Kinematic 3D Retro-Deformation of Fault Blocks Picked from 3D Seismics

Lohr, Tina
Krawczyk, Charlotte M.

Oncken, Onno

Endres, Heike
Samiee, Ramin
Trappe, Henning
Kukla, Peter A.

Philipp, Sonja
Leiss, Bernd

Vollbrecht, Axel
Tanner, David

Gudmundsson, Agust
DOI: https://doi.org/10.23689/fidgeo-1823
Abstract
Movement on fault planes causes a large amount of smaller-scale deformation, ductile or brittle, in the area surrounding the fault. Much of this deformation is below the resolution of reflection seismics (i.e. sub-seismic, <10m displacement), but it is important to determine this deformation, since it can make up a large portion of the total bulk strain, for instance in a developing sedimentary basin. Calculation of the amount of sub-seismic strain around a fault by 3-D geometrical kinematic retro-deformation can also be used to predict the orientation and magnitude of these smaller-scale structures. However, firstly a 3-D model of the fault and its faulted horizons must be constructed at a high enough resolution to be able to preserve fault and horizon morphology with a grid spacing of less than 10 m. Secondly, the kinematics of the fault need to be determined, and thirdly a suitable deformation algorithm chosen to fit the deformation style. Then by restoring the faulted horizons to their pre-deformation state (a ‘regional’), the moved horizons can be interrogated as to the strain they underwent. Since strain is commutative, the deformation demonstrated during this retro-deformation is equivalent to that during the natural, forward deformation...