Applicability of critical-wedge theories to foreland belts

Applying critical-wedge theories to foreland belts, in contrast to accretionary wedges of poorly indurated sediments, results in basic problems of physics. One key distinction between these tectonic regimes is the enormous difference in elastic strain energy that can be stored during deformation. Another key distinction is that most styles of fault slip occurring in the upper continental crust involve changes of momentum, in contrast with the stable sliding invoked in critical-wedge theories. Consequently, the mechanics of deformation are fundamentally different for foreland belts as compared with accretionary wedges of sediment.