114 .T.J.STEVENSON CARBONIFEROUS OF APPALACHIAN BASIN 



shale underlying the Jellico, as in Pike county, where they are found 

 occasionally in shales underlying the Elkhorn * 



TENNESSEE 



Passing over into Tennessee, along the western border, one has the 

 following succession : 



Corbin sandstone, 



Shales, 



Rockcastle sandstone, 



Shales, 



resting on the Lower Carboniferous. According to Mr Campbell, the 

 Rockcastle rests on the Lower Carboniferous at a little way north from 

 the Tennessee line, though eastward in Whitely county the underlying 

 shales become important and contain at least two important coal beds, 

 the " Main Cumberland " and the " Bryvan," as well as a third at the 

 bottom, which is rarely important. Above the Corbin at 50 to 70 feet is 

 the " Pittsburg or Laurel coal bed," which appears to be the equivalent 

 of the Sharon of Pennsylvania. The Corbin and the Rockcastle in Ten- 

 nessee are often conglomerate. Mr Campbell's work was carried into 

 Tennessee, so that direct linking of Kentucky studies with those of the 

 workers in Tennessee becomes comparatively simple. His notes concern 

 the western border of the Cumberland plateau in Fentress and Cumber- 

 land counties, where the Rockcastle is practical^ the highest bed of the 

 section, except near the Kentucky line, where the Corbin is seen at 100 

 feet higher. The Rockcastle, separated from the Lower Carboniferous by 

 from 150 to 300 feet of shale, loses it coarseness southward so as to become 

 merely a sandstone at somewhat more than 40 miles south from the Ken- 

 tucky line. Meanwhile a sandstone makes its appearance in the lower 

 part of the underlying shales, increasing in coarseness and importance, 

 so that where the Rockcastle ceases to be a marked feature of the topog- 

 raphy this lower conglomerate, the Bonair of Campbell, forms massive 

 cliffs at approximately 125 feet below the Rockcastle along the western 

 border. At first it rests almost directly on the Lower Carboniferous, 

 but followed southward, the interval increases until, in White county at 

 Bonair, it is 110 feet and contains mostly shales with a coal bed at the 

 bottom. Mr Campbell notes the presence of some thin coal beds between 

 the Rockcastle and the Bonair within the area studied by him, but hesi- 

 tates to make identifications with the beds observed farther south. The 

 Bonair or lowest conglomerate ceases to be an important member of the 

 section north from Monterey in Cumberland county, where a 3-foot coal 



*A. R. Crandall : Geology of Whitely County and part oi Pulaski, pp. 24, 25, 28-37, 39, 42. 



