Andrea Sembroni, P. Primerano, I. Menichelli, R. Lanari, Olivier Bellier, Lucilla Benedetti, Paola Molin, Claudio Faccenna, Università degli Studi di Firenze = University of Florence (UniFI), Texas State University, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Università degli Studi Roma Tre = Roma Tre University (ROMA TRE), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Roma Tre University, Lanari, R., Faccenna, C., Benedetti, L., Sembroni, A., Bellier, O., Menichelli, I., Primerano, P., and Molin, P.
The interaction between sedimentation/erosion and faulting represents one of the most intriguing topics in landscape and tectonics evolution. Only few studies have been able to document the feedback between faulting and sedimentary loading from field observations. Here, we focus on how sediment loading/unloading influences the dynamics of fault systems in the Fucino basin, in the Central Apennines (Italy). The Fucino basin represents a remarkable case study with respect to the other main extensional basins in the Apennines because of its large dimension, square shape, significant sediment thickness, and its endorheic nature throughout its evolution. We present a detailed structural and geomorphologic analysis of the Fucino basin and its surroundings, investigating the kinematic and geometry of each main fault strand. The slickenlines analysis reveals multiple families of slip-vectors and timing of activity, suggesting a change in extension slip-direction from N240° to N200° during middle Pleistocene. Using a local isostatic model, we estimate that up to the 30% of the vertical geological displacement of the faults, which overall ranges from 0.5 to 2.5km, is related to the sediment loading/unloading. We demonstrate a positive feedback between sedimentation and faulting which may also lead to a reorganization in fault kinematics related to a significant increase in vertical stress. We propose a conceptual model for the permanent endorheic configuration of the Fucino basin, which includes the effect of sediment loading.