Interpreted photographs of brittle structures in the Armoricain Massif and Aquitaine Basin. See Figure 2 for location. P1: panoramic view of the discontinuity between foliated micaschists and the Hettangian sedimentary unit. Note the alteration of the basement below the discontinuity and along inherited late hercynian faults. P2: horizontal veins crosscutting the Hettangian unit. P3: hydraulic breccias sealed by barite and quartz deposits. P4: vertical vein crosscutting the Hettangian unit. S2: Stereographic projection of faults and schistosity planes; late hercynian and Jurassic faults planes have been recognized on the basis of their relationship with the discontinuity.