Structural control and K/Ar dating of the Au-Ag epithermal veins in the Shila Cordillera, southern Peru

The Au-Ag epithermal mineralization of the Shila Cordillera is dated at about 10.7 Ma (K/Ar on adularia). The vein system is characterized by the association of a major approximate to east-west vein and N120-135 degrees E secondary fractures. The strike-slip faults controlling the veins indicate an initial NE-SW to ENE-WSW shortening direction, which is compatible with that generally accepted for this period. These structures were reopened during a second phase and channelized mineralizing fluids, the circulation of which may have began at the end of stage 1. (C) 2000 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.