在Shergotty石中的一个后stishoviteSiO2多态:对撞击事件的影响
T G Sharp1, A El Goresy, B Wopenka
1Department of Geology, Arizona State University, Tempe, AZ 85287, USA.
概括
火星石Shergotty含有密集的SiO2阶段,类似于地球下层地幔后的stishovite结构. 这种高密度的多态体可以作为行星体极端冲击压力的指标.
科学领域:
- 地质化学 地质化学
- 矿物学是什么?矿物学是什么?
- 行星科学 行星科学
背景情况:
- 火星石为行星的形成和演化提供了洞察力.
- 了解二氧化 (SiO2) 的高压相对于深层地球和行星内部模型至关重要.
研究的目的:
- 为了研究火星石Shergotty的矿物成分.
- 在外星样本中识别高压二氧化多态.
- 评估这些多态体作为冲击事件指标的潜力.
主要方法:
- 使用传输电子显微镜 (TEM) 来分析谢尔戈蒂石的微观结构.
- 电子衍射被用来确定已识别的相的晶体结构.
主要成果:
- 在Shergotty.发现了一种密集的正交SiO2阶段,结构上类似于具有α-PbO2结构的后stishovite,在Shergotty.发现了一种密集的正交SiO2阶段.
- 这一阶段代表了高密度的二氧化多态.
- 这种多态体在被冲击的状体中存在,表明人们经历了极端的冲击压力.
结论:
- 火星石Shergotty含有类似于地球下层地幔中预期的高压二氧化多态体.
- 石灰岩后的SiO2结构可以被用作极端冲击压力的可靠指标,在被冲击的石和潜在的行星内部.
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