Abstract Direct dating of W and W Sn deposits by wolframite is more reliable relatively to gangue mineral and important for understanding their timing and genesis. However, such analysis still lacks of homogeneous wolframite standard recently. Due to containing considerable and variable common lead, and inhomogeneous in different grains, the wolframite sample of MTM, which is a promising candidate reference material proposed by previous studies, is not suitable as a primary standard for wolframite U Pb dating by LA-ICP-MS using the normal normalization method as zircons. In this contribution, a modified normalization method is established for wolframite U Pb dating, in which NIST612 or 614 and MTM are used for correction of Pb Pb and U Pb ratios, respectively. Wolframite U Pb dating are performed on the Langcun, Xihuashan, Piaotang, Shamai W or W Sn deposits and the Baiganhu ore district, the obtained lower intercept 206Pb/238U ages are comparable with the ages from syngenetic molybdenite, cassiterite, muscovite and the genetically related granites, as well as wolframite by water vapor-assisted ns-LA-ICP-MS U Pb dating method. The results of this analysis demonstrate that the robust age for W mineralization can be determined by LA-ICP-MS U Pb dating of wolframite using this modified calibration method. Mineralization ages of 125–130 Ma by directly dating of metal minerals for the Langcun W, Jianfengpo Sn and large-size Xianglushan W deposits confirm that there exists an important W Sn mineralization event in this period. The close temporal and spatial correlation indicates the granites and W-Cu-Mo-Pb-Zn-Sn mineralization have a genetic relationship with each other and are resulted from the same tectonic-magmatic-hydrothermal events during 140 to 120 Ma in South China.

中文翻译：

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以 NIST 系列和普通含铅 MTM 为主要参考材料的黑钨矿 LA-ICP-MS U Pb 年代学：对华南成矿作用的启示

摘要 相对于脉石矿物，用黑钨矿直接测年 W 和 W Sn 矿床更可靠，对于了解它们的时间和成因具有重要意义。然而，此类分析目前仍缺乏均质黑钨矿标准。MTM 黑钨矿样品由于含有大量可变的普通铅，且在不同晶粒中不均匀，作为前人研究提出的一种很有前景的候选参考物质，不适合作为 LA-ICP- 黑钨矿 U Pb 测年的主要标准。 MS 使用正常归一化方法作为锆石。在此贡献中，建立了一种改进的黑钨矿 U Pb 定年归一化方法，其中 NIST612 或 614 和 MTM 分别用于校正 Pb Pb 和 U Pb 比率。在朗村、西华山、飘塘、沙麦 W 或 W Sn 矿床和白干湖矿区，获得的下截距 206Pb/238U 年龄与同生辉钼矿、锡石、白云母和成因相关的花岗岩以及水汽辅助 ns-LA 得到的黑钨矿的年龄相当-ICP-MS U Pb 测年法。该分析的结果表明，可以使用这种改进的校准方法通过黑钨矿的 LA-ICP-MS U Pb 测年确定 W 矿化的可靠年龄。朗村W、尖峰坡锡和大型香炉山W矿床金属矿物直接测年的成矿年龄为125-130 Ma，证实该时期存在重要的W Sn成矿事件。