522 GEOLOGY OF OHIO. 
are isolated Drift-hills scattered over the water-plain, which is bordered 
by ridges of modified Drift. 
In the south part of the county the valleys are covered with a mixture 
of alluvium and Drift, and the hills with Drift and the debris of the 
local rocks. The soil is clay, tempered with sand and gravel, and con- 
taining a great abundance of rock fragments, while granite bowlders are 
very abundant, some of them of several tons weight. The rock frag- 
ments preserve the steep cultivated slopes from washing, and cause the 
rains to penetrate the soil, and accomplish, to a great extent, the work of 
underdrainage. These hills continue to bear good crops of wheat, as 
well as of corn, oats, and other crops. The timber is beech, maple, oak, 
chestnut, hickory, etc., and on the borders of streams, elms and black 
walnut are occasionally found. In Hanover township the slopes. of the 
hills are ordinarily covered solely with the debris of the local rocks, and 
the soil is less productive. The alluvium of the valleys renders them 
fertile, and the greater part of the county has a rich, amen ay 
adapted to a mixed and varied husbandry. 
In the village of Ashland is a remarkable witness to the immense 
transporting power of the agencies which brought in the Drift. This is 
the remains of an enormous bowlder of granite, from which rock has 
been occasionally quarried for foundation purposes for the last thirty or 
forty years, and of which there is now enough remaining to load several 
railroad cars. Its original dimensions exceeded 25 x 15 xX 12 feet, and 
it must have weighed over three hundred and fifty tons. Broken up, it 
would have sufficed to load a railroad train of thirty-five cars. It is 
greatly to be regretted that it was not preserved unbroken, as a very in- 
teresting memorial of the past. 
GEOLOGICAL STRUCTURE. 
The geological structure of the county is very simple, and easily un- 
derstood. With the exception of a narrow ridge of the coal rocks, on 
the south line of Hanover township, it is a continuation to the east of 
the upper series of rocks exposed in Richland county, and is made up 
entirely of the Cuyahoga shales, capped here and there in Hanover 
township with a thin bed of the Sub-carboniferous Conglomerate. A 
geological map of the county would have a small spot of brown shading 
at the south-east corner of Hanover to represent the Coal Measures, two 
or three small patches of red in the immediate neighborhood to designate 
the Conglomerate ; and all the rest colored yellow to indicate the Waverly, 
The following is a section of the rocks disclosed in the south part of 
Hanover township, where the highest geological formation is formed, and 
