210 H. p. GUSHING UNCONFORMITY AT BASE OF BEREA GRIT 



Southward in Kentucky the Berea rapidly thins, becomes indistin- 

 guishable from the underlying Bedford, which also thins, and both dis- 

 appear before central Kentucky is reached, according to Foerste and 

 Morse.^ Either the Berea was not deposited so far south or else the de- 

 posits swerve to the east of the present erosion surface, so that their west- 

 ern edge is still under cover. 



Traced into western Pennsylvania, the Berea is found to be the equiva- 

 lent of I. C. AATiite's Corry sandstone, at least in part. Whether it in- 

 cludes more than that and comprises the Cussewago sandstone and shale 

 also, as urged by Prosser, is quite likely.' 



Xow the Corry sandstone in western Pennsylvania, notably at Corry, 

 carries a marine fauna, as White long ago sliowed. Eecently Girty has 

 published a faunal list from this formation.^ Evidently the Berea here 

 is, at least in its upper portion, a marine formation. 



Ohio Berea a xon-marine Formation 



In outcrop in Ohio certainly the entire Berea must be classed as non- 

 marine. It holds occasional fossil fishes, notably at Chagrin Falls, and 

 contains plant fragments in abundance in certain layers at many locali- 

 ties, but practically no other fossils. The plant fragments are in gen- 

 eral converted into coal, and layers with abundant plants often carry 

 clay lumps in the sand. The formation must be regarded as a continental 

 one, probably a delta deposit. 



Uplift following the Bedford 



The foregoing account enables us to picture the events which closed 

 Bedford and inaugurated Berea deposition. The Bedford is a marine 

 deposit, with the possible exception of its extreme upper portion. At its 

 close the land which lay to the north of the Bedford basin was given in- 

 creased altitude above sealevel, streams were invigorated and brought 

 down a plentiful sand supply in place of the fine muds of the Bedford. 

 The northwestern district was sufficiently far inland and of sufficient 

 altitude to enable the currents to channel deeply and efficiently. East 

 and south the sand was spread broadly over the low delta region, with 

 much minor channeling of the underlying surface, but no deep channels. 

 The sealevel was slowly rising, so that ultimately delta conditions pre- 



8 Ohio Naturalist, vol. 9, p. 516. 



7 Bull. 15, Geol. Surv. Ohio, pp. 375-377, 390-404. 



s Annals N. Y. Acad. Sci., vol. 22, p. 303. 



