EARLIER TERTIARY (EOCENE AND OLIGOCENE). 



765 



K 12. NORTHEASTERN UTAH AND SOUTHWESTERN WYOMING. 



The southwest corner of Wyoming and the immediately adjacent part of 

 Utah were mapped by Veatch,^'"' who subdivided the Tertiary (all Eocene) as 

 follows : 



Eocene: Feet. 



Bridger formation 1,200-1,800 



Green River formation 2,000± 



Wasatch group : 



Knight formation 500-l,500± 



Unconformity. 



Fowkes formation 0-2,500+ 



Almy formation 2,100-2,200 



Evaneton formation ("Upper Laramie") 0-1,600+ 



Unconformity. 

 Cretaceous. 



Veatch's table, from the Jurassic to the Tertiary, inclusive, and his comments 

 regarding the division line between the Cretaceous and the Tertiary are quoted in 

 Chapter XV (pp. 676-677). For detailed descriptions of the formations see the 

 work cited. 



The sequence of Wasatch strata thus described by Veatch is correlated by 

 Osborn with the Wasatch near Black Buttes in the Washakie Basin; with the 

 Wasatch of the San Juan Basin, New Mexico (1,500 feet); with the Wasatch of 

 the Bighorn Basin, Wyoming (2,391 feet, Loomis); and with the lower portion of 

 the Huerfano formation of Colorado. 



The Bridger and Washakie basins lie in southern Wyoming on either side of 

 the Rock Springs dome. The Eocene on the western margin of the Bridger Basin 

 has been studied stratigraphically by Veatch,^^'' and the lower Eocene on the flanks 

 of the Rock Springs dome by Schultz.'^^^^ Schultz defines the a'rea and gives the 

 following section of Tertiary rocks : 



The field here considered lies along the eastern margin of the great Green River Basin and 

 includes in part, on the east, the Great Divide Basin. It lies on the north flank of the Rock 

 Springs dome, which is completely surrounded by Tertiary beds. 



********* 



Section of Tertiary rocks of Sweetwater County, Wyo. 



« Abundant collections of plants have been obtained from- the lower third of this formation and determined by F . H . 

 iwlton, who studied the collections, as undoubtedly Fort Union. 



Knowlton 



