18 GEOLOGY OF ERIE COUNTY 



The Onondaga limestone can be observed at nearly any point 

 on the ' 'Ledge' ' where it is broken by streams or where quarrying 

 has been conducted. It crops out at Fort Erie and Erie Beach 

 where its beds are at water level. It obstructs Niagara River 

 forming rapids and maintaining the base level for Lake Erie. 

 Black Rock derived its name from a ledge of Onondaga rock 

 which jutted into the river there. An excellent section of fifty 

 feet of its lowest layers is exposed in the Barber Asphalt 

 Company's quarry, and smaller sections are exposed in various 

 other quarries nearby. The lowest, or coral, layer can be seen to 

 good advantage in the quarries at Williamsville, and better 

 still at the Carroll quarry at Clarence. This lowest layer and 

 about twenty feet of the upper layers are exposed in the Kelly 

 Island quarry at the bend of the brick road just west of Akron 

 and good exposures occur in all the quarries at Akron. Murder 

 creek flows over the Ledge at Falkirk and exposes 15 feet of the 

 lowest beds in an excellent section. Smaller sections of higher 

 beds may be seen in Cayuga creek at Depew and in Buffalo creek 

 at Winchester. Cellars excavated in the northern part of Buffalo 

 reach to the lower beds of the rock and cellars in South Buffalo 

 occasionally find the upper beds. 



The formation is highly fossiliferous, but owing to the 

 obdurate character of the rock it is very difficult to separate its 

 fossils from their matrix. As a consequence the palaentology of 

 this formation has been studied less than any other of the county. 

 For the formation in the Canandaigua quadrangle Dr. Clarke lists 

 the following : 



Fishes, 3 species. 

 Crustaceans, 39 species. 

 Cephalopods, 13 species. 

 Pteropods, 3 species. 

 Gastropods, 38 species. 

 Lamellibranchs, 15 species. 

 Brachiopods, 48 species. 

 Crinoids, 4 species. 

 Corals, 30 species. 



