Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

The Anghiari ridge is an asymmetric relief made of Pleistocene continental deposits, located in the Sansepolcro basin (Upper Tiber Valley, Northern Apennines of Italy – Fig.1), and bounded on the east side by the NE-dipping Anghiari normal fault (Benvenuti et al., 2016; Pucci et al., 2014; Delle Donne et al., 2007). A well-preserved paleosurface supposed to be as old as the Mindel-Riss interglacial period (250kyr, Cattuto et al., 1995) occurs on the top of the ridge. On the steep eastern side of the ridge, several small and discontinuous paleosurfaces separated by different strands of the Anghiari fault can be observed. Up to now, no chronological constraints about the deposits and landforms have been provided. Quantitative geomorphology and the dating of geomorphological markers, such as displaced terraces, through the cosmogenic nuclides technique are essential tools to address short-mid term fault slip rates with important implications on earthquake geology issues, particularly in estimating the displacement and slip rates of active faults through different time scales. The exposure age can be measured using the cosmogenic nuclides dating methodology. In fact, knowing the production rates of specific cosmogenic isotopes (such as 36Cl and 10Be) and measuring the concentration of those isotopes along depth- profiles dug on the top of the investigated landform, it is possible to obtain the age of exposure. The results of these analyses can be used to constrain the age of exposure of morphological markers and to estimate the fault slip rate at various time scales (Pousse-Beltran et al. 2022; Moulin et al. 2016). Fig. 1:DSM (0,5m/pixel) from Pleiades images, at the scale of the enteire Sansepolcro basin. Black box indicate the location of Fig. 2.