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 occurs 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 occasionally 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 C.roninger's mill, near 

 Pindlay, in Hancock' county (S. E. J 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 



