江西新余地区东门铜钼矿区辉钼矿Re-Os年代学特征及成矿意义  

Re-Os dating of Molybdenite of the Dongmen Cu-Mo ore area in Xinyu,Jiangxi province and its metallogenic significance

作　　者：邓杨 潘小菲[1] 杨炎申 武凯 樊献科 张智宇[1] 欧阳永棚[3] DENG Yang;PAN Xiaofei;YANG Yanshen;WU Kai;FAN Xianke;ZHANG Zhiyu;OUYANG Yongpeng(Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China;China University of Geosciences(Beijing),Beijing 100083,China;912 Geological Team,Bureau of Geology and Mineral Resources of Jiangxi Province,Yingtan 335001,China)

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国地质大学(北京),北京100083 [3]江西省地质矿产勘查开发局912大队,江西鹰潭335001

出　　处：《中国矿业》2021年第11期169-177,共9页China Mining Magazine

基　　金：国家自然科学基金项目资助(编号:92062104;41873059);公益性基础地质调查项目“阿拉善、藏东南等关键地段地壳圈层物质”资助(编号:DD20190001)。

摘　　要：江西新余东门蛇纹石矿区新发现了大量的铜钼矿化。为了理清东门矿区内铜钼矿化地质特征及成矿作用机制,本文在详细的野外地质观察和室内薄片鉴定基础上,开展了岩相学和辉钼矿Re-Os年代学研究。研究结果表明,东门岩体与围岩地层发生了强烈的矽卡岩化蚀变,主要的蚀变矿物有石榴石、透闪石、硅灰石、蛇纹石及绿泥石,伴随夕卡岩化蚀变形成了大量的铜钼矿化,主要的金属矿物包括辉钼矿、磁铁矿、黄铜矿、黄铁矿等。辉钼矿Re-Os年龄测试分析获得了模式年龄为166.9±3.2~167.7±3.2 Ma,等时线年龄为168.1±2.8 Ma(MSWD=0.023),指示东门铜钼成矿时代为中侏罗纪时期,而且与燕山期岩浆有关的东门铜钼成矿作用是早侏罗纪、中侏罗纪华南从东西向古特提斯构造域——北东向西太平洋构造域发生体制转换时的产物,其蚀变矿化特征显示它们是矽卡岩型矿化(或矿床),该区具有燕山期铜钼找矿潜力。Recently,a lot of Cu-Mo mineralization was discovered in the Dongmen serpentine ore area in Xinyu,Jiangxi province.Based on the systemic field survey and identifying the thin sections,lithologic analysis and molybdenite Re-Os dating were carried out to clarify the characteristics of the mineralization and metallogenesis in this paper.It shows that strong skarn alteration has occurred along the contact zone between the Dongmen granodiorite stock and the carbonate Huanglong formation.The major skarn minerals are garnet,diopside,serpentine,wollastonite,calcite and quartz accompanied by a certain amount of metal minerals such as molybdenite,magnetite,chalcopyrite and pyrite.Molybdenite Re-Os dating yielded model ages ranging from 166.9±3.2-167.7±3.2 Ma,with a well-constrained 187 Re-187 Os isochron age of 168.1±2.8 Ma(MSWD=0.23).It shows that the Cu-Mo mineralization related to the Dongmen granodiorite formed at middle Jurassic and is the product of magmatic and metallogenic events triggered in the transition environment from the eastern Tethyan tectonic domain to the Pacific tectonic domain during the early to middle Jurassic.There are ore-prospecting potential of Yanshanian skarn-type of Cu-Mo mineralization in Xinyu,Jiangxi province.

关 键 词：东门矿区 夕卡岩型铜钼矿化 辉钼矿RE-OS定年 

分 类 号：P618.41[天文地球—矿床学] P618.65[天文地球—地质学]