具有特殊 REE 模式的 Chondrules:对于高 C/O 的太阳星云凝结的影响
Andreas Pack1, J Michael G Shelley, Herbert Palme
1Institut für Mineralogie und Geochemie, Universität Köln, Zülpicher Strasse 49b, D-50674 Köln, Germany. apack@crpg.cnrs-nancy.fr
概括
来自chondrules的稀土元素 (REE) 数据表明,气体/固体分离发生在低氧水平. 这意味着早期的太阳星云条件比以前认为的更加缺氧.
科学领域:
- 宇宙化学 宇宙化学
- 行星科学 行星科学
- 地质化学 地质化学
背景情况:
- 普通的地铁提供了对早期太阳系过程的洞察.
- 稀土元素 (REEs) 是行星形成和分化的关键标志物.
- 之前的模型假定了正规太阳星云的特定氧气流动性.
研究的目的:
- 为了调查普通石石中明显的REE异常的起源.
- 为了测试在低氧气流动性条件下REE气体/固体分离的假设.
- 推断早期太阳星云的化学环境.
主要方法:
- 分析两种普通的地体中的稀土元素度.
- 合金石规范化的REE模式分析.
- 气体/固体分成过程的建模.
主要成果:
- 在chondrule REE数据中观察到samarium,europium和 ytterbium的明显负异常.
- 这些异常与低氧气流失率的REE气体/固体分离相一致.
- 这些发现表明,可以使用高度减少的,超耐火凝.
结论:
- 早期的太阳星云可能经历了具有显著氧气缺乏的环境.
- 高温冷凝过程发生在具有增强碳/氧比的条件下.
- 这挑战了以前关于正规太阳星云氧气流动性的假设.
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