陆地行星的挥发性积累历史和动态影响
1Ecole Normale Supérieure de Lyon, Université Claude-Bernard Lyon 1, and CNRS, 46 allée d'Italie, 69007 Lyon, France. albarede@ens-lyon.fr
Nature
|October 30, 2009
概括
地球和月球在形成后很长时间从潮湿的小行星中获得了水,这对板块构造学和生命至关重要. 在太阳系隔离后的1亿年里,这种供水达到顶峰.
科学领域:
- 行星科学 行星科学
- 地质化学 地质化学
- 天体生物学 天体生物学
背景情况:
- 包括地球和月球在内的陆地行星最初由于积累过程而耗尽了挥发性成分.
- 月球通过巨大的撞击形成,可能使原地球和月球在很大程度上处于无水状态.
研究的目的:
- 调查地球和月球在它们的历史中更晚获得挥发物质,特别是水的假设.
- 为了探索晚期挥发性物质到太阳系内部的时间和来源.
- 评估这种水供应对板块构造学和地球生命的出现的影响.
主要方法:
- 对U-Pb (-) 和I-Xe (-) 时间表的分析.
- 解释同位素数据以限制挥发性交付事件的时间.
主要成果:
- U-Pb和I-Xe的约会表明,在太阳系隔离后大约1亿年,供水量达到顶峰.
- 这种晚期的挥发性积累表明,地球和月球最初是月球后的干燥形成.
结论:
- 来自小行星带之外的潮湿物质的晚期积累是地球获取水的合理机制.
- 水进入地球地幔可能引发了板块构造,这是生命出现的关键因素.
- 这种不稳定的交付模式可能适用于金星,但对火星似乎不那么成功.
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