Geological features of the Sioule region within the Variscan Belt. (a) Distribution of peraluminous rare-metal granites and pegmatites, and main hydrothermal Sn and/or W deposits in the western part of the European Variscan belt (based on Gourcerol et al., 2021; Ballouard et al., 2024; Borrajo et al., 2024). Abbreviations: SH - Sillon Houiller fault, R - Richemont rare-metal rhyolite, A - Ambazac rare-metal pegmatite field, M - Montebras rare-metal granite, C - Chavence rare-metal granite. (b) Geological map and (c-d) cross sections of the Sioule region (based on Grolier, 1971; Cuney and Autran, 1987; Feybesse and Teygey, 1987; Thiéry, 2012, regional geological maps at the 1:50,000 scale, and own field observations). The Echassières shear zone is from Gagny and Jacquot (1987). Mineral abbreviations follow Warr (2021). Other abbreviation: RMG - Rare-metal granite.