A review on the tectonic evolution of the Paleozoic-Triassic basins from Patagonia: Record of protracted westward migration of the pre-Jurassic subduction zone

• Main Authors: Suárez, Rodrigo Javier, González, Pablo Diego, Ghiglione, Matias
• Language: English
• Published: Pergamon-Elsevier Science Ltd 2019
• Subjects: Ciencias Exactas y Naturales; Accretionary Orogenesis; Antartic Peninsula; Detrital Zircons; Paleozoic-Triassic Basins; Patagonia; Pre-Jurassic; Retreating Slab; Argentina; Pablo; Pacific; Terra Australis; antartic*
• Online Access: http://rid.unrn.edu.ar/handle/20.500.12049/5616; https://hdl.handle.net/20.500.12049/5616; https://www.sciencedirect.com/science/article/pii/S0895981119300203?via%3Dihub; https://doi.org/10.1016/j.jsames.2019.102256

Fil: Suárez, Rodrigo Javier. Instituto de Estudios Andinos (Universidad de Buenos Aires - CONICET); Argentina. Fil: González, Pablo Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Fil: Ghiglione, Matias. Instituto de Estudios Andinos (Universidad de Buenos Aires - CONICET); Argentina. Fil: González, Pablo Diego. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología. Río Negro, Argentina. The Paleozoic-Triassic Patagonian basins, at present comprising the Andean hinterland and structural basement of active basins, document a pre-Jurassic evolution associated with accretionary processes at the paleo-Pacific convergent margin. The Early Cambrian basins constitute the earliest record for the emplacement of the Terra Australis Orogen in northern Patagonia and preserve metavolcanic strata derived from an extensional magmatic arc. Together, pre-Jurassic basins document the Early Cambrian to Late Triassic oceanward migration of the trench-forearc system, evidencing that slab retreat was the common subduction setup. Tectonostratigraphy of these basins can be divided into three major sequences, from east to west: (i) early-middle Cambrian, (ii) Silurian-Carboniferous and (iii) Late Permian-late Triassic, which are separated by angular unconformities, evidencing large deformational pulses (advancing stages?) at Early Ordovician, early-middle Permian, and Late Triassic-Early Jurassic times. The Early Cambrian basins are mainly represented in the North Patagonian Massif by the Nahuel Niyeu forearc basin and the El Jagüelito backarc basin, which were closed and metamorphosed during the Early Ordovician. The Silurian-Devonian clastic sequences of the Atlantic region and Malvinas Islands evolved in an intracontinental rift setting and were deformed in the Permian when thrust tectonics took place at the continental scale, while the contemporaneous trench-forearc system represented in western ...