Lower Aptian carbon isotope stratigraphy from a distal carbonate shelf setting: the Cau section, Prebetic zone, SE Spain

A δ13C curve is reported for the latest Barremian to Early Aptian at a section located in the Prebetic zone (Cau section, SE Spain). The studied section records a hemipelagic succession of dark shales, deposited on a distal carbonate ramp with a high subsidence rate, adjacent to shallow carbonate environments. The integrated biostratigraphy of the section is based on ammonites, planktonic foraminifera and calcareous nannofossils, and it has allowed an accurate dating of the succession. The δ13C curve presented shows a distinctive evolution, leading to the recognition of three major excursions, as well as a subdivision into eight segments, which represents an improvement of the current biostratigraphic resolution. The correlation, both isotopic and biostratigraphical, with other well resolved sections is very accurate even at the higher resolution attained. Correlation with sections with low-resolution biostratigraphic characterisation from shallow platform limestones also gives good results, which supports the effectiveness of carbon isotope stratigraphy as a correlation tool.