82.] 



491 



[White. 



ing rocks can only be conjectured. The topogra])ln' -would make llieni 

 shaUs, and hence I think it probable that the sand rocks seen at Quarry 

 run are absent here, and that the hlach slate, No. 19, rests immediatelj' 

 upon the JIauch Chunk beds, but should it prove otherwise, the base of No. 

 XII would then be found about 30' below the top of No. 20, thus making 

 the entire thickness of this series 225' instead of 194', as given in the sec- 

 tion. 



The top of the Mountain Limestone must lie about 100' below the level 

 of Cheat river at this locality, where the centre of the syncline crosses. 



At the mouth of Sandy creek, a massive, bufflsh-gray sandstone makes a 

 bold clitf along the water's edge at 975' A. T. (B), and 220' below the base 

 of No. XII. 



As we pass up the river south-eastwards from the mouth of Sandy, the 

 rocks begin to rise in that direction, and at one mile and a half above, the 

 Mountain Limestone has completely emerged from the bed of the river, re- 

 vealing the following structure along a steep ravine which puts into the 

 west bank of Cheat (Sec. 11) : 



1. Gray sandstone, somewhat massive 20' 1 



2. Flaggy sandstone and sandy shales 150' 



3. Limestone, impure 10' 



4. Concealed and green sandy shales 30' 



5. Red shale 10' 



6. Limestone, massive, gray 40' 



7. Blue shale and impure limestone 4' 



8. Shaly limestone 5' 



9. Gray, calcareous shale 2' 



10. Limestone in massive beds, l'-5' thick 40' 



]\rauch 



220' 



Chunk. 



Mountain 

 Limestone 

 94 



Green shale. 

 Red shale . . 



' sandy limestone 2' | 



13. 



14. 



Sil icons 

 Limestone. 



blue limestone, rather pure. . 4' 

 silicious limestone, passing ■ 8' 



graduallj^ into sandstone be- I 



[ low 2' J 



Gray sandstone (Pocono) to level of Cheat. . 10' 

 This section is valuable, because it gives the first complete exposure 

 that we have had between l\\e Mountain Limestone and the "Silicious" 

 beds, showing them separated here by 3' of red and green shales, and thus 

 allying the "Silicious limestone" more closely with the Pocono SS. into 

 which it passes by insensible gradations. 



In continuing on up the river from this locality, the rocks still rise to 

 the southeast, though not much faster than the bed of Cheat, since its fall 

 is A'ery rapid over this portion of its course. 



In the vicinity of the "Great Falls," four miles above the mouth of 

 Sandy creek, the west wall of the canon, capped at top by the sandstone 



PROC. AMER. PHILOS. SOC. XX. 112. 8j. PRINTED DECEMBER 28, 1882. 



