J. Arnyille Taylor. [This work passed through several editions in successive years, until the publication was ordered to be stopped by W. W. M.] First Annual Geological Report of Ohio. Ohio, Assembly Doc. Third Annual Geological Report of New York, Assembly Doc. 275, p. 67-196. Second Annual Geological Report of the Ohio Geological Survey. Assembly Doc. Reports. 1839. Report on the Coal-Grove Coal and Iron property, with a description of its resources, and a minute topographical and geological map, and 12 The American Geologist. January, 1897 sections from actual survey, 4,000 acres in Lawrence County. Pub- lished by the Coal-Grove Co. in Columbus, in 1839, and in New York in 1847 by J. L. Minen & Co. Geological Report on the ‘‘Geological Reconnaissance of Kentucky, made in 1838.’’ Assembly Document, 1839. On Cupellation, an easy and accurate method with the blowpipe. Am. Jour. Science, xxxv, p. 321. 1840. P Fourth Annual Geological Report of New York. State Assembly Doc. No. 50, pp. 209-258. 1841. Fifth Annual Geological Report of New York. Assembly Doc. No. 150, p. 57. 1842. Report to the Legislature on the arranged Geological Collections for the State Cabinet, and those prepared for distribution to the Colleges and Universities of Ohio, collected on the Geological Survey. Ohio As- sembly Document. Reports, 1842. Report on the coal mines near Owensborough, Ky., [to Hon. Robert Triplett]. Published in Kentucky. 1848. Final Geological Report of the First District of New York, entitled ‘‘ Natural History of New York, Part IV, Geology, by W. W. Mather, Vol. I.” This is a quarto volume of 653 pages and 46 colored plates. Published by the State of New York in 1844, as one of the volumes of the Natural History of New York. 1844. On the possible variation of the length of the day, or of the revolution of the earth on its axis, with corrected formule of the appendix of the Final Geological Report of New York. Am. Jour. Science, xLv1i, p. 344. On the Geology of the United States east of the Rocky mountains, and an enquiry into the causes that have led to the deposition of the sedimentary rocks, and that have caused their elevation and contortion. Am. Jour. Science, xtrx, p. 1; 284. (This great physical question is considered and partially developed. This paper was written for and read before the National Institute at Washington, April, 1844, and probably published by them also, and before the American Association of Geolo- gists and Naturalists in May. and before the Athenian * * * * by request in August.) 1845. On Bromine and Iodine in the Ohio Salines. Amer. Jour. Science, XLix, p. 211. An extended series of investigation was entered into, many new com- pounds formed, improved methods of extracting bromine contrived and put in operation, with a view to manufacture, but most of the papers were lost during his absence on lake Superior in 1845-6-7. Those that remain are in an incomplete state, and neither published nor prepared for publication. Sketch of W. W, Mather.—Hitchcock. 13 1847. On Cupellation with the blowpipe, and on accurate methods of quan- titative estimation of minute quantities of silver and gold. Am. Jour. Science, (New Series) p. 409. On the meteorology of Lake Superior and the causes of the sudden and gradual changes of the level of the waters of the Lakes. Am. Jour. Science, vi, p. 1-20. Two reports to W. P. Cutler, President, and to A. B. Walker on the mineral resources along the line of the Cincinnati and Belpré railroad. Published in pamphlet form with the report of the President, 1848-9. 1848. Report and Topographical and Geological Map and sections of 7,500 acres of coal and iron land. the Robertson tract in Southern Ohio. Premium Essay on the Mineral Kingdom being the source of the | matter of the Animal and Vegetable Kingdoms. Third Annual Report of the Ohio State Board of Agriculture. 1849. Report on the practicable routes for the Scioto and Hocking Valley R. R. Various routes suggested and discussed. The route recom- mended was adopted and the road built. Scioto County papers at Portsmouth, Nov. to April, 1849-50. The question argued on the propriety of a county subscription of $100,000 by Jackson County to the R. R. Co. This question argued and all the objections answered, and advantages set forth. Resulted in a vote of 4 to 1 in favor of the county subscription. Published in the Jackson Standard, March 14-21-28, 1850. Copied into other papers. Arguments used in various counties. 1850. Report on the agricultural productions and the resources of Jackson County, O. Yifth Annual Report of the Ohio State Board of Agricul- ture. Rotations of timber growth. Ohio Agri. Rep.. 1850. Edited the Fifth Annual Report of the Ohio State Board of Agricul- ture. Assembly Document. 1851. Edited the Western Agriculturist, Jan. 1851, to July, 1852. Vol. I, pub. by J. H. Riley. Vol. II, pub. by 8S. Medary. 1852. Edited the 6th Annual Report of the Ohio State Board of Agricul- ture. Assembly Document. Report as Corresponding Secretary to the Ohio State Board of Agri- eulture. Sixth Annual Report Ohio State Board of Agriculture. Report on the Analysis of soils of Ohio, as Agricultural Chemist of Ohio. Sixth Annual Report Ohio State Board of Agriculture. Essay on the soils of Ohio, their geological relations, characters, de terioration, renovation, mineral elements of parts of plants, composition of soils. Sixth Annual Report Ohio State Board of Agriculture. 14 _ The American Geologist. January, 187 Edited the Seventh Annual Report of the Ohio State Board of Agri- culture. Assembly Doc., 1853. Report on the Agriculture of Jackson county, and on the mineral re- sources, particularly on the line of the Cincinnati, Hillsborough & Par- kersburg R. R. Seventh Annual Report, Ohio State Bd. Agri. Report on the mineral resources along the line of the Cincinnati, Hillsborough & Parkersburg R.R. [To Elwood Morris. for the Com- pany.] Published in pamphlet form by the R. R. Co., with the reports of the president (Trumble) and engineer (Ellwood Morris). Report as Corresponding Secretary of the Ohio State Board of Agri- culture, and Agricultural Chemist of Ohio: Analysis of Soils. modes, and desiderata, and objections answered; modes of improving the inter- ests of agriculture; analysis of the waters of Cleveland; analysis of Ohio coals; agricultural reconnaissance of Ohio. Seventh Annual Re- port, Ohio State Bd. Agri. Report on the analysis of the River, Lake, Well, and Spring Waters at Cleveland. [To the Water Commissioners.| Published in pamphlet form by the Water Commissioners, 1853. Report on the analysis of various coals in Ohio, with reference to their purity, heating power and adaptation for various uses. The tab- ulated results are in Seventh Ohio Agri. Report. 1853. Report on the great coal bed at Stvaitsville. [To - ident C. O. R. R.]’ Am. Jour. Sci., vol. x. p. 450. On the Argentiferous Galena of Arkansas. Am. Jour. Sci.. vol. x, p. 450. Report to the Ohio State Board of Agriculture on the importance of prosecuting a Geological and Agricultural Survey of Ohio. Read before the Board and to have been published, but lost when before the Legis- lature. Report to the Ohio State Board of Agriculture on the means nec- essary to elevate agriculture to a liberal art and science. Read before the Board, ete., as above. Essay on the same subject, and on the importance of analyzing the soils, grains, and other parts of cultivated plants from various parts of the United States. Sent to the U.S. Agricultural Society as one cf the Board, and filed for publication in its transactions. Report on the mineral resources available along the Lexington & Big Sandy R. R. [To R. Apperson, President R. R.} Published by the Company at Lexington, in the papers, and in pamphlet form. 1854. Report on the great coal bed in Perry county. and the coal lands available on this bed to the Scioto and Hocking Valley R. R. [To Is- rael Dille, Esq.] Published in New York. Duties on railroad iron should not be remitted. Rail Road Record, Wty [9b aos American and foreign railroad iron. Reasons why railroad iron has not been manufactured more extensively in the United States. Rail Road Record, 11. p. 569. Mining Magazine, N. Y., tr, p. 457-8. Sullivan, Pres- The Siudy of Natural Palimpsests —Grimsley. 15 On American and foreign railroad iron. Means by which United States railroad iron can be sold as cheaply, and on as good terms of eredit, as the Welsh railroad irons. Rail Road Recora, 1, p. 582. Min- ing Magazine, N. Y., 111, p. 570-8. On the Black Band iron ore of Ohio. Its abundance. Published in the Mining Chronicle. 1855. Report of the mineral resources available along the Pittsburgh, Mays- ville & Cincinnati R. R. [To Thos. W. Peacock, President. |] Report on the discipline in the U. S. Military Academy. General Report of the Board of Visitors at the U.S. Military Acad- emy, June, 1855. Report on the coal supply of Cincinnati, and a consideration of all the available resources of supply, with the cost of delivery, and qualities of the coals. Notes on the iron region and furnaces of southern Ohio. Am. Min- ine Chronicle, vol. x, p. 68, Sept. 1st, 1855. t 1859. Report on the State House artesian well at Columbus, O. 42 pp. This WS; STUDY OF NATURAL PALIMPSESTS. By G. P. Grimsuey, Ph. D. Paleontology has revealed a long life bistory from Cam- brian time to the present and has vainly attempted to read the obscure pages of the earlier history of Archean time. Baffled at every turn the search was abandoned, but a new science has boldly entered the field and the mysterious pages furnish a history for the petrographer which in interest rivals that of the paleontologist. This record is not written in fossil letters but in mineral characters, which so long have been meaningless geoglyphics. In making the so-called pre-historic record nature has been economical in materials and in space. She has erased some portions of the ancient record with the cleansing force of fire, rewriting on the same tablets of stone the records of new conditions. The discovery that many of the records of ancient histori- cal time were written on the erased parchments of an earlier day and that a careful investigation would reveal many of the first records, was a historical triumph, The students of ancient languages have enriched the world by their pains- taking search through old literary palimpsests. In the 16 Phe American Geologist. January, 1897 past decade the students of nature have discovered the exist- ence of natural palimpsests and they are now endeavoring to read the imperfectly erased records of the past, and thus add new chapters to the history of the earth. To the process of erasure and rewriting these investigators have given the name metamorphism, and the natural palimpsests are called meta- morphic rocks. The studies of the biologists have shown that throughout organic nature there is a most delicate adjustment to environ- ment. The researches of petrographers have shown that in the inorganic world minerals are so delicately adjusted to surrounding conditions that changes in the latter are recorded by variations in the minerals. The recognition of this fact in recent years is the foundation of the new knowledge con- cerning the Archean period. According to the Wernerian theory of the last century, _ erystalline rocks were deposited as chemical precipitates from a primeval heated ocean before life existed; they were pro- duced at their origin as they exist to-day. Near the close of the century, Hutton found granite dykes penetrating other rocks, thus proving an igneous origin. He then advanced farther and formed the interminable cycle, stating that rocks were decomposed by atmospheric¢ action, the detritus accumu- lated at bottom of the sea, where under the pressure and heat it was rendered crystalline, and later elevated to pass through the same series of changes without trace of beginning or pros- pect of end. The theory of the transformation of rocks under heat and pressure originated at this time in this rudimentary form in Scotland. Bone and Necker, nearly a quarter of a century later, transported the theory from this plutonic re- gion to Europe where it reached greater development. The Alpine region, on account of the great forces at work and the gradations in effects, from simple to complex, soon became the classic region for the study of rock alterations. In 1826 Beaumont recognized that in this region the phenomena were not confined to the oldest rocks. He observed that Jurassic fossil sediments had been changed to crystalline rocks. The old Alps now became the new Alps and the interest in the re- gion was greatly increased. The Study of Natural Palimpsests.—Grimsley. Ww In the process of adjustment of the minerals or rocks to changes in their environment new elements are often added and old ones removed. If the changes take place at the sur- face of the earth, under ordinary atmospheric or aqueous in- fluences, they are included under the term weathering and the result is usually disintegration. True metamorphism is con- nected with igneous and dynamic agencies; and while the word was first introduced by Lyell in 1832, it was not clearly defined until 1846, when Durocher described metamorphism as the sum total of all modifications in texture or structure to which rocks in nature are subjected. Daubrée limited the definition to those modifications whose causes were fire and water, and Beaumont added the agency of mineralizers. The word metamorphism is now cosmopolitan, though given differ- ent limitations by different authorities. American geologists from an early day have been prominent in this field of study. The pioneers composing the American metamorphic school, Hitchcock, Mather, Dana, Logan, Rogers brothers, were active students of these altered records and they made many valuable observations. They all regarded the process of metamorphism as confined to the sedimentary rocks, a view which long retarded progress in the work. When foliated or parallel structures were observed in meta- morphic rocks they were regarded as the old sedimentary lines which survived the alteration: A voluminous literature descriptive of this limited field of altered sediments soon filled the shelves of science. : Down to the year 1875 the province of metamorphic action was thus confined to sedimentary rocks. About this time ap- peared the epoch-making works of Heim in the Alps and of Lossen in the Harz, whereby it was shown that igneous rocks could be changed by metamorphic action. ; On account of the interesting and inviting problems con- nected with this study, it has attracted the attention of many of the younger workers; and the result has been a very great advance in our knowledge of these broken and crumpled . rocks, though the vast field yet remains practically unex- plored. Metamorphism may refer to any change in rocks, but it is restricted now to include the changes whose conditions lie in- ele, oe 18 The American Geologist. January, 1897 termediate between fusion and ordinary atmospheric action. The limits are not sharply defined, so metamorphism grades below into igneous action, and above into atmospheric action or weathering. Metamorphic rocks may be further metamor- phosed so that all rocks, sedimentary, igneous and metamor- phic, are subject to metamorphism. The agencies at work in this great process are both physical and chemical and they are classified according to the preponderating influence. If the temperature and pressure are low the action is due mainly to water, producing hydro-metamorphism, resembling very closely weathering. If the temperature is high and pressure is low, and mineralizers—gases whose presence facilitates fu- sibility are present the action is described as sublimation- metamorphism; or, if water alone be present, the action is described as thermo-metamorphism. Static-metamorphism in- cludes those changes where pressure is mainly active and where motion is absent. If motion is present the changes come under the division of dynamic-metamorphism. All of these alterations take place without any material change in bulk composition. Static metamorphism, though not accepted by many geologists, has able defenders in such men as Hall, Judd, Spring. Dynamical metamorphism has been firmly es- tablished by the classic works of Heim, Lehman and Balzer. Metamorphism may be produced by the presence of some metamorphosing agent, and it is then termed contact meta- morphism. ‘'The alteration in surrounding rocks may extend over a distance from a small fraction of an inch up to 4,000 feet, as seen in the Pyrenees. The nature of contact meta- morphism depends on the duration of the action, the depth at which the alteration takes place, whether deep enough to prevent escape of the vapors and moisture or not; andon the nature of the metamorphosing agent whether this is a gran- ite, diabase or other rock; and also on the nature of the rock altered, whether crystalline schists, carbonaceous rocks, sand- stones or igneous rocks. The nature further depends on the structure of the rocks. whether foliated or not, as demonstra- ted in Brittany by Barrois. Rosenbusch, after a careful examination of analyses, con- cludes that there is no change in the bulk composition of the altered rocks, though Michel Levy insists that there is always a very considerable addition of substance. The Study of Natural Palimpsests.—Grimsley. 19 The effect of contact metamorphism on the erystalline schists is less intense than on most of the rock types. The effects, consisting mainly of formation of new minerals, as andalusite, sillimanite and garnets, have been described in the Cortlandt rocks by the late Dr. G. H. Williams. The effect of this form of metamorphism on carbonaceous shales is to form graphite, or the diamond, as in the South African region, The etfects of contact action on clay slates have been described at a number of regions which serve as types; at Barr Andlau, in Germany, by Rosenbusch, by Lossen in the Harz, by All- port and Phillips in England, by Barrois in Brittany, Brég- ger in Norway. In these various regions it has been noted that the intensity of metamorphism at any given point is pro- portional to the nearness of the intruding rock. In limestone contacts the conditions are very favorable for tracing the beginning and development of the metamorphism. The limestone is observed to become more and more crystal- line as the intrusive rock is approached and the carbonates change to silicates. These changes are observed in the well known limestone contact region near Christiana, in Norway, and in the famous mineral locality of the Fassathal in the Tyrol. Contact action on igneous rocks has been observed at but few places. It has been described by Lossen in the Harz mountains. The pioneer in the study of dynamie metamorphism was Lossen in 1867. In 1878 Heim published his great work, the result of a long field study of the Alpine rocks, in which he developed the theory that even the most brittle rocks under pressure acted as viscous bodies and were deformed without rupture. Spring and Guembel endeavored to prove this the- ory by actual experiment, but the rocks were crushed to a fine powder. In 1884, Lehman, as a result of microscopical study of the crystalline schists of the Alps, concluded that the rocks were crushed and recemented under great pressure, thus producing an effect similar to viscous bodies, a process which might be described as rock regelation. These two works mark a new phase in the study of metamorphism the world over, through the recognition of the fact that foliation in rocks is wholly independent of original structure. Parallel arrange- Sieu 20 The American Geologist. January, 1897 ment in rocks is not proof of sedimentation, a view which be- fore this time was not recognized. Heat, water and pressure are the great agents of metamor- phism, and they produce three kinds of alterations in rocks, mineral, microstructural and macrostructural changes. Un- der mineral changes, we have among the alkaline silicates the alteration termed sericitization, forming an interlacing net- work of hydromicas. Also saussuritization, embracing the changes whereby the plagioclase feldspar is converted into alkaline earth silicates. In a/bctization the feldspar is changed into an interlocking albite mosaic. Among the iron-magne- sian silicates occurs: uralitization, where pyroxene is changed into fibrous hornblende, viridization or formation of green epidote chlorite mass, analogous to saussuritization, chloriti- zation and epidotization, analogous to albitization. Under microstructural changes are observed the strain phe- nomena in erystals, recognized by polarized light in a wavy extinction of the light as the section is rotated. If the strain has been earried farther, gliding or twin lamelle may be ob- served, as in the metamorphic marbles. Progressing to greater extent the minerals are bent. twisted and finally bro- ken into an irregular mosaic, composed of interlocking min- eral grains. Sometimes there is a stretching of the rock along certain lines, pulling the grains apart. Under macrostructural changes, the most prominent is the formation of secondary foliation or an arrangement of the minerals along parallel lines, which were so long taken as evidence of stratification. Though this distinetion between foliation and sedimentary lines was noted early in the century _ by Voigt, Mohs, and Schmidt, it attracted little attention. Later it was observed that the lines were parallel over exten- sive tracts, even when the rocks were crumpled. This was explained as the result of crystalline force or result of elee- trical currents passing around the earth. In 1846 it was shown to be due to pressure normal to that which developed the foldings. Such rocks which possess this secondary foliation are called crystalline schists. This is a purely structural term and has no connection with age. While most of these rocks are pre- Cambrian, there are numerous exceptions. The schists are The Galena and Maquoketa Series.—Sardeson, 21 divided into two main groups, those with feldspar and those without this mineral, and the former are called gneisses. This usage makes gneiss a mineralogical and structural term; mineralogical in that it contains feldspar, structural in that it is foliated. If the origin of the gneiss is determinable it has the original rock name added as a prefix. Thus a sec- ondary foliated conglomerate is called a conglomerate gneiss, a foliated granite is a granite gneiss. When the word gneiss is used alone it represents a foliated feldspathic schist of un- known origin. Down to the end of the last century geology was a collec- tion of hypotheses and sacred theories of the earth. Its stu- dents then began to observe and record facts, and later to form theories based on such observed facts. The study of the igneous rocks passed through a similar course of develop- ment. The study of the metamorphic rocks is now passing through such a course and it has entered the descriptive stage. It is now at the point reached by general geology in the time of Lyell, and reached by the study of the igneous rocks in the year 1870. The study of the crystalline schists, both of Archean and post-Archean time, now becomes the great field for work and all over the world students are trying to trace their origin and formation. Washburn College, Topeka, Kansas. THE GALENA AND MAQUOKETA SERIES. By F. W. Sarpeson, Minneapolis, Minn. AR ele New Classification. In the first part of this paper it has been shown that the local classifications of the Maquoketa and Galena series are discordant, and that a more complete and generally applica- ble system, which will embrace the elements of truth contained in each, ought to be substituted. The entire succession of strata that go to make up the Galena and Maquoketa together, is divided into about fourteen easily recognizable beds, that are, as a rule, co-extensive and continuous, and that are the component parts of all the locally designated series, forma- 1 DB 22 The American Geologist. January, 1897 tions and beds. By tracing each division continuously, we have a means for determining the value of each series and each formation, and for reducing them to uniformity. Thus it is easily proven that the basal demarcation of the Galena series is correct and uniform throughout, as heretofore known, and, indeed, the same is unmistakable because marked by the striking contact between St. Peter sandstone and the Buff limestone bed. So, likewise, the top of the Maquoketa series, which is followed by the Niagara limestone, or by the so-called Hamilton limestone, is, in either case, marked by a sharp Jith- ologic and faunal break, which is not easily mistaken. But not so with the demarcation between the Galena and Maquo- keta series, where no one horizon presents an unmistakable contrast as compared to any other. At Galena, Illinois, the Galena formation is lithologically, as it were, extended up into the Maquoketa, for the topmost bed, (number 10) contains a fauna belonging most properly with that of the Maquoketa (Hudson). Thus, also, at Du- buque, Iowa. In northeastern Iowa and in Minnesota, on the contrary, this bed has been called Maquoketa shales and mis- taken for the true Maquoketa because of its sedimentary and faunal aspect. Here, as in Illinois, are found Orthis subqua- drata H., O. kankakensis MeChes., and varieties (or species) of O. testudinaria Dal., of Plectambonites sericea Sow., of Ischa- dites and of Asaphus, such as belong to the Maquoketa and not those of the Galena series. With them are others that are common to both the Galena and the Maquoketa series. The lithological character of the Galena extends in some places to the top of this bed, but faunal characters of the Maquo- keta series are found everywhere, down to the base, and hence I prefer the latter for the divisional line. Mr. White, who first applied the name Maquoketa, intend- ed, as he says, to “use the name Maquoketa shales to desig- nate that particular epochal subdivision or formation of the (Cincinnati)group which alone is found in lowa.”* At the type locality, Graf Station, lowa, there is extant the transi- tion bed just mentioned, and two other formations. The. transition bed he certainly did not include in the Maquoketa. The second part is the one that is described by him and by *Geology of Iowa, vol. 1, p. 181, 1870. The Galena and Maquoketa Series.—Sardeson. 23 others. The third and uppermost one was not then exposed there, and was not described as different from the exposed portion,—which it certainly is—but was included within the limits of the Maquoketa, as a matter of course. Strietly in accord with the letter of Mr. White’s definition, three forma- tions should be included in the Maquoketa, but the middle one only was described by him. I propose, therefore, to in- elude all three under the name of Maquoketa (Hudson) series and to eall the middle one Maquoketa formation. Otherwise ‘the term might be rejected, as Jos. F. James has suggested.* The Galena series has been long since divided into two for- mations, the ‘Trenton proper,” or Beloit formation, and the Galena formation. The distinction was at first based on the lithological phenomena, the lower formation having thinner, more compact strata, the upper, thick porous ones; but this difference, which is best recognizable in the “lead region,’’ is not quite satisfactory, since local alteration of the rock has produced the typical Galena facies in the top of the Beloit formation, or again, the base of the former is little changed like the latter. A faunal distinction is needed in addition, and one is easily found. Taking the divisions as recognized by Prof. T. C. Chamberlin, in southern Wisconsin, the Beloit formation is the zone of Orthi’s subequata Con., (O. perveta Con., ete.), and the Galena is the zone of Receptaculites owent H. The Galena, as defined in that way, does not include the transition bed (number 10, see diagram, p. 24), and the same not being properly included in the Maquoketa formation, I have placed it as a separate formation, as part of the Maquo- keta series. The Maquoketa series may now be divided ex- elusive of the Transition formation, into two formations of which the lower is the Maquoketa formation, the upper the Wykotf formation, as I previously designated it in Minnesota, and the two represent, so far as I know, what authors have now and then alluded to as upper and lower Maquoketa, re- spectively. The relations of the five formations are shown in the diagram on the next page. The division line by which the two chief groups, the Galena series and Maquoketa series are divided, is only in a small degree more constant and distinct than those between the des- * AMERICAN GEOLOGIST. vol. v, p. 335, 1890. 24 Tne American Geologist. January, 1897 ORDOVICIAN SYSTEM. . Orthis bed. Leptzena bed. . Orthoceras bed. 14 Wykoff formation. 13. MaQuoKkeETa SERIES. 12 Maquoketa ormation. f ne Transition 10 formation. ; 9 8 Galena formation. 7 GALENA SERIES. 6 5 Beloit 4. formation. Diplograptus bed. Triplecia bed. . Maclurea bed. . Lingulelasma bed. . Camarella bed. . Orthisina bed. . Fucoid bed. Stictopora bed. . Stictoporella bed. 3 2. Bellerophon bed. 1. Buff limestone bed. Saint Peter sandstone (Chazy), 150 feet. Shakopee (Upper Calciferous), 50 feet. i> The Galena and Maquoketa Series.—Sardeson. 