Geometry and kinematics of experimental antiformal stacks

Geometry and kinematics of experimental antiformal stacks

Blog Article

Sandbox experiments with different boundary conditions demonstrate that antiformal stacks result from a forward-breaking thrust sequence.An obstacle blocks forward thrust propagation and transfers the deformation back to the hinterland in a previously formed true duplex.In PEPPERMINT GUM the hinterland, continued shortening causes faults to merge toward the tectonic transport direction until the older thrusts override the younger thrusts.In experiments a Half using thin sand layers or high basal friction, shortening is accommodated by a cyclic process of thrusting, back rotation of the newly formed thrust combined with strong vertical strain, and nucleation of a new thrust.Continuous deformation produces an antiformal stack through progressive convergence of branch lines.