Mesozoic Syn- and Postrifting Evolution of the Central Apennines, Italy: The Role of Triassic Evaporites

Jurassic-Cretaceous syn- and postrift successions from the central Apennines were backstripped to gain information on the Mesozoic evolution of the passive margin of the Adriatic Plate. Early Jurassic rifting led to the development of a horst-and-graben paleogeography (the Latium-Abruzzi Carbonate Platform and the Sabina-Umbria-Marche Pelagic Basin). Subsidence curves were built for both carbonate platform and pelagic-basin domains from original and literature stratigraphic data. The paleodepositional depths of the deepwater sediments were reconstructed from field geology data, including new paleontological data. It is proposed that after the deposition of lower Hettangian shallow-water carbonates, an abrupt increase in paleowater depth, to 600-1000 m, occurred during the late Hettangian-Sinemurian synrift stage. The postrift stage was characterized by basin filling, with decreasing paleowater depths during the Jurassic, and by a new deepening during the Cretaceous. Our backstripping curves show, for the Sabina-Umbria-Marche Basin, a short period (