WARREN COUNTY. 289 



Surface Geology. 



Two of the subdivisions of the Quaternary system, viz., the Alluvium and 

 Drift, are found in this county. The alluvial deposits are not extensive, being 

 confined to the borders of the streams, and are seldom over half a mile in width, 

 while commonly they are much less. The soil of these bottom lands is very 

 fertile, and consists of black loam, more or less mixed with sand and gravel. 



The Drift covers the whole surface of the uplands to a depth of from ten to 

 eighty feet or more. These deposits comprise a series of yellow, brown and 

 blue clays, locally intermingled with sand and gravel. In the northwestern 

 part of the county, the Drift rests upon the Kinderhook crroup and Burlington 

 limestone, but elsewhere, as far as is known, upon the Coal Measures. Loose 

 coal is frequently found in the Drift, but this is no indication that there is any 

 bed of it in the immediate vicinity. 



The older geological formations found in this county, are the 



Coal Measures, 



Burlington Limestone, and 



Kinderhook Group. 



The Coal Measures underlie nearly the whole of Warren county. Sumner 

 and the northern part of Hale townships, probably embraces the entire district, 

 or nearly so, where they are not found. The Coal Measures comprise, in this 

 county, various strata of shales, sandstones, limestones, clays and coal, and 

 attain a thickness, in some parts, of from one to two hundred feet. These strata 

 rest upon the Burlington limestone, and where this is found near the surface or 

 reached in shafting, no coal need be looked for in deeper explorations. Thus 

 far, the coal mines that have been discovered arc, with but one exception, con- 

 fined to the townships in ranges 1 and 2. There are three workable coal seams 

 found in this county. 



The upper seam is from three feet to three feet six inches in thickness, and 

 has been found at but one locality section 17, township 8, range 2. There is 

 some doubt as to which seam this may be referred, as I was unable to make 

 any measurement of the strata between it and the seam (No. 2) below, but the 

 distance is probably not over forty or fifty feet between them, perhaps less. As 

 the only open bank in this seam was on fire when I was there, an examination 

 could not be made, or any specimens of the coal obtained, but I have learned that 

 the roof is black slate and the floor arenaceous shale. It may be coal No. 3 

 of the Illinois section, and the coal obtained from it is reported to be of good 

 quality. 



The next seam, No. 2 of the Illinois section, is from one foot eight inches to 

 two feet thick, in this county. Elsewhere it attains a thickness of from three 

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