BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 30, pp. 471-498 December 31, 1919 



PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY 



PEEMO-TEIASSIC OF ^ORTHWESTEEN AEIZONA^ 



BY HERVEY W. SHIMER 



{Presented before the Paleontological Society December 28, 1918) 



CONTENTS 



Page 



Introduction 472 



Table of formations 472 



Description of sections 473 



In general 473 



a. From the Mogollons to Flagstaff 473 



7>. Walnut Canyon 473 



c. Grand Canyon of the Colorado River ; 475 



(I. Navajo Spring 476 



e. House Rock Valley 476 



/. Kaibab Plateau 479 



g. Kanab Plateau (northeastern) 479 



h. Toroweap Yallej' 480 



i. Southwest of Sawyers Tank 481 



./'. Sawyers Tank 481 



A:. Southwest of Wild Band Pockets 482 



/. Wild Rand I'ockets 483 



in. Workman Spring (Utah) 483 



n. Hurricane (Utah) 483 



Tabular list of species, with distribution 484 



Notes on species 486 



Discussion of age of formations 491 



In general 491 



Redwall limestone 491 



Supai (lower and middle ) 491 



Supai (upper) 492 



. Coconino sandstone 492 



Kaibab limestone 492 



Moenkopi formation 493 



Chinle formation 496 



Summary ^ 497 



^ Manuscript received by the Secretary of the Geological Society February 24, 1919. 



(471) 

 XXXIII — Bull. Geol, Soc. Am., Vol. 30. 1918 



