10 pp. EEPOET OF PROGRESS. FONTAINE & WHITE. 



iferous Limestone and the Conglomerate Group is occu- 

 pied by sandy shales 170 feet thick. These are of a grey 

 color, and contain no red material, except one or two feet 

 of red crumbling marlite immediately in contact with the 

 limestone. 



No plants have been found in the Umbral in W. Va. 

 and no important coal beds are known to exist in it. In 

 the western part of Greenbrier Co. and near Quinnimont 

 in Fayette Co. W. Va. one, and perhaps several coal beds 

 exist near the top of the group. This portion of the State 

 is but little explored, and may yield plants. 



The Conglomerate Ch'oup. 



. This group also, where fully developed in West Virginia, 

 forms a triple series. 



The typical arrangement is as follows : At the base we 

 find a massive conglomerate, often of brownish grey color. 

 In the center, shales and flaggy sandstones, containing coal 

 beds, alternate with massive siliceous sandstones. At the 

 top we have a heavy bedded white siliceous sandstone, 

 with many conglomerate layers. 



The upper bed is the most persistent of the series, and 

 forms the floor of Coal Measures of West Virginia. 



The Conglomerate, like the groups above described, varies 

 much in thickness and composition. This is especially true 

 of the middle and lower members. The middle, or coal- 

 bearing member, often thins out so as to bring the upper 

 and lower members close to each other, and then, the coal 

 is almost, or quite, cut out. The lower member is often 

 wanting, as in East Tennessee, and possibly in Alabama. 



The character of the strata, and of the coal beds, indi- 

 cates rather rapid subsidence, and frequent sudden changes 

 ' in the conditions of deposition. As a consequence we find 

 the coal beds varying rapidly in thickness, even when 

 workable, but usually too thin to be of much' value. The 

 variable character of the beds underlying the upper mem- 

 ber causes them to contrast strongly with the more uni- 

 form strata found above it, which constitute that portion 

 of the Carboniferous Formation commonly called "The 

 Productive Coal Measures." 



