现代地质2023，Vol.37Issue(6)：1509-1523,15.DOI:10.19657/j.geoscience.1000-8527.2023.033
三江特提斯马厂箐斑岩铜钼矿床成矿时间尺度探讨:来自石英中Ti-Al扩散年代学的约束
Delicate Timescale of the Machangqing Porphyry Copper-Molybdenum Deposit in Sanjiang Tethyan Domain,SW China:Constraints from the Diffusion Chronology of Ti and Al in Quartz
摘要
Abstract
In recent years,studies on the porphyry metallogenic timescale have become more refined and diver-sified.By using high-precision isotope dating,element diffusion chronology and thermodynamic numerical sim-ulation,the porphyry metallogenic timescale are precisely defined to be between tens to hundreds of thousands of years.Quartz is a chemically stable mineral in various mineralization stages,which can be utilized as an ideal object to explore episodic hydrothermal processes.Taking the Machangqing porphyry Cu-Mo deposit in the San-jiang Tethyan Domain as the case study,and basing on the fine arrangement of the vein relationship and mineral assemblage at each stage,we used the diffusion chronology method of Ti and Al in quartz to constrain the timescale,and discussed the practical application of diffusion chronology.The Machangqing deposit contains multi-stage hydrothermal veins,which can be divided into multiple hydrothermal stages based on their crosscut-ting relationship and mineral composition.For the quartz in the early-ore A2 and main-ore B3 veins,our finding shows that the early-ore quartz samples have higher correlation between the CL intensity and Ti element,and its timescale defined by the Ti diffusion is 10.5-57.5 ka;for the main ore stage,the quartz CL intensity has a high-er correlation with the Al element,and its timescale defined by the Al diffusion is 522.3 ka.Overall,we consider that using element diffusion chronology to constrain the porphyry metallogenic timescale may be affected by the temperature-pressure conditions,simulation location,analytical precision and accuracy.Therefore,it is necessary to construct a reasonable diffusion model based on the metallogenic conditions and mineral growth characteristics.关键词
成矿时间尺度/扩散年代学/石英/斑岩矿床/马厂箐/三江特提斯Key words
timescale/diffusion chronology/quartz/porphyry deposit/Machangqing/Sanjiang Tethan domain分类
天文与地球科学引用本文复制引用
张靓,陈奇,高添,李雯,钱金龙,刘俐君,王长明..三江特提斯马厂箐斑岩铜钼矿床成矿时间尺度探讨:来自石英中Ti-Al扩散年代学的约束[J].现代地质,2023,37(6):1509-1523,15.基金项目
国家重点研发计划项目(2020YFA0714802) （2020YFA0714802）
国家自然科学基金重大研究计划项目(92162101). （92162101）
