含鲁的耐火生态石:大陆与被耗尽的地幔之间缺失的环节
1Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138, USA.
概括
地球 地球 地球 地球 地球 地球
科学领域:
- 地质化学 地质化学
- 石化学 石化学是一门学科.
- 地球科学 地球科学 地球科学
背景情况:
- 地球的大陆地和枯竭的地幔显示出 (Nb), (Ta) 和 (Ti) 等关键元素的亚粒体比率.
- 这种元素不平衡表明,存在一个超级粒度比的未计数储库.
研究的目的:
- 研究耐火生态石在解决地球观测到的Nb,Ta和Ti的质量失衡中的作用.
- 确定能解释这些元素差异的生态石的矿物学和大质量岩石地质化学特征.
主要方法:
- 在克拉顿石层地幔的异石生态矿石中的矿物中分析微量元素组成.
- 地质化学建模,以量化生态岩水库所需的质量和组成.
主要成果:
- 异石生态矿石中的鲁在很大程度上控制了Nb和Ta的丰富性.
- 生态矿石表现出超级粒度Nb/Ta,Nb/La和Ti/Zr的比率,与所需的水库一致.
- 需要大约1-6%的生态石,以特定的元素度和比率来平衡地球的预算.
结论:
- 耐火性生态石,特别是富含鲁的品种,是解决地球Nb,Ta和Ti质量不平衡的缺失储备的可行候选者.
- 所需的生态石质量表明,很大一部分可能位于下层地幔,可能在核心-地幔边界附近.
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