Devonian Shales of Ohio and Pennsylvania. 



47 



f 



2. The shales in Ohio should be subdivided into two parts 

 rather than three, an upper predominantly black colored divis- 

 ion and a lower predominantly light colored division. 



3. The detailed correlation of the various subdivisions in 

 Ohio and Pennsylvania with those of New York is as follows : 



Ohio 

 northcentral northeast 



Pennsylvania New York 



northwest westcentral western 



Bedford 



Bedford 



Riceville 

 Venango 



(Riceville) 



Knapp 

 Conewango 



j Oswayo 



> 



■QplawarP i Hamilton (lower) 

 JJelaware -^ j^^j.^^llus 



W 



(Riceville) ^ ^ 

 Knapp ! ^ 



\ Cattaragus J Bt 



Huron (upper) 



Cleveland 



Chemung (upper)* 



Huron (lower) ^ 

 Prout V 

 Olentangy ) 



Chagrin 



( Chemung (lower) 



} Portage 



( Hamilton (upper) 



Index to Sections Used in Figures. 



The following were taken from Bull. 15 of the Geol. Survey 

 of Ohio (C. S. Prosser) :-No. 1— p. 30 ; 2— p. 54 ; 3— p. 

 185; 4— p. 242; 5— p. 300; 6— p. 316; section F.— p. 413. 

 The following from vol. vi, Geol. Surv. Ohio, 1888 (Edw. 

 Orton) A— p. 441; B— p. 348; C— p. 367. Section D by 

 courtesy of J. A. Bownocker. Section E by courtesy of Frank 

 Mossinger. 



* It is probable that the Chemung of western New York includes some of 

 the Bradf ordian also. 



