454 



J. BARRELL ORIGIN OF THE MAUCH CHUNK SHALE 



reproduced here in order that they may be compared. A good section 

 of the transition beds at the top of the Mauch Chunk at Pottsville is 

 given by D. White.* 



Sections of Maucli Chunk Shales, Winslow 



1 



Sandstone. 



Shales 



and 



sandstone. 



Shales. 



At Mauch Chunk : 



Mount Pisgah, Pottsville conglomerate and 

 sandstone with shaly bands 320 



Eed shale in the body of the conglom- 

 erate 500 



Lower conglomerate with a green matrix, 

 large quartz pebbles 120 



Upper beds of Mauch Chunk red shale and 

 sandstone 





1,662 





Sandstone, yellow and friable 



Eed shale 



83 







28 



Chocolate colored and gray hard sandstone. . . 

 Shales, mostly concealed 



28 









367 



Pocono sandstone 



















111 



1,662 



395 



At Solomons gap : 

 Pottsville conglomerate 









Mauch Chunk, red and green shale with cal- 

 careous layers 







246 



Brick red shale 







120 



Sandstone, reddish gray, with quartz pebbles 

 and also red shale pebbles 



27 







Shale and sandstone, red and massive 



335 





Sandstone, reddish and greenish gray, with 

 fine quartz pebbles 



31 





Brick red shale 





60 



Sandstone, fine, greenish gray, which might 

 be just as well made the top layer of the Po- 

 cono as the bottom layer of the Mauch 

 Chunk 183 











58 



335 



426 



It is seen from these sections tliat no marked division lines characterize 

 the formation througliout the whole region, though near the bottom in 

 each section is a considerable body of shale. The dominant stratigraphic 

 feature consists in the intimately interstratified beds of sandstone and 

 shale occupying considerable portions of the section where the formation 

 is thick. There are other portions, however, in the same sections in 

 which shale is the principal factor. It is to be noted also that shale 



• 20th Ann. Kept. U. S. Geological Survey, part ii, plate clxxxii. 



