Deep-sea trace fossils from the mixed carbonate-siliciclastic flysch of the Monte Antola Formation (Late Campanian-Maastrichtian), North Apennines, Italy

Abstract

Twenty one ichnogenera and 30 ichnospecies are recognized in the Late Campanian – Maastrichtian Monte Antola Formation of Italy, most of them for the first time. They belong to a specific mixture of the Nereites and Ophiomorpha rudis ichnosubfacies of the Nereites ichnofacies. Composition and abundance of trace fossils vary from outcrop to outcrop . Chondrites intricatus, Ch. targionii, Nereites irregularis, Cladichnus fischeri and Trichichnus linearis are most common. Chondrites patulus, Ophiomorpha recta and “ Spirophycus” bicornis trace fossils are less common in outcrops, and the other trace fossils are rare or very rare. Generally, ichnogeneric diversity in Cretaceous–Cainozoic calcareous and mixed siliciclastic-calcareous flysch deposits is distinctly lower than in siliciclastic flysch. Significantly, the foremost pre-depositional forms are distinctly rare, probably due to preservational and depositional factors.