612 



BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Page 

 Ordovician, Charactei'istics of forma- 

 tion of 407 



— fauna, Occurrence in Porcupine val- 



ley of 323, 324 



— limestone, Occurrence In Porcupine 



valley of 322-323 



, Occurrence in Porcupine Valley 



rocks of 319 



— of Upper Yukon, Unconformity of 271, 272 



— system. Bighorn limestone of... 410-412 



— - — in Central Wyoming 410-412 



— -. , Bighorn limestone of... 410 



— ■ , Fossils and age of Dead- 

 wood formation of 411 



— • , Owl Creek mountains of 



Deadwood formation of 411 



Oregon and California, Map of part of 370 



— , Jurassic flora of 367-402 



OrovillEj California, Fossils and age of 



Monte de Oro formation at 390 



, Lithology of plant beds of 388 



, Plant beds of 387-391 



, Quartz veins in plant beds of... 388 



OSBORN, H. F., cited on Nebraska "loess 



man" 245 



Ostracoda, Classification of 546-551 



Outlines of hydrology. By W J 



McGee 193-220 



Owl Creek mountains, Amsden forma- 

 tion In 413 



(Bighorn limestone of 411 



, Cloverly sandstone in 447 



, Deadwood formation on 409 



, Madison limestone of 412 



, Tensleep sandstone of the.... 415 



-uplift, Embar formation in the 416-417 



— • . — ■ — , Chugwater red beds in 432 



■ — , Sundance formation in . . . 438-439 



Oxygen, Occurrence in solar spectrum 



of 123 



Paleozoic and associated rocks of the 

 upper Yukon, Alaska, by Alfred H. 

 Brooks and B. M. Kindle 255-314 



— - — Mesozoic of central Wyoming, by 



N. H. Darton 403-474 



— of northwestern New York, Classifi- 



cation of rocks of 163 



— rocks of British Columbia, Succes- 



sion of 302 



Porcupine valley, Structure of 



317-318 



— section In northwestern New York . . 



155-176 



, Summary of 165-166 



Pamelia formation. Age of. . . .169-170, 175 



— and Theresa formations, Comparison 



of Champlaln and Mohawk sections 

 with 171 



— limestone. Character and thickness 



of 161-162 



Parabolic curves. Tendency of water 



towards 204-206 



Passarge, , cited on arid regions 



of South Africa 87 



plantation in southern Africa 74, 77 



wind erosion 90 



— , Observations on planorasion of . . . . 86 

 Patton, Horace B., elected councillor. 521 

 — , Title of paper by 568 



— , Topaz - bearing rhyolite of the 



Thomas range, Utah 177-192 



Patagonia, Extent of glaciation in.... 349 

 Peale, a. C, cited on forms of La 



Plata sandstone 57, 58 



Pegmatite, Association with hornblen- 



dic granite beds of. (Subject of 



paper read by title.) 509 



Pegmatites, Characteristics of 135 



Page 

 Pelecypoda, Classification of. 547, •^)48, 552 

 "Pelly gneiss" so termed by Mr Mc- 



Connell 267 



Penck, , cited on arid plains 86 



— cited o n wind erosion 90 



Peneplanation, Rock - floor surfaces 



caused by 74, 75 



Penhallow, D. p., elected a fellow. . . . 522 

 Penokee district. Unconformity in.... 11 

 Pentameriis ohlongus. Occurrence in Si- 

 lurian of upper Yukon of 275 



Permian-Triassic in central Wyoming. 



432-438 



— , Characteristics of formation of 407 



— , Chugwater red beds of 432-438 



— , General relations of 432 



Perjio-Carboniferous glacial period. 



The 349-353 



— tillite. Occurrence in Australia of . . 351 

 Phillips, John, Post-Archean time 



estimated by 129 



Phosphate deposits of Florida with 

 relation to the underground water 



level. (Paper read by title.) 537 



Pitchblende, Presence of radium in.. 114 

 Plains, Effect of sheetflood erosion 



upon the 81 



Planation an effect of eolian action ... 82 

 — , Rock-floor surfaces caused by. . . . 76, 77 

 — , Rock-floors of the arid country an 



effect of 82 



Planorasion, Process of 86 



Plants, Classification of 551 



Plant beds near Nichols station, Ore- 

 gon, Composition of 375 



of Big Bar, California, Occur- 

 rence of 379-382 



, Relation o f adjacent 



rocks to 382 



. Elk river, Oregon 376-377 



Oroville, California 387-391 



■ , Relation t o adjacent 



beds of 389-390 



Rattlesnake creek, California, 



Occurrence of 382-383 



Redding creek, California.. 38.3-384 



west side of Sacramento valley 



384-386 



, Oregon, Composition of 371 



, Lithification and veining of.. 



371-372 



Plants, Water in 212 



Platead country. Character of sand- 

 stones of 56 



, Climatic conditions In the 62 



east of Grand river, Utah 56 



• , Wind and water action in. . . . 61, 62 



erosion in the 53-62 



Platinum, Occurrence in solar spec- 

 trum of 123 



Playa deposits of the Basin Range re- 

 gion 83-S5 



Pleistocene glacial period. The. . . 34S-349 

 — , Interglacial periods in the .... 3oG-359 



Pleurotomaria , Occurrence of 283 



Plojids range, Arizona, Profile of the. . 88 

 Point aux Pines, Location and char- 

 acteristics of 482-483 



— , Sketch map of 483 



Point Pelee, Location and character- 

 istics of 484-486 



— , Sketch map of 485 



Poole, H. S., Fossils at Halifax dis- 

 covered by 104 



— , Reference to report by 112 



Porcupine river, Alaska, Geologic map 



of 321 



• — valley, Alaska,. Carboniferous shales 



and limestones of 330-332 



