THE MINING AND QUARRY INDUSTRY 961 



to the Clarkson Marble Co. It is intended to add new equipment 

 and to commence operations during the present season. 



In the Lake Champlain region the only producers have been Peter 

 Leyotte of Plattsburg and the BurHngton Marble Co. 



The Glens Falls Co. of Glens Falls was succeeded by Finch, 

 Pruyn & Co. 



In southeastern New York, the South Dover Marble Co., the 

 Waverly Marble Co., F. W. Jones & Co., and the O'Connell Lime 

 and Marble Dust Co., were active. The last named compan}^ uses 

 its output for manufacturing lime and marble dust. 



Sandstone 



Under this heading are included all sedimentary rocks that are 

 made up of granular quartz. Among the principal varieties dis- 

 tinguished by textural characters are sandstones proper, con- 

 glomerates, grits and quart zites. 



The wide distribution of sandstones in the geologic series of 

 New York State has given them great importance as economic 

 sources of structural materials, and in point of annual output they 

 rank second only to limestones. Nearly all of the main formations 

 above the Archean contain sandstones at one or more horizons. 

 The general properties and occurrence of the most important of 

 these rocks are here briefly reviewed. 



Potsdam sandstone. The Potsdam or Upper Cambric is the 

 oldest formation in which quarries have been opened in the State. 

 It is developed most extensively on the borders of the Adirondacks. 

 In the Champlain valley it outcrops at frequent intervals from 

 Fort Ann northward to the Canadian boundary. On the southern 

 side it is not so well represented, though there are few exposures, 

 best shown in Fulton and Saratoga counties. Along the northern 

 edge of the Adirondacks from Lake Champlain to the St Lawrence 

 river, a broad band of Potsdam crosses Clinton, Franklin and St 

 Lawrence counties and reaches well into Jefferson. It is in this 

 section, chiefly around Potsdam, that the largest quarries have 

 been opened. 



The Potsdam, typically, is an even grained sandstone of reddish 

 color, hard and compact. Owing to the cementation of the com- 

 ponent grains by secondary deposition of quartz, it combines great 

 strength with low absorptive powers, making it one of the most 

 durable building stones known. The comparative isolation of the 

 quarries from the large cities and the slightly increased cost of 

 dressing the stone due to its abnormal hardness have operated, 



