258 GEOLOGY OP ILLINOIS. 



The openings along Salt Fork, as far as the west line of township 19 north, 

 range 12 west, are all in the upper seam, though, for two or three miles above 

 Danville, the lower seam is exposed in every bluif, arid in some cases with a 

 thickness of four feet or more. Up Middle Fork, the upper seam has never 

 been fairly opened, though small quantities of coal have at times been taken 

 from the bed of the stream for local use, and it could be mined at about that 

 level as far north as the north line of section 8, township 19 north, range 12 

 west ; but the sudden dip previously mentioned here, carries it downward to 

 probably one hundred feet below the level of the stream, and it does not again 

 appear in going northward. 



The lower or "Grape creek" seam is comparatively thin at Danville, in 

 some cases not exceeding three feet*, and accordingly has not been worked suf- 

 ficiently to ascertain its quality with certainty; but, on Grape creek, it has 

 been worked by several drifts and etrippings, with a thickness of from five to 

 seven feet, and furnishes a superior coal. The portion below the clay parting 

 would in most cases probably prove satisfactory, if used in the raw state for 

 smelting iron. If nearer to railroad transportation, these mines might fairly 

 compete with any in the State. The coal still contains small portions of pyrite, 

 and here, as elsewhere, it appeared to me that this mineral became more abund- 

 ant as the seam became thicker. At Blakeney's mine, on Possum Hollow, a 

 branch of the Grape creek valley the only mine in all this region where it is 

 done T found that care was taken to separate the pure from the impure benches 

 of the scam, a difference of two cents per bushel being made in the price. As 

 n consequence, much local trade was centering here, and I heard it spoken of in 

 distant parts of the county. The following is a detailed section of the seam at 

 this point : 



FEET. IN. 



Micaceous clay shale 8 to 1 



Pyritous coal 2 1 



Pure coal 8 



Pyritous coal 1 6 



Soft drab shaly clay J 



Pure coal 1 



Pyritous coal 1 9 



Fire-clay, with thin bands of nodular limestone 8 



Along the Little Vermilion and its branches, from about four miles below 

 Georgetown to below the State line, there are frequent openings of this seam 

 for local supply, but no extensive workings. The coal appeared good. If rail- 

 road facilities could be supplied to this part of the county, these mines would at 

 once become of great value. 



*1 have not seen it where t>o thin as stated by Major Kirkland. 



