Multistage processes of sulfide segregation at the Jinchuan Ni-Cu-(PGE) deposit,NW,China
The Jinchuan Ni-Cu-(PGE) deposit is one of the world’s largest magmatic sulfide deposits.Recent study has shown the Jinchuan intrusion originally comprises two individual intrusions,referred to Eastern and Western intrusions.Two largest ore bodies (No.1&2) occur in the Eastern intrusion,and the third largest ore body (No.24) is hosted in the Western intrusion.Different from the Jinchuan Eastern intrusion,the Western intrusion consists of Upper and Lower units.In the Upper unit,weakly disseminated sulfides only occur at bases of the unit and are characterized by moderate Cu/Pd ratios and relative high PGE contents in 100% sulfide basis.Disseminated,net-textured and minor massive sulfides in the Lower unit compose the No.24 ore body.Additionally,small Cu-rich ore bodies have been discovered at the bases of the No.24 ore body or extending to small intrusions beneath the Western intrusion.The PGE geochemistry and model calculations indicate that the disseminated sulfides of the Upper and Lower units were separated from PGE-undepleted and PGE-depleted parental magmas,respectively.The differentiation of chalcophile elements between the net-textured and massive sulfides and the Cu-rich ores reveal accumulation of monosulfide solid solution and migration of fractionated sulfide liquid.The anomalous Pt depletions of the net-textured and massive sulfides were resulted from sulfide fractionation.
L.M.Chen X.Y.Song R.R.Keays L.Qi Y.F.Deng
State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Scienc School of Geosciences,Monash University,Victoria,3800,Australia
国际会议
贵阳
英文
176-179
2012-06-16（万方平台首次上网日期，不代表论文的发表时间）