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High Precision Zinc Isotopic Measurements Applied to Mouse Organs
Published on: May 22, 2015
有证据表明,地球上有一个古老的同位素储库
1Geological and Environmental Sciences, 320 Lomita Mall, Stanford University, CA 94305-2115, USA. meibom@pangea.stanford.edu
概括
地球地幔中的古老金组元素储备表明了早期的内核形成. 爱里多斯颗粒显示了极为放射性的同位素比率,这表明地球积聚后不久的核心-地幔相互作用.
科学领域:
- 地质化学 地质化学
- 同位素地质学的同位素.
- 行星科学 行星科学
背景情况:
- 来自克拉马斯山脉的矿石的矿粒显示出不寻常的地化学特征.
- 这些颗粒具有高度放射性的同位素比率 (186Os/188Os) 和古老的Re-Os年龄,从256到2.644亿年.
- 这表明存在一个古老的金组元素储库,其金/ (Pt/Os) 比率高于冠状体.
研究的目的:
- 为了调查古代金组元素储库的起源.
- 探索这些水库对早期地球过程,特别是核心形成的影响.
- 为了确定伊里多斯胺Os的同位素组成是否可以作为外核的签名.
主要方法:
- 来自黄金矿床的色胺颗粒的分析.
- 使用Re-Os地质年代学确定 (Os) 和 (Re) 的同位素组成.
- 地质化学建模,以评估潜在的Pt/Os比率的形成机制.
主要成果:
- 爱里多斯胺颗粒显示极为放射性的186Os/188Os比率,最小的Re-Os年龄高达264亿年.
- 这些发现表明,存在一个古老的水库,具有超冠状体Pt/Os比率.
- 观察到的Pt/Os比率与外核内核结晶过程中的分化相一致.
结论:
- 氨酸的同位素组成表明它与地球外核有联系.
- 如果这些Os同位素组成确实是外核的标志,这意味着内核的早期形成.
- 内核可能是在地球积聚后的头几亿年内形成的,比以前认为的要早得多.
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