Fracturing and Sealing in a Subsurface Salt Body: The Súria Anticline (SE Pyrenees)

Networks of halite veins have been analysed along galleries of the potash Cabanasses mine (Súria anticline, SE Pyrenees). The presence of a shape preferred orientation cross-cut by halite veins suggests that the rocks hosting the veins underwent ductile deformation before fracture formation and healing. The petrographical characteristics of veins and host rocks, as well as the analysis of their bromine content, reveal that the vein-forming fluids likely resulted from pressure-solution and dynamic recrystallisation of the Lower Halite Unit rocks. Fluids at high pressure migrated upwards and were arrested at the Halite-Sylvinite Unit causing fracture formation below the Potash Unit, which acted as a seal and did not experience brittle deformation.