812 NEW YOEK STATE MUSEUM 



in a local furnace, while some lias been sliipped to Troy, and at 

 times it has also been used for lime manufacture. ^ 



The best stone is found in Cornelius McCaffery's quarry. The 

 section there is nearly 60 feet thick, rather flinty in the upper 

 part but in the lower yielding stone which analyzed: 



Silica 1.2 



Ferric oxid 1.5 



Alumina . 2 



Lime 34.11 



Magnesia 8.97 



St Lawrence county^ 



The Trenton-Chazy limestones extend along the St Lawrence 

 river from Chippewa Bay to the northeastern edge of the county. 

 Their southeastern bou-udary passes through Mackville, ISTorwood, 

 iNorth Stockholm, Brasher Falls and Fort Covington Center. 



At Ogdensburg the stone has been quarried for lime manufac- 

 ture about a mile west of the town. The stone is thin bedded^ 

 and only the upper layers of the quarry are used for lime. 



The following analyses show not only the dolomitic character 

 of the rock but also the greater freedom from silica of the upper 

 layers. 



Upper stone, Howard's quarry, Ogdensburg: 



,Silica 4 . 42 



Alumina 2.23 



Ferric oxid , . .16 



Lime carbonate . 55 . 87 



Magnesium carbonate 37 . 74 



100.42 



1 Smyth, C. H. jr. A geological reconnaissance in the vicinity of Gouver- 

 neur, N. Y. {see Trans. N. Y. acad. sci. 12: 97) 



Preliminary examination of the general and economic geology of 



four townships in St Lawrence and Jefferson counties, N. Y. (see 47th an. 

 rep't N. Y. state mus. p. 687) 



