STRATIGRAPHIC SUMMARY. 637 



SUPERFORMATION. 



Sharon conglomerate (upper Pottsville). 

 {Hiatus and dis conformity.) 



Upper Mississippic. 



Shenango shale 50 ft. 



{Hiatus and dis conformity.) 



Lower Mississippic. 



Meadville shales and limestones 66 ft. 



Sharpsville shales and limestones 65 ft. 



Orangeville shales 75 ft. 



Corry sandstone 20 ft. 



Cussewango shale 62 ft. 



SUBFORMATION. 



Upper Devonic (Chemung) shales. 



The Corry sandstone is commonly correlated with the Berea of 

 Ohio. 



Further east, in the Appalachians of Pennsylvania, the entire 

 series is represented by continental deposits. These comprise the 

 Pocono sandstone and conglomerates and the Mauch Chunk red 

 shale, the latter probably equivalent to middle and upper Missis- 

 sippic time, the former to lower Mississippic. The Mauch Chunk 

 includes southward, in Pennsylvania and Virginia, the Greenbrier 

 limestone, the fauna of which is in part, upper Mississippic. 



In southern Virginia, and West Virginia, the series is more 

 strongly calcareous ; the following subdivisions are recognized :^^ 



SUPERFORMATION. 



Pottsville conglomerate (Pocahontas beds). 

 Upper and Middle Mississippic (dividing line doubtful). 



Bluestone formation (shales, sand- 

 stones and conglomerates) 800 ft. 



Princeton conglomerate 40 ft. 



Hinton formation (shales, sand- 

 stones and limestones) 1,250-1,300 ft. 



Bluefield shale (siliceous and cal- 

 careous shales) 1,250-1,350 ft. 



^" Pocahontas Folio. 



