The Pliocene-Pleistocene stratigraphic and tectonic evolution of the Central sector of the Western Periadriatic Basin of Italy

The Central portion of the Western Periadriatic Basin is a foreland basins systems associated to the Central Apennine Outer Orogenic Wedge that stretches along the Marche and Abruzzi regions of Italy; an area that has been studied since long time and where a plenty of surface and subsurface data are available. The present study is aimed to review and synthetize these data, add new surface and subsurface data in order to define a firm stratigraphic and tectonic framework that is base for the reconstruction of the Pliocene-Pleistocene tectonic-stratigraphic evolution of the Central portion of the Western Periadriatic Basin. The study integrates field mapping, published geological maps, seismic lines, well logs and an updated chronostratigraphic scheme. Six major NNE-SSW thrust stacks and eight unconformity bounded stratigraphic units have been defined; then, a NE-SW oriented zone separates a northern from a southern sector which have differences in structural styles, amount of shortening, basins' widths and thicknesses of stratigraphic units. Despite these differences, the deformation timing, the depositional history and the migration of basins system are common in both sectors and eight tectonic-stratigraphic evolutionary stages have been reconstructed with sequential restoration of two representative cross-sections.The results highlight that the Pliocene-Pleistocene stratigraphic and tectonic evolution of the Central Western Periadriatic Basin preserves the records of supra-regional and global controls which drive thrust propagation, orogen growth, basins' migration and basins' sedimentary infill. In particular, the stratigraphy preserves global third-order eustatic/climatic changes that have a strict feed-back and concomitance with tectonic pulses. The latter are regulated 1) by cyclic growth of an orogenic wedge undergoing coeval erosion and sedimentation and 2) by eastward retreat of a westward subducting and flexing continental lithosphere.

► Six thrust stacks and eight UBSU shape the Pliocene-Pleistocene Central Apennine Foreland Basins System of Italy. ► The six thrust stacks and foredeep/wedge-top basins system migrated toward east in eight steps during 5 Myrs. ► At 3,59 Ma out-of-sequence thrusting occur while sedimentation from deep marine became shallow water. ► Lithospheric flexure/retreat, orogenic wedge cyclic-growth, third order eustatic/climatic cycles were closely concomitant.