The Comparison of Newtonian and Non-Newtonian Rheology Cases of the Solution of 2D Hydrodynamic Equations in the Boussinesq Approximation: A Mechanism of Upwelling Convective Flow Transporting Hydrocarbons

Abstract

Thermo-mechanical model of the mantle wedge between the base of the overlying Scythian lithospheric plate and the upper surface of the Black Sea micro-plate subducting under the Scythian one with a velocity V at an angle β is obtained for the infinite Prandtl number fluid as a solution of non-dimensional 2D hydrodynamic equations in the Boussinesq approximation. For both Newtonian and non-Newtonian rheology cases 2D thermal viscous dissipationdriven convection mechanism in the mantle wedge above the Black Sea micro-plate subducting under the Crimea peninsula is modelled numerically. The effects of 410 km and 660 km phase transitions are taken into account. In the case of Newtonian rheology, the upwelling convective flow transporting heat to the Earth’s surface locates at far greater distance from the trench than they observed 2D heat flux anomaly. In the case of non-Newtonian rheology, the upwelling convective flow transporting heat to the Earth’s surface locates at twice greater distance from the trench than they observed 2D heat flux anomaly, the velocity in the convective vortices being over ∼10 m per year.