Geometry of indicator mineral and till geochemistry dispersal fans from the Pine Point Mississippi Valley-type Pb-Zn district, Northwest Territories, Canada

摘要

An indicator mineral and fill geochemical dispersal case study was conducted at the Pine Point Mississippi Valley-type (MVT) Pb-Zn district in northern Canada to document glacial dispersal down ice from a known orebody. Indicator minerals in the non-ferromagnetic heavy mineral (specific gravity 3.2) concentrate of fill down ice of the mined-out 0-28 Pb-Zn deposit in the east end of the district include sphalerite, galena, and pyrite, as well as secondary Pb-Zn minerals anglesite (as coatings on galena), smithsonite, and cerussite. These minerals are sufficiently physically and chemically robust to survive glacial transport as well as post-glacial weathering in the carbonate-rich fill of the region. Pathfinder elements in the 0.063 mm fraction of fill, determined using a modified aqua regia digestion, include Zn, Pb, Cd, Tl, and S.