La galerie de mine

Here, in the Clue de Verdaches, the Bès has carved its gorge into a geological structure known as the Dôme de Verdaches. The clear rock (quartzite) was formed by the accumulation of sand, gravel and quartz pebbles in braided rivers in the Triassic period, over 250 million years ago. The mineral species found here are mainly galena (lead ore), sometimes argentiferous, malachite and azurite. This mineral deposit was formed by the erosion of crystalline rocks in the Triassic period and the accumulation of minerals in river deposits. These were buried and transformed into hard rock during the Mesozoic (secondary era). The formation of the Alps created vertical fissures in which the minerals, dissolved by hydrothermal fluids, eventually recrystallized.