Experimental earth and planetary materials sciences at extreme conditions of pressure and temperature

极端压力和温度条件下的实验地球和行星材料科学

• 批准号: 105604-2008
• 负责人: Secco, Richard
• 金额: $ 3.72万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2009
• 资助国家: 加拿大
• 起止时间: 2009-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=421742
• 关键词: Experimental; earth; planetary; materials; sciences

The proposed research is a multi-pronged experimental investigation aimed at understanding the composition, state and core dynamics of Earth, Mercury, Mars and Jupiter's satellites Io and Ganymede. The central parts of these planetary bodies are composed primarily of iron and its dilute alloys of sulfur and silicon. The physical properties of these liquid iron alloys control fundamental processes such as heat flow from the core to the mantle as well as the generation and maintenance of magnetic fields inside their cores. The guiding principle of our approach is that understanding the macro-scale processes that govern global geodynamics pivots on our knowledge of the micro-scale aspects of the mineral physics and chemistry of planetary materials that control them. The research will involve experimental measurements of the electrical resistivity, density and viscosity of liquid iron-sulfur-silicon alloys and analog materials at extreme pressures (20GPa) and temperatures (2500K) in large volume presses to simulate the conditions deep inside these planetary bodies. Additional studies of partitioning of U and Si isotopes between liquid metal and silicate will be carried out. With a planned team of 10 HQP over the period of the proposal, we will employ novel techniques developed in our lab to measure density and viscoity using composite spheres in the sink/float method. Synchrotron x-ray radiography will provide real-time images of the sphere motion in the pressurized liquid. The significance of the results is expected in three areas of deep Earth and planetary studies. 1. The results will help to determine the core compositions of these bodies. 2. The measured physical properties are required for accurate models of the dynamics (geodynamo and heat flow) of the cores of these planetary bodies. 3. The results will directly address the basic physics of constant physical property behavior along the pressure-dependent melting boundary.

这项研究是一项多管齐下的实验研究，旨在了解地球、水星、火星和木星卫星木卫一和木卫三的组成、状态和核心动力学。这些行星体的中心部分主要由铁及其硫和硅的稀释合金组成。这些液态铁合金的物理性质控制着从地核到地幔的热流以及地核内磁场的产生和维持等基本过程。我们的方法的指导原则是，理解控制全球地球动力学的宏观尺度过程取决于我们对控制它们的矿物物理和行星材料化学的微观尺度方面的知识。这项研究将包括在高压（20GPa）和高温（2500K）的大型压力机中对液态铁硫硅合金和模拟材料的电阻率、密度和粘度进行实验测量，以模拟这些行星体深处的情况。对液态金属和硅酸盐之间铀和硅同位素分配的进一步研究将进行。在提案期间，我们计划有一个10 HQP的团队，我们将采用我们实验室开发的新技术，在下沉/漂浮法中使用复合球体测量密度和粘度。同步加速器x射线摄影将提供球体在加压液体中运动的实时图像。研究结果在地球深部和行星研究的三个领域具有重要意义。1. 这些结果将有助于确定这些天体的核心成分。2. 测量到的物理性质是这些行星核心的动力学（地球动力学和热流）的精确模型所必需的。3. 结果将直接解决沿压力相关的熔化边界的恒定物理性质行为的基本物理问题。