【摘要】 报道的单颗粒锆石蒸发定年方法是利用新型固体质谱计的多离子接收器配置实现的。改进的锆石蒸发207Pb/206Pb定年流程通过静态测量方式,在锆石蒸发过程中直接测定铅同位素比值,获得207Pb/206Pb年龄。应用该方法测定了元古代永宁组沉积岩的碎屑锆石,获得6颗锆石的207Pb/206Pb年龄值为1 965~2 590 Ma。与传统的蒸发法流程相比,静态测量方法省时简捷,同时可以直观地观测到锆石内部的铅同位素组成变化。这些变化反映锆石结晶历史、后期事件叠加以及锆石成因等地质信息。更多还原

【Abstract】 The single-grain zircon evaporation method reported in this study has been realized owing to a multi-ion-counter configuration equipped in a newly developed mass spectrometer.Using an improved analytical procedure to the traditional zircon evaporation ²⁰⁷Pb/²⁰⁶Pb dating,Pb isotopic ratios were simultaneously measured with static mode during evaporating the zircon grain.Six detrital zircon grains from the Proterozoic Yongning Formation were measured using this method and ²⁰⁷Pb/²⁰⁶Pb ages of 1965～2590 Ma were obtained.Compared with the traditional procedure of the evaporation dating method,this new technique is time-saving and convenient.Variation of Pb isotopic ratios of zircon grain can be directly observed during the evaporation-measurement process.This compositional variation can provide meaningfully geological information of crystallization history,overprint of late geological events and genesis of zircon grains.更多还原