Figs. 1-2-3 and 4 show increasing intensity of granitization; Forest of 
Dean mine. All taken in polarized light, nicols crossed, X 35. 
Fig. 1 Pochuck-Grenville from the footwall side of the horse; no graniti- 
zation is exhibited. 
Fig. 2 slighty granitized Pochuck-Grenville, representing the footwall at 
ore contact, 4100 foot level. The pyroxenes have been attacked. 
Fig. 3 strongly granitized Pochuck-Grenville, from a drift on the 2000 foot 
level, 45 feet from the footwall ore contact. 
Fig. 4 “the Pochuck granite,’ with nenibants of modified pyroxene, and 
plagioclase belonging to the Pochuck-Grenville, and Partially absorbed 
xenolithic blocks of the same formation. “Granitization” was accomplished 
by the extreme end- phase product (quartz) of mineralization; that is, by the 
“mother liquor” left after the greater part of the magnetite had replaced 
the rock body by deuteric processes. It is conceivable that some of the 
quartz may have been derived from the magmatic replacement and destruc- 
tion of the rock. 
134 
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