El complejo de Nahuelbuta-Queule: un posible caso de acreción paleozoica en Chile Central-Sur

Abstract

The Nahuelbuta and Queule mountains constitute the coastal range of south Central Chile. The bulk of these mountains is. formed by Paleozoic metamorphic rocks of the 50 called western and Eastern Series of the Crystalline Basement of Chile, which has been stratigraphically reclassified as the Nahuelbuta-Queule Complex. This Complex comprises three informal units which from the base to the top are: Cabo Tirúa (green schists, mica schists, serpentinites. and metacherts), Lleu-Lleu (mica schists, iron bearing metacherts and serpentinites) and Colcura (metapelites and metagraywackes). The chemical and structural characteristics of the green schists suggest that their protolith were basaltic rocks of a mid-ccean ridge origin. This, together wich the occurrences of serpentinites and metacherts, and their structural and metamorphic relationships suggest that these units were part of a. tectonic melange accreted to the South Western margin of the South American paleocontinent during the Paleozoic.