108 



C. S. PEOSSER — DEVONIAN AND SILl'JUAN ROCKS. 



General geologic Section of central New York. 



CD 



I _- 



iz 





Composite Section. — From the preceding well-sections a general section 

 has been compiled, giving the approximate thickness of the different 

 formations, together with the total thickness from the Chemung, as ex- 

 posed at Binghamton, New York, down to the Archean. 



Formation. 



Mouth of the Binghamton well in the 

 Chemung. From 900 to 1,000 feet 

 brownish-red arenaceous chips, prob- 

 ably the horizon of the "Oneonta 



sandstone." At 1,850 feet, about the 

 mouth of the Norwich well and lower, 

 the " Sherburne sandstone." Place of 

 the Genesee shale and the Tully lime- 

 stone. 



Hamilton. 



Marcellus shale. 



Upper Helderberg (Corniferous .limestone). 



Place of Oriskany sandstone. 



Lower Helderberg. 



Onondaga Salt group. 



Niagara. 



Clinton. 



Medina. 



Oswego sandstone.- 



Lorraine shale of the Hudson group. 



Utica shale. 



Trenton. 



Calciferous. 



Potsdam. 



Pre-Cambrian and Archean. 



Review of Data used. — It will he interesting to compare the thickness 

 of these formations with that obtained for them in wells more remote 

 from the meridian of this section. 



The combined thickness of the Chemung and Portage groups was 

 shown by the Bird Creek well, eight miles southwest of Elmira, to be con- 

 siderably more than 2,700 feet for that region,* while in the Ithaca well 

 the Hamilton is 1,142 feet thick : the Marcellus shale, 82 feet; the Upper 

 Helderberg (Corniferous limestone). 78 feet: Oriskany sandstone, 13 

 feet; Lower Helderberg. approximately llo feet, and the bottom of the 

 well is in the Onondaga Salt group after passing through 1,285 feet of 

 limestone, shale and salt belonging in that group. The Seneca Falls 



* Prosser : Am. I teol., vol. \ i. p. '-!"i 



