An Early Jurassic submarine scarp in the western Matese mountains

Very few data are available on the facies characters and geometric relations at the carbonate platform-to-basin transition in the Southern Apennines thrust belt. In this paper we describe an Early Jurassic submarine scarp exposed on the southern slope of Monte Capello, in the NW Matese Mountains. The paleo-scarp is cut into a Rhaetian-Lower Jurassic lagoonal to peritidal carbonate succession and is fossilized by coarse carbonate resediments with minor background hemipelagites. The contact between the slope facies and the platform limestones is a very irregular concave-upward surface. The scalloped geometry of the platform escarpment and the textures of the breccias point to local collapses along a steep submarine slope. The composition of the breccias and their contact with inner platform facies suggest that there was a considerable erosional retreat of the platform margin. Extensional faults, probably located at the platform-to-basin transition, triggered the sediment gravity flows responsible of the erosional retreat of the platform edge either directly, by fault-induced seismic shocks, or indirectly by oversteepening. This conclusion is consistent with published data indicating that Early Jurassic tectonics is a common feature in Southern Apennines as well as in Sicily, Northern Apennines and Southern Alps.