24 Report on Building Stone of New York. 



The Hudson River group in New York, is characteristically a slate 

 formation. It occupies the Wallkill valley in Orange county, the 

 valley of the Hudson river from the Highlands northward to Sara- 

 toga and Washington counties, and the Mohawk valley west, and 

 thence a belt north-west to Lake Ontario. Slates of the Cambrian 

 age are recognized east of the Hudson in Washington and Rensselaer 

 counties, near the Vermont line. It is not known that any of the 

 slaty rocks of the other geological formations in the State yield 

 slate of economic importance. Roofing slate has been sought 

 after in very many places within the bounds of these formations and 

 quarries, which have been more or less productive, have been 

 opened in Orange, Dutchess, Columbia, Rensselaer and Washington 

 counties.* At present, the productive quarries are all in Washing- 

 ton county, and are limited to a narrow belt which runs from Salem 

 north-north-east, through the towns of Hebron, Granville, Hampton 

 and Whitehall. There appear to be four ranges or belts (" veins" of 

 quarry men) first, on the west, the East Whitehall reel slate ; second, 

 the Mettowee or North Bend red slates ; third, the purple, green 

 and variegated slates of Middle Granville, and on the east, near the 

 Vermont line, the Granville red slates. These quarries of Washington 

 county produce a large amount of colored slate for decorative and 

 ornamental work, and all the red slate which is quarried in our coun- 

 try, comes from this district, f 



* See Mather's Report on the First District, pp. 419, 421. 



f The line between Vermont and New York runs so as to separate the red and sea- 

 green slates, and all of the former are in New York, while all of the latter are in 

 Vermont. 



