116S NEW YORK STATE MUSEUM 



thickness of the Salina, thus proving by the section along Wheel- 

 ock's creek the true stratigraphic position of the Cobleskill 

 limestone. 



In his section Mr Schuchert states that the Niagara is absent 

 and that " Hall was able to find the Niagara formation as far 

 east as Oneida county" [p. 162]. Vanuxem 1 records the pres- 

 ence of the Niagara in Steeles creek, Herkimer county. This out- 

 crop is about 3 miles southeast from the section under consider- 

 ation, and its presence there is also recorded by Hall. 2 The Ni- 

 agara can be observed in place there on the right of the highway 

 passing from Ilion to Cedarville. This exposure affords a favor- 

 able opportunity to study the concretionary nature of the 

 Niagara and its contact with the Salina shales. The Niagara 

 has not been observed east of Steeles creek. There are some 

 sections in western Herkimer and eastern Oneida where the 

 Niagara is covered. Hall 3 states : " Over a part of Oneida county 

 and the western* part of Herkimer, there is a space where no rep- 

 resentative of the Niagara group has been traced continuously ; 

 not that the place where it should occur has been examined and 

 found to be wanting, but because there are no good exposures of 

 the strata which enable one to examine and determine satis- 

 factorily the presence or absence of a thin bed like this one. In 

 tracing the same line eastward however, into Herkimer county, 

 there is a thin mass of limestone holding the same place, but 

 more closely united perhaps with the drab limestone above, 

 which is the thinned Onondaga-salt group." The thin mass of 

 limestone referred to is the Cobleskill. Tracing the Niagara from 

 Oneida county eastward should have brought Hall to the expos- 

 ure of the Niagara on Steeles creek, but at a point west of Steeles 

 creek, he records the presence of the Coralline thus showing that 

 the position of the Cobleskill as given by Hall was due to some 

 extent to an error in correlation in Herkimer county. 



In Wheelock's creek the Niagara is thin, but the contact with 

 the Clinton and the Salina can be favorably seen in the bed of 

 the stream. The geodic concretions containing dolomite crystals, 



1 Geol. N. Y. 3d Dist. 1842. p. 91. 



2 Palaeontology of New York. 1852. 2: 107. 



3 Palaeontology of New York. 1852. 2: 321. 



