GNGTS 2018 - 37° Convegno Nazionale

GNGTS 2018 S essione 1.2 197 Fig. 1: Geological map of the investigated area with the location of the three sections used in this study. White dashed line across section 2 corresponds to the geological cross-section described by Porreca et al. (2018). Basemap topography is from Tarquini et al. (2007; 2012). basement ranging between 8 and 12 km, being interested by major thrusts across all the three sections and slightly deepening toward ESE. In-depth layering of the basement is coherently represented across all the three sections with two basement layers contributing to the gravity and magnetic anomaly together with the deep crust. In particular, the basement and the upper portion of the deep crust contributes with low susceptibilities (0.001 SI units) while the major contribution to the magnetic anomaly has a deep origin at the base of the crust with an anomalous body with high susceptibility (0.05 SI units). This anomalous body is found to reach a thickness up to ~10 km (i.e. ranging in depths from 25 to 35 km) in the eastern part of the sections and its thickness decreases northward (i.e. from section 3 to section 1) and westward across all models. Seismic events of the 2016-2017 sequence have been plotted in the resulting models of sections 1-3 and mainshocks of Mw > 5.5 fall within the deep evaporite unit, overlying the basement, where the seismicity cutoff was previously observed (Porreca et al. , 2018). Considering the maximum depth of the seismicity across the area – i.e. 10-12 km (Chiaraluce et