The basins of the study area were filled with the following sequences: E\sb0 (lower? to middle Eocene); E1 E2 and E3 (fill middle Eocene half grabens); E-O (uppermost middle Eocene-Oligocene); M1, M2 and M3 (lower-upper Miocene); P (uppermost Miocene-Pliocene); and, Q (Quaternary). Four compressive events occurred during Paleocene?, middle Eocene?, upper-middle to late Miocene and middle Pliocene?; and two extensional episodes took place during middle Eocene and late Pliocene. Pre-Tertiary substratum was involved in all tectonic events. The Salaverry-Trujillo High which formed during the third compressive event and the Pliocene consists of a trench-parallel open flexure and a belt of middle Eocene to upper Miocene inverted wedges. The continuous uplifting of the Salaverry-Trujillo High produced a sustained shallowing of the sea floor at the slope break zone on the western side of the high and the incision of submarine canyons.