Ries — Geoilogy of Orange County. 



459 



A fine example of a camptonite dike occurs in the Bradley mines, north- 

 east of Arden, and in Monroe township. The rock is composed of plagioclase 

 and hornblende, with some magnetite. The plagioclase is altered to a serpen- 

 tine-like granular material. The hornblende is brown, strongly pleochroic 

 and idiomorphic, in lath-shaped individuals or six-sided sections showing pris- 



Plan of Forest of Deon Ore body 



Figure 21. 



matic and orthopinacoid faces. There are also large porphyritic hornblendes, 

 which commonly show zonal structure and twinning parallel to z P x. 



Two more camptonite dikes cut the granitic gneiss about one mile (512), 

 and a mile and one-half east of Stockbridge's hotel, which is on the mountain 

 east of Central Valley. They are both much finer grained than the preceding, 

 and contain numerous round or square grains of magnetite. The feldspar 

 is much decomposed. The first of these two dikes (512) is interesting on 

 account of the manner in which it 1 tranches and incloses some of* the wall- 



