赣中下桐岭钨矿辉钼矿Re-Os年龄及其地质意义  

Re-Os isotopic age of molybdenite from Xiatongling tungsten deposit,central Jiangxi Province,and its geological implications

作　　者：李光来 华仁民[1] 黄小娥[2] 韦星林[2] 屈文俊[3] 王旭东 

机构地区：[1]南京大学内生金属矿床成矿机制研究国家重点实验室,江苏南京210093 [2]东华理工大学核资源与环境省部共建国家重点实验室培训基地,江西南昌330013 [3]江西有色地质勘查局,江西南昌330001 [4]国家地质实验测试中心,北京100037

出　　处：《矿床地质》2011年第6期1075-1084,共10页Mineral Deposits

基　　金：国家重点基础研究发展计划项目(2007CB411404);国家自然科学基金项目(41073035)资助

摘　　要：下桐岭钨多金属矿床位于赣中武功山地区分宜县,以花岗岩体内外的网脉型钨钼铋矿化为主,同时发育少量大脉型矿体。文章通过对该矿床成矿期形成的6件辉钼矿样品进行Re-Os同位素定年,获得其等时线年龄为(152.0±3.3)Ma(MSWD=2.4),模式年龄加权平均值为(150.6±1.3)Ma(MSWD=1.4),二者在误差范围内一致。这一年龄与南岭地区钨成矿的爆发期一致,表明下桐岭钨矿是燕山中期华南大规模钨成矿作用的产物。与南岭东段大多数石英脉型钨矿相比,下桐岭钨矿的辉钼矿具有较高的Re含量,暗示其受到较多壳-幔相互作用的影响,这可能与它处在"钦杭成矿带"赣中段、邻近萍乡-广丰深大断裂有一定关系。The Xiatongling tungsten deposit, located in the central part of ]iangxi Province, is characterized by stock- work type W-Mo-Bi mineralization together with a small amount of wolframite-quartz-vein ore. In this study, six molybdenite samples of the ore-forming stage were collected for Re-Os isotope dating to determine the chronology of the ore deposit. The analytical results yield an isochron age of （152.0 ＋ 3.3） Ma （MSWD = 2.4） and weighted average model age of （150.6 ＋ 1.3） Ma （MSWD = 1.4）. This ore-forming age is in accordance with most age data of tungsten deposits from the Nanling Mountains and vicinity areas, indicating that the Xiatongling tungsten deposit is the product of the peak period of middle Yanshanian large-scale tungsten metallogen- esis in South China. A Comparison with most vein-type tungsten deposits in eastern Nanling shows that molyb- denite from the Xiatongling ore deposit has relatively high Re content, which suggests the addition of mantle-de- rived material, resulting probably from the closeness to Pingxiang-Guangfeng deep fault of the so-called ＂Qin- Hang metallogenic belt＂.

关 键 词：地球化学 下桐岭钨矿 网脉型钨钼铋矿 Re—Os同位素 钦杭成矿带 

分 类 号：P618.67[天文地球—矿床学]