Isotope stratigraphy (delta C-13) of the lower Aptian from Provence (SE France): Application to platform/basin correlations

Carbon isotope stratigraphy (delta(13)C) of the Urgonian limestones from th e Monts-de-Vaucluse, compared to those of the Lower Aptian historical strat o-type of La Bedoule, shows that the corresponding curves are similar. Two positive excursions separated by a negative one are observed. The first pos itive excursion covers, in the Urgonian sequence, the lower member with rud ists, which is consequently considered equivalent to the Lower Bedoulian li mestones of La Bedoule (Tuarkyricus and Weissi zones). The negative excursi on marks the base of the overlying bioclastic member, the upper part of whi ch records the main positive excursion, centered on the Grandis zone, at La Bedoule. The hard-ground which caps the Urgonian sequence and the overlyin g marls correlate with the Furcata zone. Dating of the Urgonian sequences f rom Provence, at ammonite zone level, has significant relevant implications on the stratigraphic interpretation of time equivalent platform succession s in SE France. The good quality of the isotope calibration between platfor m and basinal sequences has an important bearing on forthcoming correlation s of functional aspects of the corresponding ecosystems.