河台韧性剪切带型金矿床成矿作用地球化学研究

A GEOCHEMICAL STUDY ON METALLOGENESIS OF HETAI GOLD DEPOSIT IN DUCTILE SHEAR ZONE,GUANGDONG PROVINCE

河台韧性剪切带型金矿床产于糜梭岩之中。石英中包裹体成分及氢、氧和碳同位素研究揭示,成矿流体为雨水和变质流体的混合体,富硫和碳,早期成矿流体主要为变质作用、混合岩化和花岗岩化作用过程中产生的变质流体,成矿晚期有大量雨水参与;流体成分以K^+、Na^+、HCO_3^-、SO_4^-、CO、CO_2、CH_4和水为主。硫、铅同位素研究揭明,金等成矿物质来源于云开群上亚群。结合地层中金丰度和区域性金分布研究得出,在变质作用、混合岩化和花岗岩化作用过程中,矿源层中金发生明显活化转移,并在构造扩容带聚集成矿。

Hetai gold deposit in ductile shear zone is hosted by mylonites. Its features of inclusions, oxygen, hydrogen and carbon isotopes indicate that ore-forming fluids have a middle salinity, are rich in carbon and sulfur and come from metamrophic and migmatitic solutions in the early ore-forming stage, whereas a huge amount of meteoric water participated in ore-forming processes in the late ore-forming stage. The researches on sulfur and lead isotopes and gold abundances show that the Yunkal Group is the source strata of gold and supplies a great number of gold for formation of the gold deposit. Gold mineralisation is closely related to metamorphism, migmatization and granitization.