25 ignated formations, and the latter are, further, only the de- marecations between beds which are more constant than others. The beds, which are the smallest divisions that it bas been found practicable to designate, are not merely subdivisions of the formations and series, but are themselves nearly co-ordi- nate units of the entire succession of deposits, that are com- posed in the five formations, or two series. And if a detailed | description of the parts of the entire succession is to be given, the beds have each to be described in preference to the forma- tions. In truth the correlation and delimitation of forma- tional divisions have been practicable mainly through the knowledge obtained from a study of the subdivisions. They form a more or less interrupted series of deposits that are predominatingly transitional, the one to the other, but in part alternatingly follow one another. Regarding the single beds, they may be uniform from bottom to top, or composed of transitional series of strata or of alternating ones, they may be strikingly uniform in characters throughout the en- tire area, as for example, the dolomitic limestone at the base and the one at the top of the Galena series, or their sedimen- tary and to a less or greater degree the faunal characters change gradually between localities. The beds vary alike or unlike from place to place. Here and there the existence of any lithologie division remains doubtful, and if at the same place faunal evidence also fails a demareation is Jocally im- practicable. Particularly where the alterations have obtained that produced the typical Galena limestone phase, much dif- ficulty is experienced. No one bed is faunally distinct from the next one, but is distinguishable by some peculiar association of fossils. Some beds have one or more abundant species that are peculiar to it, others are characterized by the association of two or more, as for example the brachiopods. Orthis subequata Con., which ranges from beds one to five inclusive, snd Rhynchonella in- erebescens Hall, sensu stricto, which ranges from five to eight inclusivé, are associated only in bed number five. Besides data derived in that way from the distribution of species, others are to be taken from the minute evolutionary changes of species. The writer has been fond of using data of the latter class, but it will not be practicable to give them in con- 26 The American Geologist. January, 1897 nection with the stratigraphic descriptions because they en- tail too much discussion to permit of their insertion here. For the study of both migratory and evolutionary history of the species the division into formations is of less value than that into beds, because detail is essential. And since the purpose of the writer as paleontologist is primarily to es- tablish a complete and uniform scheme of classification of the Galena and Maquoketa series for further use in the study of the organic remains and the conditions under which the abundant fauna of these deposits lived, detailed descriptions of the beds will be undertaken. An earlier attempt* toward that end is now repeated in part but in corrected and more complete form. The average thickness of some of the beds as given is emended, the Zygospira bed is included in the Orthis- ina bed, and the new name, Triplecia bed, stands for that which was before erroneously called Maquoketa shales, and the true Maquoketa formation is placed where it belongs. In the section near Spring Valley, Minnesota, the true Maquo- keta formation is wanting between the Triplecia bed and Wykotf beds, and hence the mistake, for, having found the fauna of the Orthoceras bed in some small isolated exposures several miles farther south, it was supposed to belong to an upper Wykoff bed because it did not belong to the known section, while clearly belonging near the same. This mistake has remained already too long uncorrected, and strangely other writers have independently fallen into the same error. 1. BUFF LIMESTONE BED. The Buff (Lower Buff) limestone lies conformably upon the Saint Peter sandstone. from which it is separated generally by an abrupt transition from sand to clay or shale. The clay stratum, three feet or less in thickness, is apparently an altered portion of the regular lime- stone and contains Buff limestone fossils only. When wanting, an im- pure sandstone belonging to the Saint Peter may seem to take its place. The limestone bed itself is heavily and regularly stratified. The lamination, when evident, is irregularly lenticular, from uneven distribution of impurities.t The stone is then very little dolomitic. In many localities the lamination has been nearly all obscured by altera- tion and a porous, more dolomitic limestone, or in other cases, a com- pact crystalline limestone has resulted. In the last named condition *Bull. Minn. Acad. Nat. Sci., vol/ 111, p. 319. tSee Bull. Minn. Acad. Nat. Sci., vol. 11, p. 119, and pl. 1, fig. 1, C. W. Hall (1889). The Galena and Maquoketa Series.—Sardeson. 27 q the fossils are inseparable from the matrix. When dolomitization has taken place, then too few fossils remain. Normally, however, large numbers are found in some lamin, in the upper and middle part, be- sides scattered ones throughout. The latter are the less often wanting in altered strata. The bed is sometimes 23 feet thick, or when reduced, 18 feet. Again the limestone is 15 feet or less, not including two to four feet of clay at the base. The maximum thickness is probably the primitive one. The stratigraphic position, the coarser structure and one species of fossil, Rhynchonella orientalis Bill., may be cited as means for determining this bed. 2. BELLEROPHON BED. The new name, Bellerophon bed, is proposed here for the strata in- cluded under the name ‘glass rock’’ in southwestern Wisconsin. It is the lower half of the Lower Blue limestone. The lowest stratum is argillaceous, breaks with a conchoidal fracture and crumbles when exposed to the weather, and thus forms in most cases an easily recognized contrast to the Buff limestone. The rest of the bed is more difficult to distinguish by lithologic characters alone. It is, however, more uniform and of finer texture than the Buff lime- stone, besides containing more fossils which commonly make up inter- spersed lamin in the rock. The bed is about 12 feet thick at Minne- apolis, Minn., but has been vertically compressed. The equivalent strata in Wisconsin are 15 feet thick. The standard of thickness is rarely deceptive. Local alterations of the limestone itself are common. The numerous faunal peculiarities, on the contrary, are nearly uniform, although difficult to distinguish for they are small. Bellerophon wisconsensis Whitf. has not been found except in this bed, and although not abundant is still widely distribu- ted. B. bilobatus Sow. is very abundant in the lower half, but appears to be totally wanting in the upper half. A lithologic division were also perhaps practicable. 3. STICTOPORELLA BED. The upper half of the Lower Blue limestone of southeastern Wiscon- sin is elsewhere not simply a limestone. At Minneapolis, Minn., car- bonaceous, dark brown or gray crystalline limestone forims the lower part of the bed in main, while intercalated clay and shale lamine at the base become thicker upwards and form the main part of the upper strata. The bed is less than half limestone. Toward the southeast the amount of calcareous material is found to increase finally to the exclu- sion of the shale. At Decorah and McGregor, Iowa, the limestone far exceeds the marly constituents. At Lancaster and at Platteville, Wis- consin, some clayey shale still is found; at Janesville, none. The shale laminz are not uniform, neither are the limestone strata, in any locality, but the one encroaches upon the other alternately. The characteristic fossils, Stictoporella frondifera Ulr., associated with Rhynchonella ainsliei N. H. W., characterize the shaley portions. The limestones are often deeply carbonaceous, and deeper coloring of iron be (oa) The American Geoiogist. January, 1897 distinguishes them from the lower and next higher strata nearly every- where. 4, SricropoRaA BED. At Saint Paul, Minnesota, this bed is found thirty feet thick and con- sists of green clay, with a few thin strata of limestone that is made up of fossils. It is marked off from the bed below it by the contrasted purity of the clay and by the absence of certain species of fossils. The top is separated from the next bed along the undulating upper surface of a stratum of limestone. The Stictopora bed is seldom well exposed in Minnesota, but is known to exist in Goodhue, Olmsted and Fillmore counties, like at Saint Paul, but with fewer limestone strata. At Decorah, Iowa, it is exposed on the north side of the river, 15 feet, and is probably 20 feet or more thick, but contains no limestone and scarcely any fossils. At Lancaster, Wis., shale at the base gradates to limestone with marl! lamine in the upper partof the bed. Farther east and south in Wisconsin, carbonaceous or crystalline limestone with brachiopod shells preserved. as at Platteville, or heavily bedded dolomitic limestone, as at Dodgeville, or limestone in irregular strata, with shaley lamina, as at Beloit, are local alterations #f the limestone strata that there form this bed. The thickness of the ‘‘Upper Buff’? bed at Beloit, Wis., has been es- timated at 55 feet,* but is probably much less. The estimate is difficult to verify. The thickness is as follows: Saint Paul, 30 feet; Fillmore Co., Minn., 25 feet or more; Decorah, Iowa, 20 feet or more; Dodgeville, Wis., 30 feet; Beloit, 35 feet; Rockton, Ills., 35 feet. The name Stictopora bed was given by me from Stictopora mutabilis Ulr. Mr. Ulrich has since then changed the generic name to Rhini- dictyat and has recognized the bed under the changed name, ‘‘Rhini- dictya bed,’’{ an unnecessary correction. 5. -EUCGOID. BED. At St. Paul, Minn., the Fucoid bed is 18 feet thick and consists of fossiliferous shaley clay. Twiglike fucoids or sponges are numerous even at the base and make up more of eacb successive stratum until at the top of the bed a solid mass of them obtains. A few thin strata of fine-grained, heavy limestone are intercalated, and near the top are lamin with oolitic limonite. The latter occurs as deep as to the base of the bed in northwestern Wisconsin. It is found southward as far as Fillmore county, Minnesota. The shaley clay full of ‘fucoids’ at Saint Paul, becomes more and more calcareous and the fucoids fewer towards the south and south- east. Im Goodhue county it is very fossiliferous but is not well ex- posed. The same is true in Olmsted and Fillmore counties, where this bed seems to be thinner, although of that one is not certain because the line of springs isalong its top and local stratigraphic changes are probable in all known exposures. At Decorah, Lowa, it shows alter- *T. C. Chamberlin, Geology of Wisconsin, vol. 11, p. 295 and 297. +Vol. 111, Final rep. Geol. Nat. Hist. Survey of Minnesota, p. 125. tExtr. 19th Ann. rep. Geol. Nat. Hist. Survey of Minnesota, p. 212. The Galena and Maquoketa Series.—Sardeson. 29 ation by water which has carried away parts of the calcareous strata leaving a mar! full of calcareous lumps and of fossils. ~Lingiulce show a vertical compression of 0.1 to 0.2 of their length. This bed is seen ex- posed 15 feet thick here and may be 20 feet in all. ‘ Fucoids’ occur at this locality at the base of the bed. At McGregor, lowa, and at Lan- easter, Wisconsin, a shaley limestone with few ‘fucoids’ represents it. At Dodgeville it is changed to a porous dolomitic limestone, not easily separable from the Galena beds. At Rockton, Ill., part of this bed is quarried, and at Beloit, Wis., that part of the ‘‘ Upper Buff Limestone” that contains Cheetetes tycoperdon auct. (Prasopora contigua Ulr. etc.,) is of this bed: The association together of Plectambonitis sericea Sow.. Orthis sub- equata Con., Rhynchonella increbescens Hall (R. ineequevalvis C.) and large Prasopora, is peculiar to the Fucoid bed. 6. ORTHISINA BED. About 40 feet of strata are included in this bed. At Saint Paul, Min- nesota, 20 feet can be seen in place. The first 8 feet of it I formerly called Zygospira bed, but the same falls, as now known, truly within the zone of Orthisina americana Whitf. and is otherwise not separable throughout. Both at Saint Paul and at Kenyon, Minnesota, the Or- thisina bed is like the Fucoid bed at Decorah, Iowa, in that it is changed, probably recently, by water percolation until clay with rounded calcareous lumps represents most strata. Less changed lime- stone strata and a few compact limestone lamine form the rest of the bed. At Saint Paul there are some calcareous oolite and fine ripple marks. At Kenyon one finds manganese nodules associated with pol- ished, blackened and perforated surfaces of some limestone strata. In Olmsted and Fillmore counties this bed is a shaley limestone. At Decorah, Iowa, it is firm, gray limestone. The quarries at Oshkosh, in eastern Wisconsin. are in this bed. Elsewhere in that state the bed forms a part of the typical, cavernous Galena limestone in which few fossils remain, so that complete demarcation of this and the next suc- ceeding it is rarely possible, and is not needed. In this bed is Orthisina (Clitambonites) americana Whitf., and Plectambonites minnesotensis Sar. begins at its base. 7. CAMARELLA BED, Upon the Orthisina bed follow strata of shaley, sometimes carbona- ceous limestone, which, however, is not so shaley as the underlying bed in the same section. These strata are comparatively unfossiliferous as arule. but crinoidal limestone, brachiopod strata and fossils in large numbers do occur. The species known from this section have been found to occur in the beds next lower and higher, and, like the Sticto- pora bed (4), this one is characterized more by the absence than the presence of peculiar species. Strophomena trilobata Owen ranges from this bed upwards, and Zygospira uphami W. and S., is abundant near Wykoff, Minnesota. At Kenyon, Mantorville, near Pleasant Grove, and at Wykoff, Minne- sota, exposures indicate a thickness in al] not exceeding 30 feet. In 30 The American Geologist. January, 1897 Towa and Wisconsin a delimitation of this Led has not been attempted, from lack of suitable observed exposures with fossils to distinguish it. 8. LINGULELASMA* BED. This bed is partly extant in Goodhue county, Minnesota, but better exposures are found at Concord, Wassioja and Mantorville in Dodge county, and on section 26 High Forest, Olmsted county, and near Wy- koff, Fillmore county, Minnesota. The thickness is between 30 and 35 feet, and the contacts are not difficult to distinguish, as a rule, between this one and the Camerella and Maclurea beds. The Lingulelasma bed affords a firm limestone, less shaley than the one beneath it and finer erained than the one upon it. The upper strata are highly fossiliferous. At Dubuque, Iowa, the same is easily recognizable. Lingulelasma ga- lenensis W. and S. is not abundant and occurs moreover also in the Fu- coid bed (5) in Iowa. Lingula hurlbuti N. H. W., Camarella owatonn- ensis Sar. and Plectambonites gibbosa W. & S., belong to the Lingu- lelasma bed. 9. MAacrLUREA BED. Species of Maclurea are found in beds of the Beloit formation, but not the very large specimens, M. cuneatu Whitf., which are everywhere characteristic of this bed of coarse, porous, dolomitic limestone at the top of the Galena formation. In all known exposures of the Maclurea bed the rock shows alteration, such that internal casts of shells are dis- torted or re-imbedded in the matrix, and few fossils except large ones are preserved. The thickness is about 35 feet. Good exposures are at Wasioja and Stewartville, Dodge county, near Wykoff, Fillmore coun- ty, Minnesota, near Decorah and at Dubuque, Iowa. 10. TRIPLECIA BED. This name is to include what was called Maquoketa shales in my former description. It is the top 30 feet of the ‘‘ Galena formation”’ at Seales Mound, Illinois, and Dubuque, Iowa. At the latter place, the contact with the Maclurea bed can be seen. Here the Triplecia bed has the thinner strata which same also have shale lamine between them. Between Conover and Decorah, Lowa, an exposure shows very much more shale than in the first mentioned localities. At Florence- ville, Iowa, the contact with the Maclurea bed is again exposed and the crinoidal limestone in irregular strata with shale partings there seen is characteristic. The middle and upper strata may be seen near by at Granger, Minn., where carbonaceous and argillaceous shale predominates in the middle portion and an impure, browinish-gray limestone forms the top. The faunal characters place this bed in the Maquoketa series. Triplecia ulrichi W. and 8., Plectambonites preecosa Sar. are peculiar to this bed and Orthis subquadrata H. with O. kankakensis McChes. are found too. *For the spelling of this word see 8. A. Miller, North American Geol- ogy and Paleontology. Appendix, p. 689. The Galena and Maquoketa Series.—Sardeson. 31 i 11. DipLoGRAPTus BED. Between the Triplecia bed and the Diplograptus bed there is a well marked stratigraphic change and one finds the irregular strata of the former contrasted by the uniform laminz of the latter, except where concretionary structure has disturbed it. The change is not always from more calcareous strata to less calcareous ones as at Graf, Iowa, and vicinity, but farther north is nearly the reverse as at Granger. Minnesota, where the Diplograptus bed is a brown carbonaceous limestone underlain by shaley strata of the Triplecia bed. The fauna is meagre in both phases of this bed and local in charac- ter. Three species of Asaphus, Bellerophon bilobatus Sow., Cyrto- lites ornatus, Conularia, and Diplograptus are found in the limestone, and in the clay shale farther south are the last named with species of Lingula. Not one species is peculiar to this bed. At Dubuque, Iowa, and at Scales Mound, Illinois, one finds thousands of small fossils in a fine calcareous gravel that forms two or more thin strata near the base of the shales. They are secondary fossils and do not belong to the fauna of this time, but are evidently from the next older beds, having been torn from their matrix and transported, as the rolled and worn condition of the shells and interior casts shows. There are lacking among them many species from the next older beds of the locality, which would have been as easily transported as they, and hence they must have come a long distance from where local conditions had _ pro- duced a difference in fauna. The limestone in northern Iowa is 20 feet thick, and the clay shale equivalent at Graf, Iowa, is about the same, the division line there be- ing referred to a position close below the calcareous layers in which the Orthoceras are found. 12. ORTHOCERAS BED. At the north boundary of Iowa, in Howard county, this bed is of lime- stone 25 or more feet thick, that contains numerous quartz concre- tions and silicified fossils, and that breaks up in its natural exposures into small cubical blocks much more than into slabs. It thins out northward or at least it is traceable only a few miles, beyond which the next higher bed (13) rests directly upon the Triplecia bed (10). South- ward as at Elgin, Iowa, it is 45 feet thick and is more shaley. From thence. it has not been traced continuously to Graf, Iowa, but at that place an exposure, as well known, exists and in it 20 feet of this and part of the next lower bed are seen. At that place the limestone is re- duced to a few mainly very fossiliferous strata between which are car- bonaceous clay-shale deposits. At Scales Mound, Illinois, the shale is almost without limestone. The fauna is not more constant than the sedimentary characters. In the limestones there are Orthis emacerata H., Murchisonia milleri H., Ctenodonta calvini Ulr., Cleidophorous sp., Orthoceras, Cyrtoceras, and in the shales are linguloid shells and Diplograptus mainly, besides some small fossils that appear to be secondary. The fauna of this bed 32 The American Geologist. January, 1897 should be easily recognizable to the geologist as not Galena (Trenton) for even in the well known trilobite bed at Elgin, Iowa, where the fos- sils are a few species only, one finds Orthis kankakensis MecChes., O. emacerata H., O. insculpta H. and others that are no other than Ma- quoketa (Hudson) fossils. But in this bed as in the Diplograptus bed, Orthis subquadrata H. and Strophomena trilobata Owen (S. flexuosa Bill.) and perhaps for that reason it has been mistaken for ‘‘ Trenton.” 13. LEpra2Nna BED. The succession of small exposures that are found along the railway west of Wykoff, Minn., represent about 30 feet of fine-grained, soft limestone that there composes this bed. In some strata fossils are very numerous, often silicified, but are not accompanied by quartz concre- tions. Near the Iowa and Minnesota boundary, by Granger and Flor- enceville, it is found with the next lower bed often in one contiguous exposure. It is distinguished from the Orthoceras bed by the manner of weathering into slabs instead of into blocks, and likewise by a faunal change. Near Postville, west of Elgin and near Eldorado, Iowa, it is to be seen and is fully 75 feet thick, consisting of limestone at the top and of lime and clay or chiefly clay in the middle or lower portions. At the base there is a sudden transition to the “purer limestone of the Orthoceras bed. Farther south it has not been observed, except that there is a great bed of unfossiliferous, impure clay, evidently extant in its supposed po- sition at Graf. lowa. East of Scales Mound, Illinois, a very impure limestone, seen 20 feet, is probably the same, but there were found two species of trilobites (Asaphus) only and they are common to all beds of the Maquoketa series, hence it is not certain that the strata in question do not belong to the Orthoceras bed. At Graf, Iowa, and northward no fossils were found until reaching Elgin, but thence northward to where the bed is entirely removed in southern Minnesota fossils are more abundant, some strata near the top being full of them. Orthis subquadrata H., Plectambonites recedens (Sar.) and Rhyncho- nella perlamellosa Whitf., are very abundant in the limestone; the first is known only from this and the Triplecia bed (10), the other two in this and the succeeding bed only. Species of Leptena are most abundant. An interesting fauna is found at Wilmington, I!linois, in shales close below the Niagara limestone, and it is evidently the equivalent of this bed, or possibly of the next one. 14. ORTHIS BED. Upon the Leptezna bed at Spring Valley, Minn., near the type expo- sures of that limestone, there is found in many exposures a bed of mixed lime, clay and quartz sand in different proportions in different strata. The bed in this locality is subject to flooding by water that pours out of the crevices in rainy seasons, so that one can not rely upon the condition of the strata as positively primitive, but some sandstone strata with tine mud-covered upper faces that are here found are possi- bly proof of a litoral deposit. There are very few fossils, and in the The Galena and Maquoketa Series.—Sardeson, 33 upper part, which is an easily disintegrated marl, one finds none. The few known fossils here appear to be secondary, and one would not be able to say that this is not a part of the immediately superimposed De- vonian were the bed not traceable southward. The base of the bed is a quartz and lime sandstone of coarse texture. Nearly the same strata are to be seen two miles west of Granger. Minn., on the state boundary by the road, but nowhere does a complete section of the bed come to view, and but few fossils are found. Near Eldorado, a few miles west of Elgin, Iowa, 75 feet of clay with fine sand inter- mixed* is seen in place between the Lepteena bed and the Niagara limestone.’ Near Brainerd there is an interlaminated fossil limestone and clay of varying thickness, from zero to six feet, which in part fills up depressions on the undulating surface of the sandy clay. One finds the same along the railway one mile west of Kidder, Iowa, and fossils from it are found at Graf, and are reported from near Shullsburg, Wis- consin. The clay and limestone top is exceedingly fossiliferous, but the spe- cies in it are not different apparently from the few poorly preserved ones from the main body of the bed. - I therefore regard it as one of the len- ticular fossil strata that may be found likewise deeper down in the bed like the one in this bed at [ron Ridge, Wisconsin. The Orthis bed is much less sandy at Graf, Iowa, than at Eldorado, and perhaps not so thick, but regarding the thickness there are no_ re- liable data to be had except that there is room for very many more strata between the Galena and Niagara formations than have been supposed. The Maquoketa series is nearer 200 feet than 80 at Graf, In this bed are Orthis occidentalis H. and the typical Leptena unicostata M. and W. with Rhynchonella anticostiensis Bill. The top of this bed nearly always is variegated red, blue and yellow with iron. At Iron Ridge, Wisconsin, the ‘*‘ Clinton” iron ores rest upon it. The above brief descriptions will, it is hoped, enable others to recognize the true relation of parts of the Galena and Ma- quoketa series. The descriptions are by far not complete, for but little attention could be given to analyses such as would be necessary for the determination of sedimentary and petro- logic characters, and very much remains to be added in the way of exact measurements of the strata, as well as in that of tabulating the faunas. Whe beds described could no doubt be traced through northeastern Wisconsin, upper Michigan, St. Joseph’s island, ete., and probably they may be recognized in part, at least, in Missouri, Kentucky and New York. What is lacking in this paper may be the subjects of others; what is *T am indebted to Mr. Grant Finch, principal of the high school at West Union, Towa, for knowledge of this good exposure and others in that district. 34 The American Geologist. January, 1897 presented is intended to enable geologists who are confined to restricted areas, to present their observations in such form that they may be of greater use in the study of the history belonging to the Galena and Maquoketa deposits and their faunas. The beds one and two have had nearly the same primitive sedimentary characters throughout, and their faunas are like- wise uniform in areal distribution. Beds three to -five are limestone in the south and east, but mainly clay of shallow water deposition to the northwest, and their faunas are found to be locally different, in part because of different degrees of preservation, in part because some species like Orthis deflecta Con., never existed except in the limestone areas. From the base of the Galena towards its top there is a gradual con- vergence back to a widely uniform condition. The bed No. 10, that forms the transition formation to the Maquoketa series is less lacking in uniformity than its outward appear- ance would indicate. The beds of the Maquoketa formation (11 and 12) have local phases in predominance and merely the dark, carbonaceous color is the widest noted character. The Maquoketa formation is intercalated into the series, so to say, and only towards the top, and more particularly in the suc- ceeding Leptena bed is there a return toward the character- istics of the bed (10) beneath it. In the last of the series of beds there is evidence that a shore was not far north of the Towa and Minnesota state boundary. And the top of the bed in Iowa shows evidence of iron deposits, as it does notably in eastern Wisconsin. In Wisconsin, Illinois and Iowa the Ni- agara limestones, in southeastern Minnesota the Devonian rests upon the Maquoketa series, there being thus a varying interval of no deposit following it. One cannot fail to note the large numbers of Trenton and Hudson species of fossils that are found in the Galena and Maquoketa respectively, but there are instructive differences, such as the continuance of the Trenton form of Orthis ( Platy- strophia) biforata from bed No. 5 through both Galena and Maquoketa series, the Hudson ‘ varieties’? O. lynx, O. acutil- irata ete., not being found. Again the trilobite genus Zllenus is strangely not represented in my collections from the Ma- quoketa series but isfound in all beds of the Galena series. = Rules and Misrules in Classification.—Marcou. 35 For that same and for the range of the Maclurea, Receptacu- lites et al. we have not sufliciently full explanation. To un- derstand the history of the physical changes and faunal mi- grations in this area, will no doubt be the surest means for explaining in a satisfactory manner the relations to the type Trenton and Hudson. For the present, correlations into dis- tricts into which we cannot trace the beds by stratigraphic continuity, are to be assumed with caution, prompted by our knowledge that quite recently we have not beén entirely suc- cessful in correlating not distantly separated sections of the Galena and Maquoketa series by the lithological and paleon- tological methods. RULES AND MISRULES IN STRATIGRAPHIC CLASSIFICATION. By Jutes Marcou, Cambridge, Mass. 1% CONTENTS. PAGE. Giraud-Soulavie.— William Smith.—Alex. Brongniart......................22.-2.. BD Classification of the Niagara with the Old Red Sandstone......................... 38 Classification of the Taconic with the Hudson River...............0.-....-4:02---- 38 Me Georeia LOLrmMablon OL-ALiiptocephalus ZONE... ...5 -.cctecnveleeass sessed icees es 39 Bilitosburchtand: bointes6yis formation: .~.... <6 o/s ssce4 1 ee toe eae See eee see 43 Geology of Chazy village.. BT Ne 8 hs Sia ecu ty AE eee MR eg con tor eo pS Geology of Shoreham iuccmonty: Saco 49 Giraud-Soulavie.—— Ww Nicer Suiiche ee Tei en aviaert. At first the great stratigraphic classifications were made according to some great area of geological distribution of rocks having the same petrography, or at least having a cer- tain similitude as regard the lithology and the colors of the main strata; such as the chalk. the Red Sandstone, the Jura limestone, the slate, the carbon or coal. Great breaks and discordance of stratification were also used, as well as trans- gression and retrogression of the strata. And according to those simple and most striking rules easily recognized in prac- tical geology, the strata were divided into the Primary, the Transition, the Secondary, and the Tertiary periods or great systems, and into the Grauwake, the Old Red sandstone, the Carboniferous, the New Red sandstone, the Lias, the Jura limestone, the Cretaceous, the Calcaire grossier, ete. Then came the “ medals of creation,” or fossil organic re- mains. The first who recognized that fossils differed accord- 36 The American Geologist. January, 1897 ing to their age and the superposition of the strata in which they are found was the French abbe, Giraud-Soulavie, who in 1777 published this new principle in his works on the south of France, and particularly on the geology of Vivarais. ( His- toire naturelle de la France Méridionale, 7 vol. 8vo, Paris, 1780-1784. The Chapter VIII, in the first part, containing the chronology of fossil animals, according to the strata in which they are found, was written in 1777, and read before the Academy of Sciences of Paris, the 14th August, 1779.) Without knowing the researches and discoveries of the abbé Giraud-Soulavie, William Smith, in England, from 1794 to 1799, derived identical principles; and in 1799 he wrote a tabular view entitled, “Order of the strata and their imbed- ded organic remains in the vicinity of Bath, examined and proved prior to 1799,” which, although it remained manuscript until 1844, was copied and largely circulated among English geologists. It was not until 1815 that Strata Smith, as he is called, was able to issue his “Geological map of England and Wales, with part of Scotland”; and only in 1817, 1818 and 1819 that finally he published his two works, “ A stratigraph- ical system of organized fossils,” and “Strata identified by organized fossils.” Curiously enough, both Cuvier and Alexandre Brongniart did not know the discovery of Giraud-Soulavie, a Frenchman like them, nor of William Smith; and in their studies of the Paris basin they came to the same conclusion, of strata iden- tified by organized fossil remains—a remarkable coincidence, which, although the question of priority is unquestionably in favor of Giraud-Soulavie, shows that the progress of knowl- edge of strata and fossil remains had arrived at that period when a new and most important step was to be taken. Cuvier and Brongniart came at a most opportune moment; and their capital work, “ Essai sur la géographie minéralo- 99 gique des environs de Paris,’ written and presented to the Council of Mines, in Paris, in 1807, was issued first in the Journal des Mines, 1808, and two years after as a separate volume in 4to, Paris, 1810. It is called by a brother geolo- gist andacontemporary, J.J. d@Omalius d’Halloy, “ ’ouvrage le plus eapital de notre siécle (au point de vue de la géologie), puis qu'il contient le premier germe de la révolution qui a =~] Rules and Misrules in Classification.