1020 



NEW YORK STATE MUSEUM 



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ID 



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Rhinestreet 

 black shale 



minous, in which flags or sandstones are absent from all the 

 lower part, rare in the middle, and are a considerable portion 



of the sediment only at the very top of 

 the section. 



Calcareous concretions and concre- 

 tionary layers are of frequent occurrence 

 in all parts of the section. 



Fossils are common in the lower and 

 the upper beds but are very rare in the 

 middle ones. The fauna is composed al- 

 most entirely of cephalopods, gastro- 

 pods and lamellibranchs. Chonetes 

 1 e p i d a occurs occasionally in the 

 Cashaqua shales, a few Lingulas in the 

 black slates and a small Productella 

 near the top of the group were the only 

 other brachiopods found. 



In the exposure in the south shore 

 £|F "" cliffs, 14 m il e south of the mouth of 



Cashaqua 

 shale 



Middlesex 

 black shale 



Styliola 

 limestone 



Moscow 

 shale 



Encrinal 

 limestone 



Eighteen Mile creek, the Styliola lime- 

 stone is separated by 1 foot of dark 

 shales from the top of the Hamilton 

 shale. This limestone is 6 inches thick 

 and inclined to be shaly, but is more 

 compact and 12 inches thick where it 

 comes down to the lake leyel iy 2 miles 

 to the south. It is oyerlain by 11 feet of 

 characteristic Upper Genesee shales, 

 that are succeeded by the black Middle- 

 sex shale, which is here but 8 feet thick. 

 The Cashaqua shales, also exposed in the cliff, are 32 feet 

 thick, and consist of 24 feet of yery light colored clayey shales, 

 and above these 8 feet of light and dark shales. Concretions 

 are common throughout the formation. 



The upper part of the cliff is in the horizon of the Rhine- 

 street shale, and the rock is all black slaty shale. 



At the mouth of Pike creek 12 feet of Hamilton shales, the 

 Genesee shales and the Middlesex are exposed. 



Fig. 8 Cliff section oppo- 

 site Hotel Mortimer, Lake 

 Erie shore near North Evans. 

 Station 50 



