82 NEW YORK STATE MUSEUM 



marble. It is used also for lime and furnace flux. There are old 

 quarries on Willsboro point, Essex county. On the west side of 

 the Adirondacks the Pamelia limestone, described in the area! re- 

 ports of that section, belong to the Chazy series. It covers a con- 

 siderable area in Jefferson county between Leraysville and Clayton, 

 and has been rather extensively quarried for building stone and 

 lime, though of subordinate importance to the Trenton limestones of 

 that section. 



In the Mohawkian or Trenton group are included the Lowville 

 (Birdseye), Black River and Trenton limestones which have a wide 

 distribution and collectively rank among the very important quarry 

 materials of the State. They are represented in the Champlain 

 valley but are specially prominent on the Vermont side; from the 

 latter area a belt extends southwest across northern Washington 

 county to Glens Falls in Warren county and is continued into 

 Saratoga county. Another belt begins in the Mohawk valley near 

 Little Falls and extends northwesterly with gradually increasing 

 width across Oneida, Lewis and Jefferson counties to the St 

 Lawrence river. There are isolated areas of Trenton limestone in 

 the Hudson valley south of Albany. The limestones vary in com- 

 position and physical character according to locality and geologic 

 position. They are often highly fossiliferous. In the northern 

 section they are mostly gray to nearly black in color, contain little 

 magnesia and run as high as 97 or 98 per cent calcium carbonate. 

 The lower part of the group is heavily bedded and well adapted for 

 building stone ; the upper beds commonly contain more or less shale. 

 They are used for various purposes including building and orna- 

 mental stone, crushed stone, lime, portland cement and flux. In the 

 Champlain valley quarries are found near Plattsburg, Larabees 

 Point and Crown Point ; in Washington county at Smiths Basin ; 

 in Warren county at Glens Falls where there are extensive quarries 

 that supply material for building purposes, portland cement and 

 lime. The well-known black marble from Glens Falls is taken 

 from the Trenton. Numerous quarries have been opened in Herk- 

 imer, Oneida, Lewis and Jefferson counties. The output of the 

 -last named quarry is specially important, including limestone for 

 building' and road construction and lime for manufacture of calcium 

 carbide. The principal quarries in Jefferson county are at Chau- 

 mont. 



The next assemblage of limestones in the order of stratigraphic 

 occurrence includes the Clinton, Lockport and Guelph members 



