192 NEW YORK STATE MUSEUM 



ing in width, through Otsego, Madison and Onondaga counties, 

 farming the upper part of the Susquehanna and Chenango water- 

 sheds; thence west, across Cayuga, Seneca, Ontario, Livingston, 

 Genesee and Erie counties to Lake Erie. In this distance there 

 is some variation in composition and texture. In the western 

 and central parts of the state there is an immense development 

 of shales and the few quarries in the sandstone referable to this 

 group are unimportant. In the Helderberg region in the Hud- 

 son valley and thence, southwest, to the Delaware river, the -sand- 

 stones predominate, and all etf the beds are more sandy than at 



the west. 



Bluestone 



There is a great development of the bluish-gray, hard, compact 

 and even-bedded stone, which is known as < Hudson river blue- 



stone.' 



This is a variety of sandstone, which, by reason of its even 

 texture can be cut or sawed into any desired form and is there- 

 fore peculiarly available for house trimmings of various kinds. 

 The sandstone is usually interbedded with shale and in general, 

 the layers in the quarries vary from an inch to several feet in 

 thickness; the thinner of these are used for flagstones and the 

 thicker are cut into dimension stones for building purposes. 



The geological horizon of the commercial bluestone is very near 

 the dividing line between the Hamilton and Portage groups. It 

 is however, not usually possible to determine in which of these 

 groups a given quarry belongs, owing to the great scarcity of 



fossils. 



The bluestone industry is chiefly located in Ulster county and 

 the quarries are almost innumerable but the business is con- 

 trolled by a few large dealers who are located at points favorably 

 situated for shipment and who, to a considerable extent, buy 

 stone from the men who quarry it. Bluestone is also produced 

 in the counties of Albany, Greene, Sullivan, Delaware and Chen- 

 ango in Eastern New York and in Cattaraugus and Wyoming 

 counties in Western New York. 



