Pure CO2 fluid inclusions commonly occur in metamorphic rocks which are known to have crystallized in the presence of an H20-rich fluid. Densities are consistent with peak metamorphic conditions, but their composition is not. This project will investigate the possibility that processes attending crystal plastic flow and dynamic recrystallization of quartz may result in loss of H2O from inclusions, with CO2 remaining in the host quartz. Samples of metamorphic rocks showing strain gradients in hand specimen will be utilized to determine the variations of composition and density of fluid inclusions in relation to gradients in strain and variations of deformation mechanisms. Results are expected to clarify origins of pure CO2 inclusions and may provide a new perspective for studies of high temperature deformation mechanisms.
