GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 3.2 ___ GNGTS 2023 The rock glacier is located in the Sadole Valley (Fiemme Valley, Trento - Fig.2B), it ranges between 1820 m a.s.l. and 2090 m a.s.l. of altitude, and it is a complex geomorphological landform composed by three different and overlapped lobes (Fig.2C). The rock glacier partially fills a glacial cirque and it is bounded by steep rock walls composed of magmatic rocks (riodacitic ignimbrites - Athesian Volcanic Group), which feed the slope deposits found in the rock glacier rooting area. The Sadole rock glacier has been considered as ‘relict’ (no more ice fraction in the subsoil, Seppi et al., 2012) but the convex morphology and the low water temperature (< 1.5 °C) of its spring during the ablation season, suggested the presence of permafrost. Furthermore, ice samples have been recently collected in a well realized during the 1st World War (violet dot in Fig.2C). Therefore, soil temperature sensors (blue dots in Fig.2C) have been installed on the rock glacier surface and geophysical measurements have been performed during summer 2021 on the main rock glacier lobe. Several ERT surveys (red lines in Fig.2C) have been collected and the results suggested the presence of a discontinuous frozen layer at a depth of about 10 meters in the investigated area. Finally, in June 2022 an infiltration experiment with ERT time-lapse measurements has been carried out to evaluate the aquiclude/aquitard behavior of this mountain permafrost subsoil. The ERT monitored transect (yellow line in Fig.2D) has been placed