Aspectos petrológicos , geoquímicos y metalogénicos del magmatismo intraplaca en distintos contextos y edades geológicas

Abstract

Different ocurrences of basic-ultrabasic rocks ranging in age from Precambrian to Mesozoic reveal that intraplate magmatism is a suitable target for exploration of Ni-Cu-PGE ores (and locally, Hg ores'). Long travels o f these magmas across the continental crust favours the assimilation of enclosing siliceous rocks, promoting their saturation in sulfur and segregation of immiscible sulfide melts. This can generate a primary Ni-Cu-PGE ore which can be remobilized and reconcentrated during later hydrothermal or tectonometamorphic processes. The latter are obviously more probable in old than in young rocks, thus explaining the current association of world-grade, Ni-Cu-PGE deposits to Precambrian and Paleozoic rocks