36 NEW YORK STATE MUSEUM 



impracticable to extend the operations in the few months available 

 beyond the crystalline rocks of the Adirondacks and southeastern 

 New York, but it is aimed eventually to cover the quarries of the 

 whole State. Sufficient observations and materials are in hand for 

 a detailed description of the granites and other silicate rocks, which 

 is now being prepared. According to the plan to be followed the 

 information will include results of physical tests, chemical analyses 

 and microscopic examination of representative specimens, so far 

 as they can be secured or made for the special purpose of the 

 report. 



The last complete work on the building stones of the State is that 

 by Smock which was published over twenty years ago. 



The great expanse of crystalline rocks included in the Adirondacks 

 and the outlying region affords a variety of quarry materials, some 

 of which are suitable for building and ornamental uses and are 

 classed by the trade under the general term of granite. The most 

 widespread types comprise granites proper, syenites and anorthosites. 

 Gabbros, dike rocks and gneisses have more limited applications but 

 are serviceable for local purposes of road improvement, engineering 

 construction, or rough work in which durability rather than an 

 attractive appearance is the essential requirement. The development 

 of the quarry industry in the Adirondack region has been retarded 

 by lack of proper transportation facilities. Though these are much 

 improved, compared with the conditions twenty years ago, there is 

 less security for new enterprises by reason of competition from the 

 established industries of other states. Only for materials of excep- 

 tional beauty or quality can any extensive sale be anticipated under 

 present conditions. 



One of the better known granites of this region is found in the 

 outlying area of crystalline rocks exposed along the St Lawrence 

 river from Clayton to Alexandria Bay. The rock is called Picton 

 granite in Cushing's recent report on the St Lawrence region but 

 the general trade term is Thousand Islands granite. It outcrops 

 over parts of Wellesley and Grindstone islands, as well as many of 

 the smaller islands in the river, and has a characteristic bright red 

 color and a texture varying from coarse to fine. It has been quar- 

 ried quite extensively for building, monumental and paving stone. 

 It ranks with the best of American red granites. Picton island is 

 the main source of present supply; a fine grained variety found 

 there is distinguished by its beautiful pink color. 



An area of red granite which hitherto has not been mapped or 



