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~(40)Ar/~(39)Ar年龄谱是研究陨石冲击事件的重要资料。根据对55块陨石~(40)Ar/~(39)Ar冲击年龄和陨石暴露年龄的分析,发现陨石的冲击年龄与陨石类型之间存在对应关系。据此,将陨石冲击事件划分为九期。其中3900—4000Ma、470—540Ma和小于65Ma是陨石母体的三个重要演化阶段。阶段Ⅰ、Ⅱ和Ⅲ(冲击年龄大于30亿年)主要涉及高钙型无球粒陨石。所有球粒陨石的冲击年龄均小于30亿年。陨石暴露年龄因类型而异,铁陨石最大,石铁陨石次之,石陨石最小。
~ (40) Ar / ~ (39) Ar age spectrum is an important data for studying the impact events of meteorites. According to the analysis of ~ 40 Ar / 39 Ar impact age and meteorite exposure age of 55 meteorites, it is found that the impact age of meteorite is related to the type of meteorite. Accordingly, the meteorite impact incident is divided into nine phases. Among them, 3900-4000Ma, 470-540Ma and less than 65Ma are the three important evolution stages of the meteorite parent. Stage I, II and III (impact age greater than 3 billion years) mainly related to high-calcium non-chondrites. The impact age of all chondrules are less than 3 billion years. Meteorite exposure age varies by type, the largest iron meteorites, followed by stone iron meteorites, stone meteorites smallest.