Fig. 10

Illustration of deformation structures during an in-sequence formation of fault-propagation folds with blind thrusts. The example is forward modelled using the trishear kinematic model, combined with the fault-parallel flow method for deformation outside of the trishear zone. Ramp bisector trajectories are indicated with dot-dashed lines. a The first fold forms along a thrust with a dip of 28°. b The second fold refolds the former structure producing a secondary syncline and a part of the former thrust that is passively steepened to a dip of 50°. Note that only material which progressed across the bisector trajectory is refolded. c The third fault-propagation fold increasingly steepens and refolds both former structures. Zones are indicated, which contain important indicative tectonic structures