CHAPTER IX. 



STRATIGRAPHY THE POTTSVILLE SERIES. 



GENERAL DESCRIPTION AND SECTION. 



The Pottsville Series, or Pottsville Conglomerate, as it 

 is often called, which is the basal member of the Pennsylva- 

 nian, named from its occurrence at Pottsville, Pennsylvania, 

 where many of the sandstone members are masses of huge 

 quartz pebbles cemented together, appears above drainage in 

 Lewis only in the extreme southern end along the waters of 

 the Little Kanawha River. Here it has not the extremely 

 pebbly character of its type locality, but the sandstones are 

 massive and form cliffs that are resistant to erosion and make 

 ragged topographic forms, a condition that prevails along 

 the outcrop of the series wherever it appears in the State. The 

 hills are high and steep and the valleys narrow and V-shaped. 

 The series consists principally of gray sandstones, separated 

 by gray sandy shales, with a few thin seams of coal inter- 

 vening. No limestones or fire clays of economic importance 

 occur. Only about 325 feet of these measures are above drain- 

 age at Cleveland, where the lower horizons are exposed. The 

 total thickness, however, is determined by a great number of 

 wells drilled for oil and gas, not only in the region where the 

 series crops, but also in all the other districts in both counties. 

 The sections published in Chapter IV show that there is a 

 gradual .thickening of these rocks from the northern 'end of 

 both counties, where they total about 400 feet, to the south- 

 ern boundaries where they are about twice as thick, being 

 845 feet at Cleveland in the extreme southeastern end of Lewis 

 and 782 feet at Rosedale, just south of the Gilmer Line. Com- 

 pared to other counties of the State, the series has a medium 

 thickness, as it is about 300 feet in Preston County at the 



