湘南地区钨锡多金属矿床浆液过渡态熔体类型成因联系及其成矿意义  

Types and geological characteristics of volatile-rich hydrosilicate melts of the W-Sn polymetallic deposits of South Hunan:Genetic relationships and metallogenic significance

作　　者：沈宏飞 李厚民[1] 余金杰[1] 李立兴[1] 马收先[1] 孙燕 李小赛[1] SHEN Hongfei;LI Houmin;YU Jinjie;LI Lixing;MA Shouxian;SUN Yan;LI Xiaosai(MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing100037,China;School of Earth Sciences and National Resources,China University of Geosciences,Beijing 100083,China)

机构地区：[1]自然资源部成矿作用与资源评价重点实验室,中国地质科学院矿产资源研究所,北京100037 [2]中国地质大学地球科学与资源学院,北京100083

出　　处：《地质学报》2023年第1期109-123,共15页Acta Geologica Sinica

基　　金：国家重点研发计划项目(编号2018YFC0603904)资助的成果。

摘　　要：岩浆液态不混溶形成的浆液过渡态熔体是与高度分异花岗岩有关的钨锡多金属成矿流体的重要形式。湘南地区与钨锡多金属成矿有关的浆液过渡态熔体有两种类型,一种富钠富挥发分,以芙蓉矿田矿化蚀变碱长花岗岩中的钠长石电气石石英囊为代表;另一种富钾富挥发分,以界牌岭矿床矿化蚀变花岗斑岩中的锂白云母萤石囊(团块)为代表。两种浆液过渡态熔体可形成于同一矿床,为同期岩浆活动产物,成分上K2O与Na2O负相关,表明它们具有密切的时空和成因联系,熔体-流体包裹体发育,为高度分异的花岗质岩浆液态不混溶产物。两种浆液过渡态熔体富含成矿物质,与成矿关系密切,湘南地区多数钨锡多金属矿床的云英岩型、构造蚀变带型、钾化花岗岩型钨锡多金属成矿可能与富钾富挥发分的浆液过渡态熔体有关,钠化花岗岩型铌钽矿化与富钠富挥发分的浆液过渡态熔体有关。The volatile-rich hydrosilicate melts generated by magma liquid immiscibility represent important forms of ore-forming liquids for W-Sn polymetallic deposits associated with the highly-fractionated granite.Two types of volatile-rich hydrosilicate melts have been identified in the W-Sn polymetallic deposits of South Hunan.The first type is Na-and volatile-rich and represented by the albite-tourmaline-quartz pockets hosted in altered alkali-feldspar granite.The second type is K-and volatile-rich and represented by the lithian muscovite-fluorite pockets or blocks hosted in altered and mineralized granite porphyry.These two types of melts can be found in the same ore deposit,show negative compositional relationship between K2O and Na2O,and develop melt-fluid inclusions.They have close spatiotemporal and genetic relationship and represent different products of magma liquid immiscibility.In South Hunan,the K-and volatile-rich melt is probably responsible for the greisen-type,the structure-altered zone-type and the K-feldpar-granite-type W-Sn polymetallic mineralization,while the Na-and volatile-rich melt is linked to the albite-granite-type Nb-Ta mineralization.

关 键 词：钨锡多金属矿床 浆液过渡态熔体 熔体-流体包裹体 液态不混溶 湘南 

分 类 号：P618.2[天文地球—矿床学]