Print this pageThe Role of Footwall Release Faulting in Controlling 
Structural
Closures
in Rift Systems: Evidence from the Murchison Fault Array, Northern North Sea
Caroline E. Gill and John R. Underhill
University of Edinburgh, Edinbugh, United Kingdom
Extensional fault growth and linkage plays an important role in the
development of rift systems. Recent results have highlighted the main controls
on structural styles and their effects on the temporal and spatial evolution of
basin physiography, stratigraphic geometries and sediment dispersal in rift
basins. However, little application of these controls has been made to analogous
subsurface examples. This study uses temporally-constrained, densely-spaced 3D
seismic data from the highly prospective East Shetland Basin, northern North Sea
to document the evidence for, and effects of footwall deformation during the
Late Jurassic syn-rift episode
Interpretation of structures in the footwall to the Murchison Fault in
the East Shetland Basin shows an associated array of strike perpendicular syn-sedimentary faults. The faults, termed herein footwall release faults, range
in length and displacement but all show a marked decrease in displacement away
from the main structure. There are no partner structures in the hangingwall
where deformation is accommodated on open, long wavelength folds. These
structures are the main control on the size and location of structural
closures
along the Murchison Fault.
AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005