lime and cement industries 755 



is probably a continuous one, though not exposed at all points. 

 The most prominent exposures of the Chazy are in the quarries 

 of the Chazy marble lime co. and "William Goss, and at Grand 

 Isle. The rock is a gray, subcrystalline limestone, and affords 

 an excellent lime. The average thickness of the formation ac- 

 cording to Brain erd and Seely is about 700 feet. The character 

 of the stone is quite uniform. The Chazy limestone is not found 

 in the Mohawk valley and thins out in the central and western 

 part of the state. 



An analysis of the Chazy limestone from the quarry of the 

 Chazy marble lime co. at Chazy, shows the high degree of purity 

 of this limestone which is used in the manufacture of lime. 



Silica 72 



Ferric oxid and alumina .39 



Lime 53.9 



Magnesia 1 . 44 



Carbon dioxid , 43 . 92 



100.37 



The stone is also available for the manufacture of Portland 

 cement. 



Trenton 



The Trenton limestones involve several different members, viz, 

 Birdseye, Black river and Trenton, the last being the uppermost. 

 The most southern area is a small patch of impure, fossiliferous 

 limestone along the river road four miles north of Newburgh. 



An important belt extends southward along the Champlain 

 valley, then along the Mohawk to Little Falls and thence north- 

 westward to Watertown. Beds of the same age also occur east 

 of Lake Champlain and extend southward into Washington 

 county. 



In this belt they are often metamorphosed or folded, but along 

 the lake shore, specially along the margin of the Adirondack 



