Silurian conodonts from the Mt Cuestalta area and the Lau Event in the Carnic Alps (Italy and Austria)

Abstract The conodont biostratigraphy of two sections studied in the Silurian of the central sector of the Carnic Alps is presented herein. The sections, named Cuestalta and Hoher Trieb, are located on the Italian and Austrian flanks of Mt. Cuestalta/Hoher Trieb. The Hoher Trieb section exposes rocks belonging to the uppermost part of the Kok Formation, the Cardiola Formation and the lower part of the Alticola Formation; the Cuestalta section exposes rocks of the Alticola Formation. In terms of conodont zones, the Ancoradella ploeckensis , Polygnathoides siluricus , Jeppsonia snajdri , Zieglerodina eosteinhornensis s.l. and Oulodus elegans detortus zones are discriminated, allowing to assign the sections to the Ludfordian and Pridoli. Noteworthy the Pol. siluricus zone extends in the lowermost part of the Alticola Formation, confirming the datum from the Rauchkofel Boden section. Accordingly, the Lau event in the Carnic Alps lies in the lower part of the Alticola Formation, and not in the Cardiola Formation as previously supposed.