From downbuilding to contractional reactivation of salt-sediment systems: Insights from analog modeling

This work studies salt-detached fold-and-thrust belts involving minibasins by means of physical analogue modeling. The experimental set up consist a series and diapirs built downbuilding into regular polygonal framework. minibasins-diapir framework were then submitted to contraction, for some examples accompanied different rates syncontractional sedimentation. We aimed at evaluating the influence an initial salt basin geometry (i.e. equal thickness vs. along-strike tapered) on development salt-sediment system, how this influences geometries kinematics belts. also tested these are influenced sedimentation rates. Results show that major differences early structures occur during as result original budget from pillows diapirs), with positive correlation between amount structure development. Initial contractional deformation is localized weaker bodies, favoring extrusion. Shortening transferred forwards once vertical feeders welded secondary welds), while basal (primary) welds sheared, rolled or delaminated. Changes structural styles abruptly controlled degree precontractional structures. Relatively low rate delays forward propagation promotes tilting. With larger rates, thicker cover inhibits welding and, more coherent mechanical beam detached weld. Our modeling compared natural such Zagros European Alps. • Original conditioned shortening styles. through acting stress bridges. Low-rate syn-contractional enhances minibasin horizontal High-rate counter-tilting. Minibasins move tilt, delaminated primary form.