The role of lithospheric-deep mantle interactions on the style and stress evolution of arc-continent collision
We investigate how the mechanical properties of intra-oceanic arcs affect the collision style and associated stress-strain evolution with buoyancy-driven models of subduction that accurately reproduce the dynamic interaction of the lithosphere and mantle. We performed a series of simulations only varying the effective arc thickness as it controls the buoyancy of intra-oceanic arcs. Our simulations spontaneously evolve into two contrasting styles of collision that are controlled by a 3% density contrast between the arc and the continental plate. In simulations with less buoyant arcs (15-31 km; effective thickness), we observe arc-transference to the overriding plate and slab-anchoring and folding at the 660 km transition zone that result in fluctuations in the slab dip, strain-stress regime, surface kinematics, and viscous dissipation. After slab-folding occurs, the gravitational potential energy is dissipated in the form of lithospheric flow causing lithospheric extension in the overriding plate. Conversely, simulations with more buoyant arcs (32-35 km; effective thickness) do not lead to arc-transference and result in slab break-off, which causes an asymptotic trend in surface kinematics, viscous dissipation and strain-stress regime, and lithospheric extension in the overriding plate. The results of our numerical modelling highlight the importance of slab-anchoring and folding in the 660 km transition zone on increasing the coupling of the subduction system.
Contains the original notebooks scripts used to ran the numerical simulations presented in the paper: "Dynamics of arc-continent collision: the role of lithospheric-mantle dynamics on controlling the evolution of stress regime", within the folder "Arc-continent collision". Additionally, it contains the measured surface kinematics, slab dip, strain_rate tensor at the surface, and viscous dissipation data. These data can be found within the "Kinematics_data", "Slab_dipData", "Deviatoric_stress_strain" and "Viscous_dissipation_data", that can be processed with the scripts within the folder "Scripts for creating figures".