CHAPTER VII. 



STRATIGRAPHY THE CONEMAUGH SERIES. 



GENERAL DESCRIPTION AND SECTION. 



The Conemaugh Series of the Pennsylvania!! Rocks, first 

 named by Franklin Platt, in 1878, from its outcrop along the 

 Conemaugh River in Pennsylvania, includes a large portion 

 of the surface rocks of Lewis and Gilmer, as its areal limits 

 on Map II will show. The series has been described thoroughly 

 by White in a former volume of the Survey 1 and in Lewis 

 and Gilmer differs but little from that description in its gen- 

 eral features. It consists of numerous sandstone beds, usually 

 separated by red or sandy shales, and has several coal seams 

 of which two have minable thickness in some localities. It is 

 further distinguished by the presence of two distinct fossilifer- 

 ous marine limestone horizons, one of w r hich, the Ames, is one 

 of the most recent formations known to contain them in the 

 State. All of its limestone horizons are shaly and impure, 

 being unfit for any economic use. The thickness of the Cone- 

 maugh varies from 450 to 650 feet. The following general 

 section, compiled from numerous detailed sections in Chap- 

 ter IV, as well as from many local observations, shows the 

 characteristic features of the series in Lewis and Gilmer: 



General Section of the Conemaugh Series for Lewis and 

 Gilmer. 



Thickness Total 

 Feet. Feet. 



Fire clay and shale 5 5 



Sandstone, massive, gray, Lower Pittsburgh.. 40 



Shale, gray 3 



Limestone, Upper Pittsburgh, (seldom found). 1 



Coal, Little Pittsburgh 1 50 



'I. C. White, Vol. II, W. Va. G. S., pp. 225-230; 1903. 



