Mathematical Modeling of Geo-thermo-mechanical Processes in Lithospheric-asthenospheric Subduction Systems using Numerical Methods

Abstract

The purpose of work is to develop a numerical method for mathematical modeling geo-thermo-mechanical processes in lithosphere-asthenospheric subduction systems, which is used to predict the geographical location of deposits of rare, non-ferrous, ferrous metals. Here are given the results of anomalous heat flux distribution analysis in the back-arc part of subduction zone at the Pakistani territory, where the heat flux anomaly is by ~ 9% less than that at the western portion of this zone, despite the subduction velocity of Arabian plate, on the contrary, is 1.48 times greater (subduction angle is somewhat less) at the Pakistani block of subduction zone. The model of dissipative heating and convective dissipative heat transfer to the Earth’s surface computed with taking account of the non-Newtonian mantle rheology and phase transitions shows the water content to be by 0.54 weight % greater and activational energy by 40 (kJ/mol) less in the Pakistani mantle wedge portion as compared to the Iranian one, the maximum heat flux anomaly being shifted by ~10² km further landward from the deep-sea trench. The results of modeling of the geo-thermo-mechanical processes in the mantle wedge at the subduction zone show the copper-porphyry ore deposits to possibly be found there.