Two and three-dimensional numerical modeling of multi-scale extensional basin formation

We use new state of the art computational modeling techniques to model crust and lithosphere deformation in 2D and 3D. To date few 2D models exist that are able to bridge scales ranging from the lithosphere to sedimentary basin fill. Here we model in 2D the interaction of lithosphere deformation, high-resolution shear zone formation, and sedimentary basin fill. The models indicate a strong interaction and feedback between the structural style of deformation at crust and lithosphere scales and efficiency of sedimentary basin fill. We furthermore use large deformation 3D forward modeling techniques to study controls on the geometry and spacing of three-dimensional frictional-plastic shear zones in simple one and two-layer models. Specific focus of the 3D models are factors controlling rift propagation and rift obliquity for varying weak seed extent and obliquity with respect to far-field extensional boundary conditions. The models indicate that the style of rift linkage in 3D is controlled by the efficiency of material strain-weakening, by brittle ductile coupling, and by the amount of offset between pre-existing weakness zones.