Litología y condiciones de emplazamiento del Complejo Plutónico Valcheta (Ordovícico), Macizo Norpatagónico.

GRILLO VIDAL, CAROLINA; MARTÍNEZ DOPICO, C.I.; LÓPEZ DE LUCHI, MÓNICA G.

Córdoba

Congreso; Congreso de Mineralogía, Petrología Ígnea y Metamórfica, y Metalogénesis: XIII MINMET y IV PIMMA; 2019

Asociación Mineralógica Argentina

The different Granitoids of the NE sector of the North Patagonian Massif form the Valcheta Plutonic Complex can be distinguished areally and characterized petrographically. The Valcheta Pluton presents a muscovite variable granatiferous facies of fine to medium grain with deformation evidence. The other facies are of muscovitic-biotite granites of fine to medium grain with a penetrative fabric. Both facies present evidence of medium to high tempreture deformation, with the Muscovite facies having higher temperature traits. The published K-Ar and Ar-Ar ages indicate a younger cooling towards the edges of the pluton, with an interval of 430 ± 6 and 470 ± 2 Ma. The Stock Musters is a monzodiorite of fine to medium grain, without deformation and has generated a halo of static contact with metamorphic rock Nahuel Niyeu. With the mineral compositions of biotites and amphiboles it was possible to estimate the pressure and temperature of the emplacement of this plutonic rocks at a value close to 2 kbar and temperature between 670 ºC and 782ºC.