Fig. 1 Pochuck, Syenttic facies. Forming in part the footwall, Tower 
mine. The light minerals are alkalic feldspars. The darker ones are green 
pyroxene, somewhat altered. Ordinary light, X 35. 
Fig. 2 Pochuck-Grenville. At base of hill along railroad track, Forest of 
Dean mine. Essentially Grenville, soaked with quartz-syenite. The black 
areas are component minerals at the position of extinction, and not magnetite. 
The rock carries a colorless, monoclinic pyroxene, plagioclase ranging from 
oligoclase to andesine, alkalic feldspars of perthitic make-up, titanite, a little 
hornblende, ilmenite, and quartz. Light polarized, nicols crossed, X 35. 
Fig. 3. Pochuck, dioritic facies. The hanging-wall side of the horse, Forest 
of Dean mine. The so-called “dike,” which cuts the ore body, runs from 
this horse into the hanging wall, and is the same type. A diorite pegmatite, 
containing much plagioclase ranging from oligoclase to andesine, with little 
ferromagnesians, now altered. The feldspars are somewhat sericitized and 
carbonated, and in places epidotized; ferromagnesians changed to epidote, 
chlorite and granular magnetite. Quartz occurs in end-stage relationship 
with magnetite. These alterations are due to end-stage magmatic emana- 
tions, the ultimate expression of which may be seen as quartz (along the 
margins of the feldspars) with magnetite (black; cutting the silicates). 
Light polarized, nicols crossed, X 35. 
Fig. 4 Pochuck-Granite. Part of footwall, Clove mine. Chiefly quartz, 
carrying partially digested, corroded and altered remnants of Pochuck-Gren- 
ville in the form of badly sericitized plagioclase and altered pyroxene rem- 
nants. Believed to have been produced as an extreme end-product, essentially 
an aqueo-igneous solution, derived from the last-rejected mother liquor of the 
magnetites. See also plate 7. 
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