The Cretaceous-Paleogene boundary at Gubbio: an overview of recent stratigraphic and proxy record updates 

The Cretaceous-Paleogene (~66 Ma) boundary marks one of the ‘Big Five’ mass extinctions of the Phanerozoic. The event continues to spark discussion, and stimulating increasing focus on the study of geological records of that boundary, including the development of robust stratigraphic frameworks and new proxies. Some of the most-studied Cretaceous-Paleogene sections are those near the town of Gubbio, located in the Umbria-Marche Basin in Italy. The construction of cyclostratigraphic age models allows for the refined understanding of the timing and pacing of paleoenvironmental effects of Deccan volcanism and the Chicxulub impact. High-resolution X-ray fluorescence derived elemental profiles allow for detailed stratigraphic correlation and paleoenvironmental interpretations that can be checked across stratigraphically equivalent sections across the basin. New integrated proxy records (e.g. platinum group element and mercury concentrations, osmium isotope ratios) featuring both extraterrestrial impact and large-scale volcanism signatures can now be put on a common timeline to allow the decomposition of its relative contributions. This contribution gives an overview of such progress made for these sections over the last decade of research, and to what new insights it leads.