良山钼矿是钦杭成矿带近年发现的大中型矿床,在矿化特征分析的基础上,对其进行了成岩成矿年代学研究。采用LAICP-MS锆石U-Pb测年技术,得到矿区内石英闪长斑岩的成岩年龄为168.2±2.3Ma。通过矿床辉钼矿Re-Os同位素分析,获得其等时线年龄为168.9±1.4Ma。指示成岩作用与成矿作用同时发生,含矿热液活动与岩浆活动有密切的关系,岩浆活动可能是形成良山钼矿床的重要因素。良山钼矿床的成矿时间与钦杭成矿带内华南燕山期第一阶段大规模多金属矿化时间(170Ma)吻合。良山钼矿床形成于同一区域成矿背景下,是区域构造岩浆作用的产物,为华南燕山期成矿作用的组成部分。
The Liangshan molybdenum deposit was found in the western region of the Wugongshan-Qianshan subzone a few years ago.Based on an analysis of the mineralization features of the deposit,the authors determined LA-ICP-MS zircon U-Pb ages for the ore-bearing rocks in the Liangshan deposit.U-Pb dating of zircon by LA-ICP-MS reveals that the intrusion age of the Liangshan porphyry granite is168.2±2.3Ma.The187Re and187Os values of molybdenum from the molybdenum deposit were determined by the Inductively Coupled Plasma Mass Spectrometry(ICP-MS).Re-Os isochron of molybdenum suggests that the metallogenic epoch of the deposit is168.9±1.4Ma,indicating that this deposit had a close relation with its host rocks,the magmatic activity had a close relationship with ore-bearing hydrothermal activities,and magmatic activity was an important factor for the formation of the Liangshan molybdenum deposit.The metallogenic time of the Liangshan molybdenum deposit is consistent with south China first stage large-scale polymetallic mineralization of Yanshanian period(170Ma).The Liangshan molybdenum deposit was formed in the same regional metallogenic setting and resulted from regional tectonic magmatism,as a part of the South China Yanshanian mineralization.