«lt AW de te by hee wind Mot lal ii) $i * g 1 ‘ \ s ; wled Goh d lg bs Yakedg ts bot ' i) st “a Wests! teh dy i ie “ ¥ eda det Fateh Hae Bo \ ‘i : lide 4 ts uf 4 fe SH TATA rir ULMER etal we HUM OUNHPOTL MAHAN MERA Hoe i Geis 5 af nad ¥} ih sical Ghal ae > F, te Oe ye adetelal vil s4o¥e oe ne , an iy # . Laat: Vhaltell Aeahetagad\ ; a ' “th hae a Pyrat ata i nt \ ie Ate| nth ‘ rey Ak dl tty ‘ Wishive 4. m ’ au sea ty , ‘ haa toyis q sai det Nqhi@ n a Fate Si ae Y ewilcathisrbcrst ah Wyre ft wearich aa etait nate ie af Sratiita . le eg ee soe tated ify tw end adie [cea RUM URRONL SEH a ith i: Biya oto te 4 \ sme Yalet aa cals hiatal Maite tata t Ska Vite tate wl tn4 . ah ; TURP Lt e be bet be 43 iadyit et ett 0 ag iga 2hs 1 4a het yt eh UN els wie phe we Wei Clare aaah OC ROM Te A PbabY Dee aed te 4 ahaa tet the Parery PAPURE ERT Tl Rake 90 ba A oP stgade inde PDS vit tte lelat.! Ba’ tahe Mba stat 1h ee pte Wy HN MA Are he PPL at dae bh) eae Na “Af stake Ay VAs Made body Capote tat? Wis aay Fi " 4 i Uitte tall cy hiltee stated FU DR LSA COrPe ite t i wows ak ‘rg fackats tod aug Vins ass hs} ‘ peas tai tance? wistataiet ae Ute tite ; 4 * 1! fAgielt seed gies 4 "gitar tf Ahad 4 Pi ‘ ry hd lie 5 : whe oe « F Pen satel! iH 4 ‘ i ry othe tedd \ 4 VONg Cada Fy 8 34 oy se 4 Ve bag hetate tT aes 4 Veta! ts hy Ye tad - Ni tat i ah 4 ; 1 ‘" 3 ’ 1 Yong : wk wa} ‘ a ate Ae LEN bebo Hi! a ; ale la let 1 . >, on ae ’ : REE Ty badd te ; r 4 i - : is j ‘a4! , Yo tat tate ue es ahi ve be ae ‘ iiss , \ 4 te . 3 4 Fra Hi te th im ‘* ‘vel 14, i : a . we ea ta” Ce 1 mA We FY Pt) te} ae e! ‘ iy te t vt . ' i ‘ ae | { « sh 4 ; \; Aj ‘ Pe 4 ' 4 sear 3 ‘ ' ‘ be We , ; rn Ey i i , Re hae - ; My . yet ae A Ais Y Hh ay : : bat : 7 6 pe eitreT at & 4 i an Aelia bas Bat) . bat > . ”“ ' ‘ ; * ' ; “- i‘4 4 is aia ts beatles ; ema ek wh 4 4 ; hg tha) dod 180 Lig8 A : bYteh Ld ate ha ‘ J acd i ep dat ia ’ 4.3 hi@ene [ade ees é oy int tite ae ahr’ Poy PERRO : reetnteres ea: r ry ja th de tedy a e 7 : diets ne haps if sis ; : A ls Cedvdaneis a) eMasetsere dae ade : Ud abe 4 ‘ athlete C 4G Udy ital att [ihe ide laliete of ‘ A slo@ lege idtr 7 : du hedejulals { t oe Meca eds le jet ave ' { ‘ { ini te i tei e127 ite la is ‘ isis t Mis Mh OS Nid hh he ? ; ‘ ‘ - wee a Way de Bs bade driet ‘ 1 he he ‘ re ; i wh ksh L. thi Weeedi \ jytal ca etedia bee 4 t Per wae if tae (oat ieee sy H i és it Y! . ‘ i i) LA ‘ ' ) ' i . ‘ tat " , f Dae +e 1 t- h @iia aa | OP y 2 gas je baa 1-49 14 78) ; ; 7 ad iad AME: Mia ate igh RS .* : Lue \ ‘ we ; Liiabvee 4 bast! indy bel A ; ‘ i Ri) Tatedy 2 Aa Cet pe ‘ 7 \ ‘ ‘ sha tadaqragsads 4 MeTli sce - td Ve Rt tea 4 rPrtiice & ‘ asdede tas HE t 4 . ' ° : “ . 4 he ve : i i 7 irik ay | , WA 5 a) qitad Ae ate OG ‘ uy hte da ty dated F my , ; & wa Bde ate ve. 6 ; 1 TREULEL Achy we a 7 >. SF tg a z= «as 5 ee eee Mees BULLETIN: OF THE PeeorocicAalL SOCIETY Bi Da —_-Y OF AMERICA VOL. 29 JOSEPH STANLEY-BROWN, EprtTor NEW YORK ~* PUBLISHED BY THE SOCIETY 1918 OFFICERS FOR 1918 WuHItMAN Cross, President BalLEY WILLIS, FraANK LEVERETT, Vice-Presidents F. H. KNow1nton, EpmMunpD Oris Hovey, Secretary Epwarp B. Maruews, Treasurer JOSEPH STANLEY-Brown, Lditor F. R. Van Horn, Librarian Class of 1920 JOSEPH BARRELL, ft AY Dare Class of 1919 Councwlors Artuur L. Day, | f WiLuiam H. Emmons, | Class of 1918 Frank B. Tayior, CHARLES P. BERKEY, J PRINTERS Jupp & DETWEILER (INc.), WASHINGTON, D. C. IXSNGRAVERS THE Maurice Joyce ENGRAVING CoMPANY, WASHINGTON, D. C. Ger ; CONTENTS Page Proceedings of the Thirtieth Annual Meeting of the Geological Society of America, held at Saint Louis, Missouri, December 27, 28, and 29, 1917; PAO N Dy CURLS Ul VEIN VC CEOLUMMR He Cle ae! hee ck ST Sicla eel Snere oe adecbelepels Co ce a i ace 1 Sess Oh Mine sday, IOCCEMIDEE ass < saca seb arele Ci heacd Gels whe dec ews « 4 FUROR OE GN COUMEL eS feet a 2 oats s: «/sca ym b Sten ve iene ela. 4/5 awd e's 4 SOGhe bares WPOMOEL. vali cineca bigs hg Ra pess Cypha a, 5 RE ADRCE SEE CTIOLb oN ocr chia saad ‘by REGINALD AY DALY. <.25 by EH. W. BERBY ¢ oo GOR ' ILLUSTRATIONS X] ILLUSTRATIONS PLATES Page Siace 1l--P BNROSH: Portrait OL Amos Pr, BLOWN. .... cevcads secs cenececeee 13 2 —CAMSELE - Portrait, of Melorme .D;, CalrneS. ~ cued oe ce. c ce neces 17 re SUL eRee Orrell ot Willba mr Bullock Clark qu bee be eee 21 id 4—- BANCROFT: Portrait of Charles W.. Drysdale:s in fsck cee ces 29 * j= LPDINGS conbrare, Of Ad TONG: TRAGIC oR sie cree anche clee Se een tle ewes 35 eo G— SNE ce CORULAIE On revels, OUD TVE SOW, craicgte eke wlan sale die eae ens 48 a 7—ASHLEY: Portrait of A. H. Perdue........ PLN Sask ete etad Wn! seh ee 5D 4 Se Ss ee ON tee VOle EL t Vin MS OELY 65, ¢ 0, Hear Merete eecerwishe.are bie piale carpe 6D ee par ROR ID: Stream terraces, Littleton, New Hampshire........ 195 ee LO ep Cobble delta, Bartlett, New Hampshire............. 209 Berri b - MAtINe Fea PEres, Il OUCDEG., octets sehen ca kce nevis LO ae Sea cliff, corner of the beach, Gaspé, Quebec....... ZL¢ ohne es cs Gravel bar, corner of the beach, Gaspé, Quebec..... 218 Pikes 7 Wave-washed slope, Gaspé village, Quebec.......... 219 a 00" ie Marine cobble-plain, Pennfield, New Brunswick..... 220 ag wee Os 3 Gravel_bar.on the Pennfield iplaim.. one. soe. ete ee ss 221 ‘eae OF ie Granite block moraines, Nova Scotia............... 228 “_18—BRANSON and GREGER: Fossils from the Amsden formation.... 325 ae Ps e Fossils from the Amsden formation.... 826 “ 20—Baae: Galena limestone quarry, Neenah, Wisconsin........... 3893 ee ARE | OOULES WM THE UROO.SHAIC. 66... 5 cen pele eccalbie wabelesteevse 5S9 Ritog res bY @olites in. the vellow. shale... .i.066 sels eieie0% eet tis i) 7. See FIGURES FAIRCHILD: fisure 1-—Post-Glacial continental Wpliit. oo. 40.65. Sete cease wees 202 WRIGHT: Figure 1—Post-Glacial beaches around the southern end of Lake ; Beye Paka ieee Pa eeyAees ease Cc, vin tae ean a ate keh AOU? on cela: alleasvens 237 le 2—Stages of Glacial lakes in the Erie-Ontario basin....... 242 H 3—Section of laminated clay above the soft blue clay ap- pearing in the diversion channel at Pvanston........ 248 CLARK: Figure 1—Areal map of the Eocene deposits to the north of Mount EAU Magee Te 95 cael toh bis nace ae ohana tein RTOLS. clase bi alate ea aie 284 & 2—Cross-section showing the Hocene groups as found on the Northside of Mount Diablos vee ok ek sc ete esd See ees 285 CLARK and ARNOLD: Figure 1—Outline of sea in San Lorenzo time (Oligocene)........ 301 Re 2—Outline of sea in Monterey time (Lower and Middle WET COTA oe aie are ays a8 aia aes adawetaeies & te ieee wee se ee 302 NY 38—Outline of Oligocene sea in Washington..............5. 305 BRANSON and GREGER: 299 Figure 1—Enlarged drawing of Paleoneilo amsdenensis....... X11 BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA CHADWICK: Figure WHERRY : Figure BAGG: Figure MILLER : Figure DALY: Figure (79 KINDLE: Figure “ec 1—Correlation of Clinton strata between Genesee and Os- WeLO TIVETS . OU. st PAA. caiee nee Or etmek ao so Soe 2—Tentative correlations of Clinton strata east of Oswego 3—Reconstructed stratigraphic diagram of Eontaric strata and overlying beds from Rochester to pre-Niagaran erosional limit of the series in present line of outcrop 356 4—Diagram of thin basal divisions of the ‘Clinton,’ from Rochester eastward to Verona only...............:.- 358 5—Historical chart of ‘‘Clinton” classifieation............. 364 1—Crystalline limestone showing alteration to amphibolite. 378 2—Quartz-mica schist with sillimanite.................... 379 3—Photomicrograph of quartz-mica schist with sillimanite. 381 4—-Photomicrograph of quartz-mica schist with garnet..... 381 5—Photomicrograph of quartz-mica showing rounded zircons 381 6—Photomicrograph of granite, showing angular zircons, for Comparison: Shi. See ee Fs oe es re 381 7—Quartz-mica schist showing invasion by granite......... 382 S8—Quartz-mica schist showing invasion by granite......... 383 9—Photomicrograph of sheared granite, for comparison with qQuartz-mMica SCHISt Woo Secs cis sos cise chokes) 2 oe en 387 10—Photomicrograph of graphite-bearing quartzite......... 387 11—Photomicrograph of basic eneiss. 0.055. .2% 50 «nee 387 12—Photomicrograph of basic gneiss showing rounded zircons 387 13—Basie gneiss showing alternation of dark and light bands 390 14—Granite showing streaks of dark minerals.............. 392 1—Section of limestone quarry at Neenah, Wisconsin...... 395 1—Geologic map of central portion of Lake Placid quad- 2—Relations of Keene gneiss to other rocks on the southern - brow of Cobble Hill, in the Schroon Lake quadrangle. 444 3—Highly generalized northeast-southwest structure section through the Adirondack anorthosite body............ 454 1—Loeation of litchfieldite in Litchfield, Maine............ 464 2—Schists cut by litchfieldite at locality A, figure 1........ 466 1——Salt efflorescence ft Uinta)..550. cule). sees ata ees ae eee 472 2—Salt efloreSCenGe@s oss. os ds sce elk so on cin a ole stele se 2 oe 473 3-——Pseudomorphs of ‘salt erystals.....<0 5.0. 2s 0. see ee ee ATT 4—Desiccated saline clay from Salt River, Northwest Terri- KO) SE RL Ae A RN A ek 478 5—Mud-crack in a fresh-water mixture of slaked lime..... 480 6—Mud-crack in a salt-water mixture of slaked lime....... 482 Figures 1,8—Desert salt crusts). 75 200% 2.\. os sels wie = ie ee ee 483 ILLUSTRATIONS X1l1 Page KINDLE : Figure 9—Mounds of clay in salt plain west of Fort Smith, Alberta 484 . 10—Mud-crack with corrugated surface, Salt River, North- I TOM eer Menai? Mode neha sca hs g Maia isiye ohake Gb. aoWéeke 46 2 485 * 11—Desiccated saline clay with dried algw, Salt River, North- he Oe PEST eT FCO DEA «oe a 486 “ 12—Mud-crack in Pamelia limestone, Kingston, Ontario..... 487 DAVIS: Hicure 1-—Sketeh of Tahaa, Society Islands... i... 0.35 cc. wee eae. 496 | . 2 Ae ay, in. Pag oSOClety.. 1 SIAMGS... scx s0.cki cus Cerecctu au ecche'< 496 38—Original shoreline of Raiatea, Society Islands.......... A9T a 4—Submarine slope of a voleanic island.................. 499 ‘ 5—Contrasted consequences of Murray’s and Darwin’s theo- PRC free te cok sire ele ata atc aie Means as aaa HR chal S Bak ela sak TIE, o Bb 507 we so—-hivolition o£: Vania Mibalayu, Wijie.. 6c. 65.06 oem eee 508 74 7—Inferred structure of reefs formed during canner gence and emergence...... ERC AUR PE St RRL A ee eee Co a a 510 5 8—Unconformable contact of a sealevel fringing reef on the SpULGs Of asdissected. VolGani¢ ISlamd «6.2 sc. eo yw 513 S 9—Submerged barrier reef and a fringing reef of a new FCG RADEON, epost, eta A binhe os atebch catiad t pakeie io cauecolewe Sie fea Glad el a 514 “ _10—Malampaya Sound, Palawan, Philippine Islands........ 516 ‘“ 11—Fauro Island and its surrounding bank, Solomon Islands 525 “ 12—Murea Island, of the Society group, and Rarotonga, of AINE AOC OO oe CONN tac aaiene nc wm tet ew Sua arece etale 4 b/s a ieba ve care 539 “ 18—Diagram of the reefless coast of Madras............... 539 ‘* 14—Evolution of the reefless coast of Madras.............. 540 “ 15—The clift northeastern coast of New Caledonia......... 546 “ 16—Evolution of the coasts and reefs of New Caledonia.... 547 “. 1%(—Effects of intermittent subsidence..................6-. 563 TARR: Figure 1—Nodular structure of oolitic shale after weathering..... 588 oe 2—Distribution of the oolites in red phase of-the shale.... 590 BERRY: ene Mao Olu OME IMCELGA. 6 od 6. Gacauedelea-s © Se ace eck cele ayes gies 638 (22 plates; 67 figures) X1V BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA PUBLICATIONS OF THE GEOLOGICAL SOCIETY OF AMERICA REGULAR PUBLICATIONS The Society issues annually, in four quarterly parts, a single serial octavo publication entitled BULLETIN OF THE GEOLOGICAL SociETY OF AMERICA, the edi- tion being 700 copies. A smali supply of authors’ separates of the longer arti- cles is kept for sale by the Secretary at the prices quoted in each volume. The BULLETIN is sold at the uniform price of ten dollars ($10.00) per vol- ume, with a discount of twenty-five (25) per cent to Fellows of the Society, persons residing elsewhere than in North America, and public and institu- tional libraries; carriage extra. Subscriptions are payable in advance. Reg- ular subscribers within the United States of America and its possessions re- ceive their parts, postage paid, as issued. 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S. ibAesLER, Secretary. fo. ... 26. ek 119-160 Minutes of the Eighth Annual Meet- ing of the Pacific Coast Section of the Paleontological Society. CnHxs- MMBVSPOCK, SCCrelary... 0.66 css ee es 160-166 Experiment in geology. Frank D. RRMR PME Asc cies dase cll a x ker Hse ws 167-186 Post-Glacial uplift of Northeastern America. H. L. FArRcHILp...... 187-234 9-17 Explanation of the abandoned beach- es about the south end of Lake iichigan. G. F. WRIGHT........ 235-244 Age of the American Morrison and East African Tendaguru forma- tions. CHARLES SCHUCHERTT..... 245-280 Meganos group, a newly recognized division in the Eocene of Califor- paris a. ORARK Too. ec. ke as wes 281-296 Marine Oligocene of the west coast of North America. B. L. CiarK and RALPH ARNOLDT............. 297-808 Amsden formation of the east slope — of the Wind River Mountains of Wyoming and its fauna. E. B. Branson and D. K. Greaer...... 309-326 18-19 Stratigraphy of the New York Clin- pom Gall, CHADWICK... 00+. .6% 327-368 Scope and significance of Paleo-ecol- Omy.) F2W: CLEMENTS... 00:02. c0 369-374 Precambrian sedimentary rocks in the highlands of eastern Pennsyl- emai. 0), Ce WoRERRY « . esrs oae) os 375-392 FIGURES. 15 51 1 FIGURES. 1-14 * Preliminary pages and index are distributed with number 4. 7 Under the brochure heading is printed ProcyrDINGS OF THE PALEONTOLOGICAL SOCIETY. PRICE to FELLOWS. $2.10 2.20 2.35 9d PRICE TO FELLOWS. $1.45 .40 10 20 ars) 0) 30 XV PRICE '10 Pusiic. $3.05 3.30 3.00 1.45 PRICE v0 PuBLic. $2.15 - r= .60 bo ON 30 Xv1 BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA att Pp ; REPRIN'S. PAGES. Puatres. FIGuRES. ieee Fluorspar in the Ordovician lime- stone of Wisconsin. R. M. Baca. 3938-398 20 J $0.10 Adirondack anorthosite. Wide IMIDE RS ire) ss i A Ps 399-462 Bes 1- 3 .65 Field relations of litchfieldite and soda-syenites of Litchfield, Maine. Bone: OR) C0, os aan ema eke. 2k gee 463-470 Leas 1- 2 .10 Separation of salt from saline water andamud. .. W.-KONDIE.. 2. 471-488 Le ote 1-12 .20 Subsidence of reef-encircled islands. WV OMS DAVIS... oe So seers 489-574 Pict 1-17 .85 Ages of peneplains of the Appala- chian province. E. W. SHaw.... 575-586 ey srisge 10 Oolites in. shale and their origin. VS eA A ARR ge ene 5087-600 222 1- 2 «20 . Mesozoic history of Mexico, Central America, and the West Indies. We OW po RAN TONG iehers ¢ aise flere eee 601-606 crate apie . 10 Relations between the Mesozoic floras of North and South Amer- tea.) ESE AK NOWUTONT. ee ... 607-614 Pata may 10 Geologic history of Central America and the West Indies during Ceno- zoic time. T. W. VauGHant.... 615-630 ik Be whee 15 Paleogeographic significance of the Cenozoic floras of equatorial Amer- ica and the adjacent regions. 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XVIll BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA CORRECTIONS AND INSERTIONS All contributors to volume 29 have been invited to send corrections and in- sertions to be made in their papers, and the volume has been scanned with some care by the Editor. are deemed worthy of attention: Page 239, line sé 243, line 14 from bottom, for “stretches” read scratches 281, line 3 from bottom, for “50 degrees” read 15 degrees 288, line 7 from top, for ‘50 degrees” read 15 degrees 294, line 15 from bottom, for “Calabasis” read Calabasar 295, line 16 from top, for “Calabasis” read Calabasar 327, line 5 from top, after “Presented” insert by title. The following are such corrections and insertions as 9 from bottom, insert comma after word ‘interior’ Notre.—This paper is a subdivision of the paper by the same author entitled “Further studies in the New York Siluric,”’ an abstract of which is on page 92. Page 329. A remeasurement recently made of the section at Rochester gives: Feet Inches Trondequoit:. imestone .. See as. oo oe en eee 18 4 Walltamson:. Shale, nc idc-s aemeeest ot ek Sue aaaieiele cece aiele 5 8 Sodus sshale 3... b/s Se See a a RON Pam re oo 13 4 Reynales lamestOne’ o- Scere cee oe wut ae woes 6 ee 15 3 Furnaceville “irons Orew pe eee oe on aiess, Os eee wee ies ft: 0° Bear ‘Creek: (2), DES... 7 aeeae ee woes oe ee ae ars in eee 2 10 Maplewood ‘Shale. i. oor pene eerie a-cikiis 1015 hei Saya ate eee 18 0 ThHorold.:(?2) = Sandsron cepa wees saved «era lene av ovehae a ecae ne eee 3 2 Grimsby Tel SANGSEOUG Rei Ma scare i". wisi x whale wt tale aaltepet 53 0 The Medina base rests on eroded, thrust-faulted Queenston. Page 339, insert reference to Bulletin 69, New York State Museum: pp. 1167- 1169 (Hartnagel) for section on Wheelocks Creek, tributary to Moyer Creek. 342, line 1 from top, for ‘“Leptodesma rhomboidea’ read Leptodesma rhomboideum 348, line 6 from top, for “Palwoglossa” read Paleoglossa 344, line 2 from top, for “probably” read possibly 347, insert at bottom of page the following: The thin interleaved lime- stones in the supposed Wolcott shale above the oolitic ore at Clinton carry: Paleocyclus rotuloides (abundant) Acanthoclema asperum? Leptena rhomboidalis Plectambonites elegantulus? Camarotechia neglecta? Atrypa reticularis Crinoids Dalmanites aff, limulurus (nov. ?) CORRECTIONS AND INSERTIONS X1X Page 348, line 2 from bottom, for “rhomboidea” read rhomboideum «350, insert at bottom of the page the following: Palwocyclus rotuloides, described from Ruddock’s quarry (3:48), which Vanuxem (8:86) puts above the upper ore bed, proves to come from above the lower ore. This change probably carries with it the other species described from Ruddock’s—Conostichus circulus, Aristophycus? sp., and Lingula teniola. Rafinesquina clintoni should be queried in this list. 352, line 26 from top, Cyrtia meta is probably correctly C. bialveata (Conrad ) 363, lines 4 and 11 from top, for “rhomboidea” read rhomboideum 363, line 20 from top, Lingula teniola may be lower Clinton (Wolcott) after all; see preceding. Palwocyclus rotuloides becomes lower Clinton also. 367, at top of page, insert Cyrtia bialveata (Delthyris bialweata Con- rad; Spirifera meta Hall) 368, line 15 from top, add: New York State Museum. “ 464, line 3 from bottom, for “Scale, 1: —’ read Scale, 1: 62500 ere ao ae ae ine : ° ¥ \ Cs i x a + a, foxy ag ney AN 4 cia BULLETIN | _, Geological Society of America VOLUME 29 NUMBER |! MARCH, 1918 JOSEPH STANLEY-BROWN, EDITOR te m ~e A coilan Ino © x \o ita f %& %\ ¥ AUG 131918» *) “he > . . A “UYona| Wyse Neg Wh Sl PUBLISHED BY THE SOCIETY MARCH, JUNE, SEPTEMBER, AND DECEMBER at CONTENTS \ . Proceedings of the Thirtieth Annual Meeting of the Geological Society of America, Held at Saint Louis, Missouri, Decem- ber 27, 28, and 29,1917. Edmund Otis Hovey, Secretary ‘Officers, Correspondents, and Fellows of the Geological Society Weitesiered = = ee eet te |S) eee Proceedings of the Ninth Annual Meeting of the Paleontological Society, Held at Pittsburgh, Pennsylvania, December 31, 1917, and January | and 2, 1918. R.S. Bassler, Sec- peraty ot =. ee i ke ae, We gee a ee | Minutes of the Eighth Annual Meeting of the Pacific Coast Sec- tion of the Paleontological Society. Chester Stock, Secre- BEY mcs eR Nee a een eats ae a oe he ee Experiment in Geology. Presidential Address by Frank Daw- Perens (Aes pa nl ate eh ee ee 2 ie ee Page 1-106 107-118 119-160 160-166 167-186 BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA Subscription, $10 per year; with discount of 25 per cent to institutions and libraries and to individuals residing elsewhere than in North America. gh aah c= to foreign countries in the postal union, forty (40) cents extra. Communications should be addressed to The Geological Society of America, care of 420 11th Street N. W., Washington, D. C., or 77th Street ang. Central Park, West, New York City. NOTICE.—In accordance with the rules established by Council, claims for non-receipt of the preceding part of the Bulletin must be sent to the Secretary of the Society within three months of the date of the receipt of this number in order to be filled gratis. Entered as second-class matter in the Post-Office at Washington, D. C., under the Act of Congress of July 16, 1894 Acceptance for mailing at special rate of postage provided for in Section 1103, Act of October 3, 1917, authorized on July 8, 1918 PRESS OF JUDD & DETWEILER, INC., WASHINGTON, D. C. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL 20 PP. 115, PLUS. a1 -8 MARCH 31, 1918 PROCEEDINGS OF THE THIRTIETH ANNUAL MEETING OF THE GEOLOGICAL SOCIETY OF AMERICA, HELD AT SAINT LOUIS, MISSOURI, DECEMBER 27, 28, AND 29, 1917. EpmMunp Oris Hovey, Secretary CONTENTS : Page Peer Esa y, WECEMDET 20... 156 5. saa dss wa tee © races 3 arabe ER ES Cee ae 4 Memo OL they COuUnGI. ii See I ae OG ees BOL TATA ae eta. & 4 DCELGRU EIS Re POLE itt cele Mer tlare sista vate steam aha ott Rede re et AM Blows s ocece 5 PRCA GEICO LS MECIIOIES > Nt acaten, Oe LUSae ig Lie, eeeia sine apt nay peta ta MR ok Bie SERRE aR nel W's ia PHI IERS UCT OIE etic sce Sh araape te ote col Sane tebe adla Midte chalaenore ABEND S's, ooane vc ‘ 9 Peehionn Of Avditine Committees sac vais. 2. Stee ee ON ee ee oe is 11 UU OT OE OLICONS asst oh etait sc ae uehaee cats. cl ale Me igi ls EMEA SS 6 ae 11 BE GPEOM OL WEMOW Bi ic 7 e-speiatii ieee nie) oor ae ie Ole Beets iala4 Balser 12 MOTT MARNE nich ot ates MEN ay aphe CR a NTN eny Miattycha soeca Ota terol halle GRE MLE OD fo inthe tene Selle oe g We Vv Memorial of Amos P. Brown (with bibliography); by R. A. F. Pen- ENR ran at ccs Sea See ava 2.3 SPAY Baia Ree ke ee eee ake LU eta's, «was 13 Y Memorial of D. D. Cairnes (with bibliography) ; by Charles Camsell.. 17 Y Memorial of William Bullock Clark (with bibliography) ; by John M. CLS Se ae FARE A Ue a AR? Ca UNAS 8 US Ae od a Se 2A ¥ Memorial of Charles W. Drysdale (with bibliography) ; by J. Austen ESTLIELR CSE Mg SR Oi SCE RN Gila) Cee Mes Se CE WONG SP acs ae ee 29 is Memorial of Arnold Hague (with bibliography) ; by Joseph P. Iddings. 35 *’ Memorial of Robert H. Loughridge (with bibliography) ; by Eugene NE STUN e Pais) 2 eave a= pica (a cya nrase tae ol a] s se pale hhateule alekblete bs Waictaie we 48 ’ Memorial of Albert Homer Purdue (with bibliography) ; by George H. PARSER AU ve tic Cray Sh aio wr. orlando Sh Sot ab es deh oh «1 ceca, See PRONE Oe Sneek at a se RRs “ohSY 5 5D * Memorial of Henry M. Seely (with bibliography); by George H. EPs Me NT Sih oF ox siren chaise arstee arr on oe om Seg ne hace hoo) at bo as ab AA DOR Cen ee cane MRNA A Meas alo WEE diel 65 iepert on, Committee on, Photosrapny Ponilinson : .....0..5,5..98. sa ee Late Pleistocene shoreline in Maine and New Hampshire [ab- stract|;- by Frank J... Watziwe.: oh nce ee Glacial lakes of Saginaw Basin in relation to uplift [abstract]; by Frank Leverett..¢ i¢ 0 fein its sid odin waned it nee Se Mechanics of laccolithic intrusion [abstract]; by Charles R. Keyes Faceted form of a collapsing geoid [abstract]; by Charles R. K@y@S. oon os Dn a ad cea eiatelaicietece = a 9 ue sea S1Gee deaibtpnh one's etree Characteristics of the upper part of the till of southern Illinois and elsewhere [abstract]; by Eugene Wesley Shaw........... Pleistocene deposits between Manilla, in Crawford County, and Coon Rapids, in Carroll County, Iowa [abstract and discus- sion] ;. by George FY. Kayo. ....::wieitsee th selene kie Bie eee Loess-depositing winds in the Louisiana region [abstract]; by FE. VY.) Hmersom. .5.5 oo bps ce es a ain, eee wil Sa enn ee Stream meanders [abstract]; by E. B. Branson................ Notes on the separation of salt from saline water and mud [ab- stract];by E.. M. Mandle. oo. os. eee oe ew Oe Additional note on Monks Mound [abstract and discussion]; by A. Ri Crookes: sii fetes: sls wl 2. ee ee Salient features of the geology of the Cascades of Oregon, with some correlations between the east coast of Asia and the west coast of America [abstract]; by Warren Du Pré Smith....... Clinton formations in the Anticosti section [abstract]; by E. O. EUR og ide: awn 3 I Ses wrap he wens SR ake eae a Presidential address: Experiment in geology: by Frank D. Adams Complimentary smoker. 4 iit Shs o8 kes sus Pe sierei 0S) Sista le dw Sa Session of Friday, December 282. csi... os -vc,s.2 oie 6 oes Wlale oh> octet Titles and abstracts of papers presented before the morning session and ‘GiscusSions thereows 25s. 5 S50 ois le Seco cree wtete cm ely eee Strand and undertow records of Upper Devonian time as indica- tions of the prevailing climate [abstract and CISCHSS HORS ; by John: M.:. Clarkes. 223 aeeeies ee ae (+ vay wolbta POM ee Report of the Auditing Committee... ... ..:.s005sn0h es me eee Telegram to: Doctor Walcott :and reply. ic... 0. cat aes ee ee Announcement of the fire at Mount Holyoke. .....5........scesanem Study of the sediments as an aid to the earth historian [ab- -stract and discussion]; by Eliot Blackwelder................ Opportunities for geological work in the far Arctic [abstract and discussion]; by W. Himer Ekblaw ».<:. «.). t«. ss steele penne ae ‘ Genesis of Missouri lead and zinc deposits [abstract and discus- sion}: by: W. A, Wartes Sige waco A ae la eae ae teens 71 83 84 CONTENTS 3 Page Relation between occurrence and quality of petroleum and broad areas of uplift and folding [abstract]; by Hugene Wesley Shaw 8&7 New points in Ordovician and Silurian paleogeography [ab- stract]; by T. E. Savage and Francis M. Van Tuyl............ 88 Dating of peneplains: an old erosion surface in Idaho, Montana, and Washington—is it Hocene? [abstract and discussion]; by Mitchlatiaes Heame Gantt e tate eens MMM ea eehe te anee) eRe ARE RC Ya ales 89 Tron formation on Belcher Islands, Hudson Bay, with special reference to its origin and its associated algal limestones [ab- SEE ACU rae ellos SVLOONEigts Sars sae ets cca, PERRIS, auch atnins tel wel a ew ee 90 Titles and abstracts of papers presented before the afternoon session ME TLC) ARV ee aca whch Re ial he as reer at Cg a Mata ol Hietoellose! clans eRe ee I RLS grace 90 * Subprovincial limitations of Precambrian nomenclature in the Saint Lawrence Basin [abstract and discussion]; by M. E. TIS OO eS dc as Fyre ie irr ae eater Mag ise So Ra ag 90 Further studies in the New York Siluric [abstract]; by George H. WMO NTC Cree ers See er Nr res, Meee eaten aie a sco Siete tp as sinte 92 Relations of the oil-bearing to the oil-producing formations in the Paleozoic of North America [abstract]; by Amadeus W. Grabau 92 Revision of the Mississippian formations of the upper Mississippi Valley [abstract]; by Stuart Weller and Francis M. Van Tuyl. 93 Notes on the stratigraphy and faunas of the Lower Kinderhookian HP MVISSOUrT [AUSLTACL |: Dyodo. Bs. BransSOMs . occ ces ot se ce eas 93 Meganos group, a newly recognized division in the Hocene of Cali- HOLM LAOStLrack |. Dy BEeuce Tm. Clarks: oP iicen st bes ece awe sek 94 Age of the Martinsburg shale as interpreted from its structural and stratigraphical relations in eastern Pennsylvania_ [ab- Soleetier diye Mae ales ERRING AG ee cok teal aro acrtmrein nee a a aioe Pine a eyo 4 94 Invertebrate fauna of the Grassy Creek shale of Missouri [ab- SEraetin Wye Delite nie COS Ms: cosnc\ cong © cr ehariie ayaietete, wel oy ete ec gle le = 95 Some definite correlations of West Virginia coal beds in Mingo County, West Virginia, with those of Letcher County, south- -veastern Kentucky [abstract]; by 1."C. White. o.oo... ee ee 96 Records of three very deep wells drilled in the Appalachian oil fields of Pennsylvania and West Virginia [abstract and discus- SIMs yn dew. WIE ie aces Ris PR ate ee Me SERS ian hotles 2 96 Tentative correlation of the Pennsylvania strata in the eastern interior, western interior, and Appalachian regions by their ma- rine saunas “abstract = by Rs WH. Savage sree ok. wk COANE 97 Precambrian rocks in the Medicine Bow Mountains of Wyoming [abstract]; by Eliot Blackwelder and H. F. Crooks........... S7 Geologic map of Brazil [abstract]; by John Casper Branner.... 98 Notes on the geology of the region of Parker Snow Bay, Green- land [abstract] by BMdmund Oris: Hovey. cro. ee. ee ee Se 98 PASHATTRT ANCOR UMEIMUC Re nctatvak sl stance alate Varies vi¥) hala vols in rale «18 6 bces bakes Yonwisnavela ste eee ewes 98 pecsion of Saturday, DECOMer 29) os soci c clase ales ole ielemlcejer uiviece cvanlee eee vies 98 Titles and abstracts of papers read before the Saturday morning ses- + PROCEEDINGS OF THE SAINT LOUIS MEETING Page Field relations of litchfieldite and soda-syenite of Litchfield, Maine fabstraet]; by Reginald-As Dalyee... ode eee 99 Adirondack anorthosite [abstract and discussion]; by William J. MA Mer sacs 5. ocak s SS REA Rp ee ek tei ok eee tas se 99 Petrology of rutile-bearing rocks [abstract]; by Thomas Leonard Watsons. 6. oo oeintes eal S eee Vee ee eee 100 Internal structures of igneous rocks [abstract and discussion]; by Frank FF: Grout: . (ock6)03 ook eG bie sie Ge ee 100 Two-phase convection in igneous magmas [abstract and discus- sion]: by Frank: FP. Grout.25<.. 2<6056': 3.40 ek oe 101 Hydrous silicate melts [abstract]; by N. L. Bowen and G. W. MOTO 5 oa sow aT ee wick epee tere oso ie sae Lats. ao a oreo sete ele ee 102 Significance of glass-making processes to the petrologist [ab- stract];: by -N. .L. BOWER. <6 2.0 (es < acsis era's sneer ako ee 102 Types of North American Paleozoic oolites. [abstract]; by Francis M. Van:Tuyl and Harold ¥.. Crooks. .2... 03222%...5 ..= eee 102 Siliceous oolites in shale [abstract]; by W. A. Tarr... .......... 105 Inorganic production of oolitic structures [abstract and discus- sion]: by. W. H. Bucherves sone io. cos orn tees Oe 1058 Glauconite in dolomite and limestone of Missouri [abstract]; by hae, Clad Wy 8 bl eC ey SRE RCAC 104 Discovery of fluorite in the Ordovician limestones of Wisconsin [abstract and discussion]; by Rufus Mather Bagg........... 104 Occurrence of a large tourmaline in Alabama pegmatite [ab- \ stract]; by Frank ReiVan, Horn... 2. 6.icssi aan <0 eee 104 Cause of the absence of water in dry sandstone beds [abstract]; by Roswell, >; lotmsonmes.? 02 6.5. ese soe nus (let 105 Vote, of: thanks... 2st he eiieet ne ol « © ais dh tbo fe Rl ene pen ee aa 106 Register of the ‘Saint. Louis meeting; 1917. .)....6.<:.. <0 .. ors ss Oe eee 106 Officers, Correspondents, and Fellows of the Geological Society of America. 107 SESSION OF THuRSDAY, DECEMBER 27 The first general session of the Society was called to order at 9.40 o'clock a. m., Thursday, December 27, at the Planters’ Hotel, Saint Louis, Missouri, by President Frank D. Adams. The report of the Council for the year ending November 30, 1917, was presented as follows: REPORT OF THE COUNCIL To the Geological Society of America, in thirtieth annual meeting assem- bled: The regular annual meeting of the Council was held at Albany, N. Y., in connection with the meeting of the Society, December 27-29, 1916. A special meeting was held at New York, N. Y., February 21, 1917. COUNCIL REPORT 5 The details of administration for the twenty-ninth year of the existence of the Society are given in the following reports of the officers: SECRETARY’S REPORT | To the Council of the Geological Society of Amerwea: Secretaryship.—During the absence of the Secretary the duties of the office were efficiently discharged by Cuarues P. Berkey, Secretary pro tempore. ‘The Secretary resumed office on September 1. Meetings.—The proceedings of the annual general meeting of the So- ciety, held at Albany, N. Y., December 27-29, 1916, have been recorded on pages 1-176, and of the Paleontological Society on pages 189-234, vol- ume 28, of the Bulletin. Membership.—During the past year the Society has lost eight Fellows by death—Robert Bell, Amos P. Brown, D. D. Cairnes, William Bullock Clark, Charles W. Drysdale, Arnold Hague, Robert H. Loughridge, and H. M. Seely.t. The names of the twenty-eight Fellows who have com- pleted their membership since their election at the Albany meeting have been added to the list. The present enrollment of the Society is: Corre- spondents, 10; Fellows, 395; total, 405. Eighteen candidates for Fellow- ship are before the Society for election and several applications are under consideration by the Council. Mstribution of Bulletin.—There have been received during the year 3 new subscriptions to the Bulletin. The number of volumes sent out to subscribers is now 128. Five volumes are distributed gratis to the Library of Congress, the American Museum of Natural History, and the govern- ment geological surveys of the United States, Canada, and Mexico. The irregular distribution of the Bulletin during the past year has been as follows: Complete volumes sold to the public, 61; sent out to supply delinquents, 6; brochures sold to Fellows, 10; sold to the public, 55; sent out to supply deficiencies, 17, and delinquents, 68. Index to volumes 1-10 sold to the public, 4; to volumes 11-20 sold to the public, 3. Bulletin sales—The receipts from subscriptions to and sales of the Bulletin during the past year are shown in the following table: 1 Since the closing of the fiscal year to which this report refers, one Fellow, Albert H. Purdue, has died. PROCEEDINGS OF THE Bulletin Sales, December SAINT LOUIS MEETING 1, 191€-Noreml er 80, 1917 Complete volumes. Brochures and parts. Grand total Fellows.| Public. Total. |Fellows.| Public. | Total. Moline eae. eet 2 $12.50 $12 305) os. eae $1.65 | $1.65 $14.15 WOME oo ao ick asc as 12.90 LS. BO S| esses es pees coe 12.50 Aas I ae Veils eae i ae ent 12.50 BP ies RS Pepe 2% Pi co EN A A 12.50 WOME. As. Slew ios eh 12.50 EHO ace ass 1.00 1.00 13.50 Moline (500 es. as = 12.50 1230" eee .80 .80 13.30 Wialtame eGo) ec 12.50 12 504s ec aa oe 12.50 MoOhaIne- Tics ee oe 12.50 $9 00: We 2 ce al escreioe eee 12.50 Wonmmeart8 Sore ae 1250 P2250! tse se ae Re eee 12.50 WolGimie eae) ew isn es 1? 50 12.290 hse.5 2% wll re eee 12:5) Votume LO so as 8 it 12.50 12 00 sh c4 oe 12.50 Volnme UU 529) oo aos 12.50 12 SOF eee 7d ta 13.25 Volumesl2ne heise tes 12-50 Dec ol ixve tate She 2a el ee 12.50 Volume 193 oan tees os 12.50 1250-0, 6 cert El eee ee 12.50 Wale lay wotsco os 12.50 de EY eee eae L250 1.50 14.00 Molmeta re clis. cso 6 12.50 | pk) ee Sas 1.80 1.80 14.30. Volome; Gee) 20. %.-. $2 27 .50 2G HO. sss quelled ete ae 27 .50 Wolinnnme ess las. 6 eis 12.50 12.50 |. $0.25 1.80 2.05 14.55 Wolume US 12.50 1250 210 1.80 3.90 16.40 Volume tom. fe os). 20.00 OA Ns onthe .40 .40 20.40 Volume 20 vet os yo: 27.50 EOE YI Sas y 3.90 3.90 21.40 Waoltume: 2m toe. 20.00 24 0 Os ea 3:10 3.10 23.10 Wile ee Mice cee. 20.00 cE 0s eee 9.15 9.15 29.15 Volume 23. yobs ss bsien 15.00 BROOM Gi coo ae 7e20 7.20 22 20 Volmeoa: oii. 162) 15.00 1 te re 4.95 4.95 19.95 Wolumeco 3.30. be: 15.00 Rea vl. see 2.45 2.45 17.45 Volume Zou. olopccsc. 700 7.50 La 4.20 5.90 13.40 Viglen Soca oe 22.50 Ay cys, (ig fem Pe er 16.95 16.95 39.45 Volume ess os. 8.6 825 .00 825.00 . 90 1.95 2.85 827.85 Volume 290.2.) soc oe 127.50 127 .50: 4) -eactd. sleet sl ee 127.50 4 Ee, id Be a $1,355.00 |$1,355.00 | $4.95 | $65.35 | $70.30 |$1, 425.30 Index od =e oe eyes 9 00 BOD. s..:e cbt sie Sere ek oe 9.00 index tl-90s i 10.50 10.5055 25.04 Oe ee 10.50 Mata . Bey ice cho: $1,374.50 |$1,374.50 | $4.95 | $65.35 | $70.30 |$1,444.80 Receipts for the fiscal year...... see's deus teeet aes one aaa $1,444.80 Previously reported........... ‘Gidheue areata erie sean ean 20,610.19 Total receipts to date....... Be ig Va: aren ese erties 5) ea $22,054.99 Charged on 1917 account, but not yet received........ 101.85 otal sales to date.) .«.ve0 ocak eee ete eee $22,156.84 Expenses.—The following table gives the cost of administration and of Bulletin distribution during the past year: | ond ( COUNCIL REPORT EXPENDITURE OF SECRETARY’S OFFICE DURING THE FISCAL YEAR ENDING NOVEMBER POSEN CO oc ks os x cece es fee CAT CsA ss sce ee cam STE. G 00a ee or Messenger service..... PUMMCNGE ewe es PRETEDNONC | oo veces ee sae PE IMOE fa. aictgh wk beet ae Typewriter supplies... PRRIGP EATS Sh. eas Clerical help (Albany) Miscellaneous ........ Exchange on checks... EOWA ve rays suc utes Wnvelopes .........-... GSAS 6 oS. ee ee PSIGOE ESS sis". aise sfers ee Exchange on checks... DOREY (TCC. sos. ccs ROME ATO. Se cee gisele et Addressograph plates.. Addressing envelopes.. Rubber stamps........ MeleeTams- 5.0.06. .5 be. Storage of paper...... J 1 RS aac ee Grand total 30, 1917 Account of Administration ereersvereees eee eee e eevee eee ese eee Bee ee oo erceevcecveeeeoe eer eee ee te eee eee ee ee eee @ ee ee ee esceereeevre ee eee ees eer ees eer eee eee ee ee eoecereweeest eee ree cee ees ees se ees eee eee oe eer eeeo eer eee ees vee ees ees reese ee see ee @ see seeveeeeeeeoeeo rs eer eeereee eee eee ee 6 & Pe ee ee ee ee ervecseevree ees seo ee ee ees ees ewe ese ee eee eee esceete oe tre eee eet eee we wes e wees ees e eee ee ee eeceesevrevoreersre es eee eee eee ereer eee e ees eee @ eeoeceoeec oor eee ore es eee ees eese ees eee oe oO @ eecereecererese eee ee ews ees ewe ee + eee eee eee ees eer eee $408.36 Meee ccite acoiael anda s/t 5: eheteruiaenelnere Pye curs Picante uahekay thease ee Focivore ste arated Sialehia sale Erna Hepat RCT ilo: & Wildl ibt a ler wamaylatin ers Sea euetta Pe Petrie age ee atone chat mel 9)», acardiadalntanete Gm eisai oy eran Ss nis anna Re Renee ar gee SSS MASP oer ots area ereialein’ wre sh sn epee sis Siarorale .20 SRS Bit AU ME Re RARE ner ester Saab Mahs scab gates a usatlans vatie'sc “Ga lenaetn Ut atanoens ben RaSh AMEN ahr tla tab Sa fo okra ermaueUnuees tans Sire nest ues ule Meee ustone rea ioe 6. S oi alareb ann auaCt s taue eseeeecerereer eee eee eee ew ee eo se wee eee were eereeevree ee ees eee ees ees ees eee e ees eee eevee eee eee ceececeeee esc eee eer ewe ee wee eee weer ees eevee ee eevee Respectfully submitted, EpmunpD Otis Hovey, Secretary. TREASURER’S REPORT To the Council of the Geological Society of America: The Treasurer herewith submits his annual report for the year ending November 30, 1917. The membership of the Society at the present time is 395, of whom 303 pay annual dues. Twenty-nine new members were elected at the last 8 PROCEEDINGS OF THE SAINT LOUIS MEETING annual meeting the Council to defer his entering until later. during the year, one a Life Member. , 28 of whom qualified, one having secured the consent of There have been 8 deaths There was one Life Commutation, making the present list of life members number 92. Twenty-three mem- bers are delinquent in the payment of dues—2 for 6 years, 1 for 4 years, 4 for 3 years, 3 for 2 years—and are therefore liable to be dropped from the roll, and 13 for 1 year. RECEIPTS Balance in the treasury, December 1, 1916.............. Fellowsltip tees, 1914-(1) oscc3e6 42 seen s $10.00 1915 (3) sate ee eee 30.00 1996: ( 7) 240 5Gcs, ee eee ee 70.00 1907 C285) 4 eee eee ee 2,850.00 Initiation fees (28 io. o:c 31k Peco ee eter ca Snes hcl c oe bite commutation (G1) 2.4 3. “See eee. we ke enn Interest from investments (see list of securities)....... Interest on deposit in Baltimore Trust Company........ Collection charges added to checks.......... ashi Sure Phe a Received from Secretary : males oF, punlications, oie ce ve ae aes ohnis $1,444.80 AUtHOr'S “COrFectiOns. . 9-6 2 eee oes 6S 4.50 OSE oie o ale lo te aS og ee aco Oates c tace © a 8.44 EXPENDITURES Secretary’s office: AATIISETA TION. | oi7S sien Seca ate ais porns $408 .36 PSE Hise toa. Sam a De ee ea rate 128.48 PSE TR eee Ren aeios ait a: 4. rel se Ca eae 1,000.00 Treasurer’s office: Postage, bond, safe-deposit box.......... $40.00 Clenigver 2.645 co... oc ea ee eee 100.00 Publication of Bulletin: PERE oe bo a's bo ca viata ee ee ee $1,700.07 WBA VI iso 5 2) o. 5 occ dwa he eee 529.46 Hditers sahowanee. 2. bs v..he eee 250.00 Contribution to expenses of chairman of Geology and Paleontology Committee of National Research Council. Balance in Baltimore Trust Company, December 1, 1917.. 1,457.74 $6,261.15 $1,536.84 140.00 2,479.53 150.00 1,954.78 $6,261.15 COUNCIL REPORT ‘LIST OF SECURITIES Bonds Par $2,000. Texas and Pacific Railway Company 1st Mortgage 5's. Due June 1, 2000 (Nos. 11915 and 20892). 1,000. St. Louis and San Francisco Railroad Company Equipment 5’s. Due February 1, 1919 (No. 1171). 2,000. Fairmont and Clarksburg Traction Company 1st Mortgage 95’s. Due October 1, 1988 (Nos. 29 and 30). 3,000. Chicago Railways Company 1st Mortgage 5’s. Due February 1, 1927 (Nos. 20750, 20751, and 45871). 2,000. Southern Bell Telephone and Telegraph Company 1st Mortgage 5s. Due January 1, 1941 (Nos. M13217 and M13218). 3,000. United States Steel Corporation 2d Mortgage 5’s. Due April 1, 1963 (Nos. 2964, 2974, and 2975). 2,000. Consolidation Coal Company 1st and Refunding Mortgage 40-year Sinking Fund 5’s. Due December 1, 1950 (Nos. 11850 and 11851). 2,000. American Agricultural Chemical Company 1st Mortgage 5’s. Due October 1, 1928 (Nos. 58384 and 6356). Stocks 10 shares of the capital stock of the Iowa Apartment House Company. 40 shares of the capital stock of the Ontario Apartment House Company. Respectfully submitted, Epwarp B. MatTHEws, Acting Treasurer. E:pITOR’S REPORT To the Council of the Geological Society of America: The Editor submits herewith his annual report. The following tables cover statistical data for the twenty-eight volumes thus far issued : ANALYSIS OF COSTS OF PUBLICATION Cost. WMETLETAD GES Siccaicecticesacscssacswancosectntesssisaccestscesceasivcwstcses MANUSEALLO TIS. sa c.cce een nnee secsesecasceewnvanssnvecnss \oneesencnscnen Paper é COO rr ee a i eee ee erry ARO e POCO OOOO E HH Hee Hee arena tee seeess sees sea seeeesseeeeetes POCO rere e toe mere ee ee Oe OEs Oe asee © SH UeHOe Beeeeenss Average— Vols. 1-25.| V0l- 26. pp. 759. pp. 525. pls. 42. pls. 27. $1,807.41 $1,076.22 327.04 171.69 dsocieseatess 231.00 $2,134.45 $1,478.91 $2.83 $2.81 Wolds « pp. 757. pis. 30. $1,684.67 378.30 416.00 $2,478.97 $3.27 $3,310.52 $3.23 LO PROCEEDINGS OF THE SAINT LOUIS MEETING CLASSIFICATION OF SUBJECT-MATTER eer Mees, — Ss S = eae | | Seo) 2 ee oe ee eee + 2. | a0 | Bp Sel essere. Sree a os 7 ted oe a Se, ro) SOO! cs | cs WW] OW) Oy, ete ee 2 bo | | ee. | bp Ol Oa are Wieres = |B m1 Se) Seo les | ete ola oil os | mH | @ Volume.| 3 | ‘a ae 9 / Boia S| oe = -— | gs Total. P12 | aie ie ee fe oe) pace eA Ope Ce SPAR plete et oa S) S = Number of pages. paises 116.1187.) 92 (98 88 eae Ag ee 60 | 4| 4 |5934-xii Bt 2 gE og 56 | 110 |. 60] 111 | 52 |.168)|. 47 |. 9|| 55} 1.9% (e62eeae Bian 56 |) 4a 44 | 2a nal eee 61/15 | 1 |541+-xii ite NOs 95 | 084] 38 | 9a ae ee ate eee 47 | 32| 2 | 458+-xii RON aks 188 (185 | 970 | 54 Pee Bt IGT s ee 71 | 14] 9 | 665-+-xii 682 BO 1 Fe: | 89. Ge 00 ies 63 | 25 | 4 |538+x Fis as 38 | 77 |105| 53] 40] 21] 123| 4/{| 66 | 28 | 13 |558+x Bie hee 341 50] 98| 5 | 43) 67 | 58] 1411 70 18) Ores eo tie hed 38h a 44} 28 | 64| 16 || 64112’ Saag ae | 35| 33] 96| 37] 59] 62] 68) 28] 84 | 297 | 17 |5344-xiii i nee | 65 |.110 | 21 | 10 | 54). 81 1.188.) — 7 || 71.) 60.) 46s) Gate Cea 1199 | 39] 55| 53.) 241 981 51°55 || 70) @ ote Boo 1125 | 17|/ 13] 24{| 28] 116| 42] 4/! 165 | 32 | 99 | 583-4-mii tee 48) 67") 48 |) SO esa iB a2 1 |; 80/14] 1 |6094+xi ea OS 1-2 aes a ie” om sy Alpine aga 77/17] 3 |636+x iMacs Po Tat.) : 78 |: SO: edad PON ae, 67 | 22 | 15 | 636+-xiii i Poe eee) AGT |) AT eaeieny aaa tes eta ar: 71| 9| 2 |7854+-xiv i See | 16] 164) 141] 5 | 29] 246) 5 1]....1) 68 | 40 | 3 gee £9). ane 106 | 108 | 29.| 66] 30) 155} 321.2... ||. 56 | 15 | -2O0aigeeee rs URS 43 | 54] 35 | 29] 371 45 | 303| 8 || 60| 3 1182 | 749+x1y Be ees 72 | 234| 751 481 851° 70|106| 1 || 111 | 11 | 10 (Boa DBs Ne OR ba. | 7 28 1 OR em eel AO tS yale es 63 | 49 | 1 |747-+-xii es 75)b2 | 126°) WOR eS 4) BA ee 66 | 32] 1 | 7584+xvi 7 ee. 18 | 57] 96! 57] 49/160] 106} 23 || 1838 | 531 3 | 787+xviii Dries stor: S41. 210 | 54]: Soe apa OT teab ne 108 | 9 | 22 | 8024-xviii — Tee se pens 72. | 23-| Sas ieae ON i 14R alae | 54) 44] 6 | 5044+xxi Drees 1] 59] 125 | 31 | 146 /\.20| 271 |. 2]| 73 | 24) 5.) 980 B57 ty: 25 | 273 | 70} 69} 78 | 200] 55 | 39 || S4 {110 | 14 1005+-xxii Respectfully submitted, JOSEPH STANLEY-Brown, Hditor. December 20, 1917. The foregoing report is respectfully submitted, 3 THE COUNCIL. December 26, 1917. On motion, the report was laid on the table as usual for consideration the following day. ELECTIONS ty ELECTION OF AUDITING COMMITTEE The Auditing Committee, consisting of Eliot Blackwelder, George F. Kay, and Harry Fielding Reid, was then elected, and the Treasurer’s report was referred to it for examination. ELECTION OF OFFICERS The Secretary declared the election of officers for 1918 as follows, the bailots having been canvassed and counted by the Council in accordance with the By-Laws: President : WHITMAN Cross, Washington, D. C. First Vice-President: Barney Wixiis, Stanford University, California. Second Vice-President: FRANK Leverett, Ann Harbor, Michigan Third Vice-President: F. H. Knowrron, Washington, D. C. Secretary: EpMuND Otis Hovey, New York City. Treasurer: K. B. Matuews, Baltimore, Maryland. Editor: JOSEPH STANLEY-Brown, New York City. Inbrarvan: Frank R. Van Horn, Cleveland, Ohio. Councilors (1918-1920) : JOSEPH BarRELL, New Haven, Connecticut. R. A. Daty, Cambridge, Massachusetts. 12 PROCEEDINGS OF THE SAINT LOUIS MEETING ELECTION OF FELLOWS The Secretary announced the election in due form of the following Fellows, the ballots having been canvassed and counted by the Council: PauL BartscuH, B.S., M.S8., Ph. D., Curator, Division of Marine Invertebrates, United States National Museum. NorRMAN LEv1I Bowen, M.A., Ph. D., Petrologist, Geophysical Laboratory, Car- negie Institution of Washington, Washington, D. C. J. HARLAN Bretz, A. B., Ph. D., Assistant Professor of Cole, University of Chicago, Chicago, Illinois. LANCASTER DEMOREST BURLING, B.S., G. E., Invertebrate Paleontologist, Geo- logical Survey of Canada, Tier oe Canada. Luiz FILIpPE GONZAGA DE CAmpos, Director of the Geological Survey of Br azil, Rio de Janeiro, Brazil. J. ERNEST CARMAN, B.S., Ph. D., Professor of Geology, Ohio State University, Columbus, Ohio. SIDNEY LONGMAN GALPIN, A. B., A. M., Ph. D., Assistant Professor of Geology and Mining, Iowa State College, Ames, Iowa. FRANK Cook GREENE, A. B., M. A., Geologist, 30 North Yorktown street, Tulsa, Oklahoma. FERDINAND Friis Hintze, A. B., M. A., Ph. D., Assistant Professor of Geology, Lehigh University, South Bethlehem, Pennsylvania. GrEoRGE H. Hupson, Teacher of Biology, Physiography, and Nature Study Methods, Plattsburg Normal School. Supervisor of grade work and Na- ture Study. Plattsburg, New York. F'REDERIC H. LAHEE, A. B., A. M., Ph. D., Assistant Professor of Geology, Massa- chusetts Institute of Technology, Cambridge, Massachusetts. WILLIAM NEWTON Locan, A. B., A. M., Ph. D., Associate Professor of Economie Geology, Indiana University, Bloomington, Indiana. Rospert Witcox SAY Les, A. B., Curator of Geological Museum, Harvard Uni- versity, Cambridge, Massachusetts. JAMES HovucH Sroiter, A. B., A. M., Ph. D., Professor of Geology and Biology, Union College, Schenectady, New York. WILLIAM ARTHUR Tarr, B.S., Ph. D., Associate Professor of Geology, Univer- sity of Missouri, Columbia, Missouri. CHARLES WELDON TOMLINSON, B.A., M, A., Ph. D., Associate in Geology, Uni- versity of Illinois, Urbana, Illinois. FRANCIS MAURICE VAN Tuyt, A. B., M.S., Ph. D., Assistant Professor of Geol- ogy, Colorado School of Mines: Golden, Goinraaa: NECROLOGY Announcement was made by the Secretary that the Society had lost nine Fellows by death during the year 1917, namely, Robert Bell, Amos P. Brown, D. D. Cairnes, William Bullock Clark, Charles W. Drysdale, Arnold Hague, Robert H. Loughridge, A. H. Purdue, and H. M. Seely. Memorials of deceased Fellows were presented as follows: . BULL. GEOL. SOC. AM. VOL. 29, 1917, PL. 1 NECROLOGY is MEMORIAL OF AMOS P. BROWN * BY R. A. F. PENROSE, JR. Dr. Amos Peaslee Brown,’ Professor of Geology and Mineralogy in the University of Pennsylvania, died on October 9, 1917, in his fifi j-third year. He had not been in robust health for many years, and in spite of every effort of his physicians and his family his death was the sad culmi- nation of his depleted condition. Doctor Brown was descended from Henry Brown, who came to America from England in 1639 and settled in Massachusetts, where he was among the founders of the town of Salisbury. In the early part of the nineteenth century part of the descendants of Henry Brown went to Philadelphia and part to Maryland. Dr. Thomas Stewardson, of Philadelphia, a noted physician and botanist in the early part of the last century, was the brother of Doctor Brown’s maternal grandmother. Doctor Brown was the son of Amos P. Brown and Frances Brown and was born in Philadelphia on December 3, 1864. He was one of a family of seven brothers and two sisters, the rest of whom survive him. He received his early education at the Germantown Academy, under Dr. Wilham Kershaw, and entered the University of Pennsylvania in 1882, where he received the degree of B. S. in 1886 and of M. EH. in 1887. In 1893 he received from the University of .Pennsvlvania the degree of Ph. D. Doctor Brown joined the Geological Survey of Pennsylvania, under Prof. J. P. Lesley, in 1887, and remained on it until 1889, during which period he did important scientific work. At first he was associated with Mr. Charles A. Ashburner in the western part of the State, but during most of his time on the Survey he was associated with Mr. Benjamin Smith Lyman. The results of Doctor Brown’s work with Mr. Lyman are embodied in the publication of the latter, entitled “Report on the New Red of Bucks and Montgomery Counties,” published in the Geo- logical Survey of Pennsylvania, Final Report, Volume III, Part II, 1895. Doctor Brown’s part of this work consisted especially of a study of the igneous rocks of the district. In 1889 Doctor Brown was appointed Instructor of Mining and Metal- lurgy at the University of Pennsylvania, and in 1892 Professor of Gbol- ogy and Mineralogy in the Auxiliary Department of Medicine at ‘the 1 Presented before the Society December 27, 1917. ; Manuscript received by the Secretary of the Society January 8, 1918. 2'The thanks of the writer for much information about Doctor Brown are due to his brother, Mr. Herbert Brown, and to Dr. Witmer Stone, Dr. E. T. Wherry, Dr. F. Ehren- feld, Mr. Benjamin Smith Lyman, and others. II—Buuu. Grou. Soc. AM., VoL. 29, 1917 14 PROCEEDINGS OF THE SAINT LOUIS MEETING University. In 1895 he was appointed Assistant Professor of Geology and Mineralogy in the College of the University, and in 1903 full Pro- fessor of the same subjects—a position which he occupied until a few months before his death, when his failing health led him to resign. After Doctor Brown left the Geological Survey of Pennsylvania he carried on scientific researches covering a wide field, including geology, mineralogy, paleontology, botany, and the subject of crystallography in relation to biology. Though his early education was that of a mining engineer and his first teaching position at the university was in mining and metallurgy, yet most of his research work was in pure science. In 1893 he went to the western part of the country with Prof. E. D. Cope to make paleontological studies in the Dakotas, Kansas, Texas, and Okla- homa, and somewhat later he made other trips West on similar work. In 1902 he visited Labrador, and in later years made trips to Panama, Jamaica, Antigua, and other places in the West Indies, where he made important geological and paleontological researches. The best known of Doctor Brown’s original work was “The Crystal- lography of Hemoglobins,” published in connection with Prof. E. T. Reichert, of the University of Pennsylvania, by the Carnegie Institution of Washington in 1909. This remarkable work attracted wide attention at the time, both in America and abroad. From the standpoint of erys- tallography as well as of biology, it was an extremely valuable research and its thoroughness marked a distinct step in advance of anything that had previously been done on allied subjects. At the time the United States Government was beginning the con- struction of the Panama Canal, Doctor Brown was one of the first to recognize the importance of a study of the geologic structure of the re- gion. He visited Panama in 1910 and published several papers on the geology and paleontology of the country about the Gatun Dam. He also visited Jamaica, Antigua, and other places in the Caribbean Sea, where he made important studies of their geology and paleontology. Some of this work was done in connection with Prof. Henry A. Pilsbry, of the Academy of Natural Sciences of Philadelphia. — Doctor Brown had been a member of the Geological Society of America since 1905, and though his ill health prevented his attending many of the annual meetings, yet he always took much interest in its work. The last meeting he attended was that in Philadelphia in 1914, when he took a keen interest in trying to make it a success. For many years he was an active member of the American Philosophical Society and of the Academy of Natural Sciences of Philadelphia. He was one of the secre- taries of the American Philosophical Society from 1908 to the time of MEMORIAL OF A. P. BROWN 15 his death and was always earnest and faithful in the discharge of the duties of this office. ‘ Doctor Brown’s publications display a truly scientific spirit, and all who knew him realized that he had much more original material which he was reluctant to publish until his studies concerning it were more complete. Il] health often held him back in his work and the results he accomplished were attained in spite of physical ailments. The bibliog- _raphy accompanying this memoir is probably nearly, if not entirely, complete; but Doctor Brown wrote for journals devoted to different branches of science, and the collection of the titles of his papers has been a matter of considerable difficulty. Moreover, Doctor Brown was a very modest and retiring man; he never tried to advertise his scientific efforts ; he worked for the love of science and not for its notoriety, so that he left behind him peculiarly little classified information about himself. Doctor Brown was held in the highest regard and esteem by all who knew him, for beneath his quiet and unassuming manner they recognized ‘a man of remarkable learning, while his scientific grasp of the subjects in which he worked commanded the respect of all associated with him in similar investigations. BIBLIOGRAPHY Modes of occurrence of pyrite in bituminous coal. Amos P. Brown. Transac- tions of the American Institute of Mining Engineers, volume XVI, 1888, pages 539-546. Jade and similar green stones. Amos P. Brown. Bulletin of the Museum of Science and Art, University of Pennsylvania, volume I, 1898, pages 140- 145. : On the young of Baculites compressus Say. Amos P. Brown. Proceedings of the Academy of Natural Sciences of Philadelphia, 1891, pages 159-160. On the young of Baculites compressus Say. Amos P. Brown. The Nautilus, volume V, 1891-1892, pages 19-21. On the young of Baculites compressus Say. Amos P. Brown. The Geological Magazine (London), new series, decade III, volume VIII, 1891, pages 316- 317. The development of the shell in the coiled stage of Baculites compressus Say. Amos P. Brown. Proceedings of the Academy of Natural Sciences of Philadelphia, 1892, pages 136-141. Comparative study of the chemical behavior of pyrite and marcasite. Amos P. Brown. Proceedings of the American Philosophical Society, volume XXXITI, 1894, pages 225-243. Report on the New Red of Bucks and Montgomery counties. Benjamin Smith Lyman. Geological Survey of Pennsylvania, Final Report, volume ITI, part 2, 1895, pages 2589-2638. “Lithology,” by Amos P. Brown, pages 26238-2626. 16 PROCEEDINGS OF THE SAINT LOUIS MEETING The crystallization of molybdenite. Amos P. Brown. Proceedings of the Academy of Natural Sciences of Philadelphia, 1896, page 210. Red color of certain formations. Amos P. Brown. The American Geologist, volume XVII, 1896, page 262. Section of Chalcedony. Amos P. Brown. American Monthly Microscopical Journal, volume XVIII, 1897, pages 235-236. Bog moss leaves. American Monthly Microscopical Journal, volume XVIII, 1897, page 232. Mineralogy simplified. Henry Erni. Third edition. Edited by Amos P. Brown. Henry Carey Baird & Co., Philadelphia; Low, Marston & Co., London; 1901, pages xxvii + 383. Mineralogy simplified. Henry Erni. Fourth edition. Rewritten and edited by Amos P. Brown. Henry Carey Baird & Co., Philadelphia; Low, Marston & Co., London; 1908, pages xxx + 414. Preliminary report upon a crystallographic study of the hemoglobins: A con- tribution to the specificity of corresponding vital substances in different vertebrates, by Edward T. Reichert and Amos P. Brown. Proceedings of the American Philosophical Society, volume XLVII, 1908, page 298. The differentiation and specificity of corresponding proteins and other vital substances in relation to biological classification and organic evolution; the crystallography of hemoglobins, by Edward Tyson Reichert and Amos P. Brown, Washington, D. C., Carnegie Institution of Washington, 1909. Publication number 116, pages xx + 338. Tables for the determination of minerals by physical properties. Persifor Frazer and Amos P. Brown. J. B. Lippincott Company, Philadelphia. 1910, pages xiii + 125. The mollusca of Mandeville, Jamaica, and its environs. Henry A. Pilsbry and Amos P. Brown. Proceedings of the Academy of Natural Sciences of Philadelphia, 1910, pages 510-535. The method of progression of some land operculates from Jamaica. Amos P. Brown. The Nautilus, volume XXIV, December, 1910, pages 85-90. New cycads and conifers from the Trias of Pennsylvania. Amos P. Brown. Proceedings of the Academy of Natural Sciences of Philadelphia, 1911, pages 17-21. Variation in some Jamaican species of Pleurodonte. Amos P. Brown. Pro- ceedings of the Academy of Natural Sciences of Philadelphia, 1911, pages 117-164. The formation of ripple-marks, tracks, and trails. Amos P. Brown. Proceed- ings of the Academy of Natural Sciences of Philadelphia, 1911, pages 536- BAT. The land mollusca of Montego Bay, Jamaica, with notes on the land mollusea of the Kingston region. Henry A. Pilsbry and Amos P. Brown. Proceed- ings of the Academy of Natural Sciences of Philadelphia, 1911, pages 572- 588. Fauna of the Gatun formation, Isthmus of Panama. Amos P. Brown and Henry A. Pilsbry. Proceedings of the Academy of Natural Sciences of Philadelphia, 1911, pages 336-373. ; Fauna of the Gatun formation, Isthmus of Panama, IJ. Amos P. Brown and Henry A. Pilsbry. Proceedings of the Academy of Natural Sciences of Philadelphia, 1912, pages 500-519. 4 Me ag P ayfy ¥ 9,.1917,;,PE 2 VOL. BULL. GEOL. SOC. AM. BIBLIOGRAPHY OF A. P. BROWN 1% Notes on a collection of fossils from Wilmington, North Carolina. Amos P. Brown and Henry A. Pilsbry. Proceedings of the Academy of Natural Sciences of Philadelphia, 1912, pages 152-153. Minerals of Pennsylvania. Amos P. Brown and Frederick Ehrenfeld. Topo- graphic and Geologic Survey of Pennsylvania, 1913, Report 9, pages 1-166. Variation in two species of Lucidella from Jamaica. Amos P. Brown. Pro- ceedings of the Academy of Natural Sciences of Philadelphia, 1913, pages 3-21. Two collections of Pleistocene fossils from the Isthmus of Panama. Amos P. Brown and Henry A. Pilsbry. Proceedings of the Academy of Natural Sciences of Philadelphia, 1913, pages 493-500. ‘Notes on the geology of the Island of Antigua. Amos P. Brown. Proceedings of the Academy of Natural Sciences of Philadelphia, 1913, pages 584-616. Fresh-water mollusks of the Oligocene of Antigua. Amos P. Brown and Henry A. Pilsbry. Proceedings of the Academy of Natural Sciences of Philadel- phia, 1914, pages 209-213. . Oligocene fossils from the neighborhood of Cartagena, Colombia, with notes on some Haitian species. Henry A. Pilsbry and Amos P. Brown. Proceed- ings of the Academy of Natural Sciences of Philadelphia, 1917, pages 32-41. Discussion of the crystallization of the hemoglobin of the donkey. Amos P. Brown. Quoted in a paper by Jaques Loeb, Science, new series, volume XLV, February 23, 1917, pages 191-193. MEMORIAL OF DELORME D. CAIRNES 1 BY CHARLES CAMSELL The death of Delorme Donaldson Cairnes at Ottawa on June 14, 1917, just as he was about to leave for his summer’s field-work in the Yukon, removed from the field of geology one of the best trained and most indus- trious workers of the younger group of geologists in America. His place on the Canadian Geological Survey, to the staff of which he had been attached since May, 1905, will be difficult to fill because of his intimate knowledge of the geology and mineral deposits of Yukon Territory, where he spent in all eleven years of hard, uninterrupted work. , He was born in the village of Culloden, Oxford County, Ontario, on the 21st of August, 1879, and was thus in his thirty-eighth year when he died. Karly in his life the family moved to Stratford, where his father was engaged in business. Here he obtained his early education, passing through the public school and the Collegiate Institute up to the point of university matriculation. In 1896 the family moved to the West, and eventually settled at Grand Forks, British Columbia, where for his 1 Read before the Society December 27, 1917. Manuscript received by the Secretary of the Society December 13, 1917. 18 PROCEEDINGS OF THE SAINT LOUIS MEETING health’s sake Cairnes took up outdoor work and for several years was engaged in prospecting. Becoming interested in the study of geology through association with prospectors and mining men, he decided to pursue his studies further, and with that object entered the School of Mining at Kingston in 1901 to take the course in Mining Engineering. Of his work at the School of Mining, Prof. M. B. Baker writes: “In the meantime I had graduated and was lecturing in geology at this insti tution. I was therefore greatly surprised to see my old schoolmate in my classes, but I had no doubt of the results, for in Stratford he almost invariably led the classes. I was not surprised, however, to find that at the end of his first year in the School of Mining he had passed everything with flying colors and won the Chancellor’s prize for the students obtaining the highest average on all the examinations of the first year. Cairnes kept up this record through- out his whole course, at the end of which he had actually maintained the standard of 80 per cent on all the work of the whole four years—a record that I do not believe has been equalled at this university. While taking his post- graduate course at Yale, the Dean of the Graduates School wrote me com- menting on Cairnes’ excellent preparation.” In May, 1905, Cairnes was appointed to the staff of the Canadian Geo- logical Survey and did his first important piece of field-work that year in the foothills of the Rocky Mountains, west of Calgary. In the field season of 1906 he worked in the southern Yukon, and for the next ten years he spent every season in that territory. After three years of field experience, his ambition to reach the highest rank in the geological profession compelled him to take up post-graduate work, and with this object he spent the winter of 1907-1908 in study at the Royal School of Mines, Freiberg, Saxony, and the succeeding winter at Heidelberg University, Germany. He completed his postgraduate work by obtaining the degree of Doctor of Philosophy in Geology from Yale University in 1910. In October, 1907, he married Florence Mary, daughter of Dr. T. M. and Mary Fenwick, of Kingston, Ontario, who, however, predeceased him in November, 1914, after seven years of married life. Besides keing a Fellow of the Geological Society of America, Cairnes was a life member of the Freiberg Geologische Gesellschaft, a member of the American Association for the Advancement of Science, and of the Canadian Mining Institute, and to the publications of these societies he was a frequent contributor. His most important work, however, was done for the Canadian Geological Survey in Yukon Territory, where he spent the last eleven summers of his life in studying the geology and mineral MEMORIAL OF D. D. CAIRNES 19 deposits of different parts of that region and in preparing a number of topographic maps. The results of his field-work in that region are em- bodied in a number of reports and memoirs, of which a list is given below. The list is an index of his industry, and it constitutes a very creditable record for a young man who was of necessity compelled to spend about half the time covered by the twelve years of the productive period of his life in field-work in the remote parts of Canada. The outstanding features of Cairnes’ character were his industry, his singleness of purpose, and his persistence in following up the object he had in view. ‘To these qualities were due the measure of success which he attained and the rank he held in the geological world. - BIBLIOGRAPHY The foothills of the Rocky Mountains south of the main line of the Canadian Pacific Railway. Canada, Geological Survey, Summary Report, 1905, pages 62-67. Explorations in a portion of the Yukon south of Whitehorse. Canada, Geolog- ical Survey, Summary Report, 1906, pages 22-30. Report on a portion of Conrad and Whitehorse mining districts, Yukon. Can- ada, Department of Mines, Geological Survey, Summary Report, 1907, pages 10-15. Recent developments in mining in the southern Yukon. Canadian Mining Journal, volume 28, 1907, pages 87-90 and 121-122. Moose Mountain district, southern Alberta. Canada, Geological Survey, 1908. Preliminary report on a portion of the Yukon Territory west of Lewes River between the latitudes of Whitehorse and Tantalus. Canada, Department of Mines, Geological Survey, Summary Report, 1908, pages 26-37. The Wheaton River district, Yukon Territory. Canada, Department of Mines, Geological Survey, Summary Report, 1909, pages 47-60. Preliminary report on the Lewes and Nordenski6ld rivers coal district, Yukon Territory. Canada, Department of Mines, Geological Survey, 1910, Me- moir 5. : . Portions of Atlin district. Canada, Department of Mines, Summary Report, 1910, pages 27-58. Forestry and coal areas of the Yukon Territory. Canadian Mining Journal, volume 31, number 5, March, 1910. Antimony deposits in the Yukon Territory. Mining World, volume 32, June 11, 1910. The Wheaton River antimony deposits, Yukon Territory. Canadian Mining Institute, Quarterly Bulletin, number 10, April, 1910. Geology of a portion of the Yukon-Alaska boundary between Porcupine and Yukon rivers. Canada, Department of Mines, Summary Report, 1911, pages 17-32. Quartz mining in the Klondike district. Canada, Department of Mines, Sum- mary Report, 1911, pages 33-40. 20 PROCEEDINGS OF THE SAINT LOUIS MEETING Canadian tellurium-containing ores. Canadian Mining Institute, Quarterly Bulletin, number 13, February, 1911. Geology of a portion of the Alaska-Yukon boundary between Porcupine and Yukon rivers. Canada, Department of Mines, Summary Report, 1912, pages 9-11. Some suggested new physiographic terms. American Journal of Science, fourth series, volume 34, July, 1912. Differential erosion and equiplanation in portions of Yukon and Alaska. Bul- letin of the Geological Society of America, volume 23, number 3, 1912. Banded slates of the Orange group. Bulletin of the Geological Society of America, volume 23, number 38, 1912. The ore and coal-bearing formations of the Yukon. Canadian Mining Journal, volume 33, June 15, 1912. Wheaton district, Yukon Territory. Canada, Department of Mines, Geological Survey, 1913, Memoir 31. Portions of Atlin district. Canada, Department of Mines, Geological Survey, 1913, Memoir 37. Yukon and Malaspina. Twelfth International Geological Congress, Guide Book Number 10, 1913, pages 39-40, 51-120. Yukon coal fields. The Coal Resources of the World, Twelfth International Geological Congress, 19138. The Chisana placer gold strike in Alaska. Mining and Engineering World, volume 39, November 22, 1913. Upper White River district, Yukon. Canada, Department of Mines, Summary Report, 1913, pages 12-28. The lime belt, Quadra (South Valdes) Island, British Columbia. Canada. Department of Mines, Summary Report, 1918, pages 58-75. Explorations in southwestern Yukon. Canada, Department of Mines, Sum- mary Report, 1914, pages 10-32. Chisana gold fields. Canadian Mining Institute, Bulletin number 24, 1914. Upper White River, Yukon Territory. Canada, Department of Mines, Geolog- ical Survey, 1915, Memoir 50. . The Yukon-Alaska boundary between Porcupine and Yukon rivers. Canada. Department of Mines, Geological Survey, 1915, Memoir 67. The economic possibilities of the Yukon. Canadian Mining Institute Transac- tions, volume 18, 1915, pages 45-78. Mayo area. Canada, Department of Mines, Geological Survey, Summary Re- port, 1915, pages 10-34. Scroggie, Barker, Thistle, and Kirkman creeks, Yukon Territory. Canada. Department of Mines, Geological Survey, Summary Report, 1915, pages 34-36. Wheaton district, southern Yukon. Canada, Department of Mines, Geological | Survey, Summary Report, 1915, pages 36-49. Investigations and mapping in Yukon Territory. Canada, Department of Mines, Geological Survey, Summary Report, 1916, pages 12-44. Investigations in New Brunswick and Nova Scotia. Canada, Department of Mines, Geological Survey, Summary Report, 1916, pages 251-260. Scroggie, Barker, Thistle, and Kirkman creeks, Yukon Territory. Canada, Department of Mines, Geological Survey, 1917, Memoir 97. VOL. 29, 1917, PL. 3 oO 1) R 4 fe) A o) 4 4 =) fq MEMORIAL vA MEMORIAL OF WILLIAM BULLOCK CLARK + BY JOHN M. CLARKE It has been said of this distinguished member of our Society that he was the most useful citizen of his adopted State. The people of Balti- more and of Maryland have been called on by the public press “to pay high honor to the man who did so much for them.” i As he moved about among us in these scientific meetings, engaging us with his spirited personality, his quick and cordial appreciation of others’ achievements, his wise perceptions in the business of the Society, and his participation in our common interests in technical science, it may be that we thought he belonged to us alone, and that when he had given the passwords of our guild, spoken its vernacular, shared its spirit of research, and brought before us the sheaves of his harvest, his activi- ties were here revealed and summarized. I think he would have had us believe that the purposes and principles which we embody were his high- est concern; that the diffusion of a knowledge of geological science as a means of properly comprehending the material and spiritual relations of man to the earth and of man to his fellow was the important business of his full and vigorous life. Yet we may not have known that he turned from expositions before us of the anatomy of the Oligocene echinoids to his duties as a member of a civic commission engaged in improving the water front of the city of Baltimore; from exact determinations of coastal plain geology to the administration of child welfare problems in his adopted State. ‘To us he was the geologist and the paleontologist. His other activities, if we knew of them at all, we were most likely to learn from others. There must be some in this Society who looked on him as one of the older geologists. ‘To one who was called on to prepare the memorial notice of Doctor Clark’s predecessor at the Johns Hopkins, this hardly seems possible, and yet I suppose it may be true. We knew him here as the young Amherst graduate who had gone to the Hopkins to supple- ment the work of Prof. George H. Williams; as the promising geologist who succeeded the briliant Williams in the professorship. We knew him as the man from outside, who had the rare courage and adeptness to organize and secure public support for a new and needed geological survey of the State of Maryland. Little by little we saw the results of this survey, carefully planned, leading cautiously through ‘reports on 1 Read before the Society December 27, 1917. i Manuscript received by the Secretary of the Society December 29, 1917. 22, PROCEEDINGS OF THE SAINT LOUIS MEETING practical problems and local developments, embodied in dignified dress, continuously and respectably issued, till its founder, conscious that his foundation and his grip were secure, a commanding general of geological forces, invaded the purer fields of the science and set his monuments in a series of splendid coherent volumes, one quickly following another, giving to his State an encyclopedia of its geology extraordinary in full- ness, logical sequence, and beauty of execution. So much we knew; and some of us who have served as State geologists and dare not take such achievements for granted as, permit me to say, too many teachers and the public are likely to do, we were consumed with admiration of his performances. I have spoken of him as a commanding general of geological forces. The commanding general would never have been more than a lieutenant except as he could supplement his special knowledge with a quick, broad, and comprehending grasp of others’ knowledge and apply it best to the ' general good. There lay his genius. He knew how to guide the treasure finders into the treasure house he was raising and how to build their jewels into a proper setting. He not only inspired men, but he dis- covered them; and no man whom he discovered or inspired, whom he set upon his feet and whose feet he turned into upward paths, lost his individuality. His organizations in the State Survey and in the univer- sity were not concerns in which the efforts of his coworkers were focused on their leader; he would not have it so, but rather on their work. When his new house at Guilford was nearly finished, enough for occu- pancy, I happened to find open on the desk of his study, where the books were lying in careless piles, a copy of Grabau’s Principles of Stratigra- phy—a thoughtful volume and no reading for a summer’s afternoon. In all the confusion of an unsettled home and amidst his duties as university counselor, university professor, member of committees and commissions, scientific and civic, he was reading this book consecutively, just before going to bed each night, and he had nearly finished it. Undoubtedly he did finish it in these studious ends of busy days, and it was by such prac- tices as this that his active mind kept abreast of the advances of his own science. Thus always with a good general. The hours when he is closeted with himself and his most intimate concerns are the wellspring of his competency. Those who knew Doctor Clark closely can tell of the quality of his friendship. Unsparing in his commendation where he saw it deserved, he did not let commendation go unsupported. How often and persistently he put aside his own claims in favor of those associated with him; labored for them, forgetful of himself; how gladly he took his friends to his heart and shared with them his purposes, sought their MEMORIAL OF W. B. CLARK Din counsel, and prided himself on their companionship—these things are known only to them. They are the qualities which in this assembly have been somewhat veiled. He was a lover of men and he was wise in his use of them. He sought them, especially men who were doing things or men who could help him do the many things he was called on to do. Thus the circle of his influ- ential acquaintance was very large, and he knew which way to turn when any new demands were put on him. | There must come many times to every one of us now when we feel the State needs the service we are competent to render, but it is not given to many men to create the opportunity for such service; and it is one thing to construct a beneficial public agency which will run as long as its creator stands on the bridge, but quite another to organize so securely. that it will continue to run when the captain has left the ship and another has taken his place. The State of Maryland’s Weather Service, its fine system of public highways, its Forestry Service, its Boundary Survey— these are the permanent witnesses of his service to her. Baltimore’s streets, parks, docks, and sewers, her prospective civic center, her feder- ated charities, her aid for dependent children, her war against tubercu- losis—these, too, are witnesses of his ability and will to serve. Another place must be reserved for the measure of his university use- fulness. I have heard his students say that the Geological Laboratory at his university was the ideal place for a student, filled with an atmos- phere of lofty motives and the inspiring joy of work; and there are not a few graduates of his department who have said that he was the most potent influence in their lives. The students who gathered around him caught his ideals-—-there was to be no specializing among them till they had covered the entire broad field of the science, organic and inorganic, and were then in some more adequate measure inoculated with his vision. That this paleontologist graduated from his department geologists, paleontologists, paleobotanists, geophysicists, highway engineers, and meteorologists was a natural real- ization of his proper university business; but a more vivid expression of his earnest conviction that geology is an essential science is that he had convinced the engineering faculty of the imperative need of the full under- graduate course in geology for candidates in civil engineering. Doctor Clark’s last work was for his country. He had entered on and perfected the organization of an extensive survey of the Atlantic Sea- board and Gulf States for the purpose of locating all available materials for road construction and fortification, and to make these important data of location and transportation immediately available. Into this under- 24 PROCEEDINGS OF THE SAINT LOUIS MEETING taking he put his intense energy, made quick connections with many men and cooperating agencies, traveled far, made sharp appointments with his associates at hotels and railroad stations, grasped and covered the entire field, designated his heutenants and formulated his suggestions— and then he died, in the heart of a fine service. BIBLIOGRAPHY Ueber die geologischen Verhiltnisse der Gegend nordwestlich vom Aachen-See mit besonderer Beriicksichtigung der Bivalven und Gasteropoden des unteren Lias. Inaugural dissertation. Munich, 1887, 45 pages, 2 plates, map. A new ammonite which throws additional light on the geological position of the Alpine rhetic. American Journal of Science, series 3, volume 35, 1888, pages 118-120. On three geological excursions made during the months of October and Novem- ber, 1887, into the southern counties of Maryland. Johns Hopkins Uni- versity Circular, number 65, 1888, pages 65-67. On the geology of a region in northern Tyrol, together with descriptions of new species of fossils. Johns Hopkins University Circular, number 65, 1888, pages 67-69. On the origin, structure, and sequence of the sedimentary rocks. Baltimore, 1889, 45 pages. Discovery of fossil-bearing Cretaceous strata in Anne Arundel and ‘Prince George counties, Maryland. Johns Hopkins beredlit Circular, number 69, 1889, pages 20-21. Third annual geological expedition into southern Maryland and Virginia. Johns Hopkins University Circular, number 81, 1890, pages 69-71. The geological features of Gay Head, Massachusetts. Johns Hopkins Uni- versity Circular, number 84, 1890, page 20. On the Tertiary deposits of the Cape Fear River region. Bulletin of the Geo- logical Society of America, volume 1, 1891, pages 537-540. A revision of the Cretaceous Echinoidea of North America. Johns Hopkins University Circular, number 87, 1891, pages 75-77. Report of the scientific expedition into southern Maryland. . . . Geology. Johns Hopkins University Circular, number 89, 1891, pages 105-108. Organization of the Maryland State Weather Service. Johns Hopkins Uni- versity Circular, number 89, 1891, page 109. Correlation papers. The Eocene of the United States. United States Geol- logical Survey, Bulletin number 83, 1891, 170 pages, 2 maps. Report on short excursions made by the geological department of the uni- versity during the autumn of 1891. Johns Hopkins University Circular, number 95, 1892, pages 37-39. On certain aspects of local geology. Address before the Professional Club of Brattleboro, Vermont. The Vermont Phcenix, May 20, 1892, page 2 The Mesozoic Echinodermata of the United States. United States Geological Survey, Bulletin number 97, 1893, 207 pages, 50 plates. Reviewed, Johns Hopkins University Circular, number 103, 1893, pages 51-52. ee ee BIBLIOGRAPHY OF W. B. CLARK 25 The Eocene of the United States. Review. Johns Hopkins University Circu- lar, number 103, 1898, pages 50-51. , Maryland State Weather Service. Report of progress. John Hopkins Uni- versity Circular, number 103, 1893, pages 52-538. The annual expedition of the students in geology, 1892. Johns Hopkins Uni- versity Circular, number 103, 1893, pages 538-54. The surface configuration of Maryland. Maryland State Weather Service, Monthly Report, volume 2, 1893, pages 85-89. A preliminary report on the Cretaceous and Tertiary formations of New Jersey, with especial reference to Monmouth and Middlesex counties. New Jersey Geological Survey, Annual Report for 1892; 1893, pages 167- 239, 4 plates, map. The leading features of Maryland climate. Maryland State Weather Service, Monthly Report, volume 3, 1893, pages 1-6. The available water-power of Maryland. Maryland State Weather Service, Monthly Report, volume 3, 1893, pages 7-9. . Public water supply in Maryland. Maryland State Weather Service, monthly Report, volume 3, 1893, pages 31, 32. Physical features of Maryland. In “Maryland,” published by State Board of Managers for the World’s Fair Commission, 1893, pages 11-54. Geology and mineral resources of Maryland, by G. H. Williams and W. B. Clark. In “Maryland,” published by State Board of Managers for the World’s Fair Commission, 1898, pages 55-153. Origin and classification of the green sands of New Jersey. Journal of Geology, volume 2, 1894, pages 161-177. Abstract, American Geology, volume 13, 1894, page 210. Climatology and physical features of Maryland. Maryland State Weather Sery- ice, 1st Biennial Report, 1894, pages 1-146. [Reports on] Geology [for the years 1894 to 1913]. In reports of the Presi- dent of the Johns Hopkins University. Johns Hopkins University Nine- teenth to Twenty-eighth Annual Reports, 1894-1903. Johns Hopkins Uni- versity Circular, volume 23-32, 1904-1913. Reports on the official State bureaus connected with the Johns Hopkins Uni- versy [1894-1913]. In reports of the President of the Johns Hopkins Uni- versity. Johns Hopkins University Nineteenth to Twenty-eighth Annual Reports, 1894-1903. Johns Hopkins University Circular, volume 23-32, 1904- 1913. Cretaceous deposits of the northern half of the Atlantic Coastal Plain. Bulletin of the Geological Society of America, volume 6, 1895, pages 479-482. Description of the geological excursions made during the spring of 1895. Johns Hopkins University Circular, volume 15, 1895, pages 1-3. Two new brachiopods from the Cretaceous of New Jersey. Johns Hopkins University Circular, volume 15, 1895, page 3. . Contributions to the Eocene fauna of the Middle Atlantic slope. Johns Hopkins University Circular, volume 15, 1895, pages 3-6. ; Additional observations upon the Miocene (Chesapeake) deposits of New Jersey. Johns Hopkins University Circular, volume 15, 1895, pages 6-8. Memorial of George Huntington Williams. Bulletin of the Geological Society of America, volume 6, 1895, pages 432-440. III—Buuu. GnHou. Soc. Am., Vou. 29, 1917 26 PROCEEDINGS OF THE SAINT LOUIS MEETING The Eocene deposits of the Middle Atlantic slope in Delaware, Maryland, and Virginia. United States Geological Survey, Bulletin number 141, 1896, 93 pages, 40 plates. The Potomac River section of the Middle Atlantic Coast Eocene. Amerie ‘Journal of Science, series 4, volume 1, 1896, pages 365-574. [Review of “Mollusca and crustacea of the Miocene formation of New Jersey,” by R. P. Whitfield.] Science, new series, volume 3, 1896, pages 291-292. Geology of Baltimore and the region adjacent to the lower Patapsco River. Baltimore City Sewerage Commissioners’ Report, 1897, Appendix V, pages 198-204. Upper Cretaceous formations of New Jersey, Delaware, and Maryland. Bulle- tin of the Geological Society of America, volume 8, 1897, pages 315-358. Historical sketch, embracing an account of the progress of investigation con- cerning the physical features and natural resources of Maryland. Mary- land Geological Survey, volume 1, 1897, pages 43-138. Outline of present knowledge of the physical features of Maryland, embracing an account of the physiography, geology, and mineral resources. Mary- land Geological Survey, volume 1, 1897, pages 141-228. The stratigraphy of the Potomac group in Maryland, by W. B. Clark and Arthur Bibbins. Journal of Geology, volume 5, 1897, pages 479-506. The geology of the sand hills of New Jersey, by W. B. Clark and G. B. Shat- | tuck. Johns Hopkins University Circular, volume 16, 1897, pages 13-16. Establishment and plan of operation of the Survey. Maryland Geological Sur- vey, volume 1, 1897, pages 21-42. Administrative report, containing an account of the operations of the Survey during 1896 and 1897 and additional legislation. Maryland Geological Survey, volume 2, 1898, pages 25-43. Report upon the Upper Cretaceous formations [New Jersey]. New Jersey Geo- ‘logical Survey, Annual Report for 1897; 1898, pages 161-210. [Contribution to “A symposium of the classification and nomenclature of geologic time divisions.’”] Journal of Geology, volume 6, 1898, pages 340- 342. The relations of Maryland topography, climate, and geology to highway con- . struction. Maryland Geological Survey, volume 3, 1899, pages 47-106. [Review of “Revised Text-book on Geology,” by J. D. Dana, edited by W. N. Rice.]_ Science, new series, volume 9, 1899, page 147. Introduction, including an account of the organization and conduct of high- way investigations by the Maryland Geological Survey. Maryland Geo- logical. Survey, volume 38, 1899, pages 27-46. The mineral resources of Allegany County (Maryland), by W. B. Clark, C. C. O’Hara, R. B. Rowe, and H. Ries. Maryland Geological Survey, Ailegany County, 1900, pages 165-194. ' Maryland and its natural resources. Official publication of the Maryland Com- missioners, Pan-American Exposition. Baltimore, 1901, 38 pages, map. Maryland and its natural resources. Official publication of the Maryland Com- ‘missioners, ‘South. Carolina, Interstate, and West Indian Exposition, Charleston, South Carolina. Baltimore, 1901, 38 pages, map. The Eocene-deposits of Maryland, by W. B. Clark and G. C. Martin. Maryiog Geological Survey, Eocene, 1901, pages 21-92. . — —— PBIBLIOGRAPHY OF W. B. CLARK Ja [Systematic paleontology of the Eocene deposits of Maryland]: Mollusca, by W. B. Clark and G. C. Martin. Maryland Geological Survey, Eocene, 1901. pages 122-203. [Systematic paleontology of the Eocene deposits of Maryland]: Molluscoidea (Brachiopoda), Echinodermata, by W. B. Clark and G. C. Martin. Mary- land Geological Survey, Eocene, 1901, pages 203-205, 232. Geology of the Potomac group in the Middle Atlantic slope. Bulletin of the Geological Society of America, volume 13, 1902, pages 187-214. The Potomac group in Maryland. Abstract, Science, new series, volume 15, 1902, page 905. Correlation of the coal measures of Maryland, by W. B. Clark and G. C. Martin. Bulletin of the Geological Society of America, volume 138, 1902, pages 215-232. The Cretaceous-Eocene boundary in the Atlantic Coastal Plain. Abstract, Science, new series, volume 17, 1903, page 293. The Matawan formation of Maryland, Delaware, and New Jersey, and its relations to overlying and underlying formations. American Journal of Science, series 4, volume 18, 1904, pages 485-440; Johns Hopkins University Circular, volume 23, 1904, pages 692-699. The Miocene deposits of Maryland. Introduction and general stratigraphic relations. Maryland Geological Survey, Miocene, 1904, pages xxiii-xxxii, 1 plate. | Brief account of Maryland mineral resources and description of exhibit of Maryland mineral products in Mines and Metallurgy Building, St. Louis. 1904 . . . Baltimore, 1904, 15 pages. Systematic paleontology of the Miocene deposits of Maryland: Echinodermata. Maryland Geological Survey, Miocene, 1904, pages 480-433, Reports [to Legislature] of the State Geological and Economic Survey Com- mission for the years 1904-1905, 1906-1907, 1908-1909, 1910-1911, 1912-1913. Baltimore, 1905-1913. Origin, distribution, and uses of coal. Maryland Geological Survey, volume 5, 1905, pages 221-240. Correlation of the formations and members [of. the Maryland coal district], by W. B. Clark and G. C. Martin. Maryland Geological Survey, volume 5, 1905, pages 291-315. Distribution and character of the Maryland coal beds, by W. B. Clark, G. C. Martin, and J. J. Rutledge. Maryland Geological Survey, volume 5, 1995, pages 317-512. What should appear in the report of a State geologist? Economical Geology. volume 1, 1906, pages 489-498. The Pleistocene fauna [of Maryland]. Maryland Geological Survey, Pliccene and Pleistocene, 1906, pages 139-148. Systematic paleontology of the Pleistocene deposits of Maryland: Crustacea, Mollusca, Coelenterata, Protozoa. Maryland Geological Survey, Pliocene and Pleistocene, 1906, pages 172-210, 213-216. The Pliocene and Pleistocene deposits of Maryland: the inter pretation of the paleontological criteria, by W. B. Clark, Arthur Hollick, and Frederick Lucas. Maryland Geological Survey, Pliocene and Pleistocene, 1906, pages 189-152. ; 28 PROCEEDINGS OF THE SAINT LOUIS MEETING Report on the physical features of Maryland, by W. B. Clark and E. B. Mathews. Maryland Geological Survey, special publication, volume 6, 1906, parts 1 and 2, 284 pages, 30 plates. In Maryland Commissioners to Louisiana Purchase Exposition, Report, Baltimore, 1906, pages 137-387. A brief summary of the geology of the Virginia coastal plain, by W. B. Clark and B. L. Miller. Virginia Geological Survey, Bulletin number 2, 1906, pages 11-24. Guide to the State mineral exhibit . . . at Annapolis, Maryland. [Edition 1] Baltimore, 1906, 64 pages, 20 figures. [Edition 2] Baltimore, 1912, 61 pages. The classification adopted by the United States Geological Survey for the Cre- taceous deposits of New Jersey, Delaware, Maryland, and Virginia. Johns Hopkins University Circular, volume 26, 1907, pages 589-592. Publications of the Maryland Geological Survey, Maryland State Weather Sery- ice, and Maryland Forestry Bureau. Johns Hopkins University Circular, volume 26, 1907, pages 593-608. Some results of an investigation of the Coastal Plain formations of the area between Massachusetts and North Carolina. Abstract, Science, new series, volume 29, 1909. page 629. Description of the Philadelphia district, by Florence Bascom, W. B. Clark, and others. United States Geological Survey, Geological Atlas, Folio number 162, 1909, 23 pages, 12 plates. Description of the Trenton quadrangle, New Jersey-Pennsylvania, iy Florence Bascom, W. B. Clark, and others. United States Geological Survey, Geo- logical Atlas, Folio number 167, 1909, 24 pages, 4 plates. The geological distribution of the Mesozoic and Cenozoic Echinodermata of the United States, by W. B. Clark and M. W. Twitchell. Abstract, Science, new series, volume 29, 1909, page 635. Maryland mineral industries, 1896-1907, by W. B. Clark and E. B. Mathews. Maryland Geological Survey, volume 8, 1909, pages 97-223. Report of the Conservation Commission of Maryland for 1908-1909, by W. B. Clark and others. Baltimore, 1909, 204 pages, 13 plates, 13 figures. Contributions to morphology from paleontology. Popular Science Monthly, volume 77, 1910, pages 145-150. Results of a recent investigation of the Coastal Plain formations in the area between Massachusetts and North Carolina. Abstract, Bulletin of the Geological Society of America, volume 20, 1910, pages 646-654. Geological distribution of the Mesozoic and Cenozoic Echinodermata of the United States, by W. B. Clark and M. W. Twitchell. Abstract, Bulletin of the Geological Society of America, volume 20, 1910, pages 686-688. Systematic paleontology of the Lower Cretaceous deposits of Maryland: Mol- lusca. Maryland Geological Survey, Lower Cretaceous, 1911, pages 211- a Es The Lower Cretaceous deposits of Maryland, by W. B. Clark, A. B. Bibbins, and E. W. Berry. Maryland Geological Survey, Lower Cretaceous, 1911, pages 23-98. The physiography and geology of the Coastal Plain province of Virginia, ie W. B. Clark and B. L. Miller. Virginia Geological Survey, Bulletin num- ber 4, 1912, 274 pages, 19 plates. . ieee ect ce VOL. 29, 1917, PL. 4 BULL. GEOL. SOC. AM. | ce Bit TIF OE NERC EO CER RT ORES BIBLIOGRAPHY OF W. B. CLARK 29: The coastal plain of North Carolina, by W. B. Clark and others. North Caro-, lina Geological Survey, volume 3, 1912, 552 pages, 42 plates. The Mesozoic and Cenozoic Echinodermata of the United States, by. Ww. B. Clark and M. W. Twitchell. United States Geological Survey, Monthly 54, 1915, 341 pages, 108 plates. } The Brandywine formation of the Middle Atlantic Coastal Plain. American Journal of Science, volume XI, November, 1915, pages 499-506. The age of the Middle Atlantic Coast Upper Cretaceous deposits (with HE. W. . - Berry and J. A. Gardner). Proceedings of the National Academy of Sci- ence, volume II, 1916, pages 181-186. The Upper Cretaceous deposits of Maryland. Maryland ie See Survey, Upper Cretaceous, 1916, pages 23-110, plates I-VII. Correlation of the Upper Cretaceous deposits of Maryland (with E. W. cee and J. A. Gardner). Maryland Geological, Survey, Upper Cretaceous, 1916,. pages 315-342. ont Echinodermata: In systematic paleontology of the Upper Cretaceous deposits of Maryland.’ Maryland Geological Sued Coes aaa 1916, Dee 749-752, plate 47. Geography of Maryland, supplement to “The Tadentiais ae leedocants sha Brigham and McFarlane. Second Book. American Book Company, 1916, ' pages I- XV, 1 map, 22 figures. Geological surveys, with special reference to the work of the Maryland Geo- logical Survey. In Contributions to Geology, Johns Hopkins ies Circular, new series, number 38, 1917, pages 1-12. Introduction, physiography, general geological relations, and correlation of the Cretaceous deposits of North Carolina. In Geology and Paleontology of - the Cretaceous Deposits of North Carolina. North Carolina Geological Survey. In press. Report on the surface and underground waters of BCID Ma Prepared for the National Research Council. Public water supplies of Maryland. Prepared for the Maryland Council of Defense. MEMORIAL OF CHARLES WALES DRYSDALE + BY J. AUSTEN BANCROFT It was with widespread regret that the news was received from British Columbia that, on July 10, Dr. Charles Wales Drysdale, one of the most vigorous, efficient, and universally popular of the members of the staff of the Geological Survey of Canada, together with his field assistant, Mr. Wiliam John Gray, of Vancouver, who was a student in the University of British Columbia, had been drowned in the upper reaches of the Kootenay River. Accompanied at the time by Mr. L. D. Burling, one of 1 Read before the Society December 27, 1917. ‘Manuscript received by the Secretary of the Society December 29, 1917. 30) PROCEEDINGS OF THE SAINT LOUIS MEETING the paleontologists of the Geological Survey of Canada, Drysdale and his party approached the Kootenay River from the eastward and near the point at which it is joined by Cross River. Throughout this portion of its course the Kootenay River flows swiftly and is about 225 feet wide. Having spent the preceding day in a vain search for a possible fording place, it was decided to swim the horses and build a raft to transport the outfit across the river. The place selected for crossing the river lies about three miles above Cross River, where, near its eastern bank, a small island is situated that could be reached by fording. Opposite to this island and for about 400 yards along the western bank of the river, landings could readily be made, but just below this, at a curve in the river, the bank rises as a steep cliff, against and beneath which the water swirls with much force. A staunch raft, 16 feet by 8 feet, was constructed of logs selected from a log jam on the northern side of the island. With the impetus of a strong shove from some of the party on the island, the raft with its first load was paddled across by Doctor Drysdale and his packer, Mr. George M. Smith, and a landing was made about 300 yards above the cliff. Mr. Burling then crossed on one of the horses and assisted in towing the raft upstream, so that on the return passage it would readily make the island. As “chief” of the party, Doctor Drysdale insisted on accompanying Smith © in taking the raft back to the island for the remainder of the outfit. Having reached the island, the raft was again loaded. The horses then swam safely across with Emmons, the cook of the party, on the one that was leading. Finally, the loaded raft, leaving the island without an initial shove, but propelled in this instance by three paddles plied by Doctor Drysdale and Messrs. Gray and Smith, was rapidly carried down- stream, struck the cliff already referred to, and capsized. Doctor Drys- dale and Mr. Gray jumped toward an embayment in the bank and were immediately carried down by the heavy undertow; Smith was able to climb on the overturned raft and thus saved himself. By the death of Charles W. Drysdale, the Geological Society of Amer- ica loses a young and recently appointed member, who through untiring and enthusiastic effort had contributed much to our knowledge of the complex geology of several of the most important mining camps of Brit- ish Columbia. His was a short but exceptionally brilliant career. Born in Montreal on November 1, 1885, he was the younger son of William and Mary (Wales) Drysdale. His father is a highly respected citizen of Montreal, who now occupies the position of Government Ap- praiser for books and stationery in the Canadian Department of Customs at Montreal. MEMORIAL OF C. W. DRYSDALE a In June, 1903, after completing his preparatory course in a private school and in the Montreal High School, Drysdale determined to see something of the world before entering college, and to this end secured a return passage to South Africa as steward to the engineers on a steamer sailing from Montreal. On this trip he displayed those qualities of kindly independence and keen observation that characterized his collegiate career and later work. On entering McGill University in 1904, he spent one year in the Fac- ulty of Arts, but in the following summer, while engaged in mining de- velopment work at Mammoth, Montana, he decided to change his course of study to the Faculty of Applied Science, and, in 1909, he graduated in Mining Engineering. He was a thorough, painstaking student, possess- ing an orderly mind which, by readily sorting out facts according to their relative importance, arrived at sound conclusions. His genial disposition, his quiet, unassuming manner, and the absolute sincerity of all his activi- ties made him a universal favorite among his fellow-students. He was a member of the Phi Delta Theta fraternity. His summer holidays were devoted to acquiring a variety of experiences that later stood him in good stead. During the summer of 1906, he was a draftsman on the staft of the Dominion Coal Company, at Sydney, Nova Scotia; in 1907, he was prospecting for mineral deposits in the Gowganda district of northern Ontario. During the college session of 1907-1908, he first made his acquaintance with geology, and in the follow- ing summer gained his first experience in field-work on the Geological Survey of Canada, being sent to the boundary district in British Colum- bia as an assistant to that sterling character and inspiring geologist, Capt. O. E. Le Roy, of the 46th Battalion of the Canadian expeditionary forces, who in the latter part of last October died of wounds received while leading his men in Flanders. Drysdale returned to his senior year at McGill University filled with enthusiasm for geology and with a quiet determination to thoroughly prepare himself for work on the many prob- lems of economic geology in British Columbia. During the next three years (1909-1912), winters in the Graduate School of Yale University alternated with summers spent in field-work in British Columbia. At Yale, because of the commendable character of his work, he was awarded a fellowship, was elected to Sigma Xi, and in 1912 received the degree of Ph. D. The thesis that he submitted for this degree was entitled “Geology of Franklin Mining Camp, British Colum- bia,” and it was later published as Memoir 56 of the Canadian Geological Survey. For two years after completing his studies at Yale University, he was 32 PROCEEDINGS OF THE SAINT LOUIS MEETING Assistant Geologist on the Geological Survey of Canada and, in 1914, was appointed to the senior rank of a regular field officer. All of his geological work was done in his chosen field of British Columbia. Drysdale’s intense devotion to the geology of this field is reflected in the character and importance of the reports ‘that he produced in a com- paratively short time. In his three memoirs on the Franklin, Rossland, and Ymir camps, respectively, clear and graphic descriptions of the com- plex succession of events that produced the existing geological relations within these areas are illustrated by cleverly executed diagrams, sketches, and sections. Of especial interest also are his detailed descriptions of the. petrographical character and relative ages of the igneous rocks in these highly disturbed areas. But it is chiefly in connection with his application of geology to the solution of problems relating to the ore deposits of these mining districts that Drysdale made his reputation. Since its discovery in 1890 to the close of 1916, the Rossland Mining Camp has produced 5,282,242 tons of ore, with gold, copper, and silver contents worth $69,678,670—a pro-- duction which exceeds in value that of any other lode mining camp in British Columbia. It is merely because of the exceptional economic im-. portance of the area involved that Drysdale’s memoir on Rossland has attracted more attention than his memoirs dealing with the Franklin and Ymir Mining camps. eS In 1894 and 1896, a reconnaissance geological survey of the Rossland district was made by Mr. R..G. McConnell, who is now the Deputy Min- ister of Mines in Canada. In 1905 and 1906, this area was studied in more detail by Mr. R. W. Brock and Dr. G. A. Young and, in 1906, a brief preliminary report by Mr. Brock was published. In November, 1907, Mr. Brock assumed the duties of Director of the Geological Survey of Canada, and although a detailed geological map of Rossland appeared in 1909, he was unable to find time to prepare his final report. The geological work in this area was not completed until, in 1913 and 1914, Drysdale made a very thorough and detailed study both of the surface and underground in the mines and, making free use of the data collected by Brock and Young, produced one of the most valuable of the memoirs that have been published by the Geological Survey of Canada. During and since the Carboniferous period, the Rossland district has repeatedly been invaded by ascending magmas which at times were asso- ciated with the development of volcanic activity. The results of his ob- servations as to sequence of igneous intrusions, detailed petrographical distinctions between the various rock types and phases of the same type, the development of fault and fissure systems of different ages, and as to MEMORIAL OF ‘C. W.. DRYSDALE ao the mineralogical character, mode of occurrence, and genesis of the differ- ent types of ore deposits, Drysdale applied to the directing of development work in search for ore and with very successful results. He showed that there were at least two periods of mineralization: in the first and main period, following the intrusion of the Trail batholith of granodiorite and monzonite during Jurassic time, there were magmatic emanations con- taining copper, sulphur, nickel, iron, gold, lead, silver, cobalt, antimony, and molybdenum; in the second period, following the intrusion of the Coryell batholith of pulaskite of Miocene age, there were alkaline solu- tions containing gold During the first period, bodies of sulphide ores were developed by processes of replacement along fissure and shear zones formed chiefly im the cover rocks of the Trail batholith and along forma-: tional contacts, while the mineralization of. the second period was of the character of secondary enrichment. That Drysdale’s work was appreciated by the mining men of Rossland was shown at a meeting of the Western Branch of the Canadian Mining Institute on October 26, 1916, in Trail, British Columbia, when the fol-. lowing resolution was submitted by Mr. M. E. Purcell, the superintendent of the Consolidated Mining and Smelting Company’ s Center Star-War Hagle group of mines: “Resolved, That we express our hearty appreciation of Dr. Charles Wales Drysdale’s valuable contribution to economic geology in the work entitled ‘The Geology and Ore Deposits of Rossland, British Columbia.’ ” In supporting the resolution, Mr. S. G. Blaylock, assistant manager of: the Consolidated Mining and Smelting: Company, said: “The work which Doctor Drysdale has accomplished in this section can only be appreciated thoroughly by those who know the Rossland camp. He has solved numerous problems and pointed out a great many things that were not before known to any of us. His work was all the more valuable in that as it progressed he instructed various men interested in the district in the different rock formations and ore- -bearing measures, so that we did not have to wait a long period of time until his completed report could be issued before we could, take advantage of the knowledge he gained at Rossland. I may say that his findings have been of real value in laying out development work in the mines of the camp. I am sure we all give Doctor, Drysdale every credit and wish. him the great success he deserves.” ‘tah It is pleasing to. think that Drysdale lived to receive the above sincere tribute to the merit of his work. Moreover, the Consolidated Mining and Smelting Company offered him a-position on their staff at a salary very much larger than he was receiving, but to him, money was no measure ot” results achieved, and, in addition, feeling that during the war his'‘country 34 PROCEEDINGS OF THE SAINT LOUIS MEETING needed his services in the broader field of helping to stimulate the produc- tion in British Columbia of all minerals required for munitions and other war purposes, he declined the offer. In December, 1916, he was elected a Fellow of the Geological Society of America. He was also a member of the Canadian Mining Institute and of the Canadian Club at Ottawa. In May, 1912, he married Plessah Beryl Ogilvie, eldest daughter of P. E. Ogilvie, ex-Mayor of Glace Bay, Cape Breton, Nova Scotia, and to this union two daughters and a son were born. Shortly after Doctor Drysdale’s death, an article written by Mr. E. Jacobs, secretary of the Western Branch of the Canadian Mining Insti- tute, appeared in a newspaper in Victoria, British Columbia, which brings a review of his work to a conclusion in the following appropriate sen- tences : “Of all the men who in recent years have done field-work in British Colum- bia in connection with economic geology, the opinion may be expressed that he was distinctly in the lead. Highly efficient, untiring, assiduous in his investi- gation, and diligent in preparing for publication the results of his work, he set an example that it would be to public advantage to have emulated by others. Added to these high qualifications for his important work were kindliness and courtesy that freely and generously responded to inquiry concerning problems and difficulties met with in mining, so that all who came in contact with him in the field or underground appreciated his pleasing personality.” Doctor Drysdale has thus left a splendid record of much valuable work well done. In addition to his scientific attainments, he possessed those qualities of heart and mind which made him beloved by those who were fortunate enough to know him. His spirit should live long as a stimulus to the maintenance of high ideals in geological work in Canada. BIBLIOGRAPHY 1911, Franklin Mining Camp, West Kootenay, British Columbia. Summary Report of Geological Survey of Canada, pages 133-1388. 1912. Geology of the Thompson River Valley below Kamloops Lake, British Columbia. Summary Report of Geological Survey of Canada, pages 115-150. 1913. Rossland Mining Camp, British Columbia. Summary Report of Geo- logical Survey of Canada, page 129. Sketch of geological history of Rossland. Rossland Miner, November 22. Western part of the belt of interior plateaus of British Colum- bia (Savona to Lytton). Twelfth International Congress, Guide Book Number 8, part IT, pages 234-256. 1914. Ymir Mining Camp, West Kootenay district, British ‘Communes Sum- mary Report of Geological Survey of Canada, pages 37-38. a A ENT EO ge ea PN VOL. 29, 1917, Pie oO fo) RR 4 fe) Fa] o 4 4 p FQ BIBLIOGRAPHY OF C. W. DRYSDALE 35 .1915.. Geology of Franklin. Mining Camp, British Columbia. . Canadian Geo- ‘logical Survey, Memoir 56, 246 pages. Geology and ore deposits of Rossland, British Columbia. Canadian Geological Survey, Memoir 77, 317 pages. Note on the geology of the ‘Molly’ Molybdenite Mine, Lost Creek, Nelson Mining Division, British Columbia. Transactions of the Cana- dian Mining Institute, volume XVIII, pages 247-255; also in the Bulletin of the Canadian Mining Institute, number 48, pages 872-880. Bridge River map area, Lillooet Mining Division; Highland Valley Copper Camp, Ashcroft Mining Division; human skeleton from silt bed near Savona, British Columbia. Summary Report of the Geo- logical Survey of Canada, pages 75-92. 1916. Anyox map area; Bridge River map area; Index Molybdenite Mine; Lillooet Mining Division; Slocan area, Ainsworth and Slocan Mining divisions; general notes on stratigraphy and correlation of Kootenay terranes. Summary Report of -.the Geological Survey of Canada, pages 44-63. 1917. Ymir Mining Camp, British Columbia. Canadian Geological Survey, Memoir 94, 185 pages. « Geology applied to mining in British Columbia. National Progress, June, 1917, pages 75-78. In addition to the above, Doctor Drysdale had very nearly completed a memoir on the Bridge River Mining area, British Columbia, and had partially prepared a report on the Slocan Mining area, British Columbia. These manu- scripts are being edited and will be published by the Geological Survey of ‘Canada. MEMORIAL OF ARNOLD HAGUE? BY JOSEPH P. IDDINGS- Arnold Hague was born in Boston, Massachusetts, on December 3, 1840. His father, Rev. Dr. William Hague, was a Baptist minister, as was also his great-great-grandfather, William Hague, who was active in his pulpit at the age of eighty-five, in his home in Scarborough, England. William Hague, the father of Arnold, was born near Pelham Manor, New Rochelle, New York, being a descendant, on the maternal side, of a Huguenot family which left France for Martinique, and later moved to New York State, and settled in the place afterward called New Rochelle. ~ He was also descended from David Nimham, a North American Indian, who acted as guide for Washington’s troops through the forests of West- chester, New York. Arnold Hague’s mother was Mary Bowditch Mori- arty, of Salem, Massachusetts, a granddaughter of Deborah Bowditch -1Read before the Society December 27, 1917. Manuscript received by the Secretary of the Society: January 14, 1918, 36 PROCEEDINGS OF THE SAINT LOUIS MEETING and a relative of Nathaniel Bowditch, the mathematician. The family lived in Salem for three or four generations. When Arnold was twelve years of age the family moved to Albany, where his father was pastor of the North Pearl Street Baptist Church. In Albany Arnold attended the Albany Boys’ Academy, from which he graduated in 1854. He often attended the meetings of the State legis- lature after school hours, and with a number of boy friends indulged in a senate of their own, where they debated questions of interest to them- selves. Im 1856 his father took the family to New York City, where he was pastor of the Madison Avenue Baptist Church. In the autumn of 1861, when the Civil War was in its early stages, Arnold, at the age of twenty, having been unable to enlist in the army for physical reasons, entered the Sheffield Scientific School of Yale Col- lege with advanced standing, taking up the studies of Junior year in what was known as the Chemical Course, there being at that time only two others—the Engineering and the General. Chemistry was taught by John Porter and Samuel W. Johnson, with O. D. Allen and Peter Collier as assistants. Metallurgy and mineralogy were taught by George J. Brush; geology by James D. Dana, and modern languages by William D. Whitney. Theodore Woolsey was the President of Yale. As the attend- ance in college was affected by the war, Hague’s class, which graduated in 1863, contained only four students; so that each student undoubtedly received very direct personal attention from his instructor, and one may imagine the inspiration which the student, Hague, must have received from such men as Dana, Brush, and Johnson. When Arnold Hague entered the Scientific School, Clarence King was in the Senior class and O. C. Marsh was a graduate student, having graduated from the Academic Department in 1860 with the degree of A.B. Other students with whom Hague was associated, who were in the graduate school at that time, were J. Willard Gibbs and Ellsworth Dag- gett, who afterward became a mining engineer. The acquaintances which began in this way with King and Marsh were destined to play a great role in the future life of Arnold Hague, especially the friendship with Clarence King; for while we have no record of Hague’s experiences and aspirations during his college life, it is evident from subsequent events that the friendship for these two men influenced very much of his life’s work. After graduation in 1863 with the degree of Ph. B. he went to- Ger- many, spending a year in Gottingen, improving his knowledge of the language, and the next year in Heidelberg in Bunsen’s laboratory, where most of his time was devoted to chemistry and mineralogy. It is to be MEMORIAL OF ARNOLD HAGUE Od _ noted that in 1851 Bunsen had suggested the hypothesis of a pyroxenic magma and a feldspathic magma as the sources of all intermediate vol- canic rocks, which might be formed by their mixture—an idea he had gotten from studying the basaltic and rhyolitic lavas of Iceland. It is probable that Hague became acquainted with this theory directly from Bunsen, which may account for the hold it had on him in later years, though he never advocated it directly. From Heidelberg he went to the Bergakademie in Freiberg, Saxony, in the spring of 1865, where he met for the first time S. F. Emmons, who had been there the previous year. This was the beginning of another friendship which was to continue throughout life and was to influence the careers of both these embryo- geologists, who were within four months of the same age. Hmmons, having had a year’s experience at the Bergakademie, became the adviser of Hague as to his best course and joined him in all the week-end excur- sions with von Cotta, visiting many parts of Saxony and studying petrol- ogy according to von Cotta’s text-book. Their evenings were often spent studying the geological map of Saxony, and thus acquiring their initial experience in geological cartography. In a reference to this experience Hague has said: “Both came to realize the influence of Cotta on our future careers, as he gave us much of his time.” ? Bernhard von Cotta was the author of a text-book of petrography, “Die Gesteinslehre,” the second edition of which was published in 1862, and this book became Hague’s guide and basis of petrography. In it all rocks were classified according to mode of origin: as eruptive, metamorphic, or sedimentary ; and eruptive rocks were divided into two groups on a chem- ical basis: 1, those poor in silica, or basic; 2, those highly siliceous, or acid. Hach group was further divided into volcanic and plutonic. The separation into basic and acid appears to have been made with Bunsen’s hypothesis in mind, but not directly as an expression of it, for von Cotta, in 1858, had proposed the hypothesis that the solid crust of the earth consisted of highly siliceous substances, and that the fluid portion: be- neath had about the composition of the most basic rocks, and that the variations in composition of eruptive rocks were due to the variable amounts of the solid siliceous crust which was taken up by the basic magma during its passage toward the surface of the earth. Although Sorby had made the first use of the microscope in studying rock sections in 1851, and Zirkel had published microscopical descrip- tions of rocks in 1863 and 1864, the application of the microscope to petrography had not attracted any attention when Hague was preparing 2 Arnold Hague: Biographical memoir of Samuel Franklin Emmons. National Acad- emy of Sciences, vol. ii, 1913, p. 315. IV—ButLu. Grou. Soc. AM., Vou. 29, 1917 38 PROCEEDINGS OF THE SAINT LOUIS MEETING himself for his geological career. In fact, it was not until seven years after his return to this country that microscopical petrography began to attract general attention. In December, 1866, Hague returned to his home, which was now in Boston, Massachusetts. He was just twenty-six years old and had had a liberal education in chemistry, mineralogy, petrography, and geology, as they were taught in those days. A few weeks after his return he met Clarence King in New York and had a chance to learn from him his plans for a geological survey across the western cordilleras along the line of the proposed transcontinental railroad. One who knew King in later life can imagine the enthusiasm with which at the age of twenty-five he must have developed the prospectus of the enterprise and the romance with which he must have enveloped it. He offered Hague a position as assistant geologist if the proposed plan of the survey should be author- ized by Congress. It was naturally accepted on the spot, and Hague re- turned to Boston to find his friend Emmons and acquaint him with his good luck. Shortly afterward he introduced Emmons to King, and this led to the engagement of Emmons as another assistant, and was the com- mencement of that geological triumvirate which accomplished so much for American geology through what was known as the Geological Ex- ploration of the Fortieth Parallel. On May 1, 1867, Hague and Emmons, with several other members of the scientific party, sailed from New York for San Francisco by way of Panama—a three weeks’ trip, but much less difficult than the journey across the continent at that time, before the railroad was completed, when through travel was by Wells, Fargo and Company’s stage-coach. After a few days in San Francisco the first camp was established in the out- skirts of Sacramento, where final equipment for the field-work of the survey was completed. The field force consisted of geologists, topogra- phers, an ornithologist, a botanist, and a skilled photographer, besides packers and cooks, for field-work was conducted by three parties—one under Hague, another under Emmons, exploring separate areas, while the third party was under King, who kept in touch with the work of the two assistants, besides undertaking special researches himself. Since geological and topographical work was carried on simultaneously in the same district, the geologist did not have the map on which to plot his results until a year after the field-work of a particular district had been done. Moreover, the scale of the maps was four miles to the inch and the character of the geological work was reconnaissance. The country to be explored was a wilderness, inhabited sparsely by Indians, and to a large extent desert. It was thought advisable by the MEMORIAL OF ARNOLD HAGUE 39 War Department to provide the expedition with a cavalry escort of 25 men, and occasionally a soldier accompanied the geologist into the moun- tains. The area to be surveyed was a belt of country 100 miles wide, extending from the California State line eastward to the Great Plains of Wyoming and Colorado, east of the Rocky Mountains, embracing the hne of the first transcontinental railroad. The work of the survey began at the western edge of the great sagebrush desert, in the region of Pyramid and Winnemucca lakes, and extended through parts of Nevada, Idaho, and Utah, across the Rocky Mountains, although in the published report the region is described from east westward. The season of 1867 was spent in the Humboldt country, in western Nevada; that of 1868 was occupied with the remainder of the Great Basin as far as the western edge of the Salt Lake desert. The third field season, in 1869, was devoted to the mountains and valleys of the Salt Lake region and the Wasatch Mountains to the east of it. During the three following seasons the exploration covered the Mesozoic and Tertiary areas of Utah and Wyoming, the Laramie plains, the northern extension of the Front Range, and the eastern slopes of the mountains. In addi- tion to the survey of the area of the Fortieth Parallel, Hague explored Mount Hood, while King investigated Mount Shasta, and Emmons, Mount Rainier, each studying the glacial phenomena and _ collecting voleanic rocks. The winter of 1867-1868 was spent in Virginia City, Nevada, studying the Comstock Lode and the geology of the adjacent country situated just south of the belt of the Fortieth Parallel Survey. In Volume III of the published reports, entitled “Mining Industry,’ Hague contributed a chapter on the “Chemistry of the Washoe Process,” which included a description of the mineralogical character of the ore, the chemical action of mercury and other reagents, and pan experiments. The latter were conducted at the Sheffield Laboratory of Yale College, with the assistance of Mr. Ellsworth Daggett. Hague also wrote a chapter on the geology of the White Pine district. Successive winters were spent in San Fran- cisco, Washington, and New Haven. After the completion of field-work, in 1872, the offices of the Survey were located in New York City, where the report and accompanying atlases were prepared. The collection of rock specimens was deposited with the American Museum of Natural History for safekeeping. In 1874 Emmons was sent to Europe to study the methods of Euro- pean geological surveys and to obtain the best and latest geological litera- ture. He was also instructed to confer with Professor Zirkel, who had just published his book on microscopical petrography, in 1873, and “to 40) PROCEEDINGS OF THE SAINT LOUIS MEETING induce him, if possible, to visit America and study in the presence of the collectors their collection of rock specimens, for at that time no American geologist had any practical knowledge of this new branch of geology. From this visit resulted Zirkel’s volume on microscopical petrography, which marked the opening of a new era in geological study in the United States.7 2 | It is interesting to note the phases of petrography through which the work of the Geological Exploration of the Fortieth Parallel passed, since this was the first of the larger surveys in this country that took a deep interest in the petrography of eruptive rocks. It began with King’s interest in the lavas of the Pacific Coast volcanoes and the igneous rocks of the Sierra Nevada. This took definite form through his association with Baron von Richthofen during his visit to the Pacific coast, where he studied the Tertiary volcanic lavas and, observing their strong resem- blance to those of Austro-Hungary, wrote his paper on a National System of Volcanic Rocks, published in San Francisco in 1868. This gave King, no doubt, his definite conceptions of rock varieties and their order of eruption, which represented the most advanced views of pre-microscopic petrography and placed King in advance of his assistants of von Cotta’s school. Under these influences the volcanic rocks of the region surveyed were studied and classified. After the collection had been made and brought to New York, Zirkel, the young creator of microscopical petrog- raphy, was invited to study the specimens in the presence of the collectors, and we have been told he was much influenced by the eloquent and force- ful exposition of King and his associates regarding the nature and occur- rence of the rocks. We are led to believe that Zirkel’s judgment was warped to some extent in determining the composition of some of the specimens, in particular what were at that time called propylites and trachytes. This opinion would seem to be justified by Zirkel’s own state- ment in his letter transmitting the report to Clarence King. The report, written by Zirkel in English, was edited by King and published as Vol- ume VI, in 1876. On its receipt by the geologists of the Survey, appro- priate notes regarding the microscopical characters of particular rocks were inserted in the reports of Hague and Emmons in Volume II, which was printed the following year. In this manner were blended the best of pre-microscopic petrography with the earliest products of microscopical research. 7 The results of Hague’s geological work in connection with the explora- tion of the Fortieth Parallel are published, with those of Emmons, in Volume II, “Descriptive Geology,” each describing those parts of the 8S. F. Emmons: Clarence King. Am. Jour. Sci., 4th ser., vol. 13, 1902, p. 229. MEMORIAL OF ARNOLD HAGUE 41 region specially studied by himself, in some instances with the aid of the others field notes or those of Clarence King. Hague’s comment on it may be quoted from his memoir of Benne, prepared for the National Academy of Sciences (page 321): “Tt is a description of the country, treated geographically, beginning on the Great Plains and progressing westward across the widest part of the northern cordillera. An endeavor is made to give the structural details and salient geological features lying between the meridian 104 degrees west and the meridian 120 degrees west, the latter being the eastern boundary of the State of California. The volume of atlas maps upon which the early geology was laid down, including the accompanying cross-sections, bears the imprint of 1876. . . . Nearly all the great divisions of geological time are represented on the atlas sheets, and in Volume II are described with more or less detail. In this volume the term I.aramie formation is used in geological literature for the first time. The necessity for a formation name for a great series of beds covering many hundred square miles in area was readily recognized. The name was suggested by one of the authors of the volume and warmly indorsed by Mr. King, provided it would be acceptable to Doctor Hayden, who had, of course, observed the formation at a number of localities in the Rocky Mountains. Doctor Hayden cordially agreed to the adoption of the term Laramie. During the last thirty years probably no geological horizon has been more discussed from many points of view, with all the accumulated evi- dence brought to bear upon the study of this series of beds.” Mr. Hague is the geologist who first suggested the use of the term Laramie formation. In 1877 Hague became government geologist of Guatemala, where he spent a year studying its mines and volcanic districts. In 1878 he went to China, at the instance of Li Hung Chang, to study the gold, silver, and lead mines of north China for the Chinese government. Owing to con- flict of authorities and excessive conservatism on the part of some of the higher officials, he was not permitted to accomplish much of economic value, but enjoyed unusual opportunities for visiting remote parts of the country under government escort. He left no record of his experiences or observations during these years of service. In the spring of 1879 the United States Geological Survey was estab- lished by act of Congress and Clarence King was appointed its Director. The first field parties were organized and began work the ensuing sum- mer, and Mr. Hague was appointed a geologist, to enter on his duties on his return from China. He came back by way of London in March, 1880, and it was in London that the writer of this memoir met him by appoint- ment on his way home from Heidelberg, where he had been studying with Rosenbusch, King having promised him a position as assistant to Hague when Hague should take up his duties on the Geological Survey. The 42 PROCEEDINGS OF THE SAINT LOUIS MEETING meeting took place most informally in Hague’s lodgings, while he was finishing his morning toilet, and was followed by visits to the Museum of Practical Geology in Jermyn street, where the offices of Sir Archibald Geikie, Frank Rutley, and other members of the Geological Survey of the United Kingdom were located. The few days together in London and the voyage home to New York were the beginning of years of intimate asscciation in office and camp life, to which the writer looks back with the happiest recollections. | On reaching New York, Hague proceede:| to Washington to report in person to King and to take the oath of office, which he did on April 10. The first duties of Hague and his assistant were to arrange and catalogue the extensive collection of rock specimens made by the exploration of the Fortieth Parallel, which had been deposited in cabinets in the American Museum of Natural History, but had become displaced with respect to their lakels by the movement of the drawers containing them. This necessitated the identification of the specimens megascopically by com- parison with the descriptions in Volume II and microscopically by a study of the rock sections described by Zirkel—a study of great value to the young assistant. The work occupied a large part of the following three years, which, however, were devoted to a number of other duties. The summer and autumn of 1880 were spent by Mr. Hague in the field study of the Eureka district, Nevada. His assistants were Charles D. Walcott, fresh from the Grand Canyon of the Colorado, and J. P. Iddings, still fresher, from laboratory and lecture rooms. The district. 20 miles square, embraced Paleozoic strata and volcanic lavas, with silver- lead mines and prospects in the desert region of central Nevada. Almost the first night in camp came near being the last, for Mr. Hague in trying to drive from his sleeping-tent a foraging mule was kicked in the head above the temple and severely cut, barely escaping with his life. Fortu- nately he recovered rapidly and the field-work proceeded normally. It had been the intention of the Director that Hague should establish a branch office of the Geological Survey in San Francisco, and should undertake a detailed study of the Pacific Coast volcanoes, beginning with Lassen Peak. In fact, Hague had been appointed geologist in charge of the Division of the Pacific. But a sudden change in King’s plans, result- ing in his resignation of the Directorship of the Survey in March of the following year, 1881, caused Hague to relinquish the position and return with his assistants to New York, where they found office room in the American Museum of Natural History. Work on the Fortieth Parallel collection was continued, in addition to the preparation of the report on the geology of the Eureka district. Lo MEMORIAL OF ARNOLD HAGUE A3 No field-work was undertaken by Hague and his assistant, Iddings, during the two following years, 1881, 1882, but a microscopical study of the volcanic rocks collected by King, Hague, and Emmons from the Pa- cific Coast volcanoes, and a further study of the igneous rocks of the Great Basin of Utah and Nevada, in the collection of the Fortieth Paral- lel, were made by Iddings, and joint papers on the results were published by Hague and his assistant. In like manner a microscopical study of the collection of rocks used by Dr. George F. Becker in preparing his mono- eraph on the Comstock Lode was made, and a joint paper based on the results was published by Hague and Iddings as Bulletin 17 of the United States Geological Survey. A joint paper was also prepared on volcanic rocks from Salvador, Central America, which had been collected by W. A. Goodyear, a classmate of Hague at Yale. In 1883 Hague was appointed geologist in charge of the Survey of the Yellowstone National Park and vicinity, and began field-work in August of that year with a large party of assistants, including three assistant geologists—W. H. Weed, G. M. Wright, and J. P. Iddings; a physicist, Wilham Hallock; a chemist, F. A. Gooch; a professional photographer, W. H. Jackson, and a disbursing clerk, C. D. Davis. The completion of the Northeri Pacific Railroad later in the summer attracted general attention to the region and added to the interest taken in the natural phenomena for which the park has become famous; for besides the geo- logical features, which were the object of the survey, the park was to be converted intv a national pleasure resort for those interested in geysers, hot springs, and natural scenery of a remarkable character. It was to be placed under guard, as a huge game preserve, and was subsequently set aside as a forest reserve and a protected reservoir for the headwaters of the two great rivers—the Yellowstone-Missouri and the Snake, or Sho- shone. In the prosecution and advancement of these various phases of development of the Yellowstone National Park, Hague took an active and prominent part, urging their importance on the government authori- ties in Washington and advising as to the proper administration of the faws and regulations whereby the various features of the park could best be preserved and its functions as pleasure resort, game and forest reserve could best be maintained. He was an ardent advocate of the preservation of the striking features of the region in their natural state and for plac- ing hotels and other buildings where they would not mar the attractive- ness of the localities to which they were tributary. He was a vigorous opponent of the attempt to introduce a railroad in the national park. In the suryey of the region he was especially interested in the study of the geysers and hot springs. He maintained a general oversight of the 44 PROCEEDINGS OF THE SAINT LOUIS MEETING detailed investigations of his assistants into the geological structure of the region, which is mostly covered by igneous rocks, with smaller areas of stratified rocks exposed in several mountain ranges, and he imvesti- gated portions of the area in detail himself. The region surveyed was over 3,000 square miles in extent and the field-work continued for seven seasons, from 1883 to 1889. The following season Weed and Iddings, under the charge of Mr. Hague, explored and mapped the geology of the area north of the Yellowstone National Park, which is known as the Livingston ouadrangle. The descriptive geology, petrography, paleontology, and paleobotany of the park have been published as part 2 of the Yellowstone Park mono- graph, in which certain chapters have been prepared by Hague. He has also made reports on the work from time to time in the Annual Reports of the Director of the United States Geological Survey, besides writing several special papers which appeared as presidential addresses before the Geological Society of America and the Geological Society of Washing- ton—one on the “Early Tertiary volcanoes of the Absaroka Range”; the other on “The origin of the thermal waters in the Yellowstone National Park.” In 1893, with T. A. Jaggar, Jr., as assistant, he studied the geol- ogy of the country east of the park, which had been set aside as a forest reserve and annexed to the Yellowstone Park reserve. He visited the Yellowstone Park a number of times to continue his observations of the hot springs and geysers. A list of his scientific publications is given at the end of this memoir. In 1885 Arnold Hague was elected a member of the National Academy of Sciences, and served as its Home Secretary from 1901 to 1913, and represented the Academy at various celebrations and anniversaries of foreign universities and learned societies. He was appointed a member of the Forestry Commission in 1896 and took an active part in its work. He was a Fellow of the Geological Society of London and of the Geolog- ical Society of America, being elected its President in 1910. He was a member of the American Philosophical Society, a Fellow of the American Association for the Advancement of Science, of the Society of Natural- ists, the Institute of Mining Engineers, the Washington Academy of Science, and the Geological Society of Washington. He was a vice-presi- dent of the International Geological Congress at Paris in 1900; at Stock- holm in 1910, and at Toronto in 1913. In 1901 Mr. Hague received the honorary degree of Sc. D. from Columbia University, and in 1906 the degree of LL. D. from the University of Aberdeen. He was a member of the Century and University clubs in New York City, and of the Metro- ne i a ne ain ee cle eee MEMORIAL OF ARNOLD HAGUE A5. politan and Cosmos clubs in Washington. He was married late in life to Mary Bruce Howe, of New York. Arnold Hague was at all times and under all conditions a gentleman, whether at home, in the social life of the Capital, or about the camp fire in the mountains; considerate of the feelings of others, temperate in lan- guage and habits. By nature reticent and reserved, he was conservative in his opinions, cautious in his judgment, and deliberate in action. Pos- sessed of normal human instincts, he nevertheless exhibited admirable self-control under what were at times most exasperating circumstances, as when on one occasion his packer, with camp outfit and mules, deserted him in the mountains and left him to the chance of meeting one of his other parties or of going without food for several days. Mr. Hague en- countered one of his assistants the next day; but though he was convinced of the treachery of his own packer, he retained him in his service until the end of the season as the most judicial procedure, it being very difficult to find a substitute at the time. Mr. Hague was a man of good taste in music and in art, with a fine appreciation of the beautiful in nature, whether the grandeur. of moun- tains, the colors of a sunset, or the somber tones of an autumn meadow. Though undemonstrative by temperament, he occasionally expressed his enjoyment of beautiful scenery and his pleasure in sharing the enjoyment with others in a most effective manner. The writer recalls with emotion the interest Arnold Hague took in conducting his young assistant, with eyes shut, to the brink of the Yellowstone Falls, so that he might have the pleasure of a sudden view of the many-colored canyon beyond. Al- though Mr. Hague was greatly interested in the preservation of wild animals within the park, he was no sportsman, and said on one occasion that he had never killed anv game or fish in his life. He was not averse, however, to his assistants keeping the camp table well supplied. As a geologist and explorer Hague took a lively interest in discovery, whether a bit of geological structure or the lay of new or little known country. He delighted to follow an elk trail through a difficult region, as well as to unravel a complex piece of stratigraphy; but when he had solved the riddle his interest in it ceased, as he himself has said. He - cared little to convey his discoveries to others, and in the matter of opin- ions or theories he seemed to care less as to what others thought; so that he made little or no effort to influence them, and in consequence was indifferent as to publishing the results of his researches. Moreover, he had high standards, both as regards the character of his work and the mode of its expression in print, and this, in conjunction with his delib- erate habits of thought and action, may account for the length of time 46 PROCEEDINGS OF THE SAINT LOUIS MEETING required for him to bring his reports to what he considered a proper finish. . As his geological assistant through 12 years of field and office work, the writer can testify to the kindly interest and cordial cooperation of Arnold Hague in the work of the beginner, and the writer wishes to take this opportunity to express his gratitude for valuable advice on critical occasions and for most liberal treatment in the matter of individual research and independent publication of material investigated under the charge of his chief while in the Yellowstone National Park and elsewhere. The last years of Doctor Hague’s hfe were spent quietly in Washington and Newport, Rhode Island, his health and strength declining gradually. At the Albany meeting of the Geological Society, on a stormy night, when the pavements were covered with ice, he fell and struck his head, losing consciousness for some time. Although he appeared to have recovered from this accident, his death came suddenly the following May, on the fourteenth, in the seventy-seventh year of his age. He was laid to rest in the Albany Rural Cemetery with other members of his family, and near by are the graves not only of his brother James, but of James Hall, Ebenezer Emmons, R. P. Whitfield, Charles S. Prosser, and other. men of science. | The spirit of Arnold Hague seems to have been in accord with the tranquillity of a Chinese proverb he was fond of quoting when in the mountains : *He who dwells ’midst the turmoil of cities and towns Knows not the quiet of rivers and lakes.” 4 BIBLIOGRAPHY Chemistry of the Washoe Process. United States Geological Exploration of the Fortieth Parallel, volume ITI, 1870, pages 273-293. Geology of the White-pine district. Ibid., pages 409-421. Glaciers of Mount Hood. American Journal of Science, third series, volume 1, 1871, pages 165-167. Rocky Mountains. United States Geological Exploration of the Fortieth Par- allel, volume ITI, pages 1-155. Utah Basin. Ibid., pages 393-430. Nevada Plateau. Ibid., pages 494-514, 528-569, 618-626. Nevada Basin. Ibid., pages 627-635, 660-817. Wyoming, Utah, and Nevada (geological formations). Macfarlane’s American Geological Railway Guide, 1879, pages 166-168. Report of work in the Eureka district, Nevada. United States Geological Sur- vey, First Annual Report of the Director, 1880, pages 32-35. Report on work in the Eureka district, Nevada. United States Geological Survey, Second Annual Report of the Director, 1882, pages 21-35. BIBLIOGRAPHY OF ARNOLD HAGUE AT Abstract of report on the geology of the Eureka district, Nevada. United States Geological Survey, Third Annual Report of the Director, 1883, pages 237-290. Report of the Division of the Pacific. Ibid., pages 10-14. On occurrence of fossil plants from northern China. American Journal of Science, third series, volume 26, 1883, page 124. With J. P. Iddings. Notes on the volcanoes of northern California, Oregon, and Washington Territory. American Journal of Science, third series, volume 26, 1883, pages 222-235. Report (including statements in regard to hypersthene and augite in ande- sites). United States Geological Survey, Fourth Annual Report of the Director, 1884, pages 16-18. Yellowstone Park (reconnaissance). Science, volume 3, 1884, pages 135-136. With J. P. Iddings. Notes on the volcanic rocks of the Great Basin. Amer- ican Journal of Science, third series, volume 27, 1884, pages 453-463. Geological section of the Eureka district, Nevada. Tenth Census, United States, volume 13, 1885, page 35. Report of Yellowstone Park Division. United States Geological Survey, Sixth Annual Report of the Director, 1885, pages 54-59. The decay of the obelisk. Science, volume 6, 1885. With J. P. Iddings. On the development of crystallization in the igneous rocks”® of Washoe, Nevada, with notes on the geology -of the district. United States Geological Survey, Bulletin number 17, 1885. With J. P. Iddings. Notes on the volcanic rocks of Salvador, Central America. American Journal of Science, third series, volume 32, 1886, pages 26-31. Geological history of the Yellowstone National Park. ‘Transactions of the American Institute of Mining Engineers, volume 16, 1888, pages 783-803. Yellowstone Park as a forest reservation. The Nation, volume 46, January 5, 1888, pages 9-10. On the Archean and its subdivisions. International Geological Congress, American Committee Reports, 1888; appendix, pages 66-67. Notes on the occurrence of a leucite rock in the Absaroka Range, Wyoming Territory. American Journal of Science, third series, volume 38, 1889, pages 43-47. Report of Yellowstone Park Division. United States Geological Survey, Ninth Annual Report of the Director, 1889, pages 91-96. Wyoming, Utah, Nevada, and Idaho. Macfarlane’s Geological Railway Guide, second edition, 1890, pages 309-312, 315. Geology of the Eureka district, Nevada. United States Geological Survey, Monograph 20, 1892. The great plains of the North. General sketch. Itinerary from Jamestown, North Dakota, to Livingston, Montana. Congrés Géologique International, Compte Rendu, fifth session, 1898, pages 319-325. The Yellowstone Park. Congrés Géologique International, Compte Rendu, fifth Session, 1893, pages 336-359. Geological history of the Yellowstone National Park. Smithsonian Institution, Annual Report, 1893, pages 133-151. Yellowstone National Park. Johnson’s Universal Cyclopedia, 1895. Thermal springs. Idem. 48 PROCEEDINGS OF THE SAINT LOUIS MEETING Yellowstone National Park folio, Wyoming. General description. United States Geological Survey, Geological Atlas of the United States, folio number 30, 1896. The age of the igneous rocks of the Yellowstone National Park. American Journal of Science, fourth series, volume 1, 1896, pages 445-457. Absaroka folio, Wyoming. United States Geological Survey, Geological Atlas of the United States, folio number 52, 1899. | Early Tertiary volcanoes of the Absaroka Range. Washington Geological Society, Presidential address, pages 25; Science, new series, volume 9, 1899, pages 425-442. Descriptive geology of Huckleberry Mountain and Big Game Ridge : Yellow- stone National Park). United States Geological Survey, Monograph 32, part 2, 1899, pages 165-202. A geological relief map of the Yellowstone National Park and of the Absaroka Range. Science, new series, volume 9, 1899, page 454. Othniel Charles Marsh. United States Geological Survey, Twenty-first An- nual Report of the Director, part 1, 1900, pages 189-204. Report of the Congress of Geologists. International Universal Exposition, Paris, 1900. Report of Commissioner General for the United States, vol- — ume 6, 1900, pages 198-204. Origin of the thermal waters in the Yellowstone National Park. Presidential address. Bulletin of the Geological Society of America, volume 22, 1911, pages 103-122. Biographical memoir of Samuel Franklin Emmons, 1841-1911. National Acad- -_ emy of Sciences, Biographical Memoirs, volume 7, 1913, pages 307-334. MEMORIAL OF ROBERT HILLS LOUGHRIDGE + BY EUGENE ALLEN SMITH Robert Hills Loughridge, the son of Rey. Robert McGill Loughridge and Olivia D. Hills, daughter of David Hills, of Rome, New York, was born at Kowetah Mission, Creek Nation, Indian Territory, October 9, 1843, of which mission his father had charge at the time. His mother died when he was about two years old, and his father afterwards married Miss Harriet Johnson, of Sturbridge, Massachusetts, a graduate of Mount Holyoke Seminary and an educated, refined, Christian woman. When the Tallahassee Mission, larger and better adapted to the train- ing of Indian boys and girls, was established near Muskogee, the mission at Kowetah was abandoned, and the Rev. Mr. Loughridge was assigned to the new station. Here Robert received his early education under the careful and svmpathetic direction of his father and stepmother. When about seventeen years old he was sent to the Synodical College 1 Read before the Society December 27, 1917. Manuscript received by the Secretary of the Society January 31, 1918. Bic l. w VOL. 29, 1917, PL. 6 “ty, ee ~ Oe Nae tag ee ing MO iB ge lh ak» Ly aa ee MEMORIAL OF R. H. LOUGHRIDGE 49 at La Grange, Tennessee, where the Rev. John H. Gray was president and Rey. John N. Waddell was Professor of Ancient Languages, both of whom were close friends of his father. Robert had been at the La Grange college little more than a year when the war broke out, and he, along with William C. Gray and George Waddell, his intimate friends, enlisted in the Thirteenth Regiment of the Tennessee Infantry in March, 1862. At the battle of Shiloh, the first in which he was engaged, he was severely wounded in the face and left as dying or dead on the battlefield. Doctor Gray, on learning that his son and George Waddell were safe, but that young Loughridge was missing, went to search for him and found him living, but so seriously wounded that he was unable to talk. He was taken to Doctor Gray’s home at La Grange and was there tenderly cared for until he was able to go to the home of an uncle in Mississippi. When somewhat recovered from this wound, the scars of which he retained to the end of his life, he joined the army again and remained in it till the end, though not in active service at the front. At the close of the war he went to Texas, to the home of his father, who had been compelled by the fortunes of war to give up his work among the Indians. He had one year at school in La Grange, Texas, and afterwards taught for a year in a near-by country school. In 1867, during the epidemic of that year, he had a severe attack of yellow fever and his life was despaired of. ? In 1868 he entered the University of Mississippi, at Oxford, of which at that time his former preceptor at La Grange College, Dr. John N. Wad- dell, was chancellor, and here began his lifelong friendship with Dr. Eugene W. Hilgard. In 1871 he was graduated from the University of Mississippi with the degree of B.S. After graduation he remained at the university as Ad- junct Professor of Chemistry until 1874, taking up in 1873 a line of study looking to the degree of Ph. D., which was conferred on him by the Uni- versity of Mississippi in 1876. During the period 1871-1874 he served also as Assistant State Geologist of Mississippi under Doctor Hilgard. From 1874 to 1878 he was assistant on the Georgia Geological Survey, with Dr. George Little as State Geologist. From the Georgia Survey he _ was called to California by Doctor Hilgard to assist in the preparation of the reports of the Tenth Census on cotton culture. In this work he was engaged until its completion. From 1882 to 1885 he was assistant on the Geological Survey of Kentucky in the preparation of a report on the “Jackson Purchase” region and of a number of counties. Much of the writing of these reports was done at Columbia, South Carolina, where he was Professor of Agricultural Chemistry in the university of that State 50 PROCEEDINGS OF THE SAINT LOUIS MEETING from 1885 to 1890. From South Carolina he was called again to the Uni- versity of California as assistant to his friend Hilgard, and at that insti- tution he remained the rest of his life, as Assistant Professor of Agricul- tural Chemistry and Agricultural Geology from 1891 to 1908; as Associate Professor of Agricultural Chemistry, 1908 and 1909; and as emeritus professor, 1909 until his death. 7 He was married October 19, 1886, to Miss Bessie Webb, of New Orleans, | who died at their home in Berkeley, January 23, 1895. There were no children by this marriage. On May 22, 1917, Doctor Loughridge, while on the way to take a train at Berkeley, was seized by an acute attack of heart trouble. After a par- tial recovery he was taken to the home of his brother, James A. Lough- ridge, in Waco, Texas, where he died, July 1, 1917. He was a member of the Presbyterian Church, as was his father before him. He was a Fellow of the American Association for the Advancement of Science and of the Geological Society of America; member of the Society for the Pro- motion of Agricultural Science; of the Forestry Association, and of the American Geographical Society. : From December, 1868, to July, 1871, the present writer was assistant on the Geological Survey of Mississippi, engaged during the summer months in field-work and the rest of the time in making analyses of soils and marls of Mississippi in the university laboratory under the direction of Doctor Hilgard. Loughridge at that time was a student engaged in special chemical work in the same laboratory. In this way I came to know him very well, both as to his personal character and as to his sci- entific work. When I came to the University of Alabama, in the fall of 1871, Loughridge took up my work with the Mississippi Survey, making ‘numerous soil and marl analyses, afterwards published in the Cotton Cul- ture reports. Dr. George Little, as State Geologist of Mississippi from 1866 to 1870 and as Professor of Geology in the University of Mississippi from 1870 to 1874, had ample opportunity for becoming well acquainted with Lough- ridge’s work, and when in 1874 he became State Geologist of Georgia he offered the position of assistant on the Georgia Survey to Loughridge, who held the position from 1874 to 1878. Then came the preparation of the reports on cotton culture for the Tenth Census, which Doctor Hilgard had undertaken at the request of the Superintendent, Gen. Francis A. Walker. Loughridge was immedi- ately called into service by Dr. Hilgard, whose chief assistant he was until the Cotton Culture reports were finished and turned over to the printers, some time in 1882. During these four years Loughridge prepared the MEMORIAL OF R. H. LOUGHRIDGE ol reports on the States of Georgia, Texas, Arkansas, Indian Territory, and Missouri, which necessitated a good deal of field-work in the way of geo- logical examination in all these States. In the coordination of the State reports, and especially in the adjust- ment of the general map with the individual State maps, and of the State maps with each other, Loughridge was Doctor Hilgard’s main dependence, since he had had personal acquaintance with the geological and agricul- tural boundaries in most of these States. The soil analyses also, on which Doctor Hilgard laid much stress, were made in the summer and fall of 1880, mainly in the chemical laboratory of the University of Alabama, under the joint direction of Mr. Loughridge and myself, he having over- sight of the laboratory during the summer months, which I devoted to field-work in Alabama and Florida, while I had charge of the chemical work the rest of the time, thus liberating Loughridge for his field-work in the different States. In this way most of the chemical analyses of soils of the cotton-producing States, with exceptions below noted, were made. A great number of analyses of Mississippi soils were already avail- able through the work of Doctor Hilgard prior to 1860, and by myself and Loughridge from 1868 to 1874, but it was necessary to supplement these by analyses of soils specially selected by Doctor Hilgard to illustrate certain types which came under discussion. In a similar way, while most of the analyses of soils from the other cotton-producing States were made at the University of Alabama under conditions above described, yet it was found necessary to supplement these by analyses of specially selected soils, and these analyses were carried out by Loughridge at the University of California, whither he was called by Doctor Hilgard to assist in the final arrangement of his great report. The importance of the assistance rendered by Loughridge to Doctor Hilgard in the preparation of these Cotton Culture reports, can not well be overestimated ; for, in addition to writing the reports of the five States above named, he conducted a large proportion of the correspondence of Doctor Hilgard with the special agents in charge of the several States, necessary for the proper correlation of the individual State reports and their adjustment as parts of a consistent story of cotton culture in the United States. Besides the analyses of selected soil types, he made many special humus determinations for this report. In a word, there was no one else who could have carried out the investigations needed by Doc- tor Hilgard to make his report the complete monograph which he had planned. After all the manuscripts of the Cotton Culture reports were in the hands of the printers Doctor Loughridge accepted a position with the V—BULL. Grou. Soc. Am., Vou. 29, 1917 5? PROCEEDINGS OF THE SAINT LOUIS MEETING Kentucky Geological Survey, which he held until 1885. His first work there*was on the geology and agricultural features of the “Jackson Pur- chase” region of Kentucky, embracing descriptions of five counties. This report was published in 1888. His report on Clinton County, Kentucky, was printed in 1890, but his manuscripts of similar reports on Livingston County and on Meade County were turned over to the State Bureau of Mines, on the suspension of the Geological Survey, and have never been printed. . For the next five years, from 1885 to 1890, Loughridge was Professor of Agricultural Chemistry in the University of South Carolina, at Colum- bia. During this time he contributed several articles to the reports of the experiment station. Returning to California in 1891, he again became Hilgard’s valued as- sistant and associate in the study of the soils and agricultural conditions of California. Some of these investigations were conducted jointly with Doctor Hilgard, but most of them independently, though generally along the lines of Hilgard’s researches and often at his suggestion. At the time of his death he was engaged in the preparation for publication of a large amount of data collected by himself, Doctor Hilgard, and other members of the Department of Agriculture of the University of California. | _ The quotations given below, from friends who have known him most intimately, will perhaps best set forth the personality of Doctor Lough- ridge and his character. Dr. David P. Barrow, chancellor of the University of Georgia, who was intimately associated with Doctor Loughridge when they were both con- nected with the Geological Survey of Georgia, writes concerning him: “IT was impressed with his quiet manner and his orderliness in all that he undertook. It seemed to me, that he was very precise as a boy, I thought too much so, but I learned from him somewhat of the value of system, and a great deal of the strength which may be under a quiet, diffident manner. | “He taught me something of the amount one may accomplish by saving scraps of time. I do not recall any one with whom I have associated who was quite so careful of time as was Doctor Loughridge. He was always on a high plane in conduct and in his talk.” One trait of his character which commanded the admiration of his friends was his devotion to Doctor Hilgard, with whom he was closely associated from his early manhood. This friendship and his unselfish cooperation were fully appreciated by Doctor Hilgard, from whom we quote the following paragraphs published in the University of California Journal of Agriculture of May, 1915: “During a lifetime devoted to research and instruction in agricultural sci- ence, Dr. R. H. Loughridge has most comprehensively redeemed the promise ag
