3-D Evolution of Segmented Normal Faults and Their Impact on
Sedimentation: Combined LIDAR, Differential Global Positioning Systems (DGPS)
and Photogrammetry Analysis of the Nukhul Fault
, Suez Rift, Egypt
Rob Gawthorpe1, David Hodgetts1, and Ian Sharp2
1 University of Manchester, Manchester, United Kingdom
2 Norsk Hydro
Research Center, Bergen, Norway
We apply a combination of digital terrain modelling, high resolution 3D
laser scanning (LIDAR), digital photogrammetry and Differential Global
Positioning Systems (DGPS) to quantify normal fault
zone and folds geometry, and
pre- and syn-rift stratigraphy from an exceptionally well exposed, >11 km
long Nukhul
Fault
, Suez Rift, Egypt. These data are used to demonstrate the
interaction between growth folding,
fault
propagation, breaching of transfer
zones and migration of
fault
activity as
fault
populations evolve. During the
initial 2.4 My of rifting, the Nukhul
Fault
was composed of two en-echelon
fault
segments, separated by a relay ramp and hangingwall intrabasin high that
controlled the geometry of depocentres filled with continental deposits (Abu
Zenima Formation). Major incised valleys, at a high angle to the
fault
zone also
had a major influence on earliest syn-rift depositional systems. Stratigraphic
patterns in the overlying Nukhul Formation indicate that the two faults
hard-linked to form a single
fault
zone >11 km long. Hard linkage of the
segments resulted in migration of the zone of maximum displacement and
subsidence to the south-end of the present-day exposed
fault
trace. This
displacement distribution, the overall southward-deepening of Nukhul Formation,
and the cross-cutting relationships between the NW-SE-trending Nukhul
Fault
and
the E-W-trending Baba-Markha
Fault
suggest that the Nukhul
Fault
died and became
beheaded by the younger Baba-Markha
fault
sometime following deposition of the
Nukhul Formation. This evolving tectono-geomorphic template causes major changes
in syn-rift sediment dispersal and sequence geometries between rift initiation
to rift climax stages.
AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005