Variation in trace element content of magnetite crystallized from a fractionating magmatic sulfide liquid
Laser ablation ICP-MS analysis has been applied to many accessory minerals in order to 1) understand the process by which the rock formed or 2) act as indicator minerals in exploration.Magnetite (Fe3O4) crystallizes directly from the sulfide liquid but it is a commonly overlooked accessory mineral in sulfide deposits.We have determined trace element concentrations in magnetite from massive sulfides of several Sudbury Ni-Cu-PGE deposits.The samples represent the crystallization products of a fractionating sulfide liquid.Positive correlations are present in magnetite among Cr,Al,Ti,V,Mn,Ga,Nb,Ta and W and negative correlations between these elements and Ni and Sn.Trace element concentrations in magnetite are controlled by the degree of sulfide fractionation,for which whole rock (Pt+Pd)/IPGE ratios is a proxy.Lithophile elements are concentrated in the earliest crystallizing magnetite (in Fe-rich MSS) and depleted in late crystallizing magnetite (in Cu-rich residue).The chalcophile elements are controlled by the co-crystallization of sulfides.Nickel,Co and Mo are compatible in MSS and are hence depleted in the co-crystallizing magnetite.The concentrations of the chalcophile elements incompatible with MSS are highest in magnetite formed from the fractionated Cu-rich liquid.
S.A.S Dare S.-J.Barnes G Beaudoin
Université du Québec à Chicoutimi(UQAC),Chicoutimi,Québec,Canada,G7H 2B1 Université Laval,Québec City,Québec,Canada,G1V0A6
国际会议
贵阳
英文
38-41
2012-06-16（万方平台首次上网日期，不代表论文的发表时间）