THE PHYSIOGRAPHY OF THE BISHOP CONGLOMERATE, 

 SOUTHWESTERN WYOMING^ 



JOHN LYON RICH 



Cornell University, Ithaca, N.Y. 



Introduction. — The purpose of this paper is the description of 

 a series of peculiar, gravel-capped plateaus in the southwestern 

 part of Wyoming, and an attempt to decipher, in so far as the 

 evidence will permit, the physiographic history of the region both 

 before and after the deposition of the gravels. It will be shown 

 that a study of the physiography leads to some interesting and 

 suggestive conclusions as to past changes in the geography of the 

 region described, which on the whole agree remarkably well in 

 broader features with certain conclusions which have been reached 

 from other lines of approach. 



Geologists are recently beginning to recognize more clearly 

 than ever before the importance of climatic conditions in deter- 

 mining the nature of the geologic processes at any given time, 

 and in determining the nature of the deposits formed as a result 

 of these processes.^ At the same time they are beginning to reason 

 back from the character of a deposit to the causes which are 

 responsible for its distinctive features; to the climatic and other 

 conditions under which the deposit was made. It is one of the 

 purposes of this paper to call particular attention to this line of 

 study by attempting to show from physiographic evidences that 

 there have been in comparatively recent geological times a series 

 of marked climatic changes affecting the region under discussion. 



1 Published by permission of the Director of the U.S. Geological Survey. The 

 writer is indebted to Dr. Alfred R. Schultz for information in regard to conditions 

 on Little Mountain, for certain of the accompanying photographs, and for helpful 

 discussions in field and office; also to Professor A. C. Gill for a reading and criticism 

 of the manuscript. 



2 Joseph Barrell, "Climate and Terrestrial Deposits," Jour, of Geol., XVI; Ells- 

 worth Huntington, "The Glacial Period in Non-glaciated Regions," Bull. Geol. Soc. 

 Am., XVIII, 351-88; Chamberlin and Sahsbury, Text Book of Geology. Ill, 305-7, 



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