154 J. J. STEVENSON — CARBONIFEROUS OF APPALACHIAN BASIN 



stones are not coarse. The contrast is even more noteworthy below the 

 Pottsville, for in Wise county the Shenango (Pennington) shales are at 

 most 1,300 feet, whereas in eastern Russell and in Tazewell they are 

 represented by more than 3,000 feet of fine sediment. 



Mr Campbell offers a somewhat different grouping farther east, which 

 should be noted here, that comparisons may be made the more easily : 



Sewell formation. 

 Raleigh sandstone. 

 Quinnimont formation. 

 Clark formation. 

 Pocahontas formation. 



The Sewell formation includes the Dotson, Bearwallow, and Dismal; 

 the Quinnimont and Clark are subdivisions of the Welch, the line being 

 drawn under the " Upper Horsepen " coal bed, which on New river has 

 long been known, as the "Quinnimont" coal bed. The " Clark " is 

 bounded by two well marked sandstones, numbers 21 and 27. The 

 higher formations, Sequoyah and Tellowa, belong to the Kanawha for- 

 mation of counties farther north. 



The Tellowa and Sequoyah extend eastward only into northern Buch- 

 anan and western McDowell, and the important coal bed of the former 

 is mined in northwestern McDowell. It is at somewhat more than 600 

 feet above the Dotson (Sharon) sandstone, and evidently represents the 

 Kelly-Imboden horizon. Only the Dismal or lower part of the Sewell 

 extends eastward beyond the central line of McDowell ; the formation 

 covers the higher areas in eastern Buchanan, western McDowell, north- 

 ern Russell, and western Tazewell. Its lower coal bed, the Sewell of 

 more northern localities, the Sewanee of Tennessee, has been opened at 

 many places. The Raleigh sandstone varies from 80 to 100 feet ; though 

 retaining its thickness and identit}^, it becomes shaly sandstone west 

 from the line of central McDowell and Tazewell, but eastwardly it be- 

 comes coarser and occasionally conglomerate. It forms the escarpment 

 of the high hills in eastern McDowell and Wyoming counties known as 

 Flat Top, where it is about 80 feet thick, massive, and coarse. 



The Horsepen group of coals, numbers 20, 22, 24, and 26, belong, with 

 the exception of the Upper, to the Clark formation, and attain their 

 maximum near the line between Tazewell of Virginia and McDowell of 

 West Virginia. The " Pocahontas " coal bed has been traced along the 

 easterly outcrop in Tazewell and Mercer counties by means of openings 

 for the Flat Top Land Association. It is from 4 to 12 feet thick and 

 everywhere yields a coal of remarkable purity. 



