BIlSITT 



MACOTJPIN COUNTY. 289 



sandstones above the coal, especially Nos. 19 arid 33. The roof consists 

 first, of a dark-blue clay shale, sometimes passing into a hard black 

 slaty shale, an inch or two in thickness, resting directly on the coal. 

 This clay shale varies in thickness from two to three inches to as many 

 feet, and above this there is a compact dark gray limestone about seven 

 feet thick, which forms an admirable roof to the coal. The shale 

 immediately on the coal is more argillaceous than at the mines in the 

 vicinity of Springfield, and fossils are comparatively rare, even where it 

 becomes hard and slaty. We obtained a few of the common species 

 here, among which were Dixcina nitida, Prodiictus muricatus, Hemipro- 

 nitex rm.v.svr. Ckonftex wtefolo&a, some fragments of a Nautiluts, and teeth 

 of Petrodus occidental in. These fossils were generally poorly preserved, 

 and the shells mostly replaced with yellowish pyrite. This coal seems 

 to be the equivalent of coal No. 5 of the Fulton county section, given 

 on page 93 and 94 of the fourth volume of these reports, though in that 

 county No. 5 is not a very persistent seam in its development. It affords 

 a softer coal than that usually obtained from No. 4, and is more regu- 

 larly stratified, breaking freely into blocks of a cuboid al form when 

 carefully mined. No attempt has yet been made to determine the devel- 

 opment of No. 4, or either of the lower seams in the central portion of 

 the county, but No. 4 outcrops on Hodge's creek, near the Greene county 

 line. 



The shaft at Girard is about three hundred and forty feet in depth, 

 but as no record of it was kept by those in charge of the work, no reli- 

 able section could be obtained of the strata passed through. The coal 

 averages about seven feet in thickness, has a shaly parting similar to 

 that at Virden, and the coal presents the same general character. The 

 limestone above the coal is somewhat thicker than at Virden, being 

 about ten feet. 



Weir's shaft, at Carlinville, is two hundred feet to the top of the coal 

 passing through the following beds : 



Feet. In. 



Drift -clays 75 



Xo. 1. Clay shale 28 6 



Xo. 2. Soft coal (Xo. 8) 6 



Xo. 3. Dark and light fire-clays 5 



Xo. 4. Sandstone and shale 70 



Xo. 5. Clay shale 15 



Xo. 6. Dark shale 6 



Xo. 7. Soft smutty coal (Xo. 7) 5 



Xo. 8. Fire-clay 6 



Xo. 9. Sandstone 8 6 



Xo. 10. Clayshale 2 



Xo. 11. Limestone 3 



No. 12. Clayshale 1 



Xo. 13. Limestone 1 6 



Xo. 14. Coal.... j ....". 1 6 



Xo. 15. Shale... > Xo. 6 6 6 



Xo. 16. Coal.... ' 6 



3S 



