STEVEXSOX— INTERRELATIONS OF FOSSIL FUELS. 97 



feet in one mine near Bowie but 21 in another and 22 near Somerset ; 

 while at another locahty, no trace of it could be found. At the 

 Johnson prospect, on Minnesota creek, east from Paonia, 9 coal 

 seams, 2 to 8 feet thick and with total thickness of 43 feet, were 

 seen in the lower 300 feet of the Bowie. At the Simonton prospect, 

 about 4 miles toward the south, the exposure shows this section, 

 beginning at 37 feet above the Rollins sandstone: coal, 2 feet, 10 

 inches; shale, 10 inches; coal, i foot, 2 inches; shale, 5 inches; coal, 

 13 feet, I inch; shale, 6 feet; coal, 16 feet; bony coal, 2 feet; coal, 

 7 feet, 2 inches ; in all 49 feet, 6 inches. 



The presence of this great mass is perplexing. One cannot trace 

 the section from the Johnson prospect and Lee concludes that the 

 Simonton seam is due to the coalescence of 7 seams of the Johnson 

 section, or that it is a merely local deposit. The Bowie becomes 

 irregular in districts farther east, sometimes present, sometimes 

 absent, and the coals are extremely variable in thickness and quality. 



Lee's notes show that mineral charcoal is present in most of the 

 coals. Toward the Elk ^lountains, the region is greatly disturbed 

 by plication and by eruptive rocks ; the coal is from subbituminous 

 to hard dry anthracite. The seams are thicker on anticlines than in 

 synclines. In some localities, the stream channels, due to con- 

 temporaneous erosion, have been filled with white sandstone. 



On the northwestern side of the Uinta Basin, there is a mass of 

 deposits, o to 3,300 feet thick, which Lupton'- places in the Mesa- 

 verde — the variation in thickness being due to erosion prior to dep- 

 osition of the Wasatch beds. The lower half in this Blacktail 

 Mountain coal field is marine, without coal and is mostly sandstone 

 with sandy shale and some limestones. The upper half, apparently 

 fresh-water, has coal with sandstones, thin-bedded and cross-bedded, 

 as well as much sandy shale. This upper division has 21 coal seams 

 in 1,500 feet, 7 inches to 15 feet thick. One seam has a maximum 

 thickness of 21 feet with only a single parting, 2 inches. The coal 

 is resinous at some places. 



Gale'^^ has given some notes respecting the northern outcrop. 

 He reports the Lewis shale as about 1,000 feet thick and without 



'- C. T. Lupton, Bull. 471-/, 1912, pp. 27, 32, 33, 39, 41. 



'3 H. S. Gale, Bull. 341, 1909, pp. 287, 289, 290, 299; Bull. 316, 1907, p. 273. 



