POST-CRETACEOUS HISTORY OF WESTERN WYOMING 315 



coarse, stratified gravel deposits represent outwash from the ancient 

 glaciers rather than torrential fan deposits under the influence of 

 an epoch of desiccation. With reference to deposits now so deeply 

 weathered, I know of no criteria that could be used to decide 

 between these two modes of deposition. Whatever the origin, 

 there is a suggestive resemblance between these thick coarse gravel 

 deposits on remnants of the Black Rock plain and similar deposits 

 in other ranges of the Rocky Mountains, such as the conglomerate 



Fig. 32. — High rock-cut terrace southwest of Lander. The Carboniferous 

 strata have been planed off at the level of Table Mountain (see Fig. 30). 



of Bald Ridge on the east side of the Bighorn Range,^ the Bishop 

 conglomerate of southwestern Wyoming,^ and other well-known 

 examples. 



Between the Black Rock cycle and the next one clearly dis- 

 criminated there may well have been one or more cycles now repre- 

 sented by terraces visible here and there in the Wind River and 

 Green River bad lands. These are, however, but little known and 



' U.S. Geol. Survey, Cloud Peak-Fort McKinney Folio, No. 142. 

 ^ J. L. Rich, Jour. Geol, XVIII (1910). 



