680 



INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 



Still farther north the following section of the Cretaceous in southern Wyoming 

 west of Rawlins was observed by E. E. Smith ^'^^ in the Great Divide Basin coal 

 field: 



Section of Cretaceous roclcs of Great Divide Basin coalfield, Wyoming. 



a This formation is equivalent to the Niobrara and the basal shale portion of the Montana. A local name will 

 probably be applied to it. 



Regarding the formations, Smith remarks : 



The coal-bearing formations show considerable change in character from the southern to 

 the northern edge of the field. Those of the Cretaceous system thin rapidly toward the north 

 and the outcrops of the beds of the undifferentiated Tertiary become more and more narrow, 

 owing to the overlap of Wasatch conglomerate. The accompanying section [above] shows the 

 thickness and general characteristics of the coal-bearing formations near the Unioji Pacific 

 Railroad and in the gap between Whisky Peak and the Ferris Mountains. 



