218 DESCRIPTIVE GEOLOGY. 



obtained from the Western or Bridger Basin ; but as a group they have 

 certain specific differences, which seem to favor the idea that the Washakie 

 Basin may have been isolated from the former. 



As on the northwest, so to the south, the connection of these beds with 

 the underlying Green River beds is broken by a broad gap covered by surface 

 accumulations, in which no outcrops are found. The strata are practically 

 horizontal throughout the basin, but at the southern extremity of the line of 

 bluffs, near the Cherokee trail, some underlying beds of chalky, brittle, 

 calcareous shales were found dipping 7° to the northward; whether these be- 

 longed to the Bridger or Green River group it was impossible to determine ; 

 their angle is greater than any observed elsewhere in the Bridger group, and 

 yet, lithologically, they do not resemble any of the Green River beds 

 observed by us. 



The line of elevation of the Cherokee Ridge, so called from the old 

 Cherokee trail, which follows its summit for a considerable distance, marks 

 a comparatively sharp fold in the beds of the Green River series, which has 

 doubtless been accompanied with considerable faulting. The movement 

 which produced this fold would seem to have been continued since the 

 deposition of the Bridger beds, as indicated by the angle of 7° at the south- 

 ern edge of this basin already mentioned, if these beds really belong to the 

 Bridger series The Cherokee Ridge is made up of drab thin-bedded 

 sandstones, interstratified with buff calcareous sandstones, containing rough 

 casts of Goniohasis, which pass into a semicrystalline, whitish-brown lime- 

 stone. The ridge forms an anticlinal, whose axis has an east and west direc- 

 tion, and descends to the westward. On the southern slopes, the beds are 

 very much broken, and present irregular dips as high as 25° to 30°, while 

 on the north the average dip is about 10° to the northward. At the eastern 

 end of the ridge, near Otter Gap, the underlying reddish clayey beds of 

 the Vermillion series are exposed in the deeper cuts. From Otter Gap to 

 Washakie Mountain, the higher ridges are covered by the arenaceous and 

 calcareous beds of the Green River series, dipping westward, while in the 

 deeper ravines, and on the eastern slopes toward the Little Muddy, the red 

 sands and clays of the Vermillion Creek series give their characteristic color 

 to the country. 



