W, A. Verwiebe — Berea Formation. 45 



also created by M. C. Read in his report for Ashtabula and 

 Trumbull counties.* On the map accompanying this report 

 the Berea is shown as splitting into two parts near the Penn- 

 sylvania line. Neither of these, however, represented the true 

 Berea; the upper one being the Shenango sandstone and the 

 lower the Sharpsville sandstone (Warren sandstone of Clash- 

 ing). As a result of this, no doubt, White at first correlated 

 the Sharpsville with the Berea. f Later White reached the 

 conclusion : " It certainly looks as if . . . the Berea grit of Ohio 

 and my Oil Lake group in Crawford and Erie counties 

 occupied the same horizon.";}: 



About twelve years later, Edward Orton, in a summary of 

 the geological formations of Ohio, says that " his (White's) 

 Corry sandstone appears to be none other than the Berea 

 grit."§ George H. Girty states (1905) that in his opinion 

 " The Berea grit of Ohio is White's Cussewago sandstone, 

 together with probably the Cussewago flags and Corry sand- 

 stone,"!! though four years earlier he was inclined to limit its 

 equivalence to the Cussewago sandstone only. If Other in- 

 vestigators, including notably Stevenson** and dishing, ff 

 regarded only the upper part of White's Oil Lake group 

 (Corry) as the equivalent of the Berea in Pennsylvania. 



Thus it develops that considerable difference of opinion 

 existed in regard to the correlation of the Berea in Ohio and 

 Pennsylvania; due, no doubt, to the fact that the conclusions 

 were largely based on the literature, instead of precise and 

 careful field-work. Consequently, the credit for solving this 

 perplexing problem should go to Dr. Prosser, who first pre- 

 sented convincing evidence, based on numerous detailed sec- 

 tions. His conclusion on this point is stated as follows : " It 

 is evident from the description of sections in this bulletin, 

 extending from Cuyahoga Co., Ohio, into Crawford Co., Pa., 

 that Dr. White was perfectly correct if he intended to cor- 

 relate the Oil Lake group of Pennsylvania with the Berea 

 formation of Ohio."^ 



In Pennsylvania the Berea has been studied in Crawford and 

 Erie counties by I. C. White,§§ and along the Allegheny River 

 by Chas. Butts. ||| 



* Geol. Survey of Ohio, vol. i, pp. 483 and 505-508. 



+ Pa. 2d Geol. Survey, Q3, p. 124, 1881. See also Prosser. C. S , Devo- 

 nian and Mississippian : Geol. Survey of Ohio, Bull. 15, p. 355 ff. for a dis- 

 cussion of this. 



JPenn. 2d Geol. Survey, vol. 04, p. 91, 1881. 



SGeol. Survey of Ohio, vol. vii. p. 33, 1894. 



||Proc. Wash. Acad. Sci.. vol. vii, p. 6, 1905. 



IT Science, N. S., vol. xiii, p. 664, 1901. 



**Bull. Geol. Soc. Amer., vol. xiv, p. 41, 1903. 



f+ Proc. Amer. Ass. Adv. Sci., vol. xxxvi, p. 215, 1888. 



tJGeol. Survey of Ohio, Bull. 15, p. 394, 1912. 



§S Pa. 2d Geol. Survey, Q4, 1881. 



11 Rept. Topog. and Geol. Survey Coram, for 1906-08, p. 190. 



