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 Pb-206/U-238 ages are comparable with the ages from syngenetic molybdenite, cassiterite, muscovite and the genetically related granites, as well as wolframite by water vaporassisted 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 IN. 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. (C) 2020 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
Publication name |
GONDWANA RESEARCH Volume: 83 Pages: 217-231 DOI: 10.1016/j.gr.2020.02.006 Published: JUL 2020 |
Author(s) |
Tang, Yanwen; Cui, Kai; Zheng, Zhen; Gao, Jianfeng; Han, Junjie; Yang, Jiehua; Liu, Liang |
Corresponding author(s) |
TANG Yanwen tyw_xt@126.com Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Peoples R China. CUI Kai cuikai18@126.com Univ Sci & Technol Beijing, Civil & Environm Engn Sch, Beijing 100083, Peoples R China. | View here for the details
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