58 J. J. STEVENSON CARBONIFEROUS OF APPALACHIAN BASIN 



sandy shale. Farther south, in German township, the interval is only 

 104 feet and the top part of the Pittsburg is represented by 8 feet of 

 black shale, with 2 inches of coal in the lower part at 8 feet above the 

 roof division. There also the Waynesburg coal is 103 feet above the 

 Unionto^vn and 42 feet above the Waynesburg limestone. The Waynes- 

 burg coal bed, in numerous layers, is 7 feet 2 inches thick, but the Little 

 Waynesburg and the Uniontown are thin, only 30 inches each. Still 

 farther south the Sewickley sandstone decreases and the interval be- 

 tween Upper Sewickley coal bed and the Fishpot limestone diminishes, 

 until near the last exposure the coal and limestone are almost in con- 

 tact, the former at only 64 feet above the Pittsburg. There one is on 

 the extreme eastern edge of the basin, practically on top of the fold. 

 The Sewickley and Bedstone coal beds are 5 and 4 feet respectively, the 

 latter separated from the Pittsburg by 25 feet of sandstone; but the 

 Fishpot limestone is still important, being 10 feet thick. 



On the opposite side of the Monongahela, in Greene county, one is 

 on the west side of the basin and there is less variation in the section. 

 At about 12 miles north from the West Virginia line the Waynesburg 

 is 90 to 95 feet above the Uniontown, which is double, its benches 

 separated by 10 feet of sandstone. The Benwood limestone, resting on 

 the Upper Sewickley, is 76 feet thick and separated by 30 feet of sand- 

 stone from the Uniontown limestone above. The Sewickley sandstone 

 is 40 feet thick and the Waynesbu^rg coal bed is 370 feet above the Pitts- 

 burg. Southward the section changes little, except that the Benwood 

 limestone becomes thinner, its lower portion is replaced by sandstone, 

 and the interval from Upper Sewickley to the Fishpot diminishes. The 

 Eedstone coal bed, 36 to 54 feet above the Pittsburg, is almost invariably 

 accompanied by its limestone. The interval between Waynesburg and 

 Pittsburg is 390 feet at the last complete exposure near the West Vir- 

 ginia line.* 



The Waijnesburg basin. — In this basin, between the Wa5Tiesburg and 

 Bradys Bend (Washington) anticlines, detached areas remain in Alle- 

 gheny county north from the Monongahela river, but beyond that stream 

 the area is continuous southwestwardly into West Virginia. 



In southern Plum township of Allegheny, about 10 miles west from 

 the most northerly bore-hole in Westmoreland county, the hills rise to 

 nearly 200 feet above the Pittsburg coal bed, but show nothing, aside 

 from shales and sandstones, except a limestone, 8 to 10 feet thick and 

 70 feet above the coal. This may be some portion of the Benwood. Four 



* J. J. Stevenson: Greene and Washington (K), pp. 92, 94, 97, 98, 116, 118, 123, 

 134, 135; (K 2), pp. 204, 207, 208, 209, 210, 213, 215, 216, 233, 238, 239, 240, 241, 250. 



