Bishop — Geology of Erik County. 



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throw n up this rock along Bird avenue, near Elmwood, and in several places 

 near the Niagara river in the vicinity of Auburn and Bbuck avenues. The 

 rock is not eroded to its base so that a complete section is nowhere visible. 

 The thickness has been ascertained from well sections given elsewhere in 

 this report. 



UPPER HELDERBERG GROUP. 



Onondaga Limestone. 



In Erie county, this formation appears as a thin band lying between the 

 hydraulic limestones and the overlying Corniferous limestone. In color it 

 ranges from blue-grey to a very light grey. It varies greatly in thickness, 

 being from three to five inches at the Main street bridge over Scajaquada 

 creek, Buffalo ; seven feet in Forest lawn cemetery ; five and one-half feet in 

 the park quarry, and thirty-five feet in Fogelsonger's quarry at Williamsville. 

 At Young's quarry, two miles further east, it is thirty to thirty-five feet 

 thick, but thins out rapidly beyond to a thickness of three to five feet. 

 Speaking broadly, we may say that the formation is concretionary in character, 

 the deposits at Fogelsonger's and Young's being merely lenticular masses of 

 unusual size. Small lenses a few feet in diameter are frequent and usually 

 extend downward into the hydraulic limestone without any corresponding 

 depression above, showing that they had their origin while the latter was 

 yet in process of deposition. The larger nodules are remarkably rich in 

 organic remains. At Fogelsonger's quarry the rock in many places is a solid 

 mass of cyathophylloid and favositic corals, the latter frequently having their 

 cavities filled with petroleum and bitumen. Single specimens w ere noticed 

 four feet in diameter, and large areas of the quarry bottom show ed little else 

 than these fossils. 



The Corniferous Limestone. 



The northern edge of the outcrop of this formation is marked by the 

 escarpment already described. A deposit of drift from ten to fifty feet thick 

 covers the southern edge, so that actual contact with the Marcellus shales 

 above is not found within the county. At Corfu, three miles east of the 

 county line, the borings for gas passed through thirty feet of Marcellus shale-. 

 According to this, the Corniferous limestone should be found about a mile 

 north of that village. The most southerly outcrop of this Limestone near rhe 

 county line is near an abandoned railroad track two miles northeast of 

 Crittenden. A small exposure occurs on the edge of a marsh just northwest 



