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: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=475332
• 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.

拟议的研究是一项多管齐下的实验调查，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稀的硫和硅合金组成。这些液态铁合金的物理性质控制着基本的过程，例如从地核到地幔的热流，以及地核内磁场的产生和维持。我们的方法的指导原则是，了解管理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行星材料的矿物物理和化学的微观尺度方面的知识。该研究将涉及在极端压力（20 GPa）和温度（2500 K）下，在大体积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，以模拟这些行星体内部深处的条件。将进行U和Si同位素在液态金属和硅酸盐之间分配的进一步研究。在提案期间，我们计划组建一个由10名HQP组成的团队，我们将采用我们实验室开发的新技术，在沉/浮方法中使用复合球体测量密度和粘度。同步加速器X射线照相术将提供加压液体中球体运动的实时图像。预计这些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机构的核心组成。 2.测量的物理特性是这些行星体核心动力学（地球发电机和热流）的精确模型所必需的。3.结果将直接解决恒定的物理性质行为的基本物理沿着压力相关的熔化边界。