Geodynamic Processes in the Andes of Central Chile and Argentina: An Introduction

SEPULVEDA, SERGIO; GIAMBIAGI, LAURA; MOREIRAS, STELLA MARIS; PINTO, LUISA; TUNIK, MAISA; HOKE, GREG; FARIAS, MARCELO

Geodynamic Processes in the Andes of Central Chile and Argentina

Geological Society of London

Año: 2015; p. 1 - 12

Convergent continental margins are first order expressions of the movement of Earth?s tectonic plates atop a convecting mantle. The topography of convergent margins is due the interactions of rock uplift, climate and surfaces processes that are dominantly driven by upper crustal and internal lithospheric deformation (e.g. Molnar and England, 1990; Beaumont et al. 2004). The Andes of central Chile and Argentina (ca. 32-36ºS), straddle a potentially important transition in geodynamic boundary conditions imposed on the upper plate; a drastic change in the geometry of the subducting Nazca plate from ?flat? to normal subduction angles, from ca. 5º-10º to 30º (Cahill and Isacks, 1992, Figure 1 GREG). Thus, this segment of the Andes is a particularly suitable setting to evaluate the interplay between constructive deep mechanisms resulting in rock uplift and lateral expansion of the Andes and the many mechanisms of exhumation and erosion that shape the landscape in an active, convergent margin.