Early Career: Development of a New Rock Deformation Apparatus for Investigating Earth's Upper Mantle

该提案概述了继续开发大体积扭转仪（LVT）的计划，这是一种新的岩石变形仪器，旨在研究地壳和上地幔压力和温度下的微观结构现象。开发一种新的岩石变形仪器将在许多方面使社区受益。该设备将针对一系列关键和未充分研究的变形条件进行优化，这将为探索地球上地幔和其他类地行星的内部开辟新的途径。这种支持将有助于早期职业科学家的发展，也将加强岩石力学研究工程师的培训和发展。学生和博士后研究人员的教育机会将是重要的，因为他们将参与新设备的设计，校准和实施的所有阶段。新装置的设计将以电子方式提供，其结构细节将通过因特网传播。获得这些设计将有利于其他早期职业科学家和成熟的研究人员，因为他们计划他们的第一个实验室或扩大现有的labels.Rock变形仪器是不可用的商业和努力，设计具有独特功能的设备是必不可少的岩石力学的进步，和许多活跃的研究领域在结构地质学和地球物理学。LVT的一个关键特征是它使材料在扭转时变形。这种几何形状的好处是样品可以变形到非常大的应变。较低压力和温度下的研究强调了大应变对于形成稳态变形微观结构的重要性。需要大的应变来产生粘滞各向异性的微观结构，并再现地幔剪切带中观察到的微观结构;粘滞各向异性和局部变形是控制板块动力学的关键因素。还需要大的应变来研究晶体组构的产生;这些组构和地震各向异性之间的关系对于解释地幔中的流动模式，特别是在板块边界附近是必不可少的。通过抑制不希望的相变、熔化和脆性变形，这种装置设计可能提高的压力扩大了可以研究的材料和行星条件的范围。

This proposal outlines a plan for the continued development of the Large Volume Torsion apparatus (LVT), a new rock deformation apparatus designed to investigate microstructural phenomena at the pressures and temperatures of Earth's crust and uppermost mantle. The development of a new rock deformation apparatus will benefit the community in a number of ways. The apparatus will be optimized for a critical and under-investigated range of deformation conditions, which will open new avenues for exploration of Earth's upper mantle and the interiors of other terrestrial planets. This support will assist the development of an early career scientist and will also enhance the training and development of a research engineer in rock mechanics. Educational opportunities for students and postdoctoral researchers will be significant, as they will participate in all phases of the design, calibration, and implementation of the new apparatus. The design of the new apparatus will be made publically available, and the details of its construction will be disseminated via the Internet. Access to these designs will benefit other early career scientists and established researchers as they plan their first labs or expand existing labs.Rock deformation apparatus are not available commercially and efforts to design devices with unique capabilities are essential for the advancement of rock mechanics, and many active areas of study within structural geology and geophysics. One critical feature of the LVT is that it deforms materials in torsion. The benefit of this geometry is that samples can be deformed to extremely large strains. Research at lower pressures and temperatures has emphasized the importance of large strains for developing steady state deformation microstructures. Large strains are needed to generate microstructures that are viscously anisotropic and to reproduce microstructures observed in mantle shear zones; viscous anisotropy and localized deformation are key factors that control the dynamics of plates. Large strains are also needed to investigate the generation of crystallographic fabrics; the relationships between these fabrics and seismic anisotropy are essential for interpreting patterns of flow in the mantle, particularly in the vicinity of plate boundaries. Elevated pressures, which are possible with this apparatus design, expand the range of materials and planetary conditions that can be studied, by suppressing unwantedphase changes, melting, and brittle deformation.