Igneous-metamorphic basement of Taquetrén Range, patagonia, Argentina: A key locality for the reconstruction of the paleozoic evolution of patagonia

Abstract In this contribution, we present the stratigraphy of igneous and metamorphic rocks Taquetren Range, a sector located in southernmost margin North Patagonian Massif (42°42′00″ S - 69°30′00″ W). Its basement is composed newly defined “Lagunita Salada Igneous-Metamorphic Complex” (LSIMC), “Paso del Sapo Plutonic (PSPC) “Sierra de (STPC). The LSIMC comprises gneisses, schists, amphibolites migmatites, which share S1–S2 penetrative foliation with mean orientation 300°–330°/40°–60° NE. Based on mineral paragenesis, conditions these are result Barrovian-type metamorphism upper amphibolite to granulite facies. EPMA Th–U–Pb ages monazites display two isochron main populations at 379 ± 5 Ma 323 ± 5 Ma, suggest long-term high-temperature for region between Late Devonian Carboniferous times. Complex intruded by concordant tonalites, granodiorites, porphyric granites minor pegmatites felsic dykes, grouped PSPC. Both PSPC unfoliated peraluminous granitoids STPC. field microstructural data, pervasive identified was caused processes ranging from magmatic flow solid-state deformation, indicating syntectonic emplacement. Zircon U–Pb analysis LA-ICP-MS shows distinguishable groups concordia 314.1 ± 2.2 Ma 302.8 ± 2.2 Ma, interpreted as crystallization subsequent deformation age respectively, related protracted high-strain conditions. outcrops area represent an almost full tectonic cycle encompassing medium-high grade syn-tectonic intrusions post-tectonic intrusions, therefore configuring key locality Paleozoic evolution. Moreover, based compilation zircon ages, ~20 My gap period (360-340 Ma) recognized southwestern coeval amphibolite-granulite facies different sectors Central Belt, presenting thus important implications evolution area.