GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 3.2 GNGTS 2024 Deep Electric Resistvity Tomography (DERT) on the Cazzaso Landslide A. Bratus 1 , F. Agliardi 2 , O. Araujo 3 , G.B. Crosta 2 , G. Datola 2 , R.G. Francese 3 , P. Fratni 2 , M. Giorgi 1 , F. Kranitz 4 , S. Picot 1 1 OGS – Isttuto Nazionale di Oceanografa e di geofsica Sperimentale, Trieste, Italia. 2 DISAT – Dipartmento di Scienze dell’Ambiente e della terra, Università degli Studi Milano – Bicocca, Milano, Italia. 3 SCVSA - Dipartmento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, Parma, Italia. 4 Servizio Geologico, Regione Autonoma Friuli Venezia Giulia, Trieste, Italia. Introducton The Cazzaso landslide afects the eastern slope of Mt. Diverdalce, in the central part of the Fusea - Cazzaso - Sezza plateau, on the orographic right of the But River valley (Tolmezzo, Udine). The complexity geological and geomorphological setng in which the landslide developed motvated the Geological Survey of the Autonomous Region of Friuli Venezia Giulia to collaborate with the OGS (Natonal Insttute of Oceanography and Experimental Geophysics), to beter constrain the hydrogeological instability phenomena associated to the Cazzaso landslide by using cutng edge geophysical techniques. The resultng geophysical model of the subsoil was then exploited to study the landslide instability by the Department of Environment and Earth Sciences (DISAT) of the Bicocca University of Milan. Geological, geomorphological and landslide setngs The Cazzaso landslide complex, reported since 1807 and reactvated as of October 1851, displaced the entre Cazzaso village up to 24 m causing the destructon of some buildings (Zuliani et al., 2021). Currently, three landslide perimeters are defned in the Italian landslide inventory (IFFI) (Trigila and Iadanza, 2007): two translatonal slides and one complex landslide. Rock outcropping in the area belong to the sedimentary sequence of the Late Triassic Raibl group (Carnic). The Raibl group, between the formaton of the Schlern and the Main Dolomite, consists of a very heterogeneous lithological succession, including black limestone and red sandstone, lastroid limestone, quaternary surface deposits of both morainic and slope origin, characterized by high heterogeneity. The sequence is cut into multple blocks by a complex network of major faults associated to the Sauris line, the most important structural feature in central-western Carnic Alps, whose main branch leads the Permo-Werfen to cover the Carnic (Carulli, 2006). The Local geomorphology is substantally defned by the structural and lithological characteristcs, which were shaped by glacial, river and gravitatonal actvity, determining today’s morphological appearance.