70 J. J. STEVENSON — LOWER CARBOXIFEROUS, APPALACHIAN BASIN 



the Hinton formation includes the upper and middle portion of Fon- 

 taine's .Umbral shales. 



Beyond New river, in Summers and Mercer counties, Mr Campbell 

 finds the Hinton about 1,200 feet, very largely red shales, resting on the 

 Bluefield, 1,200 feet thick, mostly blue shale and very calcareous at the 

 bottom. The latter must be the equivalent of Fontaine's lower division, 

 and the whole is equivalent to the Pennington shale of Campbell, in 

 Scott count}^ of Virginia. Above the Hinton is a mass of sediment, 

 which Mr Campbell placed at one time in the Mississippian, but in the 

 paper just quoted it is transferred to the Pottsville.* There is substan- 

 tial agreement respecting the thickness of the Hinton formation, Fontaine 

 making it 1,130 feet on the Chesapeake and Ohio railroad, where Camp- 

 bell finds 1,050 to 1,100 feet. Stevenson gives for southern Summers 

 973 feet down to the top of the great sandstone at Hinton, while Camp- 

 bell gives as the average of the Hinton for Summers and Mercer about 

 1,200 feet. The especial difficulty is in the extraordinar}^ thickening of 

 the lower portion of the Fontaine section, the Bluefield of Campbell, an 

 increase of 400 per cent within a few miles from New river. The Green- 

 brier limestone, in northeast Tazewell, adjoining Mercer, is given by 

 Campbell as about 1,200 feet, but it decreases westwardl}^ so as to be 

 only 900 feet in the western portion of that county, where the lower beds 

 are very cherty. Northeast Tazewell is barely 25 miles north from the 

 Little Walker locality, in Wythe, where only the lowest part of the lime- 

 stone remains. 



The weakening of the faults in west-southwest direction soon cuts off 

 the narrow strips observed in Tazewell and Scott counties, and the next 

 exposures are found in Wise and Lee counties of Virginia, the latter on 

 the Tennessee border, along the edge of the Cumberland plateau. It 

 will be remembered that Mr Campbell estimated the thickness of the 

 Newman limestone in Brushy mountain near the Tennessee line at not 

 less than 1,500 feet. This is in Scott county. Barely 25 miles north- 

 west one comes to Big Stone gap, in Wise county, where Mr Campbell 

 finds"829 feet of Newman limestone and 1,025 feet of Pennington shale. 

 The latter is shown at 10 or 15 miles farther northwest, in Hurricane 

 gap, through Pine mountain, in Kentucky, with a thickness of 890 feet.f 

 The Pennington consists of shales, sandstones, and a few thin limestones, 

 one of which, near the middle, is fossiliferous. There is a similar bed 

 at this horizon in the Hinton. The lower third consists almost wholly 

 of sandstone. The limestone section as given by Mr Campbell is sep- 

 arable into an upper division of 451 feet and a lower of 378 feet. The 



*M. R. Campbell : U. S. Geol. Survey, Pocahontas folio, 1890; Tazewell folio, 1897. 

 t Professor Crandall, of the Kentucky Geological Survey, represents the Pottsville as in contact 

 with the limestones in Hurricane gap. 



