166 NEW YORK STATE MUSEUM 



CABBONIFEKOUS SYSTEM 



This system took its name from the fact of its being the chief 

 coal bearing formation of Europe. 



The Carboniferous is not well represented in New York; some 

 of the uppermost sandstones., shales and conglomerates near the 

 Pennsylvania boundary are undoubtedly of this age, but they 

 contain no fossils. 



In the endeavor to identify the Carboniferous strata of New 

 York, it has been necessary to take up the known strata of this 

 age in Pennsylvania and trace them, so far as possible, into New 

 York. 



The gradation from the rocks of the Devonian to those of the 

 Carboniferous is not abrupt. On either side of the assumed 

 boundary plane are greenish gray shales and sandstones without 

 distinctive characters. For the present purpose it is necessary 

 to describe the succession of the Pennsylvania rocks and indi- 

 cate their occurrence in New York. 



Sub-Carboniferous, Pocono group 



Above the uppermost Devonian sandstones lie the rocks which 

 are considered to be the base of the Carboniferous system. They 

 are mainly sandstones with occasional beds of conglomerate. 

 This conglomerate is said to occur on some of the peaks of the 

 Catskills, but it has not jet been recognized in southwestern 

 New York. 



Sandstones of Pocono age doubtless occur in New York near 

 the Pennsylvania boundary but they have no fossils. 



The Pocono formation attains a thickness of more than 2,500 

 feet in Pennsylvania on the Susquehanna river. Some thin seams 

 of coal occur in it. It contains no fossils except fragments of 

 plants. 



Mauch Chunk group 



The Pocono is succeeded by a formation called the Mauch 

 Chunk group, which, in Pennsylvania, is about 3,000 feet in its 

 greatest thickness, though far less in some districts. It is almost 

 entirely composed of soft, red shales and argillaceous red sand- 



