Metamorphic-hydrothermal parkerite and associated minerals in the Noril’sk ore field

Abstract

In the Noril’sk ore field, parkerite is a characteristic mineral of sulfide ore that metamorphosed under conditions of zeolite and prehnite-pumpellyite facies and of arsenide-calcite veins. The mineral occurs in ores containing bornite, anhydrite, magnetite, mackinawite (3–5 wt % Ni), valleriite, calcite, ankerite, native silver, native bismuth, violarite, Te-rich bismutohauchecornite, cupropentlandite enriched in Fe, Pd-rich breithauptite (1.5–2.5 wt % Pd), galena enriched in Cu (3.8 wt % Cu), and Ni arsenides and antimonides. Parkerite occurs in those place, where the primary ores have contained pockets and veins of graphic galena and chalcopyrite aggregates with associated Pt-Pd-Au-Ag minerals. Parkerite metacrysts in galena and Fe-Cu-Ni sulfides contain 6–16 and up to 5 wt % Pb, respectively. Parkerite rims replacing PGM aggregates and galena contain 1–3 wt % Pb. In calcite veins hosted in metamorphosed sulfide ores, parkerite is associated with native silver and bismuth, maucherite, cobaltite, chalcocite, and uraninite. Parkerite from these veins contains up to 0.5 wt % Pb. Thus, the Pb and Bi contents in parkerite basically depend on those of replaced minerals. Rare bismutohauchecornite is associated with parkerite.