THE MINING AND QUARRY INDUSTRY IQI2 6? 



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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