Combining global and lithospheric-scale thermomechanical models of continental break-up in South Atlantic

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In this project we will use thermomechanic models at both lithospheric and global scales as well as analog modeling to define possible driving forces and mechanical weakening factors that resulted in break-up at western margin of South Africa and formation of South Atlantics. In the global numerical models (GFZ+Munich) we will investigate possible role of subduction zones around Gondwana as well as effect of global mantle convection, including arrival of large plumes in generation of tensile stresses in the continental lithosphere. However, even if tensile stresses are there, the normal continental lithosphere is likely too strong to be broken by the available plate-tectonic forces. Therefore additional, still poorly understood, processes/factors leading either to the weakening of the lithosphere or to the stress concentration or to both, must be involved in the break-up. The possible candidates are: (i) thermal and chemical effect of mantle plume, (ii) sub-lithospheric melting and magma transport, (iii) inherited lithospheric weak zones, (iv) strain weakening, (v) stress concentration at the tip of propagating rift and (vi) extensive strike-slip deformation accompanied extension. The possible role of all those factors in break-up will be investigated using both lithospheric-scale numerical (GFZ) and analog (VU Amsterdam) 3D modeling techniques. Finally we will combine lithospheric and global scale models and will verify model scenarios using observations from other SAMPLE projects.