  • oc MEMORIAL OF A. H. PURDUE 59 still remember that when we were working together in the mountains of Arkansas, it was my method to fall into the ways of the people with whom we were living, especially in adopting the vernacular of the region—a habit to which Purdue always objected and for which he often chided me. He would insist that, as educated men, we had no right not to give the mountain people a glimpse of correct English. This same regard for the Queen’s English is seen in the painstaking care with which he edited all of the manuscripts published by him as State Geologist. As a field geologist, Purdue was tireless, painstaking, and thorough, and the same energy and careful attention characterized all of the prepa- ration of his reports. This desire for high quality and accuracy doubtless reduced somewhat the number and length of papers prepared by him, but his work made up in quality what it lacked in volume. While he was at the University of Arkansas he spent the summer months in the field in that State—most of the time in camp with a party of from one to three of his students—and wrote his reports at odd mo- ments during the school year. Although his field-work was varied, it consisted mainly of detailed areal mapping for the United States Geo- logical Survey in a number of quadrangles in the northwestern and west- central parts of the State. Whenever funds were appropriated by the Arkansas legislature for the State Survey he made it count as much as possible by cooperating with the United States Geological Survey. Most of his geologic work in Tennessee was administrative, but he found time to make numerous short field trips into different parts of the State. Much of the work carried on under his administration as State Geologist in that State was done in cooperation with the United States Geological Survey and the United States Soil Survey. — Among his more important papers are the Winslow and Eureka Springs-Harrison folios and the De Queen-Caddo Gap and Hot Springs folios, awaiting publication; the slate deposits of Arkansas, besides a large number of shorter publications issued by the United States Geolog- ical Survey, State Surveys of Arkansas and Tennessee, and many others published in magazines or elsewhere. Considering the large amount of administrative work in the University of Arkansas that fell to his lot, this is a rather remarkable showing of scientific results for a teaching professor occupying practically the whole bench of geology. Mr. Purdue was a member of the American Institute of Mining Engi- neers, the Indiana Academy of Sciences, the National Geographic Society, and the Seismological Society of America. He was a Fellow of the American Association for the Advancement of Science, the Geological Society of America, and the Geological Society of London. He often 60 PROCEEDINGS OF THE SAINT LOUIS MEETING attended the meetings of State Geologists, of the Conservation Congress, and of the Southern Commercial Congress. While at the University of Arkansas he was made a teacher member of the Kappa Alpha fraternity. In 1907 he was elected to the Stanford chapter of Sigma Xi. The com- mencement following his resignation as Professor of Geology at the Uni- versity of Arkansas that institution conferred on him the degree of LL. D. There was no recognition that he prized more highly than his election, in 1911, to the Council of the Geological Society of America. He was President of the Tennessee Academy of Sciences at the time of his death and was already considering possible subjects for the next annual address. As a citizen, Mr. Purdue was always public-spirited, entering in large degree into the life and activities of the place of his home and of the State at large. In Nashville, besides his interest in the Commercial Club he was, active in other civic and social clubs, including the Rotary, Freolac, Tennessee Historical Society, Nashville Engineering Society, Reynolds Lodge, Knights of Pythias; Phoenix Lodge, Free and Accepted Masons, and was a generous subscriber to the work of various organiza- tions. His home, with two boys now of college age, was always a place for real Southern hospitality, for Purdue had a large sense of humor and a live personal interest in the welfare of all of his friends, and a wife whose intellectual attainments and personal charms not only added to the welcome of the home, but were a constant inspiration to the man. There is appended a list of titles of papers and addresses, including several prepared but not yet published. BIBLIOGRAPHY 1895. Observations on the glacial drift of Jasper County, Indiana. Proceed- ings of the Indiana Academy of Sciences, 1894, pages 43-46. The Charleston (Missouri) earthquake. Proceedings of the Indiana Academy of Sciences, number 5, pages 51-53. 1896. Review of sketch of the geology of the San Francisco Peninsula, by Andrew C. Lawson. Journal of Geology, volume 4, pages 640-644. Some mounds of Vanderburg County, Indiana. Proceedings of the In- diana Academy of Sciences, pages 68-70. 1897. A strange village. “The Ozark.” Review of the former extension of the Appalachians across Mississippi. Louisiana, and Texas, by J. C. Branner. Journal of Geology, volume 5, pages 759-760. 1898. The geography of Arkansas (text). American Book Company, Cincin- nati. The function of Greek-letter fraternities. “The Ozark.” 1899. The geography of Arkansas. Arkansas School Journal. ae alt tiger Ee 1901. 1902. 1904. 1905. L906. 1907. BIBLIOGRAPHY OF A. H. PURDUE 61 Review of the department of geology and natural resources of Indiana, Twenty-third Annual Report. Journal of Geology, volume 7, pages 720-721. Valleys of solution in northern Arkansas. Journal of Geology, volume 9, pages 47-50, 2 figures. Physiography of the Boston Mountains. Journal of Geology, volume 9, pages 694-701, 2 figures. Responsibilities of university students. “The Ozark.” Illustrated note on a miniature overthrust fault and anticline. Journal of Geology, volume 9, pages 341-342, 1 figure. Lead and zine deposits of north Arkansas. Lead and Zine News, Saint Louis, volume 1, number 2. Review of evolution of the northern part of the lowlands of southeast- ern Missouri, by C. F. Marbut. Journal of Geology, volume 10, num- ber 8, pages 919-921. Demands upon university curricula. Proceedings of the Ninth Annual Meeting, Southern Educational Association, pages 188-199. Geographic processes. New York Teachers’ Monograph, volume 5, num- ber 2. Is the normal school passing? Atlantic Educational Journal. The saddle-back topography of the Boone chert region, Arkansas (ab- stract). Science, new series, volume 17, page 222. On the origin of geographic forms. Arkansas School Journal. A topographic result of the alluvial cone. Proceedings of the Indiana Academy of Sciences, 1903, pages 109-111, 6 figures. Notes on the wells, springs, and general water resources of Arkansas. United States Geological Survey Water-supply Paper 102, pages 374- 388. Water resources of the Winslow quadrangle, Arkansas. United States Geological Survey Water-supply Paper 145, pages 84-87, 1 figure. Underground waters of the eastern United States—northern Arkansas. United States Geological Survey Water-supply Paper 114, pages 188- 197, 4 figures. Concerning the natural mounds. Science, new series, volume 21, pages 823-824. Water resources of the contact region between the Paleozoic and Mis- Sissippi embayment deposits in northern Arkansas. United States Geological Survey Water-supply Paper 145, pages 88-119. Address representing the faculty at the inauguration of J. N. Tillman as President of the University of Arkansas, September 20. Is the multiplication of mining schools justifiable? Mines and Min- erals, volume 26, pages 411-412. A discussion of the structural relations of the Wisconsin zine and lead deposits, by Professor Grant. Economic Geology, volume 1, number 4. pages 3891-392. Developed phosphate deposits of northern Arkansas. United States Geological Survey, Bulletin 315, pages 463-473. On the origin of limestone sink-holes. Science, new series, volume 26, pages 120-122. 62 1908. 1909. 1910. 1911. 1912. PROCEEDINGS OF THE SAINT LOUIS MEETING Cave-sandstone deposits of the southern Ozarks. Bulletin of the Geo- logical Society of America, volume 18, pages 251-256, 1 plate, 1 figure. Abstract, Science, new series, volume 25, page 764. United States Geological Survey Geological Atlas, Winslow folio (num- ber 154), 6 pages, 4 figures, 2 maps, and columnar-section sheet. A new discovery of peridotite in Arkansas. Economic Geology, volume 3, humber 6, pages 525-528, 2 figures. The slates of Arkansas. Arkansas Geological Survey, pages 1-95, 7 plates. Structure and stratigraphy of the Ouachita Ordovician area, Arkansas (abstract). Bulletin of the Geological Society of America, volume 19, pages 556-557. The collecting area of the waters of the hot springs, Hot Springs, Ar- kansas. Proceedings of the Indiana Academy of Sciences, 1909, pages 269-275; Journal of Geology, volume 18, pages 279-285. The slates of Arkansas. United States Geological Survey, Bulletin 430, pages 317-334. Mineral deposits of western and northern Arkansas. Fort Smith Times- Record, pages 123-127. The stored fuels of Arkansas (booklet). Published by Fort Smith Commercial League, 1910; also Proceedings of Arkansas Bankers’ Association. Possibilities of the clay industry in Arkansas (booklet). Published by the Brick Makers’ Association of Arkansas, Little Rock. Some essentials of public speaking (abstract). University Weekly, Fayetteville, Arkansas. The operation of the mine-run law in Arkansas. Arkansas Gazette. Recently discovered hot springs in Arkansas. Journal of Geology, vol- ume 19, number 3, pages 272-275, 2 figures. The operation of the mine-run law in Arkansas. The Tradesman, vol- ume 66, number 19, pages 27-28. Some neglected principles of physiography. Proceedings of the Indiana Academy of Sciences, 1911, pages 83-87, 1 figure. Reported discovery of radium in northern Arkansas. Science, new series, volume 35, number 904, page 658. Compendium of the mineral resources of Arkansas. [Little Rock] Board of Trade Bulletin, 30 pages. On the impounding of waters to prevent floods. Tennessee Geological Survey, The Resources of Tennessee, volume 2, number 6, pages 226- 230. The waste from Hillside wash. Tennessee Geological Survey, The Re- sources of Tennessee, volume 2, number 6, pages 250-254. Administrative report of the State Geological Survey, 1912. Tennessee State Geological Survey, Bulletin 15, 17 pages. The iron industry of Lawrence and Wayne counties. Tennessee Geo- logical Survey,~The Resources of Tennessee, volume 2, number 10, pages 370-388, 7 figures. Failure of the Nashville reservoir. Engineering Record, volume 66, number 20, page 539. 1913. 1914. 1915. 1916. BIBLIOGRAPHY OF A. H. PURDUE 63 The zine deposits of northeastern Tennessee. Tennessee Geological Survey, Bulletin 14, 69 pages, 1 plate (map), 30 figures. The zince deposits of northern Tennessee. Mining Science, volume 66, pages 249-251, 2 figures. The importance of saving our soils. Tennessee Geological Survey, The Resources of Tennessee, volume 3, number 1, pages 50-53. Water supply for cities and towns. Tennessee Geological Survey, The Resources of Tennessee, volume 3, number 2, pages 80-83, 1 figure. Geology and engineering. Tennessee Geological Survey, The Resources of Tennessee, volume 3, number 2, pages 105-109, 3 figures. Failure of the reservoir at Johnson City, Tennessee. Engineering Rec- ord, volume 67, number 22, page 600. The gullied lands of west Tennessee. Tennessee Geological Survey, The Resources of Tennessee, volume 3, number 3, pages 119-136, 8 figures. The minerals of Tennessee, their nature, uses, occurrence, and litera- ture (literature by Elizabeth Cockrill), Tennessee Geological Survey. The Resources of Tennessee, volume 3, number 4, pages 183-230. Field and office methods in the preparation of geologic reports; note taking. Economic Geology, volume 8, number 7, page 712. The education of and for the farm. Tennessee Agriculture, Proceed- ings of the Middle Tennessee Farmers’ Institute, Twelfth Annual Convention, pages 425-428. The State Geologist and conservation. Tennessee Geological Survey, The Resources of Tennessee, volume 4, number 1, pages 24-28. A double waste from hillside wash. Tennessee Geological Survey, The Resources of Tennessee, volume 4, number 1, pages 3-37. The education of mine foremen (an address). Bauxite in Tennessee. Tennessee Geological Survey, The Resources of Tennessee, volume 4, number 2, pages 87-92, 2 figures. Road materials of Tennessee. Tennessee Geological Survey, The Re- sources of Tennessee, volume 4, number 3, pages 132-135. Some neglected principles of physiography (abstract). Transactions of the Tennessee Academy of Sciences, volume 1, pages 92-94. Zine mining in Tennessee. HPngineering and Mining Journal, volume 98, number 10, pages 419-421, 4 figures, map. Administrative report of the State Geologist, 1914. Tennessee Geolog- ical Survey, Bulletin 18, 17 pages. Why not call things by their right names? Hngineering and Mining Journal, volume 100, number 19, pages 765-766. The call of the world (an address). Oil and gas conditions in the Central Basin of Tennessee. Tennessee Geological Survey, The Resources of Tennessee, volume 6, number 1. pages 1-16, 1 plate, 1 figure. Oil and gas conditions in the Reelfoot Lake district of Tennessee. 'Ten- nessee Geological Survey, The Resources of Tennessee, volume 6, number 1, pages 17-36, 3 figures. A plea for better English. Stanford Alumnus, volume 17, number 5, pages 182-184. 64 PROCEEDINGS OF THE SAINT LOUIS MEETING Notes on manganese in east Tennessee. Tennessee Geological Survey, The Resources of Tennessee, volume 6, number 2, pages 111-1238. Materials of Tennessee that invite the chemist. Manufacturers’ Rec- ord, volume 70, number 11, page 110. The nature of private reports. Engineering and Mining Journal, vol- ume 102, number 13, page 546. United States Geological Survey Geological Atlas, Eureka Springs- Harrison folio (number 202), 22 pages, 6 plates, 13 figures. (By A. H. Purdue and H. D. Miser.) 1917. The State Geologist and conservation. Science, new series, volume 45, number 1159, pages 249-252. Administrative report of the State Geologist. Tennessee Geological Survey, The Resources of Tennessee, volume 7, number 1, pages 5-25. By-product coke and oven opportunities in Tennessee. Tennessee Geo- logical Survey, The Resources of Tennessee, volume 7, number 1, pages 26-39, 2 figures. The Glenmary oil field. Tennessee Geological Survey, The Resources of Tennessee, volume 7, number 2, pages 105-108. General oil and gas conditions of the Highland Rim area in Tennessee. Tennessee Geological Survey, The Resources of Tennessee, volume 7, number 4, pages 220-228. Things the farmer should know. Cumberland Valley National Bank letter, Nashville, Tennessee. : Bauxite in the United States, 1916. Mineral Industry during 1916, pages 42-47. UNPUBLISHED REPORTS Manganese deposits of Bradley County. Tennessee Geological Survey, The Resources of Tennessee, volume 8, number 1, January, 1918, pages 46-47. (In press. ) Gravel deposits of the Caddo Gap and De Queen quadrangles. United States Geological Survey, Bulletin 690-B. (By A. H. Purdue and H. D. Miser; in press. ) Asphalt deposits and oil and gas conditions in southwestern Arkansas. United States Geological Survey Bulletin. (By A. H. Purdue and H. D. Miser; in preparation. ) United States Geological Survey Geological Atlas, Hot Springs folio. (By A. H. Purdue and H. D. Miser; in preparation.) United States Geological Survey Geological Atlas, De Queen-Caddo Gap folio. (By A. H. Purdue and H. D. Miser; in preparation.) BULL. GEOL. SOC. AM. VOL. 29, 1917, PL. 8 MEMORIAL 65 MEMORIAL OF HENRY MARTYN SEELY * BY GEORGE H. PERKINS Henry Martyn Seely was born in South Onondaga, New York, on October 2, 1828. He died in Middlebury, Vermont, May 4, 1917, in his eighty-ninth year. He fitted for college at Cazenovia Seminary and entered the Sheffield Scientific School of Yale University, from which he graduated with the degree of Bachelor of Philosophy in 1856. During several following years he continued his studies at Yale and received the degree of Master of Arts in 1860. He was Professor of Chemistry in the Berkshire Medical Institute from 1857 to 1862, receiving from that insti- tution the degree of Doctor of Medicine. From 1860 until 1867 he was non-resident Professor of Chemistry in the Medical Department of the University of Vermont. In 1867 Pro- fessor Seely went to Germany and studied for two years at Freiburg and Heidelburg. He was elected Professor of Chemistry at Middlebury Col- lege in 1864 and, excepting the two years abroad, he lived in Middlebury until his death—that is, for fifty-five years. In 1858 he married Miss Adelaide Hamblin, of Perryville, New York, who died August 25, 1868, leaving a daughter, now Mrs. John Chapman, of Anvik, Alaska. Two years later he married Miss Sarah J. Matthews, of Fair Haven, Vermont, who is still living. Three children of this mar- riage are Mrs. John M. Thomas, Middlebury, Vermont; Dr. Henry H. Seely, Harvard, Nebraska, and Locke M. Seely, Newark, New Jersey. Professor Seely was for four years, 1875-1878, secretary of the Ver- mont State Board of Agriculture. The duties of this office called him to visit many of the towns of the State, where he arranged meetings in which subjects of practical interest to farmers were helpfully discussed. In this connection, Professor Seely edited three volumes of reports which are highly valued by the farmers of the State. While he was never active in politics, his well known and very pro- nounced temperance principles caused his nomination, in 1886 and again in 1888, for Governor by the Prohibition party of Vermont. He continued active work as professor at Middlebury until 1895, when he retired as professor emeritus. But his interest in his chosen studies did not cease so long as life lasted. Though teaching, with geology, several other branches of science dur- ing most of his life at Middlebury, he became during the latter years 1 Read before the Society December 27, 1917. Manuscript received by the Secretary of the Society December 14, 1917. 66 PROCEEDINGS OF THE SAINT LOUIS MEETING more and more devoted to geology, and toward the last his whole atten- tion was given to that science. The many and often perplexing problems presented by the rocks of the Champlain Valley were ever in his thoughts and eagerly discussed when- ever occasion offered, even to the very last; for though his bodily strength failed, so that for the last few years of his life he could not engage in the field-work of which he was so fond, his mind lost none of its wonted erasp of such problems. Of his work in Middlebury, Dr. John M. Thomas, who as student and close friend is more competent to speak than the writer, says: “During the thirty-four years in which he was actively engaged in teaching at Middlebury he taught chemistry, which was the chief subject in which he had fitted himself, but also geology, botany, zoology, for the most of the time without assistance, but was himself the sole instructor. Except the last few years, the course of study in the college was required, and every student from the class of 1861 to that of 1891 was under Professor Seely’s instruction in all of the above branches. When the elective system was introduced in 1891, electives were few and Professor Seely’s courses were taken by nearly every student.” Of Professor Seely as teacher, Doctor Thomas adds: “The kindliness and gentleness of the man, his sweetness and grace of dis- position, were perhaps the first qualities in his teaching, as they were first in the thought of any who were brought into relation to him in any way. “Students are often severe judges, and I am sure that no student ever ques- tioned the Christian character of Professor Seely. He employed his Chris- tianity in the class-room as thoroughly as he did out of it. At the same time he was a thorough and careful teacher of science. He had learned the methods of scientific investigation in Germany and his work was never superficial nor merely didactic. “So far as facilities allowed, he employed laboratory methods even in the years when they were not general. He continued to hold ideals of specializa- tion and research which he was not privileged to carry out, but he imparted the spirit and the knowledge of the goal to his disciples. “A patient, kindly, gentle man, he is remembered with peculiar affection and honor by a large proportion of the living graduates of Middlebury College as a teacher for whose Christian character and for whose zeal they are alike grateful.” ~ Professor Sanford, who for several vears was a colleague with Professor Seely at Middlebury, writes: “One characteristic of his teaching seemed to be a love for a plain setting forth and an avoidance of a spectacular method of approach. He never, so far as I know, cared to arouse or stimulate curiosity or flagging attention by novel or unusual forms of presentation of the subject, thinking that a simple recital of the laws that governed the whirlwind, or the rainfall, or the story lh MEMORIAL OF H. M. SEELY 67 implied in the fossil, or the beauty of the corolla or cell structure was in itself enough to arouse interest and awaken appreciation and enthusiasm. His own simple, but forceful manner in the exposition of natural phenomena showed the students that he was no listless teacher of great truths.” As to Professor Seely’s disposition, Doctor Sanford well remarks: “Tf ever there was in the village in which he lived a beloved son of Teuthras who lived by the road and was glad to be a friend of man it was he.” As comrade and fellow-worker in the field, the writer enjoyed the close acquaintance of Professor Seely for more than forty years, and he can most heartily indorse all that has been said concerning his character and ability as a teacher, and I may add testimony as to his unfailing patience and thoroughness as a field-worker. _ Most of our investigations were carried on in the Champlain Valley, and the numerous and varied problems which this region presents to any who will see them affords great delight as well as perplexity to those who would know its geology. The writer considers it as one of the great privi- leges of his life to have been the intimate companion of such a man and with him to have sought to bring some sort of order out of the confusion of the beds of the Champlain Valley. _ To all students of western Vermont and eastern New York the work of Professor Seely must always be of greatest importance. This is notably true of the Beekmantown and Chazy, and in this connection it would be quite unfair not to speak of Dr. Ezra Brainerd, who for some years was coworker with Doctor Seely in establishing a system of classification for these beds which must always be classic in geology and form a foundation for whatever may follow as a result of future studies. The names of Brainerd and Seely will always be inseparably associated in the minds of students of the Beekmantown and Chazy of the Champlain Valley. An important addition to our knowledge of the life of the Beekman- town was made when Dr. R. P. Whitfield described and figured in the bulletins of the American Museum of Natural History many new species of cephalopods and other mollusks which these gentlemen had secured from the limestone beds of Fort Cassin at the entrance of Otter Creek into Lake Champlain. Addison County, in which Professor Seely had spent so large a part of his life, was naturally his especial field of work, and the last scientific work which he was able to undertake was an ex- tensive article for the Seventh Report of the Vermont State Geologist. in which he summarized the labors of many years of field-work. Professor Seely was a Fellow of the Geological Society of America, the Paleontological Society, the American Association for the Advancement 68 PROCEEDINGS OF THE SAINT LOUIS MEETING of Science, the American Chemical Society, Biological Society of Wash- ington, and Vermont Botanical Club. BIBLIOGRAPHY Chemical analysis of specimens of Hydragyrum cum Creta. Berkshire Med- ical Journal, Volume 1, 1861, page 510. Death—its economy and beneficence. Address before the medical class, Uni- versity of Vermont (pamphlet), 1863. Relations of science to agriculture. Vermont Agricultural Report, 1872, pages 471-487. Establishment of a college of pharmacy in Vermont. Report of Fourth Meet- ing of the Vermont Pharmaceutical Association, 1873. Leaves. Vermont Agricultural Report, 1874, pages 631-649. The analysis of fertilizers. Vermont Agricultural Report, 1876, pages 278-289. The original Vermont plow. Vermont Agricultural Report, 1877, pages 170-181. Profits of sugar-making. Vermont Agricultural Report, 1878, pages 111-114. Value and valuation of fertilizers. Vermont Agricultural Report, 1878, pages 278-359. The yesterday, today, and tomorrow of Vermont agriculture. Vermont Agri- cultural Report, 1880, pages 9-24.. A breakfast-table talk. Vermont Agricultural Report, 1884, pages 178-180. Sawing marble. Middlebury register, February 8, 1884. The marble fields and marble industry of western New England. Procesiink of the Middlebury Historical Society, Volume I, 1885, pages 23-52. A new genus of Chazy sponges, Strephochetus. American Journal of Science, third series, Volume XXX, 1885, pages 355-357. The genus Strephochetus, species and distribution. American Journal of Sci-_ ence, third series, Volume XXXII, 1886, pages 31-34. Some agricultural problems. Vermont Bee Keepers’ Association, Middlebury Register, February 6, 1891. The geology of Vermont. The Vermonter, Volume V, 1901, pages 53-67. Sketch of the life and work of Augustus Wing. American Geologist, Volume XXVIII, 1901, pages 1-8. Some sponges of the Chazy formation, Strephochetus. Third Report of the Vermont Geologist, 1901, pages 151-160. Sketch of the life and work of Charles Baker Adams. American Geologist. Volume XXXII, 1903, pages 1-12. The Stromatoceria of Isle La Motte. Fourth Report of the Vermont Geolo- gist, 1904, pages 144-152; plates. The Cryptozoa of the early Champlain Sea. Fifth Report of the Vermont Geologist, 1906, pages 156-173. The Beekmantown and Chazy formations in the Champlain Valley. Fifth Report of the Vermont Geologist, 1906, pages 174-187. About red clover. Bulletin of the Vermont Botanical Club, 1907, pages 30-31. Stelle and rhabdoliths. Sixth Report of the Vermont Geologist, 1908, pages 187-188. Report on the geology of Addison County. Seventh Report of the Vermont Geologist, 1910, pages 257-314; plates. BIBLIOGRAPHY OF H. M. SEELY 69 A venture with the poppy. Bulletin of the Vermont Botanical Club, 1912, pages 25-26. Some features of the dandelion. Bulletin of the Vermont Botanical Club, 1913, pages 18-14. In addition to the above, Professor Seely edited three of the reports of the Vermont Board of Agriculture, 1876, 1877, 1878. In cooperation with Dr. Ezra Brainerd: The original Chazy rocks. American Geologist, Volume II, 1888, pages 3238-830. The Calciferous formation of the Champlain Valley. Bulletin of the American Museum of Natural History, Volume VII, 1890, pages 1-27. The Calciferous formation of the Champlain Valley. Bulletin of the Geolog- ical Society of America, Volume I, 1890, pages 501-513. The Chazy of Lake Champlain. Bulletin of the American Museum of Natural History, Volume VITI, 1896, pages 306-315. Reports of committees were then called for. ‘These were presented as follows: REPORT OF COMMITTEE ON PHOTOGRAPHY The collection of photographs belonging to the Society is stored in my - office, in room 2209, new Interior Department building, F and G, 18th — and 19th streets, Washington. Visiting members occasionally examine the pictures to obtain illustrations for text-books or special articles. There have been no accessions for several years. Netson H. Darron, Committee. ANNOUNCEMENT FROM COMMITTEE ON THE GEOLOGICAL MAP OF BRAZIL The Secretary reported that Prof. Bailey Willis had written in behalf of the Committee on the Geological Map of Brazil to the effect that the map, by J. C. Branner, is practically ready for publication, together with its accompanying English text and bibliography. After listening to several announcements regarding the meeting, the Society proceeded to the consideration of scientific papers. TITLES AND ABSTRACTS OF PAPERS PRESENTED AT THE MORNING SESSION AND DISCUSSIONS THEREON REPORT OF THE GHOLOGY COMMITTEE OF THE NATIONAL RESEARCH COUNCIL By JoHN M. CLARKE, Chairman (Abstract) An elaborate report, with abundance of charts and tabulations of the ma- terials suitable for rapid highway construction and fortification building from 70 PROCEEDINGS OF THE SAINT LOUIS MEETING Maine to Texas and extending 100 miles back from the Atlantic coast, has been made and submitted to the Council of National Defense. Geological sur- veys and maps of the various cantonments are in course of preparation. The special committee on war minerals, organized through the National Research Council, has instituted and carried through surveys in various parts of the country for emergency mineral supplies, and has summarized its work in the form of a congressional bill recommending the appointment of a Minerals Administrator, who shall have control of the entire mineral production of the country. Other phases of the committee’s work were referred to and its further progress along various lines intimated. Presented in abstract from notes. Doctor Clarke was followed by Dr. Edward B. Mathews, who outlined briefly what had been accomplished by the Geology Committee’s Subecom- mittee on Roads. POSTGLACIAL UPLIFT OF NORTHEASTERN AMERICA BY HERMAN L. FAIRCHILD (Abstract) Uplifted marine shores have been determined at many stations in Quebec, New Brunswick, Nova Scotia, Maine, and New Hampshire during the past field season. With the large amount of precise data distributed over the wide area and the help from published observations of other geologists, it is now possible to map with at least approximate truth the uplift of northeastern America since the removal of the latest ice-sheet. The lines of equal uplift (isobases) have been extended from the area of New York and western New England, where long study has given definite knowledge. The criteria chiefly used for determination of summit water level are the deltas, especially of south-flowing streams. The heavy, conspicuous deltas are used for approximate levels, while deltas of small streams and other shore features of the vicinity are relied on for more precise determination. Caution is necessary to avoid confusion with glacial waters. It appears that the center of uplift lies between Quebec City and James Bay, in amount over 1,000 feet. The amount of uplift found by Daly and others in Newfoundland. with the position of isobases, confirms the opinion of former students that the island, and perhaps Nova Scotia, were independent centers of glaciation. The map suggests that the Mississippi Valley experienced some uplift earlier than that recognized in the Michigan and Erie basins. Read in abstract from manuscript. DISCUSSION Mr. FRANK LEVERETT called attention to evidence that the uplift may have another dome west of James Bay, but he is not able to form any conclusions as to its relation to ice weighting. — ee ee ee TITLES AND ABSTRACTS OF PAPERS Oh Mr. W. ELMER HKBLAW remarked: I wish to state that another center of postglacial uplift is probably located in Greenland or Hllesmere Land. The reports of nearly every expedition to those lands call attention to the raised beaches and wave-cut terraces along the coast. Wegener, geologist of the Kast Greenland Danish Expedition, speaks of such a beach on the northeast coast of Greenland more than 650 feet above sealevel. Schei speaks repeatedly of the raised beaches along the west coast of Ellesmere Land and the east coast of Axel Heiberg Land. Attention has many times been called to the numerous raised beaches of West Greenland and East Ellesmere Land. PALEOGEOGRAPHY OF MISSOURI BY E. B. BRANSON The author presented a series of maps representing various seas which have occupied Missouri during geologic time and discussed some of the more impor- tant sedimentary breaks. Presented in full extemporaneously. The Society adjourned soon after noon and reconvened at 2.30 p. m., with President Adams in the chair, and proceeded according to the printed program. TITLES AND ABSTRACTS OF PAPERS PRESENTED AT THE AFTERNOON SESSION AND DISCUSSIONS THEREON SUBSIDENCE OF REEF-ENCIRCLED ISLANDS BY W. M. DAVIS (Abstract) Darwin gave two kinds of evidence in supporting his theory of upgrowing coral reefs on intermittently subsiding islands: First, his theory replaced unexplained confusion by reasonable order; second, it accounted for. the sys- tematic distribution of the reefs known in Darwin’s time. Dana added the important independent confirmation given by the embayed shorelines of reef- encircled islands. Additional verification of subsidence is found (1) in the physiographic interpretation of the slopes of reef-encircled islands, which gives a much better estimate of reef thickness than the depth of barrier reef lagoons; (2) in the geological interpretation of the unconformable contacts of reef lime- stones elevated or at sealevel, with their eroded foundations; this important matter has been very generally neglected; it applies especially to the uncon- formable fringing reefs of the Philippines, admirably shown on recent Coast Survey charts; (4) in the natural explanation of the disappearance of the detritus that has been eroded from the central islands of barrier reefs; the volume of the detritus is in some instances from 30 to 80 times as great as the volume of the reef-inclosed lagoon; (5) in the absence of reefs on coasts of emergence; (6) in the unequal depths of lagoons and submarine banks. A liberal measure of subsidence being thus indicated by various lines of VII—BUuULL. Grou. Soc. AM., Vou. 29, 1917 £2 PROCEEDINGS OF THE SAINT LOUIS MEETING evidence, it remains to consider whether the subsidence has been due to the depression of broad areas of the ocean floor or to relatively local subsidence of the reef foundations, which in most cases are volcanic islands. A broad subsidence of the ocean floor would lower the ocean surface and presumably cause the emergence of marine strata around the greater part of the conti- nental margins. The local subsidence of many volcanic islands, on which reefs are built up as the islands subside, would leave the ocean surface somewhat higher than it was before the islands were formed, and this would tend to raise the ocean on the continental margins and to embay their shorelines. As continental shorelines are very generally embayed, this evidence, as far as it goes, indicates that the subsidence which gave opportunity for reef upgrowth was relatively local. Confirmation is thus found for the suggestion recently made by Molengraaf that the subsidence of volcanic islands is an isostatic phenomenon. ; Presented by title in the absence of the author. STRUCTURE OF SOME MOUNTAINS IN NEW MEXICO BY N. H. DARTON (Abstract) In a detailed investigation of the red beds of New Mexico the author has had opportunity to observe the structure of various mountain ranges, espe- cially in the central, eastern, and southern parts of the State. A great variety of interesting details are presented, but faulted tilted blocks are the most numerous. Physiographic features are in part dependent on structure and in part independent of it, excepting so far as to influence the altitude and dis- tribution of hard and soft rocks. Read by title in the absence of the author. IMPORTANCE OF NIVATION AS AN EROSIVE FACTOR AND OF SOIL FLOW AS A TRANSPORTING AGENCY IN NORTHERN GREENLAND BY W. ELMER EKBLAW ?* (Abstract) Nivation is one of the most important erosive factors in northern Greenland. Especially is this true where the wind piles the snow in drifts. Dome-shaped drifts of snow form on plateaus, plains, and most compara- tively level surfaces; “piedmont” drifts form along cliffs; “wedge” drifts form in gullies and small gorges near the top of cliffs. Hach of these drifts pro- duces different results. The dome-shaped drifts result in horizontal solifiuc- tion and altiplanation terraces; the piedmont drifts result in solifluction slopes, and “wedge” drifts initiate cirques. These “wedge” drifts may develop into glaciers, or they may develop into circular “piedmont” drifts, as the gorge gradually changes into a cirque. In this latter case the snow completes the ~ formation of the cirque. 1 Introduced by W. 8S. Bayley. o- yn TITLES AND ABSTRACTS OF PAPERS igs: Aside from the presence of an ice-table, snowfall is probably one of the essential conditions prerequisite to solifluction in high latitudes. Snowfall and gradual, but not rapid, melting of the snow make solifluction possible. Distinction should be made between solifluction which causes progressive motion of surface materials, such as results in altiplanation terraces, solifluc- tion slopes, and soil-streams or soil-glaciers, and that which causes only circu- latory movement, such as results in “‘polygonboden.” It is the first of these forms of solifluction which is one of the most important transporting agencies in northern Greenland. On every land area of the ice-free coast the landscape presents evidences of the wide-spread activity of this agency. Read in full from manuscript. PRESENT STATUS OF THE PROBLEM OF THE ORIGIN OF LOESS BY C. W. TOMLINSON ? (Abstract) A critical analysis of existing opinions on the origin of loess, with a sum- mary of the evidence thus far presented, the conclusions derived therefrom, and suggestions for further study. Presented in full extemporaneously. DISCUSSION Mr. FRANK LEVERETT spoke of the advisability of restricting the term loess to wind deposits of uniform texture and not to include wind deposits in which sand and silt are mingled. Dr. J. L. Rich: Inasmuch as ants and several kinds of burrowing animals are constantly bringing sand and small pebbles to the surface from depths of two or three feet, it seems to me that any thin deposit of loess, three feet or less thick, would almost certainly be a mixture and would contain consider- able coarser material, even if deposited as fine, wind-borne dust, and therefore that a-distinction on a genetic basis between this and true loess, such as is suggested by Mr. Leverett, can not be made. Dr. A. R. Crook: I should like to inquire if there are many data concerning the per cent of solubility of loess in hydrochloride and in various parts of the world, since this would shed light on the source or distance of transportation of the material constituting the loess. Mr. J. H. Lees: Professor Shimek shows in Iowa Academy of Science, volume 24, that there probably is no loess in Bohemia. The material which has been called loess by the Bohemian geologists is waterlaid and the geologists them- selves are now of the opinion that it is not true loess. Mr. W. H. BucuHer: On the sides of the Rhine Valley graben the mixed character of the loess is in numerous exposures seen to be intimately con- nected with the proximity to hill and mountain slopes from which rain occa- sionally washed pebbles and talus material on top of growing loess deposits. Such material, although transported by water, only emphasizes the subaerial 1 [Introduced by Hliot Blackwelder. 74 PROCEEDINGS OF THE SAINT LOUIS MEETING origin of the bulk of the deposit. At such localities not uncommonly faunules of land gastropods are found in the loess, consisting of characteristically mois- ture-loving, forest types which are in pronounced contrast to the typical loess fauna which is generally considered to point to treeless, more or less steppe- like, vegetation. That even under present climatic conditions the winds in that portion of the Rhine Valley are competent to carry on the deposition of loess is indicated by the fact that repeatedly during exceptional storms in summer-time dust lodges in conspicuous quantity on the roof of the astro- nomical observatory at Heidelberg, at an elevation of some 1,500 feet above the plain, on top of the forest-covered slopes of the faultscarp. LATE PLEISTOCENE SHORELINE IN MAINE AND NEW HAMPSHIRE BY FRANK J. KATZ (Abstract) In the coastal region of southwest Maine and southeast New Hampshire there are uplifted beaches and deitas which lie higher than late Wisconsin marine clay deposits in their immediate vicinity. The beach phenomena, in- cluding wave-cut cliffs, wave-built terraces, and sand and cobble bars built on what were evidently prominently exposed islands and headlands, are strongly developed. A group of notable features of this character in Rockingham and Strafford counties, New Hampshire, and York County, Maine, and a second group in Cumberland County, Maine, were examined and their elevations were determined. Deltas in the valleys of Isinglass, Cocheco, Mousam, Ossippes, Saco, and Little Androscoggin rivers were also examined and found to lie at elevations accordant with those of the beaches. In height the beaches range from 155 feet in Stratham, New Hampshire, to 300 feet in Pownal, Maine, and the deltas from 200 feet in Dover, New Hampshire, to 300 feet in Paris, Maine, and all are coincident with an approximately plane surface, sloping five to six feet to the mile in a direction 40° east of south—in other words, the isobases trend north 50° east, approximately parallel to the general trend of the north shore of the Gulf of Maine. The 300-foot isobase passes through Milton, New Hampshire, and the 200-foot isobase through Dover, New Hampshire, and South Portland, Maine. If the slope is constant, the isobase zero is in the vicinity of Salem, Massachusetts. In this territory many allied features have been noted but not closely examined, nor have their elevations been reliably determined. It is plain that some of the shoreline features in the region fall below the surface indicated above, and it is also certain that none of them are higher. . The result here announced does not accord with the eastward extension of the amount of uplift and the altitude of the uplift marine plane advocated to explain the phenomena in the Connecticut River valley and the Long Island region. However, conclusions for the two regions are not irreconcilable, if it can be established that the wave of uplift that followed the withdrawal of the ice approximately parallel the continental border, or, what amounts to the same thing, if there was a local center of uplift around which the isobases curve. Read by title in the absence of the author. ~I Or TITLES AND ABSTRACTS OF PAPERS GLACIAL LAKES OF SAGINAW BASIN IN RELATION TO UPLIFT BY FRANK LEVERETT (Abstract) By the aid of topographic maps with 5-foot contours, it has been found that the higher beaches—Saginaw and Arkona—in the Saginaw Basin have been uplifted northward, but that the low beach of Lake Warren, formed at a later time, has not been uplifted in this area. It is, however, tilted in neighboring ports of Michigan to the north. The area of uplift thus became reduced on the south during the Glacial epoch. Similar phenomena have been observed in the Huron-Hrie Basin and are discussed by Taylor in Monograph LITT, United States Geological Survey. Presented in full extemporaneously. MECHANICS OF LACCOLITHIC INTRUSION BY CHARLES R. KEYES (Abstract ) Between the two extreme views concerning the genesis of laccolithic moun- tains, between the idea of an easily floated prism of strata that expands into a symmetrical, dome-shaped earth-blister, and the notion that the phenomenon is a mechanical impossibility, there now develops midway a strictly tectonic conception which, although making improbable the one and perfectly invali- dating the other, is amply supported by recent wide observation, and withal is mathematically sound. It turns out that the genetic impetus in its nature is dominantly orogenic rather than simply hydrostatic. In the Sierra del Oro, or Gold Mountains, of New Mexico, of which the Ortiz group is the best known, the structural relationships of laccolithic intrusion are especially well displayed. The ideal form of the laccolithic mass is shown to be not a symmetrical lens, but a wedge-shaped body in which a fault-plane constitutes the flat, thick base. A laccolithic mountain is not fortuitously located. In order that a laccolith be produced, rather than any other form of volcanic manifestation, it seems that the intrusive mass must have a particular tectonic setting. Profound faulting is one of the prime factors. Another is orographic flexing by which the rigidity of certain arching strata potentially carries or largely sustains the load of superincumbent beds. Probably the unusually high viscosity of acidic magmas has an important, but as yet uncalculated, influence on events. The four laccoliths of the Sierra del Oro are situated at equidistant points, where recently formed folds intersect at an angle of 45° a notable line of ancient displacement. Like circumstances may obtain for all laccoliths. A laccolith is not a locally thickened sill. The two masses are formed under entirely different physical and tectonic conditions. They are genetically dis- tinct and perfectly unrelated. Read by title in the absence of the author. 76 PROCEEDINGS OF THE SAINT LOUIS MEETING FACETED FORM OF A COLLAPSING GEOID BY CHARLES R. KEYES (Abstract) It is not necessary to postulate a cooling globe in order to consider the geometric effects of partial collapse. Because of the fact that with a given mass the body with the greatest surface area is the sphere, and the one with the least surface a four-sided form, it is sometimes thought that our planet is tending toward a tetrahedral earth. It is finally indicated that the crystallo- graphic form could hardly be so simple, but a shape in which each face of the ground-form consists of a number of smaller facets. The rhombic dodecahe- dron best fits the figure which the great mountain chains outline on the surface of the globe. In recent experiment, bearing directly on this theme, made with heavy rolled paper, the amount of collapse is measured by the diurnal change in the hu- midity of the air. On dry days the result is a surface of singularly large and perfect rhombohedrons. With paper not so tough relatively, or with the use of some brittle substance, no doubt rupture would have taken place along the edges of the facets. In all practical respects the lines of the great mountain upheavals on the earth are exactly located in miniature. Read by title in the absence of the author. CHARACTERISTICS OF THE UPPER PART OF THE TILL OF SOUTHERN ILLINOIS AND ELSEWHERE BY EUGENE WESLEY SHAW (Abstract) In 1909, while surveying the Murphysboro quadrangle, Illinois, the writer gained the impression that the stones in an upper portion of the Illinoian till are fewer, smaller, and more resistant than those of a middle and lower por- tion, and that the difference is largely original. In the field-notes the two portions are referred to as the non-gravelly and the gravelly till. Further field- work in southern Illinois covering a part of each year since that time and laboratory tests have confirmed the impression, and brief examinations of the Kansan till in northern Missouri and other till sheets elsewhere lead to the inference that the feature is rather general. In some places the non-gravelly till has been erroneously identified as loess. The character of the few pebbles in the upper till indicates somewhat definitely that this till was never like the middle and lower portions of the deposit, though no doubt contemporaneous with them. Read by title in the absence of the author. TITLES AND ABSTRACTS OF PAPERS qe PLEISTOCENE DEPOSITS BETWEEN MANILLA, IN CRAWFORD COUNTY, AND COON RAPIDS, IN CARROLL COUNTY, IOWA BY GEORGE F. KAY (Abstract) Many deep cuts were made recently in connection with the improvement of the Chicago, Milwaukee and Saint Paul Railway between Manilla, in Craw- ford County, and Coon Rapids, in Carrol] County—a distance of more than thirty miles. These cuts, some of which have a depth of more than 50 feet, furnish most interesting exposures of drift and related deposits, the study of which has enabled some phases of the Pleistocene history of Iowa to be inter- preted somewhat more clearly than was possible previously. The most significant features that have been revealed may be summarized as follows: 1. The chief kinds of material exposed are loess, Kansan gumbotil, Kansan drift, Nebraskan gumbotil, and Nebraskan drift. In no one cut is it possible to see all of these materials, nor are the two gumbotils exposed in a single cut. In some cuts the section shows loess, Kansan gumbotil, and Kansan drift; in other cuts there may be seen loess, Kansan drift, and Nebraskan gumbotil; in still others loess, Nebraskan gumbotil, and Nebraskan drift. The most com- prehensive cut is about one and one-half miles west of Manning. It shows loess, Kansan drift, Nebraskan gumbotil, and Nebraskan drift. 2. The two drifts, the Nebraskan and the Kansan, are much alike litholog- ically, and both appear to have undergone similar changes. On each of the drifts gumbotil has been developed, below which there is a narrow zone of leached drift, which grades downward into unleached drift with many concre- tions. 3. The maximum thickness of Nebraskan gumbotil is about 13 feet and of the Kansan gumbotil more than 20 feet. The zone of oxidation of the Ne- braskan drift is not fully exposed in any of the cuts; the greatest depth of oxidation seen was 17 feet. The zone of oxidation of the Kansan drift has a maximum thickness of about 40 feet. Beneath this oxidized zone, in a few cuts, there was seen less than 10 feet of very dark, tenacious, unleached, and unoxidized Kansan drift. “ 4. The Kansan gumbotil is limited in distribution to a few narrow divides which are erosion remnants of a. former extensive Kansan gumbotil plain. These divides are the present uplands of the region. The Nebraskan gumbotil is exposed only in those cuts the summits of which have been brought by ero- sion considerably below the elevations of the summits of the upland cuts. 5. The loess is present as a mantle over the maturely dissected surfaces. It varies in thickness from a few feet to more than 25 feet. Y In general, it thickens from the crests of the ridges down the slopes, and is apparently thicker on east slopes than on west slopes. The upper parts of the ridges have been broadened more than heightened by the deposition of the loess. In places the loess lies on Kansan gumbotil; in places it is on Kansan drift; in other places it mantles the Nebraskan gumbotil; and where there has been the most extensive erosion previous to the deposition of the loess, it is on Nebraskan drift. / PROCEEDINGS OF THE SAINT LOUIS MEETING ‘—J Sr 6. The loess has two phases, the upper of which is buff in color; the lower is gray. In many places the buff loess is leached for a few feet from the sur- face; in a few cuts the depth of leaching is about 15 feet. The buff and the gray phases of the loess are closely related, and the evidence indicates that their differences are the result of chemical reactions rather than of different epochs of deposition. Presented in full extemporaneously. DISCUSSION Mr. FRANK LEVERETT inquired of Professor Kay whether he had found evi- dence that the gumbotil was originally different from typical boulder-clay. In reply to a question by Professor Rich, Mr. Leverett mentioned the wide lowlands bordering the lower courses of the Embarrass and Kaskaskian and other rivers in southern Illinois as examples of areas that are not undergoing stream trenching because they are too flat for streams to form such trenches. In reply to Mr. Leverett, Professor Kay stated that the boulder-clay from which the gumbotil has been derived may have differed from typical boulder- clay, but he had no distinctive evidence in favor of this view. His impression was that in the case of the Iowan and Wisconsin drifts, which are too young to have had a gumbotil developed on them, the drift at and near the surface does not differ in any important respect from the drift which is deeper below es surface. . J. L. RicH: The speaker’s interpretation of the relations of the two ee to their underlying tills and his explanation of their origin involves a particular series of events twice repeated in identical order, namely, a long period of weathering under conditions precluding active stream erosion, fol- lowed by dissection, presumably resulting from diastrophism. It is difficult to believe that such a repetition of events is a purely accidental coincidence. If not, it seems to me that either the explanation is imperfect or there must be some causal relation between the periods of glaciation and of lagging diastro- phism which would be of great significance if discovered. In reply to Doctor Rich, Professor Kay stated that he recognized the full significance of the point raised, but he was unable to offer an explanation of the field evidence that would not involve the peculiar series of events that seem difficult to believe. But are not other series of events of the Pleistocene equally difficult to believe? What a succession of events is involved in the now generally accepted five glacial epochs and the four interglacial epochs! Mr. J. E. Topp: 1. I would like to inquire how Doctor Kay harmonizes his statement of the close similarity of Nebraskan and Kansan tills with state- ments of earlier students of the subject that they were easily distinguishable by color and composition. 2. I would like to call attention to the occurrence near Afteina: Pottawatomie - County, Kansas, of black boulders of supposed Nebraskan till in Kansas till. Furthermore, erosion is at an altitude considerably higher than central Iowa. In reply to Professor Todd, Professor Kay stated that the earlier students of the drifts did not have opportunity to study the Nebraskan and Kansan drifts in all their relationships in widely distributed areas. Many important exposures have been made available for study only during the past few years | ; i TITLES AND ABSTRACTS OF PAPERS 79 in connection with railway construction and the improvement of the roads of the State. It is quite true that in some parts of Iowa the Kansan drift can be distinguished readily from the Nebraskan drift within the same area; on the other hand, there are other places in Iowa where the color, composition, and other characters of the Kansan drift are so similar to the characters of the Nebraskan drift that it is impossible to distinguish the two drifts by such criteria. LOESS-DEPOSITING WINDS IN THE LOUISIANA REGION BY F. V. EMERSON ? (Abstract) The eolian origin of the southern loess is generally conceded by most workers who have studied the formation within the last twenty years. It has long been recognized that strong westerly winds have deposited the wide loess belt along the eastern side of the Mississippi and the less frequent and persistent easterly winds have deposited the narrower, less continuous belt on the west- ern side. The soils of the west belt contain considerably more potash than those of the east belt. The explanation offered is that the finer loess particles were carried to the west belt by the weaker easterly winds. Microscopie ex- amination of Louisiana loess shows that the potash occurs in bits of ortho- clase between 1/100 and 5/100 of a millimeter in diameter, and that practically all particles larger than this are quartz. It is therefore thought that the , weaker easterly winds carried finer loads with a consequently higher percent- age of orthoclase than the stronger westerly winds. There are two “islands” of loess nearly or quite surrounded by Mississippi alluvium, and in each case the loess at the southern ends of these areas is thicker than at the northern ends. This seems to indicate that southerly winds (probably southwesterly and southeasterly) were important loess carriers in this region. Read in full from manuscript. STREAM MEANDERS BY E. B. BRANSON (Abstract) Meanders are variously interpreted in recent text-books and articles. One text states that meanders begin to develop after a stream has cut to baselevel, while another states that they start in the early youth of a stream. This article discusses the development of meanders in young valleys. Read by title, at the request of the author. 1 Introduced by A. P. Brigham. SO PROCEEDINGS OF THE SAINT LOUIS MEETING NOTES ON THE SEPARATION OF SALT FROM SALINE WATER AND MUD BY E. M. KINDLE (Abstract) The paper described a series of experiments showing (1) the facility with which salt escapes from vessels holding saline aqueous solutions during the evaporation of the water; (2) the influence of temperature in controlling the size of salt crystals; (8) the contrast in texture exhibited by fine-grained sedi- ments formed in saline and fresh waters; (4) the different types of mud-crack developed in saline and non-saline calcareous mud. The geological significance of some of the facts illustrated by the experi- ments was brought out by a discussion of the phenomena observed on the salt plains in the Northwest Territory. The bearing of the experiments on the theories relating to the origin of salt lakes and salt domes was also considered. Mud-cracks in limestone were described, which correspond in certain peculiar features to the two types developed experimentally in calcareous sediments. Read in full from manuscript, by Dr. M. E. Wilson, in the absence of the author. ADDITIONAL NOTE ON MONKS MOUND BY A. R. CROOK (Abstract) Monks Mound, which lies about six miles east of the place of the 1917-1918 Geological Society of America meeting, in scholarly as well as in popular litera- ture, has quite generally been described as of human origin.* As pointed out in former papers before the Geological Society of America,? inquiry along lithological and physiographical lines makes evident that this and the 70 other mounds in the region are but remnants of the glacial materials which formerly filled the valley. Since presenting that paper opportunity of making further investigation has been afforded. The samples of earth constituting the mound secured for the former studies were obtained by sinking 25 holes with a post-hole digger in the north or most abrupt face of the ground. Recently ad- ditional samples were secured by sinking a hole with an earth augur from the top down 25 feet and on the east side for 15 feet farther. Earth from the tops and sides of several other mounds was taken and all of these materials were compared. The result shows general similarity of materials in all the different mounds at similar levels and a change in the soil of Monks Mound when pro- ceeding from the top to lower layers—a condition which would not be likely to exist if “Mound-builders” built these mounds, which are scattered over sey- eral square miles. It is reasonable to doubt that the so-called Mound-builders, or Indians, ever did build mounds of any considerable size. The burden of proof should rest with archeologists, who make the claims that elevations 1See Transactions of the American Philosophical Society, Smithsonian Contributions to Knowledge, American Bureau of Ethnology, Encyclopedia Britannica, etcetera. * Bull. Geol. Soc. Am., vol. 26, no. 1, 1915, p. 74, map. TITLES AND ABSTRACTS OF PAPERS 81 which would appear to physiographers to be natural mounds were built by human hands. Presented in full extemporaneously. DISCUSSION Mr. J. E. Topp: I would call attention in this connection to the fact that at the 1877 session of the American Association for the Advancement of Science, held in this city, a gentleman exhibited a model to show the similarity of the largest Cahokia mound to the pyramid structures of Mexico and Yucatan. At that meeting an excursion to the mounds was arranged. While on the trip I personally heard Doctor Worthen, State Geologist of Illinois, who had studied them, state his positive conviction that these mounds were not artificial but of natural origin. Remarks were also made by Messrs. D. W. Ohern, I. C. White, and W. J. Sinclair. SALIENT FEATURES OF THE GEOLOGY OF THE CASCADES OF OREGON, WITH SOME CORRELATIONS BETWEEN THE EAST COAST OF ASIA AND THE WEST COAST OF AMERICA BY WARREN DU PRE SMITH (Abstract) The salient features of the stratigraphic succession in the Oregon Cascades, so far as known, are reviewed in this paper. A survey of the literature and of the data gathered in recent field-work re- veals the fact that not much is known with certainty about the formations and events prior to the Tertiary. A second fact of importance, already known, is emphasized, namely, that the later geological history of California and Oregon is very much the same. This might appy to the State of Washington as well, but the writer has pur- -posely omitted a discussion of this, since he has never done any work there. The third fact of importance is the remarkable coincidences of geologicai events on opposite sides of the Pacific, which can not be fortuitous. The two most striking instances of these are the period of Tertiary gold deposition, practically contemporaneous around the entire Pacific arc, and the tremendous eruptions of basaltic and andesitic lavas which continue to this day, though not on so extensive a scale as in the past, and which have caused the regions bordering the Pacific to be designated as the “Circle of Fire.’’ The general conclusion is that the geology of the various countries bordering the Pacific must be deciphered and interpreted by duly considering the data from all these regions, and that, geologically at least, the Far Hast has much to contribute toward the solution of our Western problems and vice versa. Read by title in the absence of the author. CO nN PROCEEDINGS OF THE SAINT LOUIS MEETING CLINTON FORMATIONS IN THE ANTICOSTI SECTION BY E. 0. ULRICH (Abstract) Among the stratigraphic results of a monographic study of the Silurian Ostracoda is reasonably definite proof that the Gun River and Jupiter River formations of the Anticosti section are of Lower Clinton age. The upper part of the Gun River formation is shown to correspond to the Williamson shale in New York and to the basal 100 feet or so of the Clinton at Cumberland, Mary- land, and at places in Pennsylvania. The same ostracod fauna is clearly recog- nized also in southwestern Virginia. The Jupiter River ostracod fauna also is clearly indicated in the Clinton sections in New York and Maryland. Its zone in these States lies from 60 to 150 feet above that of the Gun River species, the variations in the thickness of the interval between them being dependent on the relative local completeness of the sequence of Clinton deposition and probably on local variations in rate of deposition and character of deposits. Both of these faunal zones underlie the zone of Mastigobolba lata (Beyrichia lata—part, Hall), which lies near the middle of the Lower Clinton (Kirkland formation) in Pennsylvania and Maryland. Read in full from manuscript. Questions were asked and remarks made by Drs..I. C. White and John M. Clarke and the author. The Society adjourned at about 6 p. m. PRESIDENTIAL ADDRESS At 8 o’clock p. m., at the Planters’ Hotel, Prof. Frank D. Adams de- livered his address as retiring President, his topic being EXPERIMENT IN GEOLOGY Published as pages 167-186 of this volume. COMPLIMENTARY SMOKER The address was followed by the complimentary smoker given by an association of citizens of Saint Louis in honor of the Geological Society of America and its friends. TITLES AND ABSTRACTS OF PAPERS 83 SESSION OF FripAy, DECEMBER 28 The Society convened at 9 o’clock a. m., with President Adams in the chair. TITLES AND ABSTRACTS OF PAPERS PRESENTED AT THE MORNING SESSION AND DISCUSSIONS THEREON STRAND AND UNDERTOW RECORDS OF UPPER DEVONIAN TIME AS INDICATIONS OF THE PREVAILING CLIMATE BY JOHN M. CLARKE (Abstract) The effort to interpret the strand markings of the Portage sandstones in the light of records made on existing strands indicates that certain of these ancient strand marks are caused by the indirect action of ice, and that some of them may be due to ice crystallization. It is further indicated that such records of long continued cold are in accordance with other evidences of pre- vailing cold conditions during a part of the Middle and Upper Devonian period. Read in full from notes. Questions were asked by Dr. E. Blackwelder and Mr. F. Leverett and answered by the author. REPORT OF THE AUDITING COMMITTEE For the Auditing Committee, Eliot Blackwelder reported that it had examined the Acting Treasurer’s accounts and had found them correctly cast and properly vouched; also that a member of the committee (Pro- fessor Reid) would later examine and report on the Society’s securities, which are kept in its safe-deposit box at Baltimore.t~ On motion, the report was accepted and ordered placed on file. The Society, on motion, took from the table and accepted the report of the Council as printed. TELEGRAM TO DOCTOR WALCOTT AND REPLY In view of the newspaper reports of the fall within the enemy lines of Dr. Charles D. Walcott’s son, a member of the American Aviation Corps 1 Report received by the Secretary: I have examined the securities of the Society and find that the list as printed in the report of the Council for 1917 corresponds to the securities held by the Treasurer. (Signed) HARRY FIBLDING Rep. February 12, 1918. 84 PROCEEDINGS OF THE SAINT LOUIS MEETING in France, the Society instructed the Secretary to send a telegram of sympathy to its former President.* ANNOUNCEMENT OF THE FIRE AT MOUNT HOLYOKE The Secretary announced the receipt of a letter from Miss Mignon Talbot, Professor of Geology at Mount Holyoke College, relating to the total destruction by fire, on December 22, 1917, of Williston Hall, with all the scientific collections and apparatus of the college, and asking the help of the Fellows in building up again the collections in geology and paleontology. The Society then proceeded to the consideration of scientific papers. STUDY OF THE SEDIMENTS AS AN AID TO THE EARTH HISTORIAN BY ELIOT BLACK WELDER (Abstract) Progress in the interpretation of the physical history of the earth depends in large measure on our understanding of the principles of correlation and the origin of the sedimentary rocks. Of the two, the study of the latter is the more urgent, because it will assist in unraveling the puzzles of the former. At present our knowledge of the sedimentary rocks is very ragged. In order to fill out the deficiencies we need many detailed investigations of modern de- posits and of the processes by which they are being made, and many equally minute studies of ancient sedimentary rocks. Important service may be ren- dered by geologists who are not specialists in sedimentation, if they will make their stratigraphic descriptions as accurate and definite as possible, give precise information regarding all chemical analyses of sedimentary rocks, and collect material with adequate field-notes from the less familiar regions of the earth, as they may visit them. Some of the problems will, of course, require expedi- tions and cooperative work beyond the power of the individual, but feasible for some of our scientific institutions. 1In carrying out instructions, the following telegram was dispatched : “Hon. CHARLES D. WALcoTT, Washington, D. C.: “Geological Society of America, annual meeting assembled, extends heartfelt sympathy in your anxiety regarding son, who may have already made the greatest sacrifice possible for his country. “EDMUND OTIS Hovey, Secretary.” Doctor Walcott’s Reply “DEAR Doctor HovEy: We greatly appreciate the thoughtfulness of the members of the Geological Society who assembled at Saint Louis in expressing their sympathy. The present situation is summed up in the following cablegram from General Pershing: “With reference to Stuart Walcott, his engagement took place in the Grand Bois de Saint Souplet region. His machine did not fall in flames and did not land so violently as to lose hope that he may be a prisoner.’ “Sincerely yours, 4 **( Signed) CHARLES D. WALCOTT.” TITLES AND ABSTRACTS OF PAPERS 85 A comprehensive understanding of the origin of the sediments will greatly facilitate the interpretation of the earth’s climatic history and the evolution of the oceans; will give us far more accurate information regarding the distribution of land and sea and the topography of both, and will greatly strengthen our knowledge of volcanic epochs and diastrophic movements. We should even be able to understand those special and peculiar conditions which apparently are not now duplicated on the earth, but are implied by such de- posits as the iron ores of eastern Brazil and the phosphate deposits of Idaho. An understanding of sedimentation is essential to the new and rapidly develop- ing method of correlating rock formations, not simply on the basis of fossils or even diastrophism, but on the compound basis of life, climate, topography, vulcanism, and diastrophism, with critical regard to the relative values, mutual relations, and dependencies of all. Read in full from manuscript. DISCUSSION Dr. J. M. CLarKe emphasized the new importance of closer study of the com- position of sedimentary rocks along the lines suggested by the author and by the participants in the symposium on this theme held at the Albany meeting. OPPORTUNITIES FOR GEOLOGICAL WORK IN THE FAR ARCTIC / BY W. ELMER EKBLAW 14 (Abstract) Great areas of Greenland and the Arctic Archipelago are nearly, or quite, unexplored by geologists. Ellesmere Land and Greenland offer the best oppor- tunities for study of glaciers fed from great ice-fields, of the climatic condi- tions under which these ice-fields are formed, and of the resulting attendant phenomena. - The Arctic Archipelago presents such a diversity of physical conditions that it affords especially favorable opportunities for the comparison of physio- graphic phenomena characteristic of Arctic climates with those characteristic of other climates. Because the land is practically free from vegetation, and during the summer months, when work is possible, most of the ground is bare of ice and snow, the numerous structural problems which are presented throughout the Arctic Archipelago are not so difficult of study as is generally supposed. In only a few localities is the stratigraphy fairly well known. Only scat- tered observations have been made and collections of fossils are few and far between. This dearth of knowledge and material is due to neglect of the field rather than to paucity of exposures or fossils, for great tracts of sedimentaries are bare throughout the summer season and many beds are more or less fos- siliferous. ; There is no lack of opportunity for geologic work in the far Arctic; the want is men to do the work. Read in full from manuscript. 1—Introduced by W. S. Bayley. S6 PROCEEDINGS OF THE SAINT LOUIS MEETING DISCUSSION Dr. A. P. COLEMAN congratulated Mr. Ekblaw on showing how large a field for geological work still remains open in the Arctic islands. On the main- land, in Labrador, there is also much room for work. Two summers’ work have shown a large area in northeastern Labrador that was not covered by the Pleistocene glaciers, as in some areas which he has mentioned in the far north. Dr. E. O. Hovey: Mr. Ekblaw’s trip across Grant Land and results obtained, including collections, testify to the value of the geological observations made in connection with the Crocker Land Expedition. In his reply the author emphasized the desirability of establishing a scien- tific station in Labrador. GENESIS OF MISSOURI LEAD AND ZINC DEPOSITS BY W. A. TARR* (Abstract) A review is made of the current views that the lead and zinc deposits owe their origin to circulating ground waters which obtained the metals from the dolomites and limestones of the Ozark area or from once overlying, but now removed, beds. There are serious objections to these views, among which are the amounts of the metals in the original rocks, their distribution in them, their relation- ship to the solution channels, and the character of the circulation of the ground waters and its quantitative possibilities. Results of recent studies in related subjects offer new evidence which favors the view that they were de- — posited by rising thermal solutions. Read in full from manuscript. DISCUSSION Dr. A. R. Crook: Has the author not underestimated the permeability of rocks, illustrated by the treatment of agate in commercial manufactures? Dr. W. H. Emmons stated that he had proved the considerable permeability of some igneous rocks by soaking them in red ink. Does pyrrhotite occur as reported by Winslow? ; The author replied that linnzite occurs and has been mistaken for pyrrho- tite. Hydrothermal action has been noted. Permeability has been studied. Dr. F. R. Van Horn: Doctor Tarr seems very certain that the Missouri zine and lead deposits were derived from igneous rocks and brought to their present position by ascending waters. This non-argentiferous type of deposit is found in three different parts of Missouri, from the upper Mississippi Valley in Illi- nois, Wisconsin, and Iowa, from Belgium and western Germany, and from Silesia, Galicia, and Poland. At all of these places the ores are associated with dolomitic limestones of Cambrian, Ordovician, Mississippian, and Triassic age. Small amounts of sphalerite are found in the Niagara limestone in Ohio, and galena occurs in the Lockport dolomite in Ontario, these rocks being of 1 Introduced by E. B. Branson. TITLES AND ABSTRACTS OF PAPERS 87 Silurian age. Both minerals are found in the Keokuk, in southeastern Iowa, as geodes. Doubtless many are familiar with other occurrences which are not known to me. The presence of zinc and lead from so many localities and different geological horizons can be no accident. From all the above places igneous rocks seem to be absent. It seems as if the metals must have been derived from associated or previously overlying eroded limestones. In my opinion, it is not necessary that the metals should have been originally pre- cipitated in sulphide form, but as carbonates. The metals found commonly in such ore deposits are Ca, Ng, Fe, Zn, Mn, Ba, Sr, Pb, and Cu. All but the last occur in the isomorphous calcite and aragonite groups. Meigen has shown that various invertebrates secrete both calcite and aragonite shells or skele- tons. When the animal forms a shell of calcite it should also take up a cer- tain amount of Mg, Fe, Mn, and Zn. If it secretes an aragonite shell it is likewise to be expected that it will absorb-some Sr, Ba, or Pb. Van Ingen and Phillips have recently shown that the bodies of gastropods, crustaceans, and echinoderms also constantly contain Cn, Fe, Zn, and Mn, with Pb occasionally. This is additional evidence:that limestones must contain disseminated metals. I have nothing to say as to how this type of ore deposits reached their present position. Of course, the lateral secretion theory of Sandberger or precipita- tion by descending waters have prevailed; but I have no objection to Doctor Tarr’s theory of ascending waters, and I certainly feel that we have good reasons for considering the limestones as the direct source of the metals, although I also feel that the metals originally came into sea-waters by the decomposition of minerals from igneous rocks. Mr. H. A. WHEELER: The permeability of compact limestone is well illus- trated in a bed of very compact, close-grained lithographic limestone that occurs in a quarry on Barton and First streets, in south Saint Louis, in the upper portion of the Saint Louis limestone. Blocks of this seemingly imper- vious rock that show no seams to the eye are found to contain vugs or cavities one to six inches in size when broken open. These vugs are lined with curved rhombic pink crystals of dolomite, through which project beautiful complex erystals of prismatic calcite, and the remaining space is more or less completely filled with millerite, or sulphide of nickel, in a filiform or hairlike form. Occasional small crystals of gypsum, galnite, and sphalerite alse incrust the calcite crystals. The Hmistein mine, 10 miles west of Frederickstown, Mis- souri, alluded to by Professor Tarr, is the largest and strongest fissure vein thus far found in the granitic area of southeast Missouri, but smaller, non- profitable, quartz veins in the granite and porphyry are quite frequentiy found that usually carry more or less argentiferous galena or copper sulphides. The silver content is usually not large, 5 to 25 ounces per ton, and the veins are apt to be only a few inches in width, with a quartz filling. RELATION BETWEEN OCCURRENCE AND QUALITY OF PETROLEUM AND BROAD AREAS OF UPLIFT AND FOLDING BY EUGENE WESLEY SHAW (Abstract) In attempting to find the cause of the fact that most of the oil and gas occurs in geosyneclines, and that there seems to be some relation between the VIII—Butn. Grou. Soc. AM., Von. 29, 1917 * 88 PROCEEDINGS OF THE SAINT LOUIS MEETING character of the hydrocarbons and general structural features, attention should be given to the following considerations, in addition to the geographic arrange- ment: (1) The fact that the strata are higher and the rocks more fractured in the regions of uplift; (2) the possibility that the present areas of geanti- clines were areas of uplift and the geosynclines areas of depression at the time the strata were laid down, and that for this, and perhaps other reasons, © conditions and original deposits were different; (3) other respects in which the history and conditions likely to have affected the formation, retention, and character of oil have been different; (4) the question of whether or not oil and gas pools were formed in the geanticlines, and if they were, what was their history and why are few, if any, traces left; (5) the extreme improba-— bility of thrust pressures affecting the fluids in rock pores to an extent greater than 50 or 100 per cent above the hydrostatic head, for higher pressures would oresumably squeeze out the fluids, and differences in superincumbent load seems to have little effect on the quality of petroleum; (6) the great and ap- parently irregular quality variations of the hydrocarbons in short distances— the innumerable and extensive departures from harmony among the data; (7) the greater abundance of salt. water in the geosynclines, indicating poorer circulation; (8) the effects of filtration during migration of the oil; (9) the quality of the relict portion of the parent material, particularly in any central vortions of the compressed areas where the pressure may have been locally relieved; (10) the principles of physical chemistry that are concerned, par- ticularly the possibility of pressure affecting the chemical transformations ; (11) the chemical reactions that may have been induced by substances other than carbon and hydrogen and their compounds, such as sulphur, chlorine, and clay. It seems to the writer (1) that more than one hypothesis is in accord with most of the available facts and established principles; (2) that, contrary to certain statements, no hypothesis thus far offered fits all the evidence; (3) that probably there are several reasons why oil and gas occur mainly in geo- synclines and more than one reason for the apparent relation between quality and distance from centers of uplift; (4) that a basinward or down-dip migra- tion has been general and has been at least a partial cause of quality relation- ships, the gas perhaps tending to lag behind in the downward movement be- cause of its extreme lightness, and possibly certain oils because of their great viscosity. Read by title in the absence of the author. NEW POINTS IN ORDOVICIAN AND SILURIAN PALEOGEOGRAPHY BY T. E. SAVAGE AND FRANCIS M. VAN TUYL (Abstract) As a result of a study of the early Paleozoic formations of the Hudson Bay region and of Wyoming, new data bearing on the paleogeography of Ordovician and Silurian time have been obtained. Presented by the senior author in abstract from notes. a?) Se 1 *eeig ea -—-4- «9 ubehane nm, 2p eee, “ow TITLES AND ABSTRACTS OF PAPERS 89 DATING OF PENEPLAINS: AN OLD EROSION SURFACE IN IDAHO, MONTANA, AND WASHINGTON—IS IT HOCENE? BY JOHN L. RICH (Abstract) The correct dating of wide-spread erosion surfaces, or peneplains, is a matter of the greatest importance because of their value as datum planes for the interpretation of recent earth history. A consideration of the probable fate in store for the elaborate superstruc- ture reared on the determination of the origin and dating of the so-called Cretaceous peneplain of eastern United States, which seems about to crumble as a result of the recent work of Barrell and Shaw, should cause physiogra- phers and geologists to pause and weigh well the evidence before accepting the fact or the dating of similar erosion surfaces elsewhere. An old erosion surface, or peneplain, which seems to have wide development in Idaho, Montana, and Washington, has been definitely dated as Eocene by Umpleby and Atwood. Inasmuch as this dating has been questioned, a de- tailed examination of the published evidence has been undertaken. The correctness of the determination of the Eocene age of the erosion sur- face hinges mainly on whether certain broad, intramontane troughs, in which lie Oligocene and Miocene sediments, were developed before or, as maintained by Umpleby and Atwood, after the peneplain was cut. Examination of the published evidence fails to reveal any convincing proof that the basins are younger than the peneplain. On the contrary, it brings out many features of the geology and physiegraphy of the region which do not harmonize with this explanation. Oligocene and Miocene sediments in the basins are commonly highly de- formed; the contacts of the sediments with the basin walls, in some places at least, are faults; the basin floors are far from being parts of a graded system, and to restore the graded condition by uplifting, dropping, or tilting faulted blocks would throw the peneplain remnants far out of harmony; and, finally, the broad basins are physiographically entirely out of accord with the valleys of the! present drainage systems, which are prevailingly narrow, V-shaped canyons, whose derivation in a single cycle from the former system by a process of headward erosion or stream piracy, as has been suggested by Umbleby and Atwood, is a physiographic impossibility. Far from proving an Eocene age for the peneplain, the field relations de- seribed by the authors of that dating seem to prove that the basins in which the Miocene sediments lie were blocked out, filled, and suffered most of their deformation before the peneplain was cut. Read in full from manuscript. DISCUSSION Dr. Bruce L. CLarK: Recent vertebrate collections made by Prof. J. C. Merriam in the so-called lake beds of Doctor Umpleby are much later in age than Umpleby supposed, being, if I remember correctly, Upper Miocene or Lower Pliocene in age. 90 PROCEEDINGS OF THE SAINT LOUIS MEETING Dr. ELtior BLACKWELDER: Adverse criticism of our colleagues is always dis- agreeable, but in such a case as this it becomes a duty. It seems to me that Doctor Rich has done us a service in analyzing the arguments relating to the alleged Eocene peneplain of the Northwest. I have followed this matter for several years and have been to some extent involved in the controversy. In my opinion, Doctor Rich is correct in his conclusions. Remarks were also made by Dr. L. G. Westgate. IRON FORMATION ON BELCHER ISLANDS, HUDSON BAY, WITH SPECIAL REFERENCE TO ITS ORIGIN AND ITS ASSOCIATED ALGAL LIMESTONES BY E. S. MOORE (Abstract) The Belchers are a group of large islands, nearly 100 miles in length, lying about 70 miles northwestward from the mouth of Great Whale River, Hudson Bay. They were little known until three years ago, when large areas of jas- pilite were discovered on their shores. The sedimentary series, with the asso- ciated igneous intrusions and extrusions, is related to the group on the east coast of Hudson Bay and bears a close resemblance to the Animikie and Keweenawan rocks of the Lake Superior region. They show, however, a re- markable development of algal structures, which indicates either that these rocks are younger than the Precambrian or that an abundance of life of low type existed in the Hudson Bay basin during Precambrian time. Since the iron formation contains outlines of weathered globular granules, it seems probable that the alge may have had a part in precipitating iron carbonate and silica in concretionary form. Read by title in the absence of the author. The Society adjourned soon after noon and reconvened at 2.30 p. m., with Dr. J. M. Clarke in the chair. The Society proceeded immediately to the consideration of scientific papers. TITLES AND ABSTRACTS OF PAPERS PRESENTED BEFORE THE AFTERNOON ‘SESSION OF FRIDAY SUBPROVINCIAL LIMITATIONS OF PRECAMBRIAN NOMENOLATURE IN THE SAINT LAWRENCE BASIN BY M. E. WILSON (Abstract) The detailed geological work carried on in recent years throughout the southern part of the Canadian Precambrian shield has shown that the geo- logical succession in the ancient terranes of this territory is regionally less uniform and includes a greater number of rock series than was formerly sup- TITLES AND ABSTRACTS OF PAPERS 91 posed. Moreover, it has become evident that the wide-spread correlations implied by the use of the same nomenclature nearly everywhere throughout this great Precambrian province assumes much more with regard to the re- gional succession in these ancient rocks than is actually known. Although it is not possible generally to demonstrate, with mathematical con- clusiveness, that geological formations occurring in different localities are equivalent, nevertheless the premature use of the same name for formations the correlation of which is open to question, or the continued use of the same name for formations after it has become evident that their correlation is in doubt, is misleading, and an obstacle rather than an aid in geological investi- gation. Hypothetical correlations of groups of rocks occurring in widely sepa- rated districts may serve for comparison or as a stimulus to investigation, but all the advantages of such tentative correlations may be attained by using a general terminology (Proterozoic, Archzozoic, etcetera), and thereby avoiding the definite correlations implied in the use of names of local origin. In the Precambrian province which occupies the northern part of the Saint Lawrence River basin there are four geographically and geologically separate subproy- inces: (1) The region northwest of Lake Superior, (2) the region south of Lake Superior, (3) the region extending northeastward from Lake Superior and Lake Huron to Lake Timiskaming and Lake Mistassini, and (4) eastern Ontario and the lower Saint Lawrence, with which might be included the Adirondack region. With the possible exception of the south shore of Lake Superior and the Lake Huron and Lake Timiskaming subprovinces, the evi- ‘dence on which the rocks of these separate regions can be correlated is exceed- ingly meager, and for the present, at least, the only logical course would seem to be to build up a separate nomenclature in these various subprovinces by using those names already defined in these localities, supplemented by such local new names as becomes necessary from time to time as geological investi- gation is continued. The wide-spread correlations implied in the use of a common nomenclature throughout all the Precambrian subprovince of the Saint Lawrence basin has been based on the assumption that the succession of formations within the various subprovinces has been worked out to a practical completeness and on the application of certain principles by which the correlation of the various formations in these widely separated areas are presumed to be established. The writer’s purpose is to point out that the assumption that our knowledge of the succession of formations in any of the subprovinces is complete is open to question, and that the principles by which Precambrian rocks are generally correlated are in part inapplicable and as a whole quite inadequate for the establishment of a Precambrian nomenclature embracing all the territory in the Saint Lawrence basin in which Precambrian rocks occur. Read in abstract from manuscript. DISCUSSION Dr. A. P. CotEMAN: Doctor: Wilson’s paper is of importance as showing the danger of extending a classification of the Precambrian worked out in one region to other widely separated regions. His suggestion of more than two ages of batholithic mountain-building lengthens out still farther the tremen- 92 PROCEEDINGS OF THE SAINT LOUIS MEETING dously long Precambrian history of the world, which probably much exceeds in length the latter parts of the world’s history. He seems a little too pessi- mistic, however, in regard to the working out of a general classification of the Precambrian. The close parallelism of the succession found in different re- gions seems to suggest a real basis for classification. Dr. W. J. MILLER: Doctor Wilson has sounded a note of comfort to some of us at least who work with Precambrian rocks. For one, I have not been able . to keep pace with the ideas definitely expressed in several recent correlation tables. In the Adirondack region I have even hesitated to use the old term “Laurentian” because there is so much difference regarding its use. I agree with Doctor Wilson when he maintains that definite correlations covering the region from western Ontario to the Saint Lawrence Valley are out of order until many more field facts are well in hand. FURTHER STUDIES IN THE NEW YORK SILURIC BY GEORGE H. CHADWICK (Abstract) The analysis and correlation of the Cayugan “waterlimes” has been carried eastward to Cayuga Lake in the effort to show the true position of the so- ealled Cobleskill and Rondout, in the western sections. Studies also made of the New York Clinton sections have suggested the necessity for some readjust- ments in the present classification. Read by title in the absence of the author. RELATION OF THE OIL-BEARING TO THE OIL-PRODUCING FORMATIONS IN THE PALEOZOIC OF NORTH AMERICA BY AMADEUS W. GRABAU (Abstract) The oil-bearing formations which will be considered are: The Trenton lime- stone, the Onondaga (Corniferous) limestone, the Upper Devonic sands of southwestern New York and northwestern Pennsylvania, and the Berea sand- stone. The widely held view that the oil of the Trenton and Onondaga lime- stones was produced from the soft part of the animals which secreted the caleareous structures from which these limestones are formed is untenable, — since the conditions of accumulation of zoogenic and phytogenic limestonés in the sea involves the destruction of the organic matter by contemporaneous scavengers. Even where the limestones are wholly composed of shells and corals, these are practically pure lime accumulations, free from organic ma- terial. That the oil of the Upper Devonic and of the Berea sandstone could be derived from the organisms contained from the inclosing beds need hardly be seriously considered. In the case of the oil-bearing formations mentioned, and probably in the majority of oil-bearing formations of all horizons, the source of the oil is to be sought in the black shales, either sapropelitic or humulitic, which occupy corresponding horizons in an adjoining area and from which the oil (and gas) TITLES AND ABSTRACTS OF PAPERS 93 passes laterally into the porous strata which bear them. This implies, of course, that the respective formations must be in replacing relationship, either that of replacing overlap or an interfingering relation. The Utica shale, in the larger sense, has a replacing overlap relation to the Trenton limestone and is the source of the oil of that rock. In the east the Trenton horizon is black shale, rich in carbonaceous matter. Westward it passes laterally into . Trenton limestone, though at any one locality Lower Trenton limestone is overlain by higher “Utica” shale. Bach division of the black shale, however, passes westward into limestone, and the passage of the oil was from the shale where it originated along the bedding planes into the limestones, where it was stored. The Marcellus shale has the same relation to the Onondaga limestone and is the source of the oil of that formation. The Portage and Chemung sands of the Bradford region apparently derive their oil from the black shales, which replace them westward and which in Ohio form the black Ohio shale, which, as I have elsewhere shown, is a stratigraphic equivalent. The Berea oil appears to be derived from a part of the Chattanooga black.shale, which replaces it to the southward. This relationship, too, I have elsewhere demon- ‘strated. Read by title in the absence of the author. REVISION OF THE MISSISSIPPIAN FORMATIONS OF THE UPPER MISSISSIPPI VALLEY BY STUART WELLER AND FRANCIS M. VAN TUYL (Abstract) In accordance with the cooperative plan of study and correlation of the Mississippian formations of the Mississippi Valley, furthered by the several State Geological Surveys of the region, the writers have been occupied with the investigation of these deposits in Iowa and western Illinois since 1913. As a result of these studies, more complete data bearing on the composition of the faunas of the more important horizons has been obtained and a revision of the boundaries of certain formations has been necessitated. Read by title in the absence of the author. NOTES ON THE STRATIGRAPHY AND FAUNAS OF THE LOWER KINDERHOOKIAN IN MISSOURI BY E. B. BRANSON (Abstract) A thin sandstone, which rests unconformably on various older formations, is the usual basal Kinderhookian, but in some places shales come in below the sandstone. The sandstone seems to correspond to the Sylamore of Arkansas... Fish remains are of common occurrence in the sandstone, while marine inver- tebrates have been found in only one locality. Presented in full extemporaneously. Remarks were made by Dr. EH. O. Ulrich, with reply by the author. 94 PROCEEDINGS OF THE SAINT LOUIS MEETING MEGANOS GROUP, A NEWLY RECOGNIZED DIVISION IN THE EOCENE OF CALIFORNIA BY BRUCE L. CLARK + (Abstract) An unconformity believed to be of more than local importance is recognized in the Eocene deposits of Mount Diablo, California, in a section heretofore recognized as representing the Tejon group of the Upper Eocene. This uncon- formity is indicated by difference in strike and dip, together with other eyvi- dences of erosion. The beds above the contact contain a typical Tejon fauna, while those immediately below contain a faunal representation differing con- siderably from that of the typical Tejon, and also differing from the typical Martinez fauna of the Lower Eocene. Strata representing the Martinez are - found in this section unconformably below the newly recognized Stewartsville group. The name Meganos is given to the new group situated between typical Martinez and typical Tejon. It is believed that deposits of the Meganos group have a wide distribution throughout the coast ranges of California. In certain localities they have been referred to the Martinez group and at other places to the Tejon. Presented in full extemporaneously. Remarks were made by Dr. Ehot Blackwelder. AGE OF THE MARTINSBURG SHALE AS INTERPRETED FROM ITS STRUCTURAL AND STRATIGRAPHICAL RELATIONS IN EASTERN PENNSYLVANIA BY F. F. HINTZE (Abstract) Isolated masses of Martinsburg shale occur several miles to the east of the main body of shale and slate rock, lying unconformably on older rocks, from the Hardyston (Lower Cambrian) to the Trenton. The Martinsburg has been correlated with the “Hudson River” shale, and its age variously determined to be Trenton or Utica on the basis of graptolite remains found at localities in Pennsylvania, New Jersey, and New York. The decided unconformity of the Martinsburg on the older Cambrian and Ordovician beds shows a period of folding and considerable erosion prior to the end of Martinsburg time, before the beds of which the isolated masses or remnants were deposited. Fossils have not been found in these detached areas of Martinsburg shale, the identification of the material as Martinsburg being based on lithologic charac- ters which bear a very striking resemblance to those of the main body of the shale. In New Jersey the Martinsburg has been described as following the Jack- sonburg limestone (Lowville, Black River, and Trenton) in normal conform- able sequence, and on the basis of graptolites found the lower part of the Martinsburg is here correlated with the middle part of the typical Trenton of 1 Introduced by John C. Merriam. —_ ea eS ee SS ee ee TITLES AND ABSTRACTS OF PAPERS | 95 New York. As no break occurs at the base of the Martinsburg, the interval of folding and erosion indicated by the unconformity above mentioned came later, the exact time being unknown at present. After the erosion interval followed more shale deposition, the new deposit overlapping the Lower Martinsburg and all the older formations that had been truncated by erosion. The upper part of the Martinsburg is thus distinctly younger than the lower part and may belong to the late Ordovician, possibly Richmond, and the break may correspond in time with that found in the Mississippi Valley between the Galena (Trenton) limestone and the Maquoketa (Richmond) shale. Read by title in the absence of the author. INVERTEBRATE FAUNA OF THE GRASSY CREEK SHALE OF MISSOURI BY. DARLING K. GREGER ? (Abstract) In a paper on the formations in the vicinity of the Cap au Gres fault, pub- lished by Keyes, in the Transactions of the Iowa Academy of Science, 1897, page 12, the Grassy Creek shale is described in the following manner: “Imme- diately beneath the well defined Louisiana limestone, in the vicinity of the town of Louisiana, there are about six feet of black and green shales carrying a characteristically Devonian fish fauna. Ten miles west, on Grassy Creek, these shales attain a thickness of 30 feet, but southward they thin out com- pletely before the limits of Pike County are reached.” North of the region of the type locality outcrops of the formation are found in Ralls and Marion counties and the maximum thickness is probably far in excess of the figure given by Keyes. The vertebrate fauna has been described by Branson, in a bulletin of the University of Missouri, and the invertebrate species of the association are de- scribed in the present paper. The fauna, as I have elaborated it, is one quite characteristic of the type of sediment, consisting in the main of inarticulate brachiopods. Without attempting to draw any definite deductions as to the age of the formation from the evidence offered by the fauna, as I have worked it out, I give the following list of species: Ptychostylus subtumidus Gurley. Lingula conklini sp. nov. Lingula missouriensis Rowley. Athyris bransoni sp. nov. Lingula pikensis sp. nov. Adolfia ef. amarus Swallow. Lingula tantilla sp. nov. Douvillina cf. mucronata Conrad. Lingula rowleyiana sp. nov. Paleonilo compressa sp. nov. Lingula insolata sp. nov. Pterochenia longwelli sp. nov. Lingula yatsui sp. nov. Read by title in the absence of the author. 1 Introduced by BH. B. Branson. 96 PROCEEDINGS OF THE SAINT LOUIS MEETING SOME DEFINITE CORRELATIONS OF WEST VIRGINIA COAL BEDS IN MINGO COUNTY, WEST VIRGINIA, WITH THOSE OF LETCHER COUNTY, SOUTHEAST- ERN KENTUCKY . BY I. C. WHITE (Abstract) The new Volume IV, Part L, Series IV, of the Kentucky Geological Survey, J. B. Hoeing, State Geologist, gives much valuable detailed information on the Kanawha Series of Coals, so extensively mined at Jenkins, McRoberts, Flem- ing, and other points in Letcher County, Kentucky. This publication, by A. F. Krider, gives for the first time such accurate and detailed descriptions of the stratigraphic column of the southeastern Kentucky and adjoining Virginia region coal fields that it now becomes possible to correlate several of these Kentucky and Virginia coals definitely with the main beds of the Kanawha Series as studied and classified by White, Hennen, and Reger in Mingo and adjacent counties of West Virginia. Presented in full extemporaneously. RECORDS OF THREE VERY DEEP WELLS DRILLED IN THE APPALACHIAN OIL FIELDS OF PENNSYLVANIA AND WEST VIRGINIA BY I. C. WHITE (Abstract) The detailed records of three deep wells are given in this paper: (1) Der- rick City, near Bradford, Pennsylvania; (2) Geary well, near McDonald, Penn- sylvania, and (3) the Martha Goff well, near Clarksburg, West Virginia, the latter two of which exceed 7,000 feet in depth. In addition to the interesting stratigraphic data afforded by the records, reference is made to the tempera- ture results obtained by Mr. C. E. Van Orstrand,-Physical Geologist of the United States Geological Survey, through the courtesy of Messrs. Pew and Corrin, vice-presidents of the Hope Natural Gas Company, who expect to make the Goff well the deepest one ever drilled, and thus exceed that of the famous one at Czuchow, which stopped at 7,349 feet. Presented in full extemporaneously. DISCUSSION Mr. DrecKER: With reference to the distribution of-the salt mentioned by Doctor White, no salt, but about 150 feet of gypsum and interstratified shales, occur in the deep well at Erie, Pennsylvania. However, in a deep well on the farm of Mr. Hindekoper, west of Conneaut Lake, Pennsylvania, a thickness of 75 feet of salt has been reported. Dr. F. R. Van Horn: In the Cleveland, Ohio, district we have five Salina salt strata aggregating something like 160 feet instead of 100 feet, as stated by Doctor White. He has indicated that in the records of these deep wells no gas was found in what he calls the Niagara limestone. In Cleveland, in what we think to be the Lockport dolomite, we have the horizon called the Newburg TITLES AND ABSTRACTS OF PAPERS 97 sand,,in which was found the famous Staddler well, which started our gas boom. This well had an initial flow of over 12 million cubic feet daily. This horizon was found about 2,400 feet below the surface. Three hundred feet below this is the so-called Clinton sand, which has been the source of most of our gas. I may also state, in the absence of Cushing and Ulrich, that for over three years they have considered the Clinton sand as Medina age, thus agree- ing with the conclusions just expressed by Doctor White. Remarks were also made by Professors A. P. Coleman and J. F. Kemp, and reply was made by the author. TENTATIVE CORRELATION OF THE PENNSYLVANIA STRATA IN THE EASTERN INTERIOR, WESTERN INTERIOR, AND APPALACHIAN REGIONS BY THEIR MARINE FAUNAS BY T. E. SAVAGE (Abstract) In this paper the faunas of the successive marine fossil-bearing horizons in the western interior, eastern interior, and Appalachian regions are compared. A study of the vertical range of the species of Pennsylvanian fossils in these regions has shown that certain species have such limited vertical range that it is thought they can be used as trustworthy markers of different horizons in the respective basins, and that these furnish more accurate means of correla- tion than any criteria that have hitherto been available. These studies indicate that the arch that at present separates the eastern interior and western interior coal basins along the Mississippi River was de- veloped at the close of the Mississippian period, before the earliest Pennsy]l- vanian sediments were laid down, and that it effectively separated the seas that occupied a large part of Illinois and Missouri during Pennsylvanian time, although toward the north these seas may have been temporarily united during a small part of the Pottsville epoch. Read in full from manuscript. Remarks were made by Dr. J. M. Clarke. PRECAMBRIAN ROCKS IN THE MEDICINE BOW MOUNTAINS OF WYOMING BY ELIOT BLACKWELDER AND H. F. CROOKS (Abstract) The Medicine Bow Range, west of Laramie, Wyoming, hitherto neglected by geologists, contains one of the most varied sections of Precambrian rocks in western United States. In addition to the usual gneissic and schistose com- plex, more than 25,000 feet of slightly metamorphosed sedimentary rocks, such as quartzites, slates, dolomites, lava flows, pyroclastics, and tillites, are ex- posed without repetition. Although but little of the detailed study of the rocks has yet been carried out, a preliminary outline can be given, and the empirical sequence will be briefly discussed. The correct interpretation of the stratig- raphy depends on an accurate knowledge of the structure, and that remains in doubt. In this interesting case it has been found that the testimony of the primary sedimentary structures is generally opposed to the apparent implica- 98 PROCEEDINGS OF THE SAINT LOUIS MEETING tion of the secondary or deformative structures. The problem thus raised will be considered and solutions offered. Read in full from manuscript. GEOLOGIC MAP OF BRAZIL BY JOHN CASPER BRANNER (Abstract) The text to accompany the new and comprehensive geological map of Brazil, which has been offered to the Society for publication, was presented. Read by title in the absence of the author. NOTES ON THE GEOLOGY OF THE REGION OF PARKER SNOW BAY, . GREENLAND BY EDMUND OTIS HOVEY (Abstract) Parker Snow Bay indents the coast about midway between Cape York and Cape Athal. The southern shere and the outer portion of the northern side consist of strongly hornblendic gneisses containing intrusive masses of basic igneous rock. The eastern portion of the northern side is feldspathic gneiss, apparently younger, which contains heavy dikes of basaltic character. The gneisses are generally considered to be Archean in age. Over the feldspathic gneiss, in the northeastern quarter of area, begins the series of Huronian (7?) quartzites, quartz schists, etcetera, which appear to be well exposed along the coast to a point beyond Etah. Solifluction, terracing, and glaciation were noted. Evidence of comparatively recent elevation was observed. . Presented in abstract extemporaneously. Scciety adjourned at about 5.30 o’clock p. m. ANNUAL DINNER The annual dinner of the Society and its friends was held at 7.30 o'clock, at the Planters’ Hotel, Fourth and Pine streets. Under the chairmanship of President Frank D. Adams, in response to the chairman’s call, speeches were made by Messrs. J. M. Clarke, A. P. Coleman, P. N. Moore, James F. Kemp, Eliot Blackwelder, and E. B. Branson. Seventy-five Fellows and guests were present. SESSION OF SATURDAY, DECEMBER 29 The Society convened at 9 o’clock a. m., with President Adams in the chair, and proceeded to the consideration of scientific papers. a SE 4 J 5 ; q 7 5 ; “ TITLES AND ABSTRACTS OF PAPERS 99 TITLES AND ABSTRACTS OF PAPERS READ BEFORE THE SATURDAY MORNING SESSION FIELD RELATIONS OF LITCHFIELDITE AND SODA-SYENITE OF LITCHFIELD, MAINE BY REGINALD A. DALY (Abstract) The original type of nephelite syenite, litchfieldite, hitherto known only in the form of glacial erratics, has been discovered in a place near South Litch- field, Maine. The rock occurs as small lenticular injections, roughly parallel to the vertical schistosity and bedding of the inclosing sediments. Nephelite- free, soda-rich syenites constitute associated injections of similar form and relations. Read by title in the absence of the author. ADIRONDACK ANORTHOSITE BY WILLIAM J. MILLER (Abstract) This paper dealt with the whole problem of the structure and origin of anorthosite, with special reference to the Adirondack region. Particular atten- tion was given to Bowen’s recent paper in the Journal of Geology, in which he elaborates an-hypothesis to account for the structure and origin of the Adirondack anorthosite. Asa result of six months of detailed field-work within and close to the great anorthosite area of northern New York, the present writer finds Bowen’s hypothesis untenable. Further evidence in support of Professor Cushing’s contention that the anor- thosite iS a separate intrusive body distinctly older than the syenite-granite series was presented, but many new points which have important bearings on the whole problem were considered. Among the principal topics discussed were the following: Variability of the anorthosite and its significance; the chilled border facies and its significance ; relation of the anorthosite to the Grenville series; relation of the syenite- granite series to the anorthosite; anorthosite and syenite-granite mixed rocks; general absence of syenite and granite from the anorthosite area, and probable origin of the anorthosite by differentiation on a laccolith of gabbroid magma. Read in abstract from manuscript. DISCUSSION Dr. W. S. Bayiey congratulated Professor Miller on his attempt to study the anorthosites in the field rather than in the laboratory. He corroborated the speaker’s observation that the anorthosites are not pure feldspar rocks. In Minnesota the anorthosite passes by uniform gradations into olivine gabbro, all phases of the gradations being recognizable. In the highlands of New Jersey—an area in which the geology is very similar to that of the Adirondacks—the quantity of syenite gneiss is so great 100 PROCEEDINGS OF THE SAINT LOUIS MEETING that it is difficult to imagine these rocks to be acid differentiates of a gab- broitic magma, since gabbros are present only in insignificant patches in the district. Moreover, the syenites are not at all like the granophyric rocks asso- ciated with gabbros in Minnesota and at Sudbury. Dr. F. F. Grout: It may be well to record two points in which the Duluth gabbro and related sills are less favorable tc Doctor Bowen’s idea of anortho- site formation than he thinks. At Duluth gabbro was intruded at two periods. The first and smaller mass seems to contain about 85 per cent plagioclase. It has large volumes of anorthosite differentiate. The second intrusion has more nearly 70 per cent plagioclase, but has numerous layers of anorthosite of smaller size. Since magmas vary from 70 to 85 per cent in plagioclase, as intruded, it seems certain that some may be intruded with over 90 per cent plagioclase when they would be classed as anorthosite. Bowen, in outlining the origin of anorthosites, refers to Winchell’s observation that some diabases have lumps of anorthosite and scattered crystals of plagioclase. I have seen the lumps described, and have seen lumps apparently identical in nature and relation in the ‘‘red rock,’ from which they could not have formed by segrega- tion. I have no hesitation in stating that these lumps of anorthosite are xenoliths, not segregations. Remarks were also made by Professors James F..Kemp and Frank D. Adams. PETROLOGY OF RUTILE-BEARING ROCKS BY THOMAS LEONARD WATSON ~ (Abstract) The paper presents a discussion based on chemical and microscopic studies of the petrology of rutile-bearing igneous rocks in general, including the more important districts in this country and abroad. Read by title in the absence of the author. INTERNAL STRUCTURES OF IGNEOUS ROCKS BY FRANK F. GROUT? (Abstract) The igneous rock structure emphasized is an alternation of bands of vary- ing mineral composition. In many places this is related to a fluxion structure and a sheet structure. Many references to descriptions of one or several such structures are cited. The Duluth gabbro shows all three structures conspicu- ously. In nearly all of the many references it is stated that the structure in the igneous rock shows a general parallelism to the contacts of the mass—that is, the structure developed under some control by its walls. There are so few exceptions that the structure may be safely used as a guide to form. The origin of the structure has been discussed by several men. Eliminating those cases in which metamorphic banding or half-fused layers are indicated, the Suggestions are: (1) Partial assimilation, (2) lit par lit, (3) deformation 1JIntroduced by W. H. Emmons. 7” ~~ —_—” Tee” 6h OO eee eee ea TITLES AND ABSTRACTS OF PAPERS 101 during or just after solidification, (4) streaked differentiation, (5) successive intrusion, (6) heterogeneous intrusion. The writer would add (7) convection during crystallization. Presented in abstract from notes. DISCUSSION Dr. W. J. Micuer: Doctor Grout should be congratulated on this paper. The Adirondack anorthosite shows many bands of varying mineral composi- tion, but not as conspicuously as the Duluth gabbro, and the bands, so far as I have observed them, are extremely variable in dip and strike, with appar- ently no general parallelism to contacts. Possibly the laccolithic structure of the Adirondack anorthosite as opposed to the sill structure of the Duluth gabbro might account for the difference. Dr. M. E. Witson: To one who is constantly encountering the phenomenon of a banded structure in igneous rocks, Doctor Grout’s paper is of special interest. ‘There is one way, however, in which I think a banded structure might possibly develop in an igneous rock that Doctor Grout did not mention, and that is by diffusion during consolidation. It is obvious that if a magma is homogeneous before consolidation com- mences, the development of individual crystals is in reality differentiation on a small scale. In some magmas this differentiation by crystal growth appar- ently continues until aggregates of crystals have developed and a rock of a very heterogeneous appearance is formed. If a magma in which this differen- tiation process was in progress was subject to differential pressure, it seems reasonable to suppose that the segregation wculd take place linearly, resulting in a banded structure. Many of the igneous Precambrian rocks of the Cana- dian Laurentian highlands are characterized by a minute discontinuous band- ing, the origin of which, it seems to me, can be best explained in this way. Remarks were also made by Prof. James F. Kemp and Dr. M. E. Wilson. | TWO-PHASE CONVECTION IN IGNHOUS MAGMAS BY FRANK F. GROUT? (Abstract) Convection is indicated by the banding in igneous rocks. It is observed in lava lakes and may be inferred from other rock structures. Convection in a deep magma chamber has usually been attributed to density differences due to temperature of the liquid. Daly also emphasizes the change of density due to a concentration of a gas phase. This paper emphasizes the density difference due to crystal phases. ; The order of magnitude of the forces is estimated. The results of such two- phase convection are outlined. Presented in abstract from notes. 1JIntroduced by W. H. I’mmons. 102 PROCEEDINGS OF THE SAINT LOUIS MEETING DISCUSSION Answer of author to questions by Dr. W. J. Miller: Regarding the regu- larity in the structure and conformity to walls, I would say that I can not assume that conformity always occurs, but simply state that of 24 recorded cases only one exception was found. New records will be welcome. One should also note whether the irregularity is general or local. HYDROUS SILICATE MELTS BY N. L. BOWEN* AND G. W. MOREY * (Abstract) The system H,O-K,SiO,-SiO, has been studied experimentally by Morey, with careful control and measurement of both temperatures and pressures. His results furnish a basis for the quantitative description of the behavior of the hydrous melts on cooling under various conditions of pressure and illustrate principles of general importance in the consideration of the behavior of mag- mas containing volatile components. Read by title in the absence of the authors. ; SIGNIFICANCE OF GLASS-MAKING PROCESSES TO THE PETROLOGIST BY N. L. BOWEN? (Abstract) Glass-making processes offer little support to the belief in immiscibilty of silicate liquids. They do, however, emphasize that the stage at which the mass is partly liquid and partly solid (crystalline) is of great significance to one interested in the differentiation of igneous rocks. It is principally at this stage that different parts of the melt may acquire composition differences troublesome to the glass-maker, though instructive to the petrologist. Read by title in the absence of the author. TYPES OF NORTH AMERICAN PALEOZOIC OOLITES BY FRANCIS M. VAN TUYL? AND HAROLD F. CROOKS 2 (Abstract) Through the cooperation of a number of geologists located in various parts of North America, it has been possible to assemble for study samples from nearly all known oolitic horizons of the Paleozoic. The varieties represented are calcareous, siliceous, phosphatic, and ferruginous. Microscopic study of these shows that they may be classified according to a few important struc- tural types. These are described and the evidence bearing on the probable mode of origin of each is summarized. Read by title in the absence of the author. 1 Introduced by H. S. Washington. 2 Introduced by Eliot Blackwelder. TITLES AND ABSTRACTS OF PAPERS 103 SILICEOUS OOLITES IN SHALE BY W. A. TARR? (Abstract) The unusual occurrence of oolites in shale from the red beds is noted. The oolites are in a sandy shale of varying colors, red, yellow, and green predomi- nating. The oolites are of two sizes, the larger averaging about .65 mm. and the smaller from .1 to .18 mm. They make up approximately 50 per cent of the rock. The large oolites are concentrically banded in their. outer parts only. The oolites are believed to be original and to have been formed through the precipitation of colloidal silica along with the materials of the shale. Read in full from manuscript. INORGANIC PRODUCTION OF OOLITIC STRUCTURES BY W. H. BUCHER” (Abstract) A preliminary account was given of the results of successful experiments made to prove that oolitic structure can be produced without the direct or indirect help of organisms in substances other than calcium carbonate. The bearing of these results on the origin of various oolitic sediments was dis- cussed. Artificial and natural specimens were exhibited. Presented in full from notes. DISCUSSION Mr. EH. G. Wooprurr: There are publications describing oolites from oil wells at Sour Lake, Texas. These oolites are from an oil-producing well which is being pumped. The well is lined with strainer and openings too small to admit oolites, but will admit nuclei-forming materials. Saline solutions enter the well. The fluids are agitated and the salts are precipitated about any solid fragment in the well. Salts are deposited in concentric layers, forming oolites as large as one-fourth of an inch in diameter. These oolites are artificial. . Dr. G. H. Cox: The tendency of colloidal materials to assume a circular form has now been appealed to by various authors to explain oolites and rounded forms. Are we therefore to assume that this is the natural structure of colloidal silica, and that therefore non-oolite cherts are of secondary origin? Dr. A. R. Crook: The statement that certain oolites lack nuclei should raise a question, since physicists and meteorologists know that raindrops always form around a nucleus of dust, it is reasonable to assume that oolites always have a nucleus, even though it may be so small as to escape detection. Dr. E..V. Emerson: In the Middle Eocene of Louisiana are beds of ostrea marl underlain by stiff plastic bluish clay. In some places there is a narrow zone in the clay, varying in width up to 10 inches, in which the clay has an apparent oolitic texture. The oolites have diameters up to 10 mm. and are 1Jntroduced by H. B. Branson. 2 Introduced by Nevin M. Fenneman. IX—Buuu. Grou. Soc. Am., Vort 21, 1917 104 PROCEEDINGS OF THE SAINT LOUIS MEETING not indurated. Possibly they may be due to the descent of calcareous water which has flocculated the underlying clay. Reply by author (Dr. W. A. Tarr) to questions: The fact that oolites might form from a colloidal silica gel at times and chert at other times can be ex- plained by the rate of accumulation of the silica and the inclosing sediments, the movement of the water, and the amount of silica added. In the case of shales, the muds are added so fast in agitated waters that when the rate of addition of silica is sufficient oolites may form. In limestones the slow rate of accumulation permits the growth of large aggregates of silica. At other times the silica added goes down as the colloidal matter of the clay. Remarks were also made by Dr. R. M. Bagg. GLAUCONITE IN DOLOMITE AND LIMESTONE OF MISSOURI BY W. A. TARR? (Abstract) Glauconite occurs in grains in the Burlington limestone (Mississippian) and in similar form, but in much larger amounts, in the Bonne Terre dolomite (Cambrian) in southeastern Missouri. It is associated with the lead ores in that district and was long mistaken for chlorite. The glauconite was deposited at the same time as the dolomite. A suggestion as to its origin is made. Presented in abstract extemporaneously. DISCOVERY OF FLUORITE IN THE ORDOVICIAN LIMESTONES OF WISCONSIN BY RUFUS MATHER BAGG (Abstract) Fluorspar has never been recorded from the Ordovician galena beds in Wis- consin, though its absence has been repeatedly mentioned in the various geo- logical reports of the State. References to this are cited and a brief discussion of this common associate of zinc-lead ores. A short description of the occurrence of this mineral and some theoretical considerations as to its probable origin are given. Other minerals present in the quarries where this mineral occurs are shown and the order of their deposition explained. Presented in abstract extemporaneously. DISCUSSION Dr. W. A. Tarr: Fluorite is found in crystals up to two inches across in geodes in the Saint Louis (Mississippi) limestone. It is usually the very last mineral to be deposited. OCCURRENCE OF A LARGE TOURMALINE IN ALABAMA PEGMATITE BY FRANK RB. VAN HORN (Abstract) In the vicinity of Micaville, Randolph County, Alabama, there are many 1Jntroduced by E. B. Branson. 7 : i TITLES AND ABSTRACTS OF PAPERS 105 pegmatite dikes striking northwest and southeast. They range from 6 inches up to 40 feet in width and occur in what is locally called “Ashland mica schist.” The chief minerals are quartz, orthoclase, muscovite, biotite, iron tourmaline, and beryl. The dikes are weathered to Kaolinite to a depth of 60 to 90 feet from the surface. The quartz crystals are very large, sometimes weighing several hundred pounds, as is also true of the micas, which are found up to 300 pounds. On the other hand, the feldspars are,seldom over a few inches in diameter. The tourmalines are commonly of all dimensions up to 10 by 6 inches in diameter, and the beryls are found up to 5 by 38 inches in diameter. At a depth of about 70 feet in the weathered dike a large crystal of iron tourmaline was found. The top of this crystal is now in the Museum of the Case School of Applied Science. The specimen is now 7 inches high and 10 inches in diameter and weighs 438% pounds. Since it was originally 3 to 3% feet long, it must have weighed from 225 to 250 pounds and therefore must have been one of the largest tourmalines ever found. The faces are _ rough and vertically striated, but the three planes of ~ P (1010) and the 6 OL o P 2 (1120) are easily distinguishable. It is terminated by R (1010), which is therefore the blunter end or antilogue pole. Presented in full extemporaneously. CAUSE OF THE ABSENCE OF WATER IN DRY SANDSTONE BEDS BY ROSWELL H. JOHNSON? (Abstract) “Dry sands”—that is, sandstone beds without water—are to be explained on the supposition that the accumulation of gas within the sand has displaced water, which it originally held. Opposed to this view are Gardner, who writes, and Reeves, who urges, that “the sediments and their porous areas were filled with air, which later prevented water from penetrating them during sub- mergence beneath the sea.” These views are held much more naively by many operators who talk of a “sood sand,” although it contains no gas, oil, or water and is in a region that is undrained, failing to realize the physical impossibility of such a condition, in view of the well known, world-wide increase of pressure with depth. Even in the rare cases when the gas is largely nitrogen we have high pressure also. No sand should be called good that is not porous, and if porous and not ex- hausted it must contain gas, oil, or water. The proof that the “dryness” is caused by gas displacement of the connate water lies in the chemistry of the gas. Only in the very rare cases where this is mainly nitrogen is the Gardner or Reeves position tenable. What little nitrogen there is is probably entrapped air from which the oxygen has been removed by oxidizing compounds, the CO in the turn forming carbonates. The Appalachian field which Reeves uses for evidence carries very little nitrogen, nor are the gases richest in nitrogen from red beds, but from sands in Kansas several hundred feet below the red beds. Read by title in the absence of the author. 1 Introduced by Charles P. Berkey. 106 PROCEEDINGS OF THE SAINT LOUIS MEETING The following resolutions of thanks were passed unanimously: To the local committee, consisting of Messrs. Branson and Buehler, for the care- ful preparations for the meeting which had been made and for the wise eare of all the Society’s wants which had been exercised, and to the Saint Louis Publicity and Convention Committee, who had been largely instru- mental in making the meeting possible and successful. The Society adjourned at noon. c REGISTER OF THE SAINT Louis MEETING, 1917 Frank D. ADAMS Rurvus M. Baae W. S. BAYLEY Eviot BLACKWELDER J. A. BOWNOCKER KH. B. Branson. H. A. BUEHLER JOHN M. CLARKE A. P. CoLEMAN A. R. Crook H. L. FarrcH inp G. P. GRIMSLEY Rs Bice Rosert T. Hinn EK. O. Hovey Ge Wy KAY. JAMES F. KEMP Cyrrit W. KNIGHT Epwarp H. Kraus JAMES H. LEES SipnEyY L. GALPIN There were also 41 visitors who registered. VOTE OF THANKS -ArTHUR M. MILLER FELLOWS-ELECT C. W. ToMLINSON A. @. LEONARD FRANK LEVERETT W. LINDGREN V. F. Marsters Epwarp B. MATHEWS WILLIAM J. MILLER H. D. MIsEr EK. S. Moore D. W. OHERN R. A. F. PENROSE, JR. JoHN L. Ricu B. Rose T. E. SAvAGe J... Poun EK. O. ULRicH Frank R. Van Horn Lewis G. WESTGATE I. C. WHITE M. E. WILson W. A. Tarr OFFICERS, CORRESPONDENTS, AND FELLOWS OF THE GEOLOGICAL SOCIETY OF AMERICA OFFICERS FOR 1918 President: WHITMAN Cross, Washington, D. C. Vice-Presidents: BaiLEyY Wiis, Stanford University, Cal. FRANK Levererr, Ann Arbor, Mich. F. H. KNowtton, Washington, D. C. Secretary: EpmunpD Otts Hovey, American Museum of Natural History, New York, N. Y. Treasurer : Epwarp B. Matruews, Johns Hopkins University, Baltimore, Md. Editor: J. STANLEY-Brown, 26 Exchange Place, New York, N. Y. LInbrarvan: F. R. Van Horn, Cleveland, Ohio Councilors: (Term expires 1918) FRANK B. Tayuor, Fort Wayne, Ind. CHARLES P. BerKty, New York, N. Y (Term expires 1919) ArtuHur L. Day, Washington, D. C. Wixtit1am H. Emmons, Minneapolis, Minn. (Term expires 1920) JOSEPH BArrELL, New Haven, Conn. R. A. Daty, Cambridge, Mass. (107) 108 PROCEEDINGS OF THE SAINT LOUIS MEETING MEMBERSHIP, 1918 CORRESPONDENTS CHARLES Barrois, Lille, France. December, 1909. W. C. Broacer, Christiania, Norway. December, 1909. GIOVANNI CAPELLINI, Bologna, Italy. December, 1910. BARON GERHARD DE GEER, Stockholm, Sweden. December, 1910. Sir ARCHIBALD GEIKIE, Hasslemere, England. December, 1909. ALBERT HEIM, Ziirich, Switzerland. December, 1909. EMANUEL KaAyseER, Marburg, Germany. December, 1909. W. KiLiaAn, Grenoble, France. December, 1912. J. J. H. Teat., London, England. December, 1912. Emi. TiETzE, Vienna, Austria. December, 1910. FELLOWS *Indicates Original Fellow (see article III of Constitution) CLEVELAND ABBE, JR., U. S. Weather Bureau, Washington, D. C. August, 1899. FRANK Dawson ADAMS, McGill University, Montreal, Canada. Dec., 1889. GEORGE I. ADAMS, 17 San T’iao Hutung, Peking, China. December, 1902. JOSE GUADALUPE AGUILERA, Calexico, Mexico. August, 1896. WiL~tiAM C. ALDEN, U. S. Geological Survey, Washington, D. C. Dec., 1909. TRUMAN H. ALDRICH, Birmingham, Ala. May, 1889. JoHn A. ALLAN, University of Alberta, Strathcona, Canada. December, 1914. R. C. ALLEN, State Geological Survey, Lansing, Mich. December, 1911. Henry M. Ami, Strathcona Park, Ottawa, Canada. December, 1889. FRANK M. ANDERSON, State Mining Bureau, 2604 Aetna St., Berkeley, Cal. Rospert V. ANDERSON, Menlo Park, Cal. December, 1911. RALPH ARNOLD, 923 Union Oil Building, Los Angeles, Cal. December, 1904. GEORGE HALL ASHLEY, U. S. Geological Survey, Washington, D. C. Aug., 1895. WALLACE WALTER ATWOOD, Harvard University, Cambridge, Mass. Dec., 1909. RuFus MATHER Bace, JR., 7 Brokaw Place, Appleton, Wis. December, 1896. Harry Foster Bain, 734 Salisbury House, London, E.C., England. Dec., 1895. MANLEY BENSON BAKER, School of Mining, Kingston, Ontario. Dec., 1911. ~ S. PRENTISS BALDWIN, 2930 Prospect Ave., Cleveland, Ohio. August, 1895. SypngEyY H. BALL, 71 Broadway, New York City. December, 1905. JosEPpH A. Bancrort, McGill University, Montreal, Canada. December, 1914. ERWIN HINCKLEY BaARzBour, University of Nebraska, Lincoln, Neb. Dec., 1896. JOSEPH BARRELL, Yale University, New Haven, Conn. December, 1902. GroRGE H. Barton, Boston Society of Natural History, Boston, Mass. Au- gust, 1890. PauL BartscH, U. S. National Museum, Washington, D. C. December, 1917. FLORENCE Bascom, Bryn Mawr College, Bryn Mawr, Pa. August, 1894. Ray SMITH Basster, U. S. National Museum, Washington, D. C. Dee., 1906. Epson S. Bastin, U. S. Geological Survey, Washington, D. C. Dec., 1909. ALAN MARA BATEMAN, Yale University, New Haven, Conn. December, 1916. Witiiam S. BayLey, University of Illinois, Urbana, Il. December, 1888. *GrorGE FEF. BEcKER, U. S. Geological Survey, Washington, D. C. LIST OF MEMBERS 109 JOSHUA W. BEEDE, 404 West 38th St., Austin, Texas. December, 1902. CHARLES P. BerKEy, Columbia University, New York, N. Y. August, 1901. Epwarp WILBER Berry, Johns Hopkins University, Baltimore, Md. Dec., 1909. SAMUEL WALKER Beyer, Iowa Agricultural College, Ames, Iowa. Dec., 1896. ELIoT BLACKWELDER, University of Illinois, Urbana, Ill. December, 1908. JoHN M. BouTWELL, 1323 De la Vine St., Santa Barbara, Cal. Dec., 1905. CHARLES FEF’. BowEN, U. S. Geological Survey, Washington, D. C. Dec., 1916. N. L. Bowen, Carnegie Institution of Washington, Washington, D. C. JoHN ADAMS BowNocKER, Ohio State University, Columbus, Ohio. Dec., 1904. *Joun C. BRANNER, Leland Stanford, Jr., University, Stanford University, Cal. EpWIN Bayer BRANSON, University of Missouri, Columbia, Mo. Dec., 1911. J. H. Bretz, University of Chicago, Chicago, I11. ALBERT PERRY BRIGHAM, Colgate University, Hamilton, N. Y. December, 1893. REGINALD W. Brock, University of British Columbia, Vancouver, B.C. De- cember, 1904. ALFRED HULSE Brooks, U.S. Geological Survey, Washington, D.C. Aug., 1899. BARNUM Brown, American Museum of Natural History, New York, N. Y. De- cember, 1910. CHARLES WILSON Brown, Brown University, Providence, R. I. Dec., 1908. THOMAS CLACHAR Brown, Bryn Mawr College, Bryn Mawr, Pa. Dec., 1915. Henry ANDREW BUEHLER, Rolla, Mo. December, 1909. LANCASTER D. BurLine, Geological Survey of Canada, Ottawa, Canada. EpwarpD M. J. BuRwaAsH, University of Toronto, Toronto, Canada. Dec., 1916. Bert S. Butter, U. 8. Geological Survey, Washington, D. C. December, 1912. G. MontacurE Butter, College of Mines, Tucson, Arizona. December, 1911. CHARLES Butts, U. 8S. Geological Survey, Washington, D. C. December, 1912. FrepD Harvey Hatt CaLHoun, Clemson College, 8. C. December, 1909. FRANK C. CaLkin, U. S. Geological Survey, Washington, D. C. Dec., 1914. HENRY DONALD CAMPBELL, Washington and Lee University, Lexington, Va. May, 1889. Marius R. CAMPBELL, U. S. Geological Survey, Washington, D. C. Aug., 1892. Luiz Fiuierpe G. peE Campos, Geological Survey of Brazil, Rio de Janeiro, Brazil. CHARLES CAMSELL, Geological Survey of Canada, Ottawa, Canada. Dec., 1914. STEPHEN R. Capps, Jr., U.S. Geological Survey, Washington, D.C. Dec., 1911. J. ERNEST CARMAN, Ohio State University, Columbus, Ohio. FRANK CARNEY, Granville, Ohio. December, 1908. ERMINE C. Case, University of Michigan, Ann Arbor, Mich. December, 1901. GrorcE H. Cuapwicxk, University of Rochester, Rochester, N. Y. Dec., 1911. RouuIn T. CHAMBERLIN, University of Chicago, Chicago, Il]. December, 1913. *T. C. CHAMBERLIN, University of Chicago, Chicago, Ili. CLARENCE RAYMOND CLAGHORN, Claghorn, Pa. August, 1891. CHARLES H. Ciapp, University of Arizona, Tucson, Arizona. December, 1914. FREDERICK G. CLapp, 120 Broadway, New York, N. Y. December, 1905. JOHN MASON CLARKE, Albany, N. Y. December, 1897. HERpDMAN F. CLELAND, Williams College, Williamstown, Mass. Dec., 1905. J. Morgan CLEMENTS, 20 Broad St., New York City. December, 1894. CoLuLierR Cops, University of North Carolina, Chapel Hill, N. C. Dec., 1894. ARTHUR P. CoLEMAN, Toronto University, Toronto, Canada. December, 1896. 110 PROCEEDINGS OF THE SAINT LOUIS MEETING GEORGE L. CoLuiz, Beloit College, Beloit. Wis. December, 1897. ARTHUR J. CoLuerR, U. 8S. Geological Survey, Washington, D. C. June, 1902. D. DALE ConpiT, Cristobal, Canal Zone. December, 1916. s CHARLES W. Cook, University of Michigan, Ann Arbor, Mich. Dec., 1915. EUGENE CosTE, 1943 11th St., West, Calgary, Alberta, Canada. Dec., 1906. RALPH DIXON CRAWFORD, University of Colorado, Boulder, Colo. Dec., 1916. ALsgA R. Crook, State Museum of Natural History, Springfield, Ill. Dec., 1898. *WILLIAM O. CrosBy, Massachusetts Institute of Technology, Boston, Mass. WHITMAN Cross, U. S. Geological Survey, Washington, D. C. May, 1889. GaRRY E. CULVER, 310 Center Ave., Stevens Point, Wis. December, 1891. Epcar R. CuMINGS, Indiana University, Bloomington, Ind. August, 1901. *HENRY P. CUSHING, Western Reserve University, Cleveland, Ohio.. RreGInaLtD A. Daty, Harvard University, Cambridge, Mass. December, 1905. EXDWARD SALISBURY DANA, Yale University, New Haven, Conn. Dec., 1908. *NELSON H. Darton, U. 8S. Geological Survey, Washington, D. C. *WILLIAM M. Davis, Harvard University, Cambridge, Mass. ARTHUR LouIs Day, Geophysical Laboratory, Carnegie Institution, Washing- ton, D. C. December, 1909. Davin T. Day, 1333 F St. N. W., Washington, D. C. August, 1891. BasHForD DEAN, Columbia University, New York, N. Y. December, 1910. ALEXANDER DEUSSEN, University of Texas, Austin, Texas. December, 1916. I'RANK WILBRIDGE DE WoLrF, Urbana, Ill. December, 1909. *JosErH S. DILueR, U. 8S. Geological Survey, Washington, D. C. EDWARD VY. D’INVILLIERS, 518 Walnut St., Philadelphia, Pa. December, 1888. RIcHARD E. DopcE, Dodge Farm, Washington, Conn. August, 1897. NoaH FIELDS DRAKE, Fayetteville, Arkansas. December, 1898. Joun A. Dresser, 701 Eastern Townships Bank Bldg., Montreal, Canada. December, 1906. *EDWIN T. DUMBLE, 2003 Main St., Houston, Texas. ARTHUR S. EAKLE, University of California, Berkeley, Cal. December, 1899. CHARLES R. EASTMAN, American Museum of Natural History, New York, N. Y. December, 1895. EpwIn C. Eckert, Munsey Building, Washington, D. C. December, 1905. *BENJAMIN K. EMERSoN, Amherst College, Amherst, Mass. WititiAmM H. Emmons, University of Minnesota, Minneapolis, Minn. Dee., 1912. -*HERMAN IL. FAIRCHILD, University of Rochester, Rochester, N. Y. OLIVER C. FARRINGTON,. Field Museum of Natural History, Chicago, Ill. De- cember, 1895. ; NEvIN M. FENNEMAN, University of Cincinnati, Cincinnati, Ohio. Dec. 1904. CLARENCE N. FENNER, Geophysical Laboratory, Washington, D.C. Dee., 1911. Cassius ASA FisHeER, 711 Ideal Building, Denver, Colo. December, 1908. Aucust F. Forrste, 128 Rockwood Ave., Dayton, Ohio. December, 1899. WituiaAM FE. Forp, Sheffield Scientific School, New Haven, Conn. Dec., 1915. Myron L. Furrier, 134 W. Upsal St., Germantown, Pa. December, 1898. Sipney L. Garin, Iowa State College, Ames, Iowa. Henry STEWART GANE, Wonalancet, New Hampshire. December, 1896. JAMES H. GARDNER, 510 New Daniel Bldg., Tulsa, Oklahoma. December, 1911. RuSSELL D. GreorGE. University of Colorado, Boulder, Colo. December, 1906. *Grove K. GiLBert, U. 8. Geological Survey, Washington, D. C. LIST OF MEMBERS ey ADAM CAPEN GILL, Cornell University, Ithaca, N. Y. December, 1888. L. C. Gitenn, Vanderbilt University, Nashville, Tenn. June, 1900. Magrcus Isaac GOLDMAN, U.S. Geological Survey, Washington, D.C. Dec., 1916. JAMES WALTER GOLDTHWAIT, Dartmouth College, Hanover, N. H. Dec., 1909. CuHartes H. Gorpon, University Library, University of Tennessee, Knoxville, Tenn. August, 1893. CLARENCE FE. Gorpon, Massachusetts Agricultural College, Amherst, Mass. December, 1913. CHARLES N. Goutp, 1218 Colcord Bldg., Oklahoma City, Okla. Dec., 1904. AMADEUS W. GRABAU, Columbia University, New York, N. Y. December, 1898. WALTER GRANGER, American Museum of Natural History, New York, N. Y. December, 1911. ULysSsES SHERMAN GRANT, Northwestern University, Evanston, Il]. Dec., 1890. JOHN SHARSHALL GRASTY, University of Virginia, University, Va. Dec., 1911. Louis C. Graton, Harvard University, Cambridge, Mass. December, 1913. Herrsvert I. Grecory, Yale University, New Haven, Conn. August, 1901. FRANK Cook GREENE, 30 North Yorktown St., Tulsa, Okla. GEORGE P. GRIMSLEY, 31st and Calvert Sts., Gilman 3-B, Baltimore, Md. Au- gust, 1895. Lron 8S. GRISWOLD, Plymouth, Mass. August, 1902. FREDERIC P. GULLIVER, 1112 Morris Bldg., Philadelphia, Pa. August, 1895. WILLIAM F.. E. R. GuRLEy, University of Chicago, Chicago, Ill. Dec., 1914 BarirD HALBERSTADT, Pottsville, Pa. December, 1909. GILBERT D. Harris, Cornell University, Ithaca, N. Y. December, 1903. JOHN BURCHMORE HARRISON, Georgetown, British Guiana. June, 1902. Curis. A. HARTNAGEL, Education Building, Albany, N. Y. December, 1913. JOHN B. Hastines, 1480 High St., Denver, Colo. May, 1889. *HRASMUS HawortTH, University of Kansas, Lawrence, Kans. RAY VERNON HENNEN, West Virginia Geological Survey, Morgantown, W. Va. December, 1914. | Oscak H. HersHey, Kellogg, Idaho. December, 1909. DONNEL Foster HEwETT, U. S. Geological Survey, Washington, D.C. Dee., 1916. RicHARD R. Hicr, Beaver, Pa. December, 1903. *ROBERT T. Hii, 702 Hollingsworth Bldg., Los Angeles, Cal. RicHarpD C. HILus, Denver, Colo. August, 1894. Henry Hinps, U. S. Geological Survey, Washington, D. C. December, 1912. FERDINAND Friis Hintze, Lehigh University, South Bethlehem, Pa. *CHARLES H. HitcHcock, 2376 Oahu Ave., Honolulu, Hawaiian Islands. WILLIAM H. Hopss, University of Michigan, Ann Arbor, Mich. Aug., 1891. *Lrvi Horsroox, P. O. Box 536, New York, N. Y. Roy J. Hoipen, Virginia Polytechnic Institute, Blacksburg, Va. Dec., 1914. WILLIAM Jacos HoLianp, Carnegie Museum, Pittsburgh, Pa. December, 1910. ARTHUR Hotuick, Staten Island Association of Arts and Sciences, New Brighton, 8S. I. August, 1898. THOMAS C. HopKIns, Syracuse University, Syracuse, N. Y. December, 1894. Witiiam OtT1s Hotcuxiss, State Geological Survey, Madison, Wis. Dec., 1911. *HDMUND OTIs Hovey. American Museum of Natural History, New York. N. Y ERNEST Howe, 77 Rhode Island Ave., Newport, R. I. December, 1903. GrEoRGE D. Husparp, Oberlin College, Oberlin, Ohio. December, 1914. 112 PROCEEDINGS OF THE SAINT LOUIS MEETING GEORGE H. Hupson, Plattsburg Normal School, Plattsburg, N. Y. WALTER F. Hunt, University of Michigan, Ann Arbor, Mich. December, 1914. ELLSWORTH HUNTINGTON, 222 Highland St., Milton, Mass. December, 1906. Lovis Hussakor, American Museum of Natural History, New York, N. Y. December, 1910. JOSEPH P. IppINGs, Brinklow, Md. May, 1889. JOHN D. Irvine, Yale University, New Haven, Conn. December, 1905. A. WENDELL JACKSON, 9 Desbrosses St., New York, N. Y. December, 1888. Ropert T. JACKSON, 195 Bay State Road, Boston, Mass. August, 1894. THOMAS AUGUSTUS JAGGAR, JR., Hawaiian Volcano Observatory, Territory of Hawaii, U. S. A. December, 1906. Mark S. W. JEFFERSON, Michigan State Normal College, Ypsilanti, Mich. De. cember, 1904. ; EDWARD C. JEFFREY, Harvard University, Cambridge, Mass. December, 1914. ALBERT JOHANNSEN, University of Chicago, Chicago, I1l. December, 1908. DovueLas WILSON JOHNSON, Columbia University, New York, N. Y. Dec., 1906. WILLIAM ALFRED JOHNSTON, Geological Survey, Ottawa, Canada. Dec., 1916. ALExIS A. JULIEN, South Harwich, Mass. May, 1889. FRANK JAMES Katz, U. S. Geological Survey, Washington, D. C. Dece., 1912. GEORGE FREDERICK Kay, State University of Iowa, Iowa City, Iowa. Dec., 1908. ARTHUR KeEITH, U. S. Geological Survey, Washington, D. C. May, 1889. *JAMES FE. Kemp, Columbia University, New York, N. Y. : CHARLES ROLLIN KEYES, 944 Fifth St., Des Moines, Iowa. August, 1890. EDWARD M. KINDLE, Victoria Memorial Museum, Ottawa, Canada. Dec., 1905. CHARLES T. Kirk, 327 S. Wheeling St., Tulsa, Okla.. December, 1915. EDWIN KIRK, U. S. Geological Survey, Washington, D. C. December, 1912. CYRIL WoRKMAN KNIGHT, Toronto, Ontario, Canada. December, 1911. ADOLPH KwNoprFr, U. S. Geological Survey, Washington, D. C. December, 1911. FRANK H. KNow ton, U. S. National Museum, Washington, D. C. May, 1889. EpWARD HENRY KRAUS, University of Michigan, Ann Arbor, Mich. June, 1902 Henry B. KUMMEL, Trenton, N. J. December, 1895. *GEORGE FEF. Kunz, 401 Fifth Ave., New York, N. Y. GrorGE E. Lapp, 6109 Brookville Road, Chevy Chase, Md. August, 1891. FREDERIC H. LAHEE, Massachusetts Institute of Technology, Cambridge, Mass. LAWRENCE Morris LAMBE, Department of Mines, Ottawa, Canada. Dec., 1911. HENRY LANDES, University of Washington, University Station, Seattle, Wash. December, 1908. ALFRED C. LANE, Tufts College, Mass. December, 1889. Esper S. LARSEN, JR., U. S. Geological Survey, Washington, D. C. Dec., 1914. ANDREW C. Lawson, University of California, Berkeley, Cal. May, 1889. Wiis THomMAs Lez, U. S. Geological Survey, Washington, D. C. Dec., 1903. JAMES H. LEEs, Iowa Geological Survey, Des Moines, Iowa. December, 1914. CHARLES K. LEITH, University of Wisconsin, Madison, Wis. Dec., 1902. ARTHUR G. LEONARD, State University of North Dakota, Grand Forks, N. Dak. December, 1901. PRANK LEVERETT, Ann Arbor, Mich. August, 1890. JOSEPH VOLNEY LEWIS, Rutgers College, New’ Brunswick, N. J. Dec., 1906. WILLIAM LiBBEy, Princeton University, Princeton, N. J. August, 1899. WALDEMAR LINDGREN, Massachusetts Institute of Technology, Boston, Mass. August, 1890. | LIST OF MEMBERS ibiclegy Micuet A. R. Lisspoa, Caixa postal 829, Ave. Rio Branco 46-V, Rio de Janeiro, Brazil. December, 19138. WittiaM N. Locan, Indiana University, Bloomington, Ind. FREDERICK BREWSTER Loomis. Amherst College, Amherst, Mass. Dec., 1909. GrorGE Davis LOUDERBACK, University of California, Berkeley, Cal. June, 1902. GERALD F. LoucHuin, U. S. Geological Survey, Washington, D. C. Dec., 1916. ALBERT P. Low, Department of Mines, Ottawa, Canada. December, 1908. RicHaRD SwaANN LULL, Yale University, New Haven, Conn. December, 1909. CHARLES T. Lupton, Cosden Oil and Gas Company, Tulsa, Okla. Dec., 1916. SAMUEL WASHINGTON McCatLiigz, Atlanta, Ga. December. 1909. Hiram D. McCasxkey, U.S. Geological Survey, Washington, D.C. Dec., 1904. RicHAarD G. McConneLL, Geological and Natural History Survey of Canada, Ottawa, Canada. May, 1889. DonaALpD FRANCIS MacDonatLp, U. S. Geological Survey, Washington, D. C. December, 1915. JAMES RIEMAN MACFARLANE, Woodland Road, Pittsburgh, Pa. August, 1891. WititiamM McINNEs, Geological and Natural History Survey of Canada, Ot- tawa, Canada. May, 1889. Peter McKetiar. Fort William, Ontario, Canada. August, 1890. GEORGE RoGERS MANSFIELD, 2067 Park Road N. W., Washington, D. C. De- cember, 1909. Curtis F. Marsut, Bureau of Soils, Washington, D. C. August, 1897. VERNON F.. Marsters, 316 Rialto Bldg., Kansas City, Mo. August, 1892. GEORGE CurTIS Martin, U.S. Geological Survey, Washington, D.C. June, 1902. LAWRENCE MartTIN, University of Wisconsin, Madison, Wis. December, 1909. Hpwarp B. MatHews, Johns Hopkins University, Baltimore, Md. Aug., 1895. FRANCOIS E. MattuHes, U. S. Geological Survey, Washington, D. C. Decem- ber, 1914. W. D. MatrHew, American Museum of Natural History, New York, N. Y. December, 1908. THOMAS PooLE Maynarp, 1622 D. Hurt Bldg., Atlanta, Ga. December, 1914. WARREN JUDSON MEapD, University of Wisconsin, Madison, Wis. Dec., 1916. Oscar E. MEINZER, U.S. Geological Survey, Washington, D.C. December, 1916. P. H. Mex, 165 East 10th St., Atlanta, Ga. December, 1888. WALTER C. MENDENHALL, U. S. Geological Survey, Washington, D. C. June, 1902. JOHN C. MerriaM, University of California, Berkeley, Cal. August, 1895. GrEoRGE P. MERRILL, U. S. National Museum, Washington, D. C. Dec., 1888. HERBERT FH. MERWIN, Geophysical Laboratory, Washington, D. C. Dee., 1914. ARTHUR M. Miter, State University of Kentucky, Lexington, Ky. Dec., 1897. BENJAMIN L. MILuerR, Lehigh University, South Bethlehem, Pa. Dec., 1904. WILLET G. MILLER, Toronto, Canada. December, 1902. WiLLIAM JoHN MiILreR, Smith College, Northampton, Mass. December, 1909. Hvueu D. Miser, U. S. Geological Survey, Washington, D. C. December, 1916. Frev Howarp Morrit, U. 8S. Geological Survey, Washington, D. C. Dec., 1912. G. A. F. MoLteneraAasr, Technical High School, Delft, Holland. December, 1913. Henry Montreomery, University of Toronto, Toronto, Canada. Dec., 1904. Huiwoop S. Moorr, Pennsylvania State College, State College, Pa. Dec., 1911. Matcotm JoHN Munn, Clinton Bldg., Tulsa, Okla. December, 1909. 114 PROCEEDINGS OF THE SAINT LOUIS MEETING *WRANK L. Nason, West Haven, Conn. Davip HALE NEWLAND, Albany, N. Y. December, 1906. JoHN F. Newsom, Leland Stanford, Jr., University, Stanford University, Cal. December, 1899. Levi F. NOBLE, Valyermo, Cal. December, 1916, WILLIAM H. Norton, Cornell College, Mount Vernon, Iowa. December, 1895. CHARLES J. Norwoop, State University, Lexington, Ky. August, 1894. IpA HELEN OGILVIE, Barnard College, Columbia University, New York, N. Y. December, 1906. CLEOPHAS C. O’HarrRA, South Dakota School of Mines, Rapid City, 8. Dak. December, 1904. DANIEL WEBSTER OHERN, University of Oklahoma, Norman, Okla. Dec., 1911. EDWARD ORTON, JR., Columbus, Ohio. December, 1909. Henry F. Osporn, American Museum of Natural History, New York, N. Y. August, 1894. Rospert W. PAcK, U.S. Geological Survey, Washington, D.C. December, 1916. SipnEy Paice, U. S. Geological Survey, Washington, D. C. December, 1911. CHARLES PALACHE, Harvard University, Cambridge, Mass. August, 1897. WILLIAM A. PARKS, University of Toronto, Toronto, Canada. December, 1906. *HorACcE B. Patton, 817 Fifteenth St., Golden, Colo. FREDERICK B. Peck, Lafayette College, Easton, Pa. August, 1901. RICHARD A. F. PENROSE, JR., 460 Bullitt Bldg., Philadelphia, Pa. May, 1889. GEORGE H. PERKINS, University of Vermont, Burlington, Vt. June, 1902. JOSEPH H. Perry, 276 Highland St., Worcester, Mass. December, 1888. Witt1aM ©. PHaen, U. S. Bureau of Mines, Washington, D. C. Dec., 1912. ALEXANDER H. PHILLIPS, Princeton University, Princeton, N. J. Dec., 1914. Louis V. Pirsson, Yale University, New Haven, Conn. August, 1894. JOSEPH E. PoGurE, Northwestern University, Evanston, Ill. December, 1911. JOSEPH Hyper Pratt, North Carolina Geological Survey, Chapel Hill, N. C. December, 1898. WILLIAM ARMSTRONG PRICE, JR., West Virginia University, Morgantown, W.Va. December, 1916. Louis M. PRINDLE, U. S. Geological Survey, Washington, D. C. Dec., 1912. WILLIAM F. Prouty, University of Alabama, University, Ala. Dec., 1911. *RAPHAEL PUMPELLY, Newport, R. I. FREDERICK LESLIE RANSOME, U. S. Geological Survey, Washington, D. C. Au- gust, 1895. j Percy EDWARD RAYMOND, Museum of Comparative Zodlogy, Cambridge, Mass December, 1907. CHESTER A. REEDS, American Museum of Natural History, New York, N. Y. December, 1913. HARRY FIELDING REID, Johns Hopkins University, Baltimore, Md. Dec., 1892. g LEOPOLD REINECKE, Geological Survey, Ottawa, Canada. December, 1916. WILLIAM NortH Rice, Wesleyan University, Middletown, Conn. August, 1890. JoHN Lyon RicuH, Army War College, Washington, D. C. December, 1912. CHARLES H. RICHARDSON, Syracuse University, Syracuse, N. Y. Dec., 1899. GEORGE BurR RiIcHaARDSON, U. 8S. Geological Survey, Washington, D. C. De cember, 1908. HEINRICH Ries, Cornell University, Ithaca, N. Y. December, 1893. LIST OF MEMBERS 115 Evmer S. Riees, Field Museum of Natural History, Chicago, Ill. Dec., 1911. HENRY HOLLISTER ROBINSON, Peabody Museum, New Haven, Conn. Dec., 1916. Bruce Rose, Geological Survey, Ottawa, Canada. December, 1916. _ Jesse: Perry Rowe, University of Montana, Missoula, Mont. December, 1911. RupoLr RUEDEMANN, Albany, N. Y. December, 1905. JOHN JoSEPH RUTLEDGE, Hxperiment Station, Pittsburgh, Pa. Dec., 1911. OrEsTES H. St. JoHNn, 1141 Twelfth St., San Diego, Cal. May, 1889. RENO H. SALES, Anaconda Copper Mining Company, Butte, Mon. Dec., 1916. RoBeRT WitLcox SAYLES, Harvard University, Chestnut Hill, Mass. *ROLLIN D. SALISBURY, University of Chicago, Chicago, Ill. FREDERICK W. SARDESON, University of Minnesota, Minneapolis, Minn. De. cember, 1892. THOMAS EDMUND SAVAGE, University of Illinois, Urbana, Ill. December, 1907. FRANK C. Scurapver, U. S. Geological Survey, Washington, D. C. Aug., 1901. CHARLES SCHUCHERT, Yale University, New Haven, Conn. August, 1895. ALFRED R. ScHULTZ, U. S. Geological Survey, Washington, D. C. Dec., 1912. WILLIAM B. Scort, Princeton University, Princeton, N. J. August, 1892. ARTHUR EH. SEAMAN, Michigan College of Mines, Houghton, Mich, Dec., 1904. Hwii1as H. SELLARDS, Tallahassee, Fla. December, 1905. JOAQUIM CANDIDO DA Costa SENA, State School of Mines, Ouro Preto, Brazil. December, 1908. MILLARD K. SHALER, 4 Bishopsgate E. C., London, England. December, 1914. GEORGE BURBANK SHATTUCK, Vassar College, Poughkeepsie, N. Y. Aug., 1899. HUGENE WESLEY SHAw, U.S. Geological Survey, Washington, D.C. Dec., 1912. SoLon SHEpDD, State College of Washington, Pullman, Wash. Dec.. 1904. EpwarpD M. SHEPARD, 1403 Benton Ave., Springfield, Mo. August, 1901. BoHUMIL SHIMEK, University of Iowa, Iowa City, Iowa. December, 1904. HERVEY WoopBURN SHIMER, Massachusetts Institute of Technology, Boston, Mass. December, 1910. CLAUDE H. SIEBENTHAL, U.S. Geological Survey, Washington, D.C. Dec., 1912. *FREDERICK W. SIMONDS, University of Texas, Austin, Texas. WILLIAM JOHN SINCLAIR, Princeton University, Princeton, N. J. Deec., 1906. JOSEPH T. SINGEWALD, Johns Hopkins University, Baltimore, Md. Dec., 1911. EARLE SLOAN, Charleston, S. C. December, 1908. BuRNETT SMITH, Syracuse University, Skaneateles, N. Y. December, 1911. CarL SmitTH, U. S. Geological Survey, Washington, D. C. December, 1912. *KHuGENE A. SmitTH, University of Alabama, University, Ala. GrorcE OTIs SmiTH, U. S. Geological Survey, Washington, D. C. Aug., 1897. Puiie S. SmirH, U. 8. Geological Survey, Washington, D. C. Dec., 1909. WarrREN Dv Pre SMITH, University of Oregon, Eugene, Oregon. Dec., 1909. W. S. TANGIER SuitH, Lodi, Cal. June, 1902. *JOHN C. Smock, Trenton, N. J. CHARLES H. SMyTH, Jr., Princeton University, Princeton, N. J. Aug., 1892. Henry lL. Smytu, Harvard University, Cambridge, Mass. August, 1894. Rosert SPEIGHT, Christ Church, Canterbury College, New Zealand. Dec., 1916 ARTHUR Cor Spencer, U. S. Geological Survey, Washington, D. C. Dec., 1896. *J. W. Spencer, 2019 Hillyer Place. Washington, D. C. FRANK SPRINGER, U. S. National Museum, Washington, D. C. December, 1911. JOSIAH FF. Spurr, Bullitt Bldg., Philadelphia, Pa. December, 1894. 116 PROCEEDINGS OF THE SAINT LOUIS MEETING JOSEPH STANLEY-BrRowN, 26 Exchange Place, New York, N. Y. August, 1892. TimotHy W. STANTON, U. 8S. National Museum, Washington, D.C. Aug., 1891. CLINTON R. STAUFFER, University of Minnesota, Minneapolis, Minn. Dec., 1911. EUGENE STEBINGER, JR., U. S. Geological Survey, Washington, D.C. Dec., 1916. EDWARD STEIDTMANN, University of Wisconsin, Madison, Wis. December, 1916. Lioyp W. STEPHENSON, U.S. Geological Survey, Washington, D.C. Dec., 1911. *JOHN J. STEVENSON, 215 West 101st St., New York, N. Y. JAMES HovuGH STOLLER, Union College, Schenectady, N. Y. RALPH WALTER STONE, U. S. Geological Survey, Washington, D. C. Dee., 1912. GEORGE WILLIS StTose, U. S. Geological Survey, Washington, D. C. Dec., 1908. CHARLES K. Swartz, Johns Hopkins University, Baltimore, Md. Dec., 1908. STEPHEN TABER, University of South Carolina, Columbia, S. C. Dec., 1914. JOSEPH A. Tarr, 781 Flood Building, San Francisco, Cal. August, 1895. MiIcGnNon TaLBotT, Mount Holyoke College, South Hadley, Mass. Dec., 1913. JAMES E. TaLMaAGE, University of Utah, Salt Lake City, Utah. Dec., 1897. WILLIAM ARTHUR Tarr, University of Missouri, Columbia, Mo. FRANK B. Taytor, Fort Wayne, Ind. December, 1895. *JAMES E. Topp, 1224 Rhode Island St., Lawrence, Kans. Cyrus FISHER TOLMAN, JR., Leland Stanford, Jr., University, Stanford Uni- versity, Cal. December, 1909. CHARLES WELDON TOMLINSON, University of Illinois, Urbana, II. ARTHUR C. TROWBRIDGE, State University of Iowa, Iowa City, lowa. Decem- ber, 1913. *HenRyY W. TURNER, 209 Alaska Commercial Building, San Francisco, Cal. WILLIAM H. TWENHOFEL, University of Wisconsin, Madison, Wis. Dec., 1913. MAYVILLE W. TWITCHELL, State Geological Survey, Trenton, N. J. Dec., 1911. JOSEPH B. TYRRELL, Room 534, Confederation Life Building. Toronto, Canada. May, 1889. JOHAN A. UDDEN, University of Texas, Austin, Texas. August, 1897. EDWARD O. ULricH, U. S. Geological Survey, Washington, D. C. Dec., 1903. JOSEPH B. UMPLEBY, U. S. Geological Survey, Washington, D. C. Dec., 1913. *WARREN UPHAM, Minnesota Historical Society, Saint Paul, Minn. *CHARLES R. VAN HIsgE, University of Wisconsin, Madison, Wis. FRANK ROBERTSON VAN Horn, Case School of Applied Science, Cleveland, Ohio. December, 1898. GILBERT VAN INGEN, Princeton University, Princeton, N. J. December, 1904. FRANCIS MAURICE VAN TUyYL, Colorado School of Mines, Golden, Colo. T. WAYLAND VAUGHAN, U.S. Geological Survey, Washington, D.C. Aug., 1896. ARTHUR CLIFFORD VEACH, 7 Richmond Terrace, Whitehall, S. W., London, England. December, 1906. * ANTHONY W. VoGpEs, 2425 First St., San Diego, Cal. *M. EDWARD WADSWORTH, School of Mines, University of Pittsburgh, Pitts- burgh, Pa. *CHARLES D. WALtcoTT, Smithsonian Institution, Washington, D. C. THomMAsS L. WALKER, University of Toronto, Toronto, Canada. Dec., 1903. CHARLES H. WARREN, Massachusetts Institute of Technology, Boston, Mass. December, 1901. HENRY STEPHENS WASHINGTON, Geophysical Laboratory, Washington, D. C. August, 1896. LIST OF MEMBERS ile Wi THomas L. Watson, University of Virginia, Charlottesville, Va. June, 1900. CHARLES E. WEAVER, University of Washington, Seattle, Wash. Dec., 19138. WALTER H. WEED, 29 Broadway, New York, N. Y. May, 1889. CARROLL H. WEGEMANN, U.S. Geological Survey, Washington, D.C. Dec., 1912. SAMUEL WEIDMAN, Wisconsin Geological and Natural History Survey, Madi- son, Wis. December, 1903. Stuart WELLER, University of Chicago, Chicago, Ill. June, 1900. LEwIs G. WESTGATE, Ohio Wesleyan University, Delaware, Ohio. Aug., 1894. Epear T. WHERRY, Bureau of Chemistry, Washington, D. C. Dec., 1915. Davw Wuirtr, U. S. National Museum, Washington, D. C. May, 1889. *ISRAEL C. WHITE, Morgantown, W. Va. GEORGE REBER WIELAND, Yale University, New Haven, Conn. December, 1910. FRANK A. WILDER, North Holston, Smyth County, Va. December, 1905. *EDWARD H. WILLIAMS, JR., Woodstock, Vt. *Henry S. WILLIAMS, Cornell University, Ithaca, N. Y. Ira A. WILLIAMS, Oregon School of Mines, Corvallis, Ore. December, 1905. MERTON YARWOOD WILLIAMS, Geological Survey, Ottawa, Canada. Dec., 1916. BAILEY WILLIS, Leland Stanford, Jr., University, Cal. December, 1889. ALFRED W. G. WILSON, Department of Mines, Ottawa, Canada. June, 1902. MorgLry EVANS WILSON, Geological Survey, Ottawa, Canada. December, 1916. ALEXANDER N. WINCHELL, University of Wisconsin, Madison, Wis. Aug., 1901. *HORACE VAUGHN WINCHELL, First National Society Bldg., Minneapolis, Minn. *ARTHUR WINSLOW, 131 State St., Boston, Mass. JOHN EH. Wo.Lrr, Harvard University, Cambridge, Mass. December, 1889. JOSEPH EH. WoopMAN, New York University, New York, N. Y. Dec., 1905. RoBERT 8S. WoopWARD, Carnegie Institution of Washington, Washington, D. C. May, 1889. Jay B. WoopwortH, Harvard University, Cambridge, Mass. December, 1895. CHARLES WILL WRIGHT, Ingurtosu, Arbus, Sardinia, Italy. December, 1909. FREDERIC EH. WRIGHT, Geophysical Laboratory, Carnegie Institution, Washing- ton, D. C. December, 1903. *G. FREDERICK WRIGHT, Oberlin Theological Seminary, Oberlin, Ohio. GrorGE A. YouNG, Geological Survey of Canada, Ottawa, Canada. Dec., 1905. VIcToR ZIEGLER, Colorado School of Mines, Golden, Colo. December, 1916. CORRESPONDENTS DECEASED HERMAN CREDNER. Died July 22, 1913. EDWARD SuEss. Died April 20, 1914. A. MicHEL-Litvy. Died September, 1911. TH. TSCHERNYSCHEW. Died Jan. 15, 1914. H. RosENBuscH. Died January 20, 1914. FERDINAND ZIRKEL. Died June 11, 1912. FELLOWS DECEASED * Indicates Original Fellow (see article III of Constitution) *CHAs. A. ASHBURNER. Died Dec. 24, 1889. ERNEST R. Buckiey. Died Jan. 19, 1912. ALFRED BE. BARLOW. Died May 28, 1914. D. D. CatrNES. Died June 14, 1917. CHARLES E. Bencuer. Died Feb. 14,1904. *SamurtCatvin. Died April 17, 1911. Ropert Bevv. Died June 18, 1917. FRANK. R. CARPENTER. Died April 1, 1910. ALBERT S. BIcKMorE. Died Aug. 12,1914. *J.H.CHaApiIn. Died March 14, 1892. Wo. PHIPPS BLAKE. Died May 21, 1910. WILLIAM B. CLARK. Died July 27, 1917. AMOS BOWMAN. Died June 18, 1894. *EHDWARD W. CLAYPOLE. Died Aug. 17, 1901. Amos P. Brown. Died Oct. 9, 1917. *THro. B. Comstock. Died July 26, 1915. 118 PROCEEDINGS OF THE SAINT LOUIS MEETING Gprorce H. CooK. Died Sept. 22, 1889. *HDWARD D. Cops. Died April 12, 1897. ANTONIO DEL CASTILLO. Died Oct. 28,1895. *JaAMES D. Dana. Died April 14, 1895. CHARLES A. Davis. Died April 9, 1916. GEoRGE M. Dawson. Died March 2, 1901. Sir J. WM. Dawson. Died Nov. 19, 1899. ORVILLE A. DerRBy. Died Nov. 27, 1915. CHAS. W. DRYSDALE. Died July 10, 1917. CLARENCE E. Dutton. Died Jan. 4, 1912. *WILLIAM B. DwieHt. Died Aug. 29, 1906. *GEORGE H. ELpRIDGE. Died June 29, 1905. *SAMUEL F. EMMoNS. Died March 28, 1911. Wm. M. FontTaAINneE. Died April 29, 1918. *ALBERT BE. Foote. Died October 10, 1895. *PERSIFOR FrRAzER. Died April 7, 1909. *HoMER T. FuLLER. Died Aug. 14, 1908. N. J. Giroux. Died November 30, 1891. ARNOLD HaGusr. Died May 14, 1917. *CHRISTOPHER W.HALL. Died May 10,1911. *JAMES Hauu. Died August 7, 1898. JouHN B. HAtcHER. Died July 3, 1904. *RoBERT Hay. Died December 14, 1895. C. WILLARD HayEs. Died Feb. 9, 1916. * ANGELO HEILPRIN. Died July 17, 1907. EUGENE W. HiuGarp. Died Jan. 8, 1916. Prank Aly Ein Died sully as; 19nd: *JosppH A. HotmeEs. Died July 13, 1915. DAVID HONEYMAN. Died October 17, 1889. *EDWIN E. Howey. Died April 16, 1911. *Horace C. Hovey. Died July 27, 1914. THomMas S8. Hunt. Died Feb. 12, 1892. *ALPHEUS HyaTT. Died Jan. 15, 1902. THOMAS M. JACKSON. Died Feb. 3, 1912. *JOSEPH F. JAMES. Died March 29, 1897. WILBUR C. KNigHT. Died July 28, 1903: RALPH D. Lacor. Died February 5, 1901. J.C. K. LAFLAMME. Died July 6, 1910. DANIEL W. LANGTON. Died June 21, 1909. *JoSEPH LECONTE. Died July 6, 1901. *J. PeTER LESLEY. Died June 2, 1903. Rost. H. LOUGHRIDGE. Died July 1, 1917. HENRY MCCALLEY. Died Nov. 20, 1904. *W J McGere. Died September 4, 1912. OLIVER Marcy. Died March 19, 1899. OTHNIEL C. MARSH. Died March 18, 1899. *FreD. J. H. Mprrity. Died Nov. 29, 1916. JAMES HH. MIuus. Died July 25, 1901. *Hrnry B. NASON. _ Died January 17, 1895. *PETER NEFF. Died May 11, 1903. *JOHN S. NEWBERRY. Died Dec. 7, 1892. WILLIAM H. Niues. Died Sept. 12, 1910. *FEXDWARD ORTON. Died October 16, 1899. *AMOS O. OSBORN. Died March, 1911. *RICHARD OWEN. Died March 24, 1890. SAMUEL L. PENFIELD. Died Aug. 14, 190s. DAVID P. PENHALLOW. Died Oct. 20, 1910. *FRANKLIN PLATT. Died July 24, 1900. WILLIAM H. PrETTEE. Died May 26,1904. *JOHN W. POWELL. Died Sept. 23, 1902. *Cuas. S. Prosser. Died Sept. 11, 1916, A. H. Purpuxr. Died Dec: 12; 1987: *TSRAEL C. RUSSELL. Died May 1, 1906. *JAMES M. SAFFORD. Died July 3, 1907. *CHARLES SCHAEFFER. Died Nov. 23, 1903. H. M. Speerty. Died May 4, 1917. *NATHANIEL S8.SHALER. Died Aprii 10,1906. WILLIAM J. SuTton. Died May 9, 1915. RaupPpH 8. Tarr. Died March 21, 1912. WILLIAM G. TIGHT. Died Jan. 15, 1910. CHARLES WACHSMUTH. Died Feb. 7, 1896 THOMAS C. WESTON. Died July 20, 1910 THEODORE G. WHITE. Died July 7, 1901. *ROBERT P. WHITFIELD. Died April 6, 1910. *GEORGE H. WILLIAMS. Died July 12, 1894 *J. FRANCIS WILLIAMS. Died Nov. 9, 1891 ARTHUR B. WILMOTT. Died May 8, 1914. * ALEXANDER WINCHELL. Died Feb. 19, 1891 *NEWTON WINCHELL. Died May 1, 1914. ALBERT A. WRIGHT. Died April 2, 1905. WILLIAM §S. YEATES. Died Feb. 19, 1908. Summary Orizinal WeEllOwWsS? -.2 .soccisye ane een ee Hlected WelMlOwW Ss) ac.a gens erence snares Membership.....: See ee eee Deceased Correspondents .......... Deceased Bellows — chin: ee he ciete ae eee BULLETIN OF THt GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 119-166 MARCH 31, 1918 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY PROCEEDINGS OF THE NINTH ANNUAL MEETING OF THE PALEONTOLOGICAL SOCIETY, HELD AT PITTSBURGH, PENNSYLVANIA, DECEMBER 31, 1917, AND JANUARY 1 AND 2, 1918. R. S. Basser, Secretary CONTENTS Page Pee CE OTT)... IIOCAMRMDET BN 6 cia 4 bye Ww lige alana mle Se ensie wredavate eave wise alae b Bice doe re MNSU Es Prmta Ta DRTC AC ORSTAGIE gk ak Saag ig (eta sus ara la's Sg SG ra en RAW Ele ade 8 a alee ie 123 Mea SMAILD ER TOMS TENT OMIGE cycle kz 8 cSiny hat Wave ua Natecdheile vale: Nuchiars eGhclara> cgMaae est RAG wile © 123 PR SOE CS MEDON Us ..s oissee wits a. caw «id state woe eberele. « Sib xCha Ru hake See where 124 Ppminen: OF Auditing Committee: oo. 2 268, cise ahs ocece be ob oie wie ed 125 Peeat 08 Officens and) MEMES « .) 2.5) fess seid a A net elas o's esldleine cs 6s 125 MEAP RaRE AONE TREN STIPE II ELIS Se) 55a a, el ceyaauel.e mis ie(love i ooo lonanatavel hl Mapel eh Babe lars dec 126 Presentation of papers on paleontology and stratigraphy............ 127 Paleozoic deposits and fossils on the Piedmont of Maryland and Virginia [abstract] ; Stl ORY aa 6 elas a 8°12 KT ERE eh, hs ee ea ae oad 127 Significance of the Sherburne bar in the Upper Devonic stratig- raphy [abstract]; by Amadeus W. Grabau......... EA ea ates Leaf Algal limestone on the Belcher Islands, Hudson Bay [abstract] ; EET) DCSE 01011 SSM Rene TI er Pree Bacar Sr re OS be eg aT 128 Symposium on problems in history of faunal and floral relationships in the Antillean-Isthmian region and their bearing on biologie rela- fionsbins of North and South Americas is cee. mad 6 8 ck ee Se owe 129 Relations between the Paleozoic floras of North and South Amer- TEE? i eR BYE 0 TE 28 Ce aOR eae e MAUI ie Mae 7 ak AR ae 129 Relations between the Mesozoic floras of North and South Amer- TCE) ON geal ENS Bea ..<.. 00. 0.o.6 42 sew. ease ee eee rere = Mesozoic history of Central America and the West Indies; by TW Stanton sess sya wo eho wens Wes ee ee 138 Cenozoic history of Central America and the West Indies; by T. W. Vat@han «ss ose Sy eeinc ate Oe le ils eee ek 138 Relationships of the Mesozoic reptiles of North and South Amer- ica: by So. W: Williston 2. .ao2% CAs obs oie oe eee ee 138 | : Affinities and origin of the Antillean mammals; by W. D. Matthew 138 | Fresh-water fish faunas of North and South America; by C. H. BUSCUMAT, SS 2 oss oe ees ee Veaas tye 138 Evidence of recent changes of level in Porto Rico, as shown by : studies in the Ponce district; by Graham John Mitchell....... 138 Presentation,.of PaperS.n.. .-4.08 06S. oe Sew oh oe Be = Ce 141 Generic nomenclature of the Proboscidea [abstract]; by W. D. — Matthewo32t fexcens eters ot u's pfmietorele bie ee mt eens 30 he ae 141 ‘Session of Wednesday, January 2...) 0. ..6000. 15.0.5 00s 0 oe 141 ; Report of. the Auditing Committee... 02... 00. 24 2054 oS ee 141 7 Presentation: of Papers...) se). 2. os. be See Sl a 142 ; Cretaceous overlaps in northwest Europe and their bearing on the . bathymetric distribution of the Cretaceous Silicispongize [ab- stract]; by Marjorie O'Connell. 0. ......%...... 2325.5 142 . New bathymetrical map of the West Indies region [abstract]; by i Chester A. Reeds. 0)... 02. 2 Jas 2 a siclsls eis 7 po cies oe 142 Isolation as a factor in the development of Paleozoic faunas [ab- 5 stract]; by Amadeus W. Grabato. 024. 22.422. eee 143 An Ordovician fauna from southeastern Alaska [abstract]; by ; Hdwin Kirk... 62.4... 20282 ok ete ee ee ee 143 :.- Affinities and phylogeny of the extinct Camelide [abstract]; by ‘ W... D. Matinee oo o:s:ct:s/ncssingsiete py cle soles o aot iaak le hen 144 ; Rocky Mountains section in the vicinity of Whitemans Pass [ab-- . stract]; by C. W. Drysdale and L. D. Burling...... eel a 145 ~ Further light on the earlier stratigraphy of the Canadian Cor- 4 dillera [abstract]; by Lancaster D. Burling........ oe eee 145 " Evolution of vertebre; by S. W. Williston...........,.......... 146 “4 Diseases of the Mosasaurs [abstract]; by Roy L. Mdndies cba 147 \ Report on a collection of Oligocene plant fossils from Montana } fabstract]; by O. H.. Jennings:.. 2... 5.9.2 oe eee 147 New Tillodont skull from the Huerfano Basin, Colorado [ab- stract] ;. by Walters Granigerian is. jeicscciersic te alae wre ee alle 0 ase 147 = CONTENTS 12a: Page Mollusea of the Carrizo Creek beds and their Caribbean affinities PapStEachl Oy Ove Lue: DICKERSON: ised. sw elc sere oca'e gisles oes 148 Proposed correlation of the Pacific and Atlantic Eocene [ab- SOEACENS TDN ECON En AOTCIKET SOM. <).evsltarclctore Gye alece’ ars. ele wieqaisce ee aeie & 148 Paleozoic glaciation in southeastern Alaska [abstract]; by Edwin Ronen. 3. BLD Gait Cac O nChEte Bee Re a near aemibe Us taker ear ee 149 Principles of classification of Cyclostome bryozoa [abstract]; by EMAC ATAU VAN PRP a a AAS SWOT nes cio tia yst acid et bin Sate of vate Mice Rie ehseyerw areca 151 Hauna ot the. Meganos group; by B. ds Clarkin soe 2 ee wes 152 - Fossil mammals of the Tiffany beds [abstract]; by W. D. Matthew DINU ae Vaca Me GTA REI oad Ss aleus clade flcka mits (o m-einehg Uisheberec dead Pence ee ea AS 152 Fauna of the Idaho Tulare Pliocene of the Pacific Coast region ; TONY yd ER EL Ges al SN eri Oy 00 Se eee ner ge cea oe ae 152 Revision of the Pseudotapirs of the North American Eocene [ab- Steve mN Oa Ne cl OUEL SOM src cxcgs «ape aie s, ob aieteikeays are wa ata slcehene @ apate's 152 Notes on the American Pliocene rhinoceroses [abstract]; by Ny reel Oncee Mica fliers oelovaiiateraitiatahe 2 cinco ale Miavte ataliiegs cididce Rae BAe obs 153 New artiodactyls from the Upper Eocene of the Uinta Basin, Wraihaistraciie by, Oc As Peterson... A eee See ios ake, a oie 153 Marine Oligocene of the west coast of North America [abstract] ; wisn Olin and Ral Armoldis. sc. ae wiales< ere ec o' de scares eons 153 The question of paleoecology; by F. E. Clements................ 154 Note on the evolution of the femoral trochanters in reptiles and Peat LS Wy NV ULEAD Ete GOP OPY ..2 220s eielerae-s celle ese’e; 04 @ atede, ave vere © 154 Carboniferous species of “Zaphrentis’; by G. H. Chadwick...... 154 Extinct vertebrate faunas from the Badlands of Bautista Creek and San Timoteo Canyon of southern California; by Childs BR Sauee cen rape ate We) WRENS eva BO Ue ea 9a Oe i SPRUE ARN ae Dey Mes MME De yc Se 154 Notes on Hifel brachiopods; by G. H. Chadwick................ 154 Hesister of the. Pittsburgh meeting, 1917. oes vice eset ee ne Seed ee canes 155 Officers, Correspondents, and members of the Paleontological Society..... 155 Minutes of the Highth Annual Meeting of the Pacific Coast Section of the Paleontological Society ; by CHESTER Stock, Secretary............e000- 160 aE O TR OTICEIS a acy oie Mere tiara cases. abe ie; oceanees eheveeale ehaiene wcebeherscarere ae ames a 161 PARE See LOMO LE AICS <.\as o0 s crson 2 oie distin Sle celblalers hardcore. ola mraraie ierepeveuh ees 161 Systematic position of the Dire wolves of the American Pleisto- CSUR lower Aer MLCT ILA IID 5 /ar5, cit ors, oy aceuter te Oneyoraus, anc eee’ 6 areeracer 6-8 <6 vile 161 Note on the occurrence of a mammalian jaw, presumably from the Truckee beds of western Nevada [abstract]; by J. C. Jones 161 Pinnipeds from Miocene and Pleistocene deposits of California tapstract | by Remineton INElOeo. Ween ecg o otcleeys s clase la Ges 3 161 Puma-like cats of Rancho La Brea; by J. C. Merriam........... 161 Gravigrade edentates in later Tertiary deposits of North America Papshinch iby Chester Stock... iwc cee sw ce cs ck Qe ss wae ew eens 161 Relationships of recent and fossil invertebrate faunas on the west side of the Isthmus of Panama to those on the east side [ab- SEARS iee LEX) meen meet LC MONG: tia, crore Sainte be miarein a c/s)e Soc kere @ alee © 6 162 Tropitide of the Upper Triassic of California [abstract]; by J. P. es ecm eeps™— — reer ree — eee eT <<< ee CC Ce 122 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY Page Fauna of the Idaho formation [abstract]; by John C. Merriam... 162 Occurrence of a marine Middle Tertiary fauna on the western border of the Mojave Desert area; by Wallace Gordon........ 162 Fauna of the Bautista Creek badlands [abstract] ; by Childs Briel os 8 ik a ey 163 Occurrence of the Siphonalia sutterensis zone, the ‘wosentiage Tejon horizon in the outer coast ranges of California [ab- stract]; by Roy HE. Dickerson... ss .si2 0. 20%... eee 163 Cretaceous and Tertiary stratigraphy of the western end of the Santa Inez Mountains, Santa Barbara County, California [ab- stract]; by H. J:- Hawley .2......5...1. 44: 25.8.9 ee 164 Geologic range and evolution of the more important Pacific Coast echinoids [abstract]; by W. S. W. Kew.............- eee 164 Evidence in San Gorgonio Pass, Riverside County, of a late Plio- cene extension of the Gulf of Lower California [abstract]: by WB: Vaughan. ooo 6 Ge eee a et 6 ee 164 Vaqueros formation in California [abstract]; by W. F. Loel..... 165 Tertiary and Pleistocene foment lise of the north coast of Peru, South America [abstract]; by G. C. Gester........ 2 at ee 165 Symposium on correlation of Olesen faunas and formations of the Pacific coast; by C. E. Weaver, R. E. Dickerson, and B. L. Clark .. o 2.) gas 2 Oe oe eh Se ee 165 Paleogeography of the Oligocene of Washington rahe ; by Charles: Ei. Weaver... o.tiec ce eb ee be he oe die = ee 165 Paleontology and stratigraphy of the Porter division of the Oligo- cene in Washington [abstract]: by Katherine E. Van Winckle. 166 Faunal zones of the Oligocene; by B. lh. Clark....... > 222.00 166 Climate and its influence on Oligocene faunas of the Pacific coast; by Roy E.. Dickerson... 2.04 .. 2.05 0.06 500. ood oe 166 Register of members and visitors at Stanford meeting, 1917............. 166 SESSION OF Monpbay, DECEMBER 31 President Merriam called the Society to order in general session at 10 a. m., Monday, December 31, in Rehearsal Hall of the Carnegie Museum. Doctor Holland welcomed the Society to Pittsburgh in a patriotic speech, which was appreciated and warmly applauded by the members. Follow- ing Doctor Holland, President Merriam opened the exercises with an inspiring address, the keynote of which was our duty to science at the present dark moment. The first matter of business before the Society was the report of the Council, which was then presented. COUNCIL REPORT 123 REPORT. OF THE COUNCIL To the Paleontological Socvety, in ninth annual meeting assembled: This year’s Council has held two regular meetings for the transaction . of the Society’s business—one at the adjournment of the meeting at Al- bany, December 29, and the second just before the present session. As usual, most of the business has been conducted by correspondence. ‘The following reports of officers give a résumé of the administration for the ninth year of the Society: | SECRETARY'S REPORT To the Council of the Paleontological Society: | Meetings—The proceedings of the eighth annual meeting of the So- ciety, held at Albany, New York, December 27-29, 1916, have been printed in volume 28, pages 189-234, of the Bulletin of the Geological Society of America, published on March 31, 1917. On account of the great delay in publication due to war conditions, only two numbers of the four published annually as the Bulletin of the Geological Society of America have been issued up to the present date, and the proceedings is the only one of our Society’s publications that has so far been printed. Number four of this Bulletin, now in press, contains three articles by members of our Society. However, a second publication—an extensive paper by Doctor Grabau, published at the end of 1916—was distributed during the present year, so that while the number of papers has been smaller the number of printed pages has been about as usual. The announcement that the ninth annual meeting of the Society would occur at Pittsburgh, Pennsylvania, beginning December 31, 1917, at the invitation of the Carnegie Museum, through the Director, Doctor Wil- ham J. Holland, was forwarded to the members on March 26, 1917, with the Council’s proposed nominations for officers. . At the meeting of the Council just concluded, it was voted that in view of the increased membership and business of the Society, the Secretary was empowered to expend not more than $25 per year for necessary clerical assistance. Membership—During the year the Society nas lost by death Prof. Henry M. Seely, who died May 4, 1917, and Prof. William Bullock Clark, who died early in July, 1917. Professor Seely was one of our oldest , members and had been Professor of Natural History at Middlebury Col- lege, Middlebury, Vermont, since 1861. His best known geologic work was on the stratigraphy and paleontology of the Beekmantown and Chazy 124 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY formations of the Champlain Valley. Professor Clark was in the prime of life, and his passing is a great blow to our science. His works on the Atlantic Coastal Plain, and especially on the geology and paleontology of Maryland, are too well known to be mentioned in detail. Eight new members were elected to the Society at the eighth annual meeting, making the enrollment at the end of 1916, 184. Nine new members are under consideration for this meeting, so that at the present rate the Society will pass the 200 mark within a year. Five members of our Society were elected to Fellowship in the Geological Society of Amer- ica at the election just concluded. | Pacific Coast Section—The eighth annual meeting of the Pacific Coast Section of the Paleontological Society was held at Stanford University on April 6 and 7, 1917, the Society participating in the second annual meeting of the Pacific Division of the American Association for the Ad- vancement of Science. On April 6 the Society met in joint session with the Geological Society and the Seismological Society, at which time Prof. John C. Merriam delivered an address on preparedness. This joint ses- sion adjourned at the conclusion of Professor Merriam’s address, and the Paleontological Society was called to order in separate session by Dr. J. P. Buwalda at 3.15 o’clock, in room 360, Mineralogy Building. The following officers were elected for the ensuing year: President, Bruce L. CLARK. Vice-President, CHESTER STOCK. Secretary-Treasurer, CHESTER STOCK. Nineteen papers, dealing with both the Vertebrate and Invertebrate Paleontology and Stratigraphy of the West Coast especially, were read at this meeting. Twenty-two members and visitors were present. The minutes of this section are printed on pages 160 to 166 of this Bulletin. Respectfully submitted, R. S. Basser, Secretary. WasHInctTon, D. C., December 31, 1917. TREASURER’S REPORT To the Council of the Paleontological Society: The Treasurer begs to submit the following report of the finances of the Society for the fiscal year ending December 19, 1917: COUNCIL REPORT 125 é RECEIPTS meeamoan hand Wecemmer-26, 1916. os cae. ehce ee a pw ever a wlelae $481.65 MMSE) FOCI FOIG)) ciao cir ies sis oie ccd aie vied wlaltne ee a eee wm 12.00 eR MEP LCES: CLONE Gav arciesais fats shud’ e sireys tel ear gicvaleys sain qpeia a fave ce 243.10 iateresc, Connecticut Savings Bank... ..)..0.. 