3D seismic geomorphology of a large Plio-Pleistocene delta – ‘Bright spots’ and contourites in the Southern North Sea

Regional 2D seismic interpretation has been integrated with high-resolution 3D interpretation in Dutch offshore blocks A–F in the Southern North Sea. 17 horizons (MMU, S1–S4, S4.1, S4.2, S5, S5.1, S6–S13) and 14 seismic units were interpreted, expanding upon studies by Kuhlmann and Wong (2008). The study presents detailed and extensive TWT-structure and thickness maps of key depositional units allowing paleogeographic reconstructions. Detailed analysis of incisional (scour marks and hypothesised iceberg scours) and constructional features (contourites, identified initially by ‘bright spots’ on seismic data) linked to bottom currents was undertaken. Paleo-paleographic reconstructions of water depth emphasise the role of hypothesised tidally generated contour currents in the late stage deltaic infill of an epicontinental basin (North Sea).

► We study the Dutch Southern North Sea Delta. ► We identify scour marks and mounded deposits on seismic data. ► Scours and deposits are parallel to delta front. ► Bright spots are identified as lithology and gas responses. ► Scours and deposits are formed by anti-clockwise bottom currents.