—Marcou. 3 eréé Pétat actuel de cette science, c’est a dire, qui a appliqué la paléontologie a l'étude da l’écorce du globe terrestre.’’* Brongniart pushed the discovery farther on and gave to the principle an extension, so great and so beneficial to progress, that after him little was left to establish the rule not only all over Europe, but to extend it to every continent and island in both hemispheres. It is in his memoir, ‘Sur les caractéres zoologiques des formations, avec l’application de ces caractéres di la détermination de quelques Terrains de Craie” (Extrait des Annales des Mines, 1821-22, Paris), in which we read at p. 9, “Je regarde done les caractéres Vépoque de formation tirés de ’analogie des corps organises, comme de premiere va- leur en géognosie et comme devant l’emporter sur toutes les autres differences, quelques grandes qu’elles paraissent.” That paper of Alexandre Brongniart is so important and so little known on this side of the Atlantic, that I am induced to quote two other sentences: “Je ne prétends pas dire cepen- dant que les caractéres tirés de Ja position relative des cou- ches, de Jeur nature (pétrographie) ete., ne doivent pas etre employés, meme avec confiance, par le géologue pour déter- miner différentes époques de formation; seuls ou réunis avec ceux qu’on tire de la nature des corps organises fossiles, ils ont la plus grande valeur; mais je pense seulement, et je crois avoir démontré de puissants motifs de cette opinion, que lorsque ces caractéres sont en opposition avee ceux qu’on peut tirer de la présence des corps organises fossiles, ces derniers doivent avoir Ja préférence.” ‘‘ Je ne dissimule pas qu’ il faut apporter beaucoup d’attention et de ménagement dans |’em- ploi qu’on en fait. Je Wignore pas qu’ il faut savoir distin- guer et évaluer meme influence des distances horizontales ou des climats sur les différences spécifiques; qu’ il faut savoir apprécier les ressemblances apparentes, quelquefois méme réelles, que présentent dans des formations évidemment trés distinctes quelques espéces qui-ont eu le privilége assez rare de survivre a Ja destruction de leurs contemporains, et de rester toujours les mémes au milieu de tous Jes changemens qui se sont passés autour d’elles, ete.” (Loc. cit. pp. 10 and 11.) * Notice biographique sur Alexandre Brongiiart, jue a la séance du 19 Mars, 1860, de la Société géologique de France, p. 2, Paris. 38 The American Geologist. January, 1867 So according to the author of the paleontological rule for determining and classifying strata, it must be used with a great deal of care, and much attention must always be paid to similar forms of fossils and even to a few identical species which enjoy the privilege to survive their contemporaries. Finally the horizontal distances or climats, as Brongniart says, exert an influence which ought to be carefully weighed. Let us see how those rules have been applied in the elassi- fication of strata in North America and point out the misrules made which have kept back so persistently the progress of American geology. CLASSIFICATION OF THE NIAGARA GROUP WITH THE OLD ReEp SANDSTONE, The first important misrule in America is found in the Second Annual Report, Geological Survey of New York, p. 291, Albany, 1838, where the author of the report of the fourth geological district, after classifying the Niagara group with the Old Red sandstone of Europe, says: “The evidence for this conclusion rests, in part, upon the organic remains, and if we can rely on these characters there appears little ques- So, ac- 9 tion regarding the age and position of our rocks cording to the writer of the report, the Niagara group is to be classified as being above the Silurian system of Murchison, instead of being the main and central part of the Upper, or true Silurian. an erroneous correlation and classification due to paleontological mistake. CLASSIFICATION OF THE TACONIC SysTEM WITH THE Huvupson RIVER GROUP. The second misrule by the same writer is even more impor- tant, for it suppressed a whole system, the greatest in regard to thickness of strata—about 25.000 feet—-and the first link in the great chain of fossil remains which have existed on our globe. Here the mistake was made by the wrong deter- mination of fossils, mainly trilobites, and a no less erroneous idea of wrong stratigraphy and wrong lithology, almost in- credible, for it was made not only against all the rules of stratigraphic classification, but against an exact description and classification of those strata made by the Strata Smith and Alex. Brongniart of North America, the late Dr. Eben- ezer Emmons. who had called them the Taconic system, con- Rules and Misrules in Classification —Marcou. 39 taining a special fauna. ‘The result of that misrule was a complete stop of progress for the Lower Paleozoic rocks of North America from 1847 until 1860, and even many years after, notwithstanding the researches and publications not only of Emmons, but also of Barrande, Billings and the pres- ent writer. The misrule adopted by the opponents of the Taconic sys- tem operates still; in a less degree, it is true, but it is sufti- ciently strong to create great confusion in the classification of those strata in the Appalachian region, New England, New York, Canada and western Newfoundland. In including Canada I do not mean the whole Canada Dominion, but only the old Canada or Province of Quebec; for in New Brunswick and Nova Scotia excellent and very remarkably good work of classification and correlation, based on exact paleontology and also on the stratigraphy, has been done by Mr. G. F. Matthew. The mistakes are still so important and so numerous that it is necessary to see each case and point out how the rules of paleontological classification and correlation or equivalency, as well as the principles of stratigraphy and lithology have been violated and misused. THE GEORGIA FORMATION OR L£iliptocephalus (CALLED sSOME- TIMES Olenellus) ZONE. After a study of the fossiliferous locality of Georgia, Ver- mont, and its vicinity, the present writer classified the Geor- gia formation with its characteristic Elliptocephalus (Olenel- lus) thompsoni as the upper part of the Middle Taconic (called by some Middle Cambrian, not of the original Cam- brian of Sedgwick), and placed it above the St. John forma- tion of New Brunswick, Massachusetts and Newfoundland, so well characterized paleontologically by its numerous and large Paradoxvides. We must add, that the direct superposition of the beds containing Lli/plocephalus (Olenellus) over the beds containing Paradowides has not yet been found anywhere round Georgia, nor in the whole Appalachian and Quebec regions. The classification was made paleontologically ; and one of the best and most exact paleontologists, the late S. W. Ford, did go so far as to show the embryologie relations of Liliptocephatus ( Olenellus ) with Paradowides ; Elliptocephalus 40 The American Geologist. January, 1897 being a metamorphosis and a descendant of Paradoxides.* Stratigraphically, at Swanton, the Liliptocephalus zone is in contact with the Phillipsburgh formation, and it is followed toward the Green mountain range east of St. Albans by a thick black shale formation, in which no fossils have yet been found. Now comes one of those cases of exact determination of generic form, on which depend not only the correlation or equivalency of strata at great distance, but also the rule of stratigraphic classification. Below the zone of Paradowides in Seandinavia, and in close contact with it, a fauna was found with a trilobite, which after being referred to Para- doxvides was finally adjudged as belonging to the American genus Llliptucephalus (Olenellus). The result was that the Seandinavian geologists insisted on placing the L/liptocepha- lus (Olenellus) zone below the Paradoxides zone. However, a Swedish paleontologist of the first order, Mr. G. Holm, gave a detailed description of Olenellus (Elliptocephalus) kjerulfi, insisting on the differences existing between that species and the true Elliptocephalus (Olenellus) as well as the true Para- dowvides; for him it was a new genus; but he did not go so far as to give a name to it. The learned paleontologist of St. John, Mr. G. F. Matthew, agreed entirely with Mr. Holm, and justly and most appropriately gave to that new genus of trilobite the name Ho/mia, in honor of Gerald Holm. As the other fossils accompanying Holmia kjerulfi are entirely dif- ferent generically from those found at Georgia, the correla- tion of the two formations in Scandinavia and Vermont, is a mistake made by a paleontologie misrule, due to an errone- ous determination of fossil remains. Then came a most unfortunate interposition of the palzon- tologist of the United States Geological Survey. In August, 1888, Mr. C.D. Walcott, in looking over the stratigraphy of *Ford showed the mistake of referring the trilobites first described by Emmons as wlliptocephalus asaphoides to Olenus, in calling it Ole- nellus, When instead of being related to Olenus it is much more close to Paradowides, reproducing in its embryology the form of a Paradoxides. In fact, the name so generally used lately ought to be dropped entirely, first, on question of priority, and second, on account of the mistake made in regard to all the European and eastern Newfoundland speci- mens, which do not belong to that genus, but are truly another genus, zalled by Mr. Matthew Holmia. k Rules and Misrules in Classification.—Marcou. 41 eastern Newfoundland, so well worked out by one of the Pro- vincial geologists, Mr. J. P. Howley, found at Manuel’s brook a new railroad cutting, showing a good, fresh section with well preserved fossils, and among them a trilobite which he classi- fied as belonging to the genus Hiliptocephalus (Olenellus), calling it Olenellus bréggert. Against all paleontological rules established by Alexandre Brongniart, which demand similar- ity and even identity of forms of fossil animals to correlate one formation with another, the beds of eastern Newfoundland containing Elliptocephalus (Olenellus) bréggeri, were regarded as the equivalent of the Georgia beds of Vermont. The two faunas have absolutely nothingin common; on the contrary, the eastern Newfoundland fauna contains forms of fossils all older than the Georgia ones, for even the Hiliptocephalus (Ole- nellus) is not an Olenellus, but a true Holmia. Following are the lists of Georgia and Manuel’s brook, as given by the Bulletin of the U. S. Geological Survey, No. 81, at pp. 260-261 and 278. At Manuel’s brook the fossils are: Obolella atlantica, Hyolithellus micans, Helenia bella, Hyo- lithes princeps, H. impar, H. quadricostatus, H. similis, H. terranovicus, Scenella reticulata, Stenotheca rugosa, varieties acuta, costa, erecta, levis, and pauper, Platyceras primevui, Microdiscus helena, M. speciosus, Olenellus (H.) bréggeri, Avalonia manuelensis, Agraulos (S.) strenuus and var. nasutus, Solenopleura bombifrons, S. harveyi and S. howleyi?. At Parker’s quarry, Georgia, the fossils are: Palwophicus incipiens, P. congregatus, Diplograptus simplex, Climacograp- tus ? emmonsi, Kutorgina cingulata, Orthisina orientalis, O. Sestinata, O. transversa, Microdiscus parkeri, Mesonacis ver- montana, Olenellus thompsoni, Oleniodes marcoui, Bathynotus holopyga, Ptychoparia adamsi, P. vuleanus, Protypus hitch- cock’, P.senectus and P. senectus var. parvulus, and it is im- possible to account for the absolute difference in the two fau- nas, by the great distance, for the true Georgia formation, with its characteristic fossil, the Lliptocephalus (Olenellus) thompsoni, has been followed through the entire province of Quebec, as far as the peninsula of Gaspé, and even on the western, or French shore of Newfoundland, where a well- preserved head of Ziliptocephalus (Olenellus) thompsoni was found by the late J. Richardson, of the geological survey of Canada. 49 The American Geologist. January, 1897 Several papers, of a character rather sensational. were pub- lished here and also in Europe, by the paleontologist of the U.S. Geological Survey, and the result as stated, in the book : Correlation papers—Cambrian, “Bull. U. 8. Geol. Survey,” No. 81, p. 360, Washington, 1891-92, is the placirg of the Georgia formation in the Lower Taconic (called by some Lower Cam- brian), below the Paradoxides zone of St. John (New Bruns- wick), of eastern Newfoundland, and of Braintree (Massachu- setts), which then is regarded as Middle Taconic (Middle Cambrian ). } Several years have passed sirfce the publication of the view and opinion, expressed with some emphasis and remarkable assurance, in the volume Correlation papers—Cambrian; and nothing has been found to sustain that classification; on the contrary, the best experts for trilobites in America consider the Elliptocephalus (Olenellus) thompsoni of Georgia as generically different from the Olenellus brégqgeri of Manuel’s brook. The latter probably is congeneri¢ with Olenellus kjer- ulfi, of Scandinavia, and both species—O. brégger’ and O, kjerulfi—belong to the genus Holmia, entirely different from the genus Hiliptocephalus (Olenellus) of Georgia. So we have an example of confusion in the classification and correlation of strata brought up by an erroneous determination of a ge- neric group of trilobites.* What a strange destiny for the Georgia trilobite; first, it was determined as an QOlenus instead of an Elliptocephalus and placed stratigraphically on the top and consequently above the second fauna, instead of belonging to the primor- dial fauna; second, it was taken from the Olenus and called Barrandia, then afterward Olenellus and considered as a Potsdam fossil, that is to say, placed at the summit of the Upper Cambrian. Finaliy it was placed at the bottom of the Lower Cambrian, running a race through 25,000 feet of strata and two great geological epochs of the earth. And now it is restored to its exact place, in the upper part of the Middle Taconic (Middle Cambrian). *The present writer pointed out the mistake in referring the New- foundland trilobite to Olenellus instead of the genus Holmia, as soon as if was published (‘‘The Lower and Middle Taconic of Europe and North America, 1890’’), and recalled it in his paper of 1892: ‘*The Geo- logical map of the U.S., and the U. 8. Geological Survey,” p.53, but to no purpose, so far as it concerned the U. S. Geological Survey. Rules and Misrules in Classification.—Marcou. 43 THE PHILLIPSBURGH AND PoIntTE LEVIS FORMATION. We come now to the second misrule in the classification of strata belonging to the lower Paleozoic rocks. Dr. Emmons recognized below the Calciferous group the Potsdam sand- stone, which according to his observations is the bottom group of the Champlain division: and below the Potsdam he saw an enormous series of strata, 25,000 feet thick, mainly slates, which he called most appropriately the Taconic system. At different levels in that system Emmons found magnesian lime- stone, some of which he called Stockbridge limestone, or marble, of Berkshire county. He was confronted with a stratigraphic anomaly, which as- tonished him considerably, finding now and‘then a limited deposit of limestone, generally more or less magnesian, but sometimes of pure or even marly limestone. These deposits, he thought, were pockets of more recent limestone deposited in holes of the slates (Taconic slates) and belonging, accord- ing to a few fossils collected at different localities, to the Cal- ciferous group, or to the Chazy and Black River divisions, or even to the Trenton limestone. Dr. Emmons maintained that there was a well marked discordance of stratification between those beds of pocket limestones and the Taconic slates sur- rounding them. It is true that a sort of unconformity, or, more exactly, of diffuse stratification exists between the slates and the small islets of limestone, due to the structural nature of these islets, which I admit are rather puzzling and difficult to account for. The first time I came in full view of some of them round St. Albans, Vermont, in 1861, I had no difficulty to see that they were lenticular masses of magnesian lime- stone, deposited at the same moment and inclosed in the slates, and consequently contemporary with the slates. But at Phillipsburgh, Canada, those islets of limestone are so nu- merous and so elongated as to present—at first sight—the as- pect of a regular deposit of limestone analogous to the depos- its of the Chazy limestone at Chazy village. It was when working out the stratigraphy of Pointe Lévis, opposite Que- bec, in 1861 and 1862, that at last I became convinced that all those outcrops of limestone were inclosed in the slates and of the same age as those slates, and that the fossils found, now and then, in some of those limestone islets, instead of in- tt The American Geologist. January, 1897 dicating that the age of some was Calciferous, others Chazy, others Black River and others even Trenton, belonged to a special fauna, older than the second fauna or Champlain di- vision of Dr. Emmons; they are in company with forms re- ralling the primordial fauna or true Taconic, but are new forms which developed completely only in the period of the second fauna proper and were found at Pointe Lévis and Phillipsburgh, only in a sporadie state without the great de- velopment they attained during the deposits of the strata of the second fauna. In one word, we have in some of those limestone islets the phenomena of colonies, as defined by Barrande. After careful surveys at Pointe Lévis, Quebec city, Phillipsburgh, Highgate-fall, Highgate Springs, Swan- ton and St. Albans’ bay it was evident that we have there di- rectly in contact and in perfect stratigraphic conformity with the Georgia formation a mass of strata, mainly black slates, of a thickness at least of 5,000 feet, containing now and then lenticular masses or islets of limestone, sometimes very nu- merous and forming large massifs like that at Phillipsburgh and Shoreham, and at other times very limited and even dis- appearing entirely. That mass of black slates, with lenticular masses of lime- stone, can be divided, on paleontological ground, into two parts, the lower one containing at Pointe Levis quite a large number of primordial fossils belonging to the following gen- era: Dikelocephalus, Conocephalites (Ptychoparia),Menoceph- alus, Agnostus and Metoptoma, mixed with special forms of marine animals entirely unknown in the typical second fauna of the state of New York and Canada, namely: Bathyurus, Bathyurellus, Remopleurites; and finally a certain number of forms which developed fully during the second fauna, and are found in the Taconic black slates, only in a sporadic state, being always rather rare, such as Jl/lanus, Ampyz2, Cheirurus, Asaphus, Amphion and Harpes. Brachiopoda, Gasteropoda and Cephalopoda, as well as graptolites are also numerous at different levels of that group of strata; but the species are generally confined to the Upper Taconic, and only very few of them pass into the rocks of the second fauna proper or Champlain system (Lower Silurian of some or Or- dovician of others). In fact, we have in America the same a Rules and Misrules in Classification.—Marcou. 45 phenomenon of mixture of forms of the primordial and _ sec- ond faunas as exists in Wales, and in England in the Trema- doe group and the Arenig or Skiddau group, and at Hoff in Bavaria. It is important to recal] that the Geological Survey of Great Britain, conducted by Sir Andrew C. Ramsay, found during 1875 that fossils passed from the Tremadoc into the Arenig, ten or eleven species, according to Etheridge, the paleontologist of the survey, and that between the Arenig and the Caradoc beds (true Ordovician or second fauna) eight species also passed, showing beyond any doubt that species are no more immutable in their position of strata in Europe than in America. As far back as 1862. the present writer divided the Upper Taconie into three parts, calling the lower part Pointe Lévis or Phillipsburgh group, with a thickness of 3,000 feet; then the middle part called Swanton slates or City of Quebee group, thickness, 2.400 feet; and finally the Potsdam sandstone, three hundred feet. Everything published since, by friends and opponents of the Taconic system, has proved the fitness and value of that definition; only itis very hard for those who are accustomed to call Calciferous formation, Chazy, Black River, Trenton, and Hudson River groups, all the outerops of some islets isolated among the black slates of the Taconic, containing a few fossils, recalling, in a small scale, those for- mations, to accept their mistake, preferring to pass over and neglect all stratigraphical, lithological and even palweontolog- ical rules. Of course they are involved in an ocean of difticul- ties, but nothing stops them, and they hope, with proper use of faults—even when faults cannot be seen—and different facies and thickness of formations to explain, satisfactorily at least to themselves, that the Phillipsburgh series belongs to the Caleiferous formation and the Quebee City or Swanton slate series, in part, to the Chazy, Black River, and Trenton, and even in some part to the Hudson River (Utica and Lor- raine shales), the most heterogenous mixture and chaotic clas- sification that it is possible to imagine. Some quotations of some of the last classification used by some observers, will give an idea of the confusion brought about by misrules. 46 The American Geologisé, January, 1897 GroLocy oF CHazy VILLAGE. The classification of the Champlain division—called first by Sedgwick Cambrian and afterward Upper Cambrian, and by some Lower Silurian and Ordovician—was made by Dr. E. Emmons, and a full description given by him in his final Re- port of the Second District of the Geological Survey of New York, pp. 102-122, Albany, 1842. The village of Chazy with its environs on lake Champlain was taken as a typical place for the section, and many geologists have been there since, visiting and studying the fine section, showing all the strata from the Potsdam sandstone to the Utica slates. Here is a résumé of the section as I took it on several occasions, extend- ing from 1849 to 1863. In discordance on the Potsdam— southwest of the village of Chazy—we see about 250 feet of CALCIFEROUS SANDROCK, containing only four or five species of fossils, such as Orthis, Strophomena, Scalites and numerous fragments of crinoids. Above it we have the CHAzY LIMESTONE; about two hundred feet in thickness, eentaining a quantity of fossils, such as Maclurea magna, Bellerophon, Asaphus, Stenopora, Ortho- ceras, Rhynchonella, crinoids, stems, ete. Then come the BrrpsEYE LIMESTONE and BLAcK RIVER FOR- MATION, called also Buack MARBLE oF IstE LA Morte; thick- ness about forty feet, containing fossils belonging to /sofelus, Orthoceras, Maclurea, Leptena, ete. Above it we have a fine development of a blue limestone, known as the TRENTON LIMESTONE, four hundred feet thick, containing a very large number of fossils such as fragments of the large Jsotelus gigas, Calymene, Trinucleus, Enompha- lus, Murchisonia, Avicula, Bellerophon, Orthis, Leptena, Athrypa, ete. Finally, we have resting on the Trenton the Uvrica sLates and LoRRAINE SHALES, with a thickness of about two hundred feet. containing in great abundance Triarthrus beckii on the shores of the lake at Rouse’s Point and all over the Alburgh peninsula. Tabular View of the Champlain system at Chazy and Vicinity. Utica and Lorraine slates and shales...........,.. 200 feet Trenton TuiIMestone...ace eee eer meet re tse laneurel= 400 °° Black River and Birdseye Limestone.............. 40‘ Chazy. himéstone.. 222+. 22 ep eee ete curren eek DOOM: G@aleiferousssandrock, -2e eee eres eee eee Pag) OC Rules and Misrules in Classification —Marcou. 47 _ The same system of strata, with the same composition and the same characteristic fossils, extends interruptedly from Chazy to Rouse’s Point, St. Jean and Montreal, and covers the greatest part of Jefferson county, state of New York, on the right shore of the St. Lawrence river and at the end of lake Ontario, and is followed without interruption through the state of New York as far as the Mohawk valley. During many years the referring of the Phillipsburgh and Pointe-Lévis group and the Swanton and Quebec city group, as defined by me in 1862, to the Calciferous and Utica-Lor- rain (or Hudson group) was rather a simple theoretical form- ula used by my critics to mean only that they ccnsidered it impossible to refer those strata to any horizon below the Potsdam, on account of some of the fossils found in them. At the same time there was a reluctance to question either the exactness of the determination of those fossils or of their scientific value in classification of strata. They were spoken of as matter of facts, not requiring descriptions and illustra- tion by figures of those on which such a correlation with the Calciferous and the Hudson was based: a sort of authorita- tive synchronism imposed as a creed in American and Cana- dian stratigraphy. Eight or ten, a dozen at most, of fossils —just the same number of species signalized by Andrew Ram- say and Etheridge as passing from the Tremadoe and Arenig divisions into the Caradoe group in Wales and England— some fossils badly determined as the d tops trilineatus wrong- ly referred to as Triarthrus beckii, the Wicrodiscus considered asa Trinucleus, and some Brachiopoda, an order of fossils more apt to possess forms which pass from one system to an- other, are the only true base made use of; a very narrow and incorrect view of the paleontological characters established by Alexandre Brongniart. But since 1888 attempts have been repeatedly made to put practically in the tabular view of the Champlain system the six or eight thousand feet of strata, called and limited by me as the Phillipsburgh and Pointe-Lévis group and the Swanton and Quebee City group; and curiously enough, although those two great groups at the typical places—the vicinity of Quebec city and the vicinity of Phillipsburgh and Swanton—succeed one another in concordance of stratification, one is placed as 48 The American Geologist. January, 1897 g Caleiferous at the base of the Champlain system and the other at the very top of that system as superior to the classi- eal Utica-Lorrain division. The process employed, if accepted, will break all the rules of stratigraphic classification, replac- ing well observed facts by hypotheses. In 1888 appeared a paper entitled, “The Original Chazy Rocks” (AmER. Geo ocist, vol. 2, No. 5, November), by Messrs. E. Brainerd and Henry M. Seely, which disposes of the typical Calciferous, recorded as existing near Chazy vil- lage by Emmons and others, as not belonging to that forma- tion. The authors of that paper have tried to make of it a new great division, regarded as the lower'part of the Chazy, which they call “Group A of the Chazy Limestone.” By that suppression of the true Caleiferous at Chazy village and town- ship we have there, according to the authors, a gap in the stratigraphy which they explain by a fault, or an instance of non-deposition,—they are not sure which—due to elevation of the sea bed in that region when what they call the Calcif- erous deposits were taking place. As the same strata of the Chazy village continue without interruption as far as lake St. Louis on the St. Lawrence river, and farther west, the typical Caleiferous of New York and Canada is suppressed without any visible fault, or without any visible break. Then comes the problem how to account for placing between, what Messrs. Brainerd and Seely call the Group A of the Chazy rocks” and the Potsdam sandstone, their new Calciferous formation or Phillipsburgh group, of a thickness of 1,800 feet, according to their calculation. They say they have found in Beckman- town, eight miles south of Chazy, their Calciferous, 300 or 400 feet only in thickness—not 1,800 feet—and they take a special care to omit to give either a section or deseription with fossil list. The views of Messrs. Brainerd and Seely have been aecepted and used lately in “ Preliminary Report on the geology of Clinton. County, New York,” by Mr. H. P. Cushing (New York State Museum, Report 47, pp. 669-683, Albany, 1894) ; but without any proofs, by well observed stratigraphy or pa- leontological researches; simply calling to the reseue the supposed existence of numerous invisible faults, ‘‘which are frequently difficult to locate from lack of outerops in sufti- Rules and Misrules in Classification —Marcou. 