Tectono-Stratigraphic Evolution of the Atuel Depocenter During the Late Triassic to Early Jurassic Rift Stage, Neuquén Basin, West-Central Argentina

Abstract

The Neuquén Basin presents an almost continuous record from the Late Triassic until the Paleocene, making it an excellent case study of the most relevant tectonic stages of southern South America during the Mesozoic. It was initiated in Late Triassic to Early Jurassic times as a continental rift basin in the context of a widespread extensional stage that affected western Gondwana and culminated with the break-up of the supercontinent. The Atuel depocenter is located in the northern sector of the Neuquén Basin. Its synrift and sag units are represented by Upper Triassic to Lower Jurassic siliciclastic marine and continental sedimentary rocks including the oldest marine deposits of the basin, of Late Triassic age. The depocenter infill has been deformed and exhumed during the Andean orogeny, being presently exposed in the northern sector of the Malargüe fold and thrust belt. In this review, we have integrated a large set of stratigraphic, sedimentologic, geochronologic, and structural data in order to unravel the tectono-sedimentary evolution of the Atuel depocenter and to evaluate the main controlling factors of the synrift stage. We analyzed data from the synrift units, such as facies and thickness distribution, sandstone provenance, detrital zircon geochronology data, kinematic data from outcrop-scale normal faults, F. Bechis (B)

The Ancient Configuration of the Southern Central Andes and Paleogeographic Reconstruction of the Late Cretaceous Foreland Basin at 34°40’S

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“…These faults were activated diachronically from north to south, and their geometries appear to be controlled by Palaeozoic lithospheric weaknesses (Bechis et al, 2010(Bechis et al, , 2014D'Elia et al, 2020). The infill of these extensional basins comprises the Precuyo Cycle that includes volcanic, volcaniclastic and non-marine and marine clastic rocks (Bechis et al, 2020;D'Elia et al, 2020;Franzese & Spalletti, 2001;Gulisano, 1993).…”