Ammoniten des Cenomans vom Südrand der westfälischen Kreide zwischen Unna und Möhnesee

Systematically collected ammonites from the different levels of the transgressive Cenomanian of the Haarstrang Mountains between Unna and Möhnesee (southern border of the westfalian Cretaceous, NW Germany) have been investigated. Twenty-one taxa (genera and species), partly previously unknown from this region, have been found and described. The fauna from the immediate transgression level is preserved as phosphoritic internal moulds (steinkerns). Fragmentary preservation and fossil condensation levels indicate reworking processes in these basal Cretaceous deposits. The age of the Cretaceous transgression in the area investigated can be precisely established as Lower Cenomanian (=carcitanensis subzone). The Cenomanian sequence, which is lithofacially very variable, can be, on the basis of the ammonite fauna, subdivided according to the modern Cretaceous stratigraphy for the boreal realm.