证据反对一个体地球的证据
Ian H Campbell1, Hugh St C O'Neill
1Research School of Earth Science, Australian National University, Canberra, Australian Capital Territory 0200, Australia. Ian.Campbell@anu.edu.au
Nature
|March 31, 2012
概括
地球的同位素比率超过了太阳的价值,挑战了状地球模型. 这表明,要么是通过碰撞侵蚀形成非地质物质,要么是通过碰撞侵蚀产生物质损失.
科学领域:
- 地质化学 地质化学
- 行星科学 行星科学
- 同位素地球化学 同位素地球化学
背景情况:
- "地质地球"模型假设地球的酸盐成分反映了地质石.
- 地球的 (142) Nd / (144) Nd比率高于太阳的 (混凝土) 比率,造成了一个地球化学悖论.
- 一个含有不兼容元素的深层地幔层,一个拟议的解决方案,与地幔羽毛热量流相冲突.
研究的目的:
- 为了调查地球的同位素比率与太阳/体价值之间的差异.
- 评估现有的地球形成和组成模型.
- 为地球化学悖论提出替代解释.
主要方法:
- 在地球的物质中分析同位素比率 ((142) Nd/ ((144) Nd).
- 陆地和体石同位素组成的比较.
- 热力学和地质模型的行星的形成和演变.
主要成果:
- 地球的 (142) Nd / (144) Nd比率明显大于推断的太阳比率.
- "隐藏层"假设与观察到的地幔羽毛特征不一致.
- 这些数据支持地球的非混凝土初始组成或在形成过程中显著的物质损失.
结论:
- 关于"地地球"的基本假设可能是不正确的.
- 偏好其他形成场景,包括非冠状状积累或碰撞侵蚀.
- 修订我们对地球大体组成和早期历史的理解是必要的.
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