Pre-Andean deformation of the Precordillera southern sector, southern Central Andes

Abstract

This paper presents a detailed investigation of the structure and evolution of the Precordillera southern sector (Argentina). We document the development and successive reactivation of regional and discrete structural grain through time, and discuss the existence of a large-scale mechanical anisotropy present in the lithosphere. Our kinematic studies indicate that the Permian orogeny generated a doubly vergent fold-and-thrust belt of transpressive deformation, where strain was partitioned into two different types of deformation domains. The west-vergent western domain was characterized by partitioned transpression with shortening dominating, and a strike-slip–dominated subdomain. The east-vergent eastern domain was characterized by pure contractional deformation.