From the structural point of view, the Couto Mineiro region is characterized by the occurrence of a large number of faults and fractures, locally well marked, indicating type of composition their orientation. Must refer the directions of the two major fault systems: those belonging to the N-S system and those belonging to the NE-SW to the ENE-WSW system. The Falha Principal (Main Fault), Fault 3W, Fault 1W, Fonte da Lameiras Fault and Vale das Freiras Fault belong to the first; Cebola Fault and Fault 8E belong to the second. It is thought that the latter were initiated with shut-off movements, strike-slip type during the Variscan episode and reactivated during Alpine Orogeny. It is a complex of left shear zone, which affects the Ordovician formations of Serra do Vidual to SW, and joining NE with the Manteigas - Unhais da Serra shear zone. At NNW of this accidents any outcropping of mineralized veins are recognised, either to tungsten or tin.