Hauterivian-Barremian (Lower Cretaceous) dinoflagellate cyst stratigraphy of the western Mediterranean

Abstract

This paper focuses on the qualitative dinoflagellate cyst distribution in the Hauterivian-Barremian rocks of the western Mediterranean. Results are presented of research on the ammonite controlled pelagic Rı́o Argos succession near Caravaca (southeast Spain) which are integrated with information on calibrated sections in southeast France and Switzerland. The ammonite framework permitted determination of contemporaneous first and last occurrences of dinoflagellate cyst taxa in the three areas. Mainly based on these biostratigraphic events, six successive dinoflagellate cyst zones are defined and identified in the Hauterivian-Barremian of the Rı́o Argos succession and the type section of the Barremian at Angles (southeast France). The established zonation, which is by definition valid for the whole western Mediterranean region, has the potential for world-wide application. In addition, a high-resolution zonation, described as a suite of subzones, is established based on six successive shifts in the Hauterivian dinoflagellate cyst development in the Rı́o Argos succession. These local palaeoecological changes are considered to reflect palaeoenvironmental and/or climatic changes of a regional, interregional or global nature.