Stratigraphy of the Middle Jurassic Sengenthal Formation of Polsingen-Ursheim (Nördlinger Ries, Bavaria, Southern Germany)

Abstract

Abstract We here present a synopsis of the litho- and biostratigraphy of the Middle Jurassic Sengenthal Formation (Lower Bajocian, Discites Zone to Lower Oxfordian, Cordatum Zone) in the section Polsingen-Ursheim (Nordlinger Ries, Bavaria). The ammonite biostratigraphy, based on bed-by-bed collections from three excavation pits, is correlated with the microfauna (ostracods, foraminifera) from the nearby drillcore VB Polsingen-Ursheim. Our results are compared with literature data from other regions. The distribution of ostracods confirms the zonation for the Middle Jurassic of Southern Germany (Franz et al. 2014a; Ohmert 2004) when correlated with the ammonite biostratigraphy of the Nordlingen Ries area (Dietze & Dietl 2006; Dietze et al. 2002, 2007). This positive correlation could be underlined by the presence of seven biostratigraphically valuable species of foraminifera. The synoptical analysis of the three fossil groups leads to a more detailed subdivision of the Sengenthal Formation and to a more pr...