Sources of the ore-forming materials of vein-type Pb-Zn mineralization in Baguamiao gold deposit,Fengtai area:Evidences from in situ sulfide S-Pb isotopes
Pb-Zn mineralization in Fengtai area of the Qinling orogenic belt consists of layered and vein-type orebodies.Some vein-type Pb-Zn orebodies are associated with gold orebodies in gold deposits,which sources of ore-forming materials have not been well constrained.Here,we take vein-type Pb-Zn orebodies in the Baguamiao gold deposit as a case,discussed their ore-forming material sources based on sulfide in situ S-Pb isotope compositions.The vein-type Pb-Zn orebodies are mainly controlled by NE-trending faults,with vein widths ranging from 10 to 20 cm.The ore minerals in the ore are mainly galena and sphalerite,with small amounts of chalcopyrite and pyrite,while the gangue minerals include quartz,muscovite/sericite,and some calcite and dolomite.The in-situ S-Pb isotope analytical results show that the sphalerite grains have relatively concentrated δ34S values(15.03‰～17.11‰),while the 834S values of chalcopyrite(14.76‰～19.91‰)and galena(12.12‰～21.88‰)are relatively variable,and the lead isotope compositions of galena are very uniform.By comparing the S-Pb isotopes of the vein-type Pb-Zn ore to possible sources,it is concluded that the ore-forming materials of the vein-type Pb-Zn orebodies are from metamorphic fluids generated by metamorphism of the wall-rocks,and also involve contributions from the coeval granitic magma,which are fully similar to those of the gold mineralization.The gold and vein-type Pb-Zn mineralization in the Baguamiao area are co-enriched but independently developed,which may be controlled by the distinct geochemical behavior of Pb-Zn and Au in the hydrothermal system.
Vein-type Pb-Zn mineralizationBaguamiao gold depositSulfide in situ S-Pb isotopesSources of ore-forming material
万方数据
维普
