La evolución magmàtica del suroeste gondwànico en el Paleozoico Inferior

Abstract

This magmatism is principally developed in N W Argentina, with some prolongations in the neighbour countries, m a in ly S.W. Peru and S. Bolivia. But the best exposures are in the Sierras Pampeanas (Salta, Tucumán, Catamarca, La Rioja, San Juan, Córdoba and San Luis provinces). In general, the whole of features of the endogenous processes show that all materials, from Middle Cambrian up to Devonian Carboniferous (?) ages are within the so called Famatinlan Cycle; according to recent informations, there was a prior distensive episode of rifting (Upper Precambrian to Lower-Middle Cambrian) and, later, a magmatism of Lower Paleozoic age with plate convergence affinities (calc-alkaline volcanic rocks: Las Planchadas and other; meta-aluminous to per-aluminous plutonio rocks, and derived hybrid of felsic and mafic magmas). The per-aluminous granites in the eastern Pampean Ranges are frequents, but its spacio-temporal relations with the meta-aluminous facies are still poorly established. There are several episodic mineralizations associated to the petrological characteristics of the plutons