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Clidptcr 4 



STRATIGRAPHY OF THE SCHOHARIE REGION (cnntimied) 



Middle and Upper Devonic strata 



Tlie smci'ssioii of (lie Devonic formations above the Esopus 

 shale is as follows in this region: 



( Catskill (Chemunn:) 



Upi)er Devonic ^ Oneonta ) /o . \ 

 ) ci 1 r (I orta<j;e) 



( bherhurne \ ^ ^ ' 



{ Hamilton 



Middle Devonic < ^^ . 



Onondaga 



[Schoharie • 



Lower Devonic Esopus, etc. 



These will he described in ascending order: 



Schoharie grit 



This formation is characteristically developed only in the 

 Schoharie valley and at several points along the northern Helder- 

 l>ergs. It is a silicions limestone, compact, mud-textured when 

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

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

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

 and in Avhich 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 the road which runs along the northern slope of 

 East hill near Ihe ci-oss road which turns down the hill to 

 SlniKcr's Corners [map: XH g, 4.*)]. Sonu^ portions of (he rock 

 arc lallier slialy and sj)aringly fossiliferous. No measurements 

 of tlic (hickness are ]>ossible wilh (h(» present imperfect exposures; 

 tiie best eslimale dial can be made is 5 or (I feet. I'^astward, beds 

 carr\ing the? fossils of the Schoharie are much thicker. At 



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