Exposure ages of carbonaceous chondrites, 1
Exposure ages of carbonaceous chondrites, 1
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碳质球粒陨石的暴露年龄，1
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
K. Kobayashi
中科院分区：
文献类型：
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作者：
K. Nishiizumi;J. Arnold;M. Caffee;R. Finkel;J. Southon;H. Nagai;M. Honda;Pankaj Sharma;M. Imamura;K. Kobayashi
最近碳质球粒陨石的暴露历史已经使用宇宙放射性核素进行了研究。我们的结果可能表明 C1 和 C2 球粒陨石的暴露年龄聚集成两个峰值，0.2 My 和 0.6 My，这可能意味着穿越地球母体的两次碰撞事件。在碳质球粒陨石中，有一些暴露年龄较短，Mazor 等人。假设聚类成少数家庭。这一假说基于 Ne-21 的散裂暴露年龄，但由于碳质球粒陨石中存在大量惰性气体，在某些情况下很难确定该年龄。此外，由于 Ne-21 很稳定，它整合了样本的整个暴露历史，因此仅使用 Ne-21 很难理解具有复杂暴露历史的陨石。宇宙放射性核素提供了确定最近宇宙射线暴露持续时间的替代方法。检验 Mazor 等人的假设。我们已经开始对南极和非南极碳质球粒陨石尤其是 C2 的暴露历史进行系统调查。
The recent exposure histories of carbonaceous chondrites have been investigated using cosmogenic radionuclides. Our results may indicate a clustering of exposure ages of C1 and C2 chondrites into two peaks, 0.2 My and 0.6 My, perhaps implying two collisional events of Earth-crossing parent bodies. Among carbonaceous chondrites are some having short exposure ages which Mazor et al. hypothesized cluster into a small number of families. This hypothesis is based on spallogenic Ne-21 exposure ages, which in some instances are difficult to determine owing to the large amounts of trapped noble gases in carbonaceous chondrites. Also, since Ne-21 is stable, it integrates a sample's entire exposure history, so meteorites with complex exposure histories are difficult to understand using exclusively Ne-21. Cosmogenic radionuclides provide an alternative means of determining the recent cosmic ray exposure duration. To test the hypothesis of Mazor et al. we have begun a systematic investigation of exposure histories of Antarctic and non-Antarctic carbonaceous chondrites especially C2s.