Recent advances in biochronology, geochronology, magnetostratigraphy, structural geology, and basin analysis make untenable the traditional correlation of the first major Andean-age deformational episode in Bolivia with the Middle Eocene "Incaic tectonic phase' defined in central Peru and instead demonstrate that the episode took place in late Oligocene and early Miocene time. This major tectonic crisis resulted in contemporary development of the Subandean external foreland basin and Altiplano intermontane basin, which were separated by the initiation of thrusting in the present Cordillera Oriental area. The deformation suggests that the Bolivian Orocline began to develop at that time. It is likely that this tectonic upheaval is genetically linked to the marked increase in rate of plate convergence produced by the contemporaneous breakup of the Farallon Plate. -Authors