Ordovician mineralizations in the Sistema de Famatina and Sierra de Velasco, northwestern Argentina

Abstract

The Sistema de Famatina is located in the northwestern sector of Argentina, sharing territories with La Rioja and Catamarca provinces. The Sistema de Famatina display N-S orientation being represented by metamorphites (Negro Peinado/La Aguadita Formations) of the Pampean Cycle. The marine clastic and volcaniclastic sedimentary rocks, the volcanic-subvolcanic bodies of basic and acid composition and the widespread outcrops of granitoids belong to the posterior Famatinian Cycle. The Sierra de Velasco is located eastwards of the Sistema de Famatina in La Rioja province. This is the largest orographic unit of the Sierras Pampeanas, nearly totaly represented by Famatinian granitoids with porfiric and equigranular textures. Epigenic mineralizations (Cu, Mo, W, Be) are recorded in the region, related to the different magmatic units. These igneous manifestations are formed by a volcano-sedimentary secuences of El Chuschin Formation and the Ñuñorco and Paimán Granites in the Sistema de Famatina, and the Huaco Granite in the Sierra de Velasco.