Integrated stratigraphy and palaeoenvironmental reconstruction for the Upper Cretaceous Danish Chalk based on the Stevns-2 Core

An integrated stratigraphy for the Stevns-2 core located in eastern Denmark is presented based on carbon isotope stratigraphy and calcareous nannofossil biostratigraphy. Carbon and oxygen isotope analyses were performed on 419 bulk samples, and 57 samples were analysed for calcareous nannofossil biostratigraphy. Original gamma-ray data from the well-log analysis are also presented. The calcareous nannofossil data span the upper Campanian (UC16^a) to the lower Danian (NNT1). These new stratigraphic data are compared with and correlated to other Boreal, Tethyan, and tropical sites to provide an age model for Stevns-2. When using this age model, differences in the sedimentation rates of the Stevns-1 and Stevns-2 boreholes are readily apparent, even though the two sites are located only 8 km from each other. The mechanisms responsible for these variations and differences are under investigation, but are probably related to a combination of variations in palaeoproductivity, palaeocurrents, geodynamics, and palaeotopography.