49 cient number” (Loc. cit., p. 669). As “the results presented are therefore merely tentative,” the two geological maps ac- companying the report do not sustain the classification of strata, with 1,800 feet of Calciferous sandrock, containing a fauna of more than one hundred species, placed between the Potsdam and the Chazy formation by Messrs. Brainerd and Seely. GEOLOGY OF SHOREHAM (VERMONT). During 1862 f visited, in company with my friend, the late John B. Perry, the village of Shoreham (Vermont) and found there a repetition of the same group of lenticular or islet masses of magnesian limestone, included in slates, as at Phil- lipsburgh, and also the same fauna with Bathyrus, Maclurea, Lituites, etc. Messrs. Brainerd and Seely have published in 1890 a geological map of East Shoreham, with two sections (‘The Calciferous Formation in the Champlain Valley,” in Bulletin Amer. Museum Nat. Hist., vol. u1, No. 1, pp. 1-23, New York), which fails to show the slates inclosing the mag- nesian limestone as lenticular or islet masses, and presents above the Phillipsburgh group (called by them Calciferous), in concordance of stratification, first the Chazy limestone, then the Trenton and above the Mica slates. Those three impor- tant groups of the Champlain system, so well developed at Chazy village and its environs. are here “rudimentary,” ac- cording to those two authors, and no description, no list of fossils found in those three groups are given; so it is impos- sible to control in any way the determination of the age of those strata. As to the Potsdam sandstone at Shoreham, no fossils are given by the authors, and the stratigraphic posi- tion assigned to it below the Phillipsburgh group (Calciferous of Messrs. Brainerd and Seely) will require careful observa- tions, as regards inclination of strata, dips, as well as fossils, if any can be found. As a conclusion, the classification of strata at Shoreham is made against all rules, and is simply an attempt by Messrs. Brainerd and Seely to suppress the Upper Taconic and refer it to the Champlain system. [To be continued. | 50 The American Geologist. January, 1897 THE RELATION OF THE STREAMS IN THE NEIGH- BORHOOD OF PHILADELPHIA TO THE BRYN MAWR GRAVEL. : By F. BAscom, Bryn Mawr, Penn. In a paper upon “The Rocks near Philadelphia,’* which was published in the Proceedings of the Academy of Natural Sciences of Philadelphia, occurs the following statement: ‘A remarkable feature of the part of Montgomery county and Chester county bordering on the Schuylkill is the diree- tion taken by the streams. The general features are high hills extending in a northeast and- southwest direction, with deep limestone valleys between, nearly at right angles to the gen- eral course of the Schuylkill. “The streams, however, do not follow the valleys. The Wis- sahickon leaves the Montgomery county valley and flows eastwardly through a deep, narrow gorge, through very hard rocks, a distance of over five miles. The Valley creek flows down the Chester valley and then turns abruptly westwardly, and flows through the northwest boundary line. The Gulf creek flows down the valley two or three miles, then turns westwardly and flows through a deep and narrow gorge into another valley on the west, with banks rising abruptly two or three hundred feet.” These three streams, the Wissabickon, Valley creek and Gulf creek, whose peculiar courses are thus pointed out, are only the more marked illustrations of features which charac- terize all streams of the same class, flowing over the Piedmont plateau, in the neighborhood of Philadelphia. The history of these streams will explain not only the diree- tions pursued by them but also by the neighboring streams. Were it possible to read their story completely much light would be shed upon the still obscure post-Newark history of this portion of the Piedmont plateau. While the following consideration of the stream history is manifestly incomplete, it still may suggest a possible criterion of the age of the superficial deposits of the plateau, which has not received much attention. The present topography will be more readily understood if the discussion of the streams is preceeded by a brief resumé *Rand, T. D., on The Rocks near Philadelphia. Proc. Academy of Natural Sciences of Philadelphia, May 29th, 1876, pp. 1-4. Relation of Streams to Bryn Mawr Gravel.—Bascom. 51 of the changes which produced the plain upon which they are at work. The pre-Newark history of the plateau must be read from the deposits and the Jarger rivers. It quite precedes the birth and growth of the present streams. Briefly, the deposits of that portion of the Piedmont plateau traversed by the streams in question (north and west of Phil- adelphia in Montgomery, Chester, Delaware, and Philadelphia counties) indicate that it must have passed through some such sequence of events as is outlined below: In later Algon- kian and Lower Cambrian time it was a land surface. In Upper Cambrian time it was depressed and recéived a thin deposit of Cambrian and Ordovician sediments. Early in the Ordovician period it was elevated, forming part of a lofty mountain range, which furnished continuous supply of material during all remaining Paleozoic time to the western sea. Then followed, upon the western portion, at least, of what was now a peneplain, the Newark depression and later elevation, reversing the direction of the rivers. Sub- sequent to this elevation occurred extended erosion, when the region was again reduced nearly to base-level. Thus, at the dawn of the Cretaceous, the Piedmont plateau was a plain slightly inclined seaward. From this point the story has been carried forward to mid-Cretaceous time by McGee.* Follow- ing upon the baseleveling mentioned above occurred, at the opening of Cretaceous time, the submergenee which initiated the Potomac deposition. This deposit was at first a gravel, later with decreased declivity of the land the materials be- came finer. About the middle of Potomac time, there was, Mr. McGee thinks, in this region a temporary emergence of the land followed by submergence, when the upper member of the Potomac formation was deposited. Since the deposition of these clays and gravels and other possible members of the Cretaceous series the plateau has perhaps been permanently above water. What McGee has called the upper member of the Potomac formation is represented near Philadelphia by the plastic clays, which have been referred by the Second Geological Survey of Pennsylvania to the Wealden. Some of the best exposures *McGee, W J: Three Formations of the Middle Atlantic Slope: Amer. Jour. Sci., volume xxv, 1888, pp. 142, 143. +Report X. Hand Atlas of Pennsylvania. J.P. Lesley, 1885, pl. 46. On bo The American Geologist. January, 1897 of this clay are found northeast of Conshohocken in the neigh- borhood of Harmanville (two miles from the Schuylkill on the county line road). At Keys’ clay pits and at Pott’s mar- ble quarry, at an elevation of one hundred and eighty feet, these mottled clays are well seen. At the former locality the clays have a thickness of fifty-five feet. The succession of colors is yellow, red, white, blue (lignitic), yellow and mot- tled, red. The clays are overlaid by gravel varying from zero to eighteen feet in thickness and at a depth of fifty-five feet gravel again appears. At Keys’ clay pits there is a steep dip to the south. About thirty feet below the surface in the lig- nitic clay were found fragments of wood. These are undoubtedly the “mottled clays’? which Ward has recently referred to the Rappahannock series or “ Basal Potomae.”’ Disassociated from and also in association with these clays is a gravel formation which has been known as the ‘ Bryn Mawr gravel.” This gravel is found in isolated patches at elevations of from three hundred and twenty-five (Media) to four hundred and fifty feet (one-third mile northwest of Gra- dyville) and is also (in the writer’s opinion) the gravel which overlies the mottled clays. It also occurs in Delaware, where it covers the summits of some of the higher hills. (It has been observed by the writer one and one-half miles northwest of Wilmington, Delaware, at the crossing of the Lancaster turn- pike by the Wilmington and Northern railroad.) The pres- ence of an ironstone conglomerate serves as a ready means of recognition of the gravel. This conglomerate is made up of rounded waterworn pebbles of pellucid quartz, of milky white quartz. of quartz stained with the red oxide of iron and of friable quartzite, both white and amethystine, imbedded in a tough sandy and ferruginous matrix. There are also present fragments of kaolinized feldspar and of what appears to be a siliceous limestone, from which the lime carbonate has been removed by solution. This detrital material ranges in size from a fine sand to pebbles which may be nearly six inches in diameter. (Pebbles of this size have been found by the writer in a conglomerate one-quarter mile *Ward, Lester F. The Potomac Formation. Fifteenth Annual Re- port U.S. Geol. Survey, pp. 324-336. Relation of Streams to Bryn Maur Gravel.—Bascom. 53 west of Grassland, Delaware county.) The pebbles of the gravel are identical with those of the ironstone conglomerate and like them are associated with sand. A section shows coarse gravel, grading below into sand and fine pebbles, which in turn passes into a reddish clayey layer. The middle layer contains the conglomerate. So far as is known to the writer the gravel is further characterized by the absence of fossilif- erous pebbles, of fragments of the Newark shale, of gneiss or garnetiferous mica-schist, or of any disintegrated igneous material. This gives it a lithological character, as well as a topography, distinct from the Jamesburg or Pensauken of New Jersey. This gravel has been referred to the Tertiary (Upper Mio- cene) by the Second Geological Survey of Pennsylvania* and by Carvill Lewist+ on the basis of lithological correlation with New Jersey gravels. On this basis it has also been referred to the Columbia,* with the Jamesburg of New Jersey. McGee claims that the gravel as examined by him, in exposures un- fortunately of a more or less evanescent character, shows all the characteristics of the Potomac and is undoubtedly iden- tical with exposures north and east of Conshohocken of a gravel underlying plastic clays, hence he makes it the “lower member” of the Potomac.§ The fact that the Bryn Mawr gravel is elsewhere found at so much higher altitudes than the clay, the presence of the ironstone conglomerate in the gravel overlying the clays at Pott’s quarry and other localities, the general lithological similarity of this gravel with the Bryn Mawr gravel, and the dissimilarity, though slight, of the underlying gravel, have led the writer to reverse MceGee’s conclusion as to position. If the Bryn Mawr gravel is a» member of the Rappahannock series, it must be an upper member of that series. The Bryn Mawr gravel has thus been referred to Mesozoic, to Tertiary and to Quaternary time. Topographical and lith- ological dissimilarity with the Quaternary gravels of New ~ *Second Geol. Survey Penn., Report C, 1885, pp. 10-13. +Proc. Acad. Nat. Sci. Phila., 1880, pp. 269, 272,488. Jour. Franklin Institute, volume 85, 1883, p. 373. Proc. Acad. Nat. Sci. Phila., 1884, p. 240. tSeventh Annual Report, U. S. Geol. Survey, p. 610. S Amer. Jour. Sci., vol. xxxv, p. 130. 54 The American Geologist. January, 1897 Jersey would seem to exclude it from that period. Will the evidence of stream erosion coneur in that exclusion? The plastic clays and the Bryn Mawr gravel rest alike upon sontorted and eroded pre-Cambrian erystallines and upon up- turned strata of Cambrian, Ordovician and Newark. age. They rest upon the baseleveled plain of marked heterogeneity. Since this plain was baseleveled these two formations covered it to a depth varying from one hundred to two hundred and fifty or more feet. With this past history thus briefly outlined, the present to- pography of the region can be readily comprehended. The ancient Cretaceous baseleveled plain now stands at a fairly uniform hight of from four hundred to four hundred and fifty feet. This plain is trenched by valleys which have been excavated since the last elevation and since the depos- ition of Potomac clay and Bryn Mawr gravel. The streams are far from reaching old age. Their head waters are still cutting back and contesting the watershed with streams farther west. The present discussion is con- cerned only with the streams and does not include the Schuy]- kiil river, which is a compound and complex decendant of an original Permian river. The Wissahickon, with its headwaters ata hight of four hundred and forty feet above sea-level, near Montgomeryville in Montgomery county, flows southwest and southeast across the Newark formation, then it turns and flows almost straight south, cutting across Cambrian sandstone and a belt of Or- dovician limestone two miles wide. It leaves this non-resist- ant belt to erode a gorge in hard gneisses and quartziferous mica schists. At Chelten avenue, Germantown, it receives a tributary and, turning abruptly, flows one and three-eighths miles south- west into the Schuylkill. Its course covers somewhat over twenty miles with a fall of four hundred and twenty feet. The gorge of the Wissahickon in the crystalline schists is from one hundred and eighty to three hundred and fifty feet deep, and the stream is still earving with youthful vigor an ancient surface which bears the sears of other and far older agents of erosion. Relation of Streams to Bryn Mawr Gravel.—Bascom. 55 The course of this youthful stream is directly transverse to the geological structure of the plateau and is entirely independent of the lithological character of the rocks over which it flows. This course admits of but one explanation, namely, that the Wissahickon is a superimposed stream, superimposed upon the Potomac clays and Bryn Mawr gravel through which it has cut its way. The gentle slope seaward of the plateau after the Cretaceous elevation determined the direction of the stream: Having trenched the clays and gravels, it found the hard erystallines beneath, but its course was too well estab- lished to be turned aside by the herterogeneous character of its newly discovered bed. The abrupt turn at Chelten avenue and the subsequent course of the stream is evidently controlled by the tributary of which the Wissahickon becomes a part. Valley creek is a stream some ten miles long which heads in the quartzite ridge forming the western boundary of Ches- ter valley. It flows northeast over the limestone of Chester valley for some seven miles before it turns to the north at an angle of one hundred and thirty degrees to flow through a gorge cut in Cambrian quartzite rising three hundred and twenty and five hundred and ninety feet above the bed of the stream. At Valley Forge it empties into the Schuylkill. (See plate II.) For the last half mile its bed lies on the New- ark formation. Like the Wissahickon, Valley creek is a su- perimposed stream. The cover of the Paleozoic sediments was undoubtedly in part the Newark formation as well as the Potomae gravels. The way in which Valley creek, after following the strike of the limestone for some seven miles, leaves that easily eroded rock to traverse the hard strata, almost at right angles to its former course, would be remarkable under any other explan- ation than that of a superimposed course. With the location of its bed due to the original slope of the land and fixed by superimposition, the subsequent erosion of a gorge through the quartzite, with the dip, becomes the most natural procedure. The tendency of obliquely transverse streams, on upturned strata of different degrees of hardness, to gradually shift their courses until they become rectangular ones, along the strike 56 The American Geologist. January, 1897 of the soft bed and across the strike of the hard bed, cannot be ascribed to Valley creek as explained by Gilbert.* Gulf creek rises in a ridge of mica-schist one-half mile uorth of Strafford station at an altitude of four hundred and eighty feet. It flows ten degrees north of east along the base of this ridge for about four miles when it turns at an angle of ninety degrees, cutting across the ridge, which, at this point, now stands at a hight of from four hundred to four bundred and eighty feet. After crossing this ridge the creek turns again at right angles and, flowing parallel to its origin- al course, it empties into the Schuylkill at a level of fifty feet. (See plate I.) Gulf creek illustrates readjustment as well as superimposition. The adjustment occurred after the stream had cut through the Potomae cover and discovered the underlying crystallines of unequal hardness. The early stream heading at ) with two tributaries, A and C, soon cut a deeper channel in the limestone which formed its bed than its neighbor, MZ, on the other side of the mica- schist divide, was able to do in the gneiss in which its bed must be eroded. The tributary A, by reason of the grade given it by the deepening channel of the main stream, was able to cut back through the mica-schist, with the dip, and eventually to rob M of its headwaters. Since the capture of the headwaters of 4, the channel of the diverted stream has rapidly deepened with the increased declivity and is now separated from the beheaded M by a low watershed, while flows through a valley larger than its present volume warrants. A natural ponding on Gulf creek resulting from the sudden accession of detrital material brought by the tributary, has been utilized for artificial dams. Similar transverse courses are pursued by Brandywine, Naaman, Chester, Ridley, Crum, Darby, Tacony, and Penny- pack creeks which drain large areas of the plateau and empty into the Delaware between Wilmington, Delaware, and Holmesburg. Pennsylvania. If these streams were superim- posed upon a cover of Bryn Mawr gravel they have accom- plished all their work of erosion since the elevation of land which followed the deposit of that gravel. *Gilbert, G. K. Geology of the Henry Mountain. Geog. and Geol. Survey of the Rocky Mountain Region, p. 130. a > VBRARY _—UNIVERS a a OF THE ITY of ILLINOIS. is ‘ ‘ | - Ban} ) a ’ — en ’ i wee ‘ . r - , | l'ae AMERICAN GEOLOGIST, Vou. XIX, PLATE II. N / 690 CHESTER ZOO 4 j Review of Recent Geological Literature, 57 Their age is approximately the age of the gravel. They cannot be older, they may be younger. If ‘the gravel is Col- umbia in age then the streams date from the close of that pe- riod or later. The question arises, could the streams have trenched such deep valleys and so extendedly contested the di- vide since Columbia time? We find the erosion in southeast- ern New Jersey of a less mature character. We find the Pen- sauken and Jamesburg gravels made up of material which must have been furnished them by streams draining this plateau. The red shale of the Newark, disintegrated gneiss. granite, trap, garnetiferous crystalline schists and gabbro (the Bran- dywine, Naaman, and Crum creeks flow across gabbro areas) and rounded fragments of ironstone would be furnished abun- dantly by just such streams as the creeks described above, eroding first the Bryn Mawr gravel, then the crystalline schists and igneous rocks of the plateau. These facts seem to concur in precluding the Quaternary age of the gravel. It is perhaps not possible to determine the age of a drain- age system with a degree of accuracy sufficient to distinguish between a late Mesozoic or an early Tertiary origin. On the other hand, the stream history furnishes no evidence against the Potomac (Mesozoic) age of the gravels. The other members of the Potomac series were in all prob- ability present in Pennsylvania and have either been com- pletely removed by an erosion, dating back to the dawn of the Tertiary, or will yet be discovered in small areas. That evidence of still more recent superficial deposits will be found seems highly improbable, hence the hypothesis has been stated that not very long after the deposit of the Bryn Mawr gravel the Pennsylvanian plateau was permanently ele- vated and the present streams began their work of erosion. ob Vel VV Ol” RECENT GHOLMOGICAL Po ERA TO The Underground Water of the Arkansas Valley in Eastern Colo- rado. By G. K. Giueert. (Extract from 17th Annual Report of the U. S. Geol. Survey, Part II.) This paper, which illustrates well the vari- ous excellencies which we have learned to expect from Mr. Gilbert, is 58 The American Geologist. January, 1897 clear, concise, and complete. Its aim is to place in possession of the citizens of the region such knowledge of the geological formations and their relations to certain economic interests as will enable them to make them most available. The region is the larger portion of the twelve or thirteen southeast- ern counties of the state of Colorado. It briefly describes the various geological formations giving the physical appearances and characteristic fossils of each. The latter are illustrated so that well diggers and oth- ers may make use of them in identifying the strata which they find. A synopsis of the formations is given in the following table: Rock Strata of Southeastern Colorado. Fox Hills, sandstone and sandy shale 450 feet. Upper barren zone, shales 250-300 ‘* Teepee zone, shales 1,000 ‘ Lucina occidentalis, Sea- phites nodosus, Bacu- lites, Heteroceras, etc. PiERRE~ Belemite zone, shales 100-150 ** Belemnites, Baculites,ete. Rusty zone, shales 600 ** Iron concretions. | Lower barren zone, shales 450-500 ‘* Mueh selenite. 1 J ~ CRETACEOUS 4 si Apishapa shales S0Oss* Fish scales and bones. Nrosrara ~ Timpas, limestone a WT ee ! Inoceramus deformis, Os- L trea congestd. ~ Carlile shales 175-200 ‘* Prionocyclus wyoming- ensis. ENTON 4 : Brenton | Greenhorn limestone 25-40 * Inoceramus labiatus. _ Graneros shales 200-210 <«* Dakota sandstones and shales 200-500 ‘* Jura-Trias, sandstones and shales of red color 2, 000K The dip of these formations, especially of the older, is to the north- northeast from the foot of the mountains. Besides these older formations of the Cretaceous there are recognized the Upland Sands and Gravels, which the author ascribes to the action of streams, lakes and winds, at a time when the drainage of the region was much more sluggish than at present; the Terrace Sands and Grav- els, which cap the higher terraces along the main streams, and the Dune Sands. which had accumulated at various epochs. Perhaps the most important economic feature of the paper is that treating of artesian wells. Water is a desideratum in that region and is obtained from two general sources: one, the deeper or artesian sup- ply, the other, the waters permeating the loose deposits near the sur- face. The artesian supply is here, as further north, mainly from the Dakota formation, which is described as being made up of different layers of a yellow or brown sand more or less separated by impervious layers of shale. The Jura-Trias is considered to be quite impervious to Review of Recent Geological Literature. 59 water. No successful wells have been obtained from it. Above the Dakota sandstone the remaining members of the Cretaceous are almost entirely impervious shales. A map is given of an elongated region cor- responding in a general way to the Arkansas valley in which flowing wells may be obtained. Along the south and west sides of this area wells may be obtained at a depth less than a thousand feet, but along the northern side throughout a narrower strip they cannot be obtained without going to a greater depth. The former area is estimated to be about 4,000 square miles, and the latter 1,500. Some valuable state- ments are given concerning the areas in which the water is collected. The average width of the exposure of the Dakota formation along the foot hills is estimated to be not more than one mile. ‘*Where it is nar- row the slopes are so steep that a large share of the storm water runs off and the sand can imbibe but little. But the broader parts of the belt have gentle slopes more or less covered by a blanket of sand, in which the rain water is stored for a time and from which it may be slowly absorbed by the sandstone.”’ He outlines several areas of this sort, one having an area of fifty or sixty square miles, another of five hundred, and a third of not less than a thousand. The author remarks, ‘‘ It is impossible to say what share of these areas contributes water to the sandstone. In part they are oc- cupied by the upper layers of sandstone, which are of so fine texture as to receive little water. The irregularity of the sandstone beds is so great as to raise the question whether all the porous beds exposed to the rain are of such horizontal extent as to carry water to the deeply buried por- tions of the formation. Such considerations make it impossible to es- timate the amount of water which may annually be imbibed, and for the present at least it is useless to discuss the annual rainfall with reference to the extent of the gathering grounds.”’ The artesian waters are found to vary much according to locality. In general they are rich in chlorides, sulphates, carbonates of sodium, cal- cium, magnesium, with frequent occurrence of silica and lithia, in pro- portions varying from .0008-.0036. The ground water of the region is derived mainly from the Upland Sand and Gravel. Considerable attention was given to circulation of water in the sand occupying the stream beds, as well as those of the terraces and upland. In the Arkansas river, as in most rivers of the plains, a large portion of the water is flowing beneath the surface of a vast amount of sand filling its channel. Upon the upland the water contributed by rainfall is found here, as in other regions, to have a very irregular surface, corresponding sometimes to the surface of the under- lying rock, sometimes to the surface of the soil and at other times ap- parently without relation to either. Some interesting experiments were made to determine the absorptive power of sands. The experiments were performed by filling a vessel with sand thoroughly dried, then pouring into it water until it was sat- urated, then by puncturing the bottom of the vessel so as to permit the water to drain away, and after a lapse of several days determining the 60 The American Geologist. January, 1897 amount of water lost. The amounts in each case were determined by weighing. It was found that the sand in one case had received 29 per cent. of its volume of water, but afterwards parted with only one-third. In one case the sand taken from an ancient deposit on the face of ‘*The Mesa’”’ near Santa Fe avenue, in Pueblo, absorbed 29 per cent. of its volume of water and delivered only 3 per cent. This illustrates forcibly the adhesion of the water to the sand, which forms an important factor in estimating its friction and the rate at which the water may percolate through sands either near the surface or in an artesian stratum. The paper may be heartily commended as a model of careful, scientific investigation and a popular presentation of economic results, such as should often be the aim of the governmental expenditure of public funds. Tepe On the Apical End of Endoceras. By GerHarp Hotm. (Om apikal- andan hos Endoceras; Geol. Foren. i Stockholm Foérhandl. vol. 18, pt. 5, p. 394-426: 1896.) Herein Holm has summarized all that is now known of the very rare fossil apical ends of Endoceras shells. The ex- cerpt at hand is in Swedish, and is accompanied by six excellent octavo plates. besides three figures in the text. In review, from the literature on the subject, Holm begins with the observations by Barrande* (1870), who described and figured a speci- men of Orthoceras marcoui Barr., and who considered the same as still possessing the apical end of the shell. Holm himself in 1885+ described and figured the structure of the apical portion of the shell as well as the development of it in Endoceras belemnitiforme Holm, and pointed out the difference between this one and the much smaller septate apex of E. bouchardi Dew. Remelé (1885){ mentioned two Orthoceras shells with bent initial part. Foord§ in 1888 showed that the Orthoceras mar- cout described by Barrande consists only of the apical portion of the siphon itself. In 1889 Rudinger|) mentioned a specimen of Hndoceras which has the apical end bent towards the siphonal side. Hyatt‘) (1889), after citing Holm’s description of E. belemnitiforme, pointed out fur- ther the relation of the diminution in size of the siphon to the septa. Again in 1892 Holm** presented his observations on three species of En- doceras with preserved apical portion, one of which is like EF. belemmniti- forme Holm, except that the initial portion or apical cone of the siphon attained less size. The other two have the apex of the shell septate, but the siphon is swelled and later constricted before assuming its nor- mal size. Both of the same are characterized by the curving of the apical end Cyrtoceras-like, toward the siphonal side. Clarkett (1894), without knowing of Holm’s description of Endoceras belemnitiforme, described the apical end of a very nearly related new *Syst. Sil., Cephalop., pl. 431, fig. 11-13; text part 3, p. 748. +Paleont. Abhandl. vol. 3, pt. L, p. 4, pl. 1, fig. 1-5. tNo. 113 in ‘‘ Katalog der von Prof. Dr. Ad. Remelé beim international Geologen- Congress zu Berlin im 1885 ausgestellten Geschiebesammlung.”’ 8Cat. Foss. Cephal., part I, p. 132. Arch. Ver. Freund. Nat. Mecklemb., Jahr, 1891. “Genesis of the Arietide, p. 13. **(Jeol. Foren. Foérh., vol. 14, p. 71-72. TTAMER. GEOL., vol. 14, Oct., 1894, p. 205, pl. 6. Review of Recent Geological Literature. 61 species from North America. which he calls a new cephalopod type be- cause of the structure of the apical end, and he called the same by a new name, Nanno aulema Clarke. Sardeson* (1894) and Batherf (1894) both pointed out that Nano is far from a new cephalopod type. Hyattt (1895) confirmed in main Clarke’s description of the apical end of Nanno aulema. Holm here quotes in a foot-note Hyatt’s introductory words, viz., ‘‘The discovery and description of this genus by Prof. J. M. Clarke has materially added to our knowledge of the structure and de- velopment of the siphon in the Fndoceratide and thrown a new light upon the affinities of the forms of this group,’’ and comments upon them as inexplicable, inasmuch as Sardeson and Bather had pointed out that Holm had in 1886, or nine years earlier, more thoroughly and extensively described the cephalopod type in question. Further Hyatt considered Nanno aulema, because of the structure of the siphonal tubes, as generically distinct from Hndoceras belemniti- forme Holm, but he seems, says Holm, not to have had sufficient mate- rials. He is quoted much in fuil because his observations are so indefi- nite. Holm§ (1895) described and figured the endosiphonal structure of Endoceras (Nanno) belemnitiforme and shows the same to be like that of E. wahlingbergi Foord, with a cicatrix opening in the same manner as in Piloceras, from which it was concluded,--Bather’s views notwith- standing,—that FE. belemnitiforme and related forms, similar to other Nautiloidea, have a fragiie, easily destructible protoconch. The near relationship between Nanno aulema Clarke and Endoceras belemniti- . forme Holm was determined and Nanno adopted as a subgenus of En- doceras. After reviewing the literature Holm presents further observations upon the apical structures of Endoceras. He recognizes two types of these structures in Endoceras, but considers the division of the genus as impracticable, since the apical cones of very few species of this large group are known, and among the few is not found the type species it- self of Endoceras. He therefore recognizes two subgenera, Nanno, type E. aulema (Clarke) and Swecoceras, type E. barrandei Dew., the former of which he considers as the more primitive form. follows: Supcen. 