GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 1.1 - POSTER GNGTS 2023 Portable seismic sensors were used to perform ambient noise measurements arranged in profiles perpendicular to the fault zone. The purpose of these measurements was to determine the presence of impedance contrasts in the subsurface materials that can be used to determine the depth of contact between geologic units and to study the response of the ambient noise to a fault zone. Fig. 2: Preliminary results. A) map of residual gravimetric anomaly. B) map of the first polynomial derivative of the residual gravimetric anomaly. C) Example of a Horizontal to Vertical spectral ratio peak obtained at an ambient noise station. D) example of a magnetic transect across the fault zone. Finally, electrical-resistivity tomography (ERT) and low-frequency georadar (GPR) profiles are intended to study the geometry of recent deposits in the fault zone, seeking information on recent fault activity. On the other hand, the campaign was complemented by the structural analysis of the exposed fault planes and the geometry of the deformation of the hangingwall block. For this, structural measurements were taken with a geological compass. In parallel, a 3D digital outcrop model was constructed using Structure from Motion (SfM) photogrammetry. This model was scaled using reference points taken with differential GNSS. Lineation measurements on the fault plane, as well as dips and dips directions of sedimentary strata, were extracted from it using different specialized software. The results were analyzed from a structural and geological point of view to characterize the kinematics of the fault.