GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.1 GNGTS 2024 Multscale geophysical investgaton on the Budoia-Aviano thrust system (NE Italy): frst results E. Rizzo 1,2 , V. Giampaolo 2 , F. Mucchi 1 , P. Boldrin 1 , G. De Martno 2 , M.E. Poli 3 , G. Patricelli 1 , A. Marchesini 3 , R. Caputo 1 1 Dipartmento di Fisica e Scienze della Terra, University of Ferrara, Italy 2 Consiglio Nazionale delle Ricerche, Isttuto di Metodologie per l’Analisi Ambientale (CNR- IMAA), Tito Scalo (PZ), Italy 3 Dipartmento di Scienze Agroalimentari, Ambientali e Animali, University of Udine, Italy The work group is involved in the framework of the PRIN2020 research project (NASA4SHA), which aims to identfy the complexity of faults in actve thrust systems in Northern Apennines and Southern Alps in Italy. The paper describes the applicaton of a mult-scale geophysical investgatons applied on the Budoia-Aviano thrust system, that is part of the Polcenigo– Montereale fault system. The investgated area, which is part of the external Plio-Quaternary front of the Eastern Southalpine Chain, is characterized by the presence of distnct WSW-ENE trending and S-verging reverse fault planes arranged in thrust systems and afectng the Quaternary succession (Poli et al., 2014). The proposed methodology included deep and shallow geoelectrical and GPR techniques to upscale the buried geological structures and to identfy the site for the excavaton of paleoseismological trenches. The adopted multscale geophysical approach was applied in the studied area perpendicularly to the morphotectonic evidence of the Budoia-Aviano fault. The frst step of the multscale approach defned a Deep Electrical Resistvity Tomography (DERT). The DERT was long around 6000m, and it was able to obtain an investgaton depth of about 1000m. The used DERT apparatus is a multchannel system designed and implemented by the CNR-IMAA (Rizzo et al.2004; Rizzo and Giampaolo, 2019). The acquired DERT data set was processed and elaborated through a procedure built ad hoc for this type of geoelectric surveys. While the frst step highlighted the deep geological structure, several shallow high resoluton geophysical surveys were planned close the morphotectonic evidence along the Budoia-Aviano thrust fault. Several shallow Electrical Resistvity Tomographies (ERT) with diferent electrode spacing were carried out. Three ERTs were carried out with an electrode spacing of about 5m obtaining an investgaton depth of about 60m. Consequently, in order to increase the shallow resoluton, a high resoluton ERT with an electrode spacing of about 1m was acquired. The results of the shallow ERTs highlighted the buried geological structures in terms of subsurface faults and geological formatons. Moreover, taking in account the previous results, several GPR profles were carried out on the investgated area and the obtained results permited to identfy the site for the excavaton of two