南岭东段岩前钨矿床地质特征及成岩成矿时代

岩前钨矿位于南岭东西向构造与滨太平洋北北东向构造带的交汇复合部位，南岭成矿带东段北部。主要矿床类型有矽卡岩型白钨矿和石英脉型黑钨矿，矿体产于燕山早期花岗岩内外接触带内。在区域地质和矿床地质研究的基础上，采用LA-ICP-MS 锆石U-Pb 法和辉钼矿Re-Os等时线方法，对与成矿关系密切的岩前花岗岩和含矿石英脉中辉钼矿进行精确定年，获得花岗岩的单颗粒锆石U-Pb谐和年龄加权平均值为(160.6±0.72) Ma，黑钨矿化石英脉中的辉钼矿为(159.2 ±2.3) Ma。这一成果揭示，花岗岩的就位年龄与含矿石英脉的形成几乎在相同热过程完成。结合前人研究，进一步得出南岭地区160~150 Ma成岩成矿作用主要分布于南岭中东段，成岩成矿作用与华南地区东部岩石圈大规模伸展的构造运动力学背景有关。岩前钨矿与区内盘古山、画眉坳、柿竹园等著名矿床具有相同的成矿时代、成矿背景和相似的成矿条件，属同一个成矿亚系列，预测岩前钨矿具有较大的找矿潜力，重点突破对象为内接触带石英脉型和接触交代矽卡岩型钨多金属矿体。

Geological Characteristics and Petrogenic & Metallogenic Ages of the Yanqian Tungsten Deposit in Eastern Nanling Region

The Yanqian tungsten deposit is located in east section of Nanling region, the conjunction of the E-W striking Nanling tectonic belt and the NNE Circum Pacific Ocean tectonic belt. The primary mineralization types include skarn type scheelite deposit and wolframite quartz vein deposit. The orebodies occur in the inner and the outer contact zone of the Early Yanshanian granite. Based on the studies of regional geology and deposit geology, the LA-ICP-MS zircon U-Pb and molybdenite Re-Os isochron dating have been carried out to accurately determine the ages of the granite pluton and the mineralized quartz vein within the pluton. The zircon U-Pb age of mineralized pluton is (160.6±0.72) Ma. The Re-Os isotopic age of molybdenite within mineralized quartz vein is (159.2±2.3) Ma. The isotopic dating results show that petrogenic age of the granite is similar with that of the mineralized quartz vein, which means that the magmatism and mineralization occurred in the same period. According to the previous research data, it was considered that the magmatism and mineralization during 160~150 Ma in the Nanling region primarily developed within the mid east section, and might be caused by the large-scale lithosphere extension. The Yanqian tungsten deposit belongs to the same sub-metallogenic series as some famous deposits in the eastern Nanling region, such as Pangushan,Huameiao and Shizhuyuan, with great exploration potential in the depth. The exploration targets in Yanqian area should primarily be aimed at skarn type and quartz vein type tungsten-polymetallic deposits in the inner contact.