The subsidence history of the northern Hyblean plateau margin, southeastern Sicily

The southeastern corner of Sicily is dominated by the Hyblean plateau which is composed of carbonate rocks of Triassic to Miocene age. The plateau forms part of the African foreland which collided during Tertiary times with the Calabrian Arc giving rise to the Maghrebian thrust belt. The present study attempts to reconstruct the subsidence history of the northern Hyblean plateau. During the Neogene climax of the plate collision this area has been a centre for widespread basaltic volcanic activity (8-1 Ma) and uplift. At the close of the collisional events (Pliocene-Early Pleistocene) the area under consideration has been affected by subsidence and the progressive consumption of the northern margin of the Hyblean plateau led to the development of the modern foredeep. A quantitative analysis was done by one-dimensional Airy backstripping of seven deep wells located on this crucial part of the Hyblean plateau. The results of the analysis show that the subsidence history of the northern Hyblean plateau area is characterized by four main phases, similar to other domains in the central and eastern Mediterranean basins. These phases are: (a) Neotethyan rifting during Late Triassic-Early Jurassic time; (b) a slow thermal subsidence from Early Jurassic until Late Cretaceous time, leading to the formation of a widespread Mesozoic carbonate platform; (c) compressional phase during Late Cretaceous-Palaeogene time, which resulted in the formation of fold systems; and (d) uplift and subsidence events during the middle Tertiary which are probably the result of the continued collision of the European-African plates. After the Early Pleistocene, unlike other terranes within the Mediterranean, an uplift occurred in the northern Hyblean plateau following the Upper Miocene-Lower Pleistocene massive volcanic activity. This uplift is probably associated with the latest stages of thrusting along the frontal part of the Maghrebian thrust belt.