Overriding Plate Topography Shaped by Subduction Evolution

Grima, A. G. , Becker, T. W. and Faccenna, C. (2021) Overriding Plate Topography Shaped by Subduction Evolution. AGU Fall Meeting 2021, New Orleans, LA, USA, 13-17 Dec 2021.

Abstract

Subduction of oceanic lithosphere is one important mechanism modifying overriding continental plates permanently and so affects the thermo-chemical evolution of our planet. In particular, overriding plate deformation and stress fluctuate as the slab transitions throughout the upper mantle, and that time-dependent deformation may be recorded geologically. Here, we use the finite element convection code ASPECT to run 2-D numerical models of subduction with a free surface to show how the topography of the overriding plate is linked with the evolution of slab dynamics. We test various subduction parameters and observe that as the slab encounters an increase in viscosity in the lower mantle, new topographic features emerge on the overriding plate compared to free-slip reference cases. There is a significant difference in overriding plate deformation in terms of inferred basin formation, depth and survival, depending on the scales of upper mantle subduction and surface boundary conditions. This may be important for our understanding of the record of slab dynamics in overriding plate topography evolution, including drainage rerouting, and surface transport.

• Item Type: Conference or Workshop Item
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Grima, Dr Antoniette
• Authors: Grima, A. G., Becker, T. W., and Faccenna, C.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences