• 2007 Ph.D. Marine Geology and Geophysics, MIT/WHOI Joint Program
Thesis: Geochemical and Rheological Constraints on the Dynamics of the Oceanic Upper Mantle
Advisors: Nobumichi Shimizu, Henry Dick, Greg Hirth
• 2000 M.Sci. Earth Sciences, University of Cambridge, U.K.
• 1999 B.A. Earth Science, University of Cambridge, U.K.
My research is focused on understanding the rheology and geochemistry of the mantle. I use peridotites — collected on land and at sea — to look at processes occurring beneath the Earth's crust, in the lithospheric mantle and the asthenosphere.
Peridotites from mid-ocean ridges contain a variety of information about source composition and about processes of melting and melt extraction. By looking at isotopes, trace elements, major elements and mineral modes, I address questions such as:
• What are the length-scales and sizes of heterogeneities?
• How do melts migrate at depth in the mantle?
• What is the effect of spreading rate on mid-ocean ridge processes?
Understanding how olivine deforms is key to understanding deformation in the mantle, both localized at plate boundaries and on the scale of mantle convection. Electron backscatter diffraction (EBSD) provides a unique tool to measure lattice preferred orientations of olivine, orthopyroxene, and other phases present in peridotites. I have used EBSD to study grain size sensitive deformation mechanisms in mylonites, with applications to shear localization and fabric randomization. I am currently working on a study of olivine fabric variations as a function of shear strain, with applications to seismic anisotropy and patterns of mantle convection.