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388 GEOLOGY OF OHIO. 
underlain by the Corniferous limestone in the township of Monroe. 
South of the Van Wert Ridge, in Reilly and Pleasant townships, the sur- 
face is also more gravelly and broken. These ridges consist of strips of 
rolling land, in which gravel and sand in oblique stratification may be 
found a few feet below the surface. They prevail in the north-eastern 
part of the county, crossing it obliquely from north-west to south-east. 
They have been fully described in the chapter on the Drift in north- 
western Ohio. With the exception of the Medary Swamp and another 
small area in Palmer township, the whole county was originally covered 
with forest. The soil is that peculiar to the Black Swamp, and consists 
largely of a close, tough clay, with but little intermixture of vegetable 
matter. It is remarkably free from bowlders and stones, not one being 
seen sometimes in a day’s travel. In the vicinity of the ridges and 
knolls in the northern part of the county it is often gravelly or sandy, 
and hence much more easily drained. In general, the whole county will 
require thorough artificial drainage. 
GEOLOGICAL STRUCTURE. 
The only rock seen in outcrop within the county is the Waterlime ; 
yet it is believed that the lower part of the Corniferous, including the 
Oriskany sandstone, underlies the most of the township of Monroe. 
The most important exposures of the Waterlime are either in the bed 
of the Blanchard, or in the streams tributary to it from the south. It 
here shows itself at numerous points, and is wrought for general build- 
ing purposes and for quicklime. The thick-bedded, soft, drab stone 
which oceurs in Wood county, and which will prove valuable for a cut- 
stone, has not been observed within the county; neither has that char- 
acter described as phase No. 1. Phase No. 3, however, is commonly seen 
in Putnam county. Besides this condition of the Waterlime (see Geology 
of Wood County), there are occasionaliy seen thick, hard beds of fine- 
grained rock, with cavities, and bands of softer or vesicular rock dissem- 
inated through the mass. Such rock was seen at Croninger’s mill, near 
Findlay, in Hancock county (S. E. } section 8, Liberty township), and 
is regarded as the equivalent of the breccia of phase No. 1, reduced in its 
dimensions and modified by the weakening of that force, whatever it be, 
which occasioned the brecciated masses developed conspicuously in the 
islands at the west end of Lake Erie, and in the island of Mackinac, at 
the head of Lake Huron. The gradual change southward in the litho- 
logical characters of the Waterlime has been already noted. In Putnam 
county its condition is usually an intermediate stage between that seen 
in Ottawa and Wood counties and that described under the Geology of 
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