066.026 8 cee wae 13.86 $750.61 EXPENDITURES Treasurer's office: Up ed Reanr apes Mears Siar ease tayeneetned oesia'ah oa) ular aneees ees eke .. $4.00 Sactomenry sat Print NS. 6c avats oOo Ware see bd proces 9.75 | $13.75 Secretary’s office: BRerebary S ahlowanee ..075. sce se hs slo's ewe »-+ $50.00 TIS St oa nooo ha cta ts asco ee ula 0 Cle ies aco oe mieie aero es 47.49 ———— 97.49 ———_ 111.24 ipalance on’ hand December 19,, VOUT oo 6 uc cei ole u scm ee aes $639 .37 REDRESS OME ETATT OLS ih 5, sore ofc: a6 Rraiie: owl Helena lay cue. eck w/e Oa Neaka ele Re enere wie wees $157.72 Meir reue PIM OIeS: (IOUG) Ase Cate aie eiaid ie cle le a dd sree s winebule bia ere $12.00 eines CUES. (LOM Oo ele Sate Sa ain oe wlan Oh ee ete regs 27.00 39.00 Respectfully submitted, RicHarD 8. LULL, | Treasurer. New Haven, Connecticut, December 19, 1917. APPOINTMENT OF AUDITING COMMITTEE Following the reading of the Treasurer’s report, on vote of the Society, Burnett Smith and W. A. Parks were appointed a committee to audit these accounts. ELECTION OF OFFICERS AND MEMBERS The announcement of the election of officers for 1918 and of new mem- bers was the next matter of business. The results of the ballots were as follows: OFFICERS FOR 1918 President: F. H. Knowrron, Washington, D. C. First Vice-President: ArtHur Hourick, New York City 126 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY Second Vice-President: L. W. STEPHENSON, Washington, D. C. Third Vice-President: F. B. Loomis, Amherst, Mass. Secretary: R. 8. Basster, Washington, D. C. Treasurer : R. S. Luny, New Haven, Conn. Editor: C. R. Hastman, New York City NEW MEMBERS F. Ek. CLEMENTS, Carnegie Institution, Washington, D. C. LEE RayMonp Dicez,. University of Montana, Missoula, Mont. CHILDS Frick, Santa Barbara, Cal.- EUGENE SCHOFIELD HEATH, Botany Hall, University of California, Berkeley, Cal. REMINGTON KELLOGG, 2212 A Union, Berkeley, Cal. WAYNE FREDERICK LOEL, Department of Geology.and Mining, Stanford Univer- sity, Palo Alto, Cal. IpA CARTER OLpDROYD, College Terrace, Palo Alto, Cal. CARROLL MARSHALL WAGNER, 2604 Etna Street, Berkeley, Cal. ELECTION OF NEW MEMBERS The President then reported that the Council had acted favorably on the request of William F. E. Gurley, of Walker Museum, University of Chicago, and William A. Price, of West Virginia University, Morgan- town, West Virginia, both members of the Geological Society of America, who had signified the wish to become members of the Paleontological Society. He also stated that the following nomination for membership, received too late for the printed ballot, was favored by the Council: Mrs. Euta D. McEwan, A. B. (1913), A. M. (1914) Indiana University, Scien- tific Aid in Paleontology, U. 8S. National Museum. Engaged in study of fossil invertebrates. Proposed by E. O. Ulrich and R. S. Bassler. On motion by Mr. David White and the unanimous vote of the mem- bers, the Secretary was instructed to cast the ballot of the Society for election to membership of Messrs. Gurley and Price and Mrs. McEwan. ABSTRACTS OF PAPERS \ 127 PRESENTATION OF PAPERS ON PALEONTOLOGY AND STRATIGRAPHY The first paper on the program, dealing with the stratigraphy and paleontology of the Paleozoic rocks on the Piedmont plateau, was illus- trated by lantern slides and was discussed by Messrs. Grabau and Mer- riam, with replies by the author. PALEOZOIC DEPOSITS AND FOSSILS ON THE PIEDMONT OF MARYLAND AND VIRGINIA BY R. S. BASSLER (Abstract) The western part of the Piedmont plateau in Maryland and Virginia contains areas of early Paleozoic limestone infolded in the Precambrian crystallines and overlaid in part by the Triassic (Newark) series. These limestones outcrop at one point next to the early Cambrian Harpers shale, and it has hitherto been believed that they represented the Shenandoah limestones of the Appalachian Valley, comprising strata from early Cambrian to Middle Ordovician time. Detailed mapping of this area and the discovery of fossils has shown that this Piedmont limestone consists of a lower massive limestone division with Lower Beekmantown fossils separated by a well marked disconformity from an upper thin bedded dark-blue limestone with a Chazyan fauna. The Lower Beekman- town division can be correlated directly with strata in the Appalachian Valley, but the Chazyan portion has no representation there. There was then presented a study of an interesting problem in Devo- nian stratigraphy by the author, illustrated with diagrams, which brought forth discussion from several members of the Society. SIGNIFICANCE OF THE SHERBURNE BAR IN THE UPPER DEVONIC STRATIGRAPHY BY AMADEUS W. GRABAU (Abstract) The original Sherburne sandstone of Vanuxem formed a bar which extended from the old-land of Atlantica on the north to the mouth of the Devonic Rom- ney River on the south. During its maximum development, shortly after the close of the Hamilton period, it was about ten miles wide and formed an effec- tive barrier between the Atlantic region which carried the typical Hamilton fauna and western New York and the region beyond. In this area a remnant of the Hamilton fauna, cut off from intercrossing with the main stock, de- veloped into the early Ithaca, or lower Portage fauna, to which were added migrants from the Traverse survivors of the west. Meanwhile the pure Hamil- ton, or Tropidoleptus, fauna continued in the embayment east of the bar, re- maining in constant communication with the center of distribution of this ‘fauna in the Atlantic. In the Far West the Naples fauna made its entrance. 128 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY so that three faunas existed simultaneously in New York—the Naples in the west, the Lower Portage, or pure Ithaca, in the center, and the Hamilton in the east. Submergence of the bar permitted an intermingling of the Hamil- ton and pure Ithaca faunas, and so produced the mixed fauna commonly taken as typical (but not the pure) Ithaca fauna. These facts are demonstrated by showing the percentages of each of the faunal units found in the successive sections from west to east. Professor Moore, a visiting Fellow of the Geological Society of Amer- ica, then gave an interesting account of algal limestones of the Far North. His paper was illustrated by lantern shdes and was discussed by Messrs. White, Merriam, Grabau, and Bassler. ALGAL LIMESTONE ON THE BELCHER ISLANDS, HUDSON BAY BY E. S. MOORE? (Abstract) , The Belcher Islands are situated off the east coast of Hudson Bay and con- sist of rocks similar in many respects to those formed on the coast and which have been described by Leith and Low. The islands were little known until recently, when considerable areas of jasper were discovered on them. Asso- _ ciated with this iron formation there is a remarkable band of concretionary limestone over 400 feet thick and consisting of spherical to subspherical balls varying from about an inch to 15 inches in diameter. These were at first re- garded as cryptozoons, but their spherical form and the almost total absence of the crenulated character of the cryptozoons seem to separate them, at least from Cryptozoon proliferum. They resemble more strongly some of the recent algal concretions found in lakes and streams and described by Clarke, Roddy, and others. A smaller type is similar in some respects to Walcott’s Collenia? frequens. In the associated iron formation there are numerous granules of calcite, silica, and iron silicate. The two former bear a close resemblance to certain granules which occur in the Lower Paleozoic limestones of central Pennsyl- vania and which grade without break into distinct oolites. The occurrence of these concretions, both large and small, and their associations point strongly to organic origin of the limestone and iron deposits, and it indicates further that these rocks are either not Precambrian, as they have been supposed to be, or that an abundance of low types of life existed in the Hudson Bay basin in Precambrian time. At 12.30 p. m. the Society adjourned for luncheon, convening again at 2 p. m. for the reading of the paleobotanic papers of the symposium. Although the absence of several of the authors prevented a full discus- sion of their papers, which were read by other members of the Society, a number of interesting and instructive points were brought out in the remarks by Messrs. Matthew, Vaughan, White, Merriam, Ami, Osborn, and others. 1Jntroduced by R. S. Bassler. ABSTRACTS OF PAPERS 129 SYMPOSIUM ON PROBLEMS IN HISTORY OF FAUNAL AND FLORAL RELATION- SHIPS IN THE ANTILLEAN-ISTHMIAN REGION AND THEIR BEARING ON BIOLOGIC RELATIONSHIPS OF NORTH AND SOUTH AMERICA RELATIONS BETWEEN THE PALEOZOIC FLORAS OF NORTH AND SOUTH AMERICA BY DAVID WHITE RELATIONS BETWEEN THE MESOZOIC FLORAS OF NORTH AND SOUTH AMERICA BY F. H. KNOWLTON PALEOGEOGRAPHIC SIGNIFICANCE OF THE CENOZOIC FLORAS OF EQUATORIAL AMERICA AND THE ADJACENT REGIONS BY EDWARD W. BERRY BEARING OF THE DISTRIBUTION OF THE EXISTING FLORA OF CENTRAL AMERICA AND THE ANTILLES ON FORMER LAND CONNECTIONS BY WILLIAM TRELEASE After the conclusion of the first part of the symposium, there was suffi- cient time before adjournment for the day for the presentation of the first paper in the list of those dealing with the invertebrate paleontology of Central America and the West Indies. This paper on the Paleozoic history was presented by the author and was illustrated by lantern slides of paleogeographic maps. Both the papers and the maps called forth such criticism and comments from Miss O’Connell and Messrs. Grabau, Matthew, Vaughan, and others that new data were added to this some- what doubtful portion of Central American history. PALEOZOIC HISTORY OF CENTRAL AMERICA AND THE WEST INDIES BY R. S. BASSLER At 5.30 p. m. the Society adjourned, meeting again at 8 p. m. at the University Club, to hear the address of the retiring President. PRESIDENTIAL ADDRESS BY J. C. MERRIAM AN OUTLINE OF PROGRESS IN PALEHONTOLOGIOC RESEARCH ON THE PACIFIC COAST } Doctor Merriam’s account of the progress of all three branches of paleontology on the west coast was followed with much interest and atten- tion by the fifty or more members and visitors who were present. LS0 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY SMOKER TO THE SOCIETY The presidential address was followed by a smoker to the Society as guests of Doctor Holland, Director of the Carnegie Museum. After re- freshments had been served and conversation had continued for an hour, Doctor Holland, the host of the evening, called the Society to order and introduced one member after another for impromptu talks and reminis- cences. The good stories related by Doctors Holland, Osborn, Williston, Ami, and Grabau, of American and foreign paleontologists, were espe- cially enjoyed. The Society also had the pleasure of listening to ad- dresses by the Chancellor of the University of Pittsburgh, members of the Board of Trustees of the Carnegie Museum, and other guests, and from several of the Fellows of the Geological Society of America. As the hour of 12 approached, Doctor Holland, in a patriotic address, em- phasized the duty of science to the nation, and asked us to mark the passing of the old year with a pledge to our country. As the whistles of the great steel mills along the three rivers of Pittsburgh, the armorer of the nation, announced the birth of the New Year, we arose and pledged ourselves anew by the singing of “America.” SESSION OF TUESDAY, JANUARY 1 Tuesday morning, at 10 o’clock, the members met in the hall of verte- brate paleontology of the Museum and were shown all the choice speci- mens of the exhibit by Doctor Holland, who pointed out the most strik- ing and interesting features in each. Time was lacking for a complete tour of the Museum, so Doctor Holland then guided us through the laboratories of vertebrate paleontology, where, with the magnificent speci- mens before us, he presented the following paper: SOME OBSERVATIONS ON THE OSTEOLOGY OF DIPLODOCUS BY WILLIAM J. HOLLAND Questions and remarks by Doctors Osborn, Williston, and Matthews, with reples by Doctor Holland, added to this interesting discussion and gave the members an insight into the great explorations by the Carnegie Museum and its richness in vertebrate remains. The recently acquired material of Diplodocus in the possession of the Carnegie Museum, in- cluding a perfect skull, in which even the sclerotic coat of the left eye-ball had been petrified, was the especial subject of Doctor Holland’s paper, ABSTRACTS OF PAPERS 131 although he touched on and disposed of the recent criticisms of Rev. H. W. Hutchinson. At 11.30 the Society commenced again in general session to continue the reading of papers, with Doctor Merriam presiding. The chairman announced that, in order to give variety to the program, papers from the three branches of paleontology would be interspersed. The first paper was a paleobotanic one, illustrated with specimens. Discussed by Messrs. Holland, Williston, Merriam, and Vaughan. CRITICAL STUDY OF FOSSIL LEAVES FROM THE DAKOTA SANDSTONE BY E. M. GRESS ? (Abstract) The study has been based on a collection consisting of about 100 specimens. About 80 of these are from a large collection of fossils purchased from Baron Ernst de Bayet, of Brussels, a few years ago, the remainder from the United States National Museum by exchange. The Bayet collection comes from Ells- worth County, Kansas; the others from different parts of Kansas and Nebraska. A few of the specimens had already been identified, some by, Leo Lesquereux ; others by an unknown person. Most of them bore no record of identification. All specimens have been carefully examined, and those bearing no labels have been identified, while those already identified have been verified. The collection is represented by about 65 species and 25 genera, among which the most common are the following: Aralia, Betulites, Ficus, Magnolia, Popu- lus, Protophyllum, Sassafras, Sterculia, and Viburnum. In our study of the fossils we have included a brief review of the history, location, and correlation of the “Dakota Formation,” with a careful description of each species and citations of available references. A critical study and com- parison of each specimen with other described and figured species and with type forms has been made. Professor Osborn then presented his interesting papers on vertebrate paleontology, both of which were iliustrated by lantern slides. In the discussion of these papers Messrs. Holland, Merriam, Peterson, Granger, and Matthew took part. OBSERVATIONS ON THE SKELETONS OF MOROPUS COOKI IN THE AMERICAN MUSEUM BY HENRY FAIRFIELD OSBORN (Abstract) Moropus is the largest and most distinctive mammal of Lower Miocene time in western North America, and has attracted a great deal of attention from 1 Introduced by O. E. Jennings. 132 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY paleontologists because of the long period of uncertainty as to its highly unique structure and adaptations and its great rarity as a fossil, the latter due prob- ably to its forest-frequenting habits. With its companions, the giant elothere pig, known as Dinohyus, and the diminutive pair-horned rhinoceros, Diceratheriwm, its remains have since 1882 been found in profusion in the Agate Spring Quarry of Sioux County, western . Nebraska. This quarry lies in the upper portion of the Lower Harrison hori- zon of Hatcher and was discovered by Mr. James H. Cook, of Agate, in the year 1877. Prof. Erwin H. Barbour collected the first actual Moropus material from the Agate Springs quarries in July, 1892. Mr. Harold Cook made a con- Siderable excavation in 1904, but it was not until 1908 that the specific name Moropus cooki was given by Professor Barbour’ (January 26, 1908), thus identifying the animal generically with Marsh’s type of Moropus from a some- what more recent deposit.2. In the meantime very extensive excavation and exploration was carried on by the Carnegie Museum for Moropus, Dinohyus, and Diceratherium remains, and after preliminary description the Moropus skeletons were described in detail in an important memoir in 1909.° These carefully conducted excavations by Mr. O. A. Peterson, under Dr. W. J. Holland’s direction, proved that the Agate Springs Quarry is the most remarkable deposit of mammalian remains of Tertiary age that has ever been found in any part of the world. Its only rival in the quantity of material preserved is the mid-Pleistocene deposit of Rancho La Brea, near Los Angeles, southern California. In 1911, through the courtesy of Messrs. James H. Cook and Harold Cook and with their highly intelligent codperation, the American Museum excaya- tions began under the direction of. Mr. Albert Thomson, assisted by Mr. Charles Barner, and continued through 1916. In the year 1911, after exposing a large Diceratherium area of closely see skeletal remains and securing parts of a Dinohyus skeleton, the border of a great Moropus area was exposed. In the year 1912 three skeletons of Moropus were secured, mingled with very abundant Diceratherium and portions of one skull and skeleton of Dinohyus. During 1913 and 1914 several more skeletons were found, and the outlines of a great Moropus bed were determined. In 1915 work was suspended. In 1916 the Moropus collections of the American Museum were completed (October 29), amounting in all to seventeen skeletons. In the five summers of excavation (1911-1914, 1916) an irregular area within a square of about thirty-six feet yielded nearly complete skulls of ten individuals and skeletal parts of seventeen more animals. It was at first supposed that this accumulation of bones came from the drift- ing of a very large number of decomposing skeletons, but the early years of careful work soon revealed the very important fact that the greater part of this skeletal material belongs to a number of individuals. These individuals 1E. H. Barbour: The skull of Moropus. Nebr. Geol. Survey, vol. 3, pt. 2, 1908, pp. 209-216, pls. 1-2, figs. 1-5. 2The type of Moropus elatus Marsh has recently been determined by Mr. Harold Cook as of Upper Harrison age. 3W. J. Holland and O. A. Peterson: The osteology of the Chalicotheroidea, with spe- cial reference to a mounted skeleton of Moropus elatus Marsh now installed in the ~ Carnegie Museum. Mem. Carnegie Mus.. vol. iii, no. 2. Jan. 17, 1914. pp. 189-406, pls. Xlvlii-Ixxvii, figs. 1-113. ABSTRACTS OF PAPERS 135 have been assembled with a considerable degree of certainty as to the associa- tion: first, through the extremely careful records which were kept of the loca- tion of every bone in the quarry; second, through their propinquity ; third, the eareful fitting and articulation of the bones; finally, through careful compara- tive measurement of size. It now appears certain that few of the bones had drifted a long distance; they were mostly deposited not far from the carcasses to which they had belonged. The last twelve months of laboratory work in the American Museum of Nat- ural History has resulted in bringing together several skeletons which are practically complete, and certainly in more than one case belonging to one individual, together with a number of skeletons in which the association of — the bones is probably but not certainly correct. From this wonderful material it has been possible to supplement the full descriptions of this animal which were published in 1909 by Messrs. Holland and Peterson, and to give for the first time the absolute form and proportions, the pose, and the articulations of the fully adult Moropus, of very large size. This and other materials will soon be described by the present author. In the meantime Moropus may be characterized as a forest-loving, slow- moving animal, not improbably frequenting rather swampy ground. The small head, relatively long neck, high fore quarters, short, downwardly sloping back, straight and elongated limbs, suggest a profile contour only paralleled by the forest-loving okapi among existing mammals. The foot structure, of course, is radically different from that of the okapi, but we should not regard it as fossorial, or of the digging type, because it is not correlated with a fossorial type of fore limb. It would appear that these great fore claws, in which the phalanges were sharply flexed, were used in pulling down the branches of trees and also as powerful weapons of defense. A LONG-JAWED MASTODON SKELETON FROM SOUTH DAKOTA AND PHYLOGENY OF THE PROBOSCIDEA BY HENRY FAIRFIELD OSBORN (Abstract) Cope’s family classifications were morphological and horizontal rather than phylogenetic and geological. Finding one or more single characters possessed in common at certain horizontal periods of geologic time by mammals in differ- ent lines of evolutionary descent, hé seized on these common characters as convenient keys to classification. First? for the order Perissodactyla and then for the families of rhinoceroses? and titanotheres* I have reached the opinion that Cope’s method of morphological classification is untenable, that the only true and permanent classification is phylogenetic. Other paleontologists, how- ever, have reached a different opinion. 1 Fossil mammals of the Wasatch and Wind River beds. Collection of 1891. (With J. L. Wortman.) Bull. Am. Mus. Nat. Hist., vol. iv, art. xi, Oct. 20, 1892, pp. 81-147. 2 Phylogeny of the rhinoceroses of Hurope. Rhinoceros contributions No. 5. Bull. Am. Mus. Nat. Hist., vol. xiii, art. xix, Dec. 11, 1900, pp. 229-267. 8 The four phyla of Oligocene titanotheres. Bull. Am. Mus. Nat. Hist., vol. xvi, art. viii, Feb. 18, 1902, pp. 91-109. 134 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY The chief advantage of the vertical phylogenetic classification is that it brings animals together in similar or closely allied lines of evolutionary de- scent; it corresponds with the branches and subbranches of the family* tree. The chief difficulty with phylogenetic classification is a technical one, namely, to harmonize it with the Linnzan and the prevailing zodlogical systems of family, subfamily, and generic nomenclature, which are alike based on the affinities displayed between the existing terminal twigs of the branches and subbranches rather than on the phyletic ancestral lines which connect these twigs with their several ancestral branches. Sometimes the subfamilies pro- posed by zoologists conform to the phyletic lines discovered by paleontologists ; sometimes they do not. The present classification and nomenclature of the Proboscidea illustrate afresh the confusion, at first glimpse apparently hopeless, resulting from the morphological classification and nomenclature of Linnzeus and of various pale- ontologists, following the zodlogical standards, such as were embraced by Cope. Upward of forty generic names have been applied to the mastodons and ele- phants, and, as pointed out by Matthew,® there is no uniformity in the usage of these generic terms, nor has any principle of arrangement been worked out by which we may at least begin an advance toward a permanent system of nomenclature of this highly important and interesting group. . In the present paper, which is the result of studies begun in 1902 and of observations carried on in American and European museums, with the valua- ble aid of the recent rearrangement of the collections of Proboscidea in the American Museum of Natural History by Dr. W. D. Matthew, I essay a phy- logenetic classification. This attempt, aided by the recent observations of Lull,* Matthew,® and Barbour,’ is preliminary to a more thorough review which is in preparation by the author.’ It will probably subserve clearness to present at once the following key to the proposed phylogenetic classification. in which are shown at least eleven distinct phyla of proboscidians, grouped into five subfamilies and three families. ORDER PROBOSCIDEA : Families DINOTHERES: I. Dinotheriide, crested teeth, down-turned tusks. . Il. Wastodontide, crested and cone teeth. MASTODONTS. A. BuNoLoPHopONT, cone-and-crest-teeth mastodonts. 1. Bunomastodontine: 5R. S. Lull: The evolution of the elephant. Am. Jour. Sci., vol. xxv, Mar., 1908, pp. 169-212, figs. 1-27, 4 charts; reprinted in Smiths. Report for 1908, No. 1909, pp. 641-674. ®W. D. Matthew: The generic nomenclature of the Proboscidea. Read before the Paleontological Society, Pittsburgh, Jan. 1, 1918. *E. H. Barbour: Mammalian fossils from Devils Guleh. Nebraska Geol. Survey, vol. 4, pt. i, Dec., 1913, pp. 177-190, pls. 1-13. A new longirostral mastodon from Cherry County, Nebraska. Nebraska Geol. Survey, vol. 4, pt. 14, Sept. 15, 1914; pp. 213-222, pls. 1-6, figs. 1-6 (tailpiece). A new longirostral mastodon from Nebraska, Tetrabelodon osborni, sp. nov. Am. Jour. Sci., vol. xli, June, 1916, pp. 522-529, figs. 1-4. ‘A memoir on the phylogeny of the Proboscidea, with illustrations of the principal American types of mastodon and elephants in the American Museum of Natural History. he Snag A head ON A ge eHTOU Nu A mC ; ar ee ae WAY 16 feet ne a ry tt L et eee ain 3) ie ang ae Ok SO BUN LA ey P ieeioane str 68 mde awa tS ete bea’ esd { Aino ol ig . ete ae nommrequrl A | finadinogor [ee Dacren ol i ago tbe aronias ae 32 eae ot 3 ; , tinge At i sad er + fA home - a ' i > pee Fiance Fie | o se ne mica i ar al ea naw ae sap ioeantentys een m ee ee ae s comaaticers me ipa Sale pee 28) OLA ; ER Gil d. ga i! . gitehomh amie 725) NOREY mages. N52. | KOBd vol inst trun tot pas Eh Tigers: ROdGHo1» | 0 ha paroboum mintn 4 ven “otis Lon oe Waeeek, Der? || 208L ,aqgo0 andy 6 en elt abt. Lene ee Ha rabortacin 99}2 a Naat ere bb oe Th hea Lig iw | ig | “allot at noboowtbylosd 8" miobwiny he Tetraganloda | S88 .wiletort af * 7 | va \* hye putt F | uk hy Py) eat é ‘ - a — ' 7 > - > As p Fav ph Ay) “4, ? 7. i sz “ie viy. : AVN ECs. ia ar wae) ey Py Se MASTODONTS BUNOMASTODONTIN®& STEGODONTS ELEPHANTS AND MAMMOTHS MASTODONTIN & STEGODONTIN- LoXxXODONTIN ae EUELEPHANTIN-E ELEp VTIN AB GENERA Trilophodon Rhyn sree se dele ok DLEPHANTIN AS ichotheri ce See y! erium Tetralophodon Mastodon Stegodon Loxodonta Euelephas Elephas RECENT (longirostral) (medirost F al ral) (brevirostral) aL. africanus . indicus PLEISTOCENE : Lower humbolatii aM. americanus L. antiquus bE. primigenius EB. columbi | ee TEE CRM ee lt = ohioticus L. namadicus P. trogontherii . imperator PLIOCENE ‘ Minas =| Sap Sa === _—————e es @ tlascalae andium b borsoni a ganesa c. meridionalis Uppers @aryernensis — Ss 2 a. hysudricus eee bare ¢mirificus tegodon ? COSRIANIIORS! ; j earnester z ower e¢morilli 9 shanotirele} vobegy dire Ullaoars ; . Guts i eo oe 1s ce . atocorgeol 4 pur aget j 4ivasdalaug i ailorasy ee eer ee ee ee ion pale + atieaed.t ib aga 4 ensbireeT ). iysli wae. | ihrsqetde T+, € o éeunabiroh + } : - } f Ps. —_—s alld _ bin sr oe tr ee rein eee . ae —— oe - ae, 6 a ea - non Dy Pr nore Di FF ESO See a a ca dE Pom ee os | i ¢ ‘ p i y eizngeriiag | ‘ =~ su@angoysem | > ; : 3 aicolbn _ enobbengas abe aoe pt ns ‘7 3 a es | Pan nanan eee mae we ; iF) ~ —s ee ee ee aD Ria ¥ | aaa Sac aoe” pr SOE aN RON Pe rea (er a ts . Aa Xo, S 4 eet ae tee RR Ae as AR OY HONE FB | 9 Ao i Meche Why 7 an 7 , thy. Lae RNS ; ae rah ABSTRACTS OF PAPERS 135 la. Longirostral, long-jawed, bunomastodonts, Africa, Eurasia, America. 1b. Rhynchotherine, beak-jawed, bunomasto- donts, North America. 1e. Brevirostral, short-jawed, bunomastodonts, Asia, America. B. ZyYGOLOPHODONT : 2. Mastodontine, typical mastodonts of Europe, Asia, _ America, Ill. Hlephantide: STEGODONTS. C. BRACHYLOPHODONT, short-crowned, crested teeth. 8. Stegodontine, stegodonts of southern Asia. “ELEPHANTS. D. HypsiLoPHopont, long-crowned, crested teeth. 4. Loxodontine: 4a. Loxodonta antiquus, straight-tusked ele- phants, Eurasia, Africa. 4b. Loxodonta africanus, African elephants. 5. Hlephantine: ae Ba. Huelephas prinvigenius, mammoths, Eurasia, North America 5b. Huelephas columbi; EH. imperator, Ameri- can mammoths. 5c. Hlephas indicus, Indian elephants. The three traditional families, namely, the Dinothertide, Mastodontide, and Hlephantide, call for no comment. The mastodonts may be divided into two subfamilies, namely, (1) the Buno- mastodontine, which are clearly distinguished by the presence of cones grow- ing in between the transverse crests and forming “trefoils,” to use the term introduced by Cuvier in his description of the grinding teeth of M. angustidens. This was the first bunomastodont discovered and is the type of a great race of longirostral, long-jawed, short-limbed forms, which ranged widely from northern Africa over Europe, Asia, and North America. As shown also in the accompanying scheme, the bunomastodonts, which sprang from Paleomastodon of the Oligocene of northern Africa and possibly as well from Hemimastodon of southern Asia, divide into three great, long-lived phyla, which may be dis- tinguished as follows: Longirostral, long-jawed, typified by the species M. angustidens. Medirostral, beak-jawed, typified by Rhynchotherium. Brevirostral, short-jawed, typified by the species M. mirificus. The long-jawed and short-jawed phyla of bunomastodonts. are comparatively well known in Burope, Asia. North and South America. The beak-jawed phylum, typified by the genus and species Rhynchotherium tlaxcale,” is pro- visionally arranged, because there is some uncertainty as to the position of the species R. euhypodon Cope, R. (2?) shepardi Leidy, and R. brevidens Cope. The rhynchotherines are readily distinguished by jaws of medium length, which tend to turn downward into a long, depressed beak, somewhat like that of ® The specific name tlagcale is suggested to the author by Dr. W. D. Matthew in refer- ence to the locality in Mexico, Tlascala. XI—BULL. Gror. Soc. Am., Von, 29, 1917 136 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY Dinotherium, in which the lower canines are laterally compressed, whereas in all the longirostral bunomastodonts the lower canines are vertically com- pressed. - All these bunomastodontine are very readily distinguished from the typical _Mastodontine, a line which is relatively conservative in its evolution, since the “intermediate” molars remain trilophodont and the crests only feebly develop the intermediate cones, or trefoils. Singularly enough, the supposed north Asiatic ancestors of this phylum are not known. It first appears in the WV. borsoni of the Pliocene of Europe. The Stegodontine may be distinguished as a phylum confined to Asia, in which the grinding teeth remain brachyodont, short-crowned, although a very large number of cross crests evolve, especially on the posterior grinding teeth. From an early member of this subfamily, perhaps of Middle Miocene time, were given off one or more branches of the elephant and mammoth phyla. Rhynchotherium from Mexico.—Extract of letter from Doctor Falconer to M. Lartet, September 12, 1856 :*° ““At Genoa I saw a cast of a large lower jaw of a mastodon from Mexico, with an enormous bec abruptly defiected downwards and containing one very large lower incisor. The beak is much thicker than in M. (Trilophodon) angustidens and larger than in M. (Tetralophodon) longi- rostris. You know that every one (Laurillard, Gervais, etc.), have insisted on the absence of the lower incisors from both of the South American species. The outline of the jaw resembles very much the figure in Alcide D’Orbigny’s Voyage, described by Laurillard as M. andium. The specimen is unpublished material and I was therefore only allowed to examine it very cursorily. The Genoese paleontologists had provisionally named it Rhynchotherium, from the enormous development of the beak, approaching Dinotherium.” The arrangement of the elephant and mammoth phyla is not clear at present, although it appears that four distinct subphyla developed. The first, to which the generic name Loxodonta applies, includes the Pleistocene and recent ele- phants of the African type, which by Falconer and other students of Asiatic forms are supposed to be related to the L. namadicus of the Lower Pliocene of the Siwaliks. The next phylum, Huelephas, by consent of all leading European authorities, begins with EH. planifrons of Asia and Europe, Middle Pliocene. It includes EH. hysudricus of the Upper Pliocene, passes into the H#. meridionalis and EF. trogontherivi of the Lower Pliocene, and thence into H#. primigenius, the woolly mammoth. From a Middle Pliocene form, in a stage of evolution similar to that of Z. planifrons, it is possible that the peculiarly American mammoths £. columbi and HE. imperator may have been given off ds a side phylum, but this is not yet determined. This leaves the typical elephant, H. indicus, as a related phylum, the ancestry of which has not yet been determined.- Thus the Proboscidea divide into at least six great phyla, to which the sub- family designations Elephantine, Euelephantine, Loxrodontine, Stegodontine, Mastodontine, Bunomastodontine, may be given. There are also some reasons for separating the bunomastodonts into three phyla, which might be known as the Longirostrine, Rhynchorostrine, and Brevirostrine, but this may be a somewhat premature opinion. 10 Charles Murchison: Paleontological Memoirs and Notes of the Late Hugh Falconer, A.M.,M.D. 2 vols., 8vo. London, 1868, vol. ii, pp. 74-75. ABSTRACTS OF PAPERS aan This discrete and profuse subfamily arrangement would be shocking to a “lumper” like our late colleague and honored friend, Dr. Richard Lydekker, who combined" all the mastodons and elephants into two genera, namely, Mastodon and Elephas. The application of subfamily names to these mono- phyletic, or similar polyphyletic ascending series, is considered preferable to the coining of a new taxonomic term. The propriety of thus applying subfamily terms is disputed by some pale- ontologists, notably by my colleagues, W. D. Matthew and W. K. Gregory. The subfamily termination, in@w, may, in the author’s opinion, be adopted with- out any real exaggeration to express the fact that many of these phyla have been distinct und separate from each other for enormous periods of geologic time. This is real hereditary relationship in the family or subfamily sense. For example, it may be shown that the longirostral bunomastodont phylum began with Palwomastodon of the Upper Oligocene, and that this animal was already too specialized as a longirostral bunomastodont to constitute the an- cestor of any other phylum than its own. This main longirostral phylum is geologically the oldest and phylogenetically the most complete. It illustrates one general law of mammalian evolution, namely, that a phylum having spe- cialized in a certain character usually tends to evolve this character to an extreme; the long jaw of Palwomastodon goes on lengthening until in Lower Pliocene time it attains the great length observed in the forms recently de- seribed by Barbour’ as Eubelodon morrilli, Megabelodon lulli. In this longirostral phylum, as well as in the brevirostral bunomastodonts, the question of the application of the generic nomenclature of Linnzeus is cer- tainly a most puzzling one. Thirteen distinct generic names have been pro- posed for the longirostral bunomastodonts and six distinct generic names for the brevirostral bunomastodonts. Several puzzling questions arise: first, how many generic names can con- sistently be applied within each of these phyla; second, which generic names in the long list shall be given precedence; third, shall the law of the technical priority of a name prevail, or shall we recognize only the priority of the first clear definition and conception of a genus which is based on one or more defi- nite and clearly described characters of its genotypic species? This whole question has been raised in the previous communication to the Paleontological Society by Doctor Matthew.* I am disposed to recommend that certain well defined generic names may, after due consideration, be adopted by the Paleontological Society as nomina servantur. 'The selection of these names will be greatly facilitated by a true phylogenetic classification of the Proboscidea, to which the present outline is preliminary. At 12.30 the Society adjourned for luncheon. CONTINUATION OF SYMPOSIUM At 2 p. m. the symposium was resumed, with the reading of a paper on the Mesozoic history by Doctor Stanton entitled 1 Richard Lydekker: Catalogue of the Fossil Mammalia in the British Museum (Nat- ural History). Pt. IV, The Order Ungulata, Suborder Proboscidea. Svo. London, 1886, pp. xxiv, 2388 (1). ' 2H, H. Barbour: Op. cit. 1W. D. Matthew: Op. cit. 138 ' PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY MESOZOIC HISTORY OF CENTRAL AMERICA AND THE WEST INDIES BY Ts W. SEANTON Discussion of this paper was deferred until the last one of the series of invertebrate paleontology was presented by the author, Doctor Vaughan. CENOZOIC HISTORY OF CENTRAL AMERICA AND THE WEST INDIES BY T. W. VAUGHAN | A general review of the problems connected with the history offered by invertebrate paleontology was brought out in the discussion of these papers, which occurred at this point. Prominent among the speakers were Messrs. Holland, Osborn, Vaughan, Merriam, Matthew, and Grabau. ‘The evidence on this history offered by vertebrate paleontology was given in the two following papers, discussion again being deferred: RELATIONSHIPS OF THE MESOZOIC REPTILES OF NORTH AND SOUTH AMERICA BY S. W. WILLISTON AFFINITIES AND ORIGIN OF THE ANTILLEAN MAMMALS BY W. D. MATTHEW This portion of the symposium called forth still more discussion, in which Messrs. Merriam, Matthew, Osborn, Eigenmann, Grabau, Willis- ton, and Price participated. During this discussion, Doctor EKigenmann was requested to give the evidence afforded by the fishes. His remarks entitled as below were highly interesting and appreciated. FRESH-WATER FISH FAUNAS OF NORTH AND SOUTH AMERICA BY C. H. EIGENMANN In this discussion Doctor Grabau mentioned the work and results of Graham J. Mitchell on recent changes of level in Porto Rico. EVIDENCE OF RECENT CHANGES OF LEVEL IN PORTO RICO, AS SHOWN BY STUDIES IN THE PONCE DISTRICT 1 BY GRAHAM JOHN MITCHELL ? (Abstract) With the inauguration of the Natural History Survey of Porto Rico, under the joint auspices of the New York Academy of Sciences and the Insular Gov- 1 By permission of the Porto Rico Committee of the New York Academy of Sciences. Report on the geology of the Ponce district in preparation. 2 Introduced by A. W. Grabau., ths 4 ABSTRACTS OF PAPERS 139 ernment of the Island, a study of the geology of the region was undertaken as one phase of the investigations. The first geological party to enter the field consisted of Doctors Charles P. Berkey and Clarence N. Fenner, who, during the summer of 1914, completed a reconnaissance of the island. Since that time an average of two parties a year have been sent into the field. In his report? Doctor Berkey noted the occurrences of terraces 100 to 200 feet above the present sealevel, particularly on the south coast near Guayama, and attributed their origin to wave action. Subsequent investigators have substantiated this conclusion. Mr. A. K. Lobeck, however, after a study of the physiography of the island, concluded that there has been only a slight differ- ential uplift of the western end of Porto Rico in very recent time, the maxi- mum change being at Rincon, on the west coast, where an elevation of 40 feet occurs. During the past summer a survey of the southwestern quarter of the island was made by the writer, that section being one which appeared favorable to the solution of the question of recent changes of level in Porto Rico. The evidence gathered in this study is summed up as follows: 1. One-half mile southwest of Juana Diaz, on the north bank of the Jaca- guas River, the folder Tertiary beds are beveled and a deposit of silt, sand, and gravel 2 to 12 feet thick covers the surface. In this surface covering, at an elevation of 130 feet, are found numerous Strombus pugilis. 2. At kilometer 72.5 on the Ponce-Penuelas road recent marine fossils are found in finely stratified material of estuarine character. In this deposit a layer of black mud averaging one foot in thickness occurs at a depth of from 2 to 5 feet below the surface. In this black mud are found Strombus pugilis, Lucina jamaicensis, Lucina tigrina, Arca tuberculosa, and Byssoarca ziebra. These fossils are also found in other parts of this deposit, the elevation of which is 180 feet. 3. Across the west branch of the Canas River, just east of the above locality, the same species of fossils which occur at locality “2” are found in the strati- fied sands and gravels at a depth of 3% feet below the surface and an eleva- tion of 160 feet. 4. Southeast of Yauco, 14%, miles, in the Rio Yauco Valley, abundant fossils are found in the surface covering of the river valley at an elevation of 150 feet. The fossils include Murezx elongatus, Arca rhombea, Lucina tigrina, Arca tuberculosa, Turritella imbricata, Pecten nucleus, Venus cancellata, Ostrea virginica, and Perna sp. 5. Hast of Yauco, one-eighth of a mile, the pre-Tertiary rocks are truncated, and in the gravel and sand which mantels the beveled strata are found Arca tuberculosa and Lucina tigrina, occurring at depths of 1 to 2 feet’ below the surface. The elevation at this point is 200 feet. 6. On the coast southeast of Yauco a terraced surface bevels the Tertiary limestone at an elevation of 60 to 160 feet, the inner margin being marked in places by cliffing. The following fossils are found on this surface : Strombus accittrinna, Fissurella nodora, Arca rhombea, and Turbo pica. 7. Just north of the lighthouse at Guanica the Tertiary limestone is beveled by terraces at levels of 10, 50, and 150 feet, and in the surface soil on the two ® Geological reconnaissance of Porto Rico. Annals N. Y. Academy of Sciences, vol. 26, 1916. 140 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY upper terraces are found Arca tuberculosa, Lucina tigrina, and Turbo pica. On the 10-foot level large numbers of these fossils are found in the lime, sand, and silt which coats this terrace. 8. East of Guanica, one-eighth of a mile, on the east side of the Susua Valley, a terrace at an elevation of 50 feet contains in the surface material the forms Lucina jamaicensis, Arca tuberculosa, and Turbo pica. 9. At the town of Ensenada (Central Guanica), the pre-Tertiary is trun- eated and a deposit of shells, muds, silt, and sand covers the surface to a maxi- mum depth of 5 feet. The fossils occur at an elevation of 45 feet and include the following: Murex elongatus, Isophyllia sp., Venus cancellata, Operculum of Turbo, Arca rhombea, Cerithium litteratum, Ostrea virginica, and Byssoarca zieora. 10. On the south side of Pardas Bay, south of Ensenada, the Tertiary lime- stone is again terraced, its elevation being 65 to 100 feet, and the fossils Arca rhombea, Arca tuberculosa, and Lucina jamaicensis are found buried in the surface soil. 11. On Cape Rojo, in the southwest corner of Porto Rico, the San Juan for- mation, which has been interpreted by Doctor Berkey as a limesand of dune origin, is found at an elevation of 75 feet overlain by 3 feet of conglomerate consisting of well rounded pebbles. In the San Juan formation oceurs a Cons very close to the recent form Conus porto-ricanus. 12. On Aguilla Point, the extreme southwestern portion of the island, recent gastropod shells are found in consolidated gravels at an elevation of 11 feet. At an elevation of 25 feet they occur on the beveled surfaces of the rocks which make up this point. 13. Three and three-quarters miles southwest of Mayaguez, on the coast near the reform school, a terrace is cut on the pre-Tertiary rocks at an elevation of 50 feet. The inner margin is marked by cliffing, and the following fossils are found in the surface soil: Arca tuberculosa, Venus cancellata, and Lucina jamaicensis. The argument has been advanced by Mr. Lobeck that where recent fossils have been found in Porto Rico they are associated with Indian mounds. Such an interpretation, however, could not explain the existence of recent shells buried in stratified material of estuarian character at depths of from 2 to 5 feet. Furthermore, although in each of the 13 localities cited above the writer made careful search for artifacts, in no instance was evidence found to sub- stantiate the Indian mound theory. Based on the evidence presented in the 13 above-mentioned cases, the writer draws the following conclusions: With the recent changes of level of land and sea the old river valleys were embayed, allowing the sea to enter with its marine fauna and to lay down deposits of sand, silt, and mud. That these deposits (for example, localities No. 1, 2, 3, 4, 5, 8, and 9) were laid down in Quaternary time is evidenced by the fact that over 95 per cent of the fossils are of the same species as those living at the present time in the adjacent sea. In the remaining instances (6, 7, 10, 11, 12, 13) the truncation of the under- lying beds of limestone and other formations along the south and west coasts and the presence of cliffing at the inner margins of some of these terraces, to- sether with the recent fossils found on the surface, are facts hard to explain if they are not in some way connected with the work of the sea. ABSTRACTS OF PAPERS tat In considering the question, Which has been the shifting element, the land or the sea? the evidence indicates a change in the elevation of the land. If the sealevel had varied, one should find some uniformity in terrace levels at particular stages. Such uniformity does not exist. In summing up the con- clusions the writer feels justified in stating that there has been differential uplift of the land in Porto Rico in recent time, with a maximum change of 200 feet. PRESENTATION OF PAPERS After the completion of the symposium, the hour for adjournment not having arrived, the reading of papers was resumed with the presentation of an interesting account of the great confusion prevailing in the nomen- clature of the Proboscidea. As a result of this paper, it was voted by the Society that the President should appoint a committee to consider the generic nomenclature of the Proboscidea and other groups of mammals and to report its recommendation at the next meeting. Doctor Matthew ‘was appointed chairman of this committee. | GENERIC NOMENCLATURE OF THE PROBOSCIDEA BY W. D. MATTHEW (Abstract) The nomenclature of the extinct Proboscidea is in a state of fearful con- fusion. Partial attempts to apply the rules of strict priority have’made matters worse, and a consistent application of the rules will apparently result in setting aside every one of the names in current use, but the proper substitute names would require a whole series of arbitrary or questionable decisions. As it is wholly improbable that such substitute names would be uniformly, or even generally, accepted, and as the object of nomenclatorial procedure is to secure uniformity, the writer proposes that certain of the current names be: sub- mitted as nomina conservanda to the committee of the International Zoological Congress with the indorsement of the Paleontological Society. At 6 p. m. the Society adjourned. Tuesday evening the members and invited guests attended the annual dinner of the Society at the University Club. SESSION OF WEDNESDAY, JANUARY 2 Wednesday morning, at 10 o’clock, the Society met in general session, with Vice-President Matthew in the chair. REPORT OF THE AUDITING COMMITTEE The only matter of business on hand was the report of the committee to audit the accounts of the Treasurer. The committee attested to the 142 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY correctness of these accounts, and it was thereupon voted by the Society that the report be accepted. PRESENTATION OF PAPERS The first paper of the morning was an interesting account of the Ore- taceous strata of northwest Europe as interpreted from the fossil sponges. This was presented by the author and illustrated with a number of dia- grams. It brought forth considerable discussion, in which Messrs. Reeds, Grabau, Merriam, Dickerson, and Holland took part, with replies by Miss O’Connell. CRETACEOUS OVERLAPS IN NORTHWEST EUROPE AND THEIR .BEARING ON THE BATHYMETRIC DISTRIBUTION OF THE CRETACEOUS SILICISPONGIA BY MARJORIE 0’CONNELL (Abstract) While studying and arranging a collection of over a thousand specimens of Cretaceous Silicispongize in the American Museum of Natural History, the author was led to consider the lithic character and areal distribution of the sediments in which these fossils were found and the problem of the bathymetric range of European Cretaceous Silicispongiz. The bathymetric ranges of Cre- taceous species which have persisted to the present time will be given and there will be a brief discussion of the conclusions which it is permissible to draw from such data. The significance of the overlaps of the sponge-bearing and other Cretaceous strata of Europe will be considered and the value of the lithogenetic method of study in the determination of habits of ancient organ- isms will be dwelt on. The next paper, which was amply illustrated by very clear and inter- esting lantern slides, was of especial interest on account of dealing with the region considered in the symposium. It was presented by the author, who replied to discussions by Messrs. Burling and Matthew. NEW BATHYMETRICAL MAP OF THE WEST INDIES REGION BY CHESTER A. REEDS (Abstract) During 1916 all of the Hydrographic and Coast and Geodetic Survey charts bearing on the West Indian region were assembled and, with chart 1290 as a -base, all soundings were plotted. The one-hundredth fathom line was then drawn, also the five hundredth, and with a contour interval of 500 fathoms successive depths were sketched down to 4,500 fathoms. The result is a con- tour map somewhat different from its predecessors. When modeled on a globe surface the features of the submarine topography are even more striking. ABSTRACTS OF PAPERS 143 Doctor Grabau then presented a study of one of the factors in faunal development, which brought forth considerable discussion from Messrs. Reeds, Parks, Williston, Matthew, Ortman, Merriam, and Bassler. This paper was illustrated by paleogeographic maps showing the development of North America in Silurian and Devonian times. ISOLATION AS A FACTOR IN THE DEVELOPMENT OF PALEOZOIC FAUNAS BY AMADEUS W. GRABAU (Abstract) Whenever a portion of a cosmopolitian fauna is segregated in an embayment of the Red Sea type, the segregated fauna being in large measure prevented from intercrossing with the main stock, and so remaining true to type, develops orthogenetically into a modified fauna which, when once established, remains ~ true to the new type and frequently thereafter becomes a ddminant one. The faunas which it is believed have thus come into existence are, among others, the Brassfield fauna of the Siluric, the Helderbergian fauna of the Lower Devonic, the eastern Michigan and Ontario Upper Hamilton fauna, and the Ithaca fauna. Illustrations of these will be given. At 12.30 the Society adjourned for luncheon. At 2 p. m. the members were called to order by Vice-President Grabau; who announced that by curtailing the longer papers somewhat separate sessions would not be necessary to complete the program. : The first paper of the afternoon session was presented by the Secretary for the author and dealt with new discoveries in the early Paleozoic rocks of Alaska. AN ORDOVICIAN FAUNA FROM SOUTHEASTERN ALASKA BY EDWIN KIRK (Abstract) The oldest fossiliferous sediments hitherto known in southeastern Alaska were of Silurian age. The discovery last season of early Ordovician sediments is therefore of considerable interest. Extending along the shore for a considerable distance to either sae) of the town of Wrangell is a great series of highly metamorphosed sediments. These consist almost entirely of greenstones, crystalline schists, and argillites. A block of fossiliferous slate was found near Wrangell by Prindle some years ago. These fossils were reported by Girty as being anything from Devonian to Recent in age. If Paleozoic, he suggested that the age was probably De- vonian or Carboniferous. The fossils were in a very poor.state of preserva- tion, and the prevailing opinion has been that the block of slate was an erratic. The beds at Wrangell have generally been assigned to the mainland belt of supposed Carboniferous-Mesozoic, that ranges from the etehian area at the south to the Juneau and Chilkat areas at the north. 144 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY On the point forming the south side of Wrangell harbor, graptolites were found that seem to fix the age of this Wrangell series. The graptolites are found both in slate and schist. The slate specimens are unrecognizable unless one knows they are graptolites to begin with. The specimens occurring in the schist, though badly preserved, are easily recognizable as graptolites, and the generic affinities of one individual may be determined with a fair degree of certainty. The specimen of chief importance and interest is referred with little doubt to Tetragraptus. It is very like a large species known in the early Ordovician of Idaho. Other specimens not so well preserved strongly suggest Phyjllo- graptus. These fossils clearly point to the Beekmantown age of the sediments. On Long Island and on Dall Island, on the southwest coast of Prince of Wales Island, are schistose sediments similar to those at Wrangell. They are even more metamorphosed than the Wrangell series where I saw them, and it seems doubtful if fossils would be preserved in them. They may well be of the same age, however. These beds fall in Brooks Wales series. As defined, the Wales series also probably included rocks of Silurian age. Aside from establishing the presence of Ordovician sediments in southeastern Alaska, this find is of interest as throwing in doubt the generally accepted views as to the age of the mainland belt of sediments west of the Coast Range batholith. It has generally been assumed that this belt was of Carboniferous and Mesozoic age, with the Mesozoic as the more important element. It wil! probably be found that, in addition to the Carboniferous and Mesozoic, which are undoubtedly present at some points, all the Paleozoic elements elsewhere known in southeastern Alaska are represented in this coastal belt. A brief summary of an extensive paper on the extinct Camelide was then presented by the author and was discussed by Messrs. Peterson and the author. AFFINITIES AND PHYLOGENY OF THE EXTINCT CAMELIDA BY W. D. MATTHEW (Abstract) The author has in preparation a revision of the extinct Camelidse, prelimi- nary results of which are presented. The relationship of the supposed Eocene ancestors of the Camelidz is discussed, but they are not included in the family. The North American genera and species are revised and their relations are dis- cussed. They afford exceptionally direct phyla from Oligocene to Pleistocene, with two distinct side branches, the giraffe-camels and gazelle-camels, and several minor twigs. The Old World camels belong to the genera Pliauchenia and Camelus, the latter not found in America, and are of Pliocene to recent age. The South American camels form a compact group of two closely related genera, Palwolama and Auchenia, and are of Pleistocene and recent age. Their nearest North American relatives are the smaller species of Camelops (Pleisto- cene), and they are doubtless derived from Pliauchenia, but not from any known species. ABSTRACTS OF PAPERS 145 The two following papers on the stratigraphy and paleontology of the Canadian Cordillera were presented together by Mr. Burling, who illus- trated them by diagrams and maps. Results of this stratigraphic work by Mr. Drysdale and Mr. Burling, the former of whom lost his life in this field-work, were discussed by Messrs. Parks, Grabau, and Burling. ROCKY MOUNTAINS SECTION IN THE VICINITY OF WHITEMANS PASS BY C. W. DRYSDALE AND L. D. BURLING (Abstract) This paper will describe the results of the fatal reconnaissance trip under- taken by the late Mr. Drysdale and the writer during the early part of the last field season. The line of section begins west of Cochrane, Alberta, and proceeds in an almost straight southwesterly direction across Whitemans Pass to a point on the Kootenay River east of the Windermere mining district of British Columbia. The region traversed by the section, which crosses the strike of the rocks, is broken into a series of longitudinal blocks, each shoved over its neighbor to the east and all more or less similarly tilted. The fossils secured show the thrust-faults between to be of large magnitude, but they coincide so largely with the valleys and with the strike and the local folding in their vicinity is so subordinate that the presence of faulting has not been recognized. Dawson is the only geologist who has made a previous crossing. FURTHER LIGHT ON THE EARLIER STRATIGRAPHY OF THE CANADIAN CORDILLERA BY LANCASTER D. BURLING (Abstract) This paper will deal with some of the more important of the discoveries of the 1917 field season. New evidence was secured bearing on the question of the age relationships of the Lower Cambrian and Beltian rocks of British Columbia, Alberta, and Montana. Careful search in the so-called “Castle Mountain” limestones at the head of Nyack Creek, Montana, yielded abundant casts of salt crystals, but no fossils. Their Siyeh age is almost unquestioned. The Mount Robson region was visited and collections secured from many horizons, all the Cambrian and Ordovician formations above the lowest quartz- itic sandstones being represented. Many doubtful points in the stratigraphy were cleared up—such, for example, as the true position of the Extinguisher (“Billings Butte”) fauna, etcetera. Hvidence secured would seem to indicate that while the Callavia and Olenellus zones are hardly to be separated as such in this region, Callavia does appear alone in the section first, later mingles with Olencllus, and finally disappears, leaving Olenellus alone. The Albertella fauna was traced to the north, south, and east and further 146 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY collections secured from the horizon itself and from the rocks immediately above and below. The Cambro-Devonian boundary was examined in numerous places, with the following results: On Roche Miette the Devonian has been described as sepa- rated from the Cambrian (in which the highest fossils now appear to be of Middle Cambrian age) by a series of beds tentatively referred to the Silurian. Further collections from these rocks appear to place them in the Devonian. In North Kootenay Pass the Middle Cambrian is separated from the Devonian by many hundreds of feet of apparently unfossiliferous strata. In the Beaver- foot Range near Golden the Devonian is absent, but the section includes sev- eral thousand feet of fossiliferous Upper Cambrian and Ordovician, up to and including the Richmond, east of Lake Minnewanka, and in the Sawback Range and upper Columbia Lake sections the Devonian rests on a series of beds whose fauna is comparable in many respects with that of the Ozarkian. Many additional specimens of Triassic (?) fish were secured from the fish locality discovered in 1915 in the “Jurassic fault block” near Massive, west of Banff, Alberta. Additional collections were made from the fossil locality discovered by Mr. Drysdale in the Laurie Metargillite near the Laurie mine, west of Glacier. These are limited to crinoid stems, but appear to indicate that the Laurie Metargillite is Upper Paleozoic in age. Additional collections were secured by Mr. Bancroft and the writer from the general horizon in the Slocan series containing the doubtful fossils first discovered by Messrs. Drysdale and Bancroft in 1916. These have been exam- ined by Mr. Kindle, who reports that they appear to be of Pennsylvanian age. Professor Williston followed with a paper on the evolution of vertebra, which was illustrated by numerous lantern slides and discussed by Doctor Merriam. | EVOLUTION OF VERTEBRA BY S. W. WILLISTON (Abstract) The evolution of the holospondylous vertebra from the primitive embolom- erous type is shown in the gradual decrease in size of the hypocentrum in the caudal vertebre of the rhachitomous amphibians and the atlas of primitive reptiles to a wedge-shaped form not much larger than the dorsal intercentra of primitive reptiles and by the corresponding increase in size of the embolom- erous disklike pleurocentrum into the body of the centrum of the primitive reptiles. It is evident that the rhachitomous amphibians have no immediate ancestral relationships with the reptiles, which must have sprung directly from the Embolomeri, probably in Mississippian times. A second interesting paper on vertebrate paleontology, dealing with the paleopathology of vertebrates, was presented by Professor Williston for the author. This paper, which was likewise well illustrated with lantern slides, was discussed by Messrs. Williston, Merriam, and Grabau. ABSTRACTS OF PAPERS 147 DISEASES OF THE MOSASAURS BY ROY L., MOODIE (Abstract) During the Cretaceous, diseases of animals reached a maximum of develop- ment in the mosasaurs, dinosaurs, plesiosaurs, and their associates. The num- ber of diseases known to have afflicted these animals are numerous and varied. Some of them are apparently identical with the diseases of animals and man today. Others have probably become extinct with the race of animals which they afflicted. The diseases of the mosasaurs may be taken as an example of the diseases of the Cretaceous. Their importance may be seen from the graph showing the general geological development of disease. The diseases which afflicted the mosasaurs, such as caries and pyorrhea, were common in geolog- ical time. Others, such as periostitis and necroses, are not so common, but are evident in the group. The paper will be illustrated by lantern slides showing examples of diseases of the mosasaurs. (This paper is not to be published separately, but is a part of a monograph, under preparation. on “Paleopathology,.a study of the antiquity of disease,’ ) A paper dealing with the paleobotanic side of paleontology was next presented by the author, who illustrated his remarks with a number of especially well preserved specimens. REPORT ON A COLLECTION OF OLIGOCENE PLANT FOSSILS FROM MONTANA BY 0. E. JENNINGS (Abstract) A report on a collection of about two hundred leaf-impressions collected a few years ago by Mr. Earl Douglass, mostly from the White River beds near Missoula, Montana, and now in the Carnegie Museum. The specimens are in a fine volcanic ash and are excellently preserved. There are fourteen species represented, five of these being conifers, the re- mainder being broad-leaved trees, with the exception of a fragment of a leaf of a sedge. The most abundant species is Carpinus grandis Unger, other com- mon species being T'axrodium dubiuwm (Sternberg) Heer and a Sequoia closely related: to S. couttsie Heer. Among notable species for North America are Chamecyparis ehrenswardi Heer and Thuyopsis gracilis Heer. There was then presented by the author and discussed by Doctor Matthew the following paper, illustrated by lantern slides: NEW TILLODONT SKULL FROM THE HUERFANO BASIN, COLORADO BY WALTER GRANGER (Abstract) Our knowledge of the skull and dentition of the large Middle Eocene Tillo- donts has previously been derived almost wholly from a single specimen from 148 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY the Bridger Basin and preserved in the Marsh collection at Yale. While mak- ing a preliminary examination of the Huerfano Basin in 1916 the author secured a nearly perfect skull and jaws of one of these forms. This new speci- men appears to be generically distinct from Tillotherium of Marsh and close to Leidy’s Trogosus, a more primitive form from the Lower Bridger, in which the second pair of incisors in the lower jaw is still present. A study of the new Tillodont and associated material from the uppermost Huerfano leads to the belief that this horizon is slightly older than the Lower Bridger. The following two papers on the invertebrate paleontology and stratig- raphy of the West Coast were combined into a single paper by their author, who illustrated his discussion with diagrams. These papers were discussed by Messrs. Matthew, Grabau, Bassler, and Miss O’Connell. MOLLUSCA OF THE CARRIZO CREEK BEDS AND THEIR CARIBBEAN AFFINITIES BY ROY E. DICKERSON (Abstract) The fauna obtained from the Tertiary beds near Carrizo Creek, San Diego County, California, have yielded several unique echinoids and corals. The echinoids were described by Doctor Kew two years ago, but unfortunately he did not obtain any direct faunal connection with other Tertiary horizons. During the past year Dr. T. Wayland Vaughan described the corals obtained from these beds and he recognized the Caribbean affinities of these forms, and from this study concluded that the beds were Pliocene in age. The mollusca obtained by Kew, Buwalda, and English confirm Vaughan’s conclusions con- cerning the Caribbean affinities of this interesting group of marine inverte- brates. Several species appear to be identical with forms which are charac- teristic of the Gatun formations of Miocene age. PROPOSED CORRELATION OF THE PACIFIC AND ATLANTIC EOCENE BY ROY E. DICKERSON (Abstract) Identical species, similar stages of generic evolution, and the mutations of Venericardia planicosta all show a much stronger relationship of the Tejon group to the three lower formations of the Gulf province—the Midway, Wilcox, and Claiborne—than was suspected. Tejon time was long and was probably equivalent to Midway (in part, at least), Wilcox, and Claiborne eons. The Jackson may be represented by the upper portion of the rhyolitic tuffs, the clay rock of Turner. This study confirms and modifies somewhat the former conclusion “that the Martinez is not only equivalent to a portion of the Midway. but represents a still earlier stage of the Eocene as well.” The generic relations between the Tejon and Midway are so close that it seems probable that they are correla- tive, at least in part. Possibly the Martinez is the marine equivalent of the Puerco and Torrejon of New Mexico—that is, Paleocene. ABSTRACTS OF PAPERS 149 Pacific province Gulf province Siphonalia sutterensis zone b Z OM OA, Vena CREA 2 DARDS a A tet mh Claiborne Balanophyllia variabilis zone Tejon , ‘ Lower Claiborne RPMLCHM OSIM PIED, ZONE. 55 eke aes ee es phen s Wilcox UGE e- RITE WON: occas i ide ids SiS Sta.'e akorw OR Rye aos eRe Rie ew one wretaverere Midway Solen stantoni zone Martinez, Trochocyathus zitteli zone \......... Puerco and Torrejon (7?) Meretrix dalli zone J New occurrences of glacial deposits in the Paleozoic rocks of southeast- ern Alaska were described in the next paper, which was presented for the author by the Secretary and illustrated by specimens. PALEOZOIC GLACIATION IN SOUTHEASTERN ALASKA BY EDWIN KIRK (Abstract) Paleozoic glaciation has not hitherto been recognized in Alaska. During the past field season a tillite of Silurian age was found in southeastern Alaska. Fairly conclusive evidence of Permo-Carboniferous glaciation was also secured. Conglomerates in the Devonian suggested the possibility of glacial beds in that period, but owing to lack of time and unfavorable weather conditions it was not possible to secure either positive or negative evidence as to their origin. The best exposures of the Silurian glacial beds seen were on Heceta Island, although good outcrops are to be found on the south shore of Kosciusko Island, about 15 miles to the north. Apparently the same beds occur along El Capitan passage between Kosciusko and Prince of Wales Islands. At the north end of Kuiu Island, some 125 miles to the north, a boulder bed holds the same stratigraphic position and I believe represents the same glacial deposit. Kosciusko and Heceta Islands, where the best Silurian glacial deposits are to be found, lie between 55° and 60° north latitude and 183° and 134° west longi- tude. These islands are situated on the west coast of Prince of Wales Island, toward the northern end. The most favorable locality for an examination of the conglomerate is in the large bay about midway on the north shore of Heceta Island. The coast here is well protected from storms and there is a continuous outcrop of the limestone underlying the conglomerate, the conglomerate itself, and the over- lying limestone. In places the conglomerate is well broken down by weather- ing, making the collection of pebbles and boulders an easy matter. As exposed, the beds outcrop along the shore between tide and levels and give an outcrop perhaps 2,000 to 3,000 feet in length. The glacial conglomerate is under- and overlain by fossiliferous marine limestones. The succession of beds is clearly shown and unmistakable. The same relations can even more clearly be seen on the bold cliff at the east end of Heceta Island as to the upper limit of the conglomerate. The relations of the conglomerate to the underlying limestone are well shown on Kosciusko Island. The strata as a whole in this region are badly disturbed and, as is 150 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY the case throughout southeastern Alaska, contacts are very poorly shown, being, as a rule, indicated by an indentation of the shoreline and a depression running back into the timber. At present, therefore, although the relative positions of stratigraphic units are obvious, the character of the unconformity and the nature of the passage beds are poorly known. The limestone series overlying the conglomerate carries a rich Conchidium fauna. In certain thin beds the rock is almost wholly made up of the brachio- pods. This fauna appears to be identical with that of the Meade Point lime- stone of the Wrights and Kindle. The type exposure of the latter is at the northern end of Kuiu Island. At the base of the limestone at this locality is a boulder bed which I believe to be glacial in origin and to be correlated with the conglomerate of Heceta. The limestones below the conglomerate likewise carry a rich fauna consisting of pentameroids, corals, and gasteropods. The general aspect of both faunas seems to place them as approximately late Niag- aran in age. The conglomerate itself has a thickness of between 1,000 and 1,500 feet. In the main the conglomerate appears to consist of heterogeneous, unstratified, or poorly stratified material. Rarely lenticular bands of cross-bedded sand- stone occur in the mass. These are clearly water laid and indicate current action. The boulders in the tillite range in size up to two or three feet in length, as seen. The boulders consist of greenstone, graywacke, limestone, and various types of igneous rocks. Limestone boulders are scarce. All the boulders are smoothed and rounded. Facetted boulders are numerous and, given the proper | type of rock, characteristic glacial scratches are common. The scratches show best on the fine-grained, dense greenstone. Limestone boulders and certain types of igneous rocks do not show them at all. The shoreline is strewn with ~ these pebbles and boulders, which were undoubtedly derived from the conglom- erate, as they are not to be found on the adjacent limestone shores. All the material collected was taken from the conglomerate itself, however. This is well broken down by weathering in some places, and the pebbles may be picked out with the fingers or tapped out with the hammer. When fresh the con- glomerate, as a rule, is massive and exceedingly hard. The lantern slides will give a good idea as to the character of the conglomerate and nature of the crops aS shown on the north shore of Heceta Island. Some of the boulders seen are entirely free arid others are still partially embedded in the conglom- erate. : The nature of the deposit is such as to suggest a till. The heterogeneous character of the boulders, both as regards size and material and the apparent lack of stratification in the main, points to a true till rather than a submarine bed of ice-transported glaciated material. Such evidence as is at hand indi- cates that the Heceta area was very near the shoreline and might easily have been land while the glacial material was being deposited. The whole Silurian section, which at its maximum farther north has a thickness of several thou- sand feet, thins out to the south and may prove to be absent at the south end of Prince of Wales Island. In Pybus Bay, Admiralty Island, and on the Screen Islands off the west shore of Etolin Island are conglomerates strongly suggesting glacial material. In both cases these overlie high Carboniferous beds which have been corre- ABSTRACTS OF PAPERS 151 lated by Girty with the Gschelian. Overlying the conglomerates are Middle Triassic beds. Where seen, the conglomerates had not weathered down and it was not possible to obtain loose boulders which might show scratches. Facet- ted boulders occur in the conglomerate, however. It will probably be found that this is a true glacial deposit and to be correlated with the conglomerate described by Cairnes near the Alaskan-Canadian boundary. A conglomerate similar to that described above underlies the Middle Triassic rocks of Dall Head, Gravina Island, and may prove of the same age and of similar character. In the Stringocephalus limestone zone of the Middle Devonian small facetted pebbles up to 21 inches in length are of fairly frequent occurrence at one locality on the west coast of Prince of Wales Island. In Freshwater Bay and in Port Frederick, which lie near the northern end of Chicagoff Island, some 250 miles to the north, conglomerates occur in the Middle Devonian. Rounded boulders up to 2 feet in diameter were seen. They are very unlike normal sedimentary conglomerates. Should the boulders in the Devonian prove gla- cial, a somewhat different origin would probably be postulated for the con- glomerates themselves. These are thin, ranging in thickness up to 25 feet or so, and would be more easily explained perhaps as consisting of berg-borne material, though glacial in origin. Bottoms of a similar nature are even now to be found in the channels of southeastern Alaska. Throughout the Paleozoic section in southeastern Alaska are vast thick- nesses of volcanic material, tuffs, breccias, and flows. Considering the sedi- ments as a whole, climatic conditions through the Paleozoic do not seem to have been very different from those of comparatively recent times and physical conditions may have been very nearly the same. Some of the results of a monographic study of American Tertiary Cyclostome bryozoa were presented by the junior author in the following paper, which was illustrated by lantern slides and specimens and dis- cussed by Doctor Grabau. . PRINCIPLES OF CLASSIFICATION OF CYCLOSTOME BRYOZOA BY F. CANU,AND R. S. BASSLER (Abstract) During the preparation of a monograph on American Tertiary bryozoa the authors extended their study of the Cyclostome bryozoa to the Cretaceous and recent forms in order to arrive at some definite data for the natural classifi- cation of this group. As the zooecial form is practically the same in all the Cyclostome bryozoa, it is impossible to base a classification on this as is done in the other groups of this class. Hitherto the classification of the Cyclo- stomata has been based almost entirely on the form of the colony or zoarium, although it has always been realized that this was a very unnatural basis. The present authors have found that the ovicell, the marsupium-like organ which is developed on Cyclostome bryozoa, affords a natural basis of classifica- tion and the families and genera group themselves according to the position and form of this organ. XII—Buuu. Grou. Soc. AM., Vou. 29, 1917 152 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY There was then presented by the author a paper on the invertebrate paleontology of a new West Coast Tertiary formation, which was dis- cussed by Doctor Dickerson, with replies by the author. FAUNA OF THE MEGANOS GROUP BY B. L. CLARK An interesting fauna of fossil vertebrates was described in the follow- ing paper: FOSSIL MAMMALS OF THE TIFFANY BEDS BY W. D. MATTHEW AND WALTER GRANGER (Abstract) The Tiffany beds are a local phase at the base of the Wasatch north of the San Juan River, in southern Colorado. Fossil mammals were first found there by J. W. Gidley, on whose invitation Mr. Granger explored the deposit in 1916 for the American Museum. A small but interesting fauna was secured there, regarded as of uppermost Paleocene age, equivalent to the Clark Fork beds at the base of the Bighorn Wasatch. The fauna includes several new or little known genera of minute size, but of considerable paleontologic interest. A paper by President Merriam on the Pliocene of Idaho was next on the program, but its presentation had to be omitted because the material illustrating it had not arrived. FAUNA OF THE IDAHO TULARE PLIOCENE OF THE PACIFIC COAST REGION BY J. C. MERRIAM President Merriam then took the chair and called for a paper on verte- brate paleontology, of which the author presented an abstract. This was discussed by Doctor Matthew. REVISION OF THE PSEUDOTAPIRS OF THE NORTH AMERICAN EOCENE BY O. A. PETERSON (Abstract) This abstract is taken from the general report on the Vertebrata of the Upper Eocene of the Uinta Basin, Utah, ready for publication. In this review is included two new genera of pseudotapirs from the Upper aes A new family and two new subfamilies are proposed. A short paper on American fossil rhinoceroses was then presented by Doctor Matthew and discussed by Professor Merriam. ABSTRACTS OF PAPERS 153 NOTES ON THE AMERICAN PLIOCENE RHINOCEROSES Ly BY W. D. MATTHEW (Abstract) Three genera of rhinoceroses occur in our Pliocene—Aphelops, Peraceras, and TJ'eleoceras. They are distinct in the proportions of the skull, character of the horn-cores, upper and lower tusks, reduction of premolar teeth, hypso- donty of molar teeth, and by the proportions of limbs and feet. Although some or all may be derived from Old World ancestry, these genera are limited to North America and are distinct specializations from any of the various rhinoceros phyla of the Old World. They became extinct apparently before the end of the Pliocene. New Upper Eocene mammals from Utah were then very briefly de- scribed by Mr. Peterson, who had prepared a much longer paper on the subject. NHW ARTIODACTYLS FROM THE UPPER HOCENE OF THE UINTA BASIN, UTAH BY O. A. PETERSON (Abstract) The paper is an abstract taken from the general report on the Vertebrata of the Upper Eocene of the Uinta Basin, Utah, now ready for publication. A number of new genera of the subfamily Homacodontine are first taken up. Secondly, it gives a short description of an American Anoplothere and its relation to Diplobune of Europe. ‘Thirdly, a brief description and complete restoration of a new oreodont from the Upper Eocene. And fourthly, a de- scription of a new Eocene hypertragulid and -a review of the relationship between the Uinta and the Oligocene genera of the Hypertragulide. A paper on stratigraphy and invertebrate paleontology was next in order and was presented by the senior author. Discussed by Messrs. Dickerson and Grabau. MARINE OLIGOCENE ,OF THE WEST COAST OF NORTH AMERICA BY B. L. CLARK AND RALPH ARNOLD (Abstract) _ A general survey of the known data concerning the paleogeography, climatic conditions, and faunal relationships of the Oligocene as found in California, Oregon, Washington, and Vancouver Island. The marine Mesozoic and Tertiary sediments of the West Coast were, for the most part, laid down in broad geosynclinal troughs, the axes of which paralleled that of the present ranges. The Tertiary sediments accumulated in these slowly sinking troughs to an enormous thickness. Roughly estimated, there are at least 40,000 feet of sediments of Tertiary age in the Coast Ranges: - of this fully 10,000 feet belong to that period of time which is here referred 154 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY to the Oligocene. In Washington there was apparently a trough of deposition during the Oligocene time whith extended from the Puget Sound district south between the Olympics and the Cascades into western Oregon. In California there was one large trough of deposition which extended from the region of Mount Diablo, middle California, to at least as far south as the San Emigdio Mountains, at the south end of the San Joaquin Valley, a distance north and south of over 200 miles. The axis of this trough, as indicated by the distri- bution of the organic shales, was in the eastern Coast Ranges. In the western Coast Ranges the Oligocene where present is represented by the shallow-water deposits; it is absent over large areas in this western field. There are two general faunas known from the marine Oligocene deposits of the west coast. They very probably belong to two distinct epochs of deposi- tion. The name San Lorenzo group is applied to the beds in which the lower fauna is found; the beds from which the upper fauna comes are referred to the Seattle group. The fauna of the Seattle group has not been determined in California for a certainty. The type section of the San Lorenzo is in the Santa Cruz Mountains of California. The fauna of the San Lorenzo group shows a closer relationship to that of the Tejon (Upper Eocene) than does that of the Seattle. On the other hand, the fauna of the Seattle group shows closer affinities to that of the Lower Miocene than does the San Lorenzo. These two Oligocene faunas show a much closer relationship to each other than does the one to the Eocene and the other to the Miocene. In the absence of the author, Professor Merriam then read the final paper of the program. THE QUESTION OF PALEOECOLOGY BY F. E. CLEMENTS? The following four papers of the program were read by title: NOTE ON THE EVOLUTION OF THE FEMORAL TROCHANTERS IN REPTILES AND MAMMALS BY WILLIAM H. GREGORY CARBONIFEROUS SPECIES OF “ZAPHRENTIS” BY G. H. CHADWICK EXTINCT VERTEBRATE FAUNAS FROM THE BADLANDS OF BAUTISTA CREEK AND SAN TIMOTEO CANYON OF SOUTHERN CALIFORNIA BY CHILDS FRICK NOTES ON EIFEL BRACHIOPODS BY G. H. CHADWICK On motion, at 6 p. m. the Society adjourned. 1 Introduced by J. C. Merriam. - LIST OF MEMBERS 15 REGISTER OF THE PITTSBURGH MEETING, 1917 Henry M. Ami JOHN C. MERRIAM fi &: BASSLER.. MargoriE O’CONNELL L. D. BurLIneG Henry FAIRFIELD OSBORN Bruce L. CLark Witu1amM A. Parks Roy E. DicKERSON O. A. PETERSON August F. ForrstE WiLuiAmM A. PRICE C. E. Gorpon , CHesterR A. REEDS AmabDEus W. GRABAU Wittiam H. SHIDELER WALTER GRANGER BURNETT SMITH WILLIAM J. HoLLAND T. W. STANTON Otto H. JENNINGS T. WAYLAND VAUGHAN K. F. MatHer Davin WHITE W. D. MattHEew SAMUEL W. WILLISTON OFFICERS, CORRESPONDENTS, AND MEMBERS OF THE PALEONTOLOGICAL SOCIETY OFFICERS FOR 1918 President: " F, H. Knowtton, Washington, D. C. First Vice-President: ARTHUR Houtick, New York City Second Vice-President: L. W. STEPHENSON, Washington, D. C. Third Vice-President: F. B. Loomis, Amherst, Mass. Secretary: R. S. Bassuer, Washington, D. C. Treasurer : | , R. 8S. Lutz, New Haven, Conn. Editor: C. R. Hastman, New York City Ot 156 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY MEMBERSHIP, 1918 CORRESPONDENTS Dr. A. C. NatHorRST, Royal Natural History Museum, Stockholm, Sweden. S. S. BucKMAN, Esq., Westfield, Thame, England. Prof. CHARLES DEPERET, University of Lyon, Lyon (Rhone), France. Dr. HENRY Woopwarb, British Museum (Natural History), London, England. MEMBERS L. A. ADAMS, State Teachers’ College, Greeley, Colo. José G. AGUILERA, Instituto Geologico de Mexico, City of Mexico, Mexico. TRUMAN H. ALDRICH, care post-office, Birmingham, Ala. Henry M. Ami, Geological and Natural History Survey of Canada, Ottawa. Canada. F. M. ANDERSON, 2604 Etna Street, Berkeley, Cal. ROBERT ANDERSON, 7 Richmond Terrace, London, England. EDWIN J. ARMSTRONG, 954 West Ninth Street, Erie, Pa. RaLPH ARNOLD, 921 Union Oil Building, Los Angeles, Cal. RurFfus M. Bace, Jr., Lawrence College, Appleton, Wis. CHARLES L. BAKER, Bureau Economie Geology and Technology, University of Texas, Austin, Texas. ERWIN H. Barpsour, University of Nebraska, Lincoln, Nebr. JOSEPH BARRELL, Yale University, New Haven, Conn. ALBERT L. BARROWS, University of California, Berkeley, Cal. PAUL BartscH, U. S. National Museum, Washington, D. C. HARVEY BASSLER, Geological Department, Johns Hopkins University, Balti- more, Md. bites Ray S. Basster, U. S. National Museum, Washington, D. C. JosHUA W. BEEDE, 404 West 38th Street, Austin, Texas. WALTER A. BELL, St. Thomas, Ontario, Canada. B. A. BENSLEY, University of Toronto, Toronto, Canada. ' Fritz BERcKHEMER, Department of Paleontology, Columbia University, New York City. Epwarp W. Berry, Johns Hopkins University, Baltimore, Md. ARTHUR B. BIBBINS, Woman’s College, Baltimore, Md. WALTER R. BILLines, 1250 Bank Street, Ottawa, Canada. Tuomas A. Bostwick, 48 Livingston Street, New Haven, Conn. KX. B. Branson, University of Missouri, Columbia, Mo. BaRNUM Brown, American Museum of Natural History, New York City. THOMAS C. Brown, Laurel Bank Farm, Fitchburg, Mass. WILLIAM L. Bryant, Buffalo Society of Natural History, Buffalo, N. Y. LANCASTER D. BuRLING, Geological Survey of Canada, Ottawa, Canada. CHARLES Butts, U. 8. Geological Survey, Washington. D. C. JoHn P. BuwawpA, Hopkins Hall, Yale University, New Haven, Conn. ERMINE C. CASE, University of Michigan, Ann Arbor, Mich. GEORGE H. CHADWICK, University of Rochester, Rochester, N. Y. Bruck lL. CLarK, University of California, Berkeley, Cal. JOHN M. CLARKE, Education Building, Albany, N. Y. a HERDMAN F. CLELAND, Williams College, Williamstown, Mass. LIST OF MEMBERS 157 ©. WYTHE Cooke, U. S. Geological Survey, Washington, D. C. Haroitp J. Cook, Agate, Nebr. WILL E. Crane, 208 13th Street N. E., Washington, D. C. EpeGar R. CuMINGS, Indiana University, Bloomington, Ind. JOSEPH A. CUSHMAN, Sharon, Mass. W. H. Datt, U. S. National Museum, Washington, D. C. BASHFORD DEAN, Columbia University, New York City. Roy I. Dickerson, 114 Burnett Avenue, San Francisco, Cal. JOHN T. DonEGHY, 5618 Clemens Avenue, St. Louis, Mo. Hart Doverass, Carnegie Museum, Pittsburgh, Pa. Henry M. DuBois, 1408 Washington Avenue, La Grande, Oreg. CARL O. DUNBAR, Peabody Museum, New Haven, Conn. CHARLES R. HastMan, American Museum of Natural History, New York City. GEORGE F.. Eaton, 80 Sachem Street, New Haven, Conn. JOHN EYERMAN, ‘Oakhurst,’ Easton, Pa... RicizarRD M. FIELD, Jamaica Plains, Mass. Aucust F. Forerste, 46 Oxford Avenue, Dayton, Ohio. J. J. GALLOWAY, Department of Geology, Columbia University, New York City. JULIA A. GARDNER, Department of Geology, Johns Hopkins University, Balti- more, Md. | G. S. Gester, First National Bank Building, San Francisco, Cal. HucH Giss, Peabody Museum, Yale University, New Haven, Conn. J. Z. GILBERT, Los Angeles High School, Los Angeles, Cal. CLARENCE E. GorpoN, Massachusetts Agricultural College, Amherst, Mass. CHARLES N. GouLp, 408 Terminal Building, Oklahoma City, Okla. AMADEUS W. GRABAU, Columbia University, New York City. WALTER GRANGER, American Museum of Natural History, New York City. F. C. GREENE, 9 West 17th Street, Tulsa, Oklahoma. . W. K. Grecory, American Museum of Natural History, New York City. NorMAN McD. Grirr, 718 Clara Street, St. Louis, Mo. WINIFRED GOLDRING, Education Building, Albany, N. Y. Wiiiam F. E. Guriry, 6151 University Avenue, Chicago, Ill. JOHN A. GUINTYLLO, University of California, Berkeley, Cal. HomMeER HAMLIN, 1021 South Union Avenue, Los Angeles, Cal. HAROLD HANNIBAL, Stanford University, Stanford, Cal. GEORGE W. Harper, 2139 Gilbert Avenue, Cincinnati, Ohio. GILBERT D. Harris, Cornell University, Ithaca, N. Y. Curis. A. HARTNAGEL, Education Building, Albany, N. Y. WintTurop P. Haynes, University of Kansas, Lawrence, Kans. Junius HENDERSON, University of Colorado, Boulder, Colo. ADAM HERMANN, American Museum of Natural History, New York City. WiLtiaAM J. HoLLANpd, Carnegie Museum, Pittsburgh, Pa. - ARTHUR Hottuick, 61 Wall.Street, New Brighton, N. Y. B. F. HoweE.x, Department of Geology, Princeton University, Princeton, N. J. GEORGE H. Hupson, 19 Broad Street, Plattsburgh, N. Y. Louis Hussakor, American Museum of Natural History, New York City. JESSE Hypr, Western Reserve University, Cleveland, Ohio. Ropert T. JACKSON, Peterborough, N. H. BE. C. Jerrrey, Harvard University, Cambridge, Mass. 158 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY Otto E. JENNINGS, Carnegie Museum, Pittsburgh, Pa. : W.S. W. Kew, Bacon Hall, University of California, Berkeley, Cal. EpWARD M. KINDLE, Geological Survey of Canada, Ottawa, Canada. EDWIN Kirk, U. S. Geological Survey, Washington, D. C. S. H. KnicHt, University of Wyoming, Laramie, Wyo. FRANK H. KNowtton, U. S. Geological Survey, Washington, D. C. LAWRENCE M. LAMBE, Geological Survey of Canada, Ottawa, Canada. Wiis T. LEE, U. S. Geological Survey, Washington, D. C. FREDERICK B. Loomis, Amherst College, Amherst, Mass. RicHArRD S. LuLu, Yale University, New Haven, Conn. D. D. LuTHER, Naples, N. Y. Victor W. Lyon, Jeffersonville, Ind. THoMAS H. McBrinpE, University of Iowa, Iowa City, Iowa. J. H. McGrecor, Columbia University, New York City. WENDELL C. MANSFIELD, U. S. Geological Survey, Washington, D. C. Ciara G. MarK, Department of Geology, Ohio State University, Columbus, Ohio. Bruce Martin, Waukena, Tulare County, Cal. K. F. MATHER, Queens University, Kingston, Ontario. W. D. MatTtHEw, American Museum of Natural History, New York City. T. PooLeE MAynagp, 1622 D. Hunt Building, Atlanta, Ga. Maurice G. MEHL, University of Oklahoma, Norman, Okla. JOHN C. MERRIAM, University of California, Berkeley, Cal. Rector D. MESLER, U. S. Geological Survey, Washington, D. C. Roy L. Moopre, University of Illinois, Congress and Honore Sts., Chicago, Ill. CLARENCE L. Moopy, University of California, Berkeley, Cal. W. O. Moony, 1829 Berryman Street, Berkeley, Cal. CHARLES C. Mook, American Museum of Natural History, New York City. R. C.*Moore, Department of Geology, University of Kansas, Lawrence, Kans. RosBertT B. Moran, 632 Title Insurance Building, Los Angeles, Cal. WILLIAM C. Morss, Department of Geology and Geography, Washington Uni versity, St. Louis, Mo. , JAMES E. NARRAWAY, Department of Justice, Ottawa, Canada. JORGEN O. NOMLAND, University of California, Berkeley, Cal. MarvorigE O’CoNNELL, Columbia University, New York Citv. HENRY FAIRFIELD OsBorRN. American Museum of Natural History, New York City. R. W. Pack, U. S. Geological Survey, Washington, D. C. Earyt L. Packarp, Department of Geology, University of Oregon, Eugene, Oreg. WILLIAM A. ParxKs, University of Toronto, Toronto, Canada. WILLIAM PATTEN, Dartmouth College, Hanover, N. H. O. A. PETERSON, Carnegie Museum, Pittsburgh, Pa. ALEXANDER PETRUNKEVITCH, 266 Livingston Street. New Haren, Conn. WILLIAM A. PRICE, JR., West Virginia University, Morgantown, W. Va. Percy E. RayMonp, Museum of Comparative Zoology, Cambridge, Mass. CHESTER A. REEDS, American Museum of Natural History, New York City. JOHN B. REESIDE, JrR., U. S. Geological Survey, Washington, D. C. CHARLES E. REsseEr, U. S. National Museum, Washington, D. C. BE. S. Rices, Field Museum of Natural History, Chicago, Il. WILBuR I. Ropinson, Vassar College, Poughkeepsie, New York. LIST OF MEMBERS 159 Paut V. Rounpy, U. S. Geological Survey, Washington, D. C. Ropert R. Row ey, Louisiana, Mo. RupoLr RUEDEMANN, Education Building, Albany, N. Y. FREDERICK W. SArDESON, 414 Harvard Street, Minneapolis, Minn. CLIFTON J. SARLE, University of Arizona, ‘Tucson, Arizona. THOMAS I. SavaceE, University of Illinois, Urbana, Ill. WiLiiAM H. SHIDELER, Miami University, Oxford, Ohio. CHARLES SCHUCHERT, Yale University, New Haven, Conn. WILLIAM B. Scott, Princeton University, Princeton, N. J. Hxur1as H. SELLARDS, Tallahassee, Fla. Henry W. SHIMER, Massachusetts Institute of Technology, Boston, Mass. WILLIAM J. SINcLaAIR, Princeton University, Princeton, NSS BuRNETT SmitTH, Syracuse University, Syracuse, N. Y. FRANK SPRINGER, U. S. National Museum, Washington, D. C. T. W. Stanton, U. S. Geological Survey, Washington, D. C. CLINTON R. STAUFFER, University of Minnesota, Minneapolis, Minn. L. W. STEPHENSON, U. S. Geological Survey, Washington, D. C. CHARLES H. STERNBERG, Lawrence, Kans. CHESTER Stock, 492 Seventh Street, San Francisco, Cal. REGINALD C. STovER, Standard Oil Building, San Francisco, Cal. CHarLes K. Swartz, Johns Hopkins University, Baltimore, Md. Mienon Tarzot, Mt. Holyoke College, South Hadley, Mass. Epgar HE. TELLER, 305 Endicott Street, Buffalo, N. Y. A. O. THomas, Department of Geology, University of Iowa, Iowa City, Iowa. ALBERT THOMPSON, American Museum of Natural History, New York City. EDWARD L. TrROXELL, Dept. of Geology, Univ. of Michigan, Ann Arbor, Mich. WittiaAmM H. TWENHOFEL, University of Wisconsin, Madison, Wis. M. W. TwiItcHELL, Geological Survey of New Jersey, Trenton, N. J. Epwarp O. ULRicH, U. 8S. Geological Survey, Washington, D. C. CLAUDE HE. UNGER, Pottsville, Pa. JACOB VAN DELoo, Education Building, Albany, N. Y. GILBERT VAN INGEN, Princeton University, Princeton, N. J. Francis M. Van Tuyt, University of Illinois, Urbana, I[]l. T. WAYLAND VAUGHAN, U. S. Geological Survey, Washington, D. C. ANTHONY W. VocpEs, 2425 First Street, San Diego, Cal. CuarLeEs D. Watcott, Smithsonian Institution, Washington, D. C. CLARENCE A. WarING, 580 McAllister Street, San Francisco, Cal. CHARLES F.. WEAVER, University of Washington, Seattle, Wash. STuarRT WELLER, University of Chicago, Chicago, II]. Davin WHITE, U. S. Geological Survey, Washington, D. C. Epwarp J. WHITTAKER, Geological Survey of Canada, Ottawa, Canada. _G. R. WreLanp, Yale University, New Haven, Conn. Henry 8S. WILiiAMs, Cornell University, Ithaca, N. Y. Merton Y. WILLIAMS, Geological Survey of Canada, Ottawa, Canada. SAMUEL W. WILLISTON, University of Chicago, Chicago, Il. ALIcE E. WixLson, Victoria Memorial Museum, Ottawa, Canada. Herrick HW. Witson, U. 8. National Museum, Washington, D. C. WiLLiaAmM J. Wixson, Geological Survey of Canada, Ottawa, Canada. 160 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY ELvirA Woop, Museum of Comparative Zoology, Cambridge, Mass. WENDELL P. Wooprine, Dept. of Geology, Johns Hopkins Univ., Baltimore, Ma CORRESPONDENT DECEASED EK. Koken, died November 24, 1912. MEMBERS DECEASED SAMUEL CALVIN, died April 17, 1911. WILLIAM B. CuLarRk, died July 27, 1917. ORVILLE A. DERBY, died November 27, 1915. WILLIAM M. FoNntTAINE, died April 30, 1918. ‘THEODORE M. GILL, died September 25, 1914. ROBERT H. Gorpon, died May 10, 1910. J. C. HAWVER, died May 15, 1914. C. S. Prosser, died September 11, 1916. HENRY M. SEELy, died May 4, 1917. MEMBERS-ELECT F. E. CLEMENTS, Carnegie Institution, Washington, D. C. LEE RAyMOND Dice, University of Montana, Missoula, Mont. CHILpS Frick, Santa Barbara, Cal. EUGENE SCHOFIELD HEATH, Botany Hall, Univ. of Califorhia, Berkeley, Cal. REMINGTON KELLOGG, 2212A Union, Berkeley, Cal. WAYNE FREDERICK LOEL, Department of Geology and Mining, Standford Uni- versity, Palo Alto, Cal. Euta D. McEwan, U. S. National Museum, Washington, D. C. ‘IpA CARTER OLpROYD, College Terrace, Palo Alto, Cal. CARROLL MARSHALL WAGNER, 2604 Etna Street, Berkeley, Cal. MINUTES OF THE EKigGHTH ANNUAL MEETING OF THE PaActFIc COAST SECTION OF THE PALEONTOLOGICAL SOCIETY By CHESTER Stock, Secretary The eighth annual meeting of the Pacific Coast Section of the Paleon- tological Society was held at Stanford University on April 6 and 7, 1917, the Society participating in the second annual meeting of the Pacific Division of the American Association for the Advancement of Science. A short, jot session with the Geological Society and the Seismolog- ical Society was held on April 6, at which time Prof. John C. Merriam spoke on preparedness. At the conclusion of Professor Merriam’s ad- dress, the meeting adjourned, and the Paleontological Society was called to order in separate session by Dr. J. P. Buwalda at 3.15 o’clock, in room 360, Mineralogy Building. ABSTRACTS OF PAPERS 161 ELECTION OF OFFICERS The following officers were elected for the ensuing year: President, Bruce L. Ciark, University of California. Vice-President, CHESTER Stock, University of California. Secretary-Treasurer, CHESTER Stock, University of California. PRESENTATION OF PAPERS ry s . U The following papers were then read: SYSTEMATIC POSITION OF THE DIRE WOLVES OF THE AMERICAN PLEISTOCENE BY J. C. MERRIAM ‘\NOTHE ON THE OCCURRENCE OF A MAMMALIAN JAW, PRESUMABLY FROM THH TRUCKEE BEDS OF WESTERN NEVADA BY J. C. JONES (Abstract) During the summer of 1916 a small mammalian jaw came into the possession of the University of Nevada that had been found in digging a shallow well near Washoe City, Nevada. While the jaw was found in the recent alluvium at present covering the greater part of the floor of Washoe Valley, yet the only sedimentary beds from which it could have been eroded are similar in composition to the Truckee beds and believed to be of the same age. Read by title. PINNIPEDS FROM MIOCENE AND PLEISTOCENE DEPOSITS OF OCALIFURNIA BY REMINGTON KELLOGG (Abstract) A new genus and species of sea-lion from the Temblor, together with seal remains from the Santa Margarita and San Pedro, are described. The dis- cussion includes a résumé of current theories regarding origin of the Pinni- pedia. PUMA-LIKE CATS OF RANCHO LA BREA BY J. C. MERRIAM GRAVIGRADE EDENTATES IN LATER TERTIARY DEPOSITS OF NORTH AMERICA BY CHESTER STOCK _ (Abstract) A review of occurrence of gravigrade edentates in Miocene and Pliocene de- posits of North America. Particular attention is directed to recent discoveries 162 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY of ground-sloth remains in the Rattlesnake Lower Pliocene of eastern Oregon and in Lower Pliocene beds exposed along San Pablo Bay, California. RELATIONSHIPS OF RECENT AND FOSSIL INVERTEBRATE FAUNAS ON TH# WEST SIDE OF THE ISTHMUS OF PANAMA TO THOSE ON THE EAST SIDE BY IDA S. OLDROYD (Abstract) The range of various invertebrate species of the marine provinces to the © west and east of the Isthmus of Panama is discussed, and attention directed to forms common to both sides of the isthmus. The report includes a state- ment concerning origin of certain of these species from a common stock, as well as observations on former trans-Panamic marine connections. TROPITIDH OF THE UPPER TRIASSIC OF CALIFORNIA BY J. P. SMITH (Abstract) A series of species of Tropites and near relatives are exhibited, showing evolution of the group and forming the basis for a discussion of species-form- ing. These are species in the making and give good examples of series diverg- ing but little from each other and from the common ancester. A discussion is also given of the correlation of the Tropites subbullatus zone and the classi- fication of the Upper Triassic of California. FAUNA OF THE IDAHO FORMATION BY JOHN C. MERRIAM (Abstract) A very extensive series of sediments exposed in the valley of the Snake River, in southwestern Idaho, described by Cope as the Idaho formation, has been carefully studied and described by Lindgren. From this formation a mammalian fauna secured by Lindgren has been listed by Lucas and referred to the Pliocene. _ The known list of mammals from the Idaho includes a number of forms which approach very closely in their stage of evolution to the Pleistocene of western North America, but differ specifically from all Pleistocene species. Such differences as appear are mainly in the direction of primitiveness. A number of other forms found in the Idaho fauna are distinctly of a Pliocene type. As nearly as can be judged, the mammalian fauna of the Idaho repre- sents a Pliocene stage later than any other Pliocene fauna of the Pacific Coast and Great Basin regions, with possible exception of the Tulare Pliocene oc- currence on the western border of the San Joaquin Valley. OCCURRENCE OF A MARINE MIDDLE TERTIARY FAUNA ON THE WESTERN BORDER OF THE MOJAVE DESERT AREA BY WALLACE GORDON Read by J. C. Merriam. ABSTRACTS OF PAPERS 163 FAUNA OF THE BAUTISTA CREEK BADLANDS BY CHILDS FRICK (Abstract) During the fall of 1916 the posterior portion of a lower jaw of a fossil horse from the Bautista Creek. badlands, near Hemet, California, came into the hands of Dr. J. C. Merriam through the kindness of Mr. J. C. Blackburn. Sev- eral weeks of systematic collecting at this locality has resulted in the gather- ing of other well preserved horse remains, some cervid material, including parts of the dentition, skull, and skeleton, as well as fragmentary evidence of an antelope smaller than Capromeryx minor, and of a small ground sloth. The dentition of the horse is of primitive character and apparently indi- eates a new form. The other species likewise appear to be new, and all prob- ably represent a new or imperfectly known stage in the faunal sequence from the late Pliocene to the early Pleistocene. “This fauna is particularly interesting in its geographic position between the marine beds of the Pacific and those of the Gulf. OCCURRENCE OF THE SIPHONALIA SUTTERENSIS ZONE, THE UPPERMOST TEJON HORIZON IN THE OUTER COAST RANGES OF CALIFORNIA BY ROY E. DICKERSON (Abstract) The uppermost horizon of the Tejon Eocene of California, the Siphonalia sutterensis zone, was described from the Hocene of Marysville Buttes and later recognized as occurring at Oroville, beneath the basalt of Oroville, South Table Mountain, at Ione, on the western flanks of the Sierra Nevada, and at Merced Falls. In the study of the Mount Diablo region, the Coalinga District, and the southern end of San Joaquin Valley, at the type locality of the Tejon group and at San Diego, this upper horizon was not recognized. The zone was placed as an uppermost phase on the basis of stage of evolution and its close connection with the Balanophylia variabilis zone of the Mount Diablo region. A year ago Mr. Reginald Stoner discovered a locality in the Santa Susana Mountains, on Aliso Canyon, of Devil Creek, just beneath Miocene strata. The fossils from this locality represent a lower phase of the Siphonalia sutterensis zone and the fauna is essentially the same as the Siphonalia sut- terensis zone of the Roseburg quadrangle, on Little River, near the confluence with the Umpqua. In the Simi Hills, a few miles away from the locality dis- covered by Mr. Stoner, the Rimella simplex zone of the Middle Tejon stage occurs. The general absence of this zone throughout most of the Coast Range region is probably due to extensive erosion during the interval between Upper Eocene and Oligocene time. At the conclusion of the reading of papers the meeting adjourned and the members of the Paleontological Society attended a dinner of the Le Conte Club, at the Stanford Union. 164 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY On Saturday, April 7, at 10.45, the meeting was called to order by Dr. C. E. Weaver. The following papers were presented : CRETACEOUS AND TERTIARY STRATIGRAPHY OF THE WESTERN END OF THE SANTA' INEZ MOUNTAINS, SANTA BARBARA COUNTY, CALIFORNIA BY H. J. HAWLEY (Abstract) The western end of the Santa Inez Mountains is made up wholly of sedi-— mentaries of Cretaceous and Tertiary age. The Cretaceous is represented by Chico sandstones, overlain unconformably by Tertiary sediments. The Tejon is the local representative of the Eocene period, and the fauna of this series shows a remarkable similarity to the fauna from the type Tejon. Lower Mio- cene, Which may be divided into Vaqueros and Monterey, represents the latest period of deposition in this regino. GEOLOGIC RANGE. AND EVOLUTION OF THE MORE IMPORTANT PACIFIC COAST ECHINOIDS BY W. S. W. KEW (Abstract) Geologic ranges of the more important echinoid genera of the Pacific coast are as follows: Cidaris, Eocene, with exception of one species in the Oligo- cene; Strongylocentrotus, Pliocene to Recent; Scutella, Upper Eocene to Plio- cene, With greatest development in the Lower Miocene; Dendraster, dominant in the Pliocene and continuing to the Recent: Astrodapsis, confined to the Upper Miocene and Lower Pliocene. Scutella, Astrodapsis, and Dendraster serve best to illustrate the lines of descent of echinoids on the Pacific coast. Scutella evolves along two main lines, that of the S. coosensis—S. norrisi group and that of the S. merriami— S. blancoensis group. Astrodapsis, derived from the Scutellas, acquires the characters of elevated petals and grooved interambulactral areas, which be- come more pronounced until the specialized A. major and A. arnoldi stages are reached. Following these stages the genus suddenly becomes extinct. Den- — draster, also originating from the Scutellas, passes from the D. gibbsi type. ‘ “ with more or less thickened test and eccentric apical system, to the thin test and extreme apical eccentricity of D.ashleyi (Arnold), and -finally to = recent D. excentricus (Eschscholtz), with a less eccentric apical system. — ae p> Bakes EVIDENCE IN SAN GORGONIO PASS, RIVERSIDE COUNTY, OF a LATE ac : PLIOCENE EXTENSION OF THE GULF OF LOWER CALIPORNTA BY F. E. VAUGHAN (Abstract) A small invertebrate fauna was collected in San Gorgonio Pass, 3 mgs ae east of Millard Canyon. Several forms from this locality are the same as 3 ABSTRACTS OF PAPERS 165 species found by W. S. W. Kew at Carrizo Creek. The beds occurring at the latter locality are considered by T. W. Vaughan as not older than Lower Plio- eene. VAQUEROS FORMATION IN CALIFORNIA BY W. F. LOEL (Abstract) The horizon markers and principal features show this division of the Lower Miocene to be a distinct and true formation, both faunally and lithologically. 1 TERTIARY AND PLEISTOCENE FORMATIONS OF THE NORTH COAST OF PERU, SOUTH AMERICA BY G. C. GESTER (Abstract) The Tertiary formations of the north coast of Peru are similar in many re- spects to the Tertiary formations of the west coast of North America. A comparison of the faunas shows many closely related species. An interesting feature of the north Peruvian coast is the elevated tableland, or “tablaza,” which extends for several miles inland from the coast. The “tablaza beds” are richly fossiliferous and probably belong to,the Pleistocene period. SYMPOSIUM ON CORRELATION OF OLIGOCENE FAUNAS AND FORMATIONS OF } THE PACIFIC COAST BY C. E. WEAVER, R. E. DICKERSON, AND B. L. CLARK PALHOGEOGRAPHY OF THE OLIGOCENE OF WASHINGTON BY CHARLES E. WEAVER (Abstract) Two Oligocene embayments occur in Washington. The northern embayment occupied approximately the area between the Olympic: Mountains and Van- - couver Island and extended into the Puget Sound Basin as far south as Seattle. The southern embayment existed in the present region of Gray’s Harbor and : extended as far south as the Cowlitz Valley, in the northern part of Cowlitz ; County. In the northern embayment there were deposited approximately 14,000 feet of sandstone and shale. In the southern embayment the deposits are 4,000 feet in thickness. The basal faunas in the southern embayment, as repre- sented at Oakville, are the same as the basal faunas in the northern embay- ment. at Port’Discovery Bay, near Port Townsend, and also the basal beds on af the south shore of Vancouver Island, which have been described as the Sooke ~ Beas. In both the northern and southern embayments the strata above the : ~ {Sooke Beds contain a fauna of subtropical character which has been designated the: Molopophorous lincolnensis zone, the type locality of which is at Lincoln Creek, in Thurston County. In the northern embayment the Upper Oligocene i 166 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY beds contain a colder water fauna, which has been designated as the Acila gettysburgensis zone. This fauna is absent in the southern embayment. PALEONTOLOGY AND STRATIGRAPHY OF THE PORTER DIVISION OF THE OLIGOCENE IN WASHINGTON BY KATHERINE E. VAN WINCKLE (Abstract) The report embodies the results of stratigraphic and faunal studies of the Porter division of the Oligocene of Washington at the type locality on Porter Creek. The formation consists predominantly of shaly sandstones and sandy shales having a thickness of 1,200 feet. These beds rest unconformably on Tejon basalts. From the lower portion of the section a marine invertebrate fauna of 20 species was obtained, while from the upper beds 30 species were secured. Twelve species occurring in the lower beds are common to those in the upper. The fauna at Porter has a closer similarity to that at Lincoln Creek than it has to the Blakely fauna at Restoration Point. It is possible ‘that the beds at Porter can be correlated with those exposed at Lincoln Creek. Read by C. E. Weaver. FAUNAL ZONES OF THE OLIGOCENE BY B. L. CLARK CLIMATE AND ITS INFLUENCE ON OLIGOCENE FAUNAS OF THE PACIFIC COAST BY ROY E. DICKERSON At the conclusion of the reading of the papers the meeting adjourned REGISTER OF MEMBERS AND VISITORS AT STANFORD MEETING, 1917 E. M. BuTTrerwortH W.S. W. Kew J. P. BUWALDA W. F. Lorn B. L. CnuarKk J. C. MERRIAM R. E. DicKERSON J. O. NoMLAND CHILDS FRICK Ipa OLDROYD Mrs. CuiLtps FRIcK K. H. ScHILLING G. C. GESTER J. P. SmitH H. GESTER W.S. T. Suita H. J. HAWLEY CHESTER STOCK EK. S. HeatH C. M. WAGNER A. R. KELLoce . OC. E. WEAVER BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 167-186 : MARCH 31, 1918 EXPERIMENT IN GHOLOGY ? PRESIDENTIAL ADDRESS BY FRANK DAWSON ADAMS (Read before the Society December 27, 1917) CONTENTS Page 2 Dre 1S APEETRSTINCTES i To ae Rene en ne es Coy 167 Pn Snaee OMeTIMNEN Al MEENOUS i. cic elie bee ee os oe ae mee esc wee eee wine lels 169 Tanith Of Experimental SCIENCE... 25... es ses diets re we bale ee als see es 171 BieeeninTe Of experimental PeolOSy «..... 66k eee ee le ee ee wesw ees 185 EARLY GEOLOGICAL LITERATURE One of the most fascinating studies which can engage the attention of a geologist is the literature of his science of a century or so ago. Some of the problems then discussed have long since received their answers and been laid aside; others, like ghosts, refuse to be laid and are still with us. But in all cases the point of view is so different from that of the present time, and in many cases the arguments adduced are so quaint and curious, that the picture of the geological science of those early days is one of peculiar interest. The theological influence of the cosmogonist permeates much of the writings of this early time, and there are scores of treatises on the constitution and history of the earth, in which the authors have drawn their material in part from a nodding acquaintance with certain of the salient phenomena of nature, but chiefly from an extended study of Holy Writ and the works of the church fathers, rounded out by con- siderations as to the manner in which they themselves would have created the world had they been called on to bend their energies to this important task. Among the works of this class, one of the best known is by Burnet, which appeared in 1697 and is entitled “The Sacred Theory of the Karth, containing an account of the Origin of the Earth and of all the general changes which it hath already undergone or is to undergo till the Consummation of all Things.” 1 Manuscript received by the Secretary of the Society December 27, 1917. XIITI—Butu. Grou. Soc. Am., VoL. 29, 1917 . (167) 168 F. D. ADAMS—EXPERIMENT IN GEOLOGY Some of the ideas presented in this early literature are not only quaint, but rather striking in their ancient dress; but when more closely exam- ined we come to recognize in them certain well known friends. For example, there is the theory, frequently mentioned, of the “vegetability of minerals.” Are the minerals in the earth’s crust found in the state in which they were originally created or are they continually growing? Such is the question put forward by John Webster in his “Metallographa, or an History of Metals,’ which was published in London in the year 1670 and in which the thesis of the growth or “vegetability’ of minerals is sustained at length under four heads. It is interesting to trace the line of argument, which in his own words is as follows: “It appears in Genesis that plants were not created perfect at first, but only in their ‘seminaries,’ for Moses, chapter 2, gives as a reason why plants were not come forth of the earth, because there had as yet neither any rain fallen nor any dew ascended from the earth whereby they might be produced or nourished. The like we may judge of minerals, that they were not at first created perfect, but disposed of in such sort that they should perpetuate them- selves in their several kinds. And to the same purpose the profound Sendi- voglus saith: ‘And what prerogative have vegetables above metals that God should put feed into them and undeservedly exclude these. Are not metals of the same dignity with God as trees are? And, further, whosoever hath diligently considered the manner how most metals do lie in their wombs or - beds in the bare rock must necessarily conclude that they could never have penetrated the clefts, chinks, and porous places in such hard bodies unless they were in principiis solutis either in water or vapours and steams, and after concocted and matured into several forms of metals, which is an analogous, if not an univocal, generation.’ ”’ A final reason, though, as the author remarks: “Some may account it light, yet I hold it to be very cogent, and so will all persons who understand the philosopher’s grand secret, is that Nature’s ulti- mate labor is in time to bring all metals to the perfection of gold, which she would accomplish if they were not unripe and untimely taken forth from the bowels of the earth.” The philosophers merely seek by their art to accelerate the work of Nature in bringing about the passage from the base metal to gold in their laboratories. “S00 16.4s clear that if metals have not a kind of vegetability in them, then is the art of the transformation of metals false and all the grounds of the more abstruse philosophy without verity.” Then we have cases cited where minerals have been found growing in nature at the present time—for example, niter in earth which has been EARLY LITERATURE 169 allowed to stand a year after a previous treatment for extraction of the substance, iron ore in lakes in several places, flakes of metallic silver in old pit timbers in certain mines—in fact, in Joachimthal silver has been seen to grow out of the stones of the mine— “in the manner and fashion of grass, as from a root in the length of a finger, very pleasant to behold. In places this silver doth embrace the stone in most tender leaves, plates, and spangles. It sometimes beareth the shape of hairs; sometimes of little twigs. Sometimes it beareth the shape of a tree.” And so we pass on naturally to the “golden tree,” to which frequent reference is made by: ancient writers and which is described by Peter Martyr in the following terms: “They have found by experience that the vein of gold is a living tree, and that the same by all ways spreadeth and springeth from the root, by the soft pores and passages of the earth, putteth forth branches, even to the upper- most part of the earth, and ceaseth not until it discover itself unto the open air; at which time it showeth forth certain beautiful colors in the stead of flowers, round stones of golden earth in the stead of fruits, and thin plates in stead of leaves. These are they which are dispersed throughout the whole island [he is speaking of Hispaniola] by the course of the rivers, eruptions of the springs out cf the mountains, and violent falls of the floods; for they think such grains are not engendered where they are gathered, especially on the dry land, but otherwise in the rivers. They say that the root of the golden tree extendeth to the center of the earth, and there taketh nourishment of increase; for the deeper that they dig they find the trunks thereof to be so much the greater, as far as they may follow it, for abundance of water spring- ing in the mountains. Of the branches of this tree they find some as small as a thread and others as big as a man’s finger, according to the largeness or straightness of the rifts and clefts. They have sometimes chanced on whole caves, sustained and born up, as it were, with golden pillars, and this in the ways by which the branches ascend: the which being filled with the substance of the trunk creeping from beneath the branch, maketh itself way by which it may pass out. It is oftentimes divided by encountering with some kind of hard stone; yet it is in other clifts nourished by the exhalations and virtue of the root.” : MopERN EXPERIMENTAL MprHops Thus we have in an antique dress the modern “theory of ascension,” as applied to the origin of mineral veins, and of the now well known fact of the derivation of placer deposits from auriferous veins. In the years which have passed since the childhood of geological science such a thorough knowledge of the structure, of at least the superficial portion of the earth’s crust, has been obtained that geological science in many fields has developed that power of prediction which by some has been cited as the characteristic of a true science—so much so that the 170 F. D. ADAMS—-EXPERIMENT IN GEOLOGY geologist now precedes the engineer in all great mining operations where these are efficiently conducted, and could with great advantage to the public purse and public welfare have preceded him in many great civil- engineering enterprises. This high attainment in our scientific knowledge of the earth’s crust has been achieved by close and long continued observation carried on by many men through many years. Observation is the great basis and foundation stone of the science of geology; but as a companion and helper on this delightful, but some- times toilsome, path—and more especially in the later years—observa- tion has had the support of experiment, which while of distinctly subor- dinate and collateral value as compared with observation, has nevertheless rendered many important services in the development of geological knowledge. Experiment in geology is in almost all cases really experimentation in physics or chemistry applied to geological problems, and we find at the very outset that here the experimental method is at a disadvantage, in that the scale on which the earth is constructed is so immense, and the forces at work so enormous, and the time concerned so vast, that in many eases the reproduction of the conditions which obtain in nature almost seems beyond our reach. This, however, is by no means always the ease, and with the ever increasing facilities at our command experiment is being carried ever farther forward into regions of geological study which in former times seemed to be forever inaccessible to it. We are said to experiment when we subject materials to varying con- ditions of pressure, temperature, chemical action, etcetera, and record the changes observed. It is thus possible to ascertain which of these conditions is the essential factor in developing the geological phenomena under observation. : Furthermore, if it be found that a chemical change or mechanical movement which takes place at the ordinary temperature with extreme slowness is expedited by an increase in temperature, it is often possible by increasing temperature to carry out in a reasonable time an experi- ment which under the exact conditions which obtain in nature might require years, or even decades or centuries, to complete. While, there- fore, many great regions of geological investigation still remain closed to the experimental method, numerous other wide fields of geological study are open to experiment and will probably continue to enlarge as time goes on. | This was clearly shown when the Governing Board of the Carnegie Institution of Washington had submitted to it the proposal for the estab- wl ae) eee Tee MODERN METHODS aly lishment of a geophysical laboratory to be devoted to advanced work in experimental geology. There was a doubt at first in the minds of some members of the Board as to whether this field was sufficiently large to warrant the very large expenditure which would be required to build, equip, and maintain such an institution. A group of geologists were accordingly asked to consider the question and to submit a list of geo- logical problems which in their opinion were susceptible of solution by the experimental method. This was done, and the list which was drawn up may be found in the “Year Book of the Carnegie Institution” for 1903. The mere enumeration of these problems showed the field to be so extensive that the Board at once decided to establish the laboratory, which with its brilliant staff and magnificent equipment has now come to be the foremost center of geological experimental research in the world. The importance of the experimental method came to be generally rec- ognized: in the world of science through the writings of Francis Bacon, who set forth its transcendent value as a path for attaining “the knowl- edge of causes and secret motions of things.” His plan for the investiga- tion of nature, outlined in his “New Atlantis,” which went through ten editions between 1627 and 1670, suggested the establishment of a “Col- lege for the Promoting of Physico-Mathematicall Experimentall Learn- ing,” what we would now call a university of research, endowed by the State, which eventually took form in the Royal Society of London, founded in 1662, receiving grants from the State for the prosecution of scientific research and acting in an advisory capacity to the government in questions requiring scientific knowledge. It is thus the oldest scien- tific society in the world, and it is interesting here to note that Benjamin Franklin was elected a Fellow of this Society in 1756. The inscription on his portrait which hangs in the Society’s rooms at Burlington House runs: “Benjamin Franklin, LL. D., F. R. 8S. (1706-1790)—American, Philosopher, and Statesman. In 1757 came to England as agent for Pennsylvania. Elected F. R. S. 1756 and contributed papers on electrical subjects to the eel Transactions. Copley Medallist, 1753.” THE GROWTH OF EXPERIMENTAL SCIENCE It is very interesting to follow the growth of experimental science as seen in the long series of papers which have appeared in the successive volumes of the Philosophical Transactions of the Royal Society from the early days to the present time. Of these, however, comparatively few deal with strictly geological problems; but in the abstract of a paper by 172 F. D. ADAMS—-EXPERIMENT IN GEOLOGY Doctor Lister, entitled “On the cause of earthquakes and volcanoes,” which appeared in Volume IJ, published in 1705, the author presents a most interesting discussion of these phenomena concerning which we are still speculating, not, however, it is to be hoped, without making some very substantial advances toward their true solution. “I have elsewhere shown,” says Doctor Lister, “that the breath of pyrites is sulphur ex tota substantsa. Again, that the material which is the cause of thunder and lightning and of earthquakes is one and the same, namely, the inflamma- ble breath of pyrites, the difference being that one is fired in the air and the other underground.” He then goes on to give his reasons, which time will not permit us here to reproduce, but which are most ingenious, and then continues: “We with great probability believe volcanoes to be moun- tains made in great part of pyrites by the great quantities of sulphur therein sublimed and the application of the lodestone to the ejected cinder.” He considers that the mountains were probably “kindled shortly after creation” and by the spontaneous ignition of this mineral. Iron pyrites giving off sulphur, as it does when heated, was looked on askance, aS In some way connected with diabolical manifestations in nature. The author of “A Theory and History of Harthquakes,” pub- lished in London in 1753, writes: “This dreadful mineral is found in England as well as in other places more subject to earthquakes, but in smaller quantities and generally containing less of the sulphur, and this may be a principal reason why our earthquakes have .. been hitherto very slight and comparatively few.” This relation. of voleanic phenomena to sulphurous minerals had fur- ther support in the general opinion coming down through the centuries from the time of the Greeks, or even earlier, that the center of the earth was a place of everlasting fire, serving, as one ancient writer puts it, as “an eternal jakes or prison, destined for the punishment of the damned.” The brimstone always associated in the popular mind with this place of plutonic punishment related itself admirably to the sulphurous exhala- tions from craters at the surface and to the occurrence of pyrites in the intervening strata, although the conception gave rise at times to certain - curious intellectual difficulties. Thus, in referring to the vent at Vulcano, in the Phlegrean Fields, the writer just quoted asks: “Tf this be hell, what a desperate end made that unhappy German who not long since slipped into these furnaces, or what had his poor horse committed that fell in with hjm that he should be damned, or at least retained, in purga- tory?” GROWTH OF EXPERIMENTAL SCIENCE i Whe: An experiment is described by several writers of this period which was considered by them to demonstrate that it was to the presence of great deposits of self-igniting sulphurous minerals in the earth’s crust we must look for the cause of volcanic action. The experiment consists in mixing several pounds of iron filings in equal parts with sulphur, moistening the mass with water, and burying it to a depth of a few feet in the ground. Presently, we are informed, it begins to heat, and in a few hours the earth will begin to tremble and crack; fire and smoke will burst through, . and it is only necessary to postulate a sufficient quantity of this mixture to produce a true Htna. “This experiment, continues one author, suffi- ciently explains and illustrates the cause of earthquakes, volcanoes, and all fiery eruptions from the earth, for nothing more is requisite than iron, vitriolic acid, and water; and iron,” he continues, “is generally found accompanied by sulphur.” Such early experiments, while they have no real ieeeeuanibe or value, may be taken as an evidence of a growing interest in the experimental method and as the forerunners of more important and serious work which was to follow in later years. Jt was the well known controversy between the Neptunists and the Plutonists that afforded the first striking example of the importance of experiment in geology. The Neptunists held that fire, while liquefying substances by aa could never produce crystalline bodies, since the -fused mass in cooling was always glassy in character. A crystalline structure could, according to their tenets, be produced only by deposition from solution. They held, therefore, that crystalline rocks—as, for example, basalt—could not have been produced by fire, but must have originated by deposition from water. They held, furthermore, that not only were basalts and similar rocks of sedimentary origin, but that the crystalline schists, gneisses, etcetera, had originated in like manner, and adduced as further proof of this fact the fact that bodies of crystalline marble were in places found inclosed in these schists, which showed that the inclosing rocks had never been subjected to heat, since, had this been the case, the carbonic dioxide would _ have been expelled from the marble and quicklime only would have remained. Hutton, on the other hand, following the teaching of the Plutonists, held that the crystalline schists and other crystalline rocks had solidified from a molten condition, and that the magmas from which they had developed would, if cooled very slowly, yield distinctly crystalline, or even coarsely crystalline, rocks, and that even “stones? of the calcareous genus 2 Playfair’s Illustrations of the Huttonian Theory, vol. i, p. 45. Edinburgh, 1822. 174 F. D. ADAMS—EXPERIMENT IN GEOLOGY have been reduced by heat into a state of fluidity; thus the saline or finer kinds of marble that have a structure highly crystallized must have been softened to a degree little short of fusion before this crystallization could take place,” and that he believed it to be possible that “calcareous earth under great compression may have its fixed air retained in it, notwith- standing the action of intense heat, and may by that means be reduced into fusion or into a state approaching it.” Here was a well defined issue between: the two great camps into which the geological world was then divided. On its outcome depended the explanation of the nature and origin of the rocks constituting a large portion of the earth’s crust. They could not settle the dispute by obser- vation in the field, but it was triumphantly decided by recourse to experi- ment. To Sir James Hall,? of Edinburgh [1761-1832], who was an intimate friend of Hutton, is due the credit of having carried out this epoch-making experimental demonstration. Taking first the “whinstone,” or intrusive olivine basalt of the district about Edinburgh, and later the lavas from Vesuvius and Etna, he fused them in a reverberating furnace and obtained from the fused material by rapid cooling a perfect glass. When, however, the rock was fused and cooled more slowly, he obtained a product which, while not like whinstone, was of an intermediate character, like the “liver of an animal,” to use his own quaint expression, and often containing “a multitude of little spheres having a dull or earthy fracture.” This we now know to be a glass filled with devitrification products, and he makes some interesting observations with reference to the sudden hardening of the glass, even if the temperature remains constant, as it passes into this devitrified con- dition. Finally he found that if the fused mass was cooled very slowly, during a period of several hours, he obtained “a substance differing in all respects from glass and in texture completely resembling whinstone.” He thus demonstrated experimentally that, contrary to the opinion of the Neptunists, a crystalline rock might be produced by the cooling of a fused magma and thus be of igneous origin. Hall‘ then carried on a long series of most brilliant, interesting, and ingenious experiments, in which he submitted powdered chalk to a red or white heat in closed gun-barrels or porcelain tubes. A portion of the chalk was thus disassociated, while the remainder was submitted to a high pressure by the carbonic acid gas thus produced. The manner in 3 Experiments on whinstone and lava. Trans. Roy. Soc. of Edinburgh, vol. v, 1805. Sir James Hall: Account of a series of experiments showing the effect of compres- sion in modifying the action of heat. Trans. Roy. Soc. of Edinburgh, vol. vi, 1812. GROWTH OF EXPERIMENTAL SCIENCE 175 which the many unforeseen difficulties, which always present themselves in such an investigation, were surmounted and the infinite patience with which the investigation was followed out mark Hall as an investigator of high rank. He carried out some 500 experiments, and a whole battery of gun-barrels burst in the course of the investigation ; but he succeeded eventually in converting the powdered chalk by heat and pressure into © a material which was to all intents and purposes a fine-grained marble, thus proving that the presence of this rock in a complex of crystalline schists could not be taken as evidence that these rocks were aqueous pre- cipitates, but that, on the contrary, it conveyed the suggestion that they had during their formation been submitted to conditions of great heat and pressure. The arguments of the Neptunists were thus finally overthrown by Hall’s investigations, and he well merits the honor which is bestowed on him when he is called “the Father of Experimental Geology.” The recognition of the fact that much valuable information, contribut- ing in no small measure to the understanding of many recondite processes which are at work in nature, might be obtained through experiments, where the conditions which obtain in the earth’s crust are reproduced as | closely as possible in the laboratory, now commenced to draw the atten- tion of an ever increasing number of geologists to the importance of ex- perimental work. Among these may be mentioned Sorby, Pfaff, Kick, Michel Lévy, Fouqué, Cadell, Doelter, Spring, Meunier, Bailey Willis, and especially Daubrée, who for over forty years devoted himself untir- ingly to the pursuit of experimental geology and whose great work, en- titled “Etudes synthétiques de Géologie Expérimentale,” published in 1879, will ever remain one of the classics in this subject. One of the lines along which such experimental study has yielded im- portant results to geological science may be referred to briefly, namely, the experimental study of the development of mountain ranges. | The Alps, situated as they are in the very heart of Europe, have been subjected to more continuous and intensive study than any other moun- tain range in the world. The serious attempts to unravel their structure may be said to have extended over the lifetime of three successive Swiss -geologists—De Saussure, Arnold Escher von der Linth, and his pupil, ' Albert Heim, representing the period from 1740 to the present time. In the earlier part of this period the mountain range was considered to be a jumbled assemblage of rock-masses without definite or recogniz- able structure of any kind—a mere chaos of broken pieces of the earth’s erust. Gradually it came to be seen that in addition to more or less massive rocks of obscure origin there were stratified elements in the vari- 176 F. D. ADAMS—EXPERIMENT IN GEOLOGY ous massifs. These beds, however, were highly inclined. “We are still ignorant,” writes De Saussure, “by what cause these rocks have been tilted. But it is already an important step among the prodigious quan- tity of vertical strata in the Alps to have found certain examples which we can be perfectly certain were formed in a horizontal position.” 'Then it came to be recognized that these inclined strata were portions of great folds, and later that the mountain system as a whole had originated through the complicated folding of a belt of country. It was Sir James Hall who, in 1812, a few years after De Saussure’s death, insisted that the cause of this folding was to be found in great tangential pressure in the earth’s crust, developing horizontal thrusts of immense magnitude. In order to demonstrate that such forces could pro- duce the results observed, he constructed a machine in which a series of layers of cloth of different sorts, alternating with stuffs of other kinds, were submitted to great lateral pressure while under a heavy vertical load. Thin layers of clay were in a later series of experiments substituted for the cloth. By these experiments Hall was able to show that folding of the type seen in mountain chains could be developed by such lateral thrusts, and that in his particular experiments the convolutions of the Silurian strata of the Berwickshire coast were reproduced in a striking manner. | He was followed after a long interval by Cadell, who, in 1888, carried out a series of experiments in which alternating layers of sands of differ- ent colors, clay, and plaster of Paris, resting on a bed of plastic wax, were deformed in a similar manner, with a view more particularly to ascer- taining under what conditions of pressure overthrusts such as those which were being discovered in the highlands of Scotland would be de- veloped.® | | Among some of the important results which he obtained were the facts that overthrusts did not necessarily originate in the disruption of over- turned folds, but were often produced directly by horizontal thrusts, and that a deep lying overthrust might pass upward into an anticlinal fold and thus never come to be visible as an overthrust at the surface. Daubrée,® Pfaff,” Meunier,® Schardt,® Reyer,*® and others carried out > Experimental researches in mountain-building. Trans. Roy. Soc. of Edinburgh, yol. Xxxv, 1888, p. 337. ® Loc. cit. 7 Der Mechanismus der Gebirgsbildung. Heidelberg, 1880. 8La Géologie Expérimentale. Paris, 1899. ®9 tudes Geol. sur le Pays-d’Enhaut Vaudois—3’ partie, A. Mechanism des Disloca- tions. Bull. de la Soc. Vaudoise des Sciences naturelles, 1884. 10 Geologische und Geographische Experimente. Leipzig, 1892-1894. Ursachen der Deformationen und Gebirgsbildung. Leipzig, 1892. GROWTH OF EXPERIMENTAL SCIENCE 177 experimental work on the same lines, directed to the solution of special phases of the complex problems presented by the intricate structure of folded mountains. . Mellard Reid," on the other hand, investigated the action of heat, in the development through expansion and flow, in sheets of lead and other metals, of structures analogous to those displayed in many mountain ranges. These led up to the more extended and important investigations car- ried out by Bailey Willis.” In these investigations, employing a machine of the same general type as that used by the earlier experimenters and layers of wax of different degrees of plasticity, moving by tangential thrust and under a vertical load produced by a heavy layers of shot, which consequently adjusted itself to the varying form and inclination of the folding surface, Bailey Willis studied the deportment under different conditions of load of a series of thin beds, a succession of thick beds, and of a sequence of thick and thin beds. He ascertained the very important role played by stronger layers in transmitting thrust for long distances and developing competent arches, and also the marked manner in which the whole character of the folding was influenced by initial dips in a stratified series. This study served to throw very important light on the mechanism of the development of the type of folding displayed by the Appalachian Mountains. A further advance was made in this line of experimental work by Paulcke** in 1912. The aim which Paulcke set before him was to repro- duce in his experiments the types of structure displayed by certain speci- fied mountain ranges, and having learned how to reproduce each type at will, to analyze the precise causes which determine the development of one or other type of structure, as the case may be. He selected for study three types of mountain structure, namely, those of : 1. The Jura. 2. The western Swiss Alps. 3. The eastern Lepontine Alps. Employing an apparatus similar in a general way to that used by Bailey Willis, he succeeded eventually in being able to reproduce at will any one of these structures, and ascertained from his experimental work that the development of the differences which characterize these several 11 The Evolution of Barth Structure. Longmans, Green & Co., London, New York. and Bombay, 19038. ‘ 2 'The mechanics of the Appalachian structure. U.S. Geol. Survey, 13th Ann. Report. Washington, 18938. 18 Das Experiment in der Geologie. Karlsruhe, 1912. 178 F. D. ADAMS—EXPERIMENT IN GEOLOGY types of structure is determined, in the first place, by the petrographical character of the sediments within the complex—that is, their relative hardness—and their position in relation to one another. Im the second . place, by the character of the basement on which the sedimentary strata le, and,thirdly, by the amount of vertical loading to which they are sub- jected during the action of the tangential thrust. Paulcke’s work thus in certain directions develops the principles dis- covered by Bailey Willis and represents the last of a series of experimental studies which have thrown much light on the mechanism of mountain- making. But while much light was being thrown on the mechanics of mountain- building by the experimental method, another and extremely obscure, but highly interesting, group of phenomena was attracting attention, namely, the movements and changes which take place within the sub- stance of the rocks themselves when subjected to these enormous forces by which they are folded into mountain chains. The results of these forces are seen in their most striking forms in those rocks which have been buried in the deeper parts of the earth’s crust, where these forces act most intensely. The phenomena are those of schistosity or foliation, rock-flow, and the accompanying aspects of metamorphism. The schistose, foliated, or gneissic structure displayed by these rocks was formerly regarded as an imperfect or partially obliterated bedding. Fox,'* however, in 1837, claimed to have determined experimentally that a current of electricity passed through damp clay would render the mass schistose, and on the basis of this observation for a time many of the lead- ing geologists looked to electric charges passing through the earth’s crust as a probable cause of the development of schistosity. Sorby,'° however, on the ground of a microscopic study of these schistose rocks, pointed out that movements under pressure determined the development of this pecu- lar structure and showed experimentally by submitting a stiff mass of micaceous iron ore and clay to heavy pressure that in such a mixture movements under pressure would produce a distinct foliation. A number of other investigators followed up this line of experimental work, among whom may be mentioned Tyndall, Daubrée, and Tresca, and showed that under such movements in plastic masses any scaly mineral present will become orientated in the direction of the movement, giving rise to a schistose structure in the mass. 'Tyndall*® even showed that in 14 Mem. Royal Cornwall Polytechnic Soc., 1837. 15 Edinburgh New Phil. Jour., vol. lv, 1853, p. 437, and London, Edinburgh, and Dublin Phil. Mag., vols. xi and xii, 1856. 16 Comparative view of cleavage of crystals and slate rocks. Royal Institution of Great Britain, June 5, 1856. ———— GROWTH OF EXPERIMENTAL SCIENCE 179 a mass of pure wax differential pressure will develop a well defined schis- tose structure through the flattening in one plane of the minute globules of which that material is composed. But the question as to whether pres- sure alone could bring about such movements in the solid rocks of the earth’s crust remained unanswered. David Forbes,” as early as 1855, carried out a series of experiments in which slabs of rock were embedded in the floor of a blast furnace, and from these concluded that not only pressure but also heat, which effected a partial recrystallization of the constituents of the rock, was needed to produce foliation. A school of later observers, again, have held that the foliation of the erystalline schists is a phenomenon due to a process of solution and re- deposition of the constituent minerals of the rock under conditions of pressure in the presence of moisture. | While, therefore, all observers agree that pressure is an agent in the production of schistosity or foliation, the relative part played in this process by pressure, heat, and solution has remained a matter of indi- vidual opinion. When mapping the very extended area of Precambrian rocks embraced by the Haliburton and Bancroft region of the Laurentian peneplain in southeastern Ontario, this ancient question as to the part played by these three factors respectively in the development of the foliated or gneissic structure, which is seen almost everywhere in more or less pronounced _ development over these thousands of square miles of glaciated exposures, continually presented itself. It was impossible to solve the question by the closest and most atten- tive observation in the field or by the most careful petrographic study of thin-sections of the rocks themselves. It seemed, however, that some light might be thrown on the problem by the aid of further experiment, for in experimentation it might be possible to separate the three factors of pressure, heat, and solution and investigate the action of each sepa- rately. It was evident from the field study that the limestones of this ancient complex were the most plastic element in the series and yielded most readily to the forces which had produced movement with its concomitant development of schistosity. It appeared, therefore, that this rock would lend itself most readily to trial by experiment. Pressure alone was first employed. And in order to reproduce the con- ditions of pressure found in the earth’s crust, a differential pressure— 17 On the causes producing foliation in rocks. Quart. Jour. Geol. Soc., 1855, p. 184. 180 F. D. ADAI that is to say, a pressure from all sides, but much greater in one direction than in the others—was required. This condition was secured by inclos- ing very accurately turned and polished cylinders of Carrara marble in heavy tubes of nickel steel of peculiar form and fitted with pistons of chromium tungsten steel. - It was found that by the application of differential pressure alone a perfect deformation of the marble was obtained—the rock flowed as a column of soft metal might. If the movement was allowed to go forward very slowly, the rock was deformed without loss of strength. The action of pressure combined with heat was then examined, and it was found that when the rock was heated to 300° C. or 400° C.—a heat which is too low to disassociate the molecule—the movement takes place more readily, and may therefore be carried out more quickly without impairing the original strength of the rock. The third factor, that of moisture, was then introduced and the rock was slowly deformed through a period of two months, while maintained at a temperature of 300° C. and with steam being forced through it while the deformation was going forward. The presence of moisture in this experiment was found to produce no noticeable effect; the character of the deformation was identical with that where pressure and heat alone were employed. A study of thin-sections of the deformed limestone, moreover, showed quite clearly the nature of the movement which had taken place. It was a movement on the gliding planes of the individual calcite crystals com- posing the rock, accompanied by a fine polysynthetic twinning, each of the original grains becoming in this way elongated, so that a schistose structure was developed in the rock. This structure, furthermore, is exactly that which is displayed by cer- tain of the limestones of highly contorted regions, so that we have experi- mental demonstration that in these cases pressure alone would i been quite adequate to produce the phenomena observed. Leaving this question of the deformation of marble, we may turn to other rocks. When various impure limestones, such as those which are commonly found in the Paleozoic and Mesozoic succession, were examined, it was found experimentally that they could also be deformed by simple pres- sure, with a development of the same schistose structure. This is also true of alabaster, steatite, serpentine, and other of the softer rocks. With the harder rocks, such as granite, diabase, and essexite, it was again found that pressure would produce a deformation of the rock with the development of a schistose or foliated structure. In these cases, also, GROWTH OF EXPERIMENTAL SCIENCE 181 the deformation was distinctly facilitated by heat (350° C. to 450° C.). The structure, however, was no longer developed by a movement on the gliding planes of the constituent minerals, but was produced chiefly by a granulation of the minerals and the alignment of the granules in the plane of the schistosity thus developed. The structure is identical with that seen in mylonite and many augen gneisses, so that experimental proof is afforded that such rocks may be produced in nature by the action of pressure alone, but that the development of the structure is more readily effected if the rocks are hot. So far as these types of rock are concerned, then, schistosity or fohation may be produced by pressure alone, without heat and in the absence of moisture. To recur for a moment to the deformation of marble. _ It will be found that when most of the foliated or schistose limestones which occur in nature are examined under the microscope, they show little or no evidence of pressure phenomena, such as those above described. The rock frequently presents the appearance of a mosaic of equidimen- sional grains, such as might be expected to have been developed by an original crystallization of the material. The schistosity in these cases is produced by an alternation of thin lamine of larger and smaller indi- viduals of calcite or by the parallel arrangement of other minerals exist- ing as impurities in the rock. A schistosity of this character, which is to be observed not only in lime- stones, but in very many other crystalline schists, has by most authors been regarded as susceptible of explanation only as being due to recrys- tallization of the rock, through the agency of moisture present in the rock as the deformation was going forward. Some very interesting ex- perimental work which has been carried out in recent years in the Geophysical Laboratory in Washington has, however, a very important bearing on this question. Reference has already been made to the experiments of Sir James Hall, in which he obtained a white crystalline marble by heating chalk under high pressure, experiments which were repeated later by Gustave Rose and the results confirmed. Hall believed that this change was due to a partial or complete fusion of the marble with subsequent crystallization on cooling. : | It has recently been found, however, that if finely powdered or loose, finely crystalline aggregates of a mineral which is not destroyed by heat are submitted for a considerable time to a temperature which, while high, is still considerably below the fusion point of the mineral, the powder will become progressively coarser in grain. The mineral slowly volatil- ee EE es. ee See: i) 1 1 | 182 F. D. ADAMS—EXPERIMENT IN GEOLOGY izes and the loss from the various grains is, of course, proportionate to their surface area; the smaller grains, having a surface area relatively great as compared with their mass, have a tendency to decrease in size and disappear, while the larger grains, owing to their greater mass, con- _ dense this vapor on their surface and thus increase in size under the operation law of surface tension.*® The process is essentially the same as that which takes place when a very fine-grained precipitate of, for mstance, barium sulphate is kept warm for some time before filtering, the grain of the precipitate thus coarsening by a process of solution and deposition. This coarsening of finely divided silicates by submitting them to a high temperature when in a state of very fine powder is now, I am informed by Dr. F. E. Wright, regularly employed at the Geophysical Laboratory in Washington for the purpose of obtaining from such fine-grained aggregates crystals suffi- ciently large for purposes of crystallographic measurement or for the determination of their optical properties. ‘The process in the case of many minerals goes forward quite rapidly. Now this fact, experimentally determined, has probably a very impor- tant bearing on the question of the origin of the metamorphic rocks in general, and especially of those crystalline schists which present the mosaic structure to which reference has been made above; for the ma- terials out of which they have been developed were fine in grain and erys- tallized not only under great pressure, but when deeply buried and there- fore at a high temperature. In many cases they may have been subjected to long-continued heat after the parallelism of constituents had been de- veloped in them by movements under pressure, in which case this coarsen- ing of grain with the final development of a mosaic structure, amounting practically to a recrystallization of the mass, would result. This is a new principle in metamorphism, but one which is probably of wide-reaching significance. It may be noted in this connection that any malleable metal, when made to flow by rolling or hammering, is deformed by the elongation of its constituent grains through movements on their gliding planes, the hammered or rolled metal thus taking on a structure identical with that in the marble deformed by pressure in the experiments mentioned above. If the metal is then heated and allowed to cool slowly, this fibrous struc- ture completely disappears and is replaced by a typical mosaic structure identical with that ordinarily seen in natural marbles. Under this treat- ment a complete recrystallization of the metal takes place in the space of a few minutes and without the point of fusion being even approached. 18 See also Justus Roth: Allgemeine Geologie, Bd. iii, 1, p. 154. GROWTH OF EXPERIMENTAL SCIENCE 183 In this connection the experimental work carried out by Spring’® should be mentioned. Although certain of Spring’s results have been called in question by Friedel’? and Jannettaz,”* the whole field has been reviewed by Johnston and Adams,?? of the Geophysical Laboratory at Washington, and the bearing of Spring’s work clearly set forth. Spring has demonstrated that under high pressure certain substances unite chem- ically with the production of new compounds. Thus copper and sulphur when compressed to 5,000 atmospheres unite to form a black crystalline ~ cupreous sulphide, while barium carbonate and sodium sulphate yield under a pressure of 6,000 atmospheres barium sulphate and sodium car- bonate. Johnston and Adams, however, have pointed out that a careful distinction must be made between simple cubic or hydrostatic compres- sion and differential pressure which gives rise to a shearing movement or flow within the mass. The former produces but little effect in developing chemical change ; the latter, however, does in many cases produce impor- tant alterations in chemical composition and is in a way analogous to a ‘long-continued grinding together of the reacting substances in a mortar. ‘In some cases the apparent interchange may be due to a process of diffu- sion occurring between the particles of the two substances brought into intimate contact by the pressure to which they are submitted. We have, ‘by submitting a mixture of certain salts to such differential pressure, giving rise to flow, obtained foliated structures with a development of new compounds, which reproduce in a striking manner certain structures seen in the crystalline schists of highly contorted portions of the earth’s crust. _ Another very important fact is that when minerals of an acicular habit are developed in a rock which is undergoing deformation by differ- ential pressure these new minerals grow in the mass with their longer ‘axes orientated at right angles to the direction in which the pressure is being exerted, as shown by the experiments of F. E. Wright?* on certain glasses which were allowed to crystallize when flowing under differential pressure, as well as by a series of experiments by the writer, the results ‘of which have not as yet appeared, in which gypsum is converted into a lower hydrate while submitted to heavy differential pressure. In these cases crystalline rocks result, showing distinct foliation, the plane of this _ © Recherches sur la Propriété que possédent les corps de se souder sous l’action de la Pression. Revue Universelle des Mines (and many other papers). _* Bull. Soc. Chem. (2), vol. xxxix, 1883, p. 626. meeeibid, (2), vol. xl, 1883, p. 51. _ #On the effect of high pressures on the physical and chemical behavior of solids. Am, Jour. Sci., March, 1913. : *% Schistosity by crystallization—a qualitative proof. Am. Jour. Sci., Sept., 1906. XIV—Bu.Lu. Grou. Soc. AM., Vou. 29, 1917 184 F. D. ADAMS—-EXPERIMENT IN GEOLOGY foliation being at right angles to the direction of the force producing the movement. In all these cases, therefore, schistosity is produced by pressure or by pressure combined with heat, but in the absence of moisture. The question of the part played by solution under pressure in the de- velopment of the crystalline schists is one of great importance. Speaking - generally, when a crystal is strained its solubility on the strained face is increased. Consequently a strained crystal in contact with a saturated solution of any solvent dissolves on the strained faces and is redeposited where there is no strain. It would thus seem that in the presence of moisture great differential pressure, even at low temperatures, might if long continued effect a gradual recrystallization of a massive rock with the development of a foliated or schistose structure in a direction at right angles to the direction of maximum pressure. Becke, Grubenmann, and others have seen in this conjectural process the chief factor in the devel- opment of great series of crystalline schists which are met with in the Alps and elsewhere and whose structure they designate as “Krystalliza- tionsschieferung.” This process of solution which seems to have taken place, in some cases at least, and to have resulted in the development of a schistose structure in the rock, has not as yet been submitted to investigation by experiment. The phenomenon attributed to it may have been produced by recrystalli- zation induced by pressure and heat. Enough has been said to show that it is impossible in the present state of our knowledge to determine in every instance the relative importance of the réle played by pressure, heat, and solution in the development of a body of crystalline schists. Some progress has been made in this direc- tion, but there is still a very wide and fruitful field open for experimental work. It would be a much appreciated boon if by such investigation it were possible to rescue our successors from that state of despair described by Sharpe “as the first impression of an observer entering a district of gneiss or schists in search of order in their arrangement.” I have dwelt at some length on what is really a single great field of experimental effort—that, namely, which has as its goal a correct under- standing of the manifold phases of the action of pressure, heat, and solu-— tion as displayed in the mechanism of mountain-making and in the de- velopment of the crystalline schists, which is another and accompanying manifestation of the same agencies. | There are, however, many other lines along which experiment in geol- ogy has made Hous conquests: and in which brilliant results have been. achieved. GROWTH OF EXPERIMENTAL SCIENCE ie hoo Time does not permit me to do more than merely enumerate a few of these. Among the best known of these is the work of Fouqué and Lévy,?4 Morozewiez,”* and others on the synthesis of igneous rocks and the eluci- dation of the processes and conditions under which the crystallization of these rocks go forward. The studies of the melting points of the rock-forming minerals, their solubilities in silicate inagmas, of eutectic mixtures, and magmatic differ- entiation, carried on by the staff of the Geophysical Laboratory im Wash- ingtoii, by Doelter?® and his pupils, by Vogt?* and others. The investigations which have been made in recent years into the true nature, mineralogical composition, and chemical relations of that great series of artificial rocks which are daily coming to be of greater impor- tance in the arts of peace and war—the cements. The extended investigations which are now being carried on im the Geophysical Laboratory, in elucidation of the field studies of Graton, into the composition of copper ores and the problems of secondary enrich~ ment—investigations which are not only of great significance from the standpoint of pure science, but which promise to have a far-reaching economic value. | As examples of Spamentdiue in very different fields, the work by Gilbert?® and Murphy on the transportation of debris by running water, that of Andrée,”® Lang and Peterson*® on the laws of geyser action, and that by Daubrée®* on the development of joints and fractures by torsion may be instanced, THE FUTURE OF EXPERIMENTAL GEOLOGY Looking into the future, it is clear that the great conquests which await experimental geology are to be won through the application of accurate measurement to all experimental work. We are passing from the quali- tative to the quantitative in experimental geology. To carry out such exact investigations in the regions of high temperature and great pres- sure, by which alone we can hope to unlock the secrets of the earth’s crust, will require not only able workers—men of skill, resource, and imagina- id °4 Synthese des Minéraux et des Roches. Paris, 1882. 2 Tscher. Mitt., 19, 1, 1899. *6 Handbuch der Mineralchemie. Dresden, 1912. 27 Die Sjjikatschmelzlésungen. Christiania, 1903. 8 U. 8. (Geql. Survey, Professional Paper No. 86, 1914: Newes Jahyp. fiir Min., Bd. 2, 1893. * 30 Neues Jahyp. fiir Min., Bd. 2, 1889. ™ 51 Hides Synthetigues de Géologie Expérimentale.. 7 It i ; a a = =. =A 186 F. D. ADAMS—-EXPERIMENT IN GEOLOGY tion—but very elaborate equipment and large endowments. The chief advances, therefore, are to be expected from great laboratories equipped for this special work, such as the Geophysical Laboratory of the Carnegie Institution at Washington, to which frequent reference has been made above, and from which, under the direction of Doctor Day, and with in- vestigators of such distinction as F. E. Wright, Washmgton, Sosman, Johnson, Bowen, and others who have been and still are connected with its staff, a continuous series of publications of the highest value has issued, which, being based on the results of accurate observation and exact measurement, will remain permanent contributions to geological knowledge. By such investigations petrology will be made an exact science, and it is difficult to overestimate the advances which may be thus made in many other branches of geology in that new era to which Daubrée** refers in the closing sentence of his great work on metamorphism, when he says: “Géologie a enfin abordé une nouvelle période ot elle s’éclairera dans ses phénoménes de tout ordre, chimiques, physiques et mécaniques, par lexpéri- mentation synthétique, subissant ainsi des phases analogues a celles que la physique a traversées pour arriver, de l’état ot la prit Galilée, au point ou nous la voyons aujourd’hui.” 32 Htudes et Expériences synthétiques sur le Metamorphism. Paris, 1860. , OFFICERS, 1918 y President: WHITMAN Cross, Washington, D. 2 J : ick ee, Vice-Presidents: ines Wits, Stanford Shavers - Frank LEVERETT, Ann Arbor, Mich. F. H. Knowtton, Washington, DiC. on i Secretary: | Bosco Onis Hoven ‘American Museum of Natural History, eaien. York jae pe get Me are © y ee a: 7 ' ~ : Yt A Say "Treasure: s K \ . “Rditor: . “i ‘Sraxty Brown 26 Exchange Blace, New York, N. Mai \ - - we Librarian: , f. R. VAN ; Horn, Cleveland, Ohio ‘ Councilors: 1 (es expires 19 18) ae DP iakgh B. Taytor, Fort Wayne, Ind. _ CHARLES ES BERKEY, New York, Ne ¥ 7 “ , — ~ . wee (Term see 1919) ~ Artuur L. Day, Washington, D0. | Winrra Hi. Emons, oe Minn. vey ; Bs ym +4 Bes (Term expires 2s 1920) ane * 9: osEPH Barrett, New Stipa: Goa By oa R. AL Daty, Cembrigee, Mass, eae “ee ; : e — - Geological Society of America ~ a Le eae 7 lhe 4 a Pp Sadi VOLUME 29 | NUMBER 2 JUNE, 1918 ee va a | \ ss PUBLISHED BY THE SOCIETY ee __- MAROH, JUNE, SEPTEMBER, AND DECEMBER aery ag ¢ CONTENTS 3 : Page Post-Glacial Uplift of Northeastern America. By Herman L. Paarchild =.= +220 Seats 2 eee ee ot ss ee Explanation of the Abandoned Beaches about the South End of Lake Michigan. By G. Frederick Wright ~ «+ “s = ~ | 235-248 Age of the American Morrison and East African Tendaguru For- mations. By Charles Schuchert - - - - - - - - - 245-280 Meganus Group, a newly Recognized Division in the Eocene ; of California. By Bruce L. Clark - - - -- - - ~- - 281-296 Marine Oligocene of the West Coast of North America. ~ By Bruce L. Clark and Ralph Amold - - - - - - - - 297-308 Amsden Formation of the East Slope of the Wind River Moun- tains of Wyoming and its Fauna. By E. B. Branson and 6 D. K. Greger - - - = - = = = = = «=. = = 309-326 : Stratigraphy of the New York Clinton. By George H. Chad- = wick =- - - - - + S202 == = - - = = = @327-366 Scope and Significance of Paleo-ecology. By Frederic E. Clem- — ents-9 - - = 4 2 Be eee ee = Gere BULLETIN OF THE GHOLOGICAL SOCIETY OF AMERICA : Subscription, $10 per year; with discount of 25 per cent to institutions and ; libraries and to individuals residing elsewhere than.in North America. Postage aay) to foreign countries in the postal union, forty (40) cents extra. : a Communications should be addressed to The Geological Society of America, care of 420 11th Street N. W., Washington, D. C., or 77th Street and Central Park, West, New York City. NOTICE.—In accordance with the rules established by Council, claims for non-receipt of the preceding part of the Bulletin must be sent to the Secretary of the Society within three months of the date of the: receipt of this nymber in order to be filled gratis. fe: Se ee t RNP Gee Fg eve 2 ‘oe avs . . has Entered as second-class matter in the Post-Office at Washington, D. C.-~— under the Act of a of July 16, 1894 Acceptance for mailing at special rate of postage provided for in Section 1103, Act of October 3, 1917, authorized on July 8, 1918 PRDSS OF JUDD & DETWEILER, INC., WASHINGTON, D. C. | cD, 0 Ae oe Pr + en eee = el ~ ~ & i 7 ee eee cee eae te ee Dig Sy wn oe “ : 4 ties iy © fi ae } oe BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA x VOL. 29, PP. 187-238, PLS. 9-17 JUNE 30, 1918 | POST-GLACIAL UPLIFT OF NORTHEASTERN AMERICA? BY HERMAN L. FAIRCHILD ' (Read in abstract before the Sociely December 27, 1917) CONTENTS , ' Page SSG, eo tag. ee ag gC A Or 187 EEE SDAIN ae OB NCE. oo. oh. 'S usa cso. ana’ o./0.J0 M4 S'S, MralasecG sho pee cud Co le.w 6, oes 189 Savemacror getermination of water levelS....... 0600. 600s cee cee wees 190 . Wigssmication and discussion of the criteria..... 5.2.00. 6. cece we eee ale 190 ¥ OUTER (SLES IS ioc (Ree nena gt aa GP age Ie ee CP e Re Aine OR an vee ow . SCT eaCR RENN CL, ok celia eka, ao) Likes acai Beles Bid g WAS ERMC iE SA brs ale 193 ‘ Petseiml Waters... osc... ae wes eit eaten ltl oo saa op en chattel Se A seem Ered Se 193 F RR ERE Me ech ene ea mars) SG wo bia bs aleie dh dia Cais Oe Miata eee 195 Paieraiowwetcer plane On Geltas.. 6. ov cece oe bk ees se bee vn eed 8s MOG Cte Walley Plains... occ ke od). ek ede v ees ceeud vacated fules swale 197 eeenee ot marine LOSSiIS! . 0.660 oc ee os ee ee a ees nea Ren et at '3t, Wie 199 ROME, STOEG! OHEMLULES «cco re ns ac as o's Some aie tha OSie 6 de whee aed s o's oe 199 MOTT. WCE AUETEINOG:. 2.s-5 ost sade 4 aie wwe ale ollions ol leals ww ardag eed 664 200 III ee eric Stree gE 2 o Me ial aiwiaa a kas Soak ad evar ah eae RE Toad Water enumerate 5 Oh yy AuD! helarion of land uplift to ice recession... .......06.6 0 wee jae Sing Snr 205 mammeermearedn Ievel... we ee ee ee pe eee ee ae eh erat ye ee 205 aaa and description Of new Gata. iis. coheed ee nt ee ele cece ae 207 Eee MED A USCUSSION a\.06. eels «ane ov v0 (66h so) ol Sie nel oe ofegeyeubyaye = « abo lohan great 207 | ° j MAC OMA IT WAP UNOW. v5 cscs: ui djersbece, Soa ast coatoue oWeterawla eoMiguarareard.e wes ©. atk! 208 Reta ANN UEVENUEE TIGL. coc oe. bdo See O ocaral bE NE APIO oP OLS Mae WR aie oats 208 : MIMI riety sh aie sd to's Me re STA eR AA See Ob A esl. aut | Ce Rh: | hair Gk SE 210 Pmner Saint Lawrence and Ottawa valleys. ...3 06. cnew ese we sees ees 214 Lower Saint Lawrence and Gaspé Peninsula.............-..eee008. 215 ' MME NUE SEER hoc aa. sig cua “as eke cad wit'o ok ols ee to WARES RR ae) SAT ianle Rip me Mole Bache ia. co euelars 220 4 ISTE TE a RS ler ie RE ST Ds Rad CIN ee tesa 222, 5 agree ane Newfoundland: ....) 