Geographical Distribution. 21 



valley, in Montgomery, Herkimer and Oneida counties. The quar- 

 ries at Little Falls, Canajoharie and other smaller openings, are in it. 

 The Sandy Hill quarry also is apparently in the same horizon. Gen- 

 erally the stone of this formation is in thick beds, siliceous, hard, 

 strong and durable. 



Chazy Limestone. 



The Chazy formation is seen in Clinton county in its typical 

 locality. It is non-magnesian and less siliceous than the Calciferous. 

 The beds are thick and often uneven. Regular joints are com- 

 mon, dividing it into rectangular masses and helping the quarry men 

 in extracting the stone. It affords strong and heavy stone at quarries 

 in the Champlain valley, at Willsboro Point and near Plattsburgh. 



Trenton Limestone. 



The Trenton here includes the Birdseye, Black River and Trenton 

 formations. And it occupies the Mohawk valley, the Champlain 

 valley, a border zone around the south-western and western sides of 

 the [Adirondack region, and the St. Lawrence valley, from the 

 Canada line south-west to Lake Ontario. The counties of Mont- 

 gomery, Fulton, Herkimer, Oneida, Lewis, Jefferson, St. Lawrence, 

 Hamilton, Clinton, Essex, Warren and Saratoga have outcrops of 

 limestones which are referred to the Trenton age. Many quarries in 

 the Mohawk valley ; the quarries at Prospect and Holland Patent in 

 Oneida county ; Lowville in Lewis county ; Watcrtown, Chaumont 

 and Three Mile Bay in Jefferson ; Norwood and Ogdensburg in St. 

 Lawrence ; and Glens F^lls are opened in these limestones. There 

 is much variation, from the dark- colored, compact marble of Glens 

 Falls to the gray, fine-crystalline stone of the Prospect quarries. 

 And these variations are often seen in vertical sections of compara- 

 tively few feet, so that the same quarry may yield a marble and a 

 coarse, rough stone fit for common walls only. Hence no general 

 description is applicable to the formations as a whole ; and it is 

 impossible to assign all of the quarries to their proper horizon. In 

 fact, in some of the quarries two formations are represented. 



Niagara Limestone. 



This formation has its great development near the Niagara river and 

 the Lockport and Rochester limestone quarries are in it. At Lock- 

 port it is a gray, thick-bedded, sub-crystalline stone, which has been 

 used widely for building. 



