GEOLOGY OF THE ATTICA AND DEPEW QUADRANGLES I3 



Exposures. A few inches of Marcellus black shale appear be- 

 neath the ledge of the Stafford limestone in the bed of Ellicott 

 creek at Wende, south of the Lehigh Valley Railroad bridge. 

 About 2 feet of black shale are exposed in Cayuga creek at Lan- 

 caster, just above the lower bridge, and also under the limestone 

 below the Lake Como dam and similarly situated, in the bed of 

 Plumb Bottom creek east of Foundry street. No other outcrops of 

 the Marcellus shale occur on these quadrangles. 



STAFFORD LIMESTONE 



In western New York the Marcellus black shale is overlaid by 

 a bluish gray compact limestone, that at its most eastern exposure 

 on Flint creek in the town of Phelps, Ontario county, is but 4 inches 

 thick but increases to 3 feet at Stafford, 8 feet 4 inches at Lan- 

 caster and, according to a well record, to 15 feet on Smoke creek in 

 West Seneca. In the Seneca Lake valley this horizon is marked 

 by a band of gray calcareous shale in which are imbedded spheric 

 concretions containing fossils of the same species as those found 

 in the limestone on these quadrangles. The largest exposure of 

 this formation and the one most favorably situated for examina- 

 tion is in the beds of Cayuga and Plumb Bottom creeks in the village 

 of Lancaster, where all the strata may be seen. It is here composed 

 of 6 to 8 layers of limestone varying but slightly in lithologic char- 

 acter and quite fossiliferous throughout. 



The Stafford limestone at Lancaster and its fauna have been 

 fully described in New York State Museum Bulletin 49, with a 

 complete list of the fossils and descriptions of species, of which 

 there are 72. The more common forms are : 



Ambocoelia nana Grabau 

 Chonetes mucronatus Hall 

 C. scitulus Hall 



Liorhynchus limitare (Vanuxem) 

 Strophalosia truncata (Hall) 

 Meristella barrisi Hall 

 Spirifer subumbonatus Hall 

 Cypricardinia indenta Conrad 

 Orthoceras exile Hall 

 O. marcellense Vannxem 

 Phacops rana Green 

 Primitiopsis punctulifera Hall 



Exposures. Besides those mentioned as occurring at Lancaster, 

 a small outcrop in the bed of Ellicott south of the Lehigh Valley 

 Railroad bridge, and a very small one in an old pit 2 miles north of 

 Alden, there is no exposure of Stafford limestone on these 



