The influence of regional factors in the expression of oceanic anoxic event 1a (OAE1a) in the semi-restricted Organyà Basin, south-central Pyrenees, Spain

The results also provide the first high-resolution δ13Corg profile for the El Pui section that replicates in greater detail the carbon isotopic signature reported for the Tethyan domain. The upper 155 m of the El Pui section include expanded and well-defined trends of the carbon isotope segments C2 (upper part), C3, C4, C5, and C6 (partial), which correlate with other Tethyan sections and allow for the recognition of the lower Aptian OAE1a in the uppermost 40 m of the section. Such improved high-resolution chemostratigraphic curve could contribute to a more precise chronostratigraphic correlation of Aptian events in a broader scale.