20 years of event stratigraphy in NW Germany; advances and open questions

Abstract

The application of event stratigraphy in the Cenomanian to Lower Coniacian (Upper Cretaceous) Plänerkalk Gruppe of northwestern Germany has advanced stratigraphic resolution considerably. For a short interval in the Upper Turonian, various genetically variable events (bioevents, tephroevents, stable isotope marker, eustatoevents) are reviewed and new data are partly added. In addition, the lateral litho and biofacies changes within individual events are discussed and provide a basis for a tentative high-resolution correlation between distal and proximal settings. The dense sequence of events permits a stratigraphic resolution of 50 – 100ky for some intervals. Beyond stratigraphic purposes, the alternation of fossil barren intervals with thin fossil beds still demands explanations. As taphonomic processes are considered to be play only a minor role, other explanations are required. It appears that trophic aspects and a calibration of planktic and benthic faunal assemblages may result in a better understanding of this biosedimentary system and its faunal characteristics.