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7th Middle East Geosciences Conference and Exhibition
Manama, Bahrain
March 27-29, 2006
Saudi Aramco, Dhahran, Saudi Arabia, phone:
966-3-873-4585, [email protected]
Located on opposite margins of the West Rub' al Khali basin, two structural trends of the Central Arabia and Eastern Arabia share a general north-south structural orientation and similar transpressional structural styles in the Carboniferous Hercynian Orogeny. Multiple seismic profile and map geometry criteria (Harding, 1990) are used to identify the magnitude and direction of strike-slip faulting for the two trends.
Transpressional structures in Central Arabia, interpreted by Simms (1994), have been validated by recent 3D seismic
surveys. The long, linear N-S trending master faults, of Infracambrian age, form an integral part of a right-lateral
transpressional fault
system with many distinctive coeval, en echelon flanking folds. Many oil fields are associated with
these structures. Right-lateral slip of a minimum of 0.5 kilometers along individual
fault
is observed based on offsets of preexisting
faults.
Recent 3D seismic interpretation of the structural trend on the east basin margin indicates a left-lateral transpressional
system, with much smaller strike-slip component. Most fault
planes are sub-parallel but discontinuous along the strike, as
opposed to their through-going and solitary counterparts in Central Arabia to the west. However, some amount of strike-slip
movement can be inferred, based on the following evidence: (1) relatively linear
fault
traces and steeply dipping
fault
planes
offsetting the top of basement; (2) relatively symmetrical shape of a few folds; (3) acute angular relationship of a few coeval,
flanking folds to the causative
fault
trace; and (4) change of
fault
dip direction with depth.