QUARRIES IN HANCOCK COUNTY. 
105 
nent armory in New York. In 1905 this quarry was supplying the 
ough stone for the Brooklyn approach to East River Bridge, No. 3, 
sew York, and the cut stone for the Manhattan approach to the 
ame bridge, the trimmings for the University Heights Bridge, New 
fork, and the stone for the Flushing, Long Island, Bridge. 
The Sherwood quarries are north of Mill Cove, Crotch Island. 
)perators, S. Clinton Sherwood Company, No. 1 Madison avenue, 
s T ew York. (See fig. 15 for location of quarries.) 
The granite of the lower and northern quarry (specimen 25, a) 
s ;: biotite-muscovite granite of light-gray shade, with a very slight 
yellowish tinge, and of very fine texture, most of its particles rang- 
ng in size from 0.11 to 1.1 mm., the average diameter being about 
1.45 mm. There are, however, occasional quartz particles and feld- 
par crystals one-fourth inch across, and of the latter rarely one a half 
nch in length, so that the rock has a porphyritic texture. The con- 
stituents, arranged in descending order of abundance, are potash feld- 
fiG. 18. — Relations of fine biotite-muscovite granite 1B1 to coarse biotite granite (A and 
O, and of sheet structure to both at nortb end of Sherwood quarry. Crotch Island. 
Length, u feet. 
par (microcline and orthoclase), smoky quartz, soda-lime feldspar 
(oligoclase ) , black mica (biotite) , and white mica (muscovite) , together 
svith accessory magnetite and secondary epidote. The oligoclase is 
largely altered to a white mica and kaolin, and all the feldspars are 
n places intergrown with quartz circular in cross section. 
The lower quarry, opened in 1889, is triangular in area, each side 
being 75 feet long and 40 feet deep, two of which are working faces. 
Hie drainage supplies the boilers. 
Rock structure: The sheets, which are from 2 to 8 feet thick, dip 
5° to 10° W. Joints, dipping 70° S. to 90° and striking N. 75° 
E., recur at intervals of 1 to 10 feet. The rift is vertical, with a 
Course W. 60° N., as at the quarries south of the cove. The rela- 
tions of this fine granite at the north end of the quarry to the coarse 
granite of the island are shown in fig. 18. The fine granite probably 
represents a later eruption through the coarser. (See p. 46.) 
