578 GEOLOGY OF OHIO. 
sibility of the authorship resting with Dr. Hawes, the value of his special knowledge 
and his opportunities for a comprehensive review, give to the chapter an authority 
that it would not otherwise possess.—E. O.] 
OHIO. 
[Compiled from notes of Professor Orton,]| 
SANDSTONE. 
SuB-CARBONIFEROUS.—Those rocks of the sub-Carboniferous 
period, called the Waverly group in the Geological Survey of Ohio, are 
the most important as to production of building stone in the geological 
scale of the state. The following shows the arrangement of this forma- 
tion, according to Professor Orton: 
1. Maxville limestone, in patches. 
. Logan group. 
. Cuyahoga shale. 
Berea shale. 
. Berea grit. 
. Bedford shale. 
No. 1 occurs but seldom. No. 2 consists of fine-grained sandstones 
SD OR oe WS 
overlying and alternating with massive conglomerates in central and 
southern Ohio. Its thickness is about 100 feet. The Waverly con- 
glomerate is a member of this group. No. 3, about 300 feet in thick- 
ness, is a blue argillaceous shale in many parts of Ohio, but in many 
places contains scattered courses of sandstone of great value. Insouth- 
ern Ohio these are concentrated and become very valuable. No. 4 is 
from 10 to 30 feet in thickness and is the equivalent of the Waverly 
black shale of southern Ohio. No. dis the Berea grit, the great quarry 
rock of northern Ohio. It is from 10 to 75 feet in thickness and ex- 
tends in a belt from Williamsfield, in the southeastern corner of Ash- 
tabula county, westward into Erie county, and thence nearly directly 
southward in Adams county to the Ohio river. This stratum of sand- 
stone, where it has its best development, consists of heavy sheets with 
often a course at the top of thin broken layers called shell-rock. How- 
ever, in many localities these thin layers are unbroken, even, and com- 
pact, and are quarried extensively for sidewalk paving. No. 6 is from 
10 to 100 feet in thickness, and furnishes no building stone exGe in 
Cuyahoga county. 
