Geological indications for Palaeogene uplift in the eastern North Sea Basin

The timing and effect of the Cenozoic uplift of Scandinavia has been invest igated using a multi-disciplinary approach involving sedimentological, seis mic and biostratigraphic data from the Danish and the adjacent Norwegian pa rts of the North Sea Basin. It is concluded that significant uplift took pl ace periodically throughout the Palaeogene possibly marking an earlier onse t of the so-called "Neogene uplift" of Scandinavia. This conclusion is base d on a number of sedimentological observations, including smectite content, grain-size variations, kaolinite thermal stabilities and T-max values supp orted by seismic reflection geometries and biostratigraphic data. These dat a indicate several phases of re-working of Palaeogene and older sediments s ituated further to the east and northeast during the middle to late Eocene and during the middle to late Oligocene. The tectonic patterns were similar during the late Paleocene and the Oligocene with some inversion taking pla ce, whereas no inversion has been observed during the Eocene. Main provenan ce areas were to the north and northeast during the Paleocene and Oligocene , whereas the Eocene sediments originate mainly from the British Isles to t he west. It is proposed that Palaeogene uplift of Scandinavia was associate d with regional tectonic movements along crustal zones of weakness, which w ere reactivated as they accommodated strain induced by the Alpine Orogeny a nd the opening of the North Atlantic. (C) 2000 Elsevier Science B.V. All ri ghts reserved.