The biostratigraphic calibration of the Scottish and Outer Moray Firth Upper Jurassic successions: a new basis for the correlation of Late Oxfordian–Early Kimmeridgian Humber Group reservoirs in the North Sea Basin

Abstract

The combined results of palynological sampling of Scottish onshore sections and offshore wells from the Outer Moray Firth and the re-appraisal of ammonites extracted from subsurface cores enable a revised, unified macropalaeontological–palynological correlation scheme to be proposed for the Late Oxfordian–Early Kimmeridgian (Regulare–Mutabilis ammonite zones) of the North Sea. The results contradict previous, controversial correlations, which were based upon reported ammonite recovery from boreholes in the Witch Ground Graben, a component part of the Outer Moray Firth Basin. It can now be shown that the Upper Jurassic biostratigraphy of Scotland and the North Sea is essentially comparable to that of the English counterpart, suggesting that no faunal provincialism persisted across the former North Sea Dome from uppermost Oxfordian times onwards. Having clarified and resolved previous conflicting views, the application of the revised scheme should aid exploration and production in the Moray Firth Basin through the construction of more accurate reservoir correlations and robust palaeogeographic (play fairway) maps.