鄂东南付家山矽卡岩型(Cu-)W矿床成岩成矿时代及地质意义  

Diagenetic and metallogenic ages,and geological significance of the Fujiashan skarn-type(Cu-)W Deposit,southeastern Hubei Province

作　　者：刘泉 李艳军[1] 蔡恒安 李红梅 曾小华 孙孝峰 刘冬勤 谭俊[1] Liu Quan;Li Yanjun;Cai Heng′an;Li Hongmei;Zeng Xiaohua;Sun Xiaofeng;Liu Dongqin;Tan Jun(School of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430074,China;The First Geological Team of Hubei Geological Bureau,Huangshi Hubei 435100,China;Hubei Geological Survey,Wuhan 430034,China)

机构地区：[1]中国地质大学(武汉)资源学院,武汉430074 [2]湖北省地质局第一地质大队,湖北黄石435100 [3]湖北省地质调查院,武汉430034

出　　处：《地质科技通报》2021年第5期210-222,共13页Bulletin of Geological Science and Technology

基　　金：中国地质大学(武汉)中央高校基本科研业务费“地学长江计划”核心项目群资助项目(CUGCJ1817);国家自然科学基金项目(41672083);湖北省地质局科技项目(KJ2021-9);中国矿产地质志项目(DD20190379,DD20160346);湖北省地质勘查基金项目(〔2019〕1号)。

摘　　要：付家山(Cu-)W矿床是鄂东南地区新近发现的大型矽卡岩型矿床之一,成矿与花岗闪长斑岩关系密切。为了精确获得该矿床成岩成矿年龄,利用LA-ICP-MS锆石U-Pb和辉钼矿Re-Os同位素定年法对其进行了系统的成岩成矿年代学研究,并基于长江中下游成矿带晚中生代沉积地层及构造变形、地球物理和岩石地球化学等证据探讨了其成岩成矿构造背景。结果显示:花岗闪长斑岩锆石U-Pb加权平均年龄为(144±3)Ma,而辉钼矿Re-Os模式年龄为(146±2)Ma,成岩与成矿作用均形成于晚侏罗世-早白垩世。付家山(Cu-)W矿床形成时代与长江中下游地区大规模岩浆成矿事件时间一致,包括鄂东南地区在内的长江中下游地区的构造演化历史及最新的年代学数据表明,付家山(Cu-)W矿床极有可能形成于岩石圈伸展减薄构造背景。付家山等晚侏罗世-早白垩世矽卡岩型(Cu-)W矿床的发现及厘定指示了鄂东南矿集区具有良好的钨矿找矿前景。The Fujiashan(Cu-)W Deposit,which is discovered recently,is one of the typical skarn deposit in southeastern Hubei.The(Cu-)W mineralization is closely associated with the Fujiashan granodiorite porphyry.In order to accurately determine the diagenetic and metallogenic ages of the deposit,ages of the granodiorite porphyry and(Cu-)W mineralization are studied by using LA-ICP-MS zircon U-Pb and molybdenite Re-Os isotopic dating in this paper.In addition,the tectonic setting of diagenesis and mineralization is discussed based on the sedimentary strata,structural deformation,geophysical and geochemical evidences in the middle and lower reaches of the Yangtze River during the Late Mesozoic.The results show that the granodiorite porphyry yields a weighted average 206 Pb/238 U age of(144±3)Ma,whereas a Re-Os model age of molybdenite of(146±2)Ma is obtained for mineralization.These isotopic ages indicate that the granodiorite porphyry and(Cu-)W mineralization at Fujiashan both formed during Late Jurassic-Early Cretaceous.In addition,the diagenesis and mineralization ages of the Fujiashan(Cu-)W Deposit are also consistent with the time of large-scale magmatic and metallogenic events for skarn Fe-Cu-Au-Mo deposits in the middle and lower reaches of the Yangtze River.According to the history of tectonic evolution and the latest chronological data in the middle and lower reaches of the Yangtze River,including southeastern Hubei,it is considered that the Fujiashan(Cu-)W Deposit is likely to be formed in a tectonic setting of lithospheric extension and thinning.The discovery and determination of Late Jurassic-Early Cretaceous skarn(Cu-)W Deposits including the Fujiashan indicate that the ore concentration area in southeastern Hubei has a good explorational prospect for tungsten deposits.

关 键 词：矽卡岩型铜钨矿床 成岩成矿时代 岩石圈伸展 付家山 鄂东南 

分 类 号：P618.2[天文地球—矿床学]