32 NEW YORK STATE MUSEUM 



West Hill flags and shales 



This formation is composed of thin sandstones and shales having- 

 an aggregate thickness of about 600 feet. It contains a mixed fauna 

 embracing species belonging to the Naples and the Ithaca faunas, but 

 is but moderately fossiliferous. 



The surface rocks in the southwest corner of the Genoa quad- 

 rangle are in the lowest part of this formation, but they are covered 

 by a thin drift mantle. 



For further description of the Grimes sandstones and West Hill 

 flags and shales see State Museum Bulletin 63. 



