CAREER: Microphysical evolution of highly sheared polymineralic rocks

职业：高剪切多矿物岩石的微物理演化

• 批准号: 1352306
• 负责人: Philip Skemer
• 金额: $ 60万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1352306&HistoricalAwards=false
• 关键词: CAREER; Microphysical; evolution; highly; sheared

The theory of plate tectonics is the basis for most Earth science, providing context for interpreting such diverse phenomena as earthquakes and volcanoes, mountain building, and global climate. In spite of its broad scientific and societal importance, there are still fundamental unanswered questions about the underlying physical mechanisms of plate tectonics. The basic differences between the manifestation of tectonics on Earth and other terrestrial bodies are a major outstanding question in geophysics and planetary science. This research applies novel experimental approaches to study how rocks deform at the pressures and temperatures of planetary interiors to help understand the origins of plate tectonics on Earth. To fulfill these research objectives, large strain torsional deformation experiments will be conducted on rocks of crustal and mantle composition. These experiments will be performed in the PI's newly built Large Volume Torsion apparatus (LVT), which has been optimized for experimental investigations at pressures of up to 6 GPa and temperatures of up to 1300 C. The focus of these investigations will be on the microphysical interaction between various mineral phases, in polymineralic rocks. The goal is to better understand how large shear strains modify the rheological properties of realistic rocks, and identify the conditions where these data deviate from experiments conducted to small strains on monomineralic material. Microstructural data will be incorporated into numerical models to simulate how variations in rheology influence the dynamical evolution of tectonic plates. This project also includes an integrated plan for teaching and research in rock mechanics at the undergraduate level. Few undergraduate curricula incorporate rock mechanics, and more exposure is needed to broaden research capabilities in this critical area. The PI will be developing a research-grade bench-top rock deformation apparatus that will be incorporated into the curricula of several undergraduate colleges with strong programs in Earth Science. Through curriculum and infrastructure development, this effort seeks to expand the number of undergraduate students who consider further research in experimental rock deformation.

板块构造理论是大多数地球科学的基础，为解释地震和火山，造山运动和全球气候等各种现象提供了背景。 尽管它具有广泛的科学和社会重要性，但关于板块构造的基本物理机制仍然存在一些基本的未解之谜。地球构造与其他天体构造的基本区别是地球物理学和行星科学中一个重大的悬而未决的问题。这项研究采用新颖的实验方法来研究岩石如何在行星内部的压力和温度下变形，以帮助理解地球上板块构造的起源。 为了实现这些研究目标，将在壳幔组合岩石上进行大应变扭转变形实验。 这些实验将在PI新建造的大体积扭转装置（LVT）中进行，该装置已针对压力高达6 GPa和温度高达1300 ℃的实验研究进行了优化。 这些研究的重点将是在多矿物岩石中各种矿物相之间的微观物理相互作用。我们的目标是更好地了解大的剪切应变如何修改现实岩石的流变特性，并确定这些数据偏离单矿物材料上进行的小应变实验的条件。 微结构数据将被纳入数值模型，以模拟流变学的变化如何影响构造板块的动态演化。该项目还包括本科阶段岩石力学教学和研究的综合计划。 很少有本科课程纳入岩石力学，需要更多的曝光，以扩大在这一关键领域的研究能力。PI将开发一种研究级台式岩石变形仪器，该仪器将被纳入几所具有强大地球科学课程的本科院校的课程。 通过课程和基础设施的发展，这一努力旨在扩大本科生谁考虑在实验岩石变形进一步研究的数量。

项目成果

Grain damage, phase mixing and plate-boundary formation

晶粒损伤、相混合和板边界形成

• DOI: 10.1016/j.jog.2017.05.002
• 发表时间: 2017
• 期刊: Journal of Geodynamics
• 影响因子: 2.3
• 作者: Bercovici, David;Skemer, Philip
• 通讯作者: Skemer, Philip