GNGTS 2022 - Atti del 40° Convegno Nazionale

162 GNGTS 2022 Sessione 1.3 GEOPHYSICAL AND GEOLOGICAL INVESTIGATION IN THE AREA NE OF MENFI (SOUTH-WESTERN SICILY) S. Bongiovanni 1 , R. Martorana 1 , A. D’Alessandro 2 , C. Bignami 2 , A. Canzoneri 1 , A. Sulli 1 1 Università di Palermo, Dipartimento di Scienze della Terra e del Mare, Palermo, Italy 2 Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Nazionale Terremoti, Rome, Italy Introduction. Following the seismic events that occurred from January to June 1968 in the Belice Valley, numerous geological studies have been conducted by various authors in south- western Sicily. Before these seismic events, which partially or totally destroyed some inhabited centers, the area was regarded as aseismic. Within this area we identified numerous morphostructural features consisting of open fractures, which compose a single main feature with WSW-ENE trend. Two other features, orthogonal to these, have NNW-SSE trend. They are visible on Google Earth frames from 2014 to 2017 and they were subsequently filled by human activities. In 2019 July a seismic swarm has again affected the area and following this event a reopening of the fractures occurred. The aim of this study is to understand the role of seismicity in the transformation of the territory, whichmay have created trenches and/or fractures of both tectonic and landslide nature. The study area. The study area is located in southwestern Sicily, precisely NE and 5 km away from Menfi (Fig. 1). The territory is characterized by a hilly landscape. The topographic features are closely linked to the combination of endogenous (tectonics, lithology) and exogenous (climate, vegetation) factors which allow to identify two sectors characterized by different evolution (Fig. 1): a) the sector to the south of the main morphostructural feature, where the “Bertolino” quarry is located, characterized by Pleistocene silty-sandy clays. The slope is constantly evolving due to the erosive action of rainwater and the accumulation of erosion products; b) the sector including the area of the morphostructural features, characterized by soils with a lithoid consistency (marly limestone, calcarenites). In this area, the erosive action is less incisive. Fig. 1 - Location of the study area. Yellow circle: area where the “Bertolino” quarry is located; red circle: area in which the morphostructural features are present; green lines: main morphostructural features.