On the influence of the asthenospheric flow on the tectonics and topography at a collision-subduction transition zones: Comparison with the eastern Tibetan margin. (October 2016)

• Record Type: Journal Article
• Authors: Sternai, Pietro; Avouac, Jean-Philippe; Jolivet, Laurent; Faccenna, Claudio; Gerya, Taras; Becker, Thorsten Wolfgang; Menant, Armel
• Is Part Of: Journal of geodynamics. Volume 100(2016)
• Page Start: 184
• Page End: 197
• Publication Date: 2016-10
• Subjects: Southeast Asia -- Collision-subduction system -- Asthenospheric flow -- Extrusion tectonics -- Topographic support -- Geodynamic modeling; Geodynamics -- Periodicals; Earth movements -- Periodicals; Rock deformation -- Periodicals; Earth -- Internal structure -- Periodicals; 551.1
• DOI: 10.1016/j.jog.2016.02.009
• Languages: English
• ISSNs: 0264-3707

Abstract

Abstract: The tectonic and topographic evolution of southeast Asia is attributed to the indentation of India into Eurasia, gravitational collapse of the uplifted terrains and the dynamics of the Sunda and other western Pacific subduction zones, but their relative contributions remain elusive. Here, we analyse 3D numerical geodynamic modelling results involving a collision-subduction system and show that vigorous asthenospheric flow due to differential along-strike slab kinematics may contribute to the surface strain and elevations at collision-subduction transition zones. We argue that protracted northward migration of the collisional front and Indian slab during south to south-westward rollback subduction along the Sunda margin might have produced a similar asthenospheric flow. This flow could have contributed to the southeast Asia extrusion tectonics and uplift of the terrains around the eastern Himalayan syntaxis and protruding from southeast Tibet. Therefore, we suggest that the tectonics and topographic growth east and southeast of Tibet are controlled not only by crustal and lithospheric deformation but also by asthenospheric dynamics.