Stratigrafia dell’area de La Valute (Monte Zermula, Alpi Carniche, Italia)

At La Valute, representing the western flank of the Mt. Zermula massif, one of the most interesting and unexplored sequences on the Italian side of the Carnic Alps is exposed. It is represented by rocks of Ordovician to Carboniferous age, characterized by the widespread mainly pelitic deposits of Silurian age. The Ordovician units are represented by siltstones and shales of the Valbertad Fm., and by the limestones of the Uqua Fm. The Silurian strata consist of the black shales with intercalated limestones of the Nölbling Fm., followed by the cephalopod limestones of the Alticola Fm. Several units follow each other in the Devonian: limestones and shales of the Rauchkofel Fm., light grey limestones of La Valute Fm., reddish nodular limestones of the Findenig Fm., grey limestones at places with intercalated dark shales and cherts of the Hoher Trieb Fm., and the limestones of the Pal Grande Fm. In addition to these rocks deposited in various open sea facies, shallow water rocks of Middle Devonian age are exposed in the eastern part of the area. Siliciclastic sediments of the Hochwipfel Fm. (Carboniferous) cap the Pre-Variscan sequence in the area. A detailed conodont biostratigraphy is developed from six sections measured in the various lithostratigraphic units, and several additional spot samples. Graptolites help to refine the biostratigraphy of some Silurian intervals.