Inverse Modeling for Evaluation of the Kinetic Parameters of Metamorphic Reactions in Texture-Homogenous Rocks

Resumo

To obtain the kinetic parameters of diffusion-controlled mineral reactions in texture-homogenous rocks, a new approach is proposed. The method is based on comparison of the modeling concepts of the thermal field evolution to the observed variations in the chemical composition of minerals within the contact aureole of the Kharlovo gabbro massif. The effective rate of mineral reactions involving biotite (~10^–12 s^–1) and the effective coefficient of diffusion (5.29 × 10^–16 cm²/s at T = 475°C) are determined. The results of theoretical modeling are in agreement with the data on the rates of reactions of contact metamorphism, as well as with the empirical estimates of the coefficients of diffusion at grain boundaries in mineral aggregates and segregations under the corresponding PT parameters.