PETROLOGÍA PRELIMINAR DE LA GRANODIORITA PASO DE ICALMA EN EL VALLE DEL RÍO PULMARÍ, NEUQUÉN

ERNESTO GALLEGOS; MARÍA ELENA VATTUONE; HÉCTOR OSTERA

Congreso; X Congreso de Mineralogía y Metalogénia; 2010

The study of the basement, both igneous and metamorphic, of the study area, located in the Northern Patagonian Andes, has been the subject of a debate during the last decades. This is given by the paucity and complexity of the outcrops. This paper aims to contribute to the knowledge of a region petrological relegated. To this end, work objectives raised as petrographic and geochemical characterization of the area studied, with the certainty that this information will form new evidence about the origin of the rocks that were found therein.The study area consists mainly of metamorphic rocks of Paleozoic and Mesozoic granitoids. The country rock of the granitoids in the study area is given by the metamorphic rocks of Colohuincul Formation. Petrographic analysis, together with geochemical information can be interpreted that these rocks are part of a co-magmatic series, with limited variability across the area studied. In this sense arises from the geochemical analysis, it is rocks formed as part of the roots of the Cretaceous volcanic arc. Where there is a lower percentage of silica and the sample is classified as diorite on the TAS diagram, and may be a slightly more basic pulse of magmatism in the area for the formation period of the batholith (Cretaceous).