1160 



NEW YORK STATE MUSEUM 



and later the salt beds. The deposition of these great beds of 

 rock salt marks the turning point in this cycle, at which time the 

 Salina sea contained very little if any water at all. With the 

 increasing depth of the sea, beds of gypsum were again deposited, 

 but never again were the conditions favorable for the deposition 

 of extensive beds of rock salt. Following the gypsum beds, we 

 have the Salina waterlime with its splendid Eurypterus fauna, 

 and associated with the Eurypterus is a species of Lingula similar 

 to the one at the base of the Salina. Above the Eurypterus beds 

 we have the Cobleskill limestone, and here again we have repre- 

 sentatives of the Niagara-Guelph fauna. 



Era or system 



Period or group 



Age or stage 



1 Ontaric or Siluric 



Cayugan 



(Neontaric) 



Niagaran 



(Mesontaric) 



Oswegan 



(Paleontaric) 



f Manlius limestone 

 I Rondout waterlime 

 I Cobleskill limestone 

 -{ Salina beds 



Wilbur limestone, 

 (Pittsford shale, 

 t local facies) 



f Guelph dolomite 

 Lockport limestone 

 Rochester shale 

 Clinton beds 



Medina sandstone 



Oneida conglomerate 

 Shawangunk grit 



Upper Siluric sections in Onondaga county 



The upper limit of the waterlime group of Vanuxem, in the 

 eastern part of the third district was marked by the Coeymans 

 limestone. At the type locality of the Manlius limestone in 

 Onondaga county, where the Coeymans limestone together with 

 the other members of the Helderbergian formation were sup- 

 posed to be absent (not being recognized west of Madison 

 county), the Waterlime group included all the strata up to the 

 Oriskany sandstone. 



In the townships of Manlius and Dewitt, Onondaga county, 

 the thickness of the strata from the gypsum beds of the 

 Salina to the Oriskany sandstone is 190 feet. The lower portion 



1 Ontaric or Siluric of the New York series as modified from Science, Dec. 15, 

 1890. 



