西藏雄村铜金矿床石英闪长斑岩中单个流体包裹体的SRXRF研究及其意义

发布时间：2018-07-14 08:57

【摘要】：雄村铜金矿床是近年来西藏冈底斯成矿带内发现的一处超大型铜金矿床,该矿床位于冈底斯造山带中段南缘。对石英闪长斑岩的石英斑晶和晚期石英脉体中的流体包裹体进行了岩相学观察和同步辐射X射线荧光微探针分析。同步辐射X射线荧光微探针分析结果表明,石英闪长斑岩流体包裹体中富含成矿元素Cu和Au,在流体包裹体气相中,Mo、S、Fe、Mn、Hg、Ni、Tl、Cr等元素的含量无一例外地相对富集,Zn、Pb、Rb、As、Br则优先进入流体液相。高温热液流体在不混溶相分离过程中,成矿元素选择性迁移,在各相中进行不均匀分配,温压等物理化学条件的变化会影响成矿元素迁移分配的地球化学行为。因此,雄村矿床成矿流体是直接从岩浆熔体中出溶的富含Cu、Au、Mo、Fe等元素的岩浆流体,成矿元素在流体出溶和分离各相中的不均匀分配是成矿元素最终富集成矿的关键因素。
[Abstract]:The Xiongcun copper-gold deposit is a super-large copper-gold deposit discovered in the Gangdis metallogenic belt in Tibet in recent years. The deposit is located in the southern margin of the middle section of the Gangdis orogenic belt. The petrographic observation and synchrotron X-ray fluorescence microprobe analysis of fluid inclusions in quartz porphyry and late quartz vein of quartz diorite were carried out. The results of synchrotron radiation X-ray fluorescence microprobe analysis show that the fluid inclusions of quartz diorite are rich in metallogenic elements Cu and Au.In the gas phase of the fluid inclusions, the contents of the elements such as Mo-PbPbRbAbAsBr are preferentially enriched into the liquid phase. In the process of immiscible phase separation, the ore-forming elements migrate selectively, and the physical and chemical conditions, such as temperature and pressure, influence the geochemical behavior of the migration and distribution of ore-forming elements. Therefore, the ore-forming fluid of Xiongcun deposit is a magmatic fluid which is dissolved directly from the magmatic melt and is rich in elements such as Cu-Au-Mo-Fe, and the inhomogeneous distribution of ore-forming elements in the fluid exsolution and separation of phases is the key factor for the final enrichment and mineralization of the ore-forming elements.
【作者单位】：中国地质调查局武汉地质调查中心;中国地质调查局成都地质调查中心;成都理工大学地球科学学院;
【基金】：国家自然科学基金项目(41172077;41502079;41503040) 中国地质调查局扬子工程“湘西-鄂西成矿带神农架-花垣地区地质矿产调查”二级项目(DD20160029)
【分类号】：P618.41;P618.51

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