The physical and chemical properties of geologic materials control the evolution of Earth’s surface and interior. Rheology is one particular branch of the study of material properties, which characterizes materials’ ability to flow or deform viscously. The rheology of geologic materials is mainly responsible for controlling mantle convection, plate tectonics, and the formation of mountains. As such, rheology is directly related to numerous natural hazards such as earthquakes, volcanoes, and tsunami, as well as the production of natural resources. In this project, the investigators are using tools from materials science to understand the rheology of minerals that make up the bulk of Earth’s crust and upper mantle. The data that result from this study will allow geoscientists to better understand how plate tectonics works, both on Earth and on other planetary bodies. This project represents a unique, interdisciplinary collaboration between Earth science and materials science that will expand the perspectives of each research group and their broader academic communities, and enhance the future research breadth of graduate students involved in the project.

The objective of this project is to investigate the viscoplastic rheology of geological materials using micromechanical methods, including nanoindentation and micropillar compression testing. Experimental results are complemented by high resolution aberration-corrected scanning transmission electron microscope (AC-STEM) imaging and electron energy loss spectroscopy (EELS) to provide insight into the atomic-scale structure and chemistry of crystalline defects introduced by deformation.

This work is supported by the National Science Foundation, Grant No. EAR-1726165. The Principal Investigators are Philip Skemer, Katharine M. Flores, and Rohan Mishra. Link to project website

Related Publications:

M.K. Sly, K. Padilla, K.M. Flores, and P. Skemer, Low temperature rheology of granitic fledspar and quartz, Tectonophysics 858, 229850 (2023). DOI: 10.1016/j.tecto.2023.229850

B. Strozewski, M. Sly, K.M. Flores, and P. Skemer, Viscoplastic rheology of a-quartz investigated by nanoindentation, JGR: Solid Earth 126 (2021). DOI: 10.1029/2021JB022229

K. Kranjc, A. Thind, R. Mishra, K.M. Flores, and P. Skemer, Amorphization and plasticity of olivine during low temperature micropillar deformation experiments, J. Geophysical Research: Solid Earth 125, e2019JB019242 (2020). DOI: 10.1029/2019JB019242

M.K. Sly, A.S. Thind, R. Mishra, K.M. Flores, and P. Skemer, Low-temperature rheology of calcite, Geophysical Journal International 221, 129-141 (2020). DOI: 10.1093/gji/ggz577

K. Kranjc, Z. Rouse, K.M. Flores, and P. Skemer, Low temperature plasticity of olivine determined by nanoindentation, Geophysical Research Letters 43 176-184 (2016). DOI:10.1002/2015GL065837.