The Pointe du Friolin and its rugged face

Between 1982 and 1984, the fall of a whole face of the Friolin mountain mobilised 10 million cubic metres, two thirds of which fell in a few months. The municipality was then forced to follow up with the support of geologists. Their studies showed that this collapse stemmed from the presence of soluble underground rocks: the anhydrous calcium sulphate crystal, also known as anhydrite, which forms gypsum by rehydration when cropped out at the surface.