Resumen
Fold and thrust belts developed in deepwater environments have generally been subjected togreater net sedimentation and different sedimentation patterns compared to subaerial or shallowmarine environments. In this study, the effects of syn-kinematic sedimentation on fold and thrust beltevolution have been evaluated by varying the rates and patterns of syn-contractional sedimentation in2D analogue models of simple thrust wedges. All models produced critically-tapered Coulomb wedgeswith topographic slopes of 7-10º. Increased rates of syn-kinematic sedimentation caused greater thrustspacings, increased the total wedge height and wedge length, and generally decreased the number ofmajor thrust structures. Progradational sedimentation caused conspicuous out-of-sequence movementin thrusts at the rear of the model thrust wedge and frontal thrusts became buried and inactive.Aggradational sedimentation caused the rapid and sequential burial of thrusts, rendering them inactiveand forcing the deformation to the front of the wedge. The geometries of the front of the Nankai accretionarycomplex, offshore Japan, and the offshore Niger Delta, Gulf of Guinea, compare well withmodels in this study and demonstrate that the addition of sedimentation during shortening of fold andthrust belts may dramatically affect the style of deformation as well as the timings and amounts of faultdisplacements in such systems.
