福建将乐县新路口石英脉型钨矿床黑钨矿电子探针分析和LA-ICPMS U-Pb测年

Electron Microprobe Analysis and LA-ICPMS U-Pb Dating of Wolframite from Xinlukou Quartz Vein Type Tungsten Deposit in Jiangle County, Fujian Province

福建将乐新路口钨矿是闽西北地区石英脉型钨矿的代表性矿床之一,然而对其成矿时代尚未开展过研究。为了了解新路口石英脉型钨矿床的成矿时代和矿石成份,对黑钨矿进行了电子探针成份分析和LA-ICPMS U-Pb测年,结果显示:黑钨矿WO3为74.147%~75.491%,MnO的含量为9.601%~16.311%,FeO的含量为8.921%~14.903%;FeO/MnO平均值为0.784,总体富锰,属于钨锰铁矿;黑钨矿LA-ICP-MS U-Pb的T-W下交点年龄为147.0 ± 2.6 Ma (MSWD = 0.51),校正后的206Pb/238U加权平均年龄为145.2 ± 2.6 Ma (n = 21, MSWD = 1.6),成矿年龄为晚侏罗世。The Xinlukou tungsten deposit in Jiangle, Fujian Province is one of the representative deposits of quartz vein type tungsten deposits in northwestern Fujian, however, its metallogenic age has not been studied. In order to understand the metallogenic age and ore composition of the Xinlukou quartz vein type tungsten deposit, the electron microprobe composition analysis and LA-ICPMS U-Pb dating of wolframite were carried out. The results show that the content of WO3 is 74.147%~75.491%, the content of MnO is 9.601%~16.311%, and the content of FeO is 8.921%~14.903%. The average value of FeO/MnO is 0.784, which is rich in manganese and belongs to tungsten manganese iron ore. The LA-ICP-MS U-Pb T-W lower intercept age of the wolframite is 147.0 ± 2.6 Ma (MSWD = 0.51), the corrected 206Pb/238U weighted average age is 145.2 ± 2.6 Ma (n = 21, MSWD = 1.6), and the metallogenic age is Late Jurassic.