Naiara Fernandez, Oliver B. Duffy, Christopher Aiden-Lee Jackson , Tim Dooley, Michael Hudec, Boris J.P. Kaus 

Minibasins are important features in salt-bearing basins and they are mostly found in salt-detached continental slopes where the sedimentary cover undergoes seaward translation. One question which is relevant to understand the structural evolution of salt-detached slopes is how fast can the sedimentary cover and the minibasins translate. The aim of this study is three-fold: 1) to compare minibasin downslope translation velocity with salt translation velocity; 2) to understand what controls minibasin translation velocity and 3) to understand how minibasins translating at different velocities can kinematically interact and modify strain patterns around them. To address these questions, we present a 2D numerical modeling study consisting of three simulation series. In the first series, we model a simple scenario where, as a result of gravity, a constant-thickness salt layer moves downslope on an inclined plane. In the second series, we use the same model geometry as in the first (i.e. constant thickness salt layer over an inclined plane), but we add a single, isolated minibasin at the updip portion of the slope. Different minibasin thicknesses, widths and densities are then tested, replicating how in natural salt basins, minibasin size (thickness and width) and fill (density as a proxy of lithology) vary as a function of their maturity, their structural position, and/or the overall regional geological setting in which they form and evolve. Finally, in the third series, we add three minibasins in the updip portion of the slope, and we assess how they interact as they translate downslope. In addition to parameters that control salt velocity on a slope, minibasin thickness is the main factor controlling minibasin velocity in the numerical models. Thicker minibasins translate slower than thinner minibasins. Findings from our numerical modelling approach have direct and significant implications for understanding minibasins behavior, kinematics and strain patterns on natural salt-detached slopes.