Inversion tectonics represent a key process in many orogens worldwide. The related mechanisms of fault reactivation and the effects of an articulated preshortening setting on thrust and fold development are still challenging questions. Modes and geometries of inversion have been the object of several analogue models. In this work, we analyzed the infl uence of an articulated high-angle preexisting discontinuity in the development of thrusts using sandbox modeling. The model geometry is based on the architecture of the major faults in the Central-Northern Apennines of Italy, where differently oriented Mesozoic–Cenozoic inherited extensional structures are clearly detectable and display contrasting styles of positive inversion tectonics. Quartz-sand is the analogue material adopted to model Mesozoic–Cenozoic sedimentary successions, and glass microbeads represent preexisting fault rocks. The geometry of the segmented preexisting structure is composed of two segments with the same dip (~60°): one oblique and another orthogonal to the shortening direction. Our results show that different styles of positive inversion tectonics can coexist and that the obliquity angle between inherited structures and the shortening direction is a leading factor controlling the degree of inversion: The oblique segment of the discontinuity exhibits a complete reactivation, whereas along the orthogonal segment, shortcut is the prevalent mechanism. The oblique element, moreover, represents a cross-strike discontinuity that guides the localization and curved geometry of the thrusts, compartmentalizing the defor\ud mation. Our fi ndings can be applied to foldand-thrust belts characterized by the presence of cross-strike discontinuities
We adopted a multidisciplinary approach to investigate the seismotectonic scenario of the 30 October 2016, Mw 6.5, Norcia earthquake, the largest shock of the 2016–2017 central Italy earthquake sequence. First, we used seismological and geodetic data to infer the dip of the main slip patch of the seismogenic fault that turned out to be rather low‐angle (~37°). To evaluate whether this is an acceptable dip for the main seismogenic source, we modeled earthquake deformation using single‐ and multiple‐fault models deduced from aftershock pattern analyses. These models show that the coseismic deformation generated by the Norcia earthquake is coherent with slip along a rather shallow‐dipping plane. To understand the geological significance of this solution, we reconstructed the subsurface architecture of the epicentral area. As the available data are not robust enough to converge on a single fault model, we built three different models encompassing all major geological evidence and the associated uncertainties, including the tectonic style and the location of major décollement levels. In all models the structures derived from the contractional phase play a significant role: from controlling segmentation to partially reusing inherited faults, to fully reactivating in extension a regional thrust, geometrically compatible with the source of the Norcia earthquake. Based on our conclusions, some additional seismogenic sources falling in the eastern, external portions of the Apennines may coincide with inherited structures. This may be a common occurrence in this region of the chain, where the inception of extension is as recent as Middle‐Upper Pleistocene.