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NEW YORK STATE MUSEUM 



in western New York and Canada on the Cobleskill. In western 

 Maryland the Oriskany is 350 feet thick, and rests on the New 

 Scotland which itself is only 64 feet thick, while the Becraft is 

 absent altogether. In many localities in New York and elsewhere 

 the unconformity at the base of the Oriskany is emphasized by 

 the fact that the lower beds are conglomeratic and contain frag- 

 ments of the underlying limestones. 1 



Clarke has suggested that the Oriskany of Becraft mountain 

 is merely the deeper water facies of the normal Oriskany which 

 is typically developed in the northern Helderbergs and the Scho- 

 harie region. The fossils of the type locality, Oriskany Falls 

 N. Y. are considered by Clarke as not indigenous, the character 

 of the deposit indicating a habitat unfavorable for the large 

 brachiopods found in the rock. In the townships of Oneida and 

 North Cayuga Out., 50 miles west of Buffalo, a remarkable assem- 

 blage of fossils occurs in the Oriskany beds, which Schuchert 

 has regarded as forming a typical late Oriskany fauna (Decew- 

 ville). The strata here rest unconformably on the Lower Manlius 

 which, as at Buffalo, is traversed by sandstone dikes, and they 

 are immediately succeeded by the Onondaga limestone. The 

 corals of the latter are mingled with the fossils of this phase 

 of the Oriskany in such a manner that except for the lithic dis- 

 similarity of the two formations, they could not be separated. 

 Out of the 71 species found in these Decewville beds " not less 

 than 12 pass up from the lower horizon into the Onondaga." 2 

 On account of the marked Onondaga aspect of the fauna, Schu- 

 chert holds that it is unwise to call these Ontario beds Oriskany 

 any longer, and has proposed the name Decewville for it, from 

 the nearest village, which in turn bears the name of the early 

 describe r of these beds, John DeCew. 



The absence of the normal (Schoharie county) Oriskany in 

 western New York and at Cayuga Ont. is readily explained by 



l 8ee Rogers, W. B. Am. Jour. Sci. 1842. 43:181, for examples of pro- 

 nounced unconformity and evidence of erosion at the base of the Oriskany 

 in Pennsylvania. 



2 Schuchert. Loc. cit. 1902. p. C53. 



