>]2 NEW YORK STATE MUSEUM 



and on the southeastern edge of the Adirondack region. These lat- 

 ter areas represent the remnants of a on e continuous belt that has 

 been broken up by folding, faulting and erosion. The Potsdam 

 sandstone has in many places the character of a quartzite, consisting 

 of quartz grains cemented by a secondary deposition of quartz, and 

 then is a very hard, tough and durable stone. The quartzite from 

 St Lawrence county has sustained a crushing test of more than 

 42,000 pounds to the square inch. The color varies from deep red 

 to pink and white. The principal quarries are near Potsdam and 

 Redwood, St Lawrence county, and Malone and Burke, Franklin 

 county. Besides building stone, which is the chief product, there 

 is some flagstone sold, mainly by the quarries at Burke, for ship- 

 ment to Montreal. 



The so-called Hudson river group is essentially a group of sand- 

 stones, shales, slates and conglomerates, ranging in age from the 

 Trenton to the Lorraine, but which have not been sufficiently 

 studied to permit the actual delimitation of the various members on 

 the map. The group is exposed in a wide belt along the Hudson 

 from Glens Falls southward into Orange county and also in the 

 Mohawk valleys as far west as Rome. The sandstone beds are 

 usually fine-grained, of grayish color and rather thinly bedded. 

 Over wide stretches they provide practically the only resource in 

 constructional stone and consequently they have been quarried at 

 a great number of places to supply the local needs for building and 

 foundation work. Some of the stone is crushed for road metal 

 and concrete. 



The Medina sandstone is found along the southern shore of Lake 

 Ontario from the Niagara river east to Oswego county : in entral 

 New York it is represented by a coarse conglomeratic phase called 

 the Oneida conglomerate. As developed in the western part of 

 of the State, where it is principally quarried, it is hard fine-grained 

 sandstone of white, pink and variegated color. The pink variety 

 is specially quarried for building stone and has an excellent reputa- 

 tion. Many of the larger cities of the country and most of the 

 important towns and cities of the State contain examples of its 

 architectural use. The large quarries are situated in Orleans 

 county, near Albion, Holley and Medina, along the line of the Erie 

 canal, but there are others at Lockport and Lewiston, in Niagara 

 county and at Brockport and Rochester in Monroe county, The 

 Medina sandstone also finds extensive applications for curbing and 

 flagging and for paving blocks. It is employed more extensively 

 for the latter purpose than any other stone quarried in the State. 



