Chemical heterogeneities in the early Earth and planetary analogues: their formation, preservation and destruction

早期地球和类似行星的化学异质性：它们的形成、保存和破坏

• 批准号: RGPIN-2015-03982
• 负责人: RizoGarza, Hanika
• 金额: $ 1.97万
• 依托单位: Université du Québec à Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=589512
• 关键词: Chemical; heterogeneities; early; Earth; planetary

A fundamental question in Earth and planetary sciences is how the planets formed and how they evolved through time. Geochemical and numerical models, as well as planetary analogs suggest that Earth accreted from complex processed materials and then evolved rapidly after its formation. Early events such as core segregation, mantle differentiation and crust formation seem to have occurred shortly after the Earth’s accretion. Furthermore, the composition of the Earth’s mantle was modified by the continued accretion of materials during the final stages of formation. In the past few years, the development of short-lived isotopic chronometers has allowed chronological studies of the events that followed shortly the Earth’s accretion. Mixing through mantle convection and crustal recycling associated with plate tectonics has attenuated the magnitude of primordial mantle heterogeneities. However, recent documentation of early-formed isotope variations in Archean rocks requires the persistence of primordial chemical reservoirs for > 1 billion years.

地球和行星科学中的一个基本问题是行星的形成方式以及它们如何随着时间的流逝而发展。地球化学和数值模型以及行星类似物表明，地球从复杂的加工材料中获取，然后在形成后迅速进化。早期事件（例如核心隔离，地幔分化和地壳形成）似乎发生在地球积聚后不久。此外，在编队的最后阶段，材料的持续积聚来改变地球地幔的组成。在过去的几年中，短暂的同位素天文组织的发展允许对不久之后地球积聚的事件进行时间顺序研究。通过地幔构造和与板构造相关的地壳回收混合，已衰减原始地幔异质性的大小。但是，最近关于早期岩石的早期同位素变化的文献需要原始化学储层的持久性超过10亿年。