铜陵蛤蟆岭岩体锆石U-Pb同位素年代学特征及其找矿意义

Zircon U-Pb Isotopic Geochronology and its Prospecting Significance of the Hamaling Granodiorite in Tongling

铜陵蛤蟆岭铜金钼矿是近年来铜陵地区重要的找矿新发现之一,具有层控型+斑岩型+矽卡岩型“三位一体”特征,为一套岩浆热液成矿系统。蛤蟆岭铜金钼矿位于铜陵矿集区西南部,该地区勘查程度较低,蛤蟆岭花岗闪长岩体作为该矿的主要成矿岩浆岩地质体,以往地质工作对其系统研究较少,缺乏精确的同位素年代学资料。通过对蛤蟆岭岩体锆石进行激光剥蚀-多接收器电感耦合等离子体质谱(LA-ICP-MS)U-Pb定年,得出其年龄为(140.4±1.9)~(137.7±1.1)Ma,形成于燕山期早白垩世,与铜陵矿集区的成岩成矿时代段基本吻合,佐证了蛤蟆岭铜金钼矿找矿成果,对于该地区进一步找矿工作有着重要的指示意义。

The Hamaling Cu-Au-Mo Deposit is one of the important newly discoveries made recent⁃ly in Tongling,it is characterized by strata-bound type+porphyry type+skarn type,which all belong to a uni⁃fied magmatic hydrothermal metallogenic system.The deposit is located in the southwestern margin of the Tongling ore cluster area,the exploration degree in here is low.The Hamaling granodiorite as the main metallogenic magmatic rock geological body,in the past there were few systematic studies on it in geologi⁃cal work,especially lacking of accurate isotopic chronological data.(LA-ICP-MS)U-Pb dating of zircon from the Hamaling granodiorite is conducted,it is concluded that its age is(140.4±1.9)~(137.7±1.1)Ma.It was formed in the Yanshanian period Early Cretaceous Epoch,which basically coincides with the diagene⁃sis and mineralization period of the Tongling ore cluster area.The analysis results support the prospecting re⁃sults of the Hamaling Cu-Au-Mo Deposit,and has important indicative significance for the prospecting work in this area.