Estimation of net apparent erosion in the SW Barents Sea by applying velocity inversion analysis

摘要

The SW Barents Sea was subjected to significant uplift and erosion during the Cenozoic, processes that are believed to have had a significant impact on hydrocarbon maturation and migration in the area. The current study uses compaction of shale- and sand-dominated layers to make a map of net apparent erosion throughout the SW Barents Sea. The map shows regional trends consistent with deep-seated isostatic uplift of the crust in combination with glacial erosion as a driving mechanism for the erosion. We find increased erosion towards the north and decreased erosion towards the west, in the western Barents Sea. The trend of highest erosion has an axis stretching in a SE-NW orientation towards Svalbard. This indicates a major change in the crustal uplift pattern in the transition from the Norwegian mainland to the Barents Sea. The velocity inversion method used in this study combined with a two-baseline normal compaction trend model demonstrates a reliable procedure for accurate erosion estimations. It allows erosion estimates from layers with different lithologies to be integrated into a common interpretation and differences to be interpreted geologically: for example, an apparent facies change to a mixed sand-shale lithology, possibly with reservoir quality sands developed, in the Cretaceous on the Bjarmeland Platform.