Integrated stratigraphy of an Early Cretaceous (Barremian–Early Albian) North Sea borehole (BGS 81/40)

The Early Cretaceous (Barremian–Albian) sedimentary succession of a cored borehole (BGS 81/40, Central North Sea Basin) has been examined. The 41.30-m-thick sequence has been studied for calcareous nannofossils, planktonic foraminifera and bulk-rock carbon isotopes. The core was dated by applying the well-established calcareous nannofossil zonation schemes of the Boreal Realm. Planktonic foraminifera were observed throughout the late Barremian–Early Albian interval. The fragmentary and inadequate planktonic foraminiferal zonation of the Boreal Realm has therefore been replaced by a new zonation scheme (Boreal Planktonic Foraminiferal Zones 1–6). This new zonation scheme allows for a comparison with the established Tethyan planktonic foraminiferal zonation schemes. Furthermore, carbon isotopes were correlated with Tethyan records. The resulting integrated stratigraphical framework of the core suggests a Barremian–Albian age, with hiatuses for parts of the Early Aptian and Aptian/Albian boundary interval.