火星上的火山活动是由上层地幔早期氧化控制的
1Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK.
Nature
|June 21, 2013
概括
火星 火星 火星 火星 火星
科学领域:
- 行星科学 行星科学
- 地质化学 地质化学
- 天文地质学 天文地质学
背景情况:
- 谢尔戈提特 - 纳克利特 - 西尼特 (SNC) 石为火星的化学组成和演变提供了关键的见解.
- 与陆地玄武岩相似的SNC石,与火星表面岩石相比,具有更高的铁和挥发性元素,以及较低的和硫.
- 由Spirit探测器分析的古塞夫火山口的老火星表面岩石显示出与SNC石不同的组成,挑战了'SNC模型'.
研究的目的:
- 为了调和火星石和地表岩石之间的组成差异.
- 为了研究氧气流失在火星地幔演变中的作用.
- 为火星地质历史建立一个统一的模型.
主要方法:
- 对SNC石和古塞夫火山口表面岩石进行比较地质化学分析.
- 在不同氧气流失条件下模拟地幔融过程.
- 同位素和元素组成分析.
主要成果:
- 石和地表岩石组成的差异可以通过在地幔融化过程中的不同氧气流动性来解释.
- 火星的石和地表岩石起源于同一个富含硫的地幔来源.
- 火星上层地幔的早期氧化事件 (>37亿年前) 影响了表面岩石组成,而不是更深层地幔区域.
结论:
- "SNC模型"可以通过考虑氧气流动性的变化来扩展到包括表面岩石.
- 火星地幔经历了重要的化学进化,特别是早期的氧化事件.
- 通过对石和现场表面数据的综合分析,可以实现对火星化学组成和演变的统一理解.
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