QUARRY MATERIALS OF NEW YORK 1 53 



about 2 miles in maximum diameter from northeast to southwest 

 and is about i mile wide. It is thus sufficiently large to permit the 

 location of many quarries within its bounds, although as yet un- 

 developed. The rock is very fine-grained and is somewhat vesicular 

 in places ; it may be a surface development of the Palisades diabase. 



SUFFERN, ROCKLAND COUNTY 



Union Hill, near Suffern, consists of a mass of trap from one- 

 fourth to one-half of a mile in diameter. The rock is a fine-grained, 

 compact diabase of the same composition as the Palisades rock. 

 The Ramapo Trap Rock Co. has opened quarries in the exposure 

 for the production of crushed stone. 



PORT RICHMOND, RICHMOND COUNTY 



The southern end of the Palisades diabase is found on Staten 

 Island where the intrusion forms a low ridge that extends south- 

 southwest from Port Richmond. The exact limits of the area are 

 not well marked, but it probably is from one-fourth to one-half of 

 a mile wide and terminates somewhere near Linoleumville. Quar- 

 ries have been opened at Graniteville and Port Richmond. For the 

 last few years they have been inactive. 



