GEOLOGICAL POSITION AND GEOGRAPHICAL DISTRIliUTION 217 



There are, In consequence, large sandstone areas and dis- 

 tricts in which there is an absence of local development, or 

 abandoned enterprises mark a change in conditions, which 

 has affected injuriously the quarry industry in them. 



Followino^ the oreoloorical order of arrano^ement and begfin- 

 ning with the Potsdam sandstone, the several quarry dis- 

 tricts are here reviewed briefly. 



Potsdam Sandstone 



This formation is the oldest in which, in this state, sand- 

 stone is quarried."^ 



The bottom beds are a fine, siliceous conglomerate ; above 

 are sandstones and in thin beds generally. It is gray-white 

 yellow, brown and red in color. In texture it varies from a 

 strong, compact quartzitic rock to a loosely-coherent, coarse- 

 granular mass, which crumbles at the touch. 



Outcrops of limited area occur in Orange and Dutchess 

 counties, and in the Mohawk valley. In the Champlain 

 valley the formation is well developed at Fort Ann, White- 

 hall, Port Henry and Keeseville, and quarries are opened at 

 these localities. The stone is a hard, quartzose rock, and 

 in thin beds. North of the Adirondacks the formation 

 stretches westward from Lake Champlain to the St. Law- 

 rence ; and there are quarries in the towns of Malone, Bangor 

 and Moira in Franklin county ; in Potsdam and Hammond 

 in St. Lawrence county; and, in Clayton, Jefferson county. 

 In parts of Clinton county the stone is too friable for 

 building uses. 



The most extensive openings are near Potsdam, and the 

 stone is hard, compact and even-grained, and pink to red in 

 color. Some of it has a laminated structure and striped 

 appearance. It is an excellent building stone and Is widely 

 known and esteemed for its beauty and durability. 



* Some of the sandstones east of the Hudson and in the Taghanic range may belong 

 to the Lower Cambrian. See Am. Jour, of Science, iii series, vol. 35, pp. 399-401. 

 But there are no quarries opened in these localities. 

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