Subduction initiation without a prescribed weak zone: What’s gonna happen?
Abstract
Subduction initiation is one of the main unclear aspect of plate tectonics. When studying subduction processes,
subduction initiation is therefore generally avoided as it constitutes a problem in itself. The easiest way to avoid this
problem in numerical models is to start the simulations with either a pre-existing subduction zone or a pre-existing
weak suture zone. In the Wilson cycle, as subduction initiation is often supposed to correspond to the first stage
when an oceanic lithosphere formed during extension turn in compression, we here present 2D thermo-mechanical
models of continental rifting followed by compression. While some of the models evolve toward subduction(s),
they often do not occur at the expected location. This poster aims to discuss the results obtained in such models
and the consequences of prescribing initial weak suture zones in the numerical models.