152 J. J. STEVENSON — CARBONIFEROUS OF APPALACHIAN BASIN 



boring counties of Kentucky show that the intervals above the Glade- 

 ville sandstone to the Cannel are larger there than in the Stone Gap 

 region. This decrease southwardly in the Allegheny is a foreshadowing 

 of conditions which will be observed farther north. Below the Glade- 

 ville sandstone the increase is very marked, the interval to Sharon in- 

 creasing from less than 500 to about 800 feet. The succession below the 

 Gladeville sandstone would make the first coal bed equivalent to the 

 " Kentucky 3a," and the " Elkhorn " equivalent to the "Kelly;" but 

 the interval from Gladeville to Elkhorn in the Pound Gap region is 

 much less than farther south in Kentucky. The structure of the bed, 

 its peculiar variations in thickness, the remarkable excellence of the 

 coal — all tend to ally it more closely with the Imboden. At present, 

 however, the sections have not been made across the area, and one can 

 go no farther than to recognize in the Kelly-Imboden horizon the repre- 

 sentative of the Mercer beds of Pennsylvania and Ohio, represented in 

 Kentucky by coal 3 and in some portions of the state by coals 3, 3o, 

 and 3b. 



No study of the region immediately northeast or northwest from Wise 

 county has been published ; but at about 25 miles from the Wise count}'' 

 line one reaches the extensive area studied by Mr Campbell, beginning 

 with Tazewell and Buchanan counties of Virginia and continuing thence 

 through Mercer, McDowell, Raleigh, and Fayette counties of West Vir- 

 ginia to the New river, and thence along that and the Kanawha river 

 almost to the Ohio. In much of this area, as well as between it and the 

 Kentucky line in West Virginia, one has Dr I. C. White's careful obser- 

 vations, as well as notes by Mr McCreath, some measurements by Mr 

 d'Invilliers in Wyoming and Boone counties of West Virginia, and Mr 

 Lyman's report on the Coal River region of the same state. 



The eastern edge of the coal area beyond Wise county swings abruptly 

 toward the east, the direction being but little north of east, whereas in 

 Tennessee as well as in Lee county it is somewhat north of northeast. 

 This change carries one quickly into a region where the sedimentation 

 is different in type, and the tracing of minor horizons, in the absence of 

 sections in Russell and western Tazewell of Virginia, must be somewhat 

 hypothetical. The section for Tazewell, eastern Buchanan of Virginia, 

 and western McDowell of West Virginia, as compiled from Mr Camp- 

 bell's text, is as follows : 



' Peet. Inches 



Tellowa formation : 



1. Sandstone and shale - ■ 350 



2. Coal bed 5 8 



3. Sandstone and shale 150 



