GNGTS 2021 - Atti del 39° Convegno Nazionale

115 GNGTS 2021 S essione 1.2 system formed by a mix of upwelling gas, condensed, and meteoric water. The detected faults and fractures act as the preferred pathway for hydrothermal fluid circulation, whose surface expression is testified by the occurrence of aligned fumaroles and by the strong hydrothermal alteration affecting the rocks of the whole area. The preferred fluid pathways, are mainly located along main faults that affects the oldest part of the volcanoclastic succession, and at their crossing where highly fractured rocks occur. Resistivity surveys furnish shallow depth structural information, up to 100 m at depth. A de- eper ERT survey, indicating the same structural trends observed in the Earth’s surface was publi- shed by Troiano et al. (2019) and reached the depth of 500 m. Considering that the mapped faults are the principal pathways for the uprising magmatic fluids and the close geometric relation between the earthquake distribution and the surficial fault array, we suggest that the investiga- ted faults are the shallow expression of deep-seated faults. The results of this multidisciplinary investigation provide new elements of knowledge of fun- damental importance for the forecast of future eruptive scenarios related to phreatic and hydro- thermal explosions, as well as to better define the monitoring strategy for these active structures. Fig. 3 - ERT profiles and geological cross-sections of Solfatara volcano and Pisciarelli Fumarole Field (modified after Isaia et al., 2015, 2021)