Conditions, timescales and cosmochemical evolution during the early accretion of terrestrial planets

类地行星早期吸积过程中的条件、时间尺度和宇宙化学演化

• 批准号: 145634996
• 负责人: Professor Dr. David Rubie
• 金额: --
• 依托单位: Bayerisches Forschungsinstitut für Experimentelle Geochemie und Geophysik (BGI)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/145634996?language=en
• 关键词: Conditions; timescales; cosmochemical; evolution; during

The most important differentiation event to affect the terrestrial planets was their segregation into metallic Fe-rich cores and silicate mantles. The concentrations of a wide range of both siderophile and lithophile elements in planetary mantles provide major constraints on the conditions of core formation and the composition of the accreting material as a function of time. We have shown recently that a multi-stage model in which core formation occurs progressively, as the consequence of impacts between the proto-Earth and smaller differentiated bodies, can best reproduce mantle geochemistry. In this project we will further develop this preliminary model using a multi-disciplinary approach by (a) integrating it with the results of N-body accretion simulations, (b) including the Hf-W isotopic system in the model to provide additional constraints on timing and disequilibrium processes, and (c) obtaining new experimental partitioning data for silicon, oxygen and the volatile elements Sb, Pb, Cu, Sn, Ge, P, Ag and As. The latter studies will enable a large number of new elements to be included in the core formation/accretion models and will enable the mechanisms and timing of volatile element accretion to the terrestrial planets to be investigated.

影响类地行星的最重要的分化事件是它们分离成金属富铁核和硅酸盐地幔。行星地幔中各种亲铁和亲石元素的浓度对核心形成的条件和作为时间函数的吸积物质的组成提供了主要的限制。我们最近已经表明，一个多阶段的模型，其中核心形成逐步发生，作为原地球和较小的分化机构之间的影响的结果，可以最好地再现地幔地球化学。在这个项目中，我们将使用多学科方法进一步发展这个初步模型，通过（a）将它与N体吸积模拟的结果相结合，（B）在模型中包括Hf-W同位素系统，以提供对时间和不平衡过程的额外约束，以及（c）获得硅、氧和挥发性元素Sb、Pb、Cu、Sn、Ge、P的新的实验分配数据，Ag和As。后一项研究将使大量新元素能够纳入核心形成/吸积模型，并将使挥发性元素吸积到类地行星的机制和时间得以研究。