Convergent plate boundaries Densification Density Density (specific gravity) Melt Melting Metamorphic rocks Metamorphic structures Metamorphism Phase transitions Structural geology Subduction Subduction zone modeling Tectonics Thermo-mechanical modeling Thermodynamic equilibria Thermodynamic model Thermodynamic modeling Thermodynamics Thermomechanical model mantle structure metamorphism plate boundary plate convergence slab subduction zone thermodynamics