180 



NEW YORK STATE MUSEUM 



Chapter 1 



STRATIGRAPHY OF THE SCHOHARIE REC-ION (continued) 



Middle and Upper Devonic strata 



The succession of the Devonic formations above the Esopus 

 shale is as follows in this region: 



( Catskill (Chemung) 



Upper Devonic < Oneonta ) ,p . 



( Sherburne \ * ° J 



{ Hamilton 



Ar - j n -r, . j Marcellus 

 Middle Devonic - 



I Onondaga 



[ Schoharie 



Lower Devonic Esopus, etc. 



These will be described in ascending order: 



Schoharie grit 



This formation is characteristically developed only in the 

 Schoharie valley and at several points along the northern Helder- 

 bergs. It is a silicious limestone, compact, mud-textured when 

 fresh and of a dark bluish gray color, somewhat like the Upper 

 Oriskany. It effervesces readily with acid and weathers by solu- 

 tion of the lime into a brown porous sandrock not affected by acid 

 and in which the fossils remain as molds. Fragments of this rock 

 are commonly found scattered about on the Esopus slope but out- 

 crops of this formation are rare. The best opportunity for the 

 study of this rock is found on the northern end of both West and 

 East hills, the latter being the most accessible. The best exposures 

 are found above 1 the road which runs along the northern slope of 

 East hill near the cross road which turns down the hill to 

 Shutter's Corners [ma]): XII g, 43]. Some portions of the rock 

 are rather shaly and sparingly fossiliferous. No measurements 

 of the thickness are possible with the present imperfect exposures; 

 the best estimate that can be made is 5 or G feet. Eastward, beds 

 carrying the fossils of the Schoharie are much thicker. At 



