Fig. 1 Silicated rock, O’Neill mine. Ordinary light, X 35. 
Lime-garnet (rough, gray) spinel, phlogopite (smooth, light gray with 
cleavage) and magnetite (black). The rock contains glaucophane in abund- 
ance, also. This rock represents the silication of either a richly calcareous 
phase of the Grenville or an interbedded limestone. 
Fig. 2. Mineralization of the silicated rock, O’Neill mine. Magnetite 
(black) is replacing glaucophane (rough, gray). Ordinary light, X 35. 
Fig. 3 Silicated limestone from dump at Tilly Foster mine. Ordinary 
Ibedaye, SC 6G 
The rough darker gray, fractured mineral is diopside, the rough, fractured 
lighter gray mineral is olivine, and the smoother gray areas, some strongly 
twinned, are carbonate. 
Other minerals typical of contact types occur, such as chondrodite, spinel, 
clinochlore and tourmaline. 
Fig. 4 Hanging wall, Croft mine. Ordinary light, X 65. A “contact- 
assimilation” product. Interbedded limestone, invaded by syenitic facies of 
Pochuck, pegmatitic variety. Lime-iron garnet is shown in rough, dark-grayv 
grains, quartz in light-gray, smooth grains almost free from inclusions, and 
wernerite, in light-gray grains crowded with inclusions. 
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