The role of strain hardening in the transition from dislocation-mediated to frictional deformation of marbles within the Karakoram Fault Zone, NW India

Wallis, David; Lloyd, Geoffrey E.; Hansen, Louis S.

doi:10.1016/j.jsg.2017.11.008

Cited by 12 publications

(9 citation statements)

References 59 publications

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“…If the grain boundaries were to impose obstacles for the transfer of dislocations, we expect lattice distortion to increase near the grain boundaries (e.g., see Fig. 4d in Wallis et al (2018)). However, a correlation between the distance to the grain boundary and the local misorientation each map pixel at the given distance to the grain boundary (i.e., on a column-by-column basis) to account for the higher likelihood for any given pixel to be near a boundary rather than in the center of a grain.…”

Section: Accepted Articlementioning

confidence: 99%

The Effect of Grain Boundaries on Plastic Deformation of Olivine

2021

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 We investigated the interaction of grain boundaries and dislocations in olivine deformed experimentally. Our results suggest that high-angle boundaries evolve from low-angle grain boundaries by absorbing dislocations, changing the orientation of the low-angle grain boundaries. This process geometrically requires adjacent grains to slide past each other. Specific grain boundaries form and evolve as a result of deformation and activation of a specific slip system. Our results provide evidence that the rate of deformation in the disGBS regime is controlled by the rate of assimilation of dislocations into the grain boundaries.

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Section: Accepted Articlementioning

confidence: 99%

The Effect of Grain Boundaries on Plastic Deformation of Olivine

2021

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“…Other data sets characterize intragranular microstructures, particularly intragranular lattice misorientations, which are used to constrain the types of dislocations present (Bestmann & Prior, ; Lloyd, ; Trimby et al, ). Due to the relative ease with which these rich microstructural data can be acquired, EBSD analysis has become routine in many earth science laboratories and, while these data are employed in a wide range of geoscience subdisciplines, they have become particularly central to the study of deformed rocks (Ceccato et al, ; Cross et al, ; Parsons et al, ; Prior et al, ; Tasaka et al, ; Tommasi et al, ; Wallis et al, ; Weikusat et al, ).…”

Section: Introductionmentioning

confidence: 99%

High‐Angular Resolution Electron Backscatter Diffraction as a New Tool for Mapping Lattice Distortion in Geological Minerals

et al. 2019

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Analysis of distortions of the crystal lattice within individual mineral grains is central to the investigation of microscale processes that control and record tectonic events. These distortions are generally combinations of lattice rotations and elastic strains, but a lack of suitable observational techniques has prevented these components being mapped simultaneously and routinely in earth science laboratories. However, the technique of high-angular resolution electron backscatter diffraction (HR-EBSD) provides the opportunity to simultaneously map lattice rotation and elastic strain gradients with exceptional precision, on the order of 0.01°for rotations and 10 −4 in strain, using a scanning electron microscope. Importantly, these rotations and lattice strains relate to densities of geometrically necessary dislocations and residual stresses. Recent works have begun to apply and adapt HR-EBSD to geological minerals, highlighting the potential of the technique to provide new insights into the microphysics of rock deformation. Therefore, the purpose of this review is to provide a summary of the technique, to identify caveats and targets for further development, and to suggest areas where it offers potential for major advances. In particular, HR-EBSD is well suited to characterizing the roles of different dislocation types during crystal plastic deformation and to mapping heterogeneous internal stress fields associated with specific deformation mechanisms/microstructures or changes in temperature, confining pressure, or macroscopic deviatoric stress. These capabilities make HR-EBSD a particularly powerful new technique for analyzing the microstructures of deformed geological materials.

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“…Other data sets characterize intragranular microstructures, particularly intragranular lattice misorientations, which are used to constrain the types of dislocations present (Bestmann & Prior, 2003;Lloyd, 2004;Trimby et al, 1998). Due to the relative ease with which these rich microstructural data can be acquired, EBSD analysis has become routine in many earth science laboratories and, while these data are employed in a wide range of geoscience subdisciplines, they have become particularly central to the study of deformed rocks (Ceccato et al, 2018;Cross et al, 2017;Parsons et al, 2016;Prior et al, 2009;Tasaka et al, 2017;Tommasi et al, 2017;Wallis et al, 2018;Weikusat et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

High-angular resolution electron backscatter diffraction as a new tool for mapping lattice distortion in geological minerals

Wallis¹,

Hansen²,

Britton³

et al. 2019

Preprint

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Analysis of distortions of the crystal lattice within individual mineral grains is central to the investigation of microscale processes that control and record tectonic events. These distortions are generally combinations of lattice rotations and elastic strains, but a lack of suitable observational techniques has prevented these components being mapped simultaneously and routinely in earth science laboratories. However, the technique of high-angular resolution electron backscatter diffraction (HR-EBSD) provides the opportunity to simultaneously map lattice rotations and elastic strains with exceptional precision, on the order of 0.01° for rotations and 10^-4 in strain, using a scanning electron microscope. Importantly, these rotations and lattice strains relate to densities of geometrically necessary dislocations and residual stresses. Recent works have begun to apply and adapt HR-EBSD to geological minerals, highlighting the potential of the technique to provide new insights into the microphysics of rock deformation. Therefore, the purpose of this overview is to provide a summary of the technique, to identify caveats and targets for further development, and to suggest areas where it offers potential for major advances. In particular, HR-EBSD is well suited to characterising the roles of different dislocation types during crystal plastic deformation and to mapping heterogeneous internal stress fields associated with specific deformation mechanisms/microstructures or changes in temperature, confining pressure, or applied deviatoric stress. These capabilities make HR-EBSD a particularly powerful new technique for analysing the microstructures of deformed geological materials.

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The role of strain hardening in the transition from dislocation-mediated to frictional deformation of marbles within the Karakoram Fault Zone, NW India

Cited by 12 publications

References 59 publications

The Effect of Grain Boundaries on Plastic Deformation of Olivine

The Effect of Grain Boundaries on Plastic Deformation of Olivine

High‐Angular Resolution Electron Backscatter Diffraction as a New Tool for Mapping Lattice Distortion in Geological Minerals

High-angular resolution electron backscatter diffraction as a new tool for mapping lattice distortion in geological minerals

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