0... +0. mu damoran wcohey es amice ts 226 TRS LT s.r aati dg: Sekt > in, SPA Wei'g x a dA nla Rd a eR ae Gy a 229 a. INTRODUCTION . For over half a century the certainty of some post-Glacial submergence - of northeastern America has been recognized, yet the maximum submer- | 1 Manuscript received by the Secretary of the Society January 14, 1918. XV—BULL. Grou. Soc. AM., Vou. 29, 1917 ’ (187) ‘§ A, : - : : Ararat a 4 JANZ11919— FAM 188 H.L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA gence or, conversely, the height of the subsequent uplift and the limits of the affected area have not been determined. In recent years there has been a tendency to minimize the diastrophic movement and even to deny its occurrence along the south border of the glaciated territory; but Pro- fessor Shaler believed that Marthas Vineyard had been submerged 300 feet and Mount Desert 1,300 feet, and several eminent geologists have found abundant and positive proof of Pleistocene submergence of the lower Hudson Valley and New Jersey (see number 84 of the bibliographic list, page 288). The radical difference-of opinion on a subject open to direct observation is a problem in psychology. Canadian geologists have-recorded many localities of marine fossils at high altitudes in the Saint Lawrence and Ottawa valleys and eastward, with the other attendant evidences of standing water. Similar evidence is abundant in New England, but at less altitude. This proof of deep submergence while the Labradorian ice-sheet was passing off led the earler geologists to overemphasize the work of floating ice and icebergs in the explanation of glacial phenomena. The later recognition that most glacial features are the effects of land ice has resulted in the com- parative neglect, especially by geologists of the United States, of the fact of deep marine submergence. With emphasis on direct glaciation, we have neglected the observations of the “diluvialists’ and “icebergists” and have minimized the effects of oceanic waters. However, it must be admitted that in the deep marine waters of the valleys of Canada and New England the students of half a century ago had good basis for the theory of iceberg agency. In the recent examination of eastern Canada and New England? the study has been systematically extended from an area in which the post- Glacial uplift had been well determined. The Hudson, Champlain, Saint Lawrence, and Connecticut valleys hold a clear record of the earliest and deepest sealevel waters and afford a long base-line for the extension of the isobases. In the Hudson-Champlain depression is inscribed a record of Pleistocene history for all the time during which the waning Labradorian glacier lay on any part of the United States. On this meridian the tilted uplift has been determined as over 800 feet on the north boundary of Vermont. The results of previous study are on record in papers numbers 81 to 85 (see bibliography), but the detailed description of the critical features in New York is awaiting publication by the New York State Museum. 2The writer makes grateful acknowledgment of financial aid from the researeh fund of the American Association for the Advancement of Science. PSP? eae oe ee ee me REVIEW OF STUDY METHODS 189 MernHops or Stupy The failure to determine the facts relating to Pleistocene submergence and to reach agreement in opinion must be due either to inherent diffi- culty of the study, or to defect in methods of study, or to lack of clear, unbiased vision. Probably all of these factors contribute, but especially the second. A discussion of study methods is in order. (1) Successful attack of the submergence (uplift) problem requires correlation of data over the entire glaciated area, but the studies have usually been local and detached. (2) Equality of uplift over considerable area has too often been as- sumed; but this is impossible, except perhaps in the central area of the upraised dome. } (3) Systematic exploration must postulate an irregular doming up- lift, with the horizontal lines of equal uplift (isobases) curving about the convexity and with declining gradients in radial directions. The gra- dients on the radii must diminish to zero both at the margin and near the center of the domed area. (4) The critical element everywhere is the maximum uplift in each location, the determination of the initial or summit shoreline. This is the difficult and elusive element, and most recorded elevations give only the conspicuous, inferior phenomena. (5) For any district a working theory is needed of the approximate direction and spacing of the isobases or, in other words, the direction and gradient of the steepest slope. Then the location of two positive stations on the summit level affords a reference or base for further search, and with accumulation of data the search becomes proportionately easier. For success in determining at least approximately the total uplift over a large area the writer has relied chiefly on criteria not generally recog- nized. Instead of depending on bars, cliffs, and features of wave work, which are excellent when found, but which are capricious, commonly wanting, and rarely produced as initial or summit inscriptions, he has depended primarily on stream deltas. These are almost unfailing and are positive indications, even if not very precise, of the initial water plane. In a new or unknown district the primary determination of the approxi- mate level is made on larger streams, preferably in south-leading valleys, and the more precise determination of the summit water level is made by examination of the smaller deltas of lateral streams and the shore features in the vicinity. As the railroads, with their elevations giving datum for altitudes, nearly always follow river valleys,.it has been feasible to tra- verse rapidly a large territory with positive results. A proof of the sound- 190 4.L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA ness of the method and the truth of the results is the fact that in many cases predictions of the location of deltas and of the height of the summit plane have been closely verified. In his discriminating and admirable work on the surficial geology of Maine, Mr. George H. Stone recognized the utility of deltas in determi- nation of water planes (68). He writes, page 483, as follows: “. . . If we should find a great change in the coarseness of the sediments taking place within narrow vertical limits, proving considerable slowing of the waters at that point, and especially if this were observed in several valleys at the same relative position to the lines of highest elevation, as determined by observation of the coast beaches, we should have probable proof that the streams of the land poured into the sea at those points. Thus far I have not been able to apply the method satisfactorily, in part owing to the rarity of known elevations in these valleys. Where the streams were large compared to the breadth of the valleys it is doubtful if this method can be applied with certainty. The broader and shorter valleys off the lines of the glacial rivers are the most promising cases for the application of the method.” The discrimination and caution observed in the use of deltas for find- ing water planes will be described in the next chapter. CRITERIA FOR DETERMINATION OF WATER LEVELS CLASSIFICATION AND DISCUSSION OF THE CRITERIA A brief discussion of shore features and the character of the primitive or summit marine plane and the criteria employed in their study will clarify this subject. In the order of importance or usefulness the classes of features which may be used for the location of static water levels are listed as follows: Stream deltas. . Bars; wave-built embankments. Wave-erosion lines; cliff and terrace; boulder fields. . Drift-denuded surfaces; bare-rock areas. . Wave-smoothed stretches; leveled kames and sand-plains. Valley plains. Marine fossils. Hs 09 2 ZD The second class—bars of cobble, gravel, or sand—is the least common in occurrence, but is ranked high because of the unequivocal, positive character and reliability for even the less experienced student. However, by themselves bars are no conclusive proof of initial or summit level, even if they he against slopes which offer no evidence of higher stand of waters. Such negative evidence is unreliable. It is a mistake to rely CRITERIA FOR DETERMINING WATER LEVELS 191 wholly or even mainly on features of wave construction or wave erosion— classes 2 and 3. At the initial or summit level of the sealevel waters with the short life of the latter, these are the rarest of features, but when found are, of course, conclusive proof of standing water. The same is true of number 7; but it must be understood that marine fossils never mark the initial water level and are usually far below, 100 or 200 feet. For close determination of the standing water surface, heavy deltas, those of vigorous and well loaded streams, are not so precise criteria as bars and cliffs. - But their practically unfailing occurrence at the highest or initial water level makes them more useful over large areas, and for long distances in comparison of far-separated valleys they are sufficiently accurate. Because of their more common occurrence, the classes 3 to 6 are more useful, taken together, than class 2 for the geologist with experience in shoreline study; but they are less definite and often equivocal, and ex- perience and skill are required for confident use. They may vary in char- acter with the lithology, the nature of the drift, and the topography of a district. When well determined they have value at least as showing minimum uplift, which is all that classes 2 and 7 give. The best use of these features is for confirmation of the. shoreline over intervalley areas or between more definite features. SUMMIT DELTAS By far the most useful class of shore features in locating summit water levels is stream deltas, the deposits built at the debouchure of streams in static waters. They are practically certain of production at the initial level of the receiving water body, are scarcely ever wholly destroyed, and are quite unmistakable. Any possible conditions that might inhibit con- struction of deltas in the far-inland valleys must be exceedingly rare. In the large sense this class of deposits might include the broad valley plains of river detritus built in lowering waters in the downstream sec- tions of an uplifted main valley. But the term as here used is meant to cover only the more or less localized bodies of coarse detritus which have an evident genetic relation to the work of some living or extinct stream, without distinction of shape, size, or composition. It is a matter of origin by interaction of flowing and static water. Perhaps an addition to our terminology is desirable. The mistake has been made of regarding broad sand or silt plains as marking the highest or summit level of the standing waters. Except as lateral floodplains, such fine detritus is not dropped near the water sur- face. The broad, smooth plains are nearly always of inferior level. In 192 H.L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA wide valleys where waves were competent to distribute detritus, or in con- stricted valleys where the volume of the river was sufficient to produce some current in the estuary, the plains could not form at the water sur- face. ‘The phenomena of the initial or summit level may be miles away, far inland, and much higher in altitude. | When extensive delta sand-plains are used as criteria for summit levels they must be judged by the local or neighboring conditions and no special rule or quantitative expression can be given. Many factors are involved: the volume and velocity of the contributing stream; the volume and character of the detrital load, and the capacity of the water body, with the topography of the under-water slope. The small! deltas built by little streams, even wet-weather runs, in quiet or shut-in waters are much better indexes of the precise level of the stand- ing water than the heavy deltas of large streams or the broad plains in the open valleys. Of course, these small deltas require sheltered locations, where waves and shore currents are incompetent to remove the delta stuff. The tiny benches, perhaps only rods or yards in area, on the border of small ravines or gullies give the true summit level of secluded waters; and even on the walls of exposed valleys the small-stream deltas may be the best criteria of the primitive water surface. Such small features have commonly been ignored, because they were small and inconspicuous, de- tached, usually inland, and not evidently related to the obtrusive features of the great valleys. The deltas of the higher levels in the lateral or inland valleys have been attributed to glacial waters, local ice-border lakes, or pondings due to ice-lobes, and consequently have been slighted. The fact that under certain conditions glacial lakes faced the receding ice-margin certainly requires that caution be used in the study of the water levels, especially — in north-sloping valleys. In this study the main reliance is placed on streams with southward flow, or having such direction and relation to the large topography as to avoid blockade by any lobation of the ice-front. Deltas and channels of glacial drainage are most positive records of the initial water level. The ice-border streams were ephemeral and they dropped their detritus in the waters that laved the ice-margin, which were then at maximum altitude relative to the land. Sand-plains which can be correlated with extinct glacial streams that debouched in marine estu- aries must give the primitive water level. In the Hudson and Champlain valleys the glacial stream channels and deltas have afforded excellent, precise data. DISCUSSION OF CRITERIA FOR DISCRIMINATION 193 DISCRIMINATIVE CRITERIA GLACIAL WATERS The study and explanation of puzzling or equivocal features, like high- level sand-plains, appears to have been evaded by referring them to the limbo “glacial.” The term is overworked. It is unscientific to attribute such plains and unexpected shore features to glacial waters without prool, and it is unfair when other explanation has been given. It seems neces- sary to discuss the criteria for discrimination of the glacial plains. In valleys declining northward, or in any direction toward the waning ice-sheet, ice-impounded or glacial waters were certainly held. This may also be true of some valleys with only a part of their course so oriented — as to permit temporary blockade. The Androscoggin Valley is a possi- ble example. In all such valleys high-level deltas and shore features are regarded with suspicion and are not used as evidence of sealevel waters, at least not without careful discrimination. Many such examples of ice-damned valleys are found on the north-facing slopes of the basins of the Great Lakes and on the south wall of the Saint Lawrence Valley in New York, Vermont, and Quebec. Many of the glacial lakes in New York have been the subject of published papers. Glacial lakes were practically impossible in the great south-leading valleys like the Hudson and Connecticut, the reasons being given in a former paper (84, pages 291-292). The same is true of all valleys which were normal to the glacier front and opened freely seaward, like those of Maine and New Brunswick. The glacial waters, which were temporarily held in embayments of the walls of large valleys, like the Hudson, Penobscot, or Saint John, did not commonly produce any important features or any difficult of diagnosis. Deltas and short features in the lateral valleys are the only ones of doubt- ful origin, and of these some discussion is desirable. The damming of waters, with efficient length of life in the tributaries of the south-leading trunk valleys, required decided lobation of the ice- margin, probably to an amount not common, and something more than a low tongue of the thin edge of the ice-front. But such pondings in the lateral valleys did sometimes occur. Tigh-level phenomena above the well-determined marine level are so explained. To have a long life and steady level, so as to produce good shore features, glacial lakes, like any other class of lakes, required fixed out- lets. That means outlet over land, and such outlet should be located, if a long-lived, constant-level glacial lake is postulated under doubtful con- ditions. Most glacial waters had their outflow along the margin of the 194 H.L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA ice-lobe, as ice-border drainage, and such dams were weak and shifting. In consequence of this fact most glacial waters were ephemeral in life, inconstant in level, and sudden or spasmodic in extinction. The last con- dition is especially important. Glacial sand-plains rarely exhibit any regular succession of terraces, because of the sudden or irregular down- draining of the waters. By contrast, the ocean-level waters of the estu- - aries and their branches fell away (relative to the land) by steady, slow decline, and the sand-plains built in these waters commonly present a series of terraces, even down to the present stream floodplains. Sand-plains built in glacial waters may reveal some evidence of ‘the presence of the ice-margin; shown by ice-contacts, or by kettles, or by included till masses, and less clearly by irregular deposition and poorly assorted materials. Some deltas deposited in sealevel waters might have been built near or even against the ice-front and might contain unas- sorted materials. Any deposits made by glacial drainage, directly from the ice-front or along the ice-border, are not likely to have good delta form or relationship to land drainage, but may be good index of the sum- mit sealevel. The most important distinction between glacial sand-plains and estu- ary plains is the fact that the former, in independent, separated basins would have no genetic correspondence in altitude. A series of detached lakes, with accidental correspondence of height over a long distance, is very improbable. But, on the other hand, the plains built in the estuaries have close accordance in altitude over hundreds of miles along an uplifted and tilted water plane. Glacial waters could never have height inferior * to the sea. By chance they might be near, slightly above, the sealevel. Usually they were a recognizable distance above the marine plane, the latter being determined by a variety of positive features over long dis- tances and wide areas. A vertical interval with no, or very weak, deposits suggests the relatively sudden drop of the glacial waters to the marine level. 3 It is only the sand-plains or shore forms very close to the marine plane which are liable to confusion with the sealevel features. An example may be helpful. Many years ago Professor Davis described the delta of the Catskill Creek, built in the Hudson estuary, at South Cairo, some 7 miles from the Hudson River (Coxsackie and Catskill sheets). The relation of the Catskill tributary valley to the Hudson trunk valley might permit glacial damming in the former. The South Cairo plains have every char- acter and relationship of an estuary delta built in slowly subsiding waters. Tt may be conceded that we have no absolute proof that the Catskill waters a [QAI] OUTAVU OY} 0} pap eM ‘ya0y GE) JnNoqe sureq auerd Slegmaciael 91301003 oq} yo0y Gg), qnoqe ‘g0Bad0} zaddn au} ‘Jo apniniv SNSOOUOTMUTY IT} JO YIO\\ ‘ASVI[JA JO oSpo ysaM ‘Joos ULVPT JO [OAV] WoOAY META ‘AO[[VA OY} JO eps YINOS oy} TO avodde sa0Bato} aatuL FTUIHSdANVH MON ‘NOLAILLIT :‘SHOVaAUAL WVAULS 6 "Id ‘LI6T ‘62 "IOA ‘AV ‘OOS "1089 “TTNA ; DISCRIMINATIVE CRITERIA 195 were not glacial; but we do have the positive proof that an estuary occupied the trunk valley at the altitude of the Catskill delta, with a splendid barat Hudson Village, on the-east side of the open valley, at cor- responding elevation (84, page 290).' In practically every tributary valley on both sides of the Hudson-Champlain, from New York City to Canada, we find delta plains in precise agreement with the uptilted water plane of the open valley. Such correspondence in level in a multitude of in- dependent water bodies would be impossible. Glacial deposits at higher levels are often recognized. The Catskill delta is simply one of very many estuarine features in accordance through 300 miles of uplifted territory. Most geologic reasoning is based on the kind of cumulative evidence which we have in this case. It is possible that a few high-level features regarded by the writer as marine level may be glacial; but they are certainly exceptional. ‘he deltas and shore features marking the stand of the sea on the depressed land occur in every one of the hundreds of valleys opening to the sea. In the tracing of the marine plane many features have been ignored because of some doubt. THRRACES It is important to discriminate the terraces formed in subsiding static waters from the benchings on stream-cut valley sides. That this has not always been done is shown by the reference of terraced estuary deposits to river work. ‘The successive banks of rejuvenated streams may repre- sent floodplains that were aggraded much above the highest static water level, both in horizontal and vertical distance. The genetic distinction is necessary for the clear recognition and close determination of the sum- mit marine plane, although for long distances over the great uplifted area even the superior stream benches are useful in indicating approxi- mate levels. The description of a typical example will illustrate the topic. At Littleton, New Hampshire, the valley of the Ammonoosuc, a tribu- tary of the Connecticut, is about one-fourth mile wide. Horizontal benches are conspicuous on both sides of the narrow valley. The main street of the village is on the north side main terrace. On the south side three benches occur, shown in the photograph, plate 9. These benches are partly erosional, cut in the till, and partly constructional as flood- plain deposit. The constriction of the valley rules out efficient wave action. It is apparent that: the river flow-was up to the highest bench, some 10 to 15 feet above the railroad station, which is given as 772 feet, and that the lower lines were produced as the river fell in adjusting itself to a falling baselevel. Ads 196 H.1L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA These aggraded river deposits are at least 60 feet higher than the estu- ary levels a few miles below at Barrett and Sugar Hill, and they extend upstream over a mile to Apthorp, where the plain is about 30 feet higher than at Littleton, being given as 814 feet. Below Littleton the valley widens, with broad lateral embayments at the junction of the tributary valleys. In these embayments are high- level deltas, sculptured into terraces, which mark falling stages of the estuary waters. The summit planes at Barrett and Sugar Hill were estimated at 705 to 725 feet. The theoretic altitude, according to the isobases, is about 720 feet for the marine plane. That these terraces on the detached deltas are the work of standing water, combined with the depositional work of the inflowing streams, is perfectly evident. Ter- races are limited to the deltas, with no benching of the till walls of the valley. The width and irregularity of the valley rules out river work. Precisely the same characters belong to the terraces of the Connecticut, Hudson, Champlain, and all the large valleys open to the sea. Another point in way of discrimination may be noted. In the narrow river section of the valley there are no deltas at the mouths of the tribu- tary valleys, as the contributed detritus was carried away by the trunk stream current. And the lines along the valley sides have a continuity and straightness impossible to weak wave action. On the other hand, the convex and irregular outlines of the delta fronts in the estuary section of the valley, with absence of erosion lines on the till salients of the valley walls, rule out river work. To most students all this will seem very elementary and quite common- place; yet the significance of these features appears not to have been recognized by those who regarded the high-level terraces of wide valleys as the work of enormously flooded rivers. INITIAL WATER PLANE ON DELTAS A heavy delta in a relatively narrow valley may be built far out in and beneath the static water and also be aggraded upstream far beyond and much above those waters. On these ancient “fossil” deltas we may have a horizontal extent of several miles and a vertical range of even 100 or 200 feet. Such is the character of many of the heavy deltas built by the glacial outwash and later land streams at the initial plane of the sealevel waters. The discrimination of the subaqueous portion of the primitive delta from the subaerial, aggraded part becomes important for the close determination of the earliest marine plane. In other words, the problem is to locate along the sloping surface of the delta the intersection of the initial or highest static water level of the estuary. A close determination == Ss ee DISCRIMINATIVE CRITERIA 197 is not easy and often is impracticable, but there are some suggestive features. The materials composing the subaqueous plain are finer and more uni- form or better distributed than the subaerial or stream-laid deposits. They have a smoother and more nearly horizontal surface, and usually display a series of steps or terraces with definite cliff borders, produced in the subsiding waters. These are sometimes of such dimensions as to be indicated by 20-foot contours. A good example is seen in the lower left corner of the Glens Falls (New York) sheet. On the other hand, the upper aggraded part of the delta was affected only by the river flow and will have no transverse cliffs, though it may be cut by the rejuvenated stream into longitudinal steps or stream-banks. This suggests the 1m- portance of criteria for discrimination between wave-cut cliffs and stream- _ cut banks. The subaerial part of the delta has more continuous, average upslope, the materials are more varied, and the surface locally more irregular, more likely to display stronger distributary channels in the course de- tritus. The lower reach of the cobble and the change to sand or finer gravel may be taken as the limit of unchecked flow. As with most complex natural phenomena, it is easier to state theoretic distinctions than it is to apply them in the field. The determination of the initial marine plane on large deltas is only approximate and requires checking by the study of neighboring features. The best practice is to use the great deltas for approximate height, and then to make close determination by study of the small deltas of the lateral streams and of the shore features of the near-by valley walls. In districts of great tidal range, like the Bay of Fundy, the determi- nation becomes more a matter of judgment based on experience than in regions of steadier water level. INFERIOR VALLEY PLAINS The highest of the broad, conspicuous valley plains have sometimes been accepted as the summit level of the standing waters. When the . stretches of open valleys, like the great valleys of New England, are in - question this decision must always be an error. The only detrital plains that could be laid near the surface of the primitive estuaries must have been related to the headwater deltas or to the deltas of lateral valleys, and such plains were coarse materials—cobble, gravel, or sand—never silt or clay. The valley plains of fine material were either accumulated in considerable depth of water or as floodplains of an inferior level. 198 H.L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. BE. AMERICA The greater thickness of the broad valley deposits is usually massive clay or silt and is capped by sand. The deep clays of the Hudson, Cham- plain, Connecticut, and other New England valleys are well known and are often 100 or 200 feet in thickness. W. A. Johnston says that in the lower part of the Ottawa Valley the clays have a vertical range of 600 feet (48, page 20). The occurrence of finely laminated clay and silt is proof of a higher surface of relatively quiet water. The depth is variable, according to variant combination of factors; but the least depth noted by the writer is at Bradford, Vermont, where, in the valleys of Waits River and Mink Brook, the clay reaches up to within 60 feet of the theoretic and the measured water surface. At Ottawa City the land uplift is about 700 feet and the clays lie at 600 feet. | In his monograph on the glacial gravels of Maine, previously noted, George H. Stone makes special mention of the clays. Like the Hudson and the Connecticut, the deep valleys of Maine afford good examples of the fiord or estuarine character. And as the valleys open directly south- ward to the sea there can be no doubt of the nature of the flooding. Con- cerning the valley plains, Stone writes: “The hypothesis that there was a greater elevation of the interior than of the coast region of Maine helps clarify some heretofore very doubtful points of interpretation. At elevations extending from 350 to 450 or 500 feet are plains of valley sediments up to 5 miles in breadth, and in a few cases they are somewhat wider. If these great sheets are valley drift, they demand very large rivers. But if they are in large part marine beds—that is, fluviatile deltas formed offshore in bays or fiords—we do not need so large streams to account for them” (page 488). “Below Moscow and Bingham the sedimentary plain of the Kennebec is from 1 to 6 or 7 miles wide” (page 489). Concerning the clays, Stone says: “. . . For instance, a nearly continuous sheet of clay extends from the sea up the valleys of the Kennebec and Sandy rivers to a height of 450 feet or more’ (page 56). Stone’s map of the marine clays (his plate 2) makes the clay extend up the Penobscot Valley to the isobase of 500 feet uplift and up the Ken- nebec Valley to the 650-foot line. This implies a depth of 200 feet of water over the northern Kennebec clays. The mistake in regarding the wide silt plains of the broad lower valleys as indicating the earliest water planes was probably due to mental pre- possession of the theory of small land uplift or none at all. Like other features in the valleys, these plains have no satisfactory explanation except by deep submergence. . DISCRIMINATIVE CRITERIA 199 ABSENCE OF MARINE FOSSILS The entire absence of marine fossils in the higher sand-plains and throughout some valleys has been sufficiently explained in former writ- ings. Only fresh water existed in the Hudson, Champlain, and Saint Lawrence valleys until the ice-front receded from northern New Bruns- wick and Gaspé Peninsula. Then salt water passed up the Saint Law- rence Valley; but by that time the wave uplift had raised the lower Hud- son district to something like its present height, and the primitive and highest sealevel shoreline was lifted much above the marine waters. W. A. Johnston says that marine fossils do not occur above 510 feet in the Ottawa district (48, page 27). This is 190 feet beneath the uplifted marine plane. Because of the free connection with the sea, marine fossils might be ex- pected in the early deposits of the New England valleys. But the physical factors argue for unfavorable biologic conditions when the early deposits were laid. The waters in the broader, lower stretches of the estuaries must have been affected by the copious glacial flood added to the land drainage. The coarse detritus was piled near the mouths of the streams and only the deeply submerged clays could preserve the salt-water or- ganisms. As the ice-front receded and uncovered the upper stretches of the estuaries, the constriction of the valleys increased the percentage of the fresh water. No marine fossils are found anywhere in the deposits near the summit water level, and they should not be expected. Regarding fossils in the inferior deposits, Stone writes: “The fact that fossils are rarest where the clay is deepest proves unfavor- able conditions for marine life near the mouths of both the glacial rivers and the ordinary rivers. In other words, the vast influx of ice-cold and muddy fresh water during the final melting of the great glacier was destructive of marine life. “The rarity of fossils contained in the upper clays and silts makes it very difficult to determine where the marine beds end and those of estuarine and fresh-water origin begin” (page 56). Absence of marine organisms can never be taken as proof of non- marine water or lack of confluence with the sea. ABSENCE OF SHORE FEATURES The lack of positive shore features even on long stretches of the old and uplifted shorelines is not valid negative proof. In production of shore inscriptions the principal factor is duration, and the rise of the land more or less promptly after the removal of the ice-load prevented concentrated attack by the waves not only at the initial level, but at all inferior levels. 200 4H. LL. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA On exposed coasts the tidal variation of the water level inhibited rapid production of shore features, while inland and along the entangled valleys wave action was too weak. Every experienced observer knows that over wide areas where it is certain that standing water existed for ages the surfaces today may show no clear evidence. Apart from deltas the constructive shore feature is gravel bars. But their production requires a concentration of coarse material, with fayor- able conformation of the shore, and these conditions are rarely fulfilled apart from deltas or kames. A supply of well rounded cobble or coarse gravel is requisite to enable the waters, short-lived at any horizon, to pile the stuff into bars. They need not be sought on shores exposed to erosive action, and scarcely ever on sandy tracts, for reasons previously given (84, pages 299-301). For erosion features perhaps no coast presented more favorable ex- posure than that of Maine. The comparative failure of wave-work there is shown by the following quotations from Stone: “At the higher elevation (on the islands of the coast) the surf had time to erode the till from the more exposed shores, but it had not time to form a cliff of erosion in the solid rock before a change of level transferred the wave action to higher or lower rock. In other words, the changes of level of the sea were relatively rapid” (page 44). ep The fact that those valleys of most uniform slope and exposure to the sea do not show well defined beach terraces proves that at least the fall of the sea proceeded at a nearly uniform rate, unless the pauses at 225 to 230 feet and 20 feet be exceptions” (page 53). “The fact that the till was only partially eroded from the outer islands proves that the retreat of the sea was geologically rapid’ (page 486). To limit the height of an upraised shore to the conspicuous beach fea- tures seen along a slope or valley side, or even to the outer deltas, will nearly always result in serious error. VARIATION OF BEACH ALTITUDE Shore phenomena may be quite unequal in height, even when made in identical water level, on account of variation in the factors or combina- tion of factors concerned in their production. These variables may be noted as (1) tidal range; (2) different exposure to winds and storms; (3) slope, conformation, and character of the shore; (4) topography of the neighboring coast; (5) character and volume of the detritus; the latter related especially to (6) stream contributions or deltas. The variation that an observer might find within a mile might be 10 or 15 feet, particularly in comparing bars and cliffs. Even along a con- tinuous bar a difference in the crest height may be 5 feet in a short dis- tance. DISCRIMINATIVE CRITERIA PAU For the above reasons very precise determination of water levels, to the exact foot, is usually impracticable, and is possible only by detailed and intensive study over some distance, and even this is an average. Of course, it is understood that deformation must be expected on hnes that eut the isobases. Thus it becomes necessary to discriminate clearly be- tween beach variation due to variables of the shore and that due to land tilting. THE Map The map of isobases, figure 1, shows the total post-Glacial uplift, which is all of Wisconsin or post-Wisconsin time, except possibly territory west of Ohio and Michigan. The map published as plate 10, in volume 27 of the Bulletin of the Geological Society, is confirmed in essential features by all subsequent study and constitutes the nucleus of the present map. The chief modification of the former map is the slight curvature given to the isobases in their extension over the greater area. For example, Ottawa City here lies on the 700-foot isobase, while with the direct lnes of the former map it lay at about 730 feet. These isobasal lines are drawn in three forms or degrees of reliability. The heavy solid lines are quite positive, being located by clear evidence of the summit sealevel waters. The light solid hnes are approximately correct, based on suggestive data and their position being necessitated by the relationship and control of the heavy lines. The broken hnes are more or less hypothetic, but the only lines which are wholly theoretic are the extensions of the isobases of zero to 500 feet over Indiana, Illinois, and Wisconsin. The map strongly indicates the causal relationship of the ice-caps to the Pleistocene diastrophic land movement. The uplifted area shown by the isobases is also the glaciated territory. The glaciers deployed on the land to thin borders, but where the sea was reached the more rapid melt- ing and erosion limited the extension of the ice-sheet. In other words, on the land the ice extended farther from its gathering ground or alimen- tation area than it did on the oceanic spaces. In consequence the flow was more rapid and the surface gradient was steeper along the radii toward the marine borders. In the Mississippi Basin glaciation extended to the Ohio River, and, judging from the apparent relation of land movement to glaciation over the greater area, it would seem probable that this region should have suffered some movement. As the Mississippi Basin was occupied by ice- sheets antedating the more easterly Labradorian glacier, and with greater reach to the south and southwest, it is possible that the early unloading XVI—Buu. Grou. Soc. Am., Vou. 29, 1917 9202 4H. L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA of the southwestern border permitted some rise in the district previous to the waning of the Labradorian sheet. It is therefore probable that the differential uplift shown in the glacial lake beaches of the Michigan and Erie basins is not a record of the earliest nor the total uplift in the west- ern area. The wavelike uplift of the earth’s surface following the re- a (3— “oh, Pane _ . Ae Oy Eves “ee ae NN : 09 ISOBASES OF POST-GLACIAL UPLIFT Figures show altitudes in feet. Solid lines are positive, or approximate. Broken lines are hypothetic, HL. Fairchild. (917- I'rGure 1.—Post-Glacial continental Uplift The lines indicate, in feet, the amount of land uplift following the removal] of the Labradorian ice-cap moval of the ice-burden probably raised the territory southwest of the Michigan and Erie basins, at least in greater amount, before the lake inscriptions were completed. The near horizontality of the southwestern stretches of the ancient beaches is not proof of lack of land uplift, because some reasonable rela- tion of lake history to rise of land might leave the shorelines quite level. DISCUSSION OF THE MAP 203 -Taylor’s “Whittlesey Hinge Line,” his zero of land uphft, hes 250 miles north of the ice hmit of the Wisconsin stage and 350 miles north of the extreme glacial limit (80, figure 14, page 503), and it has no reference to the ice lobations. The thickness of the ice at this line was 3,000 to 4,000 feet (80, page 511). It would appear more probable that some combination of wave uplift with the lake history has left the southern beaches with small deformation than that such great thickness and extent of the ice had no diastrophic effect. The map shows that the post-Glacial land uplift of northeastern Amer- ica is fairly proportionate to the area and thickness of the latest ice-sheet, and it appears legitimate to suggest similar relation in the Mississippi and Great Lakes region. The southward curve given to the lower-value isobases may be excessive, but they suggest an uplift for which evidence should be sought. _ It should be understood, therefore, that the isobases as extended in the Mississippi Basin are intended to be only suggestive of the southerly limit of the Pleistocene land uplift, and that the lines of the rest of the map, east of Michigan and Ohio, indicate the total rise of land during and following the removal of the latest, or Labradorian, ice-cap. The location of the central area of uplift between Quebec City and James Bay agrees with the conclusions reached many years ago by J. W. Spencer, using a different method. He located the area of maximum uplift by triangulation on points of the deformed shorelines. As early as 1889 he summarized his conclusion as follows: “At any rate, it is in the region southeast of James Bay that the maximum differential elevation of the earth’s crust, which involved the Iroquois Beach, is to be found.’’? ® And in 1913 he wrote as follows: “By triangulating the Iroquois, Algonquin, and other beaches, the dome of the greatest deformation of the Great Lakes region is found to be situated approximately in latitude 50° 30’ north, longitude 75° west. This is confirmed by the course of the drainage of the highlands. It is the locality where the ‘height of land’ reaches its most southern lobe” (79, page 227). _ The map also suggests that the latest ice-sheet on North America would more appropriately have been named from Quebec instead of Labrador. Over Labrador the isobases have been adjusted with particular refer- ence to Professor Daly’s figures for the raised beaches along the north- east coast (39). His study seems to locate fairly the 300- and 400-foot *'Dransactions of the Royal Society of Canada, vol. 7, 1889, p. 129. Journal of Geol- ogy, vol. 19, 1911, p. 57. 204 H.L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA lines. Force is also given to some unpublished figures by Professor Cole- man. Professor Daly’s altitudes for the east coast of Newfoundland are har- monized with the isobases of the mainland only by regarding the island as an independent area of depression of about 600 feet, which implies a separate ice-body. This carries the study over into meteorology. Criticism may possibly be offered that the isobases in the map are too regular and parallel. Any irregularity in the direction and spacing that would appear on a map of this scale would be due to irregular uplift or local warping. Perhaps there is such in slight degree, but it would be attributed to, or confused with, the local variation in height of the shore features. However, the depth of terrane involved in the diastrophic movement would appear too great to permit any sharp or local warping of the surface, under either the hypothesis of compression and elastic reaction or the conception of deep-seated flowage. No recent faulting has been seen sufficient to produce any change in beach levels. The isobases as drawn are, of course, somewhat generalized, but they represent the facts in surprisingly accurate degree. The variations of the summit fea- tures from the theoretic height, as indicated by the isobases, are given in the tabulations below. These seem small when all the causes of alti- tude variation are considered, as described above. Shorelines traced in the field and the isobases as drawn have no con- _ sideration for mountain mass or valley deficiency. Apparently the sur- ficial relief of the continent had no measurable effect on the amount of uplift. This should be expected when it is remembered that the large topography was pre-Glacial and isostatic equilibrium had long been estab- lished. The truth of the map is not dependent on the precision of a few sta- tions, nor on the approximate figures for many stations, but on the gen- eral accordance of the field data with the adjusted isobases over the great area. Whatever correction the future may make in this map is more likely to be in the increase of the amount of submergence and uplift, as we may have to recognize some rise of the ocean level after land uplift had begun, and also some lifting of the central part of the area while vet beneath the ice-sheet. The writer has been conservative and careful not to overesti mate, and he has the feeling that he has sometimes committed, in smaller degree, the usual mistake of minimizing the height of the upraised marine plane. —_ i — 7 LAND UPLIFT AND CHANGE OF OCEAN LEVEL 205 RELATION OF LAND Upuirr To Ick RECESSION This topic has been discussed in a previous paper (82, pages 249-252). It was there argued that the rise in the marginal areas of the glaciated territory could not begin until the ice-front was some distance removed ; that the uplift was by a wave movement; and that the wave did not over- take the retreating ice-margin in the Hudson-Champlain Valley. Later study suggests that possibly the uplift wave did overtake the ice-front at the north boundary of New York; in other words, that there might have been a small amount of land rise beneath the thin edge of the ice- sheet while this lay against Covey Hill. The reasons for this are given in the detailed of of the New York features now awaiting publi- cation. Theoretically, it seems possible that while the nucleus of the Labra- dorian ice-cap, relatively small in area and much reduced in thickness, lingered in the cool chmate of the Laurentian highland some uplift affected that ice-buried area. Whatever rise of the land took place while it was yet covered with ice would not be recorded by aqueous deposits. This conception suggests that the isobases for the central part of the glaciated region may represent only the later portion of the uplift. The study of this matter is bequeathed to the future. In this paper it is not practicable to consider the geophysical problem of diastrophism as related to glaciation. A recent discussion of the subject by Taylor is to be found in the paper listed as number 80, pages 508-518. CHANGE IN OCEAN LEVEL The Pleistocene ice-caps consisted of water withdrawn from the ocean. The total mass of the several ice-sheets represented an enormous volume of water, and. if the continental glaciers were contemporary the reduction in the level of the ocean was considerable. Even the Labradorian ice- sheet alone must have changed the sealevel. On northern coasts this low- ering of sealevel was in some small amount counterbalanced by the gravi- tative effect of the ice-caps. When the ice-caps melted, the water was returned to the sea and the original level restored. Estimates have been made to the effect that in the equatorial zone the seas were lowered about 200 feet (41, 42). Evidently this is a complicated problem, involving many meteorologic, geologic, and geophysical factors; and especially difficult when applied to the.closing stage of the latest North American glaciation, with its elements of uncertainty. Without attempting any serious discussion of 206 WH. L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA this extremely difficult, but interesting problem, the altitude relation of the hypothetical change of water level to the post-Glacial land uplift may be briefly outlined. : Assuming an effective rise of the ocean level, due to the return of the glacier water to the sea, the following conditions seem imperative or highly probable: 1. The rise of ocean level (flooding) was proportional to the waning of the glaciers, and was contemporaneous, not subsequent. 2. In at least the peripheral portion of the uplifted area the rise of the land was subsequent to the removal of the ice (unloading) from such area. 3 3. The land uplift was by a progressive wave movement. 4. Toward the center of the glaciated area the wave of uplift might have overtaken the slowly receding margin of the diminished ice-body, so that some uplift occurred beneath the ice-sheet while the sea was yet excluded from the district, the sea being nearly restored to full height. From the above conditions the following conclusions are derived: (a) About the borders of the uplifted area, where the rise was small, diminishing to zero, and where the ocean flooding was the maximum, the primitive shore features are all submerged. ) (Db) The primitive marine shore features at any point are now above the present (flooded) sealevel only where the total land uplift has ex- ceeded the rise of the ocean, which occurred subsequent to the beginning of the uplift at that point. (c) Therefore the total land uplift at any point is the present apparent and measurable height above the sea plus the vertical amount of ocean flooding subsequent to the initiation of land uphft at that point. The above conclusions may be restated in the following generalizations: (A) Except at the center of the uplifted land area, the total amount of land uplift is everywhere greater than the apparent rise. (B) The amount of marine flooding is maximum at the periphery of the glaciated area and declines to zero at the center. (C) Conversely, the apparent or visible uplift, like the total uplift, is greatest at the center of the area and diminishes toward the margin. The immediate practical application of the above conclusions may not be unimportant. As the datum level for all land uplift is the present sea surface, it is not feasible to determine the amount of non-apparent or flooded rise of the land; but the relation of the apparent uplift to the glaciated borders, as indicated by the map, may be significant. — The only locality east of the Hudson Valley where the terminal mo- raine lies on the land is Long Island. At the middle of the Island the CHANGE IN OCEAN LEVEL 2.07 uplifted marine shore is 100 feet above tide. With this amount of visi- ble uplift at the limit of latest glaciation, it would seem either that the rise of ocean level had been small or that the uplifted area extends far out under the sea and much beyond the loaded area. Nova Scotia was wholly glaciated. Multitudes of huge erratics are piled along the southeast shore and in the harbors (plate 17) ; but part of the south shore exhibits no uplift (see the zero isobase of the map). Hither there has been no uplift here or else the flooding of the sea has exceeded the uplift. On the coast of Maine the ancient beaches are from 200 to 400 feet above tide. At Saint John, New Brunswick, the uplift is 200 feet. On the east coast of Newfoundland the apparent uplift is even greater, be- ing at Saint John, according to Daly, about 575 feet. It appears prob- able that the independent Newfoundland ice-cap spread widely beyond — the present shores, yet 575 feet seems a large amount of rise if some non-visible rise is to be added. It should, however, be emphasized that no changes of sealevel, by what- ever cause, can account for the great differential elevation of the shore features found in passing inland, rising from zero at Yarmouth and Sydney to over 1,000 feet northwest of Quebec City. TABULATION AND DESCRIPTION OF NEW .DATA GENERAL DISCUSSION In the column of “definite” altitudes are placed only those measure- ments which were taken on fairly clear features. The observations which were uncertain, either for lack of time or lack of good datum or for poor behavior of the aneroid, are placed in the other columns. The range of error for the definite figures will usually lie within 5 or 10 feet. No figures are placed in that column which are not regarded as correct within 5 feet. In many cases the altitude is quite precise and subject to’no serious change. The sources of error are: (1) wrong figures for the railroad elevations, which were chief datum for most of the area in Canada and for some territory in New England; (2) the variation of aneroid, which was usually checked and corrected; (3) the uncertainty of the contours of the older topographic sheets, here no precise altitudes are given except the useless hilltops. A coincidence of errors is as likely to neutral- ize as to magnify. . The chief uncertainty in the study arises from failure, due to lack of time or want of good altitude data, to determine closely the initial 208 H.L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA water plane on some of the larger deltas. In some cases instead of a defi- — nite figure the two figures for the vertical range within which the plane lies are given. While more intensive study will change some of these figures, the writer is confident that the future will confirm the general accuracy of the figures in the column of theoretic altitudes. | It will be noted that the figures are usually in multiples of 5. It is not now practicable to make the theoretic figures more refined, although it may be so eventually, and for the measured altitudes it is unnecessary to take time and give labor to secure precision to the foot when there is so much variation in the height of shore feature, as previously de- — scribed. 7 HUDSON-CHAMPLAIN VALLEY The altitudes of the shore features on the marine plane in New York, including Long Island, have been partially given in previous papers, listed in the appended bibliography as numbers 81-85. The detailed description of the closing Pleistocene of New York State, giving altitudes of the features in the Hudson, Champlain, Saint Lawrence, and Ontario valleys, is awaiting publication. The shore features on the Vermont side of the Champlain Valley are described in paper number 83. WESTERN NEW ENGLAND For the State of Connecticut, verified altitudes are limited to the Con- necticut River Valley. For Massachusetts, the figures given by Emerson (64, 65) for the static water levels (“Connecticut Lakes”) in the Connecticut Valley are re- garded as precise. Some of them have been personally verified, especially for the 400-foot isobase. The streams tributary to the Connecticut River afford interesting op- portunity for this study, care being taken to discriminate the sealevel deltas from the glacial water deposits. An example is found at Shelburne Falls, on the Deerfield River. Under the village and northward are handsome gravel plains rising to 428 feet, but the isobase of the locality is about 375 feet. Some of this superior altitude might be attributed to aggradation above the static water plane; but more probably these high plains represent glacial ponding, by the lobation of the ice-margin in the Connecticut Valley. The marine delta has probably been destroyed by the river erosion in the narrow valley, although some remnants should be found. The true plane of the ocean-level waters may be determined by careful study of the sides of the Deerfield Valley below Shelburne Falls. “yS0M\ ‘OpPLAUNLVY ‘esBI[LA ay} JO JSeMq}10U So [por nN i) pue auQ ‘AdT[VA Od9VG ay} JO Sao}e Jeasfeos oy} UT 4TINq TUIHSAdWVH MON ‘LLFILYVa :VLTEa FIAT [ey-ou0 OL ‘Id ‘LT6T ‘63 "LOA ‘AV ‘(N08 “10D "TINd . TABULATION AND DESCRIPTION OF NEW DATA 209 For Vermont some new data is given below, description of the details being reserved for the report of the State Geologist. At Bradford massive clay reaches up to 600 feet, to within 50 of the summit sand-plains. The features here, as at many other points in the valley—Brattleboro, White River Junction, Norwich, Lewiston, and Hanover, New Hampshire—are on the sides of the open Connecticut Valley, with no relation to any possible glacial waters by lateral ponding. In New Hampshire several localities have been examined with definite results. Good bars and other features along the south side of Lake Win- nepesaukee definitely locate the 600-foot isobase. Through the Saco Valley the sealevel waters reached into the White Mountains as far as Bartlett, where clear features are found south, west, and northwest of the village (see plate 10). Eastern Massachusetts and Rhode Island have not yet been examined by the writer. Most of the area is beneath the summit marine plane, as shown by the topographic sheets, but a few hills should preserve records of the highest wave-work, and a few streams from higher ground will probably exhibit the summit deltas. The topographic sheets lack suffi- cient relief expression to indicate the summit sand-plains. As a whole, the region must be difficult for this study, one proof of which is the fail- ure of students to recognize the initial or summit marine level. Prob- ably the delta plains, which have been attributed to glacial waters (70, 71, 73, 75), were mostly built in the lower levels of the marine waters. The fine succession of sand-plains in the Sudbury Valley described by Goldthwait (75) is the condition to be expected in the slowly falling marine waters, but is very unusual in glacial lakes. The later level of Crosby’s glacial waters in the Nashua Valley(370 feet) probably repre- sents the summit marine level. Altitudes of the earliest and highest Marine Levels i S bu Location. 2 F Observed altitudes, as 2S sted ne amv yisa st Rs cites” ONE ts See oo | e str ; eas Ne Defi- Ap- Mini Stream valley and station. x ane. prox. ee MASSACHUSETTS | | | Dcerfield HOLY O Tin raves tee Shelburne -Fallvos wees UT Me ee Connecticut River...... Northficld: and. Fast 450 -|* -400 Northfield. (See Emerson’s papers) . | ET MUOINS SEBIV OY ine) dae s AUN GTeUGhe saacs'a a opwle erate 38) | 380 | 365 MOU Wasi River)... RUtChDUnS .. 6. ned sews 395 | 400 210 H.L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA ~n Location. = a Observed altitudes. 25 es . Sa Defi- A p- Mini- Stream valley and station. = yite. prox. | mum. J VERMONT (CONNECTICUT VALLEY ) Whetstone Brook....... Brattleboro ={" 24.15 APO. 4?5 West. River sa).< 2225 352.2 ee oe ee eee eee eee) ote Saxtons GeuVGie se on ete Saxtons River villag . ATD AGD Williams “Rivers ass. = Bartonsyvilie au) a. eoeqecess saps 375 300 Black: Wapes, so ks ss ae 355 ; C71 1 0 1A aA Rae RR Cr 350 Bonaventure ¢. 0.054%: 325 New Carlisle...... ‘alee oa 1 EST NYS 0 IE Re A Meir 300 okie MMP eee ASe tok SrA cae 280 230 Bort DWamiells 2%, wales 275 240 PEW OUI. ons coe Gyan seacateis 255 : 185 EAN: MRTVED sio 0 csi oee 240 ak 200 Perce, northwest..... 225 225 re Corner of the Beach...| 225 er RCHOIS? oh: ovis ~ 3a alee 225 | : NEWT ns.-ccare con cena ees 230 | eat Douglastown ......... 235 my CUT eas eda oan seceacoas 245 240 | 220 4H. L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA NEW BRUNSWICK The positive determinations of the summit marine level in New Bruns- wick are relatively few, but they are widely distributed and some are of excellent quality. The Saint John Valley is all too low for any record by the great river, and time did not permit exploration of the -tributary valleys in the wilderness; for it should be understood that the great part of northern Quebec and New Brunswick and the interior of Gaspé and Nova Scotia are still in forest. The village of Grand Falls is on a gravel deposit in the midst of the valley, the summit, on the main street, being 520 feet altitude. Chalmers gives it as 522 feet. The full height of the summit water there is about 550 feet. The Grand River, joining the Saint John above Saint Leonard and Van Buren, carries high gravel plains up to the theoretic level, but the forest prevented precise measurement. The features about Saint John City deserve particular description. Fortunately the Canadian Survey has recently mapped the quadrangle, and the writer is indebted to the Survey for an advance photolithograph and to Mr. A. O. Hayes, in charge of the topographic work, for directing attention to the critical locality. Southwest of the city and south of South Bay is a heavy kame-moraine in which the Canadian Pacific Railway has a large gravel pit. The sum- mit of this deposit has been swept by the sea, and along the Manawagon- ish road (old Saint Andrews road) for about four miles southwest of Fairville the cliffs and bars of the summit level are conspicuous. The middle section of this four-mile stretch is a ridge capped by wave-built gravel bars, which at two points rise to 200 feet. The western height is on land of Harold Chadwick and the eastern carries the home of A. H. Clark. The house of Mr. Clark is encircled by low bars of fine gravel, while a heavy bar extends northeastward. On the south face of the ridge just beneath the crest is a strong sea cliff with cobble and boulder terrace at elevation of 185 to 190 feet. Due east of the city about three miles a careful examination was made of one locality, with discovery of a large and handsome gravel bar with altitude of 185 feet. No distinct wave-work could be found above the bar. This bar is on land of Michael Ryan and crosses the road just west of the second forks in the highway. West by south of Saint John, 38 miles by rail (30 miles in direct line), is Pennfield Station, on the Saint Stephen branch of the Canadian Pacific Railway. This station is on a very extensive wave-swept gravel plain and has altitude 228 feet. For some four miles along the east and BULL. GEOL. SOC. AM. VOL. 29, 1917, PL. 15 | : Z MARINE COBBLE-PLAIN: PENNFIELD, NEW BRUNSWICK . At Pennfield Station, 30 miles southwest of Saint John, New Brunswick. Looking southeast. Altitude, 228 feet. Compare plate 16. eze ‘epnqniv ‘GT a7R]d o1vdWOD “4SeM SUTYOO]T MOTA *"jOeZ ; i ‘saoT10D ABO JO YINOS ou YINOJ-ou0 puv ‘yoIMsUNIG MON ‘UYOL JuLeg JO JSeMYINOS SOIT OMJ-AyATGT, NIVId GIGIINNGd FHL NO Ava THAVAY 9T "Id ‘LI6T ‘63 "IOA ‘WV ‘NOS "10D “TTNA TABULATION AND DESCRIPTION OF NEW DATA iAll west road this plain is level, except for slight swells and hollows running across the road and declining seaward (plate 15). These are very evident to the eye, but have a relief of only one to three feet, except where deep- ened in a few places by recent drainage. The Pennfield Ridge post-office, one-half mile from the station, and McKay Corners, two miles west, have practically the same height as the station. On the road leading south from the school-house, near the post-office, is a remnant of a well stratified deposit of fine gravel and sand, with elevation 230 feet. One-fourth mile south of McKay Corners, on the road to Beaver Harbor, is a splendid bar of gravel lying across the road, with elevation 225 feet (plate 16). Effective flow over the plain is shown by the abundant cobbles, up to six or eight inches diameter, with some subangular stones, built into piles over the fields or along the fences. We have here a plain swept by the tides, with a “washboard” surface declining seaward. The fluting is more apparent in the coarse detritus along the road and flattens out on the lower part of the plain composed of finer material. This fluted plain suggests the marine plain of the south side of Long Island, with its “creases,” “furrows,” or “dry rivers’; but the scale and relief here are smaller, probably related to the coarser material, steeper slope, and less width of the plain. Apparently this was the plain noted by Chalmers (6, page 10), with altitude 225 feet. Other evidence of high-level waters is conspicuous in the region. The “Pocologan Barrens,” northeast of Pennfield, stretch along the railroad for five miles—a waste of gravel and sand rising to at least 220 feet and carrying bars. | The great tidal range on this coast brings in a possible complication in the determination of the sealevel and the locating of the isobases. Today the tide at Saint John has a range of 27 feet. When the land stood some 200 feet lower and the Bay of Fundy was much enlarged, being really a strait connecting the Atlantic with the much enlarged Saint Lawrence Gulf, the tides here must have been much less, perhaps comparable to the present tides in the Saint Lawrence Gulf. A range of 15 feet is sug- gested. With this variation we may regard the summit bars on the Mana- wagonish ridge as highest tide-work and the 185-foot cliff as the principal horizon of wave action. This imples about 190 feet as the proper figure at the ridge. ‘Taking into account the height and location of the bar east of the city and the Pennfield features, the 200-foot isobase is drawn through Saint John City. The north and east portions of the province are not as closely deter- mined for uplift, but the area lies between the precise stations of Saint John and Gaspé. A number of stations are given in the following tabu- 292 HH. L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA lation, with other theoretic altitudes, which may be guide for future study. Everywhere in the Maritime provinces beneath the theoretic plane the land shows standing-water features. Altitudes of the earliest and highest Marine Levels Location. Observed altitudes. Theoretic altitude by isobases | Stream valley and station. te | one bia! moar | ee Saint Croix River...... Saint) roim cancers 395 | .... | A Pennfield Pigin. Vea es DO i) a =. oe Saint John, Valley::...% Saint. JW ee oserc sete 200 | 200 igs Manawagonish Ridge.| 195 190 (eee Ryan Bar, east of city! 185 | 185 oe Keswick River..... Upper Keswick....... 400 oxen cea eae 360 Nashwaak River... Cross Creek..........- 375 eats 360 oes Upper: Saint John «Grand “Walls... As... - 550 1) eae & 520 River. Grand. River. 2...) North of Saint Leonard | 585 atk 590 | | 570 Gres Brook wi 05 syne sia Mallets ..22eh fo. tee 500 asl ee | 476 (Cepibaran: FRAVETS sisi! eee New. Canaan oo: ae 200. | vot 3 )aeeee Salmon: Rivera. a. sees Wide MOR ESe 3 g5.4 aie edie 280) | See bate Petiteodiac River....... Northeast of Moncton. | 190 NC 175 Riehibucto River ss... -':* Coal: Bran... ..2..% 2 250 wee ie) ee ope 225 Barnawy Wivers. ..< <:.s\. FROSErS Villers Steen ei 300 =< eu heen S. W. Mirimichi River.. Boiestown ............ By (tS ) ae N. W. Mirimichi River.. Sevogle. .............. 345 0). 2 Mirimichi, River... 660. North of Neweastle...| 315. se 310 Nipisiguit Valley....... Red mes ass eee Oe 330 a 340 NOVA SCOTIA It appears that the south and east points of the peninsula and the east part of Cape Breton were not submerged, or, if so, the evidences are drowned. There is the lack of any of the ordinary phenomena produced | by standing water; no stream deltas; no valley fillings; no wave-work on slopes and headlands. No record of submergence was found at Sydney, North Sydney, Sydney Mines, and Glace Bay, nor any along the coast from Liverpool around to Yarmouth. Near the middle of Cape Breton, at Shenacadie station and southwest, along the secluded waters of Saint Andrews Channel, are weak but dis- tinct bars and plains that have been raised a few feet above the reach of the present water. These shore features rise toward the southwest. until — a ae eo A = le — a : — a —— — — a = ° “ VILOOS VAON ‘SANIVHOW MOOTA ALINVUD - ‘a10Y4S GINOS vy} Suo[e yooTq vyraeas Jo Suryrd uommod aq, “s1j0oOog BAON JO Julod qj}NoOS suId1}xKe JW VILOOG VAON ‘H9VSSVG NOLONIVAVG : ANIVUOW MOOT ALINVUH—'Z Tuo - "BIJOOG BAON JO BOYS YINOS 9Y} UO JILIP og} JO OSLIojPIVIVY,) ‘“VRI[IA OY} JO Vspa JSVO 7B 4SBA SUTYOOT ‘“YOOIpsd o}IUVAS TO YOo[G oj1UwV.1x) VILOOG VAON “IOOdUMAIT LY GUOHRS—T Aun y ~» LI ‘Id ‘LI6T ‘63 “ION ‘WV ‘OOS "I0R9 ‘TTNG TABULATION AND DESCRIPTION OF NEW DATA 223 at New Glasgow they are 85 feet and somewhat higher at Truro. At the latter place and other stations on the Bay of Fundy and its branches the marine level is complicated by the probably large tidal range, even at the time of deep submergence. At Truro some weak evidence of water work was seen up to 100 feet, but excellent plains at 85 feet. The theoretical level is taken as 90 feet. At Halifax the uplifted shore features are weak and rather uncertain, and on account of continuous fog they were not sufficiently examined ; but the final adjustment of the isobases confirms the determination made on the ground, about 60 feet. Weak evidences at about the same height appear along Saint Margaret and Mahone bays. From Liverpool around to Yarmouth the coast is strewn with huge eranite blocks derived from the land on the northwest (plate 17). From Yarmouth to Digby the shore was not seen, the railroad lying across the interior, mostly in forest. At Digby and along the Annapolis Basin good delta plains and shorelines are conspicuous and were estimated in height up to 90 feet; but the maximum was not determined. According to the isobases, the altitude of the summit level here should be about 100 feet. The famous Annapolis Valley is filled with handsome gravel plains. The railroad, passing northeast, drops to 27 feet at Bridgeton and then rises steadily on the plains to 100 feet at Aylesford and to 138 feet at Berwick, the summit of grade. Probably some allowance must be made in this valley for the very high tides and storm waters forced across the col. The map makes the marine plane here about 125 feet, in agreement with the field conclusion. | About the Minas Basin the land is low. Up the Kennetcook River the delta and stream plains in the narrow valley are excellently displayed. The county of Cumberland, north of Cobequid highland, exhibits abun- dant submergence features, and the same is true of all the coast of Cum- berland Strait and George Bay, counties of Pictou and Antigonish. In the district of Amherst and Springhill detrital plains are seen much above the theoretic marine level. These are attributed to the smoothing work of the extreme high tides which probably swept this area during the sub- mergence. In the valley of West River, between Antigonish and James River sta- tion, is a very heavy gravel kame area, and the aggraded plains rise from about 15 feet at Antigonish to 235 feet in the 914 miles to James River, giving a gradient of 23 feet per mile. Hast of Halifax the multitude of streams with flow direct to the At- lantic should hold excellent and positive summit deltas, but the coast is not easily accessible and is very wild away from the shore. 224 H. L. FATIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA As the isobases record, negatively, the post-Glacial submergence, they should have some suggestive relation to the glacial load, and the disposi- tion of the ice over Nova Scotia is important. The glacial features have heen well deseribed by Chalmers (8). He postulates several ice centers, or independent bodies on the higher tracts, with at least the later flow controlled by the large topography, and all toward the sea and larger bays. He attributed many inscriptions to icebergs, which may be true (8, pages 95-97). He seems to have minimized the ice-flow of the conti- nental sheet southeastward across the Chignecto Isthmus (8, pages 93- 95), for an area of drumlins in the Amherst region indicates a consider- able current of ice from New Brunswick. This flowage probably deployed some distance over the peninsula; but Chalmers was probably correct in his view that the ice-sheet did not cross the Bay of Fundy, and that the flow in the southern peninsula was radial from the interior. Chalmers found no evidence of glaciation on the Magdalen Islands nor on the northern part of Prince Edward Island. He says, page 91: “The Magdalen Islands are non-glaciated, and it would seem that the main- land ice has gone no farther than the eastern and northeastern border of Prince Hdward Island, the southeastern part having, apparently, been glaci- ated by the ice which accumulated on the island itself.” Chalmers gives in this report a tabulation of the marine beaches (pages 21-25), and while his figures are not always consistent among themselves and are partly of inferior features, they are in general decidedly con- firmatory of the isobases as drawn for Nova Scotia, and some are in close or precise agreement. ‘The 100-foot isobase has been laid in accord- ance with Chalmers’ levels for the Magdalen Islands, 110 to 115 feet. But the map does not agree with his figures for Prince Edward Island, which are all 75 feet except one station for 80 and one for 95 feet. Per- haps his 75-foot shore correlates with the strong beach in the Gaspé district at 85 feet and represents a relative pause in the later uplift. Tyrrell’s Newfoundland terrace at 100 feet may represent the same pause (see later reference to this). The local glaciation of the Nova Scotia region helps to explain the lack of deep submergence. The piling of immense quantities of hugh granite blocks along the coastal area, at least from Liverpool to Barrington Passage (Cape Sable), might, at first thought, suggest that the ice-body was sufficient to depress the land to an extent inconsistent with the evi- dence ; but the drift is piled in practically block moraine along the land border (plate 17). The ice did not have sufficient. depth and push to sweep the drift into the sea. As stated above, only a tongue of the Labra- TABULATION AND DESCRIPTION OF NEW DATA 925 dor ice-sheet reached the peninsula, and the local ice-bodies were prob- ably thin and short-lived. On the other hand, Newfoundland, larger in area and farther north, held a massive glacier with effective weight. Examination should be made of the Cape Canso district and the east part of Cape Breton. The Nova Scotian region is a critical area for checking the relation of the glacier to the diastrophic movements. Altitudes of the earliest and highest Marine Levels + UW Location. 2 R Observed altitudes. os ie ; 54 Stream valley and station. 27 Defi- | Ap- | Mint- rae nite. | prox. mum. |) OCGA SHONE.. 2.2. cece Yarmouth to Liverpool Or 0 aig Lahave River...... cco. Bridvewater: choco! ys ala a 20 Mahone Bay...... BAR een BI ets eh oe eee ane eL i8 50 75 . 50 panne Marcvaret: Bay.... Hubbard -........00..4. s51 | 53 45 Penne ATAYDOT... « - soso a MAE AK 2 ees Ar DOR 22 60 a 50 Pianos: Valley. isi. DISD ors. oct be bole 105. | 90 AGIVEN PIES? oc. 0c -a/ctadel vanes Pier! was 3 d Lawrencetown ........ 120 ows JA WUES TORE! Go oh cae Save ees 125 aNeits 110 POW LC warps wake rede ‘ 125 138 125 125 Tasweream River.....+. Gaspereau ......0ce 0: 120 oi ; Saint Croix River...:... ING W POs, cote state ‘ 110 Bcc , Kennetcook River...... WKWenmelcogk? yoise e.nte sake 100 ae 100 95 Sammon River... ...- Dea) Wu ib eo pate ee Gat Me nie Serie 90 100 ae 85 90 85 [PLUG Ca a gle) gi a Oxrord SPunerom cae 150 - 160 125 Maccan River.......... Springfield Junction...| 165 hen 200 150 125 Pee Ore IVE: sce ec ess New Glasgow.......-. 80 85 Soy WVESGOEMIVET . 5.00 eee AD TISOMIUSHS = 344.0 25ighee se 50 30 SOM EVER... oc 6c ois wo Soutiy Iiver.. «sees 45 22 About George Bay...... Poma@wet:&. 222.5) ae AO. : 30 PSEA CA GICY he, 8 atcha knee 340 5 25 Mona Stery:. 5c ciek: seteiehs oh 20 als mene ‘hivyer,. Cape River Denys.......<.. 10 10 Breton. On Bras D’or Lake..... Oraneedale. vicng s Cacawre 15 ; Re 12 ; : MeKinnon Harbor..... 10 wg an 7 Saint Andrews Channel. Shenacadie ........... 5 3 . 226 H.L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA A few selected stations from Chalmers’ tabulation of ancient marine levels (8, M, pages 22-25) are given below in comparison with the theoretic altitude by the isobases of the map: Chalmers’ Chalmers’ _ Isobasal number. Station. elevation. value. NOVA SCOTIA 20 Half a mile north of Nappan station, I. C. R....... 143.72 175 23 Between Wallace Harbor and Pugwash........... 133 140 24 On peninsula north of Wallace Harbor, in several DIACeS: -GiIStihiCt 3e oh hoe aes Race ae ee 133 140 25 |East of Wallace, on road running south from Plaster: Coveces. 6: ke lives Seekers ee eee 138 135 26 On Wallace Ridge, east of road going south from Plaster Cove, in several places... .s.:.2..5s.. 2: 133 135 20 At Mhemson- stations 3). dey WReie aes oe ee eee eos 138 140 31 On east side of Halfway River, at northern base of Cobequid Mountains... 55 sai. eee oes ot ee 170.84 155 31 At mouth of L. Quille Brook, south of Annapolis... 110-115 110 42 Near head of Saint Marys Bay, at base of North Mountains. 2% oo Bs. eee ers aun she ee Eire eae 110 110 MAGDALEN ISLANDS 53 On Amherst, Entry, Grindstone and Alright Islands 110-115 110 LABRADOR AND NEWFOUNDLAND Fortunately we have for mapping of the uplift of the Labrador coast a consistent set of carefully determined elevations of summit beaches by Professor Daly (39), including three well distributed altitudes in New- foundland. These figures are the basis for the isobases of those provinces. The isobases of 300 and 400 feet along the Labrador coast appear to harmonize all of Daly’s beach levels, and his figures are supplemented by at least one observation by Professor Coleman. In a letter relating to exploration in the summer of 1916 Coleman says: “The highest levels along the northern part of the coast where I was work- ing are below those of the Saint Lawrence region. Four hundred and thirty feet was the highest certain beach, in about latitude 56° 30’. From this north- ward there is a lowering to 225 feet at Komaktorvik Bay, about latitude 59° 30’, my most northerly point. “The beaches in Newfoundland seem higher than in the part of Labrador I have studied, reaching 500 feet or more.” Coleman’s higher elevation does not harmonize with the map, but his lower figure, 225 feet, lymg north of Daly’s farthest and lowest station at 250 feet, is in perfect accord. . TABULATION AND DESCRIPTION OF NEW DATA DIM A. P. Low has given (20, page 310) an elevation of 180 feet for the high beach at Nachvack Bay. Evidently Low did not find the summit level, and the figures of A. 8S. Packard, 200 feet for the highest beach of the coast, are also beneath the Summit (24, page 310). But Low’s beach elevations for the coast of Hudson Strait (22, page 47 Li), 405 feet, are in good accordance and are used for the 400-foot isobase of that coast. Of these beaches he said: “The terraces at Dyke Head lie in a small valley at the bottom of a cove facing the strait, and afforded one of the best examples of terraced beaches seen on the coast, the heights being 405, 330, 275, 255, 220, 175, 90, and 85 feet.” His figures for Ungava Bay, 300 to 325 feet, must be of inferior water levels. For the Hudson Bay coast the only available figures are those of Low. Hiss description of the successive levels in the district of Richmond Gulf (21, page 41 L) seem accurate and discriminating, and his reiterated statement (22, page 46 L; 23, page 81 D) that the marine summit is 700 feet or over is relied on for the position of the isobase of that value. In his papers on the wide region west of Hudson Bay, J. B. Tyrrell has noted high-level beaches which he discriminates from those of Lake Agassiz and of other glacial waters (30, 33). He found beaches which he regarded as marine up to 490 feet near Doobawnt Lake, northwest of Hudson Bay; and up to 600 feet south of Nelson River, between Lake Winnepeg and Hudson Bay (30, pages 190-193 F). It appears probable that the ice displaced the shallow waters of Hudson Bay, and that the isobases should lie across the bay, but the present information is too meager to justify the westward projection over that area. For Newfoundland it seems necessary to recognize an independent area of glaciation and uplift amounting to at least 600 feet. The observa- tions of Daly and others are for the coast, but the interior of the island, where the ice-burden was greater, must have suffered more movement. In a personal communication Professor Daly expresses confidence in the practical accuracy of his figures for Cape Rouge Harbor, 505 feet, and Kirpon Island, 450 feet plus; but he hopes that the level at Saint John, which he estimated at about 575 feet, may be more leisurely and precisely measured (39, pages 257-259). Besides the figures by Daly on the northeast coast, we have some sug- gestive ones by Tyrrell on the west coast. Writing of a visit to New- foundland during the summer of 1917, he says: . “In Newfoundland the last glaciation, which was very strong, was from the center outward both eastward and westward. If the glacier from Labrador 928 HH. L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA had ever reached the island, evidence of its presence should have been dis- cernible on the west coast, but in the short time I was there I was not able to find any such evidence. “The presence of post-Glacial terraces is quite strong along the west side of the island from Bay Saint George up to Bonne Bay, especially as looked at from a boat half a mile or so off the shore. One terrace is about 30 or 40 feet above sealevel. Above this is a rather extensive plain about 100 feet above sealevel, composed on the surface of sand and gravel. The old beach on the border of this plain might be 15 or 20 feet higher. . . . Other terraces ex- tend 200 or 300 feet higher, and while in some places, at an elevation of, say, perhaps 300 feet, I saw clear evidence of the work of the tide in cutting little runnels on a steep limestone slope, I was not able to measure the exact height of this beach.” The stations and altitudes which have been used in placing the isobases of Labrador and Newfoundland are listed below: LABRADOR From Daly, going north from Belle Isle Strait: Saints Wrancis, Harbor. .c.6 ose a te Sec a. See ee 365 lee: Pieldes nis... os Ve oe a ee eee “Wie sale iene Sai eee 265 Northwest of Conical Island, mainland... .........% .<2<6%..s. nas eee 290+ Pontindluk Point |: so iissek s o's ee A Se oe we a ees © er 345 PRTUAD TS SEGA a aval le RSE eta espa eo wk ars se 355 FAGWOG AME! es. 5 6.5 geile See Bieisvaial S SR e pola baperalinte pete hats Gre femal stele eet ee 390 PAY TGRD Cos Wo dee ee me Nese er ayer mabe SP MaeR MIMS SCNT 340 eit cer() ———— rr en ee en Pere ew See 290 Black Wslund Harbor (Newark Usland) J. ....3.5,.6 26 2/6 « ale ace stcce 290 Porte REATIVORS R55 occa kek, SS had ees wills onde gles oe ee Sa 285 Cutthreat Tiekle: 25: milessnorth: 250. O48 ae oe Wie be SS es ee 270 Marea iG e wo. oe hie iene 2 SS a ig abe scene ecard ella ier a oe 265 EV GUAT aires. os 5 2% is wd as ew dew Son Deere Shah teaeed alianerss eee eee ree 260 Kipsimarvils, Nachvak. Bay: > oe se <2 cals incite = «foo a 2.0 eines © rier Sel 250 From Coleman: Latitude 59° 30’... 22... ee cece eee cece eee cece eee e cere eceenences 225 From Low: Hudson Strait, Douglas Harbor, southwest arm.............2--s2seces 405 Hudson Strait, near Dyke Head, over 100 miles east...............e220% 405 Hudson Bay, vicinity of Richmond Gulf... 2... 00 je 6.06% ties on 700+ NEWFOUNDLAND From Daly: Saint Fons festimid FEC) 5 a sees. nee eae eee Wee tauhe a eee Whee ee 575 Cape Rouge Harbor. - é 2). 6.02: ayes interes oe = cee ole oi «nie = 505 Kirpon Island) os wins 2.5 cs oe eee gee Be eels Ae ee elsyelsine = ne ne 450+ From Coleman: Locality NOG RIVE. cups oii. 5 ojeie 05 Gwe Hctaleigie = Sele o's winiola wreteinloje.etelb, oor Wim aint ee 500+ TABULATION AND DESCRIPTION OF NEW DATA 229 From Tyrrell: FTO Ne oe! paced Et aL akal aD VSS] en ge a Gente Ae aie i i Os ic Geer aera 300—400 Brn aP A Uysal Wir) WOE GIA ME OMT ig Scan. d bye bie: Li's. ats i's: sllala) Boweava a ayes wide: GleMelnle Braue * 300-400 All available information on the glacial geology of Newfoundland favors an independent ice-cap, with radial flow.* And when we con- sider the large area and mountain heights of the island; the northern position ; exposure to ocean on all sides; and location in the paths of the cyclonic storms of America, it appears certain that the island was the | locus of heavy snow precipitation and a massive ice-cap—the Newfound- land continental glacier. . The opinion of some Canadian geologists assigning local ice centers to Gaspé, the highlands south of the Saint Lawrence, Nova Scotia, and Newfoundland is quite certainly true for Newfoundland, probably true for Nova Scotia, and possibly true for other highland districts, at least for the waning stage of glaciation. The ice-sheets deployed widely on the land, but seem to have been inhibited by the sea, especially where the tides were strong and heavy storms were frequent. BIBLIOGRAPHY Lists of writings which have some bearing on the problems of post- Glacial continental uplift, particularly on the area of New York and the adjacent territory, have been published in the papers numbered 81-84 in the following list. Only a very few titles from the former lists are re- peated here. The present list is mostly of papers relating to Canada and New England. Bibliographies by other authors on elacial geology have been published as follows: On the Pleistocene of the New England coast, to the year 1899, by Upham, in the paper number 52 below. . On the Pleistocene of New England northeast of Boston, to 1908, by Clapp, in number 74, by references. A very full and well annotated list of the glacial literature, relating especially to the region of the Great Lakes, to 1915, is given in Leverett and Taylor’s monograph, number 80. The publications of the Geological Survey of Canada, up to 1908, are listed and classified in detail in the two volumes of the Survey entitled “Index to Reports.” 47, C. Chamberlin: Notes on the glaciation of Newfoundland. Bull. Geol. Soe. Am.. vol. 6, p. 467. This brief article was inadvertently omitted from the bibliography, 230 HH. L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA J 2 =I 10. iBE 12. 13. 14. 15. 16. 17 18. 19. . Rosperr BELL: Superficial geology of the Gaspé Peninsula. Canadian Naturalist, volume 8, 1863, pages 175-183. . ———-: Evidence of northeasterly differential rising of the land along Bell River (Canada). Bulletin of the Geological Society of America, volume 18, 1897, pages 241-250. . ———: Rising of land around Hudson Bay. Report of the Smithsonian Institution for 1897, 1898, pages 359-367. . G. F. MAatHEw: Surficial geology of southern New Brunswick. Geological Survey of Canada, Report of Progress, 1877-78, part EEK, 1879, pages 1-36. . ROBERT CHALMERS: Surface geology, northern New Brunswick and south. eastern Quebec. Geological Survey of Canada, volume 2 (1886), part M, 1887, pages 1-39. : Surface geology of southern New Brunswick. Geological Survey of Canada, volume 4 (1888-89), part N, 1890, pages 1-92. : Height of Bay of Fundy Coast . . . marine fossils at Saint John, New Brunswick. Bulletin of the Geological Society of America, volume 4, 1893, pages 361-370. ———: Surface geology of eastern New Brunswick. northwestern Nova Scotia, and a portion of Prince Edward Island. Geological Survey of Canada, volume 7 (1894), part M, 1895, pages 1-149. . ———-: (In summary report), Geological Survey of Canada, volume §& (1895), part A, 1896, pages 94-97. : Pleistocene shorelines of the Saint Lawrence Valley. Geological Survey of Canada, volume 10 (1897), part A, pages 64-74; part J, 1898, pages 12-19. : Surface geology and auriferous deposits of southeastern Quebec. Geological Survey of Canada, volume 10 (1897), part J, 1898, pages 1-160. ———: Notes on the Pleistocene marine shorelines and landslips of the north side of the St. Lawrence Valley. Geological Survey of Canada. volume 11 (1898), part J, 1900, pages 63-70. : Surface geology of northwestern New Brunswick. Geological Sur- vey of Canada, volume 13 (1900), part A, 1901, pages 151-155. : Artesian borings, surface deposits, and ancient beaches of Ontario. Geological Survey of Canada, volume 15 (1902-03), part A, 1903, pages 270-281. ——-—: Surface geology of the southern part of the Province of Quebec. Geological Survey of Canada, volume 15 (1902-03), part AA, 1903, pages 140-143. : Surface geology of eastern Quebec. Geological Survey of Canada, volume 16 (1904), part A, 1904, pages 250-263. A. P. Low: Explorations in James Bay and country east of Hudson Bay : Geological Survey of Canada, volume 3 (1887), part J, 1888, pages 1-62. : Notes on the glacial geology of western Labrador and northern Quebec. Bulletin of the Geological Society of America, volume 4, 1892, pages 419-421. : Marine terraces (in Quebec). Geological Survey of Canada, volume 5 (1890-91), part L, 1892, pages 58-64. 20. 21. BIBLIOGRAPHY 23h A. P. Low: Explorations in Labrador Peninsula along the East Main, Kok- soak, Hamilton, Manicuagan, and portions of other rivers in 1892-1895. Geological Survey of Canada, volume 8 (1895), part L, 1897, pages 1-311. : Traverse of the northern part of the Labrador Peninsula from Richmond Gulf to Ungava Bay. Geological Survey of Canada, volume 9 (1896), part L, 1898, pages 1-48. —: Exploration of part of the south shore of Hudson Strait and of Ungava Bay. Geological Survey of Canada, volume 11 (1898), part L, 1899, pages 1-47. . ——-—: Exploration of the east coast of Hudson Bay, from Cape Wolston- holm to the south end of James Bay. Geological Survey of Canada, volume 13 (1900), part D, 1902, pages 1-84. . A. S. PAckARD: The Labrador Coast. 1891. . F. B. Taytor: The ancient strait at Nipissing. Bulletin of the Geological Society of America, volume 5, 1893, pages 620-626. : The limit of Postglacial submergence in the highlands east of Georgian Bay. American Geologist, volume 14, 1894, pages 273-289. : (Later glacial lakes.) United States Geological Survey, Niagara Folio, number 190, 1913, pages 18-24. J. B. TyrreE_u: Is the land around Hudson Bay at present rising? Ameri- can Journal of Science, volume 2, 1896, pages 200-205. 29. ———_: The glaciatiion of north-central Canada. Journal of Geology. volume 6, 1898, pages 147-160. 30. ——-—-: The Doobaunt, Kazan, and Ferguson rivers and the northwest coast of Hudson Bay. Geological-Survey of Canada, volume 9 (1896), part F (marine deposits), 1898, pages 190-193. - 31 : The Patrician glacier, south of Hudson Bay. International Geo- logical Congress, XII, 1914, pages 523-534. 32. —: Gold-bearing gravels of Beauce County, Quebec. American Insti- tute of Mining Engineers, Bulletin No. 99, 1915, pages 609-620; Canadian Min‘ng Journal, volume 36, No. 6, 1915, pages 174-178. So. : Notes on the geology of Nelson and Hayes rivers. Transactions of the Royal Society of Canada, volume 10, 1916, pages 1-27. 34. : Remarks on Lake Agassiz (discussion). Bulletin of the Geo- logical Society of America, volume 28, 1917, pages 146-148. 35. R. W. ELLs: Sands and clays of the Ottawa basin. Bulletin of the Geo- logical Society of America, volume 9, 1897, pages 211-222. 36. ————: Surface Geology (Quebec and Ontario). Geological Survey of Canada, volume 12 (1899), part J, 1902, pages 90-94. 37. A. P. COLEMAN: Marine and freshwater beaches of Ontario. Bulletin of the Geological Society of America, volume 12, 1901, pages 129-146. 38. : Sea beaches of eastern Ontario. Bureau of Mines of Canada, Report for 1891, pages 215-227. R. A. DAty: The geology of the northeast coast of Labrador. Bulletin of L360: 40. the Museum of Comparative Zoology, volume 38, 1902, pages 205-270. ———: The geology and scenery of the northeast coast (Labrador). In “Labrador, the country and the people,” by W. T. Grenfell and others. 1909, pages 81-139. 232. A. Le FAIRCHILD 44. 61. 62. POST-GLACIAL UPLIFT OF N. FE. AMERICA . R. A. DAty: Pleistocene glaciation and the coral reef problem. American Journal of Science, volume 30, 1910, pages 297-308. . ————: The glacial-control theory of glaciation. Proceedings of -the American Academy of Arts and Sciences, volume 51, 1915, pages 157-251. . A. F. Hunter: Raised shorelines along the Blue Mountain escarpment. Geological Survey of Canada, volume 16 (1904), part A, 1905, pages 225-228. JOSEPH KEELE and W. A. JOHNSTON: Superficial deposits near Ottawa. International Geological Congress, XII, Guide Book No. 3, 1913, pages 126-135. (Issued by the Geological Survey of Canada.) . ————: Preliminary report on the clay and shale deposits of the Province of Quebec. Geological Survey of Canada, Memoir number 64, 1915. . W. A. JOHNSTON: The Trent Valley outlet of Lake Algonquin, etcetera. szeological Survey of Canada. Museum Bulletin number 23, 1916. —: Late Pleistocene oscillations of sealevel in the Ottawa Valley. Geological Survey of Canada, Museum Bulletin number 24, 1916. . ———: Pleistocene and recent deposits in the vicinity of Ottawa, etcetera. Geological Survey of Canada, Memoir number 101, 1917. . WARREN UPHAM: Terminal moraines of the North American ice-sheet. American Journal of Science, volume 18, 1879, pages 81—92.°197-209. . ——: A review of the Quaternary era, with special reference to the deposits of flooded rivers. American Journal of Science, volume 41, 1891. pages 33-52. —: Late Glacial or Champlain subsidence and re-elevation of the Saint Lawrence basin. American Journal of Science. volume 49, 1895, pages 1-18. : : Glacial history of the New England Islands, Cape Cod, and Long Island. American Geologist, volume 24, 1899, pages 79-92. ——-: New evidences of epeitrogenic movement causing and ending the Ice Age. American Geologist, volume 29. 1902. pages 162-169. ——: The glacial lakes Hudson-Champlain and Saint Lawrence. Ameri- can Geologist, volume 32, 1903, pages 223-230. —-: Glacial lakes and marine submergence in the Hudson-Champlain Valley. American Geologist, volume 36, 1905, pages 285-289. . N. S. SHALER: Report on the geology of Martha’s Vineyard. United States Geological Survey, Seventh Report, 1885-86, 1888, pages 297-363. . ———: The geology of the island of Mount Desert. Maine. United States Geological Survey, Eighth Annual Report, 1886-87, part 2, 1889. pages 987-1061. . ———: The geology of Nantucket. United States Geological Survey, Bul- letin number 53, 1889. . ———: Evidence as to the change of sealevel. Bulletin of the Geological Society of America, volume 6, 1895, pages 141-166. : Geology of the Cape Cod district. United States Geological Sur- vey, Eighteenth Annual Report, 1896-97, 1898, pages 497-593. GERARD DE GEER: On Pleistocene changes of level in eastern North America. American Geologist, volume 11, 1893, pages 22-44: Proceedings of the Boston Society of Natural History, volume 25, 1892, pages 454477. J. D. DANA: In Manual of Geology, fourth edition, 1895, pages 981-993, BIBLIOGRAPHY 233 63. G. K. GILBERT: Recent earth movements in the Great Lakes region. United States Geological Survey, Eighteenth Annual Report, part 2, 1898, pages 595-647. 64. B. K. EMERSonN: Geology of Old Hampshire County, Massachusetts. United States Geological Survey, Monograph 29, 1898. : Holyoke folio, Massachusetts-Connecticut. United States Geo- logical Survey, folio 50, 1898. 66. M. L. FULLER: Champlain submergence in the Narragansett Bay region. American Geologist, volume 21, 1898, pages 310-321. -: The elevated beaches of Labrador. Science, volume 25, 1907, page 67. 32. 68. G. H. Stone: The glacial gravels of Maine and their associated deposits. United States Geological Survey, Monograph 34, 1899. 69. W. O. CrosBy: The glacial lake of the Nashua Valley. Science, volume 9, 1899, page 106; American Geologist, volume 23, 1899, pages 102-103. 70. ——-—: Structure and composition of the delta plains formed during the Clinton stage in the glacial lake of the Nashua Valley. Technology Quarterly, volume 16, 1903, pages 240-254; volume 17, 1904, pages 37~75. 71. A. W. Grasau: Lake Bouvé, an extinct glacial lake in the southern part of the Boston basin. Boston Society of Natural History, Occasional Papers. volume 4, 1900, pages 564-600. 72. J. B. WoopwortH: Note on the elevated beaches of Cape Ann, Massachu- setts. Bulletin of the Museum of Comparative Zoology, volume 42, 1908, pages 191-194. . 73. F. G. CLAPP: Relations of gravel deposits in the northern part of glacial Lake Charles. Massachusetts. Journal of Geology, volume 12, 1904, pages 198-214. 74 ———-: Complexity of the Glacial period in northeastern New England. Bulletin of the Geological Society of America, volume 18, 1908, pages 505-556. 75. J. W. GOLDTHWAIT: The sand plains of glacial Lake Sudbury. Bulletin of the Museum of Comparative Zoology, volume 42, 1905, pages 263-301. 76. : Records of Postglacial changes of level in Quebec and New Bruns- wick. Geological Survey of Canada, Summary Report, 1911, 1912, pages 296-302. 77. ——-—: Excursion in eastern Quebec and the Maritime provinces. Inter- national Geological Congress, XII, Guide Book number 1, 1913. (Issued _ by the Geological Survey of Canada.) 78. : The upper marine limit at Montreal; at Covey Hill and vicinity. International Geological Congress, XII, Guide Book number 38, 1918, pages 119-122. (Issued by the Geological Survey of Canada.) 79. J. W. SpeNcER: Postglacial earth-movements about Lake Ontario and the Saint Lawrence River. Bulletin of the Geological Society of America, volume 24, 1913, pages 217-228. 80. FRANK LEVERETT and F. B. Taytor: The Pleistocene of Indiana and Michi- gan and the history of the Great Lakes. United States Geological Sur- | vey, Monographs, volume 53, 1915. XIX—Buuw. Guor. Soc. AM., Vor. 29, 1917 234 H.L. FAIRCHILD—POST-GLACIAL UPLIFT OF N. E. AMERICA S1. H. L. FarrcuiLp: Pleistocene marine submergence of the Connecticut and Hudson valleys. Bulletin of the Geological Society of America, volume 25, 1914. pages 219-242. S2. ————: Pleistocene uplift of New York and adjacent territory. Bulletin of the Geological Society of America, volume 27, 1916, pages 235-262. : Post-Glacial marine waters in Vermont. Report of the Vermont State Geologist for 1915-16, 1917, pages 1-41. 84. —-——: Post-Glacial marine submergence of Long Island. Bulletin of the Geological Society of America, volume 28, 1917, pages 279-308. 85. ——-—: Post-Glacial features of the upper Hudson Valley. New York State Museum Bulletin, number 195, 1917. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 235-244 JUNE 30, 1918 EXPLANATION OF THE ABANDONED BEACHES ABOUT THE SOUTH END OF LAKE MICHIGAN ? BY G. FREDERICK WRIGHT (Presented in abstract before the Society December 28, 1916) CONTENTS Page PPPeeEN RUC Ot EMG WEMGINES 2's. 4 tre e-w ie ee baie a we Waele bw aie sans ass ORG ahae Sete cer aeed Peat deposits between the second and third beaches.................... 297 Ere ate OL TMG. aes es en his Gee a ek ale vale 6 Ble aealeddelts oe wks dena SOS Perea Giant r to MNGAkO OULIET eco os.ctalstoesoe a os btepare som died go Yee eens Havers Oo Pre emaneres HOt TANG LOVES. oie hoes. ee. Sh oie aie aleve ble Sele wider eiels ee cles ee 240 Popmuceuseanier openin= of the Sag outlet. ... veces ss cee eee eee eee es PAO Iiffects of the diversion of the water in the glacial lakes in the L[rie- (La TESST aie Sa 9 BO Ba ir ole ee ee A 241 Glacial and clay deposits underneath Chicago.............. tee ee ceca. re 243 Provisional estimates of glacial time afforded in this area............... 244 DESCRIPTION OF THE BEACHES Three abandoned postglacial beaches at the south end of Lake Michigan have been known for many years. In 1870 Dr. Edmund Andrews de- scribed them in a very elaborate paper published by the Chicago Academy of Sciences. Later, Mr. Leverett, in his monograph, “Illinois glacial lobe,’ and Mr. William C. Alden, in his Chicago Folio of the U. 8. Geological Survey, have collected the facts in very full measure. From these and other published observations it appears that, surrounding the south end of Lake Michigan from about the vicinity of Waukegan, on the west side, and extending indefinitely northward on the east side, there is an abandoned beach approximately 60 feet above the level of the lake. This is called the Glenwood beach. Twenty feet lower, or about 40 feet above the present level of the lake, occurs what is called the Calumet beach. Twenty feet lower still, or approximately 20 feet above the level of tht lake, occurs the 'Volleston beach. These are shown on the accompanying map (figure 1), compiled 1 Manuscript received by the Secretary of the Society March 19, 1918. (235) ppb Ree, : = a ae me r a P 3 ~~. oS i... A eee OS , —_ . : ry , 3 ed e ma R , ri : ~™ ; vy @ ANIVHOW eee OSIVUVA TVA aNTHABT OSIVEVAIVA LYIYD ir J 5 oe 5 Buff and red sandy shale with chert horizons. Weathers rapidly. Belemnites at about 5 and 35 feet from base. About.......... 50 TYPICAL SUNDANCE AND MORRISON SECTIONS 253 Coarse, heavy-bedded, buff sandstone. About................... 10 Green to buff sandy shale with Ostrea strigilecula, Pseudomo- notis (Humicrotis) curta, Belemnites densus, and Cardioceras cordijorme. Weathers rapidly: Abouteceond os coed ek lees 20 Red and white sandstone and red shale, passing upward into thin- bedded, white, coarse sandstone somewhat conglomeratic at the EME me MILL rae Rs ge date ie aoe is Ye leis and.loo a: ai see enGe OMRON Oeecolig tare hee Mos Wire Sea a ae ate 22 Break in deposition. Triassic. Chugwater red sandy shales between white sandstones. FREEZEOUT HILLS, WYOMING North of Medicine Bow. Adapted from W. C. Knight, Bulletin of the Geological Society of America, volume 11, 1900, pages 381-382. Veet Comanchian. Cloverly conglomerate and sandstone. Originally called Dakota sandstone. Probable break in deposition. Morrison formation. Drab marls and clays, with some thin sandstones a ON Wa CRIA) pM URES Se ucbicy Spcne sch anes Soh acticin ce ¢ inh ele dod dh abd msah scoala o MO SEETA, awh eile waa 55 Hard clay and sandstone with naiids and teeth of crocodiles... 1.5 Drab mar ls and clays with a few beds of calcareous sandstones. Has Allosaurus fragilis, Diplodocus longus, Brontosaurus ex- celsus, Morosaurus grandis, Stegosaurus ungulatus, Campto- Sours dispar. OC eratogus, and TUTTLE 2 ss... celc aks gs, Sale ae ere 24.5 Drab marls and clays with thin soft sandstones.............. 46 Yellowish soft sandstone with cycads and wood....... page te sete 10 Brown sandstone, cross-bedded..... 0. cee ee ecw ees cen ae 2 Prab she ae Pies Wee ne) «ka ene 30 Soft, buff, sandy and shaly sandstones terminating in indurated brown-stained beds. Has Belemnites and, at the top, nuculoids. 30 White, thin-bedded sandstones... 05... .0...2:.5. 0S eee é White, thick-bedded and irregularly layered sandstones...... ae Total: >. caster eee cee hee oe eo ea oe 55 be eee 1438 Break in deposition. Triassic. Chugwater formation. Red and green sandy shales. EASTERN SIDE OF FREEZEOUT HILLS, WYOMING Near Dyer’s ranch house. See W. N. Logan, Kansas University Quar- terly, volume 9, 1900, pages 109-154. His section considerably altered by Schuchert, from observations made September 11, 1899. Feet Comanchian. Cloverly formation. Originally correlated with the Dakota formation. Thin-bedded sandstone (top not seen; total thickness elsewhere about 75 feet)..... beet. SE ISOS. 10 Blue shale, “hard: oo. SSSR aes See, eee eee « wae 2b oie Heavy-bedded, coarse sandstone and conglomerate............. ae Total sees. 25.2). eee weet eee eee eee eens eae 2h eee bea .0 wean Probable break in deposition. ; Morrison formation. Jointed clay, greenish, with an occasional sandstone layer. Has sauropods, Stegosaurus, and Allosaurus............ +. Arenaceous limestone, bluish to brown. Unio knighti, U. willis- toni, U. baileyi, Valvata leei, and Planorbis veternus.......... 1 TYPICAL SUNDANCE AND MORRISON SECTIONS 255 Feet Jointed clay, greenish, with small concretions. Brontosaurus, Diplodocus, and Morosaurus. First appearance of Planorbis (ONSTAR COLORS CUNO COR ASTOR FOL CX2) 0 a GR ar Agra eR 30 MM SMMC hm OE BONED Scoala We now know that there are three brackish- to fresh-water dinosaur horizons inter- bedded with three zones more or less replete with marine mollusks, and of these, two indicate very clearly their own age as well as that of the interbedded dinosaur horizons. As these age-determined dinosaurs ap- pear to be much like those of the American Morrison formation, whose time in the geological scale is not fixed, it is desirable to present a sum- mary of the African studies, at least in so far as they bear on the age of the Morrison and the habitats of these reptiles. A preliminary statement of the African discovery was presented by the writer in 1913.7° GENERAL RESULTS The director of the Geological-Paleontological Institute of the Royal Museum in Berlin, Professor Branca, informs us that the expedition to * Wissenschaftliche Ergebnisse der Tendaguru-Expedition 1909-1912. Published in Archiv fiir Biontologie, Berlin, vol. iii. Part i, 1914, pp. 1-110, has six papers of a gen- eral nature by Wilhelm Branca and W. Janensch. Part ii, 1914, pp. 1-276, has four papers on the geology, stratigraphy, geomorphology, tectonics, and peat-moors, by Edwin Hennig, H. von Staff, and W. Janensch. Part iii, 1914, pp. 1-312, has six papers on the invertebrates and fishes by W. Janensch, J. Zwierzycki, W. O. Dietrich, Edwin Hennig, and Erich Lange. For the work on the armored dinosaurs, see Hennig, Kentrosaurus zthiopicus der Stegosauride des Tendaguru, Sitz. d. Gesell. Naturf. Freunde zu Berlin, 1915, pp. 219-247. 2% C, Schuchert: The dinosaurs of East Africa. Am. Jour. Sci. (4), vol. 35, 1913, pp. 34-38. TENDAGURU SERIES 265 the southern part of German Hast Africa was led by Dr. Werner Janensch, assisted by Doctors Hennig, Von Staff, and Reck, during the years 1909- 1912. During this time in the dry season they always employed from 150 to 500 natives, whose wages averaged about twelve cents a day. The shipments to Berlin totalled 1,050 cases, weighing about 250 tons, the whole costing about $58,000. No complete single skeleton was found, though the museum hopes to mount from four to five great sauropods, one or more small ornithopods, and one armored predentate. Of large skulls, they have found three fairly complete ones and the back parts of eight more, and of small skulls there are six. Of marine invertebrate fossils there is a great and varied quantity, and most of these are carefully col- lected as to horizons. GENERAL STRATIGRAPHY Branea*’ tells us that “even now we have attained the important conclusion that the dinosaurs of German East Africa belong to the Upper Jurassic and the Lower Cretaceous, and accordingly these animals lived not later than those [of the Morrison] of North America.” The invertebrate and fish faunas interbedded with the dinosaur zones establish the conclusion “that the saurian beds are not actually continental deposits . . . but are also deposits of waters of a nearby shore; but laid down under especial conditions that can be determined, at least to a certain degree, from the inherent character of the formation.” For easy reference the writer will insert here a table of the succession as determined in the area about Tendaguru: Mikindam fluviatile sands and conglomerates. Great break in section. Makonde unfossiliferous series, 617 feet thick. To the north has marine Urgonian and Aptian fossils. Probable break in sedimentation. Tendaguru series, 400 feet. 4 Marine Trigonia schwarzi sandstones, 16 feet. Neocomian......... Upper or main dinosaur limy-sandy clay. | 130 feet. [ Dinosaurs, Morrison-like. Lower Cretaceous SEE “7 Op. cit., part i, p. 68. XXI—BULL. Grou. Soc. AM., Vou. 29, 1917 266 Cc. SCHUCHERT——MORRISON AND TENDAGURU FORMATIONS ( Yo break in sedimentation. Marine 7’. smeei sandstones, 65 feet.. | Kimmeridgian...... ) Middle dinosaur limy-sandy clay, 50 feet. Upper Dinosaurs, Morrison-like. Best skele- Jurassic i tons here. ; Exact age not yet j Marine Nerinea sandstones, 80 feet. established ! Lower dinosaur sandy clay, 65 feet. ~ Ancient granite and gneiss. Possibly Pre cambrian in age. oS The Tendaguru series of brackish- to fresh-water shales and shallow- water marine sandstones, together a little over 400 feet thick, overlaps an old gneiss-granite foundation, possibly. of. Precambian age; all are fully described by Janensch and Hennig in Parts I and II of the German publication. The series is exposed in southern German East Africa in an east and west direction for at least 27 kilometers and north and south for over 100 kilometers. The deposits were laid down between hills and islands of granite. At the base the Tendaguru series is marked by a great unconformity, and on it lies the Makonde formation, and all are to be seen on the high plateaus and in the many deep ravines cutting through them. The three marine zones, together 130 feet thick, are hard, coarse-grained, or even conglomeratic (arkosic), cross-bedded sandstones, with the fore- setting toward the east and northeast, and this feature is in harmony with the general dip, which is in the same direction. The dinosaur zones consist in the main of greenish shales, though certain beds are brick-red in color. The latter color appears to be due to secondary causes, as weath- ering or the percolating of aerial ground waters. In places the dinosaur shales become sandy and are then also cross-bedded, rippled, and have some intraformational shale pieces. Nowhere do the authors mention the presence of sun-cracking. The Makonde variegated red and white muddy sandstones are unfossiliferous, 617 feet in thickness, and are said by Hennig to lie unbroken on the Tendaguru series. Beyond the Tendaguru region the Makonde formation becomes abundantly fossiliferous and the fossils correlate the sandstones with the Urgonian and Aptian, or, in other terms, with the Lower Cretaceous. It would therefore seem that the Makonde is also an overlapping formation and toward the southwest. This feature indicates to the present writer that there is in all probability a break in deposition between it and the Tendaguru series, at least in the Tendaguru area. Unconformably over the Makonde series are the very young Mikindani beds of fluviatile sands and conglomerates (Scholter). TENDAGURU SERIES 267 Hennig** is convinced that there is no break in deposition in the Ten- daguru series, and that the three dinosaur horizons are intimately united by transition zones with the three interbedded sandstones that are clearly of marine origin. The transition zones are proved to be such not only by ‘their petrographic nature and transitions, but by their included faunas as well. The whole consists of both marine and brackish-water deposits, though the latter in the proximity of rivers may have been completely of fresh-water origin. Ammonites persist longest in the transition zones, but most often it is the guards of belemnites which occur, and they may be as common as the associated dinosaur bones. Hennig writes :°° “The vanishing of the generally varied and rich life of the marine horizons is somewhat sudden toward the dinosaur zones. There appears to be a re- _markable loss of marine forms: aside from a very few molluses, there are only belemnites, and these persist into the base of the dinosaur zones. They, too, then disappear, and of nfarine inhabitants that go to disprove the con- tinental origin of the dinosaur beds there are, besides [ganoid] fishes, a few [brackish-water] bivalves. Of these quite a number were found, but this is mainly due to the extensive quarrying for dinosaurs. We have here a Mytilus and one or more species of Cyrena. The former is a marine shell, while the - latter is a brackish-water genus, though both may occur in either habitat.” “In particular abundance and at times in colonies so as to make entire beds within the dinosaur zones occur cyrenas and less commonly Mytilus. The former are especially common at the base of the upper dinosaur zone, and the latter at the base of the middle dinosaur zone. . . . In the transition beds between the Nerinea and middle dinosaur zones, and even at the base of the latter, in connection with skeleton p, were associated nests of [marine] snails. Locally throughout the upper dinosaur zone occur very rarely genera of [pul- monate] snails. . . . Highly interesting was the occurrence of a small marine fauna located within the ribs of a great sauropod at Mtapaia. This skeleton was found at the top of the middle dinosaur zone, practically in the transition bed, for immediately above it came the hard sandstone of the Tri- gonia smeev horizon, rich in marine shells.” In fairly typical dinosaur clay there was found, in one case only, a single bone overgrown with oysters. In the marine zones the species of T'rigonia play an important part and are good guide fossils if one takes the time of their greatest individual abundance as the zonal marker. The species themselves may have a long time range, passing even into other zones (7. smeei is rare in the T. schwarz and Nerinea zones), but the time when they make up whole beds of shells occurs but once. The gastropod Nerinea is often abundant, but is not a trustworthy guide.*® Dinosaur bones are of very rare occurrence *8 Op. cit., part iii, pp. 164-166. * Op. cit., part ii, pp. 17-18. 80 Hennig: Op. cit., part ii, pp. 15, 16. ll 268 C. SCHUCHERT——-MORRISON AND TENDAGURU FORMATIONS in the marine horizons, and when such are present they are isolated bones that have been washed in from lower beds.** SECTION IN DETAIL The following detailed section is compiled in the main from J ane and relates to the immediate area of Tendaguru Hill: Tendaguru series. (1) Upper sandstones with Trigonia schwarzi. Thickness at least 5 me- 31 Hennig : ters, but the top is not seen. The upper 4 meters or more consist of yellowish brown sandstone that has silky bedding surfaces, with calcite crystals and bullet- like concretions up to the size of a human head. When these beds are calcareous they hold a rich marine fauna. Lower, coarse, whitish sandstone, about 1% meter thick. The material is an arkose of sharp or rolled quartz, feldspar, and granite pieces (up to several centimeters across), cemented by carbonate of lime. The fauna in the main consists of thick- shelled mollusks and numerous corals. The following described species occur in the 7’. schwarzi zone, those in italics being guide fossils: CEPH ALOPODA: 82 species, of which 19 are either new or can not be identified. Belemnites pistilliformis, B. aft. subfusiformis, Duvalia (D. elegantissima, new), Nautilus pseudoelegans, N. cf. bouchardianus, NV. cf. neocomiensis, N. expletus, Phylloceras aff. mfundibulum, P. serum perlobata, P. deplanatum (new), Lyto- ceras, Astieria (4 spp.), Holocostephanus, Holcodiscus (2 spp.), Hoplites cf. neocomiensis, Crioceras aft. duvali, C. aff. meriani, Hamulina cf. quenstedti, Bochianites. None of these species occur below in the T'rigonia smeei zone. GASTROPODA: 17 species. Solarium, Pleurotomaria, Trochus bran- cai, Tectus, Chrysostoma, Natica, Mesalia, Omphalia, Nerinea, Nerinella, Cerithium, Chenopus eurypterus. None are from lower zones. BivaLvEs: Of species listed by Lange there are 83 in 37 genera. From 20 to 50 per cent are related to Mediterranean forms. Of these may be mentioned Gervillia dentata (also occurs be- low), Camptonectes striatopunctatus, Syncylonema orbiculare, Hinnites, Cyprina, Exogyra coulom, Modiola equalis, Cucullea gabrielis, Trigonia schwarzi, T. smeei (rare here, from below), T. transitoria, T. conocardiiformis, Sphera cordiformis, Phola- domya gigantea, Panopea gurgitis, Protocardia schencki (from below), and Vola atava. BRACHIOPODA: Rhynchonella raufi, Zeilleria dubiosa, and Kingena transiens. Op. cit., part iii, p. 164. TENDAGURU SERIES >. 969 (2) Upper or third dinosaur zone. Limy-sandy marls. About 40 meters. This is the most widely exposed zone of the Tendaguru. Gray sandy marl, 2 meters. Usually intensely red sandy marl, 5 meters. Light yellowish gray, very soft sandstones, with zones of sandy marls, 10 m. Red sandy marls rich in clay, 2 m. Yellowish gray soft sandstone, 1.5 m. Red sandy marl rich in clay, about 5 m. Gray and reddish sandy marl, about 4 m. Has saurians. Gray sandy marl with occasional interbedded sandstones and a basal red layer, about 5 m. Has saurians. Transition zone. Gray sandy marls that often pass into soft sandstones with local accumulations of bones, and occasionally with marine fossils, as belemnites, 3 meters thick. The following Sauropoda occur in this zone: Gigantosaurus afri- canus (most closely related to American Diplodocus), G. ro- bustus, Brachiosaurus brancai (this genus also in the Amer- ican Morrison), B. fraasi, Dicrewosaurus sattleri (this genus seems to be closely related to Brontosaurus and Diplodocus). Here also are armored dinosaurs related to the Wealden Omo- saurus and Polacanthus, and, rarely, Theropoda. Isolated crocodilian teeth, along with those of selachians (Orthacodus) occur near the base of this zone, and here are remains of the ganoid Lepidotus minor, a Wealden form. Fresh-water snails are very rare. Physa tendagurensis was found associated with Mytilus cf. galliennei and Cyrena. At the base of the zone Cyrena occurs in colonies. oc bec ec sais eee as Upper and middle dinosaur zones. DP UCTIVOSQUTUS SATII... ce cee ee Upper dinosaur zone. Dicreosaurus hansemanni.........+.. Middle dinosaur zone. Kentrosaurus cethiopicus.............. Upper and middle dinosaur zones. RTS ILE IES. (0). artak got eg a delays wie Mal vecegin ee Upper and middle dinosaur zones. PCLILCCLILGIUIUGB (7 Jote eis cn w'cle Pele < c' vie views as Upper dinosaur zone. 280 Cc. SCHUCHERT——-MORRISON AND TENDAGURU FORMATIONS We have long been holding that land vertebrates, living under more variable conditions, change far more quickly than do the marine inverte- brates of long-enduring equable environments, and yet in the present case hardly any of the species of the T'rigonia smeei beds continue into the time of T. schwarzt. There are only five marine bivalves known to bridge this time, a class of long-lived animals and as such having the least value as zonal markers; yet Brachiosaurus brancar, B. fraasi, and the genera Dicreosaurus and Kentrosaurus lived longer, across the time from Ju- rassic into Lower Cretaceous. If the dinosaurs are correctly determined, then all of the invertebrates of the 7’. smeet zone should be reinvestigated to see if some of them can not be referred to the Lower Cretaceous and so brought into harmony with the evidence of the dinosaurs, or the latter seemingly must be shown to be dissimilar in the two upper horizons. Under these circumstances, it appears best, at least for the present, to follow the suggestion of Buckman, who regards the middle and upper dinosaur zones as of Upper Jurassic age. This does not necessarily mean that there is a time break between the upper dinosaur and the 7. schwarzt zones, though the present writer is inclined to look on the available evi- dence as indicating a hiatus here between the Jurassic and the Lower Cretaceous. On the other hand, it is plain that the faunas of the upper marine horizons and the two upper dinosaur zones are more closely related to one another than they are to those of the Nerinea and lower dinosaur hori- zons. ‘The writer therefore raises the further question whether the Ten- daguru is actually a continuous series of deposits or is again broken at the top of the Nerinea zone? The fauna of the Nerinea beds is a small one, with forms that have little stratigraphic value, and this nearly all of the paleontologists concerned with the work have noticed. As for the dinosaur evidence in the lowermost zone, it is as yet unknown other than that they are all small, and this is a very significant fact; all large sauro- pods appear to be absent. The writer therefore thinks that the evidence -as it now stands indicates rather that the lower dinosaur zone and the Nerinea beds are of earlier Jurassic time, followed by a break in the ~ Tendaguru series. Then come the two higher marine and the two main dinosaur horizons that may be of continuous deposition and, if so, bridge over the time from the Jurassic into the Lower Cretaceous. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 281-296 JUNE 80, 1918 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY MEGANOS GROUP, A NEWLY RECOGNIZED DIVISION IN THE EOCENE OF CALIFORNIA * | (Read before the Paleontological Society January 2, 1918) BY BRUCE L. CLARK CONTENTS Page Pereira ree tA TCMICIIE .)<.2-<-)h's os oie «Wie eos wicunwle's elvis eid ent oR poke dele ee GR ds 281 Previous literature concerning the Eocene of the Mount Diablo quadrangle 282 messes Proup north of Mount Diablo.............6. 00sec ccecercecees 283 Senaroranhiy ang, NEHOOLY toa. 62k ec eek Nees Me eek eas 283 Be aaren WNnGeN CONSIGETATION .-< F002 24s sie ud Sic eld avo tta weed ee 5 283 SMA y Of, MibnOlOgy Of SOCHOM ws . 6/60 ers cess. 5 sites wc wide ow cine 285 Evidence for unconformity between Meganos and Tejon......... 288 J TVETSE | TISU OS WG see ane ape Ey en ee ie ere a hr naan Mer meena i 289 Comparison of Meganos ‘and Tejon faunas..:..........0.00000ccaes 289 Meganos group fo south and west of Mount. Diabloe...2.5. . sis. aveoees 290 areata AeA C2 TUN STNG ofa hs of Shc a des cst so Jak cht Sat eel pa sews! uate Lae ue vandals ae, @ 290 SEE EM Vara MI MLEMOLOS Vs a. ase js, x szausce pent soe digas tecod alae va Bakes « 0-20 Wnceiiorm iy 2. ee es eee TR. KE. Dickerson: Univ. of California Publ. Bull. Dept. Geol., vol. 8, no. 6. 1914, p. 71. 286 B. L. CLARK—-THE MEGANOS GROUP ; / | " S & : C. = ( B. 5. See Sse Se Se ee ee J | | Martinez Group... 4 | Chico. Clay shales and sandstones at top, grades down into fine, massive, poorly indurated sandstone; exposures of the beds of this division are very POOP hs. wR Foti WSS eee eee Sandstone of medium texture; thin-bedded near Oo bottom; more massive at top; yellow brown to gray in color. The massive sandstones near top contain lenses of harder, calcareous and fossiliferous: sandstones .. $0... sf.) 3c ee . Dark slate-gray shales; bedding planes fairly distinct ; light calcareous nodules and lenses. . Sandstone, fine to coarse in texture; in places forms a grit; contains thin clay lenses; in places contains considerable carbonaceous Ma tertah- O50 3 sig ah oe ae oe Oe eee . Dark slate-gray shales, similar to (1) and (5). . Sandstone, medium to fairly coarse; weathers on surface a rusty brown; grains chiefly of quartz and mica...... Our present knowledge of the stratigraphy and faunas of the Oligocene of Oregon, Washington, and Vancouver Island is due, to a large extent, to the work of Ralph Arnold, Harold Hannibal, and C. EH. Weaver. It was largely through the field-work of Hannibal during the years of 1911 and 1912 that the stratigraphic sequence, now for the most part generally accepted, was first established. The Oligocene-Miocene sequence, as recognized by Arnold and Hannibal in their paper, “The marine Tertiary stratigraphy of the north Pacific Coast of America,’’ Proc. Amer. Philos. Soc., vol. 52, 19138, pp. 573- 589, was, beginning at the base: . The Sooke formation. The San Lorenzo formation. . The Seattle formation. The Twin River formation. The Monterey formation. We now know, due to the discovery of a vertebrate fauna in the Monterey of Coalinga region (J. C. Merriam: Tertiary vertebrate faunas of the north Coalinga region of Cali- fornia, Amer. Philos. Soc., n. s., vol. xxii, pt. 3, 1915, pp. 21-26), that this epoch of deposition extended into the middle Miocene, and it seems more than probable that the lowest Vaqueros beds are not older than Lower Miocene. For map showing distribution of Oligocene deposits in Washington, see paper by C. E. Weaver: “Tertiary formations of western Washington,” Wash. State Geol. Surv. Bull. 13, 1916, pp. 138-271. oR wh Fe a 304 CLARK AND ARNOLD—MARINE OLIGOCENE this general horizon. This fauna is much better known in Oregon and Washington than in California; the beds of this age in these northern areas are not, as a rule, so highly folded and faulted, thus giving more favorable conditions for preservation. In California, on the other hand, the stratigraphic relationships are more easily determined, due to the semi-arid climatic conditions which have been the cause of better ex- posure. FAUNAL ZONES In Washington three fairly distinct faunas are found in the 10,000 feet or more of sediments, which are considered of Oligocene age. These, be- ginning with the oldest, will be referred to as the faunas of the Agasoma acuminatum beds, of the Molopophorus lincolmensis zone, and of the Acila gettysburgensis zone. The stratigraphic equivalent of these faunal zones, as described by Arnold and Hannibal,® are the Sooke, San Lorenzo, and Seattle formations respectively. The lowest of these faunas, that of the Agasoma acuminatum beds or Sooke formation, has been found at a number of localities in Oregon, Washington, and Vancouver Island, and in every place where the stratigraphic relationships could be determined it is in beds below those of the Molopophorus lincolnensis zone. The two faunas are very different, few species being common to the two. How- ever, the beds containing this lower fauna appear to grade up into those of the other horizon, and in no locality studied have they been found to have any great thickness. For this reason it is probable that the former fauna is a facies of the latter. Apparently the difference between the fauna of the Agasoma acuminatum beds and that of the Molopephorus ® Ralph Arnold and Harold Hannibal: “The marine Tertiary stratigraphy of the north Pacific Coast of America,.’” Proc. Amer. Philos. Soc., vol. 52, 1915. pp. 573-589. These formational names were used by Arnold and Hannibal in a faunal rather than a stratigraphic or lithologic sense. Originally they recognized four divisions between the Eocene and the Monterey—the Sooke, San Lorenzo, Seattle, and Twin River forma- tions. C. E. Weaver has apparently shown that the beds forming the Twin River forma- tion are a part of their Seattle formation, which haS been repeated by folding. See “The Oligocene of Kitsap County, Washington,” Proc. California Acad. Sci., 4th ser., vol. vi, no. 3, 1916, pp. 41-52. The name Agasoma acuminatum beds is used here for the first time. As will be seen from the discussion further on in the paper, it is still doubtful whether the fauna in these beds belong to a zone distinct from the Molopo- phorus lincolnensis zone. This latter name was first used by C. E. Weaver in his Ter- tiary faunal horizons of western Washington. Univ. Wash. Publ. Geol., vol. 1, no. 1, 1916, pp. 4-6. Weaver divided the fauna of the San Lorenzo, as recognized by Arnold and Hannibal, into two horizons. which he called the Lincoln and Porter horizons and to which he also applied the names Molopophorus lincolnensis and Turritella porterensis zones. Later work by Doctor Weaver and his students has shown that the faunas of the Lincoln and Porter beds are much more similar than was at first supposed, and that in all probability they are contemporaneous faunas. Thus only one faunal zone can be recognized: for this it is agreed that the name Molopophorus lincolnensis zone should be used. OF THE WEST COAST 805 lincolnensis zone is due, in large part, to differences in the temperature of the waters in which the faunas lived. The former fauna undoubtedly existed under more temperate conditions than did the latter. This is shown by the fact that a number of the species in the Agasoma acumi- natum beds show very close affinities with certain species which are now living off the coast of Vancouver Island, Washington, and Oregon. The fauna of the Molopophorus lincolnensis zone is more tropical in character, containing a fairly laree number of species which are closely related to ee ie ee a a cee ’ ) ’ ) 1 I | I J 1 ' HWiGuRE 3.—Outline of Oligocene Sea in Washington Tejon (Upper Hocene) species, and if we should look for their recent affinities we would expect to find them in the tropical and subtropical waters off the coasts of Lower California, Central and South America. The latest of the Oligocene faunas in Oregon, Washington, and Van- -couver Island is that from the Acila gettysburgensis zone. The beds in which the Acila gettysburgensis fauna is found are several thousand feet in thickness. On Vancouver Island and in the vicinity of Restoration Point, near Port Blakeley, heavy conglomerates are found which sepa- ( 306 CLARK AND ARNOLD—MARINE OLIGOCENE rate this fauna from that of the Molopophorus lincolnensis zone. Later work’ may possibly show that here we are dealing with two distinct epochs of deposition. This Acila gettysburgensis fauna also is very different from that of the Molopophorus lincolnensis zone, as well as being de- cidedly different from that of the Agasoma acuminatus beds. However, considerably fewer species are known from the Acila gettysburgensis zone than from the Molopophorus lincolnensis zone, and it may be that the difference between the two faunas is more apparent than real. CLIMATIC CONDITIONS R. E. Dickerson,* in a recent publication, has expressed the opinion that the fauna of the Acila gettysburgensis zone lived under more tem- perate conditions than that of the Molopophorus lincolnensis zone. We are left to infer from that that very probably the big difference between these two faunas is due to temperature rather than to the time factor. That Dickerson’s observations are, at least in part, true is apparently shown by the work of B. L. Clark on the fauna of the San Lorenzo of middle California. Here in the same beds is found a considerable num- ber of species which in Oregon, Washington, and Vancouver Island have been found only in the Agasoma acuminatus beds, the Molopophorus lincolnensis zone, or the Acila gettysburgensis zone, thus showing that apparently all three faunas are more closely related in time than was indicated by the data obtained from the northern localities. Some of the species, which in the northern localities have been found in distinct zones, are found in California associated in the same horizon. As these species are highly ornamented gastropods, forms which one might expect to have a rather short life period, they indicate nearly the same, if not identical, age. This intermingling in the California localities of certain of the species of the three faunas as recognized in the northern areas, as cited above, suggests very strongly that in the southern localities conditions of tem- perature existed which were intermediate between the temperature condi- tions which existed during the accumulation of the Agasoma acuminatum beds and the beds of the Acila gettysburgensis zone and the more tropical conditions represented by the deposits of the Molopophorus lincolnensis 7If this should prove to be the case, the lower beds would be referred to the San Lorenzo Group, the upper to the Seattle Group. However, at the present time we do not propose such a classification. The name Acila gettysburgensis zone was first used by Weaver in the paper already referred to. 8R. E. Dickerson: Climate and its influence upon the Oligocene faunas of the Pacifie Coast, with descriptions of some new species from the Molopophorus lincolnensis zone. Proce. California Acad. Sci., 4th ser., vol. vii, no. 6, 1917, pp. 162-163. OF THE WEST COAST 307 zone, thus giving what might be expected, an interfingering of certain elements of the three faunas. FOCENE-MIOCENE RELATIONSHIPS Of the three Oligocene faunas, that of the Molopophorus lincolnensis shows a closer relationship to the fauna of the Tejon (Upper Hocene). A considerable number of the species of the Molopophorus lincolnensis zone are undoubtedly closely related to certain Tejon species. The Kocene character is also shown in the close similarity of the generic as- semblage. C. H. Weaver has listed several highly ornamented gastropods in the Molopophorus lincolnensis zone as common to the Tejon fauna. On the other hand, the Agasoma acuminatum fauna, which is found in deposits lower stratigraphically than that of the Molopophorus lncoln- ensis zone, has nothing in common with that of the Tejon; its fauna is more Miocene in character, so much so that when first described it was considered to be of later Miocene® age than the Monterey (Lower Mio- cene). The highest of the Olhgocene faunas, that of the Acila gettysburg- esis zone, 1s also more closely related to the fauna of the Miocene than to that of the Eocene. Undoubtedly these Miocene and Kocene relationships of the Oligocene faunas, just pointed out, are very largely the result of differences of tem- perature conditions. During Tejon periods tropical conditions prevailed and the tropical marine faunas held sway well up into northern waters. The Agasoma acuminatum fauna, which follows that of the Tejon, repre- sents more temperate conditions of deposition. ‘The Hocene representa- tives of this fauna very probably were living during the Hocene period in the region of the Arctic Circle. Following this the waters, at least locally, as shown by the character of the fauna of the Molopophorus hn- colnensis zone, were again much warmer and tropical species replaced the temperate forms, to be later replaced by a more temperate fauna during the deposition of the beds of the Acila gettysburgensis zone. At the present time we can not say for a certainty that the Oligocene fauna everywhere followed in the sequence as outlined above. As has already been stated, it is still an open question whether the Agasoma acuminatum fauna and that of the Molopophorus lincolnensis zone belong to distinct horizons, the Oligocene opening with temperate conditions, later to be - followed by tropical, or whether these two faunas were contemporaneous, the differences in temperature being local and the two faunas living in 9J. C. Merriam: Note on two Tertiary faunas from the rocks of southern coast of Vancouver Island. Univ. of California Publ. Bull. Dept. Geol., vol. 2, no. 3, 1896, pp. 101-108. : 308 CLARK AND ARNOLD—MARINE OLIGOCENE the same general areas. We find the same difficulty in evaluating the causes of the differentiation of the Molopophorus Betas fauna and that of the Acila gettysburgensis zone. We may say with certainty, however, that during the Oligocene on the West Coast we find the beginning of conditions like those which existed during the Miocene and Pliocene, a beginning of the differentiation of the climatic zones, which were not defined during the Eocene, and with it the local differentiation of faunas, due to temperature barriers—a con- dition which did not exist to any appreciable extent during the Eocene. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 309-326, PLS. 18-19 ‘ JUNE 30, 1918 AMSDEN FORMATION OF THE EAST SLOPE OF THE WIND RIVER MOUNTAINS OF WYOMING AND ITS FAUNA* BY E. B. BRANSON AND D. K. GREGER (Presented in abstract before the Socvety December 29, 1916) CONTENTS Page Seen MT LAE ATISUEM 2 ff iis. s. Cu wean Allein eaane a SR eels co eee le ds 309 ee SITE GOI ENE, co farce aiea oanreca's fu iar ind «hey SRM EMEL EA ema Oreo ah Re alzice: & dial wale 309 See ZONS ANG TOCHLIONS. «ics vic «Ags ste erolmerane Be ols mal avis eck eae ale dia’ 310 Bammer: GEScription Of the ANISeM.,. . «c's we pclasie tie die ccd vials wees wieie oes 310 Pimumiea iC! COPFelatiONS. 2.22. 6. c ee ee ee ee eee cet ee ng oo ay 312 eee nT SEE CSIC CIOR oy al. Sas sande ae wera shee oe Ss SE MOL GREE eet et 313 Mamlaiarion Of plates......5...0.s085 PU MPC. OA ot sie 5 5a Fee hs 2 Rag 325 DISTRIBUTION OF THE AMSDEN The Amsden formation was described by Dartont in 1904 from its out- crops along the Amsden River on the east slope of the Big Horn Moun- tains in northern Wyoming. ‘Since then he has described and mapped it along the Wind River Mountains from Circle on the north to south of Dallas on the south, in the Rattlesnake Mountains, and in the Owl Creek Mountains, and Blackwelder writes of its occurrence in southern Mon- tana. According to Blackwelder, “it can be followed with more or less confidence clear across the State (Wyoming) from the Black Hills to Idaho.” ? Only the Amsden of the east slope of the Wind River Moun- tains from Bull Lake southward is treated in this paper. AGE OF THE AMSDEN Darton has called the upper Amsden Pennsylvanian, on the basis of fossils collected from near Leo and Shirley, and the lower part probably Mississippian. Blackwelder* has found two faunas in the Gros Ventre * Revised manuscript received by the Secretary of the Society April 2, 1918. 1 Bull. Geol. Soc. Am., vol. 15, pp. 396-397. * Am. Jour. Sci., vol. 36, 4th ser., p. 175. 3 Bull. Geol. Soe. Am., vol. 19, pp. 414-415. (309) 310 BRANSON AND GREGER—AMSDEN FORMATION OF WYOMING Range, one of which is Pennsylvanian and the other Mississippian, ac- cording to Girty.* Data presented in this paper indicate the homotaxy of the Amsden of the east side of the Wind River Mountains and the Sainte Genevieve of the Mississippi Valley. Fossiz Horizons AND LOCATIONS Several years ago Mr. N. H. Brown, of Lander, Wyoming, called Mr. Branson’s attention to some fossils that he had collected in outwash from an irrigation ditch a few miles south of Lander, and in 1911 Branson collected some of these, but could not find from whence they came, though the probable source was the Amsden. In 1913 the fossils were found in place a few miles south of the Little Popo Agie River, in the Wind River Mountains, and collections were made from several localities. In 1916 Branson made a small collection in the Bull Lake region northwest of Lander and further collections in the Little Popo Agie region. The fossilization differs sharply in different regions. Near Bull Lake the fossils are of calcite and poorly preserved; at one place south of the Little Popo Agie they are all silicified and the silica is often highly col- ored, while three miles from the silicified fossils the preservation is mainly in hematite. In the Popo Agie region the exact horizon of the fossils was not deter- mined, as both the top and bottom of the formation are covered. Good exposures of the Amsden seem to be absent from the southern Wind River Mountains, and at the best the outcrops consist of a few feet of rock in place. In section 19, township 31 north, range 99 west, about four miles south of the Little Popo Agie canyon, more than three feet of sandy, highly ferruginous shales outcrop about 60 feet from the base of the for- mation. In places these shales grade into a concretionary iron ore, and fossils occur above them and probably in and below them. Above they are in a yellow, impure limestone, and in a red to purple impure lime- stone. The purple limestone was not found in place, but in the float in the same locality as the red shales. The fossils occur weathered out on the slopes for about 20 feet above the shales. SECTION AND DESCRIPTION OF THE AMSDEN There are exposures of the entire formation in vertical cliffs in the Bull Lake region. The iron, sandstone, and shales of the Popo Agie region do not appear and the rock is mainly dolomite and limestone. The following Am. Jour. Sci., vol. 37; 4th ser., pp. 175-176. . SECTION AND DESCRIPTION ile is a section four miles west of Bull Lake, in section 11, township 2 north of the Wind River base line, range + west of the Wind River meridian. The contact between the Amsden and the overlying Tensleep is one of disconformity, with a clear-cut wavy line of demarcation. 1. Compact, fine-grained, light-gray limestone................ 8 feet 2 inches PeeLuie pmne-ocrained, Sandy limestone. o.. 6... ce cc ae cane 4 feet 3. Butf, compact, sandy, thin-bedded limestone much like 1 and 2 but without the gray. The lower part weathers to a pinkish color while retaining its strength and compactness 14 feet 4. Dark-gray, compact, hackly limestone.............. Me hanks kc 7 feet 6 inches 5. Dark-gray, friable, coarsely crystalline limestone, inter- bedded with thin, discontinuous layers of darker gray, compact, lamestone, FOSSIIFETOUS ..... 62... Lew he we ee Sees 23 feet 6. A heterogeneous mixture of limestone, sandstone, shale, and conglomerate in a peculiar arched structure. The under part of the arches weathers out, leaving caves. At the bottom occurs a conglomerate which generally contains many fragments of Madison. In many places breccias resulting from cave-filling occur. Contact with the Madi- RE ST ITY Cl SCONE OMT LE GS ba asa, decd eis wie cule oieepal ane o 6 oatw ateseh a 20 feet Bier ealen tare. sc a eye eta lake Wh na el sa eter manna pace Oak 76 feet 8 inches Measurements were mace on the face of a vertical cliff, excepting the last 20 feet, which was estimated, because the top could not be reached. Many caves occur at the base of the Amsden, and in early Pennsylva- nian time the caves were more extensive than at present. In the Bull Lake region the base consists of a thin, irregular basal conglomerate, above which there is a dolomite containing old caves filled with large, angular fragments of Amsden hmestone mixed with greenish shale and lenticular sandstone beds. Only one filled cave was noted near the top of the forma- tion and it was filled with sand, like that of the overlying Tensleep, the sand occurring as filling matter between Amsden boulders. The sand in the caves near the base also resembles the Tensleep and occurs as filling matter, indicating that the caves were formed in pre-Tensleep time and filled during the Tensleep. Where the base of the Amsden is well ex- posed the lower 20 to 30 feet appear as a series of arches with the over- lying beds overhanging. The tops and sides of the old caves form the tops and sides of the present arches and the old cave-fillings have weath- ered back, forming reentrants. A coarsely crystalline bed of limestone, 3 to + feet thick, that is highly fossiliferous, occurs 35 feet from the top, but fossils were not found in any other bed. 312 BRANSON AND GREGER—-AMSDEN FORMATION OF WYOMING FAUNAS AND CORRELATIONS Three men spent about five hours in collecting in the locality where the section was made, and specimens of the following species were ob- tained: Zaphrentis amsdenensis, Sprrifer pellensis; Spuifer shoshonen- sis, Composita trinuclea, Humetria marcyt, Pugnoides ottumwa, Spiri- ferina brownt, Orthotetes kaskaskensis, Chonetes chesterensis, Tetra- camera subcuneata, Phillipsia sp. ? In the Little Popo Agie region, where all of the fossils were collected on the weathered slopes, the fauna consists of the following species: Zaphrentis amsdenensis Orthotetes haskaskiensis Ortonia cf. blatchleyi Nchizophoria swallovi Orbiculoidea wyomingensis Cliothyridina hirsuta Composita trinuclea Meekella amsdenensis Diaphragmus phillipsi Bulimorpha canaliculata Spirifer welleri Loxonema worthent Spirifer pellensis Bucanopsis or Bellerophon Pustula genevievensis Myalina sancti-ludovici Spiriferina browni Microdon cf. oblongus Martinia sp.? . Crinoid Eumetria verneuiliana Orthoceras Pugnoides ottumwa The most abundant forms in the Wind River Amsden are Composita trinuclea, Spirifer pellensis, Diaphragmus phillipsi, Spirifer wellert, Zaphrentis amsdenensis, and Spiriferina brownt. Composita trinuclea, Humetria vernewiliana, Spirifer pellensis, Pug- noides ottumwa, and Orthotetes kaskaskiensis are positively identified on the basis of minute characters. All of these species occur in the Sainte Genevieve of the Mississippi Valley and none of them ranges below the Salem. The Salem species, Tetracamera subcuneata and Bulimorpha bulimiformis, are not identified with equal positiveness, but the evidence of most of the species indicates that the Amsden should be correlated with the Sainte Genevieve. On the other hand, if the Amsden is of the same age as the Sainte Genevieve, Meekella, represented by M. amsdenensis, occurs earlier here than any place else in America. But M. amsdenensis is a non-plicate form, and in this respect is similar to Meekella leet, from the Lower Car- boniferous® of England, and differs from the Pennsylvanian Meekellas. Pustula genevievensis has often been identified as Productus nebrask- ensis, but agrees better with the Sainte Genevieve form. > Memoirs of the Geological Survey of Great Britain. Paleontology, vol. 1, part 2, pp. 112-114, pl. 13, figs. 1-2. : FAUNAS AND CORRELATIONS ao An unidentified coral that resembles Chetetes milliporaceous, of the Pennsylvanian of the Mississippi Valley, is a disturbing element in draw- ing positive conclusion, but we do not attach great importance to it. Blackwelder’s list of Amsden species from the Gros Ventre Mountains contains no species identified by us from the Wind River. However, our Composita trinuclea may be the same as his C. subtilita as Compositas, scarcely to be distinguished, range from the Amsden to near the top of the Embar (Permian). Productus nebraskensis of the Gros Ventre may be the same as the form identified by us as Pustula genevievensis. Schizo- phoria aft. resupinoides may be our S. swallovt. The evidence of the fossils indicates that the Wind River Amsden is probably older than the Gros Ventre Amsden. It is possible that the two were contemporaneous, but that the Wind River basin was connected with the interior basin and the Gros Ventre was not. DESCRIPTION OF SPECIES . ZAPHRENTIS AMSDENENSIS na. sp. Plate 19, figures 19-20 Corallum horn-shaped, circular in cross-section, slightly curved, sides diverging at an angle of about 30 degrees. Surface marked by incon- spicuous wrinkles, unequally spaced. Calyx shallow; fossula indistinct on the shorter, concave side of the corallum; septe averaging 36, ap- proaching the center in pairs, but leaving a small central area clear. Dimensions of largest specimen collected: Length, 51 millimeters; diameter, 24 millimeters; average specimens, length, 35 millimeters; diameter, 15 millimeters; smallest specimens, length, 14 millimeters; diameter, 8 millimeters. Z. amsdenensis differs from 7%. pellensis, probably the most closely re- lated species, in the absence of spines, smaller angle of divergence of the sides, and less conspicuous fossula. From Z. dwlt Milne Edwards and Haime, another closely related species, it differs in the absence of spines and the less conspicuous fossula. CHATETES ? Plate 19, figures 21—22 Three fragments of a form resembling Chetetes milliporaceous were collected. The best preserved specimen is silicified and details of struc- ture are obscure or absent. No connecting pores have been observed. The small size of the corallites and their angular shape, triangular to hexa- gonal, give the species a close resemblance to Chetetes malliporaceous. XXIV—Butu. Grou. Soc. Am., Von. 29, 1917 314 BRANSON AND GREGER—-AMSDEN FORMATION OF WYOMING BRYOZOANS A few fragments too imperfect for generic reference were collected ; one group is fenestelloid and another batastomelloid in appearance. ORBICULOIDEA WYOMINGENSIS n. sp. Plate 19, figures 7 and 8 Cotypes three specimens from Bull Lake Creek. Shell subcireular in outline; brachial valve with apex about one-fourth the diameter from the posterior margin; surface in front of apex parallel to plane of valve for about one-half the diameter of the shell, thence sloping gently to the | anterior margin. Laterally from the apex the sides are gently concave, behind the apex strongly concave. Surface marked by ordinary, concen- tric lines of growth, 2 to 3 to the millimeter. Pedicle valve with apex a short distance anterior to the center of the shell. Shell slightly convex. Delthyrium extending from apex three-quarters of the distance to the posterior margin of the valve; gradually narrowing posteriorly; com- pletely closed by the listrium. Lines of growth like those on the brachial valve. Diameter of the larger specimen about 25 millimeters, of the smaller specimens 15 millimeters and 16 millimeters. ORTHOTETES KASKASKIENSIS (McChesney) Plate 19, figures 3 and 4 1860. Orthis kaskaskiensis McChesney, Descriptions of New Paleozoic Fossils, page 81. 1892. Derbya kaskaskiensis Hall and Clark, Paleontology of New York, volume 8, part 1, plate 110, figure 6. 1914. Orthotetes kaskaskiensis Weller, Monograph 1,° Illinois Geological Sur- vey, page 77, plate 6, figures 1-14. 1916. Orthotetes kaskaskiensis Weller, Contributions from Walker Museum, volume 1, number 10, pages 245-246, plate XVI, figure 1. The specimens of this species from the Amsden are slightly larger than examples from the Pella beds of Fort Dodge, Iowa. They agree more fully with specimens from the Saint Louis oolite of Lewis County, Mis- sourl. The two specimens in the collection measure: Length, 30 milli- meters ; breadth, 43 millimeters; and length, 32 millimeters; breadth, 46 millimeters. DIAPHRAGMUS PHILLIPSI (Norwood and Pratten) Plate 19, figures 5-6. 1854. Productus phillipsi Norwood and Pratten, Journal of the Academy of Natural Science of Philadelphia, volume 3, second series, page 8, plate 1, figures 2a, bande. ®Synonomy given by Weller in the Illinois monograph is not repeated in this paper, but the original reference is given. DESCRIPTION OF SPECIES 315 1898. Productus phillipsi Weller, Bibliographic Index of North American Car- boniferous Invertebrates, page 498. 1915. Productus phillipsi G. H. Girty, Missouri Bureau of viopciked and Mines, volume 13, series 2, page 347. Original description—*Shell rather small, nearly as long as broad, dorsal valve slightly gibbous, its anterior part flattened, with a wide shal- low sinus on old specimens, while young ones do not show it. The beak, although slightly enrolled on itself, does not pass the cardinal border. The ears are small, flattened, and smooth, showing no trace of either folds or tubes. The surface is covered with coarse, irregularly sized ribs, which are generally broader than the furrows separating them. Many of the ribs are bifurcated. The cardinal line measures four-fifths of the greatest breadth of the shell. The sides fall perpendicularly on the ears. ‘The only traces of tubes are a few indistinct ones on the flanks. “Ventral valve concave, with a very slight varix. The visceral disk has ribs similar to those on the other valve; beyond the disk they are obliter- ated, the surface being covered with nine or ten broad lamelle, the edges of which are turned sharply upward, presenting acute wavy ridges, which are continued on to the cardinal border on each side.” Remarks on Amsden specimens.—The beak passes the cardinal border in some Amsden specimens and in some the ears have incipient folds and a few small spines. Six specimens give the following measurements: Length, 17 to 2414 millimeters; breadth, 20 to 24 millimeters; thickness, 6 to 9 millimeters. The surface of the pedicle valve is marked by avons 28 ribs. Near the anterior border there are from eight to ten ribs in the space of 10 milli- meters. This species may be easily distinguished from any other by the coarse, irregular ribs of the valve and by the visceral portion only of the ventral valve possessing ribs, with broad, ridged lamelle around it. The pedicle valve does not appear to have possessed an anterior prolongation, as its present front is without one and is bounded by a sharp margin. Next to Composita trinuclea this is the most abundant species in the fauna. PUSTULA GHENEVIEVENSIS (Weller) Plate 19, figures 1-2 1914. Hchinoconchus genevievensis Weller, Illinois Geological Survey, mono- graph 1, pages 140-141, plate 18, figures 1-6. The collection contains a few poorly preserved specimens of a Pustula that resemble “Hcehinoconchus” genevievensis of Weller. The specimens 316 BRANSON AND GREGER—-AMSDEN FORMATION OF WYOMING are too poorly preserved to show whether there were fine spines on the concentric raised lines, and the concentric lines are indistinct on most of the exfoliated surfaces. The measurements of the specimen figured are: Length, 23 millimeters; greatest breadth, 27 millimeters. MEEKELLA AMSDENENSIS nb. sp. Plate 18, figures 22-25 Shell shightly smaller than in M. striatocostata, longer than broad, the greatest width near the anterior margin. Length from umbonal region to front margin, 25 millimeters; greatest breadth, 23 millimeters; thick- ness, 17 millimeters. Pedicle valve convex, with umbo prominent, eccentric, flattened. Car- dinal area narrow and high, relation about 16 to 9, with the delthyrium occupying about one-fourth of the area. Surface marked by numerous minute coste, subequal in size, separated by slightly wider interspaces, and increasing toward the margin, in the main by intercalation, but also by bifurcation. About three coste to the millimeter. Brachial valve more convex than the pedicle, subcircular, strongest slope toward the hinge line. Surface marked by coste similar to those on the pedicle valve. Internally the pedicle valve bears two parallel dental plates, about one millimeter apart, which extend forward about half the length of the valve. This is the first Meekella reported from below the Pennsylvanian in America and, like the Lower Carboniferous Meekellas of England, it lacks plications.* SPIRIFERINA BROWNI 2. sp. Plate 18, figures 15 and 17 Shell below medium size; broader than long; the greatest width a short distance in front of the hinge line; cardinal extremities rounded. The dimensions of a nearly perfect specimen of medium size are: Length, 15 millimeters; breadth, 18 millimeters; thickness, 10.5 millimeters; height of cardinal area, 2.4 millimeters. Pedicle valve strongly convex, most prominent in the umbonal region; each lateral slope marked by 6 to 7 rounded to subangular plications. Mesial sinus sharply defined, rounded; beaks small, slightly incurved ; cardinal area well developed, concave; delthyrium as wide as high. In- ternally a strong median septum reaches half the length of the valve, and the dental plates are about half the length of the median septum. 7 Memoirs of the Geological Survey of Great Britain. Paleontology, vol. 1, part 2, pp. 112-114, pl. 138, figs. 1, 2. coil DESCRIPTION OF SPECIES oe Brachial valve less convex than the pedicle; highest at the front of the fold; each lateral slope marked by 6 to 7 rounded plications. Mesial fold sharply defined, rounded, much elevated in front. Cardinal area very narrow and nearly at right angles to that of the pedicle valve. Beak small, incurved. Lines of growth not imbricating. This is the only species of Spiriferina found in the fauna. It differs from S. salemensis in the greatest width being in front of the hinge line, the cardinal extremities being rounded, cardinal area much lower and narrower, mesial sinus rounded, delthyrium wider compared to height, usually one or two more plications on each side of a valve, median septum longer and mesial fold rounded. It differs from S. spinosa in lacking the spines, in the median septum being larger, and the cardinal extremities never being angular. SPIRIFER PELLAINSIS (Weller) Plate 18, figures 7-9 1914. Spirifer pellansis Weller, Illinois State Geological Survey, monograph 1, pages 340-341, plate 45, figures 1-31. This species is abundant and has a wide variety of shapes and sizes. The number of plications is fairly constant, varying from 18 to 22 on the pedicle valve in 25 specimens chosen at random. Usually there is one well developed plication in the sinus and two weaker plications formed by the bifurcation of the marginal plications. Some specimens show three well developed plications in the sinus and two weaker plications formed as mentioned above. Most of the forms from the Amsden agree with Weller’s description, but there is one distinct variation in which the hinge line is constantly longer than the shell, and the fold is much more elevated than in the type. Measurements of eight typical specimens show an average length of 19.9 millimeters; breadth, 26.5 millimeters; thickness, 12.7 millimeters. Measurements of four of the other variety show average length, 20 milli- meters; breadth, 36 millimeters; thickness, 16.5 millimeters. _ The typical forms are much the more abundant in the fauna and the larger variety is relatively rare. SPIRIFER WELLERI 20. sp. Plate 18, figures 10, 11, and 16 Shell below medium size; length and breadth subequal; greatest breadth in front of the hinge line; cardinal extremities rounded. The average size of eight full-grown specimens is: Length, 16 millimeters; breadth, 17.6 millimeters; thickness, 10.4 millimeters. — ‘ 218 BRANSON AND GREGER—AMSDEN FORMATION OF WYOMING Pedicle valve strongly convex, with greatest convexity opposite the hinge line; beak strongly incurved ; cardinal area high, short, height and breadth as 1 to 3. Cardinal area not sharply defined, but with the shell rounding to meet the area; lateral slopes of the valve convex, marked by 9 to 11 subangular to rounded plications. The mesial sinus is broad and shallow and originates at the beak; a median plication starts at the um- bone and increases in size backward; two plications come into the sinus by bifurcation of the marginal plications, and these may remain small or become subequal to the median plication. Brachial valve much less convex than the pedicle. The mesial fold which originates at the beak is set off from the rest of the shell by grooves that are deeper and wider than those between the plications. Near the beak the fold-is not elevated above the rest of the shell, but anteriorly it becomes prominent. A median furrow originates at or near the beak, and two shallower, lateral furrows originate about the middle of the fold. Remarks.—In our earlier work on the Amsden we included this form with S. pellensis, but we now give it species rank on account of the con- stantly short hinge hne and high and narrow area. It is the most abun- dant Spirifer in the Amsden. SPIRIFER SHOSHONENSIS 2. sp. Plate 18, figures 26 and 27 Shell of medium size; wider than long; greatest breadth at hinge ine. Width of largest specimen, 50 millimeters; of smallest specimen, 29 milli- meters; length of largest specimen, 32 millimeters; of smallest, 12 miulli- meters. Thickness of pedicle valve of largest specimen, 12 millimeters. Pedicle valve strongly convex; greatest. convexity a little in front of the hinge line; beak strongly curved and projecting about one-fourth of the length of the valve beyond the hinge line. Lateral slopes of the pedicle valve convex, each marked by about 17 rounded plications. The first eight lateral plications on each slope are formed by the bifurcation of plications near the back of the valve. The plications outside of the first eight do not bifurcate. The mesial sinus is shallow and poorly de- fined. A median plication starts at the umbone, increases slightly im size forward, and in some specimens bifurcates. Two plications come into the sinus near the umbone by bifurcation of the marginal plications and be- come subequal in size to the median plication. Brachial valve much less convex than the pedicle. Greatest convexity near the middle of the valve, with lateral slopes and front slope subequal. Each lateral slope is marked by about 15 subangular to rounded plica- DESCRIPTION OF SPECIES 319 tions, the first eight of which are formed by bifurcation of four plications. The plications outside of the first eight do not bifurcate. The mesial fold originates at the beak and is set off from the rest of the shell by grooves that are deeper and wider than those between the plications. The fold is narrow and elevated near the front margin of the shell. Two plications on the fold originate at the beak and each subdivides into three or four before reaching the front margin. MARTINIA 0. Sp. Plate 19, figures 17-18 The collection contains a single example of a shell that agrees, in gen- eral, with the genus Martinia. Its dimensions are: Length, 9.5 milli- meters; breadth, 6.5 millimeters; greatest thickness, which is in the umbonal region, 4.5 millimeters. Absence of growth lines suggests an immature shell. Compared with the Mississippi Valley species, M. con- tracta and M. sulcata, the most striking difference is the greater length over breadth. PUGNOIDES OTTUMWA (White) Plate 18, figures 12-14 1862. Rhynchonella ottumwa White, Proceedings of Boston Society of Natural History, volume 9, page 23. . 1914. Pugnoides ottwmwa Weller, Illinois Geological Survey, monograph 1. pages 193-195, plate 25, figures 7-17. 1916. Pugnoides ottwmwa Weller, Contributions from Walker Museum, volume 1, number 10, page 246, plate XVI, figures 7-8. This species is common, but most of the specimens are not well pre- served. It agrees with Weller’s description, but seems to average a little narrower compared to the length. The means of the measurements of seven typical specimens are: Length, 11 millimeters; breadth, 11.2 milli- meters; thickness, 6.2 millimeters. A young specimen, 8 millimeters long, 8 millimeters wide, and 4 millimeters thick, has no plications on the fold and in the sinus and has incipient plications on the margins. COMPOSITA TRINUCLEA (Hall) Plate 18, figures 1—4, 9 1856. Terebratula trinucleus Hall, Transactions of Albany Institute, volume 4. page 7. 1914. Composita trinuclea Weller, Illinois State Geological Survey, monograph 1, page 486, plate 81, figures 16-45. 1916. Composita trunclea Weller, Contributions from Walker Museum, volume 1, number 10, page 246, plate XVI, figures 3-6. 320) +=BRANSON AN AMSDEN FORMATION OF WYOMING This species is three to four times as abundant as any other in the fauna. It is referred to C. trinuclea, though the larger forms might with equal propriety be referred to C. subquadrata. The means of the meas- urements of a series of eight specimens are: Length, 18.5 millimeters; breadth, 16.2 millimeters; thickness, 10.7 millimeters. There are many smaller specimens in the collection, but they are prob- ably immature and show practically the same ratio of length, breadth, and thickness as those measured. The largest specimen measured had a length of 21 millimeters; breadth, 19 millimeters; thickness, 13 milli- meters, and the smallest: Length, 16 millimeters; breadth, 14 miulli- meters; thickness, 9 millimeters. Some specimens show rather wide variations from the type, one having a length of 22 millimeters; breadth, 12.5 millimeters; thickness, 14 millimeters. Some forms show distinct furrows on either side of the fold, while in others this feature is entirely lacking. An arranged series would show all gradations from the deep furrows to the absence of furrows. EUMETRIA VERNEUILANA (Hall) Plate 18, figures 20-21 1856. Retzia verneuiliana Hall, Transactions of Albany Institute, volume 4, page 9. 1914. Humetria verneuiliana Weller, Illinois Geological Survey, monograph 1, pages 442-444, plate 76, figures 18-24. Only eight specimens of this species were collected. They agree with Weller’s figures and descriptions excepting in the number of plications being slightly smaller. Weller gives the usual number as 46 to 50, while the eight specimens show brachial 36 to 42 and pedicle 36 to 40. CLEIOTHYRIDINA HIRSUTA (Hall) Plate 19, figure 14 1856. Spirifera hirsuta Hall, Transactions of Albany Institute, volume 4, page 8. 1914. Cliothyridina hirsuta Weller, Illinois Geological Survey, monograph 1, pages 479-480, plate 80, figures 13-24. Two specimens from the Amsden are in the University of Missouri — collection. TETRACAMERA SUBOCUNEATA (Hall) Plate 18, figure 18 1856. hynchonella subcuneata Hall, Transactions of Albany Institute, volume 4, page 11. 1914, Tetracamera subcuneata Weller, Illinois Geological Sur vey, monograph 1. pages 214-215, plate 28, figures 13-24. DESCRIPTION OF SPECIES | yaa Two imperfect specimens of this species were collected from the Amsden, and the reference to 7’. subcuneata Hall is provisional. SCHIZOPHORIA SWALLOVI ? (Hall) Plate 19, figures 12-13 1858. Orthis swallowvi Hall, Geological Survey of Iowa, volume 1, part 2, page 597, plate 12, figures 5a-b. 1914. Schizophoria swallovi? Weller, Illinois State Geological Survey, mono- graph 1, pages 167-168, plate 22, figures 1-6. This is one of the rare fossils in the association. A single immature specimen, with conjoined valves, is illustrated. Fragmentary specimens in the collection show that the species reached the following dimensions: Length, 36 millimeters; breadth, 34 millimeters; thickness, 26 milli- meters. This species has not hitherto been recorded from above the Bur- lington, but specimens from the Saint Louis of Knox py, Missouri, are in Mr. Greger’s collection. CHONETES CHESTERENSIS (Weller) Plate 18, figure 19 1915. Chonetes chesterensis Weller, Illinois Geological Survey, monograph 1, page 83, plate 8, figures 31-34. Only one specimen was collected from the Amsden. It is referred to C. chesterensis, though it seems to agree as well with C. cherokeensis Snider.’ ORTONIA cf. BLATCHLEYI (Cumings and Beede) Plate 18, figure 15 1905. Ortonia blatchleyi Cumings and Beede, Indiana Department of Geology and Natural Resources, thirtieth annual report, page 1273, plate 19, figure 8. Only one specimen of this species was collected. It is approximately 5 millimeters long and 114 millimeters wide at the open end. Attached for the entire length; trumpet-shaped ; the small end bent; strong annu- lations, but overlapping not determinable. Agrees in most respects with Ortonia blatchleyt. MICRODON cf. OBLONGUS (Hall) Plate 19, figures 25 and 11 1856. Cypricardella oblonga Hall, Transactions of the Albany Institute, volume 4, page 18. ¢ 8 Oklahoma Geological Survey, Bulletin 24, p. 77, pl. iii, figs. 16-18. 322 BRANSON AND GREGER—-AMSDEN FORMATION OF WYOMING Only one specimen was collected. It agrees with MW. oblongus, save in the shape of the anterior end, which is less prominent than in the type. Figure 25 does not represent the lateral ridge as prominently as it shows in the specimen. Figure 11 may be of an internal mold of this species, but there is no way of making this determination positive. MYALINA SANCTI-LUDOVICI (Worthen) Plate 19, figure 26 1873. Myalina St. Ludovici Worthen, Geological Survey of Illinois, volume 5, page 540, plate 22, figure 3. 1894. Myalina sancti-ludovici Keyes, Missouri Geological Survey, volume 5, page 117. 1898. Myalina sancti-ludovici Weller, Carboniferous Invertebrates, page 364. 1909. Myalina sancti-ludovici Grabau, North American Index Fossils, volume 1, page 453, figure 600. Six specimens of this species are in the collection. The largest, 20 millimeters in greatest length and a little more than 12 millimeters along the hinge line, is almost two-thirds the size of the type. A series of four measurements on the drawings of the type and on this shell showed: Length of type, 30 millimeters; Amsden shell, 20 millimeters; hinge-line of type, 17144 millimeters; Amsden, 12 millimeters; end of hinge line to lower side of shell: Type, 2514 millimeters; Amsden, 15 millimeters; width of type, 15 millimeters; Amsden, 10 millimeters. The greatest thickness, 10 millimeters, is near the beaks. . In some of the specimens the beaks project above the hinge line, but the prominence of the umbones makes this almost inevitable when the shells are shghtly crushed, and we do not regard this characteristic as of specific value. The specific reference is not considered as certain. BULIMORPHA CANALICULATA Hall Plate 19, figure 15 1856. Bulimella canaliculata Hall, Transactions of the Albany Institute, volume 4, page 29. Polyphemopsis canaliculata (Hall) Meek and Worthen, Geological Report of Illinois, volume 2, page 372. 1882. Bulimorpha canaliculata Whitfield, Bulletin of the American Museum of Natural History, volume 1, page 74, plate 8, figure 41. 1883. Bulimorpha canaliculata Hall, Twelfth Report of the Geological Suryer of Indiana, page 367, plate 31, figure 41. 1889. Bulimorpha panucuedte Keyes, Proceedings of the Academy of Natural Science of Philadelphia, page 300. 1898. Bulimorpha canaliculata (Hall) Weller, United States Geological Survey, bulletin 153, page 151. DESCRIPTION OF SPECIES 323 1905. Bulimorpha canaliculata Cumings and Beede, Department of Geology and Natural Resources of Indiana, thirtieth annual report, page 13438, plate 25, figure 41. Three imperfect specimens were collected. ‘Two specimens lack the tip of the apical coil and part of the first coil, and one is slightly crushed. The spire angle, 41 to 45 degrees, is the same as in B. canaliculata, and in other respects the specimens agree with that species. PALEONEILO AMSDENENSIS na. sp. Plate 19, figures 23-24. Text figures 1-2 Twenty-five specimens, most of which are fragmentary, are in our collections. All of the specimens but one have the shell | removed. In general outline the shell is subelliptical, but the posterior end is about two-thirds as wide as the anterior. Length of shell, about 17 millimeters; greatest rcurn 1.