Heat Generation Due to Friction in Shear Zones of the Crust as a Factor of Metamorphism and Anatexis: Results of Computer Modeling

Resumo

The effect of heat generation due to friction in faults under the conditions of shear and thrust was evaluated by computer modeling, and 3D and 2D thermomechanical numerical models were developed. The equations of solid mechanics in a coupled formulation were solved: the equations of mechanical equilibrium and the equation of thermal conductivity. The model of an elastic–plastic material with the Drucker–Prager and Huber–Mises yield function is applied. In the 3D shear model, heating was 100–110°C for the friction coefficient of 0.3; 180–190°C, for the friction coefficient of 0.5; and ~300°C, for the friction coefficient of 0.65. In the horizontal thrust, the heating at the contact zone was 120–130°C at a shear plane depth of 20 km and 150–160°C at a shear plane depth of 30 km, for the friction coefficient of 0.3. The results obtained may be considered as a lower estimate for the value of thermomechanical heating of rocks of the Yenisei collision–shear zone.