120 



NEW YORK STATE MUSEUM 



the mouth of which is just above the CobleskiU, and Becker's 

 cave below Lasell park, the entrance to which is in the Manlius 

 above the waterlime. Numerous other caves occur in this rock 

 in eastern Xew York. Caverns are much less frequent in the 

 coarser grained limestone, though fissures of considerable width 

 are common. They generally open to the surface however. It 

 seems that the lime mudrocks are more readily dissolved than 

 the lime sandrocks which generally are more or less crystalline 

 and that furthermore the thin bedded character of the rock is 

 more favorable to the passage of underground water than is the 

 coarse massive-bedded lime sandrock of the higher formations. 



In the western part of the State of Xew York the Siluric 

 (Ontaric) section is as follows, the thicknesses given being those 

 found in the Niagara section. 



Devonic Onondaga limestone 



iluric 

 or 

 Ontaric 



Hiatus 



f CobleskiU 1 (Bullhead) limestone 



Bertie waterline 



J Camillus shale 



Cayugan A &yY „ beds 



i Vernon shale ) 

 LPittsford shale j 

 fGuelph dolomites | 

 J Lockport dolomite \ 



) Rochester shale 



[ Clinton beds 



[ Medina sandstones 



{ Medina shales and sandstones . . 

 L Oswego sandstone 



JS iagaran 



Oswegan 



FEET 



7-8 

 60 

 15o 



35 



200 



200 



75 

 40 



125; 

 1U0: 

 75; 



( Jhamplainic Lorraine shales 



In central New York the Oswego sandstone merges into the 

 Oneida: a pure white quartz pebble conglomerate. At Washing- 

 ton Mills, Oneida CO. this conglomerate rests directly on the 



'The name (Jreenfiold limestone has been used by the author for this 

 western type ot Ihe CobleskiU, from Greenfield ()., where it is well .de- 

 veloped. Science, Dec. 2, ISDN. v.s. no.205, p.800. 



