甘肃天水宽沟金矿床同位素地球化学特征研究

Research on the Isotope Geochemical Characteristic of Kuangou Gold Deposit In Tianshui City,Gansu Province

通过对李子园地区宽沟金矿床氢、氧、硫、铅同位素特征的分析研究,讨论了该矿区成矿流体性质、来源及成矿物质来源等问题。氢氧同位素结果表明,宽沟金矿床成矿流体是一种混合源,以岩浆热液为主,有部分大气降水和变质热液的混入。硫同位素组成表明,宽沟金矿床矿石硫以岩浆硫为主,同时混入了地层中的硫。铅同位素组成表明,成矿物质主要来源于深部的下地壳和上地幔,为壳幔混源,在成矿流体向上运移的过程中,有地层铅的混入,成矿与燕山期石英正长岩体关系密切。

By analysis on the characteristics of hydrogen,oxygen,sulfur and lead isotope of Kuangou gold deposit in Liziyuan area,we discuss the issues about the nature and source of ore-forming fluid and the source of metallogenic material.Hydrogen and oxygen isotope results show that ore-forming fluid of Kuangou gold deposit is a mixed sources,it is mainly magmatic hydrothermal,mixed some precipitation and metamorphic hydrothermal.Sulfur isotopic composition show that ore sulfur of Kuangou gold deposit is mainly magmatic sulfur,and mixed stratigraphic sulfur.Lead isotopic composition show that metallogenic minerals are from lower crust and upper mantle,it is the crust-mantle mixed source.During the process of upward migration of ore-forming fluids,it is mixed stratigraphic lead,and mineralization has close relationship with quartz syenite rock in Mesozoic.