An integrated carbon isotope and bio-sequence stratigraphic study of the Early Cretaceous to Paleogene, Central North Sea

Abstract

A stable carbon isotope (δ13C) profile of the Early Cretaceous to Paleogene (Berriasian – Danian) was generated from ditch-cuttings material recovered from well 30/2a-7, Central North Sea. The profile of δ13C values was integrated with calcareous nannofossil biostratigraphy and sequence stratigraphy from the Cromer Knoll Group to provide an integrated stratigraphic framework for the Early Cretaceous. Although, nannofossil data was not collected from most of the overlying Chalk Group, the associated δ13C profile was sufficiently resolved to correlate with other similar δ13C records from both the Boreal and Tethyan Realms. The δ13C profiles and nannofossil data from well 30/2a-7 were stacked with the nearby Shearwater A9 well data to create a composite section that provides a long-term near continuous record of the Early Cretaceous to Paleogene from the basinal deposits of the Central North Sea. Sequence stratigraphic analyses was conducted to provide an integrated bio-chemo-sequence stratigraphic framework for regional correlation. Several major globally recognized δ13C events that are recognized in the wells are seismically resolvable and can be correlated regionally across the Central North Sea, providing a chronostratigraphic framework for constraining hydrocarbon play elements for both exploration, production and carbon capture and storage projects.