Conodont biostratigraphy of the Norian-Rhaetian deposits in the Northern Calabria: the Valle Corvino and Grisolia sections

The present paper deals with the bio-chronostratigraphy of the Upper Triassic sediments in the Northern Calabria. The study has been carried out through the conodont biostratigraphy of two sections (Valle Corvino and Grisolia, Cosenza, Italy) representing, as a whole, the Triassic basinal successions pertaining to the Verbicaro Unit Auct. The sections yielded three distinct monotypic faunas of Norian and Rhaetian age, represented, in the stratigraphic order, by: a) Epigondolella n. sp. C population Orchard, 1983; it has been found in the lower part of the Valle Corvino section as well as in the upper slope of the adjacent carbonate platform; it allows to refer the upper part of the Lower Unit to Mid-Alaunian; b) Epigondolella slovakensis (Kozur) emend. Budai and Kovacs, 1986; it occurs through Large part of the Valle Corvino section, within the Upper Unit, and can be referred to the Late Alaunian-Sevatian; c) Misikella posthernsteini Kozur & Mock; it occurs in the lower part of the Grisolia section and, being preceded by M. hernsteini, marks the base of the Rhaetian Stage. Therefore, in this sector of Northern Calabria, it has been possible to date accurately the basinal successions and the correlated carbonate platforms. The monotypic nature of the faunas and the presence of E. slovakensis suggest that the studied sediments have been deposited within an intraplatform trough characterized by disoxic to anoxic conditions.