82 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



The relations are sufficiently clear in the main portion of the 

 Green River Basin with Wyoming. In Uinta County, the basal 

 200 feet of " Laramie " with alternating marine and land deposits 

 includes among others the great Adaville-Lazeart coal seam, lo to 

 84 feet thick ; Veatch's brief summary of the coals gives no details 

 respecting the accompanying rocks. Schultz found in the Rock 

 Springs field of Sweetwater County a yellowish white sandstone at 

 base of the " Laramie," overlain by sandstones, clays and coal beds ; 

 in some places fossils abound. The basal sandstone rests on the 

 upper member of the Pierre. The coal of this Fox Hills is in- 

 ferior and is no longer mined. Smith reports that in northeastern 

 Carbon County, marine fossils are present up to 500 feet from the 

 base of the " Laramie," which, he says, is a common condition in 

 southern Wyoming and northern Colorado. Here as in other parts 

 of the basin, a great sandstone is at the base. Coal is present in 

 the Fox Hills, but the beds are unimportant, the thickest being only 

 18 inches. Veatch^° separates the beds with marine fossils in east 

 central Carbon from the Laramie and places the great white sand- 

 stone with its overlying beds in the Pierre. No occurrence of coal 

 is noted. Ball and Stebinger in southern Carbon place the sand- 

 stone and the overlying beds in the Laramie, but state that marine 

 fossils have been up to 400 feet above the sandstone. They give 

 no details respecting the character of the beds and apparently they 

 saw no coal. 



The Raton-Trinidad coal field of New Mexico and Colorado is 

 at the eastern foot of the Front Ranges. The earlier students re- 

 garded the coal-bearing rocks as conformable throughout and placed 

 them in the Laramie. The numerous unconformities observed were 

 thought to be merely local variations, characterizing deposits on 

 the rudely level strand area. Lee, however, has proved that the 

 irregularities are far greater than imagined by his predecessors and 

 that a great unconformity by erosion separates the column into the 

 Raton and Vermejo formations, the former most probably of Ter- 

 tiary age. The Vermejo, resting on the Trinidad sandstone, is 

 taken by the writer to be Fox Hills but Lee is inclined to regard it 



^0 A. C. Vcatch, Bull. 285, 1906, p. 333; Bull. 316, 1907. pp. 246, 248; E. E. 

 Smith, Bull. 341, pp. 225, 228, 229; M. W. Ball and E. Stebinger, Bull. 341, pp. 

 246, 247; Bull. 381, 1910, p. 193. 



