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瑶岗仙钨矿床是南岭地区最典型的石英脉型钨矿床之一。本文对该矿床黄铜矿和黑钨矿中流体包裹体的氦、氩同位素进行了较系统地测定。研究表明,黄铜矿和黑钨矿流体包裹体中3He/4He分别为0.37～0.43Ra和0.05～0.49 Ra,明显高于地壳值;黄铜矿和黑钨矿流体包裹体中的氩同位素分别为673～886和325～903,均明显高于饱和大气雨水的40Ar/36Ar值。这些氦、氩同位素组成揭示该矿床的成矿流体具有壳、幔两端元混合的特点。结合区域地质构造演化和成矿年代学的研究成果,本文认为瑶岗仙钨矿床的成矿流体是由瑶岗仙S型花岗岩浆分异出的含有地幔He的岩浆流体与大气成因地下水的二端元混合产物,S型花岗岩的形成也是壳幔相互作用的结果。
Yaoguanxian tungsten deposit is one of the most typical quartz vein type tungsten deposits in Nanling area. In this paper, helium and argon isotopes of fluid inclusions in chalcopyrite and wolframite in this deposit are systematically determined. The results show that the 3He / 4He ratios of fluid inclusions in chalcopyrite and wolframite are 0.37 ~ 0.43Ra and 0.05 ~ 0.49 Ra respectively, which are obviously higher than the crustal values. The isotopes of argon isotopes in the fluid inclusions of chalcopyrite and wolframite respectively 673 ~ 886 and 325 ~ 903, which are obviously higher than 40Ar / 36Ar values of saturated atmospheric rainwater. These helium and argon isotopic compositions reveal that the ore-forming fluids of this deposit are characterized by the mixing of the crust and mantle. Based on the research results of regional geological tectonic evolution and metallogenic chronology, the author thinks that the ore-forming fluid of Yaogangxian tungsten deposit is composed of magmatic fluid containing mantle He and magma fluid derived from the S-type granite magma in Yaogangxian, The formation of S-type granites is also the result of the interaction between crust and mantle.