—Bnlarged Drawing of height at umbones, 9 millimeters; greatest I OA Na EST CNCn sts Mucienecs directly below the umbone, 6, _“DOWs°tmamentation. Enlarged about 21% diameters. millimeters. The beaks are subcentral, but are slightly nearer the anterior end and are directed toward the posterior end. Both extremities are gaping. The posterior extremity is pinched and much thinner than the anterior. The shell is marked by unequally spaced growth lines, which are crossed by very fine irregular lines that radiate from the beaks and are most prominent on the umbones. The specimen that retains the shell is the only one that has these lines preserved. A short external ligament was present. The dentition is taxodont and not interrupted below the beaks. The teeth are longest at the beaks and broadest behind the beaks. About 16 teeth are present and the number is about the same in front and behind the beaks. Musculature obscure in the types. Our specimens resemble Girty’s figures of Yoldta glabra,® but the radi- ating lines are not mentioned in descriptions or shown in figures of that species. The dentition differs, as shown in plate 19, figure 24, of this paper, and plate 13, figure 9a of Girty’s paper. Evidences of an external hgament are clear in our species and are doubtful in Girty’s. ® Fauna of the Wewoka formation of Oklahoma, pl. 13, figs. 9-15. / 324 BRANSON AND GREGER—AMSDEN FORMATION OF WYOMING BUCANOPSIS or BELLEROPHON Plate 19, figures 9-10 Two interior casts representing two species of Bucanopsis or Bellero- phon were collected at locality number 1. LOXONEMA WORTHENI (Weller) Plate 18, figure 6 1916. Loxonema worthent Weller. Contributions from Walker Museum, volume 1, number 10, page 261, plate XVIII, figures 18-20. Originally we identified our fragmentary specimens with Loxonema yandellana Hall, but they agree with Weller’s species, L. worthent, de- scribed in 1916, in every detail. CYCLOCERAS sp.? One fragment that resembles Cycloceras sequoyahensis Snider was col- lected. ORTHOCERAS sp.? A few specimens too fragmentary for identification were collected. PHILLIPSIA sp.? Plate 19, figure 16 Several specimens of Phillipsia were collected, but most of them were lost during transportation. ‘The ones in the collection are too imperfect for specific reference. From all collections made from the Amsden the number of specimens of each species hsted below were selected as worthy of placing in our cabinets. These numbers furnish a rough approximation of relative abundance. OUDICUIOIDEA (52.0 Mterd dole Eauiesepslers 3 Gletoth yrs) 2... 60s) «6.0 ee 5 OTEMOLGEES -. 5 Bi5rs.5 dee teyehol ac ks Se ee 37 Composite. -o.5 06.6 bos. ae 314 MICO AGH eS vig ob ie fans os helen, “os tora 3 OrtoWia: =. 6.5 sean eos eee Sensi 1 MOMERCS Pe ss, aes cores are Nete eee ik Mierodon. 2. °:<..4)6 » earthed) amt Coe. op ne sean ge MR MELI MMU HONING MOT aie ne shslatare nc? sua oa Se ine i Lome RECREATE Carat eh ties fe PEGOOGEAUOIE LIMESTONE 0... cic entire 9 one eee ees Penis sitedhanse sia bya BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 327-368 JUNE 30, 1918 STRATIGRAPHY OF THE NEW YORK CLINTON } BY GEORGE H. CHADWICK (Presented before the Society December 28, 1917) CONTENTS > We eu @) a) e. 8a le | = 2 (6 (6. ws) 9) 6 a,» (6) wie) 6) 8). eee 9) © 6 ae, 6s) (0! @. = @ » #0! 6 \e (0 6 Se). 6) Oats) (oe (ee) 6) wesw a ‘he 6) 9‘) © a (6) pie le vm 0) 6 6) e's (6, (el ee) Be mew was og 6 6k oe ae Gia’ -¢ eo) Ue ele pe) em fe) ea ce) oA) eh le) \ehie we ke) 8/6) a eee leh et ee ee wee €) ee Siimcim (ela) Sis ie ee (e: by. ‘o)°6 S108) 8) Jee! (6) «) @ @ 1 G10 Se pease @ eine se 8 6 Ue hi iee 6. e, = @ € 'e 99 - oe wo 1 Se) Go wo) Wen we) 41 328 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON Page GClassificatién and faunas. ; See i. es eee ee See ee eee 359 GOMCTESTONE 55 5 65 5 5 SSS wpw shes Ses wren ee eee ee ce 365 Paleontolozic SUMMATY 2.5.02 Ses Se aes bo wee aes he ei el 366 Important. papers < . 62.0 25g. eee © OS Bie wee tm ie ee eco 367 HistoricaL INTRODUCTION The “Clinton group” of western New York has been supposedly a well known formation. Hall (2)?, in 1843, described the section on the Gen- esee River at Rochester, whose various subdivisions of shale and limestone he believed he had correctly traced eastward to the limit of his district (namely, Red Creek), and he affirmed the stratigraphic equivalence of five of these to the series of sandy shales at Clinton, in central New York, described in the preceding year by his colleague on the Survey, Van- uxem (1). Hall also followed the same group of strata westward to the Niagara River, where he correctly noted that the “Clinton” portion had diminished in thickness by the nearly total loss of its shale members, thus becoming a continuous massive limestone. It should be recalled that two of the sections just mentioned, namely, the Genesee gorge at Rochester and the Niagara gorge above Lewiston, are the only complete expesures of the group in New York State (9: 9-10), and that it would be difficult, 1f not impossible, to find any errors in Hall’s work from a surface examination alone. No criticism can there- fore be made of his work or of those who have builded on it, though his correlations are now found to be partly in error. The section of the so-called Clinton at Rochester, long taken as the standard for comparison with other regions, is given below, together with the names used by Hall (3), those applied by Hartnagel (8) in 1907 on the basis of Hall’s correlations, and the revised names, the necessity for which is brought out in the sequel. This section now proves to be far from a complete section of the New York Clinton, since several impor- tant members are entirely missing. It is as follows, every inch being accessible : ? The numbers in parenthesis refer to the list of works at the end of this paper. HISTORICAL INTRODUCTION 329 Hall’s names, 1845. Section. Hartnagel, 1907. This paper. (Rochester shale conformably overlies) See OMT ecto Vy ihre ee ee eWC es, ame ef a | Crystalline limestone... 7’ : ; [ Irondequoit | ILrondequoit limestone (and Pheenix ) Upper (Clinton) limestone sa lt Es Ree Re a ees eee | | —- | ae Shaleis sce eds Williamson | Williamson Second green wie | (eee ey shale ) Pues cine ae shale with ne pearly shale Sodus (true) [ TRAVERSE echoes ccd es ote Pentamerus lime- if IEAMIGSCONGE 0.5 isi erke ace ee eer micicor ~ Reynales stone | limestone Oolitic iron ore 4 Plemiatitie Ore). . vscwes eek aly \Furnaceville Furnaceville Shale with limestone.... 3’ Bear Creek Lower green shale fa SS Sti | seek al [Green Shale. 235 occ ark 21’ _ Maplewood (Thorold gray sandstone conformably underlies) The reason for the changes here made might never have appeared from a study of the outcrops alone. But fortunately Hartnagel, returning to the attack, conducted for the State a series of drillings for iron ore in the drift-covered Clinton belt (9:10) of central New York which re- vealed some totally unexpected relations. The results of this investiga- tion were briefly stated in 1908 in a paper (9) by Newland and Hart- nagel, of an economic nature, in which intimation was given of a fuller report to come on the paleontologic and stratigraphic data secured ; this expected sequel, however, has not yet appeared. Meantime, because of the burial of Hartnagel’s results in a report os- tensibly economic, their revolutionary character has been generally missed, as an inspection of the later papers cited will show. It is proposed, there- fore, to epitomize the published information on our Clinton strata, with the aid of the charts (figures 1 and 2) of the sections and well records, and to make those changes in the nomenclature which have been rendered necessary. To Newland and Hartnagel belong the chief credit for the field obser- ations employed in this revision. Their careful records of the diamond- drill cores for eight judiciously placed test holes, besides much other data assembled by them, will always be of inestimable service to all workers. An extensive series of rocks presented to the University of Rochester by { 330 Gc. H. CHADWICK—-STRATIGRAPHY OF NEW YORK CLINTON the early New York survey from the localities described im their reporis (1, 2) has been of much assistance. “The cooperation of one of our students, Miss Flora Crombie, and aid received from Mr. Ira Edwards, now of the Milwaukee Museum, and from Prof. W. J. Miller are gratefully acknowledged. Since the prepa- ration of the manuscript very kind criticism and suggestions have been received from Doctors M. Y. Williams, E. M. Kindle. and C. K. Swartz, and especially from the censor of the paper, Professor Schuchert. CoMPARISON OF WESTERN SECTIONS The sections will be considered in order from west to east, beginning at Rochester. The horizontal datum line in the charts is the base of the Rochester shale. The Rochester section of the “Clinton” has just been summarized and will be found drawn to scale at the left end of figure 1. It consists, in the old interpretation, of two limestones and two shales, with an iron-ore bed. The next continuous section is that of the test hole at Wallington, near Sodus. In this there are, however, three limestones and three shales, with the same bed of iron ore. The new limestone member is found to come in between the dark grapiolitic portion of the upper shale at Rochester and the purplish shale portion with its “pearly layers.” Both of these two upper shale members have gained considerably in thickness, whereas the bottom shale and also the upper limestone have apparently diminished. It is evident on closer consideration, however, that it is the lower shaly portion of the upper limestone at Rochester which in this well has become the topmost 20 feet of shale—a shale said to be similar to the Rochester shale and highly fossiliferous. But the graptolite shale itself has also expanded to 15 feet. At the base of the section the Thorold sandstone appears to be missing, so that the attenu- _ ated basal “Clinton” shale rests directly on the variegated Medina shale. With but minor variations, the relations shown i in the Wallington well continue eastward to the Oswego River. All the limestone members, it should be observed, become increasingly shaly, while the shale members (except the basal shale) continue to thicken and several new ore seams make their appearance. Two of these new ore horizons occur first in the section next east of Wallington, that of the test hole at Wolcott. Here an important ore comes in just above the middle limestone. This ore outcrops at the old furnace north of Wolcott and at a few other points to the west. Another new but thin ore bed appears at the top of the lower limestone (here mostly shale) and is exposed in the diggings at Sterling Station, a few COMPARISON OF WESTERN SECTIONS eae miles east, where it is 8 feet above their main ore bed (9:57). In the well at South Granby a fourth thin ore and limestone are inserted be- tween the graptolitic shale and those shaly members above which seem to represent shale replacements of much of the wpper lmestone of the Rochester section. Meantime the lowest ore bed, so persistent from the Rochester meridian, has abruptly disappeared (9:35) between Red Creek and Martville (compare text-figure 4). Now the exceedingly interesting point brought out by Hartnagel (9: 21, 22) is that in the absence of good continuous exposures the middle limestone of the Wolcott region was confused with the lower limestone at Rochester, both of them carrying Pentamerus oblongus abundantly at their respective localities ; and in consequence the middle shale at Sodus, with its pearly layers and purple color, was forcibly connected with the bright green barren basal shale of Rochester. It will be seen that the latter is nearly or quite missing on the meridians of Sodus and Wolcott, while its overlying limestone has become so shaly as to seldom outcrop. In the typical Sodus section, that of the old Shaker settlement on Second Creek, this lower limestone with its ore bed is beneath the waters of Sodus Bay. The long list of fossils described by Hall from the “lower shale at Sodus” are all forms of the middle or purple shale, which must accord- ingly take the name of Sodus shale, and whose place is in the lower part of the “upper shale” at Rochester. Similarly the only limestone with Pentamerus at or near Wolcott is the middle limestone, which is absent from the Rochester section, and this must retain the name Wolcott lime- stone, while both the lower limestone and the basal shale at Rochester remain yet to be named. The necessity for these changes is discussed again beyond. A glance at the chart shows how easy it was for this confusion to arise. Had we not the intervening section at Ontario, with its thinned basal shale and absence of the Thorold, we might readily ignore the incisive evidence of the fossils and repeat Hall’s error, which was the more ex- cusable since a shale seeming to occupy the position of our basal green shale carries the Sodus Ccelospiras at Niagara. This Niagara section is accordingly also given on the chart, together with two others to the west as reported by Schuchert (12: 308-311), in order to show that the “Clin- ton basal shale” at Niagara is not the barren green basal shale of Roches- ter; for, according to Logan (Geology of Canada, 313)*, the latter re- appears in the next section west of Niagara and there carries the Medina worm burrow, Arthrophycus. These relations, as understood by Schu- chert, are shown in the diagram, which thus clearly brings out a discon- ooo ee >>-----—|—V——-—>—>—-— +--+ ® Footnote 8 is on page 334. 332 G. H. CHADWICK——STRATIGRAPHY OF NEW YORK CLINTON = a Ree « ysea -Yssok sajru fo ae92 SO eo grr0 | ehipaly ti es S Aes SU i | D : oy, Of Ns iigeee ee : , —— — SF OPZI WO, “OSL ee Pd d UYVIELL, apryn fay s27Byo Ses Nae Y227Q UP? ALO “os oc ee SS —— — aS 22 ae boyy, ra) amano a7 1) fe) ig bg tigi te euipa uojselusoeg 3212125 ioe : : Payee | Ky 08 | 4 aos pet one * ploysp VA — ~ ; : eye of oR 2047 kd of poam aBueys pean WNW 4 -ap “or ) vpdand S49 Koy hypsead uc Lf 2uo2,6pUuResS SSeS pes |: eur arly/ oo en Pig ae P}240Y / escrel (| Verona iron ore...... phages ehcite hyree OC «ayaa tec Important to east. Sodus shale with lime lentils.... 31 feet........... - Purplish to west. Sterling Station iron ore........ Trace only........ See note below. Beymales limestone......1....: ANA CET BI Uh sabe Here mostly shale. Unnamed dark shale........... Feet. 5 sis ee Part of Reynales? SPurnaceyville iron ore’... ..0t. 0)... i footie. its tice See note below. 4 Somewhat exceeded in the Chittenango well a few miles south. ©The identification of the basal ore bed here and at Brewerton as a reappearance of the Furnaceville instead of an extension of the Sterling Station ore may be erroneous, but it involves us in fewer difficulties to find the latter in the “trace of ore’ occurring at the proper interval above this one. Text-figure 4 shows how easy a different correla- tion would be, though the black pebble zone supports that here made, 336 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON Bear: Créeli Shale. #.. 5 ieoke ee 4: inGhes Foes es sae L. See discussion beyond. Martville? (Otsquago?) sandstone 2 feet?.......... Somewhat reddish color. Maplewood: shale. . x... 5-2 sees Absent (hiatus)... 21 feet at Rochester. Oneida conglomerate*........... Entered? (6”)..... “White sandstone.” (* In the western sections the Thorold sandstone occupies a similar position beneath the Maplewood green shale.) Too much emphasis can not be placed on the significance, for purposes of classification, of the hiatuses in this, the thickest Clinton section in New York. They accord with gaps already recognized in the previous sections. Special attention should be called to the presence here, but with greatly reduced thickness, of the Rochester shale, 20 miles to the east of its last known outcrop and apparently without noteworthy change in character. These facts point to its total extinction within a few miles to the east- ward. But beneath this shgle, separated from it by a limestone that Hartnagel clearly considered the top of the Clinton (see 9:25) is the 60-foot shale mass carrying the first of the economically important sand- stone intercalations of the Clinton that occur in outcrop at several points along the south side of Oneida Lake east and west of this well (1:89), becoming of increasing importance eastward (1:87). This mass we believe to be identical with the shale division seen at Phoenix (11: 57-58), with its large element of Rochester shale fossils. In the six feet of eri- noidal ore-bearing limestone below these 60 feet of beds we recognize the first definite presence of the upper (fossil or “red flux’’) ore of the Clinton district, while in the thin ore above them we see, with Vanuxem (1: 88), the equivalent not only of Donnelly’s ore (9:26), but also of that over Tipple’s quarry, near Verona (1: 87-88). For the Verona region Professor Fairchild’s field copy of the topo- graphic map with his memoranda of outcrops has aided greatly. The vertical adjustment of the partial well section and the important ex- posures have been arrived at by computations of altitude and dip that would be wearisome here, but which seemed to clear away the problems of correlation between Lakeport and Clinton as soon as they were plotted on the chart. The limestone members are now all shale, identifiable only by their attendant ore bodies; but Vanuxem’s correlation of the layers above the Verona ore bed with those exposed in the village of Martville and “in contact with the ore at Wolcott furnace” (1:87) on the basis of the guide fossil “Retepora clintont” (Hall’s “Fenestella prisca?’) is amply confirmed by the stratigraphy. So also is Hartnagel’s seemingly contradictory assertion (9:26) that the Verona fossil ore “occupies the same relative horizon in the formation as the Clinton oolitic bed.” In THE TYPE SECTION DOr our belief they are identical. Their apparent difference in character will be explained later. If the Kirkland (“red flux”) limestone carries no more ore around Verona than in the Lakeport well, it is not surprising that its horizon has failed of recognition in the outcrop. The seam alluded to by Hartnagel (9:26) as found in excavations in Verona village—probably the same as that mentioned by Vanuxem (1:87)—is not likely to lie more than 20 feet above the Verona ore (if it is not indeed that bed itself), and so just barely above the horizon at which the drill entered the rock or in the place of the Wolcott Furnace bed. It can not be the red-flux bed. Great interest attaches to the lower part of the Verona well record. The proximity (on the north) of the type exposure of the Oneida con- glomerate indicates that the drill must have stopped within a few feet of that rock. In the absence of the lower ore layers, it becomes impossible to recognize the Reynales horizon in the record as given, though the thicknesses would suggest that it is still present above the lower 10 feet of sandy beds. These sandstones mark, therefore, the inception of that great basal expansion which impresses one in the Clinton region (9:26). It will soon be shown that they are approximately Martville. THE Typrt SECTION The literature on the remaining sections is far from satisfactory, the measurements being largely estimates, often between rather wide limits, while almost no measurements whatever are reported east. of Tisdale’s mill, but merely the order of succession. Yet on piecing together the available data one gets a more complete concept of the stratigraphy than (in default of measurements) can be shown on the chart. At Clinton village we have at the top (excluding whatever may lie in the concealed interval just above) the mass of calcareous sandstone and thin shale part- ings which is clearly our Phcenix division growing more sandy toward the shoreline. Its thickness is given as 50 feet plus, with an unmeasured gap between it and the Lockport, the Rochester not being seen. These Phoenix sandy shales, with their prenuncial Rochester fauna, contain the explanation for the rather reasonable belief (9:19, 27; 10:7) that the Rochester shale horizon is embraced in the type Clinton section. Further evidence to the contrary will be recited farther on. - Next below the Phcenix beds is the calcareous “red-flux” ore, 6 feet thick. Even within sight of Clinton village (1:86) this ore is known to pass westward into an ore-bearing limestone with crinoids, and its identi- fication with the ore-bearing limestone beneath the upper shale in the 338 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON Lakeport Clinton series is certain. Its extension eastward in a long row of outcrops on the steep south wall of the Mohawk Valley is also beyond question. The interesting thing is to see it change from a calcareous fossil ore at Clinton to a siliceous oolitic ore at Steeles Creek (1: 82), and then into a highly ferruginous sand (see Vanhornsville sandstone later). On inspection we find that the Furnaceyille ore (if correctly — identified east of Martville) undergoes a similar change to an oolitic ore in passing eastward from Rochester, and we are now prepared to assert that the Verona fossil ore is likewise converted into the oolitic or lower ore bed of Clinton. This is indicated by the rate at which this ore has been rising in the diagram from Lakeport to Verona, and is corroborated by the presence throughout the underlying 35 to 40 feet of shale (1: 84) of the fossil Beyrichia lata (Vanuxem’s “broad Agnostis,” 1:83, 84)—a form very characteristic of the true Sodus shale and its “pearly layers” as well. Below this shale, with a suggestion of disconformity that did not escape Vanuxem’s eye (1:83), are the sandstone quarries of Black- stone and Davis, south of Utica, with their remarkable “fucoids.” Some- where in this mass Hall reports Pyrenomeus cuneatus (3:87) of the Bear Creek fauna, indicating the Martville age of these sandstones. The red coloring in some of the upper layers (1:82) helps to place their horizon in the sections farther east, and also ties them to the supposed Martville of the Lakeport well (compare text-figure 4). The strata be- neath become more shaly again, and it is wholly possible that they signify a return of the basal or Maplewood shale of the Rochester section—a sug- gestion that is heightened by their holding a similar conformable relation to the Oneida sandstone and conglomerate below them as the Maplewood does to the Thorold. Although we can thus pick out rather confidently the presence of cer- tain members in these 100 feet of lower beds at Clinton, their exact dis- crimination, with discovery of the fate of the Reynales and other mem- bers, awaits patient field-work. It is desirable meanwhile to have a term for the whole mass from the oolitic ore to the Oneida, and the name Sau- quoit is therefore employed on the chart and defined beyond. As to the 21 feet of strata between the two ore beds, and which are open to easy study in the old workings at Clinton, the fossils will un- doubtedly decide what horizons have been compressed into this small span, which probably contains at least one important hiatus (see page 359). From the intercalations of ferriferous limestone in the 20 feet (15 ® Doctor Swartz writes: “I find it difficult to believe that the Verona iron ore is cor- rectly identified with the Oolitic ore at Clinton. It seems to me not impossible that it is a lower bed which corresponds in position with a heavy bed of iron ore in Maryland.” THE SHOREWARD REGION 309 at Clinton) of blue shale next above the oolitic bed at Lairdsville (1:8), it is a safe hazard that the Wolcott is still included, but whether forming the whole shale mass or only the lower few feet up to the thin middle ore found on Stebbins Creek (1:85) is uncertain; and whether the cal- careous sandstone below the red-flux ore is Williamson or Brewerton can be. only conjectured, though the rumor of “guide Clinton graptolites” somewhere in the upper beds (10:7, footnote) is reminiscent of the former.’ THE SHOREWARD REGION The section given by Hall (3:16) in the quarries on the hill south of Utica and the better one on Swift Creek, near by, described by Vanuxem (1: 84-85), are fundamental, though because of certain unmeasured in- tervals they appear but imperfectly on the chart. Beyond these comes Steeles Creek, south of Ilion, and then the place Hall calls Tisdale’s mill, at both of which (1:82, 81; 3:16) is a resistant sandstone, 60 to 70 feet thick, known as the “upper gray band,” forming the summit of the Clin- ton. In the largely unique and mostly molluscan fauna of this mass Trimerus delphinocephalus is the only definitely Rochester element, whereas two of the other eight or ten species (3: 100-105) are common to the Brassfield of Ohio (13: 1484, 1487-1488). But Vanuxem says (1: 82) that Trimerus begins in the iron ores, and Hall (3: 299) also reports it far down in the Chnton. This sandstone continues unabated west toward Moyers (“Myers,” 1: 257) Creek, then suddenly drops out of the sections. Five or six miles west of Moyers Creek, at Utica, the equally | thick mass of the Phoenix shales (here mostly sandstone) is at the Clinton summit in the same relative position and carrying fucoids, as does the gray band at Wick’s store east of Tisdale’s (1:81), where it also includes shale. Were the “gray band” still present as a distinct member above the Phoenix beds, it could scarcely fail to outcrop in the excellent section on - Swift Creek, and the conclusion is therefore drawn that this heavy white stratum, which for convenience we will call the Herkimer sandstone, is the strand facies of the Pheenix (Schrcoeppel) shale, and so of some part of the lower Irondequoit limestone of the Rochester section, rather than, -as has been claimed, of the much attenuated Rochester shale of the Lake- port well. We will recur to this question beyond. 7 A different interpretation has been adopted in text-figure 3, where the 6 feet of sand- stone is identified as Brewerton and the underlying 15 feet of shale is all referred to the Wolcott, the Williamson being shown as lapped out. This is the relation suggested by the physical history as discussed beyond. / 340 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON The rest of the Tisdale section (9:27; 3:16) appears simple. Under the gray band are two feet of shale (which may be a misprint, since Hall (3:16) gives “thickness ?’’), then “red sandstone with a sparkling grain” (1:81), together with gray sandstone, shale, and iron ore, about 20 feet. Since the upper ore bed is known to come as far east as Steeles Creek (1:82) or within five miles, meantime becoming oolitic, there seems no reason for not treating these beds as the middle ore-bearing portion of the Clinton region (see 9:42). The coarse, friable mixture of sand and hematite (9:47) at this level becomes more marked (1: 80-81) at Van- hornsville (spelled “Vanhornesville” on the topographic map and in 9: 28), near the eastern limit of the group, but just how much it represents of the Verona-Kirkland span at Clinton is unknown. The three lower strata are clearly the Sauquoit beds in their triple aspect, the middle sandstone being the beds of the Blackstone quarry here become heavily cross-bedded (1:82), and thus passing eastward into the cross-bedded red laminated sandstone of the Otsquago Creek below Vanhornsyille (1: 80, 81; 9:28), which may just possibly become the “coarse (red 3: 15) sandstone with much iron ore” next below the Camillus shale at Salt Springville (9:28), the last Clinton exposure, though this sounds more lke the Vanhornsville bed. The Oneida conglomerate lies beneath in all these localities (1: 80-82 ; 3: 15-16; 9: 27-28), but from its erratic thinning and rethickening it appears likely that some portion of the basal Clinton shale may be merged with it at the east. It must not be forgotten that Vanuxem (1:75) con- sidered the Oneida “a part of the Clinton group,” separated, he says, for convenience. We would reverse this statement and consider the unfos- siliferous part of the basal shale below the Otsquago-Martville as a part of the Oneida in its broader application, including, it would seem, the Thorold and Maplewood of western New York, but not any part of the true red Medina. The belief that Upper Medina strata existed in these ~ eastern sections above the Oneida conglomerate (see 7: plate 2, and Sci- ence, new series, volume 28 (1908) : 347) undoubtedly grew out of the presence here of the cross-bedded and normally red Otsquago sandstone ; but as the red color of this fades away westward, while the Medina dark- ens in coming east, they grow more and more unlike as they approach the common meeting-point, and so can have little in common. The evidence in hand favors the conclusion of Vanuxem (1: 75-78) and Hartnagel (7:36) that the Oneida is “never far below the base of the Clinton” and is closely connected with its basal shale. HORIZONS AND FOSSILS _ ot] Horizons AND FOSsSsILs GENERAL OBSERVATIONS The subdivisional names used in this paper will now be defined and their best known fossils listed, beginning with the basal shales. The Thorold and Oneida need no redescription. The lists of fossils are pre- liminary, compiled chiefly from Hall (3) and admittedly incomplete, but they may be useful. In some instances the fossils have*furnished gratify- ing confirmation of the correlation based on the stratigraphy, and in no case have they conflicted with it. But the stratigraphy has always been the main guide. MAPLEWOOD SHALE The maximum exposure is in the Genesee gorge at Maplewood Park, Rochester, where 21 feet of fine-grained, unctuous, bright-green, non-fos- siliferous shale of uniform texture rest on the Thorold sandstone. ‘This is Hall’s “lower green shale” and Hartnagel’s “Sodus” (8:18), exclusive of the uppermost three feet. This shale probably terminates eastward without reaching Sodus, the true Sodus shale being a higher member. The stratigraphic relations of the Maplewood are with the beds below rather than above it. So far as now known to the writer, its only fossil is the Arthrophycus alleghaniense, reported by Schuchert (following Logan, Geology of Canada, page 313) at Thorold (12: 310) im a green shale of similar position.’ The fossils sometimes quoted from this horizon appear all to come from the Bear Creek or other higher division. SAUQUOIT BEDS This name is temporarily extended over all the shale and sandstone beds between the Oneida conglomerate and the oolitic ore bed in the Oris- kany and Sauquoit valleys, about 100 feet thick, with the type section on Swift Creek, north of Sauquoit village (1:84) and in its vicinity. It may be desirable later to restrict the term to some definite unit within this series, in which are probably present Sodus, Martville, and perhaps Maplewood and other horizons. The fossils are: Aristophycus? cf. heterophyllum Rusophycus subangulatum Buthotrephis gracilis Rusophycus pudicum (biloba 1:83) Buthotrephis gracilis intermedia Asterophycus? palmatum (3:20, PI. 6) Chondrites? ramosus (3:21) Blastophycus? impudicum (3:20) Paleophycus sp.? (3 99 Pl. 8, f. 3) Arthraria dicephala, nom. nov. Rusophycus clavatum Dactylophycus? sp. (3: Pl. 8, £.5) 8 See preceding footnote 3, p. 334. / XXVI—-BULL. Grou. Soc. Am., Von. 29, 1917 342 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON Dactylophycus pes-avis, nom. noy. Leptodesma rhomboidea Ichnophycus tridactylus Pyrenomous cuneatus Conostichus? medusa, nom. nov. Bucanella trilobata Conostichus? polygonatus, nom noy. Beyrichia lata Camarotechia wquiradiata Bollia lata (?) Pterinea emacerata Tracks and trails (3:27-29) -MARTVILLE SANDSTONE The type locality is Bentley’s quarry (1:89, 78, 74), intermediate be- tween Martville and Hannibal (the latter name is preoccupied in stratig- raphy), where about 10 feet of thin grayish green sandstone and shale, with fossils, are seen at the top of the quarry resting with a shale contact on the four or five feet of light gray or slightly mottled sandstone con- sidered Oneida (or Thorold) by Vanuxem, below which is the red Medina sandstone. The Martville is uppermost of these three sandstones and carries—® “Numerous fucoids and other forms” (compare the preceding list). Inngula clinton (L. oblonga Conrad), “besides some other fossils” (1:89). Probably also Dolichopterus? prominens (Paleontology of New York, volume 7, page 157; Memoir 14, page 200). . This stratum appears to be only three or four feet thick in the Martville well, where it lies beneath the horizon of the Furnaceville ore with an intervening breccia, the ore being absent and the Reynales limestone suc- ceeding. Though similar conditions exist in the Verona well, whence the sandstone extends eastward through the Blackstone quarry and eventually merges into or is supplanted by the red Otsquago sandstone, yet in the territory adjacent to Martville it is unrecognized in the sections, its place being taken by a calcareous or a limestone-interlarded shale. Whether this is contemporary or successive is not now evident, but since it is a marked zone with black pebbles in its upper layer in five consecutive wells and again in the well at Lakeport (compare text-figure 4) it is here given separate consideration. The problem of these thin lentils in the lower- most Clinton will be considered in the chapter on “Physical History.” BEAR CREEK SHALE At the old “Wolcott ore bed” on Bear Creek (9:68, Black Creek of the topographic map) Hall found an interesting pelecypod fauna (2: 76- ® Professor Schuchert pertinently inquires whether these Martville and Bear Creek faunas may not be Medina rather than Clinton in content. To the writer they seem rather to help efface the old sharp line between the two ‘“‘groups.”’ HORIZONS AND FOSSILS 345 ?77) in the shale just beneath (3:83) the Furnaceville ore (9:22, 68), wrongly identified by him with the upper (Wolcott Furnace) ore. The fossils are: | Lingula oblata Clenodonta? lata Lingula subelliptica Orthodesma curtum Paleoglossa acutirostris Cuneamya alveata Pterinea leptonota (emacerata?) Pyrenomeaus cuneatus Modiolopsis subalata Cyclora? subulata Ctenodonta macheriformis Bucania bellapuncta Ctenodonta curta Dawsonoceras americanun Ctenodonta mactreformis The three feet of beds below the Furnaceyille ore at Rochester formerly embraced in either the lower shale (8:13) or the lower limestone (12: 305) are referred to this horizon (compare Conrad’s annual report for 1836, page 176) and are believed to be the source of all the fossils re- ported from the lower shale, both here and at Ontario, including the erinoid of 8: 181, plate Axli, figure 6, of which a nearly entire specimen is at hand from Rochester. If distinct from the Martville, the Bear Creek shale will lie above rather than below it. (See the Lakeport well.) OTSQUAGO SANDSTONE This heavily cross-bedded red laminated sandstone is typically seen in and near the Otsquago Creek (spelled also Otsquak and Squak) below Vanhornsville (1: 80-81), whence it extends westward with gradual loss of color to near New Hartford (1:85), where it seems to merge into the supposed Martville. From Vanuxem’s belief (1:83) that it was cut off westward by the disconformity seen at the top of Blackstone’s quarry, it may be a distinct member wedging in above the “Martville,” or equiva- lent to the Bear Creek. The record of the Lakeport well favors the last (see figure 4+), as does the occurrence of Pyrenomceus near Utica. No other fossils seem to be reported from it. : . A typical illustration of the remarkable structure of this stratum is given in plate 2 of Hartnagel’s paper on the Oneida (7, opposite 32). - FURNACEVILLE IRON ORE Hartnagel, 1907 (8:14). The lowest Clinton ore bed anywhere recog- nized in New York extends from the Orleans-Monroe County line (letter from Ira Edwards) unbrokenly to Sterling Station, supposedly reappears as an oolitic ore in the Brewerton and Lakeport wells, but fails at Verona and eastward. As noted by Schuchert (12: 305), it is decidedly a shal- ( 2344 &. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON low-water deposit,?° and its basal contact at Rochester suggests to the writer a disconformity, probably the same as that at Blackstone’s. In any case the bed marks the introduction of a varied fauna, much of which yet remains to be studied. It includes: Buthotrephis gracilis ?Senricoscinium clintoni (3 :50) Peronosporites globosus “Orthis” trinucleus (3: T4) Peronosporites minutus Strophonella patenta? Peronosporites ramosus Hyattidina congesta Enterolasma caliculus ? Celospira nitens (“hemispherica”’ °) Caninia bilateralis Celospira plicatula Ptiloporella ? sp. Botryocrinus plumosus Phenopora constellata (9: Pl. 8) Tentaculites minutus Phenopora ensiformis ? Actinoceras vertebratum The basal shale at Niagara likewise holds Celospra mitens and pl- catula (10:7; 12:309) and Pterinea (?). We can not at present feel sure what this shale represents, but it is surely not the Maplewood (“Sodus” of Rochester). DARK SHALE IN LAKEPORT WELL It would be hazardous to draw any parallel between this and the bed at Niagara just mentioned. Since it is not known to outcrop in New York, it can not be named. REYNALES LIMESTONE If the shale equivalent of the Lower Clinton limestone of Rochester carries any Pentamerus at its sole exposure in the town of Wolcott, namely, at the old ore bed on Bear Creek, this fact could hardly have escaped such acute observers as Hall and Vanuxem. Hall distinctly mistook this stratum there for the upper—that is, Williamson—shale (2:75)..* The true Pentamerus.limestone of Wolcott furnace, which must inherit the name Wolcott limestone, is a higher bed. The only complete exposures of the lower limestone, in its typical western develop- 10 The problem of the origin of these ores has been treated by Smyth in Am. Jour. Sci. (1892), vol. 48, pp. 487-496 (Am. Geol., vol. 10, pp. 122-124). All the ores seem to be Marine, or at least to contain marine material, perhaps reworked. They must, however, have accumulated exceedingly slowly, each through a long time interval, during which the supply of ordinary clastic sediment was nearly suspended. A certain amount of wave-ablation and of concentration of previous deposits may also have gone on, remoy- ing the finer particles and converting the coarser into ore—in the landward zone by oolitic coating of sand grains; in the more open waters by ferruginous replacement of calcareous fragments. ‘These processes constituted pauses in the ordinary sedimentary record, perhaps of the type that Professor Barrell calls a “diastem,’’ and they are from time to time contemporary with diastrophic readjustments. 11JIn his second annual report, 1838, p. 327, Hall reports the Wolcott ore bed as “immediately below the Rochester shale.”’ HORIZONS AND FOSSILS 345 ment as such, are at Rochester, Lockport, and Niagara, where available formation names are exhausted. The largest fauna of this division is that _ reported by Hall (3) from Reynales Basin (also spelled Reynolds, 2: 71), eight miles east of Lockport (10, map; 2:63), and while we must go to Lockport or the Rochester gorge for the typical section this name Rey- nales automatically connotes a very definite faunule, including: Fungispongia irregularis Camarotechia neglecta Favosites favosideus Celospira plicatula Favosites hisingeri? Pentamerus oblongus Caninia bilateralis (marcoui?) Stricklandinia canadensis (Can. ) Cannapora junciformis Botryocrinus plumosus Halysites catenularia? Ichthyocrinus ? clintonensis Acanthoclema asperum Holopea obsoleta Helopora fragilis Hormotoma subulata Phenopora constellata Bucania stigmosa Ptilodictya (obliqua?) Oncoceras subrectum Diamesopora tubulosa Actinoceras vertebratum Rhipidomella circulus Orthoceras virgulatum Rafinesquina corrugata Discosorus conoideus Strophonella patenta Sphyradoceras? malti (unpublished ) Platystrophia brachynota (2:71) Encrinurus ornatus Hyattidina congesta Goldius sp. noy. Camarotechia? bidens Also probably Clintonella vagabunda, Atrypina clintoni, Clorinda areyi, Ptilograptus hartnageli. Westward the Reynales limestone is persistent as a massive member to the last exposure (12:316), but eastward it grades into shale, finally indistinguishable in the sections from the Sodus shale above it. STERLING STATION IRON ORE Unfortunately this seems to be the only name available and unpreoc- cupied for the 4-inch seam of ore 8 feet above the principal ore bed (Fur- naceville) at Sterling Station (9:57) which is not known to outcrop elsewhere, but appears in several wells. Fossils unknown to the writer. SODUS SHALE Hartnagel, 1907 (8:13), emended. MHartnagel defined this name as from the town of Sodus, “where this division is well shown in the vicinity of Sodus bay”; but, misled by Hall’s error, he extended it to the basal or Maplewood shale at Rochester. Near the mouth of Salmon Creek, nearly two miles west of Sodus Bay, Hall reports the lower members of the Clinton group (2:66, 42), but the basal shale must there be very thin?” 2 “At Cental’s mill, near Sodus Bay, . . . the green shale below [the Reynales] is but two or three feet thick’? (Hall: Ann. Rept. for 1838, p. 328). 346 G. H. CHADWICK——STRATIGRAPHY OF NEW YORK CLINTON (only five feet in the Wallington well just south) and is probably all Bear Creek instead of Maplewood, or equivalent to only the upper 3 feet of what has been called “Sodus” at Rochester. It would be absurd to attach the name Sodus permanently to this feeble unit, which is below water level (9: 21-22) at Hall’s favorite collecting grounds around Sodus Bay, where his “lower green shale” is the middle shale, with its purple-brown middle part (2:59, 60) and thin intercalated “pearly” limestones (2: 60) filled with fossils (2:66). This shale, which constitutes the major part (18 feet) of the “upper” shale at Rochester, and which, inclusive of the olive portions at base and summit, reaches a maximum of 69 feet in the South Granby well (nearly 55 feet at Sodus), is therefore the true Sodus shale. It is perhaps the most persistent member of the group in New York State, traceable almost to its eastern terminus. It carries: Lichenalia concentrica Tentaculites minutus Dalmanella elegantula var. (8:57) Strepula? sp. Rafinesquina corrugata Beyrichia lata Atrypa reticularis (3:72) Bollia lata Calospira nitens (Vanurem) Phacops trisulcatus Strophostylus cancellatus Calymenella rostrata Strophostylus ventricosus Calymene vogdesi? The “pearly layers” consist chiefly of the shells of the “Orthis nitens” of Vanuxem (1842, 1:90), whose description is perfectly recognizable (as first pointed out to me by Mr. Ira Edwards) and whose specimens are before me—usually identified with the European Ce@lospira hemi- spherica (Sowerby, 1839). Equally abundant in the purple shale is the “Stropheodonta’ corrugata, which is plainly a Rafinesquina, as it has no hinge denticulations. VERONA IRON ORE This ore, typically exposed in the old workings north and west of Ve- rona (9:67, map on 66, 26, 40), is herein identified with the highly im- portant oolitic lower ore of the Clinton region’? and eastward. A similar shoreward transition is found to affect all the ores when traceable far enough to eastward, whereas westward they grade into limestone as does this ore in the Lakeport well. Its fauna is unknown, except that Van- uxem found Beyrichia? lata in it near Utica (1:84). Dictyonema scalari- forme, Cyclograptus rotadentatus, and Palwodictyota clintonensis are from the shale that “directly overlies” it (New York State Museum, Memoir 11, page 185). The writer obtained Cyclograptus from the ore itself. 18 See preceding footnote 6, p. 338, which suggests caution. = HORIZONS AND FOSSILS 347 WOLCOTT LIMESTONE Hartnagel, 1907 (8: 14-15), emended. Here, again, in following Hall, two horizons were confounded in the original description, namely, the lower and the middle limestones; but the type locality was specified as “Wolcott in Wayne County,” and emphasis was laid on the “large brachio- pod Pentamerus oblongus.” But in the type region specified this fossil fails in the lower (Reynales) limestone at its sole exposure, on Bear Creek, six miles northeast of Wolcott, which is there so shaly that Hall (2: 66, 64) mistook it for the upper shale. The name Wolcott limestone, therefore, must clearly be restricted to the rock which 1s a limestone and does carry Pentamerus and which alone of the two limestones crops out on Wolcott Creek, namely, at the old Wolcott furnace, just north of Wol- cott village (9, figure 3; 2:66). Its thickness in the Wolcott test well is» nearly 22 feet. Wolcott village itself is on fossiliferous Rochester shale, which may have caused the citation (13:95, 858) of two Rochester shale species as from the Wolcott limestone. Though absent at Rochester and westward, where the Reynales has masqueraded for it, the Wolcott hmestone (shale to east and north) is an important member in all sections from Wayne County to Clinton and its fauna should be fully investigated. The only species now known with certainty are: Semicoscinwum clinton (Vanuxem, 1:87, 89), (“Fenes- tella prisca?” Hall), “Fenestella” tenuis (8:51; compare 2:62, 66 for location), Pentamerus oblongus (9:21, 31, 32), Calymene clinton (3: 298). Vanuxem (1:89) reports “a specimen” of Spirifer niagarensis, but this needs confirmation. Vanuxem’s specimens of his “Clinton retepora” (on which he based his correlations now confirmed by the State drillings) are before me from Verona and Martville, bearing the Survey label (Hall’s?) : “Fenestella prisca.” 'This form is highly characteristic of these beds and will prob- ably prove distinct from S. tenwiceps of the Rochester shale. Our Verona specimen contains also a pygidium of Calymene, probably vogdesi. In the shales above the oolitic ore at Clinton, which seem to occupy the Wolcott horizon, the following graptolites occur (New York State Mu- seum, Memoir 11): Cactograptus crassus Also, close to the ore, Dendrograptus rectus Palwodictyota clintonensis Dictyonema retiforme Palwodictyota bella recta (collected by the writer) Cyclograptus rotadentatus ' Dietyonema scalariforme The finding of the Rochester Dictyonema in these dark blue-green 348 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON shales far down in the Clinton, like the recent discovery of the “Clinton” (Brassfield) Dictyonema pertenue in the Rochester shale at Rochester, proves only that these species have a less restricted vertical range than is commonly assigned to the graptolites. WOLCOTT FURNACE IRON ORE This is another unsatisfactory name, with all else preoccupied, unless we use some other binomial, such as “Shaker settlement’ or “Second Creek,” from the other, rather dubious, occurrence near Alton. The bed crops out at the old Wolcott furnace on Wolcott Creek, a mile north of Wolcott village, but is of limited extent even in the wells. It appears to carry the two bryozoans of the limestone below, and perhaps also Spirifer radiatus (3:66) and Halysites (3:44). WILLIAMSON SHALE Hartnagel, 1907 (8: 15-16), restricted. Hartnagel does not specify his type locality, but as he was following Hall he doubtless had in mind Hall’s only mention of Williamson (2:66), which reads: “In the eastern part of Wilhamson, a little north of the Ridge road, the green shale with graptolites occurs, and a short distance to the north of this the Pen- tamerus limestone.” This may mean the outcrops on Mink Creek at the cusp of the “ridge” (Iroquois beach) between Williamson and Hast Wil- liamson villages. In any case the mention of the graptolites (compare 2:75, where the species are described) fixes the horizon, while it is eyi- dent from the chart that the limestone a “short distance” north must be the true Wolcott rather than the Reynales. Since the so-called William- son or upper shale at Rochester mcludes both the graptolite shale and (in the absence of the Wolcott limestone) the Sodus purple shale beneath, we must either restrict the name to the graptolitic beds as here done or else, if the usage at Rochester be insisted on, abandon it altogether. The Williamson as restricted by Hall’s locality reaches the extreme of 105 feet in thickness in the Lakeport well as against its five feet at Rochester and possible failure at Clinton. These rapid changes in bulk indicate some minor diastrophic movements just prior to its deposition, as is brought out by text-figure 3. Its fossils are: Monograptus clintonensis Chonetes cornutus Retiolites venosus Spirifer radiatus Semicoscinium tenuwiceps (?) Camarotechia emacerata ?Paleoglossa perovata ?Atrypa reticularis Pholidops squamiformis Leptodesma rhomboidea Plectambonites elegantulus (2:73) Modiolopsis subalata HORIZONS AND FOSSILS 349 Leptena rhomboidalis Orthocerdas sp. noy. ?Rafinesquina corrugata (3:71) ?Calymene clintoni Schuchertella subplana var. ? * Bollia? lata BREWERTON SHALE From the shales at Brewerton, which Hopkins (11:7) calls “bluish” and Burnett Smith (11:57) “olive,” dredged out of the Barge canal, Smith obtained (11:58): Rusophycus biloba Conularia sp. Pholidops squamiformis Orthoceras sp. Atrypa reticularis Kledenella symmetrica (7?) Pterinea emacerata Arctinurus boltont [var. nov. | “Orthonota curta”’ Calymene sp. [clinton] Although we have already presented evidence that this fauna must lie a long way below the true Rochester shale (see figure 2) and scarcely above the Williamson shale, yet it is mostly a list of Rochester shale spe- eies in which Rusophycus and Orthonota curta are the only distinctly Clinton components. It is entirely probable that more of the Rochester species range downward into the Lower Clinton members than the lists already given would betoken, but even so this fauna forges a further link with that later congeries. Just how much of the shales overlying, or of those in the adjacent wells, is to be referred to this faunal zone is uncer- tain ; but we have rather confidently assigned here the 26 feet of fossilif- erous shales just under the Kirkland limestone in the Lakeport column, which terminate downward with a black pebble seam. Much further work is needed to determine the limits and areal extent of this division, which is of great moment in the stratigraphic and faunal succession. KIRKLAND IRON ORE This is really a ferriferous limestone, conspicuously crinoidal, and is known locally as the “red-flux bed.” Its finest exposures are across the town of Kirkland, in which lies Clinton village, though it is traceable to Steeles Creek (1:82), where it has/furnished Crinoid joints (1:79, figure 3), Beyrichia? lata, Calymene | clintoni. On Swift Creek (1: 84- 85) it or the associated rocks carry heptena rhomboidalis, Rafinesquina clintont (1:84; R. obscura of Hall, 3: 62). 14This species would appear to the write’ to be a Schellwienella, as that genus is defined by Weller in his “Mississippian Brachiopods.” It is not the species identified as S. subplana at Waldron, Indiana (NS. hemiaster Winchell and Marcy). r 300 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON VANHORNSVILLE SANDSTONE Though the exposures of this red, coarse hematite-quartz mixture at Vanhornsville (1: 80, 81; 3:15) are meager, the rock itself is indubita- ble and striking. Its possible equivalency has been already mooted. From the “shaly laminated sandstone highly charged with oxide of iron, associated with the iron-ore beds in the town of Kirkland” (3: 64), Hall gives: Leptena rhomboidalis (1:86) Whitfieldella? sp.(3 :78, Pl. 24, f. 3d) Rafinesquina clintoni (obscura) Pterinea emacerata Strophomena? orthididea Diaphorostoma sp. Stropheodonta prisca This fauna can scarcely lie lower than the Brewerton, while the rock suggests a westward extension of the Vanhornsville. From about the same horizon came probably the types of “Palewophy- cus” (Hophyton?) striatum, and perhaps also “Orthis’ tenwidens. PHG@NIX OR SCHRGPPEL SHALE The type locality is at Phoenix, on the Oswego River, where Burnett Smith (11:57, 58) obtained the following faunule: Chasmatopora angulata Kionoceras subcancellatum Leptena rhomboidalis Dawsonoceras americanum Plectambonites transversalis . Orthoceras sp. Atrypa reticularis affinis Calymene sp. Spirifer (Hospirifer) radiatus Dalnanites limulurus Pterinea emacerata From the proximity of the Lockport limestone at Three River Point (11:9), and of the lower Rochester shale nearly due east of Phoenix, this is high up in the Clinton group, to which its olive color assigns it. The rifts in the river (1:89) indicate a firmer rock-mass than-that at Brewerton, such as the upper 62 feet of Clinton shale in the Lakeport well with its intercalated sandstones, which again is connected by numer- ous outcrops (1: 89, 272, 87) with the upper sandy layers at Clinton and Utica. These last localities supply the following additional forms: Rusophycus biloba Lingula taniola (3:55) Paleophycus bacterium, nom. noy. Rafinesquina clintoni (obscura) Conostichus? circulus, nom. noy. “Stenoscisma”’ sp. (1:89) Aristophycus?? sp. (3 :P1. 10, f.5) ?Pentamerus ovdlis Paleocyclus rotuloides ?Diaphorostoma sp. Westward the sandy layers at this horizon drop out and then thin limy ones come in, increasing until finally the division seems to merge into the HORIZONS AND FOSSILS oO L Irondequoit limestone. Whether the lower shaly part of this limestone at Rochester contains any representative of the Brewerton is not yet de- termined ; it is not very productive, except for Buthotrephis crassa, and has not been carefully collected from, but Rusophycus biloba and Hophy- ton? striatum occur in a brillant green shale film at the basal contact zone. ? Since “Phoenix” has been used by Keith for a limestone lentil in Utah and by Daly for a volcanic formation in British Columbia, recourse may be had, if necessary, to Schroeppel, the township in which Phoenix les. HERKIMER SANDSTONE This name is derived from Herkimer County and is here applied to the Upper Clinton. “gray band” of Eaton, which stretches conspicuously across the southern part of this county with a maximum thickness of 70 or 80 feet at the type locality on Steeles Creek (1: 81-82, 257; name pre- occupied), five miles southwest of Herkimer village, where it has yielded (3: 100-105) : Mytilarca mytiliformis Orthoceras clavatum Modiolopsis ovata Trimerus delphinocephalus Modiolopsis subcarinata “Tcehthyodorulite”’ Ctenodonta elliptica As a part of this congeries, but from localities farther west that seem to belong to the Phoenix division, Hall has described also: Rafinesquina obscura? (probably Schuchertella subpland!) Pentamerus ovalis Diaphorostoma sp. These have been listed under the Phoenix, of which we believe the Her- kimer is indeed only a sandstone phase, as before argued, and as Hall apparently suspected. DONNELLY IRON ORE The ore “at Thomas Donnelly’s” (1:88) has been correlated (9:26) with the thin seam at the base of the upper Irondequoit (Lakeport) lme- stone in the Lakeport well and with that at Tipple’s quarry, near Verona (1:87), all of which are above the Phoenix and close to Lockport quarries. Vanuxem (1:89, 272) describes other doubtful exposures along Oneida Lake and a 2-foot bed of ore at Joscelin Corners, only a mile or so from the drilling. He lists from Donnelly’s the following, two of which occur also at Tipple’s: | i. | Leptena rhomboidalis Atrypa reticularis affinis Spirifer (Hospirifer) radiatus Pentamerus “oblongus” (ovalis?) 302 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON IRONDEQUOIT LIMESTONE Hartnagel, 1907 (8: 16-17). In its lower shaly half at Rochester the Irondequoit limestone appears to comprehend western phases of the Pheenix, or perhaps Brewerton (text-figure 3 illustrates the causes of uncertainty ), and it is even possible that it embraces an important hiatus, in which case the name might be restricted to the upper crystalline part with its curious “reefs” *° and Rochester fauna. Preferably it could be retained in its original scope for the western sections not susceptible of easy subdivision. It is interesting to note that Hall hesitated whether or not to include the Irondequoit limestone in the Rochester (Niagara) shale, and felt obiged (2:82) to present his reasons for adding it to the Clinton. These reasons still apply to its lower and major portion. The fossils listed are derived mostly from the upper half: Buthotrephis gracilis crassa Receptaculites tessellatus Favosites niagarensis? Chilotrypa ostiolata Hallopora elegantula Orthis flabellites Bilobites biloba Rhipidomella hybrida Brachyprion profundum Leptena rhomboidalis Spirifer radiatus Spirifer crispus (8:17) Cyrtia meta Rhynchotreta americana (12 :310) Rhynchotreta robusta (10:7) Camarotechia acinus (5 :193-194) Camarotechia neglecta (8:17) Atrypa reticularis ajfinis Atrypa nodostriata Whitfeldella intermedia Whitfieldella naviformis Anastrophia interplicata Clorinda fornicata Pisocrinus globosus Pisocrinus pyriformis Stephanocrinus gemmiformis Closterocrinus elongatus Caryocrinites ornatus Strophostylus cancellatus? (3:91) “<2” Cyclostomiceras? abruptum Protokionoceras crebescens (7?) Dawsonoceras americanum Cycloceras “imbricatum”’ Cornulites clintoni Calymene niagarensis Trimerus delphinocephalus Bumastus iozus Perhaps also: Whitfieldella nitida Whitfieldella cylindrica ? Goldius niagarensis (13:559, 1488) Except for the forms that are unique, this list is overwhelmingly of Roch- ester species, though it still lacks over one hundred of the indicial species of the Rochester shale.** It is hard to see on what grounds it should be subordinated to the Clinton group. We have in the uppermost beds © usually assigned to the Irondequoit limestone a great inrush of the Roch- ester-Waldron fauna. These beds have more than twice as many species 1% Sarle (Am. Geol., vol. 28, p. 284) reports 99 species as found in the “reefs,” but his lists of species are not published. See also Am. Nat., vol. 16, p. 711; Am. Geol., vol. 1, p. 264; Rept. N. Y. Pal. for 1899, p. 672, and for 1901, p. 428. UPPER LIMIT OF THE CLINTON 353 in common with the Waldron shale as with the Osgood beds, and espe- cially such index species as Clorinda fornicata, Camarotechia acinus, Brachyprion profundum, and Whitfieldella nitida. Consequently we may, perhaps, have to approximate the Waldron and Laurel more closely to the Irondequoit and the Osgood to the Brewerton when we know these New York faunas better. LAKEPORT LIMESTONE Immediately below the typical fossiliferous Rochester shale and above the Donnelly ore in the Lakeport hole there are 16 feet of “limestone with considerable shale” (9:38) that have been interpreted by Hartnagel (9:25) as summit Clinton. Corresponding to these in position in the South Granby well, the next hole west to penetrate this horizon, are but 18 inches of “impure limestone with fossils’ “grading apparently into the’ Rochester (9:36, 24). Without knowledge of their fauna the im- portance of these beds can not well be evaluated, so it will be safer to employ temporarily a local designation for them. The underlying Don- nelly ore crops out at Joscelin’s Corners (1:89; 9:26) and elsewhere in the vicinity of Lakeport, and must expose some portion of this limestone along with it. Conditionally we may follow Hartnagel’s apprehension of the mass as summit Clinton, but whether uppermost Irondequoit coordinate with the “reef” zone at Rochester or a new intercalated member is as uncertain as the third possibility—that it is a calcareous eastern facies of the lower true Rochester (above the “reef” horizon). The last suggestion gathers force from the fact that, contrary to the Clinton rule, the Rochester shale grows more calcareous in passing eastward from Niagara to Rochester—a tendency that may still prevail toward the east, where its outcrop is under the drift. Upper LIMIT OF THE CLINTON The higher beds at Clinton contain small faunas consisting largely of Rochester shale species, from which it has been argued that the Rochester horizon is itself present in the type Clinton section. But the drillings show that these beds lie below the Rochester around Oneida Lake, with the Lakeport (upper Irondequoit) lmestone and Donnelly ore interven- ing. The Rochester shale, which is at least 75 feet thick at Wolcott*® (Hall thought it nearly 100; 2:97), has thinned to 29 feet at Lakeport, though still quite recognizable, and is wholly unknown east of this well. The only apparent bond between this dwindling shale and the 70-foot 16 Including probably the division presently to be distinguished as the Gates. 354 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON mass of Herkimer sandstone east of Utica is the trilobite Trimerus, but Hall says of this that it ranges “as low as the ferruginous sandstones of Oneida County, which appear to He near the base of the formation” (3: 299). 1G no To complete the adverse evidence on this point, the nature of the un-— conformity at the summit of the Clinton should be studied on the chart (figure 2) and in text-figure 3. The Lockport dolomite, still probably 150 feet thick in the Syracuse wells, has become possibly 75 feet (mostly shaly) at Clinton and scarcely separable from the overlying Pittsford horizon (see New York State Museum Memoir, 14: 421), which is prob- ably the rock that makes its last appearance on Steeles Creek (1:90). At Tisdales all these are gone, and a still higher Silurian formation, the Vernon shale, rests directly on the Herkimer sandstone, with a thickness of possibly 50 feet (1:96, 258), though it was fully 80 feet at Steeles (1:96) and 150 at Clinton (W. J. Miller, New York State Museum, Bul- letin 107:150). At Crills, five miles beyond Tisdales, the Vernon is wholly lapped out, and the overlying Camillus gypseous shales of the ~ higher Silurian repose directly on the lower part of the Herkimer sand- stone (1: 100, 258), which does not show itself again beyond this place. At Vanhornsyville the upper members of the Camillus come down within a few feet of the red hematitic sandstone (1:81, 99), and in a short dis- tance beyond they are in contact with the Ordovician Frankfort shale (9:28; 1:253; New York State Museum Bulletin, 162: 36), the Clin- ton having disappeared ; compare text-figure 3. There is thus a steady loss of members from both the top of the Clinton and the bottom of the Niagara and Salina as the hiatus enlarges eastward. To whichever group we refer the Rochester, it should therefore be one of the first to go; indeed its sharp reduction in the Lakeport well was our first intimation that this process of elimination had commenced as we came east. Along with it vanishes the upper Irondequoit (Lakeport) and then the Donnelly. The resistant Herkimer, however, persists east- ward as an ancient cuesta, with a steep in-face. Stratigraphically, then, the Rochester shale is excluded from the type section of the Clinton. Considering the Waldron aspect of the upper Trondequoit fauna as just observed, the paleontologic testimony is not any more favorable. The comparatively small number of “Rochester” species in the upper Clinton divisions (Brewerton, Phcenix, Donnelly, Kirkland, Herkimer) loses all weight when it is realized that Plectambonites, Spirifer radiatus, Lepteena, Pterinea, Dalmanella, Atrypa, Semicoscinium, Dawsonoceras, Trimerus, Calymene, Dalmanites, Camarotechia neglecta, Dictyonema retiforme and areyt, all get started either in or below the —_ PHYSICAL HISTORY | 300 Williamson shale, whereas in none of the Clinton divisions does there appear more than a mere fragment of the large and typical Rochester fauna (about 230 species recorded; see 8:19; 10:7; 13: 1487-1489). ex- cept in the upper Irondequoit, especially its “reefs.” On the other hand, the sifting of the faunules reveals a surprising in- coherence faunally in the stratic units of the Clinton itself. There is here no discernible “Clinton fauna” in the sense in which there is a Ham- ilton fauna or a Naples fauna. While intensive collecting may give ereater homogeneity to the stratic paleontology, the larger disconformi- ties will always isolate rather definite assemblages, as will be further shown after the physical evidence for these disconformities has been pre- sented. PHysicaAL History The straight-line correlations of figures 1 and 2 fail to bring out vividly the diastrophic movements, with their resultant overlaps, often alluded to above. ‘To visualize these, and to bring together all the sec- tions on a uniform scale, text figures 3 and 4 have been prepared. While drawn to measurement with the same care as the plates, the sections have been connected in these diagrams by smooth curves, so as to reconstruct more nearly the actual strata. As a result, some things that before ap- peared as difficulties now prove highly significant. For instance, the apparent excess at the summit of the Red Creek. section (see figure 1) serves to locate an accessory syncline in figure 3 (section “6”). Simi- larly the deficient thickness of the Reynales limestone at Ontario marks a secondary anticline in figure 4 (section “2’’). The strata in figure 3 are given the attitude they are believed to have had approximately during Rochester time. The overlying formations are then fitted over these in their proper thicknesses, in order to emphasize the great summit unconformity and the cuestas of firmer rocks over which the Mesontaric sea transgressed eastward. At the east a similar basal unconformity of the Oneida conglomerate -on the Ordovician shales has long been recognized, and it has been cor- rectly argued (by Grabau and others) that the amount of summit erosion of these shales demands a later age for the Oneida than pre-Medina or (as some have even thought) Oswego. In short, here also was an east- ward transgression. Next most striking is the evidence of a post-Woleott diastrophism—a weak compression from the cast, producing a marked syncline in the region of Oneida Lake, with its maximum at Lakeport (section “9”). Simultaneously the bordering regions rose into the zone of wave-plana- 306 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON ‘pop VilassVxa ALPYSTS (ORG UL) spueq o10-UOAT OT} JO ssouyoiq., ‘“AOTIVA AMIGO ‘GL ‘OT[[ASUIOYULA "PT ‘SOTVPSLE “ET “BOVIO “SL “UOPUTID ‘TT ‘“BUOTOA “OT ‘“JaodayUy *G = ‘“WoJTOMOIG "g ‘AquRIyH NOG *Y. ‘ITAMBIE “9 “JOD Poy “M “OOTOAA "G “WOPSUTIVA “HP “MOSUIVITTIM "§ “OPIBIUO “GZ *A9}SOYOOY *T : SOT -[OJ SB poroquinu ‘sainsodxo 018 SOUTT 9TQNOpP PUL So[OY-910q OY} 91V SOUT] [Bd]TZAVA O[SuIG °Z puv T SoINnSy oaiRdmod ‘uoT}RIVAIL0D AO do10yng fo auvT 2uUasasd Ut sawag ay2 fo WUVT 170U018049 WHADDDIN-O4d 07. 49180400 vy mod spag Bwhjw010 pun 090.48 24DQUO Jo wosbnIg dNYdDAb1QDAGS PIZONAQsUuoddy—'e AUN | SY AM-2EO / | SI4NSOAX TF X0S8 XJ wor Or o/ ue aovfune peuesd- 3A Cff SOF S/PYS Uoy 94,9 217) li AP ff P7 PY S Mr yee —— ela eres seen — L0G OL 1) 14973. OF SS 2ue}s salut) FTES nae =< : res SS PS aS es YH HV ere jdeahend weenie aheedi Londo hen dtednwenhendh lhe hed indi md Z a/eEY S Pe pe - Lap SOY OO 1 240g 807) 90224 —— So “y Wy 6 seein) nae LCI 7 O /2 Riot yoo7 jp? Lf l2 PHYSICAL HISTORY Bor tion, as should be expected. Hence, while the sub-Wilhamson formations maintain a marked uniformity of thickness in sections “4” to “10,” they are rapidly beveled away from the top downward to the west of section “4” (Wallington) and are overlapped successively by the mueh attenu- ated Williamson. At Rochester, where the Williamson is very thin and rests directly on the lower Sodus, it contains slightly rounded flat pebbles of limestone at and near its basal conduct, often standing obliquely and sometimes two or three inches in diameter. There are also in the shale worn favosite corals of similar size whose calcareous or yellowish matrix indicates extraneous origin, presumably from wave destruction of neigh- boring Wolcott limestone. The strata above the Williamson do not participate in the undulations of the sub-Williamson beds, except that the Brewerton sags shghtly into the main (Lakeport) trough. But a general excess of upward movement at the west seems to have persisted until the close of Irondequoit time, maintaining clear-water (but shallow) reef’ conditions from Niagara nearly to Rochester and catching all the land wash in the sinking hinter- land to the east. ; ° The nature and distribution of the Rochester shale show that these canting movements suddenly ceased and a general submergence ensued, whose terrigenous sediments appear to have come largely from a new direction (farther west). Further field-work is necessary before the na- ture of the sub-Rochester plane can be confidently asserted, as also the relations to the upper Irondequoit and Rochester of the Lakeport lime- stone. One gathers from figure 3 that the Lakeport would go more ac- commodatingly below rather than above the wave-erosion plane. Pro- visionally, however, the lime has been drawn at the Donnelly ore. Another marked feature of the diagram is the great expansion already described (page 337) of the basal beds at Clinton (section “11”). This is now seen to be due to an earlier (pre-Martville) diastrophism, in which was produced the Sauquoit synclnal. The beds involved are the Oneida and supposed Maplewood. The effects of this movement farther west- ward are best brought out by means of the extreme exaggeration given to the thin basal members in figure 4, in which the summit of the Rey- ~nales limestone is taken as the horizontal datum. Two movements are evident in this figure: First, the post-Maplewood Alton anticline (corre- sponding to the western rim of the Sauquoit synecline just mentioned), and, second (after wave planation and deposition of the Martville- en 17 This has no reference to the so-called local ‘‘reefs’’ of the increscent Rochester sub- mergence, but to the crinoidal and other organic rubble of which the Irondequoit itself is composed. XXVII—BvuLuL, Grou. Soc. AM., Von. 29, 1917 ee 358 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON Otsquago-Bear Creek), another faint compression that converted the ero- sion-weakened crest of the previous arch into a double anticline before the Reynales limestone was deposited. Less evident from the diagram is an overlap relation of the Thorold-Maplewood on the red Medina, which would be more easily demonstrated had the wells penetrated deeper. These diagrams indicate the following “order of events”: (1) Post-Ordovician erosional unconformity and transgression. (2) Post-Maplewood diastrophism—Sauquoit syncline, Alton anti- cline. 7 (3) Post-Wolcott diastrophism—Lakeport syncline, Rochester parma. (4) Pre-Rochester submergence; source of sediment shifted to west. (5) Pre-Lockport erosional unconformity, terminating the Hontaric. a oe West <= io fiewrohn: re Ser eA ROG Gt tin ae eae 3 aq Posse? Shale _« DM sey ore ced bed, Sauguoct hia di : 10 ft 7est-wells | Exposures I i : @ve-planed surface 7. FPeebhle zone in shale coco 20 OOO. ee Figure 4.—Diagram of thin basal Divisions of the “Clinton,” from Rochester eastward to Verona only The vertical exaggeration is excessive. Solid vertical lines are the test-wells terminat- ing in these strata and are numbered as in figure 3. Oneida conglomerate largely in- ferred from outcrops to north; it may extend farther west. The diagram suggests that Bear Creek sedimentation was both preceded and followed by faint diastrophic move- ments, and that these movements were initiated still earlier at the close of Medina red- bed deposition. Iron ore in solid black. The horizontal datum is the top of the Reynales limestone. Interspersed between these are minor diastrophisms and those weaker pauses in deposition, such as Professor Barrell is calling “diastems,” of which the various iron-ore beds furnish special illustrations. The most significant of these minor breaks seem to be those at (a) the top of the red Medina, (0) the Furnaceville iron ore, (c) the Kirkland iron ore, and (d) the base of the Gates limestone.** 18 This name is defined at the beginning of the following chapter on classification. PHYSICAL HISTORY 359 The extent and importance of these interruptions in sedimentation are best exhibited by the following distribution chart of horizons. The locali- ties are chosen to avoid duplication, and from Rochester east they are spaced at moderately equal intervals. Thin ore beds not associated with significant diastrophic changes are omitted. The asterisks signify pres- ence of the horizon. e ajwm] ew aw r) t=) (=| A>) > _— Low) > . 2 ~- a o Glahe a +s o< al al] > W t m i= > ® ~|* | @ Hilo; - Uy 6g alol@/ulerlolwlealolelaHlal ola East o;~)] #1] Of] Ql apa] & HLOLO!] —/| & aim] od ul OF] Mime lola] Of ale a3}; o a Co ne ee ee — 7~P i, ez] oO;alu]a [=| =| Cs] 9 Ol rl a | cu a ® | da |= ola wm | Ol} OO} CO] AB] eO!]@O] Of] &] Bla] ~-| a Alpel=z[oal/alyol=l/ein\ialsaslo)}] =|/> Mesontaric Lockport dolomyte series (Decew, etc.) tel | belle fe] | AT Rkester eee eee Irondequoit ie Brewerton Breverton || Williamson Pee > Pees zz ae 3 | a | 9¢ | 36 | 36 [90 | ae | mel ae] | Phoenix-Herk . Wolcott Furnace Wolcott ee ge Sodus agit: bee | ” Turnaceville ae See ee 2 Boar OF -Hartville Hoh asst tele raelt é Maplewood ("Sodus") Yt fuel | faefoel TT TT Tae? Thorold | fetal [sel | [2 ]e| eee” Oneida. iodine ate [oe [oe |e fe fe oe Del? | Ordovician JQueenston red sandy shales 7% Bae Unseparated at Clinton The hour-glass pattern of this chart is even more convincing than the diagrams, as to the prime import of the middle (post-Wolcott) discon- formity. ‘This break forms the natural division between lower and upper Eontaric. CLASSIFICATION AND FAUNAS On the basis of these unconformities, disconformities, and “diastems” found in the New York strata, we may forecast some future readjustments in the classification of the Hosiluric (Hontaric). The summit of the 360 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON latter will be the great unconformity whose eastern manifestation has just been discussed and whose western development has been traced by Schuchert (12). No comparable break is known to exist further up be- tween the Niagara and Salina. Its character is strikingly exhibited in the new barge canal rock-cut at Rochester, where, furthermore, there are beneath it about 20 feet of beds at the top of the Rochester shale which are apparently not present at Niagara and which are really a limestone, being quarried and sold as such at the North Goodman Street quarry in Rochester (12: 304). These beds were noted by Hall (2:82). On their eroded upper surface rests the Decew (basal) member of the Lockport. They are separated from the shale below by a perfectly clean-cut line, or clay seam, and carry few fossils save Lingula lamellata. It is proposed to eall this division the Gates limestone, from the town in which the beds appear in the canal prism, and to restrict the term Rochester shale to its proper expression as a fossiliferous calcareous shale below them. The full list of horizons'® from the Gates down to the Champlainic (Ordovicic), with its major (~———) and minor (...... ) disconformi- ties and the maximum known thicknesses in New York State, is: Upper Eontaric Lower Eontaric. Feet Feet -22. Gates limestone @.......... 20 14. Wolcott Furnace orec..... 4 Dre ated, Seema nee ee per neers 13. Wolcott limestone -..7 2a 2l. Rochester shale: ssc... ax. 65 12. Verona Ore -... 1.7) 2s eee 5 20. Lakeport limestone........ 16 11. Sodus shale ...:.:.23 69 19.4 Monvielly Ores ce .. eee ass 2 10. Sterling Station -ore....... 1% 9. Reynales limestone ....... 24 18. Phoenix shale and _ sand- (Dark shale in Lakeport well 7) SEO DY hs Se eet phe hom 2 70? §. Furnaceville orec ......... 2% 17. Kirkland ore and limestone. ee eee ee . Bear Creek shale and =| @ les) ©) eh a eee ele ee ie) ake he ls) ©) ee) wel.e) 4 \0 16. Brewerton shale .......... 36 6. Martville sandstoned ..... 10 15. Williamson shale ......... 105 ee aa 5. Maplewood shalee ........ pA | ae 4. Thorold sandstonef ....... 10 SUA ACE lice. Steph B20 ike oils nile aehee CL ae 3. Grimsby (Medina) sand- stone 9 ........ eee 60 2. OALAT AGE (Manitoulin) + shale g (in New York).. 29 1. Whirlpool sandstoneh..... 22 CLASSIFICATION AND FAUNAS 361 About 475 species of fossils are known from these strata in New York and southern Ontario. With our present imperfect knowledge of the range of these species (particularly in the Wolcott limestone), it is not desirable to cumber these pages with an extensive tabulation by horizons : but an abbreviated summary by groups of strata will serve to show how few species are known to pass the diastrophic barriers above indicated. (The table appears on the following page.) The surprising thing about this table, however, is that the largest number of species in common be- tween any two groups within the EHontaric is that between opposite ends, the Rochester shale and the Cataract-Edgewood-Brassfield faunas—23 species. ‘This may have some paleogeographic meaning, or it may merely measure our ignorance of what hes in between. The Rochester has its largest quotas in common with the Niagaran faunas above it, whereas the Cataract-Medina fauna shows less species in Common with the entire Ordovician (including Richmond) than with the Rochester, and espe- cially with the unquestioned Niagaran (Lockport-Guelph, Louisville, etcetera). The small Martville-Bear Creek fauna is more largely unique (73 per cent) than any other (except the debated “Niagaran dolomite” of Hamilton, Ontario), and the large Rochester fauna stands next (67 per cent unique). In confirmation of the deductions already made from the stratigraphy, it should be noted that the typical “lower Clinton” group (Furnaceville to Wolcott Furnace), which carries the largest assemblage between the Cataract and Rochester, has its faunal affinities most decidedly with the Cataract-Brassfield (23 per cent), whereas the overlying Williamson- Brewerton-Phoenix division aligns itself equally decidedly with the Roch- ester shale in its faunal association (25 per cent). The current reference of the Williamson Monograptus fauna to the lower Clinton has clearly 19q@ The Gates probably continues to thicken east of Rochester under the drift, and is very likely the rock forming the falls at Wolcott village which Hall (2:82) speaks of as the “higher beds’ of his Niagara shale. 6b The Herkimer, supposed equivalent of the Pheenix, is said to reach a maximum of 80 feet. ec The iron ores (Donnelly, Wolcott Furnace, Furnaceville) really are in the disconformity rather than above or below it, since they represent concentrations of iron oxide during the depositional interruption ; but their fossils are in general those of the adjoining limestone member. d The supposed equivalents of the Bear Creek and Martville forming the middle member of the Sauquoit beds about Clinton and Utica have there a thickness of approximately 30 feet (2: SGI) e The beds correlated with the Maplewood likewise approach 50 feet thickness in the Sauquoit syncline. f Should the “gray band” of Rochester prove distinct from the true Thorold, the list will need to be amended at this point. g The Grimsby and Cataract are equivalent beds of different facies, with contemporary overlap toward the west, as interpreted by Schuchert (12: 294); in Canada the Cataract eventually embraces the entire interval, with a thickness equal to the sum of the measures here given, and is there subdivided into the Manitoulin dolomite below and the Cabot Head shale above. h The Whirlpool is considered by Professor Schuchert the basal member of the Cataract. NEW YORK CLINTON | H. CHADWICK—STRATIGRAPHY OF G. ‘[VjpUoMeTddus ATOLLS ST SomMsy JO JOS ISB] SIG, “UOLPV[OIIOD S.lo[ssvg SUTMOT[OJ ‘st }VY}J—SoToods UOAp[VA\ [1B Fulpn»orga ‘jueyeambe aaoid ABUL TOAPTBAL OY} 9dUTS ‘ATMO TOAP[VA, Of} 0} TOUUIOD a1B 7BY} (SoP0ds G ‘ATIUTVM) BSOT} OpPNOUL Aa}saqIOY oY} 0} AvTTMOed sv MeATS sopoods LET oY} Jnq fyAsYoNYoS puv syavgq AQ sv yLOdyooT] peaspiIsmod St (GSFL i EL) OfvjJUO ‘UOZ]TUIR_T JO ,,a}1MO[Op URIVSRIN,, 94} SeINSY JO Jos siyy ‘oOVdS DABS 0} WUIN[OD [BOT}.I0A OY} WAT pazIIWO st BUNR] [LeUS ul p: ‘onbiun Apjsour ‘varie yronbnueg oy} Wor ,,sploony,, OZ JNOoGR soptIseg_ 2 SITE @ ‘MMOsstY pure ‘sioul[y ‘olgO JO pleyssuiq puv poomMospy sulpnypouy v % LT Og % GS 8g - 9 9G %GG cr WO 1G ‘pauiqutos SUIN[OD 93014} 4Se7T | % cl Or g FG GG WET yh MTL 8 0 0G 1G | “919 MAUB | Speq seysIy 19430 | WF TP api ied (68) | WFP | = 96 %GL | cae rE | 82 %0% || %¥G S.) GG %WE1 i WES or | 8st WO | %TT L $8 Sal COG é L %L || %ET ey FIL : P<) BA ) aay a ec) ce Ba |e Be || & ee) St he %8 ¥G %6 aa IF %6 G %T T WG 1 %9 L ‘ylonbepuoly | %F ST %Y SI WME g | -u0Oq 0} UOSUIEITIIM | -Ay]ou %$ OL WE S %G L -208UINY 3300 JOM 0} O[[JAsovUINY | / / = | | : Ajoewvu ‘sdno1s JayjO YIM UOWWOS uy D8 7. &G WOT 83 OB UT. L % GT 8 WES Lit %O9T § p'sjua|evAInbs pue eurIpan jOBIE}ED | YT. P EYE F AXE %00OT 966 %OOT. GES %OOT IF %OO1 6G %OOTL eye %(OOL 961 %OOT. 90T VOL 63 WEL Ts WE OL WT. 8 YA | “MO[Oq 2 9AOGY % LT 0G % GP 8g oy) 63 VTE LI % GS -aAoqe sseg Gh 9 GGG %L9 *1el[noag ‘sotoeds jo Joquinyy WS8t Gg 1G 6F %6G cL MEE LT YEG 4 ax) I g %( TL *MO]Aeq W014 ‘peMO IIB POOMOIAB puv ploO1ogy, Wat1eq ApAVIM OUT, o« < OUTULOTOP UBIB -BBIN,, DUB 1d}SoTPOOIY p'Soyex) YUMA o[BYS 1a}Ss9To0Y “1eddn Apery ‘4tonbepuoay ‘AT [ou -U0G 0} UOSUIBITITA ‘OOBUAN,T 7400 -[OM 0} d[[TAvoRUIN | Q° 9019 Iwsq pue dITAweyy “BUIPIY PUB JORIRIRO “SUIpscoid 4si] 94} ul se pednois ‘suozjiopy og OLMDIUNUGQ, UMAYINOY PUY YOK NaN {oO spunny olupquom oy. fo woyng.ysiq fo a1Qn],, hanunuyatd CLASSIFICATION AND FAUNAS 363 resulted from the inclusion in the Williamson of the true Sodus shale, which is now found to be markedly disconformable with it, and with which it has almost no species in common (probably only Atrypa reticu- laris and Leptodesma rhomboidea). Chonetes cornutus, which at Roch- ester and Sodus always occurs on the same slabs as Monograptus and Retiolites, is already listed as upper Clinton PY Bassler (13: 1487), as also Monograptus. The transfer of the true Williamson to the upper Clinton makes but inconsequential changes in Bassler’s lists. Monograptus clintonensis and Pts Plociambonites transversalts (that is, P. elegantulus) are erased from the lower Clinton, while Leptodesma rhomboidea is added to the upper Clinton. Retiolites venosus and “Rhynchonella” (Camarotechia) emacerata, with possibly Lingula (Palwoglossa) perovata, are also re- moved to upper Clinton. In addition to these the following have been inadvertently admitted to the lower Clinton list and must be transferred to the upper Clinton-Rochester imdependently of the rectification of boundaries here proposed: Atrypina disparilis and Nucleospira pisiformis of the Rochester shale at Wolcott village and many other localities, Cyrtia meta of the upper Irondequoit and Rochester, Pentamerus ovalis and Inngula teniola of the Phcenix-Herkimer, Palewophycus striatum of the Brewerton, and probably also Kionoceras (sub) cancellatwm of the Iron- dequoit and Rochester. “Holopea fragilis” should read Helopora. While the dividing line between lower and upper “Clinton” thus grows more clear cut, that between “Medina” and “Clinton” since the discovery of the Medina age of the so-called Clinton of Ontario (Cataract) and Ohio (Brassfield) correspondingly fades away. The same argument that would include the Rochester shale in the upper Clinton would embrace the Medina (excluding Queenston) in the lower Clinton. Neither one is present in the type “Clinton” section. But faunally the affinities named are unquestionably great, emphatically greater than those between lower and upper “Clinton.” In short, the major faunal and stratigraphic break within the Eontaric is at the Wolcott Furnace ore and cleaves the “Clin- ton” into two parts, one of which falls naturally into company with the Rochester and the other with the Cataract-Medina, though each still re- tains a minor individuality from either of these. The name Clinton, like the “Silurian” of older writers, has been doing double duty. The writer is not prepared to offer names for the combined “Lower Clinton”-Medina and the “Upper Clinton”-Rochester, respectively lower and upper Eontaric. Preferably these names should come from the thick sections in Pennsylvania or Maryland. But it is interesting to note that the four chief divisions now outlined (approximately Medina, lower YORK CLINTON NEW OF STRATIGRAPHY 364 G. H. CHADWICK X te (|S ly kK % o1S Clee ale 3 x Ol et CHINA IHL e. | AepsayIol/ “ Lockport /imestone series (Decew, ¥e) of Niagaran|\ fe Se Me eer 4 ‘f & WwW Pf? eo Bs +4o SH O-f Boy “So es - Ae ee) a a) nut a, O's — NYILSODILNY ——¢-— 40 suezUuoz seS/p) “opUipy se ASa/p DUOLS a lit // saddn [0g lip) 7} yy aera NS Oy | w]'o = ee : S319 NES R |) t] 9 4 x) YS] 819 = silo sie b Q] :. by S} ols RIES N aes elins NPE ies t Ss INIA ~ SIRIRS IES BIC A)S ay UOful{) 1eMo7 “se A ARACEAE TTT “4 baauvs ayeys [UOZsUY J] PU022O : LopulsD fPusOls4C $4 af N Snows ne | i w i eae eres (Ord, SSchuchert ’Tworotdn * aE) 4GRIMSBY re CATARACT WHIRLPOOL’ § rf a — Queenston shale of Flichmond s ee eee PUL palT/ Pu iPaltf J? ody) Pf Bt yf §| avoyspues pur S| S9/PYS Pal PUIPALL/ | peusStsQ- Wiliams. FIGURE 5.—Historical Chart of “Clinton” Classification “Grabau. “4/3 // IS 39, shandouned /. (The Lakeport limestone probably belongs in the ‘“‘Upper Clinton’’) CONCLUSION 365 Clinton, upper Clinton, and Rochester) are closely paralleled by the four Silurian divisions of the Anticosti series (13, plate 4, omitting Gama- chian), and that the term Anticostian is indeed the best available series name for the Eontaric as here defined. The chart (figure 5) will serve to express the present summation of the problem of the New York “Clinton” and its associate strata. The section is based on the thicknesses given in a preceding list of horizons. The columns on the left show the main steps in the nomenclatural history and those on the right the writer’s conception. Under the caption “Al- lowable (?) usage” is a possible compromise or transitional terminology entailing the least displacement of familiar terms, though such a Pro- crustean solution is not wholly unobjectionable. CoNCLUSION The New York “Clinton” holds but the thin overlapping edges of the more wide-spread members of the strata which in Pennsylvania are re- puted to be nearly half a mile thick.** Between these rhythmic waves of submergence must be many disconformities in the strata, especially in the basal ones, which (when marine) should be thin and non-persistent as compared with the higher. Though thus fragmentary, the New York record is perhaps the more valuable for purpose of classification, since it isolates and emphasizes suc- cessive faunules that in areas of continuous sedimentation may so blend or overlap as to obscure their systematic value. The section at Clinton was a most unfortunate one on which to base a name for a group, as its elements have long remained undifferentiated, are largely lacking in discriminative criteria, and are far from typical for nearly every component. The faunal characterization of the group had to be made from other localities lying beyond a wide drift-covered interval, beneath whose veil the lithology and fossils change so completely that the original correla- tion was scarcely more than a “good guess,” fortunately now justified by the well records. But the “Clinton group” as generally interpreted proves to consist of two incongruous portions, belonging one with the Rochester, the other with the Cataract-Medina. Hence, since the name “Clinton” can not with- out much inconvenience be extended to embrace these last, and so to cover the whole Eontaric (Anticostian), nor can it well be restricted to either of its two components, as was done with the name Silurian, it would ap- 21 Professor Schuchert comments that a lot of this is ‘Salinan. 366 G. H. CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON pear logical to gradually eliminate it by substituting a name for each half. It is not expected that this step, or indeed any of the changes herein pro- posed, will be adopted without full discussion (see Science, new series, volume 39, 1914, footnote to page 918) and much further field-work, par- ticularly in the eastern area. The proposals must be considered tentative, opening the way to restudy of the whole problem. PALEONTOLOGIC SUMMARY In order to complete the faunal lists, the following names are applied to some of the “fucoids” described without names by Hall (3) : Arthraria dicephala, nom noy., for New York Paleontology, volume 2, plate 10, figure 6. Conostichus? medusa, nom noy., for New York Paleontology, volume 2, plate 7, figure 2. Conostichus? polygonatus, nom noy., for New York Paleontology, volume 2, plate 10, figures 9, 10. Conostichus? circulus, nom. noyv., for New York Paleontology, volume 2, plate 10, figure 4. Dactylophycus pes-avis, nom. noy., for New York Paleontology, volume 2, plate 10, figure 3. Paleophycus bacterium, nom. noy., for New York Paleontology, volume 2, plate 9, figure 4. Sphyradoceras? malti, sp. nov., is used without description for a new form of considerable beauty from the Clinton drift boulders at Clarendon that have afforded also a handsome new Goldius. The descriptions of these and other new forms obtained from our Silurian strata are deferred to a later publication. The following combinations believed to be new are used herein: Aristophycus? heterophyllum (Fucoides heterophyllus Hall). Aristophycus? cf. heterophyllum, for New York Paleontology, volume 2, plate 8, figure 4. Asterophycus? palmatum (Buthotrephis palmata Hall, plate 6, figure 1). Atrypa reticularis affinis (Atrypa affinis Vanuxem, not Sowerby?). Blastophycus? impudicum (Buthotrephis impudica Hall). Botryocrinus plumosus (Glyptocrinus plumosus Hall). Camarotachia? bidens (Rhynchonella bidens Hall). Camarotechia? emacerata (Rhynchonella emacerata Hall). | / Chondrites? ramosus (Buthotrephis ramosa Hall). Celospira nitens (Orthis nitens Vanuxem; Atrypa hemispherica Hall, not Sowerby ?). ee Cycloceras “imbricatum” (Orthoceras imbricatum Hall, not Wahlenberg). Wahlenberg’s species is an Actinoceras, according to Foord. Cyclora? subulata (Murchisonia subulata Hall pars, figure Ta only). PALEONTOLOGIC SUMMARY 367 Cyclostomiceras? abruptum (Orthoceras abruptum Hall). Dactylophycus? sp., for New York Paleontology, volume 2, plate 8, figure 5. Dawsonoceras americanum (Orthoceras annulatum americanum Foord). Clearly distinct from the type of D. annulatum, but possibly not from Dawsonoceras nodocostatum (McChesney). Hophyton? striatum (Paleophycus? striatus Hall). Kionoceras subcancellatum (Orthoceras cancellatum Hall preoec., O. swbcan- cellatum Hall in Miller). Paleoglossa acutirostris (Lingula acutirostra Hall). Platystrophia brachynota (Delthyris brachynota Hall). Plectambonites elegantulus (Strophomena eclegantula Hall; Leptena sericea Hall: New York Paleontology, volume 2, page 59). Pterinea leptonota (Avicula leptonota Hall). Rafinesquina clintoni (Strophomena clintonti Vanuxem; Leptena obscura - Hall). Rafinesquina corrugata (Strophomena corrugata Conrad). Schellwienella? subplana (Strophomena subplana Conrad). ~ Semicoscinium clintoni (Retepora clintoni Vanuxem; Fenestella prisca? Hall, not Lonsdale). IMPORTANT PAPERS The following list includes only those of prime importance in the study of New York Clinton stratigraphy: (1) 1842. LarpNER VANUXEM: Geology of the Third District, New York. 75-78, Oneida conglomerate. 79-90, Clinton group. 257, 262, 272, County reports. (2) 1848. James Hatt: Geology of the Fourth District, New York. 58-79, Clinton group. 81-83, 97, 100-117, Niagara shale. 414, 422, 433, 440, County reports. (3) 1852. James Hai: Paleontology of New York, volume 2. 15-17, Clinton group, strata. 18-105,, 179-184, 297-301, 353, Clinton fossils. 106-108, Niagara group. 109-176, 185-295, 302-320, 351-353, Niagara fossils. (4) 1898. F. J. H. Merritt: Guide to the geological collections of the New York State Museum, Bulletin 19. 153, 190, 219, Clinton group. Plates 44, 49-57, Views of Clinton sections. (5) 1901. AmapEus W. GraBpau: Geology and paleontology of Niagara Falls. New York State Museum, Bulletin 45. 95-102, Clinton beds. 102-105, Rochester shale. 130-228, Fossils of the Niagara region. (6) 1902. F. J. H. Merritt: State geologic map of 1901. Bulletin 56, New York State Museum, opposite page 34, Comparative table of geologic nomenclature. (7) 1907 (S) 1907. (9) 1908. (10) 1913. (11) 1914. (12) 1914. (13) 1915. . CHADWICK—STRATIGRAPHY OF NEW YORK CLINTON CHRIS A. HARTNAGEL: Stratigraphic relations of the Oneida con- glomerate, in Bulletin 107, New York State Museum, pages 29-38. C. A. HARTNAGEL: Geologic map of the Rochester quadrangle. 2-17, Clinton formation. 17-19, Niagara formation, Rochester shale. D. H. NEWLAND and C. A. HarTNAGEL: Iron ores of the Clinton formation in New York State. Bulletin 125, New York State Museum. ek E. M. KinpLe and F. B. Taytor: Niagara Folio number 190, United States Geological Survey. 6-7. Clinton formation. 15-16, Silurian period. T. C. Hopkins: Geology of the Syracuse quadrangle. Bulletin ye 7-8, Clinton-Rochester shales. 57-58, Fossils from the Niagaran formations—BURNETT SMITH. CHARLES SCHUCHERT: Medina and Cataract formations. Bulletin of the Geological Society of America, volume 25, page 277. 292-293, Contact with Medina. 296, Summary of sections. 304-316, Sections in detail. Ray S. Bassiter: Index of American . . . Silurian fossils. Bulletin 92. United States National Museum. 1486-1489, Faunal lists of New York Clinton. POSTSCRIPT The writer desires also to thank Dr. Burnett Smith for the privilege of ex- amining the collections from Brewerton, Phenix, and near Three Rivers Point. These confirm the deductions above made. The faunas, partly new, are being studied for publication by one of Doctor Smith's students. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 369-374 JUNE 30, 1918 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY SCOPE AND SIGNIFICANCE OF PALEO-ECOLOGY BY FREDERIC E. CLEMENTS 1 (Read before the Paleontological Society January 2, 1918) CONTENTS Page muempecovince Or TUNCtION Of ECOlOPY. 2. ok ele ke eee eee bk wen ease 369 ECM AUTON Ol, CCOUGL I 6 bas oc ou ie! 0 Slawald lc Bi ee WO Ras a Ska Ps dee wy 370 Symractic: Character of paleo-ecOlogy. i... occ Os See ae Cee ec te ewe ae 370 Methods of employing previous ecological results.................5--2008- 371 iieemiack on developmental correlation... 2.250. ..00. ce ec kelte a bees 374 PN ke oe hee we de we i A Ae a ade ap day beer cities itr 0 eA ya ER 374 Tur PROVINCE OR FUNCTION OF ECOLOGY At the outset it seems desirable to emphasize the view that ecology is not a new division of biology, or indeed a division at all. It is merely a point of view, a new method of attack, which has been as natural a re- bound from the intensive laboratory research of the last twenty-five years as this was a logical reaction from the more diffusive studies of natural history. ‘The viewpoint of ecology inheres in the “oikos,” or habitat, as the motive force in the life processes of plants and animals, both as indi- viduals and as communities. As a consequence of this vital relation ecology is essentially synthetic. It is deeply concerned with soil and cli- mate, but never as ends in themselves, merely as intrinsic parts of basic biological processes. While the ecologist can not ignore the static forms of plant and animal life, he is interested in them chiefly as the end-forms of responsive processes. In short, ecology deals primarily with processes and is inherently and universally dynamic. This means that it should be experimental in the highest degree, and that development is the one great clue which it must follow throughout. As a result, it must be quantitative in method, beginning with the habitat in which measure- ments are relatively simple, and running through individual and com- munity responses in which they are difficult: Further, the name itself 1 Manuscript received by the Secretary of the Society March 7, 1918. (369) 370 F, E. CLEMENTS—SIGNIFICANCE OF PALEO-ECOLOGY makes it clear that living things and processes are to be studied first and last in the oikos, or habitat—whether forest, prairie, desert, or cultivated field—though with the fullest use of controls wherever these are necessary or desirable. Finally, the method of the ecologist must be at the same time intensive and extensive if he is to follow processes accurately and to apply them broadly. THE UTILIZATION oF EcoLoGy It is perhaps puzzling to understand how the demands of ecology can be met in a field where processes have ceased. The readiest answer, and a fairly complete one, is afforded by the principle of uniformity of proc- esses, the use of which has made modern geology possible. The value of this principle has recently been recognized in climatology, and it is also proved to be of wide application in plant succession. The initial use of it in succession has met with such success as to suggest its wide applica- tion in the whole field of paleo-ecology. As a consequence, it has become clear that the development of the ecological aspects of paleontology must depend absolutely on the progress of present-day ecology. In just the degree that the latter becomes synthetic, experimental, and quantitative will it be possible to apply it accurately and thoroughly to the interpre- tation of past life processes. In this connection there is no thought of minimizing the ecologic contributions of paleontology; but these have usually been a by-product of taxonomic, phylogenetic, or stratigraphic studies, and their ecological orientation has been difficult or uncertain. SYNTHETIC CHARACTER OF PALEO-ECOLOGY It is assumed that paleo-ecology must be primarily synthetic: that it must deal chiefly with processes, their development and correlation. In fact; the latter stand out in bolder relief because th® phenomena are fewer and more isolated. Moreover, special fields have not been differen- tiated in it, and it is possible to follow sequences through without stopping at artificial boundaries. This is especially significant at a time when the conviction is slowly growing among ecologists that the life of a habitat must be studied as a unit complex and not in two detached parts. The feeling that correlation is the paramount method leads to the realization that it must be based on natural and hence causal sequences. This is what is meant by saying that the clue to ecology is found in the habitat. The latter is the complex of causes or of factors which act on the plant and the animal: but the habitat acts directly on plants, while it affects land animals for the most part indirectly through the food and. shelter control exerted by plants. As a consequence, the plant may be looked on SYNTHETIC CHARACTER OF PALEO-ECOLOGY wel! as the middleman between the habitat and the animal life. It is an effect to the one and a cause to the other. It is obvious that the total relation is far more complex than this, since factors do act directly on animals as well; but it must be granted that the study of plants and plant communi- ties does enable us to look in both directions—that is, back to the physical factors of the habitat and forward to the animal responses. In addition to this basic causal sequence is the resulting reaction sequence in which animals react on plants and plants on soil and climate, to say nothing of the direct action and reaction between habitat and animals. In empha- sizing the primary value of sequences, there is no need to assume that plants are the most important part of paleo-ecology because of their strategic medial position. They do, however, afford the best points for entering this vast field. METHODS OF EMPLOYING PREVIOUS ECOLOGICAL RESULTS The methods by which the ecological results of today can be carried back into the past have been briefly discussed in “Plant Succession” and it will suffice to pass them in review here. For the most part these are methods with which the paleontologist is already familiar, since they have to do primarily with the translation of facts from the present to the past. The foremost is the method of causal sequence, already mentioned, with its basic relation of habitat, plant, and animal. This is well illus- trated by the occurrence of Stipa in the Miocene of Florissant, which indicates not merely the existence of prairie, but also, of course, a grass- land climate and a grazing population. A similar but even more funda- mental sequence begins with deformation and passes through grada- tion, climate, and vegetation to exhibit its final effects in the fauna. The method of phylogeny which has been the most serviceable of taxo- nomic tools is likewise of great value in the reconstruction of the life forms and communities of the past. It shares with the method of suc- cession the credit of permitting us to give more and more detail to the bold outlines of past vegetations and vegetation movements. The method . of succession is based on the great strides made by the developmental study of vegetation during the last twenty years. When successional studies become the rule in zoo-ecology as well, there will seem to be no limit to the increasing perfection of detail in picturing the rise and fall of past populations and communities. In the case of vegetation, this method has already gone so far as to bring conviction that all the essen- tial features of successional processes and climax communities as seen today already existed in the past. As indispensable corollaries of the methods of phylogeny and succession are inferences from distribution in Sie F. E. CLEMENTS—SIGNIFICANCE OF PALEO-ECOLOGY space and in time and from association. The former enables us to close many a gap in the fossil record and to fill in the areas outlined by the known distribution of dominants. Inference from association, for ex- ample, aided by phylogeny, makes it all but certain that swamps of reed- grass, bulrushes, and cattails existed as far back as the Cretaceous, though Phragmites is the only one of the three dominants recorded for that period. The most recent is the method of cycles which gives promise of becom- ing one of the most important. It is perhaps too soon to insist that eyelie processes are universal in time and in space; but the great mass of evi- dence from geology and climatology is matched by an increasing body of facts from biological succession. The most fertile of all these assump- tions is that climatic changes recur in cycles of various intensity and duration. It is a matter of congratulation that climatic cycles can be studied by their effects almost as well in the past as in the present. This is particularly true in peat bogs and in badlands where fossil trees, alter- nating or recurring deposits, and cycles of erosion furnish a wealth of virgin material. Fossil wood is fortunately of the widest occurrence, and it is proposed to study the annual rings of fossil trees from those of recent peat bogs back through the Pleistocene and Tertiary into the later Mesozoic. Preliminary studies in the Pleistocene, Miocene, and Eocene already suggest the existence in these periods of a sun-spot cycle identical with that demonstrated by Douglass, Huntington, Kapteyn, and others in the trees of today. Similar cycles seem to be recorded in the rings of sagebrush, saltbush, and other desert shrubs, and these have been used in studying shifting cycles of erosion in badlands. Like its modern representative, paleo-ecology must focus its attention on the three great and interrelated problem complexes, namely, the hab- itat, the biotic community, and the development of the latter. While it comes first causally, the habitat actually must wait on biological inter- pretation, as its biological effects are about all that remain of it. Thus it becomes the biome, or mass of plants and animals of a particular area or habitat, on which attention must first be fixed. The direct outcome of this is to reveal the successional movement, and on this as well as on the adaptive features of species and genera must be based our assump- tions as to geological climates and soils. In phytoecology the concept advanced in 1901, that the plant com- munity is a complex organism, with structure and functions and with a characteristic development, appears to be slowly making its way. The admission of animals into the community with full rights and privileges promises to open a new period in synthetic ecology. In paleo-ecology the concept of the biome, or biotic community, seems to have peculiar value, as it directs especial attention to the causal relations and reactions of the EMPLOYMENT OF PREVIOUS ECOLOGICAL RESULTS OTe three elements—habitat, plant, and animal. Fortunately this viewpoint is so new that there are no landmarks or traditions to handicap. It is possible to deal with causes and reactions from a single vantage ground of developmental processes. As already stated, the plant community appears to have unique advantages in tracing the concomitant develop- ment of habitat and biome and in determining the structural responses of the latter. Here, again, ecology is fortunate in that zoologists have but recently turned to the development and structure of animal communities. It is thus necessary to follow the causal sequence and to base the treat- ment primarily on vegetation as the effect of habitat and as a cause in relation to animal communities. The opportunity is also given to test the successional method of vegetation study in its application to develop- ment when animals are regarded as an intrinsic part of the community. This application has already begun both in ecology and paleo-ecology, and this use of successional methods gives every promise for the future. The developmental method is based on the universal fact that bare areas of rock, soil, or water, and areas denuded of vegetation by fire, cultivation, erosion, etcetera, become occupied by pioneer plants and ani- mals. These react on the habitat in such a way as to change it in favor of organisms of greater requirements, which then invade and replace the pioneers. ‘This process of reaction and successive invasion continues through more or less definite stages until a final population appears and_ the climax is reached. The climax once reestablished will maintain itself indefinitely unless a change of climate occurs or the climax is destroyed wholly or in part as a result of external forces. One of the most familar examples of such a unit succession, or sere, is afforded by a pond or lake in which the submerged plants and associated animals are gradually re- placed by floating plants, and these in succession by reeds, sedges, grasses, and scrub, until, in a forested region, the final forest is reached. Similar cases of biotic succession occur in dunes, badlands, lava flows, burns, fallow fields, etcetera, throughout the world. Similar seres also must have been abundant throughout geological periods since the Devonian, at least, except for those due to the agency of man. For certain periods, such as the Pleistocene in particular, the Miocene, and the Triassic, the plant remains have recorded the unit successions beyond any question. This is most graphically shown in the peat bogs of Scandinavia and Britain, where two or three successive seres have left a complete record of their plants. Such a successional series may be termed a cosere. It is of the first importance in connecting succession in the present with the same clevelopmental process in the past, and hence in putting the suc- cessional study of paleo-ecology on a firm basis. The peat cosere furnishes the best evidence of population shifting through climatic changes, and XXVIII—BUuLL. Grou. Soc. AM., Von, 29, 1917 > er al sr. > - ee eee Ce! eee Pee a” oe , eh te pl ee ee 374 F, E. CLEMENTS—SIGNIFICANCE OF PALEO-ECOLOGY provides an assured method for the reciprocal correlation of climatic changes and biotic movements in the past. These are involved in still greater successional movements having to do with the appearance of new biomes and the disappearance of preceding ones. The grand succession of the globe falls readily into four great successions characteristic of the four eras. In each era occurred major successional shifts which consisted, in turn, of coseres and seres, such as are capable of actual study today. THe ATTACK ON DEVELOPMENTAL CORRELATION In planning an attack on the developmental correlation of plant and animal communities in the past as well as in the present, the badlands of the West early suggested the most promising field. A badland is an extremely dynamic area, scarcely excelled by dunes in this respect. It is one in which the rapid changes in habitat are clearly reflected in the de- velopment of the biotic community. In addition they afford a unique chance to relate minor cycles of erosion to climatic cycles and to fix the dates of these cycles by means of the annual rings of the characteristic shrubs. As is well known, the badlands are not only classic ground for the paleontologist, but they also furnish a practically complete series from the Permian through the Miocene. This series embraces practically the whole panorama of terrestrial life and affords an exceptional oppor- ‘tunity for organizing the vast field of paleo-ecology. The recognition of these facts has led during the past four years to an intensive study of twenty or more badland formations in seventy-five localities in twelve States. All the major areas have been visited, many of them several times, and most of the minor ones as well. The most generous assistance has been accorded by paleontologists, and the results will appear as soon as the live-stock crisis in the West permits the transfer of interest from the pressing ecological problems of the present to those of the past. SUMMARY To sum up, paleo-ecology is characterized by its great perspective, due chiefly to the absence of a large body of facts. This causes the funda- mental correlations between the physical world and vegetation on the one hand and between vegetation and the animal world on the other to stand out in clear relief. As a consequence, paleo-ecology is an unspecialized field in which the interrelations of climate, topography, vegetation, and animals play the paramount réle. The emphasis necessarily falls on vegetation, because it is an effect of climate and topography, and a cause in relation to the animal world, and hence serves as the keystone in the whole arch of cause and effect. OFFICERS, 1918. President: “Warracaw Cross, Washington, D. C. wine vadidinte: , “-Barey Wis, Stanford University, Cal. Frank Leverett, Ann Arbor, Mich. = Ee KNoWLTon, Washington, PG: Bs aah “New York, N. ee bs “Treasurer: AnD Be ‘Marnews, a ohns Hopkins Univensity, Baltimore, Md. — \ ‘Editor: ‘ un » cLaeanae: : we Rs F RB Van Horn, Cleveland, Ohio Z Councilors: (Porm expires 19 18) Se B. Taytor, Fort Wayne, Tad. - Cannes P. BERKEY, New tor N. Y (Denia expires s 1919) Siactes L, Day, Washington, DC. | Winnam H. EMMons, Minneapolis, Minn. E = (Term expires 1920) é an OSEPH ines New Haven, ck OR A Daty, $ Denboaes, Mass. BULLETIN OF THE ' VOLUME 29. -NUMBER 3 SEPTEMBER, 1918 fe * MARS 45 Mon al Muse 7 PUBLISHED BY THE SOCIETY MARCH, JUNE, SEPTEMBER, AND DECEMBER be y Po ‘4 . Bal pte ge 0. Neagktd Kay he “cae ‘. ie or oF hy . r¢ ja alee. © CONTENTS . .Page Precambrian Sedimentary Rocks in the Highlands of Eastern | Pennsylvania. By Edgar T. Wherry - - - - - - - 375-392 Fluorspar in the Ordovician Limestone of Wisconsin. By Rufus Wiather Bagg: <:- .- he ey ee ee ee Adirondack Anorthosite. “By William J. Miller - - - - - - 399-462 Field Relations of Litchfieldite and Soda-Syenites of Litchfield, Maine. By Reginald A. Daly - = - - --- - - - 463-470 Separation of Salt from Saline Water and Mud. By E. M. Keedle fe = A ee ee i ere een Subsidence and Reef-encircled Islands. | By W.M. Davis - - 489-574 Ages of Peneplains of the Appalachian Province. By Eugene Wesley Shaw - -.--- 0 9) 2 2s See ee Oolites in Shale and Their Origin. By W. A. Tarr - - - 587-600 BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA Subscription, $10 per year; with discount of 25 per cent to institutions and libraries and to individuals residing elsewhere than in North America. Postage to foreign countries in the postal union, forty (40) cents extra. Communications should be addressed to The Geological Society of America. care of 420 11th Street N. W., Washington, D. C.,- or 77th Street and Central Park, West, New York City. : NOTICE.—In accordance with the rules established by Council, claims for non-receipt of the preceding part of the Bulletin must be sent to the Secretary of the Society within three months of the date of the receipt of this number in order to be filled gratis. Entered as second-class matter in the Post-Office at Washington, D. C., under the Act of Congress of July 16, 1894 Acceptance for mailing at special rate of postage provided for in Section 1103, Act of October 3, 1917, authorized on July 8, 1918 PRESS OF JUDD & DETWEILER, INC., WASHINGTON, D. C. ~ “ P tm 2 - a -. > BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 375-392 SEPTEMBER 20, 1918 nian PRECAMBRIAN SEDIMENTARY ROCK E aC EDN DS OF HASTERN PENNSYLVANIA * ‘2 \ MARS 1919 *) BY EDGAR T. WHERRY * a 8tigy ev, 4 (Presented wm abstract before the Society Dee gal Museen” : CONTENTS ' Page 1 pul. S02 Sipe ON SU A gee ae aren Si UIA |) i an 375 hE ee bg i ee en CIR Ee aR Gs Ao es ae Bert SC RIE ITE CHONG c s.6 0s dats ee oa oo ee NO) Pr ee Oe 378 DMN PR EE eo eye nek cin 55 Gal Sets s Siar oa, Bee os Ripa Pd ae an ae 378 TI aks gee SR Re oe a agi aly Gee Rte Pry” — en OE ee oat A 379 IE a IMIS Fo Bo. iy nla KOs ahs soot kw ve Rw Soa pw wide: Rent ein okie, Se ee 379 TIE RE rt ah PON Sen oe Vault Sie BOLAL ns ehoviilece, GoW ets Suid cE eee ke 379 7 ELL. ecteiel eed oe a a A RED SoM Em oR aR go 882 PEMA CERMOCEMCH TION C2. aos dic Fareis sad s oe Re Seo hiions oon Re hind Sees MteRe eS Memrine, QUAETZIEG. ook. sik. eco ds eves ols os ba dons ows wb ane Chae. 385 mIPTRC I TEMG e reas) 4. house arias .. « Dine eee pee etre at 51.2 52.9 48.5 50 S@LICHC: . ess Oe ee es ee ils, = 9.8 4.0 10.0 5 Sillmmanite ... . occ ee owes ee ewes = 17.6 1S 4.3) eee ee Weldspars:. < ..¢t-ctee Pepe eee oe eine ose Ooh. coos Shaan a ees 25 Orthoclasets ans yo seiowteee Se eae BAER ai De a ee Microperthite ges tacks tate a eee 18.6 25.9 30.0 OUZOCIASE eee wee aoe ateie pen ale ye eat: PB eee meee Accessories 33 eerie oe ea eee i Se re ees I - 10 Garnet: Sees sce a as eee tice oho ahaere refi hea ears ee aia 8.5 Timenite yor oe ae oe nae oe neh Qed 2 en PAL CIA ee ee Ao ee nS mic Be eee obo 0.05 0.10 0.15 Apaitbeate ects tes. es ois os bo aise Pals 0.05 0.05 0.05 Miscellanedus stams, ete... 2.2... 2: - 0.6 4.35 2.8 get tee te te a wee ae oP aa or 100.00 100.00 100.00 100 The specimens in table 3 were also collected on the Allentown quadrangle at the following localities: 1. One and one-half miles east of Mountainville (7323). 2. Two miles southeast of Freemansburg. (The same place as No. 2 in table 2.) (226.) . 8. One mile northwest of Springtown (253). 4. The rounded-off average of 1, 2, and 3. Intimately associated with the rocks above described occur finely banded eneisses which are believed to represent the extreme stage in the action of the magma on the schist. In mineral make-up these rocks are essen- tially identical with the igneous rocks of the region, but their ultimate sedimentary origin is indicated by the following points: 1. Close association with undoubted sediments. QUARTZ-MICA SCHIST 385 2. Persistence of well developed minute lamination in straight lines for many meters. 3. Marked variation in mineral content in adjacent lamine, as brought out in table 4. TABLE 4.—Mineral Composition of four successive Laminw in a banded Gneiss 1 2 3 4. Gray White Gray White TAGE EO ee Sas tS savor une Wikies wee Fe oo 40.0 51.2 45.0 40.0 Feldspars: Microcline (kaolinized) .......... 56.0 18.8 46.2 32.0 TCT OMETEMIIC Me ak hee gees ces 'e eie 8 4.0 24.4 2.0 ZBI AG) Accessories : LET ACTETULE tis Ste RG Si eG Oa i go 6.8 2.0 Fra ben RPS IGN USP Nees aa areas Va,) Siac ja on ae gyoba a wile, ay cmd ajar IGS ai ene ee 2.4 0 ALA SS aE AEN en eI Oat eect auc ae MIRO en Se ncpemeta vation tes tal aia! oss sets 100.0 100.0 100.0 100.0 Locality, one mile west of Seidersville, Allentown quadrangle; the same as that of specimen No. 1, table 2 (5781). GRAPHITE-BEARING QUARTZITE CHARACTER Many of the features of this formation have been previously described," but some will be noted here to show how analogous it is to the preceding one. The phase which can be regarded as most closely approaching the original unaltered rock is a bluish gray quartzite, made up of interlocking erains of quartz interspersed with more or less parallel flakes of graphite. The most noteworthy accessory constituents are apatite, biotite, garnet, pyrite, and zircon. In thin section the bluish hue of the quartz is often seen to be connected with the presence of included carbonaceous dust, as typically shown in the section, figure 10. Apatite and garnet are at times more prominent in this rock than they are in the quartz-mica schist. - Round zircons are frequent, as in that rock. In contrast to the quartz- mica schist, however, unchanged beds are rare in the graphite-bearing formation, feldspathization having almost always taken place to a marked degree, as described below. Table 5 presents counts of the areas occupied by the minerals in sec- tions of three specimens of the quartzite phase. 11 Benj. L. Miller: Loe. cit. 386 E. T. WHERRY—PRECAMBRIAN OF PENNSYLVANIA TABLE 5.—Mineral Composition of Quartzite 1 2 3 4 (QUATIU AS ere ee se w acs co aleve Saetane sac eer 78.5 18.2 57.0 70 (CoE?) O01 ek Oe te REM ALA a En 8 ore ee AOS 7 pn es 0.1 10 ACCESSOTIBSE Ss. 6 ois be os Giles bie se Re Boats eethe vine 20 i BIG: Gly Se ea ea Me, Eh 2 Gatente seues 0.5 10.6 RSTHGCTE Cpt 5 cus, 0.0 «10:0, SPa\ site Rinse ste Sear 3.9 suisvds Heer Heljepar, altered 4 ic s.u 2. anereenee 0.9 Be 2.2 RRTHICL 55,0050 cs othe tee 2 ae eee Ese 30.0 Pyrice and Hmonite.s., 2... o-ee eee 1.8 5 Suure sere . PNECOBITI 4 os eR OAL Se Eee 0.05 0.05 0.05 ATI AUTEE: | oct is:s 2 sige ehod 2 Wotton Ate epe ae 0.45 0.05 0.05 WOUAIS f 65264 666 oe oe 100.00 100.00 100.00 100 The above sections were made on specimens from: 1. One mile east of Vera Cruz station (7842). 2. Three-fourths mile southwest of Vera Cruz station, near southwest corner of the Allentown quadrangle (7788). 3. Two miles southwest of Lower Saucon (6887). 4. The rounded-off average of 1, 2, and 3. ORIGIN The quartzitic character of this phase of the graphite-bearing forma- tion makes its sedimentary origin seem above question. Confirmatory evidence is found in the presence of the graphite itself, in the occasional appearance of notable amounts of apatite, which may perhaps be regarded as implying the animal derivation of the carbon, and in the rounded zir- cons. Finally, the inferences drawn from lamination and relation with igneous rocks in the case of the quartz-mica schist hold with equal force here. The rock is totally unlike the products of shearing of the igneous rocks, both mineralogically and structurally, and shows feldspathization, injection, and assimilation by the granite rather than transition, which would result from its origin by the shearing of the latter rock.’” MAGMATIC MODIFICATION ' Introduction of feldspar and other constituents by the invading mag- mas has been even more extensive in the case of this graphite-bearing formation than in that of the schist, but instead of the orthoclase and plagioclase feldspars showing microperthitic intergrowth they tend to appear separately, as brought out in the following table of mineral com- 122Jn the Raritan folio reasons are given for the assignment of an igneous origin to some of the graphite-bearing rocks, and some of the schists are believed to result from the shearing of these. No corresponding occurrences have been found in the Pennsyl- yania area thus far. GRAPHITE-BEARING QUARTZITR 387 Photomicrograph of sheared Granite, for Comparison with the Quarte-mica Schist. >< Nicols. (X 20) Locality, 14% miles northeast of Hellertown, Allentown quadrangle. Specimen 6749. Shows microperthite and quartz, much shattered, and surrounded by secondary micaceous material (dark) ; a large grain of perthite on the left has resisted the force, but is tray- ersed above by a tiny fault-crack containing angular. fragments. FIGURE 9. WiegurE 10.—Photomicrograph of Graphite-bearing Quartzite. Ordinary Light. (xX 20) Locality, three-fourths mile southwest of Vera Cruz, Allentown quadrangle. Specimen 7788. The pale mineral is quartz, the dark graphite; carbonaceous dust spreads out from some of the graphite plates into the quartz, appearing to cause a bluish color in the latter. Figure 11.—Photomicrograph of basic Gneiss. Ordinary Light. (x 20) Locality, 114% miles southwest of Lower Saucon, Allentown quadrangle. Specimen 6876. The dark mineral is hornblende, the white oligoclase feldspar, the .gray band crossing horizontally below the center sericite with dark patches of augite; there is no indication that the hornblende is an alteration product of the augite, and both are thought to have formed simultaneously in the course of feldspathization of a shale. Figure 12.—Photomicrograph of basic Gneiss showing rounded Zircons. Ordinary Light. (xX 100) Locality, 3 miles northwest of Boyertown. ‘The clear mineral is orthoclase feldspar, and several zircons are visible, standing out in relief, near the center of the field; they are well rounded and of different sizes. 388 E. T. WHERRY—PRECAMBRIAN OF PENNSYLVANIA : 7 position. The phenomena of feldspathization are in every respect like those described in connection with the quartz-mica schist above. When eraphite is present in the granitic bands it is, as a rule, coarser than in the quartzitic ones, showing that recrystallization of this mineral has taken place (as with sillimanite in the other rock). Indeed, when the magma has been pegmatitic the graphite plates are at times 3 to 5 centi- meters across, whereas in the original rock they are measured in as many millimeters. TABLE 6.—Mineral Composition of feldspathized Graphite-bearing Quartzite 1 2 3 + QUaTEZ .5 cae ee riclicte fore. eipal ors 48.9 43.4 34.9 40 Feldspars =). 4 <. Seabee eee OLS Sees Arie, 45 Orthoclase- sce eee eos ae ee 182% 26.8 35.4 Oligocla Sei cere oteislate wis new ny 14.6 Braet, 20.5 ae Graphite gels oo a ee ise one ese era 14.9 3.4 4.6 10 ACCESSOLICS?. 5c Pete) aera ss as Dae selene ae +) Bighte 2 see ee ee a oe pate 5.5 4.3 Garnebl esate en te, 6 os Ona 1.4 i Bg 2 ZITCOR..: oe eee ee ee ae inintane 0.05 0.05 0.05 Pyriteland “monies ietestck eae ss SaaS | 15 «nee ADAtIlG 25s Meee ee eco. 0.05 pow 0.05 POLS Fee eis aie ae 5's 100.00 100.00 100.00 100 The localities of the above are all on the Allentown quadrangle, as follows: 1. One-fourth mile southwest of Shimer station (which is wrongly located on the topographic map) (5217). 2. One-fourth mile east of Limeport (7947). 3. One mile southwest of Lower Saucon (6854). 4. The rounded-off average of 1, 2, and 3. BasIC (AMPHIBOLITE) GNEISS _ CHARACTER The nature of the original materials from which the basic gneisses'® of this region have been derived can only be conjectured, since none but rocks resulting from profound magmatic modification are now known. These feldspathized phases are characterized by the abundance of quartz, hornblende (or biotite or augite), and of both orthoclase and oligoclase feldspars; a typical section is shown in figure 11. Ilmenite or magnetite is a prominent accessory, and rounded zircons can sometimes be found, 13Jn Canada and the Adirondack region rocks like these are called amphibolite. The origin here assigned corresponds to one of those described in Adams and Barlow’s much quoted paper: Can. Dept. Mines, Geol. Survey, Memoir 6, 1910, p. 87, etcetera. BASIC (AMPHIBOLITE) GNEISS 389 as seen in figure 12. Counts of the areas occupied by these minerals in several thin sections are given in tables 7 and 8. TABLE 7.—Jineral Compositions of typical basic Gneisses ik 2 3 4 Bp 2 oy a GRIN es Oe a eg i133 EWgere: 27.8 25 Feldspars: MENS ants Biv alt sak se ela! Aleta Wes 48.5 49.0 52.9 45 RUBIES HINES ea ihn. SEI ayy Lie ai) blew ai'e ofat's.s Dass SE eNe 2.8 3 MaRS SEN ego leary cle Raaralia vs Geis) also ahaus SO 1.3 0.6 1 MRIN DE EMERN SD er eye ea ane who. ace ate eee se 24.6 Aes Bie} 20 Se NEM Nc OYE ey ce sg nile ela aie: s 0 eie'cecwse esis 8.0 4.0 IAL) 5 MEMS rey ae Puna es ae ew sss Sis eee Ae tee aes BU RN SRN O Loe olka reed Os ba Alef Sea's via 1.55 0.05 1.05 (ES IR en a 0.05 0.05 0.05 1 ON ET ES ae 100.00 100.00 100.00 100 The localities represented are as follows, all being on the Allentown quad- rangle: 1. One mile northeast of Limeport (7916). 2. West end of Seidersville (5873). 3. One mile southeast of Mountainville (290). 4. The rounded-off average of 1, 2, and 3. TABLE 8.—Mineral Compositions of unusual basic Gneisses Bt 8 3 aE MOET oan chew oo eae a e's) 8c See oe ew Oe Ree ESO tee ie ie 2.0 Feldspars: ULL OG 2 Rain Sein mma mmmEIe ERE eee me ye... orl Pus 226 Daa ais eis MIPCEODETLNME si... od so we peta ae gh a hate Sees Beet Blt eey pe Wie orci Pe teed aiiens (L100) | SB Aa Pee PAPE sg eps Doles eaene Seslon ten + ony ah 1.2 BEY OQUIPESY 6.5 PMN ETN ES Seb 5 “2 oc 5 ph Sovasthike hate tae nee Doe Mr aeeee eet eee ee en a 65.2 URE TMO MAT 6c a Fs. wise is Ahad, eiloue Myer ch omrenibia teehee meee ee eis AT al ea, ee oe IS I 9 Va. 5g: n 15 Lapin Ver-ai vine Anan, Seca: Rep MRS eee ee SSO Re bay! jis a tele shencoh spews TL SIS SE Ae aS ne re ne MPM APA 5 ie ate nn a waa 25.6 17.8 UD CISLINS: Jao) hokey gle A Aaa eat Aa is San AEE TL on TR SE 14.8 Accessories : | IMEVE SSS os BOSC oer eee ee URN fa Pe cn Sin (A ae 0.4 0.2 LP SEETIICT ES aw ik. EaU Ae apne ei ge ASE Ra oy, CI Ts Ziel ile studs Grae tis li Frat eset rte a Ne, 2c8w ac ase esk wAde 4 8 3oo. e ate Ss es 100.0 100.0 100.0 These are from: 1. One mile southeastof South Bethlehem (5869). 2. Near Seidersville (335). 3. One mile east of Freemansburg (6458). 390 E. T. WHERRY—PRECAMBRIAN OF PENNSYLVANIA ORIGIN As noted above, under the heading “Crystalline limestone,” amphibo- litic and pyroxenitic gneisses have locally been developed by metamor- phism of that rock, but there is no evidence that any considerable propor- tion of the basic gneisses of this region have been thus formed. The primary rock in the majority of cases was more probably shale. The most important point to be decided, however, is not what sort of sediment they may have arisen from, but whether they are of sedimentary origin at all; for the gneisses produced by the recrystallization of igneous rocks, such as gabbro, may be similar in some respects. In the Piedmont belt of Precambrian rocks the basic gneisses are regarded as almost exclusively metamorphosed gabbro.’* But the relations in the northern belt are believed by the writer to indicate the ultimate sedi- mentary origin of the bulk of these rocks. In addition to the reasons for the conclusion that much of the corresponding Po- chuck gneiss is a metamorphosed sediment, given in the New Jer- sey folios above cited, the fol- lowing points are worthy of note: The mineralogical evidence in FIGURE 13.—Basic Gneiss showing Alternation i we of dark and light Bands. (xX %) favor of a sedimentary origin of Locality, same as figure 12. The right-hand these rocks is not as complete side of this specimen was sawed off and thin as in the case of the formations sections made all the way across; counts of the minerals in these are given in table 9, the previously described, since only mumibers marked ca the figure corresponding to feldspathized phases are known. those in the table; No. 5 is a sill of granite. g F The rounded zircons which can be found in these basic gneisses are, however, as pointed out above, an excellent evidence of sedimentary origin. The presence of augite is not regarded as opposing such an origin, for augite frequently forms during the metamorphism of sediments, especially if they are somewhat cal- careous. The original minerals having been extensively, if not completely, re- crystallized and rearranged, it is unsafe to base any conclusions on the present mineralogical features of the rock as a whole. But the structural relations shown in many instances are similar to those of the previously **F. Bascom and others: Philadelphia Folio, U. S. Geol. Survey, No. 162. BASIC (AMPHIBOLITE) GNEISS | ool described formations. For instance, rapid alternation in composition across the bands, but persistence of individual bands for considerable distances along the strike, are more suggestive of sedimentary than of igneous origin. ‘To bring out the manner in which alternation occurs, a specimen 8 centimeters across—shown in figure 13—in which six bands could be recognized, was sawed through and thin sections of its entire cross-section prepared; counts of areas occupied by the several minerals are recorded in table 9. TABLE 9.—Mineral Composition of a banded basic Gneiss 1 2 3 4} Spe gee may Width of band, centimeters. 2.0 a arg 1.4 bh 0.5 IG SD Sas eae gray ~- black gray black white black OS Ar 11.4 TO 20:4 ° 20.6 Sats 3.6 Feldspars: DPEENOCIASE 6 ok. cece ew 54.2 EA 57.8 BEG feces aye ss 49.7 UOPERAC .. 5 5. a0 ese ass 7.2 De ee lee a 5.6 Microperthite .......... Wns, ois weve coe 80.2 [8 | Lol 90 ee ay La eg aa ee Sha ine veg Sve d anes HIMPHOIENOE 2. ee wee 6.6. ~ 50.0 3.0 perk fie 36.8 Accessories : ee: Eo 5.35. A.25 5.05 4.05 0.05: 7.4525 AMOI... aro ss 0,0 dak ieet 0.05 0.05 0.05 0.05 0.05 0.05 BENG ches cc. seas 100.00 100.00 100.00 100.00 100.00 100.00 Locality—Three miles northwest of Boyertown. Band 5 is shown by its macroscopic aspect and its mineral content to be a tiny sill of granite, but the other bands show no evidence of igneous origin, except in so far as feldspathization has been produced in them by emanations from magmas. The relations to the other rocks of the region are equally significant. The basic gneisses are almost always intimately associated with the other sedimentary formations here described. 'They are in particular frequently interbedded with the graphite-bearing quartzite, and they may always be - found to a greater or less extent adjacent to the limestones and to the quartz-mica schist. | When the basic gneisses occur in the vicinity of the granites, many features indicate the subsequent age of the latter. In this respect the relations described by Doctor Fenner in the paper above cited are dupli- eated repeatedly in the present region. Basic lamine often come to an end against typical granite, and angular inclusions of basic rocks are fre- quent in the latter. Evidence that the granite magma has softened the basic rock is found in the pinching and swelling of some layers while ' XXX—BuLL. Geox. Soc. AM., Vou. 29, 1917 392 E. T. WHERRY——PRECAMBRIAN OF PENNSYLVANIA adjacent ones remain straight, and in other similar ways. It is thereby rendered certain that the basic bands can in no way represent dikes of gabbro or anything of that sort penetrating the granite; they must have been solid and laminated before the granite came in. This fact alone, as Doctor Fenner cautiously points out, is not a proof of the sedimentary origin of the basic bands, for they might be igneous rocks which had been laminated by metamorphism prior to the granitic intrusion; taken in connection with the evidence favoring a sedimentary origin derived from other relations, however, it has strong confirmatory value. From these basic gneisses, in which the dark minerals are so large in amount as to render the whole rock dark in color, there exist all grada- tions to acidic igneous rocks which are mainly light in color, but show lines and streaks of dark minerals; a speci- men of one of these is shown in figure 14. To what extent the latter represent pri- i : tabular minerals, on Ficure 14.—Granite showing Streaks of dark Minerals. (x 4) the one hand, and rem- Locality, near South Bethlehem, Allentown quadrangle. nants of preexisting i 22 i : ° Specimen 222. The dark bands are believed to represent laminated rocks which lamine of basic gneiss, which has been melted up and largely assimilated by the granite. have been melted up in the magmas with- out losing their structure entirely, on the other, it is impossible to decide from the limited exposures in this region. The association with basic gneisses which these occurrences show indicates, however, that the second relation holds in many cases. The original extent of sedimentary Pre- cambrian formations in this region was therefore, no doubt, even greater than that described in this paper. SUMMARY In the foregoing pages descriptions have been presented of several types of rocks occurring in the northern belt of Precambrian in Pennsylvania which give evidence of ultimate sedimentary origin. The evidence is partly mineralogical, partly structural, and partly derived from relations to rocks of igneous origin. These sediments have been extensively feld- spathized and more or less completely assimilated by the magmas, but enough of them is preserved to indicate the existence in this region of a considerable body of Precambrian sedimentary formations. mary alignment of the © ‘K1IBND JO asvq 7B o[VYS on]{q peppeq-uryL *G ‘euojs -OU[] UVPOTAOPAQ PYZI[ [VISA OAISSVIY ‘P ‘OUOZ OILION[W “E “(AJLIP WISMOOSTAL) [PABA MOTIOX °Z NISNOOSIM ‘HVNGEN ‘AUUVNO ANOLSAWIT VNA'IVY TH peu TT "YSIMYJNOS SULYOO], MTA 4 ae {- si’ 03 "Id ‘LI6T ‘63 "IOA { | i j ‘INV ‘008 “IOGD "TTA BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 393-398, PL. 20 SEPTEMBER 380, 1918 FLUORSPAR IN THE ORDOVICIAN LIMESTONE OF WISCONSIN * BY RUFUS MATHER BAGG (Read before the Society December 29, 1917) CONTENTS Page Ss Stace MON 0 SESS oar ee re A eg eee ee 393 ECL A DOTNET, ODSEE VETS f° cnc o's «lo oso vic pale wipe, Cle wialeroe bo sie ieee Sete we 393 Location of the quarries and glacial deposits therein................... 394 Pee OeCurrence OF thE MINCTAIS... 02.6. ce eve ee eee esac dees bane 394 Se TORIUS TICS ccna, 5 ailo gu 58 sie. Sos w ples mo oe die Wie etaieie bis ee wide wd ee 4 eleee 396 INTRODUCTION. Fluorite was discovered last summer by the writer while examining the galena limestone quarries at Neenah, Wisconsin, when on a field excur- sion with the geological students of Lawrence College. Since this min- eral has never been mentioned as occurring in the Ordovician of this State, and also beeause its apparent absence has been the repeated cause for especial mention in various State geological reports, it seems worth while to call attention to this discovery. REFERENCES BY OTHER OBSERVERS Prof. J. D. Whitney,” in discussing the minerals of the “lead region” in 1862, gives the following description of fluor: “The element fluorine seems to be very scantily and irregularly distributed through the Paleozoic rocks of the Northwest. Even where these have been partially metamorphosed by igneous agencies, as on Lake Superior, fluorspar is of very infrequent occurrence; indeed, we are not aware of its having been discovered in more than two or three localities.” 1 Manuscript received by the Secretary of the Society December 28, 1917. 2 Geology of Wisconsin, vol. i, 1862. Mineralogy, by J. D. Whitney, p. 205. (393) 394 R. M. BAGG-——FLUORSPAR IN THE ORDOVICIAN | OF ‘WISCONSIN He then states hae is more significant with reference to our discovery : “No traces of this mineral have been observed in any of the unaltered rocks of Silurian age farther west than New York, so far as can be ascertained.” “The lead region of Wisconsin, Iowa, and Illinois has failed to furnish a single specimen.” ‘Nor has a trace of fluor been observed in the oneal expanse of Sooeas y covered by the Niagara limestone in Illinois and Iowa. Teas years later, when R. D. Irving? published his check list of min- erals found in Wisconsin, fluorite is mentioned as occurring in minute purplish particles in the pink granite of Ashland County; but he further adds: “The complete absence of fluorite—which is so common an asso- ciate of lead ores—from the lead ores of Wisconsin is worthy of note.” Since both galena and fluorite are present in small amounts in the strata of the Neenah quarries, even though not abundant enough to be- ‘come of commercial value, the above statements no longer hold true, for these dolomitic limestones are of the same horizon as those of the lead region. LOcATION OF THE QUARRIES AND GLACIAL DEPOSITS THEREIN The quarries described in this paper are situated in the southeast edge of Neenah, below the city park and about 1,000 feet west of Lake Winne- bago. The upper surface of the limestone shows strong glacial planation cut by striz trending north 25° east (magnetic), with some weaker stria- tions crossing these, while on the southeast margin of the smaller quarry some small cuplike depressions occur. The southwest border of the larger quarry is covered by 7 feet of glacial drift, which is sharply divided into two deposits. The lower formation is 4 feet thick and rapidly thins out northward. It is overlain here by 3 feet of glacial till, resembling the red clay so extensively developed along the Fox River valley. There are some rather large striated and faceted gabbro and granite boulders scattered sparingly through this upper deposit, but beneath this is a yellow gravel composed of small fragments of angular lmestone with but few of the larger igneous glaciated boulders present. The accompanying vertical section shows the relation of these glacial deposits to the underlying Ordovician limestone. “a MopeE oF OCCURRENCE OF THE MINERALS The fluorite occurs in a definite layer of massive limestone about 5 feet from the bottom of the main quarry. It consists of bright purple coat- 2 Geology of Wisconsin, vol. i, 1882. Minerals of Wisconsin, pp. 309, 314. MODE OF OCCURRENCE 395 ings in seams and joint planes and encrusts some vein fillings beneath it. The first vein crystallization is usually calcite in thin, almost transparent, Bees aac of Neenah Gity Quarry Set ScaleuOwe: Incltv=2: Ft, Till. (Red) Wisconsin Drift. ( Yellow) Pelee ee Elser eas Galena Limestone l ake SOP Mineralized Zone > Pyrite 3 = Calcite Fluorite 7] Galena — | Irv Dolomite = Egrela soe /2 Sphalerite 2 R™M.B. Figure 1.—Section of Limestone Quarry at Neenah, Wisconsin rhombs, but often with scalenohedron combinations in the more open vugs. The calcite was followed by a layer of iron pyrites, which as tiny 396 R. M. BAGG—FLUORSPAR IN THE ORDOVICIAN OF WISCONSIN cubes and pyritohedrons ¢over the calcite surface. In some cases these pyrite crystals formed before the calcite was completely solidified, as shown by intergrowths, but as a rule the two layers are quite distinct. The third coating of vein matter filling the joint-planes and seams is fluorite, but in some places this seems to cover the blue limestone surface without the two minerals above referred to underneath. Since the pyrite is highly tarnished and iridescent, it shows in places through the fluor- spar. Galena occurs in this same zone and appears as a thin coating on the joint surfaces, with here and there a large well defined cube in the solid crystalline dolomite. . While the fluorite usually coats the calcite and pyrite, it is also found on some of the galena seams and more rarely on the limestone walls, but in every case it is the last mineral which was deposited. This Neenah fluorite does not develop, however, into good crystals, at least so far as observed, but the coating is heavy, the color intensely purple, and there is sufficient present to give a good etching test. The minerals above re- ferred to appear to be confined to the south side of the larger quarry, where they develop in a massive blue limestone 1 foot thick and some 5 feet above the bottom workings. Underneath the upper massive dolomite strata the beds become shaly — and are very rich in bryozoa, brachiopod, and alge remains. When quar- ried these dark blue shales are so soft that they can be broken in the hands and the rock is discarded in crushing. The calcite occasionally assumes a beautiful and delicate rose color, and in one geode center of an orthoceras cast the pink lies in a zonal band surrounded by transparent spar, while the outside of the cast showed galena over the argillaceous surface and stained with purple fluorite. ORIGIN OF THE FLUORITE It is unlikely that the fluorite under discussion could have been derived from igneous rock which lies deeply buried in the Neenah region. Gran- ite is 675 feet below this same formation 16 miles to the southwest at Oshkosh, and as these quarries lie directly along the strike this same granite can not be far from 700 feet deep under Neenah. These limestones dip slightly eastward, and from well borings at Ap- pleton and at Hortonville we have determined this regional dip to be 17 feet to the mile. At the Neenah quarries there is a small dome-shaped curvature and the dip is not uniform, but this may not be structural if the strata were laid down on an undulating base. ORIGIN OF THE FLUORITE 397 At Kaukauna, a few miles farther north,.similar Ordovician strata show small fault-planes, and these are filled with calcite and pyrite, as at Neenah. No such faulting was observed at Neenah, however, and the vein fillings are not as pronounced as at Kaukauna. If the fluorite came from below, we should find it at Kaukauna, where faulting occurs in the same limestone, and it should be distributed in more than one stratum. Large and pronounced rhombic jointing at Neenah cut all the upper layers on massive dolomite, but these joints do not extend downward into the bryozoa shales at the base, at least not where at present exposed. It seems more probable, therefore, to the writer that this fluorite was syngenetically deposited in very minute quantity with the galena dis- semination from mineralized Ordovician waters, and that later this was precipitated as a thin coating along more open joint-planes and solution chambers in more crystalline dolomite. The presence of fluorine is definitely known in existing oceanic waters, and in Ordovician oceans may have been locally present in larger amount, and thus could have been contemporaneously deposited in the dolomite along with galena, iron sulphide, and calcite, whose secondary enrich- ments now fill these openings. Since the jointing is very limited vertically and because we find no evidence of faulting at Neenah, we believe the fluorite was precipitated from lateral secretion. It is not impossible, however, that meteoric waters percolating downward in strata now eroded have added some mineral matter in this layer above the more impervious shales. We do not believe that it came from any deep-seated action, as was so often the case in the igneous rocks of the West. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 399-462 SEPTEMBER 30, 1918 ADIRONDACK ANORTHOSITE * BY WILLIAM J. MILLER (Presented in abstract before the Society December 29, 1917) CONTENTS : Page SNE COANE CUED Nene erty ioh SVU asad, 5 aa: W rao Rania a) Meier ost hom RG Rae GA) tiake: Meta ealene aT anise 400 een eTOCIS. 1 SOMOCTAL. (vite. eis 5 ayers .a)s toile ew ng sham ace altel Pellet a4 ayolia 401 Sere OeSerintion Of The anorthosite ¢ oj... ose ua wie'e ales ote sun yay 0) ees gis ees 403 werent oF the anorthosite area. ss i. 66. 6 oe. ees sees wea eneln ss ee as 403 Perri yvne OF tie aMOMEMOSTUG sci oa: 5 erate ahs ope tare waite wi seaten el 4 clanaheleene ee 403 Chilled border facies of the anorthosite (Whiteface anorthosite).... 404 Sem EEL AC PIT ENO STL NON 2). cs aiehals cima Crores, "oink Goa eiGie sd Aideny ancora Ne ta eaaR Ee. cn 3 406 Bowen’s hypothesis regarding origin of anorthosite..................... 406 Significance of the variable composition and structure of the anorthosite. 408 The chilled gabbroid border facies and its significance............ BAL cg: 414 PBT ANMOUSEE VA LONG... at. Fito Bas Aid Mise npaunaleia eons Brabeeie Sarees wphoats Paardlerd 414 Preceipunon and. nelation) to; other LOCKS. cic o.s cies eae ain b's 85,8 4 alee we 414 The border facies both an outer and an upper limit of the anorthosite. 417 prenincance Of the chilled border facies....... 0000/2020. 00+ 00s anaes 419 Relation of the anorthosite to the Grenville series.....5......0. 000000: 420 Grenville-anorthosite mixed gneisseS........... ce cee cece ec cee ecees 420 Inclusions of Grenville in anorthosite................. Sate etre tenner erage ah 423 Pies Ol AnOrchosife. iM, Grenville. . «, Y Eoeccocod SS S Zasanoqoogen H QO Hy SS SQ SH oP? POND Maisie COPPERAS Hf Granitic phase of syenife [s|Prerstocen e COS oe % KRRRRRQOQO XX SOO ——— Grenusrile strata XXX Mite face anorthosite FIGURE 1.—Geologic Map of central Portion of Lake Placid Quadrangle RELATION OF SYENITE-GRANITE SERIES ; 429 On the mountain spur, 114 miles northeast of the summit of Little Whiteface Mountain (Lake Placid quadrangle), a number of tongues of granite cut the Whiteface anorthosite. The relations are very clear in the big bare ledges, the dikes being small tongues of the large body of granite across the southern face of Mount Whiteface. One of these tongues is only 20 feet wide, but the others are each a number of rods wide at the summit of the mountain ridge. They pinch out eastward. The granite is clearly gneissoid and it contains several per cent horn- blende. Immediately to the south several dikes of granitic syenite, none over 3 feet wide, sharply cut Whiteface anorthosite. Most of the anor- thosite cut by these dikes is white and nearly free from femic minerals, and hence probably far within the border facies—that is to say, close to the outer part of the Marcy anorthosite (see figure 1). During the summer of 1917 my work in the Schroon Lake quadrangle brought to hght still other examples, these all being dikes or small tongues of granite, which is there the more prominent member of the syenite-granite series. One of these is well shown by the road 114 miles west of Boreas River, Where a dike of granite 5 feet wide cuts rather femic Whiteface anorthosite. Another is a dike of typical pinkish gray granite, 25 feet wide, 1 mile west of the summit of Sand Pond Mountain. It sharply cuts Whiteface anorthosite, which lies near, and closely resem- bles Marcy anorthosite. Both dikes last mentioned are quite certainly offshoots from large bodies of typical granite which in a general way cut into the marginal portion of the great body of anorthosite. Still another dike of granitic syenite or granite cuts Marcy anorthosite just north of the summit of Texas Ridge. : I am confident that many other clearly defined dikes of syenite and granite in anorthosite exist in the Lake Placid and Schroon Lake quad- rangles, but it is difficult to locate and demonstrate their presence in such a rough, densely forested country. It should be emphasized that at least some of these dikes cut right into the typical Marcy anorthosite. The evidence, therefore, from the dikes, that the syenite-granite series is dis- tinctly younger than the anorthosite, is very strong and by no means confined to the Long Lake quadrangle. Dresser* states that on the south side of the Canadian Saguenay anor- thosite border syenite grades into granite which clearly cuts the anortho- site, thus exactly corroborating similar evidence from the Adirondacks. Coleman*® says, regarding the largest area of anorthosite in the Rainy Lake district, that the granite “has sent apophyses into the anorthosite 3 J, A. Dresser: Bull. Geol. Soc. Am., vol. 28, 1917, p. 155. 3% A, P. Coleman: Jour. Geol., vol. 4, 1896, p. 911. 430 --w. J. MILLER—-ADIRONDACK ANORTHOSITE and has pushed its way through a schist conglomerate containing pebbles and boulders of quartz-porphyry, sandstone, green schist, and occasion- ally also anorthosite quite like some facies of the adjoining mass. Ap- parently a long interval separated the anorthosite eruption from that of the anorthosite.” Not only is this granite distinctly later than the anor- thosite, but also there is no evidence of gradation of anorthosite into granite or even syenite. BROAD INTRUSIVE TONGUES OF SYENITE AND GRANITE IN ANORTHOSITE The broad tongues of syenite and granite extending, in a number of places for miles, into the great body of anorthosite furnish perhaps even more impressive evidence than the dikes that the syenite-granite series is really younger than the anorthosite. Regarding an excellent example of such an intrusion of syenite into the anorthosite of the Long Lake quadrangle, Cushing*’ says: “It cuts into the anorthosite for a depth of 2 miles, cutting out much of the gab- bro and anorthosite-gabbro border, though these appear in full width on both sides of the salient.” This intrusive tongue is from 1 to 3 miles wide. In the Schroon Lake quadrangle I have mapped a tongue of granite from 2 to 4 miles wide which extends into the anorthosite for fully 4 miles, reaching all the way through the border facies and into the Marcy anorthosite. A large intrusive mass of still later gabbro appears within this salient. In two places I have found small dikes as offshoots of the salient sharply cutting the anorthosite. My Lake Placid map shows a fine example of a tongue of syenite grad- ing into granite and extending for several miles into the Whiteface anor- thosite across the southern portion of Wilmington Mountain. On the south a considerable body of Grenville lies in contact with this intrusive tongue. This tongue, with a width of 144 miles on the west, gradually becomes narrower toward the east, till finally it sends the dikes of syenite, already described, into the anorthosite. A great body of syenite, with locally developed granitic facies, varying in width from 1 to 6 miles, extends into the anorthosite area 13 miles across the Lake Placid quadrangle, and thence for an unknown distance into the Mount Marcy quadrangle. I confidently believe this to be intru- sive into the anorthosite, my reasons being stated beyond in this paper. This big tongue of the syenite-granite series extends much farther into the great body of anorthosite than any other thus far mapped in detail. 37H. P. Cushing: Jour. Geol., vol. 25, 1917, p. 506, RELATION OF SYENITE-GRANITE SERIES 431 Another body of syenite, shown in part only in the southeastern por- tion of the Lake Placid quadrangle, extends northeastward into the Ausable quadrangle and possibly connects with the great tongue of the syenite-granite series which extends southward for some miles into the anorthosite of that quadrangle, but this has not yet been proved. Kemp’s Elizabethtown-Port Henry map shows the syenite to cut out the whole border facies of the anorthosite in several places. About 214 miles northeast of Mineville a tongue of syenite only one-fourth of a mile wide extends almost a mile into and through the border phase. These facts, together with the occurrence of the small mappable masses of border anorthosite in the syenite 1 and 2 miles, respectively, from the main area, make it seem reasonable to regard the whole body of syenite shown on the map as a great intrusive salient which cuts out the anorthosite body for miles. SYENITE-GRANITE AND ANORTHOSITE MIXED GNEISSES Areas of mixed rocks of this sort represent masses of Whiteface anor- thosite which have been more or less shot through and cut to pieces by syenite or granite. Locally the rocks exhibit their characteristic features, but they are too intimately associated to be separately shown on the geo- logic map. In the Lake Placid quadrangle two areas of such rocks, each about 2 miles long, lie far within the general anorthosite area southwest of Wil- mington (see figure 1). Irruptive contacts of syenite against Whiteface anorthosite are not uncommon. ‘These contacts are usually not perfectly sharp, as though slight fusion of the anorthosite by the intruding magma took place along the immediate borders between the rocks. The intricate relationship of these rocks is very evident. In the Schroon Lake quadrangle I have been obliged to map a very irregular-shaped area of some 4 or 5 square miles of similar mixed rocks. In this case the Whiteface anorthosite is badly cut to pieces mostly by granite, but also by some syenite. | INCLUSIONS OF ANORTHOSITE IN THE SYENITE-GRANITE SERIES The inclusions of anorthosite in the syenite-granite series furnish very strong evidence that the syenite-granite body is an intrusive distinctly separate from and later than the anorthosite. Such evidence is scarcely, if at all, touched on by Bowen, probably because few examples of such inclusions were known to him, these being the ones within the Long Lake quadrangle. XXXIII—BuLu. Grou. Soc. Am., Vou. 29, 1917 432 W. J. MILLER—ADIRONDACK ANORTHOSITE It seems evident from a glance at my Schroon Lake geologic map that the anorthosite once extended out as a continuous broad belt at least 7 or 8 miles beyond the present margin of the Marcy anorthosite, because within that distance from the Marcy anorthosite there are many inclu- sions of anorthosite (many of sufficient size to be mapped) in the syenite- granite series all the way across the quadrangle. In other words, only mere remnants of the former anorthosite here remain. With the excep- tion of one locality, these are all inclusions of Whiteface anorthosite. The exceptional locality is of particular interest. It is on top of the small mountain of typical granite a little over a mile north-northeast of Pat Pond. One* patch of the granite 12 feet across contains large dark bluish gray labradorites an inch or more across and several small pieces of typical: Marcy anorthosite as distinct inclusions mostly arranged roughly parallel to the folhation of the granite. Immediately around the larger fragments the granite shows fine magmatic flow-structure. A sim- ilar exposure occurs close by. My interpretation is that the granite magma moving upward enveloped two small masses of Marcy anorthosite and tore them into small fragments, which became somewhat’ scattered and arranged parallel to distinct magmatic currents, which worked its way up nearly vertically, as shown by the high angle of dip of the flow- structure foliation. In the Schroon Lake quadrangle several inclusions of Whiteface anor- thosite bear exactly the same relation to the inclosing syenite-granite series as neighboring inclusions of Grenville, and it seems clear that the upward moving syenite-granite magma enveloped masses of both of these rock types in exactly the same manner. A very fine display of many inclusions of fragments of Whiteface anor- thosite of all sizes occurs in typical granite on Cobble Hill, 1 mile due south of Bailey Pond, in the Schroon Lake quadrangle. A wide zone fully one-fourth of a mile long in the granite contains the inclusions, most of which are arranged parallel to the foliation of the granite (see figure 2). Inclusions of Whiteface anorthosite in the syenite-granite series were also observed by me in a number of places in the Lake Placid quadrangle. A few will be described. Ledges of syenite by the river one-fourth of a mile east.of High Fall contain inclusions of the Whiteface rock arranged parallel to the foliation of the syenite. Similar inclusions occur in sye- _ nite by the river one-half of a mile southwest of The Flume and also on top of the hill in the area of mixed gneisses 214 miles north-northeast of Keene. An 8-foot boulder of syenite, in the bed of the river about a mile northeast of High Fall, contains several very distinct inclusions of White- RELATION OF SYENITE-GRANITE SERIES 433 face anorthosite whose borders were fused by the enveloping magma. A big ledge of typical syenite, 114 miles west of East Kilns, contains many inclusions of Whiteface anorthosite which are bunches, lenses, or bands from 2 or 3 inches to several yards long. Their borders are not always sharp against the syenite. A small body of Whiteface anorthosite 1 mile north of Middle Kilns is really a distinct inclusion in the granite. The same is true of the small body of Grenville-anorthosite mixed rocks a few rods east of Silver Lake at the map edge. In the Long Lake quadrangle the broad tongue of syenite, already - referred to as cutting almost through the border facies of the anorthosite, contains five mappable inclusions of the border facies. From 5 to 7 miles southwest of these the map shows three small masses of Marcy anortho- site, one with sharp contacts against the inclosing syenite, according to Cushing. These are reasonably to be interpreted as inclusions. The two small mappable bodies of border anorthosite in the Elizabeth- town quadrangle, already referred to as occurring in the syenite 1 and 2 miles, respectively, from the main body of anorthosite, are also quite cer- tainly inclusions. | AREAS OF SYENITE SURROUNDED BY ANORTHOSITE In some places small isolated masses of syenite are completely sur- _ rounded by anorthosite. Several such are represented on my Lake Placid geologic map—two of them near Keene, one a mile west of Upper Jay, and another 2 miles southwest of East Kilns. The largest area is only one-half of a mile long, and all are surrounded by the Whiteface type of anorthosite. Kemp’s Elizabethtown map shows three such areas—one at the top of Giant Mountain, another a mile north of Chapel Pond, and a third, over a mile across, a few miles west of Elizabethtown. These are all surrounded by Marcy anorthosite except the third, whose eastern side comes against basic border anorthosite. Cushing’s Long Lake map shows two small masses of syenite (not including the narrow dikes) surrounded by the basic border anorthosite within a mile of its outer margin. Neither my Schroon Lake map nor Doctor Ogilvie’s Paradox Lake map shows a single mass of syenite or granite within the anorthosite. The few small areas of syenite above mentioned are the only ones rep- resented as completely surrounded by anorthosite on any of the detailed geologic maps. Of these the only ones within Marcy anorthosite are in the Elizabethtown quadrangle. It is therefore a striking fact that such syenite areas are almost entirely absent from the great area of Marcy anorthosite. ‘The significance of this fact is considered beyond, under another caption of this paper. 434 W. J. MILLER—ADIRONDACK ANORTHOSITE According to Bowen’s hypothesis, these isolated masses of syenite might be‘regarded as remnants of a former cover of syenite over the anorthosite. But, although positive proof for their intrusive character is, so far as I know, lacking, it is much more reasonable to interpret them as intrusive into the anorthosite. The field relations are in most cases clear enough to make it certain that these syenite masses are rather sharply separated from the anorthosite, which would not be the case if they were differen- tiates of the same intruded magma. RELATION OF THE SYENITE-GRANITE SERIES TO CHILLED BORDER OF THE ANORTHOSITE For the Long Lake quadrangle Cushing*® says: “The field evidence seems clear that the anorthosite had solidified, with a chilled border, and had then been attacked from the side by a mass of molten syenite, which in places cut deeply into it.” With this statement I am in agreement; but I would go further in saying that both granite and syenite of the syenite-granite series have, in certain other districts like the Lake Placid and Schroon Lake quadrangles, not only cut deeply into, but also they have either largely cut out or more or less assimilated, the border facies of the anorthosite. Thus in the Schroon Lake quadrangle only mere remnants of the original wide border facies are left. Cushing further maintains that the chilled border is fatal to Bowen’s conception that molten overlying syenite may have been faulted down against solid anorthosite, so that it could have laterally attacked the anorthosite, thus accounting for the intrusive features, including the syenite dikes. From the detailed field evidence above presented, under the caption “The gabbroid chilled border facies and its significance,” it is very certain that the chilled border grades directly into the typical anorthosite, and that there is not the slightest reason to think that the syenite or granite ever developed between the chilled border and the typical anorthosite. Two seeming exceptions should be mentioned. One is the broad belt of syenite which separates the Whiteface type from the Marcy type of anorthosite north of Lake Placid, but, as shown below, it certainly was intruded into this position. The other is a nearly circular area over a mile in diameter a few miles north of Elizabethtown, but the very shape of this mass strongly points to an intrusive origin rather than to its origin as a differentiate in situ. Even if we assume, what has not been found in the field, that some such syenite or granite exists as a rock - intermediate between the chilled border and the typical anorthosite, it is 3H. P. Cushing: Jour. Geol., vol. 25, 1917, p. 507. RELATION OF SYENITE-GRANITE SERIES 435 most unreasonable to suppose that the chilled border would in some places grade first into the syenite or granite and then into the anorthosite. Hither one of these might be the case, but not both. Bowen suggests that the syenite-granite may have developed between the chilled border and the Marcy anorthosite and then have been rein- truded through the chilled border. But by what stretch of the imagina- tion can we regard the syenite-granite series to have been so largely rein- © truded that not any of it has been discovered in its supposedly original position? Also when we think of the tremendous volume of syenite- granite immediately around the anorthosite, how can we possibly imagine the reintrusion of so much magma through the chilled border facies, leaving this latter as a definite fringe about and grading into the anor- thosite for so many miles? SYENITE-GRANITE BODIES OF THE LAKE PLACID AND AUSABLE QUAD- RANGLES ARE NOT DIRECT DIFFERENTIATES OF ANORTHOSITE In discussing the distribution of anorthosite and syenite, Cushing*® says: “The continuity of the main mass (anorthosite) is interrupted by two considerable inlying bodies of other rock (chiefly syenite), one in the Lake Placid region and the other near Keene. . . . Both of these in- liers are entirely surrounded by anorthosite and lie well within the mass.” These relationships were, no doubt, suggested by the highly generalized State geologic map. He suggests that the anorthosite body, while cooling, may have developed a syenite cover, and that the two so-called inliers just mentioned may be remnants of that cover which have not been removed by erosion. The field facts, as I interpret them, are fatal to this view. In the first place, the Lake Placid mass referred to is not an “inlier’’ (or, I would say, “outlier’”) at all. It is a great body of syenite, with locally developed granite facies, varying in width from 1 to 6 miles and extending into the anorthosite area for 13 miles across the Lake Placid quadrangle, and thence for an unknown distance into the Mount Marcy quadrangle. I have definitely traced this mass right into the extensively developed syenite-granite series of the Lake Placid and Saranac quad- _rangles, so that there can be no doubt about its being an offshoot from the great syenite-granite body. ‘The syenite mass north of Keene extends eastward into the Ausable quadrangle, and there very likely connects with the broad tongue of the syenite-granite series which reaches southward for a number of miles into that quadrangle (see State map). Whether the Keene syenite area actually connects with this broad tongue is not 99H. P. Cushing: Jour. Geol., vol. 25, 1917, p. 502. . 436 W. J. MILLER—ADIRONDACK ANORTHOSITE known because of lack of detailed field-work. In any case, if there is no direct surface connection, the space between must be narrow. In the second place, the syenite of these bodies grades into granitic syenite and even into granite, and is in every way exactly like the usual syenite throughout the Adirondack region. In the third place, I have proved that the Lake Placid syenite-granite mass is intrusive into both the Whiteface and Marcy types of anorthosite, as shown by the dikes, inclusions of anorthosite in the syenite, and the irruptive contacts (see above). There is considerable evidence of some- what finer grained syenite and granite due to border chilling near the contacts with the older rocks. The distribution of this syenite-granite mass with respect to the surrounding rocks also strongly indicates its intrusive character. It is also very distinctly intrusive into Grenville, as proved both by inclusions and irruptive contacts. In short, the evidence that this body of syenite-granite is really intrusive into and distinctly later than the anorthosite is fully as strong as Cushing’s evidence that the syenite of the Long Lake quadrangle is distinctly younger than the anorthosite there. In the fourth place, as already shown, the chilled border facies of anor- thosite certainly developed as a marginal mass lying directly against and grading into the typical Marcy anorthosite. This is clearly true of the border facies (Whiteface anorthosite) in the Lake Placid quadrangle. There is no positive evidence that syenite ever developed as a rock inter- mediate in position and character between the border facies and the Marcy anorthosite of the quadrangle. A seeming exception is the broad belt between Marcy and Whiteface anorthosite north of Lake Placid; but the facts that this is only a part of the clearly intrusive body both to the north and the south, and that transition rocks are absent, make its intru- sive character certain. The narrow belt of transition rock between the syenite and anorthosite on the Sentinel Range is much more plausibly explained as due to assimilative attack on the anorthosite by distinctly Jater syenite magma (see discussion of “Keene gneiss” below) rather than’ differentiation in situ. | : In the fifth place, the foliation of this Lake Placid syenite-granite mass is usually distinct and, as I have elsewhere shown,* this is a magmatic flow-structure foliation. The dips are usually high, indicating a notable upward movement of the magma, such as would scarcely be expected to have taken place with a magma developed by differentiation in situ be- tween the border facies of the anorthosite and the Marcy anorthosite. 