Fig. 1

Position of the Oxfordian/Kimmeridgian boundary in northern Switzerland and southern Germany and alternative correlations with the standard zonation in southern England and the Russian platform according to successive authors (ammonite specimens cited in the text are shown together with the lithostratigraphic succession at the sampling localities): 1. Moesch 1867 (top of Knollen Bed in Aargau) = base of the Subtethyan “Crussolian” sensu Schweigert and Callomon 1997 (top of Bauhini Horizon, whereas the base of the Subboreal Kimmeridgian is correlated with the base of the Bauhini Horizon) 2. (green) Heim 1919 (top of Villigen Formation in Solothurn and Schaffhausen) = base of Platynota Zone as defined at the Colloque du Luxembourg (Maubeuge 1964), followed by Atrops (1982), Atrops and Gygi (1990), Gygi (1990) and (2003) = correlation L (Gygi and Persoz 1986) 3. (blue) Correlation between the Subtethyan and Subboreal Provinces according to Matyja et al. 2006 (see also Wright 2010 and Wierzbowsky et al. 2010) 4. (red) Position of the Oxfordian/Kimmeridgian boundary and correlation proposed in this paper. Abbreviations for Swiss cantons: AG Aargau, JU Jura, SH Schaffhausen, SO Solothurn. Abbreviations for lithostratigraphic units: BAD Baden Mb., BAN Banné Mb., CRE Crenularis Mb., GEI Geissberg Mb., HOB Hornbuck Mb., HOL Holzflue Mb., KB Knollen Bed, KÜS Küssaburg Mb., LAM La May Mb., LET Letzi Mb., OLT Olten Mb., POR Porrentruy Mb., STE Steinibach Mb., VAB Vabenau Mb., VER Verena Mb., WAN Wangen Mb., WAT Wangental Mb., WET Wettingen Mb