146 J. J. STEVENSON — CARBONIFEROUS OF APPALACHIAN BASIN 



is shown at about 190 feet above the Coal Creek (Sewanee) coal bed, or 

 20 feet above Bradley's u Coal G," while at 235 feet higher, about' 480 

 feet above the Coal Creek, is a great sandstone, 75 to 100 feet thick. 

 This is about 50 feet above Bradley's " Coal I " and 560 feet above the 

 Bonair conglomerate, a decided increase of thickness of measures toward 

 the east, for at Rugby road, 12 or 15 miles west, the interval between 

 Bonair and Rockcastle is about 350 feet. The lower sandstone is evi- 

 dently that between the Sewanee coal bed and the Rockcastle, which is 

 persistent in all the sections. At 370 feet above this great sandstone, 

 taken to be the Rockcastle, is another, 60 to 90 feet, which is in the 

 place of the Corbin, the top of the Rockcastle formation of Crandall, the 

 Lee formation of Campbell's Kentucky folios, while at approximately 

 800 feet higher is a massive sandstone, 100 feet thick, capping the peaks 

 in Safford's area and evidently almost immediately underlying k ' Coal 

 P " of Bradley's section. At about 250 feet below it in Safford's section 

 is a bed of fine coking coal, 6 feet thick and divided by a 6-inch cla}^ 

 parting. This is Bradley's " Coal O," which in his section is 300 feet 

 below " Coal P." 



The intervals observed at Coal creek, Harriman, and Dayton may be 



compared. 



I II III 



Feet. Feet. Inches. Feet. Feet 



Coal bed 4 16 



Interval 230 193 



Corbin 60 to 90 193 75 



Interval.... 370 320 334 



Rockcastle 75 to 100 50 to 70 70 



Interval 235 180 to 200 121 



Sandstone 50 to 80 40 to 45 25 



Interval 190 117 75 



Sewanee coal bed 



The interval from Sewanee to Rockcastle shows constant increase in 

 northeastward direction, but that from the Rockcastle to the Corbin is 

 practically uniform throughout, and that between the Rockcastle and 

 the coal bed at the top shows no change between Harriman and Coal 

 creek. The section below the Sewanee coal bed shows a similar increase 

 northeastwardly. The Bonair and. lower rocks are not more than 800 

 feet at Harriman. The thickness at Oliver springs, according to Mr 

 Keith, is about 900 feet, but at Coal creek it is 1,100 to 1,200 feet. 



This grouping of the measures is of interest not only as showing the 

 relation to the Kentucky coal field, but also as binding the Tennessee 

 work to the detailed studies of Mr Campbell in southwest Virginia. The 

 great sandstone crowning Professor Safford's section is that which under- 



