From the river to the sea: Pramollo, a new ichnolagerstätte from the Carnic Alps (Carboniferous, Italy-Austria)

From the river to the sea: Pramollo, a new ichnolagerstätte from the Carnic Alps (Carboniferous, Italy-Austria) - Pramollo Pass and its surroundings have been celebrated since the 19th century for the outstanding palaeontological heritage preserved in the Permian-Carboniferous units, especially palaeoflora and palaeofauna. The exceptional ichnological record of the Pramollo area is – for the first time – described in this study. The ichnofauna is abundant, diverse, and exceptionally well-preserved. For these reasons, Pramollo can be erected as one of the major Palaeozoic ichnolagerstätten of the Alps. The most recurrent ichnogenera include Parataenidium moniliformis, Dictyodora liebeana, Curvolithus simplex (form 1 and 2), Psammichnites cf. plummeri, Nereites jacksoni, Ancorichnus isp., Beaconites isp. (form 1 and 2), Cylindrichnus isp., Planolites isp., Helminthoidichnites, Skolithos isp., Zoophycos isp., Archaeonassa isp., Protopaleodictyon isp., Asterosoma isp. (form 1 and 2) and the new ichnogenus Pramollichnus pastae. The trace fossil analysis has evidenced 9 recurrent ichnoassemblages, covering a wide environmental spectrum from estuarine to marine settings. Estuarine settings comprise the ichnoassemblages Skolithos-Cylindrichnus (estuarine point bars), Psammichnites-Skolithos-Cylindrichnus (lower estuarine deposits), Zoophycos-Skolithos-Cylindrichnus (storm-derived sand bodies), Curvolithus(large)-Ancorichnus-Skolithos (deltaic-influenced nearshore) and pyritised burrows (anoxic shallow environments). Marine environments are defined by the assemblages Curvolithus (small)-Beaconites (transition to offshore), Zoophycos-Beaconites (distal settings below wave influence), Zoophycos (lower offshore) assemblages. The Dictyodora-Nereites ichnoassemblage is interpreted as corresponding to deep marine settings associated to delta-front, organic-rich muds