1. Nanno (Clarke). Siphon with the apical end strongly swelled so that back of the first loculus there is formed an apical cone of the shell, which is entirely filled by the siphonal apical cone, the latter equalling in length, in all known cases, the combined width of at least three of the first chambers. Thereafter the siphon tapers for- wards so rapidly that the same attains its normal dimension within the third septal chamber. SuspeGen. 2. SuecoceraAs Holm. He defines them as Siphon completely filling the shell’s apical end, with narrow apex, and on the siphonal side in contact with *AMER. GEOL., vol. 14, Dec., 1894, p. 402. t+tNatural Science, vol. 5, No. 34, Dec., 94, p. 481. tAMER. GEOL., vol. 16, July, 1895, p. I, pl. 1. SGeol. Foren. Férh., vol. 17, p. 616, pl. 22, fig. 9-13. 62 The American Geologist. January, 1897 the outer shell of the conch, forming within a series of the first loculia quickly expanding initial cone, likewise again decreasing in size to its normal dimension. The first loculus therefore includes the apex itself. In some forms of Swecoceras the apical cone is a little curved, Cyrto- ceras-like, towards the siphonal side, the point of greatest curve coin- ciding with, or a little forward of, the siphon’s point of greatest diam- ever. The following species are described: Endoceras (Nanno) aulema (Clarke), F.(Nanno) belemnitiforme Holm, E. (Nanno) fistula Holm, n. sp., E£. (Nanno) pygmeeum Holm, n. sp., EH. (Suecoceras) barrandei Dew., H. (Suecoceras) gibbum Holm, n. sp., #. (Swecoceras) reeurvum Holm, n. sp., #. (Suecoceras) dux Holm, n. sp., £. (Swecoceras) sp., E. (Suecoceras) papilla Holm, n. sp., EB. (Suecoceras) marcout Barr. F.W.S. Faunas of the Pavadowides Beds in Eastern North America—No. 1. By G. F. Marruew. (Trans. N. Y. Acad. Sci., vol. xv, Aug. 3, 1896, pp. 192-247.) In his introduction to the paper on the Protolenus Fauna* the above author outlined the subfaunas into which the American Par- adoxides fauna may be divided. More detiniteness is given this view of the life of the middle Cambrian by showing the species which are pe-. culiar to each subfauna, so far as they are described in this article. Only the smaller crustaceans are dealt with in this paper, which is — valuable especially as giving a full account of the species of Agnostus and Microdiscus as they appear in the Paradoxides beds of America. A good many European species of Agnostus are recognized as occur- ring in these beds, either in their European form or as varieties, show- ing the close relation that existed during Middle Cambrian time, between the faunas on the two sides of the Atlantic. Some points interesting to the biologist are made out by a study of the development of the larva in Agnostus. The earlier moults show a near resemblance to other trilobites of the Paradoxides beds. This resemblance is appa- rent in the form and details, both of the headshield and pygidium. As regards the latter it is said to show three stages of development during erowth. Ist, The early larval stage—nonagnostiform—when it posses- sed 1-3 somites; 2d, the later larval stage—agnostiform—when it had about 4-5 somites; 3d, the adult condition when it had about 6-7 somites and the three main lobes of the rachis were developed. Of these somites, 4-5 were in the posterior lobe of the rachis of the pygid- ium. The special features of the sections of Agnostus designated Par- vifrontes and Levigati by Tullburg resulted from the progressive effacement of those of the earlier types, presumably impressed in early larval stages. The species of Agnostus recognized as occurring in the middle Cam- brian of eastern North America ere the following: Reatr, A. regulus Matt.; A. rea Barr., var. transectus, n. var.: Fa- Laces, A. fallax Linrs., var. vir Matt., var. concinnus Matt., var. trilo- Trans. Nie. Acad. Sci.. vol. xiv, Mar. 17, 1895. — Review of Recent Geological Literature. 63 bafus, n. var.; A. acadicus Hartt., var. declivis Matt.; Parvirronres, A. purvifrons Linrs., var. tessella Matt.. var. truncatus, n. var.?: A. unbo Matt.; Loneirrontes, A. obtusilobus Matt.: A. davidis Hicks, A. gibbus Linrs., var. partitus Matt., var. acutilobus Matt.: A. na- thorsti Brogg., var. confluens, n. var., A. fissus Lundg., var. trifissus, n. var.; A. punctuosus Ang. Lavicati, A. levigutus Dalm., var. ter- ranovicus, n. var., var. ciceroides, n. var., var. mamilla, n. var.: A. nudus Beyr.? Figures of these Agnosti appear on three plates of the memoir. The Disseminated Lead Ores of Southeastern Missouri. By ArvHurR Winstow. Bulletin 132, U.S. Geological Survey: 31 pages, with six plates (maps and cross-sections), and three figures in the text: 1896. The structure and areal geology of this district are described and map- ped, with notes of recent progress in mining and the general distribu- tion of the ore as revealed by drilling. The ore-bearing formation is the St. Joseph limestone, in which galena is desseminated through beds varying within short distances from one or two feet up to ten or twenty feet in thickness. Mining on a large scale began soon after the close of the civil war. and several new mines have been opened during the last five years. Ww. U. Contributions to the Cretaceous Paleontology of the Pacific Coast: The Fauna of the Knowville Beds. By TimorHy W.Sranvron. Bulletin 133, U. S. Geol. Survey : 132 pages, with 20 plates; 1895. Structurally and faunally, these Aucella-bearing beds, occurring in the Coast ranges of California, Oregon, and Washington, seem to constitute a single and well defined geological formation. The fauna, however, shows a grad- ual change from the lower to the upper beds, while yet having no dis- tinct break which would justify referring one portion to the Jurassic and another to the Cretaceous. The author regards the whole formation as of Neocomian age. It has 77 species and varieties of invertebrates, as here described, of which 50 are new, 12 have been previously de- scribed, and the remaining 15, on account of insufficient material, can be only generically determined. Ww. U. Bibliography of Missouri Geology. By C. R. Keyes. (Mo. Geol. Surv., vol. 10, pp. 219-523, 1896.) This article is the last in the tenth volume of the present Missouri Survey, which volume will soon be dis- tributed. The bibliography includes (1) an authors’ index, containing the full title, pages, etc., and a very brief synopsis of each article; (2) a title index; and (3) subject entries and cross references, In this manner each article is entered at least three times and many appear more than three times. Moreover, whenever an article is entered it appears with its full title, author and place of publication. This of course much ib- creases the bulk of the bibliography, but at the same time it makes it more serviceable in doing away with the necessity of turning from one title to another to find.a complete reference. The present work differs considerably in plan and scope from the earlier bibliography of Missouri geology by ks A. Sampson (Mo. Geol. Surv., Bull. 2, 1890). U: 8: 'G. 64 The American Geologist. Sanuary, 1897 The Eocene Deposits of the Middle Atlantic Slopein Delaware, Mary- land and Virginia. By Wituram Buttock CrarK. (U.S. Geol. Sur- vey, Bull. 141, 167 pp., 40 pls., 1896.) The Eocene strata (Pamunkey formation of Darton) of the Middle Atlantic slope form a distinet unit, being separated from the Cretaceous below and from the Miocene above by erosion intervals. In lithologic character these deposits are essen- tially glauconitic, and they contain a considerable fauna, although the state of preservation of the fossils has heretofore caused a large number of the Eocene forms to be overlooked. The strata strike north and south. or northeast and southwest in the northern part of the area, and the dip is toward the east or southeast, averaging twelve and one-half feet per mile. The average thickness is about 200 feet, although in places the beds attain a thickness of 300 feet. From the Potomac River section, which is the best and most characteristic section exposed, the author has been able to establish two clearly defined paleontologic stages,—a lower or Aquia Creek stage, and an upper or Woodstock stage,—but it is not possible to recognize over the whole area minute paleontologie or lithologic divisions. In discussing the correlation of the Middle Atlantic Slope Eocene with the Gulf Eocene Prof. Clark calls attention to the diverse views on this subject and also to the different conditions under which the depos- its were laid down. In the former region the strata were accumulated slowly at some distance from the shore and along a coast which received no large rivers, while in the latter region the accumulation was rapid and more extensive and was largely influenced by the débris brought down by large rivers. The author concludes that the Middle Atlantic Slope Eocene is the equivalent in a broad way of most of the Gulf series, except that the upper part of this series is probably lacking in the re- gion he is discussing. The Aquia Creek stage is broadly the equivalent of the Lignitic, and the Woodstock of the Claiborne. The work contains a bibliography of the subject, a historical review of investigations, a brief outline of Coastal Plain history, a discussion of criteria of correlation, and descriptions of the fauna, which is illus- trated by thirty-six plates. U.S..G. The Cambrian Rocks of Pennsylvania. By CHarues D. Watcorr. Bulletin 134, U.S. Geol. Survey; 43 pages, with 15 plates; 1896. This paper gives the results of field work in 1892 and 1893. The discovery of the Olenellus or Lower Cambrian fauna in the Reading sandstone sup- plies the completing link in the correlation of the basal quartzites of the Cambrian series along their entire extent from Vermont to Tennessee. Much further work is needed for determination of the division between the Cambrian and Ordovician series in this region. Intraformational conglomerates, in thin bands, are described as observed in many locali- ties. Their origin is ascribed to tidal action on gently sloping shores or on the flats of estuaries, hardened layers due to drying when exposed by the ebb of the tide having been broken up by the incoming tide. WwW. U. ~ Recent Publications. 65 Annual Report of the Inspector of Mines of Kentucky for 1895. By C. J. Norwoop, Chief Inspector and Curator of the Geological Depart- ment, and W. U. Griper, Assistant. Pp. vii, 326, Louisville, 1896. This report is not, like so many which deal with mine inspection, sim- ply a list of mines and of the accidents which have occurred in them during the year. Planned and prepared on a liberal scale. by a compe- tent geologist, it contains the usual statistical data in considerable de- tail and then goes on to give an account of the various mines in one chapter of 70 pages, a paper on ‘‘Coal-dust as an Explosive Agent,” pp. 171-191; one on “Coking and Coal-washing at Earlington.” by J. B. Atkinson, pp. 191-207: a chapter on ‘‘Steam Tests of Kentucky Coal,”’ pp. 208-243: a general article on ‘‘Kentucky Mineral Wealth,” by C. J. Norwood, pp. 243-292, and chapters on petroleum and phosphates in Kentucky and the prevailing laws relating to mining. From the statistical data we learn that there were 138 coal mines in operation in 1895. These produced 3,207,770 short tons of coal, worth 80.5 cents per ton at the mine. There were produced 25,450 tons of coke in 214 ovens. The paper on the mineral wealth of the state is a valuable resume and contains references to the coal. iron ores, fluor spar, baryta, lead, as- phaltum, clays, petroleum and building stones. H. V. W. REGENT PUBLICATIONS: IV. Excerpts and Individual Publications. Manual of determinative mineralogy, with an introduction on blow- pipe analysis, by G. J. Brush. Revised and enlarged by 8S. L. Penfield. 8vo, ix, 163, 63-108 pp.: New York, John Wiley and Sons, 1896. L’extension du systéme taconique vers |’Ouest, N. H. Winchell. Compte-rendu du Cong. géol. intern., Ge Ses. (Zurich, 1894), pp. 272-308, 1896. Faunas of the Paradoxides beds in eastern North America, No. 1, G. F. Matthew. Trans. N. Y. Acad. Sci., vol. 15, pp. 192-247, pls. 14-17, Aug. 3, 1896. The Jura of Texas, Jules Marcou. Proc. Boston Soc. Nat. Hist., vol. 27, pp. 149-158, Oct., 1896. On the fracture system of joints, with remarks on certain great frac- tures, J. B. Woodworth. Ibid., pp. 163-483, pls. 1-5, Nov., 1896. A new occurrence of Carboniferous fossils in the Narragansett basin, M.L. Fuller. Ibid., pp. 195-199, 1896. Bibliography of Missouri geology, C. R. Keyes. Mo. Geol. Survey, vol. 10, pp. 219-523, 1896. Catalogue of the fossils of the Trenton and Cincinnati periods oc- curring in the vicinity of Cincinnati, O., G. W. Harper and R. S. Bass- ler. 34 pp.; Cincinnati, W. B. Carpenter Co., 1896. A geological reconnaissance in northwestern Oregon, J. S. Diller. U. S. Geol. Survey, 17th Ann. Rept., pt. 1, pp. 1-80, pls. 4-16, 1896. 66 The American Geologist. January, 1897 Traces of organic remains from the Huronian (?) series at Iron Moun- tain, Mich., W. S. Gresley. Trans. Amer. Inst. Mining Eng., Colo- rado meeting, Sept., 1896; 8 pp. Faulting in glacial gravel, W. 5S. Gresley. Ibid., 2 pp. The geology of the Sand hills of New Jersey, W. ‘B. Clark and G. B. Shattuck. Johns Hopkins Univ. Circulars, vol. 16, 4 pp., 1897. V. Proceedings of Scientifie Laboratories, ete. Bull. Mus. Comp. Zool., vol. 28. no. 2, (Geol. Ser. vol. 3), pp. 29-62, pls. 1-26, Oct.. 1896. The elevated reef of Florida, Alexander Agassiz; with notes on the geology of southern Florida, L. S. Griswold. Same, vol. 28. no. 3, (Geol. Ser. vol. 3), pp. 65-91, Dec., 1896. Notes on the artesian well sunk at Key West, Florida, in 1895, EK. O. Hovey. CORRESBONBEN CE: THE AGE OF THE CALIFoRNIA Coast Rances. Mr. Fairbanks having seen fit to offer, under the foregoing heading, certain friendly criticisms upon a recent paper by me, on the Great Valley of California, a few — words in reply may not be amiss, as showing that the real difference be- tween our views is not so wide as he seems to imagine. To begin with, the criticism seems to have rather overlooked the fact that the main object of the paper discussed was a study of the theory of isostasy with special application to the Great Valley, and not an ex- haustive discussion of the various oscillatory movements that may have affected that portion of the earth’s crust now occupied by the Coast ranges. It was far from my intention to deny the fact of these oscilla- tions, or the former existence of pre-Miocene land masses within this area. Asa matter of fact, such older land areas are distinctly men- tioned on page 424, and elsewhere within the paper. But to speak of these older land masses as ‘‘ the Coast ranges,’’ and to assume that they held substantially the same relations toward the interior valley and coast line that the mountain ranges of that name now do, or have done since the close of the Miocene, is a very different matter. It may be true, as Mr. Fairbanks suggests, that the discussion of such oscillations as he refers to might materially strengthen the case against isostasy, but it is also conceivable that the discussion of such a broad principle may have its value largely increased by a decided tendency toward conservatism in the selection of the fundamental data from which the deductions are drawn. In the present state of our knowledge it does not appear possible to connect these movements with the mor- phogeny of the Great Valley in a sufficiently definite manner to add any value to the discussion in hand. Mr. Fairbanks says that ‘‘ the Miocene was terminated by one of the most marked changes of level recorded in the history of the region. This change was in the nature of a great uplift with the formation of several new ranges,’’ and with this statement I am in substantial agree- ment. Our main difference is purely one of definition. He would include : E Personal and Scientific News. 67 under the term ‘‘ Coast Ranges” such land masses as may have existed on or near the line of the present mountains prior to that upheaval, while I am disposed to restrict the name (particularly in the present discussson) to the physiographic features initiated by so radical a trans- formation as then took place. We do not know how far or in what di- rection these older landmasses extended. The conditions, during the Miocene, which allowed the accumulation of the very extensive Miocene deposits which make up so large a portion of the Coast Ranges, were certainly very different from those which have obtained since the be- ginning of the Pliocene ; and it does not appear that sufficient corres- pondence has been made out between the early Miocene distribution of land and sea, and that of the present day, to warrant us in speaking of these earlier landmasses as the ‘‘ Coast Ranges.’’ There is, in brief. nothing in the literature that will enable us to reconstruct a Miocene or pre-Miocene ‘‘ Great Valley” which can be satisfactorily shown to have any direct genetic connection with the present Great Valley of Califor- nia. The quotation from Diller which is advanced as indicating the existence of the Coast Ranges and interior valley in Cretaceous times. namely, ‘“‘that during the Shasta-Chico period the Coast range existed, but did not furnish sufficient obstruction to keep the open sea out of the Sacramento Valley,”’ contains within itself the suggestion of my objections to Mr. Fairbanks’ terminology. Moreover, this statement refers only to the northern part of what we know as the Great Valley, and leaves room for the interpretation of a very different physiography from that which is known to date from the post-Miocene uplift and folding. F.. Lestre Ransome. Harvard University, Dec. 9, 1896. PERSONAL AND SCIENTIFIC NEWS THe MaryLanp GroLocicaL Survey has undertaken a mag- netic survey of the state. ‘This work is under the direction of Prof. L. A. Bauer. Already observations of the three mag- netic elements have been made at about forty stations, aver- aging one station to every 250 square miles. The ultimate average will be one station to about 140 square miles. s 2 Oot: Georgia: *4 7 Faas a OS Younger igneous rocks. = : ; ; ee = Ancient crystalline rocks, < a divided in six groups. The western, or fourth district, as well as the central por- tion, or third district, are the easy part of the work; the for- mations and beds following one another with the regularity of tiles upon a roof, or steps on a staircase, without any difticul- ty of succession, of disturbance or faulting. For that part of the map, all that was required, to make it more exact, was to mark the limits of each group or formation with more ac- curacy, and to add some details in the classification of some of the great and important groups like the Chemung and Portage, where a new division has been introduced between 128 The American Geologist. February, 1897 them, under the name of ‘Oneota.” Besides it was important to establish the correlations with the great stratigraphic sys- tems of Europe, a work so well done by De Verneuil in 1846, and which wanted to be transferred on the official geological map of the state. The state geologist, Mr. James Hall, has followed closely the researches of Vanuxem, Conrad and De Verneuil, improy- ing by well observed details the stratigraphy of all the coun- try between Schenectady, Schoharie, Buffalo, and the bound- ary line of the state of Pennsylvania, and his map of 1894 is a great improvement on the geology and geography of the third and fourth districts. So now, thanks to the Geological Survey of New York, and its director, Mr. James’ Hall, we possess for that important portion of the state a correct and excellent geological map. But the other portions, especially the eastern, or first geolog- ical district, are still far from satisfactory, on the map of 1894. Dr. Ebenezer Emmons, on his geological map of 1844, with the approbation of Vanuxem, introduced a new great system of deposits of about 25.000 feet of strata, lying east of the Hud- son river and of lake Champlain, which he proved by strati- graphy, paleontology and lithology to be older than the Lower Silurian or Champlain system, and which he called most appropriately the Taconic system. It was a stroke of genius on the part of Dr. Emmons, who, before any other geologist or any other country, found in America the true base of the sedimentary strata, the primordial fauna, and consequently the first and most important great geological period in the his- tory of the earth. Dr. Emmons did not color any of the divisions made by him inthe Taconic, and he was satisfied to place the whole of it under a single color. The map of 1894 follows Emmons in using also a single color for the strata of the Taconic system, only it replaces the name Taconic by a name of a village of the state of Vermont, Georgia”; and almost two-thirds of the strata of the Taconic are cut off and placed farther -up in the scale of formations, as we have seen and explained in the first part of this memoir. The Georgia group of Mr. Hall oceu- pies, on his map, first, narrow lines in the southern part, east of the Hudson river, then going northward the lines be- Rules and Misrules in Classification.—Marcou. 129 come patches, and finally when the southern boundary of Rensselaer county is reached the Georgia formation takes the form of broad bands, extending through the state of Vermont. If we compare those Georgian outcrops with the Taconic of the map of Emmons of 1844, we see that the main part of the original Taconic between Williamstown (Massachusetts), and Albany and Troy (New York), is inclosed in the Georgian. The only difference consists in the broadness of the great band of Primordial, the map of 1894 reducing the dimension of the band on both sides (east and west) so as to frame and involve almost totally the Taconic within strata which are called Si- lurian. Here now comes the delicate and not satisfactory point, for whatever may be the opinions or personal inclinations, it is difficult to accept as identical, formations differing in every way, Stratigraphic, lithologie and paleontologic, and with thickness absolutely most disproportionate with the standard and typical formations close by—being separated by distances less than the range of a cannon-ball shot. In order to avoid this difficulty Mr. Hall has created two new divisions in the Lower Silurian or Champlain system under the names of “Metamorphic Trenton and Calciferous” and “Metamorphic Hudson River formation.” The state geologist, instead of preserving distinct the two divisions of the Hudson or Lor- raine and Utica, as they are on the maps of 1842 and 1844, has united them in a single division called “Hudson River and Utica,” with the omission of the word ‘“Lorraine.’’ In the legend the position occupied by the two new ‘‘meta- morphic” divisionsis misleading, for the metamorphic Trenton and Calciferous is placed between the normal Calciferous and the normal Trenton, and the metamorphic Hudson is placed . between the normal Trenton and the normal Hudson, which seems to imply that the metamorphic divisions preceded the normal divisions with which they are identified, being, accord- ing to the legend. older than their typical and normal forms; which would be just the contrary, for if they are truly the metamorphie of the divisions they are claimed for, they ought to be placed above those divisions and not below, for the metamorphism as the word implies came always after the deposition of the regular strata and consequently succeeded in the chronology of geologic history. 130 The American Geoiogist. February, 1897 On the map of Mr. Hall those two divisions cover vast sur- faces in the most eastern parts of New York, entering the state of Massachusetts and extending northward through the state of Vermont. In order not to embarrass the reader with too many techni- eal and geographical details, we can say, that in the main, the new geological map of New York concedes to the Taconie of Dr. Emmons about one-third of the surface occupied by that stratigraphic system. The two other thirds are regarded by Mr. Hall and his assistants as belonging to the Silurian, call- ing, when it suits them, the strata ‘““metamorphic” Calciferous, Trenton, Hudson, and even Oneida (the last under the name of Rensselaer grits). Why the name ‘‘Metamorphic” is used, there is no explanation, and if we consult the works published by members of the United States Geological Survey on the Rensselaer grits plateau, the Green mountains of Massachu- setts, ete., we do not see any trace of metamorphism among all the strata there; and, as farther north, in Vermont and in Canada, no metamorphism exists also, we have no explanation whatever of what is meant by “metamorphic Calciferous, Trenton, Utica, and Hudson.” But supposing that the strata under discussion are metamorphic, that does not imply the apparition of completely different faunas, of thickness ten and even twenty times greater, of slates instead of limestones. Metamorphism, no more than invisible faults or invisible bar- riers, can not be of any use to explain the existence of five thousand and more feet of strata at Quebec city, Pointe Lévis, Phillipsburgh, Highgate, Swanton, Shoreham, Troy, Stock- bridge, ete., ete., with their numerous fossils, almost totally different,—with only an exception of ten or a dozen forms— from those found in the typical and classic Caleiferous, Tren- ton, Utica and Lorraine (Hudson). A misuse of paleontology against the rules advocated by Alexandre Brongniart, Edward Forbes, Thomas Huxley, and others, cannot change the age of strata. The Upper, the Middle,and Lower Taconic, with a thick- ness of 25,000 or 30,060 feet of strata, not metamorphic, con- taining at different levels, several faunas most characteristic and quite rich in number and forms, exist in eastern North America; and the sooner the different organizations of official surveys accept the plain facts, as they are in the field, the bet- ter for the practical geology of the western hemisphere. \4 & : 5 f ye Pe items: cit eas 7 i ." op Nem sone LIBRARY OF THE __SINIVERSITY of ILLING:S. \\ aid in ins *sojilu 9844} JNOGe ‘UIsABUI-9d! yuesoid Woda sOURYSIG ‘e4ey4 PpuNOJ sa|qqed peyiodsueiy 300 OSG9ST EPNIIV "FINQHL S 42.68 44.77 47.50 38.45 DOs, eine canes ee aia Bai ota ng Ate eae eS Al,0, nos See atts aera 9.42 17.82 19.32 19.68 11a) Ne 71g eo se eee 1/55) 5.05 4.75 4.01 TXO) 55 EO Ee ee 023 6.95 5.20 iOS: Ja O) es Re Se eee oh traces ee trace CAOMCR Me ca. dees. 1B 10.36 8.37 9.37 ITSO): BR le ees 10.09 8.22 4.36 6.65 16S), USE EER OF ah See 1.16 .92 2.3) 17 Pitt ects oaks oy 2's Pali 2.13 7.63 ZTE Tl ee RBS ele 1.06 2.64 0.46 1.49 99.05 P,O; .72 OFZ 4.82 —Co, 12 0 Ae eee 1.29 ee PO arose) shah hcly st les LOOM OOM SOO: 15 In chemical composition the California rock lies between that of Todtenkoépfehen (No. 1) and of the Kula basin (No. The rock described by Sommerlad gelatinizes by hydrochlo- ric acid, and is reported to contain nephelite. Kulaite con- tains much more Na,O, but no reaction for nephelite was obtained. However, a trace of leucite was found. The Kosk creek rock does not gelatinize. The large amount of water it contains is due to the serpentine. J. Hazard has recently described* from the Lausitz, in eastern Germany, an interesting series of - hornblende-basalts occurring in voleanic necks (Ausfiillungsmasse der Eruptions- candle). The surface flows (Decken) and the dikes (Ginge) of the same region, are free from hornblende. Although many basalts occur in that region, all forms of them appear to con- tain nephelite. *Tschermak’s Min. und Petrog. Mitt., vol. x1v, 1894, p. 297. 256 The American Geologist. April, 1897 THE GEOLOGY OF A TYPICAL MINING CAMP IN NEW MEXICO. By C. L. HERRICK, Socorro,.N. Mex. Plates XIII and XIV. The Magdalena mountain range forms a comparatively iso- lated district and illustrates many of the conditions of min- eral accumulation, as well as a variety of geological problems exceptionally well. Situated about twenty miles west of the Rio Grande valley, it forms a secondary axis parallel to the major one which must at one time have occupied the site of the present valley. The Magdalenas are situated upon the margin of the belt of Carboniferous limestone and sandstone strata so well seen at various points in the valley. As in the ease of the other north and south ranges, the present moun- tain axis is near the base of the original anticline and exhib- its the uptilted strata, here dipping with an inclination of about 45° to the southwest. The principal intrusives are found near the synclinal axis and contribute to the ore con- centration. The range, so far as studied, is about thirty miles long and, like all other axes of uplift in this region, is interrupted at intervals by local craters. In the present case the northern portion is relatively less disturbed, while the southern three- fourths is chiefly voleanic. The mineral association in the two portions obeys different laws and affords instructive evi- dence of the constancy of these principles under similar con- ditions. It may be premised that in this portion of New Mexico the sequence of eruptives has been from basic to acid. The older flows being usually andesitic, the following trachy- tie, while the latest are rhyolites. True, there are basaltic flows of a still later age, producing mal pais and recent cra- ters, but this does not alter the general fact that the flows chiefly concerned in outlining the present geotechnic of the region obeyed this rule. Again, it is necessary to note that the stratified series is chiefly sandstone below and limestone above, so that in each ease of uplift the lime has suffered dis- placement, while the subjacent sandstone has frequently been greatly metamorphosed even to the extent of transformation into gneiss or granite. In a general way it may be said that the northern portion of the range, being less fundamentally “SNIVLNOOW VNAIVGDVIN-—'S ‘DIA DUNN Wig, WNaIWaoVIN, Win Ze % \\y F- LEZ Z ® SS al (Whe ZB — ROS wt, . Nan Woe QW ATA ae ae TM ayppsm tn aS MY, AWC 1 Mann saqyf ang Maya yy ln gM 7 S Wow Dy WS uh > Mm s pln Iii ein WHS w RS 2 = mi = yl Sy ys! mi eA /Lh) ey Il gst8 ZB = ~ mis® wy ‘i = ~ ipa = Wp Ze my SC bs z al i Mi 2 = a Bes t ginein — ay, (7 eS Uf ie — My nian = ge = AAS = a BY = r 4 , = 4, "”, Ait! ‘XTX ‘IOA ‘LSTDOTORH NVOIYANY FHL ‘TIIX FLV 1g UNIVERSITY of ILLINOIS. ce ot a . THe AMERICAN GEOLOGIST, Von. XIX. PLATE XIV. Fic. 1.