The role of structural inheritance in the evolution of fold-and-thrust belts: Insights from the Umbria-Marche Apennines, Italy

The Umbria-Marche Apennine range, part of the Northern Apennines of Italy, is a classic example of a fold-and-thrust belt developed at the expense of a formerly rifted, passive continental margin that experienced various degrees of postorogenic extension and/or collapse. This setting comprises the outer zones of the Northern Apennines, a collisional orogen, and their adjacent Adriatic foreland domain, where the effects of superposed deformations are mild to very mild, making it possible to recognize and separate structures produced at different times and to correctly estab- lish their relative chronology and time-space relationships. In this paper, we integrat- ed subsurface data (seismic reflection profiles and well logs) and surface structural field evidence with the aim to reconstruct and refine the structural evolution of these two provinces, the Umbria-Marche Apennine range and adjacent Adriatic foreland, which were subject to repeated pulses of alternating extension and compression. The main outcome of this investigation is that the tectonic evolution of the study area may be effectively described in terms of a deformation history characterized by structural inheritance, where structures emanating from the basement that developed during the pre-orogenic rifting stage were effective in controlling stress localization along faults affecting younger sedimentary cover rocks during the subsequent orogenic and postorogenic events.