The rift to break-up evolution of the Gulf of Aden: Insights from 3D numerical lithospheric-scale modelling

The Gulf of Aden displays an ideal setting to study oblique rift processes since numerous structural data are available onshore and offshore, down to the ocean-continent transition (OCT). We investigate key observations by means of 3D numerical thermo-mechanical experiments on lithospheric scale. The Gulf formed with a rift-normal of -15° azimuth and under the influence of a supposedly 25° trending far field extension. By reproducing oblique rifting with 40°, we study the evolution of the Gulf of Aden in terms of crustal fault geometries and stress patterns from rift initiation to break-up. Our model suggests that intermediate faults dominate during the initial rift phase, followed by rift-parallel normal faulting at the rift flanks and strike-slip faults in the central part of the rift system. Upon break-up, displacement-orthogonal as well as intermediate faults occur. We compare our results to previous analogue experiments of oblique rifting on lithospheric scale as well as to the structural evolution of the Gulf of