Abstract
This work presents depositional and structural model of Plio-Pleistocene delta of southern Central Graben offshore basin of Netherlands, based on seismic reflections and well logs tools. The studied interval of the Plio-Pleistocene delta is divided into 5 seismic super units, 11 seismic units, and 24 seismic subunits. Seismic reflections were correlated with the wire line records that lead to identification of depositional sequences and parasequences. The seismic units contain 27 well log units interpreted as depositional sequences. Each depositional sequence in term is composed of component parasequences corresponding to progradational and aggradational/retrogradational systems tracts. The main regional interpreted units can be correlated with the regional seismo-stratigraphy, chrono-eustatic and chronostratigraphy. Other previous works show that the Mid-Miocene to top Pleistocene interval is divided regionally into 13 seismic units and 18 log units. Coastline shifting and the sediment supply direction through Plio-Pleistocene time have been detected by lateral changes in clinoform geometry captured via construction of seismic unit's time structure maps. Seismic super unit and seismic unit boundaries have been delineated by onlaps, downlaps, toplaps, truncations of seismic reflectors, which show the significant landward and basinward shifting of coastline. Boundaries of seismic subunits are marked on the basis of depositional cycles. Depositional cycles are characterized on the basis of gamma ray log trends (funnel shape, bell shape, and cylindrical shape) and their associated geometry of parasequences (lowstand, transgressive, and highstand, systems tracts). This work results in a sequential and geometric characterization of the defined deep-seated sedimentary units. It provides a better comprehension of the sedimentary, eustatic, and geodynamic evolution of the North Sea domains, and consequently a better evaluation of its economic interests.