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...conferenc
