Crustal deformation and magmatism at the transition between subduction and collisional domains: insights from 3D numerical modeling
Résumé
Geodynamics evolution of subduction zones is often complex, notably due to the variable nature and rheology of interacting lithospheres, 3D slab geometry and related mantle flow. In order to understand the temporal evolution of this dynamics, the long-term geological record should be considered, including the present-day kinematics, the long-term history of deformation and magmatism within the upper plate. In this study, we focus on the eastern Mediterranean region where a long-lived subduction zone has been active since the Mesozoic. In this region, the Tethyan active margin is notably characterized by successive subductions of oceanic and continental ribbons, slab retreat episodes and possible slab tearing processes, notably interpreted from tomographic models showing low-velocity anomaly beneath Anatolia. Using G-Plates software, we first modeled the kinematic evolution of the eastern Mediterranean in the last 100 Myrs. Using high-resolution 3D thermo-mechanical numerical modeling, we reproduce a relatively simple model of retreating subduction neighboring a collisional domain that we compare with these geological observations. These numerical experiments are performed with the code I3ELVIS, considering non-newtonian visco-plastic rheologies and notably integrating partial melting and melt extraction processes as well as fluid and melt transport mechanism.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...