Quaternary geology and drift prospecting in the Mount Polley region (NTS 093A)

摘要

Drift prospecting studies were conducted in the Mount Polley Mine region, integrating surficial mapping, paleoflow measurements and Quaternary stratigraphy to infer glacial history. Eighty seven till samples were taken with the objective of determining the geochemical and mineralogical dispersal in till down-ice from Mount Polley. Surficial mapping identified till as the most abundant surficial material. Colluvium was mapped at high elevations and on steep slopes, and glaciofluvial and alluvial sediments are widespread in the river valleys. The stratigraphic record documents till associated with Fraser Glaciation followed by retreat phase glaciolacustrine and glaciofluvial sediments. Two distinct ice-flow movements have been identified; an initial west, southwestward flow during glacial advance, followed by a northwestward flow. The till sampling survey identified mineralized glacial dispersal up to 10 km to the northwest, Hg and Zn as pathfinder elements and apatite, andradite, chalcopyrite, epidote, gold grains and jarosite as porphyry indicator minerals (PIMs).