220 GEOLOGY OF ILLINOIS. 



Two miles east of Hampton, several shafts have been recently sunk 

 on a good seam of coal from four to five feet thick. The coal and the 

 associated strata are the same as at Carbon Cliff. The coal here has a 

 tendency to the block character, breaking easily into quadrangular 

 pieces. 



It is overlaid by bituminous shales, and argillaceous and silicious 

 limestone, which is capped with a band of chert from four inches to a foot 

 in thickness, above which we find silicious shales and sandstone. The 

 dip of the coal is very irregular here, sometimes rising nearly to the sur- 

 face level and then sinking to the depth of sixty to seventy feet; proba- 

 bly conforming to the irregular surface of the underlaying limestones. 

 The coal at this point appears to occupy a limited basin, that has been 

 proved by borings to extend for about three-quarters of a mile in one 

 direction, by about half a mile in the other, covering a portion of sec- 

 tions 15, 16 and 22, in town 18 north, range 1 east. The Hampton 

 shaft, ^Etna Coal Co., Durfee shaft and Davenport & Co.'s shaft are all 

 on this little basin. 



The Carbon Cliff mines were located on Sec. 4, T. 17 X., E. 1 E., and 

 were among the earliest mines worked on the west side of Eock river. 

 For many years extensive coal operations, in connection with an estab- 

 lishment for the manufacture of pottery and fire brjck, were carried on 

 at this point under the management of W. S. Thomas, Esq., but the 

 limited supply of coal finally became so nearly exhausted that mining- 

 was no longer a profitable investment, and the mines have been aban- 

 doned. A section of the Coal Measures at this point, the upper part 

 obtained by surface exposures, and the lower part furnished from the 

 records of a boring made by Mr. Thomas, will give a general idea of 

 the measures as they are developed in this part of the county : 



Feet. 



No. 1 Streak of bituminous shale, probably indicating the horizon of coal No. 2 1 



No. 2 Silicious shale and sandstone It* 



No. 3 Blue argillaceous shale and limestone, with a band of chert 15 



No. 4 Bituminons shale 1 



No. 5 Coal 3 to 4 



No. 6 Fire clay 2 to 3 



No. 7 Sandstone, dark blue clay shales, with bands of iron ore, and thin coal, or bituminous 



shales, passed through in the boring 70 



No. 8 Gray Devonian and upper Silurian limestones penetrated to the depth of two or three hundred 



feet. 



The baud of chert in the shales over this coal forms a reliable guide 

 to the identification of the strata both in this county and in Henry. It 

 varies in thickness from four inches to two feet, and in color from 

 a light gray to black. It has the conchoidal fracture of a true flint, 

 and was used by the Indians for the manufacture of their implements 

 of war and of the chase. The limestone over the coal contains but few 

 fossils at this locality, but the Spirifer cameraiiis and Atliyris xullilita 



