STRATIGRAFIA DEL GIURASSICO DEI DINTORNI DI FOZA (ALTOPIANO DI ASIAGO)

Abstract

The Middle and Upper Jurassic sequence near Foza (Asiago plateau; Venetian Alps) is characterized by important hiatuses. The relevant deposits are furthermore often found as sedimentary dikes, filling up fractures in the underlying carbonatic platform of the Calcari Grigi, Middle Liassic in age in the uppermost levels.
The normal Middle and Upper Jurassic sequence includes, aver the Calcari Grigi the following formations: Lower Rosso Ammonitico Veronese and "Lumachella a Posidonia alpina", both Middle Ju­rassic in age; "Scisti ad Aptici", Upper Rosso Ammonitico Veronese and the basal part of the "Biancone", Upper Jurassic in age.
In the Foza area the stratigraphic sequence changes quite rapidly in very short distances, with hiatuses involving one or more of the above mentioned formations. The presence of these hiatuses and of sedimentary dikes is in agreement with the location of the studied area near the edge of the "Trento plateau" during the Jurassic.
A fossil assemblage was collected from a sedimentary dike near Lazzaretti of Foza. It consists of Brachiopods, Belemnites, Bivalves and Crinoid remains. Brachiopods are prevailing both in specimens and species number; among them 6 species, even if generally poorly preserved have been determined and described.