26 ECONOMICAL GEOLOGY. 



Ft. In 

 20 



Clay shale 



Sandstone 



Clay shale 



Coal No. 1 : " 



Fire clay " 



Sandstone 



Shale 



Sandstone 



Lower Carboniferous limestone fl 



Total depth 20 4 



The following record of a boring made at Charleston, in Coles 

 county, was furnished by Mr. C. B. Swan, under whose direction 

 the work was done: 



Ft 



No. 1. Soil and surface clay 15 



No. 2. Hard-pan 15 



No. 3. Gray shale 30 



No. 4. Fire-clay 3 



No. 5. Shale 20 



No. 6. Limestone 4 



No. 7. Shale 3 



No. 8. Limestone 20 



No. 9. Green shale 2 



No. 10. Black shale 3 



No. 11. Limestone 7 



No. 12. Black shale 5 



No. 13. Gray slate 45 



No. 14. Coal 2 



No. 15. Fire-clay 3 



No. 16. Gray shale 28 



No. 17. Black shale 10 



No. 18. Coal 3 



No. 19. Fire-clay 3 



No. 20. Gray shale 16 



No. 21. Limestone 2 



No. 22. Black shale 9 



No. 23. Limestone 15 



No. 24 Light shale 43 



No. 25. Black shale 44 



No. 26. Bed shale 10 



No. 27. Limestone 20 



No. 28. Clay shale 30 



No. 29. Coal 4 



No. 30. Fire-clay 4 



No. 31. Limestone 6 



No. 32. Clay shale 32 



No. 33. Limestone and shale 11 



No. 34. Sandy shale 40 



No. 35. Black shale 5 



No. 36. Coal .". 5 



Total depth... ..523 



