Mass transport in minerals

Abstract

Diffusion data for silicate minerals are essential for understanding the development of microstructural features in rocks and calibrating the timescales of geological processes. An outline of current experimental techniques is given, and illustrated with studies of cation diffusion in garnet, pyroxenes and olivines. Oxygen diffusion in silicate minerals under ‘wet’ conditions is characterised by fast diffusion rates and low activation energies; diffusion under ‘dry’ conditions is characterised by small diffusion coefficients and high activation energies. Major trends in the diffusion data are summarised. Achievements and problems in experimental studies are discussed.