TERTIAEIES OF THE UINTA VALLEY. 307 



SECTION V. 



TERTIAEIES OF THE UINTA VALLEY. 



The examinations of the Tertiary beds of this basin have been extremely 

 cursory, being confined principally to the line of travel along the imme- 

 diate foot-hills of the range. Our party found no fossils in any of these 

 beds; but Professor Marsh and his assistants, who followed them from below 

 the mouth of the Ashley Creek, up the valley of White River, south of the 

 limits of this exploration, succeeded in securing a very valuable suite of 

 vertebrate fossils from the latter locality. 



The following are some of the principal forms collected and deter- 

 mined by him : 



Diplacodon elatus. 

 Orohippus Uintensis. 

 Orohippus gracilis. 

 Agriochcerns pumilus. 

 Diceratherium advenum. 



Although some of the forms collected have a generic resemblance to 

 those of the Bridger beds, others again have somewhat of a Miocene facies; 

 the preponderance being in favor of the former, he has regarded the whole, 

 while representing a later period than that of the Bridger beds, as probably 

 of Middle or Upper Eocene age. Although the whole area has been des- 

 ignated by the one color of the Uinta Eocene, certain considerations, which 

 will be more fully explained later, suggest the possibility that an older series 

 of beds, probably corresponding in age to the Vermillion Creek series, may 

 also have been deposited in this basin. 



The lowest Tertiary beds observed are apparently those which rest 

 unconformably on the upturned edges of the Fox Hill sandstones, on the 

 southeastern end of the Won sits Ridge. Here they dip from 8° to 10° to 

 the southwest, and consist of a coarse sandstone containing beds of coarse 

 structureless conglomerate, hardly to be distinguished from the Wyoming 

 Conglomerate, being made up of rounded pebbles of Weber Quartzite and 

 Upper Coal-Measure limestone, overlaid by several beds of coarse greenish 



