grained 



grained 



2.655 



2.64 



.06 



■13 



18.8 



18.9 



12. 



13-5 



QUARRY MATERIALS OF NEW YORK 77 



inch. An absorption test on a 4-inch cube dried to constant weight 

 and immersed in water for five days showed .023 grams of water 

 absorbed for each square inch of surface. 



Specimens of the medium-grained and fine-grained granites 

 from these quarries were submitted for testing to the bureau of 

 research, State Department of Highways with the following results: 



Medium- Fine- 



Specific gravity 



Absorption, pounds a cubic foot 



Hardness 



Toughness 



ALEXANDRIA BAY AREA 



An exposure of granite or granitic gneiss around Alexandria Bay 

 has been of some importance in the quarry industry of the St Law- 

 rence river region. It has furnished little building or monumental 

 stone, but is chiefly valuable for paving material and rough work. 



The granite differs markedly in appearance from the granite 

 quarried on Grindstone and Picton islands, having usually a finer 

 grain, lighter color and a texture that in places is distinctly gneiss- 

 oid. The occurrence is described by Gushing under the name of 

 the Alexandria bathylith and is placed by him in the Laurentian 

 gneiss group, older than the characteristic massive granite of the 

 neighboring islands. The fine grain, as well as the gneissoid ap- 

 pearance which it exhibits in some places, is a secondary feature 

 superinduced by regional compression; occasional uncrushed rem- 

 nants of larger crystals (mainly feldspar) are still in evidence. The 

 composition is that of a typical granite, with feldspar, quartz and 

 mica as the principal minerals, ranking in the order given. 



The granite extends for several miles north and south of Alex- 

 andria Bay along the river. Few ledges suitable for quarry sites 

 occur as the country is generally flat and the higher ground often 

 is mantled by Potsdam sandstone which rests in horizontal beds 

 upon the granite. Much of the rock, also, carries inclusions of 

 darker color and is seamed with quartz and pegmatite. 



Quarry of J. Leopold & Company 



The principal quarry in the Alexandria granite is situated about 

 one-half of a mile south of Alexandria Bay and belongs to J. Leo- 

 pold & Gompany of New York. A knob of the granite rises lod 

 feet or more above the river, forming the most conspicuous ele- 



