INGEIS   05370
INSTITUTO DE GEOCRONOLOGIA Y GEOLOGIA ISOTOPICA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Cooling age constraints on the tectonic activity of the Los Túneles shear belt, Eastern Sierras Pampeanas of Córdoba, Argentina
Autor/es:
MARTINO, R., GUERESCHI, A., WEMMER, K., LÓPEZ DE LUCHI, M.G., STEENKEN, A SIEGESMUND, S
Lugar:
Punta del Este, Uruguay
Reunión:
Simposio; Fifth South America Symposium on Isotope Geology (SSAGI); 2006
Institución organizadora:
Universidad de la Republica del Uruguay
Resumen:
In the Sierras Pampeanas of Córdoba sixteen ductile shear belts were so far recognized. The north-south Los Túneles Shear Belt (LTSB), at least 75 km along strike and 1-5 km in width, is located at the western tract, mainly in the Sierras de Pocho and Guasapampa. By its tectonic significance, LTSB is one of the most important at the regional scale. New K/Ar dating in amphiboles from amphibolites and micas from protomylonites and mylonites constrains the tectonic activity of the LTSB. This belt was nucleated after the metamorphic peak M2 (ca. 534 Ma) unroofing the Cambrian Orogen and exhuming it until the Lower Ordovician (the beginning of the Famatinian subduction), when the Charquina granodiorite was emplaced (474 Ma). The period of tectonic activity of the LTSB (ca. 64 Ma) coincides with the approach from the Cuyania terrane to the Gondwana margin, before its docking and final collision in the Medium-Late Ordovician. At the same time, in the Pampean setting, the last contractional stages related to the collision of the Pampia terrane against the western margin of Gondwana occurred. Later on, the LTSB were cooled until the Medium Silurian, when the Sierra de Córdoba and San Luis continued its exhumation going through the muscovite thermochron. After this generalized cooling, the Devonian deformation and magmatism that pervasively affected to the Eastern Pampean Ranges followed.
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