134 NEW YORK State museum 



In southeastern New York, the Highlands of the Hudson consist 

 almost entirely of granite and gneiss. Quarries have been opened 

 at numerous localities, particularly along the river where convenient 

 transport facilities can be had. In Putnam county, Breakneck 

 mountain, just north of Cold Spring, supplies a medium grained 

 grayish gneissoid granite which has been used extensively for build- 

 ing material and crushed stone. At Garrisons a true granite of 

 massive character outcrops and has furnished building stone to 

 New York city. Farther south around Peekskill there are several 

 quarries producing gneissoid granite. 



In Westchester county granitic roc)<:s are abundant and of varied 

 character. One of the principal formations is the Fordham gneiss, 

 a well foliated grayish biotite gneiss that has supplied much mate- 

 rial for foundations and rough masonry. The quarry localities 

 include Hastings, Lowerre, Bryn Mawr and Uniontown. The 

 Yonkers gneiss, more massive than the former and containing horn- 

 blende, affords a durable building stone which is obtained at Dun- 

 woodie and Scarsdale, while a similar rock occurs at Hartsdale, 

 Hastings, Tarrytown and White Plains. Dikes and bosses of mass- 

 ive granite are quite common and have been worked at New 

 Rochelle, Mount Vernon, Lake Mohegan, Westchester co. ; Round 

 Island, Rockland co. ; and at Pine Island, Orange co. The last 

 named locality affords a coarse hornblende granite much used as a 

 dimension stone. The Cortland series of gabbros and diorites out- 

 cropping south of Peekskill may be mentioned among the quarry 

 resources of this region. 



The crystalHne rocks of the Adirondacks extend over a great 

 area, but their inaccessibility has prevented the opening of quarries, 

 except on the borders. The varieties found here include massive 

 granites, syenites, gabbros and anorthosites, as well as gneissoid 

 phases of each. 



Building and monumental stone is quarried largely in Jefferson 

 county. Grindstone island, in the St Lawrence river, is noteworthy 

 as a locality for red granite of very attractive appearance. The 

 latter has a coarsely crystalline texture, takes a lustrous polish, and 

 on account of its deep red color has been employed as a substitute 

 for Scotch granite. It is used for building, monumental and decora- 

 tive purposes in many of the western cities and in Canada. 



At Little Falls, Herkimer co., there is an outlet of Adirondack 

 syenite which is worked to some extent. It is a closely textured 

 rock, well adapted for all construction work. In Fulton county 



