Reptile footprints on a pelagic seafloor as a vestige of a synsedimentary seismic event in the lower Campanian Scaglia Rossa basin of the Umbria-Marche Apennines (Italy)

A group of free climbers by chance discovered a large number of footprint traces deeply impressed on a vast pelagic limestone slab on the steep northeastern limb of the Monte Cònero anticline, near the city of Ancona (Marche region of central-eastern Italy). The footprints probably represent a stampede of panicking sea turtles that were mobilized en masse by an earthquake. These tracks were subsequently covered by a fluxoturbidite triggered by the same earthquake. The same layer is exposed in a 40-m-thick section along the littoral zone below. This new section provides the ability, through combined bio- and magneto-stratigraphic analysis, to place the footprint layer in the lower Campanian foraminiferal biozone Globotruncanita elevata and the lowermost part of magnetochron C33n. Most of this section comprises calcarenitic and calcilutitic turbidites interbedded with pelagic biomicrites, which witnessed a period of enhanced seismic activity exacerbated by a climate change-driven eustatic sea level fluctuation. Following a review of the sedimentological and tectono-seismic history of the Cretaceous Umbria-Marche paleobasin with particular attention to the Monte Cònero area, we describe and document our integrated stratigraphic analysis of the new section exposed along the northeastern littoral known as La Vela Beach.