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 Lingule and Discine. 
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 80 feet. In the Amherst quarries the upper 
