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

Résumé

The concentrations of Au, Co and PGE have been determined in sulphide minerals from zoned sulphide droplets to establish which minerals host these elements and to test the model that suggests the zonation in the droplets is caused by crystal fractionation of monosulphide solid solution. Less than 10 % of the Au and Pt were found in the sulphides. Palladium was found to be present mainly in pn. Osmium, Ir, Ru and Rh were found to be present in both po and pn. The concentration of Os, Ir, Ru and Rh in the exsolution products of mss (po and pn) and the low levels of these elements in the exsolution product of intermediate solid solution (cb and cp) supports the crystal fractionation model. However, the enrichment of Pd in pn and the low levels of Pt and Au in cb and cp require that these elements migrate into pn and discrete PGE minerals during the exsolution of iss.