CARACTERIZACIÓN PETROLÓGICA DEL COMPLEJO VOLCÁNICO AGUA DE LA

REMESAL, MARCELA B.; SALANI, FLAVIA M.; CERREDO, MARÍA E.

Buenos Aires

Congreso; VIII Congreso de Mineralogía y Metalogenia 2006; 2006

Asociación Mineralógica Argentina

The Neogene Agua de la Piedra Volcanic Complex is a postshield eruptive assemblage located at the western border of the Oligocene basaltic plateau Somún Curá of the northern extrandean Patagonia. This volcanic building is composed of basal pyroclastic flows of trachytic composition and upper lava flows which span from early trachyte and lesser amount of rhyolite to posthumous basaltic compositions. The series is characterized by its alkaline nature and displays a typical compositional gap in the mesosiliceous realm. The inferred evolution from the basic rocks to the trachyte-rhyolite differentiates would have been controlled by the early olivine-clinopyroxene fractionation and later by plagioclase+feldspar crystallization. The facies association and chemical evolutionary path relates this volcanic complex to other post-plateau assemblages of the Somún Curá environment.