THE GEOLCGY OF THE SYRACUSE QUADRANGLE 59 



lying red Vernon shale is unfossiliferous. In the succeeding Camil- 

 lus formation gypseous shales and the casts of halite crystals indicate 

 a body of water cut off from the sea and rendered so saline by ex- 

 cessive evaporation that life within its confines was all but impossible. 



In a limestone (Fiddler's Green) lying near the top of the Camil- 

 lus series, a poorly preserved Leperditia is encountered in great 

 numbers. This horizon is both overlaid and underlaid by gypsum 

 beds and points to a slight freshening of the water which permitted 

 this hardy form to swarm into the area. 



Above the gypseous shales and limestones of the Camillus comes 

 the Bertie waterlime, regarded as the final stage of the Salina group. 

 Though noted in western New York and in Herkimer county for its 

 beautifully preserved eurypterids, the Bertie is here lacking in or- 

 ganic remains. 



The entire Salina group of strata, beginning with the Pittsford 

 and ending with the Bertie, represents a nonmarine series. During 

 its deposition any communication with the sea was, at best, inade- 

 quate and transitory and was never sufficient to allow the invasion 

 of a marine fauna. 



THE FAUNAS OF THE UPPER CAYUGAN GROUP 



This group of strata is ordinarily made to comprise the Cobleskill 

 dolomite, Rondout dolomite and Manlius limestone. 



Cobleskill dolomite. In central New York this oldest member of 

 the group is -difficult of discrimination on a paleontologic basis. As 

 a rule the rock is unfossiliferous, but Hartnagel 1 has reported 

 Spirifer crisp us var. corallinensis Grabau, W h i t - 

 fieldella nucleolata Hall, Chonetes jersey- 

 e n s i s Weller and Strop heodonta bipartita Hall from 

 the town of Dewitt. The rich and decidedly late Siluric fauna listed 

 by the same author 2 from Schoharie county has not been detected 

 in the local outcrops. 



Rondout dolomite. The Rondout is a very sparingly fossiliferous 

 formation, generally regarded as representing a partial return to 

 Salinalike conditions. Eurypterids occur at this horizon near 

 Union Springs, Cayuga county, and at Seneca Falls, 3 but in the 

 Syracuse area the only fossil so far observed is a small Spirifer ap- 

 parently identical with S. vanuxemi Hall. This species, 



1 N. Y. State Mus. Bui. 69, p. 1161. 



2 Ibid, p. 1126-28. 



S N. Y. State Mus. Bui. 69, p. 1157. 



