Seismic-derived seabed topography: Insights from the outer fold and thrust belt in the deep-water Niger Delta

Abstract

Seafloor mapping of the outer fold and thrust belt in the deep-water Niger Delta using high-resolution 3D seismic data has revealed a variety of geomorphic features related to gravity-driven compressional tectonics, submarine sedimentary processes, and fluid migration as evidenced by bathymetric ridges caused by folding of the underlying sedimentary succession, gravity slide scars, submarine canyons and pockmarks all clearly imaged on the seismic-derived seabed bathymetry. The largest canyons, typically 25–35 km in length with widths of up to 5 km, incise an EW-trending arcuate zone of elevated bathymetry across the area. This ridge is the reference point for dividing the seabed topographic pattern into distal and proximal domains. Generally, seabed topography is gentle and less complex in the proximal domain and the major structures in the area include circular clusters of fluid-escape features primarily along channel margins and in places along discontinuities and ridges in the eastern half of the seabed. The large-scale distribution of these structures in the proximal parts of the study area may be related to fluid venting from shallow and or deeper reservoirs.