§26 — GEOLOGY OF OHIO. 
from its great hardness, that its fragments would long withstand abra-. 
sion, and be found in greater or less abundance in the sandy or gravelly 
debris. | 
A quarry, one-half mile north-east of Ashland, exposes rock precisely 
like the stratum below the Fossiliferous limestone indicated in the sec- 
tion above. | 
Three-fourths of a mile north-east of Mifflin, on a small branch of 
Black Fork, a quarry shows the following section: 
Coarse, shaly ferruginous sandstone .............--..- pe EAN we ORI 4 
Coarse; yellow, massive: StONC a: ce nas yan rete eee ere ee rey ee er na enema 8 
Shaly sandstone, with alternate layers of argillaceous shale...........--.. 25 
On the opposite side of the stream, the section is as follows: 
Coarse, yellow, ferruginous sandstone, thin layers........-..........--e<-- 10 
Coarse;nyellonalayersiterian cer slas eee a ste cine saa ener pe yay se eran Pe haere nea 
Thin layers, at bottom, blue, alternating with argillaceous shale .......... 20 
Two miles north of Mifflin, the rcck is imperfectly stratified, massive 
in places, and colored red, somewhat like the Mansfield stone. It forms 
a steep ridge on the east side of Black Fork, the slope being covered with 
the debris of the ledge, which resembles the debris of the Sub-carbonifer- 
ous Conglomerate. At the height of forty feet, is a bench, showing the 
presence of argillaceous shales ; and another ridge beyond, rising ninety- 
five feet above the top of this coarse sandstone, has its slopes covered 
with the debris of Cuyahoga shales. 
Southward from this point, this coarse rock rises to the height of two 
hundred and fifty feet above Perrysville Station, showing a thickness of 
one hundred and seventy-five feet, and indicating either a great uplift of 
the Waverly Conglomerate, or that the ordinary olive shales take, at this 
place, the form of the Conglomerate. Much of this rock contains a great 
number of partially formed concretions of white quartz, the blocks which 
have been weathered, presenting to the eye the appearance of being 
filled with quartz pebbles. These concretions are all small, have a par- 
tially radiated structure, and shade off imperceptibly into the uncrystal- 
ized rock. The rock is sometimes broken through them, leaving a mam- 
milary surface on the face of fracture. Their appearance recalls the old 
controversy in regard to the origin of the quartz pebbles of the Carbonif- 
erous Conglomerate, and, at first, seems to favor the hypothesis that they 
may be formed by the aggregation and crystallization of the quartz during 
the consolidation of the rock. But these concretions all lack the homo- 
geneous structure, the regular cleanage, and polished and smooth outline 
which characterizes the transported and water-worn pebbles. This ledge, 
