EASTERN COUNTIES OF ALLEGHENY PLATEAU 63 



This shows a notable increase southward, for under this axis in Somer- 

 set county, Mr Piatt estimated only about 200 feet. The section can not 

 be compared in detail with those already given, but the typical section 

 can be recognized thus : 



Feet 



Home wood sandstone 60 



Mercer group, shales, and coal bed 57 



Connoquenessing 92 



Sharon shales and coal beds 78 



Sharon sandstone with sandy shale 55 



In any event, whether or not this grouping be exact in detail, the 

 section shows clearly the presence of the Sharon sandstone at the 

 bottom. 



Mr Martin measured the section on the Youghiogheny river in Garrett 

 county, Maryland, almost midway between the last section and that at 

 Westernport. He gives 



Feet. Inches 



1. Massive sandstone, Homewood , 50 



2. Shale 6 



3. Mount Savage fireclay 4 



4. Coal, Mount Savage 3 



5. Shale 5 



6. Sandstone 5 



7. Coal, Lower Mercer 10 



8. Conglomeritic sandstone, Upper Connoquenessing 75 



9. Black shale 2 



10. Coal, Quakertown 1 6 



11. Shale , 6 



12. Concealed 8 



13. Massive conglomeritic sandstone, Lower Connoquenes- 



sing 75 



14. Concealed 60 



15. Shale 5 



16. Coal, Sharon 1 4 t 



17. Shale 6 



18. Sandstone 25 



Total 327 8 



One recognizes here very clearly the typical section of northwestern 

 Pennsylvania, both members of the Connoquenessing being present as 

 massive more or less conglomerate beds, whereas farther west the lower 

 sandstone, as at so many localities in the northwest, is represented 



