274 GEOLOGY OF ILLINOIS. 



The gravel beds contain the ordinary variety of metamorphic rocks, with 

 not unfrequent larger or smaller masses of galenite from the Galena region, and 

 native copper from Lake Superior ; but the larger part of the pebbles and rock 

 masses consist of the Niagara limestone, or " Kankakee stone," and the shales, 

 sandstones and limestones of the Coal Measures. 



The sands and gravels of these beds furnish abundant supplies of water at 

 moderate depths; and the white quicksand, lying between them and the under- 

 lying rocks, yields inexhaustible quantities, though generally at too great a 

 depth to be readily pumped up. 



Underlying Rocks. The boring above reported as having reached blue shale 

 at one hundred and sixty-eight feet, is said to have encountered, at one hun- 

 dred and seventy-six feet, a bed of coal five feet thick, which is supposed to be 

 equivalent to the Danville seam, " No. 7." As the synclinal axis of this part 

 of the Coal Measures crosses the Salt Fork of the Big Vermilion river at Con" 

 kcytown, five miles east of the east line of Champaign county, with the Dan- 

 ville seam not far from two hundred feet below the surface, while the under- 

 lying beds begin to rise slowly as we ascend the river from that point, it seems 

 not improbable that this seam may be found at the depth reported, but its ex- 

 istence there seems still uncertain. 



It appears almost certain that the northern strip of Ford county is destitute 

 of coal ; but no boring has proved its absence in the southern portion of the 

 county ; judging, therefore, from the data obtained in the surrounding region, 

 it seems probable that the whole of this district is underlaid by one or more 

 workable seams of good coal, the uppermost probably lying nowhere more than 

 three hundred and fifty feet below the surface, and generally at a much less 

 depth. There appears, therefore, to be no good reason why shafts should not 

 be sunk to furnish a home supply in place of that now transported from a dis- 

 tance. And, as both counties are crossed by the Illinois Central railroad, giv- 

 ing direct connection with Chicago, a ready market could be found for any 

 surplus of this sole source of wealth, aside from those which are strictly agri- 

 cultural. The heavy bed of quicksand which is said to rest directly upon the 

 rock, under a part, at least, of this district, presents the only obstacle to easy 

 mining; and this could be readily overcome by any engineer of ordinary skill. 



It is reported that at Urbana, starting fifty feet lower than the surface at 

 Champaign, coal was encountered at two hundred and twenty-five feet. 



Borings made near Rantoul in 1857, whose results were then suppressed, are 

 now said to have found, about a half a mile south of the station, a nine-foot seam 

 of coal at a depth of one hundred and twenty feet, having struck rock at a depth 

 of eighty feet; and one and a half miles east of the station, the same seam at 

 one hundred and sixty feet. ,. 



