BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 VOL. 16, PP. 447-498, PLS. 82-85 DECEMBER 15, 1905 



RED BEDS OF SOUTHWESTERN COLORADO AND THEIR 

 CORRELATION* 



BY WHITMAN CROSS AND ERNEST HOWE 



(Read before the Society December 29, 1904) 

 CONTENTS 



Page 



Part I. The Red beds of southwestern Colorado, by Whitman Cross and 



Ernest Howe 448 



Introduction 448 



Literature concerning San Juan " Red beds " 449 



Reconnaissance explorations 449 



Work of the United States Geological Survey 451 



The Ouray unconformity 453 



Description of formations 459 



Cutler formation 459 



Selection of name 459 



General characterization . 461 



Details of lithologic character 461 



Typical section 463 



Age of Cutler beds 466 



Dolores formation 467 



General characterization 467 



Lower fossiliferous portion 467 



Upper red sandstone member 468 



Fossils • 468 



La Plata formation 469 



McElmo formation 470 



Part II. Correlation of the formations, by Whitman Cross 470 



Introduction 470 



Relations of Colorado formations to those of the Plateau province 471 



Formations of Dolores Valley and Uncompahgre plateau 472 



The region in general 472 



Observations of A . C. Spencer 472 



Comparison with Peale's section 474 



Newberry's section 475 



Formations of the lower San Juan valley 475 



In general 475 



Observations by H. S. Gane 476 



♦Published by permission of the Director of the U. S. Geological Survey. 

 LXI— Buix. Oeot.. Soc. Am., Vol. 16, 1904 (447) 



