GEOLOGY OF THE WEST POINT QUADRANGLE, NEW YORK 87 



could be discovered in those beds it is not likely that any of them 

 would be worked for the present. 



A very small outcrop of quartzite has been noted east of Peeks- 

 kill along the east margin of the Peekskill granite area, but its extent 

 is undetermined and its quality is unknown. 



If a high-grade quartzite could be shown to have a quality for 

 structural purposes not fully met by the siliceous limestone and 

 trap and other rocks, which supply stone in such immense quantities 

 and under such favorable conditions along the Hudson river, it 

 might be that the quartzites of this quadrangle would ultimately 

 become the foundation of a large industry. The question has 

 received attention recently, but thus far no development has been 

 undertaken. 



Iron. A good many years ago iron was produced from this 

 quadrangle at several points and a furnace was located at the mouth 

 of Peekskill creek. A narrow gauge railway connected this plant 

 with the producing properties, but this, together with the plant and 

 the workings, have been abandoned for so many years that only 

 obscure ruins remain. Iron was brought froml the belt of iron- 

 bearing rocks which follows the west side of Sprout Brook valley 

 and extends almost exactly through the center of the quadrangle 

 in a long belt running northeast-southwest. The ore is magnetite 

 and has pegmatitic associations and probably igneou's origin. The 

 bodies proved to be rather small and the mineral considerably mixed 

 with silicates. Doubtless large quantities still remain and it is 

 possible that modern treatment of some of these deposits would be 

 found practicable. Occasional occurrences of similar sort lie out- 

 side of this belt already referred to, but nothing of consequence has 

 been noted of any different relation or origin. 



Pyrite. At a point somewhat east of the summit of the moun- 

 tainous mass known as Anthony's Nose, was formerly located a 

 mine producing sulphide of iron, the product of which was used 

 in an acid plant near the present Highlands station on the New York 

 Central Railroad. This plant was in operation up to about 15 years 

 ago, but has been abandoned in recent years. Its total supply was 

 not obtained from this mine, however, and finally the mine was not 

 depended upon at all. 



What the actual condition is at the old mine can not be deter- 

 mined because of danger of entering the workings. It is clear, 

 however, from inspection of the occurrences at the surface and from 

 the material on the dump that the ore was associated with pegma- 



