THE MERCER LIMESTONE AND ITS ASSOCIATED 

 ROCKS IN THE NEWARK-ZANESVILLE REGION' 



Clara Gould Mark 



CONDENSED HISTORICAL REVIEW 



The Potts ville formation in Ohio consists of the following mem- 

 bers, as given b,v Dr. Orton in the Geological Survey of Ohio, vol. 

 vii, 1893, p. 36: 



' ' Conglomerate group 

 Homewood sandstone 

 (Tionesta Coal) 

 Upper Mercer Group 



Ore 



Limestone 



Coal, No. 3a, Newberry 

 Lower Mercer Group 



Ore 



Limestone 



Coal, No. 3, Newberry 



Massillon sandstone, upper 



(Quakertown Coal), Coal No. 2, Newberry 



Massillon sandstone, lower 



Sharon Coal-Coal No. 1, Newberry 



Sharon Conglomerate." 



The limestone of the Lower Mercer Group is usually referred to 

 as the Mercer limestone, the name having been first applied to 

 it in 1858 by H. D. Rogers from its exposures in Mercer County, 

 Pennsylvania {Geology of Pennsylvania, vol. ii, pt. 1, 1858, p. 

 476). The occurrence of this limestone in Ohio was mentioned 



1 This paper is part of a thesis presented for the degree of Master of Arts in the 

 Ohio State University. The work was done under the direction of Dr. Charles 

 S. Prosser to whom I am greatly indebted for his kind assistance and advice. 



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