Late Paleocene - earliest Eocene prograding system in the SW Barents Sea

Abstract

Two-dimensional seismic data and a regional seismic sequence analysis of the Paleocene succession in the southwestern Barents Sea are presented and discussed. The Paleogene Torsk Formation is bounded by a Cretaceous – Paleogene hiatus at the base and an erosional truncation at the top. Well data was tied to the seismic to define the base and top of the Torsk Formation. Based on reflection terminations, three Paleocene progradational units are defined within the Torsk Formation in the Hammerfest and Tromsø basins. A regional depositional model for the prograding system is outlined and applied to describe the depositional history for the Paleocene succession in the SW Barents Sea. The base of the Paleocene succession is an unconformity related to uplift and erosion. Subsidence of large parts of the Barents Shelf generated accommodation, and deposition initiated in Late Paleocene. The deposition in earliest Paleocene started out as widespread aggradational shelf deposits over large parts of the Barents Shelf, and was later succeeded by a Paleocene progradational system. The system prograded from ENE towards WSW, and uplifted areas on the northern Barents Shelf acted as sediment source. The geometry of the prograding system towards Loppa High shows that the area was a part of the shallow Barents Shelf during the Early Paleogene, which differs from earlier publications. The area was not a topographic or bathymetric high, but part of the wider Barents Shelf depocenter. Most of the Early Paleogene succession is missing in the Barents Sea due to Late Cenozoic uplift and erosion, but it is expected that the prograding system covered large areas with a significant thickness prior to uplift and erosion.