Margin curvature at 28º-33ºSL induced by oblique subduction of the Juan Fernández aseismic ridge: paleomagnetic constraints

JAPAS, MARÍA SILVIA; RÉ, GUILLERMO H.

Antofagasta

Simposio; 8th International Symposium on Adean Geodynamics; 2012

IRD

The geodynamic effect of subduction of oblique aseismic ridges is usually analyzed considering only shallow subduction. However, another perceptible consequence remains obscure: i.e. the change in continental margin trend in those flat slab segments (Japas & Ré 2005, 2006). These authors interpreted such continental margin bends as the mechanical response of the plate boundary system in obtaining a minimum friction during aseismic ridge subduction. Since minimum friction arises when the ridge is subducted normal to the trench, strike-slip and thrust motions along previous structures would accommodate deformation in the upper plate in order to rotate the margin to this most favorable position. Reactivation of appropriate ancient anisotropies will depend on it trends in respect to the convergence direction.