Mineral Structure and Deformation as Key Recorders of Earth and Planetary Processes

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My research uses minerals to interpret processes on Earth and other planetary bodies. Minerals record their formation conditions: pressure, temperature, and composition (P-T-X), and subsequent events such as deformation, thermal metamorphism, metasomatism (fluid interaction) and aqueous alteration. Terrestrial rocks, meteorites, impacted rocks and synthetic analogues provide key information about mineral associations, textures, mineral compositions, crystal structures and cation ordering that can reveal past processes. My group is at the forefront of applying in situ micro X-ray diffraction (µXRD) to study minerals in Earth and planetary contexts, including its key role in providing phase identification, textural information and deformation-related features in Earth and astromaterials. We are also unique in Canada in using solid state nuclear magnetic resonance (NMR) spectroscopy for elucidation of mineral behaviour in geological contexts. Using the complementary techniques of X-ray diffraction and NMR spectroscopy, as well as optical and chemical methods (EPMA), my group seeks to interpret and quantify mineral properties to understand the geologic processes at work in the Earth and other Solar System settings. My long-term research goals are to investigate the evolution of our solar system and its rocky planetary bodies, including Earth, by examining terrestrial mantle and crustal rocks, meteorites, and returned samples from the moon and eventually from asteroids and Mars - using the combined study of mineral compositions, crystal structures, cation ordering and textural evidence. My research themes are twofold: 1) to quantify and calibrate minerals as recorders of strain, and to discriminate between deformation due to meteorite impacts (shock) and terrestrial tectonic deformation (directed strain); and 2) to quantify and interpret minerals as recorders of temperature in the early solar system and terrestrial mantle rocks, by making systematic observations of crystal structure and cation order-disorder for key mineral suites, and deriving thermodynamic parameters.  This research will place students at the forefront of current debates on the formation conditions and thermal evolution of early planetary bodies, the extent and variation of shock metamorphism in planetary materials, and the genesis of mantle-derived magmas.