Structure and Evolution of the Central Mediterranean (Pelagian and Ionian Seas)

Abstract

Four main extensional phases affected the Central Mediterranean from the Permo-Triassic to the Quaternary. The first, active during the Middle-Upper Triassic, produced continental rifting with prominent effects in the Streppenosa Trough (Sicily-Malta platform area) and in the Ionian Sea. A second extensional phase occurred in the Middle Jurassic and opened the Ionian Sea and Eastern Mediterranean. The Pelagian Sea and Sirte Rise (excluding the upper Sirte Slope, where sedimentation commenced in the Upper Cretaceous), comprise a thick to very thick sedimentary sequence that includes deposition from the Triassic to the Quaternary. The Sirte Rise and other eological provinces in the studied area were stretched considerably during the third extensional phase of the Middle-Upper Cretaceous. A paleo-oceanic crust continuously covered by deep-water sediments from the Middle Jurassic to Quaternary is proposed for the Ionian abyssal basin area. In the central part of the Ionian Sea, where the maximum Bouguer anomaly of the Mediterranean occurs, the sedimentary sequence as well as the lower crust are considerably thinner. The youngest extensional phase OCCUlTed from the middle-upper Miocene to the Quaternary and affected the greater part of the Pelagian and Ionian seas. In particular, the areas of MaltaPantelleria- Linosa and Medina grabens, comprising the Sicily Channel rift zone, were affected by pull-apart and strike-slip movement.