GEOLOGIC MAP OF THE BUFFALO QUADRANGLE 



19 



east it increases more rapidly and attains a thickness of 350 feet 

 in the Tully valley in Onondaga county. 



The extreme western exposure of the Ludlowville shale in New 

 York is at the base of the south shore cliffs, which extend for 1$ 

 miles southwest from the mouth of Eighteen Mile creek, 5$ miles 

 beyond the south line of this quadrangle. The lower beds in the 

 cliffs at Idlewild and nearly all of those exposed in Wanakah 

 cliff belong to the Ludlowville shale. 



On this quadrangle good exposures may be seen along Avery's 

 creek where the limestones at the base of the formation produce a 

 small cascade just above the lake shore highway bridge; along 

 Rush creek, near Wosgwah station of the Hamburg Electric 

 Railroad; along the south branch of Smoke's creek near Windom; 

 along its east branch, 1 mile southwest from Reserve and along 

 Cazenovia creek, 1 mile east from Reserve. 



There are further large exposures of these beds at several locali- 

 ties east of this quadrangle, some of the best being in Ontario county 

 on Shaffer's creek and in the lower part of the ravines on both 

 sides of Canandaigua lake north of Menteth point; on the shore of 

 Cayuga lake between Aurora and King's Ferry from 10 to 16 

 miles north of Ludlowville; and in Onondaga county, in the Bear 

 mountain and Fellows falls ravines; in the Tully valley and at 

 Pratt's falls in Pompey. 



The Ludlowville shales abound in fossils most everywhere. 

 Dr Grabau's list of those obtained from this horizon in the vicinity 

 of Eighteen Mile creek names 120 species, embracing 6 crustaceans, 

 4 cephalopods, 4 pteropods, 29 lamellibranchs, 50 brachiopods, 

 1 crinoid, 8 bryozoans and 7 anthozoans. 



Some of the more prominent or abundant forms are: 

 Phacops rana (Green) Orthothetes arctostriatus Hall 



Crypheus boothi Green Chonetes lepidus Hall 



Nautilus magister Hall . Chonetes scitulus Hall 



Orthoceras nuntium Hall Spirifer mucronatus (Conrad) 



Tentaculites gracilistriatus Hall Sp. granulosus (Conrad) 



Styliolina fissurella (Hall) Sp. subumbonatus Hall 



Platyceras attenuatum Hall Sp. fimbriatus (Conrad) 



Diaphorostoma lineatum (Hall) Ambocoelia umbonata (Conrad) 



Pterinea flabellum (Conrad) Athyris spiriferoides (Eaton) 



Actinopteria decussata Hall Atrypa aspera (Dalman) 



Modiomorpha subalata (Conrad) Camarotoechia dotis Hall 



Paleoncilo tenuistriata Hall Liorhynchus multicostum Hall 



Cypricardinai indenta Conrad Tropidoleptus carinatus (Conrad) 



Stropheodonta demissa (Conrad) Stictopora incisurata Hall 



Leptostrophia perplana (Conrad) Pleurodictyum stylopora (Eaton) 



Rhipidomdla vanuxemi He-' Streptelasma rectum Hall 



