Experimental deformation of (Mg,Fe)O ferropericlase at high-pressure and simultaneously high-temperatures

(Mg,Fe)O 方镁石在高压高温下的实验变形

• 批准号: 275722583
• 负责人: Dr. Hauke Marquardt
• 金额: --
• 依托单位: Deutsches Elektronen-Synchrotron (DESY)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/275722583?language=en
• 关键词: Experimental; deformation; Mg; Fe; ferropericlase

(Mg,Fe)O ferropericlase is the second most abundant mineral of Earths lower mantle. It is considered to be rheologically weaker than bridgmanite, the most abundant mineral of the lower mantle. This relative weakness can lead to strain partitioning into ferropericlase in large strain areas of the mantle, such as in boundary layers or areas around subducting slabs. In this scenario, the deformation behavior of ferropericlase will govern the bulk deformation of the mantle. This proposal aims at studying the deformation behaviour of (Mg,Fe)O ferropericlase at simultaneously high-pressure and high-temperatures, approaching the conditions relevant to Earths lower mantle. Measurements will be performed by using synchrotron radial x-ray diffraction in a graphite resistive-heated diamond-anvil cell employing a dedicated experimental setup that is now available at the Extreme Conditions Beamline of PETRA III (DESY). The expected outcome will impact on several key questions regarding the structure and dynamics of Earths lower mantle, including the fate of subducting slabs and the interpretation of seismic anisotropy observations in the D`` layer above the core mantle boundary.

(Mg铁方镁石是地球下地幔中第二丰富的矿物。它被认为是流变性弱于硼镁石，最丰富的矿物下地幔。这种相对的弱点可能导致应变分配到铁方镁石在大应变区域的地幔，如在边界层或俯冲板片周围的地区。在这种情况下，铁方镁石的变形行为将控制地幔的整体变形。本文旨在研究（Mg，Fe）O铁方镁石在高温高压条件下的变形行为，接近地球下地幔的变形条件。测量将通过使用同步辐射X射线衍射在石墨连续加热的金刚石压砧单元中进行，该单元采用专用的实验装置，该实验装置现在可在PETRA III（DESY）的极端条件光束线上获得。预期的结果将影响到有关地球下地幔结构和动力学的几个关键问题，包括俯冲板块的命运和对核幔边界以上D``层地震各向异性观测结果的解释。