ABSTRACT

Mixed siliciclastic-carbonate and siliciclastic turbidites of the Saraceno Formation (Eocene) in Calabria, southern Italy, contain diverse trace-fossil associations. The depositional setting appears to have been a small, tectonically isolated, rapidly subsiding borderland basin into which turbidity currents dumped a variety of sediments. The formation comprises four sedimentary facies, each of which is characterized by a distinctive ichnofacies (from bottom to top): Facies I (alternating calcarenite and thick-bedded shale), Chondrites-Muensteria-Rhizocorallium; Facies II (alternating calcarenite and thin-bedded shale), Chondrites-Muensteria-Zoophycos; Facies III (thin-bedded siliciclastic sandstone), Zoophycos-Helminthoida-Palaeophycus; Facies IV (alternating sili iclastic sandstone and shale), Zoophycos-Helminthoida-Phycosiphon.

The trace-fossil associations are dominated by fodinichnia, such as Chondrites in the lower part of the formation (Facies I and II) and Zoophycos in the upper part (Facies III and IV). The agrichnia (graphoglyptids) and pascichnia that usually dominate turbidite ichnofacies are uncommon, perhaps owing to a) a fairly shallow water depth, b) an extremely high frequency of turbidity currents, and/or c) dysaerobic or anaerobic interstitial conditions within the sediment.