社垌钨多金属矿床位于大瑶山隆起区东南部,是近年来发现并受到广泛关注的大型矿床,目前对其成矿流体来源,尤其是否存在壳幔相互作用机制尚缺乏深入认识.通过对矿区流体包裹体He-Ar、H-O同位素的研究,结果显示,矿区斑岩型铜矿的3He/4He为0.7~1.46 Ra,40Ar/36Ar为294.02~316.96;石英脉-夕卡岩型钨钼矿3He/4He为0.46~0.67 Ra,40Ar/36Ar为303.83~388.62,成矿流体δDV-SMOW介于-84‰~-61‰,δ18OH2O为-0.48‰~5.09‰,表明石英脉-夕卡岩型钨钼矿和斑岩型铜矿成矿流体主要为岩浆水,成矿后期有较多大气饱和水的混入,成矿过程均有不同程度的幔源流体参与,前者的成矿流体幔源He含量为10.7%~15.5%,后者成矿流体幔源He含量达16.3%~33.9%.幔源流体加入是由矿床所处的大地构造背景所决定的,石英脉型钨钼成矿幔源流体的加入是由于扬子板块和华夏板块于加里东晚期发生碰撞导致地幔物质上涌而产生,斑岩铜矿地幔流体的混入则因为燕山晚期大陆边缘持续伸展、钦杭结合带较为薄弱而产生强烈壳幔相互作用而形成.%Shedong tungsten-polymetallic deposit is located in the southeastern Dayaoshan uplift. It is a large scale porphyry-skarn-quartz vein type deposit discovered in recent years. Some study achievement is available on its chronology, ore-forming fluid, petrogeochemistry and mineralization pattern, but little is known about the origin of ore-forming fluid, especially the crust-mantle interaction during its metallogenesis. In this study, we carry out the analysis of He-Ar and H-O isotopic components of fluid inclusion in Shedong deposit. The results show that 3He/4He content of porphyry Cu orebodies is 0.7~1.46 Ra, 40Ar/36Ar 294.02~316.96, and 3He/4He content of skarn-quartz vein type W-Mo orebodies is 0.46~0.67 Ra, 40Ar/36Ar 303.83~388.62. The δDV-SMOW and δ18OH2O of ore-forming fluid in skarn-quartz vein type W-Mo orebodies is -84‰~-61‰ and -0.48‰~5.09‰, respectively. It indicates that ore-forming fluid of skarn-quartz vein type W-Mo mineralization and porphyry Cu mineralization mainly evolved from magma, and mixed by the meteoric water later. The mantle fluid played an important role during ore-forming processes of them ,and He content from mantle fluid in skarn-quartz vein type W-Mo mineralization and porphyry Cu mineralization is 10.7%~15.5% and 16.3%~33.9%, respectively.
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