Introducing the Våle Formation in the southern central North Sea Basin, offshore Netherlands

Abstract

Based on the re-interpretation of well (log) data this study shows that the Vale Formation was deposited over large areas (> 100 km) in the southern central North Sea Basin (offshore Netherlands). Up to now, the Vale Formation (and the lateral equivalent Maureen Formation) were only described in the nearby offshore Denmark, Norway and UK. In the latter areas, the Vale Formation consists of sandstones, marlstones and marly mudstones. The results of this study show that in the northern offshore Netherlands, the lithology of the Vale Formation ranges from marlstones to marly claystones. Biostratigraphic analyses by previous studies on samples within the (newly interpreted) Vale Formation indicate a similar age (latest Danian and Selandian) and depositional environment (open marine) in the offshore Netherlands compared to the areas further north. Well correlation panels indicate that the Vale Formation obtains it highest thicknesses (over 30 m) in the western study area from where it thins (to less than 10 m) and changes its log-signature towards the - tectonically uplifted - Dutch Central Graben in the eastern study area. On top of the Dutch Central Graben, the Vale Formation and overlying claystones locally seals off an oilfield in the underlying chalks.