Schematic illustration of the tectonic-magmatic and metallogenic evolution of the Sioule region from ca. 355 to 305 Ma. (a-c) evolutionary geological maps. (d) Conceptual cross sections of the Echassières and Pouzol-Servant /Champs magmatic system at ca. 325-305 Ma. In (b-c), the N60-striking thick dashed red line corresponds to the strike of mid-Variscan volcanic grabens in the northeastern FMC (Bertaux et al., 1993), while the sinistral strike-slip shear zone affecting the Colettes granite was documented by Gagny and Jacquot (1987). The main regional shortening directions (σ1) are from Thiery et al. (2009).