Biostratigraphic analysis of condensed pelagites from Sant’Angelo Romano (Cornicolani Mts., Italy)

This study presents the first integrated sedimentological and biostratigraphic investigation of a Jurassic condensed deposit exposed in the Cornicolani Mountains at Sant'Angelo Romano, on the southern margin of the Sabina Plateau (central Italy). Detailed field sampling and laboratory analyses, including macrofaunal identification and microfacies examination of thin sections, reveal a condensed pelagic carbonate platform (PCP) succession, characterised by hazel-coloured packstone-wackestones rich in ammonites, brachiopods, crinoids, radiolarians and sponge spicules. Fossil assemblage and facies analysis allow us to refer the outcropping condensed deposit to the Calcari nodulari dell'Infernaccio, representing the first unit of the Bugarone Group. Biostratigraphic data confirm that the faunal association belongs to the naumachensis Horizon, part of the Emaciatum Zone, referring the analysed section to the Upper Pliensbachian. Therefore, the contribution improves our knowledge of sedimentological and biostratigraphic aspects of the southern margin of the Sabina Plateau, which are still underinvestigated to date.