HR: 1340h
AN: T33C-1477    [Abstracts]
TI: Can trishear explain strain distribution in syn-tecontic sedimentary growth faults: evidence from deep water Niger Delta?
AU: * Paton, D
EM: d.a.paton@leeds.ac.uk
AF: School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom
AU: O'Dowd, D
EM: ear6dod@leeds.ac.uk
AF: School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom
AU: McCabe, N
EM: ear6nmc@leeds.ac.uk
AF: School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom
AU: Butler, R
EM: butler@earth.leeds.ac.uk
AF: School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom
AU: Mortimer, E
EM: e.j.mortimer@leeds.ac.uk
AF: School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom
AU: Morgan, R
EM: richardmorgan@sussexenergy.com
AF: Sussex Energy, Global House 1 Ashley Avenue, Epsom, KT18 5AD, United Kingdom
AB: This study uses a 3D seismic reflection volume, courtesy of CGG Veritas, in the deepwater fold and thrust belt of the Niger delta to investigate variations in strain distribution between pre-tectonic and syn-tectonic sedimentary strata. Two en-echelon reverse faults and associated pre and syn-tectonic strata are evident. Despite opposing polarity both faults have similar fault geometry, limb angle (30°) and a reduction of fault displacement from ca. 700 m to zero in the zone of en-echlon overlap. Furthermore, in the pre-tectonic strata both faults are characterized by an abrupt termination of seismic reflections along a narrow zone (ca. 100 m) with little or no deformation within hangingwall or footwalls. In contrast, within the syn-tectonic package variations in reflection characeter suggest heterogenous strain and significant deformation of both hangingwall and footwall within a triangular zone. The application of trishear reproduces the observed fault and stratal geometries and variations in strain distribution associated wtih the stratigraphic variations. In addition, trishear successfully results in a line balance section
DE: 8005 Folds and folding
DE: 8010 Fractures and faults
DE: 8104 Continental margins: convergent
SC: Tectonophysics [T]
MN: 2007 Fall Meeting