Browsing by Author "Qi, Chao"

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    EBSD data for sheared partially molten rocks (olivine + basalt)
    (2018-01-04) Qi, Chao; Kohlstedt, David L; qixxx063@umn.edu; Qi, Chao
    This data set contains the EBSD data for samples of olivine + basaltic melt deformed in torsion. The results are published in "Crystallographic preferred orientation of olivine in sheared partially molten rocks: The source of the 'a-c switch'" by Chao Qi, Lars Hansen, David Wallis, Ben Holtzman and David Kohlstedt on Geochemistry, Geophysics, Geosystems (G-cubed) 2018.
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    Optical micrographs of olivine + melt samples deformed in torsion
    (2018-02-09) Qi, Chao; Kohlstedt, David L; qixxx063@umn.edu; Qi, Chao
    This data set contains high-resolution micrographs of the transverse sections of partially molten samples deformed in torsion. These micrographs present the distribution of melt induced by deformation, which is a test of the melt segregation processes predicted by the two-phase flow theory incorporating viscous anisotropy.
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    Stress-driven melt redistribution in partially molten rocks deformed in torsion: from pressure shadows to base-state segregation
    (2014-10) Qi, Chao
    The redistribution of melt in partially molten rocks during deformation plays an important role in the evolution and dynamics of Earth's mantle. Previous studies discovered different scales of melt redistribution: melt alignment and melt segregation to form melt-enriched bands , both of which have demonstrated their importance to the deformation of the mantle. In this dissertation, two new forms of stress-driven melt redistribution in deformed partially molten rocks are produced: a formation of pressure shadows around rigid particles and a large-scale, base-state melt segregation. For pressure shadows, observations on the microstructure around the rigid particles revealed the melt distribution and solid flow field, which will provide a constraint on the bulk viscosity of the partially molten rock, if associated with theoretical studies. The presence of base-state melt segregation validated a hypothesis of viscous anisotropy, which provides explanations for melt segregation processes and will cause a significant impact to the dynamic of the mantle. Therefore, the studies of stress-driven melt redistribution in this dissertation are of great significance that will influence the future studies of Earth's mantle.