U ECONOMICAL GEOLOGY. 



Ft. In. 



I mpure limestone 



Black shale 



Gray shale 2 10 



Dark blue shale 6 



Fossiliferous limestone 2 



Dark gray sandstone 1 5 



Shah- and limestone 5 3 



Fossiliferous limestone * 



Black slate 6 



Coal, (No. 5j 7 



Total depth 348 



At Auburn coal No. 5 was reached at a depth of 268 feet. The 

 coal ranges from six to seven feet in thickness, with a good roof of 

 black slate and limestone. No details of the shaft could be 

 obtained. 



In Menard county several shafts have been sunk since the publi- 

 cation of the report on that county, among which are those at 

 Sweetwater, Athens, Greenview and Tallula. The following record 

 of the Sweetwater shaft was kindly furnished me by Mr. W. PAKKIN : 



Ft. In. 



No. 1. Soil and brown clay 20 



No. 2. Hardpan 70 



No. 3. Sand 10 



No. 4. Clay 3 10 



No. 5. Black mucky soil (forest bed) 1 2 



No. 6. Clay with streak of smut six inches 9 6 



No. 7. Limestone 1 2 



No. 8. Clay shale 35 



No. 9. Limestone 1 3 



No. lo. Bituminous shale 3 



No. 11. Coal 5 6 



No. 12. Fireclay... ....... .6 



Total depth 166 5 



In this shaft they evidently struck the bed rock about the horizon 

 of another coal seam, probably Nos. 6 or 7, as the lowest clay bed 

 in the above section was reported to have a streak of black clay 

 about three feet from the bottom six inches thick, which no doubt 

 came from the decomposition of a black shale, or a thin seam of 

 coal. 



The Greenview shaft is 97 feet to the top of the coal. The seam 

 is about six feet thick with a roof of black shale. Bed rock was 

 struck at the depth of forty feet. 



The Tallula shaft is 175 feet in depth. Coal five to six feet in 

 thickness, with the usual black shale roof. The fire clay below the 

 coal is reported to be 14 feet thick. 



