MULTI-PROXY CRETACEOUS-PALEOGENE BOUNDARY EVENT STRATIGRAPHY: THE GUBBIO AND OTHER UMBRIA-MARCHE BASIN SECTIONS

The classical sections of Gubbio are well-known from a variety of studies, especially from the pioneering work done in the fields of biostratigraphy, magnetostratigraphy and the Cretaceous-Paleogene boundary (K-Pg B). This study aims to investigate the event stratigraphy related to the K-Pg B transition in the pelagic carbonate sections of the Umbria-Marche basin, including the Gubbio sections. The selected stratigraphical interval contains various events such as the second and third Deccan volcanic phase, the K-Pg B impact, the post mass extinction recovery and the beginning of the occurrence of the Paleogene hyperthermals.

Existing high-resolution (cm-scale) proxy series (magnetic susceptibility, calcium carbonate content, bulk carbonate δ¹⁸O and δ¹³C) for the Gubbio sections of the Bottaccione Gorge and the Contessa Highway were complemented with elemental data acquired by portable X-ray fluorescence (XRF), ⁸⁷Sr/⁸⁶Sr and ¹⁸⁷Os/¹⁸⁸Os isotope ratio’s. In addition, analogue sections in the Umbria-Marche Basin were selected (mainly “the Morello section”) to carry out parallel proxy measurements in order to compare the reproducibility of proxy series inside the basin itself.