Post-Early Cretaceous uplift and erosion on the southern Barents Sea: a discussion based on analysis of seismic interval velocities
pp. 3-20

Interval velocities from seismic sections are used to estimate the amount of post-Early Cretaceous uplift and erosion within the study area on the southern Barents shelf. Emphasis is laid on the Lower Cretaceous (Aibian-Aptian shale) as this is the youngest unit which is preserved throughout the entire study area. The validity of the method is evaluated through a discussion of possible sources of error. In this context lithological variations within the Albian-Aptian sequences throughout the study area constitute an important factor which is evaluated by a seismic interpretation with emphasis on the Lower Cretaceous. The discussion indicates that interval velocities in this case can be used to evaluate maximum values for the Late Cretaceous and Cenozoic erosion on the Southern Barents shelf. The total Late Cretaceous and Cenozoic erosion increases from the Hammerfest Basin in the southwest ( < 1300 m) toward the Bjarmeland Platform in the northeast (1700-2000 m). We assume that the time of maximum burial occurred in Late Paleocene-Early Eocene prior to uplift and erosion related to the opening of the Norwegian-Greenland Sea. By combining earlier works on the Plio-Pieistocene erosional products with the estimated values of total erosion, we have been able to evaluate the importance of the Plio-Pleistocene erosion relative to the earlier Eocene, Oligocene and Miocene erosion on the southern Barents shelf. Depending on the calculated volumes of the Plio-Pleistocene erosional products, the Plio-Pleistocene erosion varies between 650 and 950 m. This implies on erosion between 600 and 1200 m during the Eocene, Oligocene and Miocene in the southern Barents Sea.

Geir Richardsen, Saga Petroleum a.s., P.O. Box 1134, N-9401 Harstad, Norway;
Tore O. Vorren, University of Tromsø, Dept: of Geology, N-9000 Tromsø, Norway;
Bjørn O. Tørudbakken, Saga Petroleum a.s., P.O. Box 490, N-1301 Sandvika, Norway.