Interpretation of remotely sensed data over the South Armorican shear zone, Brittany, France: contribution to exploration for gold mineralization

A methodological investigation to define favourable areas for the development of gold-bearing shear zones within regional tectonic belts was centred on the South Armorican shear zone (Brittany, France), which is the largest shear in the European Hercynian basement. Structural analysis (carried out over the last few years, mainly on the gold deposits of the French Massif Central) has shown a relationship between phases of deformation and polyphase emplacement of mineralization. The hydrothermal processes responsible for the economic concentrations of gold are related to Neo-Variscan (350 to 290 Ma) transcurrent faults contemporaneous with the South Armorican shears which they locally extend to the east. The South Armorican shear zone, therefore, has great potential for gold mineralization.