Famatinian orogen on the South American plate: An introduction

Abstract

This Special Issue gathers together a series of contributions related to the Famatinian orogen in the South American plate. This orogen was initially defined in northwestern Argentina by Aceñolaza and Toselli (1976) and is currently understood as a subduction-related accretionary orogen that was formed during the Ordovician. It extends along the proto-Andean margin of Gondwana from Venezuela to Patagonia (Cawood et al., 2009). Magmatism took place mostly between c. 490 and 460 Ma along the entire proto-margin, suggesting global geodynamics as the prime controlling factor. Recently, Rapela et al. (2018) published a detailed isotope-geochemical review of Famatinian magmatism in the Argentinean Sierras Pampeanas where its areal extension is greatest. They concluded that recycling of mainly Mesoproterozoic subconti- nental mantle and mafic lower crust on the one hand, and crustal melting of Early Paleozoic supracrustal rocks on the other, account for most of the magma generation (Cordilleran-type and metamorphic related respectively).