788 NEW YOEK STATE MUSEUM 



The otlier limestone formations found in tlie county are of 

 mncli greater importance. The Helderberg limestones extend 

 across tlie soutliern edge of the county as a belt several miles 

 wide, whose northern limit passes through the towns of Jordan- 

 Yille, Columbia, C'edarville and Cedar Lake. They have been 

 quarried at several places, Columbia among them, for lime burn- 

 ing, but their distance from the railroad is a serious objection. 



The Tentaculite limestone is utilized at Columbia south of 

 Little Palls for the manufacture of lime, and a sample from A. 

 Manning's quarry showed the following composition. 



Silica 4.91 



Ferric oxid 53 



Alumina . , , 48 



Lime 51 . 82 



Magnesia 1 . 16 



Carbon dioxid , 41 . 9 



100.8 



The same quarry shows two thin layers of waterlime. 



The group of Trenton limestones is of some importance in 

 Herkimer county, but only the Birdseye and Trenton members 

 are present. 



Around Little Falls the Trenton is not over 4 feet thick accord- 

 ing to Darton, but at Ingham Mills the rock is well exposed in 

 the lime quarry of Sherman Butler (pi. 41), where nearly 15 feet 

 of good stone can be seen. The better stone is bluish, fine grained 

 and massive, but in the upper part of the quarry it passes into 

 the Utica slate. The following analyses represent its composi- 

 tion, no. 1 being the lower massive rock and no. 2 the average 

 of the quarry face. 



1 2 



Silica 6.7 8.45 



Alumina 3.03 2.72 



