OUTCROPS IN TENNESSEE 71 



upper contains only 155 feet of limestone in nine beds, all of them im- 

 pure and many of them apparently approaching calcareous shale. Of 

 the rest, 81 feet are described as calcareous shales or calcareous sand- 

 stones. The important sand deposits are at about 90 feet from the top. 

 It is evident that in this direction the mass is not only thinner, but less 

 calcareous than in the Brushy Mountain region. The lower division is 

 described as " heavy blue limestone, becoming cherty toward base."* 

 This must be kept in mind during the study of the Bangor limestone 

 farther south. At Pennington gap, in Lee county, Stevenson estimated 

 tlie lower part of the Pennington shales at 350 feet and the limestone at 

 765 feet. The characteristics of the several portions resemble those 

 given by Mr Campbell. Heavy sandstones are at the bottom of the 

 shales, and the lower part of the Newman is a massive limestone. The 

 conditions suggest that the lower part of the New River section has dis- 

 appeared in the shales, and that there remains here only the Hinton of 

 Campbell, the upper and middle portions of Fontaine's grouping. 



Eastern outcrops in Tennessee. — The Brushy Mountain strip of New- 

 man (Greenbrier) limestone extends into Tennessee not more than 

 15 miles, as the Saltville fault loses strength. The thickness remains 

 about the same as in Virginia, 1,500 feet, but, excepting 100 feet of mas- 

 sive limestone at the bottom, it consists of shales and shaly limestones. 

 Farther westward, in Claiborne county, along the face of the Cumberland 

 plateau, it has 700 feet of solid limestone, strangely in contrast with the 

 condition in Lee and Wise counties of Virginia along the same line. 



A petty area like thos.e of Wythe and Montgomery counties of Vir- 

 ginia remains in Blount county on the Chilhowie mountains, not more, 

 according to Safiford's map, than 15 miles from the pre-Cambrian rocks. 

 There the thickness of the Newman is about 600 feet, with limestone at 

 the bottom, rich in fossils, but the greater portion above consisting of 

 shales carrying a little limestone. The thickness increases somewhat 

 northwestwardly, so as to become 700 feet, with the lower portion con- 

 taining much chert. Along the face of the Cumberland plateau the 

 condition observed in Claiborne county continues southwestwardl}^ 

 through Campbell and Anderson, the Newman limestone varying from 

 600 to 700 feet, mostly limestone, and with few beds of shale. Near 

 Big Spring gap it shows 130 feet of cherty limestone at the bottom, which 

 is not equally conspicuous elsewhere. The Pennington shale, like the 

 Newman limestone, increases southwardly, and varies from 160 to 400 

 feet; but the whole series decreases westwardly, for in Morgan county 



*M. R. Campbell : Geology of Big Stone Gap coal field. Bull. U. S. Geol. Surve\^ no. Ill, 1893, 

 p. 39. 



X— Bull. Geol. Soc. Am., Vol. 14, 1902 



