“…Cretaceous to Paleogene shortening and strike-slip deformation has been reported for the forearc region and Western Cordillera along a belt of poorly understood structures [Chong, 1977;Scheuber and Reutter, 1992;Kuhn and Reuther, 1999;Horton et al, , 2002aMcQuarrie et al, 2005]. In the Eastern Cordillera, shortening was accommodated by complex east and west directed thrusts that probably involve crystalline basement, although no Precambrian rocks are exposed [Roeder, 1988;Sempere et al, 1990;Baby et al, 1992;Hérail et al, 1996;Tawackoli et al, 1996;Kley et al, 1997;Lamb and Hoke, 1997;Horton, 1998;McQuarrie and DeCelles, 2001;Müller et al, 2002].…”