88 GEOLOGY OF OHIO. 



Waverly sandstone in the southern part of the State. It also becomes 

 more arenaceous in Ashland, Richland, and Knox counties, being there 

 represented by a fine-grained, yellow, ocherey rock, half way between a 

 sandstone and shale. In the northern and eastern portions of the State 

 the base of the Cuyahoga shale is formed by a fine, thinly laminated, 

 dark gray, sometimes black, clay shale, full of Lingulse and Discinse. 

 This bed is exposed at a great number of localities, of which Berea and 

 Chagrin Falls, in Cuyahoga, and Warren, in Trumbull county, may be 

 cited as examples. At all these places this stratum rests directly upon 

 the next succeeding member of the series, the Berea grit, is crowded with 

 its characteristic mollusks, and with the bones, teeth, scales, and spines 

 of fishes. 



In the gorge of the Cuyahoga, the Cuyahoga shales contain but few 

 fossils; but at Richfield, Royalton, Weymouth, Medina, Seville, and Lodi, 

 in Medina county, and at Ashland, it includes strata which are not only 

 crowded with fossils, but are literally made up of shells. As is usual in 

 cases where clay shales contain layers which are specially fossiliferous, 

 the carbonate of lime from the shells of the mollusks has formed strata 

 of limestone of greater or less thickness, and the most fossiliferous beds 

 in the localities I have cited are generally quite calcareous, though never 

 pure limestones. In the weathering of these beds — which are usually 

 only a few inches in thickness — the limestone is dissolved out, and their 

 exposed edges appear as brown, ferruginous layers, sometimes ocherey, 

 and at other times compact limonite, every where filled with the impres- 

 sions of mollusks. 



2. Berea Grit. — The second member of the Lower Carboniferous series 

 in Ohio is a distinctly marked and very persistent bed, or series of beds, 

 of sandstone, which I have designated as the Berea grit, from the fact 

 that it is the rock so extensively quarried at Berea, Cuyahoga county. 

 This is also the rock quarried at Amherst, at Elyria, at Independence, at 

 Peninsula, at Stewart's quarries near Cleveland, at Chagrin Falls, at 

 Thompson, Geauga county, at Windsor, Ashtabula county, and at Ver- 

 non and Kinsman, Trumbull county. This stratum has acquired some 

 notoriety from the fact that it is the rock penetrated by the oil wells in 

 Grafton, Lorain county; Liverpool, Medina county; and Mecca, in Trum- 

 bull county; all of which have yielded considerable quantities of petro- 

 leum. 



The Berea grit is usually divisible into two distinct portions : the upper, 

 a series of thin beds, used for flagging; the lower, more massive, and quar- 

 ried for building stone. At Berea the upper member has a thickness 

 of about 20, the lower of 30 feet. In the Amherst quarries the upper 