40 W. J. Miller: Jour. Geol., vol. 24, 1916, pp. 600-612. a] TRANSITION ROCKS 43 ANORTHOSITE AND SYENITE-GRANITE TRANSITION Rocks (KEENE GNEISS) GENERAL STATEMENTS One of the most interesting rock types of the region is locally developed as belts or irregular bodies along portions of the borders between the anorthosite and the syenite-granite series. Both the Marcy and White- face types of anorthosite show such border rocks. There is very strong evidence, based on field-work and a study of thin sections, that this is really a transition rock between anorthosite and syenite or granite due to actual digestion or assimilation of anorthosite by the invading syenite- granite magma along portions of its borders. It is here proposed that this rock be called “Keene gneiss,” because a fine exposure of the typical fresh rock occurs by the road just north of the village of Keene, in the * Lake Placid quadrangle. In view of the fact that many geologists main- tain that there are no definitely proved cases of magmatic assimilation, on considerable scales at least, the evidence furnished by these rocks, especially in the Lake Placid and Schroon Lake quadrangles, has been very carefully considered by me, and I am convinced that actual assimi- lation has taken place. In other words, the Keene gneiss is quite cer- tainly a good example of hybrid rocks, to use the term suggested by Harker, who maintains that such rocks may be produced either by the mixing of two distinct magma or by the assimilation of solid rock by a magma. Fifteen areas of mostly Keene gneiss are represented on my Lake Placid map. Several areas containing considerable developments of Keene gneiss I have also found in the Schroon Lake quadrangle, one of these occupying about 6 square miles and another about 3 square miles. Others probably exist, but were not located owing to scarcity of outcrops or roughness of country in some places. Cushing has described rocks, which I would put in the same category with the Keene gneiss, from two localities on the western side of the great anorthosite area. Kemp has described certain peculiar types of gabbro, probably also to be classed as Keene gneiss, as occurring in the Elizabeth- - town quadrangle. Cushing suggests that these rocks in his districts are magmatic assimilation products, but Kemp says nothing regarding the origin of the peculiar types of gabbro in his district. So far as I know, | these are the only rocks of the sort regarding which even brief published statements have been made. Obviously, there is great need of more data regarding such rocks, because the problem of their origin and relations to other rocks has a very important bearing on the whole problem of the anorthosite. Since I have observed these rocks, often with the exhibition 438 W. J. MILLER—ADIRONDACK ANORTHOSITE of significant relationships, I shall enter somewhat into the details of their description. The typical Keene gneiss presents a different appearance from any of the other Adirondack rocks. In the Lake Placid and Schroon Lake quad- rangles the typical rock is medium grained, gneissoid, notably granulated, and looks much like a rather basic facies of the syenite except for scatter- ing phenocrysts of bluish gray labradorites up to an inch long. ‘These phenocrysts, which are rounded and usually elongated parallel to the foliation of the rock, doubtless represent cores of crystals which survived the process of granulation. Locally the phenocrysts are absent or spar- ingly present, and ledges of such rock are difficult to distinguish from a basic phase of syenite. Under the microscope, however, the distinction may generally be made. The fresh rock is greenish gray and it weathers brown. The mineralogical composition of selected samples of various phases © of the rock from the Lake Placid quadrangle are shown in the table on the opposite page. Labradorite and andesine are always present and oligocene usually.’ Microperthite occurs in most specimens in varying amounts up to 30 per cent, and orthoclase in most specimens in varying amounts to over 50 per cent. A little quartz is generally present. All the thin sections examined show greenish: gray monoclinic pyroxene; sometimes diallage. A little green hornblende nearly always occurs up to 14 per cent. Garnet varies from none to 12 per cent. Ilmenite or magnetite up to a few per cent never fails. Apatite and pyrite nearly always occur in small amounts. In his recent paper, Bowen states that he has observed, in the transition rocks from anorthosite to syenite, inclusions of potash feldspar, which are small patches, uniformly oriented, and in some cases surrounded by areas of plagioclase differing from the crystal as a whole. A few slight sugges- tions of this sort were noted by the writer, but certainly this is not a characteristic feature of the Keene gneiss thin sections examined. SOME OCCURRENCES IN THE CAKE PLACID QUADRANGLE Occurrence near Keene village——The type locality of the Keene gneiss is a ledge by the side of the State road at the northern end of the village of Keene, where an excellent opportunity is afforded for the study of the rock and its relations to both anorthosite and syenite. All three of the rocks show as unweathered material in this one ledge, which has recently been blasted open. The anorthosite, which occurs in minor amount, is the typical Marcy facies, consisting mostly of dark bluish gray labradorite up to an inch across, embedded in some granulated labradorite, and asso- eee 439 TRANSITION ROCKS Slide number wo 10 11 12 41 45 Field number 4f8 Tf7a 14¢4 14b4 1657 1k10a 1k10b Plagioclase An.—Lab. 70 Ol.—Lab. 40 Microperthite 20 32 Orthoclase 20 20 10 Quartz 6% Monoclinic py- roxene i) Diallage ioe) Hornblende 14 6% Ilmenite or mag- netite = oN 2) Garnet little 12 Apatite VA little little Ye vA 1, Zircon little V4 little a) Pyrite little little Vy little Titanite little Calcite (second- ary ) 440 W. J. MILLER—ADIRONDACK ANORTHOSITE ciated with 10 to 15 per cent ferro-magnesian minerals. The syenite is quite normal in every respect except that it is a little finer grained than usual. A thin section shows the following percentages of minerals: Microperthite, 64; orthoclase, 5; oligoclase, 20; quartz, 6; hornblende, 214, and other very minor constituents. Most of the rock of the ledge, however, is clearly an assimilation prod- uct of syenite and anorthosite. This rock (Keene gneiss) exhibits at least three distinguishable facies. One is highly gneissoid, with elongate cores of labradorite crystals as phenocrysts, up to an inch long, arranged parallel to a distinct foliation. Its mineral content is given as number 42 of the above table. A second facies is only faintly gneissoid, with lab- radorite phenocrysts only roughly parallel to the foliation. Its composi- tion is given as number 45 of the table. The presence of orthoclase and a greater amount of microperthite makes this rock more syenitic than the first facies. In the two facies just described the phenocrysts of labra- dorite not only finely exhibit polysynthetic twinning, but they are also perfectly and conspicuously twinned according to the albite law, thus giy- ing the freshly broken surface a striking appearance. Both of these facies are notably granulated, and the rounded phenocrysts are the uncrushed portions of what were once still larger crystals. A third facies, in minor quantity, is non-folated and contains no phenocrysts, but it does contain a few rounded red garnets up to an inch across. This third facies is the most syenitic of the three. All three facies just described grade into each other and they are quite certainly only phases of a single cooling magma. Also it is important to note that the Keene gneiss is not sharply separated from the true syenite on one side and the true anorthosite on the other, but rather by narrow transition zones. All three facies of this Keene gneiss are certainly inter- mediate in composition between the syenite and anorthosite, the first one described having decided anorthosite affinities, the third having decided syenite affinities, and the second being no more syenitic than anorthositic. The conclusion, therefore, based on the field relations and composition of the rocks, is that we have here a true magmatic assimilation product, the invading syenite*magma having actually incorporated and digested more or less of the anorthosite material. The close juxtaposition of the syenite and Keene gneiss may be reason- ably explained by considering the syenite to have been an intrusive off- shoot from the near-by large body of syenite into previously formed and cooling, or possibly solidified, Keene gneiss magma, the temperature then having been high enough only to permit fusion along a narrow border TRANSITION ROCKS 44] zone between the intruded and intruding masses, thus accounting for the narrow transition zone between the two in the ledge. The foliation of this Keene gneiss is quite certainly an original struc- ture due to magmatic flowage under moderate pressure, and accordingly the marked differences in degree of foliation within this one outcrop are regarded as the result of differential magmatic flowage. It is clearly evident that the typical Keene gneiss just described is of very local origin. Evidence of the local origin of other Keene gneiss is presented below. The larger bodies of Keene gneiss are in every way like these smaller ones, and there is good reason for believing, therefore, that all the Keene gneiss, even where present as considerable bodies, is of rather local origin due to assimilative attack of molten syenite or granite on anorthosite. This is, of course, directly opposed to Bowen’s hypothesis, which regards the transition rock (Keene gneiss) as having formed by differentiation in situ between syenite and anorthosite. Area near Upper Jay.—In the area of over one-half of a square mile, just east of Upper Jay, there are many good exposures, certain of them of particular interest because they throw important light on the origin and relations of the Keene gneiss. Near the top of the hill, at the northeast- ern border of the area, syenite and Whiteface anorthosite in big exposures are separated by a zone, a few feet wide, of basic syenite-like rock with scattering bluish gray labradorites. This is certainly a transition zone of typical Keene gneiss produced by the assimilation of Whiteface anortho- site by syenite magma. On the little hill, just south of the center of the area, several outcrops of typical Keene gneiss contain bands or lenslike inclusions of Whiteface anorthosite, Keene gneiss magma, moving from a lower level where it was formed, evidently having penetrated or caught up small masses of unchanged Whiteface anorthosite at a higher level. The Keene gneiss here contains many tiny red garnets, and the labra- dorites are very conspicuous on the weathered surfaces. Sentinel kange area.—This long narrow area extends east-west across the middle of the Sentinel Range. It is about 4 miles long and nowhere over one-fourth of a mile wide. It is all in a rough, densely wooded ~ country, but a good many outcrops make the mapping fairly satisfactory. Perhaps the most instructive ledges are on the little hill 1 mile northeast of Maleom Pond. The top of this hill is quite typical Marcy anorthosite. On the southern side the rocks are variable, being mostly fine to medium grained, gneissoid, and of gabbroid appearance, with some closely involved basic syenite-like rock containing a few small, scattering labradorite phe- nocrysts. Near the top of the hill, on the west side, the rock is coarser 442 W. J. MILLER—ADIRONDACK ANORTHOSITE grained, with few dark minerals, and this appears to be quite typical Keene gneiss. All the types mentioned gtade into each other. On the hillside, one-half of a mile southeast of the hill just mentioned, there are outcrops of a moderately coarse grained, rather gabbroid rock with some labradorite phenocrysts. Its mineralogical composition, num- ber 3 of the above table, shows that it is Keene gneiss with strong anor- thosite affinities. There are still other good exposures in this Sentinel Range area. Sunrise Notch area.—This is the largest area of Keene gneiss in the quadrangle (see figure 1). It is about 314 miles long and from one-half to two-thirds of a mile wide. Most of the outcrops are quite typical Keene gneiss, though usually not strongly foliated. The rock is generally medium grained, with scattering labradorite phenocrysts. It weathers brown. | A locality of special interest is a cliff on the southern border of the area, three-fourths of a mile east of the summit of Sunrise Notch. Most of this rock is very gneissoid and only moderately gabbroid Whiteface anorthosite, a little finer grained than usual. Within this rock there is a wide band of fine grained, very gneissoid, gray rock with a reddish tinge due to numerous tiny garnets. The composition of this local band, num- ber 10 of the above table, causes it to be classed as Keene gneiss with strong syenite affinities. Its contact against the anorthosite is not very sharp. Evidently a dike or tongue of the Keene gneiss magma here in- truded the Whiteface anorthosite near its border, and the temperature was high enough to cause fusion of the anorthosite walls of the dike or tongue. Area west of East Kilns—This area, between 1 and 2 miles west of East Kilns, shows certain interesting and important features. Much of the rock has strong syenite affinities because of the high content of ortho- clase. Near the middle of the northern boundary syenite contains inclusions of Whiteface anorthosite as bunches, lenses, and bands from two or three inches to several yards long, the boundaries of the inclusions usually not being very sharp. Evidently very little assimilation of anorthosite took place here. Along the northwestern side several ledges are very gabbroid in appear- ance, in some places very gneissoid and in others not. Locally there is very intimately associated syenite and Whiteface anorthosite. Appar- ently these ledges show the effects of partial digestion or assimilation of anorthosite by the syenite magma. TRANSITION ROCKS 443 Along the main brook, for one-fourth of a mile after it enters the area, there are good exposures of homogeneous, scarcely gneissoid Keene gneiss, with phenocrysts not as large as usual.. This rock, whose composition is given as number 41 of the above table, has strong syenite affinities because of its high orthoclase content. In this portion of the area syenite magma quite certainly completely assimilated more or less anorthosite. At one place on the little hill, in the eastern part of the area, fairly coarse granite is intimately associated with gabbroid Whiteface anortho- site with local development of what appears to be an assimilation product containing some quartz. SOME OCCURRENCES IN THE SCHROON LAKE QUADRANGLE An outcrop on the southern brow of Cobble Hill, 1 mile due south of Bailey Pond, is very significant because of the light it throws on the local origin of the Keene gneiss. The accompanying sketch (figure 2) shows the relationships. This Keene gneiss is distinctly granitic in appearance except for the many labradorite crystals, mostly about an inch long, which stand out as distinct phenocrysts more or less parallel to the crude folia- tion of the otherwise medium grained rock. Within this rock are inclu- sions of Whiteface anorthosite, which contains some large labradorites and also scattering femic minerals up to two inches long, more or less lenslike and parallel to a distinct foliation. Contacts between the inclu- sions and the Keene gneiss are not very sharp. Immediately above this Keene gneiss, but not in very sharp contact with it, is a very gneissoid granitic gneiss which contains many garnets. This granitic gneiss grades upward into typical, medium grained, only moderately foliated granite ' without garnets. A similar typical granite lies against the Keene gneiss at the bottom, but the contact there is quite sharp. My interpretation is that the upward moving granite magma more or less assimilated some Marcy anorthosite at a considerable depth, and that this molten mass (Keene gneiss magma) having risen still higher caught up and only fused the borders of fragments of Whiteface anorthosite. The origin of the garnetiferous granite is not so certain, though it may represent a mass of granite with a small quantity of anorthosite very thoroughly digested. Interesting exposures occur in a small area near the southeastern base of Severance Hill. The rocks are mostly peculiar basic-looking syenitic gneisses, well foliated, medium to fine grained, garnetiferous, and green- ish gray where fresh, but they are quite variable with considerable local development of quartz. They differ from the typical Keene gneiss in not having the large bluish labradorites. I have not yet had opportunity to study thin sections of this rock. One large exposure shows numerous 444 W. J. MILLER—ADIRONDACK ANORTHOSITE small inclusions of Whiteface anorthosite whose borders against the sye- nitic looking rock are by no means sharp. Apparently quartz syenite or granite magma rising through anorthosite assimilated some of it and then, rising still higher, caught up numerous small fragments which were not completely digested. + + Se 5F Tr + +o sheets + + ++ = +- fe “Vv - nn + yt == = + r+ ‘fer t+ + Tie + Hi, st + + a fa rage ata, = ab ae FicurE 2.—Relations of Keene Gneiss to other Rocks on the southern Brow of Cebble Hill, in the Schroon Lake Quadrangle Dimensions, 30 by 30 feet. K = Keene gneiss, W — Whiteface anorthosite, FG = highly foliated granite with garnets, and G — typical moderately foliated granite. Not very sharp contacts between K and W and between K and FG. G grades perfectly into F@. / By the trail, 2 miles northeast of Bailey Pond, there is a large outcrop of peculiar variable rock. There are some small patches of Whiteface anorthosite embedded, but most of the rock looks like granite or granitic syenite with scattering bluish gray labradorites up to an inch long. This latter looks very much like the Cobble Hill rock above described, except TRANSITION ROCKS 445 for fewer labradorites, and I believe it to be Keene gneiss with the same history as that on Cobble Hill. On much larger scales I have mapped two areas of Keene gneiss, one occupying about 6 square miles and the other nearly 3 square miles. Be- fore the intrusion of a large gabbro stock the two areas were probably connected with a total length of nearly 7 miles. These bodies of Keene gneiss lie against typical Marcy anorthosite, the border facies of anor- thosite here having been very largely assimilated by granite or syenite- granite mdgma. Throughout the larger area especially there are a good many small masses of Whiteface anorthosite, a few of sufficient size to be mapped, and some outcrops of fairly good granite or. granitic syenite, thus showing that the assimilation was not everywhere thorough. The main bodies of the rock are quite typical Keene gneiss. ‘The inclusions of anorthosite indicate the true intrusive character of the Keene gneiss. Enough examples have been described to prove that Keene gneiss has developed on small and large scales by assimilation of anorthosite by eranite or granitic syenite magma instead of by syenite magma, as is usually the case in the other Adirondack districts thus far studied. If we adopt Bowen’s hypothesis, this Keene gneiss must be regarded as hav- ing developed by differentiation in situ between an overlying sheet of syenite-granite and underlying anorthosite. If one admits, as I do not, that syenite usually may have developed by differentiation in situ close on the Marcy anorthosite, how can one imagine, in other places like the Schroon Lake quadrangle, a similar development of granite close on the anorthosite? It might be argued that the granite magma formed at a higher level and was then forced downward. But, if so, it must have been forced downward through the still lower syenitic material. Not only is the field evidence against this view, as already pointed out, but even if we grant it, we are still forced to the conclusion, by the obvious field facts, that the granite magma produced the transition rock (Keene gneiss) by assimilation of more or less anorthosite, and that the Keene gneiss was not formed as a differentiate im sitw between an overlying sheet of syenite- granite magma and underlying anorthosite. KEENE GNEISS OF OTHER ADIRONDACK REGIONS In Cushing’s report on the geology of the Long Lake quadrangle, he describes a basic phase of the syenite which grades into a rather fine grained, even granular, gneissoid rock with few feldspar phenocrysts and dark minerals often equaling or exceeding the feldspar in quantity. Some of the feldspar is microperthite and some oligoclase-andesine. 446 W. J. MILLER—ADIRONDACK ANORTHOSITE “The most of the basic syenite, and all of the more gabbroic of it, is in close association with the anorthosite border. . . . Now the syenite is unques- tionably younger than the anorthosite, and the observed relations seem to point to the conclusion that the change (in the syenite) is due to actual diges- tion, by the molten syenite, of material from the (anorthosite) gabbro.” “ The Keene gneiss of the Lake Placid region differs in being coarser grained, distinctly porphyritic, and not so rich in dark minerals; but both Cushing’s basic syenite and the Keene gneiss are intermediate in position and composition between the anorthosite and the syenite-granite in their respective regions, and I believe Cushing’s suggested explanation is the correct one. Another rock, earlier described by Cushing*® from a railroad cut nearly 5 miles north of Tupper Lake Junction, is regarded by him as interme- diate between the syenite and anorthosite. Judging by the description, this rock is in most ways similar to the typical Keene gneiss, except that the phenocrysts of labradorite are not so large. In Kemp’s report on the geology of the Elizabethtown-Port Henry quadrangle,*? he describes two peculiar types of gabbro with distinct anorthosite affinities. One of these, called the Woolen Mill type, “‘is dark, gneissoid, and of moderate coarseness of grain. It resembles a rather basic member of the syenite series, but has occasional blue labradorite _ phenocrysts which ally it with the anorthosites.” The minerals contained are green pyroxene, plagioclase, orthoclase, quartz, garnet, pyrrhotite, apatite, and sometimes biotite and hornblende. Kemp states that this sort of rock also occurs along the southern border of Blueberry Mountain. Having seen this rock in the field, I quite confidently class it with the Keene gneiss. He says that the rock called the Split Rock Falls type “is suggestive of the anorthosite in that labradorite is the chief feldspar pres- ent, but the dark silicates are more abundant, and when crushed and sheared the rock yields a decidedly foliated gneiss. It then becomes a hard-dense rock, exceedingly tough. Nevertheless, large phenocrysts of labradorite are not uncommon.” Both of these types are demonstrably younger than the anorthosite, the first showing an irruptive contact against the anorthosite and the second containing inclusions of anortho- site. The fact that these rocks are intrusive into the anorthosite har- monizes with my own observations (see above) on the Keene gneiss—that is to say, in such cases the Keene gneiss magma developed as an assimila- tion product at a lower level and was then forced upward in some places 41H. P. Cushing: N. Y. State Mus. Bull. 115, 1907, p. 479. 42H, P. Cushing: N. Y. State Mus. Rept. 54, vol. 1, 1902, pp. r43 and r68. - 4 J. F. Kemp: N. Y. State Mus. Bull. 138, 1910, pp. 37-40, TRANSITION ROCKS 447 to include fragments of the anorthosite and in other places to yield irrup- tive contacts against the anorthosite at higher levels. SIGNIFICANCE OF THE DISTRIBUTON OF THE KEENE GNEISS That the Keene gneiss is actually an assimilation rock, the product of fusion and digestion of anorthosite by syenite or granite magma, is re- garded proved by the evidence above presented. It can not be a direct differentiate of either the syenite-granite series or the anorthosite, be- cause it never occurs except on the border or close to the contact between the syenite or granite and the anorthosite. But such rock is not univer- sally present. For instance, the long boundaries between the Whiteface anorthosite and granite of Mount Whiteface and between the Whiteface anorthosite and syenite from the southern side of Mount Whiteface to west of Knapp Hill were crossed by me at a good many places without noting any rock like the Keene gneiss. Some other places also have no Keene gneiss asa border rock. It is probable that some masses of Keene > gneiss may have been overlooked in the rough, densely wooded country, and that some may lie under cover of Pleistocene deposits; but, in view of the detailed surveys of the Lake Placid and Schroon Lake quadrangles, it is certain that any such masses must be relatively small in those dis- tricts. By way of contrast with the conspicuous development of Keene gneiss, the syenite-granite series about the great anorthosite body shows little evidence of having assimilated Grenville. rocks. The Keene gneiss, par- ticularly in the Lake Placid quadrangle, forms belts between the syenite- granite series and the border (Whiteface) facies of the anorthosite as well as between the syenite-granite and Marcy anorthosite. In both cases the Keene gneiss exhibits essentially the same characteristics. Not every- where does the Keene gneiss exist as definite zones or belts with syenite or granite directly adjacent on one side and anorthosite on the other. How are these differences in distribution of the Keene gneiss to be ac- counted for? Also, why do the borders between the Grenville and syenite- eranite, as well as the Grenville and syenite-granite mixed gneisses, show little or no evidence of magmatic assimilation? I believe the answer to these questions may be found in the temperature relations of the rocks at the time of the intrusion of the syenite-granite series. If we consider that the great mass of anorthosite was still at a relatively high tempera- ture, though not necessarily molten, it would have been only necessary for the syenite-granite magma to have raised the temperature of the borders of the anorthosite comparatively little to have effected actual assimilation. . XXXIV—BULL. Grou. Soc. AM., Vou. 29, 1917 448 W. J. MILLER—-ADIRONDACK ANORTHOSITE The tongues of syenite cutting Whiteface anorthosite on Wilmington Mountain, and the tongues of granite cutting similar anorthosite on the side of Mount Whiteface (see figure 1), furnish important evidence in support of this view, because these tongues or dikes, instead of being in sharp contact with the anorthosite, show very narrow transition zones due to slight fusion of the anorthosite. Now it does not seem probable that even small amounts of comparatively cold anorthosite could have been fused and assimilated by such small masses of intrusive magma, but with the anorthosite at a high temperature, though not really molten, the borders might very conceivably have been fused. Thus, if we make the very simple and plausible assumption that the anorthosite was still very hot when the syenite-granite magma was intruded, or, in other words, if this latter magma was forced up comparatively soon after the development of the anorthosite, the usual strong objection to magmatic assimilation, namely, that a magma does not possess a sufficiently high temperature to raise relatively cold country rock to the point of fusion, is distinctly obviated. Where no Keene gneiss occurs along the borders, it may be plausibly conceived that either the anorthosite or the syenite-granite, or both, may not have been hot enough to permit assimilation. In this connection, it should be noted that the prominent mass of syenite-granite which projects for many miles into the anorthosite of the Lake Placid quadrangle (see above) shows little or no development of Keene gneiss along its borders except well within the quadrangle, where it is reasonable to believe that the anorthosite was hotter, due to greater thickness and slower cooling of the laccolithic body there. In both the Schroon Lake and Long Lake quadrangles, however, considerable developments of Keene gneiss took place along or close to the outer margin of the great body of anorthosite, probably because on the south and west sides the anorthosite of the lacco- lith was notably thicker, and hence kept hot longer (see figure 3). The presence of Keene gneiss in one place and its absence from the same border near by may in some cases have been the result of unequal upward intrusion of Keene gneiss magma which originated at a lower level. The failure to find any considerable assimilation of Grenville either along its border with, or where involved with, the syenite-granite series may be explained on the basis of a temperature of the Grenville too low to have permitted any more than comparatively slight assimilation by the invading syenite-granite magma. It should be borne in mind, however, as pointed out in a recent paper by the writer,** that local assimilation was not uncommon in certain parts of the Adirondack region. “#W. J. Miller: Bull. Geol. Soc. Am., vol. 25, 1914, pp. 254-260. TRANSITION ROCKS 449 How shall be explained the fact that typical Keene gneiss in some places forms belts between syenite or granite and Marcy anorthosite and in other places between syenite or granite and the border (Whiteface) facies of the anorthosite, the Keene gneiss exhibiting almost exactly the same characteristics in each case? If we adopt Bowen’s hypothesis, we are obliged to imagine the development of two sheetlike masses of Keene gneiss, one just above the syenite-granite and the other just below it. Is it not most unlikely that two masses, formed under such different condi- tions, would be almost exactly the same? This difficulty is obviated by regarding the Keene gneiss as an assimilation product. In my experi- ence, particularly in the Lake Placid quadrangle, Keene gneiss seldom formed except well within the outer margin of the great body of anor- thosite where the temperature was still relatively high. The field rela- tions strongly indicate that assimilation of Whiteface anorthosite took place only where that rock was well within the outer margin—that is to say, where such Whiteface anorthosite was near its change to Marcy anorthosite. | In the mixed rock areas, where anorthosite has been cut to pieces by intrusions of syenite, the few contacts observed are not very sharp. Ap- parently in these areas either the syenite magma or the anorthosite, or both, were not hot enough, or the syenite was not in sufficient bulk to effect more than slight fusion of the borders of the invaded anorthosite. Another important fact is that in the field the Keene gneiss by no means universally forms a narrow zone or belt with syenite-granite di- rectly adjacent on one side and anorthosite on the other. A fine case in point is the eastern part of the Sunrise Notch area (see figure 1), where Keene gneiss for 114 miles lies between granitic syenite on one side and syenite on the other. A different case is the Oak Ridge area northeast of Keene. This is bordered on the south by Whiteface anorthosite and on the north by Grenville, Marcy anorthosite, and syenite. How can areas of this sort possibly be explained by Bowen’s hypothesis, which assumes that the anorthosite was never a real magma, but that it was formed by sinking of plagioclase crystals with the development of a transition rock _ (Keene gneiss) occupying a position distinctly intermediate between the syenite-granite and anorthosite? Is it not much more in harmony with the field relations to conceive that Keene gneiss magma was produced by - assimilation at a lower level and then rose to invade previously formed Grenville and anorthosite, or moved upward, flanked on either side by syenite or granite? Also, are not elliptical areas like those just east of Upper Jay and 114 miles west of East Kilns much more satisfactorily accounted for in this manner than by Bowen’s hypothesis? Again, do 450 W. J. MILLER—ADIRONDACK ANORTHOSITE not the inclusions of anorthosite in the Keene gneiss (see above) strongly support my view that the Keene gneiss, in some places at least, moved upward as a true magma? Finally, while there are such good reasons for believing that in many cases the Keene gneiss magma formed at lower levels and rose to higher levels in true intrusive fashion, it is also true that in many places, par- ticularly in the Long Lake quadrangle, there appear to be no evident irruptive contacts of Keene gneiss against anorthosite, but rather a gra- dation. In such cases the assimilation or digestion of anorthosite by | syenite or granite magma is conceived to have taken place with little or no movement of the resulting hybrid magma. This seems also to be essen- tially true of the long, narrow area of Keene gneiss between syenite and Marcy anorthosite across the Sentinel Range, in the Lake Placid quad- rangle. BOWEN’S SUGGESTION OF POSSIBLE ORIGIN OF SOME KEENE GNEISS BY ASSIMILATION To argue that because there is a transition rock (Keene gneiss) does not prove Bowen’s hypothesis of a stratiform arrangement with syenite- granite above and anorthosite below, the transition rock being a differen- tiate in situ between the two. This utterly ignores the possibility of the origin of the Keene gneiss by magmatic assimilation. In his second paper, Bowen emphasizes the point that much of the syenite magma, which he conceives to have been formed just under the upper gabbroid border phase of the great intrusive, could have intruded and partially assimilated the border phase, thus giving rise to some rocks intermediate between syenite and gabbroid anorthosite, such as those described by Cushing. Now, while it is significant that Bowen admits the possible origin of some such rocks by magmatic assimilation, the plain fact is that no syenite ever formed as a rock intermediate between true anorthosite and the gabbroid border phase, as already proved, so Bowen’s hypothesis to account for certain rocks intermediate between syenite and gabbroid anorthosite is wholly out of the question. SIGNIFICANCE OF THE DISTRIBUTION OF FEMIC MINERALS According to Bowen, a sheetlike arrangement of syenite-granite, anor- thosite, and pyroxene or peridotite developed, due to settling of crystals in an original gabbroid magma, the femic minerals having very largely gone to the bottom, except probably from the very uppermost chilled border facies. Thus the syenite should be notably poorer in femic min- erals than the anorthosite, and also the transition rock which, according TRANSITION ROCKS Ad51 to Bowen, formed between the syenite and anorthosite should be poorer in femic minerals than the anorthosite. Now, in my experience, just the ° reverse is true. The average syenite is notably, and the average transi- tion rock (Keene gneiss) is perceptibly, richer in femic minerals than the anorthosite. This is a fact overlooked by Bowen. Why were more femic minerals left in the overlying syenite and transition rock magmas than in the underlying anorthosite, according to his view, when the ten- dency was for such crystals to go to the bottom? ‘This serious difficulty is entirely obviated if we consider the anorthosite to be a separate instru- sive distinctly older than the syenite-granite series. SIGNIFICANCE OF THE THICKNESS OF THE KEENE GNEISS The thickness of the Keene gneiss is very significant. It almost always occurs as narrow belts or zones between syenite or granite and anortho- site. A very fine example is the narrow belt forming a transition between syenite and typical Marcy anorthosite across the Sentinel Range of the Lake Placid quadrangle. If we consider its thickness to be approximately represented by the width of the outcrop, it would be but little more than a thousand feet; and this is my view. But, according to Bowen’s hy- pothesis, this Keene gneiss must extend as a layer southward under the syenite, and hence its thickness would be much less; in fact, scarcely more than a few hundred feet. Now, within this short distance the passage from typical quartz syenite into typical Marcy anorthosite takes place. The Marcy anorthosite is certainly at least some thousands of feet thick, several thousand feet in thickness being exposed in single mountains, and so with the syenite. I can not conceive of the development of two rock masses, syenite above and anorthosite below, on such a grand scale by the sinking of plagioclase crystals in a slowly cooling magma under deep- seated conditions, as required by Bowen’s hypothesis, without the forma- tion of a notably thick transition rock, fairly comparable in bulk to the overlying syenite and the underlying anorthosite. But this is far from the case as demonstrated by the field relations. As matter of fact, as _ already pointed out, such a transition rock never formed at all in some places. GENERAL ABSENCE OF GRENVILLE AND SYENITE-GRANITE FROM THE ANORTHOSITE AREA It is a striking fact that both Grenville and syenite-granite are almost, if not entirely, absent from a large part of the area of anorthosite. 452 W. J. MILLER—ADIRONDACK ANORTHOSITE Bowen** says: “Not only is the anorthosite unbroken by areas of Gren- ville, especially away from the margins, but it is likewise practically free from protrusions of the syenite.” Although this statement needs to be modified, I believe it constitutes the strongest single argument in fayor of Bowen’s hypothesis. It is not, however, opposed to my conception of the structure and origin of the anorthosite. The statement is by no means true for the northeastern half-of the anorthosite area which is covered by the Lake Placid and Ausable quadrangles and the northern portions of the Mount Marcy, Elizabethtown, and Port Henry quadrangles and the western half of the Willsboro quadrangle. There are extensive develop- ments of both Grenville and syenite-granite throughout this northeastern half of the anorthosite area. In the southwestern half of the area, how- ever, the absence of Grenville and syenite or granite is indeed an impress- ive fact, though it must be remembered that many square miles of this have never been carefully surveyed. The detailed Long Lake, Schroon Lake, Paradox Lake maps and the southern half of the Elizabethtown map show no areas of Grenville or syenite-granite. As I understand it, this is also true of the southern half of the Mount Marcy quadrangle. According to Bowen :* “If one pictures the syenite and the anorthosite as conventional batholiths, some difficulty is experienced in accounting for the foregoing facts. It is necessary to imagine an early intrusion of a huge plug of anorthosite followed by an intrusion of syenite which took the form of a hollow cylinder circum- seribing it and invading it only peripherally. . . . On the other hand, if ohne pictures the Adirondack complex as essentially a sheetlike mass with syenite overlying anorthosite . . . one would expect to find areas of Gren- ville roof covering the syenite in places and to find it relatively little dis- turbed. In the interior and eastern region of maximum uplift one would ex- pect to find the deep-seated anorthosite laid bare and to find it free from areas of the roof.” Also, because of the deep erosion in the region of maximum eae one would expect to find the layer of syenite removed. My view is quite different. As I have repeatedly shown in this paper, it is certain that the anorthosite represents a separate and distinctly older intrusion than the syenite-granite, so that the sheetlike arrangement ad- vocated by Bowen is out of the question. But it is by no means necessary, therefore, to assume that both syenite-granite and anorthosite were batho- hthic intrusions. I believe the anorthosite represents a laccolith not much greater across than the present area of outcrop, and that its intru- sion was soon followed by a very irregular intrusion of the great body of 4#N. L. Bowen: Jour. Geol., vol. 25, 1917, p. 223. 46N. L. Bowen: Jour. Geol., vol. 25, 1917, pp. 223-224. ABSENCE OF GRENVILLE AND SYENITE-GRANITE 453 generally rather highly fluid syenite-granite magma. That the syenite- granite magma was rather highly fluid is proved by its great power to cross-cut, intimately penetrate, break up, and tilt the Grenville strata. Only exceptionally did local portions of this magma invade the Grenville strata in true laccolithic fashion. | Both the anorthosite and the syenite-granite, I believe, intruded a very thick mass of essentially undisturbed Grenville strata, largely or alto- gether free from orthogneiss. The southwestern half of the anorthosite body, which is so free from masses of Grenville and syenite-granite, I believe represents the greatest bulk of the anorthosite where the lacco- lithic magma was thickest and reached the highest level. The northeast- ern half of the anorthosite, as now exposed, I regard as the portion where the magma spread out as a relatively much thinner layer whose surface was at a notably lower level than that of the thicker portion to the south- west (see figure 3). Because of the greater uplift of the southwestern portion the Grenville cover has been almost, if not completely, removed by erosion. But many areas of the Grenville roof remain over the thinner northeastern part where the uplift was much less. Thus we have a simple explanation of the absence of the Grenville from so much of the anor- thosite area. After the solidification of the great body of anorthosite, the syenite- granite magma was batholithically intruded in a rather highly fluid state and tended to avoid penetration of the anorthosite which was much more massive, homogeneous, and resistant than the great mass of surrounding practically undisturbed Grenville strata. This satisfactorily explains not only why syenite-granite masses are scarcer within the anorthosite area than in the Adirondack region in general, but also why syenite-granite masses are almost, or entirely, absent from the southwestern half. I do not believe it necessary to assume that the feeding channel of the lacco- lith was as small as generally represented in diagrams of laccoliths. May not there have been a wide feeding channel extending northwest by south- east under the main body of the southwestern half of the anorthosite ? On this view, the thickest portion of the laccolith developed directly over the wide feeding channel which extended far down, with the result that this portion of the anorthosite intrusive body was very resistant to intru- sion by the syenite-granite magma. ‘The northeastern portion of the anorthosite, because notably thinner, was penetrated by considerable masses of the syenite-granite magma, as in the Lake Placid and Ausable quadrangles. Here, again, we have a simple explanation of the field facts. If we do not accept the hypothesis of stratiform arrangement of the syenite-granite and anorthosite, we are therefore not forced, as Bowen A/a Ww. J. MILLER—-ADIRONDACK ANORTHOSITE says, to imagine a batholithic intrusion of the anorthosite followed .by a batholithic intrusion of syenite-granite which took the form of a hollow eylinder which invaded the anorthosite only peripherally. This statement by Bowen is opposed by the field facts, since the whole northeastern half of the exposed anorthosite body has been deeply invaded by very consid- erable masses of syenite-granite. , ) If we adopt Cushing’s view of Grenville resting on older orthogneiss, this latter rock would have made the country rock distinctly more resist- ant to intrusion by the syenite-granite magma, and hence we should not expect the relative amounts of syenite-granite within the anorthosite area and the region outside of it to be so notably different. So far as I know, O CK K ls corr i a 5% Her ‘ N xy) orth a 5 coo , 4 {S FS a2 SR2T he > gagogaog ggogagg Et SHH HT exX™ IO @ > > o, uoggogsao Bogarec ee Oo oS RRS ggegeogg aoe ay JS O6 Wy, LLDEKKK_XY (E--Grenuille strata a FH Marcy anorthosite ReOY)S yenite-granite ser/es Fre] Chille d border of anorthosite LineA B= present erosion. surface BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 463-470 SEPTEMBER 30, 1918 FIELD RELATIONS OF LITCHFIELDITE’ AND SODA- SYENITES OF LITCHFIELD, MAINE? BY REGINALD A. DALY (Presented before the Society December 29, 1917) CONTENTS Page BMMNMCTUOU he Seti eee oC bok eb wees 6 wl due ae pCR AMM aie 463 pre meeeet of biehbtieldites . oly. s face sc lng wae os te, hon vices 464 Pere CDN HE MED” PbANCCies o0G C2. < 5. oes. slave racey a. aye tetas ACU Mees Boe Stalag oud wie 465 Soda-syenites......... Ree he oh Ct a he aka ee hg yee EE ae AL Ae Ae Elta dd ce 467 Relation of litchfieldite to the nepheline-free syenites and to quartz peg- NRG SPE Pitre hs pees 8 cs ue ead. © aiaut Ge ae SNM 2 eo as 468 Seen MOROCCO MEN a et, on ale if ice Ké whic oS Sate PRET eeu al Sa O RE UM Sita aice es 6 ‘eiay's 468 Ce ea TONITE PE ba TOMS 6/650 was. 3 4 8 o's es sine eae ood a ela OMe oe afere e's slerelate Bie « 469 INTRODUCTION In 1892 Bayley gave a thorough petrographic description of the rare variety of nephelite syenite, litchfieldite, found in the town of Litchfield, Maine.? Since then this remarkable rock has been noted in the standard works on petrography. It was known only in the form of numerous boulders, which were movéd from their parent ledges by Pleistocene ice. During the field seasons of 1916 and 1917 the writer visited the district with the aim of discovering, if possible, the bedrock source or sources of these erratics and therewith the structural relation of the igneous rock to the associated formations. The litchfieldite was found in place at two localities and other allied alkaline intrusives were discovered. The posi- tions of most of the bodies are indicated by the accompanying sketch map (figure 1). | The area which was particularly studied is easily reached. from the town of Gardiner by the electric car-line to Lewiston, shown in the middle 1 Manuscript received by the Secretary of the Society December 12, 1917. 2W.S. Bayley: Bull. Geol. Soc. Am., vol. 3, 1892, p..232. XXXV—BULL. Grou. Soc. Am., Vou. 29, 1917 (468 ) 464 Rk. A. DALY—LITCHFIELDITE AND SODA-SYENITES OF MAINE of the map. Spears Corner is 6 miles (nearly 10 kilometers) from Gardiner. Bouupers oF LITCHFIELDITE Little need be added to Bayley’s account of the nephelite syenite com- posing the boulders. These may be readily recognized because of their Y \ Ss SN AX) eS et rae! OD Ficur® 1.—Location of Litchfieldite in Litchfield, Maine ; Exact position indicated by the dots marked A and B. Soda-syenites at C and D (fine Areas showing outcrops indicated by shading, the lines drawn parallel to the strikes of the schists. S. L.—South Litchfield. Contour interval, 100 feet. Scale, 1:—. pitted surfaces, the pits being due to the specially rapid solution of the nephelite in rain-water. The rock is usually coarse and even pegmatitic, BOULDERS OF LITCHFIELDITE 465 so that the pits, like the associated feldspars, range from 1 centimeter to 8 centimeters in length. The content of nephelite is variable, from less than 1 per cent to more than 20 per cent of a boulder. Much less abun- dant are cancrinite and sodalite. The former seldom forms as much as 1 or 2 per cent of the rock and appears to fail entirely in most of the boulders when studied with the hand lens. The sodalite is still rarer, constituting isolated grains, narrow veinlets, and schliers. Most of the rock is composed of microcline, microperthite, microcline-microperthite, orthoclase, soda-orthoclase, and a lustrous lepidomelane with strong ple- ochroism in green tintes. Zircon and magnetite are rather rare acces- sories. Bayley gives the following analysis of the boulder rock: Per cent Calculated Composition (Bayley) So 21, WAG ea eee 60.39 Pee e AlsOg 222s eee senescence eees 22.51 Albite molecule... .:...+.2+. 46.92 BesOs 2-0 eee eee eee eee eee 42 Orthoclase molecule........... 27.01 FeO os cece eee eee eee eee e ee 2.26 NETIC TUCO Sse a, Steieeersvais,le\e%e, ocie.be. 8 17.04 MnO... eee eres eee eee CB OREO as eet e.: i aaa 6.89 MZO .-- esse eee eee eee eee eee 18 CANCEINITE TY. -. neste Leer ee es 1.99 COVES. AEDES le ea Rae ara Hoe Perea Mer ar, Pena 5, Ste ce gichetelas o d.8 06 8.44 99 .85 RON wfoh cc ulics as, UPd alates! s eae 4.77 BE ay cals aoe d a 2 Sahel Srels, os 57 a kn oa eee ees tr 99.95 Details as to the chemical analyses and physical properties of the con- stituent minerals may be found in Bayley’s paper. LITCHFIELDITE IN PLACE The glacial strize of the region trend south 15° east to south 26° east, with an average trend of south 18° east. Neither in the many stone fences nor in undisturbed morainal deposits were boulders of nephelite syenite found to the northwestward of the broken line X-Y of. figure 1. Search for parent ledges was therefore concentrated on the areas showing outcrops south of that line. Two separate bodies of the nephelite syenite im situ were discovered at the points marked with heavy dots, A and B. Since abundant boulders of the same material occur also to the northward and westward of A and B, it is certain that the litchfieldite is in place between the line joining those points and the line X-Y ; but, as shown on the map, that part is quite lacking in outcrops. 466 Rk. A. DALY—LITCHFIELDITE AND SODA-SYENITES OF MAINE Locality A is on the road, 310 meters north of Spears Corner. One considerable outcrop is in the middle of the road itself and another larger one is in a field a few meters to the west. Both are probably parts of one body, with total exposed length of 20 meters and exposed maximum width of about 10 meters. The litchfieldite is clearly intrusive into the adjacent schists, sending many tongues into them and inclosing shredded xenoliths (figure 2). On the north, east, and south outcrops are abundant enough to prove that the intrusive mass does not extend more than a few tens of meters in any of those directions. Its extension to the westward could FiGurRE 2.—Schists (shaded area) cut by Litchfieldite (blank area) at Locality A, Figure 1 Length of map represents 2 meters not be determined. The maximum width of the body from north to south is less than 75 meters and is probably less than 25 meters. The outcrop at locality B measures 30 meters from east to west and 18 meters from north to south. Here no actual contact with the invaded schists was seen, but mapping of the neighboring outcrops showed that this mass of litchfieldite is less than 50 meters wide and probably less than 125 meters long. The longer axis seems to be parallel to the bed- ding and schistosity of the inclosing formation, which strikes north 45° east, with steadily vertical dip. ea Both bodies are probably short, thick pods, injected along the planes of the schists, though locally cross-cutting those planes. The concordance of the intrusives with the older structures seems to be like that manifested by the many quartz-pegmatite lenses of the region. LITCHFIELDITE IN PLACE 467 Petrographically, the litchfieldite of the two injections can not be dis- tinguished from the normal rock of the boulders described by Bayley. In both cases cancrinite and sodalite are present as quite subordinate acces- ~ gories. The museum specimens exceptionally charged with either of these minerals have been derived from local schhers in the boulder rock and do not represent typical litchfieldite. Apatite occurs in the ledge litchfield- ite, though not reported by Bayley as in the boulders; on the other hand, zircon has not been identified in the ledge rock. Otherwise Bayley’s de- scription applies essentially also to the rock in place. The ledge rocks are strained and granulated to about the same degree as that illustrated in the boulders. SODA-SYENITES At locality D is a large exposure of a nephelite-free, alkaline syenite which is doubtless intrusive into the schists surrounding it. The outcrop measures 30 meters from east to west and approaches 10 meters in width. At locality C a much larger body of a closely similar syenite sends tongues into and incloses blocks of the schists. This intrusive body is at least” 300 meters long and 75 meters wide. Its longer axis is parallel to the bedding of the sedimentary schists, here vertical and striking north 60° to 80° east. At one visible contact the eruptive is concordant with the schists, and there can be little doubt that it is a thick lens injected along the plane of schistosity. About 100 meters northwest of locality B is a third lens of the nephelite-free syenite, about 20 meters in maximum thickness. Judging from the distribution of glacial erratics composed of the soda-syenite, several other small intrusions not cropping out must be assumed in the area of figure 1. . These syenites are medium grained to coarse, often pegmatitic, and generally charged with large bent foils of biotite, identical in habit with the mica of litchfieldite. The feldspars are also the same, with a specially noteworthy development of untwinned, metamorphic albite in the crush- - mosaics like those seen in the litchfieldite. The large body at C is made up partly of this biotitic syenite, partly ~ of an amphibole-bearing mica-free phase which appears to graduate into the former through mica syenite with accessory amphibole; the feldspars and subordinate accessories remain the same throughout. The amphi- - bole, a new variety, is powerfully pleochroic, with tints of deep grayish blue and greenish yellow. The axial plane is perpendicular to the plane of symmetry. The extinction in the prismatic zone is everywhere sensibly zero. ‘The amphibole obviously belongs to the alkaline series, and in its 468 Rk. A. DALY—LITCHFIELDITE AND SODA-SYENITES OF MAINE properties approximates osannite. In one thin section are grains of a pleochroic, green pyroxene, probably egirite. A little calcite appears to — be primary. ? RELATION OF LITCHFIELDITE TO THE NEPHELITE-FREE SYENITES AND TO QUARTZ PEGMATITES About 35 meters northeast of the litchfieldite outcrop at B, at the road, is an exposure of a coarse, pegmatitic syenite which is essentially the equivalent of the mica syenite except for the appearance of secondary muscovite due to crush metamorphism. Probably the two rocks form parts of a single intrusion. A close genetic connection between the two types is more evident in a large boulder occurring about 200 meters west of A. It is chiefly composed of coarse mica syenite bearing only a trace of nephelite, and in the hand specimen practically indistinguishable from the nephelite-free mica syenite in place at C and D. Within the domi- nant syenite of the boulder are narrow schliers of coarse, nephelite-rich _ litchfieldite. This combination suggests that the litchfieldite is, in part at least, a desilicated, pneumatolytic phase derived from a magma which normally crystallized as a feldspar rock free from nephelite. Some of the nephelite-free syenite bears accessory quartz, and in one specimen quartz is pretty clearly of direct magmatic origin and must be rated as an essential constituent. Hence there is some ground for the hypothesis that all these syenites are, in origin, related to the much more abundant, common quartz-microcline pegmatites, which, as sills, lenses, and dikes, cut the crystalline schists of the district. The quartz-bearing pegmatites are strained ‘or crushed about as conspicuously as the quartz- free injections. Country Rocks Throughout the area of figure 1 the intruded rocks form a compara- tively uniform assemblage of rusty-weathering schists and micaceous quartzites, cut by numerous sills of orthogneiss. The schists are gener- ally basic and rich in biotite. Abundant green hornblende, plagioclase, and orthoclase, as well as biotite, were found in one, apparently common, fine-grained phase of the crystalline complex. All transitions between biotite schist and typical quartzite seem to be represented, and one can hardly doubt the sedimentary origin of all these schists. No other sedi- mentary types were found in place, but several angular boulders, evi- dently not far from their parent ledges, were seen to contain thin beds of COUNTRY ROCKS 469 limestone inclosed in the usual, well bedded mica schists. The ortho- ‘gneiss seems to have been uniformly a common biotite granite. Wherever observed, bedding and schistosity are parallel in the meta- morphosed sediments. The dip is very seldom as low as 60° and is gen- erally vertical. As indicated in figure 1, the strikes vary from north 30° east to north 80° east, with an average near north 45° east—the Appa- lachian trend. Because of the strong contrasts of the micaceous, quartz- itic, and orthogneiss bands in their degrees of yielding to weathering agents, the usual outcrop of these steeply dipping beds is strikingly fur- ' rowed. The age of the sediments is quite unknown, and no definite hint has yet been forthcoming as to the date or dates of the various intrusions. There is no reason for assigning any of the rocks to a date later than the _ Precambrian. SUMMARY OF FIELD RELATIONS Outcrops in Litchfield are relatively rare. Hence thorough search by several observers has not yet afforded the data for a complete account of the litchfieldite. Judging from the visible masses and from the number and distribution of boulders, it is tolerably certain that there is no large mass of litchfieldite in the region. The celebrated boulders seem to have been derived from short, sill-like pods injected into the prevailing crys- talline schists. ‘The invisible lenses are probably little larger than the two so far discovered and have lengths measuring tens of meters or, at most, hundreds of meters, and maximum widths of a few meters or tens of meters. , The largest single injection observed, at C (figure 1), is a highly alka- line, but nephelite-free, syenite. This, like other syenite masses and like the much more abundant quartz pegmatites, seems to have been injected concordantly with the layering of the schists, though with local cross- cutting. The igneous rocks may have been intruded before the upturning of the sediments. No information is yet at hand as to the precise condi- tions for the metamorphism of the various formations. Before the sye- nites and litchfieldite were injected the sediments seem to have been com- pletely recrystallized, possibly through static metamorphism. The rela- tive importance of dynamic metamorphism is most uncertain. The coarse grain and general mineralogy of these igneous rocks strongly suggest that magmatic gases were largely concerned in their emplacement and in the concentration of the alkalies. Cancrinite in the litchfieldite and calcite, probably primary, in the soda-syenite tend to show that car- 470 R.A. DALY—LITCHFIELDITE AND SODA-SYENITES OF MAINE bon dioxide was one ofthe gases involved. Chlorine participated in the formation of the sodalitic schliers; water in the formation of lepidome- — lane and other minerals. The influence of gases is further illustrated in the thorough impregnation of the schists by the litchfieldite magma for distances of 5 to 15 centimeters from the contact of schist and intrusive. The origin of the magmas is a problem which can not be intelligently discussed without additional information concerning the petrography of the schist terrane and without a solution of the present mystery as to the nature of the terranes beneath the visible sediments. Further observa- — tions on the igneous history of the whole region are also necessary. Any future attack on the problem must include the consideration of three possibilities: (1) The magmas may be purely juvenile. (2) They may be purely resurgent, due to “selective solution” (Lane) among certain components of the visible schists.or underlying formations. (3) The magmas may include both juvenile materials and resurgent materials— that is, country rock dissolved by juvenile magma. The cause of the local deficiency of silica, signalized by the crystallization of nephelite, cancri- nite, and sodalite, is a related question. The small size of each of the undersaturated bodies is not a feature favorable to the prevailing dogma that nephelite syenite is a differentiate of a primitive magma specially rich in alkalies. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 471-488 SEPTEMBER 80,-1918 SEPARATION OF SALT FROM SALINE WATER AND MUD? BY E. M. KINDLE (Read before the Socrety December 28, 1917) CONTENTS Page MRMMPMINATIETOO DUCT ae alee) chs) o G0k doses as bo 0-0 5, 8 sip, eveudbatd ohdia ere Mayors voustonctay alain’ a lotopatara’ aa. y 471 MrcetepVari Ol, GAMME WATCE. .... chaise s'eus petbonate v .ehiareid Witla teed Bis woe tetos areca y 471 See Pra aiTOM OY IMCCAING «i .c°s s 6 ace da. 51e trepediel & aos we en yaa Te) Miealaca’e @ vie we a\s 475 eee Bre aT Sel CLVSCAUS a. 5 0, 6.a ales ae'se ai"e waa ee vane Erte eremeleuenteraie lee mitsherlens piece 476 SMMC OR (Sa NTS. MNWGS 2 eo.) ev sieves dcaiels ate Ooncene Vigh es Sawin oldete a Nise amet 479 INTRODUCTION The following notes relate to laboratory observations by the writer on the behavior of salt in the evaporation of saline mixtures and to a discus- sion of their geological significance. The important bearing on geolog- ical theory of the phenomena resulting from the separation of salt from water and desiccated saline mud under experimental conditions is evident to the stratigrapher who has to interpret the meaning of salt crystal casts, mud-cracks, salt domes, and other features associated with the occurrence of salt in nature. The memoranda which follow relate to various experi- ments designed chiefly to permit observation of the features incident to the evaporation of salt water and to a discussion of.geological phenomena on which they throw light. EVAPORATION OF SALINE WATER Saline water possesses the peculiar property of being able to circumvent the action of gravity and to ascend the vertical sides of any vessel in which it may be placed. This curious characteristic of salt water evidently rep- resents a phase of the phenomena of capillarity. It is not immediately active or apparent on filling a vessel with salt water. If, however, an ordinary drinking glass is filled three-quarters full of brine, it will be 1 Manuscript received by the Secretary of the Society January 238, 1918. Published with the permission of the Director of the Geological Survey of Canada. XXXVI—BULL. Grou. Soc. AM., Vou. 29, 1917 (471) 472 E. M. KINDLE—SEPARATION OF SALT FROM SALINE WATER noted in a few days that a thin film of salt has formed a narrow linear band around the inside of the glass and extended above the original sur- face of the water. This film widens through evaporation of the water around the sides of the glass, depositing a layer of salt on the glass just above the upper margin of this film. The film of salt continues to ad- vance slowly upward by capillary attraction and subsequent evaporation of saline water until the top of the glass is reached. It then in the same manner grows downward and eventually covers entirely the outside of the vessel. If the supply of saline water is renewed from time to time, the FIGURE 1.—Salt Effiorescence The efflorescence has completely covered five vessels through the creep of the salt water over the sides of the innermost vessel water will be found to flow out of the glass quite rapidly after the salt incrustation is well developed and down over the outside in a continuous trickling sheet. The glass if set inside a series of larger vessels will in this way cascade its saline contents into each one in turn through the medium of the salt film. Constant thickening of the salt layer on each of the vessels is a concomitant feature of this barrier-climbing process. The salt incrustations on the five vessels shown in figure 1 were produced by placing salt water only in the inner vessel, from which it slowly cas- caded into the others. EVAPORATION OF SALINE WATER AI3 Another illustration of the ability of salt in solution to escape from any open containing vessel in which it may be placed is furnished by a second experiment which was designed originally to elucidate another subject. A tube was used in which clay and sandy sae were depos- ited from a saline solution. A bit of pine stick was left standing in the top of the tube until the water had completely evaporated. It was then observed that the salt had also entirely left the tube, so far as the eye could detect, and formed an in- crustation about the upper part of the stick. Although the surface of the salt water containing suspended clay was never higher than one inch below the top of the tube, the salt as the water evaporated formed an incrustation which extended nearly an inch above the original surface of the water. In another experiment an open fruit jar was partly filled with saline water which was allowed to evaporate slowly. The supply was renewed from time to time till the upward creeping salt had entirely closed the mouth of the jar and formed a considerable mass above it, as seen in figure 2. The dome which completely closed the top of this jar was found to have a maximum thickness of about 114 inches, but showed no crystals. The bottom oh ae oy ae covered; cara ack th The glass jar was kept partially filled with of about one-half inch with salt a saline solution until the ascending salt had crystals from one-sixteenth to one- Pa ae aie the mouth and coated the eighth inch thick. , i These examples illustrate a process which must be continually in prog- ress on the seacoast, particularly in dry climates, through which on rocky shores large quantities of salt are separated from the sea-water and be- come subject to the action of the wind. Such incrustations would be FicurE 2.—Salt Hfflorescence 474 E.M. KINDLE—SEPARATION OF SALT FROM SALINE WATER easily removed by wind-driven sands and carried inland to indefinite dis- tances. ee | In recent years the view that many salt lakes have derived most of their salt from the sea through the agency of the wind has gained ground over the older opinion that the salt of such lakes had been gathered from their drainage basins as a result of land-locked drainage. The trend of the former view is illustrated in Ackrad’s? conclusion that the salt of the Dead Sea has been carried by the wind from the Mediterranean Sea. R. Angus Smith has shown that the amount of salt in rain-water varies with the distance from the sea.* In the salt desert region of India even the dew which collects on the Faras trees is said to be distinctly saline.* Prof. J. B. Woodworth has called my attention to a map of the State of Massachusetts? which shows by “isochlorine lines” the normal chlorine of ground waters from the seaboard inland, varying from 2.16 in 100,000 parts on Nantucket to .07 at the New York line. The photographs here shown (figures 1 and 2) support the newer views _ regarding the origin of salt lakes to the extent of showing the marvelous facility. with which salt separates itself from saline solutions and forms deposits which are most accessible to wind action. It may be pointed out here that the activity of the migratory tendency which characterizes the behavior of salt in aqueous solutions is not con- fined to subaerial conditions. The peculiar features in the behavior of saline water which have been described are worthy of careful considera- tion by the geologist, for because of them the opening of a fault-line or joints to a bed of salt at any depth would afford a means of its escape or migration upward. The same tendency which enables all of the salt in a glass tube to remove itself from that tube by ascending the sides of a pine stick, as already described, or to form a cap at the top of a glass jar would cause it to migrate laterally or vertically through the rocks which possess the proper porosity to admit of the movement of water which would aid in such a transfer. We should therefore expect salt deposits to remain in the beds where originally laid down only when these beds are sealed by impervious clays or other beds, as in the Salina formation. It is quite possible for the migratory propensity of salt in many instances to cause its transposition to a part of the geological section remote from the hori- zon of its original deposition. The great salt domes of the Louisiana ~ 2 Chemical News, January 8, 1904, p. 13. 3 Air and rain, p. 263. *T. H. Holland and W. A. K. Christie: The origin of the salt deposits of Rajputana. Rec. Geol. Surv. of India, vol. 38, 1909, p. 166. 5 Twenty-second Ann. Rept. of the State Board of Health of Massachusetts. - Public © Document No. 34, Boston, 1891. EVAPORATION OF SALINE WATER AT5 salt district appear to afford examples of such migration of salt upward in great quantities. Isolated domelike masses of salt more than 2,000 feet thick occur there in beds of Quaternary age® which have evidently been derived from older beds through the agency of salt-bearing waters rising along fault-planes and depositing their salt at the intersection of the faults.’ The salt hill south of Algiers, in Africa, which has been de- scribed by Ville,* appears to be another example of a great secondary salt deposit. The shallow salt lakes of northern Patagonia, with floors of salt 2 or 3 feet in thickness, described by Charles Darwin,°® illustrate the conditions under which some of the continental deposits of salt are now accumu- lating. SALT SEPARATION BY FREEZING It is a familiar fact that the freezing of saline water is accompanied by a partial mechanical separation of the salt. In the case of sea-water, Mawson,*° in recording his observations in the Antarctic on this subject, states that “the sea-salt mechanically separates from the ice as the latter forms and is partially forced out into the sea-water below and partly in- cluded in white, vertical tracts between the ice prisms. . . . During the formation of surface ice some of the sea-salts are squeezed upward through capillary cracks to the surface and then, in the form of concen- trated brine, eventually freeze as cryo-hydrates and form nuclei from additions from atmospheric water vapor.” ‘These are the ice-flowers of Captain Scott.** Regarding the salt lakes of the Antarctic, Mawson re- ports that “as refrigeration goes on in the lakes, the saline contents are gradually concentrated in the residual liquid and a continuously increas- ing cold is required to freeze each succeeding separation. Ultimately a meshwork of ice and cryo-hydrate crystals are formed at the bottom of the lakes. As some of the lakes are very saline, this cryo-hydrate often bulks large. Some of it freezes at as low as a temperature of 50 degrees Fahrenheit below freezing point.” A salt deposit in the Salt River valley of the Northwest Territory, Canada, which was recently examined by the writer, shows that small deposits of salt may, chiefly through the freezing of salt spring water, 6G. D. Harris: Bull. Geol. Surv. of Louisiana, No. 7, 1908, pp. 15, 24. 7Ibid., pp. 79-81. 8 Ann. des Mines, 5th ser., vol. 15, 1859, p. 365. ® Jour. Researches during the voyage of the Beagle, 1860, p. 75. 10 Douglas Mawson: Notes on physics, chemistry, and mineralogy. The heart of the Antarctic, by E. H. Shackleton, vol. iii, 1909, pp. 354-859. ; 11 Capt. R. F. Scott: The voyage of the Discovery, vol. i, pl. opp. p. 268. 476 E. M. KINDLE—SEPARATION OF SALT FROM SALINE WATER accumulate under subaerial conditions more rapidly than it can be re- moved by denudation in a climate which is far from arid. The Salt River is a small tributary of Slave River, which it joins from the west about 170 miles south of Great Slave Lake. A flat plain 4 or 5 miles wide, through which Salt River flows, is characterized by highly saline springs which flow from limestones of Devonian or Silurian age. The region is characterized by a heavy snowfall and a rather large summer rainfall, but the precipitation fails to prevent the accumulation of con- siderable masses of salt near some of these springs. In front of one spring visited by the writer there was a mass of salt about 40 feet by 15 feet, with an average thickness of about 10 inches. More than 100 sacks of salt are annually taken from this deposit by the people of the district. But the supply is promptly renewed. A considerable portion of this salt bed rises a few inches above the flat sun-cracked saline mud which imme- diately surrounds it. Most of this salt doubtless accumulates through its mechanical separation by freezing of the saline spring waters during the winter, when temperatures often as low as 60 degrees Fahrenheit pre- vail. It is doubtless also receiving continuous accretions from the saline mud under the deposit in summer; from the spring water flowing under it and from the damp salty mud near by it probably adds constantly to its volume in the same way that the mass of salt which seals the fruit jar in figure 2 was accumulated. At La Saline, on the Athabasca River, McConnell’? has reported a small deposit of salt formed by a saline spring, which also deposits gyp- sum and native sulphur. The occurrence of subaerial deposits of salt like the Salt River deposits in the Northwest Territory and the separation of salt from salt lakes at winter temperatures in high latitudes place in the category of conditions favoring the natural formation of salt deposits, alongside of high tem- perature and aridity, very low temperatures acting under average condi- tions of precipitation. FORMATION OF SALT CRYSTALS At temperatures of about 85 to 110 degrees Fahrenheit, evaporation of a saturated solution of salt results in the formation on the surface of the brine of cubical or prismatic forms in which the upper surface is depressed into an inverted pyramid. This hopper-shaped depression always de- velops on the uppermost side of the figure and causes it to float during the early stages of crystal growth or until it is overturned, when it imme- 12 Canada Geol. Surv., vol. v, pt. i, 1893, p. 35D. FORMATION OF SALT CRYSTALS ~ ATT diately sinks. A shght jarring of the water when these crystals are form- ing results in many of the smaller ones showering to the bottom. Crys- tals of this type after sinking to the bottom perfect the cubical shape by growing a thin layer of salt over the base of the inverted pyramid, thus leaving a hollow pyramid inside the cube of salt in which water is often inclosed. Salt crystals formed at temperatures about 110 degrees are apt to be larger than those formed at lower temperatures. ‘They usually de- velop at the surface of the brine from a very small initial cube of salt, which is partially submerged by the growth from its four upper angles of four other small cubes, to each of which still others are added. sae 533 Cutt islands. imi the: eral seas. «2 2s. oso 0. oe als oS ee eee 533 Reefs around deeply eroded: islands.........0<6..ceeess eee: Sees 534 The submerged cliffs of reef-encircled islands..................-+.. 536 Absence of reefs on coasts of emergence... |... 2.200254 cnes oe one 537 Reefless coasts in the Australasian archipelagoes................... 537 The reefless coast of southeastern India.....2..:..-2. 22s0seeeeeee 539 Reefs on coasts of submergence. ... 2. 200565 ase bus wb eee eee 540 Reefs on coasts of recent and continued submergence............... 542 Smothered reefs on coasts of less recent submergence.. ...........05 542 Reefs on coasts of emergence, afterward submerged... ............2. 543 The half-submerged cliffs of New Caledonia.............«.«=se0sseE 545 Unequal depths of lagoons and banks: .-:....5.¢0....+..... «1255 549 The requirements of the Glacial-control theory....................- 549 The expectable form of abraded platforms................s.eeeeRee 550 - The requirements of the subsidence theory.........:.<.':5..:.eeeeeee 552 The smoothness and depth of lagoon floors.....:2.....- cc ccsencccece 553 Variations in the depth of submarine banks...............-.sHeeeee 555 Banks around: reef-free clift islan@sS-.. 2... 0s scescs ons cs on 555 The depth of barrier-reef lagoons .4 2.47 .55....25-060 00+ oe ee ee “558 The yelrme of reels... 2. o. sees on ek wh ee meee ed eee eee oes eee 560 Contrasts of the central and the western Pacific.................e02. 560 Average and individual values of lagoon depths.................... 561 The detailed form of island spur ends as evidence for intermittent subsi- UENCE E Soo cic cc eee Sve win w on ec cee Sie oreie Sele whe a tain ore Steele 5 eee ee 562 ‘Tie Otietm et AtOUSs oo o,f kee Seek ws Wiad oan eed ete st eee eee 564 Indirect evidence from barrier reefS..........-.eeeeee eee sone eee 564 The Wanafuti boring... .. . 06 2 — Ml] FIGURE 4.—Submarine Slope of a Volcanic Island islands, like Tahaa, figure 1, that consist of single volcanic cones, more or less dissected. As the thickness thus determined may in many cases be 1,000 feet or more, it testifies much more’strongly for subsidence than a lagoon depth of 40 or 60 fathoms does. However, if it be assumed that an initial cone of resistant lavas was cloaked with a thousand feet of loosely compacted ash beds, then while the island stood a little higher than now, the ash beds might have been worn down to a lowland rim, leaving the resistant lava slopes with a rela- tively steep inclination; a slight submergence of such an island would provide a shallow submarine platform from which an offshore barrier reef might grow up; and the small depth of such a foundation would not be indicated by prolonging the lava slopes beneath sealevel. But there'is no \ 500 W.™M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS reason to suppose that volcanic islands in their originally completed form usually possessed a weak ash cloak over a resistant lava core; and in the absence of such a cloak, the strong slopes now visible in dissected volcanic islands above sealevel may be reasonably supposed to extend with but small decrease of declivity to a considerable depth below sealevel. It is also possible that a sloping platform might be produced by the offshore deposition of waste from a reef-free island, but in this case the island would be strongly clift by the unrestrained waves; and the cliffs would still be partly visible after moderate submergence., The best way of making a platform in the coral seas is in association with reef up- growth around subsiding islands, or with reef outgrowth around still- standing islands, as Darwin supposed. The reasonableness of the supposition that supermarine slopes may be prolonged below sealevel is increased when the depth of the sea-bottom, C, figure 4, outside of a barrier reef, R, is taken into account; it then ap- pears more clearly than before that the reef foundation is best indicated by prolonging the visible slope, AB, of the island spurs down to the sea- bottom, C, outside of the reef. The total reef is thus seen to form a huge terrace-like mass on the submarine flanks of the volcanic cone; and the thickness of the terrace is thereby shown to be much greater “than the depth of the lagoon; indeed, judging by the slopes that prevail in dis- sected volcanic islands, the thickness of the reef mass may usually be taken at a fifth or a quarter of the lagoon breadth: a barrier reef that stands a mile away from its encircled island may well have a thickness of 1,000 or 1,300 feet. Subsidence is manifestly necessary to produce reef upgrowth of so great a measure. But it is eminently possible that lagoons several miles in breadth, containing eccentrically placed islands, may be underlaid by an uneven surface of hills and valleys, maturely worn down on a group of volcanoes of unequal heights: here the slope of a ides 2 island can not be safely prolonged far from its shoreline. In the case of barrier reefs along continental borders, the large area of land back of the shoreline will usually afford opportunity for better de- termination of changes of level than is provided by comparatively small volcanic islands: thus the Great Barrier reef of Australia is best inter- preted by taking account of the physiographic development of the interior highlands as interpreted by Andrews (1903), from which it appears that the reef foundation probably subsided while the highlands rose, thus indi- cating, as I have lately shown (1917, c), that the coast and the adjoining sea-floor have been flexed, the coast up and the sea-floor down, and that the reef, growing up from the down-flexed area, has a great thickness. I must therefore dissent from the conclusion reached by Vaughan, that INFERRED PLATFORMS AS REEF FOUNDATIONS 5OL “the width of a submerged platform [assumed to underlie a barrier-reef lagoon] bordering a land area is indicative not of the amount of sub- mergence, but.of the stage attained by planation processes” (1914, 60) ; for without fuller evidence that a platform on which planation processes have acted underlies a reef, this assertion is open to misapprehension, as will now be shown. REEFS DO NOT USUALLY REST ON SHALLOW PLATFORMS If it be urged, in opposition to the view expressed above as to the sub- marine extension of supermarine slopes, that marine deposition and abrasion have, with or without the aid of subsidence, fashioned a plat- form-like foundation for barrier reefs at a small depth, certain principles of subaerial and of marine erosion must be recalled in order to test the correctness of this view. First, reef-encircled islands are so well pro- tected from wave attack that their form is almost wholly carved by sub- aerial erosion, the work of the lagoon waves being nearly negligible. Second, volcanic islands that are exposed to wave attack in the open ocean are cut back in cliffs somewhat faster than their small-stream valleys are cut down by streams and much faster than the valleys are widened by weathering; abrasion then takes place near shore, and deposition offshore. Third, the height of wave-cut cliffs on volcanic islands will ordinarily be about a quarter of the breadth of the abraded and aggraded platform from which they rise. To these three theoretical considerations, a fact of observation must be added: the spur ends of reef-encircled islands are, as already noted, rarely cut back in cliffs; when cliffs occur, they are in nearly all cases of small height and they rise from narrow rock-platforms that have been cut by lagoon waves at present sealevel. Hence, if a barrier reef be supposed to have grown up from the outer margin of an abraded and aggraded platform, the spur ends of the island should, as above noted, be cut off in cliffs having a height equal to about a quarter of the lagoon breadth, and the cliffs should still be partly visible after moderate submergence; but such cliffs are almost unknown. If a platform has really been abraded it must have been strongly submerged by subsidence since it was abraded, in order that the spur-end cliffs back of it shall no longer be visible; the measure of the subsidence must be about a quarter of the lagoon breadth at least. It thus appears probable that, even if abrasion produced a platform before reef growth began (as will be later shown to be probable), the thickness of the reef built up on the platform margin must be much greater than the depth of the aggraded lagoon that it incloses; and reef growth must therefore have been accom- panied by a rather strong subsidence of the reef foundation. 502 W.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS Reference may be made here to other statements by Vaughan, as sequels to the one quoted above; they are to the effect that “many, if not all, barrier reefs stand on iataiudl platforms [corrected by the author to read “stand on or margin platforms”] which already existed previous to Recent submergence and the formation of the modern reefs” (1914, a, 59) ; and that “a study of the charts of barrier-reef islands, as Viti Levu, Fijis, and Tahiti, Society Islands, shows that the platforms are inde- pendent of the presence of reefs, and therefore the relations in these islands are similar to those indicated for barriers off continental shores, for here the reefs are also superimposed on platforms antedating their presence” (1914, b, 33). As far as I can penetrate the problem, these inferences are not borne out by the facts. | It is probable enough that pauses in the submergence of a reef, such as could be caused by the coincidence of slow subsidence and the slow lowering of the ocean surface during the oncoming of a Glacial epoch, might have caused a previously narrow barrier reef to widen greatly while its lagoon was nearly or quite filled up with detritus, so that the reef and lagoon together came to form what may be called a mature reef plain. It is also possible enough that during a rapid submergence, such as might be caused by the coincidence of slow subsidence with the slow rising of the ocean surface during the passing of a Glacial epoch, might cause a relatively narrow barrier reef to grow up on or near.the margin of a- previously formed, mature reef plain, and more or less completely encircle it. But the implication of the above quotation is that the platforms there mentioned are not of coral-reef origin; and this is confirmed by the ex- plicit statements regarding many reef-bordered lands, to the effect that “the platforms have an existence independent of coral reefs and were formed by other than coral-reef agencies,” and that “an inspection of the Admiralty charts for the eastern coast of Australia shows conclusively that the platform on which the Great Barrier reef of Australia stands has an existence independent of the Great Barrier reef” (1914, 33, 32). | FACTS AND INFERENCES FROM CHARTS Vaughan’s opinions regarding reefs in the Pacific are, as the above quotations show, based not on local observation, but on a study of hydro- graphic charts, and such charts do not give enough information—apart from the occurrence of embayments—regarding the physiographic devel- opment of reef-bordered coasts to lead to safe conclusions. It has been well said that “the principal value of the coral-reef investigation to geol- ogy consists not so much in what has been found out about corals as in the study of a complex of geological phenomena, among which coral reefs FACTS AND INFERENCES FROM CHARTS 503 are only a conspicuous incident”: and it may be added that the shore outlines and offshore soundings given on hydrographic charts do not suffice for the satisfactory study of such a complex. The flat floor of a barrier-reef lagoon is well shown on charts, but it should not be thereupon assumed to represent a platform produced by other than reef-making agencies, for the floor is aggraded by an unknown thickness of detritus on a foundation of unobservable form. Again, the change from a gentle slope to a steep pitch at a depth of about 40 fathoms is a persistent feature in the exterior profile of many reefs, but it is less satisfactorily explained as the edge of an antecedent platform made independently of reef formation than as a miniature continental shelf made by the action of marine agencies on reef detritus with respect to present sealevel; for, as Daly has pointed out, “the break of slope’ on continental shelves formed by wave and current action is “near the 40-fathom line” (1915, 199). Likewise, the change at about 40 fathoms depth from a nearly flat floor to a steep pitch where a lagoon is not completely inclosed by a reef, or where a reef stands back from an exterior bench margin, finds competent explanation by marine aggrada- tion of an earlier reef or reef-plain with respect to present sealevel, and should not be taken to indicate the existence of a platform at that depth, formed independently of reef-making agencies. I have treated this aspect of the coral-reef problem more fully in an article on “Coral reefs and submarine banks” (1918, a). THE EVIDENCE OF VITI LEVU, TAHITI, AND QUEENSLAND Viti Levu (Fiji), Tahiti,.and Queensland (northeastern Australia), associated in the above quotations from Vaughan’s essays as if their reefs had all been formed under similar conditions, are found to have really had very different histories, when the coasts back of the reefs as well as the charts of the reefs are studied. The present barrier reef of Viti Levu has, I believe, been formed by upgrowth on the more or less aggraded borders of a greatly eroded volcanic mass of complicated history, during a slightly unequal subsidence, of greater measure on the northwest than on the south; there is no sufficient reason for thinking that a flat plat- form, formed independently of coral-reef agencies, serves as its founda- tion, as will be further shown below. The French island of Tahiti is a submaturely dissected volcanic island that has truly had a platform a mile or two wide, backed by cliffs 1,000 or 2,000 feet in height, abraded around its shores; the proof of this statement is, however, not found in the soundings recorded on charts, but in the cliffs observed around the island border, of which the charts give no proper indication and of which XXXVIII—BuLu. Grou. Soc. AM., VOL. 29, 1917 504 Ww.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS Agassiz alone has given an adequate description. ‘The barrier reef of Tahiti surmounts the margin of the abraded platform, now submerged to a depth of a hundred fathoms or more, as I have shown in detail in an article to be published in the Annales de Géographie during 1918; but no other member of the Society Islands is similarly cut back in sea-cliffs, and hence no other reef in that group rests on a submerged abraded plat- form—unless, as will be shown on a later page to be eminently possible, the submergence of the platforms has been so great as completely to drown the cliffs that must have risen to heights of 1,000 feet or more from their inner margin; and platforms so greatly submerged have no close relation to the shallow platforms inferred by Vaughan, which are supposed to lie about 40 fathoms below present sealevel. . According to the best application that I could make of Andrews’ physio- graphic studies of eastern Australia during my journey there in August, 1914, the Great Barrier reef of the Queensland coast has been formed by upgrowth during the long continued but intermittent down-warping of the continental margin; and the conditions for reef growth during the earlier stages of down-warping appear to have been just as good as they are today. The total thickness of this vast reef may well be thousands rather than hundreds of feet. The present reef is more probably con- structed on or near the margin of a preexistent, mature reef plain than any other reef that I have seen, as I have shown elsewhere in some detail (1917, c). Thus the reefs of Viti Levu, Tahiti, and northeastern Aus- tralia have been formed under diverse conditions that do not by any means support Vaughan’s conclusions. All of these reefs owe their oppor- — tunity of upgrowth to the subsidence of their foundations, whatever the previous form of the foundations may have been. DETAILS CONCERNING FIJI REEFS As my acquaintance with the reefs of the Fiji Islands is more extended than with those of most of the other groups that I visited in 1914, it is particularly with respect to the Fiji reefs that I must take exception to Vaughan’s opinion, quoted above, that they are “superimposed on plat- forms antedating their presence”; and especially to his later statement to the effect that “Andrews has essentially confirmed” this opinion (1916, 133). There is nothing in Andrews’ recent article on Fiji to warrant such an assertion ; his brief summary regarding the largest island of the group is that its “present great barrier reef, which rises to the level of the sea, has thus, in all probability, been built up by coral-reef organisms on the submerged lowlands of Viti Levu” (1916, 138) ; but the lowlands that are submerged along the southern border of the island, where An- DETAILS CONCERNING FIJI REEFS 505 drews observed them over 17 years ago, consist of the maturely dissected strata of a slanting marine coastal plain, as will be further explained in a later paragraph; and as such they constitute a moderate submarine slope of rather uneven surface, but not a “platform” in any proper sense of the word. As to the northwestern side of the island, where the barrier reef incloses an exceptionally broad lagoon interspersed with volcanic islands, no one knows what the shape of the reef foundation is; its outer part is imperfectly charted. The only geological observer who has lately visited that district is Foye, who writes: “In general the present coral reefs [of Viti Levu] are developing on platforms which originated dur- ing the deposition of the coastal series” (1917, 306) ; but the word “plat- form” is here used in a very general sense, inasmuch as it applies to the uneven surface of the formerly uplifted, then dissected, and now sub- merged coastal plain on the south, as well as to the extensive lagoon area of the northwest, regarding the foundation of which no details are at hand. All the facts that I noted in Fiji confirm the opinion that the barrier reefs of those islands have grown up from submerged insular slopes, whateyer form the slopes happened to have when they were submerged. They were presumably less inclined beneath the broad lagoon northwest of Viti Levu than beneath the narrow lagoon on the south; the same state- ment may apply to the second largest island of Vanua Levu. The larger the land area concerned, the larger its rivers and the better the oppor- tunity for the formation of sloping offshore deposits, to which the term, “platform,” may perhaps apply: it is probably for this reason that the two largest islands of Fiji lend some color of support to Vaughan’s view. The submerged slopes are pretty surely of moderate inclination around the small Exploring Isles also, for there a worn-down barrier reef of earlier origin, now submerged, appears to furnish the foundation for the present barrier reef; but the earlier reef was formed on a strong volcanic slope (1916, b). Around all the other Fiji Islands that I saw—Mbengha, Kandavu, Ono, Matuku, Totoya, Moala, Ngau, Ovalau, Nairai, Makongai, Wakaya, Rambe, and a few more, all smaller than the two larger ones— _ there is no indication that the submerged volcanic slopes were signifi- cantly less steep than the strongly inclined visible slopes. J must there- fore conclude that submerged platforms “formed by other than coral-reef agencies” are unessential to the formation of barrier reefs in Fiji. NEGLECT OF PHYSIOGRAPHIC EVIDENCE A paragraph may be given to inquiring why considerations so manifest as those presented above regarding the submarine slope and other features 506 W.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS of reef-encircled islands have not ordinarily been given greater weight by students of the coral-reef problem in the Pacific. As far as I can judge, after an extended review of many articles on the subject, the answer to this inquiry is that both the inductive and the deductive sides of the problem have generally been neglected, in so far as they concerned the physiographic features of reef-bordered coasts. The deductive phase of physiographic investigation in particular has been overlooked: how can the prevalent inattention to the embayments of reef-encircled islands be explained otherwise! A simple matter of observational record, such as the depth of a lagoon, is treated with due respect; but the equally perti- nent matter of physiographic inference touching the submarine prolonga- tion of an island slope has usually been mistrusted or disregarded by the | objectors to Darwin’s theory. Of course, an inference of this kind is not so well assured as an observed fact; but when it comes to estimating the thickness of barrier reefs and the conditions and processes of their forma- tion, not only every recorded fact, but every pertinent inference, such as that above presented concerning the relation of supermarine and sub- marine slopes, should be given due weight. UNCONFORMABLE HLEVATED REEFS NEGLECT OF GEOLOGICAL EVIDENCE Since the contact of reef limestones on their foundation of volcanic rocks is a geological rather than a physiographic matter, it may be said that the geological as well as the physiographic aspects of the coral-reef problem have been too generally neglected; for the prevailingly uncon- formable’ nature of reef-limestone contacts is discovered by observation of reef-encircled islands as easily as the prevailing inattention to the nature of such contacts is discovered by inspection of standard works and articles on the coral-reef problem. It would not seem to require a lofty flight of scientific imagination to deduce the unlike consequences as to reef-limestone contacts that are involved in the theories of outgrowing reefs, as shown in sectors A, B, C, figure 5, on still-standing, down-wear- ing volcanic islands, and of upgrowing reefs, as shown in sectors X, Y, Z, on intermittently down-sinking volcanic islands. In the first case, if the reefs are not smothered by outwashed detritus, as will be shown on a Jater page to be probable, all the reef limestones must lie conformably, as is shown in the section of sector B, on a non-eroded submarine slope of constructional origin. In the second case, all the limestones that are deposited, as the island subsides, above the level of the original reef at- tachment must lie, as is shown in the section of sector Y, more or less UNCONFORMABLE ELEVATED REEFS 507 unconformably on a sloping surface of subaerial erosion, perhaps clift at the base; only the exterior talus deposits can lie conformably on a non- eroded volcanic slope, and even these may, in certain cases noted below, lie unconformably on a slope of subaerial erosion. UNCONFORMABLE ELEVATED REEFS IN FIJI Furthermore, it would not seem to require a very penetrating use of scientific observation to determine which one of these contrasted conse- quences is confirmed by the facts. Elevated reefs in particular should offer excellent opportunity for applying so crucial a test, and, as will ap- pear below, their unconformable contacts have truly enough been noted in a fair number of cases; but unhappily this important matter has ordi- FIGuRE 5.—Contrasted Consequences of Murray’s and Darwin’s Theories narily been overlooked, and even when noted the consequences following from it have not usually been correctly inferred. One of the best exam- ples of the kind that has come to my own attention, and of which I have already given a brief account (1915, 250), is found on Vanua Mbalavu, one of the Exploring Isles that are inclosed in a great barrier reef, 23 miles in longest diameter, in the eastern part of the Fiji group. Here the largest volcanic island, 13 miles in length, partly shown in figure 6, has a maturely carved form, and rises to an altitude of 930 feet; it is in part unconformably covered up to heights of 500 or 600 feet, as shown diagrammatically in sector EH, by a deeply dissected and well embayed mass of limestone, which is therefore probably, as Agassiz said, the “‘frag- mentary remains of the land which must have once occupied the area of the lagoon,” now inclosed by the great barrier reef. 508 Ww.M. DAVIS—-SUBSIDENCE OF REEF-ENCIRCLED ISLANDS The surface of unconformable contact has about the same slope as the uncovered spurs; it dips under sealevel to an unknown depth, z, as shown in the section within sector E: hence the volcanic island must have for- merly stood, while suffering erosion before the limestones were formed, x feet higher than now, as in sector A. The limestones are much eroded and their upper surface must once have been y feet higher than now. Hence after the island had been maturely eroded it must have subsided (x + 600 + y) feet while receiving the unconformable limestone cover, which presumably assumed the form of an almost-atoll, sector B—that is, a barrier-reef mass in which only a very small central island 930 — (600 + y) feet high survived. As the present limestone remnants are greatly reduced from their initial form, whatever that form was, it is SANS IY Hit pL} LIZA FIGURE 6.—Evolution of Vanua Mbalavu, Fiji manifestly only as an inference that the initial form is here described as a “barrier-reef mass”; but that inference appears to me a very reasonable one, in view of all the elements of the case. Had the original limestone mass accumulated as a shoal or submarine platform, 30 or 40 fathoms deep, bearing patches of coral here and there but not inclosed by a mar- ginal coral reef, the volcanic island that rose from the shoal would have been clift; but the volcanic island, where the limestone remnant lies unconformably on it, as in sector E, has a moderate slope: hence the limestones were probably accumulated as part of a great barrier-reef and lagoon mass, as above stated. Had the central island of such a shoal been protected by fringing reefs, it would not have been clift, but the altitude of the fringing reefs above the general surface of the shoal would demand a greater subsidence than is here assumed. ELEVATED REEFS OF VANUA MBALAVU, FIJI 509 The present remnant of the limestone mass, where it has not been wholly stripped from its voleanic core, has an embayed shoreline, indicat- ing a recent submergence of z feet; hence, after the formation of the lime- stones, the compound island must have been elevated by (y+ 600 + z) feet, as in sector C, and long exposed to erosion, as in sector D. The ele- vation as well as the preceding subsidence need not have been precisely uniform; both may have included a moderate tilting such as will be shown below to have accompanied a following subrecent subsidence. It was during this subrecent subsidence, after the island had stood z feet higher than today, that the present barrier reef shown in sector E must have grown up. The present lagoon, the floor of which is more or less aggraded, is only 20 fathoms deep on its western side, but slants down to a depth of 80 or 90 fathoms on its eastern side, as Agassiz pointed out; hence the measure, z, of recent submergence is a variable quantity, and the submergence could not have been due only to the postglacial rise of ocean level, but must have involved a slanting subsidence which, where greatest, appears to have been about 600 feet. Moreover, the subsidence must have been relatively local, for 30 miles to the southwest the undissected and there- fore recently elevated atoll of Vatu Vara rises to a height of 1,030 feet. I have employed the evidence of local elevation and subsidence furnished by Vanua Mbalavu to determine the conditions of origin of several small near-by atolls (1916, b), and believe that thus, for the first time, fairly direct proof has been provided for the upgrowth of atolls during subsi- dence. Although good evidence of repeated changes in level and of reef-lime- stone formation during times of subsidence seems to be furnished by Vanua Mbalavu, there is no reason for believing that this interesting island is an exceptionally favorable illustration of Darwin’s theory. My reason for visiting it was not that its history was thought to be more sig- nificant than that of other islands in Fiji, but simply that it was on the route of a small trading steamer: a hurricane happened along as we arrived there, and refuge was taken for two nights and a day in one of the limestone embayments; the volcanic part of the island was seen on the following day of fine weather, after which another limestone embay- ment was entered for a night. In the first embayment the limestones were seen to be horizontally stratified, as shown in section in the middle of sector H, figure 6. The geological history above inferred for the island has been confirmed by Foye’s more detailed observations (191%). Other islands may well have an equally suggestive story to. tell; thus the volcanic island of 510 W.M. DAVIS——-SUBSIDENCE OF REEF-ENCIRCLED ISLANDS Lakemba, somewhat farther south, has been lately interpreted by Foye as having been first maturely eroded, then submerged 320 feet or more and bordeied by an unconformable cover of coral limestone, and finally ele- vated with a tilt to the east (1917, b, 348). And yet, simply because uplifted limestones occur on various members of the Fiji group, these islands have been said to occupy a “region of elevation”; and, no atten- tion being paid to the unconformable contact of the elevated limestones with their volcanic foundations or to the embayed shorelines of the vol- canic and limestone islands, subsidence has been excluded from the con- ditions of reef-making around them. ELEVATED REEFS MAY HAVE BEEN FORMED DURING SUBSIDENCE Elevated reefs have often been treated by observers who took no account of unconformable contacts, as if the reef had been formed during pauses oA a Lam N Figure 7.—Inferred Structure of Reefs formed during Submergence and Emergence in the elevation of their foundation, and as therefore invalidating Dar- win’s theory. Yet it should be manifest, as soon as the unconformity with their foundation is recognized, that submergence must have taken place before emergence, and hence that such reefs are reasonably explained either as formed during pauses in submergence, followed by an emergence too rapid for reef growth, or as formed during pauses in emergence pre- ceded by a submergence too rapid for reef growth. Safe choice between these evident alternatives can be made only by detailed observational studies of reef structures, which, as is always the case in such problems, are much facilitated if the theoretical possibilities are carefully deduced while or before observation is in progress. For example, section K, figure 7, illustrates the expectable relations of a-series of unconformable reefs formed in ascending order during inter- mittent subsidence; section M shows the expectable relations of a series of reefs formed in descending order during intermittent upheaval; sec- UNCONFORMABLE ELEVATED REEFS 511 tion O shows reef 1 formed during a movement of subsidence, which is then continued so rapidly that no other reef is formed until, after a pause, upheaval sets in; reefs 2 and 3 are thus formed above reef 1. Continuous submergence followed by a similar emergence might produce such a struc- ture as section R; continuous emergence followed by similar submergence might result in a structure like section 8. It is easy enough to deduce these and other expectable conditions; it is a difficult matter to apply them in the examination of uplifted reefs, where clear sections are rarely exposed; but the difficulty of examination is certainly lessened if the critical points are thought out beforehand. The numerous elevated fringing reefs of the New Hebrides seemed to offer good opportunity for detecting their structure; a few of them on the island of Efate were therefore examined, in company with EH. C. Andrews of Sydney, on my journey of 1914, with the problem as here stated in mind. The results gained will be set forth in my final report; while not conclusive, they gave much reason for thinking that the reefs are uncon- formable, and that some of them at least were formed during the subsi- dence of their foundation previous to the later movement of elevation. ACCOUNTS OF CINE Ore ne REEF CONTACTS It is ae however, only in Darwin’s writings that the unconformable contact of reef limestones with their foundations is overlooked, both as a manifest fact of occurrence and as an inevitable consequence of the theory of subsidence. Nearly all. other writers on the coral-reef problem have past over this significant structural matter in silence. Among the few who have mentioned it are Richthofen, who many years ago explained an uplifted reef on the south coast of Java, 40 feet above sealevel, as a bar- rier reef that had been built during subsidence on the worn edges of hori- zontal Tertiary strata (1874, 246); Walther, who explicitly recognized the importance of unconformable contacts as proving subsidence, in his study of uplifted coral reefs in the Red Sea (1888) ; Lister, who described the unconformable contact of elevated reef limestones on their founda- tion in the island of Eua, a small southeastern member of the Tonga group (1891); Brouwer, who describes Roti, a small continental island near Timor, in the Hast Indies, as composed of deformed strata, uncon- formably covered with terraced limestones which form the greatest heights (214 meters) ; hence this island is an elevated atoll with visible, non- volcanic, unconformable foundation (1914); and Molengraaff, who has described unconformable elevated reefs in the small island of Letti, in the same region (1915). 512 w.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS PREVAILING INATTENTION TO REEF CONTACTS Various other writers on the islands of the Australasian archipelago have noted the unconformable contacts of elevated reef limestones with the underlying rocks, but few of these writers have emphasized the bear- ing of such contacts on Darwin’s theory of coral reefs, and the majority of writers on elevated reefs have paid no attention to the nature of the reef contacts. The unconformity of sealevel reefs, to be considered below, appears to have been even more generally overlooked. Indeed, uncon- formable reef contacts, ike embayed shorelines, have no generally recog- nized place in the discussion of the coral-reef problem in standard text- books. These two fundamental principles are, with three exceptions noted below regarding embayed shorelines, not mentioned in the discus- sion of coral reefs in Bonney’s Story of our Planet (1893), Credner’s Ele- mente der Geologie (1897), Green’s Physical Geology (1882), Geikie’s Text-book of Geology (1893), Giinther’s Lehrbuch der Geophysik (1885), Hahn’s Inselstudien (1883), Hann, Hochstetter and Pokorny’s Allge- meine Erdkunde (1881), Haug’s Traité de Géologie (1907), Jukes- Brown’s Handbook of Physical Geology (1892), Kayser’s Lehrbuch der alleemeinen Geologie (1893), Lake’s Physical Geography (1915; em- bayments are briefly mentioned), de Lapparent’s Traité de Géologie (1906), Leconte’s Elements of Geology (1895), Lyell’s Principles of Geology (1872), de Martonne’s Traité de Géographie Physique (1909), Neumayr’s Erdgeschichte (1886), Penck’s Morphologie der Erdober- fliche (1894; embayments are briefly considered), Peschel-Leipoldt’s Physische Erdkunde (1879), Pirsson and Schuchert’s Text-book of Geol- ogy (1915; embayments are briefly mentioned), Prestwich’s Geology (1886), Phillip’s Manual of Geology (1885), Richthofen’s Fihrer fiir Forschungsreisende (1886), Scott’s Introduction to Geology (1897), Suess’ Antlitz der Erde (volume ii, 1888), Supan’s Grundziige der physischen Erdkunde (1896), Tarr and Martin’s College Physiography (1914), Toulet’s L’Ocean (1904), Wagner’s Lehrbuch der Geographie (1908), or Walther’s Allgemeine Meereskunde (1893) and Hinleitung in die Geologie (1893). In view of such neglect of essentials, it is not too much to say that the treatment of the coral-reef problem in our text-books is in serious need of critical revision. UNCONFORMABLE FRINGING REEFS MANY FRINGING REEFS TESTIFY TO SUBSIDENCE The evidence of unconformity, frequently detected in studies of ele- vated reefs, may be found about as easily in the case of sealevel fringing UNCONFORMABLE FRINGING REEFS 513 reefs, whether they front the open ocean, as will be shown to be usually the case in the Philippine Islands, or lie along the shore of a lagoon inclosed by a barrier reef, as commonly happens in the Fiji and Society Islands. For the maturely carved spur ends of the embayed shorelines around which fringing reefs, whether standing alone or inside of barrier reefs, are ordinarily formed, as shown in figure 8, have manifestly been much modified by subaerial erosion from the initial slopes of a young volcanic cone: truly not so much modified in quantity as the inter-spur valleys, but as plainly modified in quality. Reef contacts around such spur ends are evidently unconformable and therefore testify to submer- gence. Yicure 8.—Unconformable Contact of a sealevel fringing Reef on the Spurs of a dissected volcanic Island It is not simply that fringing reefs testify unqualifiedly in favor of uncontormable contacts, and therefore in favor of submergence, in prac- tically every case where the inquiry thus suggested has been made; they also testify in many cases to a pre-submergence erosion of so great an amount and therefore of so long a duration, and also to a submergence of so great a measure, that the submergence can be fully explained only by the aid of subsidence and not alone by the rise of ocean level at the end of the Glacial period. Unconformable contacts involving moderate measures of erosion and of submergence might be developed on still- standing islands as a result of the moderate lowering of the ocean during the several moderate time intervals of the Glacial epochs; but the great 514 W. M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS unconformities of certain slightly elevated fringing reefs on the pro- foundly eroded older (western) volcanic mass in the Oahu doublet, of the fringing reefs in the lagoon of the barrier reef that surrounds the skeleton island of Borabora in the Society group, and of the fringing reefs along the greatly degraded lowlands along the southwestern side of New Caledonia and along the Queensland coast inside of the Great Barrier reef of Australia—these and many other similar unconformities stand incontestably for Darwin’s theory. DARWIN ON FRINGING REEFS The testimony of fringing reefs thus appears to be in most cases the very opposite of that usually credited to them. It has been noted above Ficgurr 9.—Submerged barrier Reef and a fringing Reef of a new Generation that Darwin regarded most fringing reefs as formed on rising coasts; it is not generally understood that he also perceived that they might be formed on subsiding coasts, where the subsidence has been so rapid and so great as to drown any preexistent reefs. The statement of the young naturalist on this point is brief but explicit: “If during the prolonged subsidence of a shore, coral reefs grew for the first time on it, or if an old barrier reef were destroyed and submerged, and new reefs became attached to the land, these would necessarily at first belong to the fring- ing class’ (1842, 124). It is to be regretted that this passage has not been more frequently quoted. The point of it has been independently stated by Chantérac (1875, 635), but by no other author I have read. FRINGING REEFS OF THE PHILIPPINES 515 Fringing reefs thus formed may be described as of a new generation. The dimensions of the embayments of the shore that they border may indicate a greater submergence than would be inferred from the small advance of the reefs from the shore; and this I found to be the case on certain members of the New Hebrides group. The external talus of such reefs as well as the reef proper may rest unconformably on a slope of subaerial erosion, now submerged: they may be frequently associated with drowned fringing or barrier reefs of earlier origin, as indicated in figure 9. Unfortunately reefs of this kind received no further attention from Darwin than the above statement, apparently because the records available to him showed the frequent occurrence of elevated reefs or of marine fossils on the slopes above fringing reefs and thus led him to associate such reefs with areas of elevation; but also because he did not perceive that when fringing reefs lie unconformably on a surface of sub- aerial erosion, as reefs of a new generation must, submergence should have preceded or accompanied their formation, even if the submergence | had been preceded by elevation. Unfortunately, also, many other students of coral reefs have overlooked the occurrence and the significance of the structural relations between sealevel fringing reefs and their foundation, as here indicated. FRINGING REEFS OF THE PHILIPPINE ISLANDS Unconformable fringing reefs of a new generation appear to character- ize the shores of the Philippine Islands to a remarkable degree, while barrier reefs and atolls are rare thereabouts, as may be learned from the admirable charts recently issued by our Coast and Geodetic Survey; and yet no one has, so far as I have read, perceived that the facts thus pre- sented afford strong testimony for Darwin’s theory of subsidence. The manifestly unconformable contacts of the fringing reefs on the maturely dissected and more or less embayed shores of many members of the much disturbed Philippine group, largely formed of non-voleanic rocks, demand long continued erosion while the islands stood. higher—in several cases much higher—than now, and a correspondingly great, though by no means uniform or universal, subsidence to bring them down to their present _ position ; and this at so rapid a rate that preexistent reefs, if they existed, were drowned, and at so recent a time that the fringing reefs on the headlands and the deltas in the bay heads have not as a rule attained great development. The west coast of Palawan, the southwesternmost member of the Philippines, gives many striking illustrations of these features, none more impressive than at Malampaya Sound, here shown in figure 10, reduced from a part of Coast Survey chart 4316. Joubin’s 516 w.M. DAVIS—-SUBSIDENCE OF REEF-ENCIRCLED ISLANDS i | t i 5 H 4 i : mire aA canoe Aaditinie enineica tee se gma Cottera) 16 4 Ficure 10.—Malampaya Sound, Palawan, Philippine Islands From Coast Survey chart 4316 FRINGING REEFS OF THE PHILIPPINES 517 chart of coral reefs (1912) gives the fringes of the Philippines a much greater breadth than they usually possess. The existence of earlier formed reefs at lower levels, now 2g ae is highly probable on many of the Philippine Islands; for the absence of strong cliffs on the headlands of their embayed shores indicates the pres- ence of protecting reefs while the coasts were suffering erosion before their recent subsidence; thus all the more does the absence of an exten- sive system of offshore barrier reefs, which should have grown up from the preexistent reefs during a slow subsidence, indicate that subsidence was more rapid than reef upgrowth. “Moreover, the submarine platforms that border some of the islands are best explained as submerged and more or less aggraded reef plains, on the outer margin of which new barrier reefs have failed to reach the present surface because of rapid and recent subsidence ; indeed, some of the platforms have no sign of upgrow- ing marginal reefs, and these must have been submerged with unusual rapidity at a very recent date. It is quite possible that some of the shore- lines here treated as showing recent submergence may have afterwards emerged by a moderate amount from a previous greater submergence of moderate duration, for charts do not always suffice to distinguish between these two cases; but in either case, the fringing reefs would rest uncon- formably on their foundations. The facts here discovered seem to me to vive strong confirmation to Darwin’s views; not only so, they show that, after the many other move- ments the Philippines have suffered, the recent subsidence of many of _the islands has been more rapid than reef upgrowth, and hence more rapid than the subsidence of most of the islands in the central Pacific around which barrier reefs or above which atolls are commonly found. In this respect I believe the recent history of the Philippines to be representative of that of the other archipelagoes of the western Pacific, where, in spite of the evidence for submergence given by strongly embayed shorelines, barrier reefs are imperfectly developed and atolls are rare. The smaller islands of the archipelagoes, although often possessing embayed shorelines, are not as a rule encircled by well developed barrier reefs, such as those which characteristically surround the islands of the Fiji and the Society groups. No such extensive barriers as those of New Caledonia and the Queensland coast of Australia are known around the larger islands of the archipelagoes today. Nowhere are the larger islands bordered at present with barrier reefs at all comparable to the barrier which, when certain islands stood higher in the recent past, fronted the northwest coast of Palawan for 300 miles, as further stated below; nowhere at present is there an atoll or almost-atoll comparable to the 518 Ww.M. DAVIS-—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS exceptionally long one which, when certain islands stood lower, crowned the long ridge of Cebt where, according to Becker, a mantle of coral reaches “to the very crest of the island. . . . 2,362 feet in elevation” and gives it “an: even line many miles in length” (1901, 69, 75). The occurrence of elevated reefs, probably fringes or barriers, has been recorded on many other islands of the Australasian archipelagoes ; Semper found what he took to be an elevated atoll at an altitude of more than 3,000 feet on Luzon, and Drasche found reef limestones on the same island at altitudes of 3,500 and 4,000 feet (1871, 31-, 42-) ; but these and other earlier authors do not state whether the limestones rest con- formably or unconformably on their foundation. This critical matter is later touched on by Becker and Smith, though without full application of its meaning. Becker states that the Philippines suffered deforma- tion and uplift in late Eocene time, that they sank in late Miocene time, and that general upheaval with oscillations has taken place since. “All the evidence thus far adduced, both paleontological and structural, points to a progressive uplift of the archipelago, beginning in the late Miocene and still proceeding. . . . Evidences that the islands are rising at the present time, or have been rising within a few years, abound from one end of the group to the other. It is also clear that the amplitude of the movement has been very great” (1901, 79, 77). Furthermore, Becker notes, that Cebt in particular is covered for the most part by a mantle of coral, 100 or more feet in thickness, which reaches from the crest of the island to the sea and forms “a vast num- ber of terraces, all of which are sensibly horizontal” (1901, 19, 79), while in Negros there is “a series of hills flanking the main range with excessively steep slopes and crests only a few feet in width. They were composed of rough coral and seemed to represent barrier reefs” (75). The same observer states explicitly that there is a “great unconformity both in Cebt. and in Negros. It lies between the [Miocene] lignitic series and the coral mantle” (69), but he inclines to believe that the elevated reefs of these islands were formed during the elevation of their foundations and not during the preceding subsidence; and perhaps for this reason he gives some credence. to Semper’s objections to Darwin’s theory. . W. D. Smith, whose latest paper on the Philippines makes reference to “coral platforms” (fringing reefs) on which the outwash of alluvium is rapidly forming coastal plains, notes that “in a few places the reefs were found to make an unconformable contact with eroded igneous rocks beneath” (1917, 540), but no inference is drawn from this as to rapid subsidence preceding the formation of the present reefs, presumably because the origin of reefs was not the special subject of study of this CHANGES OF LEVEL IN THE PHILIPPINES 519 observer. It is probably because of the great extent of the Philippines and the complications of their history that neither Becker nor Smith is very explicit regarding the physiographic aspects of the development of the archipelago. For example, Smith states: “There undoubtedly has been a general subsidence at times of the whole archipelago,” and “a corresponding and a very general elevation” (521); but it is not clear from the context what form the islands had when these movements took place, and without an understanding of that physiographic element the progress of events is not clear. The best inferences that I can make lead me to think that oscillations of large value, varying from place to place, have been added to the simple scheme of a Miocene submergence and a later emergence of the whole group; for Pliocene, Pleistocene, and Recent time are long enough for many changes of level, as well as for much erosion and deposition during such changes. The sharp irregularities of the shorelines of many islands can hardly be explained by a simple three-phase scheme of (1) Eocene de- formation and uplift, with the addition of erosion that 1s implied but not physiographically expressed ; (2) Miocene depression, with the deposition of reef limestones as well as of sediments, which should be abundant in a mountainous and rainy archipelago, and which should cover over and soften the submerged surfaces of subaerial erosion, but of which little is said; and (3) post-Miocene elevation, with reef growth during pauses. It therefore seems legitimate to expand this simple scheme by the addi- tion of later and more or less recent oscillations, and in connection with the coral-reef problem to give special emphasis to the recent movements of depression that are attested by the submerged platforms, the minutely irregular shorelines, and the narrow fringing reefs of certain islands. This conclusion is fully borne out by studies of other archipelagoes, where reef limestones occur at altitudes of 1,000 or 2,000 feet and where Pliocene and Pleistocene deposits are frequently deformed; and from all this it must be inferred that upheavals as well as subsidences of various measures have been much stronger and more frequent in the Australasian archipelago than in the central Pacific, east of Fiji and Tonga, where elevated reefs are comparatively low and rare. The archipelagoes thus appear to be the seat of active and diverse movements of subsidence and upheaval, while the central Pacific is characterized by relatively slow sub- sidence. Return will be made to this subject on a later page. FHE PHILIPPINES AND THE GLACIAL-CONTROL THEORY The discontinuous reefs of the Philippines not only support the expla- nation given by Darwin for fringing reefs of a new generation, but also XXXIX—BuLuL. Grou. Soc. AM., Vou. 29, 1917 520 W.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS provide strong testimony against certain essential features of the Glacial- control theory, which is today the only serious competitor of the theory of subsidence. All other modern theories, of which I have elsewhere given a somewhat detailed review (1914), are discredited by their neglect of the submergence that is demanded by embayments and unconformities. The principles involved in the Glacial-control theory were briefly stated in an earlier paragraph, but will now be considered more deliberately. According to the Glacial-control theory, which assumes reef-encircled islands to be stationary as a rule, there might have been narrow pre- glacial fringing reefs on the Philippine Islands where the shores pitch down steeply into deep water; and if the corals on the exterior slopes of such reefs were killed by the cooled waters of the lowered Glacial ocean, the reefs should have been cut away by the waves. Now if the abrasion then operative endured long enough to cut down the large hypothetical, still-standing volcanic island in the center of the China Sea, at present represented by the Macclesfield bank, which measures 95 by 35 nautical miles, as is also assumed by the Glacial-control theory, then a compara- tively broad platform backed by strong cliffs should have been abraded on all the exposed island slopes of the Philippines; and when the ocean rose to its normal level again in postglacial time, a barrier reef should have grown up on the outer margin of the abraded platform, and the tops of the cliffs should still be visible above sealevel. On the other hand and as a matter of fact, barrier reefs and high shore cliffs with submerged bases are hardly known in the Philippines. Sub- marine platforms of various breadths up to 30 miles, and at various depths from 20 to 60 fathoms, are truly enough found bordering some of the islands, but the island shores are nevertheless characterized by unclift promontories, sometimes without reefs, as along the mid-west coast of Palawan, figure 10, but usually margined with unconformable fringing reefs from 500 to 5,000 feet in breadth, and indented by drowned valley embayments more or less filled with deltas. On a number of islands the fringing reefs are so narrow and the bayhead deltas are so small that the submergence which lowered these islands to their present altitude must be of more recent date than that which lowered other islands, where the fringing reefs are already a mile or two wide and the deltas are well developed, and surely of much more recent date than the submergence which permitted the formation of the great fringing reefs, a mile or two broad, on Yap, in the Caroline group of the North Pacific, or on Rodri- guez, a lonesome island in the Indian Ocean; more recent also than the submergence which determined the formation of the broad barrier reefs of Mbengha in Fiji, of Borabora in the Society Islands, and of the Great SUBMERGED PLATFORMS OF THE PHILIPPINES Swale Barrier of Australia. Hence not only does the absence of shore cliffs in the Philppines testify against the abrasion of platforms, on which so much weight is laid in the Glacial-control theory, but the submergences of different members of the Philippine group by different amounts and-at different dates testify to local subsidences and not merely to a universal rise of ocean level. THE SUBMERGED PLATFORMS OF THE PHILIPPINES In view of the absence of shore cliffs, the submarine platforms which are to be expected in association with new fringing reefs, and which are well developed in certain parts, but not in all parts, of the Philippines, and which, furthermore, are sometimes imperfectly rimmed by reefs that do not reach the sea surface, may as above noted be much better explained as submerged and more or less aggraded reef plains than as abraded plat- forms cut on still-standing islands when the ocean was lowered in the Glacial period. The intermittent development and the varying depths of the platforms are strongly confirmatory of this view. For example, the long island of Palawan, which stretches 300 miles southwestward toward Borneo, is surrounded by an extensive submarine platform with a width of some 30 miles along the northwestern coast, where it is imper- fectly rimmed by a discontinuous marginal reef that rises to depths of 10 or 20 fathoms. Opposite the middle of the island the platform sinks to depths of 50 or 60 fathoms, which is greater than can be accounted for by the Glacial-control theory; this part of the island coast is extraordi- narily embayed, fringing reefs are almost wanting, and delta flats are small. If observation on the ground should discover signs of a moderate emergence along this part of the coast of later date than that of the sub- mergence to which the embayments are due, then the submergence must have been for a time even greater than it is now. Farther south, in the ~ neighborhood of Balabac Island, between Palawan and Borneo, the plat- form has a depth of only 25 or 30 fathoms, many isolated reef patches reach the sea surface, and the shore of Balabac has fringing reefs from two to three miles wide. Farther north a large part of the island of Luzon has a comparatively simple shoreline and no submerged platform ; the lowland plains of this island seem to be the physiographic contem- poraries of the submerged platform of Palawan. These unlike features of the Philippines are much better explained by subsidence, varying in date, rate, place, and amount, than by any other process: northern Luzon seems to have stood almost stationary, while Palawan was downwarped. ‘The frequent recurrence of depths of about 40 fathoms on the margin of many submerged platforms is, like the depth 522 W.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS of 40 fathoms at the change, already discussed, from a moderate slope to a steep pitch on the exterior profile of barrier and atoll reefs, much better explained as an aggradational adjustment of the platform margin to the present action of waves and currents than as recording a surface of abra- sion that was cut when the ocean was 30 or 40 fathoms lower than now. The abundant and elaborately charted facts on which these statements concerning the Philippines are based merit detailed treatment, for which space can not be afforded here. It may, however, be the case that those who are convinced of the cor- rectness of the Glacial-control theory would insist that platforms and cliffs were really cut during the Glacial period on all the exposed coasts of the Philippines, and that they are not to be detected today because they have been greatly submerged or emerged since they were abraded; but if so great a measure of postglacial deformation is accepted for the Philippines, it is unreasonable to assume a long period of stability for the Macclesfield, Tizard, and other banks in the China Sea which the Philip- pines inclose from the Pacific; yet the processes of the Glacial-control theory involve a period of stability for the bottom of that sea long enough for the production of extensive banks by the degradation of volcanic islands, almost as large as Hawaii, to low relief chiefly by subaerial ero- sion in preglacial time, for their complete abrasion to submarine banks by the waves of the lowered ocean during the Glacial period, and for the more or less complete upgrowth of barrier reefs on the bank margins in postglacial time. ; So long enduring a stability in a deep-sea basin bordering a continental margin of the Pacific Ocean seems to me not only inherently improbable on general principles, but seriously discredited by the many signs of geologically modern movements in the Philippines and elsewhere in the Australasian archipelagoes, whether such movements have caused the dis- appearance of abraded platforms and cliffs or not. The assumption of prolonged stability of the islands or banks thereabouts is, indeed, without sound support; no warrant for the assumption, based on an inquiry into the geological history of neighboring islands and continental coasts, has - been published, and, as far as I can learn, no such warrant can be found. The explanation of the banks in the China Sea by the processes of the Glacial-control theory—among which two processes, the killing of the reefs and the abrasion of platforms, are already discredited by the absence of spur-end cliffs on the central islands of close-set barrier reefs in other regions—thus becomes improbable in a very high degree. * 7 et FRINGING REEFS ON CLIFF-RIMMED ISLANDS 523 UNCONFORMABLE FRINGING REEFS IN SAMOA According to the recent observations of Mayer, Tutuila, a well embayed member of the Samoan group, has strongly clift spurs, “some of the sea- cliffs being 500 feet high”; and the cliffs are fronted by a “fringing reef which forms a mere veneer over the modern offshore marine platform, and extends a short distance seaward, its precipitous outer edge being from 5 to about 20 fathoms deep” (1917, 523, 522). A recent small emergence is indicated, for “a platform about 8 feet above high tide juts out to seaward from the ‘base of practically every promontory.” The composition of this platform is not stated and its genetic relations are not explained, but it would seem to be a young platform cut at mid- height in partly submerged sea-cliffs. An unpublished chart of Tutuila, which I have lately had opportunity of seeing in the Hydrographic Office, Washington, contains a great number of new soundings, and reveals the existence of a submerged platform, from one to three miles in breadth and from 30 to 50 or more fathoms in depth, the presence of which could not have been proved by the scanty soundings of earlier charts. The outer part of the platform is usually somewhat shallower than at half distance offshore, as if a poorly developed barrier reef inclosed it; the most strik- ing example of such a reef rises to less than 10 fathoms depth outside of Pagopago harbor, the chief embayment of the island; inside of this reef the platform has its maximum depth of 66 fathoms. Such a platform must have been backed with high cliffs, now partly submerged. In view of these facts, it seems probable that the partly submerged cliffs of the spur ends were, like those of Tahiti, cut back by the sea when the island stood some 50 fathoms higher than now, and that the valleys, now embayed, were eroded while the cliffs were cut back, under conditions that prevented reef growth, as outlined on a later page. If this be the case, a rock platform of marine abrasion, from one to three miles in breadth, 50 fathoms or more below present sealevel, and covered by later deposits, must extend seaward from the submerged base line of the great cliffs; the imperfect barrier reef on the platform margin would then be explained _as the first result of a moderate submergence, afterward followed by a rapid submergence, when the incipient reef was drowned and young cliffs were cut at mid-height in the great cliffs. The narrow platform of the young cliffs is now slightly emerged and margined by a fringing reef. The Marquesas Islands resemble Tutuila, for the spur-ends of their embayed shorelines are strongly clift, and the cliffs plunge into water 10 or 20 fathoms in depth near shore, except that young cliffs and plat- forms are cut in the great cliff faces at present sealevel; but these islands a aS ee ee) ee ee ee Se Oe Oe ll 524 Ww.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS are still free from fringing reefs, as if their submergence were more recent than that of Tutuila.. The above opinion about Tutuila is, how- ever, only provisional, until fuller information is gained about the “mod- ern offshore marine platform” beneath the fringing reef. It is therefore to be hoped that Mayer may be successful in his plan to bore through the reef and “study the existence or non-existence of a submerged marine platform” (1917, 526) underneath it. The spur-end cliffs of Tutuila and the Marquesas Islands, as well as those of Tahiti, seem at first thought to give support to the Glacial-control theory of coral reefs; but in reality they contradict it, for if the cliffs of these exceptional islands were cut under the conditions which that theory — postulates, then the central islands of all barrier reefs should be clift, and they are not. The cliffs of volcanic islands are best explained as the result of conditions determined by the islands themselves, as stated below. UNCONFORMABLE FRINGING REEFS IN THE SOLOMON ISLANDS Many other occurrences of unconformable fringing reefs of a new gen- eration might be adduced, but space will be allowed only for a striking example on the small island of Fauro, in the western part of the Solomon group. The island is described by Guppy as “the basal wreck of some huge voleanic cone” (1887, 33); “so great has been the degradation of the surface that we have nothing more than the cores or basal remains of the ancient volcanic cones, which have built up this island” (40): some of the higher knobs consist of massive igneous rocks, and are interpreted as denuded volcanic necks (37). This painstaking observer says: “It is worthy of note that neither in this . . . island . . . nor in the adjacent smaller islands of voleanic formation did I find any raised coral rock. Narrow shore reefs fringe the coast” (38). Although Guppy mentions the “deeply indented sea-border” of Fauro as well as the great denudation that the island has suffered, he did not infer subsidence either . from the embayed shoreline of the island, well shown in figure 11, or from the manifestly unconformable fringing reefs, or from the party reef-rimmed platform that surrounds the island, on which the northward increase of depth strongly suggests a gentle tilting in that direction. On the contrary, he rejected Darwin’s theory, which he had previously held, and regarded all the reefs of the Solomon group, whether at sealevel or above it, as having been formed during “an alternation of long periods of upheaval with lengthened intervals of repose” (127). Not only so: Guppy’s book was favorably reviewed in Nature and in — the Geological Magazine, aud the reviewers completely failed to notice the neglect of matters so manifest and so critically significant as embayed FRINGING REEFS IN SOLOMON ISLANDS 525 8 a North Bay ? « 35 FAURO ISLAND Densely wooded! 34 SE 8 35 ; 2 Ad. mney > 1BGFt Rian eg? _ 4 Be] a oS a“ TI Sursrcrvie ices 80% igh: . ‘ ee EO Mantra 80% Mig Note. Abnormal magnetic variation! ofr the southeast coast of Bi Gyprtan Bridget. : FIGcurRE 11.—Fauro Island and its surrounding Bank, Solomon Islands From Hydrographic Office ‘chart 2900 526 W.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS shorelines and unconformable contacts, the occurrence of both of which - may be clearly inferred from the detailed accounts of the islands and reefs. One of the reviewers congratulated the author on having “demonstrated that the old theory [of subsidence] fails and the new | Murray’s theory of outgrowth] succeeds”; the other commented on “the nervous reluc- tance of many geologists to accept any explanation of the origin of coral reefs unconnected with or adverse to the subsidence theory”; and urged that “no matter how great may be the authority of any one individual if a series of facts, such as those recorded in the work before us, are plainly repugnant to the theory of subsidence, . . . it is the mani- fest duty of geologists especially to examine such facts without prejudice and to be ready to modify their views in accordance with the ever-advane- ing tide of scientific knowledge.” The literature of the coral-reef prob- lem is overcharged with uncritical and inconsequent discussions of this kind; for example, the Duke of Argyle’s “Great Lesson” in the “Nine- teenth Century” for 1887. It was in reply to this article that Huxley wrote an amusing comment in the same review, answering the charge that a “conspiracy of silence” was suppressing Murray’s and Guppy’s views in order to maintain the acceptance of Darwin’s theory. DISTRIBUTION OF SUBMARINE BANKS REPLACEMENT OF ATOLLS BY SUBMARINE BANKS NEAR THE PHILIPPINES The prevalence of unconformable fringing reefs on the embayed shores of the Philippines, in association with the irregular development and varying depths of submarine platforms, gives for Darwin’s theory of intermittent subsidence a confirmation that is as strong as it is unex- pected; and still further confirmation for this theory is found when the rarity of atolls in the region of the Philippines, already briefly alluded to, is further considered. For if the rapid subsidence, which has resulted in the submergence of previously formed fringing and barrier reefs and the establishment of many narrow fringing reefs of a new generation in that archipelago, extended to the adjacent seas from which no high islands emerge, it would there result in the submergence and more or less complete drowning of all preexistent atolls; and this is precisely what seems to have happened, for the number of submarine banks that appear to be drowned atolls in the region west of the Philippines is extraordinary. But atolls of good size, submerged or drowned by rapid subsidence, should be distinguished from small atolls that have been extinguished by de- | crease of diameter during slow subsidence, as seems to have been the case DISTRIBUTION OF SUBMARINE BANKS D2 with a number of minute reefs which I have described in Fiji and which are now brought to the surface again by elevation (1916, b). The Sulu Sea, inclosed by the southern Philippines and Borneo, con- tains near its middle the Sultana bank, 18 miles long, with very little marginal reef; near by are the Kagayanes reefs, which imperfectly inclose a bank of similar length; farther south, where the occurrence of broader fringing reefs indicates a less rapid subsidence, the sea is occupied by smaller, atoll-like surface reefs of irregular development. The China Sea is much more remarkable for the number of its submarine banks, of which the Macclesfield, above mentioned as lying in the center of this sea, is the largest. Westward from the Macclesfield bank, a third or half way to the coast of Tonquin China, a number of smaller banks are partly rimmed with reefs, as if subsidence were of smaller measure or slower in that direction. Farther south is a remarkable group of banks—the Tizard, Rifleman, Prince of Wales, Prince Consort, and Vanguard—with imper- fect reef rims or with no rims, and with varying depths, as will be more fully shown-below. It may here be noted that Niermeyer (1911) and Wichman (1912) have called attention to the relative rarity of atolls in the East Indies and to the small size of those that occur. Both these authors, although differing in other points, agree that the reefs which are found there can not be explained according to Darwin’s theory: but the discussions are so incomplete—the evidence of embayments and unconformities being overlooked—that the conclusion seems untrustworthy. Sluiter’s expla- nation of the scarcity of reefs in the shallow Java Sea, 10 or 20 fathoms in depth, as a consequence of the inability of corals to establish them- selves on the muddy bottom (1889), is better supported. Whether atolls were more numerous in the southern archipelagoes when the non-embayed islands stood lower will be determined by future exploration; Roti, near Timor, must, according to Brouwer (1914), have been an atoll when its highest limestones were formed, and certain other limestone islands, less satisfactorily described, appear to be of the same origin. It seems impossible to make the peculiarly grouped facts of the Philip- pines and the China Sea accord with the sharply defined requirements of the Glacial-control theory, though they accord remarkably well with the more elastic requirements of the theory of subsidence. One theory de- mands that atoll lagoons and submarine banks shall have depths of about _ 40 fathoms or less; that islands shall, as a rule, be bordered by platforms of similar depth, fronted with barrier reefs and backed with partly sub- merged cliffs; that the cliffs shall not be interrupted by embayments of 528 W. M. DAVIS—-SUBSIDENCE OF REEF-ENCIRCLED ISLANDS greater width or greater rock-bottom depth than can have been eroded while the ocean was lowered in the Glacial period; and that the geological history of the islands shall, as a rule, indicate recent stability and shall not discountenance too strongly a long period of stability for neighboring atolls and banks. The other theory does not set any small or uniform limit to the depth of lagoons and banks or to the depth of platforms along island borders; it demands that such platforms shall be, as a rule, backed by an embayed and not clift coast, but the embayments may be of any dimensions, and the geological history of the islands may indicate any degree of stability or disturbance. The chief features of this theory are that when a coast stands still reefs shall grow outward from it; that when subsidence does not take place too rapidly it shall be accompanied by a corresponding reef upgrowth; and finally that when subsidence takes place more rap- idly it shall for a time at least cause the submergence of preexistent reefs. Rapid subsidence should therefore produce drowned atolls or submarine banks in the open sea, while along island coasts it would change surface reefs into submerged platforms fronted with incomplete barriers and . backed with fringing reefs of a new generation on an embayed and little clift shoreline. The submarine banks of the China Sea and the fringing reefs and submerged platforms of the Philippimes give unexpectedly strong corroborating testimony for the second theory. SUBMARINE BANKS IN THE PACIFIC AND INDIAN OCEANS Fifteen or more submarine banks of moderate or small size occur north of the Fiji group, as will be more fully stated below. Several larger banks occur around the Tonga Islands; their variations in depth strongly suggest slanting subsidence. Apart from these examples, few others are known in the vast area of the central Pacific. On the other hand, the central Indian Ocean, much less provided with atolls than the central Pacific, contains a good number of extensive submarine banks, brief ac- count of which will be given in a later section on the unequal depths of banks and lagoons. Submarine banks are therefore not distributed equally through the coral seas; they occur in groups, as if controlled by some local process. When all factors of the problem are considered, the most probable process of the kind is accelerated regional subsidence. Submarine banks may therefore be regarded with good reason as drowned atolls. The group of banks north of the Fiji Islands gives, to my reading, remarkable support to this view. It occupies a region measuring about 200 miles north-south by 800 miles east-west, between the Samoa Islands SUBMARINE BANKS IN THE CENTRAL PACIFIC 529 with their active volcanoes on the east, the Ellice group of atolls on the north, the Santa Cruz, Banks, and New Hebrides Islands with active volcanoes on the west, and the Fiji archipelago on the south. Its mem- bers vary from less than a mile to over 20 miles in diameter, and from 10 to 30 fathoms in central depth. It is difficult, if at all possible, to explain these banks under the uniform conditions of the Glacial-control theory; for if preglacial atolls and barrier reefs were cut down during the Glacial period and have now been built up to the surface again in the Hllice group on the north and in the Fiji group on the south, they should have been similarly built up in the intermediate area; yet there they remain below sealevel. It is, on the other hand, a simple matter to ex- plain this extraordinary group of banks under the variable conditions of Darwin’s theory merely by postulating moderate inequalities in the rate or amount of recent subsidence, the greater or more rapid subsidence being in the region of the submarine banks, and the smaller or slower subsidence being to the north in the Ellice group and to the south in the Fiji group. ‘But it is evidently desirable to find some independent confirmation for the postulate of recent and rapid subsidence in the region of these banks, such as neighboring high islands might furnish, similar to the confirma- tion given by the submerged bank bordering the embayed and fringed shore of Palawan for the recent and rapid subsidence of the banks in the China Sea; for it 1s plain that if high islands occurred in or near the region here under consideration, they should have been surrounded by sealevel barrier reefs when the now submerged banks existed as sealevel atolls, but that their barrier reefs should now be more or less submerged as a result of the rapid subsidence by which the atolls were converted into submarine banks; and inasmuch as submerged barrier reefs are rarely found, the occurrence of one in this particular region would be significant. By good fortune, two high islands occur in association with this group of submarine banks. Uea or Wallis island is in the southeastern part of the area; it is shown on Hydrographic Office chart 2019 to be 6 miles long, about 200 feet high, and surrounded by a barrier reef about 2 miles offshore: subsidence here must have been at a moderate rate. More im- portant is Rotuma, near the center of the area; chart 1978 shows it to be 7 miles long, 690 feet high, and closely surrounded by a fringing reef ; but it rises eccentrically from a submarine bank, 3 miles wide on the | north and extending 6 miles to the west; the bank is for the most part 25 or 30 fathoms deep, but it has a rim about 15 fathoms deep; hence it is an excellent counterpart of a submerged -barrier reef, such as the sub- sidence theory suggests should occur here. Whale bank, a rimless shoal, 5380 Ww.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS 3 miles long and 15 or 20 fathoms deep, lies a mile farther on the west. Gardiner is the only student of coral reefs who has described Rotuma in detail. His accounts permit one to suppose that the eccentric position of the volcanic island with respect to the bank is due to the recent unsym- metrical addition of new cones to an older island that was more centrally situated. It may indeed be by reason of the “broad lava streams” which “can be traced to the sea” from several craters, the appearance of which led to the belief that “they have not been long inactive” (1898, a, 438), that “the coast is fairly even with a complete absence of the ‘long points and deep fiord-like bays’ which, according to Dana, would on a volcanic island give indubitable evidence of subsidence” (499). Some of the re- cent ash cones are clift to a height of 700 or 900 feet, this being a natural result of the absence of reefs around their young shoreline; but they now have narrow fringing reefs; one of these, a few yards wide, drops off ab- ruptly into 20 fathoms of water (440). As to the fringing reefs, it may be agreed that they have “been formed entirely at the present level” by outgrowth; but the submarine bank and its 15-fathom rim, together with the plunging cliffs, strongly suggest that rapid submergence has taken place here as well as in the area of the isolated banks. Inasmuch as, with the exception of Tutuila, described above, there is no other known example of a submerged barrier reef so good as Rotuma in the vast extent of the open Pacific, its occurrence in close association with the chief group of Pacific submarine banks has an almost demon- strative value for the subsidence theory; for, as Darwin said, “If an old barrier reef were destroyed and submerged, and new reefs became attached to the land, these would necessarily at first belong to the fringing class.” It is interesting to note that the young naturalist went on to say that, fringing reefs being all colored red on his maps as indicating stationary or rising coasts, examples of exceptional fringing reefs, formed as above suggested, would be given the same color, “although the coast was sink- ing”; but he added, “I have no reason to believe that from this source of error any coast has been wrongly colored with respect to movement indi- cated” (124). With reference to Rotuma, it is later said in explanation of the colors on the chart of reef distribution: “From the chart in Du- perrey’s atlas, I thought this island was encircled [that is, by a barrier reef], and had colored it blue; but the Chev. Dillon assures me that the _ reef is only a shore or fringing one, red” (162). One may imagine the pleasure that Darwin would have felt on learning more fully the facts about this curious island and the numerous “drowned atolls” with which it is associated, and thus recognizing that he might restore the blue color originally assigned to Rotuma. One may, indeed, here quote what Geikie SEYCHELLES BANK IN THE INDIAN OCEAN 531 has so well said of Darwin, though with a somewhat altered application : “No one would have welcomed fresh discoveries more heartily than he, even should they lead to the setting aside of his own work.” Various additional details regarding certain islands of neighboring groups might be given in confirmation of the postulate of rapid subsi- dence for the region of these submarine banks, but space can not be granted them here. I propose, however, that this group of banks should be called the “Darwin hermatopelago,” hermato being from the Greek word for “submerged reefs.” THE SEYCHELLES BANK It is evidently conceivable that the various submarine banks men- tioned in earlier paragraphs are neither drowned atolls, as they are supposed to be under the theory of subsidence, nor stationary islands trun- cated by abrasion, as they are supposed to be under the theory of Glacial- control; but still-standing submarine mountains that have been built up to a moderate depth by pelagic aggradation, as is supposed under Murray’s theory of atolls. The improbability of so stable an origin for the banks of the China Sea and of the Pacific north of Fiji is very great. Most of the great banks of the Indian Ocean stand so far from high islands of a decipherable history that their origin is more in doubt; the Seychelles bank, however, is surmounted by several high islands, and if this bank may be taken as a fair sample of its neighbors, their stability is improbable, to say the least. The vast bank of the Seychelles in the Southern Indian Ocean, the largest bank in the coral seas, measures about 200 by 80 miles and has a maximum depth of 40 fathoms near its center; its northeastern side is partly reef-rimmed, and a few small coral islands there reach the sur- face. Near the center of the bank several mountainous granitic islands emerge; the largest of them, Mahé, rises to an altitude of 2,993 feet; its shoreline has many bays divided by sloping, non-clift points, around which unconformable fringing reefs are formed; such features” testify immediately for instability of their region. The present depth of the great bank is not excessive, but there is an elevated fringing reef on Mahé at a height of 80 feet; and when that was at sealevel the central depth of the bank must have been over 50 fathoms. Thus uplift as well as subsidence has occurred here. The abrasion of a bank so large as that of the Seychelles during the Glacial period is in any case altogether improbable, and all the more so as the granitic islands near its center are not clift. However, if abrasion be assumed, the present depth of 40 fathoms might possibly be explained as a result of wave-work by the oe W. M. DAVIS—-SUBSIDENCE OF REEF-ENCIRCLED ISLANDS lowered Glacial ocean; but the former depth of 50 or more fathoms, at the time when the elevated fringing reef was forming, can not be safely explained without subsidence. On the other hand, even with the aid of subsidence, it may seem diffi- cult to explain the vast Seychelles bank as a drowned and partly rebuilt almost-atoll, for its dimensions are far greater than those of any known sealevel atoll. The difficulty here is, however, more apparent than real, for while the time demanded for the production of a bank by edgewise abrasion increases more rapidly than the increase of its diameter, the aggradation of an atoll lagoon by locally formed sediments, such as are provided by floating foraminifera and bottom nullipores, is independent of the diameter, inasmuch as the agency here grows with the area. Hence if this bank be a drowned almost-atoll, it may have as small a propor- tion of coral-reef limestone to lagoon limestone as Vaughan has found in the reef and lagoon area of southern Florida. The upshot of all this is that in so far as the Seychelles bank may speak for its neighbors, the submarine banks of the Indian Ocean have suffered changes of level in late geological time; and this is more consistent with Darwin’s theory of coral reefs than with any other. RECENT ORIGIN OF GREAT OCEAN DEPTHS In view of these various considerations one is led to think that, as Suess has suggested, the deep mediterranean seas, of which the China Sea is a typical example, resemble lofty mountains in resulting from comparatively recent deformation. Certain members of the Philippines as well as the bottom of the neighboring China Sea basin may therefore be regarded as having, on the whole, subsided so much, so rapidly, and so recently that reef upgrowth could not keep pace with their submer- gence. ‘They are therefore characterized rather by imperfectly rimmed submarine banks and by narrow fringing reefs of a new generation than by barrier reefs and atolls. I believe the same statement may be made regarding various other parts of the Australasian archipelago, not that subsidence alone has taken place in this great region, for elevated reefs occur on various islands up to altitudes of 1,600 or 2,000 feet; but that diverse and rapid downward movements of the sea borders and basins, often associated with corresponding upward movements in the larger islands, to which Molengraaff (1916) and Abendanon (1917) have lately given much emphasis, result in the present prevalence of fringing reefs here, in association with submerged barrier reefs and atolls, while sea- level atolls and barrier reefs prevail in the quieter regions of the open Pacific, where submerged atolls are almost unknown. It is certainly RECENT ORIGIN OF GREAT OCEAN DEPTHS Hoo remarkable that the best explanation for the fringing reefs so prevalent around the shores of the Philippines is to be found in the brief passage above quoted from young Darwin’s book, in which their origin was clearly stated though the unconformable nature of their contact with the shore rocks was not mentioned. | In this connection it is desirable to point out that certain ocean-bottom troughs of exceptionally great depth occur in close association with islands of more or less disturbed history, from which the recent deepening of the troughs may be inferred. Thus a long deep trough closely adjoins the Philippines on the east. Another passes next to the east of the Pelew Islands, where recent tilting is indicated. A third lies next west of the Solomon Islands, and a fourth les west of the New Hebrides, in both of which groups many and diverse modern changes of level are inferred. A fifth les east of the Tonga Islands and banks, where recent tilting has occurred. Whatever degree of quietude may be inferred for other parts of the Pacific, these areas can hardly be regarded as having long enjoyed a stationary condition. DISAPPEARANCE OF DETRITUS FROM DEEPLY ERODED ISLANDS CONDITIONS OF REEF ESTABLISHMENT Reef-building corals need a firm rock foundation for their attachment and clear water free from wave-shifted detritus for their growth. Reefs are therefore wanting on beached shores, from which a sheet of detritus, supplied by streams and waves, usually extends offshore into deep water. Incipient reefs formed on a rocky shore will be destroyed if detritus is spread over them by wave or current action. In the absence of reefs on shores thus characterized, a cliff-backed platform will be abraded along them ; and as long as no change of level takes place, the sheet of detritus, which ordinarily lies on such a platform and which is shifted about at time of storms, will be maintained and reef growth will be excluded. Only when subsidence takes place rapidly enough to drown the valleys and pocket their stream-washed waste in embayments, and to submerge the cliff base so that waves beat ineffectively on the cliff face, may reef growth begin, either as a fringe on the cliff face or as an offshore reef which may grow up as a barrier from ledges laid bare on the margin of the submerged platform, where detritus, no longer supplied, has been drifted away. CLIFT ISLANDS IN THE CORAL SEAS If these principles are correct, it follows that no large reefs can be formed around the shore of a lofty young volcanic island; for even if 534 W.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS fringing-reef patches are formed here and there on lava points, detritus will be so abundantly supplied by actively outflowing streams that the incipient reefs will be smothered. Wave action will thereupon set in, and the island will be benched and clift as long as no change of level occurs. It is thus that the scarcity of reefs is explained around the immaturely dissected volcanic island of Reunion, where the retrograded cliffs have well developed beaches along their base and where the non-embayed val- leys are fronted by still wider beaches. The former absence of reefs and the cutting of high cliffs around the immaturely dissected island of Tahiti must be similarly explained ; the frmging and barrier reefs that now im- perfectly encircle that island must have been formed after submergence, presumably due to subsidence, had drowned the cliff-base and embayed the valleys to a depth of 600 or 800 feet, as I have briefly stated elsewhere (1916, a), and as is much more fully set forth in the forthcoming article in the Annales de Géographie, above mentioned. The cliffs and reefs of Tutuila may be provisionally explained in the same way, as noted above. REEFS AROUND DEEPLY ERODED ISLANDS Many other volcanic islands, much more deeply and maturely dissected than Reunion and Tahiti, are surrounded by barrier reefs; and it has usually been assumed that such reefs began their growth when volcanic action ceased, and continued their growth, according to Darwin’s theory, as the island subsided. Other theories, however, assume that reef-encir- cled islands have not subsided, and that their barrier reefs have been formed by the outgrowth of fringing reefs. If the physiographic devel- opment of the deeply dissected islands be attentively considered, both of these explanations for their reefs become untenable. Not only are the embayed shorelines and the unconformable reef contacts of such islands beyond explanation by all theories which assume still-standing islands, but in view of the enormous volume of detritus that has been discharged from the islands in the course of their deep dissection, the reefs are also beyond explanation as continuous upgrowths on slowly subsiding founda- tions since eruptions ceased. In the maturely dissected island of Huaheine, in the Society group, the volume of detritus discharged during the erosion of the former volcanic cone is from 50 to 70 times the volume of the lagoon inclosed by the present barrier reef; in the skeleton island of Borabora of the same group the ratio of discharged detritus to lagoon volume is probably greater still. In Murea, near Tahiti, in the Society group, the enormous volume of discharged detritus may be inferred from the depth and width of its valleys, as sketched in the upper part of figure 12; the narrow lagoon, REEFS AROUND DEEPLY ERODED ISLANDS 550 half a mile across, is so fore- shortened as not to be vis- ible between the barrier reef and the shore, both of which are shown by the same sea- level line. In Rarotonga, a lofty member of the Cook group, drawn in the lower part of figure 12, the shore lowland consists of a slightly elevated reef, which would have been completely smoth- ered by detritus if the deep valleys had not been eroded and the island partly sub- merged before the reef be- gan to grow. The transfor- mation of Fauro, figure 11, in the Solomon group, from the initial form of a vol- canic cone or group of cones into the present “wreck” of branching ridges surmount- ing a submerged platform, 40 fathoms or more in depth, is utterly impossible by any combination of ero- sion and abrasion, without the aid of recent subsidence. Any incipient reefs that may have been formed around the shores of these islands before the erosion of their valleys must have been soon overwhelmed by outwash detritus; cliff-cut- ting must have thereupon set in, and thereafter the excess of detritus delivered anorp YooD ayy Jo “‘phuojouwy pun ‘dnouwp fyav0g ay, fo “puns, vainyy—ZT anni, Sie. | IN ae SS > S, oS Jr, ie = a ss MLE, er eae es Nias Se eS US Se eet SSE ee ae a eee Cp oe an Sen ee se ye os -4 2 bs ‘ = uw QF é o) Bea AG rar ya ERY’ é dé 3 ra Ra 3 st : ; gh q y nS hee y at Th By on 5) a 4 " » v) é Kir on Soe By Sh, 43. G q et 4, c\ Ma Maran re 5 TANS iy M, ny ‘ ‘ , Pi je ‘ fe ie a . PETE Se eeieewa pts , Ae Fad ey ot = Ges =x Me jt ie XL—BULL. Grou. Soc. AM., Vou. 29, 1917 5386 W.M. DAVIS—-SUBSIDENCE OF REEF-ENCIRCLED ISLANDS from the valleys and detached from the cliffs must have been swept off- shore by the cliff-cutting waves. If no subsidence had taken place, the islands would be today not reef-encircled but cliff-rimmed. Even if the changes of ocean level during the Glacial period be considered, high cliffs must have been cut around the still-standing islands in preglacial time; and the erosional and abrasional changes accomplished during the Glacial epochs of lower sealevel could not have transformed the cliff-rimmed and non-embayed islands of preglacial time into the non-chft and broadly embayed islands of today. The only reasonable explanation that I have been able to invent for the disappearance of the great volume of detritus shed from a deeply dis- sected, reef-encircled island involves the aid of wave abrasion during a considerable reef-free period of erosion before subsidence began or when it proceeded slowly, and the absence of effective abrasion during a follow- ing period of greater or more rapid subsidence of the island accompanied by reef growth, after erosion was well advanced. Under such conditions, most of the detritus would be swept offshore and deposited, while subsi- dence was slow or absent, on the submarine flanks of the island before it was encircled by reefs; after subsidence became rapid or great enough to permit reef establishment and upgrowth, the coarser part of the detritus still to be discharged would be laid down in embayment deltas, and some of the finer part would be swept out of the lagoon through the passes in the reef, which were probably broader and more numerous in the earlier stages of reef growth than they are today. | THE SUBMERGED CLIFFS OF REEF-ENCIRCLED ISLANDS If the processes thus sketched have really taken place on such islands as Huaheine and Borabora, they must have once had a rock platform, DH, figure 4, and strongly clift spur ends, EF, around their shores; if the platform gained a width of a mile, the spur-end cliffs must have had a height of 1,000 or 1,300 feet. But Huaheine and Borabora have taper- ing spurs, at the ends of which any little cliffs that occur, as at B, have been cut by lagoon-wave abrasion at present sealevel, for they rise at the back of narrow, low-tide rock platforms. Hence the greater cliffs, that were presumably cut before reef growth began, have disappeared by sub- mergence, and submergence of so great an amount as is here implied can be accounted for only by subsidence. It is not necessary, however, that the island should ia stood still and that the inferred platform and cliffs should have been cut back to a great breadth, DE, and height, EF, before any subsidence took place; it suf- SUBMERGED CLIFFS OF REEF-ENCIRCLED ISLANDS 537 fices, as above noted, that subsidence should proceed so slowly as not to interrupt cliff-cutting, but rather to aid it by gradually and continually deepening the water on the abraded platform, and thus allowing the.at- tacking waves to reach the cliff face with much less diminished force than if no subsidence took place. Thus the platform might be more inclined and the cliff lower than if they had been cut during a long still-stand, or the platform and cliff might be subdivided in many little treads and rises. But in order to explain the growth of a wide-lagoon barrier reef, R, offshore from a steep-sloping island, AB, after a series of small treads and rises had been cut during intermittent subsidence instead of a broad platform during a stationary period, abrasion must have begun farther down the volcanic slope, as at C, and ceased at D, so that reef growth beginning at D could rise to R; and this involves a greater total subsi- dence than the preceding supposition requires. It is possible that occasional more rapid subsidences during the abra- sion of the benched slope, CD, permitted the temporary establishment of reefs, Q, which grew upward until they were overwhelmed by outwashed detritus, whereupon abrasion would again set in. But eventually, when the discharge of detritus was decreased by reason of the advanced stage of island erosion then reached, subsidence, especially accelerated subsi- dence, would gain the upper hand; the reefs thereupon established would thereafter persist, and thus the present condition of a reef-encircled, em- bayed, non-clift island would be attained. This evidence for Darwin’s theory is manifestly of a theoretical nature ; but the evidence supplied by unconformable reef contacts is also theoret- ical. The difference between the two lines of evidence is not so much that one is theoretical and the other is not, as that the principles and processes involved in one are here applied in a novel manner and are not yet gen- erally accepted, while those involved in the other have long been familiar in geological science and are universally accepted, even though they have not been usually utilized in the coral-reef problem. ABSENCE OF REEFS ON CoAsts OF EMERGENCE REEFLESS COASTS IN THE AUSTRALASIAN ARCHIPELAGOES Conditions favorable to reef establishment are not, as a rule, provided on coasts of recent emergence, because the simple shoreline and the smooth adjacent sea-bottom are occupied for scores of miles together by uncon- solidated sediments on which corals can not grow. In the absence of reefs such coasts are attacked by the waves. and cut back, except that where large rivers mouth their deltas may be built forward. Stationary 538 W.