Abstract
Scaled physical models of progradational sand wedges above a ductile polymer substrate have successfully simulated the formation of delta-top graben systems synchronous with the development of delta-toe fold-thrust belts. delta-top graben systems are characterized by paired regional and counter-regional listric growth faults. The latter form without total removal of polymer from beneath the graben system. The delta-toe fold-thrust belts are formed by polymer bulges and fault-related detachment folds that have thickening of the ductile polymer in their cores. Multiload wedge models show the formation of younger delta-top extensional graben systems above older fold-thrust belts. The analog model results show structures similar to those found in many delta systems and provide kinematic models for their evolution.
