Cyclochronology of the early Eocene carbon isotope record from a composite succession of the composite Contessa Road-Bottaccione section (Gubbio, central Italy)

High-resolution geochemical time series from the composite Contessa Road-Bottaccione (CR-BTT) section (central Italy) allows testing the global significance of early Eocene short- and long-term carbon isotope trends by comparison with available records from oceanic successions. Spectral analysis reveals orbitally forced fluctuations in the percent concentration of CaCO3. Extraction of the short- and long eccentricity orbital periodicities from the wt.% CaCO3 record provides a relative cyclochronology for the interval spanning ~49.5 Ma to ~52.5 Ma, thus extending the cyclochronology already available from the same section in the interval between ~52.0 to ~56.5 Ma. Recognition of orbitally-forced sedimentary cycles, corresponding to the long (405 kyr) and short (100 kyr) eccentricity, allows to test the chemostratigraphic alignment with ODP Site 1258 and ODP Site 1263 records and to obtain an unambiguous correlation of hyperthermal events to an unambiguous magnetostratigraphic record across the interval corresponding to the Early Eocene Climatic Optimum and to refine the astrochronological interpretation of the Ypresian.