Geology of the central Apennines: a regional review

The Meso-Cenozoic stratigraphical successions that crop out in central Italy are part of the sedimentary wedge developed on the southern Neotethyan passive margin. On the previous Late Triassic shallow-water carbonate platform, a basin-platform system developed in the area as a consequence of a rifting stage that affected the whole Neotethyan region during the Middle Liassic. The palaeogeography related to the basin-platform system was persistent until early Tertiary time. During the late Miocene, the central portion of the Apennine palaeogeographical domain was involved in the evolution of a post-collisional orogenic system, consisting of a thrust-belt/foredeep couple migrating toward more external domains. The central Apennine palaeogeographical domains were located on a peri-cratonic region, which experienced several tectonic events in response to the Neogene tectonic interaction between the European and African plates, leading to the peri-Mediterranean orogeny. In particular, during the post middle-Tortonian orogenic phases of the Apennines, the Adria microplate played a significant role. Interactions between its boundaries and the surrounding continental plates controlled the evolution of the Adria-verging orogenic system. These plate interactions caused the building of both the Apennine and of the Dinaric segments of the peri-Mediterranean chain. The structural setting of the Apennine tectonic units is similar to other post-collisional thrust-belts, and consists of basement and cover thrust-sheets developed in an ensialic context. The geometry of the chain, the diachronism of the eastward migrating foredeep basins, and the different ages of the forethrusts are consistent with a regional foreland propagation model for the central Apennines.