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

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。 

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

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 206Pb/238U 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.