

CORRELATION 





• 



11. Shale 





12. Sandstone 





13. Shells 





14. Shale 







f- Upper Pottsville 



16. Shale 





17. Coal and shale 





18. Sandstone 





19. Slate 





20. Sandstone 





21. Shale •> 



22. Sandstone } Lower Pottsville 



201 



{ 



Feet 

 21 

 15 

 19 

 45 

 10 

 20 

 15 

 25 

 45 

 45 

 15 

 20 



275 



At Lock number 6, 20 miles southeast from Winfield, 35 miles south- 

 southwest from Spencer, and 5 miles northwest from Charleston, the 

 succession, according to Doctor White, is 



Feet 



750 

 45 

 35 



220 



10 



40 



50 



10 

 \ Upper Pottsville \ nr 



45 

 3 

 7 



35 

 Lower Pottsville 480 



1. Pittsburg coal bed 



2. Interval ^ 



3. Shales and coal . . . J- Conemaugh and Allegheny. 



4. Sandstone -> 



5. Shales and shells. 



6. Sandstone ........ 



7. Shales and shells. 



8. Sandstone 



9. Shale 



10. Limestone , 



11. Sandstone 



12. Coal bed 



13. Sandstone 



14. Slate 



15. Sandstone 



The rapid decrease of the lower members northwestwardly is shown 

 by these comparisons : 



Pittsburg to Stockton 



Stockton to Lower Carboniferous. 



Charleston. Lock 6. Winfield 

 Feet. Feet. Feet 



800 750 737 

 692* 



1,155 975 



Correlation 



The reader who has followed this tracing of the Pottsville section is 

 ready, doubtless, to unite with the writer in a pious expression of relief. 

 It remains, however, to give a general summary of the relations, and to 



*I. C White : Op. cit., vol. ii, pp. 400, 401. 

 M. R. Campbell : U. S. Geol. Survey folios, Charleston. 



