Cretaceous to early Paleogene tectonic evolution of the northern Central Andes (0-18 degrees S) and its relations to geodynamics

The tectonic phases, subsidence patterns and location of the magmatic are along the Peruvian margin during Late Cretaceous and Paleogene times are compared with the main geodynamic parameters: absolute plate motion; convergence velocity and direction; age of the subducted slab; and accretional events for the same periods. During the Late Cretaceous, long-termed compression seems to be controlled by the absolute trenchward motion of the overriding plate, and, to a minor extent, by the young age of the subducted lithosphere. Short-lived contractional or extensional phases are mainly linked to the acceleration or deceleration of the convergence between the oceanic and continental plates, and probably to changes in the convergence direction. Periods of high and low convergence rates coincide with increased and decreased subsidence rates along the margin, respectively, and seem to be independent of compressional-tensional regimes. During the Paleogene, in addition to the mentioned processes, the eastward shift of the magmatic belt acid subsidence in the forearc zone are interpreted as the result of the subduction erosion of the margin. This process seems to be related to the decrease of the dip of the Benioff zone, expressed by the drastic widening of the magmatic arc.