—GENERALIZED SECTION SHOWING THE RELATION OF STRIKE FAULTS TO THE ORE HORIZONS. Fic. 2.—ILLUSTRATING THE EFFECT OF FAULTS IN APPARENTLY INCREASING THE NUMBER OF ORE HORIZONS. - 2 > Lad UNIVERSITY of ILLINOIS. Geology of Mining Camp in New Mexico.—Herrick. 257 altered, forms a lead mining region, including the famous Kelly camp with the Kelly and Graphic mines, which have produced a number of independent fortunes, as well as a large number of properties of less importance. The southern part of the range, on the other hand, is essentially a gold district, which, although still awaiting development, promises to be of substantial importance, as in Water Canon, Six Mile Cafion and others. The conditions at the north end of the range are apparent- ly simple (plate x11). An extensive uplift between the So- corro mountains and the present site of the Magdalenas has suffered erosion, leaving the western base as the present range. The three or four hundred feet of the upper series, consisting of limestone and sandstone in alternating layers has been tilted to an angle of 45°, exposing on the eastern slope several hundred feet of the altered acid series beneath. This series has here been transformed into a granite with only here and there a thin band of lime to indicate the origi- nal stratified condition. Dykes of quartz intersect this series at intervals and are occasionally mineralized, but, as in the case of acid intrusives in acid country rock elsewhere, the concentration is appa- rently never sufticient to warrant exploration. No very definite estimate can be made of the thickness of this lower series, for it has been too completely fused to re- tain any adequate data. It is frequently penetrated by bands of schist and dykes of diorite, but its upper layers retain a schistose or gneissvid character, and where they approach contact with the limestones become quartzites. The contact of the quartzite with the lime is everywhere in evidence along the eastern face of the axis of the range in its northern portions and lies all the way from a few feet to two or three hundred from the summit, and is capped by one or more of the lower lime belts. ‘The contact is apparently only irregularly conformable or the original conformity has been disturbed by more or less extensive interpenetration or solution along the lower contact. This contact is usually mineralized and forms the outcrop upon which many exploratory workings and a few producing mines have been placed. 258 The American Geologist. April. 1897 The mineral association is usually iron, lead, silver and zine with a predominance of sulphides. The quartzite is not rarely altered near the contact with the line to a chloritie si- licious schist with epidote and caleite. This phase is called ‘‘oreenstone” by miners. At various places dioritie intrusions penetrate the quartzites and cause local and perplexing dis- turbances in the rather uniform stratigraphy. We may pre- sume that the leadin this region has been derived from more or less generally disseminated deposits throughout the lime- stone, and the probability is that it was originally in the form of galena. The present situation and composition of the lead is, however, to be ascribed chiefly to the influence of per- colating waters with the codperation of metamorphism. At this lowest lime contact both factors assisted. The limestone is between seventy-five and one hundred feet thick, and has been greatly altered in so far that it forms a coarse white marble in several localities. The effect of metamorphism is” seen not onlyinthe crystallization and decolorization of the lime, but also in the segregation of the silicious matters as bands of chert or flint. The lower portions especially are si- licious and metamorphic. The fossils have usually suffered from metamorphism, though occasional crinoid stems occur. The location and association point to a middle Carboniferous age. The ore is usually near the contact, though it may be several feet distant. In at least two horizons within this limestone other ore concentration has occurred, but only in certain localities do they become important; yet where this is the case they are often very valuable, since the ore is collected in old water courses lying in plains of seepage, under condi- tions for solution of lime and redeposition of ore. The lower contact, as stated, contains chiefly sulphides, yet the jead is frequently reduced to sulphate or altered to a carbonate in such situations as have permitted a free percolation of waters from higher deposits. It is interesting to note that the mines opened along the summit of the range where cut off from such supplies are usually of small value, being poor in ore, which is here chiefly a sulphide. The silver value is, it is true, higher than farther down, but as this is subordinate practically to the lead, it does not repay for a lower lead contact and the ab- sence of large cavities with carbonate of lead. This difference Geology of Mining. Camp in New Mexico.— Herrick. 259 between the higher and lower portions of the same series is in conformity with what has already been said as to the proba- ble method of concentration. Here at the summit there is less opportunity for percolation and none for deposition of solutions from other regions. The leaching, if it has occurred, has only impoverished the strata. In general, it may be said that any one of a number of im- pervious strata (quartzite or silicious shale) associated with the several limestone belts may become barriers to the trans- verse motion of the mineral-bearing waters and, by conse- quence, give rise to a metalliferous horizon. The ore in such cases is usually concentrated along lines of least resistance, inclining at various angles within such horizons. These water courses produced “pipes” or “shoots” in the ore zone where great masses of lead carbonate, smithsonite and other miner- als were deposited obviously from aqueous solution. The lead, however, must have originally been galena, as cores of that mineral are very generally found within masses of lead carbonate. The larger cavities or chambers are fre- quently exceedingly beautiful, and a single such chamber has frequently yielded a good fortune. The walls are water-worn, encrusted or stalactitic. Oracalcite, smithsonite and blende oceur with the prevailing cerussite. Were the conditions as simple as hitherto implied the work of prospecting would be of the easiest, but, on the contrary, the whole area is intersected by faults in two or more parallel series. One series of strike faults give rise to minor ridges parallel to the main axis on its western slope, repeating the sequence to a greater or less extent in each case till the level of the valley at the foot of the isolated Mt. Magdalena about three miles west of the main range is reached. The western margin of this faulted area is formed by an independent basic uplift, which may be said to have prevented the sheet from reaching the degree of depression to be expected theoretically. This intrusive may be traced to the most northern crater of the series and is approximately parallel to the main axis. The strike faults above mentioned are quite numerous—from six to twelve major ones and many minor ones can be recognized. They are not strictly parallel to the range, but extend south 30° east at right angles to the dip. The dip of the western 260 The American Geologist. April, 1897 blocks is less, a fact accounted for, as above seen, by the up- lift of the secondary intrusive. The fault planes have an important bearing on the ore con- centration in two distinct ways. The larger faults toward the west. i. e. nearer the theatre of true volcanic activity, have afforded means for introduction (by sublimation) of other minerals than those indigenous to the limestone strata. These breaks intersect the several ore horizons and may afford op- portunity for concentration, and they also afford outcrops or surface indications which, in several cases have led to the discovery of the real “blankets” of ore below. The second way in which the faults contribute to ore accumulation is by interrupting the downward movement cf waters carrying mineral in solution. Where the throw has been slight this has produced an accumulation in the space between the lower and upper intersections of the faulted ore zone with the fault plane, thus, fig. 1. These accumulations had been recognized by the more intelligent miners, though not explained by them. The fault plane, though mineralized, contains less lead and more iron (sulphides), and frequently more silver (a fact sug- gesting that the silver has had a different origin from the lead—perhaps sublimation). The fault planes of this order have also greatly interfered with the working of many mines by causing obscurity as to the actual number of ore horizons. The apparent number is often the result of reduplication, as indicated in fig. 2. Still more annoying, and without any compensating advantages, are the dip faults, which are even more numerous and far less regular than the previously mentioned. SS VV V Vv Vv VA Y Vv WA \ V 8 ef 2 J ust} cy SS oS aS = ‘5 SS ead s Sule & Sess Rags Ss . 2S SSS ~s 8 Sa ; 1 ® e S'S. & Se e Ss &es:s 3 Ss 5.8 oS of 8 6 5 oe “3235 [ sf2a5 BIOL | = LIBRARY OF THE UNIVERSITY of ILLINOIS. AMERICAN GEOLOGIST. Vor. XIX. JUNE, 1897. No. 6 EVIDENCE OF CURRENT ACTION IN THE ORDOVICIAN OF NEW YORK. By R. RuEDEMANN Pu. D., Dolgeville, N. Y. Plate XXII. The remarkable parallel arrangement of the rhabdosomes of graptolites. spicules of sponges, fragments of bryozoans and shells of Endoceras protejforme in the Utica shale near Dolgeville, N. Y., has been noticed by the writer ever since he has studied this terrane, but it was not given any special at- tention, as it was supposed to be due only to local and chang- ing movements of the water. The observation, however, that these fossils, through a whole series of beds of shale and in- tercalated limestone, pointed apparently in the same direction suggested the tentative measuring of the directions of the fossils in this series, which examination gave the result that all pointed nearly in the same direction, viz. Z. N. E. It was soon found that this direction is kept in all shales exposed in the neighborhood of Dolgeville. This again suggested that the phenomenon might be of more than local importance. The writer, therefore, made excursions to the exposures of the Utica shale in the Mohawk and Black River valleys. The re- sults of these excursions are seen in the submitted tables. which show that those shells which can be easily displaced by 368 The American Geoiogist. June, 1897 = moving water, show a general E. N. E.-W.S. W. bearing in the Utica shale of the Mohawk valley.* Section on first curve of East Canada Creek, below Dolgeville. The rock is thin-bedded shale and slate with occasional in- terealations of thin calcareous bands. 1. Four layers of shale, with crinoid joints, sponge spicules, speci- mens of Climacograptus bicornis and a few Endoceras shells. Bearing of all, N. 70 degrees E. The apices of the Endoceras shells point E. 2. Above a layer covered with fragments of Triarthrus, all directed N. 60 degrees E. Fourteen surfaces of shale exposed, with sponge spicules, Diplograp- tus pristis and Endoceras. Bearing, N. 60-70 degrees E. Graptolites point E. with the sicular ends and Endoceras shells with the apices. Bank of limestone (without fossils). 3. Shale with fragments of Triarthrus, all directed N. 50-70 degrees E., giving the slabs a furrowed appearance. Eight surfaces with prevailing sponge spicules, a few Diplograptus pristis and Endoceras, all pointing N. 50-70 degrees E. Apices of Hn- doceras shells E. Layer with sponge spicules and numerous rhabdosomes of Climaco- graptus bicornis. Bearing, N. 65 degrees E. Sicular ends of most stipes west. Calcareous bank, without fossils. 4. Hight layers with numerous specimens of Endoceras. Bearing, N. 70 degrees E. Apices E. Layer with trilobite fragments, numerous specimens of Climacograp- tus and some Hndoceras shells. Bearing, N. 50-60 degrees E. Layer with Climacograptus bicornis. No direction. Layer with Climacograptus and Endoceras. Bearing, N. 70 degrees E.. Fourteen shells of Endoceras were counted pointing east, two west. Apices of Climacograptus in both directions. Numerous layers with Diplograptus pristis and Cliomacograptus. Bearing, N. 60-70 E. Sicular ends mostly west. Caleareous bed, without fossils. 5. Four layers full of sponge spicules. Bearing, N. 80 degrees E. *It is to be remarked that layers which yielded no fossils at all or on- ly single specimens of the displaceable fossils have not been mentioned; further that among the given bearings are certain ones to which the fossils are almost mathematically parallel (especially in certain layers near Dolgeville and on Otsquago creek), while in other layers there is only a general, though distinct tendency to arrangement in a certain direction. In the latter case the limits of the directions haye been given. It is evident that the differences in the regularity of the ar- rangement are due to differences in the velocity of the moving water. The approximate value of 10 degrees for the present western mag- netic declination of the needle in the middle Mohawk valley has been used for the correction of the readings. Current Action in the Ordovician.—Ruedemann. 369 Bed with prevailing spicules, some shells of Endoceras and Clima- cograptus, gathered in patches. Bearing, N. 50 degrees E. Calcareous bed. 6. Many layers densely covered with fragments of Triarthrus. Bear- ing, due east. : : Two beds with Climacograptus. Bearing, due east. Sicular ends, W. Layer with Vriarthrus fragments, Climacograptus and Endoceras. Bearing, N.. 70 degrees east. Apices of Endoceras and sicular ends of Climacograptus E. (14 &ndoceras shells E., none W.) Layer with the same fossils, but 8 Endoceras W.,3E. The numer- ous sponge spicules and Hndoceras shelis in this layer are directed N. 70 degrees E., while the rhabdosomes of the graptolites are parallel to N. 15 degrees E. The appearance of this layer, which is exposed over a large surface, suggests the directing action of two successive motions of water of different strength. Layer with Endoceras and Climacograptus. Bearing, N. 70 degrees E. The apices of the Hndoceras shells point east (41 E., 3 W.); those of Climacograptus in both directions. Numerous layers with trilobite fragments and rhabdosomes of Cii- macograptus. Bearing, N. 85 degrees E. Sicular ends in both direc- tions. Layer with spicules, N. 85 degrees E. Numerous layers with trilobite fragments. Bearing, N.85 degrees E. Layers with Triarthrus fragments, spicules and long drift-ridges of fragments of Diplograptus pristis and Lingula. Bearing, N. 80 degrees E. Layer with spicules and shells of Hndoceras. No distinet direction. Bed of calcareous shale. This bed is covered with projections, each consisting of around nucleus from which proceeds a gradually broad- ening and flattening ridge. The bearing of these ridges is N. 80-90 de- grees E., the nuclei being towards the east. The latter generally contain some small fossil, usually a gasteropod. It is evident that the ridges result from the deposition of fine calcareous mud behind the shells, and, therefore, allow the inference that the water came from N. 80-90 degrees E. 7. Numerous layers with sponge spicules. Bearing, N. 60 degrees E. Layer with furrows, as from flowing mud, running N. 60 degrees E.- S. 60 degrees W. Layer with Triarthrus fragments, crinoid joints, and sponge spicules. Bearing N. 60 degrees E. Eight layers with sponge spicules and rhabdosomes of Climacograp- tus. Bearing, N. 70 degrees E. Layer with Climacograptus bicornis and Endoceras. Bearing, N. 65 degrees E. Apices of Endoceras shells E. Five sponge beds. Bearing, N. 75 degrees E. Two layers with Triarthrus fragments and Endoceras shells. Bear- ing, N. 80 degrees E. All Endoceras shells point E. Six sponge beds. Bearing, N. 55-70 degrees E. 370 The American Geologist. June, 1897 Layer with Triarthrus fragments and spicules. Bearing, N. 60 de- grees E. Calcareous bed. 8. Layer with trilobite fragments. No direction. s Layer with Diplograptus pristis. Bearing, N. 60-70 degrees E. Numerous layers with Endoceras shells. Bearing, N. 55-65 degrees EK. All point east except in one layer where 5 point west and 2 east. 9. Layer with trilobite fragments, rhabdosomes of eraptolites and casts of Trochonema. Behind the latter there are drift lines of frag- ments and before them lie fossils in a transverse position, as if arrested while drifting. The motion of the water must here have been quite strong, as the slabs appear furrowed in a parallel manner by the fossils. Bearing, N. 62 degrees E. Drift-lines extend towards S. 62 degrees W. Layer with Endoceras. Bearing, N. 65-70 degrees E. Two were seen to point east, none west. Behind the Hndocoras shells, towards the west, drift-lines of trilobite fragments, ete., are found. Layer with Endoceras. Bearing, N. 70 degrees E. Caleareous bed, contains some complete specimens of Triarthrus becki, while in the shale only dislocated fragments are met with. This difference in the preservation is probably due to the different velocity of the depositing water, the calcareous mud being a still-water deposit. 10. Three layers with Diplograptus pristis. Bearing, N. 60 degrees E. Sicular ends point both ways. Layer with Hndoceras.- Bearing N. 75 degrees E. 6 point east. 2 west. Layer with Diplograptus pristis. Bearing, N. 70-80 degrees E. Layer with fragments of Triarthrus and scattered rhabdosomes, ar- ranged in a general easterly direction, but not so strictly as to approach parallelism of the fossils. Layer with numerous large Hndoceras shells. Bearing, N. 35 degrees E. 36 pointing east, 2 west. Layer with many rhabdosomas of Diplograptus pristis arranged in long drift-lines running N. 80 degrees E., while many stipes outside of the drift-lines point in various directions. Below a great many layers with outcrops too narrow to give sufficient evidence. The rhabdosomes observed show an easterly direction. Calcareous bed. 11. Three layers densely covered and paralle! striated by specimens of Diplograptus pristis and Endoceras. Bearing, N. 70-75 degrees E. Apices of the fossils eastward. Layer with Diplograptus pristis. Bearing, N. 80 degrees E. Apices east. Layer completely furrowed by rhabdosomes of Diplograptus pristis. Bearing. N. 80-90 degrees E. Layer exposed with large surface, on the whole of which the direction of the rhabdosomes shows no change. Bearing, N. 70 degrees E. Layer with shells of Endoceras. Bearing, N. 65 degrees E. Four point east, none west. Current Action in the Ordovician.—Ruedemann. 371 Three layers with mud-flow structure and rhabdosomes of Diplo- graptus. Bearing, N. 75 degrees E. Apices or sicular ends point east. Two layers with Diplograptus pristis. Bearing, N. 70 degrees E. Layer with mud flow and Endoceras. Bearing, N. 77 E. Nine Ln- doceras shells point east, none west. Two layers with Endoceras, all point N. 60 E. Behind the apertures of the shells are piled up smaller shells of Hndoceras, gasteropods and brachiopods. Layer full of shells of Endoceras, all exactly parallel in N. 63 degrees E. direction, the apices being east. The shells are arranged in rows and connected with long mud eee extending from the shells towards the southwest. Layer with Endoceras shells, 2S. W., 4 in differing directions. Layer with rhabdosomes of Diplogruptus; no direction. Layer with spicules of sponges, Hndoceras and small brachiopod shells, (the latter with their beaks toward east). Bearing, N. 65-70 de- grees E. 6 Hndovcras shells pointing east, none west. Caleareous bank. 12. Seven feet of shale, containing: Layer with Diplograptus, Endo- ceras and spicules. Bearing, N. 76 degrees EK. Ten shells of Hndoceras point east, one west. Apices of graptolites point east. Seven layers striated by parallel spicules: besides numerous grapto- lites and some shells of Hndoceras. Bearing, N. 65-70 degrees E. Shells of Endoceras point east. Layer with spicules and Hndoceras, the latter lying N. 30 degrees E, and 6 pointing west, 1 east. The sponge spicules, however. show in some places the same direction, in another place their bearing is N. 60 to 70 E., and in other places they lie in all directions. There was, there- fore, apparently no general equal motion of the water or the flow was so slow that it had no constant directing influence. Two layers with Endoceras(a small surface only exposed). Bearing, N. 70-80 degrees E. 8 point east, 2 west. Layer with Hndoceras. ‘Thirteen specimens arranged in N. 50-80 de- grees E. direction, 4 others under right angles to these directions. The apices of 12 of the former specimens are directed toward west. As the 4 specimens with varying directions show, there was no constant direct- ing, or a very weak directing force. Layer with Hndoceras. Bearing, N. 80 degrees E. Seven directed eastward, none westward. Three layers of Endoceras. Bearing N. 80 degrees E. Two point west, six east. The average of the bearings observed in this whole section which comprises some twenty-four feet of shale, is N. 68 de- grees E.. or a direction falling near E. N. E. Continuous with this exposure is another one in the over- lying rock. A few layers of the latter are exposed over a large surface and show distinctly the parallel direction of the 372 The American Geologist. June, 1897 numerous shells of Hndoceras which they contain. The bear- ing is N. 60-80 degrees E. and the apices lie towards the east. On the tumulus, slabs with well-preserved rhabdosomes and whole colonies of Diplograptus pristis are found. The rhab- dosomes point in all directions, in accordance with the obser- vation made in other localities, that, wherever colonial stocks are preserved, the water was not in fast motion during the de- position of the sediment. Following the creek along the left bank over the “ High falls” we meet with the exposure which furnished the rhab- dosomes and colonies of Diplograptus ruedemanni* and the sessile specimens of Conularia gracilis.4 The shales are here, on account of a dyke which approaches the creek from east, in too steep a position to furnish conclusive readings of the directions of the numerous graptolites. Yet the locality is of great importance because it exhibits large surfaces complete- ly covered with the parallel arranged small rhabdosomes of the above mentioned graptolite. The continued action of the directing force during the deposition of many layers is, there- fore, here more strikingly exhibited than anywhere else. The most important layers are the following: Layer of shale with numerous brokeh fragments of a bryozoan (Stic- toporella}, all parallel. Layer with colonies of D. ruedemanni, no direction. Two layers, densely covered with rhabdosomes of D. ruwedemanni, all parallel and pointing east with the sicular ends. Layer with fragments of trilobites and bryozoans and shells of Endo- ceras. Parallel arrangement, the apices of the Hndoceras shells point- ing east. Layer with rhabdosomes of D. ruedemanni wm great multitudes; all sicular ends point east. The fossils in«these layers all show the same direction, which, under the supposition that the strata have only been tilted and not twisted, is in the neighborhood of E. N. E. It is worth mentioning that in the same locality, a little higher in the series of interstratified shales and limestone banks, a layer is exposed which shows the rhabdosomes of D. ruedemanni pointing west, instead of east, as in the other layers. The direction is N. 40-50 degrees W. As the ex- *Cf. Amer. Jour. Sci., 1895, p. 453; Jour. of Geology, 1896, p. 307- +Am. Grot., 1896, vol. xvii, p. 159, and vol. xviri, p. 65. Current Action in the Ordovician.—Ruedemann. 373 posed surface is only small (53 graptolites have been counted ) it could not be ascertained whether this opposite flow of the water was of wide extent or only the result of a small local eddy. Farther down the ereek, in the gorge below the High falls, some 80 feet of shale are exposed, only the lower part of which is accessible. This as well as the numerous other expos- ures of Utica shale along the creck, is instructive on ac- count of the regular alternation of shales and banks of limestone which it exhibits. The readings which could be obtained in these exposures from the graptolites, bryozoans and the mud flow structure, ranged between N. 60 degrees E. and N. 80 degrees E. and gave as an average the E. N. E. direction, the bearings towards N. 60 degrees E. being the more common. “Mat Halls” of Fast Canada creek. Here the change of the Trenton limestone into the Utica shale is well exposed. The regular succession of limestone bands and shales becomes here still more apparent than above. The writer sees from his notes that he counted and measured, beginning from the typical Tren- ton limestone, 95 regular alternations. While, at the base of this series the intercalations of shale are still very thin (a few inches), they increase in thickness towards the top, while the bands of limestone decrease at the same time. Together with the gradual change of the rock, a change in the fossils takes place. The Trenton limestone here is rich in very large, conical and branched specimens of Monticeulipora lycoperdon, fragments of Isotelus gigas and Calymene senaria as well as in the Trenton brachiopods, while some bands consist entirely of crinoid joints. Monticulipora shows the first and most marked change, in be coming smaller before disappearing, while the trilobites and brachio- pods disappear without apparent change. Inthe ninth intercalation of shale two specimens of Diplograptus pristis were found, while Caly- mene, Orthis testudinaria and Monticulipora still continue in the su- perjacent limestone. At the 17th intercalation, the last specimens of Monticulipora were noticed, and Calymene alone continued further. The 5lst intercalation of limestone consisted entirely of crinoid joints. The shales in all these alternations up to the 50th, are almost barren, only an occasional Diplograptus pristis being met with. Then, heads of Triarthrus becki appear and soon become common in the shale. while the limestone begins to contain the whole carapax of the same animal. The rhabdosomes of Diplograptus pristis, though met with in the 58th and 64th stratum of shale (in the latter also some specimens of Hndoce- ras proteiforme and Trochonema were observed) do not become common until the 69th stratum of shales, where they, however, show no di- rection. 374 The American Geologist. June, 1897 In the 75th intercalation of shales Diplograptus rwedemanni appears in great abundance, together with a few specimens of Hndoceras pro- teiforme. The bearing is N. 82 degrees E., and the apices of the fossils point eastward. Above this shale, however, a layer of shaly limestone appears unex- pectedly, which consists largely of crinoid joints, fragments of Jsotelus gigas and the brachiopods which apparently had disappeared far below. The rock has the appearance of -typical Trenton. The next shale above abounds again in heads of Triarthrus. The 81st bed of shale proved to be rich in Triarthrus, Lingula, Schiz- ocrania, and Leperditia. The 87th bed abounds in heads of Triarthrus and rhabdosomes of Diplograptus pristis. A few entire colonies of the same graptolite and young and old specimens of Conularia gracilis occur. Bearing, due east. The 90th bed is full of shells of Lingula and Leperditia arranged in long drift-lines, the latter running due east. The 92d bed of shales exhibits 19 surfaces, all covered with Diplo- graptus pristis. These fossils are arranged in a due east direction on all surfaces, except three. which gave the readings N. 70 degrees E., N. 70 degrees E., N. 65 degrees E. The alternation of shales with Utica slate fossils and more or less caleareous barren banks continues upward. That the shaly interealations also reach farther down into the Trenton than it might appear from the exposure at the ‘Flat falls” be- comes obvious in the quarry at Ingram’s mill, from which N. H. Darton* reports eight feet of limestone with shaly intercala- tions, on top of the exposed series of rocks. The conclusions which can be drawn from the observation of this alternation of shales and calcareous layers in the lowest Utiea shale is that there were, for a long time, changing con- ditions which caused the water in this region to be alternat- ingly clear and then again turbid and moving. It seems also that the appearance of the turbid, moving water exterminat- ed gradually the clear water fauna of the Trenton and intro- duced new forms, more adapted to the muddy flow. A similar series of successive shaly and calcareous beds was observed by the writer above Harris’ quarry which is near Middleville on the West Canada creek. 'The series, though not so well exposed as the above described one shows at least the occurrence of Diplograptus pristis in the shaly intereala- tions of the upper Trenton. *Rep. of the State Geol., 1893, p. 422. Current Action in the Ordovician.—Ruedemann. 375 The rhabdosomes pointed in one layer N. 55.65 degrees E.; in another in directions in the neighborhood of N. 65 degrees E. A small outcrop about a mile north of Dolgeville deserves to be men- tioned because the outcropping shale belongs to a higher horizon, in which the limestone intercalations of the lower Utica shale are ab- sent. On top there are found numerous layers with Diplograptus pristis. The fossils are excellently parallel and lie in N. 65 degrees E. direction. Several layers with mud-flow structure occur below. The latter con- sists here in the presence of elliptical projections with a system of cres- ent-shaped, transverse wrinkles on the eastern end. The whole indi- cates a flow of water from N. 85 degrees E. A layer with trilobite fragments. Bearing, N. 60-70 degrees E. A layer with Diplograptus pristis. Beéaring, N. 60-70 degrees E. Eight layers densely covered with parallel fragments, especially pleura of Triarthrus. Bearing N.60 degrees E. Layer with Diplograptus pristis. Bearing, due east. Layer with trilobite fragments. Bearing, N. 48 degrees E. Layer with Diplograptus pristis. Bearing, N. 50 degrees E. The average of the readings taken in this exposure is N. 63 degrees E. J After the above described observations and others had shown that throughout the series of shales observable in the neighborhood of Dolgeville, there are indications of a constant E. N. E.