GEOLOGY OF THE LARAMIE PLAINS 



Hills is quite ferruginous and nearby the Platte River cuts 

 through nearly horizontal beds o( Fox Hills. 



The Fox Hills sandstones imperceptibly pass into the Lara- 

 mie above, which is largely of sandstone but contains more 

 clay and frequent carbonaceous shales. 



East of the Rocky Mountains, the Fox Hills contains one 

 coal bed near its eastern limit. On Cooper and Rock Creek 

 are several coal seams. At Coalville, the workable coal is 

 Fox Hills. The upper limit of the Fox Hills is known by the 

 cessation of true Pelagic forms. 



King says: "From the west, eastwardly, the Cretaceous 

 series rests with absolute conformity upon the Jura." 



At the Dutton coal bank the coal is overlaid by a very 

 friable, somewhat carbonaceous shale, full of dicotyledonous 

 leaves. This is again overlaid by a soft yellowish brown sand- 

 stone with fossil leaves in the lower beds. I did not have 

 an opportunity of examining the Laramie beds at any other 

 place. 



Lesquereux divided the Laramie into three sub groups. 



1st — Bitter Creek, or lower group, flora Eocene. 



2d — Evanston, or second group, flora Miocene. 



3d — Carbon, the third group, upper Middle Miocene. 

 Dinosaurs have been reported from the uppermost Laramie. 



All the various geologists, who have spoken of the Laramie 

 group, assign its position at the top of the Cretaceous, with the 

 exception of Hayden and Lesquereux. They consider it to 

 be basal Tertiary, considered so by Lesquereux on account of 

 the fossil plants found therein. 



In Wyoming and on the plains east of the Rocky Moun- 

 tains and south of the 41st parallel, the Laramie rests conform- 

 ably upon the Fox Hills Cretaceous. 



