Deformation styles of allochthonous salt sheets during differential loading conditions: Insights from discrete element models.

The Discrete Element Method (DEM) was used to model the advance of allochthonous salt sheets through differential loading. The effects of basal slope angle, initial salt thickness, sediment thickness, loading time, progradation rate, and the mechanical strength of the overburden were tested to determine their influence on the development of stratigraphic and structural relationships in the emerging salt and sediment structures. These simulations show that the advance of salt is driven by gravitational instability and sediment loading. Salt advance is greatest with high basal slopes, thick salt, weak sediments, and high sediment progradation rates. The rate of salt advance determines the angle of a subsalt sediment ramp, which influences the final geometry of the system. High angle ramps form with slow salt front advance rates and tend to form counterregional sediment geometries, while low angle ramps form with rapid salt front advance and tend to produce roho geometries.