Anatomy of a post-subduction collision

Abstract

Abstract The spatiotemporal interplay of long-lasting post-orogenic deformations make continental collision zones among Earth’s most enigmatic systems. Here, we employ three-dimensional thermomechanical modeling to decode mantle dynamics of the Arabian-Eurasian collision—an archetype of post-subduction tectonics. Our key findings reveal that plumelet-plate interactions drive deformation both within and at the margins of convergent plates, forming modern kinematics, surface tectonics, and plate boundary configurations. We document previously unrecognized segmentation of the subducted Neotethyan slabs (Bitlis and Zagros) accompanied by upper-plate tearing, which fundamentally modifies the seismotectonic stress accumulation along the Arabian-Turkish-Iranian boundary. The convective support from the plumelet beneath the former Tethyan magmatic arc drives drip-like lithospheric removal under the southern Georgian highland, providing a regional-scale example of arc-to-intraplate deformation transformation. Our results offer a unified framework for understanding how upper mantle processes control surface deformation in post-subduction systems dominated by plumelet dynamics.