PGE Characteristics of Cu-rich Ores in the Jinchuan Cu-Ni Sulfide Deposit and Its Genesis

The Jinchuan intrusion hosts the largest single magmatic Ni deposit in the world.Net-textured sulfide ores are the main ore type,Cu-rich ores are nest-like distribution in the ore deposit.Spatial distribution,ore structure,composition of sulfide and PGE geochemistry of Cu-rich ores,the authors put forward its genesis: sulfide experiences Mono-Sulfide Solution (MSS) at later stage,the residual sulfide with Cu-,Pt-,Pd-rich concentrates at local space by gravity differentiation or tectonic activities.According to statistics and modeling of more than 300 PGE data,the PGE concentrations of the Jinchuan parental magma are concluded: Os=0.355×10^-9,Ir=0.267×10^-9,Ru=0.277×10^-9,Rh=0.144×10^-9,Pt=4.94×10^-9,Pd=2.32×10^-9,Ni=338×10^-6,Cu=174×10^-6.The average R factor of the Jinchuan ore deposit is 567,which is higher in ore body 1 and 24 than ore body 2.