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS coasts of more ancient emergence are also generally ill adapted to reef establishment, because as long as they stand still the frontal slopes of the deltas that are built forward and the broad surface of the platforms that are cut backward are overspread with shifting detritus, on which corals can not attach themselves. Moreover, in virtue of coastal emergence, the rivers of the region will, as a rule, be revived to more active erosion than before; the detritus that they discharge, added to that spread from the cliffs by the waves, will cloak the platform with loose seaiments and pre- vent coral growth. The following examples may be cited: Part of the southwest coast of Sumatra is, according to Erb (1905), a coastal plain of Phocene strata, bordered by a beach of gravel beaten by heavy surf and drifted northwestward by the long-shore current; dis- continuous fringing reefs are found near the southeastern end of the coast, where the gravel beach is less developed, and some of them are at- tached to the eroded margin of uplifted reefs which stand 20 or 30 me- ters above sealevel and seem to offer a firm support for the new growths. The southwest coast of Java as described by Guppy consists of a coastal plain of gently inclined foraminiferous tuffs, and seems to offer an ex- ample of a simple shoreline of emergence in a later stage of development than that of Java, for it has been retrograded so that the emerged strata are cut off in a bluff, 40 or 50 feet in height (1889, a). Beneath the bluff lies a beach of dark volcanic sand, on which the heavy surf breaks unre- strained by coral reefs. But fringing reefs do occur on short stretches of the shore, and “there was a time, in fact, when a large portion of this coast was fronted by shore reefs, which have since been killed and over- whelmed by the great quantities of sand and mud brought down by the rivers (1889, b, 630). The last statement seems to justify one of the principles adopted above in the section on the development of clift vol- canic islands in the coral seas. | Borneo appears to be, according to Molengraaff, reef-free around most of its shoreline, because of the abundant outwash of detritus since its late Tertiary uplift, whereby extensive alluvial deltas have been built forward from the margin of its emerged coastal plain; it is “a worn, much de- nuded mountain land, surrounded for the greater part by broad tracts of low land, covered with fluviatile deposits . . . the result of prolonged and intense erosion of a mountainous island surrounded by a shallow sea” (1902, 453). Coral reefs seem to have been absent previous to the late Tertiary uplift as well as now, for the mass that then emerged is described as an older nucleus unconformably surrounded by nearly horizontal coal- bearing strata, which were presumably formed under conditions very similar to those obtaining on the aggraded fluviatile lowland of today. REEFLESS COASTS OF EMERGENCE 539 The Gulf of Carpentaria, on the northern coast of Australia, is shown on the geological map of Queensland by Jack and Etheridge (1892, map, sheet 5) to be mostly bordered by low alluvial delta flats, often occupied by mangrove swamps. The shallow sea-border is free from reefs, and thus presents a strong contrast to the eastern coast of Queensland, where reefs abound along a bold embayed coast fronting deep water. Whether this example belongs under coasts initiated by emergence or by submer- gence I can not say. Young volcanic islands may be treated under coasts of emergence; their shorelines are comparatively simple, and the detritus washed from their slopes may form a gravelly or sandy beach. Ambrym, in the New Hebrides, culminating in an active volcano from which streams of lava and showers of dust have been given forth in recent years, has a beach and bluff cut in loose ash deposits along part of its circuit; here reefs are absent and the surf becomes dark and turbid as it falls on the black volcanic sand. THE REEFLESS COAST OF SOUTHEASTERN INDIA The Madras district of southeastern India, of which Cushing (1911, 1913.) has given excellent descriptions, is a remarkable example of a FiGgurRE 13.—Diagram of the reefless Coast of Madras reefless coast of subrecent emergence. It is bordered by a belt of marine strata, forming a coastal plain the shoreline of which is either fronted by sand reefs or built forward by deltas, roughly shown in figure 13; but coral reefs are almost wanting in spite of the high temperature of the sea- water. Furthermore, a much more ancient emergence of this region, by 540 W.M. DAVIS—-SUBSIDENCE OF REEF-ENCIRCLED ISLANDS which the interior highlands gained most of their altitude, must also have had a reef-free shoreline, as in block B, figure 14, for previous to the sub- recent emergence of the coast the seaward slope of the uplifted highlands had been cut back many miles by the waves, thus producing a broad and low rock-platform backed by high cliffs, block C, which are now, since the later emergence, seen inland from the low coastal plain, as in block D, figure 14, or as in figure 13. | This region may therefore be taken as exemplifying the principles above stated regarding coasts of ancient as well as of modern emergence, and as warranting another of the principles expressed above in the section Figure 14. Hvolution o rts the reefless Coast of Madras on clift islands in the coral seas, to the effect that as long as a coast of emergence stands still enough not to interrupt the action of abrasion in wearing it back, no reefs can be formed along its shore. If, then, reefs can not be developed on coasts of emergence, either at the time of emer- gence or during a succeeding stationary period, they must be developed on coasts of submergence. REEFS ON COASTS OF SUBMERGENCE / The bearing of the reef-free condition of coasts of emergence on the coral-reef problem will be clearer if the favorable conditions for reef erowth on coasts of submergence are considered. Unlike the simple shoreline of a coast of emergence, the shoreline of a coast of submergence is of irregularly varied pattern: it usually presents a succession of ad- DESTRUCTION OF REEFS ON STATIONARY COASTS 541 vancing headlands and outlying islands alternating with reentrant embay- ments branching into many coves. The headlands are soon swept clear of detritus, and thereupon they become bordered by outgrowing fringing reefs and are thus protected from further wave attack. The bayheads on the contrary are invaded by delta deposits and, if submergence cease, any fringing reefs at first formed in the bays are in time overwhelmed. The longer such a coast stands still, and the higher and larger and rainier the drainage area of its rivers, the farther forward will the deltas ad- vance; the detritus may indeed be eventually drifted so abundantly along the prograding shore as to smother the headland reefs: thereupon the waves will cut away the dead coral rock, and the delta fronts also if the rivers are not too strong, and in time the waves will attack the headlands again. It thus seems eminently possible that the coast of a considerable land area that was bordered with reefs for a time after submergence took place, will later become reef-free and so remain as long as the land stands still and the shoreline suffers uninterrupted abrasive retrogression. It is manifest, however, that this untoward result may be prevented if the submergence of the coast be intermittently continued at frequent in- tervals; for if the bays are lengthened and deepened and the headlands are shortened by renewed submergence before detritus overwhelms the previously established reefs, the reefs will grow upward and more or less ' outward, and will thus be transformed into discontinuous barrier reefs; at the same time new fringing reefs will grow on the shortened headlands, and the intermediate lagoon will be aggraded with deposits inwashed from the outer reef and outwashed from the land, as well as by organic deposits formed in the lagoon itself. It also appears probable that small islands, once partly submerged, will retain their reefs indefinitely in a succeeding stationary period, because the detritus that they shed will not suffice to fill the lagoon and smother the corals on the reef face. This scheme represents, I believe, the ordinary condition of reef growth, for most reefs occur on mountainous coasts of long-continued submergence, as has been shown in the preceding chapter; in other words, reefs are ordinarily formed as Darwin explained. In case renewed submergence should be more rapid than reef upgrowth, the previously formed reefs will be drowned and fringing reefs of a new generation will be formed along the new shoreline; and reefs of this kind are also, as has already been shown, explained by a special phase of the theory of subsidence which Darwin explicitly announced. If our observational acquaintance with the coasts of the world covered several geological periods, we might reasonably expect to find actual ex- amples of reef-fronted and reef-free coasts in all stages of developmen? 542 Ww.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS here sketched; but our acquaintance is limited to a geological moment known as “the present,” and our knowledge of even the present condition of many coasts is not yet intimate, for it has not been gained by a seru- tinizing inquiry during which all problems of coastal development were consciously held in mind. It is therefore natural enough that some of the stages of coastal development above outlined should not yet have found their counterparts in nature. The best that we can now do is to discover counterparts for as many stages as possible; we may then, accord- ing to the success with which some of the deduced stages match the facts, judge of the correctness of the other stages and thus of the whole sequence of changes involved in our theoretical scheme. Coasts of recent or of long-continued submergence will first be considered ; coasts of less recent submergence will next be examined. REEFS ON COASTS OF RECENT AND CONTINUED SUBMERGENCE Reefs are, as above stated, abundantly developed on coasts of submer- gence in which the embayments are not yet filled with deltas. The lower- ing of the Glacial ocean may have contributed to this result by enabling the streams to wash away the detritus which had previously accumulated, but, as has been shown in several previous paragraphs, the changes of ocean level thus accounted for do not suffice to explain nearly all the ero- sion and submergence that many reef-fronted coasts have experienced. Long-continued, intermittent subsidence, varying in place, amount, time, and rate, and not infrequently alternating with elevation, is demanded by the multitude of varied facts. This point need not be dwelt on longer. SMOTHERED REEFS ON COASTS OF LESS RECENT SUBMERGENCE The mountainous and embayed coast of southern New Guinea is fronted by barrier reefs for much of its length, but in a large reentrant near its middle the Fly River—named after the British exploring vessel on which Jukes was geologist—has formed an extensive delta prolonged in muddy shoals; here reefs are now absent, but it is highly probable that they were present along parts of this coastal reentrant before the delta gained its present size. The great deltas of the Irrawaddy in Burma and of the Me- kong in Cochin China are built forward from coasts of fairly strong relief, that have been embayed and morcellated by submergence; reefs are want- ing on the delta deposits, but they occur in patches on the adjoining coasts. Many smaller examples of this kind are known in the lagoon of the Great Barrier reef of Australia, where advancing deltas have appar- ently smothered previously formed fringing reefs. Certain stretches of GREAT BARRIER REEF OF AUSTRALIA 543 the coast of Tahiti, where the last important movement was a submer- gence, are now fronted by reef-free beaches of volcanic sand, where the deltas of the larger streams have outgrown the embayments in which their formation began. Reasons might be adduced, if space permitted, for in- ferring, in advance of observation, that smothered reefs exist under the coastal lowlands of Luzon. No examples have been found to illustrate the general retrogradation of a delta-fronted coast of submergence, but a complete search of existing coasts has not yet been made with this object in view. It may well be, however, that the postglacial rise of ocean level has, in combination with movements of subsidence, held the development of most coasts back to an earlier stage than that in which general retrogradation should be ex- pected. There are reasons which I have elsewhere set forth for thinking that the Great Barrier reef of Australia, which today incloses a broad lagoon, had reached a more advanced stage of development before the last strong subsidence of its region, and that its lagoon may then have been converted into a plain, across which the rivers from the rainy highlands of the back country carried their detritus to the reef front and over- whelmed its corals (1917, ¢, 350). REEFS ON COASTS OF EMERGENCE, AFTERWARD SUBMERGED It is evident from the foregoing discussion that a reefless coast of emergence may be converted by submergence into a reef-fronted coast. I have not yet found any examples in which a reef-free coastal plain of emergence has after partial dissection suffered so recent a submergence as to be bordered only by newly established fringing reefs; but the south- ern coast of Viti Levu, the largest island of the Fiji group, is an example of a somewhat later stage of this sequence, as it is bordered by a dissected and embayed coastal plain, reference to which was briefly made in an earlher paragraph, and fronted by a barrier reef that is on the verge of being overwhelmed where the deltas of two large rivers are advancing toward it. The island is chiefly composed of resistant volcanic rocks, on _ which the coastal-plain series of marine strata, formed of foraminiferous volcanic muds and locally known as “soapstone,” has been unconformably laid down. Since their emergence along the southern coast the strata have been maturely dissected, so that they no longer form a coastal plain but a littoral belt of hills; and since their dissection they have been partly submerged, whereby their shoreline became well embayed. The strong offshore barrier reef of this embayed coast incloses a lagoon, usually a mile or more in width; but the Navua and Rewa rivers have 5044 ‘W.M. DAVIS—-SUBSIDENCE OF REEF-ENCIRCLED ISLANDS formed deltas, well shown on charts in Agassiz’ Fiji report (1899, plates 5, 6), that have not only filled the embayments in which the rivers must have mouthed when the last submergence took place, but have advanced so as to narrow and shoal the lagoon. Many fringing reefs must have been smothered under the widening front of the advancing deltas. The Rewa, the largest river of the island, discharges a great volume of water when in flood; its delta has already covered certain parts of the barrier reef, and has converted the narrow lagoon, ordinarily 15 or 20 fathoms deep, into shallow mud flats for a long-shore distance of 15 miles. A continuance of delta growth, undiminished by future subsidence, may be expected to kill the corals on the outer face of the barrier reef as far as the river muds are spread, and the progradation or retrogradation of the delta front will then depend on the relative strength of the constructive river and the destructive waves. It is stated above that the “soapstone” strata of the dissected and partly submerged coastal plain of mid-southern Viti Levu rest unconformably on an eroded foundation of resistant volcanic rocks, and this implies that subsidence took place during the deposition of the coastal-plain strata. A coral reef should have been formed during that subsidence, first as a fringe, later as a barrier, and it is highly probably that a reef of this kind was formed during the earlier stages of soapstone deposition ; but no such reef is now visible in the soapstone district, although an elevated reef, apparently of “soapstone” age, occurs farther west, where the soap- stone is of small thickness or wanting. The elevated reef at Suva, in the soapstone district, is a small affair that was formed and buried as a con- formable member of the soapstone series. It is therefore permissible to suppose that the incipient barrier reef, which should have been formed in the earlier stages of soapstone deposition, was smothered and buried in the later stages. This supposition is made the more reasonable when it is recognized that the delta deposits now accumulated within and on the present barrier reef are small in volume compared to that of the soapstone series, and yet they are almost sufficient, near the rivers, to smother the barrier reef of today. As far as information is at hand, the northwestern side of Viti Levu is not bordered by soapstone strata; and the barrier reef there incloses a vast lagoon, which deepens offshore to nearly 60 fathoms, as has ‘been adverted to above and as will be further noted below. Thus here, as at Vanua Mbalavu, a tilting of the land-mass seems to have accompanied the uplift by which the soapstones were emerged, and the subsidence in response to which the present barrier reef grew up. Changes of ocean level could not determine unequal changes of this kind. REEFS OF FIJI AND NEW CALEDONIA 545 THE HALF-SUBMERGED CLIFFS OF NEW CALEDONIA If after its broad rock platform and high cliffs had been cut by the waves, the Madras district of southeastern India, block C, figure 14, had subsided beneath the sea, block EH, instead of risen from the sea, block D, it might be today fronted by a long barrier reef inclosing a lagoon, the waters of which would lie against the partly submerged cliffs where fring- ing reefs would thrive and enter many cliff-breaching valleys in the form of branching bays. The amount of the subsidence could not be well measured by the depth of the lagoon, because its floor would be aggraded by an unknown thickness of sediments; still less by the depth of the bays, where river sediments would accumulate; the subsidence could be better measured by the downward prolongation of the bay-side slopes with grad- ually decreasing declivity, until their intersection marked the bottom of the drowned valley that the bay represents. _ As the Madras district was fated to rise, we must go elsewhere for the realization of a similar coast that has subsided; we fortunately find it along the northeast side of New Caledonia, which exhibits all the features just outlined. Much of that side of this long island is cut off in strong cliffs, which, although by no means vertical, still rise 500 or 1,000 feet above sealevel, as in figure 15, although their base line is submerged sev- eral hundred feet. The upper view, looking south, shows Thio, a delta- front port at the mouth of an embayed and aggraded valley, from which much nickel ore is shipped ; the high cliffs of the outer coast on the left are followed by low cliffs on the spur ends of the valley side, a short distance inland. The second view, also looking south, near the bay of Ba, illus- trates the maturely even alignment of several cliffs that truncate the spur ends of the dissected highlands. The third and fourth views are of a strongly truncated promontory between Laugier and Kuaua bays; one shows the face of the cliffs, looking south; the other, looking southeast, gives the profile of the cliffs in strong contrast to the maturely carved forms of subaerial erosion on the east side of Kuaua Bay. In these two views the little vertical cliffs cut by lagoon waves at present sealevel are _. seen at the apparent base of the great slanting cliffs of earlier origin, the real base of which lies, as well as can be inferred from the slopes of the bay sides, several hundred feet below present sealevel. Singularly enough, these great cliffs are hardly mentioned in the published accounts of New Caledonia ; or if mentioned they remain as completely unexplained as the beautiful embayments by which they are interrupted. True, the cascades that here and there leap down the cliff face from small hanging valleys have occasionally excited comment; thus Brenchley noted “a fine water- - 546 W.™M. DAVIS——-SUBSIDENCE OF REEF-ENCIRCLED ISLANDS > : NN oN Y Wye A : . "iy Wk 2 iow ever INS) alee Vit piano re = : ae / Yi > “ xy fo 258 ~ 7 Lg SANS. ee Vi PHYSIOGRAPHIC EVOLUTION OF NEW CALEDONIA HAT fall . . . of considerable height, coming down a channel it had worn for itself on the mountain side, and finally falling over a steep cliff into the sea” (1873, 326); but he went no farther: a cascade on an island rim a simple cascade was to him, and it was nothing more. It is conceivable that the cliffs of the New Caledonian coast are due to a great fault, but as well as I could judge by careful scrutiny from the deck of a passing steamer and from excursions ashore at several points, no associated step-faults are to be seen in the uplands back of the cliff top, and this suggests that the cliffs were cut by the waves while the island stood higher than now. The cliffs are repeatedly breached by branching embayments, the rock-bottom depth of which was estimated at 600 or 800 SCOTT ii, == UT i FicgurE 16.—LHvolution of the Coasts and Reefs of New Caledonia feet. ‘Thus the total height of the cliffs may be from 1,000 to 1,800 feet. The abraded rock platform in front of the cliffs might well have a breadth of 5 or 10 miles, for the seaward slope of the uplands back of the cliff tops is moderate. Deltas are now filling the bayheads, fringing reefs are growing along the shoreline on the face of the partly submerged cliffs, an imperfect barrier reef rises 5 or 10 miles offshore, and the lagoon has a depth of 30 or 40 fathoms. In strong contrast with the clift northeastern coast, M, figure 16 (look- ing west), the southwestern coast of New Caledonia descends with gentle slopes to a greatly embayed shoreline, L, bordered by fringing reefs, ex- cept where deltas of the current cycle of erosion prevent coral growth, 548 | W. M. DAVIS—-SUBSIDENCE OF REEF-ENCIRCLED ISLANDS and fronted by a superb barrier reef several miles offshore. Cliffs do not seem to have been cut on the southwestern side of the higher-standing land-mass, G, J, during the penultimate cycle of erosion and abrasion, blocks 4, 5, that was occupied by the cutting of great cliffs, K, on the northeastern side and closed by the general subsidence which introduced the present cycle, block 6: hence the penultimate cycle was probably in- troduced by a flexure of a preexistent island, EF, which caused elevation along the northeast side of the island, H, and depression along the south- west side, G; thus there would have been a reef-free shoreline of emer- gence along the northeast coast, where cliffs, K, would be cut as long as the island stood still or subsided slowly; and a reef-fronted shoreline of submergence along the southwest coast, where deltas would advance in the bays, while the offshore reefs would grow up and broaden; until the later and more general subsidence of the whole island caused reef up- growth to the present sealevel, much less continuous on the northeast than on the southwest, but in general extending all around its long oval cir- cuit, a crosswise segment of which is shown in block 6. Irregular deformation, in which subsidence ultimately dominates, seems indispensable in explaining these various features. The northeast- ern side of the island, M, finds its best explanation as a recently sub- merged coast of long previous, H, and long enduring, K, emergence; the recent submergence must be due to subsidence, because it is of greater measure than can be reasonably explained by a rise of ocean level, and it was this subsidence that gave opportunity for the imperfect upgrowth of the present barrier reef. The earlier stages of this scheme are manifestly hypothetical in a high degree, but they have at least the merit of taking account of all that is known of the geology of the island, and of proceed- ing by reasonable steps from its former subcontinental area, block 1, of unknown extent, AB, through such a series of longer or shorter erosional cycles as will account not only for the present shoreline and reefs, but also for the special features of the uplands and the lowlands that are seen on the two sides of the actual island. The physiographic evidence in support of the successive deformations shown in figure 16 can not be fully given here, but the coherence of the scheme thus graphically repre- sented certainly speaks in its favor and warrants the association of New Caledonia with Tahiti in confirmation of the hypothetical views expressed above as to the probable development of cliffs around many emerged islands during an early reef-free stage of their development. The upshot of all this chapter is that coasts of recent emergence and coasts of more remote emergence, as well as coasts (except small islands) of remote submergence, do not offer conditions favorable for reef growth; UNEQUAL DEPTHS OF LAGOONS AND BANKS 5AY but that, on the contrary, coasts of recent submergence, and especially coasts of long-continued submergence, offer highly favorable conditions. Hence either a slow rise of the ocean or the slow sinking of a coast will favor the growth of reefs, all the more if the change of level be long continued at not too rapid a rate. But as reef-bordered coasts have suf- fered submergences of various amounts and dates, frequently associated with neighboring emergences, they can not be accounted for by a uni- versal, uniform, synchronous rise of the ocean, and must therefore be accounted for by local, variable, and non-synchronous subsidences of the coasts concerned ; and this conclusion supports Darwin’s theory. UnEQUAL Dreptus oF Lagoons AND BANKS THE REQUIREMENTS OF THE GLACIAL-CONTROL THEORY It is desirable, before the facts as to the depths of lagoons and banks are examined, to define as clearly as possible the unlike requirements re- garding them that are demanded by the Glacial-control and the subsi- dence theories. The Glacial-control theory, as set forth by Daly, recog- nizes that “there has been Recent crustal warping in certain oceanic areas affected by coral reefs” (1915, 222), but places much greater weight on “a long period of nearly perfect stability for the general ocean floor’; this is clear from the statement: “Most of the reef platforms, like many banks situated outside the coral seas, have such forms, dimensions, and relations to the sealevel that they appear to have originated during a long period of nearly perfect stability for the general ocean floor. . . . That is a conclusion forced on the writer by a close study of the marine charts. Its validity is a matter quite independent of the validity of the Glacial- control theory. . . . Submarine topography seems impossible of ex- planation without assuming crustal quiet beneath most of the deep sea during at least the later Tertiary and Quaternary periods. The new theory, therefore, is based on the necessity of assuming general crustal stability in the coral-sea area during the formation of the existing reefs and platform surfaces” (162). | The theory then postulates a lowering of ocean level by some 30 or 40 fathoms during the Glacial period, the abrasion of platforms by the low- ered ocean, and the upgrowth of reefs on the platform margins as the ocean rose to its normal level. Little attention is paid to the replacement of abrasion by reef growth during inter-Glacial epochs; it is stated that “wave abrasion began before the clmax of the Kansan stage and con- tinued without serious interruption until the Wisconsin climax” (181) ; the much longer duration and the somewhat higher temperature of the 550 Ww. M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS last inter-Glacial epoch than of the present post-Glacial epoch are thus set aside; “‘the sea was actively attacking the islands and continental coasts throughout nearly the whole Glacial period. The reef-building corals were largely killed off long before the ice-caps of the first Glacial stage reached their full size” (180); broad platforms were therefore abraded. . In spite of the confidence with which these assertions are made, and notwithstanding the apparent plausibility of the assumption that reef- building corals should have been killed by the temperature of the Glacial ocean, I can not find independent proof that abrasion actually took place as the Glacial-control theory demands. For, as already noted, the spur ends of reef-encircled islands are not clift as they should be if the reefs were killed and if abrasion endured long enough for the truncation of large preglacial islands now supposed to be represented by the Macclesfield and other banks. Nor are they clift as they should be if the shores of such islands were attacked by waves while their now-embayed valleys were deepened, for abrasion by open-ocean waves is a much faster process than valley deepening by small streams and valley widening by subaerial weathering. J have prepared a special discussion of this aspect of the problem in the article on Tahiti, above mentioned, and need not pursue it further here except to note that the rock-resistance of an island does not affect the conclusion reached. For if the embayments of an island are well opened, it follows that stream erosion and subaerial weathering must have had opportunity of working for a long enough period to deepen and open the embayed valleys to their observed form, whatever the resistance of the rocks may be; and hence that during such a period the waves must have had abundant time to cut great cliffs on the island margin. The prevailing absence of such cliffs compels me to believe that the organisms on the flanks of the encircling reefs were not so completely killed as to permit abrasion; the exceptional occurrence of cliffs, as on one side of New Caledonia and all around Tahiti, only serves to emphasize the rule of non-clift shores that elsewhere obtains. THE EXPECTABLE FORM OF ABRADED PLATFORMS However, in order to give the fullest consideration to the Glacial-con- trol theory, let it be accepted that abrasion proceeded as therein assumed. As a result, all coasts of continents and islands then exposed to wave- work would have been cut back in platform and cliffs, of dimensions pro- portionate to the resistance of their rocks, of their exposure to the waves, and of the duration of wave attack. Let the narrowness of abrasion on many reef-encircled islands—such as Kusaie in the Caroline group, where EXPECTABLE FORM OF ABRADED PLATFORMS 55] the spur ends are not clift, although the reef on the east and north is a narrow fringe or close-set barrier, only a quarter or half a mile in width— be overlooked, and the floors of barrier reefs and atoll lagoons and the floors of submarine banks be regarded platforms of abrasion, now more or less covered by postglacial reef growth and sediments. The problem is to determine the features by which the existence of the abraded plat- forms beneath the aggraded floors can be discovered. A general treat- ment of this problem has been given by Barrell (1915). I have discussed it in some detail in an article on “Submarine banks and the coral-reef problem” (1918, a), and will therefore present here only its leading con- clusions. First, abraded platforms must have a gentle seaward slope; hence a large platform which completely truncates a preglacial island 50 miles or more in diameter should be 20 or 30 fathoms deeper around its margin than at its center; as a whole such a platform should have the form of a very flat cone. Second, the center of a platform of complete truncation and the inner cliff-base margin of an island-benching platform should give the best indication of the level of the sea at the time when abrasion took place. ‘True, the center of a truncating platform might, if abrasion continue long enough, be worn down to a moderate depth below the level of the abrading waves, but the inner margin of an island-benching plat- form ought to he close to the mean sealevel at the time of abrasion. Third, the level of the abrading sea thus recorded ought to be everywhere at about the same depth below present sealevel. Fourth, postglacial aggra- dation will make the depths of lagoons and banks less than that of the underlying platforms, and the decrease of depth thus caused will be, as Daly has shown, “in indirect proportion to the width of the platform” (1915, 192)?; for the smaller the platform the greater the aggrading effect of waste inwashed from the upgrowing reef around its margin. The central area of very large lagoons and banks will be aggraded chiefly by locally formed organic deposits. Fifth, a further consequence of plat- form abrasion to a fairly uniform depth followed by marginal upgrowth of reefs in a uniformly rising ocean is that barrier and atoll reefs today - should be, as a rule, of similar dimensions in cross-section. It follows that large lagoons and banks will give the best indication of the depth of the (supposed) underlying abraded platforms; that the depths thus found should be less, by reason of their aggradation, than the 30 or 40 fathoms by which the ocean is supposed to have been lowered in the Glacial period; and that depths of barrier-reef lagoons should always 2The original statement is misprinted “in direct proportion,’ and is here corrected with the approval of the author. XLI—BvuLL. Grou. Soc. AM., Vou. 29, 1917 552 W.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS be less than 30 or 40 fathoms, unless postglacial subsidence has taken place, or unless the glacial lowering of ocean level was more than 40 fathoms, which seems improbable. THE REQUIREMENTS OF THE SUBSIDENCE THEORY It is well, when we attempt to determine the features of lagoons formed according to Darwin’s theory, to bear in mind his original statements regarding the fundamental postulate of subsidence. Many statements indicate intermittent movements; thus, “Subsidence supervening after long intervals of rest . . . is probably the ordinary course of events” (1842, 130). Subsidence of different islands at different times is clearly conceived. Recent subsidence is illustrated by Vanikoro, in the Santa Cruz group of the western Pacific, where “the unusual depth of the chan- nel [lagoon] between the shore and the [barrier] reef, the entire absence of islets on the reef, its wall-like structure on the inner side, and the small amount of low alluvial land at the foot of the mountains, all seem to show that this island has not long remained at its present level, with the lagoon channel subjected to the accumulation of sediment, and the reef to the wear and tear of the breakers.” More remote subsidence is inferred for the Society Islands, “where . . . the shoalness of the lagoon channels round some of the islands, the number of islets formed on the reefs of others, and the broad belt of low land at the foot of the mountain indicate that, although there must have been great subsidence to have produced the barrier reefs, there has since elapsed a long station- ary period” (128). The relation of subsidence to lagoon depth is ex- plicitly stated: “The lagoon channel will be deeper or shallower, in pro- portion to . . . the accumulation of sediment; . . . also to the rate of subsidence and the length of the intervening stationary periods” (99), and the effect of a long stationary period in nearly filling a lagoon with sediment is mentioned (102). The effect of unusually rapid subsidence in producing fringing reefs of a new generation, as was so clearly, though briefly, explained by Dar- win, has already been sufficiently considered. The effect of rapid subsi- dence on atolls was more fully stated and has been more generally recog- nized: “There is nothing improbable in the death . . . from the sub- sidence being great or sudden, of the corals on the whole, or on portions of some of the atolls. ... . Further subsidence [of a submerged atoll], together with the accumulation of sediment, would often obliterate its atoll-like structure |form?] and leave only a bank with a level surface” (108, 107). Elevation also has its due in Darwin’s discussion, as well as oscillations of level (145, 146). In thus accepting the possibility of both AGGRADATION OF LAGOON FLOORS aoa kinds of change of level, the theory of subsidence appears to me more probably correct than the Glacial-control theory, in which, although ele- vation is accepted wherever high-standing reefs occur, subsidence is re- garded as very exceptional. Changes of ocean level were mentioned very briefly by Darwin: the need of combining the oscillations of ocean level during the Glacial period with submergence due to subsidence of reef foundations is, to my mind, the most important contribution of the Gla- cial-control theory ; but, as far as I have been able to interpret the history of coral reefs, oscillations of ocean level have been of less importance than island subsidence. Certain special consequences of intermittent subsi- dence must next be considered. THE SMOOTHNESS AND DEPTH OF LAGOON FLOORS The smoothness of lagoon floors, whatever the form of their buried rock foundation, was ascribed by Darwin to aqueous deposition (26). This finds confirmation in Gardiner’s detailed studies of the Maldive lagoons, of which he says: “It is only in a few protected situations, where the depth is as great as 40 fathoms or more, that the lagoon bottom appears not to be churned up by the currents and waves. In heavy weather the lagoon water is almost milky, and floating surface nets are almost useless on account of the enormous amount of mud in suspension. The total amount of mud that passes out of the lagoon in the water is enormous” (1903, 210). My own limited experience in the Pacific included two examples of rough weather—one in Fiji, one off the Queensland coast in the lagoon of the Great Barrier reef—during which the water of inclosed lagoons was turbid with suspended sediments. It therefore seems reasonable to follow Darwin in this matter and not Wharton, who ascribed the smoothness of lagoon floors, some of which have very uniform depths at 25 fathoms, to abrasion by waves, at present sealevel (1897, 392) ; still less can I follow Daly in-saying: “Wharton’s choice of the agency which produced the flatness of lagoon floors and of banks seems irresistible. He rightly regarded this flatness as no less than fatal to the Darwin-Dana theory” (1915, 196). The lagoon floors to which Wharton especially referred have, as above noted, depths of about 25 fathoms, and these must, even according to the Glacial-control theory, have been aggraded by postglacial deposits 15 or 20 fathoms in thickness: hence their flatness must be due not to abrasion, but to the even distribu- tion and deposition of sediments by the agitation of the lagoon waters; for this process would, as Darwin perceived, produce a smooth floor, what- ever the form of the rock foundation. The depths of lagoons may vary, according to the subsidence theory, 554. Ww.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISBANDS through a considerable range; but the inwash and the local supply of sediments will tend to lessen the depth that uncounteracted subsidence would bring about. Furthermore, the inwash of sediments from encir- cling reefs will be, as above noted, more effective in aggrading small lagoons than large ones, in whatever way the reefs are formed. More- over, the effect of a rapid subsidence in deepening a lagoon will be lessened by the more active inwash over the reef that will then be for a time partly submerged; and conversely the effect of a stationary period in shoaling the lagoon will be lessened by the obstruction to imwash caused by the sand islands which are formed on the broadened reef during such a period. Hence it is reasonable to expect that the average depths of a good number of lagoons, which are divided into classes according to their breadth, should vary in indirect proportion to the lagoon breadth, whether the reefs have been formed by upgrowth during the subsidence of their foun- dations or by upgrowth in a rising ocean over non-subsiding foundations ; but it should also be expected that individual lagoons of the same breadth should, according to the Glacial-control theory, have closely similar depths, while, according to the subsidence theory, their depths might vary through a considerable range. It may be stated at once that the facts agree better with the latter than with the former expectation: thus Ringgold and North Argo atolls, in the Fiji group, have the same breadth of about 5 nautical miles, although the first is much longer than the second; but the maximum lagoon depth of the first is 48 fathoms, although the breadth of its reef, nearly a mile, suggests a considerable aggradation of the lagoon floor, while the maxi- mum depth of the second is only 21 fathoms. Again, Budd reef, west of Ringgold atoll, in northeastern Fiji, an almost-atoll inclosed by an unu- sually narrow reef rim, measuring 12 by 6 miles, has a maximum depth of 47 fathoms; two lagoons imperfectly inclosed by barrier reefs near the islands of Rambi and Taviuni, not far to the west of Budd reef, have depths of 47 and 49 fathoms, thus strongly suggesting recent and rapid subsidence; while Ngele Levu, to the northeast, measuring 13 by 7 miles, and therefore a little larger than Budd reef, has a maximum depth of only 10 fathoms; and the maximum depth of the much larger Great Argo atoll, farther south, is no more than 36 fathoms, although it measures 22 by 8 miles in diameter. Other examples of the same nature might be adduced, but lack of space forbids their citation here. In addition to the examples of atolls of similar breadth and unlike depth, instanced above, the depths of the Maldive lagoons in the northern Indian Ocean west of India have an interest in the present connection. They vary from 20 or 30 fathoms in the northern members to 40 or 48 ~~ ee UNLIKE DEPTHS OF SUBMARINE BANKS 5DD in the southern members, the over-all distance being 400 nautical miles. Darwin was aware of these facts, yet said in the first edition of his book: “T can assign no adequate cause for this difference of depth” (1842, 34) ; but in the second edition he added, “excepting that the southern part of the archipelago has subsided to a greater degree or at a quicker rate than the northern part” (1874, 47). No one since Darwin has suggested a more adequate cause. It is interesting to note that the “drowned atoll” known as the Great Chagos bank les farther south in the same line. VARIATIONS IN THE DEPTH OF SUBMARINE BANKS The numerous facts here pertinent must be briefly summarized. ‘The central depths of certain large banks ought, according to the Glacial- control theory, to be of similar measure, and less by the thickness of their aggrading sediments than the 30- or 40-fathom depth of their buried platforms; but according to the subsidence theory, they need show no close accordance. The facts are that while depths of less than 30 or 40 fathoms prevail, certain banks have greater depths: thus the Macclesfield bank in the China Sea has central depths of 45, 55, and 60 fathoms; the Tizard bank, farther south, in the same sea, 48 fathoms; the Vanguard bank, farther southwest, 50 to 57 fathoms; the Saya de Malha bank, a rimless bank in the southern Indian Ocean, has depths up to 64 fathoms; the Great Chagos bank, in the same ocean, is 48 fathoms in depth near the center, though it has a rim of less than 20 or 10 fathoms. A great bank in the Tonga group of the open Pacific slants to a depth of over 50 fathoms. None of these depths are fairly compatible with the requirements of the Glacial-control theory; still less so, when it is recognized that several of them, like Macclesfield and Great Chagos, have been changed by mar- ginal reef growth and surface aggradation from their supposed initial form of flat cones that abrasion would have given them to their existing form of shallow saucers; and as this change demands a marginal reef- thickness of some 50 fathoms and a decreasing aggradation from rim to center, it must be supposed that a significant thickness of sediments has been laid down over the central area also; hence the depths of 60 and 48° fathoms there measured must be significantly less than the depth of any buried rock platform that may exist beneath. This aspect of the coral- reef problem is more fully treated in another article (1918, a). BANKS AROUND REEF-FREE CLIFT ISLANDS It may be fairly urged that the amount of lowering of the Glacial ocean ought, as long as it is in doubt, to be independently computed by each 556 W.M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS student of the coral-reef problem, and especially by those who question the correctness of the Glacial-control theory, into which the change of ocean level enters as an important factor. While recognizing the pro- priety of this opinion, I have excused myself from the labor involved in adopting it, because an independent observational test of the general value of ocean lowering seems more desirable than a numerical recalcula- tion of its measure. The desired test is found in the depth of several submarine banks, from the central part of which reefless and clift islands rise. The survival of the clift central islands proves that the banks are in part at least due to abrasion, and that the truncation of the islands was incom- plete. Hence the depth of the rock-floor in such banks at the base of their cliffs would give a good indication of the position of ocean level when their abrasion took place. The rock-floor depth can not be directly deter- mined, because some aggradation of the banks has been accomplished since abrasion ceased. Aggradation from the surviving islands can not, however, be of great amount, because the cliffs still plunge down below the sea surface and are as yet little benched at present sealevel. Whatever aggradation has taken place ought to be less and not greater than the aggradation of reef-rimmed banks, where organic sediments are supplied in relative abundance and where the supplied sediments are largely re- tained on the saucer-shaped surface. Now if we examine charts of the banks around Tutuila (Samoa), and especially around the Marquesas Islands, the clift spur ends of which are — reef-free though the islands lie near the equator in the eastern Pacific, and © also around a number of small and clift residual volcanic islands on the border of the coral seas, such as certain northwestern members of the Hawaiian group, and Norfolk Island between Australia and New Zealand, the depth of the inner, cliff-base margin of the banks is found to be about 20 fathoms, although their outer border may be twice as deep. The aggra- dation of the extratropical banks, where coral growth is scanty or want- ing, is probably less than that of the intertropical banks. Hence if the extratropical banks were cut during the lower stand of the Glacial ocean, ‘the measure of 30 or 40 fathoms given by Daly as the amount of ocean lowering may be taken as liberal, and certainly as not erring in the way of being too small. Several interesting inferences follow. First, it does not seem possible that the removal of aggrading sediments would bring about an agreement between the smaller depths of the aggraded surface over the undoubted rock platforms around the clift residual islands of the extratropical seas, and the greater depths over the center of the very hypothetical rock plat- ORIGIN OF FORTY-FATHOM BANKS 557 forms of the intertropical banks. The differences of from 30 to 50 fath- oms here disclosed between the depths of banks that should, according to the Glacial-control theory, be closely comparable are not easily explained without the aid of unequal subsidence. Second, the strong cliffs cut in the resistant volcanic rocks of the cen- tral islands on these reefless extratropical banks show that the waves of the lowered ocean, which abraded the platform around these islands, were abundantly capable of cliffing the intertropical volcanic islands, now sur- rounded by fringing or by close-set barrier reefs, provided the reef-build- ing organisms were killed while the ocean was lowered; and as those islands are not clift, we find here again reason for rejecting the assump- tion that the reefs were dead. We are thus fortified in the conclusion, which may have been lost sight of by the reader during the discussion of the possible truncation of the Macclesfield and other banks on earlier pages, that submarine banks can not be the result of abrasion and in the associated belief that their present unequal depths are due to subsidence. Third, the considerable extent of some of the banks on the border of the coral seas—the bank around Norfolk Island measures 55 by 20 miles in extent and the banks around some of the northwestern members of the Hawaiian group are of similar dimensions—makes it improbable that they are due chiefly to the abrasion of still-standing volcanic islands by the lowered Glacial ocean; and the record of “coral” in some of the sound- ings suggests that part of the banks may be made of reefs. It is therefore worth considering whether these banks may not have been inclosed by extensive barrier reefs during the last inter-Glacial epoch, which is be- heved on good grounds to have been warmer and longer than the present post-Glacial epoch ; for, if so, we should most appropriately have here, on the border of the present coral seas, precisely the consequences deducible from the Glacial-control theory, including the cliffing of central islands as well as the truncation of reefs; and in the association here of those two elements we should have proof that the theory does not apply within the coral seas of today, where clift central islands are of rare occurrence. Fourth, the depths of about 40 fathoms, which characterize the outer margin of the extratropical banks above named, are, like similar marginal depths elsewhere, in my opinion more reasonably explained as the result of wave and current agencies working on loose sediments with respect to present sealevel than as a mark of any former lower level of the sea; for the various indications of recent upheavals and subsidences found in other islands, such as Oahu and New Zealand, not far from the banks in ques- tion, make it altogether improbable that the banks have long been sta- tionary ; and if they have moved either up or down, some agencies such 908 W. M. DAVIS—SUBSIDENCE OF REEF-ENCIRCLED ISLANDS as those above suggested must have since then been in operation in order here to develop marginal depths that so well accord with the marginal depths which are elsewhere believed to be the work of those agencies. THE DEPTH OF BARRIER-REEF LAGOONS The greater depths than 40 fathoms discovered in certain barrier-reef lagoons appear to be beyond explanation by the Glacial-control theory, while they are perfectly expectable under the subsidence theory. Depths of 80 or 90 fathoms on the eastern part of the great barrier reef that in- closes the Exploring Isles in eastern Fiji have already been mentioned as indicating a recent slanting subsidence of that district, which is confirmed -by finding recently elevated reefs to the southwest. The gradual increase in depth to the exceptional measure of 56 fathoms, with a strong proba- bility of greater depths in the uncharted area of the lagoon northwest of Viti Levu, the largest island in Fiji, is especially significant because of the gradual submergence of the accompanying barrier reef, as is well shown on a chart in Agassiz’ Fiji report (1899, plate 3). The two fea- tures together strongly suggest a slanting subsidence; and for this again confirmation is found by the occurrence of moderately elevated reefs on the southern, but not on the northern, side of this large island. Addi- tional confirmation for the occurrence of slanting subsidence may be found in the southwestward increase of depth, well shown on the charts of a great bank in the Tonga group, above mentioned, to which Daly refers (1916, 208); in the visible slant of the uplifted coral island of Salayer, south of Celebes, as described by Weber (1902, 87) ; in the slant of Tinian Island in the Mariana group, as described by Seidel (1914) ; in the slanting emergence of half of the atoll of Uvea, in the Loyalty Islands, of which I had a good view in 1914, and in the presence of up- lifted reefs in the southern part of the Pelew group and of sealevel reefs in the northern part, which strongly indicate the emergence of one area and the submergence of the other, in spite of Semper’s opinion long ago expressed to the contrary. The depth of 60 fathoms at mid-length of the imperfectly inclosed bank or platform on the west side of Palawan, in the Philippines, in contrast to smaller depths at its southern end, has been instanced above in evidence of a warping subsidence; here the movement must have been more ‘rapid and more recent than the slanting subsidence in eastern Fiji, because the bank is bordered only by a very imperfect and discontinuous reef rim, and. because the fringing reefs of middle Palawan are unusually narrow or wanting. Depths of from 60 to 70 fathoms are recorded in the lagoon of Vanikoro, in the Santa Cruz group, where many other soundings DEPTHS OF LAGOONS AND PLATFORMS 559 reached 45 fathoms and no.bottom. in his monograph on the northern Appalachians, describes the Kittatinny peneplain, but passes over its age with the statement on page 189: “Geologists date this Kittatimny plain as of the so-called Cretaceous period of the earth’s history.” In a later paper,'® however, he says: “The surface of the crystalline rocks beneath these (Mesozoic) sedi- ments . . . is a plain sloping beneath the sediments toward the Atlantic, rising from under the sediments westward toward the Appalachian Moun- tains. . . . By filling the valleys in such a manner as to connect all ridges whose crests fall into the general slope, there is restored the plain, which was eroded nearly to sealevel during the Cretaceous period. “That old plain, now elevated and dissected, has been traced over New Eng- land, over the Middle States, and over the South Atlantic States. It coincides with the summits of the highest ridges, which in Maryland are represented by the Catoctin, the Blue Ridge, the Alleghany ridges, and the Cumberland plateau. Only in North Carolina and the interior of New England are surviving moun- tain summits of that date. “Recognition of the old Cretaceous plain, surviving in the ridge summits of the present time, is the first step in reading the Cenozoic history of Appalachia.” It will be noted that Willis, like others, speaks of the plain as passing under Cretaceous deposits and yet as having been formed during Creta- ceous time. The Appalachian folios of the Geologic Atlas of the United States treat the subject of peneplains in various degrees of detail. For example, Hayes’ ** discussion of peneplains in the Columbia, Tennessee, folio seems surprisingly brief. It is found under the heading topography, the chap- ter on history treating only the sedimentary record. It is stated that “the elevation of the region to its present altitude (after the formation of the Highland Rim peneplain) was not continuous, but occurred at several periods separated by intervals of repose.” It is interesting to note from this quotation that Hayes recognized more than one erosion stage after the formation of the Highland Rim peneplain, this position seeming to accord more closely with Keith’s idea of multiple peneplains, expressed in 1895, than with his own of two peneplains, expressed in the same year. In most of his folios Keith speaks of peneplains which evidently are not equivalent to the two described by Hayes and Campbell, or the three % Bailey Willis: Nat. Geog. Soe. monographs, vol. 1, 1896, pp. 169-202. 16 Bailey Willis: Paleozoic Appalachia, or the history of Maryland during Valeozoic times. Geol. Survey Special Pub., vol. iv, pt. 1, 1902, pp. 91 and 92. 17C, W. Hayes and BH. O. Ulrich: U. S. Geol. Survey Geol. Atlas, Columbia Folio, No. 95, 1903, p. 1. 580 E. W. SHAW—AGES OF APPALACHIAN PENEPLAINS described by Hayes, or even the several later referred to by Hayes. For example, in the Roan Mountain folio he speaks of four peneplains which - are represented in the one quadrangle, although he does not state their age. | 17h Although some folios refer to the age of the peneplains in general terms only, some are more specific. For example, in a late folio Camp- bell, Clapp, and Butts'® say: 2 “Evidence of at least one cycle of erosion and of subsequent uplift in the Mesozoic era is preserved in the Appalachian province. “The old peneplain can be traced eastward and southward, and in New Jer- sey and Alabama passes beneath deposits of early Cretaceous age. This fact proves that the peneplain was completed and submerged around its margins previous to early Cretaceous time.”’ Thus, according to what treatise one chances to pick up, he may infer, with more or less uncertainty, that the Cretaceous peneplain was com- pleted some time before the opening of the Cretaceous period and was remodeled by the advancing Lower or Upper Cretaceous sea, or that it was completed at one time or another in this long period, or even in the early part of the following Tertiary. Many writers are not explicit and precise ; some, perhaps, because they believe the information insufficient to warrant exact dating of the surface. In any case the most prevalent impressions seem to be that the Cretaceous, Kittatinny, Schooley, and Cumberland peneplains are approximately equivalent in age and slope down below the Cretaceous system of deposits, and that the Tertiary, Summerville, Highland Rim, and Shenandoah are equivalent and their development occupied the latter part of Cretaceous and the early part of Tertiary time. : The statements regarding the ages of the Appalachian peneplains, though somewhat indefinite, seem to have been accepted almost without question or critical examination. They are repeated in a multitude of publications and are used as perfectly good foundation material for other inferences. | Peneplains many hundred miles away, and far beyond the limits of continuous tracing, have been correlated with the Appalachian peneplains. In northwestern Illinois, Hershey’? and Bain*® describe peneplains of Tertiary and probable Cretaceous age. 18M. R. Campbell, F. G. Clapp, and Charles Butts: U. S. Geol. Survey Geol. Atlas, Barnesboro-Patton Folio, No. 189, 1913, p. 9. ; 1 OQ. H. Hershey: Pre-Glacial erosion cycles in northwestern Illinois. Am. Geol., vol. 18, 1896, p. 72. The physiographic development of the upper Mississippi Valley. Am. Geol., vol. 20, 1897, pp. 246-268. ; 2°07. F. Bain: Zine and lead deposits of the upper Mississippi Valley. U. 8S. Geol. Survey Bulletin 294, 1906, pp. 15 and 16. TIMES OF FORMATION OF THE PENEPLAINS 581 Some have gone so far as to work the rule the other way, and instead of dating a peneplain by deposits of known age date a deposit by a pene- plain on which it is believed to rest. Fuller and Clapp,”* for example, map and describe a formation as Eocene because they believe that the Tertiary peneplain was completed at about that time and that the deposit was laid down on the old plain. » The general implicit faith in the statements as to the age of the Ap- palachian peneplain is further exemplified by the dating of peneplains thousands of miles away by comparison with the Appalachian peneplains of supposedly known age. In his Forty-ninth Parallel report Daly”? says: “The evidences against the hypothesis of a mid-Tertiary peneplain on the Front ranges seem to be powerful. First, the time allowed is not sufficient for peneplanation or even past-mature development, followed by uplift and mature dissection in a second cycle. All post-Cretaceous time has not been enough to destroy the large monadnocks on the well established Cretaceous peneplain of the Appalachians, though their rocks are not sensibly stronger than those of the Front ranges of the Cordillera.” EVIDENCE AS TO AGE OF PENEPLAINS GENERAL STATEMENT The best evidence as to the age of the Appalachian peneplains seems to the writer to lie in the results of correlation with unconformities and deposits in the Coastal Plain and in knowledge concerning the rate and amount of erosion. The correlation rests on continuous tracing of pene- plains and coincidence of their projected planes and on the principle that deposits laid down near the close of an erosion cycle are more scant and finer in grain than those connected with an earlier part. The data as to rate and amount of erosion consist of (1) the present rate under various conditions and an estimate of the length of certain periods of geologic time, (2) the amount of material which has certainly been removed from some areas, and (3) the quantity of the deposits which have been derived from the province in various periods and epochs. CORRELATION WITH BURIED PENEPLAINS Statements concerning the local altitude and slope of peneplains in various parts of the Appalachian province are much more,abundant than those concerning the supposed buried correlatives. It is often remarked concerning a peneplain being described that it has such and such alti- “1M. L. Fuller and F. G. Clapp: U. 8S. Geol. Survey, Patoka Fofio, No. 105. “2h. A. Daly: North American Cordillera at the Forty-ninth Parallel, pt. ii, Memoir No. 38, Canada Department of Mines, 1912, p. 608. 582 E. W. SHAW—AGES OF APPALACHIAN PENEPLAINS tudes, and that, sloping seaward, it passes beneath deposits of a certain age, but it is rare that the slope of the buried surface for even a short distance is set forth. However, from published and unpublished observations together, the general lay of the buried peneplains can be ascertained fairly satisfac- torily. One in particular—the floor under the Cretaceous formations— can be determined with considerable accuracy. The facts come from (1) outcrops in a belt along the landward side of the Coastal Plain, (2) well records in this belt, and (3) well records in the middle and seaward por- tions. They show that to the east, south, and west this surface slopes away from the Appalachians at a rate generally about 30 feet to the mile. In places the slope is steeper. In the District of Columbia it is fully 100 feet to the mile. In a few places, as in North Carolina, where there has been uplift near the present coast, it is more gentle. But such departures are not enormous and are found in only a few places. The slope as a whole seems remarkably uniform. On the other hand, according to all descriptions and maps, the slopes of all peneplains about the adjoining margin of the Appalachian province is much less, ranging from 5 to 15 feet to the mile. This is especially noteworthy and reliable in the south, where there has been httle deforma- tion. Therefore, testimony based on projected planes indicates that the floor under the Cretaceous deposits is older than the so-called Cretaceous peneplain ; older even than the monadnock tops supposed to rise above the surface. Even the unconformity at the top of the Cretaceous seems to have a steeper slope than the adjoining portion of the so-called Cretaceous peneplain. If it be argued that a gradual increase in slope toward the sea is to be expected, it may be replied that according to descriptions and general altitude data the slope of exposed peneplains in a broad belt adjoiing the Coastal Plain decreases seaward, and the belt of greatest slope is many miles landward from the Coastal Plain border. Probably all will agree that cross and longitudinal profiles of Appalachian peneplains would show, as a general rule, a nearly horizontal central portion from which the slope increases in all directions outward for some scores of miles, be- yond which the inclination decreases as the altitude approaches sealevel, the central mountainous portion having suffered much the greatest uplift. Indeed, there is a generally accepted inference that in the upper portion of the Mississippi basin two or more of the peneplains, each approaching sealevel (or local baselevels not far above sealevel) at a declining rate, become so nearly coincident that they can not be distinguished. Downwarping due to isostatic adjustments can scarcely save the good EVIDENCE AS TO AGE 083 standing of the inferences concerning the ages.of the peneplains, for in the first place it would simply destroy the principal line of evidence as to their age, and in the second it could scarcely account for an abrupt down- bend along the original margin of the Cretaceous and Tertiary deposits, and surely not along what happens to be their present margin, for this is continually shifting seaward. It may be argued that since remnants of the so-called Cretaceous peneplain are scarce in a belt bordering the Coastal Plain, it may have been uplifted in this belt, so as to give it a greater slope on the seaward portion of the belt and make it harmonize with the peneplain under the Cretaceous deposits. This also would set aside the line of evidence generally regarded as most valuable, namely, that concerning coincidence of projected planes. If the possibility is real, then we must at least abandon such inferences as that the Cumberland and sub-Cretaceous peneplains are the same, for any other correlation would be as reasonable. On the other hand, since, with the possible ex- ception of the Nashville dome, which has been slightly uplifted, and a district just west of Washington, D. C., there is little indication of differ- ential uplift in the Piedmont province and other portions of the border- ing belt; the general discordance in positions and slopes of plains that have been correlated requires presumably some other explanation. The following table shows the general form and extent of the Coastal Plain deposits: EXTENT OF ATLANTIC COASTAL PLAIN DEPOSITS Distance from inner border Approximate to— ‘| Thickness of Place eee section ae. vee border. Present ae) oeen paar. coast. contour. | contour. Feet Miles | Miles Miles | ‘Feet Southern New Jersey.... 200 60 130 140 | 2,000 District of Columbia..... 400 120 160 obra eee 2,500? MOOK) Va. dsacdeiieese 250 90 155 160 | 2.5004 Wilmington, N. C........ PES) 115 Gee We ae eOD | 1,600+ Pharleston, S.C......... 425 125 17 |) 255 | 2,500 PawannaniGa,. ... 6.60 ce 400 125 195 240 | 2,500? 8 Montgomery, Ala., and Pensacola, Wla.......:. 550 165 200 | 250" | . 4,0007" Approximate (average)... 400 115 170 200 | 2,500 The figures in the above table are believed to represent correctly the general cross-section form of the land portion of Coastal Plain deposits 3 According to T. W. Vaughan and L. W. Stephenson, perhaps somewhat too low (oral communication). 584. E. W. SHAW—AGES OF APPALACHIAN PENEPLAINS and to give some indication of the form and seaward extent of the sub- merged portion. They are based on a large number of observations made along the outcrops of the various beds and in the drilling of wells. They show a generally uniform seaward slope of the floor under the Cretaceous of 25 to 30 feet to the mile. Data on the slope of the base of the Tertiary — are not so abundant, but apparently this slope is more lke that at the base of the Cretaceous than like the present surface, the average general seaward slope of which is less than four feet to the mile. The extent of the submerged portion of the Coastal Plain deposits can only be conjectured, still from a study of the fairly definite information concerning the land portion, the shape of the continental shelf, ‘and the known Cretaceous and Cenozoic history of the Atlantic coast some infer- ences can be drawn which carry a rather heavy weight of probability. On such a basis, involving seaward extrapolation of the base of the de- posits, the following table has been compiled: Average Cross-section Area of Atlantic Coastal Plain Deposits Hand portion oot Veet weet. Wawa hee 760 million square feet (estimated) Between coast and 50-fathom contour. 840 million square feet (conjectural) Between 50-fathom and 400-fathom CONUOUTS Bees othe been eee ee ees 400 million square feet (conjectural) Between 400-fathom and 1,500-fathom CONTOUTS fee eee ee ee Oe ae 200 million square feet (conjectural) MOtAl ccpls ie aeeke ke ie eee ah oa oi 2,200 million square feet (conjectural) Even in the Gulf embayment, where the deposits extend much farther inland and the base slopes not toward the sea, but more nearly toward the axis of the embayment, the rate of decline is still the same, being gen- erally from 27 to 30 feet to the mile. A dip section along a curving line from the northeast corner of Mississippi southwest and south would show the altitude of the inner border of the Coastal Plain about 850 feet, the distance to the present coast 440 miles, to the —300-foot contour 500 miles, and the —2,400-foot contour 530 miles, figures more than twice as great as those for corresponding features given in the above table. But the slope of the peneplain on which the Coastal Plain sediments rest is certainly about 30 feet to the mile for 100 or 200 miles, and several deep wells recently drilled near Vicksburg and Jackson, together with other wells in Louisiana that although thousands of feet deep do not reach strata within thousands of feet of the base of the Cretaceous, indicate that this slope continues nearly, if not quite, to the Gulf. The Coastal Plain deposits at Vicksburg are probably 4,000 to 4,500 feet thick and at the EVIDENCE AS TO AGE 585 coast southwest of New Orleans between 11,000 and 15,000 feet, the base being far lower than the continental shelf and one-half to three-fourths as low as the bottom of the Gulf. NATURE OF DERIVED DEPOSITS The use of fineness of grain and chemical deposits in dating peneplains seems rather unsafe, because it so generally depends on which peneplain and which limestone are to be correlated, and there seems to be much dif- ference of opinion as to the length of erosion cycles. Does the develop- ment of a peneplain generally require periods or epochs, or less than an epoch, or is it quite impossible to estimate? If it were known that about a period is required, that there are in the Appalachian province but two or three peneplains, and in the deposits two or three main limestones separated by many formations, the presumable implication would be clear. AMOUNT AND RATE OF EROSION If 30 million years have elapsed since Paleozoic time and the rate of erosion of the province has been the same as the present average rate for the United States, an average of over 3,000 feet of rock would have been removed, and it would seem very unlikely that any portion of a surface formed in pre-Cretaceous time could have survived this general degrada- tion. To be sure, ‘this figure may be far from correct, but it seems doubt- ful if it is many fold too large. So surely as rain has fallen on the earth, every square mile of the land area has annually lost through solution alone a great many tons. Furthermore, the streams of lowlands, com- monly at least, carry much sediment; so that, whether high or low, no part of the Appalachian province except those areas where deposits have been formed can have escaped continual reduction. If the Cretaceous and Cenozoic deposits of the Coastal Plain were to be spread evenly over the area outside the Coastal Plain now draining to the Atlantic and eastern Gulf, they would apparently make a layer about 3,200 feet thick, and probably the reduction that they represent is con- siderably more, one reason being that much of the lime, etcetera, of the eroded area has been carried far away. True, the Coastal Plain border has been shifting seaward ; the eastern border of the Mississippi basin has migrated more or less, and some of the Coastal Plain sediments may have been brought along shore from other regions; but after allowances are made, it seems probable that the quantity of Coastal Plain sediments indi- cate a removal from the Appalachian region of an average thickness be- tween 2,000 and 5,000 feet. If the amount were only 1,000 feet, it would still be sufficient for the present argument. 586 E. W. SHAW—AGES OF APPALACHIAN PENEPLAINS In areas of intense deformation a total reduction of 10,000 to 30,000 feet can be demonstrated, yet these are the areas in which surfaces older than the so-called Cretaceous peneplain are said to be preserved. If the central part of the province has been reduced from 3,000 to 30,000 feet, it seems improbable that any portion of the present surface is even as old as early Tertiary and doubtful if any is a fourth or even a tenth as old as Jurassic or pre-Cretaceous. SUMMARY Although the published statements concerning the ages of the Appa- lachian peneplains are inharmonious and many lack clearness, precision, and supporting evidence, they seem to be accepted with implicit confi- dence. In particular the conclusion that parts of all peneplains developed since Paleozoic time have endured to the present, and that some of these are early Cretaceous or older seems to be unquestioned; yet data which have been generally available indicate that all peneplains of which rem- nants exist today are younger than the floor under the Cretaceous with which one or more have so frequently been correlated, and additional data along several lines gathered during the past ten years support this infer- ence. It is the writer’s opinion that no portion of any surface so old as early or even late Mesozoic can have endured exposure to the elements in the Appalachian province until the present day, and that the oldest peneplain of which remnants exist was finished in Tertiary time. It seems to him probable that no portion of a surface even so old as Middle Tertiary has been preserved intact without perceptible reduction and remodeling. But however this may be, the evidence as to the ages of the peneplains seems to be fairly harmonious and to indicate ages more recent than those here- tofore assigned. BULLETIN: OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 587-600, PLS. 21-22 SEPTEMBER 30, 191S OOLITES IN SHALE AND THEIR ORIGIN? BY w. A. TARR (Read before the Society December 29, 1917) CONTENTS Page eo Dy DEAE aie LAER OKC ET TEC fol 15 Ve SUS ges ORR IPs care 588 Sree UNI Ol CMC OORU OS watern <:cim sicher oc od Custer ode Weenie AESTSIRIG™R TS wke Gis sce scenes 589 eM T SUAROEAO Ieper nonctercrahverets. cus sealel arate ieee eines Koceara ksve'as ben ee sae 589 HMC LOOMILGSmIny Ener eG. CU AIC. - 0/5, liscarcbal avelvar ilar sche cde ale occ paces 589 Pe OOlMLES Eilts DHE VeMOW TSINAIG 0: yk a citecperc ein vicele is cece Sin ec cece ees 591 SRE ROOMTES aM MEME VeTECON: SMANC acs. arciacnic vane.c «j« cbodassleve deepen dete ss eee eee 592 eR Vie AEN enlalrnies ‘acd ay ta cavsteoe ate an ic mo, skagen eRe eheinrie oe ea cae es 593 Gyrisine ss. 2: fee He Aha od OL tbe CR lo. 9 © Soe Ace an, 593 SEPT ULC TCIM rote caret ayctcre/s*araseRaterats *eNde relic a alley aielateve teolack re %io's io myale ss cee ewes 593 Evidence for the theory of primary deposition....................- 594 Pridence against the replacement theony. «00.006 sce neces cc ewe ee 595 Demeter DE IKE SURGE oa fopanar etc © «lane kasonala ees cc lerekerek oaletovere CAME c. o's GAG Stes oe eee ewes 597 Cause of the precipitation of the colloidal silica as oolites............... 599 LUT S TS ERS AG Ss a Aner © oo Pa er arr mr Ree ae oy 8. 2) 600 GEOLOGY OF THE OOLITIC SHALE Oolites are most commonly found in limestones, dolomites, or iron ores. Their occurrence in shale has not been recorded, as far as the writer is aware. The oolites described in this paper are found in a shale member of the red beds of the Wind River Mountains near Lander, Wyoming. These red beds of Wyoming owe their name to their prevailing color. They. consist of a series of shales, sandstones, thin beds of limestone and dolomite; and some lenticular beds of gypsum. The various beds show all degrees of gradation into one another, the majority being somewhat calcareous. The shales are often sandy and the sandstone may contain some argillaceous material. The limestone and dolomite beds are, how- ever, quite pure. As this formation is very poor in fossils, its age is still a matter of conjecture. Paleontologic work by Williston? and Branson® 1 Manuscript received by the Secretary of the Society December 29, 1917. 2S. W. Williston: Jour. Geol., vol. 12, 1904, p. 688, ff. B. Branson: Manuscript. at (587 ) 588 W. A. TARR OOLITES IN SHALE AND THEIR ORIGIN show that the upper portion at least is Triassic. Their conclusions are based on reptilian and amphibian remains found in a member of this upper portion. Williston has given the name Popo Agie to this fossil- bearing member.* It is this fossiliferous member that is discussed in this paper, as it is oolitic, in considerable part at least. Branson has described these beds,? and although the writer has studied them in the field, the following notes regarding them are based on Branson’s description, as he has studied them along the entire front of the Wind River Range. The thickness of the beds vary, ranging from less than 20 to more than 60 feet. In the main, this member is a sandy shale. The upper bed is FIcurE 1.—Nodular Structure of oolitic Shale after Weathering massive, ranging up to 15 feet in thickness, and “consists of nodules of purplish, argillaceous sandstone.” Branson suggests that the massive character of this bed may be due to the destruction of the bedding planes through the exposure of the beds and the alternate development and filling of sun-cracks, as described by Barrell. The color of the Popo Agie beds shows a remarkable variation, ranging through shades of green, red, brown, yellow, purple, and tan, “with occasionally white beds and now and then carbonaceous bands. Not infrequently included fossil bones are black, owing to carbonization.” 'The beds are fine-grained through- out, and much of the formation is decidedly oolitic. The amount of the ‘ Ibid. ’E. B. Branson: Origin of the Red Beds in western Wyoming. Bull. Geol. Soc. Am., vol. 26, 1915, pp. 217-230. ® Joseph Barrell: Bull. Geol. Soc. Am., vol. 23, 1912, p. 426. BULL. GEOL. SOC. AM. VOL. 29, 1917, PL. 27 I iGURE 1.—LARGE AND SMALL OOLITES AND THE I. IGURE 2.—DISTRIBUTION OF THE SAND GRAINS DISSEMINATED SAND GRAINS. (X 25) AND THE ZONES IN THE OOLITES. (XX 41) Pe FIGURE 5.—IRREGULAR DISTRIBUTION OF THE SAND GRAINS IN BOTH SHALE AND OOLITES A is a hole in the slide. ( 87) OOLITES IN THE RED SHALE GEOLOGY OF THE SHALES 589 oolites varies in the different colored phases, but they are uniformly dis- tributed within each phase. The structural features of the beds are interesting. Evidences of cross- bedding are rare, and “here and there a conglomerate, varying in com- position from pebbles of various kinds of rocks to pieces of bone and teeth of reptiles and amphibians, occurs among the other rocks.” All the beds show rapid lateral variation in composition, as well as in color, and a given bed may change in this way within a few feet. Nodules of ealeite which are 8 to 10 inches in diameter occur locally. A remarkable feature of the beds is the nodular form the material assumes on weather- ing. Many of these nodules are 12 to 14 inches in diameter and most of them are well rounded (figure 1). In the upper massive layer this nodular structure is especially well developed. DESCRIPTION OF TITE OOLITES GENERAL STATEMENT The material which the writer collected for study represents principally the red, yellow, and green phases of the formation. Oolites occur in other colored shales, but the above are taken as being typical of the oolitic phases. Whatever the color of the rock, the oolites are white. Only one exception to this was observed, the interior of an oolite being pink and the remainder white. THE OOLITES IN THE RED SHALE This shale is a dark purplish red in color, and the oolites in it comprise ‘more than 50 per cent of the rock. The shale is sandy. The grains are very small and not readily recognizable, although they may be seen through a binocular with a magnification of twenty-five. The oolites show a tendency to aggregate into groups of from 6 to 25 in number. They are rarely near enough to touch one another in these aggregates, but are merely more numerous there than elsewhere (figure 2). They are not related in position to any structural features of the rock. Under the microscope the sand is seen to be uniformly disseminated throughout the shale and the oolites (plate 21, figures 1-3). It consists of angular quartz grains, which are rarely over .1 millimeter in diameter, the majority being less than .05 millimeter. The oolites occur in two distinct sizes. The larger ones average about .65 millimeter in diameter, ranging from .5 to .? millimeter. This con- stant uniform size of about .65 millimeter should be noted. The smaller XLIV—Bu.Lu. Grou. Soc. Am., Vou. 29, 1917 090 W. A. TARR—OOLITES IN SHALE AND THEIR ORIGIN oolites are rarely larger than .26 millimeter and range from .1 to .13 millimeter. Those of the larger size comprise about 17 per cent of the slide and the smaller ones probably twice this amount. The larger oolites are concentrically banded (plate 21, figures 1 and 3), and: this feature is occasionally seen in the smaller ones. There is no FIGURE 2.—Distribution of the Oolites in red Phase of the Shale Slightly enlarged variation in their color, as the rings are due to the variations in the dia- phaneity of the material. The interior is more opaque than the outer zone, due, in part, to included clay. When several rings occur they are always in the outer portion of the oolite (plate 21, figures 2 and 3). The outer edge is not smooth, but irregular. Measurements of the central BULL. GEOL. SOC. AM. VOL. 29, 1917, PL. 22 FIGURE 1.—LARGE AND SMALL OOLITES. (X 25) FIGURE 2.—FouR NARROW ZONES IN THE OUTER PORTION OF THE LARGE OOLITES. (xX 87) OOLITES IN THE YELLOW SHALE DESCRIPTION OF THE OOLITES O91 opaque zone indicate that all these inner zones are of the same size. Like- wise, the outer spheres are of equal size in all the oolites. These facts point to uniform conditions during the periods of growth of the oolites. The oolites are composed of silica and are without a visible nucleus, unless the assumption is made that the smaller oolites acted as nuclei. This may have occurred in some of the oolites. They have a faintly granular appearance under the higher power of the microscope. Grains of sand preserve their uniform spacing in the oolites as in the shale, and may occur anywhere in the oolite (plate 21, figure 3). There is no evi- dence that they were pushed aside during the growth of the oolite, and their position indicates that they have not acted as its nucleus. This is of interest, for most oolites are usually described as having a ‘nucleus. This, however, is not essential, as oolites may develop without a nucleus. No cross is produced under crossed nicols, which is usually the case when the material is chalcedony, as these oolites appear to be. ‘Two oolites may oceur so close together that they have interfered with each other’s growth on the sides in contact, but there is little or no distortion of the concentric zones as a result, and the line of contact is a straight line (plate 21, fig- ure 2). OOLITES IN THE YELLOW SHALE The yellow shale is distinctly less sandy than either the red or the green shale. The spacing of the oolites in this rock is like that in the red shale (plate 22, figure 1). Under the microscope the ground-mass is seen to be opaque yellow clay, and occasionally there are a few grains of calcite. The oolites are of two sizes, as in the red shale. The larger ones aver- age about .62 millimeter in diameter and the smaller about .156 milli- meter, ranging from .130: millimeter to .260 millimeter. The larger oolites comprise about 14 per cent of the slide and the smaller more than 50 per cent. It should be noted that the large oolites are of approximately the same size as are those in the red shale (see plate 21, figure 1, and plate 22, figure 1). | The oolites, especially the large ones, are concentrically banded, the concentric rings being due to variations in the diaphaneity of the material. There is usually an opaque central sphere in the large oolites which is of nearly the same diameter, .09 millimeter, in all. This opaque zone, with its uniform diameter, occurs in the small oolites also when their diameter exceeds that of the opaque zone. The next prominent concentric sphere is .368 millimeter in diameter and occurs in all the large oolites, whether or not the above noted central opaque zone is present. Immediately out- side of this sphere are four concentric spheres having a total width of 592 W. A. TARR—OOLITES IN SHALE AND THEIR ORIGIN 078 millimeter (plate 22, figure 2), and the next is the outermost sphere, which is quite translucent. There is a suggestion of a radial structure in some of the oolites, but it disappears entirely under crossed nicols. All the large oolites and many of the small ones show a slight flatten- ing, so that they have a somewhat elliptical form. The concentric spheres are slightly broken at the sides. In all the oolites the borders are not distinct and sharply cut, but are more or less irregular. There is no evidence of a nucleus in any of the oolites, and the sur- rounding material is not disturbed in any way, showing that all growth of the oolites had ceased before the consolidation of the material. A striking feature of the rock is the development, on a microscopic scale, of the structural feature called stylolites. Their description will be included in a forthcoming paper on stylolites. THE OOLITES IN THE GREEN SHALE The green shale is sandy, like the red shale, and contains more oolites than either of the others, especially more of the large oolites. They show the same tendency to aggregation, but are in no way related to bedding planes or other structural features of the rock. The microscope shows that the oolites contain less sand than those in either of the other shales. It is scattered throughout the rock as im the other shales, and when an oolite contains one or more grains they are in no way related to the oolitic structure, but occur in any portion of it, the oolite having simply inclosed them. The diameter of the oolites averages slightly over .6 millimeter, while occasionally there is one which has a diameter of nearly a millimeter. The small oolites are about the same size as those in the other shales. The numerous concentric rings of the oolites in the red and yellow shales - are missing in those of the green shale. There is one narrow, translucent ring which is practically the same size im all the oolites—that is, .266 millimeter in diameter. This uniformity in diameter was noted in the oolites of the other shales. This would hardly be expected, for the ma- terials came from different portions of the formation, and, as already noted, a characteristic feature of the beds is the abrupt variation in com- position. The larger oolites and the smaller ones appear to be of about the same average size in all the shales. ; Numerous grains of calcite occur in the green shale and sometimes fie partly within the oolites. These grains are very irregular in shape and may occur in any portion of the shale. This distribution indicates that the grains of calcite are not unchanged portions left by a replacement of calcite by silica, but that the calcite grams, like the sand grains, were DESCRIPTION OF THE OOLITES 595 deposited at the same time as the oolites and other materials of the shale. A megascopic study of a piece of the material different from those de- scribed above shows many small, irregular pieces of impure calcite or rather calcareous shale. This material contains also small nodules of limonite, some nodules being one-half inch in diameter. The oolites are disseminated through the sandy shale which surrounds this calcareous, hmonitic material. All the different materials occurring in these shales show by their relationship that they were deposited simultaneously. Some of the shales contain numerous grains of what appears to be glau- conite. It is possible that the green shale may owe its color, in part at least, to this mineral. The color of the red and yellow phases is due to iron oxides. SUMMARY The oolites are found scattered throughout the shale, which may or may not be sandy. They are of two sizes, the larger averaging about .6. milli- meter and the smaller about .15 millimeter in diameter. They are com- posed of silica and are made up of concentric spheres. These concentric spheres have approximately the same diametér in each sort of shale, but not the same in the various sorts. None of the oolites have a nticleus, although some of them contain considerable clay in the inner sphere. As a rule, they are without a radial or tangential arrangement. There is a faint radial arrangement in the oolites of the yellow shale, but they do not show a cross between crossed nicols. Sand grains are scattered throughout the shale and the oolites, but are in no way related to the growth of the oolites. Irregular grains of calcite occur in the green shale and in the oolites in it, but are not related to the oolites. The relation- ship of the oolites to each other and to the surrounding material indicates that their growth was attained before the beds were consolidated. ORIGIN INTRODUCTION The writer believes that the oolites were always siliceous as they are now. While this conception of the origin may appear unusual, vet the evidence is such as to strongly support the view. As will be shown later, much silica is being added to the waters of the sea by all streams. This silica must be deposited because it is not now a constituent of the sea- water in appreciable amounts, so it should not be regarded as so very unlikely that some of it may have assumed the spherical form of oolites in the rocks. Such forms are typical of all amorphous substances, and o94 W. A. TARR—OOLITES IN SHALE AND THEIR ORIGIN gels are especially apt to assume such shapes because of the lack of any cohesive force save surface tension. Surface tension serves a very 1mpor- tant part in the development of the oolites, as it tends to aggregate the gel into small spherical bodies. It is this combination of much silica being added to the seas, its precipitation as a gel, and the tendency of gels to assume spherical forms that strongly favor the view that the siliceous oolites are original. EVIDENCE FOR THE THEORY OF PRIMARY DEPOSITION The following reasons are the most important for believing that the silica was deposited at the same time as the inclosing rock, which was a sandy shale in this case: 1. The uniform distribution of the oolites through the shale without any evidence of accumulation along a given plane is in favor of this view. The shale itself may or may not be entirely without banding. Uniform distribution is what would be expected if the siliceous material accumu- lated along with the muds of the shale, both settling to the bottom as they were added to the water. 2. The uniform distribution of sand grains in both oolites and shale favors the primary deposition theory. The sand grains were carried down by the muds and were included in the gel of the siliceous oolites. Their arrangement in the oolites shows that they were simply included im the soft material and were in no way affected by further enlargement of the oolites—a fact wholly compatible with the growth of gels. Possibly some of the sand grains were acquired by adhering to the gel. There is also considerable kaolin scattered through the oolites, especially in the central zone of some of them. This is evidently due to the central zone forming soon after entering the water, where it was, of course, very muddy. 3. All growth of the oolites ceased as soon as they were buried in the muds. They could grow as long as they were settling through the water and until they had been buried by the accumulation of mud on the bot- tom. Practically all the silica went into the oolites, for the shale is only shghtly plastic. 4. The interference of the oolites is a very suggestive feature. As can be seen in the plates, the oolites are frequently in contact, the line of con- tact usually being regular. There is no evidence in any of the shales that the inner zones have been deformed by their growth. The oolites have evidently continued to grow after coming to rest on the bottom. Two adjacent oolites grew uniformly and thus preserved a regular line of con- tact. If a small oolite was in contact with a large one it was usually partly surrounded by the larger. ORIGIN OF THE OOLITES 595 This interference is characteristic of this type of oolites. A large num- ber of slides of calcareous oolites from all parts of the United States were examined, and in not a single instance had the oolites interfered with each other’s growth. They were always merely in contact. This is sig- nificant as showing that the oolites were growing in the muddy water, and that their growth was not due to material acquired by rolling about on the bottom. | 5. There is a slight flattening of the oolites in the yellow shale, but it is not noticeable in the other phases. This flattening was produced dur- ing the consolidation of the shales, but after growth of the oolites had ceased. 6. The growth of the oolites was stopped by the accumulation of suffi- cient mud above the oolites to prevent any more silica reaching them. This was evidently the factor which produced the uniform size of the oolites, and it points to a uniform rate of deposition. 7. The beds which contain the fossils were deposited in shallow water and were probably loose, soft, sandy muds. Branson’ has cited the evi- dence and come to the conclusion that the red beds are, in the main, of marine origin, but that the Popo Agie beds show several evidences of subaerial origin and were formed as marginal deposits, partially marine and partially subaerial. The writer believes that the Popo Agie beds were practically continu- ously under water, but that it was very shallow water and comparatively near the shore. These points, in connection with the points made in regard to the silica, are believed to be favorable to the view that these siliceous oolites were deposited at the same time as the inclosing shale. EVIDENCE AGAINST THE REPLACEMENT THEORY Since the prevalent view is that all siliceous oolites are due to the re- placement of calcareous oolites by silica, it will be of value to note the evidence against this view in this case. The following reasons are be- heved to be against it: 1. The oolites occur in shale. The writer has found no record of either siliceous or calcareous oolites occurring in shale. Under the above pre- cipitation theory the occurrence of oolites in shale would not be unlikely, however. Leith and Mead* have suggested that “a large part of the silica carried in solution by rivers is deposited with the muds and clays” (page 7h. B. Branson: Origin of the Red Beds in western Wyoming. Bull. Geol. Soc. Am., vol. 26, 1915, pp. 217-230. : 8C, K. Leith and W. J. Mead: Metamorphic geology, 1916, pp. 81, 402-104. 596 WwW. A. TARR—OOLITES IN SHALE AND THEIR ORIGIN 81), and that “colloidal silicic acid is believed to be deposited largely with the clays and muds, as the same processes of flocculation which precipi- tate the colloids also throw down the finely divided sediments” (page 102). The plasticity of shales is due to colloids and the principal colloid in them is Silica; so the view that the silica might assume the oolitic form at times is quite probable. That oolités are not more common in shales is due to the lack of favorable conditions for the rapid precipitation of the colloids and a lack of an abundance of colloidal silica. 2. There are no residual grains of calcite or aragonite present in the oolites. Even though aragonite is the form:in which most calcium car- bonate is precipitated, it is soon converted into calcite and would appear as such in the shales. A few grauis of calcite, very irregular in shape, are found in the yellow and green shales. Some of these grains are in the oolites, but the majority are in the shale around them. Their form, dis- tribution, and relationship to the surrounding material is such that to assume that the grains in the oolites are residual is to assume that the erains in the shale are also residual, and that the calcite has been replaced by shale, an assumption no one would agree to. The calcite is original, as are all the constituents of the shale.’ The writer has-a large collection of slides of caleareous-and siliceous oolites from previously described and new localities. Some of them show replacement by silica; some are wholly _calcareous, and none of the siliceous oolites in shale show the character- aS of those siliceous oolites which have replaced calcite. . All silicified calcareous oolites show siliceous cementation. This is never present in the oolitic shale. ; 4. The imperviousness of clays and shales preclude any possibility of the introduction of silica into the shales. All men ‘recognize shales as being impervious barriers to the passage of water in controlling artesian water supplies, in ore deposits, in oil fields, and also to the passage of gas in gas fields. The following extract foi Leith and Mead testifies fur- ther to the imperviousness of shales: “Argillaceous sediments, although very porous, are characteristically imper- vious and do not permit even moderately free circulation of solutions. Water circulation depends on size and continuity of openings rather than on total volume of openings or degree of porosity. Cementation by infiltration of materials from extraneous sources is believed to be largely inhibited by the imperviousness of clay to free water circulation. Induration is probably ac- complished mainly by compression and internal rearrangement of original con- stituents” (ibid., p. 108). >. There is no adequate source of the silica with which to produce re- placement. If it can not come from the outside, then only the minerals ORIGIN OF THE OOLITES 597 in the shale can be a source. Very evidently it is not the quartz, for the quartz grains in the shale are sharply angular, showing no evidence of solution. The only other constituent is kaolin, and it is unlikely that any solutions in the shale would attack this extremely resistant mineral. No other silicates could be recognized in the shale. There is no more likely source from the outside, as the adjacent beds also are sandstones and shales. Suitable solvents for silica are extremely rare among ground waters, yet one must be sought if the oolites originated by replacement. The view that organic acids are adequate solvents has fallen into disfavor in recent years. The conclusion is reached that siliceous oolites in shale do not owe their origin to the replacement of calcareous oolites. SOURCE OF THE SILICA It is believed that the oolites are due to the precipitation of colloidal silica, which was brought by the streams into the sea or inclosed body of water. The streams which flowed into this body of water drained from an unknown area to the west. The character of the rocks of this drainage area is, of course, unknown, but some part of the material in solution, at least, may have been derived from any exposed Lower Paleozoic forma- tions. Possibly the larger portion of the drainage area consisted of Pre- cambrian and igneous rocks. It would appear that the character of these stream waters would be comparable to those of the streams that are drain- ing areas of mixed types of rocks today. Many analyses of the waters of such streams are available, and these afford data to test the adequacy of the idea that the streams may be a source of silica. There is only one analysis of the water of the streams in this region, and that is of the waters of the Popo Agie, which drains mainly a granitic area, but crosses Paleozoic sediments in its lower course. Slosson’s® analy- sis shows that approximately 8 per cent of the material in solution is silica. Headden’® gives an analysis of the Arkansas River at Canon City, Colorado, which shows 8.19 per cent silica, while another stream, the Poudre River, in northern Colorado, after flowing for fifty miles over eranitic rocks, contains 23.5 per cent silica. It will be necessary for our purpose to give only some averages of a number of streams in various parts of the United States. Dolet’ gives analyses of the principal streams of 9H. EH. Slosson: Bull. Wyoming Agri. Exp. Sta., No. 24, 1895, p. 119. OW. P. Headden: Bull. Colorado Agri. Hxp. Sta., No. 82, 1903. UR. B. Dole: The quality of surface waters in the United States. Water Supply Paper No, 236. 0298 W. A. TARR—OOLITES IN SHALE AND THEIR ORIGIN the eastern United States, and the following averages were made from his paper: Percentage of silica Streams draining sedimentary and glacial areas........... 7.8 Streams draining Precambrian, sedimentary, and metamor- Dic, TOCKSE.ys2 cee ae ene ces eee Sek Fas ee eee 21.2 Streams draining Precambrian and igneous areas.......... 28.5 The climatic conditions for these stream areas are those of the United States east of the one hundredth meridian, so they vary widely. Data for the streams of the Pacific coast are given by Van Winkle.*? The average silica content for California streams is as follows: Percentage of silica Grantie?) APeas soi se sc ee Sw as ap slo 8's Bas oe a ee 14.3 isneous rocks of all kimds. 2... «<2. <5 «+2 i.e eee 17.6 Igneous and Sedimentary areas......-..--.> o..c8esteeeeeee 8.0 All sedimentary TOCKS o..5.0 05 cents 2+ sia «=o mret ss oe ee 6.7 Averave Tor ‘Catitornia streams...........¢ sc. ese ene eee 14.3 The following figures are of interest in showing the lack of climatic influence on the amount of silica in solution: Percentage of silica Average of all streams with rainfall over 15 inches........ 14.4 Average of all streams with rainfall under 15 inches....... 14.2 The majority of the Oregon streams drain areas of igneous rocks or of igneous, metamorphic, and sedimentary rocks. Percentage of silica Average’ GE 1¢neous TOCKS. =o. 2-0 Di se 2 eee eee 30.5 Average of igneous, metamorphic, and sedimentary rocks... 22.6 Averaze: ot ail. Oregon: sireams..... si...» a0seeee eee eee 26.82 These streams are all high in silica. | Washington streams show the following silica content: Percentage of silica Areas Gf ISNne@GES TACK: teow cd inlet bes su eee eee . Oo Areas of igneous and metamorphic rocks.................. 27-3 Areas of igneous, metamorphic, and sedimentary rocks..... 14.8 Average of all streams, including some from wholly sedi- : mentary aPGas. 225 2 ‘ fal Muses JOSEPH STANLEY-BROWN, EDITOR PUBLISHED BY THE SOCIETY MARCH, JUNE, SEPTEMBER, AND DECEMBER \ 4 eS eR ee SLR ok: San . » 4 ~~ er ‘ er > ac ee Oe: Mes (ee - v Pm t t ys x J CONTENTS 3 = a aT — en Mesozoic . History - of Mexico, Central America, and the West Indies. By T. W. Stanton - - - - - - = - = = Relations betwen the Mesozoic Floras of North and South America. b + F:H: Kaowlton. —- =) = ee ee Geologic History ofCentral America and the West Indies during Cenozoic Time. By Thomas Wayland Vaughan - -- - Paleogeographic Significance of the Cenozoic Floras of Equatorial America and the Adjacent Regions. By Edward W. Berry Age of Certain Plant-bearing Beds and Associated Marine For-. mations in South America. By Edward W. Berry - - - Bearing of the Distribution of the Existing Flora of Central America and the Antilles on Former Land Connections. By eaiiam avelease oes oo ee eg ee ee Affinities and Origin of the Antillean Mammals. By W. BD. Wiatthew.- -- = Ne ae ee ee Se aeataticotame. 29> = ele hae oe taf ie eee eee ee Title, Contents, etcetera, of Volume 29 - - - - - - - | Page 60 1-606 607-614 615-630 631-636 637-648 649-656 657-666 667-679 1-x)X BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA Subscription, $10 per year; with discount of 25 per cent to institutions and libraries and to individuals residing elsewhere than in North America. Postage to foreign countries in the postal union, forty (40) cents extra. Communications should be addressed to The Geological Society of America, care of 420 11th Street N. W., Washington, D. C., or 77th Street and Central co West, New York City. NOTICE.—In accordance with the rules established by Council, claims for non-receipt of the preceding part of the Bulletin must be sent to the Secretary of the Society within three months of the date of the receipt of this number in order to be filled gratis. Entered as second-class matter in the Post-Office at Washington, D. G:, under the Act of Congress of July 16, 1894 Acceptance for mailing at special’rate of postage provided for in Section 1103, Act of October 3, 1917, authorized on July 8, 1918 PRESS OF JUDD & DETWEILER, INC., WASHINGTON, D. C. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA \ VOL. 29, PP. 601-606 DECEMBER 30, 191S =~ PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY MESOZOIC HISTORY OF MEXICO, CENTRAL AMERICA, AND THE WEST INDIES + BY LL OW. STANTON (Read before the Paleontological Society January 1, 1918) CONTENTS Page MMEEITUE ifort 7G era rv ako svi S acinus & OBE haaetats Moa es tle ss sicisies sce ess 8 601 2) Sa aha, calle Ais" as atte 'a ato'g. alain Whetela our axeutetomattal grees AE spot twists Mela Salts 602 EM era ie tere N ce ete, « o.6 Wx SMe ee eek wks Va ween a's 604 TEM Ee! LPs ihe Sayre aches Shap 5 OER DAs a Oe eh ra la wolvs vie bea eid weed 605 INTRODUCTION This résumé deals only with those phases of Mesozoic history which have a direct bearing on the biologic relationships of North and South America by indicating on the one hand epochs of probable marine con- nection between the Pacific and the Atlantic through tropical America, and on the other hand epochs of probable land connection between North and South America. The evidence to be presented consists of the distri- bution of the sediments of different epochs on the present land area, their character as marine or continental, and the relationships of the marine faunas found in them. Most of the data are recorded on the Geologic _ Map of North America compiled by Willis and Stose, and in the litera- ture abstracted by Willis in his Index to the Stratigraphy of North America. These have been supplemented by the consideration of more recent papers by C. Burckhardt, H. Bose, G. R. Wieland, J. P. Smith, and others, and by a few, collections of fossils which have been studied by me.., Through the courtesy of Professor Schuchert, I have also had the use of manuscript notes on the stratigraphy of Mexico prepared for him by E. Bose. Our knowledge of the character and distribution of the Mesozoic faunas of Mexico has heen greatly increased during the last fifteen years by the * Manuscript received by the Secretary of the Society August 22, 1918. XLV—BuLL. Grou. Soc. AM., Vor. 29, 1917 (601) 602 T. Ww. STANTON—-MESOZOIC OF MEXICO AND CENTRAL AMERICA work of Burckhardt, Bose, and other members of the Geological Institute of Mexico, but many desired details are still lacking, especially concern- ing southern Mexico, and the faunas and formations of the Central Amer- ican: States are known only in a general way. It is obvious that deduc- tions from such incomplete data must be only tentative. Even in areas where the stratigraphy, paleontology, and areal distribution are thor- oughly known, there is usually an element of doubt and uncertainty in interpreting sea and land connections. There is nearly always more than one possible explanation of the facts observed, and the most obvious ex- planation may not be the true one. A great difference between contem- poraneous marine faunas such as is found between the Shasta fauna of the United States Pacific coast and the Comanche faunas of Texas and Mexico strongly suggests a persistent land barrier; but other conditions, such as climate, character of bottom, etcetera, may be equally effective in causing differences in faunas, and when the Comanche, or Gulf, type of sediments and fauna seems to extend entirely across southern Mexico, reaching the Pacific coast, it becomes necessary either to abandon the land barrier or to shift it westward beyond the present continental area. There is equal difficulty in establishing particular interoceanic connec- tions. Close similarity of contemporaneous marine. faunas with consid- erable specific identity is good evidence of an open route for migration between the two areas, but that route may not always have been the one which now looks easiest. Certain of the Triassic and Jurassic faunas of California show close relationship with the corresponding faunas of the Mediterranean province in Europe, and their relationship has very natu- rally been attributed to migration through the Central American portal, as J. P. Smith has called it, but the possibility of an Indo-Pacific route, or even of an Arctic route, should not be overlooked. With these general words of caution concerning the nature of the data and the conclusions that may be placed upon them, we may proceed to sketch the oscillations of land and sea in Mexico and Central America during the Mesozoic era, beginning with early Triassic time. | TRIASSIC The Triassic was in general a period of emergence for the North American Continent. Practically the whole of the continent was above sealevel most of the time, and the minor recorded changes in strand-line in the area north of Mexico affected only the Pacific coast. Marine Lower Triassic deposits are known only in eastern California, Utah, and southeastern Idaho, probably extending into western Wyoming. The earliest fauna in these beds, the Meekoceras fauna, is Asiatic in its affini- TRIASSIC 608 ties, its nearest relatives being found in India and Siberia. It is there- fore a reasonable inference, both from the faunal relationship and the areal distribution of the deposits, that there was no direct connection between Atlantic and Pacific waters through the Mexican-Central Amer- ican region. A later fauna in the Lower Triassic, the Tirolitic fauna, is known only in the Mediterranean region and in Idaho, and hence an open route of migration through the Central American region has been in- ferred, but no deposits or other direct evidence in support of this inference are known. The facts are similar for the Middle Triassic when the sea retreated still farther, so that the known marine deposits are restricted to eastern California, central Nevada, and British Columbia. In his recent mono- graph of the Middle Triassic marine invertebrate faunas of North Amer- ica, J. P. Smith states that “the faunas of the American and of the Mediterranean regions during the Middle Triassic are more closely re-: lated to each other than either is to the Indian or to the Boreal fauna.” He further says that “in the zone of Ceratites trinodosus, in the West Humboldt Range of Nevada, out of more than 100 species more than one-fourth are either identical with or very closely related to forms from this zone in the Mediterranean region. It is possible that during the Middle Triassic a connection was established between these regions through some other way than the Indian branch of the old central Med- iterranean, or “T'ethys.’” In another paper he definitely states that the Central American portal was reopened at this time. Again, the oceanic connection is based on faunal relationships of distant regions only. During Upper Triassic time the Mediterranean element in the Califor- nia faunas continues large and is especially predominant in the Tropites subbullatus fauna of the Hosselkus limestone, which is referred to the Karnic epoch. The only marine Triassic deposits known in North Amer- ica south of the United States are also of Karnic age and have yielded a meager fauna which is closely related to that of the Mediterranean on the one hand and to that of California on the other. These beds are in central Mexico, near the city of Zacatecas, with possibly another area southeast in Guanajuato. On account of these faunal and geographic relations, Burckhardt has suggested a marine connection between the Atlantic and Pacific across central Mexico, and Smith has inferred an open “Central American portal.” That there was a passage somewhere between Panama and central Mexico seems reasonable. The Upper Triassic submergence was of brief duration, and not Lene thereafter, either in latest Triassic or earliest Jurassic time, or possibly in both, there was an epoch of continental sedimentation during which, 604 TT. w. STANTON—MESOZOIC OF MEXICO AND CENTRAL AMERICA in several widely distributed areas, cycads and other land plants were embedded in non-marine deposits. Newberry has described some of these plants from Honduras and from Sonora as Rheetic, and somewhat similar floras have been described by Logano as Lower Jurassic (Liassic) from the States of Vera Cruz and Puebla, and by Wieland from the State of Oaxaca. Non-marine deposits similar to those containing the plants are distributed through Chiapas, Guatemala, Honduras, and Nicaragua. (Incidentally it should be mentioned that in Willis’s Index to the Stra- tigraphy of North America, page 500, through an error in transcription or proof-reading, Sapper is made to call these rocks marine. 'The original word is Mergel, which of course was translated marls.) The length of the epoch or epochs represented by these plant-bearing deposits and their exact place in the general time scale must be determined by further studies and discussions by the paleobotanists, supplemented by thorough investigation of the stratigraphy of each area involved. Meanwhile these floras may be used as proof of extensive land areas near the close of the Triassic and continuing into Jurassic time. JURASSIC That the plant-bearing beds of southern Mexico just mentioned are actually of Jurassic age seems to be established by their association with marine beds containing characteristic Jurassic ammonites. According to Bose, those of Puebla are lower Liassic, while those of Oaxaca described by Wieland are in part Middle Jurassic, perhaps extending down into the Upper Liassic. Bose reports marine Liassic beds with Arietites and a varied molluscan fauna in northern Puebla and neighboring parts of Hidalgo and Vera Cruz at elevations of over 2,000 meters, and another possible occurrence of marine Liassic in Oaxaca. All the other known areas of marine Lower Jurassic in North America are confined to the Pacific border north of Mexico, and the imperfectly known fauna seems to be sufficiently related to that of Europe to indicate direct connection. The marine deposits in southern Mexico strongly suggest that the inter- oceanic passage was in that region. Similar conditions prevailed in Middle Jurassic time, when the faunas of the Pacific coast of the United States were related to those of the Mediterranean region, and the presence of marine Middle Jurassic sedi- ments in Oaxaca and Guerrero indicates that the interoceanic connection may have been across southern Mexico. The wider distribution of Upper Jurassic sediments in Mexico, in Cuba, and in west Texas seems to indicate a greater submergence than at any previous epoch in the Mesozoic era. Marine rocks of Upper Jurassic JURASSIC AND CRETACEOUS 605 age are found in Chihuahua, Durango, Nuevo Leon, Zacatecas, San Luis Potosi, Puebla, Guerrero, Oaxaca, and the Isthmus of Tehuantepec, and include Oxfordian, Kimmeridgian, and Portlandian. According to Burckhardt, the faunas are related to those of central Hurope and the Mediterranean, but also include elements derived from the faunas of India, of the boreal region, and of the Andes, together with a character- istic element which may be called Mexican. This Mexican element seems to be represented in the Jurassic of western Cuba, which is the oldest known Mesozoic of the West Indies. A reasonable interpretation includes the Mexican and Texan Upper Jurassic in the Atlantic or Gulf of Mexico sedimentation, with one or more temporary connections with the Pacific to admit the boreal and Indian elements of the fauna. CRETACEOUS Cretaceous limestones with minor shales and sandstones have a great thickness and wide distribution in Mexico and Central America. Much the larger part of them are referred to the Comanche series by American geologists, and assigned to the Lower Cretaceous. Both the rocks and the faunas are of the same facies as the typical Comanche series of Texas, though it.is recognized that some of the beds in southern Mexico are probably older than any of those in Texas. The Mexican geologists have divided these rocks into Lower and Middle Cretaceous, and all are agreed ‘In assigning the rocks overlying the great limestones to the Upper Cre- taceous. It is well known that the Comanche fauna is related to the Cretaceous fauna of the Mediterranean province and is totally distinct from any of the Shasta faunas of the Pacific coast of the United States, which must be in part contemporaneous with it. The difference is so great that a connection between the Pacific and the Gulf of Mexico has not been thought possible, in spite of the fact that the Comanche type of sediments and faunas seems to reach the present Pacific coast in southern Mexico. ‘The difficulties in placing a land barrier west of the present west coast of Mexico and Central America are realized, for the 100-fathom line is only 10 to 100 miles off the coast, and the 1,000-fathom line is approximately parallel to it and only a few miles farther out. The fact that the 1,500-fathom line extends on the Equator out beyond the Gala- pagos Islands may have some significance, and the 2,000-fathom line sweeps far out opposite the Gulf of California as well as on the Equator. Though the difference in facies of both sediments and faunas in the Co- manehe as compared with the Shasta may be again mentioned, by way of caution, as partly accounting for differences in the faunas, it is be- lieved that such a complete lack of common species must have been caused 606 T. w. STANTON——MESOZOIC OF MEXICO AND CENTRAL AMERICA by a land barrier between the Atlantic and Pacific throughout North America. Comparatively little is known about the Cretaceous rocks of Central America which have been mapped by Willis as Lower Cretaceous in Guatemala, Honduras, Costa Rica, and Panama. Some geologists have described them as Upper Cretaceous, but from the brief statements about the fauna found in them it is inferred that they are probably Comanche.’ No Lower Cretaceous rocks are known in the West Indies, with the pos- sible exception of some imperfectly known beds on Trinidad. The Upper Cretaceous faunas of the Pacific border, while complex and showing many local and temporal variations, are bound together by com- mon species, so that in a broad sense they form a unit which is distributed from Alaska to the peninsula of Lower California. These faunas are remarkably distinct from the Upper Cretaceous faunas in and east of the Rocky Mountains, which also show considerable regional differentiation among themselves and are yet more or less bound together by relation- ships of various kinds. In Mexico the Pacific, or Chico, fauna is known only in Lower California, while the Gulf and Interior types of faunas do not extend much west of the meridian of El Paso, on the northern border, but are widely distributed east of that line in the northern half of Mexico. Farther south, in Puebla and Guerrero, isolated areas have been referred to the Upper Cretaceous, apparently of Atlantic type, but in general the Upper Cretaceous seems to be absent from southern Mexico. Near Car- . denas, in southeastern San Luis Potosi, there is a Lower Senonian fauna, described by Bose, which differs markedly in facies from all the contem- poraneous faunas of the Gulf Coastal Plain of the United States on account of the abundance of Acteonella, Rudistz, corals, etcetera. It shows, however, close relationship with the West Indian Cretaceous fauna as developed in Cuba, Jamaica, and Santo Domingo, and also resembles the Gosau fauna of Europe. All the known facts of faunal relationships and distribution seem to call for a continuous land during Upper Cretaceous time extending par- allel with the Pacific border from British Columbia and farther north to South America. The history of the Mesozoic changes in land and sea which probably involved land connections between North and South America, or marine connections between the Gulf of Mexico and the Pacific, is epitomized in the tabular summary submitted by Doctor Vaughan. 2A small collection of fossils from the Cretaceous limestones of Honduras received from Mr. R. W. Pack since these lines were written seem to belong to the Comanche ' fauna. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 607-614 DECEMBER 30, 1918 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY RELATIONS BETWEEN THE MESOZOIC FLORAS OF NORTH AND SOUTH AMERICA? BY F. H. KNOWLTON (Read before the Paleontological Society December 31, 1917) CONTENTS Page Sie est igi OU sod as) hs Waa MBN BSUENIAN <) mslciS "oceania! ends, A cbt elalie a er oe tele ws 607 PNRM cs ec ao oe da etd laccroas Mma SRATR cae yeaa Taare Rhee, wl ee wines tao # ene wale we wales 607 ERM oe ae Win shcse tke tuole sw EAM pee ef che aN Meroe ancanciace te Sars 609 CAML eee Phe ck ts ia hers aren eRe MPS Re oe eles Aa wleitdteaes syere a eae 611 SEER avite. Ge eGtis sheet as Pie ere kis ele es Ted yc ARE Can cain garner arr 612 INTRODUCTION The natural order of sequence in considering the relations between the Mesozoic floras of North and South America must be the Triassic, the Jurassic, and the Cretaceous. TRIASSIC Rocks of Triassic age are known in many and widely separated parts of the world, and they are of great thickness, which imphes a varied and relatively long-continued period of geologic activity. It is also evident from the thick deposits of coal known at several points, and in other ways, that vegetation must have been fairly abundant and considerably varied in character ; yet the determinable forms of plant life that have thus far been recovered from the Triassic are surprisingly few in number—in fact, it is doubtful if the known flora far exceeds 300 species. This is, of course, to be largely attributed to the fact that much of the deposits were laid down under marine conditions, where one would hardly expect to find the remains of land plants preserved except near shore and more or less fortuitously ; and, further, if the evidence believed by some to indi- 1 Manuscript received by the Secretary of the Society August 22, 1918. (607) 608 F.Ww. KNOWLTON—MESOZOIC FLORAS OF THE AMERICAS cate aridity is really valid—it is not altogether accepted—it might ac- count to some extent for the absence of plant remains in certain very thick and generally barren deposits. But, be these controlling factors what they may, the fact remains that the known Triassic flora is but scantily preserved to us. In addition to the scantiness of the plant remains, there is another element that must be mentioned, namely, the authenticity of the reference of certain deposits to the Triassic. Though quite generally considered as referable to this epoch, there is some lack of confirmatory data—that is, in the absence of thoroughly satisfactory information it is often difficult to decide between Upper Triassic and Lower Jurassic. The Triassic flora of North America north of Mexico numbers 136 nominal species. Of this number about 120 species are confined to the eastern province—that is, to Massachusetts, Connecticut, Pennsylvania, Virginia, and North Carolina. The remaining 16 forms are distributed as follows: Abiquiu, New Mexico, 11 species; fossil forests of Arizona and vicinity, 4 species; and Alaska, 1 species. Passing south into Sonora, Mexico, it is to be noted that Newberry described a small collection belonging to 9 genera and 13 species that were supposed to be in the same stratigraphic position as those at Abiquiu, New Mexico, though only one species is common to the two areas. From the so-called Mixteca Alta, or high country, on the southern edge of the Cordilleran system facing the Pacific, in the Mexican State of Oaxaca, Wieland has reported the presence of Triassic plants; but it is my opinion that these plants are younger than this, though it is not definitely settled just what their position is. In 1888 Newberry’ reported the presence of Rhetic plants from San Juancito, Honduras, enumerating 11 genera and 14 species. In a num- ber of subsequent publications Carl Sapper® has intimated that New- berry’s age determinations should be accepted only with doubt; they are possibly Jurassic. Passing now into South America, so far as I am able to determine the first plants of supposed Triassic age were reported by Zeiller,* in 1875, from La Ternera, northern Chile. They were found in a rather impor- tant coal-basin and comprise only six species, belonging to the genera Jeanpaulia, Angiopteridium, Pecopteris, Dictyophyllum, Podozamites, and Palissya; they were referred to the Rhetic. 2J. S. Newberry: Am. Jour. Sci., 3d ser., vol. 36, 1888, pp. 342-351. 3 Bol. Inst. geol. Mexico, no. 3, 1896, pp. 5-8. *R. Zeiller: Note sur les plantes, fossiles de la Ternera (Chili). Bull. Soc. geol. de France, 3d ser., vol. 3, 1875, pp. 572-574. TRIASSIC 609 In 1899 Solms-Laubach® reported on a much larger collection from the same locality. He was able to enumerate about a dozen genera, but did aot give specific names to all. They were still considered to be of Rheetic age. ‘ About the same time that the discovery of Triassic plants was made in Chile, plants presumed to be of the same age came to hght in Argentina. They were first reported on by Geinitz,° in 1876. He enumerated 14 species, referred to 12 genera. Only one or two of the forms are identical with those described from Chile. , A few years later Szajnoche’ described a small flora of 11 species, re- ferred to 8 genera, from Cachenta, in the Province of Mendoza. Only two species appear to be identical with those described by Geinitz. Szajnoche compares this flora with beds of similar age in Queensland, New South Wales, India, Germany, and Bjuf, in Sweden. It does not appear that any of the Argentinian forms are identified with North American species. From this hasty review it must be very evident that the data are lack- ing for an adequate comparison of the Triassic floras of North, Central, and South America. The localities are few, are often separated by thou- sands of miles, and, moreover, there is still more or less doubt in some eases as to their position. JURASSIC No’ Jurassic floras are at present known from eastern North America. From western North America—principally California, Oregon, and Alaska—about 125 species have been recognized. Of these, two locali- ties—Kadiack Island and the Matanuska Valley, Alaska—with about a dozen species each, are referred to the Lias, and the remainder are re- ferred to the Middle and Upper Jurassic. The latter find their close parallel with the well known Jurassic floras of eastern Asia. Within the past year two small floras thought to be of Liassic age have been described by Lozano* from the States of Vera Cruz and Puebla, Mexico. Although certain of the forms described are seemingly abundant 5H. Grafen, Solms-Laubach: Zu Beschribung der Pflanzenreste vy. La Ternera. Neues Jahrb., Beilage, vol. 12, 1899, pp. 593-609, pls. 13, 14. °H. B. Geinitz: Ueber Rhatische Pflanzen-und Thierreste in den argentinischen Proy- inzen La Rioja, San Juan und Mendoza. Paleontographica, Suppl. 3, 1876, pp. 1-14, pissed, 2: _'L, Szajnoche: Uber fossile Pflanzenreste aus Cachenta in der argentinischen Repub- lik. Sitzr. d. Akad. wiss. Wien, vol. 97, 1888, pp. 1-20, pls. 1, 2. 8. D. Lozano: Description de unos plantas Liasicas de Huayacocotla, Ver., Algunas plantas de la flora Liasica de Huauchinango, Pueb. Bol. Inst. geologico de Mexico, no. 84, 1916, pp. 1-18, pls. i-ix. : 610 ¥F. W. KNOWLTON—MESOZOIC FLORAS OF THE AMERICAS and well preserved, the flora as a whole is small and poorly represented. Only eight genera are recognized, and of these several are so poorly pre- served that specific identification was not attempted. A number of the forms recognized are identical with those described by Wieland® from the Mixteca Alta, in Oaxaca, from beds also referred to the Lias. This is a comparatively rich flora, comprising 21 genera and about 60 forms. It is especially rich in forms as well as individuals of the peculiar William- sonias. This flora can hardly be accepted at its face value. It seems to me that there must have been either a mixture of horizons or a misiden- tification of generic types. If the genera Noeggerathopsis, Trigonocarpus, Rhabdocarpus, Alethopteris, Sphenopteris, and, above all, Glossopterts, have been correctly identified, it would certainly argue for a much older position than the Lias, and the Williamsonias and other types of cycads would not be out of place at a higher horizon. : The entire South American Continent is without a known locality for an undoubted or at least adequate Jurassic flora. As already pointed out, the floras from Chile and Argentina above referred to the Triassic may possibly be referable in whole or in part to the Lias instead of the Rheetie, but further data must be forthcoming before the matter can be settled. Thus, from Piedra Pintada, on the northern border of Patagonia, Kurtz has described a small collection of plants procured by Roth. They are associated in beds with marine fossils considered to be of Liassie age. Kurtz has compared the plants with the Rajmahal flora of the Upper Gondwanas of India. The largest and by all odds the most interesting Jurassic flora is really extralimital. This is the Middle Jurassic flora described by Halle’? from Hope Bay, Graham Land, 63° 15’ south, and just outside the Antarctic Circle. It embraces 61 forms, of which number 21 are definitely identi- fied with previously known forms, and of these 17 are found elsewhere in strata believed to be of Middle Jurassic age, although it includes some types that are older and some that might be younger. The closest affilia- tion of this flora is shown to be with the well known Jurassic of York- shire, England, there being no less than 9 of the 21 species in common. There are no South American floras of any importance that can be con- sidered contemporaneous with this Graham Land flora. Possibly contemporaneous with the Graham Land deposit is a collec- §G. R. Wieland: La flora Liasica de la Mixteca Alta. Bol. Inst. geologico de Mexico, no. 31, 1914. 107T,. G. Halle: The Mesozoic flora of Graham Land. Wissen. Ergebnisee d. Schwe- dinschen Siidpolar-Exped. 1901-1903, vol. 3, no. 14, 1913. JURASSIC AND CRETACEOUS 611 tion described by Hallet! from Bahia Tekenika, Tierra del Fuego, which is about 60: nautical miles northwest of Cape Horn. It comprises only two generic types (Sphenopteris or Coniopteris and Dictyozamites), nei- ther of which was sufficiently well preserved to admit of specific determ1- nation. It can not have very much weight in the present connection. CRETACEOUS Just as it has been found difficult on the basis of available data to dis- tinguish between Triassic and Jurassic, so is it difficult to decide between Jurassic and Cretaceous. Thus, from middle Peru, Neumann’ enumer- ated seven species which he held to be of Wealden age, although they in- clude some apparently Upper Jurassic elements. The same year Lukis mentioned three poorly preserved species of plants from a coal mine near the same locality as those mentioned by Neumann, referring them to the Neocomian. Later, in 1910, Salfeld*® procured about a dozen species of plants from the same general area, referring them in part to the extreme Upper Jurassic and in part to the lowest Cretaceous. Halle has expressed the opinion that they are probably all to be best regarded as lowest Cre- taceous; also transitional between the Jurassic and Cretaceous, or pos- sibly belonging wholly to the latter, is a small collection described by Halle** from Lago San Martin, central Patagonia. It embraces about twelve generic types and a slightly larger number of species. Some are older in affinity as some are somewhat younger, but on the whole Halle concludes that there is nothing to militate seriously against their extreme Lower Cretaceous age. | One of the most important discoveries bearing on the present discussion was that of an extensive dicotyledonous flora at Cerro Guido, Province of Santa Cruz, Argentina. This flora was listed in a short, unillustrated paper published by Kurtz! in 1902. It enumerated 31 forms, of which 21, or 75 per cent, are characteristic types of the Dakota group. Although these plants have never been figured, and it is consequently impossible to check up the identifications, they are mostly such characteristic species uT. G. Halle: Kungl. Svenska Vetensk. Handl., vol. 51, 1913, no. 3, pp. 6-12. 2 Richard Neumann: Beitrage zur Kentniss der Kreidformation in Mittle-Peru. Neues Jahrb., Beilage, vol. 24, 1907, pp. 69-132. 3H, Salfeld: Fossile Pflanzen aus dem obersten Jura, bzw. der untersten Kreide von Peru. Wissen. ver offenntich. d. gesell. f. Erdkunde, Leipzig, vol. 7, 1911, pp. 211-217. “47. G. Halle: Kungl. Svenska Vet.-Akad. Handl., vol. 51, no. 3, 1913. 6H, Kurtz: Contribiciones 4 la palseophytologia Argentina. Sobre la existencia de una Dakota flora en la Patagonia austro-central, Revista Museo La Plati, vol. 10 (1899), 1902, pp. 43-60. 612 ¥F. Ww. KNOWLTON—MESOZOIC FLORAS OF THE AMERICAS that it is hardly possible to suppose that all or even any considerable per- centage have been incorrectly determined. Therefore, taking the list at its face value, it might well enough have been made of a collection from the Dakota of Kansas or Nebraska. In the 5,000 miles between Kansas and this locality in Argentina no trace of this flora has been reported. Argentine geologists regard these beds as Cenomanian; but, as Berry, Halle, and others have suggested, they are probably not older than Turonian. SUMMARY With the exception of the Dakota flora from Argentina just mentioned, there is comparatively little demonstrable relationship between the Meso- zoic floras of North and South America. The total known Triassic flora from South America hardly exceeds 30 species, and of these no more than two or three are specifically identical with North American forms, though it is but fair to state that when the floras of the two continents come to be revised in the light of existing knowledge more species will probably be found to be common to the two. As the matter now stands, a majority of the South American species are regarded as endemic, and many of the others are either questionably identified or referred to Old World species. Demonstrable specific relationship between the Jurassic floras of North and South America is, if possible, less satisfactory than in regard to the Triassic floras. The Jurassic floras on the South American Continent are so fragmentary and generally unsatisfactory that it is hardly worth while to attempt comparisons. The only flora of importance is the extra- limital one found on Graham Land. This and such as we know from South America are clearly but integral parts of the great world-ranging Jurassic floras. In fact, remoteness appears to have had little influence on distribution. . Witness this Graham Land flora, which finds its closest relationship with that of Yorkshire, England, and important relationship with other parts of Europe as well as India, and, it may be added, it is not greatly different from the well known Jurassic floras of California, Oregon, Alaska, and Siberia. The relationship between the Upper Cretaceous Dakota group flora of Argentina and the Dakota flora of Texas, Kansas, and Nebraska is direct and positive. The now dominant group of dicotyledons clearly originated in the north, and in late Lower Cretaceous time had spread south over eastern North America and western Europe. By latest Lower Cretaceous and early Upper Cretaceous time they had spread west in North America, SUMMARY 613 to become the Dakota flora of the central Western States. This Dakota flora undoubtedly spread southward to find its southernmost known limit in Argentina. The pathway between these areas, although now largely buried beneath later sediments, was undoubtedly open in Upper Cre- taceous time. The presence in the Argentine “Dakota” flora of a very few elements of possibly later age may be sufficient to make it slightly younger than the principal Dakota floras of the north—that is, it may have taken an appreciable time for its journey, and it may not have reached there until early Turonian time. A word may be said as to the possible, not to say probable, routes by which the Triassic and Jurassic floras reached South America. It is necessary to review briefly the plant distribution during Permo-Carbon- iferous time in order to get a proper perspective. In Permo-Carbonifer- ous time the world was divided into two phytogeographic provinces—a northern and a southern—and there was extremely little commingling of plant types between them. The southern province, characterized by the so-called Glossopteris flora, embraced portions of India, Australasia, South Africa, Antarctica, and eastern South America. It reached the northern province at a single point in north central Russia. It has been found within 5 degrees of the South Pole. To my mind the facts all point to the origin of this flora in the south, either in Australia or on the Antarctic land-mass, and I believe there was in Permo-Carboniferous time a practically continuous land connection between the Antarctic Continent (Gondwana Land) and south Africa, Australia, India, and South America. Any attempt to derive the Glossopterts flora of Brazil, the Falkland Islands, and Buckley Island (85 degrees south) from the north by way of North America is without supporting data. Some students—notably Ettingshausen—have held that the differences between the northern and southern phytogeographic provinces that are so marked in Permo-Carboniferous time continued well into the Jurassic. This appears to be true only in part, for while there are some notable differences in the floras of the two areas, the differences are by no means so sharp as in Permo-Carboniferous time. For example, the Ginkgoales, a dominant and widespread group of the north, did not reach the southern province, and Podozamites, abundant in the north, is but sparsely repre- sented in the south. From available data it appears that at least the major portion of the early Mesozoic flora originated in the north, whence they spread pretty much over the globe. Their routes of travel are not always clear, however. It is possible that the Jurassic flora found on Graham Land may have reached this far southern point by way of North 614 ¥F. w. KNOWLTON—MESOZOIC FLORAS OF THE AMERICAS America, Central America, and the entire length of South America; but the fact that the obvious affinity of this flora is with the floras of India, Kurope, and thence to England, rather than with western America, leads me to think it at least possible that the land bridge over Antaretica was still existent. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 615-680 DECEMBER 80, 1918 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY GEOLOGIC HISTORY OF CENTRAL AMERICA AND THE WEST INDIES DURING CENOZOIC TIME? BY THOMAS WAYLAND VAUGHAN (Read before the Paleontological Society January 1, 1918) CONTENTS Page DEMTUMOGUCTION «2's 56.5 06 0 Bera Fed Sha RNa ee TEE EE IE OO ko wince aie 615 Geographic relations of the three Americas...............00 cee cece: 616 Correlation of the Tertiary formations of the south Atlantic and eastern Gulf Coastal Plain......... Be Recta eo er SNR EER ge oer ath 8 621 Correlation of the Tertiary sedimentary formations of Panama and the Ve OO S rope HEISE Rabu avons metas eicvaeres wvelel ov bere cia die wales 621 Seer eat DOM STLININVAEY oes cid. assis oh Rel ec aR e Olle Bis web wv ebe.e Cw Ra eee es 622 UTE DEG chau a'ss in aia 6 eo a eles lates, Dre ane Ae et Re ae eee DR Re 622 PRM BOAT he io Fe ait) wes acre sone sige TSM SA ca ete G ome Voee le A eA Sree 458s 622 Oo SD INESIIS hes Ba Bs So Re nO a er Soy omanee a OR 623 Hocene and Oligocene....... Ree aire RE PAIA chor Ch tate a he a aos 625 RUM ET ES eh cs) visitas occ cbr eva on tates Getto Sea EEL SO RETIN Coe cars tela ete ara eaomlere 624 iptoeene ands later). .1 0. eae eee eo ie he oe ue 2 625 Tabular summary of some of the important events in the geologic history mune yy est Indies and, Central Amerieg ie, fio cio tesa oleic ne cle wows ache! avela 629 INTRODUCTION During the past two or three years several papers of unusual impor- tance, in my opinion, have appeared on the geographic distribution of terrestrial organisms. ‘These include “Climate and evolution,” ? by W. D. Matthew; “The development of the natural order Myrtacecer,”* “The 1 Manuscript received by the Secretary of the Society August 22, 1918. The article herewith presented is based upon a paper by me, entitled ‘“‘The biologic character and geologic correlation of the sedimentary formations of Panama in relation to the geologic history of Central America and the West Indies,’ now in page proof, as the closing part of Bulletin 103 of the U. S. National Museum, which bears the general title ‘‘Contributions to the geology and paleontology of the Canal Zone, Panama, and geologically related areas in Central America and the West Indies.” The two correla- tion tables contained in the present article have been published in the Journal of the Washington Academy of Sciences, vol. 8, no. 9, May 4, 1918, pp. 272-275. 2 New York Acad. Sci. Ann., vol. 24, 1915, pp. 171-318. % New South Wales Linn. Soc. Proc., vol. 38, 1913, pp. 529-568, (615) 616 T! Ww. VAUGHAN—GEOLOGIC HISTORY OF CENTRAL AMERICA development and distribution of the natural order Luguminose,” * and “The geological history of the Australian flowering plants,” * by C. E. Andrews; and “Plants, seeds, and currents in the West Indies and Azores,” by H. B. Guppy.* These three authors agree in their main thesis, namely, that vertebrates and plants have spread from northern areas ra- dially southward over Africa, South America, southeastern Asia, Malay- sia, and Australasia. They all deny direct land connection, at least since Paleozoic or early Mesozoic time, between Africa and South America and between South America and Australia, and they question there ever hay- ing been any such bridges. Furthermore, they all agree, explicitly or im- plicitly, in the essential permanence of the continents and of the great oceanic basins. There are other points of agreement, but these are the ones I wish particularly to emphasize in this connection. Although I may not accept every detail of the conclusions of these authors, it is my belief that their main contention is incontrovertible. : All geologic evidence known to me supports the theory of the perma- nence of continents and oceanic basins, but the validity of this theory does not exclude there having been great differential crustal movements in some areas. As I shall speak of certain earth blocks that, in my opin- ion, have changed their position with reference to sealevel, I wish to re- mind you that faults and folds causing great vertical and horizontal displacement of strata now above sealevel are known to all geologists, and that it is reasonable to expect in other areas of disturbance that down- thrown blocks or the synclines of folds lie below, while only the upthrown blocks or the anticlines stand above ocean level. GEOGRAPHIC RELATIONS OF THE THREE AMERICAS The boundaries of the Gulf of Mexico and the Caribbean Sea form a parallelogram; those on the north and south extend along east and west lines, those on the east and west are northwest to southeast, while the basins are separated by east and west structures. There are two land- locked basins, except that between Florida and Trinidad relatively shal- low passages between land areas connect with the Atlantic Ocean. ‘The two basins are separated by structures transverse to the continental trend in Yucatan and Cuba, and the Gulf of Mexico is a simple while the Caribbean Sea is a compound basin. *New South Wales Roy. Soc. Proc., vol. 48, 1914, pp. 333-407. 5 Amer. Jour. Sci., 4th ser., vol. 42, 1916, pp. 171-232. ®* Published by Williams and Norgate, London, 1917, pp. 531, 3 maps and a frontis- piece. GEOGRAPHIC RELATIONS OF THE THREE AMERICAS 617 Twelve major tectonic provinces, with several subordinate provinces, may be discriminated, as follows: . Bahamas. . Atlantic and Gulf Coastal Plain. . Mexican Plateau. . Oaxaca-Guerrero. . Yucatan. . Guatemala-Chiapas. . Cuba and northern Haiti. . Honduras and its continuation to Jamaica, southern Haiti, Porto Rico, the Virgin Islands, and the outlying island of Saint Croix. 9. Costa Rica-Panama. 10. Andes. 11. Maritime Andes. 12. Caribbean Islands. 12a. Barbadian Ridge. 12b. Main Caribbean Are. 12c. Aves Ridge. ANa»krwnhd Of these provinces, (1) the Bahamas, (2) the Atlantic and Gulf Coastal Plain, and (3) the Mexican Plateau will be only mentioned, but the others will be briefly described. 4. Oaxaca-Guerrero: A structural axis extends through Michoacan,, Guerrero, and Oaxaca, almost at right angles to the trend of the Mexican Plateau. The northern boundary of this province is the escarpment at the southern margin of the Mexican Plateau; the western and southern boundary is the Pacific Ocean, while the eastern boundary is the Isthmus of Tehuantepec. It is thus set off from the Mexican Plateau and the Yucatan lowland. 5. Yucatan: This province consists of lowlands under 600 meters in height, underlain by only-shightly deformed Tertiary strata, except some problematic rocks west of Belize.; The Yucatan Peninsula and Campeche Bank are comparable to the Floridian Plateau. They are developed along a structural axis almost at right angles to the continental trend. Cam- peche Bank projects northward from the shoreline of the peninsula 170 nautical miles to the 100-fathom curve, and has a width of nearly 360 nautical miles along an east and west line. On the east the depth of water between it and Cuba exceeds 1,000 fathoms and the axial trends are not coincident, but the axis of Yucatan Bank and that of the Province of Pinar del Rio, Cuba, curve so that they are nearly parallel, with a trough, Yucatan Channel, between them. 6. Guatemala-Chiapas: This province lies between the Yucatan low- land on the north and Rio Motagua on the south. It is an upland domi- XLVI—BuLL. Grou, Soc. Am., Vou. 29, 1917 618 T. W. VAUGHAN—GEOLOGIC HISTORY OF CENTRAL AMERICA nated by east and west tectonic lines, and has been called the Guatemala- Chiapas Plateau by Tower.’ 7. Cuba: This province is coincident with Cuba and its submarine continuation, the Cayman Ridge. At least four subdivisions should be recognized: (1) The Isle of Pines, which is composed of mountains of schists and marbles with piedmont plains and marsh, separated from the main island by water less than ten fathoms deep. (2) Organos Moun- — tains of Pinar del Rio and the accompanying piedmont plains. The 1,000-fathom curve is less than 20 miles off the north shore. (3) Central Cuba, from the east end of Organos Mountain to Cauto River, is mostly a plain broken by some hills of serpentine and granite, and in Santa Clara Province, near Trinidad, mountains reported to be composed of Paleozoic sediments attain an altitude of about 2,000 feet. (4) Sierra Maestra and Cayman Ridge. This subprovince hes between the Cauto Valley and the south shore and is continued westward as the submarine Cayman Ridge, along the axis of which only the Cayman Islands project above water level. The axial trend is nearly east and west between Cabo Cruz, Cuba, and Little Cayman, whence it curves to the southwest and pitches toward the head of the Gulf of Honduras, which is an area of depression. Between the Caymans and the Isle of Pines the depth of water exceeds 1,000 fathoms, while the Bartlett Deep to the south, sepa- rating Cuba and Jamaica, exceeds 3,000 fathoms in depth. _ Ya. Haiti, northern part: The Island of Haiti lies at the convergence of the trend of the axis of the central subprovince of Cuba and the Hon- duras-Jamaican axis. The dividing line in Haiti is from Port aw Prince to Ocoa Bay. The area south of this line belongs to a Jamaican axis, while that to the north belongs to the central Cuban trend. The struc- tural axes of the mountains in the northern and northeastern part of Haiti are from northwest to southeast and are parallel to the axis of elongation of Cuba from the Sierra Maestra to Santa Clara. In Cuba this trend is cut diagonally by the axis of the Sierra Maestra, which is bounded on the south by a tremendous fault-scarp. Previous to this faulting it seems that central Cuba and Haiti formed parts of the same land area. The Island of Haiti might be treated as separate from Cuba and Jamaica, but lying at the intersection of two tectonic trends. 8. Honduras and the Jamaican Ridge: The Honduran Province in Central America is dominated by tectonic lines extending from southwest to northeast, of which Telusa Mountains are representative. A line from the Gulf of Honduras along Motagua River to a point north of Jalapa, 7 Ww. L. Tower: Investigation of evolution in chrysomelid beetles of the genus Leptino- tarsa: Carnegie Inst. Washington, Pub. No. 48, 1906, p. 50. GEOGRAPHIC RELATIONS OF THE THREE AMERICAS 619 thence southwest to the Pacific coast, may be taken as the northern bound- ary and Rio San Juan and the southern side of Lake Nicaragua as the southern boundary. From the northeast coast of Honduras and Nicaragua a great sub- marine plateau continues, with depths of less than 1,000 fathoms, to Jamaica. Above it rises numerous banks and keys and along its course are Thunder Knoll, Rosalind, Seranilla, and Pedro banks between the continental shore and Jamaica. The principal old tectonic lines of Jamaica trend northwest to south- east. As these are parallel to the shore northwest of Cape Gracias a Dios and to the northeast edge of Mosquito Bank, there are evidently cross- tectonic, lines nearly at right angles to each other in this ridge. A submarine ridge extends some 45 miles from the east end of Jamaica and overlaps on the south side a ridge which protrudes westward from the west end of Haiti. The two ridges, however, do not connect, but are separated by water over 1,000 fathoms deep. The ridge representing an eastward submarine continuation of Jamaica indicates a third tectonic line in that island. The last mentioned line nearly parallels the Bartlett Deep, which hes to the north. The submarine slopes to the southeast are toward the bottom of the Caribbean basin. — . 3 8a. Haiti (southern part), Porto Rico, and the Virgin Islands: The political division of Haiti designated Sud is dominated by east and west trending mountains, which parallel in direction the east and west axis of Jamaica. As the maximum depth between Haiti and Porto Rico is about 318 fathoms, they rise from a common, not greatly submerged, bank. (See statement on preceding Dane in regard to considering Haiti as a separate province. ) The main mountain mass of Porto Rico, the Sierra Central, the maxi- mum altitude of which is 3,750 feet at El Yunque, trends east and west, paralleling in direction Sud, Haiti. There is coincidence in the direction of elongation of the Jamaican bank, Sud (Haiti), and Porto Rico. The relative truncation of the west end of Porto Rico, except the pro- tuberant which forms Cabo de San Francisco, is striking and suggests faulting. The declivities both to the north and south of the island are great, over 4,000 fathoms in depth being reached within 40 miles of the north coast, while 2,000 fathoms are attained within a shorter ED from the south coast. A submarine bank extending from the east end of Porto Rico to Ane- gada Passage is known as Virgin Bank. The depth of water between the islands rising above this bank is less than 20 fathoms, which is a maxi- mum for the amount of submergence they have recently (geologically es *) undergone. ‘These islands are detached outliers of Porto Rico. 620 T. W. VAUGHAN—GEOLOGIC HISTORY OF CENTRAL AMERICA 8b. Saint Croix: Although Saint Croix is separated from the Virgin Islands by a depth as great as 2,400 fathoms and is joined to the Saint Christopher chain by a ridge less than 1,000 fathoms deep, it possesses great similarity to members of the Virgin group. The west end is trun- cate and the submarine slope precipitous; the submarine slope to the north is also steep. There is clear evidence of faulting on the west and north sides. A ridge, largely of igneous rock, stands against the north shore from the west end of the island for some distance to the east. South of the ridge is a sloping, rolling, calcareous plain. The east end has a submarine continuation in a bank less than 50 fathoms deep. ‘The tec- tonic axis is east and west, the rocks resemble those of the Virgins, and the zeogeography indicates former connection with them. For these rea- sons it seems probable that this island was formerly a part of the Porto Rican-Virgin Island land-mass and has been sundered from it by dias- trophic processes: However, Saint Croix might be accorded separate status as a province, or referred to the Saint Christopher axis; but it ap- pears to me preferable to classify it with the Virgin Islands. 9. Costa Rica-Panama: Between the Nicaragua-Costa Rican boundary ~ and the mouth of Rio Atrato is an S-shaped land area which does not ex- hibit striking tectonic lines, although some deformation axes are obvious in Panama. The region is largely one of vulcanism, present or past, which, although occurring within limits, does not follow continuous straight axes, but occurs in a curving belt. The topography appears dis- ordered, with volcanic protuberants here and there without perceptible system. The volcanic heaps range from a few hundred to nearly 10,000 feet in altitude. 10. Andes: The south-north trending ranges of the Andes reach the shores of the Caribbean Sea between the gulf of Darien and Venezuela, and send a spur, Cordillera de Merida, northeastward to Porto Cabello, where the main Andean trend is crossed by that of the Maritime Andes. The shore of the Caribbean Sea lies across the northern end of the Andes in a way similar to the manner in which the landward border of the Coastal Plain crosses the southwestern end of the Appalachian Mountains. The islands of Curacao, Arube, and Bonaire lie off the Venezuelan coast in the angle between the ends of the main Andes and the Cordillera de Merida. 11. Maritime Andes: The Maritime Andes lie along the Veneztela coast from Caracas eastward. Trinidad and Tobago are outlying islands. On the south side of these mountains is the great valley of the Orinoco. 12. Caribbean Islands: These islands lie along triple arcuate ridges, the Barbadian Ridge, the main Caribbean Arc, and Aves Ridge, the second of which is double at its northern end. A, Woes ma Sie! x ups 72. ‘ agar! ak 1 ak ' i é i ' Prect sodutanseooln2, videttenoxth | he yfasnir. guteny it -pariol | H bas alo sory i \feverg valle nol). | oarteiaos ySeT ra) Pi laanes A fs hey shi so 2D “ay : ‘ —gursol lity rou dont! aphid tal” on a Seas t \ a a A a i Pm eae ne bassaonaiannearis a ware as LOFT lagi jovi (norte a i eee hs eee es Cr oe pay ett i Pe aan 2 redaned {> veka ‘BIO 2 B21 BME ii Seco Prent alogint: ao tetnnd “7 ¥ ry : | reared SEH aootiediad a. 1 _nobtserot 4 oh oS aie BS “Ue ) Snosarwit fons it Mf cate Ce pinot T ne Beau a: e ae : Sa Biorb bn . rere Sagoo YO Penge enensayee i eee a ! ‘ be : : 5 Ms a 2 ie ; Y ; a Lay ee ss . ‘4 aa t ; aes ; ale) + ing as 7 ape z - By he we | | ty ‘hres aii ; ; | bar dra, mild... Sea roetihnue) | Pract alae. 6 PY . ay j Apis wee ers ee a km | re i ( a LS eearaan fi, SER Oe | yiinrroloon UW | é . A 8 hee ae ae oeiba | = { , } = ) hen beokt ants vA } £ tt ie ne en ee -anyagre| Peal se a cL ae gti C7 ed : 1 vam Rabsconie. | NN Mite Viaiibeter gS tata ; gots. .... fon. | ae fa re ye er me Ee: < q hs 7 as me alte chy ts hi A aE la a oct de i = hers vee % —— che Fam tem met tap mm Tae Ea) toi ; : ‘ $3 Aah gindtad ity | Sas tala RRS, rae . iP tihan trae Se dees: >in ig am Se ae f a ater PA ae teehee tiie CORRELATION OF THE TERTIARY FORMATION 621 12a. Barbadian Ridge: As Barbados is connected undersea with To- bago Island by a ridge less than 1,000 fathoms deep, and as the depth between it and Saint Lucia is less than 1,000 fathoms, there is a closed basin over 1,000 fathoms deep between the Barbadian Ridge and the main Caribbean Are. 12b. Caribbean Arc: The Caribbean Arc is a ridge that extends from north of the Gulf of Paria to Anegada Passage. The islands occurring along it from the Grenadines to Dominica are entirely or predominantly voleanic. Guadeloupe is a compound island; the western half is volcanic; the eastern half, with the outlying Marie Galante, is mostly composed of calcareous sediments. North of Martinique the are splits; along the inner fork are the voleanic islands Montserrat, the members of the Saint Chris- topher Chain, and Saba; along the outer fork are Antigua and Barbuda, and the Saint Martin group. The latter islands are largely or predomi- nantly composed of sedimentary rocks resting on an igneous basement of pre-Tertiary or early Tertiary age. 12c. Aves Ridge: This ridge takes its name from Aves Island, which stands on a ridge running from the north coast of Cumana to Saba Island at depths slightly less than 1,000 fathoms, while water of greater depth occurs both east and west of it. CORRELATION OF THE TERTIARY FORMATIONS OF THE SOUTH ATLANTIC AND EASTERN GULF CoASTAL PLAIN The accompanying table indicates the present status of the correlation of these formations, and, although it may have to be modified to accord with the results of additional investigations, there is every reason to be- lieve that subsequent changes will be only in matters of minor refinement. However, I wish to say that I believe four paleontologic zones will be discriminated and defined in the Chattahoochee formation, and that the collections on which to base these subdivisions have already been made and in large part described, but I will not take the time to discuss these details. I also confidently expect the Ocala limestone to be subdivided into two or more zones, for the genus Orthophragmina, so abundantly represented in the lower part of the formation, appears to be absent in the upper beds. CORRELATION OF THE TERTIARY SEDIMENTARY FORMATIONS OF PANAMA AND THE West INDIES A summary of these correlations is given on the accompanying table. Only one point appears to need special comment—that is, whether the A _A PROVISIONAL CORRELATION TABLE OF THE TERTIARY FORMATIONS OF THE SOUTH ATLANTIC AND HASTERN GULF COASTAL PLAINS OF UNITED STATES SOUTH CAROLINA AGE OF rs rite ae SOUTH CAROLINA Pes | (Giatienese wae efarara TER ENRERG tc MISSISSIPPI LOUISIANA DEPOSITS petty) (Santee drainage) AEE H s Hatteras axis) 5 (Savannah drain- | drainage | age) | oa pre = Ke ‘ a = ——— a | pale eenatcler ues Siena j Z | ashua marl, Ala- | Citronelle 3 . 2 3 a ? | chuaclay,andBone| forma- Citronelle formation Citronelle formation Citronelle for 4 Waccamaw marl Waccamaw mar! (Not recognized) | Valley gravel cee mation a H (largely contempo- | ton a | raneous) = a =< ———____—_— | a ; | : i | Faektonvltietomias lle eeeee P la cl Pascagoula Duplin marl Duplin marl Duplin marl | pee epellenorns hatchee Pascagoula clay ascagoula clay Oe i } marl a Unconformity —Unconformity— |——Unconformity— | is ‘>__ —Unconformity © 2 | Shoal River marl member 3 P a Alum Bluff | Hattiesburg | Hattiesburg clay Hattiesburg 2 Alum Bluff forma- | Alum Bluff for'ma g § Oak Grove sand member formation clay clay io) tion tion 3 8 |————_———_ a Chipola marl member oe = a Tampa forma- a tion : . ae Chattahoochee for-| Chattahoochee for-}| Chattahoochee | Chattahoo- | Catahoula Catahoula sandstone Catahoula 2 mation mation formation chee for- sandstone Sandstone ce mation a | @ fi esse nrconformity — , 8 a a | Byram calc. marl \ 3 3 g oy [eee ee a xy i) 5) > : ° \ 3 = fh y| Marianna limestone | © | Marianna limestone 2 . , w| Marianna limestone (west- | m&| (with Glendon lime- te | (with Glendon limestone| Vicksburg E Vicksburg forma- | Wicksburg for)na- a ba : 2 tion iigsine 3 ern Florida) EI stone member) 2 | and Mint Spring calca- | limestone a wi % | reous marl members) 4 a 4 \ 2 2 0 S > Red Bluff clay > | Red Bluff clay = | 5 | Cast e Hayne lime- Barnwell formation Jackson formation (with a (o} B it - Jack Yazoo clay member and | Jackson forma- a ooper arnwe : =! Ocala Jackson azoo y a~ a stone marl formation (with Twiggs clay; Ocala limestorie Ocala limestone niectone formation | Moodys calc. marl mem- tion Trent marl member) ber) a Gosport sand S Yegua formation & weeun s 5 = 5 formation 3 McBean formation McBean formation | McBean forma:tion (Buried) ¢ | Lisbon formation ¢ | Lisbon formation g FI ue i “ 3 o 6 s eaeaer eee ae| N= 3 St. Maurice ; a & = 7 a | © | Tallahatta buhrstone © | Tallahatta bubrstone 5| formation fa ie | sie et es : S 2 b Congaree shales of © | Hatchetigbee formation g Grenada formation & i ; (Probably over- - i Buried 3 Bashi formation Holl a a Wilcox forma anhiieeaverse lapped) Walcoxtornintyan (pred) & | Tuscahoma formation 6 oly Spring sean tion une urge forma = Nanafalia formation 5 Ackerman formation 5 13 Se NT EES ses A rae : ~ A 3 | Naheola formation =| Tippah sandstone of | = | Sucarnochee clay 2 | Lowe i e : be a &| Porters Creek clay Midway forma aieCe Mingo forma- | (Probably over- | Midway formation (Buried) Be Be ee tion tion lapped) | z s 4 Clayton limestone ab- = Clayton limestone | sent or replaced by | | al =| sand GEOLOGIC HISTORY OF CENTRAL AMERICA G22 T. W. VAUGHAN limestone containing Orthophragmina on Haut Chagres and at David, Panama, should be referred to the uppermost Eocene or to the basal Oli- gocene. The Ocala limestone contains large stellate species of Ortho- phragmina, and I collected a similar species in Saint Bartholomew. Of the Eocene age of these deposits, of the typical Brito formation in Nica- ragua, and of certain limestones containing Orthophragmima in Cuba there seems to be no reasonable doubt; but, according to Douvillé, the small stellate Orthophragmina (subgenus Asterodiscus) ranges upward into the lower Oligocene. The association of Asterodiscus and small, even non-stellate, species of Orthophragmina with species of Lepidocy- clina that at some localities are found in association with a coral fauna of middle Oligocene affinities has inclined me to the opinion that certain peculiar species of Orthophragmina occur in deposits of lower Oligocene age. Doctor Cushman, however, is disposed to regard the beds in which these species of Orthophragmina were found as of Eocene age. At present the evidence is not decisive and additional studies are needed. PALEOGEOGRAPHIC SUMMARY IN GENERAL As Doctor Stanton has summarized in the preceding paper of this series the Mesozoic history of Central America, Mexico, and the West Indies, and as his conclusions are incorporated in the tabular statement on page — of this paper, I need not repeat anything he has said, but regarding the Paleozoic history I will state a few of the important events. LATE PALEOZOIC The great Appalachian revolution occurred in late Paleozoic, Permian time, and resulted in the northern boundary of the Gulf of Mexico—the southern Appalachian, the Ouachita, and Wichita Mountains. The east and west trend in southern Mexico and in southwestern Chiapas already existed or was developed about this time, while farther to the southeast, as Sapper has shown, Rio Motagua, in Guatemala, divides two chains of this age—one to the north, the other to the south— with spurs of a third chain farther toward the southeast. The nearly north and south trend of the Coxcomb Mountains, in British Hon- duras, which are composed of sediments apparently of pre-Paleozoic age, indicates that the Yucatan protuberant had been outlined in Paleozoic, perhaps early Paleozoic, time. Granitic debris in Costa Rica and Panama suggests old deformation along east and west lines in those areas. The east and west mountains of Venezuela have an old foundation and cer- tainly date back to the Paleozoic in origin. There is evidence: of old + %e y 3 ae 9 L pp hi opphe “ ad ae ae! ee ~ , i WA worn ere : a, Y ae af Aas Oo 8 my 4 oe ena 704 sed aht: APRA MA TAM PAS ATER or atipnldign Blapepenlictes nde PST were am 1 ns napa ae enemy ees ae me nee RD wed wad tei i | Pa e { Sra en tilt L potlotmtapoois baa lige ayes iver Wetheoon | norsk ban osteo’ Jo oe | ahr MEET ’ bee nanan? ¥iakee) os i Sela Oe any , + ‘ . é < ‘ ‘ VB. By s . eer wa \ se eye yebparrND) are ob eeepoennpenrstch a ie = oe a ibs + st ee se s Poorer bee adi dabaetsiiniaetpaneas sow kegemre a . “petal odhonest a aor) thes vhrage rhs aut jwoisaario} nwatsioY | *, : eS me. : ‘ ’ ' > ght ngne- 4 i. ORT suite oe vine: a} Deru : i 4 > 2 crema gett, 5 tay Ne genet Radney = se " “- ~ a piv — aids not am ne 2 any . : f ’ 4 i , ¢ *. ' i i a Ms ee goltem 20? & By 7aNM BY ae 7 + tha ey . om, cad a +: Se catty : bbagest 101 Araigady | . n -_ * is AS ek : gatioiie)T 3. se ays He et ine) ee ae a; oe < i y qy 22. ‘ ran ' , 1 ( i’ a aie cr eis frases to heer! adiel a E } Ate aoa ony aie, Pe aptiarhe —-ensiny - me nen Air ough mi een a - 1 a ane aKa Ratha : , t he = . s ) meleyisH |. ‘ 1 SR TN ae iit \ ee ‘ ae') i 9 iy are ‘a ; ‘ ' . a: eae, ‘ eswmeowzd ee Vigan? hie D ida} Bi) jo faneo wu (ened pacts Tere rovis aod aS + . ‘oa pea soles aT }rauiel © jcpweyesih |. # | ewiieshbas *) onlenae bus s¥o3e). And; a obist Lecce tes PT hee. 1 i RVD, © Oe ye a j yedmen Itetd os mili = PRiaEP SW r * = 4 ‘ y ; : . ies . Ae oi eh fiom captained lates cee ; a Pear eee nis Ug } yw * cae ‘ Fs , -$ af = . 