QUARRY MATERIALS OF NEW YORK II9 



Millstone Hill or Cornell quarry 



The largest opening in the Peekskill granite is on Millstone hill 

 south of the highway leading east from Peekskill and adjacent to 

 the line of the Catskill Aqueduct. It is across the valley and a 

 mile distant from the Mohegan Granite Company's quarries, in 

 Cortlandt township. The main development of the property re- 

 sulted from the operations by Coleman, Breuchaud & Coleman, the 

 contractors for the new Croton dam which was constructed entirely 

 from material secured at this place. The quarry has furnished also 

 some stone for buildings in the vicinity, notably the Drum hill 

 school at Peekskill. It has been idle for the last few years, but 

 recently has come into the control of Rudiger Brothers who aim to 

 reopen it. 



The quarry lies east and west on the ridge, about 150 feet above 

 the highway. The lower ground is heavily covered with soil and 

 drift. The excavation measures about 500 feet long and 200 feet 

 wide in extreme dimensions and has lDeen carried downward to a 

 depth ranging from 30 feet on the north side to 75 feet on the 

 south. No hoists or other equipment are standing on the property. 

 In the period of operation the stone was transported on a tramway 

 to the Croton dam, but the road has been torn up. The outlet is 

 by way of Peekskill to the railroad or the Hudson river, involving 

 a haulage of about 4 miles. 



In the C[uarry the granite shows the characteristic massive struc- 

 ture; joints are rather wide apart and irregularly spaced, except on 

 the west end where they form a heading. The joint systems include 

 a north-south series which dips 80° west and an east-west vertical 

 series. Horizontal division planes have little persistence, hardly 

 justifying their reference to sheeting, though there is some tendency 

 toward division on planes dipping slightly south and west. The 

 rift is reported to run parallel with the north-south joints. No dikes 

 or large inclusions are observable in the quarry walls. 



At this quarry there is no capping of yellow granite, so prominent 

 in the Mohegan property, and the only suggestion of any color 

 change consists of a slightly mottled effect produced by a little 

 lirn'onite stain around the biotite crystals, like the rust on iron. This 

 is apparently the initial step in the transformation from gray to yel- 

 low. The granite from the deeper parts of the quarry, however, 

 is entirely free of limonite with a very uniform body that appears 

 almost white. The quality is excellent for all architectural purposes. 



