The Berriasian/Valanginian boundary in the Mediterranean region: new data from the Caravaca and Cehegín sections, SE Spain

Biostratigraphic data provided by the sections of the Caravaca–Cehegı́n region, SE Spain, have contributed decisively to the lively debate that has taken place in recent years concerning the Berriasian/Valanginian boundary. This work presents the results from new integrated stratigraphic analyses of these sections, based on the distribution of ammonites, calpionellids and calcareous nannofossils, and their calibration with the magnetic polarity scale. It is confirmed that the conflicting interpretations in the literature on the distribution of some ammonites and calcareous nannofossil species are mainly due to differences in taxonomic assignment. The event succession observed allows precise characterization of the Berriasian/ Valanginian boundary, defined by the first occurrence of Calpionellites darderi. Some of the sections studied fulfil the prerequisites to be considered as potential boundary stratotypes. 2000 Academic Press