Geochemical self-organization. III: A mechano-chemical model of metamorphic differentiation

Abstract

The interaction between deformation, mineral reaction, and mass transport in a rock with even small textural heterogeneities at metamorphic conditions is shown to lead to differentiation between quartz and muscovite on relevant geologic time and length scales. A quantitative reaction-transport model that describes the temporal and spatial evolution of this differentiation combines equations for grain growth and dissolution, diffusional solute transport, and rock flow. The spacing of differentiated domains depends on transport coefficients, the magnitude of the imposed strain rate, and lithology. In the case of enhanced dissolution kinetics at quartz-mica interfaces an additional lithologic dependence is manifest. -from Authors