MACOUriX COUNTY. 29;3 



Ft. III. 



Xo. 16. Coal ] 1 8 



No. 17. Xodular limestone and shale J. Xo. 6 10 



No. t-. Coal j 1 



Xo. 19. Limestone 8 



Xo. 20. Shale 7 



Xo. '21. Limestone 1 



Xo. 22. Black shale 2 



Xo. 23. Coal (Xo. 5) 6 



253 7 



The coal at this miue varies in thickness from five to seven feet, and 

 is divided below the middle by a shale parting, the coal above the part- 

 ing being of a better quality than that below it. and having a tendency 

 to the block character. The coal has a bright glistening color on the 

 faces of transverse cleavage, and the layers are separated by ill in layers 

 of charcoal or carbonaceous clod. 



At Mr. Howard's mine, in the valley of Wood river, the < oal was 

 reached at a depth of one hundred and sixty feet, but as we could obtain 

 no section of the shaft, we are unable to say whether the coal mined 

 here is the same with that in the other shafts or not. The seam is only 

 about four feet thick here, and it may be that it is Xo. 6 instead of Xo. 

 5. that is worked at this point. 



In the vicinity of Plainview, the Carlinville limestone is found out- 

 ri opping on one of the small tributaries of the Maeoupiu, and following 

 down the railroad grade as it descends into the creek valley, the follow - 

 inu beds may be seen : 



Xo. 1. Compact V>rowaish-gray limestone 6 feet. 



. Calcareous shale with chonetes, etc i " 



L Dark-blue clay shale, with ferns 3 ' 



X>. 4. Sandy shales and shaly micaceous sandstones extending below the creek level.. .50 to 60 " 



The buff-colored calcareous shale immediately beneath the limestone 

 was found at one locality filled with fossil shells, Chonetes, Athyris and 

 Product us, but mostly in a crushed and flattened condition. The dark- 

 blue clay shale. Xo. 3. is partly bituminous, and contains fragments of 

 fossil ferns of two or three species. It seems probable that the Carlin- 

 ville limestone. Xo. 1 of the above section, is the stratigraphical equiva- 

 lent of the Shoal creek limestone, mentioned iu the reports on Madison, 

 Clinton and Marion counties, in the third Volume of these reports, and 

 it so, this bituminous clay shale may represent the thin coal immedi- 

 ately below that limestone, which would be coal Xo. of the general 

 ion. and is from eighteen inches to two feet thick in the vicinity of 

 Highland, in Madison county, where it has been worked for many years 

 iu a small way. to supply the local demand for coal. 



In the section given above, it will be seen that there is a very decided 

 increase in the thickness of the beds intervening between the Carlinville 



