790 KEW YOEK STATE MUSEUM 



Magnesia 22 . 1 



Carbon dioxid 47 . 39 



100.65 



If tills rock sliowecl tlils same character at other points, it 

 would show it to be an important bed, and to determine this 

 additional analyses were made by Mr !N^ewland. The first of 

 these represents the average of several samples taken from 

 Snow's quarry at Gates near Rochester. i 



Silica . .' 7 



Magnesia 20.05 



Lime 30.5 



Alumina 95 



Ferric oxid 8 



Carbon dioxid 45 . 24 



Ignition 073 



Undetermined 2 . 687 



The last analysis is of a sample from the Copeland quarry in 

 Rochester, collected by G. van Ingen. 



Silica 29 



Alumina .43 



Terric oxid 46 



Loss on ignition 07 



Lime carbonate 56.01 



Magnesium carbonate 43 . 3 



100.56 



This shows the rock to be an almost pure dolomite. 

 The Clinton also occurs in Monroe county, and is to be seen 

 outcropping at the middle falls in the gorge of the Genesee river 



