Calcareous nannofossil and foraminifer biostratigraphy of the Campanian–Maastrichtian chalk of the Femern Bælt (Denmark–Germany)

Abstract

A new study based on calcareous nannofossil and benthic and planktonic foraminifer biostratigraphy is presented for the upper Campanian – Maastrichtian chalk of the Femern Bælt (Denmark and Germany; Fig.1). The results are consistent with recent studies of the Danish chalk for this interval, allowing correlation across the Danish Basin and forming the basis for correlation further afield within the Boreal Realm. Numerous studies have been carried out recently on the upper Campanian – Maastrichtian chalk of the Danish Basin, covering aspects such as sedimentology, depositional environment, macrofossil biostratigraphy, carbon isotope stratigraphy as well as nannofossil and dinoflagellate biostratigraphy. However, very few published studies on foraminifers exist across this interval in this area. The 09.A.006, 09.A.007 and 09.A.008 boreholes (Fig. 2) were drilled in 2009 in preparation for construction of a fixed link across the Femern Bælt, which will connect Denmark to Germany (Rambøll Arup JV 2011). The boreholes penetrated glacial till, Paleocene– Eocene clay and chalk (Sheldon et al. 2012). Here, for the first time, the Boreal foraminifer biostratigraphy of the late Campanian – Maastrichtian interval is investigated and presented alongside nannofossil biostratigraphy.