INSIGHT INTO THE BASIC IGNEOUS AND METAMORPHIC ROCKS WITHIN THE EARLY PALEOZOIC MINA GONZALITO COMPLEX, NORTHEASTERN PATAGONIA

MARTÍNEZ DOPICO, C.; LÓPEZ DE LUCHI, M. G.

Cordoba

Simposio; 19 Congreso Geológico Argentino; 2014

Asociación Geológica Argentina

The Mina Gonzalito Complex (Ramos 1975) is an igneous-metamorphic block which classically encompasses migmatitic gneisses, mica schists, amphibolites, marbles and siliciclastic levels, as well as variably deformed felsic to basic intrusions (Giacosa 1987, Dalla Salda et al. 2005, among others). Available U-Pb SHRIMP ages for a bt-grt paragneiss in the eastern section point towards a ~472 Ma metamorphic event at medium grade conditions (Pankhurst et al. 2006) whereas in the western section, a granodiorite orthogneiss yielded a 492±6 Ma (Varela et al. 2011). The aim of this short contribution is to present a preliminary study about petrographical and geochemical features of several localities of massive and banded amphibolites as well as an assemblage of quartz diorites and gneisses within the western and eastern blocks of the Mina Gonzalito Complex. Basic rocks from the Mina Gonzalito Complex, are found wherever as isolated bodies or also as small lenses within migmatitic gneisses and mica schists. These rocks are envisaged as equilibrated at amphibolite facies conditions close to ~472 Ma (Pankhurst et al. 2006).