湘东邓阜仙Nb-Ta-W-Sn-Pb-Zn岩浆热液成矿系统:铌钽锰矿U-Pb年代学约束  

Magmatic-hydrothermal metallogenic system in Nb-Ta-W-Sn-Pb-Zn Dengfuxian orefield,eastern Hunan:constraint from U-Pb geochronology of columbite-tantalite

作　　者：毛禹杰 邵拥军[1,2] 熊伊曲 蒋少涌 文春华 MAO Yujie;SHAO Yongjun;XIONG Yiqu;JIANG Shaoyong;WEN Chunhua(Key Laboratory of Metallogenic Prediction of Nonferrous Metal and Geological Environment Monitoring,Ministry of Education,Central South University,Changsha 410083,China;School of Geoscience and Info-Physics,Central South University,Changsha 410083,China;School of Earth Resources,China University of Geosciences,State Key Laboratory of Geological Processes and Mineral Resources,Collaborative Innovation Center for Exploration of Strategic Mineral Resources,Wuhan 430074,China;Hunan Institute of Geological Survey,Changsha 410116,China)

机构地区：[1]中南大学有色金属成矿预测与地质环境监测教育部重点实验室,湖南长沙410083 [2]中南大学地球科学与信息物理学院,湖南长沙410083 [3]中国地质大学资源学院,地质过程与矿产资源国家重点实验室,紧缺矿产资源勘查协同创新中心,湖北武汉430074 [4]湖南省地质调查院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2021年第9期2959-2972,共14页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划项目(2017YFC0602405);国家自然科学基金资助项目(41803044);湖南省重点领域研发计划项目(2019SK2261);湖南省科技厅科普专题(202K4082);湖南省地质院科研项目(HNGSTP202105);湖南省自然资源厅科技项目(2021-16)。

摘　　要：金竹垄矿床是华南邓阜仙地区一个大型的花岗岩型铌钽矿床,与区内典型的热液脉型湘东钨锡矿床紧邻,但两者成因联系不明。首先,在对金竹垄矿床详细的地质特征观察基础上,结合镜下岩相学观察,查明矿床的矿物共生组合特征;其次,通过电子探针分析矿石的铌钽矿物化学组成;最后,通过铌钽矿物的原位LA-ICP-MS U-Pb定年分析,厘定矿床的成矿时代,并探讨铌钽与钨锡矿床间的成因联系。研究结果表明:本区铌钽矿物主要为铌钽锰矿,总体趋势是从富Nb端元往富Ta端元演化,结晶分异程度逐渐升高;含铌钽花岗岩中的铌钽矿物U-Pb年龄为158~153 Ma,与湘东钨锡矿床晚侏罗世的成矿时代和区内晚侏罗世花岗岩形成时代一致。经综合研究认为,邓阜仙矿田为典型的Nb-Ta-W-Sn-Pb-Zn岩浆热液演化的产物。Jinzhulong deposit is a large granite-type Nb-Ta deposit in Dengfuxian area,South China,which is adjacent to typically hydrothermal vein-type Xiangdong W-Sn deposit.However,the genetic relationship between them is still unknown.Firstly,based on the detailed observation of geological characteristics of Jinzhulong deposit and combined with microscopic petrographic observation,the characteristics of mineral symbiotic association of the deposit were revealed.Secondly,chemical composition of coltan minerals was analyzed by electron microprobe.Finally,the timing of Nb-Ta mineralization was determined by in-situ LA-ICP-MS U-Pb dating for coltan minerals,and the genetic relationship between Nb-Ta and W-Sn mineralizations was discussed.The results show that coltan at Jinzhulong are mainly mangancolumbite,and the evolution trend of coltan is from Nb-rich to Ta-rich endmember which is accompanied with the increase of differentiation degree.The age of coltan minerals in Nb-Ta bearing granite ranges from 158 Ma to 153 Ma,which is consistent with the late Jurassic mineralization age of Xiangdong W-Sn deposit and the emplacement age of late Jurassic granite in the district.It is concluded that Dengfuxian ore field is a typical product of Nb-Ta-W-Sn-Pb-Zn magmatic-hydrothermal evolution.

关 键 词：华南 金竹垄铌钽矿床 铌钽矿物U-Pb定年 岩浆−热液演化 成矿系统 

分 类 号：P588.1[天文地球—岩石学]