Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

In magmatic Ni-Cu sulphide deposits pyrrhotite (Po) and Pentlandite (Pn) are assumed to form essentially by exsolution of monosulphide solid solution (MSS) into Po and Pn, or by exsolution of intermediate solid solution (ISS) into chalcopyrite (Ccp) and Pn. In the process of investigating trace element contents of Pn from the Kharealakh Intrusion, we found that two types of Pn are present. Contact Pn, located between Ccp and Po, and the other side, in contact with the Ccp, enriched in Pd. The second type of Pn is granular and occurs in association with either Po or Ccp, but not both. It is unzoned, and enriched in Zn, Sn, In, TI, As, Pb, Bi, Cd, Ag, Cu, Te and Pt relative to the contact Pn. We propose that the contact Pn formed via peritectic reaction, whereas the granular Pn exsolved form MSS and ISS.