188 GEOLOGY OF OHIO. 
Bedford Shale.—Below the Berea sandstone is a bed of shale forty to 
sixty feet in thickness, which is sometimes blue or banded in color, but 
more generally red. This red shale is conspicuously shown in the val- 
ley of the Vermilion, and is exposed at many places in this section of 
the State immediately underlying the Berea sandstone ; it may, therefore, 
serve as an important guide to those who are seeking for the excellent 
quarry stone furnished by that formation. Neither the Berea sandstone 
nor the red shale have in Erie county furnished any fossils; but at Elyria, 
Lorain county, and at Berea and Bedford, Cuyahoga county, a large num- 
ber of remains of mollusks and fishes have been taken from these strata. 
Cleveland Shale—Under the red shale in the banks of the Vermilion 
occurs a black, bituminous shale, here sixty or more feet in thickness. 
This is a constant member of the Waverly or Lower Carboniferous 
group, and forms the base of that series. It is unusually well exposed 
in the vicinity of Cleveland, and I have therefore called it, for conveni- 
ence sake, “the Cleveland shale.” In its lithological characters this 
shale is hardly to be distinguished from the great black shale (the 
Huron shale) which is a member of the Devonian system, and which 
here lies only a little below. Further east, however, they are separated 
by an interval of several hundred feet, and the fossils which they con- 
tain are widely different. In the Cleveland shale are bones, scales, and 
spines of fishes of small size and of Carboniferous types. In the Huron 
shale, on the contrary, we find the remains of fishes of enormous size, of - 
most peculiar structure, and such as clearly belong to the Old Red Sand- 
stone fauna so fully described by Hugh Miller. 
Erie Shale-—The lake shore from the Pennsylvania line to Erie county 
is, for the most part, formed by a series of green and blue shales, which 
represent the Chemung and Portage rocks of New York, and belong to 
the Devonian formation. These shales thin out rapidly westward, and 
cease to be recognizable beyond the point under consideration. In the 
valley of the Cuyahoga they are exposed to the depth of one hundred 
and forty feet, and have there yielded the most characteristic fossils of 
the Chemung. 
The upper layers of the Huron shale are interstratified with the lower 
ones of the Erie in the north-eastern portion of the State, as we learn by 
borings made at Cleveland and further east. Some traces of this inter- 
locking may be seen at Monroeville, where the well sunk at the railroad 
station cuts some blue as well as black shales. South of this point, how- 
ever, the Erie shale has not been recognized, and it probably reaches but. 
a little way back from the lake shore. | 
Huron Shale-—This is a name we have given to the great mass of black 
