MAROELLUS LIMESTONES OP LANCASTER 177 



Syringopora sp. 

 Pentamerella arata (Conrad) 

 Keticularia fimbriata (Conrad) 

 Phacops rana (Green) 



The contact between the Marcellus and Onondaga is supposed 

 to be about half way between Wende station and Mill Grove.^ 

 l"he eastward extension of this line of contact would carry it 

 about a mile north of the outcrop of Onondaga limestone at 

 Alden. The occurrence of the latter limestone so far to the 

 south may perhaps best be accounted for by postulating a gentle 

 undulation of the strata in this region. Only a slight elevation 

 need be assumed, for the top of. the Onondaga is reported to 

 be only 20 feet below the Stafford limestone, and the locality 

 at Wende where the base of the latter is exposed is about 2^ 

 miles from the outcrop of Onondaga at Alden. An elevation, 

 therefore, of 20 feet in a distance of 2J miles would be sufficient 

 to bring the Onondaga to the surface, and the extent of deflec- 

 tion of the outcrop would depend on the shape of the fold. 



West of Lancaster an outcrop of limestone in the bed of 

 Buffalo creek below Gardenville appears, from its lithologic 

 character and its relations to the Marcellus shales, to corre- 

 spond with bed H of the Plumbottom creek section. 



The Stafford limestone was passed through in digging the 

 sewer trenches near the corner of Buffum and Seneca streets, 

 but for the thickness at this locality no accurate data could be 

 secured. Another exposure of Stafford limeetone in Erie county 

 is mentioned by Bishop at the point where the Buffalo, Rochester 

 and Pittsburg railroad diverges from the Western New York 

 and Pennsylvania, and the Lake Shore railroads, but the thick- 

 ness is not given. From these facts it appears that the lime- 

 stone forms as bed rock, a band approximately J to ^ a mile wide 

 extending across the county in a slightly southwest direction 

 from the vicinity of Wende station to Lake Erie. 



The rapid increase in thickness in the comparatively short 

 ■distance between Stafford and Plumbottom creek and the 



1 Bishop. Structural and economic geology of Erie county. 



