Thrust anticlines responding to gravitational instability deep water offshore, Niger Delta Basin

The deep-water slope area of the Niger Delta is increasingly becoming one of the world’s hydrocarbon potential areas as the progress of exploration off the shelf and down the slope has intensified. High-resolution three-dimensional (3-D) seismic data from the outer fold and thrust belt region of Niger delta are used to investigate the geometry and progressive development of thrust anticlines through a detailed structural restoration. The results show that the outer fold and thrust belt region of the Niger Delta is characterised by closely spaced synthetic forethrust faults, antithetic backthrust faults and verging thrust anticlines with a well-developed NW-SE linear trend perpendicular to the gentle seabed bathymetric slope. These structures respond to accommodate up-dip extension due to instabilities at the shelf by sliding down the detachment to form toe thrusts and associated folds. Identifying the geometry and progressive development of thrust anticlines is key to understanding how thrust anticlines evolve and grow. It also provides information on the timing of fault activity, a parameter directly affecting sub-surface fluid flow in geological reservoirs.