南极-艾特肯大规模撞击425亿年前由6号样本揭示
Bin Su1, Yi Chen1, Zeling Wang1
1State Key Laboratory of Lithospheric and Environmental Coevolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
National science review
|May 20, 2025
概括
这是一个变化,一个变化.
科学领域:
- 月球地质学 月球地质学
- 星球科学 星球科学
- 撞击坑的形成 撞击坑的形成
背景情况:
- 南极-艾特肯 (SPA) 盆地是一个重要的,古老的月球撞击结构.
- 准确地确定SPA盆地形成的日期对于了解太阳系早期历史至关重要.
- 从火山口计数和阿波罗样本中得出的以前的年龄估计缺乏明确的验证.
研究的目的:
- 为了确定SPA盆地冲击事件的确切年龄.
- 分析从SPA盆地返回的月球样本的石化,地质化学和时间表.
- 精确月球早期进化和撞击坑形成的时间表.
主要方法:
- 分析Chang'e-6任务返回的诺莱特岩石石块的石化和地化学分析.
- 精确的- (Pb-Pb) 约会在诺里特中含有的矿物.
- 将样本特征与已知的月球样本和冲击融板指标进行比较.
主要成果:
- 诺里特石团表现出独特的矿物成分 (富含安诺的青酸盐,富含Mg的氧化物),与月球附近的样本不同.
- 有证据表明,来自冲击融板的结晶,由Fe-Ni金属,挥发性耗尽和可变的冷却速率表示.
- Pb-Pb约会揭示了在3.87 Ga (重置) 和4.25 Ga (SPA影响) 的两个冲击事件.
结论:
- 4.25亿年前的年龄为SPA撞击提供了坚固的,完善了月球石坑的时间表.
- 这项研究完善了早期月球进化和撞击事件的时间表.
- 这些发现凸显了SPA盆地对理解行星历史的重要性.
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