Transactions . Platk I The Alexo Mine—Uglow 661 from the wall the ore practically disappears, and a pure serpentinerock may be seen, containing small stringers of asbestos. A considerable quantity of promising ore has been taken fromthe pits. On megascopic examination, the ore .seems to be mainlypyrrhotite with here and there some chalcopyrite, which chieflyoccurs very close to the foot-wall. The whole ore-body as revealedby the development work is not more than two hundred feet long,but it is quite possible that further stripping along the contactwill expose additional Tlgur^ jy 662 The
Transactions . Platk I The Alexo Mine—Uglow 661 from the wall the ore practically disappears, and a pure serpentinerock may be seen, containing small stringers of asbestos. A considerable quantity of promising ore has been taken fromthe pits. On megascopic examination, the ore .seems to be mainlypyrrhotite with here and there some chalcopyrite, which chieflyoccurs very close to the foot-wall. The whole ore-body as revealedby the development work is not more than two hundred feet long,but it is quite possible that further stripping along the contactwill expose additional Tlgur^ jy 662 The Alexo Mine—Uglow III. Petrography. It is a matter of much difficulty to work out the field relation-ships of the rocks of the district. Figure II shows the exposures,but unfortunately contacts are rarely to be seen. For somereason or other, these are usually drift-covered. In most cases,it is necessajy to rely on megascopic and microscopic character-istics for the determination of these relationships. (a) Serpentine.—The oldest rock in the district is probablythe so-called serpentine. Along its contact with the andesite as exposed at the time of examination, no phenomena were observedthat would lead to an establishment of the age relationship of thetwo rocks; but it is quite likely that in this case, as in othersimilar ones in the north country, the acidic series of the Keewatincuts the basic. The only exposure of the serpentine found inthe township occupies the low ground close to the pits at theAlexo Mine. Under the microscope, sections appear light in colour,
Size: 1378px × 1812px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1800, booksubjectmineralindustries, bookyear1895
