Precious -metal mineralization and sulfide -silicate relationships in some Canadian nickel-copper sulfide deposits: Thompson mine, Manitoba; Sudbury, Ontario; Dundonald Beach, Ontario.

摘要

Platinum-group minerals (PGMs) and native gold are reported in association with gersdorffite and nickeline from the Thompson mine, Thompson Nickel Belt, Manitoba. Four PGM-gold bearing ore types are distinguished on the basis of mineral assemblages and host rocks: (I) irarsite in massive Ni sulfide ore hosted by metapelite; (II) gold, sudburyite, testibiopalladite-antimonian michenerite, unnamed PGM, and merenskyite in As-rich Ni sulfide ore hosted by metapelite from the T-1 mine; (III) gold with tellurides in As-rich Ni sulfide ore hosted by metapelite from the open pit; and (IV) gold, majakite, kotulskite, merenskyite, and michenerite in As-rich Ni sulfide ore hosted by pegmatite from the T-1 mine. Native gold is argentian (Ag;PGMs and gold presently reported from the Sudbury mining camp include michenerite and merenskyite at the Lindsley mine, and sperrylite, michenerite, merenskyite, Pd-melonite, and electrum at the Lockerby mine. At the Dundonald Beach exploration property, Ontario, electrum, Os-Ni-Fe alloy, froodite, and an unnamed PGM phase (Pd-Sb-Bi) occur in komatiite. The alteration assemblages in these deposits also favour the possible involvement of hydrothermal fluids in the PGE-Au mineralization.;Investigation of the partitioning of Ni between olivine and Fe-Ni monosulfide reveals that the Fe/Ni distribution coefficient (K;All ore types are associated with a pervasive hydrothermal alteration event that post-dates the regional amphibolite facies metamorphism (presently constrained around 600-700