Dr. Stephen Mackwell
Dr. Steve Mackwell performs research into the dynamics of the lithospheres and interiors of the terrestrial planets through experimental studies of the deformation of rocks and minerals at high-temperature and pressure conditions. Such studies have focused on the mechanical behavior of rocks of basaltic composition, as well as upper mantle rocks and minerals. Particular attention has been paid to the role of chemical environment, notably the water and oxygen partial pressures. Weakening effects due to textural evolution during high-strain deformation have also been studied.
Dr. Mackwell also investigates the role of chemical environment on diffusion within minerals and on kinetics of mineral reactions. In particular, he has focused on the rates of water uptake and loss from minerals in mantle xenoliths during transport from the mantle source region, with implications for the water content of Earth’s interior. His work on mineral reactions during high-temperature experiments has enabled calculation of grain boundary diffusion rates in polymineralic aggregates, with implications for phase transition kinetics and rheological behavior.