At present,there are only a few reference standards used in(U-Th)/He and fission track geochronology such as Durango apatite in Mexico,FCT zircon in the United States and MK-1 apatite in Myanmar,and most of them are standards for single dating method.Three independent thermochronological methods are used to predict the same eruption age by apatite and zircon.Whether the tuff is suitable for single or combined fission track,(U-Th)/He and apatite U-Pb dating age reference standards is evaluated by observing age reproducibility and dispersion.In this paper,the tuff of Dingqinghu Formation in Lunpola Basin of Tibetan Plateau is selected as research samples,and the apatite and zircon are selected for cross-calibration between multi-geochronological methods.The Lunpola(LPL)apatite yields a weighted average(U-Th)/He age of 24.4±0.3Ma(1s)with MSWD of 4.25.While 21 LPL zircon single crystals get a weighted average age of 19.2±0.5Ma(1s)with MSWD of 2.5.The fission track age of LPL apatite is 22.8±0.8Ma,while the U-Pb age of LPL apatite is 16.3±13.9Ma with MSWD of 0.29.After comparing LPL apatite with Durango and MK-1 apatite,we infer that there are two populations of apatite crystals.Therefore,it is not suitable for LPL apatite to be used as a(U-Th)/He reference standard.After comparing LPL zircon with FCT and Penglai zircons,we conclude that LPL zircon has good age results with high accuracy and precision,and low age dispersion,and can be used as a potential(U-Th)/He reference standard.
Reference standardApatiteZircon(U-Th)/He datingFission track dating
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