Partial Melting of Aluminous Metagreywackes in the Northern Sierra de Comechingones, Central Argentina

Abstract

We describe a suite of metamorphic and migmatitic rocks from the represent the source regions of anatectic magmas (e.g. Brown, 1994; (1996) showed that diatexite migmatites have rheological and chemical properties that suggest that they are The gneisses are aluminous greywackes metamorphosed in the amphibolite grade and are likely to have been the protoliths for the parental to granite magmas. It is also known that granulites depleted in incompatible major and trace higher-grade migmatites and granulites. Mineralogical characteristics and major and trace element compositions show that metatexite elements are present in the lower continental crust (e.g. Lambert & Heier, 1968). These rocks have been migmatites, diatexite migmatites and granulites are all melt-depleted rocks. The migmatites (both metatexites and diatexites) have underinterpreted as refractory residues of partial melting complementary to granitic magmas (e.g. The granulites are rocks from which essentially all the granitic components have been extracted, whereas (e.g. The only evidence for the presence of melt in the study Patin o It is thus possible that the source regions of some granitic magmas could area, apart from migmatitic leucosomes, are dikes and sills of leucogranite rich in cumulate K-feldspar. These leucogranite bodies consist of a wide spectrum of migmatites and meltdepleted granulites. may represent the pathways along which melt was drained from the exposed rocks. Our study shows that in the Sierra de Comechingones