Microfossil and nannofossil analysis of the Upper Cretaceous to Lower Paleogene interval from two wells in the locality of the U.K. North Sea 'Silverpit Crater'

Abstract

Micropaleontological and nannopaleontological analyses have been carried out on ditch cuttings samples from two wells (Arco British 43/24-3 and British Gas 43/25-1), which penetrated the 'Silverpit Crater' structure in the Southern North Sea Basin (UK Sector). A stratigraphic gap (within the limits of resolution imposed by sampling constraints) has been identified between chalky limestones of Maastrichtian age, which are overlain by sediments of latest Paleocene age or younger. Accepting an impact-origin for the structure, the gap represents an impact-event, which occurred almost certainly post Cretaceous and Early Paleocene times and thus probably within the Late Paleocene, close to the Paleocene-Eocene boundary, ruling out an association with the K/P extinction impact. In well 43/25-1 a short interval of mixed microfaunas and nannofloras was observed, which is suggested as being related to 'resurgence deposits' entering the crater immediately after the impact-event.