STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 115 



years ago, Gilbert discovered in Washington County a mass of shale 

 about 635 feet thick, including at base a coal group, somewhat more 

 than 130 feet thick, with 5 seams, 4 inches to 4 feet thick. Howell, 

 in Park County, next east, found two coal groups, separated by 

 500 feet of barren measures, containing Benton fossils. The lower 

 coal group is capped by an oyster bed i to 5 feet thick. Thirty- 

 five years later, Richardson examined some small fields in Washing- 

 ton, Kane and Iron Counties.^"" The coal seams are from 50 to 500 

 feet above the assumed base of the Cretaceous and they are lenses. 

 Ordinarily only one workable bed appears in a section but in some 

 cases there are as many as six. In the Harmony field, only 600 

 feet of Cretaceous remain, containing 6 seams of coal and shale, 7, 

 II, 6, II, 17 and 6 feet respectively, with 4, 5, 4, 7 and 4 feet of 

 coal. At best this coal is very poor, two air-dried samples having 

 22.89 ^"d 33.96 per cent, of ash. The seams are similarly lenticular 

 in the Colob field. In this field on the North Fork of Virgin River, 

 Richardson saw, at about 100 feet above the basal conglomerate, a 

 coal seam with this structure : carbonaceous shale with fossils ; 

 bituminous coal. 2 feet 5 inches ; cannel, 5 feet 6 inches. This seam 

 disappeared quickly toward the north, east and southeast ; but a 

 similar seam was found at 10 or 12 miles toward the southeast. The 

 cannel at these localities is brownish black with dull greasy luster. 

 The violatile is very high and the hydrogen in dried coal is prac- 

 tically tw^ice as much as that in the ordinary coals. D. White ex- 

 amined it under the microscope and ascertained that its structure 

 and composition are essentially those of high-grade cannel. The 

 Colob coals are better than those of the Harmony field and have 

 from 10 to 15 per cent, of ash. They vary from low grade bitumi- 

 nous to subbituminous. In many cases a coal seam overlies or 

 underlies fossiliferous limestone. 



Lee examined a small field in Iron County, north from Washing- 

 ton, where he measured a section of 1,200 feet in which sandstone 

 predominates. The coal seams are in a group of shales and thin 

 limestones, about 150 feet thick, beginning at nearly 800 feet from 

 the basal conglomerate. The fossils are of Benton age. One coal 



107 G. K. Gilbert, U. S. Geog. Explor., etc.. Vol. III., pp. 158, 159; E. E. 

 Howell, the same, p. 271; G. B. Richardson, Bull. 341, pp. 379-400. 



