Carbon-isotope stratigraphy and cyclostratigraphy of shallow-marine carbonates: the case of San Lorenzello, Lower Cretaceous of southern Italy

We estimate that the influence of the depositional environment and diagenesis on the delta C-13 signal is negligible and that the carbon-isotope composition of bulk carbonate, as well as of the individual grains, indicate a similar response to an original climate-ocean forcing. However, no clear relationship emerges between the delta C-13 variations and the sea-level changes.

A high-resolution (cm-scale) carbon-isotope stratigraphic study has been carried out at San Lorenzello (Matese Mountains, southern Apennines, Italy) on a shallow marine carbonate section previously correlated with coeval sections by using a combination of biostratigraphic, cyclostratigraphic, and sequence-stratigraphic criteria. This succession, deposited along the southern margin of the Alpine Tethys, is late Valanginian-early Hauterivian in age; it consists of a hierarchy of shallowing-upward cycles (elementary cycles, bundles, and superbundles) linked to Earth's orbital oscillations.