Structural evolution of the offshore forearc basins of Peru, including the Salaverry, Trujillo, Lima, West Pisco and East Pisco basins

Abstract

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.