F17-Chalk: new insights in the tectonic history of the Dutch Central Graben

Abstract

AbstractWintershall Noordzee BV recently discovered and appraised two Chalk oil fields (Rembrandt and Vermeer) in the Dutch North Sea with wells F17-10, F17-11, F17-12 and F17-13x. Extensive core material is available, and biostratigraphical analysis plus sedimentological evaluation results are presented here. Integration of these data with detailed 3D seismic interpretation results in interesting conclusions on the tectonic inversion of the Dutch Central Graben. It can be determined that the main inversion event is the Sub-Hercynian Phase, after which an island was formed in the Chalk sea during the Campanian and Maastrichtian. Around this island, erosion products can be found in the Chalk intervals. These sediments are time and facies comparable to the Vaals Formation in the south of The Netherlands, adjacent to the inverted Roer Valley Graben. Maastrichtian sediments are seen to onlap onto the island, decreasing it in size and influence as a sediment source. It is proposed that the Laramide inversion phase in the Dutch Central Graben is a period of non-deposition and, possibly, this is also the case for most of the other Dutch inverted basins.