The Gondwana Orogeny in northern North Patagonian Massif: Evidences from the Caita Có granite, La Seña and Pangaré mylonites, Argentina

• A Triassic foliated granitic body and two mylonitic belts were studied in El Cuy-Caita Có area, northern Patagonia.
• The pluton intruded as a sheet-like body into an opening pull-apart structure during the Gondwana Orogeny.
• U-Pb dating of the Caita Có granite indicates ages between 224 ± 5 and 206 ± 6.7 Ma for the emplacement.
• Shortening directions are E–W, coincident with escape tectonics of northern Patagonia.

Structural analyses in the northern part of the North Patagonia Massif, in the foliated Caita Có granite and in La Seña and Pangaré mylonites, indicate that the pluton was intruded as a sheet-like body into an opening pull-apart structure during the Gondwana Orogeny. Geochronological studies in the massif indicate a first, lower to middle Permian stage of regional deformation, related to movements during indentation tectonics, with emplacement of foliated granites in the western and central areas of the North Patagonian Massif. Between the upper Permian and lower Triassic, evidence indicates emplacement of undeformed granitic bodies in the central part of the North Patagonian Massif. A second pulse of deformation between the middle and upper Triassic is related to the emplacement of the Caita Có granite, the development of mylonitic belts, and the opening of the Los Menucos Basin. During this pulse of deformation, compression direction was from the eastern quadrant.

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