浙江临安夏色岭钨矿含矿岩体特征及LA-ICP-MS锆石铀-铅年代学研究

Characteristics and LA-ICP-MS Zircon U-Pb Geochronology Study of Metallogenic Intrusion in the Xiaseling Tungsten Deposit in Lin′an,Zhejiang Province

夏色岭钨矿是浙江省内已知规模最大的石英脉型钨矿,其形成与夏色岭花岗岩体关系密切,前人对该岩体的年代学研究方法比较局限。本研究采集了夏色岭钨矿区的新鲜花岗岩样品,从岩石的矿物学特征及地球化学特征出发,讨论了岩体与成矿作用之间的关系。通过分析精度更高、结果更可靠的激光剥蚀-电感耦合等离子体质谱(LA-ICP-MS)锆石U-Pb测年技术,获得206Pb/238U加权平均年龄为(126.9±1.7)Ma,表明为燕山晚期早阶段(早白垩世)的产物,结合区域上的找矿成果,对本地区的地质找矿具有一定指导意义。

The Xiaseling tungsten deposit is the largest discovered quartz-veined tungsten deposit in Zhejiang Province, which is closely related to Xiaseling Granite. The geochronological study on this granite has been very limited in previous studies. Fresh granite samples were collected from the Xiaseling tungsten deposit. The relationship between Xiaseling Granite and mineralization is discussed by mineralogy and geochemical characteristics of the rocks. The in-situ zircon U-Pb dating was performed with Laser Ablation-Muhicollector Inductively Coupled Plasma-Mass Spectrometry （LA-MC-ICPMS） with higher accuracy and greater reliability than previously achieved. Our result indicates that the weighted average ^（206）pb/^（238）U ages for zircons from the Xiaseling granite is （126.9 ± 1.7） Ma, suggesting the granite was intruded in the early stage of the late Yenshanian Period of the early Cretaceous era. Together with regional prospecting findings, it is also important for ore exploration work in this area.