298 GEOLOGY OF ILLINOIS. 



FEET. IN. 



1. Burlington limestone. , 32 6 



2. Compact, calcareous clay shale, from 6 inches to 1 



3. Blue clay shale, to the level of the creek 16 



In the south part of section 15, there is another outcrop of a few feet along a 

 small branch, and in section 9 there is an exposure of shale which probably 

 belongs to the Kinderhook. At this point, one or two shafts have been sunk, 

 for a short distance, in search of coal. It is reported that the water came in 

 so fast that the work was suspended, without, of course, having found any indi- 

 cations of coal. 



North of here, the beds of this group are not exposed, but may extend for 

 some distance in that direction beneath the Coal Measures, but, like the other 

 members of the lower Carboniferous series, this group also soon thins out. 

 There were no fossils found in these beds at any point in the county. 



As these shales very closely resemble those of the Coal Measures, those 

 unacquainted with geology will be very likely to mistake them for the latter. 

 This has been done at nearly every exposure, though, as far as 1 learned, but 

 little time had been spent in examinations. Notwithstanding all that experi- 

 enced coal-miners may say to the contrary, it is useless to search for coal in the 

 shales of the Kinderhook group. 



Economical Geology. 



Goal. The supply of this valuable mineral is mostly obtained from seams 

 Nos. 1 and 2, the upper bed, No. 3, affording but a small amount. Coal No. 2, 

 though thinner at most places than No. 1, is more extensively worked, as it is 

 generally more easily got at, and affords an excellent quality of coal. This seam 

 has been worked principally in townships 8, 9 and 11, ranges 1 and 2. At 

 most of the mines, there is more or less sulphuret of iron mixed with the coal, 

 which has to be separated from it before sending it to market. 



The lower seam is, at nearly all localities, considerably thicker than No. 2, 

 and hence the yield is much greater. This coal, though generally of fair qual- 

 ity, is not as good as that from the bed above. It has been worked principally 

 in township 9, range 1, township 11, range 2, and township 12, ranges 1 and 

 2. It probably underlies the whole of the township 9, of range 1, and a consid- 

 erable portion of each in range 2, and, perhaps, a portion of townships 8, 9 and 

 10, of range 3. At a single place in range 3, along the dividing line between 

 townships 9 and 10, coal, apparently belonging to this seam, has been found, 

 and a mine opened. The coal is but twenty-six inches thick at this point. 



Building Stone. The Burlington limestone furnishes a good article of build- 

 ing stone, and is found along the southern part of township 12, range 3, and 



