Cenozoic tectonic subsidence from 2D depositional simulations of a regional transect

Abstract " The Cenozoic depositional history along a regional E-W profile across the northern North Sea has been simulated using a forward process-based simulation program of dynamic-slope type. It involves a depth-dependent, dual-lithology diffusion equation that handles transport, e osion and deposition of sediments. The data used in the simulation were derived from a seismic line calibrated against wells, and from the regional iterature concerning the northern North Sea. The most important of the factors used are: the initial basin form (Paleocene bathymetry), tectonic subsidence, isostatic variables, sediment supply (sand-shale), sediment compaction (porosity-depth relationships for sand-shale) and eustatic sea-level changes. The interaction between the data values extracted from the literature could not reproduce a cross-section similar to the observed cross-section fi'om seismic data. Therefore, the subsidence pattern and the initial basin form were reconsidered. The resulting model gave an anomalous Cenozoic subsidence pattern, different from the expected post-rift thermal subsidence, with deviations corresponding toPaleocene and Late Miocene Pliocene times. The model-derived Paleocene subsidence mighthave been overestimated by using an over-shallow palaeobathymetric value, although a deepening o