U–Pb geochronology of the meta-volcanic rocks from Sierra de Calcatapul: Implications for the Middle Triassic syn-rift volcanism and tectonic evolution of northern extra-Andean Patagonia

This contribution deals first new ICP-MS U–Pb zircon ages that indicate Middle- and Late Triassic magmatic episode tectonometamorphic events, respectively, for the central Patagonia region, instead of a Paleozoic history as previously estimated. The Calcatapul Formation consists (meta-) volcano-sedimentary syn-rift sequence deposited unconformably, shortly after extensional Gondwanide orogenic collapse, over basement composed Permian granites. Two 206Pb/238U yielded 245.1 ± 2.8 244.8 4.1 Ma to crystallization ignimbrites, along with another weighted mean 226.7 4.4 interpreted age event D1-M1 affecting sequence. open insights into tectonomagmatic evolution area because wedge in Uribe Yancamil half-grabens under tectonic regime was then inverted basin-bounding faults like fault. Inversion tectonics involved reverse fault-related uplift against buttress rigid granitic block, dynamic greenschist-to-amphibolite facies metamorphic conditions, before Late-Triassic magmatism Lipetrén Suite took place. pre-rift represents southern extension main phase Choiyoi Province Patagonia, whereas Middle recorded extensional, post-Choiyoi magmatism. local, compressive D1 punctuated an overall widespread lithospheric leads Gondwana breakup since earliest Jurassic times.