4 ; ‘Sis “ RRP 6k yy Ms ensues coed ra i ee eS eee : é ~ = - e : . je aa ae Pere aptnind le els Neprtine Sa ty mee, co Tha? i ob bna BAM seg ° hi imwot, h° Hae-oetsat iitiwe ee ey: ee tea) , . . ab abtosisien hte ontb ogra fi eahehaned: i ae rf : ee ‘ 1 S -" Bed — ST one Oe ee ee Dae ae NTS Zz rs “ to ‘Aowanestt a _—: 4) atttlaoist - . py fse je pO | t fs 2h — ae ‘ 5s —_ in “ a > <4 — = ee eee 3 in Oe er TENTATIVE CORRELATION TABLE FOR THE TERTIARY Maginn SEDIMENTARY FORMATIONS OF PANAMA ME = : AMERICAN TI PANAMA JAMAICA OTHER ANTILLES sUBDIVISIONS ME3\co AND CENTRAL AMERICA SOUTHEASTERN UNITED STATES ape ad eae ala, SUBDIVISIONS Manchioneal : formation f f A i Pliocene Toro limestone Rineetontior Pliocene of Guantanamo, Cuba P 'Wotene of Yucatan and Limon, | Waccamaw marl, Nashua marl, and Caloosahatchee Pen: | sta Rica marl (nearly contemporaneous) stian matio ! t ‘ n | Plaisancian Bet eS |e (ee ee ee Yorktown formation, Duplin marl, and Choctawhatchee | Pontian marl (nearly contemporaneous) Sarmatian upper St. Marys formation Choptank formation Tortonian Calvert formation Marks Head marl) Miocene “5 oa er horizon * middle La Cruz marl|Upper horizon Hee Do- Helvetian / (Cuba) in Martinique 3 Gati CEE = ~~ we ; r mIngEO ati in for-| pacific Exposures Gatun\formation Ma\tion | Coast of |o2 Isthmus Shoal River marl member (Cijsta | Nicaragua| of Tehuan- lower Bowden marl| Marl at Bara- |Lower horizon Zones Gs Ri fa) tapec Alum Bluff formation + Oak Grove sand member Burdigalian Geen Cnn in Martinique | to Domingo if Chipola marl member | = Se ai a) See Emperador limestone i > Ba upper Anguilla formation (Anguilla) and beds at Tampa formation Aauitenee Upper part of many localities in Cuba | Culebra eect Chattahoochee Chattian forma- $a Rafael formation formation aus middle| tion Lower part of Cu- Coralreef| antigua |Pepinofor-| Lower | r: lebra and lime- at Guan- | ¢o;mation mation {horizon in) Rupelian stone at Tonosi tanamo, | (Antiguas| (Porte Santo | 7 Cuba d Rico) | Domingo | ye? Oligocene = as | Limestone, with Or- f Byram calcareous marl thophragmina, on pit Montpelier \ Mar jzanilla, Costa Rica, and de- cee sae . : orfian lower | Haut Chagres@ and Y Br white lime- PC jsits with Pecten aff. P. poul- | Vicksburg group 4 Marianna limestone (adeqatetan) limestone at David |°°"®""| stone S50; n¢ and large discoid orbitoids, (contemporaneous) M exico Red Bluff clay Cambridge Brit i i ia . o formation of Ludian (Pria: Msper formation St. Bartholomew limestone (St Bartholo-| yj earned (iepieal Frioclay | yackson formation Ocala limestone bonian) Richmond mew). Widely distributed in Cuba Bi -ito) Fayette ss. Bartonian formation | Gosport sand Auversian ¢ 2 Claiborne group Lisbon formation 4 middle| Eocene of Tonosi Clai jborne group ue allahatta bubrstone Lutetian Eocene A J = = ec 5 ar 3 Hatchetigbee formation Ypresian ¢ wil ‘ a wil or, Bashi formation cox formation y WTS 8 FAIS Tuscahoma formation é ie Nanafalia formation Sparnacian'¢ ' wae a ae ca rome | | 5 Naheola formation Thanetian ¢ Mid ,way formation z Midway group! Sucarnochee clay | , Clayton limestone WAS BENG | : 2 : , aReported by H. Douvillé and referred to “Stampien inférieur Bartholomew limestone in the table. b May belong stratigraphically somewhat higher. c Correlations proposed by BD. W. Berry. +” — Vicksburgian = Lattorfian. Cus) hman thinks these deposits should b e referred to the upper Hocene and placed opposite the Saint i ' i a. Pace 29U41T*4 AMHTO SOr : wRawal ype ers AMAMAT MS bee ‘ : , (ere ® ’ ’ + 2. waa ee ee ee eee Saaiedineieedeter ae ee mlcsiae Re og ares 47 se. ¢ cata hoe : js = ‘ saodeensif sot eolegnia | ; nota: . - Waronbew \ sia omteneigags by angoolt'! ie Bne rh Forza We ell / che ‘ 4 PE cae ate oF | ee prin | ’ , - “ Se en eae . Snir ea EEE eee ne dt eS dD i goisiiecol yep: - hae | i potaraangtig® f F ( ; ©. wen olen ih Pee ey ee hE gone ie ; . em ote ame ee aes i> RFE 5 igpeé- a 7 Ay ; ‘ » a n te - ; ‘ft >) me PALEOGEOGRAPHIC SUMMARY 623 deformation in Cuba, rendering it highly probable, if not certain, that the major tectonic trends of Cuba are as old as the Paleozoic. Although no Paleozoic rocks have been identified in Jamaica, the inference appears warranted that Jamaica itself dates back to late Paleozoic, as it has been shown by Sapper that the west end of the tectonic features represented in Mosquito and Rosalind banks and Jamaica already existed in late Paleo- zoic time. The Cuban and Jamaican trends meet in Haiti and continue through Porto Rico to the Virgin Islands, while Saint Croix, which is closely related in its geologic features to the Virgins, was probably at one time a member of that group and has been separated from them by fault- ing of comparatively late geologic date. There is no direct evidence of the existence at this time of any of the Caribbean Islands, but certain relations suggest that at least parts of the Caribbean Arc may be old. Saint Croix stands on the western end of a ridge between 600 and 700 fathoms deep, on the eastern end of which is Saint Christopher. This ridge extends northward to the Saint Martin Plateau, eastward to Anti- gua and Barbuda, and southward from the latter islands through Guade- loupe, Saint Lucia, and the Grenadines to South America. These rela- tions suggest that the eastern perimeter of the Caribbean basin may have been outlined in late Paleozoic time. From the preceding statement it is evident that the principal tectonic lines of the perimeters of the Gulf of Mexico and Caribbean Sea existed at the close of the Paleozoic. The northern, western, and southern boundaries had been outlined and the major transverse trends had also been formed—the more northern through Oaxaca and Chiapas, including the northward trending Coxcomb Mountains of British Honduras; the more southern through Honduras and Nicaragua. The first may have connected along the axis of the Coxcomb Mountains with Cuba and thence with Haiti; the second probably connected with Jamaica, Haiti, Porto Rico, and the Virgin Islands, and there are vague suggestions that the Caribbean Arc also existed. As the positive and negative areas so early outlined dominated the tectonic development during later geologic time, the subsequent history consists in tracing the modification of these old features. CENOZOIO The Cenozoic history may be summarized as follows: Kocene and Oligocene-—The West Indian Islands, because no old Ko- cene sediments are known in any of them except Trinidad, which is South American in its affinities, are supposed to have stood above sealevel at that time. In Cuba and Jamaica there are Upper Cretaceous and upper Kocene sediments without the intervention of lower Eocene deposits. 624 T, W. VAUGHAN—GEOLOGIC HISTORY OF CENTRAL AMERICA During later Eocene (Ludian) and middle and upper Oligocene (Ru- pelian and Aquitanian) time there was extensive submergence in the West Indies and interoceanic connection through a number of straits across Central America. There may have been interoceanic connection during lower Oligocene (Lattorfian) time, but this is not established. The maximum submergence was in middle Oligocene (Rupelian) time. Vulcanism was widespread in Central America and the Antilles during Kocene and probably also during earlier Oligocene time. The line of the great Mexican volcanoes had its inception at the close of the Cretaceous, near the beginning of the Tertiary, according to Felix and Lenk. In Jamaica, Cuba, Saint Bartholomew, and Antigua, the later Eocene age of some of the volcanic rocks is established. There was between the upper Eocene and the middle Oligocene deposition periods great defor- mation in the Antilles. The folding in the principal mountains of Ja- maica, the Sierra Maestra of Cuba, and apparently those of Haiti, Porto Rico, the Virgin Islands, and Saint Croix, appears to have taken place at this time. Diastrophism seems also to have been active in Chiapas, Tabasco, Petén, Guatemala, Nicaragua, Costa Rica, and Panama. Miocene.—During older Miocene (Burdigalian) time apparently there was in places connection between the Atlantic and Pacific oceans, as is shown by deposits of this age containing fossils of Atlantic affinities on the Pacific coast of Nicaragua and at other localities in Central America, ’ but such connections seemingly were restricted, not of wide extent, as in upper Eocene and Oligocene time. As no upper Miocene has yet been identified in the West Indies, this is supposed to have been a period of high uplift which terminated the con- nection between the Atlantic and Pacific oceans. The middle and upper Oligocene and lower Miocene sediments of Mexico, Panama, Cuba, Haiti, Jamaica, Porto Rico, Anguilla, and Antigua, although deformed by tilt- ing and faulting, are not intensely folded, as are the older sediments. According to Hill, “In mid-Tertiary time granitoid intrusions were pushed upward into the sediments of the Great Antilles, the Caribbean, Costa Rican, and Panamic regions.” The information I obtained in Antigua and Saint Bartholomew accords with this opinion, That there was at some place interoceanic connection subsequent to lower Miocene (Burdigalian) time is suggested, if not actually proven, by the presence on Carrizo Creek, Imperial County, California, of a coral fauna of post-Miocene affinities.® 8T. W. Vaughan: The reef-coral fauna of Carrizo Creek, Imperial County, CoN etc., U. S. Geol. Survey Prof. Paper 98, Reig pp. fei: 386, pls. 92-102. PALEOGEOGRAPHIC SUMMARY 625 Roy S. Dickerson,® in the paper cited below, says regarding my conclu- sion that the coral fauna of Carrizo Creek is of probably Plocene age: “His [Vaughan’s| conclusions concerning the Pliocene age of these beds rests upon the infirm basis of comparison with a Pliocene coral fauna of Florida,” and “All the coral genera except one occur in the Bowden or associated horizons.” The last statement is correct, and the first is cor- rect in that I compared the fauna from Carrizo Creek with that from the Pliocene Caloosahatchee marl of Florida; but Doctor Dickerson evidently did not comprehend the entire basis for my opinion. The following genera, now extinct in the Atlantic Ocean, but lving in the Indo-Pacific, oceur in the Bowden marl and related zones, but are not known from Carrizo Creek or from the Caloosahatchee marl!: Placocyathus Antillia Placotrochus Syzygophyllia Stylophora Pavona *” Pocillopora Goniopora Neither the coral fauna of Carrizo Creek nor that of the Caloosahatchee marl, as at present known, contains any of the coral genera distinctive of the Bowden and related zones. These distinctive genera became extinct in the Atlantic during upper Miocene time, according to present infor- mation. It therefore seems to me more probable that the fauna of Carrizo Creek migrated to the head of the Gulf of California after these forms had become extinct than that they were eliminated after migration at an earlier period. Pliocene and later.—Subsequent to the Miocene there have been many oscillations of the West Indian area, and during perhaps Pliocene time there was profound deformation. Zeogeographic data, in the opinion of several investigators, seem to demand former connection, probably during late Miocene or Pliocene time, from Yucatan across Cuba to Haiti, Porto Rico, and the Virgin Islands; from Honduras to Jamaica; and from Anguilla to South America. It also appears that Saint Croix was once joined to Anguilla and to the eastern end of the Virgin Islands. There are certain geologically late fault-lines which perhaps date from this time, _and the severance of the old ridges into the islands we now know may be largely due to movement along them. One of these fault-lines forms the northern boundary of the Bartlett Deep and passes between the east end of Cuba and the west end of Haiti. Another tectonic line which forms the south side of the Bartlett Deep converges toward the former in the Wind- ® Ancient Panama canals. California Acad. Sci. Proc., vol. 7, 1917, pp. 197-205 (date printed with title, July 30, 1917; received by me on October 16, 1917). 10 Added from Miss Maury’s Santo Domingan collections. 626 T. W. VAUGHAN—GEOLOGIC HISTORY OF CENTRAL AMERICA ward Passage. A downthrown block between these lines has separated Cuba and Haiti and produced the Bartlett Deep. Probably there was also faulting or flexing between Cayman Ridge and the southern shore of Cuba west of Manzanillo Bay, while either faulting or flexing may have separated Cuba and Yucatan. There is evidence of a downthrown fault block between Saint Thomas and Saint Croix, the two sides converging toward Anegada Passage. This will account for the deep of over 2,400 fathoms north of Saint Croix, and the severance of Saint Croix and the Saint Martin Plateau group of islands from the Virgin group. There are three kinds of evidence that bears on the age of these faults, namely: (1) In eastern Cuba, as the Miocene La Cruz marl is abruptly eut off at the shoreline in the vicinity of the Morro, at the mouth of Santiago Harbor, the faulting must be subsequent to old or middle Mio- cene; (2) as the sea along fault shores has been able subsequent to the faulting to cut only narrow benches into the fault-planes on the upthrown side, the fault-planes are physiographically young; (3) the biologie evi- dence, in the opinion of most of those who have recently considered it, demands land connection in late Tertiary time between Cuba, Santo Domingo, Porto Rico, and thence to South America. Miller has shines published an important paper on this subject,** and states: ‘With the characters of so many [eight] genera known it becomes possible to gain some idea of the Antillean hystricine fauna.” The most noticeable feature of these genera, considered as a group, is their similarity to the Santa Cruzian and Entrerian rodents which Ameghino and Scott have deseribed and figured. In no instance has the same genus been found in both the West Indies and Argentina or Patagonia; but the Antillean rodents thus far discovered never show such peculiarities that their remains would appear out of place - among those of their extinct southern relatives, while as a whole they would at once be recognized as foreign to the present South American fauna.” On the following page of the same paper he says: “So far as can be judged from eight * very distinct genera, the Antillean hystricine rodents do not present the characters that would be expected in animals derived from South America during any period geologically recent. Neither have they the appearance of an assemblage brought together at differ- ent times by migration or chance introduction. On the contrary, they suggest direct descent from such a part of a general South American fauna, probably not less ancient than that of the Miocene, as might have been isolated by a splitting off of the archipelago from the mainland. Of later influence from | the continent there is no trace.” 11 Gerrit S. Miller, Jr.: Bones of mammals from Indian sites in Cuba and Santo Do- mingo. Smithsonian Misc. Coll., vol. 66, no. 12, 1916, 10 pp., 1 pl. 122 Op. cit., p. 3. 13 “Two more were described by Anthony in January, 1917. They bear out my state- ment about the eight and make it stronger.—G. S. M., Jr.” PALEOGEOGRAPHIC SUMMARY 627 The mammals furnish more ‘evidence of this kind than | am present- ing here, and Barbour and. Stejneger, from their study of reptiles, have reached similar conclusions, which accord with the tectonic history of the region, namely, that in late Tertiary, probably Pliocene, time the West Indian Islands as we know them were produced by block-faulting which broke into pieces a far more extensive land area. Dr. W. D. Matthew does not agree with the postulated connections from Cuba to Yucatan, from Jamaica to Honduras, and from Anguilla to South America.'* The method of distribution of the terrestrial organisms must be left for the consideration of those best versed in such subjects, and I am only war- ranted in saying that at present there is no known geologic evidence against a late Miocene or early Pliocene connection from Anguilla to South America or from western Cuba and Jamaica to Central America. Following this geologically late episode of cataclysmic faulting, it ap- pears that in some areas there was minor submergence of the margins of some of the West Indian Islands and parts of Central America—for in- stance, Panama and Costa Rica. | According to Hill, the volcanoes of the Windward Islands date back at least to the Eocene. He says: “After the Miocene, vulcanism became quiescent in the Great Antilles and the Coastal Plain of Texas, but has continued to the present in the four great foci of present activity—southern Mexico, the northern Andes, Central Amer- ica, and the Windward Islands. In the last two regions mentioned, the greater masses of the present volcanic heights were piled up before the Pliocene, and the present craters are merely secondary and expiring phenomena.” The last important shift in position of strand-line along the Atlantic coast of the United States and around the shore of the Gulf of Mexico and the Caribbean Sea has been by submergence of land areas, but subse- quent to this there has been local emergence, often accompanied by minor tilting or warping. > ; Except vulcanism, the following table presents a succinct summary of the major events considered in the foregoing remarks. My primary in- tention has been to characterize biologically and to correlate the marine formations of the Canal Zone and the geologically related areas in Central America and the West Indies, and to lay particular stress on the succes- “Miller says in a letter to me: “Matthew's argument seems to me to have two very weak spots in it: He minimizes the variety of structure shown by the W. I. rodents. and he hanks altogether too heavily on what we don’t know—that is, on the apparent absence of ungulates and other things that ought to be present in a continental fauna. When it is remembered that all but three of these ten genera of rodents and the insec- tivore Nesophontes were unknown five years ago, we ought to be very shy of predicting what the next digging will not turn up. But it seems to me that what you have quoted of mine contains about all the comment I need to make in print.—G. S. M., Jr.” 628 T. W. VAUGHAN—GEOLOGIC HISTORY OF CENTRAL AMERICA sive periods of emergence and submergence of the land and the crustal deformation, folding and faulting, concomitant with changes of that kind. Comparison of the table showing the correlation of the Tertiary formations of Panama with the tabular summary will reveal that the story told by the two tables is essentially identical, the erosion intervals and the marine formations in the correlation table representing respec- tively the periods of emergence and the periods of submergence in the tabular summary. TABULAR SUMMARY 629 TABULAR SUMMARY OF SOME OF THE IMPORTANT EVENTS IN THE GEOLOGIC HISTORY OF THE WEST INDIES AND CENTRAL AMERICA HWpoch Hvents pee) so eae bon 0 Se Sa gow Re « Submergence of land areas, probably resulting from deglaciation, except local differential crustal movements, in places producing uplift. PVEISHOCENE. .. 0. eee ee eas . Emergence of large areas, probably due to with- drawal of water to form the continental ice- sheets; also oscillation of land areas by differ- ential crustal movement. PATOCENE!, «0s. 8 Sie asete . Local moderate submergence, period of cataclys- mic faulting breaking up a large land area and forming the Antilles nearly as they are at pres- ent. Probably a narrow interoceanic connec- tion that admitted an Atlantic fauna into the present site of the Gulf of California. Upper...... Extensive emergence of the land joining North and South America through Central America ; Greater Antilles joined to each other, and possi- bly to Central America, by bridges from Jamaica to Honduras and from western Cuba to Yueca- tan, and to South America along the Caribbean are. All these supposed connections not neces- Miocene....< sarily contemporaneous. ! ® Middle...... Hxtensive marginal submergence in some of the West Indies and on the Atlantic side of Central , America. No known interoceanic ¢eonnections. Lower...... Extensive submergence in the West Indies and | around the continental margins; narrow, areally limited interoceanic connections; land emerging in Central America. ae ES eae eI eC ae St Upper...... Hxtensive submergence with interoceanic connec- tions. Middle...... Maximum areal submergence with extensive inter- 0 oceanic connections. Oligocene... J Lower...... Extensive submergence in Céntral America and the southeastern United States; local emergence in the West Indies. Hxtensive diastrophism and mountain-making by folding. 630 T. W. VAUGHAN—GEOLOGIC HISTORY OF CENTRAL AMERICA Epoch Events Upper...... Extensive submergence with interoceanie connec- tions. : Hueeie Middle...... Apparently interoceanic connection across Central America. Lower...... Emergence of the Greater Antilles and Central America. No known interoceanic connection. Upper...... Extensive submergence, but without interoceanic connection. Lower...... Submergence in southern Mexico and Central America, especially in late Comanche time. Probable emergence in the Greater Antilles. No interoceanic connection. Cretaceous * and west Texas, without interoceanic connec- tion, except possibly in late Upper Jurassic time. Middle.. Submergence in southern Mexico (Oaxaca and Guerrero), with possible interoceanic connec- tion. Lowetr.. . Submergence in southeastern Mexico (Puebla, Vera Cruz, and Hidalgo, possibly also in Guer- rero), with possible interoceanic connection. Non-marine plant-bearing beds in same region and also in Oaxaca. Possibly the latter may be of same age as the supposed Rheetic plant- bearing beds of Honduras and Nicaragua. ? Jurassic. . ss TOT en eae Mae 9. CE SS ae ...+e- Submergence in western Cuba, eastern Mexico, SSE date i ERE coe.) SN RAS Hl ge a es ee eee 5 ee Plant-bearing beds in Honduras and Nicaragua, (Rheetic) above mentioned, bespeak land conditions in latest Triassic or earliest Jurassic. Upper...... Submergence in central Mexico (Zacatecas), with rag SSC. "2. 4 (Karnic) probable interoceanic connection. Middle...... Probable land conditions throughout Mexico and Central America. Lower....-. Probable land conditions throughout Mexico and Central America. i Late Paleozoic....... ...-.- Formation of the major tectonic axes of Central America and the initial east and west axes of the Greater Antilles. 3 Mesozoic history of Central America, Mexico, and the West Indies, by T. W. Stanton. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 631-636 DECEMBER 380, 1918 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY PALEOGEOGRAPHIC SIGNIFICANCE OF THE CENOZOIC FLORAS OF EQUATORIAL AMERICA AND THE ADJACENT REGIONS? BY EDWARD W. BERRY (Read before the Paleontological Society December 31, 1917) CONTENTS Page JOSE) SER TERN RE a Re a PEAR, ONS Feanaraclis |) So Ay ek Sn ny ee ar 631 Sener TEST CE ONIS) 5 60 ve, fea vei -eiia vhs, 01'o nee sue RNasin arebe eRe aint ITAL Ak. Uie 6 vn) obs ake aa ose 632 Muay wocene flora of North AMe@rica. cl. seta ck ee cence gees 632 Tonnes Hocene flora of North AMe@PiGd. 0. eens ce cs ee ees ene eens 632. RENNES AUN 23 ei wile aves hie sever w Rom feo we eee ain etna “cee Ae) RE Se NEO ao 632 Claiborne (Auversian) Kocene flora of southeastern North America... 633 Jackson (Priabonian) flora of southeastern North America.......... 633 Catahoula and Vicksburg (Oligocene) floras of North America.. ....... 633 Peadanr MOraAs OF: SOUL ATMEIICE a. « Salaun eaten oct alee Cee its ous Sb soba en 633 MMM VC asec as chev area ce hata ele eee her Tee I. Fb eC NR CAT aE ORI cs SEY SN Sta eos oe ove 634 UEMEMMERPE NR yf 02 52 aha c check Fok whol chal ieee reo Meenad ate a AL ETE IER. Soc ee ea bag 635 INTRODUCTION In order not to occupy too much time or confuse my auditors with details, it has seemed best to give a brief summary of the known fossil floras bearing on the problem of intercontinental land connections be- tween North and South America, followed by the conclusions which it has seemed might be legitimately drawn from their evidence. This evidence is not presented in detail, since it has been given at length in publications recently printed or now in press.? 1 Manuscript received by the Secretary of the Society August 22, 1918. 21. W. Berry: The physical conditions and age indicated by the flora of the Alum Bluff formation. U.S. Geol. Survey Prof. Paper 98 B, 1916. : The Lower Eocene floras of southeastern North America. Idem, 91, 1916. —: The Pliocene citronelle formation of the Gulf Coastal Plain and its flora. Idem, 98 L, 1916. ———: The Catahoula sandstone and its flora. Idem, 98 M, 1916. : The Upper Cretaceous floras of the eastern Gulf region. Idem (in press). : The Midde and Upper Wocene floras of southeastern North America. Idem (in press). (631) 632 E. W. BERRY—CENOZOIC FLORAS OF EQUATORIAL AMERICA UprEer CRETACEOUS The flora which commenced to radiate from Arctogea in the Ceno- manian, and which during the Turonian and Emscherian covered most of North America and Europe, and presumably Asia, penetrated as far as southern South America before the close of the Upper Cretaceous, and at least 26 typical species have been recorded from Argentina.* ‘This would seem to indicate that there was some land connection between North and South America throughout the greater part of the Cretaceous, during which time the prevailing direction of migration was from north to south. Mipway EocENE FiorAa oF NortH AMERICA ~ The small Midway Eocene flora recorded from the Gulf Coastal Plain contains five species belonging to the genera Pourouma, Cecropia?, Asimina, Dolichites, and Terminalia which I have regarded as having been derived from tropical America and as lacking direct ancestors in the Upper Cretaceous of North America. Witcox Eocene Frora or NortH AMERICA | IN GENERAL This very extensive and well preserved flora comprises to date 345 described species, distributed in 136 genera. There are in common with the almost unknown Tertiary floras of South America 2 species in 2 genera. Those that I consider as having originated in Arctogeea number 179 species in 57 genera. Those whose place of origin is unknown num- ber 65 species in 29 genera. Those that appear to have originated in the American tropics number 101 species in 50 genera. I do not consider the relationship of the existing flora of the Antilles with that of South America to be as intimate as was the relationship of the Lower Eocene flora of southeastern North America with that of South America. This statement is not true of Central America, where the present lowland flora is a direct continuation of that of South America, while the upland flora is a mixture of survivals from the southward mi- gration of North American types in the Miocene mixed with later immi- grants from both the north and the south. *E. W. Berry: The fossil flora of the Panama Canal Zone. U. 8S. Natl. Mus., Bull. 103, 1918, pp. 15-44, pls. 12-18. : The Tertiary flora of Peru. Proc. U. S. Natl. Mus. (in press). 3}. Kurtz: Revista Museo La Plata, vol. 10 (1889), 1902, pp. 43-60. WILCOX EOCENE FLORA 633 CLAIBORNE (AUVERSIAN) EOCENE FLORA OF SOUTHEASTERN NORTH AMERICA The Claiborne flora as at present known comprises 78 species in 59 genera. Of this number 7 genera, with 8 species, are considered as new arrivals from tropical America. JACKSON (PRIABONIAN) FLORA OF SOUTHEASTERN NORTH AMERICA The known Jackson flora comprises 79 species in 60 genera. Of this number 6 genera, with 6 species, are regarded as new arrivals from trop- ical America. These are species of Phoenicites, Myristica, Burserites, Dombeyoxylon, Rhizophora, and Calocarpum. In addition to these, Palmoxylon lacunosum (Unger) Felix of the Jackson is probably com- mon to the lower Oligocene (Sannoisian) of the Island of Antigua. CATAHOULA AND VICKSBURG (OLIGOCENE) FLoras or NorrH AMERICA The known flora from these formations is a small one, numbering but 24 described species in 15 genera. The only new genus derived from tropical America is the genus Embothrites. 'T'wo species of palms, how- ever, are common to the lower Oligocene of the Island of Antigua, an- other is very close to an Antigua and Panama form, and a third occurs in southern Mexico. There is in addition an undescribed petrified wood in the Vicksburg that is common to Antigua. TERTIARY FLORAS OF SouTH AMERICA The origin of such South American Eocene floras as are known at present may well have been from Arctogea; but if this was the case, as seems probable, their ancestors reached South America during the Cre- taceous, since they are found at a number of widely scattered localities in rocks of earlier Tertiary age, namely, at Coronel, Chile ;* Santa Ana and Caucathale, in Colombia;> Tablayacu and Loja, in Ecuador,® and near Tumbez, in Peru’. Moreover, the evergreen beeches (Nothofagus) which are found in the lands bordering the present Straits of Magellan® appear to be of northern, probably of Asiatic, origin. *H. Engelhardt: Abh. Senck. Naturf. Gesell., vol. 16, hft. 4, 1891, pp. 629-692, pls. 1-14. Abh. Sitz. Naturw. Gesell., Isis in Dresden, 1905, pp. 69-82, pl. 1. 5H. Engelhardt: Abh. Senck. Naturf. Gesell., vol. 19, 1895, pp. 1-47, pls. 1-9. 6 Tdem. 7 Berry: Op. cit. SC, von Ettingshausen: Sitz, k. Akad. Wiss. Wien, vol. 100, 1891, pp. 114-137, pls. 1, 2. A. Gilkinet: Resultats voyage du 8. Y. Belgica en 1897-1899, 1900. : A. Dusen: Svenska Exped. till Magellanslanderna, vol. 1, 1899, pp. 87-107, pls. 8-13. XLVII—BuLu. Grou. Soc. AM., Vou. 29, 1917 634 E. W. BERRY—CENOZOIC FLORAS OF EQUATORIAL AMERICA The exact ages of these various South American Tertiary floras has never been accurately determined. De Lapparent regarded the first as Eocene, probably Sparnacian. Dusén, following Wilckens, regarded them as Oligocene. It is extremely unlikely that they all are of the same age. Those from Colombia, Ecuador, and Peru J am inclined to regard as the same age as the flora from the Isthmus of Panama,*® which appears to represent various stages of the Oligocene plus the Aquitanian and Bur- digalian, and these find their counterparts in the floras of the Catahoula, Vicksburg, and Alum Bluff formations of the United States and in the petrified woods of Antigua and others of the Antilles. Part of the Chilean and Patagonian floras appear to be older than these, for they have a few but striking elements in common with those of the lower Eocene of the Mississippi embayment region. Later Tertiary floras from South America not previously mentioned include the Pliocene flora of Bolivia, amounting to 85 species and strictly endemic in character,*° and a Pliocene flora from the province of Bahia, Brazil, comprising about 70 species, some of which are of North American ancestry.” SUMMARY The following somewhat categorical conclusions are indicated by a de- tailed study of the foregoing floras: | 1. There appears to have been free intercommunication between North and South America during the Upper Cretaceous, with the invasion of the northern (Holarctic) flora into all parts of South America and prob- ably to Antarctica. 2. Continued land connection between North and South America dur- ing the basal and lower Eocene, which, combined with the ameliorating climate of southeastern North America, resulted in the introduction of many new types in that region which were derived from the south. 3. During the middle and upper Eocene, as well as during the Oligo- cene, there was a continued influx of a few tropical American types into our Southern States, but these were not in sufficient force to demand a land connection between the two regions, nor can it be certain that these types came from South America and not from the intermediate region — of Central America and the Antilles. . 4. During the Oligocene there appears to have been a rather free inter- change of plant types between Panama and the Antilles, best illustrated ® Berry: Op. cit. 10. W. Berry: Proc. U. S. Natl. Mus., vol. 54, 1917, pp. 103-164, pls. 15-18. 1. Krasser: Sitz. k. Akad. Wiss. Wien., vol. 112, abh. 1, 1903, pp. 852-860. Ed, Bonnet: Bull. Mus. d’hist. Nat., année 1905, pp. 510-512. SUMMARY 635 by the extensive flora of petrified woods found on Antigua, which has several forms common to Central America and the southeastern United States. 5. In formations correlated with the Aquitanian and Burdigalian of the European section, but generally considered as upper Oligocene by American geologists, the tropical types of plants become fewer on the North American mainland and are largely replaced by temperate forms. 6. The land emergence of the Miocene appears to have developed land connections in Central America and the Antilles reflected in the floras by a general spreading southward of the temperate flora of North Amer- ica. This emergence resulted in the connection of the Windward Islands with South America, Cuba with Yucatan, and the Jamaica, Haiti, and Porto Rico axis of elevation with Honduras. To this period may be at- tributed the original colonization of the many North American types that still persist in the Antilles and Central America. The invasion of the latter regions, and that beyond in South America, by the oaks (Quercus), walnuts (Juglans), and many é6ther Holarctic types probably occurred at this time, since some of them are found in the Pliocene of Brazil. The radiation of the agaves may also be more appropriately dated from the Miocene rather than from the Pleistocene, as is done by Trelease,’? since while there was considerable elevation during the Pleistocene the major tectonic lines were. established during the Pliocene by block faulting, as Vaughan has shown, and the failure of Agave to penetrate to any consid- erable extent into South America was due to the impenetrability of the tropical rain forest and not to geographical barriers. 7. North and South America were connected during the Pleistocene and there was considerable elevation in the Antillean region, resulting in a northward spread from South America of various elements from the rain forests of the Amazon and Orinoco basins, one or two of which occur in the late Pleistocene of southern Florida. Actual land connections among the Antilles or with Florida are not considered probable. NoTE There are a number of reasons why the arguments against a land bridge between North and South America based on the evidence of vertebrate paleontology can not be regarded as conclusive. It is opposed by the evi- dence derived from the study of the distribution of other animal types, as has been already pointed out by several students. First, as regards actual changes in level. The general thesis of the 122 William Trelease: Mem. Natl. Acad. Sci., vol. 11, 1918. 636. E. W. BERRY—CENOZOIC FLORAS OF EQUATORIAL AMERICA permanency of ocean basins, as developed by Matthew in “Climate and evolution,” +2 seems unquestionably sound in the present state of our knowledge of isostatic compensation. Whether the latter was always as complete as it seems to be at present may well be doubted—certainly we know of remarkably great epeirogenic changes, and, furthermore, a rather good case can be made out for the theorem advanced by Walther and others, that the deep seas are post-Mesozoic in age. Be this as it may and while its acceptance does not directly oppose Matthew's contention, the present continental scarps can not be regarded in all cases as the metes and bounds of the continents in past times, and a very strong case can be made out for Suess’s sunken block theory in a large number of areas, and especially in the Caribbean region. It seems to me, as I review the various lines of evidence, that the long region of weakness extending from Graham Land to the Antilles may well indicate that the Antilles were once a part of South America, and that the latter continent was connected with Antarctica. I have recently shown that the change of elevation of the great central plateau of Bolivia and the eastern Andes in that region has amounted to a minimum of 21% miles since the Pliocene,** and the weight of this argument is not dis- posed of by calling these changes orogenic instead of epeirogenic. I am therefore the more inclined to believe that comparable changes of level have taken place in the Caribbean region during the Tertiary. In all discussions of paleogeography based on the distribution of the mammals it should be constantly borne in mind that the facts, in so far as they contribute toward an understanding of the relations between North and South America, are derived almost entirely from the region of the Great Plains and Rocky Mountains in North America and from Argentina in South America—regions which were separated, at least during the Eocene and the Oligocene, as they are today, by the greatest extent of tropical rain forest on the globe. The fact that the edge of this equatorial American rain forest appears to have covered the southern shores of the United States during the first half of the Tertiary renders it obvious why the Artiodactyla and Perissodactyla of our western plains were not exchanged for the typotheres and litopterns of Patagonia. 1% W. D. Matthew: Annals N. Y. Acad. Sci., vol. 24, 1915, pp. 171-318. j 14. W. Berry: Proc. U, S. Natl. Mus., op. cit. ; BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 637-648 DECEMBER 30, 1918 PROCEEDINGS OF THE FALEONTOLOGICAL SOCIETY = AGE OF CERTAIN PLANT-BEARING BEDS AND ASSOCIATED MARINE FORMATIONS IN SOUTH AMERICA? BY EDWARD W. .BERRY (Read before the Paleontological Society December 31, 1917) CONTENTS : Page OPMENT CSE TEV ER oo So hs: dias hats 0. wrk, ea nO CEM aMeeEMeE a ay NceIe Gy a) oto is oo 0 ete ows. 8 637 MPT ote. Eas! wis Sa a ieee aaa va Gms ee at ees alee ERM Gee. oh etel vial sail i ar: « ce SBR eas 639 Op pa 6 etal ARR Re Veer aie 08 acy Me sh aa a 63 po LT ELON RISE ce UU One ae yee SE Aig PORIR es aA ee | or ea a 640 MMP IMIUMMR re 2 a0 eat 0 01a. Soars val ace Pasa Grams Meavieyns ah as AE hc gatiee ode Ce Natmeb ee el te ioig wikne sec ae be 641 RT Feed sean gs Sis taha) Mois x. antl Slop AR akan a nec aah at Sd RON Eee Aare CadeustioNe yeu o sae fpleustans Saja. 65 642 00 TE Oe eee rh Meer i apt AR leer har Bonk galt Se eae eee 646 INTRODUCTION Tertiary sediments are found at scattered localities throughout the continent of South America, and the Argentina Tertiaries in particular have been extensively exploited in connection with the study of the varied vertebrate fossils which they contain. Marine Tertiary deposits are found in the latter region as well as around the margin of the Brazilian plateau; they are widely distributed along the west coast, and in the Andean re- gion they are scattered from Colombia and Venezuela to Tierra del Fuego and beyond. Our knowledge of all of these is very fragmentary and is limited for the most part to incidental descriptions in connection with the study of the contained floras or faunas rather a on detailed areal and stratigraphic work. In the present brief contribution the discussion is centered on the pre- Pliocene Tertiary of the Andean region and of the west coast, since the data at hand seem sufficient for tentative correlations and it is the beds in this part of the continent that may be expected eventually to unravel the geological history of the Andean chains. In the Andean region itself 1 Manuscript received by the Secretary of the Society August 22, 1918. (637) 638 E. W. BERRY—CERTAIN PLANT-BEARING BEDS IN SOUTH AMERICA | Cae ly ee ree 3 - or ee Be } a ud an j= | A A HosSsert LTT ttl) ee ae | ep wo mo a AAA ae TH AANUNURRURRREL: HL ce , > ee Ra sauna EE : 4 60 ee pee ee £0 JOHNSTON SERIES OF DESK MAPS : : Corymon T1915. A.J. NvsTROM & CO. CHICAGO. Ficurt 1.—Map of South America Showing distribution of lower Miocene plant beds: 1, Canal Zone; 2, Santa Ana, Rio Magdalena Valley, Colombia; 3, near Buga, Rio Cauca Valley; Colombia; 4, 7 Ce Rio Jubones basin, Ecuador; 5, Loja basin, Ecuador; 6, near Tumbez, Peru ; , Coronel, ’ Chile; 8, Navidad beds, Chile; 9, Patagonian beds, Argentina. CANAL ZONE AND COLOMBIA 639 certain localities are not mentioned, either because of the absence of fossil plants or for the reason that no definite opinion seemed permissible. The principal localities that are referred to are shown on the accompanying sketch map (figure 1) and will be discussed in regular order. CANAL ZONE The described section in the Canal Zone (locality number 1) is of the greatest importance in this connection, for while it is not a part of the Andean system, the Canal Zone, because of its nearness to South America and the rather definite correlation of its Tertiary formations, offers a convenient standard for comparison. Moreover, the geological history of the Isthmian region has a direct bearing on the facies of the marine faunas of the west coast and the history of the terrestrial floras that have entered South America from North America during those times that the Isthmus was above the sea. The section need not be quoted in the present connection, since the formations have recently been described by Mac- Donald,? and their correlation with the Tertiaries of our Southern States, the Antilles, and Europe has been given in an important paper by Vaughan.* ; The geological history of the Isthmus arrived at by Vaughan indicates that the region was emerged, and that there was no interoceanic connec- tion across it during the whole of the Cretaceous and the earlier half of the Kocene, and that there was free communication between the two oceans during the Upper Eocene, Oligocene, and Lower Miocene. This has an important bearing on the history of the floras and faunas of the region to the southward, as I have already mentioned, and it will develop on subsequent pages that this history corresponds with the history of the opposite end of South America, and also accounts for the Mediterranean elements found in the Tertiary marine faunas of Peru and Chile. COLOMBIA Fossil plants have been described from two localities in Colombia. These are Santa Ana (locality number 2), along the western margin of the Rio Magdalena Valley, and near Buga (locality number 3), in the Rio Cauca Valley. The first is between the eastern and central and the second between the central and western Andean chains. At both locali- 2D. F. MacDonald: U. 8. Bureau of Mines, Bull. 86, 1915; U. S. Natl. Mus. Bull. 103 (in press). , ®1T, W. Vaughan: U. S. Natl. Mus, Bull. 108 (in press). 640 E. W. BERRY—CERTAIN PLANT-BEARING BEDS IN SOUTH AMERICA ties the fossil plants occur in tuffs,* and there is no evidence of contem- poraneous or subsequent marine deposits in this general region, although it must be constantly borne in mind that the area has been very imper- fectly explored. The flora found near Buga is very limited in extent, . and while it is probably the same or very nearly the same age as that found in the Rio Magdalena Valley, this can not be demonstrated. The flora of Rio Magdalena Valley comprises 35 species, well distributed among the natural orders. It is clearly a mesophytic tropical flora and it contains numerous elements that are strictly South American in exist- ing floras. Among these are the genera Stenospermatium, Goeppertia, Acrodiclidium, Condaminea, Vochysia, Trigonia, etcetera. Nine of the Santa Ana species have an outside distribution. Seven of these have been found in Peru, two in Ecuador, and two in Chile. These afford a basis for tentative correlation which will be referred to in a subsequent para- eraph, since the basis for all of the proposed correlations rests on various collateral lines of evidence rather than on direct individual comparisons. Stille’ has described coarse valley filling in the Rio Magdalena Valley which he calls the Honda beds. These may possibly be of the same age as the plant-bearing tuffs, but they are probably much younger and may be considered to represent upper Miocene or Pleistocene continental sedi- ments or possibly both. ECUADOR Fossil plants are known from two principal localities in Ecuador. These are Tablayacu (locality number 4), in the Rio Jubones basin, and several localities in the Loja basin (locality number 5). Only three spe- cies are recorded from the former, but one of these is also found in the Loja basin, and it therefore seems probable that the two deposits are of the same age. The occurrence of lignites and associated leaf impressions in the Loja basin has been known for a generation or longer. Engel- hardt’ has described 40 species of fossil plants from this locality, but the age of the beds has never been fixed beyond that they were Tertiary. One of the Loja plants occurs in the Colombia deposits, another in the Caimito formation of the Canal Zone, three are found in Chile, and one in Peru. The flora, judged by modern standards, is distinctly South American in its facies, with species of Arthante, Hieronymia, Cam- *H. Engelhardt: Abh. Senck. Naturf. Gesell., Band 19, 1895. 5H. Stille: Geologische Studien im Gebiete des Rio Magdalena. von Koenen Fest- schrift, 1907, pp. 277-358. °T. Wolf and G. Rath: Zeits. Deutsch. Geol. Gesell., Bd. 28, 1876, pp. 391-393. 7H. Engelhardt: Abh. Senck. Naturf. Gesell., Bd. 19, 1895. PERU 641 phoromeea, Luhea, Banisteria, Tapiria, Vochysia, and other South Amer- ican types, and denotes a mesophytic tropical environment. ( PERU From near Tumbez (locality number 6), on the coast of Peru, I have recently described a small flora of 14 species,® of which several are only tentatively identified because of the fragmentary nature of the material. Seven of these species are common to the Tertiary of Colombia, one is found in the Culebra, Gatun, and Caimito formations of the Canal Zone, one in the Loja basin of Ecuador, one in Chile, and another is close to if not identical with a Chilean form. This flora denotes very different cli- matic conditions from those that prevail at the present time in this semi- desert coastal region. The plant localities in Colombia and Ecuador represent continental deposits and lack marine faunas. In the case of Tumbez, however, we are dealing with lagoonal deposits intercalated in a marine fossiliferous series, so that the evidence of the flora can be checked by a certain amount of faunal evidence. The general section of the Tertiary of the coastal region of Peru is segregated by Grzybowski° into the following units, to which he assigns the ages as given below: aE SEALC.. 6 cine sole ren re A atta Be tis orarer EOCENE Malara, stages... “sda alld opal be ate be tehy eRe od aera ses Upper Miocene MOEPICOS: StAWO ai.oc a apn bela teeiatale aNeRe ORE: ed ee ae Miocene PACA SCALES, one sicid's SP oie ace eee eee -... Lower Miocene VIDIO: - STARE. 6 sen svac io pie, hr eanenen eel eee RP etc ereers Oligocene The fossil plants come from the Heath stage. The small fauna found in the associated beds of this stage comprise 19 species, representing the genera Arca, Turritella, Pyrula, Puncturella, Ostrea, Venus, Cytherea, Cardium, Lutraria, Dosinia, Leda, and Lucina. Venus miinsteri and Lutraria vetula are common to the Navidad beds of Chile, Cytherea plani- vieta occurs in the Bowden marl of Jamaica, and Turritella altilirata in the Gatun formation of the Canal Zone. The genera Lutraria, Ostrea, and Cardium have closely related species in the Navidad beds of Chile, and Dosinia is represented by a closely related species in the Miocene of the Island of ‘Trinidad. The Bowden marl has been shown to be of Burdigalian age by Woodring, while the Gatun formation, according to Douvillé and Vaughan, represents both Burdigalian and Helvetian. The $I. W. Berry: U. S. National Museum, Proc., vol. 55, 1919, pp. 279-294, pls. 14-17. ®°J. Graybowski: Die Tertiiirablagerungen des nérdlichen Peru und ihre Mollusken- fauna, Neues Jahrb. Beil., Bd. 12, 1899, pp. 610-664, pls. 15-20. 642 §. W. BERRY—CERTAIN PLANT-BEARING BEDS IN SOUTH AMERICA fossil plants associated with the foregoing mollusca in Peru appear to be Aquitanian or Burdigalian in age, and a consideration of both classes of evidence leads to the conclusion that this flora and the associated fauna of the Heath stage are of Burdigalian age. CHILE There are at least two Tertiary fossiliferous horizons in Chile. These are the Coquimbo beds and the Navidad beds. The former do not concern the present discussion, particularly since they are probably of Pliocene age and correspond to the Paita stage of Peru. The second, or Navidad, beds (localities 7 and 8) have an important bearing on the present dis- cussion. They comprise prevailingly arenaceous deposits carrying locally an abundant marine fauna, and toward the base, according to Steimmann, coal beds and an associated terrestrial flora. While their areal distribu- tion and stratigraphic or structural relations have never been described, they have been recognized at a number of scattered localities and there has been a tendency, exemplified by Moricke, to carry the name Navidad to more or less uncertain correlatives in other parts of South America. Along the west coast of Chile, however, at Navidad, Matanzas, Lebu, Coronel, Lota, Puchoco, Island of Chiloé, and elsewhere, they have been definitely recognized and they may extend as far southward as the Straits of Magellan. The Navidad fauna, which is extensive, has been described principally by Philippi’® and Moricke.** It shows closer relationships with the Ter- tiary faunas of Europe than with the corresponding faunas of Australia and New Zealand, although it contains some elements common to the latter. Engelhardt?” has described an extensive flora from the coal-bear- ing sandstones in the Navidad beds near Coronel. This flora consists of 94 species, well distributed among the natural orders and indicative of tropical humid conditions. It is of great interest, in that it contains a considerable element derived from the north and also found in the Eocene of southeastern North America. This element includes the genera Zamia, Anona, Myristica, and representatives of the families Papilionacee, Bom- bacaceze, Dilleniacee, Lauraceze, Myrtacee, Boraginacee, and Rubiacez. Compared with the known fossil floras from other parts of South Amer- 10R. A. Philippi: Die tertiiren und quartiren Versteinerungen Chiles. Leipzig, 1887. 11 W. Moricke: Versteinerungen der Tertiirformation von Chile. Neues Jahrb. Beil., Bd. 10, 1896, pp. 548-612, pls. 11-13. 22H. Engelhardt: Ueber Tertiirpflanzen von Chile. Abh. Senck. Naturf. Gesell., Bd. 16, hft. 4, 1891, pp. 629-692, pls. 1-14. Bemerkungen zu chilenischen Tertiirpflanzen. Abh, naturw. Gesell., Isis in Dresden, 1905, pp. 69-82, pl. 1. CHILE 643 ica, the Navidad flora contains 8 species in common with that found in the Loja basin of Ecuador, 2 species in common with that found in Co- lombia, and 2 species in common with that described recently from Peru. When compared, on the other hand, with the geographically much less remote flora found in the Magellanian beds along the straits of that name and on Tierra del Fuego, it is found to have nothing in common with the latter except a single species of Flabellaria, about which Dusén expresses the opinion that it could not have come from the Magellanian beds, and in this Dusén appears to be perfectly justified. It appears that the Navidad flora is younger than the floras known from farther south. Before discussing the age of the Navidad beds, I wish to refer to the so-called Patagonian beds of southern Argentina, the marine fauna from which has been admirably described by Ortmann.** This fauna has been satisfactorily shown to be of lower Miocene age, and while the Australian and New Zealand element is more pronounced than in the Navidad beds, nevertheless the Patagonian has, out of a total fauna of 151 species, 34 that are identical with and 15 additional that are closely allied with Navidad species. Ortmann quite rightly concludes that the Patagonian is synchronous with at least a part of the series referred to the Navidad. In conformity with the conclusions of invertebrate paleontology as ex- pressed by Steinmann, Moricke, Ortmann, and others, and from a con- sideration of the flora found in these beds, I would confirm the lower Miocene age of a part at least of what goes under the name of Navidad beds and I would consider them as representing the Burdigalian stage and possibly the’ older Aquitanian stage as well, since transgression was continuous in Europe from the one to the other as it was also in the Canal Zone. The presence of some of the mollusca of the Navidad beds in the Magellanian Oligocene may indicate that a part of the former is still older than Aquitanian, but this I greatly doubt, since the facts can be explained by intermigrations of the forms better than by postulating con- temporaneity. The facies of the Navidad flora appears to be slightly older than the previously mentioned fossil floras from Colombia, Ecuador, and Peru, and it may well fall within the Aquitanian, but it is surely not so old as Hocene, as Steinmann and De Lapparent suggest, nor is it so old as the Fagus flora of the Straits of Magellan and Tierra del Fuego, which I have considered as Lower Oligocene in age. Windhausen** has recently described the hitherto unknown (wrongly A. HE. Ortmann: Tertiary Invertebrates. Princeton Wxped. to Patagonia, vol. 4, 1901-1906, pp. 45-332, pls. 11-39. 144A, Windhausen: The problem of the Gratheun ie: Tertiary boundary in South America and the stratigraphic position of the San Jorge formation in a Am. Jour. Sci. (iv), vol. 45, 1918, pp. 1-58. 644 &. W. BERRY—CERTAIN PLANT-BEARING BEDS IN SOUTH AMERICA correlated) transgression of what he calls the San Jorge formation, which in the early Eocene flooded the east coast of southern Argentina and pene- trated northwesterly up the Roca Valley. I mention this admirable con- tribution in the present connection, since it has a bearing on the age and antecedent history of the Magellanian beds. At Punta Arenas and elsewhere along the Straits of Magellan and at various localities in Tierra del Fuego a series of sandy lignitic beds have been described by Ortmann, Hatcher, Nordenskjold, and others, which are of the greatest interest to paleobotanists because of the remarkable flora contained near their base. The section, somewhat abbreviated, is as follows: 1. Sands, lignitic sandstone, and conglomerates — horizon V of Hatcher — Patagonian formation of Ortmann — Burdigalian. 2. Sandstones with lignite beds and fossil plants —= horizon IV of Hatcher = Upper lignites or Punta Arenas coal = Miocene Araucaria beds of Dusén == Acquitanian. . Sandstone with oyster beds = horizon III of Hatcher — Oligocene. . Sandstones with fossiliferous calcareous lenses — Oligocene. . Fossiliferous beds — horizon II of Hatcher = Oligocene. . Sand and sandstone with fossiliferous calcareous concretions and fossil plants — horizon I of Hatcher — Oligocene Fagus zone of Dusén == Oligocene. 7. Lignitic shales —= Lower lignites of Hatcher — Oligocene (?). Oo Ol HB CoO This section presents the record of a minor oscillation of the strand- line with continental deposits passing into lagoonal, and these into littoral and shallow-water marine, and then gradually shallowing and perhaps becoming emergent during the Aquitanian, followed by a marked trans- gression in the Burdigalian. At present our chief interest centers in the Fagus zone and its flora. This flora, as described by Dusén,’ consists of 29 species, of which the Flabellaria, previously mentioned as doubtful, is the only one that occurs in the Tertiary floras already enumerated from South America. The particular facies of this flora is furnished by the abundance of Fagacee. This family is represented by two species of Fagus and by 13 species or varieties of Nothofagus. This flora is cer- tainly older than those already mentioned and it is as certainly Tertiary in age. It unquestionably had its beginnings in the Northern Hemi- sphere and has also been found to be represented at somewhat similar horizons in Australia, New Zealand, and Antarctica. That it did not migrate into Patagonia from North America appears to be probable from | the absence of any definite ancestral assemblage in the abundantly fos- %* P. Dusén: Ueber die tertiiire Flora der Magellansliinder. Svenska Exped. till Magel- — lanslinderna, Band 1, 1899, pp. 87-107, pls. 8-13. ‘ CHILE 645 siliferous Upper Cretaceous or Eocene of the latter continent from which it seems probable that it could have been derived. Nor are any traces of it found at more northern localities in South America. The explanation seems to be that it reached southern South America from the opposite direction, namely, Antarctica. A very interesting Tertiary flora has been recently described’® from the border of the Antarctic continent on Seymour Island, off the east coast of Graham Land. .This flora contains a large element of subtropical types like those found today in southern Brazil, and another large element of forms suggestive of the existing temperate flora of southern Chile and Patagonia, and including species of Fagus and Nothofagus like those found in Patagonia, Chile, Australia, and New Zealand. Dusén, ignor- ing the usually mixed climatic character of early Tertiary floras, and the association of tropical and temperate types under favorable conditions of humidity, and basing his conclusions on the broken character of the fossil remains of these temperate types, reaches the conclusion that the tem- perate and the subtropical elements were contemporaneous, but that the latter were coastal forms under a subtropical climate, while the former grew in the vicinity at elevations which he suggests amounted to 6,500 feet. or more, and were brought by streams to the littoral basin of sedi- mentation. If this is true, it indicates a considerable mountain chain of the Andean type forming the axis of Graham Land at that time as it does at present. ‘The only evidence bearing on the age of the folding, which may really have little bearing on the time of elevation, is the presence at Hope Bay, on Graham Land, of an extensive late Jurassic flora’’ found in continental beds which are involved in this folding. Dusén concludes. that this Tertiary Antarctic flora is older than that of the Fagus zone of the Magellanian beds. Poorly preserved mollusks associated with the plants are considered by Wilckens to represent what he calls the Patagonian molasses, but since the latter is more or less composite, as Windhausen*® has shown, and includes faunal elements belonging to the lower Hocene San Jorge formation as limited by the latter author, the evidence for the correlation adopted by Andersson’? can not be said to be conclusive. The presence of Zeuglodon vertebrae, described from this locality by Wiman, should probably be con- 1% P, Dusén: Uber die Tertiiire Flora der Seymour-Insel. Wiss. Hrgeb, Schwed. Siid- polar-Exped., Band 3, 1908, 27 pp., 4 pls. wl, G. Halle: The Mesozoic flora of Graham Land. Swedish South Polar Exped., 1901-1903, Band 3, lief 4, 1913, 123 pp., 9 pls. EOD Cite 1 J. Gunnar Andersson: On the geology of Graham Land. Bull. Geol. Inst. Upsala, vol. 7, 1906, pp. 19-71, pls. 1-6. > 646 E. W. BERRY—CERTAIN PLANT-BEARING BEDS IN SOUTH AMERICA sidered as evidence of Eocene age. J would therefore dissent from Wilcken’s conclusions that this plant-bearing sandstone is Upper Oligo- ~ cene or Lower Miocene in age and would consider this flora as of Middle or Upper Eocene age. SUMMARY Summarizing the foregoing brief notes and going beyond them into the Mesozoic in order to indicate land connections that were barriers to ma- rine dispersal and avenues for the migration of terrestrial faunas and floras, it may be noted that South America and Antarctica were con- nected during the late Jurassic, and that this connection was not inter- rupted during the long ages of the Lower Cretaceous. At the other end of South America Panama appears to have been emerged throughout the Lower Cretaceous, but there was no direct connection between Antarctica and North America, unless it was over an Antillean land bridge, until near the end of the Lower Cretaceous, at which time a continuous land connection was established which continued with various modifications throughout the Upper Cretaceous. During the Upper Cretaceous the world-wide Emscherian-Lower Aturian transgression is recorded in the Quiriquina beds of Chile, at various localities in Peru and Patagonia, and in the richly fossiliferous deposits of Graham Land, with their Indo-Pacific ammonite faunas. Although it was perhaps possible for these latter faunas to have invaded the margins of Graham Land from the east, it seems more probable, in view of the similarities of the fauna to that found in the Quiriquina beds of Chile, that the land connection with Antarctica which had persisted since Jurassic time was interrupted during the middle part of the Upper Cretaceous, at which time shallow marine waters permitted the invasion of the region by these ammonite faunas. Toward the close of the Upper Cretaceous, however, and throughout all of southern and western South America, there is evidence that this Upper Cretaceous submergence was followed by a negative movement of the strand-line and emergence of the land. This occurred during the time interval of the Maestrichtian and Danian stages of the Upper Cre- taceous and continued for a much longer time than this throughout most of South America. This,late Upper Cretaceous emergence is shown by the absence of any known faunas representing these stages, by the litho- logic indications in the higher levels of increasing shallowness of the waters, and by the continental variegated sandstones of this age in Pata- gonia. At this time, then, Antarctica was connected with Patagonia and the Isthmus of Panama was dry land. SUMMARY 647 This emergent phase continued throughout nearly the whole of the Eocene, for while there was a local transgression from the Hast, repre- sented by the San Jorge formation in Patagonia, this was not of sufficient magnitude to connect the waters of the Atlantic and the Pacific. There was thus afforded an opportunity for the flora of North America to in- vade South America at the beginning and toward the close of the Upper Cretaceous, already indicated by the presence of representatives of the Dakota sandstone flora in Argentina,”° and similar land connections were available throughout most of Eocene time. Similar opportunities for the interchange of terrestrial life, both animal and vegetable, between South America and Antarctica were also present during these same intervals. During the Oligocene there is evidence of minor transgressions in ° Panama; on the Peruvian coast, where the Ovibio stage contains two or three marine forms but is mainly a littoral and continental flysch-like sandstone ; in Patagonia, where the Magellanian beds contain oyster beds and a few other shallow-water. marine forms between two lignitic hori- zons. ‘This Oligocene emergence is marked in Chile and Graham Land, and by the continental Deseado formation (Notostylops, Pyrotherium beds) of Patagonia. | Toward the end of Oligocene time or the beginning of Lower Miocene (Aquitanian-Burdigalian stages) we everywhere find evidence of marked submergence. This is shown by the Culebra, Emperador (continental), and Gatun formations of Panama; by the Zorritos and Heath stages of Peru, and by the Navidad beds of southern Chile. The faunas of these west coast beds are remarkable for the Caribbean and Mediterranean elements that they have furnished, thus affording collateral evidence of the free mingling of the waters of the Atlantic and the Pacific where the ‘Isthmus of Panama now stands. Similar evidence of submergence is furnished by the marine Patagonian beds, whose fauna has been described by Ortmann, and possibly by a part of the younger Seymour Island beds of Andersson. The upper Miocene is, so far as I know, a time of rather widespread emergence and land connections. No marine upper Miocene is known from Panama, Chile, Patagonia (continental Santa Cruz beds), or Ant- arctica. The 'Talara stage of Grzybowski in northern Peru is the only exception to this statement, and if it is cor rectly correlated it represents a very minor movement of the strand. Following the widespread upper Miocene emergence, there is an equally widespread Pliocene submergence, illustrated by the Toro limestone of 2 1, Kurtz: Sobre la existencia de una Dakota-Fl6ra en la Patagonia austro-occidental. Revista Museo de La Plata, vol, 10, 1899, pp. 48-60. 648 E. W. BERRY—PLANT-BEARING BEDS IN SOUTH AMERICA Panama, the Paita stage of Peru, the Coquimbo and Caldera beds of Chile, the Parana beds of Patagonia, and the Pecten beds of Graham Land. It is also emphasized by the presence of a marine Pliocene fauna at elevations of over 13,000 feet in the eastern Andes of Bolivia.2t The subsequent history need not be discussed, although this widespread simi- larity of events continued throughout the coastal region down to the present. This parallelism in the movements of the strand over so vast an area is so remarkable that I have gathered together such information as is available in the accompanying table. While this is very incomplete, it seems worth presenting in tabular form and it will also serve as a graphic summary, without additional discussion, of the correlations that I have arrived at from a study of these various plant-bearing horizons and asso- ciated beds in South America. ; 21), W. Berry: U. S. Natl. Mus., Proc., vol. 54, 1918, no. 2229. Recent. Late and post-Glacial. Glacial. » Pliocene. Upper Miocene. Lower Miocene, Burdiga- lian, and Aquitanian. Oligocene, Chattian, Stam- pian, Sannoisian, Rocene. y 3 Danian and Maes- 2 8 trichtian. a) ie oo iS} o | Campanian, Emsche- | EKme ry [ rian, Turonian. = i Lower Cretaceous. Eme Emergence. Submergence. Emergence. Parana beds. Emergence (Santa Cruz beds). Patagonian beds. Punta Arenas coal (Arau- earia). Deseado (Notostylops and Pyrotherium beds). Local submergence in the Magellanian beds. Fagus and lower lignite beds. HWmergence. Local transgression of San Jorge formation (Roca beds). Emergence with varie- gated continental sand- stones. Submergence. Hmergence (local marine beds) .*? GRAHAM LAND. Wmergence. Submergence. Wmergence. Pecten beds. Wmergence. Possibly a part of the younger Seymour Island beds of Andersson. Hmergence. Littoral sediments with fossil plants. Emergence. Wmergence. Rich Indo-Pacific Ammo- nite faunas, Hmergence. TABULAR SUMMARY vine beds* (Wealden beds) .*? 2 a ae ee ee . | : PANAMA. | COLOMBIA. HcCuApDor. PERU. Boutvia. CHILE. } PATAGONIA, | GRAHAM Lanp, = | | Recent. Wmergence. Emergence. Wmergence. Wmergence. Emergence, Hmergence, | Emergence, Inmergence i | 1 Late and post-Glacial. Submergence. ? 2 Submergence (‘‘tablaza’”’ 2 Submergence. Submergence. Submergence, % | beds). Valparaiso stage. ‘ a ¢ Glacial. mergence. ” 2 Emergence, 2 Hmergence. Emergence, Emergence. i | SSP Toro limestone. ? ? Paita stage. Discinisca and plant} Coquimbo and Cal-| Parana beds. Pecten beds. 2 Pliocene, tuffs of Potosi dera beds. =a and Corocoro, Upper Miocene. mergence. Honda beds? i Talara stage. Emergence. Wmergence (Santa Cruz | Hmergence, | beds). Lower Miocene, Burdiga- | Gatun formation, Em- | Andean plant beds. | Andean plant beds. | Zorritos and Heath stages. Navidad beds. Patagonian beds. Possibly a_ part of the lian, and Aquitanian. perador limestone, Up- | Santa Ana. Loja coal, Fossil plants of Tumbez. Fossil plants of | Punta Arenas coal (Arau- younger Seymour Island per Culebra.2# Coronel and Lota. earia). beds of Andersson. Oligocene, Chattian, Stam- | Lower Culebra, Tonosi Ovibio stage, mainly con- smergence, Deseado (Notostylops and | mergence. pian, Sannoisian, limestone, Bohio con- tinental sandstones. Pyvotherium beds). glomerate. Local submergence in the Magellanian beds. merged? Fagus and lower lignite beds. THocene, Transgression in Upper Wmergence, Emergence. mergence. Littoral sediments with Eocene. Local transgression of fossil plants. Emergence, San Jorge formation | Nmergence. (Roca beds). a | $ | Danian and Maes-| Dmergence. Dmergence, Nmergence. | Wmergence with varie- | Emergence. Ss trichtian. gated continental sand- £ stones. o icine 2 | u | Campanian, Emsche- | Hmergence. Submergence,”3 Quiriquina stage. | Submergence. Rich Indo-Pacific Ammo- Bt rian, Turonian. | nite faunas, SL | | Lower Cretaceous, DPmergence, Emergence. Local ma- Emergence. | Wmergence (local marine | Hmergence. if | flora). 21 More or less contemporaneous. * Halle (1913) has recorded Lower Cretaceous, perhaps Aptian, on the Lago San Martin. *s Neumann: Neues Jahrb, Beil., Bd. 24, 1907. ow eon, * ae e Ea < i‘ \ 4 - F ee 7 > r e ‘a x i. + ii. . as Ja Al PRI L re ea We) pil ch * ~ OTe Ne a beg : 13 1a sor ; + bey j Av 4 CAT ts x . ame i oe c ~ aa = eae eas i be 7, 5°35 rssh ¥( (eat -y- s° eorgeg ion pte SOT99 19 - 4 48 BOE a yee ee See oe eee ie 2 es be Bidet he leet oa -_ Sree | amt ee: wn? ia Share 4 urge 5 ig ee - - — ~ : + RK , =) ; f te eee, — emai aw te ee eet on — me ye . ve = acia aiaen.? ¥ b ‘ f , 7 ro (2900 pes? if nee), gic (gd REPOST LOU ER SEGET vay | 4 { 1 | + | | aie elificacee tesla =e "y. = —y owen - _ ee ‘ ; - siteeehe tented) Mite ae b's toot: Pt ae f, one fy } Bie g4, 4090 ebrrokt. AOGS2 TH | q . : | 5 294 ‘ : A ; ; ‘ i “+ ; 19h Teen - ee ~~ - a - . ¥ , ee 3 f. wondied imal mavbirite she zbed taal; agcobua -* A hae shoibes > MPA Bt Re oe dG a Tn iolinwmD) wan |. . yy Ha eaetit soles: im be ad : Se ae yin: Sanity OGOD. tel. towel ~cme 4 ‘ ; “805. Otto lenajanmls ; ova y . i samote ’ ~ Mets! || ao ros) i) a aolevsizener? |. , . , sane Pye TE: SORTER 1 ot te i aia ein samen Toe 3 ¢ at . ral \ . i Dy Gen soe Pep eee Ce bs oy ® ‘ y j bs i aa! ee ie “¥ BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 649-656 DECEMBER 30, 1918 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY BEARING OF THE DISTRIBUTION OF THE EXISTING FLORA OF CENTRAL AMERICA AND THE ANTILLES ON FORMER LAND CONNECTIONS * BY WILLIAM TRELEASE (Read before the Paleontological Society December 31, 1917) CONTENTS Page Break in West Indian flora between Saint Croix and Saint Thomas ..... 649 Quercus suggests lack of land connection with North America..... ..... 650 Nolinee and Yuccee indicate absence of continental land connection..... 651 Phoradendron and Furcrea suggest land connection with North and South 2 SIS ePrice cry conc, Bd cag At yen to Seen ca 652 Agave indicates relationship to a successively fragmented Antillean bridge er spur extending southeastward from Yueatan...2 5... cee. wie ec ce nee 653 TREECMENGES. 0.5. ccc sees ese BAPE aaa mat ada tas 5 oe ea 656 BREAK IN West INDIAN FLORA BETWEEN SAINT CROIX AND SAInt THOMAS Apart from weeds of various origin and occurrence, the West Indian flora is an intricate blending of plants identical with or closely related to those of South America on the one hand and of North America on the other hand, with a relatively small proportion of true endemism of types. The chain of islands has been held for a “province” of the Tropical Amer- ican floral region, correlated with the tropical Mexican province of North America and the subequatorial Andine and cisequatorial Savanna prov- inces of South America and contiguous Central America. The flora of Trinidad and other islands close to the South American coast is essentially a South American flora except for obvious introduc- tions. The flora of the Bahamas may be said to have contributed char- acteristic elements to subtropical Florida, rather than to be a temperate North American flora, and it appears to be largely of Cuban derivation. A number of years since, Baron Eggers' showed that a considerable * Manuscript received by the Secretary of the Society August 22, 1918. For references, see page 656, XLVIII—Boutu. Grou. Soc, AM., Von, 29, 1917 (649) 650 W. TRELEASE—FLORA OF CENTRAL AMERICA percentage (25) of the species of higher plants, as he understood them, of Saint Thomas and the adjacent Cretaceous Virgin Islands are not found in the Tertiary island Saint Croix, only some 30 miles away, and that only about 11 per cent of the species of Saint Croix occur also in Saint Thomas. As a general fact, it may be stated that those which stop in Saint Croix are endemic or derived from or represented by species of the Lesser Antilles, and of South American affinity or origin, and that those which stop in Saint Thomas, if not endemic, are of North American origin or affinity, with representatives in the Greater Antilles. Here North America does not mean or include, so far as cases are significant, the subtropical or even warm part of the United States, but it is to be understood as referring to the Mexican and Yucatecan floral zones. It has been my privilege to become so familiar with the world repre- sentation of a few groups of plants that I may venture to speak of their geographic distribution with some confidence. What I know of them in this respect may be stated as follows: QUERCUS SUGGESTS LACK OF LAND CONNECTION WITH NortH AMERICA The oaks (Quercus)? constitute an ancient genus, dating from the Cre- taceous, scarcely changed since the Pleistocene, and apparently going well into the Pliocene essentially in their present specific forms. The genus is world-wide in its distribution in the Northern Hemisphere now. In America it is essentially North American. Only a few oaks now occur in South America—in the Andes of Colombia. These appear to me closely related to certain Costa Rican species, and thus far support the recogni- tion of a subequatorial Andine province comparable with the cisequatorial and Central American provinces with which the West Indies are corre- lated in their flora. If their remains have been identified correctly, a few oaks occurred in Pliocene time in what is now arid equatorial Brazil. I have not seen specimens or illustrations of these, but should have diffi- culty in comparing them, as described, with existing species or with other Pliocene species of the genus. Only one oak, scarcely differentiable from the live-oak of our Gulf States and its equivalent of the Mexican and Central American coastwise region, occurs in western Cuba. This can hardly be regarded otherwise than as an introduction from the north. The live-oaks of this type appear to represent a rather early stock among modern oaks. In the absence of paleontological evidence, it may be unsafe to attempt to say when the live-oak entered Cuba, but evidence is more necessary for the support of a hypothesis that this was in Tertiary times than for my personal view INTERPRETATION OF QUERCUS 651 that it was later than the Pleistocene. Some of Catesby’s oak localities have been misunderstood because of the inclusion of both continental and insular species in his illustrations; but it may be said with confidence that Quercus is unrepresented in the West Indian flora except by this single Cuban form. So far as fossil and existing oaks are known, they offer no facts pointing to a connection of the West Indies with North America in recent time. The absence of such facts may be taken | as indi- eating that no such connection has existed. . Norns” AND YUCCE.® INDICATE ABSENCE OF CONTINENTAL LAND CONNECTION Among the xerophytic lily-like plants I may claim sufficient familiarity with the liliaceous groups Nolineew and Yuccee and the Amaryllidaceous group Agavee to discuss their bearing on this question. Unlike the oaks, these are all exclusively American ; and they appear to be of late Tertiary origin, though very little is known of them except as more recent plants. The Nolinez* are not known to occur away from continental North America. They range from southern Colorado southwestward through Baja California and southeastward over the tableland, one of their four genera (Beaucarnea) dropping into the tterra caliente of Vera Cruz, Yucatan, and Chiapas in Mexico and the lower mountains of Guatemala. An eastern extension of another (Nolina) is known for South Carolina, Georgia, and Florida through evident derivatives of its Texan representa- tives, though it is absent from the intervening Gulf States. This group of the tableland, therefore, throws no light on the question, unless, nega- tively, the absence of its representatives from the West Indies indicates that Cuba has been connected with neither Yucatan nor Florida since the appearance of Beaucarnea in the former and of Nolina in the latter. ~The Yuccee, also absent from South America, appear to be more dis- tinctly boreal plants than the Nolinee are. They range southward from the great bend of the Missouri River to the Atlantic and Pacific coasts, and, over the tableland, to Puebla and Jalisco. In the West Indies only one representative of this group is known, the common Spanish dagger of our Gulf States. This is fairly wide-spread through the islands, but perhaps never free from question as to spontaneity, because it is planted everywhere.* In its genus, this species (Yucca aloifolia) is dis- tinct in lacking a papery core to its fleshy fruit and in having acquired or retained a power of self-pollination which its congeners do not possess. If these differences are significant, and if the Spanish dagger is native to the islands, it may be that this species acquired its distinctive charac- 652 W. TRELEASE—FLORA OF CENTRAL AMERICA ters either in the Antilles or in the Gulf region of our Atlantic States or of Mexico, and passed from the one into the other. Since this is the only yucca with pulpy fruit in our Atlantic region, while baccate species range through Mexico as far as the genus reaches, the probability is that its prototype originated on the mainland to the south, and that in its present form it recrossed into its now rather limited areas to the north and west. Neither of these suppositions need be regarded as indicating a land connection between the West Indies and North or Central America, for a plant with edible fruit may have passed easily greater barriers than those separating the West Indies from North America. In any event, the Yuccez offer no other indication of such a land connection, and they give no suggestion of a connection between the West Indies and South America. PHORADENDRON AND Furcr#A suGGEst LAND CONNECTION WITH NortH AND SouTH AMERICA The distinctively American mistletoe genus Phoradendron possesses a vastly greater American range than either of the groups so far considered. Species are found from ocean to ocean, and from the extreme northwest- ern limits of the United States to the mouth of the river La Plata, in South America. Unlike the other groups, this genus is evidently as much at home in the West Indies as it is on the continent. While the others are preponderatingly, if not exclusively, North American, this genus is almost equally well represented north and south of the Isthmus; but something like one-third as many species occur in the West Indies as on either continent. It may be, and I think is, older than either genus of Nolinee or of Yuccee and younger than Quercus, but no very dependable or direct evidence as to this exists. In my study of Phoradendron,® I became convinced that two very dis- tinct groups—subgenera, if you like—make up the genus. One of these (the Boreales) includes 23 per cent of the known species; the other 77 per cent belong to the other group (Aequatoriales). The significance of the names used for these groups lies in the fact that the first centers in Mexico and the United States, only 2 of its 66 species reaching Central America and none being found in either the West Indies or South Amer- ica. While none of the Aequatoriales occurs in the United States, over half of them are South American. Of this group more occur in the West Indies than in either Mexico or Central America, though the group is well represented in both of these regions. Unlike the oaks, these mistletoes have not passed at all from Florida INTERPRETATION OF PHORADENDRON AND FURCRAA 653 into the West Indies, nor have they passed from the islands into the United States. A few very polymorphous species or scarcely segregable groups of species, like “P. latifoliwm” and “P. rubrum,” are common to Brazil, Mexico, and the West Indies; except for these, the insular species are different from those of North America, and both differ from those of South America. Have the insular species come from the northern or the southern main- land, or both, or have they passed to the tropical mainland im either or both directions and spread over it? As with Yucca alovfolia, it is not necessary to assume a land connection for the dissemination of these mistletoes. Hven more than the baccate yuccas, they appear able to pass ordinary barriers, for their seeds not only are contained in edible fruits, but they are so viscidly adhesive as to be likely to be transported to con- siderable distances by birds which feed on the berries. As a matter of fact, the several species do not range over large regions, except for the few cases noted; but these and, in general, groups of intimately related species, occur in such a way as to lead one to believe that they may have passed into the Greater Antilles from the west or into the Lesser Antilles from South America. The greater part of the Antillean species appear to me to possess South American affinities. AGAVE INDICATES RELATIONSHIP TO A SUCCESSIVELY FRAGMENTED ANTILLEAN BRIDGE OR SPUR EXTENDING SOUTHEASTWARD FROM YUCATAN I have deferred until the end a discussion of the Agavex. Its two genera, apparently, are relatively modern. One (Furcrwa) appears to center in South America, though it ranges from temperate Brazil to the Mexican tableland ; the other (Agave) centers in Mexico, but ranges from Arizona to the Isthmus, extending across the continent in Mexico, and in some equivocal forms it occurs in tropical Florida and in Venezuela and Colombia. Both genera are found throughout the West Indies: Furcrea in few and rather similar species; Agave in many species of several very distinct types. /urcrea appears to have entered the islands chiefly from South America. Agave is absent from South America except for a few species confined to the extreme northern region, the Colombian part of which show Costa Rican affinities. This genus appears to have penetrated the West Indies from the Mexican or Central American side. Furcreas and agaves frequently are bulbiferous. Their bulbils are very tenacious of life ; there is no telling, therefore, how far a species may 654 W. TRELEASE—FLORA OF CENTRAL AMERICA be carried by water. Their seeds are fairly resistant, thin, and easily blown about by the wind; but there is no reason to think that this insures dissemination to any great distance. Even on the mainland, as in the classic region of Tehuacan, the species are often narrowly limited geo- graphically. In the West Indies this restriction is accentuated, no doubt as a result of water barriers. The few Antillean species of Furcrea are suggestive. One of them (F’. cubensis) which occurs in Cuba and Haiti is very closely related to the Yucatecan cahum (/’. cahum).6 The commonest and most wide- spread (F. tuberosa), which is found throughout the chain, is a close relative of the Brazilian species, which has been grown so long in Mauri- tius as to have acquired the name Mauritius hemp (Ff. gigantea). A third species (Ff. macrophylla), which seems to be indigenous to the Ba- hamas, is very like a form of northern South America. So far as these facts are indicative, they suggest immigration from both south and west; the former apparently earlier, if extent of distribution bears any relation to time. Agave, which is represented in the West Indies by about 50 indigenous and endemic species,’ presents these in 6 distinct types: the Antillane, of a dozen species, are confined to the Greater Antilles; the Bahamane, closely allied to the preceding, and with half as many species, are exclu- sively Bahamian; the Caribe, with 15 species, are confined to the Caribbees, or Lesser Antilles. These plants are all large, of the “century plant” or “maguey” type. The southernmost islands also possess a re- duced edition of this type, the Vivipare, with five species, of which one is peculiar to Trinidad and the adjacent coastwise islands, and a sixth species of the group occurs in the coast region of Venezuela. In the northern islands, also, a smaller type occurs, represented on the Greater Antilles by five species (Antillares) and in the outlying Bahamas by two very xerophytic species (Inaguenses). The Antillane, Bahamane, An- tillares, and Inaguenses of the north are clearly differentiated from the equiv alent Caribeze and Vivipare of the south. There is no evident reason why a species of either group should not range through the entire chain of islands, like the wide- spread species or group of scarcely segregable species of Furcrea (FP. tuberosa), but they do not do so.” The Agave of Saint Thomas (A. missionum) is one of the Antillana ; the Agave of Saint Croix, 30 miles or so away (A. Egger- siana), is one of the Caribe. Less striking, but even more suggestive, are the facts that the species of either group are severally localized on a single island or on contiguous islands, and that species of any group INTERPRETATION OF AGAVE 655 differ in proportion to the depth of the water barriers that separate their islands and not merely in relation to the width of these barriers. Unless Agave is assumed to have originated in the West Indies, and the problem of distribution and its present bearing would remain un- changed if this scarcely plausible assumption were made, the genus must have entered the islands from the mainland. The possibility that it entered in two directions, through northern South America and also Mexico or Central America, is not excluded. In the former case the parent stock from the south would have given rise to the Caribe and Vivipare, and that from the north to the Antillane and Antillares, with their respective offshoots, the Bahamane and Inaguenses. The proba- bility, however, is that it entered from the Central American region, and that its greater groups were differentiated at a relatively early date. Hither supposition calls for belief in an essentially continuous, though not necessarily direct, land connection (perhaps broken at the present Anegada Passage) between the islands and the continents, as well as between the several islands; for as they exist today the agaves of even adjacent islands do not pass back and forth. ; From what I know of the representatives of this genus in the West Indies, I am compelled to believe that they were derived from the main- land at some late Tertiary or early Quaternary time when islands and continents were continuous; that then or subsequently they have spread through the chain over continuous land; that this continuity was broken by subsidence or fault when the very deep Anegada Passage was formed ; and that later subsidences have caused in succession the deeper and lesser water gaps by which the Antilles are divided into groups successively more and less distinct in their agave flora. These conclusions are in accord with some of the less sweeping indi- cations afforded by the other groups that I have analyzed in detail, and with the general interblending of northern and southern elements in the Antillean flora; and they are not necessarily in conflict with the negative suggestion of a lack of land connection afforded by Quercus and the Nolinee. They harmonize also with the fact indicated by Eggers, that the greatest break between these elements occurs where the deepest and presumably the oldest break in an Antillean bridge occurs, at the place where the Anegada Passage separates the islands Saint Thomas and Saint Croix, now under the flag of the United States. 656 W. TRELEASE—-FLORA OF CENTRAL AMERICA REFERENCES * Bulletin of the U.- S. National Museum, volume 138, 1879, page 13. * Proceedings of the National Academy of Sciences, volume 2, 1916, page 626. * Proceedings of the American Philosophical Society, volume 50, 1911, page 406. *Report of the Missouri Botanical Garden, volume 13, 1902, page 89. ° Proceedings of the National Academy of Sciences, volume 1, 1915, page 30. W. Trelease: The genus Phoradendron, 1916, page 16. * Annales du Jardin Botanique, Buitenzorg, 2 ser., suppl., volume 3, 1910, page 908. * Memoirs of the National Academy of Sciences, volume 11, 1913, page 10. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 29, PP. 657-666 DECEMBER 30, 1918 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY AFFINITIES AND ORIGIN OF THE ANTILLEAN MAMMALS? BY W. D. MATTHEW (Read before the Paleontological Society January 1, 1918) CONTENTS Page Limitations and relationships of West Indian mammal faunas, living and MANO oS eae so 0 bv 0 0s 0 0 08's a ehahere nO CMen seamen atenetar saee Pate ere Tere asters so sva'e so 657 AY EOTIOVAL 6 ois’ ec al e.e-al's ba) als ae Aenea eiedake SRE Mapes) BAe lekki AEd ao sloe wars eo ace 406 657 PPS) INSECULVOLED «ce core aetere Sshaeyees Wat clare gain tates aie Saks 5 Od eo ee on a 658 Mive” TOdeNtIars 6. ss kis. cs te; soy baeheerie Mate Msi tny oa aR ais a cio Mae TES ies wy nay & 659 PIE? QCLETHG ATA. 50 oc sno, oie 5 nO Rage ER ret toUe aM Oa lea teerasumersy tends Selehehiareré ails 6 <-ey% 660 aes AME. DATOS sa: 4) «aia: oo ue epea a en eten hacer aa cect apes Reee tetas onal ia false sae #6 661 RPE UIVES: (5c 'c ahcia:aihs. de Oa oe eee REA. shoereeaeue te Ora) Cote Eo ee ee 661 Summary of affinities and probable origin of the vertebrate groups....... 662 Is the incomplete and unbalanced character of the fauna real or only CRUE CU 2 a: és in, «scan! oe lol's ds Ow sad eran cals NEMA Denes NPE Deuce tin Or Stig Ss a ary 663 Conclusions as to former geographic relations and manner of colonization. 664 LIMITATIONS AND RELATIONSHIPS OF WEST INDIAN MAMMAL FAUNAS, Living AND EXTINCT IN GENERAL The indigenous land mammals of the West Indies consist of three groups: (1) Insectivora, (2) hystricomorph rodents, (3) gravigrade edentates. No perissodactyls (horses, rhinoceroses, tapirs, etcetera), no artiodactyls (peccaries, deer, antelopes, etcetera), no proboscideans (ele- phants, mastodons, etcetera), no true carnivores (dogs, cats, raccoons, mustelines, bears, etcetera). Nor are there any sciuromorph, lagomorph, or myomorph rodents, shrews, moles, hedgehogs, or opossums. All these large groups, most of them abundant and varied in Tertiary North Amer- ica, are wholly absent. Nor do the Insectivora, rodents, or edentates in- clude anything at all nearly allied to any North American members of 1 Manuscript received by the Secretary of the Society August 22, 1918. (657) 658 W. D. MATTHEW—ORIGIN OF THE ANTILLEAN MAMMALS the order or derivable from anything known to have inhabited North America in the later Tertiary. Most of these North American groups invaded South America in the Pliocene and are part of its later fauna. In the Miocene and early Ter- tiary they are not found in South America, but their place is taken by a number of other groups. In place of perissodactyls, artiodactyls, and proboscideans were a number of groups of hoofed animals peculiar to Ter- tiary South America—the toxodonts, typotheres, litopterns, homalodon- totheres, astrapotheres, pyrotheres. In place of the true Carnivora is a variety of marsupial carnivores (Borhyenide) paralleling the true car- nivores in structure and taking their place in the fauna.? All of these abundant and varied groups of ungulates and pseudo-Carnivora are lack- ing from the Antillean fauna, nor do the rodents represent more than two or possibly three of the numerous hystricomorph rodent stocks of Miocene South America, while the edentates represent only one group of the ground-sloths, the three or four other ground-sloth groups, as well as the several kinds of armadillos and the glyptodonts, being quite unrep- resented. THE INSECTIVORA It appears to be reasonably certain that the Antillean rodents and edentates came from South America and from Tertiary South America. Hystricomorph rodents and edentates are unquestionably South Amer- ican Tertiary types, which invaded North America when the two conti- nents were joined, toward the end of the Tertiary. The insectivores, however, are more probably derivable from North American sources; 2A similar but distinct group of marsupial carnivores (Dasyuride and Thylacinide) developed in Australia in absence of true Carnivora and still survives there. Norgs.—In this paper no account is taken of animals which may have been brought to the islands by man, whether intentionally or by accident, in post-Columbian or pre- historic time. Some of these have evolved under insular conditions into races distinct enough to be recorded as species or subspecies. The majority are identical with species of North or South America, Europe, Africa, etcetera. Some are known to have been introduced ; others may be so explained by reason of associations of one kind or another. The formation of distinct races, such as are classed as species by modern mammalogists, does not necessarily take many centuries under these conditions—as witness the Porto Santo (Madeira) rabbits and other instances. Some of these supposedly introduced forms may have been brought in through natural means and be truly indigenous, ‘al- though not very ancient; but it is impossible to prove such cases. It seems better here to omit all this doubtful evidence and consider only the fauna that is proved to be indigenous either by occurrence in the Pleistocene cave and spring deposits, by its sharp distinctions from any continental relatives, or by the high improbability that the animal could have been transported through human agency. Dr. G. M. Allen has compiled an annotated list of the West Indian mammals which includes both introduced and in- digenous types, and Dr. Thomas Barbour has done the same for the reptilia and batra- chia. The evidence therein summarized will be discussed in a memoir on Cuban fossil mammals now in preparation. THE INSECTIVORA 659 for, with a single somewhat doubtful exception, the entire order of Insec- tivora is absent from the Tertiary faunas of South America, while they were many and varied in North America, especially in the older Tertiary. The two Antillean insectivores are not nearly related to each other, nor to any other genera of the order; they are placed in families by them- selves. It has been repeatedly stated that Solenodon is related to the Malagasy Centetide, but in fact the affinity is a very distant one. Neso- phontes is equally peculiar, and while it has some affinities with the Soricoidea (moles and shrews), they are very distant. The nearest rela- tives of both—collateral ancestors, perhaps—are certain imperfectly known insectivores of very primitive type in the North American Kocene and Oligocene. | THE RODENTIA The rodents are clearly of South American affinities. They are all hystricomorphs—a group chiefly South American since the middle ‘T'er- tiary (if not before). ‘The only North American hystricomorph is the porcupine, Pleistocene and Recent, and whose ancestors have been recog- nized in the South American Tertiary. No traces of the hystricomorphs have been discovered in the Tertiary of North America.*. There are cer- tain Old World hystricomorphs, the Hystricide and certain Octodontide, and the early Tertiary Theridomyide of Europe have been considered ancestral to the group, but they have no significant relations to the Antil- lean genera and their affinities are disputed, so that they may be passed over for the present problem. The Antillean hystricomorphs are clearly related to the South Amer- ican types, but it is equally clear that the relationship is not close. There are apparently three groups. One, including Amblyrhiza. of Anguilla, Hlasmodontomys and Heptaxodon of Porto Rico, is related to the chin- chillas, but not closely related. Anthony* places them in separate sub- families. Miller’ states that they are more nearly related to the extinct Megamys and its allies than to the living chinchillids. These genera (Megamys, Tetrastylus, etcetera) are found in the Entrerian, Rio Negran, Hermosan, and Araucanian formations of Argentina accom- panied by a fauna which is closely related to the Pampean, but contains a few little altered survivals from the Santa Cruz Miocene and compara- tively few of the North American. invading types. All should, in my 3 Except Leidy’s Hystrix (Hystricops) venusta, based on two teeth of doubtful affini- ties and uncertain geologic age. 4 Anthony: New fossil rodents from Porto Rico. Bull. Am. Mus. Nat. Hist., vol. xxxvii, 1917, pp. 185-186. 5 Miller: Bones of mammals from Indian sites in Cuba and Santo Domingo. Smith- sonian Miscell. Coll., vol. Ixvi, no. 12, 1916, p 3.” 650 W. D. MATTHEW—ORIGIN OF THE ANTILLEAN MAMMALS judgment, be referred to the Upper Pliocene; they are certainly much later than the Santa Cruz. Although Megamys and Tetrastylus are without doubt more nearly related than any modern type to the Antillean chinchillids and are con- siderably older, they can not be regarded as ancestral. The common ancestral stock is to be found in the Santa Cruz chinchillids, all of which are of small or medium size. These Santa Cruz species are much more primitive, and the precise relationships will require more careful study.® The remaining Antillean rodents are of South American type and broadly derivable from Santa Cruz rodents, but their more exact affini- ties are disputed and require more thorough and critical consideration and, if possible, more complete material. A thorough revision of the fossil rodent faunas of South America is an almost necessary groundwork for a correct estimate of their affinities. It is clear, however, that with the exception of Capromys they are not very closely related to the South American rodents, the common ancestral stock dating back probably to Pliocene or late Miocene, as Miller believes. Capromys (and Geoca- promys) would seem to be an exception, being quite close to the Vene- zuelan Procapromys. THE EDENTATA The edentates include four quite distinct genera from Cuba and a fifth from Porto Rico, all referred to the family Megalonychide, but not closely related to any of the mainland forms. The largest, Megalocnus,’ is about the size of a black bear; the smallest, Microcnus, about the size of a eat, and there are two of intermediate size, Mesocnus, with a rather long, narrow muzzle, and Miocnus, with a broad, square muzzle. The Porto Rican genus is related to Miocnus, both having heavy triangular tusks like the modern Cholepus; the other three genera have large tusks, but of a peculiar dished shape, with a tendency to approach toward each other like the incisors of rodents. (They are not at all of the scalpriform gnawing type, however.) While these ground-sloths are sufficiently re- 6 Miller apparently associates the Santa Cruz fauna of southern Patagonia with the very different and much Jater Entrerian fauna of northern Argentina, as he speaks of the two as though they were essentially one fauna, and refers to the ‘‘enormous extinct Pagatonian rodents’ as the nearest relatives of the Antillean chinchillids. The largest Santa Cruzian rodents are species of Perimys, which is not nearly related to the Antil- lean genera. Most of the species are quite small. As between the Santa Cruz and the Hermosan (Pliocene) group of faunas, the tendency to rapid increase in size and speciali- zation of numerous phyla is very marked, and is further emphasized in the Pampean (Pleistocene) group of faunas. ™ Megalocnus, Leidy, 1868. Proc. Acad. Nat. Sci. Phila., 1868, p. 179. Microcnus, ete., La Torre and Matthew, 1915. Bull. Geol. Soc. Am., vol. xxvi, p. 152 (names only; descriptions have been reserved pending the securing of more complete and better associated skeleton material). THE EDENTATA 661 lated to the North American genus Megalonyx to be placed in the same subfamily, they are quite evidently not descended from it, but con- temporaneous specializations from the primitive Megalonychide of the South American Miocene, as represented in the Santa Cruz fauna. Among the known genera of this fauna there is only one, Wucholewops (including Megalonychotherium), which can be regarded as ancestral either to the Cuban ground-sloths or to Megalonyx. The others all have the canini- form teeth much reduced or vestigial and in series with the cheek teeth. To the best of my judgment, the anatomical evidence is not decisive as to - whether the five Antillean genera are descended from one or from two or more nearly allied Upper Miocene or Lower Pliocene genera, but leads to the conclusion that the common ancestor or ancestors was very close to or identical with the Upper Miocene ancestor of Megalonyz, and was either the genus Hucholeops or one or more genera closely allied thereto. The Antillean genera represent, therefore, only the megalonychine divi- sion of the Megalonychide. The other families of ground-sloths—Mylo- dontidee, Scelidotheride, and Megatheriide—are not found ; nor are there any armadillos, glyptodonts, or anteaters. BATS AND BIRDS In addition to the terrestrial mammals, bats are numerous in the cave deposits, and a number of birds, lizards, crocodiles, and turtles have Be found at the Ciego Montero locality and elsewhere. Concerning the bats, there is very little to say. Most of them are nearly allied to or identical with species now living on the islands. The Antillean bats include a number of peculiar genera, besides others com- mon to the continental parts of tropical America. Their relations are much the same as those of the birds, and in either case it is obvious that the intervening seas would act as a hindrance to migration, but not as an absolute barrier, and would be more of a hindrance in some groups than in others. The result would be the presence of a number of peculiar types, preserved by relative isolation and specialized in adaptation to the peculiarities of their habitat, along with other widely ranging forms closely allied to or identical with those of the mainland. The distribu- tion of the birds has been carefully studied by Chapman and others. REPTILES The distribution of the lizards has been recently studied by Dr. Thomas Barbour, and his conclusions as to the paleogeography are sharply at variance with mine, owing to different methods of interpreting the data. I shall not take this part of the problem up at present. 662 Ww. D. MATTHEW—ORIGIN OF THE ANTILLEAN MAMMALS The fossil crocodiles have been examined by Dr. Barbour, who informs me that they are all referable to Crocodilus rhombifer, a species still living on the island of Cuba.§ The origin of this species might be either North or South American; but too little is known of the phylogeny and distribution of the Tertiary Crocodilia for any conclusions to be drawn as to the time or method of its arrival. The fossil chelonians have not been carefully studied, but they include two species—one a giant tortoise, Testudo cubensis Leidy, which, like the giant tortoises of the Galapagos and Indian Ocean islands, has the carapace much thinned out, so that the plates are apparently more or less discontinuous. There is one North American Phocene species, 7’. per- tenuis Cope, from Texas which has a remarkably thin carapace, but apparently not discontinuous. The precise significance of this species in the paleogeographic problem must also await more careful study. The genus Testudo occurs sparingly in South America, and is recorded as a fossil in the Pliocene and Pleistocene formations—not earlier, so far as I know. On the other hand, species of Testudo are the most abundant of fossils in the Oligocene to Pliocene formations of North America; in the Pleistocene and Recent their range is restricted to the Southern States and Mexico. The indications point, therefore, preferably to North Amer- ican origin for this Cuban tortoise, although not decisively. . The second fossil chelonian is one of the Emydide, or marsh-turtles: it appears to be a species of Graphemys, probably the same as the still existing Cuban species, which is said to be a close ally of G. sceripta of the Southeastern States. Whether the two are specifically distinct has been questioned. The discovery of this species (if it be the same) fossil in the Ciego Montero locality removes any doubt as to its being indigenous to the island, as it carries it back into the Pleistocene, and probably to a time before the arrival of man. Its close relationship with G. scripta and limitation to the western islands, Cuba and Haiti, is a strong indication of its having come from Florida, and the time of its arrival probably would be not earlier than Pleistocene or at most late Pliocene. SUMMARY OF AFFINITIES AND PROBABLE ORIGIN OF THE VERTEBRATE GROUPS Summing up the indicated sources of the fossil and recent vertebrate fauna, we find it to be as follows: 8 Leidy’s Crocodilus pristinus (1868, 1. c.) was based upon a vertebra not distinguished from C. rhombifer. The skulls obtained by La Torre and Brown represent, in Doctor - Barbour’s opinion, a series of growth stages of the modern species, the largest much exceeding any modern specimens. Part of a skeleton associated with one of the largest skulls equals or exceeds Leidy’s type of pristinus in size. SUMMARY OF AFFINITIES AND ORIGIN 663 1. The Insectivora, Solenodon and Nesophontes, of very ancient arrival, probably early Tertiary, and apparently of North American origin. 2. The ground-sloths, Megalocnus, Mesocnus, Miocnus, Microcnus in Cuba and Acratocnus in Porto Rico, of moderately ancient arrival, prob- ably late Miocene or early Pliocene, and of undoubted South American origin. The rodents, with the exception of Capromys, fall also into this category. , 3. The peculiar groups of birds, bats, and lizards are also no doubt of comparatively ancient arrival, but their source is unknown, as we know nothing of the Tertiary distribution of related groups on the mainland. The modern distribution of such related groups can not be relied on, for we know that among terrestrial mammals various groups which are today exclusively or chiefly Neotropical were Nearctic until the end of the Ter- tiary and unknown in South American faunas until the late Pliocene. Presumably corresponding changes in distribution have occurred among the bats, birds, and reptiles, but we have no records as to what groups were affected. The Cuban crocodile may also be placed in this category. 4, Of the two chelonians the giant tortoise may be placed as more prob- ably of North American than of Central or South American origin, but its time of arrival can hardly be estimated until its relations to the con- tinental Tertiary species are known. ‘The terrapin is almost certainly of North American origin, derived from the Southeastern States, and of comparatively late arrival, probably late Pliocene or Pleistocene. 5. Capromys and Geocapromys are undoubtedly of South American derivation, like the other rodents; but, so far as may be judged from their comparatively near affinity with the Venezuelan Procapromys, are of later arrival, perhaps late Pliocene or Pleistocene. It appears, therefore, in sum, that the vertebrate fauna, fossil and recent, represents only a few selections from the continental faunas of either North or South America; that it falls into several groups of diverse origin, and judging from their degree of differentiation, of diverse times of arrival. Is THE INCOMPLETE AND UNBALANCED CHARACTER OF THE FAUNA REAL OR ONLY APPARENT ? In the absence of hoofed animals, which form the greater part of all continental faune, in the tendency of races normally of small size to assume relatively large size and importance, in the relative fragility, so to speak, of the fauna, leading to its early disappearance when man ‘invades the region—in many further points of detail—it parallels the faunas of those islands which lie beyond the continental shelf, and differs t 664 Ww. D. MATTHEW—ORIGIN OF THE ANTILLEAN MAMMALS from those islands which lie within the shelf. In particular, the paral- lelism with the Madagascar fauna is made much closer by the recent dis- coveries. On the other hand, the contrast with the fauna of continental islands such as Borneo or Sumatra is a marked one. On these islands the fauna, although considerably specialized by isolation in Borneo, less so in Sumatra, is a fairly representative one. It includes all or nearly all of the important mammalian groups of the mainland save those which there is reason to believe are of too recent arrival or of unsuitable habitat to be present. It may be objected that this difference is merely apparent; that the Pleistocene fauna of the Antilles was really of continental character, but because they are islands and not continents, it has been easily extermi- nated by man, and that the cave and spring deposits present only two dis- tinct and very limited facies, not including the ungulates, carnivores, etcetera, which have been present. The best reply to this objection is to test it by comparison. Sumatra or Java are islands of comparable size to Cuba; Borneo is larger; Formosa or Hainan are comparable to Porto Rico. In none of these islands has the indigenous fauna been wiped out to anything lke the extent necessary to obliterate its continental char- acter, although all have been inhabited by man for a much longer time and in much larger numbers than the Antilles. The indigenous faunas of Great Britain or Ireland are far from exterminated, in spite < the great density of population and of modern civilization. Nor can we assume that a cave or a spring fauna is so limited in its facies as to disguise a continental fauna type. The faunas of numerous caves in Europe and North America have been examined, and wherever any considerable collection is obtained it is clearly representative of the continental type. Spring or bog faunas sometimes contain little except hoofed animals, but I never heard of one in which hoofed animals and carnivora were absent. I can not escape from the conclusion that the Pleistocene fauna of Cuba was not a normal fauna, but deficient in most of the more abundant groups and composed of a selection of a very limited number of types which had expanded to a disproportionate variety and importance, owing to the absence of the rest of the fauna. CONCLUSIONS AS TO FORMER GEOGRAPHIC RELATIONS AND MANNER OF CoLONIZATION As to the diverse origin of the several groups and the varying time during which they have been isolated on the islands, I have stated my interpretation of the evidence. I do not feel, however, that evidence of this sort leads to positive and certain conclusions. so CONCLUSIONS AS TO FORMER GEOGRAPHIC RELATIONS 665 As to the former connection of the Antilles with each other and with the mainland, my conclusions with the proviso just stated are as follows: 1. That the Greater Antilles have probably been united with each other, as far east as the Anguilla bank, in the late Tertiary or Pleistocene. This I conclude from the near affinity of representative species of the same or closely allied genera and the general similarity, of the fauna, so far as known, in the different islands. 2. That they have not at any time during the Tertiary been united with North America. If they had been we should find North American ungu- lates, rodents, carnivores, etcetera, differentiated in accord with the length of subsequent isolation, but of clearly recognizable affinities, and it would be a balanced or representative fauna. We might object that such a fauna had perhaps existed, but been wiped out by subsequent submergence. But the presence of Solenodon and Nesophontes negatives that, for they repre- sent a very ancient survival, and if there had been a representative fauna it is hardly credible that submergence would have spared just two insecti- vores and destroyed all the rest of the fauna. | 3. That they probably have not been connected with South America, either via the Lesser Antilles or via Central America, during the Ter- tiary ; for if they had the fauna should be of continental South American type, with South American ungulate groups, marsupial carnivores, and a full representation of the rodents, edentates, etcetera. 4, The mammalian fauna appears to me to be reducible to perhaps three primary rodent stocks, one or more primary ground-sloth stocks, and two Insectivora. These I conceive to have arrived at various times during the ‘Tertiary, the rodents and ground-sloths from South or Central America, the insectivores from North America, by accidents of transportation, of which the most probable for the mammals would perhaps be the so-called “natural rafts’ or masses of vegetation dislodged from the banks of great rivers during floods and drifted out to sea. The probabilities of this method I have elsewhere discussed.® For birds and bats, for the smaller reptiles, amphibians, fishes, and invertebrates, the problem of oversea transportation is a much simpler one.*° That successful colonization in this way can occur is shown by their presence on nearly all oceanic islands ; for it will hardly be maintained by reasonable men that every oceanic island has been joined to the mainland and has been continuously above water since its separation. Obviously, the larger the island and the nearer to continental land, the more often such colonization will occur. ® Matthew: Climate and evolution. Annals N. Y. Acad. Sci., vol. xxiv, 1915, p. 206. Tropical storms, as Wallace pointed out years ago, probably play a principal part in transportation of very small animals or their eggs. Mammals could hardly be carried that way nor survive if they were. XLIX—Buru. Grou. Soc. AM., Vou, 29, 1917 666 W. D. MATTHEW—ORIGIN OF THE ANTILLEAN MAMMALS 5. The geology of the Caribbean region appears to me to afford no positive evidence against union of the Antilles either with South America or Central America; but neither does it afford any evidence that there ever was such union. Undoubtedly there is a line of disturbance and uplift along the Lesser Antilles, and another stretching through Haiti and Jamaica to Nicaragua; but evidence of similar and contemporaneous upheavals and similar sedimentation in two portions of this line of dis- turbance that are now separated by abyssal depths does not in the least prove that the intervening depths were formerly continuous land bridges. They may have been, but I do not see how any geologic evidence can prove that they were so. If we have evidence from some other source that there must have been a land bridge somewhere, then these lines of disturbance show its most probable location. That is all. Land union with Florida appears to be distinctly against the geologic evidence, as in this region we have extensive flat-lying Tertiary marine and littoral formations which indicate that there has been very slight movement during the Tertiary, and that the present limits of the conti- nental shelf represent probably the extreme extension of the land in the Pleistocene. Dall has shown the evidence very clearly in the case of Florida. Apparently the conditions in Yucatan are partly similar, but Vaughan has shown that its tectonic relations to the Antillean ridges are — - more favorable to a former union. INDEX TO VOLUME 29 Page ABENDANON, Ii. C., cited on fringing reefs yen ACKRAD, ; cited on Dead Sea...... 474 ADAMS, F. D., cited on anorthosite. 408 —; Experiment in geology, Presidential REMUS SO Viaes ons ae heiatie shevetatione ace arse Sen —, Meeting called to order by President 4 ADDITIONAL note on Monks Mound; A. R. Crook ADIRONDACK : Miller 99, 399 AFFINITIES and origin of the Antillean mammals; W. D. Matthew... 138, 657 —-— phylogeny of the extinct Camel- seme ID) Matte wean. s oo ieieis 0) ea ae 0 cin ee 151 CARBONIFEROUS species of ‘‘Zaphrentis”’ ; G. H. Chadwick... eee 154 CARIBBEAN Are, Reference to.......... 621 — Islands, Reference 0... 3. sso. geen 620 —, Mollusea (of. .... 5. se. ssc eee 148 CARRIZO Creek beds, Mollusea of...... 148 CATAHOULA floras of North America... 633 CAUSE of the absence of water in dry sandstone beds; R. H. Johnson... 105 CENOZOIC floras of equatorial America. 129, 631 — geology of Central America and the West Indies. =... ......2- 455 615 —history of Central America and the West Indies; T. W. Vaughan...... 138 CENTRAL AMERICA, Cenozoic geology of. 615 — -—- history of................... 138 ==) Mora of. i 5. oe 2 eee 129, 649 — -—, Mesozoic history of........ 138, 601 — -—, Paleozoic history of............ 129 CHADWICK, G. H.; Carboniferous spe- cies of “Zaphrentis”. .> 2. eee 154 —j;fFurther studies in the New York Siluvie |... 06.4 «6 ¢ sets ss ae ee 92 —;Stratigraphy of the New York CHHtOR. 5 5 6. + nos 3) s 5 327 CHALMERS, ——-, cited on Nova Scotia glaciation |... ....s..i5):..4. epee 24 —-—-Nova Scotia marine levels.... 226 — — — Saint Lawrence Basin..... 214-217 CHAMBERLAIN, T. C., cited on Newfound- land glaciation... ..........22 eee 229 — -—- Pennsylvania peneplains...... 578 CHARACTERISTICS of the upper part of the till of southern Illinois and elsewhere; BE. W. Shaw.......... 76 CuiIco and Martinez beds, Unconformity between ~... os. cc cisteue Sie eee 2 CHILE, Tertiary fossiliferous horizons of 642 CHRISTIE, W. A. K., cited on salt de- DOSICS 222...6.6 <5 ddan se es 474 CLAIBORNE. Hocene flora. =. < «4. ss. seen 633 CLAPP, F. G., cited on peneplains..... 581 CLARK, B. L., and RALPH ARNOLD; Marine Oligocene of the West Coast of North, Ameviesi.a.3 5. 5seee 153, 297 — cited on San Lorenzo fauna........ 306 —, Discussion of peneplain dating by.. 89 —;Faunal zones of the Oligocene..... 166 —; Fauna of the Meganos group...... 152 —;Meganos group, a newly recognized division in the Eocene of California 281 —;Stewartsville group, a newly recog- nized division in the Eocene of California 9 CLARK, J, D., cited on gel molecules... 599 6.0 2 0 @ fa St eye es) ue we) ae INDEX TO VOLUME 29 Page CLARK, WILLIAM BULLOCK, Bibliography Girone gents Galle eee sears ee stes eob alsa a eee CLARKE, F. W., cited on melting IMMTINITTETIUS was yesie cai eis eth as od an doe CLARKE, J. M., Discussion of need for study of sedimentary rock compo- SSIS MIMMDVanie ee rcsust = aut ee pe ites ele) wld: oc sna —, Memorial of William Bullock Clark. —, Report of the Geology Committee of the National Research Council by chairman .......; tre a seta supe —;Strand and undertow records of Upper Devonian time as indications of the prevailing climate......... CLEMENTS, I’. E.; Scope and significance COleeACO=CCOlOGY. © a. osc ale ae oon scene ; The question of paleo-ecology...... CLIMATE and its influence on Oligocene faunas of the Pacific coast; R. EH. RITES OM tee iahay etsiabinel Adios ie, Si siee sa yer ores wie CLINTON formations in the Anticosti Sections: by ©. WIrTich,. 3.62... «00 —of New York, Upper limit of. Sls COASTAL Plain deposits, Extent of At- NENEUETIC@ TA Sires ot aaaes Wo loa rs cue arr eear ee mre ren to Te COLEMAN, A. P., cited on anorthosite. . ——w— [Labrador coast.............. parsed beaches... 250. 0s ees oe —, Discussion of Precambrian nomen- CHA TITAS LO ere ee eee a ears eae eR COLLAPSING geoid, Faceted form of a.. Sonowmsrd. Geology Of ....02.2...6055%5- CoLoraAbDo, Section of Morrison in..... =——Mbodont skull from.............. CONNECTICUT, Glacial phenomena in.. meme. ATtILUGeS. Ts co 6 2s we wesc es CONRAD, , cited on California Wo- RET Meee Rua) k easis ctr Aslolatbueim aed e CONVECTION in igneous Magmas....... Coon Rapids, Carroll County, Iowa, Pleistocene deposits in........... CORDILLERA of Canada, Stratigraphy of. Cosme: Rica, Geology Of. . 2.0... Setecmts COUNCIL’S report of the Geological So- ciety — — Paleontological Society..... CRETACEOUS and Tertiary stratigraphy of the western end of the Santa Inez Mountains, Santa Barbara County, California; H. J. Hawley. —of equatorial America, Upper....... — — Mexico —— North and South America....... —overlaps in northwest Europe and their bearing on the bathymetric distribution of the Cretaceous Silicispongize ; Marjorie O’Connell. — stratigraphy, Santa Inez peneplains, Santa Barbara County, California.. CriricaL study -of faunal leaves from the Dakota sandstone; HW. M. Gress CROMBIB, FLORA, Acknowledgments to. CROOK, "A, R.: Additional note on Tomes NOUN Gl. xin s Shetbah bene p alo temane ==, Discussion of loess DY.... ch... 20% CRooKS, H. F.; Precambrian rocks in the Medicine Bow Mountains of Wyoming —;Types of North American Paleozoic oolites CUBA HROLORY OF 6. 5 sce vce Wren pee nomena CusHING, H. P., cited on anorthosite. . Sy CLOSTOMEA bryozoa, Classification principles: Of... 66. vce els os ales Bs: ve) 0: ©) 2 is) 0) e: ve) (eo, 640, @) ie) 6 08) @ fe) wre nive eoeceewewr eee eee eee ee ee se ee hs ee ee es ee oe em 5 21 82 3538 669 Page . DAKOTA sandstone, Fossil leaves from. DALE, R. B., cited on analysis of stream 131 waters of the United States...... 597 Day, R. A., cited on anorthosite..... 414 = albradon-coaSst..n....46.. 2lo, 226 ——-——pemeplains ...............005. 581 —— — — raised—beaches............... 203 —— Samia dour wpMh ty. st. sa ele we os 207 —;Field relations of litchfieldite and soda-syenites of Litchfield, Maine. . 99, 463 —, Reference to use of term Phoenix by 3851 Dat, WiLLIAM H., cited on Florida’s land relations southward......... 666 Dana, J. D., cited on island phenomena. 494 Darton, N. H., cited on Amsden forma- LOM ween reiterates: Sit oie ta iste tees Scala 309 == —— — Morrison: formation... ...7... .-. 251 —, Report of Committee on Photographs LDN2 Mc eich ty OBOE he (GRCN ORO ROE REPENS Dae —;Structure of some mountains in ING Wee RC Ome atte state orate setae es TC DARWIN, CHARLES, cited on coral reefs. 490 DatinG of peneplains: an old erosion surface in Idaho, Montana, and Washington—is it Hocene?; J. L. TRC e ems Gir meuRante, oboe ar al ae a. sacs 89 DAUBREE, , cited on experimental LEOLO LV ANG eae ree a Sl eee stele’. wi 75 DAVID, = ChLCOwOMmaTOlS. «ss res. es 565 Davis, W. M., cited on deltas......... 194 — — Pennsylvania peneplains...... 576 —; Subsidence of reef-encircled islands. 71, 489 Day, D. A., Reference to work of...... 186 Dr LAPPARENT, , cited on island SUMDSTal CMC Orde ie ennuer teumcissw tere obs wheal ome Me 493 —cited on Tertiary floras............ 634 ADD) yy TUARS AS UTI eeyisee Aetyle, Gh o's se; eee Sixers 191 Dr SAUSSURE, , cited on structure OLAS eee wee Naser a ioc dive: aot! oa one 175 Drvonic stratigraphy, Upper........:. ATE DICKERSON, R. E., cited on California WMOGEIG I rete seas reder a ahare olathe 283-284 — —- fauna of Tejon Hocene of Cali- AON ge etn ete eotnks eae sieeve tonne hehe G 294 — — — Oligocene climatic conditions. 306 7 eo FSTCTON DY) WI reennas LeeeeRe Se aee 290 ; Climate and its influence on Oligo- cene faunas of the Pacific coast. 166 —;Mollusea of the Carrizo Creek beds and their Caribbean affinities..... 148 ; Occurrence of the Siphonalia sutter- ensis zone, the uppermost Tejon horizon in the outer Coast Ranges Oly Me AOI eid ota Sat ap aber 6 Sve! scare 163 —; Proposed correlation of the Pacific and Atlantic Hocene. %.. 0). cs a 148 DirtrricH, W. O., cited on gastropods of the Tendaguru series............. 278 —- — Tendaguru series............. 264 DipLopocus, Osteology of............ 1380 Dir® wolves of the American Pleisto- ETI E ToL Ie. Worth one Pps ees oma nase 1s) So aie ulas'arta 161 Discovery of fluorite in the Ordovician limestone of Wisconsin; R. M. Bagg 104 DISEASES of the mosasaurs; R. L. LGTY eV Bin ak, Gs. But ane erare e a 147 DOELTER, , cited on experimental PER Miran tard sa eiela ee tie eli Ge cis; ies Seiahora ails 175 DoLomitHT of Missouri, Glauconite in. 104 DDO Nene GL OMe OO Re eins Coad x vase shee aisha 351 Dresser, J. A., cited on anorthosite. 429 DRYSDALB, C. W., and L. D. BURLING | Rocky Mountain section in the vicinity of Whitemans Pass....... 145 —=, BUDIIGREEPNY OL. es ewe 34 ramos TIVE TIMIN EDOM e arane. aie ele! see ole elavel wre ist $c 29 670 Page DUMBLE, E. T., cited on California Martinez .tieiqercis eit ree core 293 - Dust&n, A., cited on Tertiary floras of Straits of Magetlani:3..., 234.0208 633 Dus&n, P., cited on flora of Fagus zone. 644 EAST AFRICAN Tendaguru formation, AO OL sy n3 2 ene isos ee ee ee 245 ECHINOIDS, Pacific Coast, Geologic range and. eyolutions Oss. ete ccs cee eee 164 HCUADOR;. Bossi 41ora vof..N ee eee 640 EDENTATE deposits of North America... 161 HIDETOR’S-Fepoltaco ame cea Cee ee ee 9 EDWARDS, IRA, Acknowledgments to... 330 —— e1ted=on: Clintons oresbeds. oe ee 343 IXGGERS, BARON, cited on West Indian HOTS 8. 15 once hence oe eae ae 649 EIGENMANN, C. H.; Fresh-water fish faunas of North and South America 138 EKBLAW, W. E., Discussion of post- Glacial uplift in Greenland and Hlesmere Wand: by.c 2 ss. eee Tfal —;Importance of nivation as an ero- sive factor and of soil flow as a transporting agency in northern Greenlandgrericc. tote ae a2. — ; Opportunities for geological work in the: far ATChero stein see ee 85 ELBERT, , cited on Sumbawa Island 561 ELECTION of Auditing Committee...... 11 = NBO WS anette: sie ic%o eee ee ee iy >=. OUICETSe, shies. ba ocr ill —-—-—and members of the Paleonto- logical Sociebye.c (Shere ee 125 ELLESMERE Land, Discussion of uplift TI 35 Gi sihree oc bees eee See ae (fa EMERSON, F. V.; Loess-depositing winds in the Louisiana region.......... 79 IENGLEHARDT, H., cited on fossil plants In: HHIESSSe Les 6 Ses See 640 —-— — Navidad beds................ 642 —— — Tertiary floras of Chile....... 633 EOcENE, Atlantic and Pacific correla- TION LOE. sc eet eee re ee 148 — flora of equatorial America......... 632 —in Idaho, Montana, and Washington. 89 — Miocene relationships on West Coast 307 —of North America, Pseudotapirs of the .2., tse eee ete Eee 152 —-— California, Meganos group of the. 281 —-—-—, New division in............. 94 —= ==, Section: of 2.2 53 ie eee ee oe ee 285 — — —., Stratigraphic relationship of. 300 —-—the West Indian Islands........ 623 —-— Utah, Artiadactyls from......... 153 EQUATORIAL America, Cenozoic floras of 631 ETHERIDGE, , cited on Misima Island 559 EUROPE, Cretaceous overlaps in....... 142 BLIVANSWTON: “PCa t....:\c< sarcie seit ee eras 237 EVIDENCE in San Gorgonio Pass, River- side County, of a late Pliocene ex- tension of the Gulf of Lower Cali- fornia:; ts . Vanghan nice sete —of recent changes of level in Porto ; Rico, aS shown by studies in the Ponce district; G. J. Mitchell..... 138 EVOLUTION of vertebre; S. W. Williston 146 EXPERIMENT in geology, Presidential ad- dress (by. f. D. Adams). .).cicces 82, 167 EXPLANATION of the abandoned beaches about the south end of Lake Michi- San Ge he WLIEDE: <3 owes ne ExtTiInct vertebrate faunas from the padlands of Bautista Creek and San Timoteo Canyon of southern Califomiae Childs Erickio7. 3 cs 164 235 BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA Page FACETED form of a collapsing geoid; C..R. Keyes... . 22 2 See 6 FAIRCHILD, H. L., Acknowledgments to. 336 —; Postglacial uplift of northeastern AMe@PiCa 2.6. ec be eee eee 70, 187 FAUNAL zones of the Oligocene; B. L. Clark: 24 2:0 cet ae a on eae 166 Fauna of the Bautista Creek badlands; Childs Brick... ... 5.2.8 eee 163 — -—-JIdaho formation; J. C. Mer- TIAM 3s... 2 oss ee ots wee 162 —w-——lIdaho Tulare Pliocene of the Pacific Coast region; J. C. Merriam 152 —-— — Meganos group; B. L. Clark.. 152 —-— southern California............. 154 FELLOWS, Election of... .... csc 12 FENNER, C. N., cited on Pennsylvania Precambrian’ ..% . olenelele eee FRESH-WATER fish faunas of North and South America; C. H. Eigenmann. 138 Frick, CHILDS; Extinct vertebrate faunas from the badlands of Bau- tista Creek and San Timoteo Can- yon of southern California........ 154 —;Fauna of the Bautista Creek bad- landS cs... .s2 soe 3 Cee 63 FRIEDEL, ——, cited on experimental LCOlOLY 2 os oles vc as 0 0b eee 183 FuLuer, M. L., cited on peneplains.... 581 FurRCR@A of the West Indies......... 652 FURNACHVILLE iron ore... .. o- ae 343 FURTHER light on the earlier stratigra- phy of the Canadian Cordillera; L. D. Burling... 6022. eee 145 —studies in the New York Siluric; G. H.+ Chadwick: . > ..442223eee GaABB, W. M., cited on California Eocene 282 GARDINER, J. S., cited on coral reefs... 530 GASPE, Pleistocene submergence at....., 217 GEIKIE, A., cited on island subsidence. 492 GEINITZ, H. B., cited on South American TOSSHUS 2. 0 ois's.2 Stale. ee ee 609 GENERIC nomenclature of the Probos- cidea.; W:. DD; Matthew.:. =-oeee 141 GENESIS of Missouri lead and zine de- posits ; “W. yA are. Oye 1. sie eee 86 GEOLOGIC history of Central America and the West Indies during Ceno- zoic time; SZ) W. Vaughan: 2. .:..:2 615 —map of Brazil; J. C. Branner...... 98 INDEX TO VOLUME 29 Page GEOLOGIC range and evolution of the more important Pacific Coast echi- MOUS Wie Ser Wie INOW. cys ets ocecohel's aveis GEOLOGY Committee of National Re- search Council, Report of........ GERLAND, G., cited on island subsidence GustrErR, G. C.; Tertiary and Pleistocene formations of the north coast of Berd SOUthyAIMEeTICA.eeni& cre cle GILBERT, G. K., cited on transportation Of CEDEIS DY Watelew ws. ecek cre oes eh hs GILKINET, A., cited on Tertiary floras of Straits of Magellan........... Girty, G. H., cited on fauna of Amsden formation GLACIAL beaches about Lake Michigan. — flakes of Saginaw Basin in relation to NOME tis yo, MUO VOECCU Lc acy cie ec ele.’ — literature, Bibliography of......... GLACIATION in Alaska GOLDMAN, M. I., Photographs by...... GOLDTHWAIT, J. W., cited on marine levels of Saint Lawrence Valley. a SC) UAT. soe es ee 6 nee see valle GORDON, WALLACE, Occurrence of a ma- rine Middle Tertiary fauna on the western border of the Mojave Des- PSEA CS ious sate cle iaiciele sic. @ yecalelichiaverien sl 9% GLASS-MAKING processes, Significance of GLAUCONITE in dolomite and limestone of Missouri; W. A. Tarr......... GraBau, A. W., cited on unconformity of Oneida conglomerate........... ; Isolation as a factor in the devel- opment of the Paleozoic faunas. + Relation of the oil-bearing to the oil-producing formations in the Paleozoic of North America....... ; Significance of the Sherburne bar in the Upper Devonic stratigraphy. GraFEN, H., cited on South American fossils GRANGER, WALTER, and W. D. MATTHEW ; Fossil mammals of the Tiffany beds - New Tilladont skull from the Huer- fano Basin, Colorado............ Grassy Creek shale, Invertebrate fauna Ske. Ohba: e) oy em, ©) ie) eye eae’ oa oenie- «ie oer eee eee eee eee aitetes a ete He a4 (ae ere ae een ese les an ees) Oe 8. fo) GRAVIGRADE edentates in later Tertiary deposits of North America ; Chester RS TRNOIC eee rahe calcite ocehal oh aleiole elie relate Grecrer, D. K., and HE. B. BRANSON; Amsden formation of the east slope of the Wind River Mountains of Wyoming and its fauna.......... -Invertebrate fauna of the Grassy Creek shale of Missouri.....:.... Gruecory, W. H.; Note on the evolution of the femoral trochanters in rep- tiles and mMammals.............- GREENLAND, Discussion of uplift in. —, Geology of Parker Snow Bay...... GRESS, KB. M.; Critical study of fossil leaves from the Dakota sandstone. GRIFFITHS, JOHN, cited on Chicago blue ROMY sy 2k tuo beki's bi ecata Soe ey wo aes, kaa GROUT, ye F.; Internal structures of igneous rocks LSS har a ah caste nia eae macs ; Two- pare convection in magma Gazyvsowsxt, J., cited on Peru geology. South American Miocene...... GUATHMALA, Geology of............2.. Guppy, H. 1 cited on island subsidence 2 kee West Moka ht: o vb ole) Ge hen raeen Neck muricie ket Hacup, ARNOLD, Bibliography of...... —, Memorial Oat RES a hele eee ate) Walesa 164 69 571 165 616 HAHN, , cited on island subsidence. HAIvr, Geology of. 61 HALL, JAMES, cited ‘on Clinton of New York — — — mud-cracks HALL, Sir JAMES, Reference to work of. 174 HALLE, T. G., cited on Jurassic flora of ore eee eee eee ee) Graben aM rsa celearstens ratseuera onete 645 — —- Middle Jurassic flora...... 610-611 HANNIBAL, HAROLD, cited on Oligocene. 303 Harris, G. D., cited on salt.......... 475 HARTNAGEL, C. A., cited on New York CUMOM tec iepeieate se ect cee HeecnsLenecy.ce 328 Hawtety, H. J., Cretaceous and Ter- tiary stratigraphy of the western end of the Santa Inez Mountains, Santa Barbara County, California. 164 Hayss, A. O., Acknowledgments to.... 220 Hayes, C. W., cited on Appalachian PCNGDIAING Seoheeae escuela erate ge one as 576 HEADDEN, W. P., cited on analyses of Arkansas River water............ 597 HEILPRIN, A., cited on California Eo- CONG Se ean eer eres cam ne oler tesa ate 283 Hum, A., cited on structure of Alps... 175 HENNIG, EDWIN, cited on Tendaguru SGPIOS ese eer cu rs Clas ellgn Aik oe, ove 264 HRKIMBER SANGStONE. 2. 6 cis ee se ee 351 HERSHEY, O. H., cited on peneplains... 580 - Hin, R. T., cited on volcanoes of the Windward Islands... 5 6 2s. 55). eee 349 KNIGHT, S. H., cited on Morrison for- IMATION. cic sso. sels ateqetanel eee ee 255 KNIGHT, W. C., cited on Morrison for- MAatliON =. 6 ssis.S ae « 3s eee 255 KNOWLTON, F. H., cited on fossils from Morrison formation... 00. 260 —y;Relations between the Mesozoic floras of North and South America 129, 607 KIXRASSER, E., cited on Tertiary floras.. 634 KIXKRENKEL, E., cited on fossils from Afri- can Tendasuri.... 6. no selene 275 Kurtz, F., cited on Argentine flora. 632, 647 —-— -— Argentine fossils............. 611 LABRADOR coast, Uplift of 55% ossp ene 226 LACCOLITHIC intrusion, Mechanics of. 75 LAKE Michigan, Abandoned beaches about the south end: Of .../5 (eee 235 Placid quadrangle, Geology of...... 428 LAKEPORD limestone... 5423220 oe 353 LANG, , cited on geyser action.... 185 LANGE, ERICH, cited on Tendaguru se- PIGS e's) sie! «, seine 2.3 0.8 Semeyene eee rn 264 LATE Pleistocene shoreline in Maine and New Hampshire; F. J. Katz...:.. 74 LAWSON, A. C., cited on anorthosite... 409 LEAD deposits in Missouri, Genesis of.. 86 LEE, W. T., cited on Morrison forma- GOMES Mid eke ks eee 247, 249, 251, 263 LEES, J. H., Discussion of loess by.... 73 LEITH, C. K., cited on origin of oolites. 595 LEO, , cited on Amsden formation. 309 LESLEY, J. P., cited on Pennsylvania Precambrian LetcHer County, Kentucky; Coal beds a TM. 5's jase) 2 spares fs Coches Sale ae LEVERETT, FRANK, cited on Glacial time 244 — -— -— Lake Michigan beaches... 235, 237 —, Discussion of James Bay uplift by. T70 ———]oess by... ... cee eee ee ee eee 73 — -—-— Pleistocene deposits by....... 78 —; Glacial lakes of Saginaw Basin in relation: to Wpllft. «....... 22 eee 75 Lévy, MICHEL, cited on experimental TOOlOLY hc bbs eS view cus we See 175 LIMESTONE of Missouri, Glauconite in. 104 LISTER, , Reference to work of.... 172 LITCHFIELD, Maine, Field relations in.. 99 LITCHFIELDITE and soda-syenites from Maine: 5.2 seis clos. shee ste elope ee 463 —, Relation to soda-syenite of........ 99 LorL, W. F.; Vaqueros formation in California: oi. tissice ue ee eee 165 LOESS-DEPOSITING winds in the Louisi- ana region; F. V. Emerson....... 79 — discussed by A. R. Crook...........% a3 — —— Frank Leverett.............. Ts — —— J: H. Lees. . i... .s4 na cee ae 73 i Ge pec, 2 eee eee 73 ——— W. H. Bucher............... 73 —, Present status of the problem of ' OLIgIn'. OF <).¢2 os. cheese ee ae 73 LOGAN, Sir W. N., cited on Clinton basal: ‘Shaleics 12 Seis see epee onene oom — — -— Morrison formation........... 254 Lone Island, Altitudes of shore features OF yo:5 43d a’ 3 of eda ehcree Cee ee 208 Loomis, F. B., cited on origin of fossils from Niobrara Walley nics tcibeserer. cores 2% LOUGHRIDGE, ROBERT HILLS, Bibliogra- yO 0, 2a 0] Leer re err one Are cic eMepeeMcr cr 2 53 <= Memorial OL. .eiace ec antec ek 236. Soe INDEX TO VOLUME 29 LOUISIANA, Loess-depositing winds in.. 79 Low, A. P., cited on beach at Nachvack TOD Ms COR AEE 1 ae ea PPPAT, LOZANO, WH. D., cited on Mexican fossils. 609 LuLu, R. 8., cited on Morrison forma- FDTD Cin a oi eee ar 249, 261 MAcDonaLp, D. F., cited on geology of CETTE VAG) a etease ie ee se ao eae 639 Maine; Glacial beaches: in............ 207 —, Late Pleistocene shoreline in...... 74 —, Litchfieldite and soda-syenites from. , 463 eM MELOM DIS: STOW 1s) 0) 0.2 5 apslelignes ws de s,s 10 rs 463 Rp ODOR AIC Olt creistaia eles sie «ates 0 ea 210 MAMMALIAN jaw from the Truckee beds of western Nevada............... 161 MAMMALS ‘of the Antilles............. 658 MANILLA, Iowa, Pleistocene deposits in. 77 MAPLEWwoop lea reiecge os ctecteuesistus'tel oy tivine. sivelia se 341 MARCOU, JULES cited on California Eo- SOCOM rome ne atraliskees. crigieieiciceweniece cg Sirgheita tte 283 MARINE faunas in Pennsylvania strata. 97 — Oligocene of the west coast of North America; B. L. Clark and Ralph JANTRD ONG hese aa Au ame oe ee ayes, PAST MARTHAS VINHYARD submergence...... 188 MARTINEZ group of California, Section (GE CIS ares ee hen Ne PRET CR OEIe cM acne ee rman 286 MARTINSBURG Shale, Age of........... 94 DEAR IV ATH) SANGSTONE «oe ches wee cee 342 MARYLAND, Paleozoic deposits of the TOM Pils ncc''e ia enews: «cals wom dlovet'e UAT MASSACHUSETTS, Altitudes in......... 208 MASTODON from South Dakota......... 133 MATHER, K. F., Photographs by....... 487 MATHEWS, EH. B.; Outline of accomplish- ments of subcommittee on roads... 70 MATTHEW, W. D., and WALTER GRANGER ; Fossil mammals of the Tiffany beds 152 —; Affinities and origin of the Antillean PUMEMTNATIN Si scocsch cone oe tel ay ence ayiodoceuee 138, 657 ——-— phylogeny of the extinct Cam- MCU ESM, caper deme i io sdekecendlena unto altedanene 144 — cited on climate and evolution...... 665 * ——-——-—— Cuba’s land connections...... 627 ——~»— ocean basins...............2- 636 —; Generic nomenclature of the Pro- WNOSCHGGD, Se geo ensce sch ahh oleme ye toon tects 141 —;Notes on the American Pliocene LUI OGELOSCS: Aca cusy oueneriadetens osis mae etees —, Reference to “Climate and evolu- TALON AED LWace ib. shal easier achie mietaswete) sla tekauenen 615 MAOH Wale, Mia Of 3. sete ee cis aie! eevee 242 MAwson, DOUGLAS, cited on salt....... 475 McCoNNELL, R. G., cited on salt...... 476 Mmap, W. J., cited on origin of silica... 595 META MDE S LOL SCCM sits le oan onthe, cuaueee 79 Mecuanics of laccolithic intrusion ; ORS ISOWCRG ais, shud aapeh bscenat cyonoeine heels 75 MEDICINE Bow Mountains, Precambrian TOK Sad. s) cries col eteccten at Mesebentebewen omneat ens 97 MEGANOS group, a newly recognized division in the Eocene of Califor- Mae ees dos! Chalk 5 sus ccvokaneus aveidactemehens 281 eee —— LAIN OF >TO! ss (oisi'e; oltre s leitelledalswayeiiens 152 Penrte, ELydrous silicates. sci sess 102 MrmpBrrs of the Geological Society.... 107 MemoriaAu of Albert Homer Purdue; George: MH, ASHIGCY....¢cisc wFsisnsuene oy nace 55 —-— Amos P. Brown; R. A. FEF. Pen- [Hots 3e ae gaa OR EMME RES trees ch eien Calce irl cy ap 138 —-— Arnold Hague; Joseph P. Iddings 35 —-— Charles Wales Drysdale; J. Aus- Se OTe ES TUCTIONL 5) «: aleccteress te euacanieen abate 29 — — Delorme D. Cairnes; Charles Cam- LEAN AR SUP RABEME REM GORE UPI he ces mn bata rg Page MeEMorIAL of Henry Martyn Seely; George HesPerkams 3 joc eee se 65 —-— Robert Hills Loughridge; Hugene AS Mesran she nO Oia) epee cakcited sbretrolley e-lek shee sy o's. i ae —-— William Bullock Clark; John M Clatehee gleam rarsaote ie shemes cbalwhie) alae eos « a MrrriaAM, J. C.; An outline of progress in paleontologic research on the Pa- cific coast, Presidential address by. — cited on fauna of Coalinga region... — —-— Tertiary faunas.............. 307 —j; Fauna of tue Idaho formation..... — ——— Tulare Pliocene of the la- CIE COASE MOSTOM 45 sceieieneeleiris «eo ls 15 —, Meeting called to order by President 195 —; Puma-like cats of Rancho La Brea. 161 —;Systematiec position of the dire wolves of the American Pleistocene 161 MerEsozoric history of Mexico, Central America, and the West Indies; AMA Ye ACh altonay cs ang iceeecia icee term ares 138, 601 — floras of North and South America. 129, 607 MEUNIR, , cited on experimental SC OMO LW Mra a aaa ae ewebton gs 2,6 aia aki abet) Mexico, Mesozoic history of.......... 601 IY IOUS ECUNN = Dh albiie hives hs a ye cic Oeeneeneecnte 201 Miuurre, G. S., cited on mammalian fos- sils of Cuba and Santo Domingo.. 626 —-— — West Indian mammals........ 659 Miturmr, W. J., Acknowledgments to... 330 —,; Adirondack anorthosite........ 9, 399 — cited on New York Clinton......... 354 —, Discussion of Precambrian nomen- ClayUIRee Dives mene + vashenehtessomihta's.. 92 MIND RAT Sietromr Matimeto. S226. Scans sce 463. —in Pennsylvania, Precambrian...... 378 —-— the Adirondacks................ 399 =i WISCONSIN gente peeves ds rote Ep ke abe 393 MINGO County, GO SSUIN: sts Cee Anat elec Jaci clsecieb eine boom: aes 96 MINUTES of the Highth Annual Meet- ing of the Pacific Coast Section of the Paleontological Society ; Ches- ETM SiO Cheney nweie, ers MA Pails fete coos celserce 160 MIOCENE deposits, Pinnipeds from..... 161 — Hocene relationships on West Coast. 307 -——of the West Indian Islands........ 624 —sea of the West Coast, Lower...... 301 MISSISSIPPIAN formations, Revision of. 3 MISSISSIPPI limestone containing fluo- rite discussed by W. A. Tarr...... 104 — Valley, Mississippian formations of iE} OWE LN os OXS) the be hos een Cee acta RE NO Re ee 93 MIssourRI, Grassy Creek shale of...... 95 — lead and zine deposits, Genesis of... 86 —, Lower Kinderhookian faunas of.... 93 —, Occurrence of glauconite in........ 104 —, Paleogeography of................ fal —, Zine and lead deposits discussed by MIMNGTAD EIS) seusret eller enw. gle cahske Sie ie Bees aces 86 MiItcHELL, G. J.; Evidence of recent changes of level in Porto Rico, as shown by studies in the Ponce dis- aM EN paar vec Ser A aCe Cun waste ai vie.g. § 1388 MosaAve Desert area, Tertiary fauna of. 162 MOLENGRAAFR, G. ae ., cited on island subsidence Baa Ea Toe ee eee 511 Mouuusca of the Carrizo Creek beds and their Caribbean affinities ; R. EB. TRGICOMR OTe iepertth iis cose huis: « ivr ate a. Gs 'e 148 MoNKS Mound, Additional note on..... 80 IMENT ts OG RTNG* LIV rasa ualvi cd ob clase cs 89 —, Oligocene plant MOSSIUS HOE. wie 5 wapecw Ais 147 Moopin, R. L.; Diseases of the mosa- PAPI URS alate Le ER AL ONET CUR Sar aguacsacki'c, fics vaiacwnn 147 Mook, C, C., cited on Morrison forma- MERI MM Te Raker ON 6 ised usi“as «x 249, 251 674 Page Moore, E. S.; Algal limestone on the © Belcher Islands, Hudson Bay...... 128 —j;Iron formation on Belcher Islands, Hudson Bay, with special reference to its origin and its associated algal TIMVESTONES |): cis)) bp. yes eee eee 90 Mornry, G. W.; Hydrous silicate melts.. 102 MOrRICKE, W., cited on Navidad fauna.. 642 Moropus cooki, Skeleton in the Amer- ican: Museum cots sto. eee ee Maal MorozEWICZ, , cited on igneous TOCKS SoA e ee ee Sr Re Se aa eee 185 Morrison formation compared with other formationS-.. cco oe ere ae 246-248 —-—, Names applied to the........... 248 — of America, Age of.............. 245 MOSASAURS; Diseases: 685. 5 055262 2 a 147 MouNnpbs and their origin discussed by MEMPEIS tas bie sweet ere eevee eae 81 MoUuNTAINS in New Mexico, structure OF*SOME 22 eee heehee ee ee Fe Mount HoLtyoKker, Announcement of fire bee UR Suis echo etches eae) Geet ss MurpHyY, —, cited on transportation Of debris: Dy Water < .S:25 54 oem eis ose 185 Murray, ALEXANDER, cited on marine Clinton beds. c. = 220s echelons Sindee 334 MURRAY, cited on island subsi- GEDCE Sere ee ct ore eke ous e G 493 NATIONAL Research Council, Report of Geology Committee of............ 69 NAVIDAD eTaAUN Ae: se. = saneratets eho ies ere Ss 642 PIP CROMOGS << hoc. wees wre ce miereitetn ete bie sere) 12 NEUMANN, R., cited on Peruvian fossils. 611 NEVADA, Mammalian jaw from the Truckee beds of western.......... 161 New Artiodactyls from the Upper Eo- cene of the Uinta Basin, Utah; @. oA SPELETSOM ais ose Creare eee 153 — bathymetrical man of the West Indies Tesion Co AL weCCUS aes le ate oa ee eek 142 Neweserry, J. S., cited on Honduras fos- SAS he seas te Stecekee eevee ods eee etenere eee rene 608 NEw BrUNSWICK, Marine levels in. 220 NEWFOUNDLAND, Altitudes of east coast . OF oes Ha eee celeste ie erenate 04 coast, Changes in elevation of...... 226 NEw JERSEY, Submergence of......... 188 NEW HAMPSHIRE, Glacial phenomena THs, cs keds Rise he Pee eae ee 195, 209 —, Late Pleistocene shoreline in...... 74 NEWLAND, D. H., cited on New York CYinton: hae ae ee eee eee 29 New Mexico, Structure of some moun- tains ink. oss Ree ee a eee G2 New points in Ordovician and Silurian pileoneenr as T. E. Savage and M. Van Pfuyls ss eee bthiGaont skull from the Huerfano Basin, Colorado; Walter Granger.. 147 NEw VonikK Clintons. croc tee colette ee leye arr ——. Glacial phenomena ini); -<)..2 . 2k - : 197 — Siluric, Further study-in:......... 92 . NIERMEYER, J. F., cited on atolls...... D27 NIVATION as an erosive factor in north- ern Greenland, Importance of..... is NoLINEZ of the West Indies.......... NortH AMERICA, Edentate deposits of. 161 —, Eocene pseudotapirs of............ 152 —, Fresh-water fish faunas of......... 138 —, Marine Oligocene of. .-........ 5. 153, 29% = PRO AGIC GMOLHS JOE. 6 <9. 2 «am 129, 607 Bares iS. Po Ros ee ae eine 138 SAP ARANG DEAS. OE o.oo J lore shoe 129 OIL CR POE c erates foes vie wet cleo eee 102 —5, Wileox Mocene flora‘of......5..%2. 632 BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA : Page NORTHEASTERN America, Post - Glacial Uplift, OF... 2.2.85 oe Se 187 NORTHERN Greenland, Importanee of nivation as an erosive factor and aout flow as a transporting agency ase e vce cee S05 ste G2 Nowa on Eifel brachiopods; C. H. Chad- WICK 6. iis Se be le whe ee 154 —w—the American Pliocene rhinoce- roses; W. D. Matthew... 222.5. see 153 —-——eevolution of the femoral tro- . chanters in reptiles and mammals; W. H. Gregory... /:2222 eee 154 — — — geology of the region of Parker Snow Bay, Greenland: E. O. Hovey 98 ——— occurrence of a mammalian jaw, presumably from the Truckee beds of western Nevada: J. C. Jones 161 —-—— separation of salt from saline water and mud; E. M. Kindle.... 80 —— — stratigraphy and faunas of the Lower Kinderhookian in Missouri; BH. B. Branson... .. 2202 = 2s eee Nova Scoria, Glaciation in... 72s sesee —~-, Marine levels “in... 2.2... 3 OBSERVATIONS on the_ skeletons of Moropus cooki in the American Museum; H: EF. Osborn... 2. eee O’CONNELL, MARJORIE; Cretaceous over- laps in northwest "Europe and their bearing on the bathymetric distri- bution of the Cretaceous Silici- spongiz OcCURRENCE of a large tourmaline in Alabama pegmatite; F. R. Van Horn —-——marine Middle Tertiary fauna on the western border of the Mo- jave Desert area; Wallace Gordon. ——the WSiphonalia sutterensis zone, the uppermost Tejon horizon in the outer Coast Ranges of California ; R. E. Dickerson... ... 2 22> OFFICERS and members of the Paleonto- logical ‘Society, Election of....... —, correspondents, and members of the Paleontological Society........... — Mlection Of. 5. 5.5 5. 20 3 ee OcILvI£, I. H., cited on anorthosite... 01, 416 OHIO gas wells discussed by F. R. Van -Horn uplift In. ..5 5. 2.'s. 5) ee ee OIL-BEARING and oil-producing forma- tions, Relation: of.... .. <=... =e OxupROYD, IpA S.; Relationships of the recent and fossil invertebrate faunas on the west side of the Isthmus of Panama to those on the east side. . OLIGOCENE, Faunal zones of the....... —,Faunal zones of West Coast....... —'faunas and formations, Symposium of 165 —+=— of the; Pacific coast...) +. eee 166 — floras of ‘North America... . 2.3.0 = of North America, Marine> 2 .o-acee — — Washington — paleontology Washington —, Plant ‘fessils Of. ~ .. sss een Lier —'of the West Indian Islands........ —-—— West Coast of North America.... == seq) of West Ceasba nner a er OoLITES in shale and their origin; 131 142 104 coececeomse see ee oe ee 6 «6s Ss oe ee 162 eneevecevuvusanee ese es 6 Se ee eee citi: Genieee ee aa INDEX TO VOLUME 29 Page OoLitTic structures discussed by mem- [OVEIENSS. “5. Boca ORSON CRC a en TPA Se — -—, Inorganic production of......... OPPORTUNITIES for geological work in the far Arctic; W. H. Ekblaw..... 85 ORDOVICIAN limestones in Wisconsin, EVINTONTE TUB TIN: 90s hie seneiialss lsveuei ieee eve em — paleogeography, New points in...... 88 OREGON Cascades, Geologic features of. 81 —, Marine Oligocene OL ee nt sei. 297, ORTMANN, A. H., cited on Argentine marine fauna. cits Stowal elrebiny apealval ch aratalees 643 Osporn, H. F.; A long-jawed mastodon skeleton from South Dakota and phylogeny of the proboscidea..... 133 — cited on fossils from Morrison forma- HALON Irene neveu'e:ailel-aniiter sittetey ert eusite haat Cabs —; Observations on the skeletons of Moropus cooki in the American Mu- SERCH IN Nurs scrote uch oWenicwelicsibatiey. oleaigene (er lalei tar la vatrov's aleial OTSOUAGO SANASTONE.. «65 ose ce ew en we 343 Paciric coast, Geologic range and eyo- lution of echinoids..... ES on — —, Progress of paleontologic research ——, Symposium of Oligocene faunas ONION te TR Heras se Seleyra i ureisohiisessectvetiel wisi clue ce — WHocene, Correlation of............. PackarD, A. §S., cited on highest beach POP ATAU OT 6 o's Gave ckile kua/nees d5, hooey 0% 227 Pack, R. W., cited on Monterey deposits 299 — — — Turritella andersoni beds...... —, Reference to Cretaceous fossils col- MECC Crs Sites Lene otieaette > SIM Wusuotiaa Wee's 606 pene ECOLOGY, Scope and significance —, The GATES CLOT OL 5 FP skeen) 2s oes a sey st ler PALEOGEOGRAPHIC significance of the Cenozoic floras of equatorial Amer- ica and the adjacent regions; WH. W. IS@IRE. 55 O erordcceann Clolord Coo Dhoko Or 129, 631 PiungauognaPny, New points in Ordo-. vician and Siltiniamvrs gochett 88 —of Missouri; E. B. Branson........ 71 ——the Oligocene of Washington ; CREM VWCDVEL... sere eis seers dea eNethetplians PALEONTOLOGICAL Society, Highth An- nual Meeting of the Pacific Coast SV@TEG Nal 00 Bee ey ee RRO cnc OMe Oe Chemcits Onor PALEONTOLOGY and stratigraphy of the Porter division of the Oligocene in Washington; K. EH. Van Winckle. PALEOZOIC deposits and fossils on the Piedmont of Maryland and Vir- ginia; R. S. Bassler...........-- — faunas, Development of............ — floras of North and South America. — glaciation in southeastern Alaska ; HAY serait) = ANCUUR IS cy hsscd Suyayret elie sitcweiie ers) waanabtatn —history of Central America and the West Indies; R. S. Bassler....... 129 —of North America, Oil-bearing and oil-producing formations in....... 92 —oolites, North American...........-. 102 —rocks on the Piedmont plateau dis- eussed by Grabau and Merriam. PANAMA, Invertebrate faunas of....... 162 PARDEE, , cited on Morrison forma- tion BR er afc evar oeoratien ce NME eles aaa Che ING 246 ParkKrR Snow Bay, Geology of......... 98 PAULCKDE, , cited on experimental geology Savi Wacte: svvteling ie ante atlaneh apseatente a teaabate 177 Prat at HWvanston, Illinois............ 2a Puck, F. B., cited on Pennsylvania tale and serpentine:........s.esenuas 379 Pramatitp of Alabama..........seee. 104 Page PENEPLAIN dating discussed by mem- DEES Werbieteteo sisal cheer tt a aera ok 90 PENEPLAINS, Dating Of;.............. 89 —of the Appalachian province........ 575 PENNSYLVANIA, Oil fields in........... 96 —, Martinsburg shale in eastern...... 94 — Precambrian sedimentary rocks in CASTOR MRE ase er tetemnenens se cueealu ier aienicos 375 — strata, Marine faunas in........... 97 — wells discussed by Mr. Decker...... 96 Prnrosn, R. A. F., Jr., Memorial of Amos 72s Brown by. .esseeee: - as PERKINS, GrorGE H., Memorial of Henry Martyh: Seely" Dyjscc tare eee 65 PERRIER, , cited on island subsi- GENCe i ee ee Man areata DO ce eee 493 GEN HOSSil ora Osis sivccens: tsi eeesiele ans. 641 —, Tertiary and Pleistocene formations OE paint) aye beeem ore rela eee eee mae c 165 PETERSON, O. A., cited on fossils from Niobrara AVialley ae ios seco s eon 274 —=—= == SEY Ser ACtlOMi,s . vice wis.« ois) o cee ae 185 ; New Artiadactyls from the Upper HKocene of the Uinta Basin, Utah.. 158 ; Revision of the pseudotapirs of the North American Hocene.......... 152 PETROGRAPHY of Pennsylvania minerals 881, 387 PETROLEUM, Relation between uplift and folding areas to occurrence and QUAL OL irr a. teicscree es aiecet ckdtouen ec weker ieee 87 PETROLOGIST, Significance of glass-mak- TING? ROL hia te eae eet ca ehtnec ee Me eee PETROLOGY of rutile-bearing rocks; T. L. WiatSOme cement: ais con acne ameee PFAFF, OlO LYM tas Cet iheeehs ihe a eae ne 175 PHILIPPI, R. A., cited on Navidad fauna 642 PEP GUINUER@ IS TVGe ices re eeste oe, to cutee y aac eee 350 PHORADENDRON of the West Indies.... 652 PHOTOGRAPHY, Report of Committee on. 69 PHYLOGENY of the Proboscidea........ 133 PIEDMONT, Paleozoic deposits in the... 127 PINNIPEDS from Miocene and Pleisto- cene deposits of California; Rem- INStOM EMO a mie ss eG tare ik he 161 Pirsson, L. V., cited -on Bermuda bor- TI a Rises EE aes Get anal ene o! CRG aM SaMRoma: ty 566 PLANT-BEARING beds in South America. 637 PLAYFAIR, Reference to work of.. 173 PLEISTOCENE deposits between Manilla, in Crawford County, and Coon Rapids, in Carroll County, Iowa (I th had) CES Ton Secor hoe eet ates CaeGto ete: (C0 —-—in Iowa discussed by members... 78 —-—, Pinnipeds from................ 161 —,-Dire wolves of American.......... 161 — formations OE REGUS SROs oh be Bas eons 165 — shoreline in Maine and New tiamp: Shute wba tewwawie Sais enhe ioe Beare elec 74 — submergence at Gaspé............. 217 —-— of Hudson Valley and New Jersey 188 PLIOCENE extension of the Gulf of Mower California... ics es wre ks 164 —— Of Idaho, Tulane ive cs sic cael w cle eas 152 — -— the west coast, Reference to..... 308 — —— West Indian Islands.......... 625 —, Notes on American rhinoceroses.... 153 POPOWAGIM DeGuise tas cee kee Glh ee 595 Porto Rico, Recent changes of level in. 188 heb heen literature, Bibliography (ireaec csctciascie, Cua OcOROLE Gene ged atic te. adele 22 — uplift of northeastern America; H. L. PANO UG ak naared tis Susie Awl elwiels 70, 187. PRECAMBRIAN nomenclature discussed by JUIVGROGU GS Alaeeic ec wich. via. sete ee en ee 91-92 —-— in Saint Lawrence basin, Limita- MUON STO Laan serrate v arena tiewincl vei eoeigueialete a tag 676 Page PRECAMBRIAN rocks in the Medicine Bow Mountains of Wyoming: E. Black- welder and H. F. Crooks Sree cc: 97 — sedimentary rocks in the highlands of eastern Pennsylvania: E. T. MCG VET she ve gt So ee er a 375 PRESENT status of the problem of the origin of loess: C. W. Tomlinson... 73 PRESIDENTIAL address by J. C. Merriam 129 —, Experiment in geology; Frank D. [at G hPL Gy eth oe eS a 82, 167 PRINCIPLES of classification of Cyclo- stome bryozoa; F. Canu and R. 8. PSS ESS ere Ue eo hs ae ee ee ae 151 PROBOSCIDEA, Generic nomenclature of. 141 Saou Hint Cea h ti eS rr 33 PROCEEDINGS of the Ninth Annual Meet- ing of the Paleontological Society, held at Pittsburgh, Pennsylvania, December 31, 1917, and January 1 and 2, 1918. R. S. Bassler, Secre- TEETCY Uap eR ete eee ai shee ae Blane orene 119 ——-—Thirtieth Annual Meeting of the Geological Society of America, held at Saint Louis, Missouri, De- cember 27, 28, and 29, 1917. E. O. PG VEVE IS CGECIAI Ys ho cia see ee 1 PROPOSED correlation of the Pacific and Atlantic Eocene; R. E. Dickerson. 148 PSEUDOTAPIRS of the North American WiecOnowmrre terns atic cic os cise eee ee 152 PuMA-LIKE cats of Rancho La Brea; TG Tee he Sa oe ee 161 Purpvue, A. H., Memorial and bibliog- rer id th RO: eo rr 55, 60 Querctus of the West Indies.......... 650 Rancnuo La Brea, Puma-like cats of... 161 Ratu, G.. cited on Loja Basin fossils.. 640 Reck, F. B., cited on Tendaguru series. 265 REcoRDS of three very deep wells drilled in the Appalachian oil fields of Pennsylvania and West Virginia; Lie Pidinte ee os ees ae we > 96 ReEEpDs, C. A.; New bathymetrical map of the West Indies region........ 142 REEF-ENCIRCLED islands, Subsidence of. : 71. 489 REESIDE, . cited on Sundance for- OH i}LEA” © ets uc. Ce thre eee 257 REGISTER of Pittsburgh meeting of Paleontological Society......:.... 155 —-— the Saint Louis meeting, 1917... 106 iological Se CO RE ee ee ee 166 REID, MELLARD, cited on heat action. ot RELATION between occurrence and qual- ity of petroleum and broad areas of uplift and folding; E. W. Shaw... 87 —-——the Mesozoic floras of North and South America; F. H. Knowlton. . 129, 607 — — — Paleozoic floras of North and South America; David White..... 129 RELATIONSHIPS of recent and fossil in- vertebrate faunas on the west side of the Isthmus of Panama to those on the east side; Ida S. Oldroyd.. 162 — — the Mesozoic reptiles of North and South America; S. W. Williston... 138 RELATIONS of the oil-bearing to the oil- producing formations in the Paleo- zoic of North America; A. W. Gra- RPE a et eae wie hag! Sells wlleNete ore ale 92 Report of the Auditing Committee.. 83 i 69 BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA —; Tentative correlation of the Penn- sylvania strata in the eastern in- terior, western interior, and Appa- lachian regions by their marine faunas C8 0) 0) a6 eel eo 6. m. a.6, at ete Le ee hee Page REporT’of the Council... .”...: --- see 4 — —of the Paleontological So- élety =... eee se be eee 123 — — — Wditor ... 20.2... os ee eee 9 — —-— Geology Committee of the Na- tional Research Council by John M. ~ Clarke, chairman. .2: 225.250 008 69 — —— Secretary ...........2685 555m 5 ——-—-—of the Paleontological So- elety: 2... eos . 2 ek oe eee 128 — —— Treasurer ..:.. 3. ee eee t —-—--—of the Paleontological So- Ciety .. i ./ e. Hee oe 2 eee 125 —on a collection of Oligocene plant fossils from Montana; O. E. Jen- 5 NINES... 2 se a oe ae eee 147 REPTILES of the Mesozoic of North and South America. ...:-../2 3. eee 138 REVISION of the Mississippian forma- tions of the upper Mississippi Val- ley: S. Weller and F. M. Van Tuyl 93 —_—_— pseudotapirs of the North American Eocene; O. A. Peterson. 152 REYER, cited on experimental geology ...:.:.::.+2 20. eee 176 REYNALES limestone... .-: => i=. eee 344 RHINOCEROSES, Notes on Pliocene...... 15s RicH, JOHN L.:; Dating of peneplains: an old erosion surface in Idaho, Montana, and Washington—is it HMocene? 2.45.3 062 S245) 89 —., Discussion of loess by...........-- 73 — — — Pleistocene deposits by....... 78 Rocky Mountain section in the vicinity of Whitemans Pass: C. W. Drys- dale and L. D. Burling...........- 145 tocErs. H. D., cited on Pennsylvania Precambrian .......+.02. 4a 376 Roru, Justus, cited on experimental Seolory. «.-..s2 At sews noe ee 182 RUTILE-BEARING rocks, Petrology of... 100 SaGInaw Basin, Relation to uplift of glacial] lakes of.......<... S309 75 SAINT Croix, Geology of. . 2.25 seer 620 SAINT LAWRENCE basin, Changes of alti- tude of the... ...2....5 72.4822. 214 ——, Limitations of Precambrian no- menelature in.......-=2=.0neneee 90 Saint LOUIS meeting, Register of...... 106 SALFELD, H., cited on Peruvian fossils. 611 SALIENT features of the geology of the Cascades of Oregon, with some cor- relations between the east coast of Asia and the west coast of Amer- ica; W. du P. Smith........ 0. oe 81 SALINE ‘water and mud, Separation of salt: from: 2... 0 o..2)2 «ose eee 80 SaLisspury, R. D., cited on Pennsylvania peneplaims ......-%+-«)) 0. 578 Sat from saline water and mud...... 471 —separation from saline water and mud G6€). 02. 6.2 ses ee eee 80 ie eres beds, Absence of water in GY aisceia le ae ole cee ae ee 105 San Toieene formation of California... 299 Sapper, CARL, cited on Honduras fossils 608 SARLE, . cited on fossils from Iron- dequoit limestones! i... <-; ) 2 dete ee 352 Sauquore beds). . 6 nis) as tee ee 341 SAVAGE, T. E.; New points in Ordovician and Silurian paleogeography...... 88 INDEX TO VOLUME 29 Page SCHARDT, , cited on experimental ERED CA 5, ie RACER Ea 176 SGEMROMPPR DT, SMATG Ec. oy beats a see Gece 350 ees, CHARLES, Acknowledgments EME Peart iee for stab iS aus Yasd ew ane elee’y 330 —citea on Clinton basal shale........ 331 ; Age of the American Morrison and East African Tendaguru forma- ELOIDEN Ales Patani er BROTH, ORC aoa ae eee 245 —cited on Martville and Bear Creek HEDIS Es pay ab Woh stat oguslesehaligdns ies sis let sne 342 -———- —— Mexican stratigraphy......... 601 Scorer and significance of paleo-ecology ; Me OVCTINOMES se U8 eto whe wierd dete ease 369 Scort, , cited on ice-flowers...... 475 SSECHMPARY SS TCDORE . << ceils c vies Sess os 5 123 SEDIMENTARY rock composition study discussed by J. M. Clarke........ 85 SEDIMENTS, Usefulness in studying earth IDEISTROTEVAD (OE gud ecg eee op ee eee 84 Snety, Henry Martyn, Bibliography of 68 —-, Memorial ONT patiecs oteteie ee ay signee eiretee 65 SEIDEL, , cited on uplifted coral ESM. SWMCHAN Soir iicecv eh ancy a0 slates whew au elses 558 SEPARATION of salt from saline water qmaomud + 1. M, Kindle... .... 5... 471 SHACKLETON, HE. H., Reference to work Ram te ce cPele aren ree iaranstitgn aueke lela able usian'e 475 Sauer, N. S., cited on Marthas Vine- yard submergence..........-+---- 188 ———————MOUME DESert... 2... +s. ence eg 212 a= SS SEAS CICIIO LI GR ee Gecaer ens Ca oeelicanepac 213 SHaw, E. W.: Ages of peneplains of the Appalachian DEOQVANCE cei ii dc si a shaneos 575 : Characteristics of the upper part of the till of southern Illinois and USE WANE OH chau ay-ucl o\ suatist s lotaiet snanel ol oeyens 76 - Relation between occurrence and quality of petroleum and _ broad areas of uplift and folding........ 87 Suepp, C. B., cited on Chicago blue clay 243 = land- level changes due to gla- TRON graves Ar ict Ge ap oharieet eine lalpeiiatta wate fs 240 SuEepp, Miss Lonig, Acknowledgments AGRE eran ek as Rh CRD ee ee eRS ee tah Saenteb auras 242 SHERBURNE bar in Devonian stratigra- POE Aon chs. ve ck cnas ort bam eene ot lem muntetennl PAT SHIRLEY, , cited on Amsden forma- ALITA OES race sa ete Ratton ire Ratauee ealetiol nae toa 309 SHORELINE in Maine and New Hamp- shire, Late Pleistoceme.........-. 74 SIGNIFICANCE of glass-making processes to the petrologist ; N. L. Bowen.. 102 —w—the Sherburne bar in the Upper Devonic stratigraphy ; A. W. Grabau 127 SipicatH melts, Hydrous............. 102 SiILIcEoUS oolites in shale; W. A. Tarr. 103 SILICISPONGI@ of the Cretaceous. eee 142 SILURIAN paleogeography, New points Be TEL ens Pea. Whe iveee ARE tn oe sttey wioaina e Pateenaey ts Sinuric, Further studies in New York.. 92 Siphonalia sutterensis zone of California 163 Sxrats, HE. W., cited on atolls........ 565 SLOSSON, B. E.,. cited on Popo Agie 10k fo} i en NC Marae rer coy Mech ne hiry CRE 597 Suurrer, C. P., cited on coral reefs.... 527 Smitu, BurNET?T, cited on Brewerton Watt Otis oss re chara 349 SmitH, Evcene ALLEN, Memorial of Robert Hills Loughridge by....... 48 Smrru, J. P., cited on Mesozoic fossils. 601 —_— — — Sundance LOTMATION. 4: s4) 0 ol viet 257 ; Tropitide of the Upper Triassic of CLV IETOU NaN Tie, APR Re neem oats Ore eee: Ncmpse dr ok 162 Smitu, R. A., cited on salt in rain- Syischit(2) Deana a BRP RC RORC Be RCPE ICS UN WC MPM APE ccc’ 474 SMITH, W. GENGCOT Ale Peake iets er east See ciclice Gi ct aya ts 518 SMITH, WARREN DU PRE; Salient fea- tures of the geology of the Cas- eades of Oregon, with some correla- tions between the east coast of Asia and the west coast of America.... 81 SMOKDR (to) the Society 2) acne oe eee? 130 SMyTH, ——, cited on Furnaceville iron OTS EN Se eae a Guek epee fais 343 SopDA-SYENITES from Maine............ 463 —, Relation of litchfieldite to......... 99 SopUS! Wale) hs oe a aealses see ois emer e ania 345 So1t flow as a transporting agency in northern Greenland, Importance of 72 Somp definite correlations of West Vir- ginia coal beds in Mingo County, West Virginia, with those of Letcher County, southeastern Kentucky ; Pe CLL WT Sate 8 oie cu re cts ce — observations on the osteology of Dip- Jodocus; W. J. Holland.......... 130 SoRBy, , cited on experimental geol- OLYS cicada noel oeeneh eee named auealiote tvie tel ees 175 ‘SSOSMAN, , Reference to work of... 186 SoutH Amprica, Age of certain plant- bearing, DEMS IM seaieascessnenel +) sucess aden 637 —, Fresh-water fish faunas of......... 138 —, Mesozoic floras of............ 129, 607 —— —+ Tepitiles: Ofte secene: ok oie. Bvavec ey eotey's 138 ==, Paleozore, MOTAS Olas stele eye cts) stnlete akan 129 —, Tertiary and Pleistocene Ponttrione OLS POLIS 5A Ra ee ae eA Ohno onde 165 SoutH Daxota, A long-jawed mastodon skeletons ir Onis sites k .| we erle. se) #88) 6 \e) el ie eel ee) #0 ele) (a ee ' WILLISTON, S. W., cited on age of oolitic shale —;Comparison of Sundance with Ox- ford clay formation by........... WILLIS, BAiLby, cited on experimental geology ——-— Pennsylvania peneplains...... ——-— unconformity of San Lorenzo BEGSE Heer ee ropene sett oeaerac oso kodetinnel @revreaay —, Reference to geologic map by... 69, WILLISTON, S. W.; Evolution of verte- {OL MUR, GHG T RGEC i Seen S tontire ey ERC ome ; Relationships of the Mesozoic rep- tiles of North and South America. WINCHELL, N. H., cited on anorthosite. WINDHAUSEN, Vee cited on Patagonian fossils —-—-San Jorge formation.......... WIND RivER Mountains, Amsden forma- TIOMBO ESR eter oe sane sean eet A ease WISCONSIN, Discovery of fluorite in... ==; Minerals Tiny cies ct hicueinanery slelah soetekone =—= time “Ui laity NMS sti cs vente creneuaee eeeses, wires Wo.ucorr furnace iron ore............ Wo.r, T., cited on Loja Basin fossils. . WoopFrorpD, C. M., cited on atolls...... WoopwortH, J. B., cited on chlorine in STOUNGS Watery. ci s2: ve: Wieser euete ak eee WriGuHT, F. E., cited on coarsening of finely divided silicates by heat. WricHT, G. F.; Explanation of the abandoned beaches about the south end of Lake Michigan............ WYOMING, Amsden formation in —, Precambrian rocks in eines oe velete 6 \e «06 © @ © @ 6) 9% .0 te) ie 6) m e 6), 6) 2s) g) es) pe 16: 6, (8) 10 (0. 0) :0 eee «se is <6) fa 2 es) we) le) cei ey atalays <8) \e “ZAPHRENTIS,” Carboniferous species of ZEILUER, R., cited on Honduras fossils. ZINC deposits in Missouri, Genesis of. ZWIERZYCKI, J., cited on Tendaguru SELES emer Re eo eleianek em bik kon 154 608 86 7 ist il 2 iA ih x’ May ~ ay Oh: 8 01309 1996 oe sig 7