The Bottaccione section at Gubbio, central Italy: a classical Paleocene Tethyan setting revisited

Abstract

The Upper Cretaceous to Paleocene succession cropping out at the Bottaccione section (Gubbio, central Italy) represents a classical Tethyan setting that served as a standard for the construction of the geomagnetic polarity time scale. Available biomagnetostratigraphy suggests that the Danian interval of the Bottaccione section is condensed relative to other outcrops in the area and/or might contain a non-identified stratigraphic gap. By contrast, a new high-resolution integrated stratigraphic record presented here, including bio-, magneto-, chemo-, and cyclostratigraphy, provides evidence that the Bottaccione record is complete and comparable to other successions outcropping in the Umbria-Marche. However, the paleomagnetic signal of this classical section is partially corrupted in the upper Danian. Recognition of orbitally-forced sedimentary cycles, corresponding to the long eccentricity (405 kyr), and litho- and biostratigraphic correlation with the nearby Contessa Highway which provides a robust magnetostratigraphic record, allows a cyclochronological comparison with ODP Sites 1209 and 1262 and the Zumaia land-based succession. Cycle counting suggests the presence of 10 long-eccentricity cycles between the Cretaceous/Paleogene (K/Pg) boundary and the top C27n event, which has implications for the age of the latter chronohorizon.