Seismic stratigraphy and foraminiferal biofacies in a profile into the Central Trough, North Sea

摘要

Cutting samples from the exploration wells, Cleo-1, Mona-1 and Kim-1, in the Central Trough area in the northwestern part of the Danish North Sea, have been investigated for their foraminiferal content in the section above the prominent mid-Miocene marker. Benthonic foraminifers have been used to produce a stratigraphic subdivision by reference to the standard North Sea zonating of King. The North Sea Benthonic zones (NAB zones) 11 to 17 (Middle Miocene to Middle Pleistocene) have been identified above the event. The palaeoenvironmental indications of the zones are interpreted in each borehole. These results are compared to the seismostratigraphic framework of seismic profiles connecting the boreholes. Palaeoenvironmental reconstruction shows that generally sediments from the investigated interval from Cleo-1 were deposited in a shallower situation than equivalent deposits in Mona-1, and these again shallower than at Kim-1 and that the depocenter was changing through time as it prograded out into the basin. A conspicuous hiatus is identified in Cleo-1 and Mona-1 at the Pliocene-Pleistocene boundary. The seismic interpretation support the environmental interpretation of the bentihic fauna. (au) (20 refs.)