-W. S8.W. flow of the water which deposited the shale, the writer extended his observations to other localities of Utica shale in this part of the state, occasionally also visiting the well known strata outcrops of Hudson River shale at Schodack Janding, Norman’s kill. Cohoes and Waterford. None of the latter, however, were able to furnish any indica- tions of a motion of the depositing water, on account of the highly folded condition of the rocks, One exposure of Hudson River rocks deserves mention, that is at Shear’s Blue-stone Quarry near Schenectady, where some interesting indications as to the water-flow in the Hudson River epoch could be obtained. Between the heavy banks of blue stone, intérealations of a black shining shale oeceur, which are characterised by a very distinct mud-flow strue- ture. Whitfield* described the same as follows: “One pe- culiar feature * * * is the appearance as of flowing mud suddenly fixed and hardened on the harder layers, the old de- pression between the folds being filled with fine mud shale *Wheeler Exp. West of the 100th Mer., 1v« Pt. 1, Pals p. 19: SFO The American Geologist. June , 1897 partings. upon which the layers separate with clean sur- faces.” In one part of the quarry the flow structure indicated a flow from due north on top, and one from N. 15 degrees in the next deeper interca- lation. Huge ripple marks, running N. 28 degrees W. and in the next underlying bank N. 25 degrees W., appear there. A deeper shale ex- hibited again a distinct flow structure with the flow coming from N. 25 degrees E. Another intercalation contained a small form of Diplograptus (cf. marcidus Hall). the rhabdosomes of which were generally arranged in N. 10 degrees E., and in another intercalation in N. 16 degrees E., while the underlying bank was marked by wide parallel rills, probably ripple marks, running N. 10 degrees W. At the bottom of that part of the quarry, ripple marks running N. 45 degrees E., appear again. In another part of the quarry, flow structure could be observed in two succeeding intercalations, running due north and N. 28 degrees E. Though the composition of the rocks and the ripple marks indicate that these strata were deposited in shallow water and that therefore the conditions since the deposition of the Utica shale had changed, it seems as if there was still a pre- vailing motion of water coming from a little east of north (average N. 13 degrees E.) or from the site of the Lake Champlain valley. The next locality visited by the writer was the Schoharie Kill near Fort Hunter. A large boulder of black shale, full of siculae and other stages of growth of Diplograptus pristis was found in the river bed. The fossils pointed in all directions, as they mostly do, where the young are found. At the base of the outcrop of Utica shale on the right bank near Diemendorf’s farm, a layer is exposed which contains Climacograptus typicalis and fragments of a bryozoan. Both kinds of fossils are arranged in N. 55 de- grees E. direction. The superjacent layer showed the same fossils ar- ranged between N.30 degrees E. and N. 60 degrees E., while the grap- tolites in the following layers, some of which were rich in specimens of Climacograptus typicalis, showed no arrangement. The average of the few indications of a directing force is N. 50 degrees E. The next large outcrop of Utica shale in the Mohawk val- ley was found in the Flat creek, near Sprakers. In following the gulf one passes at first over Trenton limestone. The boundary between the Trenton and Utica terranes is not well exposed. The first layer with Diplograptus pristis shows a distinct N. 70 degrees E. direction in the fossils, the next a N. 60 degrees E. direction. Current Action in the Ordovician.—Ruedemann. 377 Farther up appear shales with Diplograptus pristis, arranged in a N. 80 degrees E. direction. Another exposed layer showed the same fossils arranged in two direc- tions, viz: N. 80 degrees E., and 8. 80 degrees east, indicating a change of 20 degrees in the direction of the flow. Then a series of 19 layers was observed, which were densely covered with graptolites. The general bearing was N. 80 degrees E. Near the falls two layers were found to be striated with specimens of Diplograptus pristis ina due west direction, and above the falls two layers with the same fossils, pointing S. 80 degrees E. Farther up the writer met with layers containing rhabdosomes of Climacograptus typicalis arranged in a N. 50 degrees E. direction, and a flow structure, indicating a flow from N. 80 degrees E. The average bearing of the graptolites along the Flat creek is N. 80 degrees E. re In the beautiful gulf of the Canajoharie creek one passes at first over Trenton limestone with wide and huge ripple- marks. In the shale, many long parallel drift-lines of fossils, one of which measured over seven feet, were first noticed. The direction of the drift-lines indicates a flow from due east. Farther upa layer with numerous specimens of Climacograptus typi- calis in a N. 80 degrees E. direction appeared, then drift-lines of trilo- bite fragments, brachiopod shells, etc., indicating a flow from N. 50 de- grees K., overlaid by layers with flow structure towards due west. Then two layers striated with Climacograptus, bearing N. 80 degrees E., and two layers with the same fossils in N. 76 degrees E. direction. Farther up only one more layer with graptolites came to notice and the fossils in it showed no arrangement at all. ° The average direction of the fossils is also here, as at Spra- ker’s, N. 80 degrees east. In the bed of the Ofsqguago creck,near Fort Plain, below the old cheese factory, layers of Utica shale were found, with specimens of Climacograptus and Eudoceras, the bearing be- ing N. 50-80 degrees E. In a small exposure, on the right bank, above the factory, layers full of Diplograptus pristis were found. The graptolites were mostly de- posited in drift lines about one foot long and indicate a flow from N. 70 degrees E. Farther up, in the bed of the creek, widely exposed, layers were ob- served which are densely covered with rhabdosomes of Diplograptus pristis hardly varying from N. 60 degrees E., while another layer above showed no general direction, but had quite a number of rhabdosomes directed toward the southeast. 378 The American Geologist. June, 1897 A remarkable series of layers was found below the mouth of the Ox- tungo creek. The layers are completely covered and striated by paral- lel rhabdosomes of Diplograptus pristis, which point in the successive layers: N. 60 degrees E., due N.. due E., N.40 degrees E., N. 60 degrees K.,then a layer with Climacograptus bicornis in different growth stages and no direction followed. ‘The surprising angle of 90 degrees between two layers, only a few inches apart and the change in the fossils indi- cate the very slow manner of deposition of this material. It seems also that the changes in the direction of the flowing water caused the sepa- ration into the thin layers. The average of the directions, on account of the abnormal northern direction, on one layer. is only N. 63 degrees K. On Oxtungo creek, a layer with Endoceras shells, which pointed with the apices to N. 70-80 degrees E., was found... It was covered by a layer with excellently preserved specimens of Climacograptus bicornis ina N. 70 degrees EK. direction, while a few superjacent layers, which were sufficiently exposed, and contained specimens of Climacograptus bicor- nis and a few young of Conularia gracilis, showed no arrangement. On Fulmer creek, near Mohawk shales were found containing Clina- cograptus typicalis, which pointed to N. 50-60 degrees E., then due north, then N. 80 degrees E. (only the majority of the rhabdosomes, and many exceptions), then N. 85 degrees E., then a layer with rhabdo- somes of Diplograptus pristis in a general N. 80 degrees E. direction was found; then again a layer with Climacograptus typicalis; the fos- sils were arranged in a N. 40-80 degrees E. direction. Farther up, several other small exposures with Climacograptus typi- calis were observed which did not show any arrangement. The average of the readings is in the neighborhood of N. 70 de- grees EK. In the Deerfield ravine (Real’s creek) north of Utica, the writer found Utica shale rich in spechnens of Climacograptus typicalis which gave the following readings in the layers met in following up the creek: S. 80 degrees E. (many exceptions), N. 80 degrees E., S. 65 degrees H., S. 70 degrees E., S. 65 degrees H., N. 40 degrees E., S. 85 degrees E., then a layer with colonies of Climacograptus typicalis and no direction, then a general arrangement to 8S. 65 degrees EK. and to N. 60-80 degrees E. At another exposure farther up the creek, the basal layers showed no direction, after which followed a layer with S. 60 degrees E., then two layers with a few colonies and detached rhabdosomes, the latter pointing to 8. 65 degrees E,, then a layer with graptolites distinctly ar- ranged in §. 60 degrees E. and finally one exhibiting a N. 80 degrees E. direction. In a third exposure many layers were measured which exhibited the numerous specimens of Climacograptus typicalis in directions ranging from N. 80 degrees E. to S. 50 degrees E. The characteristic features of the exposures near Deerfield are that, lst—the fossils are not so strictly parallel as in the middle part of the Mohawk valley, that the directing force, therefore, apparently was ee Current Action in the Ordovician.—Ruedemann. 379 weaker, 2d—that the general direction is not, as in the other ex- posures, somewhat north of east, but a little (about 10 degrees) south of east. Other exposures of lower Utica shale were found along ‘‘Nine Mile creek”’ from South Trenton to Holland Patent. In a small exposure in the village of South Trenton, some layers covered with parallel rhab- dosomes of Climacograptus typicalis were observed, which gave the following readings: N. 80 degrees KE... N. 60 degrees E., S. 79 degrees K. Below the village. the directions in successive layers were: N. 60 de- grees E., N. 70 degrees E., N. 40 degrees E., and a little farther down a layer with N. 75 degrees E. was observed. In an exposure near Holland Patent, extending down to the Trenton limestone, shale with distinct drift lines of fragments of fossils in N. 76 degrees E. direction, was observed, underlying a layer with graptolites in a N. 70 degrees E. direction; the latter again being overlain by layers with graptolites pointing to directions between N. 60 degrees E. and N. 70 degrees E. The interesting fact which appears in the readings from Nine Mile creek is that, though the exposures are farther north than all the other localities visited and even north of the southern border of the Archzean region of the Adirondacks, yet the flow that arranged the fossils must have come from about N. 70 degrees E. which is the average of the readings. In Lee’s Gulf near Turin (Black River region west of the Adiron- dacks) lower Utica shale appears not far above the Trenton. Only specimens of Hndoceras were found besides the heads of Triarthrus, the former showing no direction. Bouldersin the gulf were found to be rich in specimens of Climacograptus typicalis, which also failed to show any arrangement at all. In the Turin Gulf (along the road to Welsh hill) in the first exposure a layer with Climacograptus typicalis and Thamnograptus, and sever- al layers with specimens of Hndoceras were found, none of the fossils of which showed indications of arrangement. In a small quarry farther up the gulf, numerous layers containing Climacograptus typicalis were found. None, except one in which the majority of the fossils were arranged in a N. 10-20 degrees E. direction, showed any arrangement. Ina third exposure the graptolites were irregularly distributed in all layers. In a fourth quarry no fossils, but a layer with a mud-flow structure was found, indicating a motion of the water from N. 12 degrees E. in the Black River region. 7 The two localities which the writer had an opportunity to see, gave no indications of the presence of a constant flow of water in the lower Utica shale epoch. The two layers with indications of arrangement are opposed by too many layers without any arrangement of the fossil to in dicate more than an occasional southerly flow of the water. 380 The American Geologist. June, 1397 GENERAL CONCLUSIONS. The following conclusions can be drawn from the preceding observations: 1. here existed, at the time of the deposition of the lower Utiea shale, a general and constant flow of water from the ay- erage direction N. 78° E., in the region south of the Adiron- dacks, while this flow does notseem to have been present west of this ancient land area. The averages of the readings in the visited localities are: (Schenectady) concent oe (N. 13 degrees E.) (Hudson R.) Sprakersu Ge eet eniee ae N. 80 degrees E. JANA] OWMATIC tae paneer N. 80 degrees E. Osquago-Oxtungo creek...... N. 65 degrees E. Dolgeville: pee a Me N. 70 degrees E. Mio hia wikkat sy. -2 Seetetemtanieen s ohaksn ne N. 72 degrees E. DP) Gertiel diss i eee eo hay crete S. 80 degrees E. Nine Mile ereek............. N. 70 degrees E. TIN eg nb. oo oe 0 degrees. The total average of the readings (excepting those of Sche- nectady and Turin) is N. 78° E.* That the flow came from N. 78° E, and ran toward §. 78° W., can be inferred from the appearance of the mud-flow structure, the drift-ridges behind the fossils (Zndoceras), the eastward pointing of the apices of the Hndoceras shells, and often also of the sicular ends of the graptolites. . From the common occurrence of drift lines of longitudinally arranged fossil fragments and of smaller shells of Hndoceras, behind the apertures of larger shells of Mndoceras, it becomes appar- ent that the apices of these shells would generally point towards the slowly flowing water. As now the apices of the shells of Endoceras mostly point eastward, the water must be supposed to have come from the east. In layers containing specimens of Endoceras and graptolites together, the sicular ends of the latter have been observed to point in the same di- rection as the apices of the Hndoceras, hence the general east- ward pointing of these sicular ends in the layers without any shells of Hndoceras, or mud-flow and drift-lines may also be regarded as indicating a flow from the east (or more exactly north of east). Gasteropods have been noticed with trans- *Compare the accompanying chart (plate xx1) which shows the avy- erage directions of the flow at the different localities. Current Action in the Ordovician.—Ruedemann. 881 versally arranged fragments which apparently were arrested by the immovable shell, on the east side, and with a drift- ridge of longitudinally arranged fragments on the west side. 2. The motion of the water brought about, in this district, the changes in the sedimentation and in the fauna which constitute the differences between the Trenton and Utica ter- ranes. This assertion is principally based on the following observations: a. The approach from the Trenton limestone to the Utica shale, as well as the lower Utica shale itself are, as described before, from the East Canada creek near Dolgeville, marked by a regular alternation of beds of limestone and shale, the shaly interealations at first being far apart and thin, but in- creasing steadily until the limestone bands dwindle into in- significant intercalations and disappear at last entirely. This gradual change has already been observed by Vanuxem* on the West Canada creek, near Herkimer, and also north of Little Falls. It is also observable in the localities south of the Mohawk river, where Hall+ described Sphenothallus angustifolius as being found in the shaly upper Trenton lime- stone, near Canajoharie. Walcott? reports from the town of Deerfield that ‘‘the Trenton and Utica formations are inti- mately connected lithologically.” Prosser§ found sixty feet of passage beds, consisting of shale and limestone beds in a 99 well at Chittenango, which is south of lake Oneida and west of Utica. b. Further, as already observed by Vanuxem and verified by Hall|| the Trenton limestone and the Utica shale are in the state coextensive and concordant. ‘The whole of the Utica rests upon the Trenton and upon no other rock.’ (Vanuxem). Changes in the depth of the water can not, therefore be ad- duced to account for the change in the composition of the sediment. ce. The change in the fauna is gradual, as shown by the section near the Flat falls on East Canada creek and gives the impression that part of the Trenton fauna,especially the corals, *L, Vanuxem, Nat. Hist. of N. Y., pt. 111, 1842, p. 58. tJ. Hall, Pal. of New York, vol. 1. p. 261. TC. D. Walcott, The Utica slate, etc.. Trans. Albany Inst.. vol. x, pp. 1-17. §$Ch. 8. Prosser, Bull. of Geol. Soc. of Am., vol. 1v, p. 91. |Proe. Am. Asso. Adv. Sci. 1878, pp. 259-265. 382 The American Geologist. June, 1897 were unable to continue to live in the mud-bringing, moving water and gave place to other forms thriving under the new condition. The differences between the Trenton and Utica formations, as established in New York state, are not local or prevailingly lithologieal. This fact, as wel] as others valuable to the under- standing of the nature of the motion of the water are excel- lently presented in the papers of Walcott on the Utica slate.* That author states that from lake Huron, across the province of Ontario to New York state and thence by way of the Black river, Mohawk, Hudson, lake Champlain, St. Lawrence valley to Anticosti and from the valley of the Hudson to Vir- ginia the differences between the: Trenton and Utica forma- tions are essentially the same. The black bituminous shale forms a distinet horizon above the Trenton. Thus it beeomes apparent that the change in the physical conditions which in- augurated the Utica epoch in the Mohawk region extended over a wide area, along the southern and eastern coast of the then existing land and over the site of the present Appalach- ian mountain system. It must be added that the alternations of limestone beds and shales in the upper Trenton and lower Utiea shale are also widely extended. Cushing} expressly mentions the shaly interealations in the Trenton limestone on the shores of lakes George and Champlain while the Geology of Canadat reports that “the limestones of the Trenton formation are generally separated by thin layers of black or blackish brown bitumi- nous shale. The layers in some places become thicker to- wards the top and present a passage to the sueceeding de- posit,” the Utica shale.§ *C. D. Waleott: The Utica slate and related Formations; cf. above. C. D. Walcott: The Value of the Term—Hudson River Group. Bull. of Geol. Soc. of Am., vol. 1, pp. 335-356. +Rep. of the State Geologist for 1895, p. 483-486. {Geology of Canada, p. 198, 1863. $Walcott reports that there are no limestone interealations in the 180 feet of Utica shale, measured by him in Jefferson county, (east of lake Ontario). A like observation has been made by the writer near by, in Lewis county. As there, however, the shaly intercalations of the upper Trenton are quite conspicuous it seems essentially a question as to the drawing of the line of separation and it is possible that there the Trenton conditions continued a little longer and terminated more sud- denly. The reappearance of a Trenton-like bed in the series of passage beds on East Canada creek is certainly indicative of such a possibility- i a ae. "Tea rs Current Action in the Ordovician.—Ruedemann. 388 The general occurrence of the passage beds gives evidence that the change from the physical conditions of the Trenton epoch to those of the Utica epoch was not a sudden one, but consisted in a transition by numerous oscillations. But after the conditions favorable to the deposition of the Utica shale had once gained prevalence, they must have continued for a long time. - This can be inferred from the extensive geograph- ical distribution of the Utica slate and its retaining its char- acteristic black carbonaceous slaty character, which shows the rock to be a slow deposit of deeper water, and from the comparatively large volume, notwithstanding its probably slow deposition. Waleott further develops the important fact that, while all along the coast of the old continent the Utica shale was formed, the formation of limestone continued towards the cen- ter of the Appalachian basin.* That author shows that the same change which terminated the Trenton formation in the east and north of the Appalachian basin, and inaugurated the Utica epoch, also wrought some change in the fauna of the limestone-forming sea in the center; a change which is recog- nized in the difference between the faunas of the Trenton and the superjacent Galena limestones. While the Utica shale has fifty-four species limited to its boundaries, and thirty-six derived from the Trenton, the Galena limestone has only nine- teen species peculiar to it, and fifty-six passing up from the Trenton formation beneath. ‘‘This diversity is undoubtedly owing tothe greater variation in the character of the sedi- ments of the Utica slate as compared with the Galena, when the change from the Trenton limestone-forming deposit oc- curred.” While this diversity, on the one hand, proves that a change in the physical conditions in the east and north must have changed the fauna there, it demonstrates also, on the other hand, that this same physical change made its influence felt even in the center where the limestone formation continued. While Walcott, on the evidence of Prof. Orton’s report on the geology of Ohio (1880), shows that the Utica shale is still met with in wells drilled in northwestern Ohio, but is reduced *This term includes the interior continental basin from the Appala- chian system to the Mississippi. Later the Galena has been referred to the Trenton of New York state by several geologists, viz., N. H. Win- chell, E. O. Ulrich and F. W. Sardeson, vol. 111, part 11, Final Report Minn. Survey, 1896. 384 The American Geologist. June, 1897 and altered as it approaches the Ohio valley, and is finally lost, it becomes also apparent that the cotemporary Galena limestone has been found as far northeast as on the Escanaba river in the peninsula of Michigan (Hall), but going northward also, it becomes reduced and interstratified with shales. Cham- berlin (Geology of Wisconsin, vol. 11) reports asimilar change in the Galena limestone towards the northwestern portion of Wisconsin. The modification consists mainly in the introdue- tion of more clayey material in the form of shaly leaves and partings. The change is gradual and progressive from forty to fifty miles. _ The statement that in Iowa, Wisconsin and Minnesota the Trenton limestone has been found to pass into the Galena by slow stages proves that, exactly as in the east, the change was not a sudden but an oscillatory one. From the distribution of the Galena limestone in the north- west, and especially from its occurrence on the Escanaba riv- er, it seems that this limestone facies of the Utica shale ap- proaches the coast in the northwest much more than it does in the east. This observation, together with the reported thinning out* and final disappearance of the Utica shale to- wards the northwest along the Archvean area, and with the re- markably wide extension of the Utica shale through Ohio and to Kentucky—where the lower part of the Cincinnati shale by the presence of Utica graptolites and Tréarthrus beck? is still characterized as a deposit of the Utica epoch—are of signifi- cance in regard to the nature of the change, for they indicate a farther transference of the mud in the direction of the mo- tion of the water in the Mohawk region, than towards the northwest. It has so far been demonstrated that in the region south of the Adirondacks, the close of the Trenton and the beginning of the Utica epochs evidently stood in causal connection with the coming in of a sediment-bringing west southwest current, and not with changes in the sea level. It has further been shown that the change from the Trenton to the Utica forma- tion took place throughout the north and east of the Appala- chian basin where the shale overlies the limestone. and also *On Manitoulin island the Utica shale has a thicknes of only 50 feet. Current Action in the Ordovician.—Ruedemann. 385 somewhat modified, in the center of the basin where the Gal- end limestone represents the Utica epoch. The change to Utica shale and Galena limestone was not a sudden but a gradual one, by a series of passage beds, and the Utica shale has been shown to extend farther away from the old coast- line in a south-westerly direction than towards the northwest, in which latter direction it diminishes remarkably in vol- ume. The direct conelusion, which one might be inclined to draw from the foregoing statements, is that the current observed in the Mohawk region is responsible for all these phenomena. But a comparison of the relatively small area over which the influence of the motion of the water has been proved, with the immense area involved in that general conclusion, will at once demonstrate the great disproportion between the studied area and the conclusion, and will prove the necessity of complet- ing the work by studying the outcrops of Utica shale in the Appalachian region, in the lake Champlain valley—which on account of its lying in the direct line of water-motion, observed in the Mohawk region, is especially important—in the Cana- dian basin, and in the northwest. The writer hopes to have an opportunity to do this work next summer. Meanwhile it may be allowable to discuss the character of the oceanic motion observed in the Mohawk valley under the supposition that it was part of a more extensive marine cur- rent which brought about the widely extended change from the Trenton to the Utica epoch, The motion of the water could have consisted in coastal tidal currents, in wind-drifts, or it could have been part of the general oceanic circulation. It is obvious that the receding and advancing tide alone could not have produced a motion apparently in only one di- rection and parallel to the coast, as the motion south of the Adirondacks must be supposed to have been. Powerful tidal currents sweep along many shores. They are best known from the straits around Great Britain and from Long Island sound, but they occur as real currents only in straits, while along open shores the translation action of the tide is only small. The Ordovician sea. which was at the present site of the Mo- hawk valley, was, however, open towards south and therefore 386 Tne American Geologist. June, 1897 affords no reason for assuming the presence of a strong tidal current. A constant and only slightly changing current produces an even bedding in the deposits, while beneath strong tidal eur- rents. owing to the strong flow during the incoming tide and its alternation with high-water and low-water quiet, in the ebbing tide, layers that are obliquely laminated alternate with ordinary layers. The Utica shales and slates in this neigh- borhood are remarkably even-bedded and there are no traces of cross bedding noticeable.* It is possible that the lack of oblique lamination in the Utiea shale is due to the greater depth in which that sediment was deposited, but thenit would seem strange that an inconstant and irregular tidal current near the coast should have resulted in a constant, apparently regular current in water of a greater depth such as that de- positing the Utica shale most probably wos. Tidal currents further are, however strong they may become in certain places, only local phenomena, their influence extends neither far into the open sea nor into the oceanic depths. The uniform litho- logieal and faunistic character and wide extension of the Utica shale, however, show that it cannot be the result of lo- ‘al and irregular physical agents. Moreover, the fine grain, even bedding, and rich admixture of carbonaceous matter in- dicate that the shale is the result of a very slow and equal deposition, such as generally takes place only in the deepest part of the littoral region. It is the concurrent opinion of ge- ologists that the graptolite shales and slates, in general are slow, deep-water deposits. This opinion is founded on the wide horizontal and small vertical distribution of the grapto- lites and graptolite shales. Hall has already reached this conclusion in his exhaustive study of the Quebec graptolites. A glance at the accompanying map will show that the shale in the localities where the parallel arrangement of the fossils has been observed, must have been deposited in consid- erable depths, for the outliers of Utica shale at Wellstown on *Oblique striation in the Trenton limestone has heen observed east of the Hudson (cf. Report of State Geologist for 1893, p. 428) which is of interest as it probably points to the presence of shallower water in that region during the Trenton epoch and, as during the Trenton and Utica epochs the sea stood at the same level, also toa shallow region in the Utica epoch. ee? Te Current Action in the Ordovician.—Ruedemann. 