THE MINING AND QUARRY. INDUSTRY i012 67 
NOTES ON GRANITE QUARRYING IN NEW YORK 
Peekskill. The Mohegan Granite Co., owning quarries east of 
Peekskill, supplied a large part of the architectural granite produced 
in the last year, shipping most of the output to New York for use 
in the Episcopal Cathedral. .The company is enlarging its facilities 
for handling this material which has obtained much favor among 
architects and builders on account of its rare and attractive color. 
At present it has three derricks in the main quarry, which is an 
opening 300 feet long with a face from 40 to 50 feet high. Except 
for large inclusions of hornblende schist which occur here and 
there, the granite is free of knots and streaks. It has a slight 
tendency to sheeting and is intersected by two sets of vertical joints 
which occur at such intervals as to admit the extraction of blocks 
as large as can be handled. The company has recently erected 
a steel-frame cutting shed at the quarries, which will afford room 
for 40 or 50 cutters. 
The yellow and brownish varieties which have been mainly quar- 
ried are developed in the upper surficial part of the granite boss, 
as a result of the seepage of iron oxid into the minute cracks and 
pore spaces of the stone. The iron is principally concentrated 
about the quartz grains. It seems to have been derived from altera- 
tion of the biotite in the overlying portion which has since been 
eroded away, as the quarried stone appears quite fresh when ex- 
amined microscopically. The granite is rather porous, but in 
crushing strength compares favorably with other granites. 
_ The normal or original color of the Peekskill granite is light 
gray, or pinkish gray, as seen in the quarries of Rudiger Bros. on 
Millstone hill, across the valley from the Mohegan Company’s quar- 
ries and in a smaller quarry near Peekskill. The change from gray 
to brown takes place at a variable depth, usually 40 or 50 feet 
from the surface. 
Kensico. Quarries have been opened in the last year at Kensico 
for the construction of the new reservoir which is to form a part 
of the Catskill water-supply system. The quarries are situated on 
the ridge that limits the reservoir on the east, about three-fourths 
of a mile from the dam location with which they are connected by a 
railway. The rock is Yonkers gneiss of medium grayish or brown- 
ish gray color and more massive texture than the usual average of 
the rock. The grain is medium or fine. Several acres have been 
cleared of overlying earth and soil, showing fairly uniform and 
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