Abstract

We have reanalyzed the pattern of paleomagnetically detected rotations in the central Andes (the central Andean rotation pattern) in order to investigate the temporal and spatial distributions of rotations. The dominant pattern of rotation is well known with counterclockwise rotations in the northern Andes (clockwise in the southern Andes) linked to Neogene orogenesis and shortening. However, much of the rotation in the forearc of northern Chile (23–30°S) is distinctly anomalous because of markedly high rotations that appear to predate rotations observed elsewhere in the central Andes. We argue that the data define a domain located in the forearc of northern Chile marked by major (>25°) clockwise crustal rotations related to late Paleocene–early Eocene highly oblique convergence. This rather diffuse and cryptic deformation style accommodated strong shortening perpendicular to the Andean margin by vertical axis rotations rather than by conventional fold-thrust belts or transpressional fault systems.

You do not currently have access to this article.