387 the Sacondaga river and on the west shore of lake George, as well as the direction of the fossils as far north as Nine Mile creek, leave no doubt that the coast-line of the sea of the Utica epoch must have been considerably farther north than the present extension of the Utica shale as surface rock would indicate. For the shale near Dolgeville, twenty miles ean be regarded as the minimal distance from the coast-line. The measurements of the dip in the Mohawk river valley are unreliable on account of several faults in the rocks, they would point to an angle of several degrees, which would mean an unusual ‘steep incline,” for an angle of about three de- grees gives a descent of one mile in twenty miles, which is a comparatively rare occurrence in modern seas. Williams* ob- tained some exact figures in central New York. He found in Cortland county a descent of fifty-six feet per mile. As the dip increases a little towards east, sixty feet per mile can be regarded as a minimal value, on account of the greater ap- proach of the strata to the Goast line in Herkimer county. These two data, twenty miles distance and a descent of sixty feet per mile, however, would give a depth of 1200 for the sea in the Mohawk region. It must, therefore, be concluded that the depth, in which the Utica shale, showing the arrangement of the fossils, has been deposited, was considerable. It agrees with this, that the preservation of the delicate rhabdosomes of the graptolites points to avery gentle motion of the water, which, in most cases did not so much transport the organic relies, as arrange them. It is especially this gentle, but con- stant, deep-reaching action of the moving water, which, to the writer, seems not to be quite in accordance with the influence to be expected from a tidal current, but rather with that of a branch of the general oceanic circulation. The apparent in- dependence of the current from the coast, which is indicated by the distant transference of mud towards the Ohio river and by the approach of the Galena limestone to the coast in the northwest, also seems not to indicate the action of a tidal current. Finally, it is very doubtful, whether a tidal current would have been able to influence the fauna of the entire Appalach- ian basin in such a degree, as is indicated by the difference *Dip in Central New York. Am. J. of Science, vol. 26, p. 303. 388 The American Geologist. June, 1897 between the faunas of the Trenton and Galena limestones. The constant deep-reaching and equally directed character of the water motion also excludes its having consisted of local wind-drifts. These considerations have induced the writer to see in the observed movement of the water, a part of the general ocean- ic circulation and to suppose the passing of an E. N. E.-W.5. W. current along the southern coast of the Adirondack land- area. It is probable that the obstacle offered by this project- ing land decreased the depth of the current and made thus the phenomenon of the arrangement of the fossils especially visible in the Mohawk river region. As the transporting power of the currents has been found to extend to a depth of 300 fathoms, there can be no doubt that the influence of the supposed current could have reached to the depth in whieh the graptolite-shale of the Utica epoch was deposited. It might seem unreasonable to speak of a strong, deep- reaching current action in an age, in which the distribution of the fossils generally has been regarded as proving the absence of all diversity of climate and of oceanic temperature.* But, accepting the first of the two rival theories as to the cause of the oceanic circulation, namely, that which claims that the latter arises entirely from differences of temperature and sal- inity, it will be easily seen, that the latter again are due to differences in the insolation on the surface of the ocean. But the insolation must always have been different at different latitudes, and this unequal distribution of solar heat must al- ways have disturbed the equilibrium of the spheres and hence must have constantly produced currents to restore the equi- librium. Accepting the other view, that oceanic currents are caused by the atmospheric circulation, would be only insert- ing a new link into the chain of conclusions, as the circula- tion of the air itself is due to unequal insolation. Investigators like Dana, therefore, have always regarded the existence of a system of oceanic circulation, similar to the present, even in Paleeozoie¢ times, as self-evident. Danat in discussing the presence of the Trenton lime- for instanee, * Barrande has distinguished two bands in the Cambrian of Europe which are thought to represent climatic zones. +James D. Dana; Manual of Geology, 3rd ed., p. 208. b Current Action in the Ordovician.—Ruedemann. 389 stone over the whole breadth of the continent, seeks an ex- planation in the theory, that, “the currents of the ocean which ordinarily swept over the land (the Labrador current from the north, along the eastern border, and the Gulf stream from the south, over the interior), must have had their action partly suspended.” This view not only includes the assump- tion that current-action terminated the Trenton epoch, but it suggests also that the current observed in the Utica shale of the Mohawk region was part of the Labrador current. It came from north but under the influence of the diurnal rota- tion had a tendency to deviate in a westerly direction on ac- count of which tendency it pressed toward the east border of the then-existing land, crossed the region of comparatively shallow waters, which is supposed to have foreshadowed, dur- ing the Ordovician era, those ranges which arose at the end of that era—namely the Green mountains and parts of the Ap- palachian system—and entered the continental basin in east- ern New York asa W.S. W. current. Dana says regarding this shallow region (op. cit. p. 211): ‘ Along its course, there were Archean islands and reefs, when the Silurian era opened,—portions of the Blue Ridge to the south, the High- lands of New Jersey and Orange and Putnam counties, N. Y., and the patehes of Archean rocks in New England being some of these areas. It was hence a barrier region to the con- tinent, over which the Atlantic currents flowed and waves broke; and here, therefore, fragmental rocks—rocks of sand. pebbles, mud and clay—ought to have abounded.” Investi- gations of the present currents have shown, that, on account of the increased velocity in the straits of an archipelago, the finer partly suspended silt, such as evidently formed most of the Utica shale, is carried farther away, while in the straits themselves, former deposits may be swept off the floor of the sea. The Gulf stream has been found not to drop any de- posits in its direct course in the strait of Florida, while its lower part from the exit at Florida, where the current rapid- ly decreases in velocity, to cape Hatteras has been compared to amuddy river. Places where “hard bottom” ha’ been met with on account of the scouring action of the currents, have been found in various places and often in considerable depths, especially between submarine ridges and islands; between the 890 The American Geologist. June, 1897 Canary islands for instance, in a depth of 6,000 feet.* Simi- lar conditions must have prevailed in the eastern border re- gion; hence the absence of the typical Utica shale and its fauna in eastern New York and the region east of the latter, its fast increase in volume towards west,+ from where the material could not have come. At Glens Falls the velocity was still too great to allow the deposition of the fine detritus ; but in entering the wide continental sea, the current rapidly decreased in velocity and consequently the increase in the thickness of the deposits until the maximum of sedimentation seems to be reached at the present site of Utica, where also the obstruction to the current from the projecting Adirondack land is removed and the waters, being allowed to spread a lit- tle towards the north (the readings obtained at Deerfield seem here to be significant), a somewhat abrupt decrease in the velocity of the current must have occurred. This, however, must necessarily have resulted in a sudden inerease of the quantity of sediment. As the current now, on its W.S, W. progress left all shores behind, it received no new supply of terrigenous sediment, hence, the rapid decrease again to the west of Utica, as indicated by the measurements obtained in drilling wells in the western part of the state. In a well at Chittennago, south of Oneida lake,only 200 feet of Utica shale have been met with. But then, this decreased Utica shale extends over a wide area, as far as the Ohio river, in the di- rection of the observed current, while it thins out towards the north and northwest, where the Galena limestone formed at the same time. In those regions to which the current could not carry its silt. the difference in temperature and sal- inity which necessarily must have existed between the cur- rent water and the quiet Trenton sea, were sufficient to pro- duce a change in the fauna, though the limestone formation did not cease. These differences may have been only slight, for the fauna of the deeper littoral zones, in which the lime- stones probably formed, is known to be very sensitive to such differences. 7M: Reade, Phil. Mag. vol. xxv, p. 392. +Walcott states that the fauna of the upper part alone of the Utica formation occurs within the valley of the Hudson. {Dana (op. cit. p. 196) gives only 15 to 35 feet at Glens falls, while in Montgomery county it is 250 feet and near Utica amounts to 710 feet. : Current Action in the Ordovician.—Ruedemann. 391 The cause of the extension of the Trenton limestone all over the continent, even over the eastern border region, has been sought in the existence of a “barrier region outside of the limestone area, near or outside of the present Atlantic coast line.”* Billings+ also explains the prevention of Brit- ish specimens from being introduced into the Trenton sea by the presence of this eastern coast barrier; which latter dipped down beneath the ocean in the following period and allowed the incursion of British species, which he observed. Geolo- gists, in general, have resorted to the assumption of the for- mer existence of this land in order to account for the enor- mous accumulation of sediments in the Appalachian region, during the Paleozoic age. The writer sees in the observation of the arranged fossils a new argument in favor of this theory, for the direction from which the current comes must also im- plicitly indicate where, in the: preceding Trenton period the barrier was, that closed the Appalachian basin towards the Atlantic ocean. As the transition from the Trenton limestone to the Utiea shale in the east, and to the Galena limestone in the west, takes place only gradually, by a hundredfold alter- nation of the relative rocks, it must be concluded that there has been a long period of oscillations of the barriére, these oscillations alternatingly closing and opening the continental basin to the Atlantic current in the northeast. As the limestone continued to form in Anticosti during the Hudson River epoch (including the Utica shale) and only thin beds of shale are reported to occur in the series, it is: possible that this region already lay outside of the shallowSea and of the archipelago which Dana supposes to have oceupied the site of the present Appalachian region and Green mountain system, and which, under the wearing action of the sea waves must be supposed to have furnished part of the fine mud con- solidated into the Utica slate and shale. ‘Towards the end of the Hudson period, the uplift of the Green mountains and theemergence of the Appalachian folds probably turned the Labrador current again into the Atlantic ocean. *Dana, op. cit., p. 208. tCf. Dana, op. cit., p. 250. 392 The American Geologist. June, 1897 LAKE ADIRONDACK. By B. F. Taytor, Fort Wayne, Ind. Early in October, 1893, I joined professor J. W. Spencer for a reconnoissance of the slopes of the northeastern portion of the Adirondack mountains. The trip was made on Prof. Spencer’s invitation, and his lead was followed. Our efforts were directed toward a search for evidences of Pleistocene submergence, and more especially to an attempt to trace the Iroquois beach at high levels. The Iroquois beach had been traced by Mr. G. K. Gilbert along the south side of lake Ontario and northward along the east side to cape Rutland, about four miles nortbeast of Watertown, several years before.* To this point the beach is a prominent feature, easily traced, but the character of the country changes here to one of rocky knobs, largely bare and with sandy wastes between. Gilbert and Spencer both made repeated efforts separately, and once jointly, to carry the tracing farther, but without much success. Mr. Upham also entered the field with Mr. Gilbert. Asa result of his several excursions Prof. Spencer believed that he had traced the Iro- quois beach in somewhat modified form past Carthage, Natu- ral Bridge, Harrisville, East Pitcairn, Fine, Clarkesboro, and South Colton.+ Just before we met he had taken up the line again at South Colton and carried it farther northeast past Parishville and Dickinson Center and on the south to a point on Salmon river near Owl’s Head station about ten miles south of Malone. It is not the object of this paper to go into details of the observations made except in two or three instances. A few gen- eral statements of results will suffice. Terraces were seen in the distance near Standish, on Upper Chateaugay lake, but *“The History of Niagara River.” In the Ann. Rept. Commissioners of State Reserv. of Niagara, 1889. Alsoin Rept. of Smithsonian Insti- tution for 1890. +The [Iroquois Shore North of the Adirondacks,” Bull. G. S. A., vol. 3, 1891, pp. 488-495, including discussion by Mr. Gilbert. The writer also made an attempt to trace this beach northeastward from Watertown, early in November, 1893, but with only limited success. It seemed to be traceable in one form or another along the line indicated by Prof. Spencer to the vicinity of East Pitcairn. But it passes thence to the north by South Edwards and Edwards. Littoral features doubt- fully referred to this beach were followed still farther north from Ed- wards to Russell and thence northeast to Colton. Lake Adirondack.—Taylor. 393 their character remained a matter of doubt. Terraces, mostly rather faint and poorly formed, were also seen around Chazy lake. These suggest the presence formerly of static waters in these basins at higher levels than now but nothing indicating wave action was seen. Passing over to the Saranac valley at High falls, above Mof- fittville, terraces were found at about 1025 and 1100 feet and others at higher levels half a mile northwest of Moftittville. None of these, however, were as distinet and finely formed as two terraces that were found higher up the valley on the north side on the farm of Mr. Wilcox, about a mile and a half west of Redford. Here, about forty rods back from the road, are two flat-topped terraces each with a distinet bluff front, the upper about twenty-five feet above the lower. The upper one extends a considerable distance back to the northwest to a small stream. These two terraces are part of an old delta of a creek that comes down from a high mountain about three miles to the northwest. Standing on the upper terrace we saw a distinct bench around the valley on the other side, at about the same level. Towards the southwest, and less noticeably towards the south and northeast also, this bench was discernible. The al- titude of the upper terrace is approximately 1,370 feet (an- eroid from Dannemora). Nothing marking a water margin was seen at a higher level, but a few terraces and deltas were found at lower levels. About a mile east of Dannemora, on the south slope of Rand hill, there is adelta of rounded grav- el which is cut by the Chateaugay narrow gauge railroad and excavated for ballast. Its upper level was not measured, but at the pit the top of the bank is about 25 feet high or about 950 feet above tide, while the top of the delta is probably somewhat higher. -This delta may correspond with the lower terrace at High falls. In the Au Sable valley northeast of Black Brook we found a few faint terraces up to correspond- ing hights, but nothing so definite. Only a small part of this valley, however, was examined. After a little over a week together we separated, Prof. Spencer going south along lake Champlain, while I began a search for beaches, mostly at lower levels, on the northern slope of the mountains. In several favorable places evidence 394 The American Geologist. June, 1897 of wave action was looked for on the exposed outer slope, at levels corresponding to the valley terraces, but none was found. Afterward I learned from credible sources that there are sandy terraces in the valley of the east fork of the Au Sable river near Keene, atlevels which seem to correspond with those near Redford. The reconnoissance which we made was not a thorough one and the facts gathered are too few for positive statements. Butit seems pretty clear that at least in the Saranac valley there was still water at the level of the Wilcox terraces,and later at that of the High fallsand Dannemora terraces. The absence, so far as observed, of any evidence of wave action at these levels, even on the outer exposed slopes, suggests that this body of water was not of great size, but was confined to this valley and perhaps one or two other adjacent valleys separated by cols a little below the terrace level, Apparently the only ex- planation of such a lake is that it was held up by an ice-dam —by the great glacial tongue that extended southward in the valley of lake Champlain. It is not certain, but seems likely that at its greatest extent this lake included the valleys of both the east and west forks of the Au Sable river. This would give it a quite irregular shape with three expanded parts. For this lake I propose the name lake Adirondack. There was probably no other glacial lake of equal size within the Adirondack area. The outlet of lake Adirondack was not found, but the Wil- cox terraces are close up to the general floor or half-finished peneplain of the Adirondacks. Nearly all the modern lakes in the central area of the mountains lie in basins only slight- ly depressed below this plain, which is between 1,400 and 1,600 feet in altitude, and the higher mountain peaks stand as monadnocks or clusters of monadnocks upon it. In one or two seasons after our joint excursions Prof. Spen- cer carried his explorations into the mountains of New Eng- land. He reported his results at the Springfield meeting of the American Association for the Advancement of Science in August, 1895, and claimed to have found evidences on both the north and the south sides of the mountain masses of New England that indicate post-glacial or glacial submergence to Lake Adirondack.—Taylor. 395 at least 2700 feet.* In making his statement Prof. Spencer re- ferred to other similar high level terraces farther west, meaning apparently the terraces which we had seen in the Adirondacks. Having been with Prof. Spencer when he made the Adirondack observations I desire to say that in my opinion nothing we saw there could bear the interpretation which he has given. Not the slightest evidence of wave action was seen—nothing that might not have been made in lakes of small or moderate size ponded by the ice sheet. Nothing was seen that is not better and more easily explained in that way than by the sup- position of high marine submergence. Furthermore, the ob- servations which I made on the northern slope after the joint excursion, occupying over three weeks of the fine autumn of that year, enable me tosay with some confidence that there is no evidence of wide-spread high level submergence on that slope. . If lake Adirondack was a glacial lake as supposed, then some other interesting conclusions follow. It is a common as- sumption with some writers on glacial subjects that the Adir- ondacks continued to be an important center of glacial growth and dispersion for a considerable time after the front of the main ice-sheet had withdrawn from the Ontario basin entirely, and partly or entirely from the Champlain basin. Those who favor the idea of so-called “sedentary” ice-sheets are particularly inclined to this view. But if lake Adiron- dack existed as supposed, then its very existence is in con- flict with such an idea. No doubt there were some more or less important local glaciers among the high peaks of the Adirondacks after the main sheet had uncovered the south, east and west flanks of the mountain mass, but they did not deploy far on the peneplain below and certainly did not con- stitute anything that could properly be called a local ice-cap like that which Prof. Chamberlin deseribes as covering the Redcliff peninsula of Greenland. This conclusion is further strengthened by the observations of Prof. C. H. Hitchcock, who recently ascended to within a hundred feet or so of the top of Whiteface mountain (4871 feet altitude) and found its * The writer was not present at Springfield, and has gathered the main points of Prof. Spencer’s communication from two abstracts. Proc. A. A. A.S., vol. xtiv, p. 189. Also Am. Grou. for October, 1895. p. 249-50. 396 The American Geologis:, June, 1897 slopes all the way up plentifully strewn with bowlders and fragments of Potsdam sandstone which must have been car- ried up by the ice from a northward or northeastward quar- ter.* This seems to indicate that the main ice-sheet over- rode the higher peaks at least for a time, and it seems to im- ply further that there was no considerable amount of vigor- ous glaciation by local glaciers of notable size or by a local ice-cap, either following the retreat of the main ice-sheet, and probably none preceding its advance. Such facts shed an important and very welcome light upon the climatic condi- tions that prevailed along the ice-front. They show us that the peripheral belt of ablation on the surface of the ice-sheet must have been at least one hundred miles or more wide, (it may have been even three or four times this width) and hence that the névé line on the ice-sheet itself was well back from the front. For when the reentrant front of the ice-sheet rested against the northeast corner of the Adirondacks at an alti- tude of 1400 feet or over, the peneplain at 1400 to 1600 feet was distinctly below the snow or névé line. WHAT IS THE OLENELLUS FAUNA? By G. F. MatrrHew, St. John. St. Jonn, N. B., 23d March, 1897. Pror. N. H. WINCHELE, Dear Sir:—As you have requested me to express in your journal my views as to what the Olenellus fauna is, and what its relation to Paradoxides, I have briefly outlined inthe following article the data bearing on this point, known to me. I hope it may stimulate some of the American geologists to seek a solution of the prob- lem that shall be more direct. In the great body of slates existing at lake Cham- plain and along the valley of the Hudson, with their enclosed limestone bands and lentilles. there must be faunal groups other than have been described, and the means of a better presentation of those already known. A careful search and mapping of exposures where fossils are found, would reveal the structure, and prove or disprove the theory of the mingling of the Paradoxides and Olenellus faunas in the Hudson valley. Hoping that the following paper may meet your wishes, I remain Yours sincerely, G. F. MAarrHEw. In view of the tendency that exists at the present time to refer all pre-paradoxidean faunas to the Olenellus horizon, * Stated by Prof. Hitchcock at Buffalo in August, 1896, in his report to the Geological Society of America on the petrographical excursion in the Adirondacks. What is the Olenellus Fauna?—Matthew. 397 whether they contain that genus or not,* the present seems an opportune time toinquire how far such a practice is advisable, in view of the wide range that has been given to that fauna by the addition of numerous faunas, mostly pre-paradoxidean in Europe, America, and elsewhere.+ It is not known that all these branches of the Olenellus stem preceded Paradoxides, nor is it known that even the type species preceded this genus. That Olenellus is older than Paradoxides is altogether a mat- ter of inference, based partly upon the const.tution of the Ole- nellus fauna itself, and partly upon the fact that related subge- nera are found below Paradoxides. Yet suchis the effect of the strong plea that has been made for the greater antiquity of Olenellus, that faunas older than Paradoxidest have unhesi- tatingly been referred to the Olenellus horizon, though no spe- cies of Olenellus has been found in them. Why, then, should they be referred to the Olenellus zone? Let us see if we can gather any information on this still obseure question. the age of Olenellus, from the pre-Paradox- idean faunas. There are two aspects of proof available from the olenellid faunas themselves which may throw light upon the matter. One is the individual form and development of the several olenellid species; the other is the associated spe- cies found in the several faunas. Criterion of Structure and Development. Among the olenellid trilobites which have been found ac- tually to precede Paradoxides, there are two principal types, one represented by Holmia kjerulfi and the other by O. ( Calla- via)§ bréggeri and O. (Schmidtia) michwitzi; and although the latter is separated to another sub-genus on account of its tho- rax, if we regard the head-shield, and especially the glabella, we shall be inclined to associate it with the second of the above species rather than with the first. And this is probably * T confess to having been influenced by this tendency myself in for- mer years, as we then had not come to appreciate the individuality of the pre-Paradoxidean genera as we now do. +The Fauna of the Lower Cambrian or Olenellus Zone. Extract from the 10th Annual Report, U. S. Geol. Survey, pp. 572 to 575. tIn Bohemia, France and Spain. $I propose this subgeneric name for O. bréggeri and O. callavii be- cause the glabella differs from O. (/1.) kyerulfi, ete. 398 The American Geologist. Sune, 1897 the natural arrangement, as, if we may judge by the analogy of the young of other trilobites, the generic features of the head-shield would have been developed, before the posterior segments of the body were defined. Such being the case we should look upon the characters of the head-shield as of vital importance in defining relationships of the trilobites. In this view it seems natural to look upon O. michwitzi as the oldest form known of the root stock of Olenellus, and to associate with it, as somewhat nearly related, O. callavii and O. bréggeri. In a discussion of the age of the Olenellus fauna it should be borne in mind that only 0.(C.) bréggeri and Holmia kjerulfi have been found in actual infra-position to Paradoxides. But there are several things which indicate the antiquity of O. michwitzi, e.g., the long eylindrieal glabella, the short pleura and the small size. On the other hand the differentiation of the thorax into two regions and the great thoracie spine, show that we are not dealing with the earliest representative of the stock.* The branch of the olenellid stem to which O. michwitzi be- longs, if we limit it to the three species above referred to, is pre-paradoxidean, and none of its species enter the Paradox- ides zone. But can we say the same of the stock at the base of which we find Molmia kjerulfi ? This branch of the ole- nellids is characterized by an enlarged front to the glabella after the manner of Paradoxides; the feature is well marked in O. (Llliptocephala) asaphoides and is less distinetly shown in O. (Mesonacis) vermontana; and although Mr. Walcott in- cludes the former species and the associated genera in his Olenellus fauna, he intimates that they may be of the “Mid- dle” Cambrian, 7. e., Paradoxides zone. In MU. vermontana we seem to have the highest expression of this type of structure in a trilobite apparently adapted for living on a muddy bottom. With some primitive features, as for example, the long glabella, there are others which show an advanced stage of development, as the shortened eye-lobes, the numerous joints to the thorax and the differentiation of this part into two regions. This species, according to Wal- *On account of these features, Peach thinks this species more modern than Holmiakjerulfi in which there is an equal development throughout; but for the reasons given above, and others, I do not concur in this view- What is the Olenellus Fauna?—Matthew. 399 cott, belongs to the Olenellus fauna, being associated with the original Olenellus of Hall. There stil] remains another group of olenellid trilobites represented by the type species and remarkable for their tel- son-like pygidia. All these have the enlarged Paradoxides- like front to the glabella. Are they to be referred to Holimia kjerulfi branch of the olenellid stock or to an ancestral type unknown? We think to the latter. This seems to have been a branch which has left widespread evidences of its distribu- tion, having been found in Scotland and both in the east and west of America, but nowhere has it been seen beneath the Paradowides beds. It isa branch of the olenellid stock, whose position relative to Paradoxides has yet to be determined. That it is a highly developed branch of the olenellids may be inferred from its glabelia and peculiar pygidium, and we there- fore think it is not the oldest. From the study of the youngest of Paradoxides we judge that the enlargement of the front lobes of the glabellain this genus and in Olenellus is not a primitive character. It is not analogous to the enlarged front of the axial lobe of the cephalic shield seen in the protaspis and early larval stage of many trilobites, for we find that in the larval condition of Par- adoxides these lobes are shorter than in the adult forms. Notwithstanding the difference in the facial suture we feel that Paradoxides and Olenellus are not far removed from each other, and that the enlarged front of the glabella in both points to a similar development in the two genera in this respect. Nor can we suppose that the spine-like pygidium is a protas- pid character in Olenellus (sensu stricto); we would rather expect to find that in the early stages of growth this branch of the olenellids would be found to have a normal pygidium like that of the other two branches of the stock. Peach, who has written on the question of the relations of the ditferent forms of the olenellid stock to each other,* looks upon H. kjerulfi as the initial form of the olenellids. but we must remember that this form is in the beds which in Sweden lie immediately beneath the Paradoxides beds. A thickness *Addition to the Fauna of the Olenellus Zone of the Northwest High- lands, by B. N. Peach., Esq., Quart. Jour. Geol. Soc., Nov., 1894, p. (ge 400 The American Geologist. June, 1897 of only six feet separates the two faunas, and there is no physical break between them. We think the Schmidtia michwitzi stock older, and imagine there is a parallel in the development of the olenellid stem similar to that which is seen inthe paradoxidean. Protolenus is undoubtedly older than Paradoxides, but is very similar in structure, differing most markedly in the form of the glabella which is cylindrical in place of club-shaped.