2io bulletin of the new york state museum 



Calciferous Sandrock 



The rocks of the Calciferous formation in the Mohawk 

 valley and in the Champlain valley are more siliceous than 

 at the south-west, in Orange county and in the Hudson val- 

 ley, and hence the designation as a sandrock. Much of it 

 at the north is a limestone rather than a sandstone, and may 

 be termed a magnesian or siliceo magnesian limestone. 

 Nearly all of the limestones, which are quarried for build- 

 ing stone, in Orange and Dutchess counties are from this 

 formation. The stone occurs generally in thick and regular 

 beds. It is hard, strong and durable and is adapted for 

 heavy masonry as well as for fine cut work. The quarries near 

 Warwick, Mapes' Corners and near Newburgh in Orange 

 county and those on the Hudson river, near New Hamburgh, 

 are in the Calciferous. The Sandy Hill quarry and those 

 at Canajoharie and Little Falls are also in it. 



Trenton Limestone 



Under this head the Chazy, Birdseye, Black River and 

 Trenton limestones are included. 



The Chazy limestone crops out in Essex and Clinton 

 counties and in the Champlain valley — its typical localities. 

 The beds are thick and generally uneven. Regular systems 

 of joints help the quarrymen in getting out large blocks. 

 Quarries at Willsborough Point and near Plattsburgh are 

 opened in the horizon of the Chazy. The stone is suitable 

 for bridge work and for heavy masonry. 



The members of the Trenton above the Chazy limestone 

 are recognized in many outcrops in the south-eastern part 

 of the state ; in the Hudson-Champlain valley ; in the Mo- 

 hawk valley ; in the valley of the Black river and north- 

 west, bordering Lake Ontario ; and in a border zone on the 

 north of the Adirondacks, in the St. Lawrence valley. In 

 so widely extended a formation there is, as might be ex- 

 pected, some variation in bedding, texture and color. Much 



