Metamorphic Facies Distribution in the Western Alps Predicted by Petrological‐Thermomechanical Models of Syn‐Convergent Exhumation

The distribution of metamorphic rocks throughout the western European Alps indicates subduction-related metamorphism. However, processes by which high-grade exhume remain disputed. Here, we present two-dimensional petrological–thermomechanical numerical models to investigate facies evolution during orogenesis. We model closure an oceanic basin with exhumed mantle bounded passive margins. To ensure thermomechanical feasibility, also this configuration. Before convergence, replace uppermost portions serpentinite. Location and orientation subduction are not predefined initiates self-consistently convergence. A weak interface develops if serpentinite is initially thick enough (here 6 km) can distribute along interface. Syn-convergent exhumation (ultra)high-pressure occurs minor erosion, enabled local upper-plate extension a crustal-scale normal-sense shear zone. calculate evolutions peak P T values 10’000 markers. Results show: (i) agreeing estimates from natural rocks, (ii) exhumed, structurally coherent regions identical facies, indicating absence significant mixing (mélange), (iii) distributions corresponding that Western Alps, eclogite blueschist greenschist when going internal external domains, (iv) velocities larger than burial velocities. Models stronger (3 km thickness) develop orogenic wedge vertical gradient exhumation. feasible for calculating useful testing applicability orogens.