Ries — Geology of Orange County. 



Matter refers to n cliff of limestone one-quarter of ;i mile southwest of 

 Tuxedo lake, and states that it is traversed by a faulted dike. A search w as 

 made for this outcrop at the point indicated by Mather, but the writer was 

 unable to find it. Quartzose gneiss forms a steep and possible fault cliff in 

 the road-metal quarry south of Southfield, striking X. 40° E. and dip 7<» c E. 



One mile south of Southfield, along the road through the woods, is an 

 area of very coarse diorite. The rock is a coarse mixture of labradorite and 

 hornblende, and shows well the crushing which it has undergone. This same 

 rock also crops out in the field along the upper side of the road, until the 

 latter begins to curve around the hill, when it is succeeded by a massive 

 gneiss, w ith quartz orthoclase and biotite. This gneiss becomes very coarse 

 in places, when the biotite is replaced by hornblende. It continues with 

 somewhat variable character to Little Long pond, with a strike that varies 

 from N. 20 to 50° E. and a prevailing steep eastern dip. At the west end of 

 this pond, the gneiss strikes N. 20° E. and dips 30° E., while at the east end it 

 dips 80 to 90 e E. Along the road leading up the hill west of the pond, is a. 

 pegmatite vein cutting the gneiss, and this latter is cut by five camptonite 

 dikes in a space of 200 feet. They may be possibly branches of the same 

 dike. They vary in width from two inches to one foot. 



Monkoe Township. The gneisses cover nearly one-half of the township, 

 their western border being along the eastern side of the valley, extending 

 from Greenwood lake to Monroe. 



East and northeast of Long pond, which is two and one-half miles south 

 of Monroe, the normal grey gneiss is composed of orthoclase, quartz and 

 biotite, with subordinate hornblende. The rock sometimes becomes coarsel\ 

 crystalline, with an increase of the hornblende, and this passes into the 

 normal facies again. Southeast of Long pond, and on the crest of the ridge, 

 the strike is N. 20 p E., dip 70° W. A common form of the gneiss in this 

 region is a red rock consisting of quartz, orthoclase, plagioclase and some 

 biotite. The plagioclase frequently exceeds the orthoclase in amount. The 

 quartz commonly has a zonal structure and contains apatite and zircon as 

 inclusions. 



In the region south of the Clove mine the grey gneiss is general 1\ 

 quartzose, with few variations. On the eastern side of .Mount Basha lake ir 

 becomes garnetiferous. 



The O'Neil mine is three miles southeast of Monroe. It is a large 

 opening about 200 feet west of the road, and below it. The pit is about fifty 

 feet deep and 600 feet long, extending northeast and southwest. The wall 



