Formations in eastern Central New York. 



205 



the lowest beds of shale finally merge into hard, coarse-grained, 

 cross-bedded gray sandstones which then extend eastward 

 through the Catskill Mountain immediately above the Oneonta 

 formation. Westward the shales with Chemung fossils attain 

 a thickness of about six hundred feet near Susquehanna, bed 

 after bed of sandstone becoming liner grained and finally 

 merging into shale of soft fine grained sandstone. This 

 change of character continues to ascend in horizon westward 

 through southern central New York and northern Pennsyl- 

 vania, until according to Sherwood,* Chemung fossils are 

 found within one hundred and fifty feet of the base of the 

 Lower Carboniferous, nearly a thousand feet above the begin- 

 ning of red beds in that region. 







C" 





£.'■'■■ '•--. 



T 



=T=. 



\^v= 



= 



A 



£m 



= 



- - 





- S= 



.-- 



.77: 



.^f 



= ~ 















§' 



a. 



s.s 



z^i 



..:.- 



-.--=y-t 











OfiRK SHALES 



RED ShAl.ES = 



Fig. 2. — A, section through Susquehanna ; B, through Oneonta and Franklin ; 

 C, Schoharie Creek ; D, West of Palenville (C, D, Catskill Mts.). 

 Scale, 2,000 feet to the inch. 



Fig. 2. — Columnar sections at intervals along the same line 

 as the section in figure 1, to illustrate the prominent variations 

 in stratigraphy. 



From these statements it is evident that the great mass of 

 coarse sandstones with red shale intercalations in the Catskill 

 Mountains gradually changes westward into fine grained sedi- 

 ments with Chemung fossils, the change beginning in the 

 basal beds just above the Oneonta formation in northern cen- 

 tral Delaware County. The Oneonta formation is character- 



* 2d Geological Survey of Penn. ; Report on Bradford and Tioga Counties, G. 

 Harrisburg, 1878. 



