Department of Earth Sciences
Major gaps exist in our knowledge of the viscous properties of the upper mantle and lower crust, introducing uncertainty into estimates of geodynamic processes such as the formation of tectonic plate boundaries, the nature of the lithosphere-asthenosphere boundary, stress-relaxation in the seismic cycle, and sea-level rise associated with post-glacial rebound. Much of this uncertainty results from the large extrapolations inherent in applying laboratory-derived models of rock deformation to large-scale processes. This research group strives to overcome those uncertainties by developing a robust understanding of the microscopic mechanisms of deformation over a range of time scales, linking laboratory experiments, outcrop-based field work, and geophysical observables. Some current phenomena of interest include shear zone formation through strain localization, the evolution of dislocation density during deformation, transient creep at low strain, the mechanisms of seismic attenuation, and the role of melt and water in modifying rock viscosity. Potential projects are likely to consist of laboratory-based deformation experiments, high-resolution microstructural characterization, detailed field work, and/or numerical modelling.
Associated Research Streams
rock rheology, upper mantle and lower crust, lithosphere, ductile faults and shear zones, high-resolution electron microscopy, mineral physics,