Caracterización petrográfica y geoquímica del batolito Cerro Aspero-Alpa Corral (32°34'-32°42' LS y 64°43'-64°52' LO), provincia de Córdoba, Argentina

Abstract

The Cerro Aspero-Alpa Corral (CA-AC) batholith is a 440 km² granite body present in the Southern edge of the Eastern Pampean Ranges, Córdoba province, central Argentina. The intrusive body of probably paleozoic age shows both post-tectonic and epizonal character. Country rocks include Upper Precambrian-Lower Paleozoic metasedimentary rocks mainly represented by mica-schists, gneisses and migmatites, locally interrupted by minor amphibolite and marble outcrops.

This paper deals with representative petrographic and geochemical data that characterize a 150 km² central stripe between 32°34'-32°42'S and 64°43'-64°52'W.

Three granitic facies have been distinguished based on their distinctive modal mineralogy and texture, and upon well known chemical parameters.

A K-feldspar megacryst porphydic-type is the areally prevalent facies, but dykes of micro- leucogranites and biotite-phenocryst bearing granite are also well represented. They are all monzogranites of subalkaline and peraluminous chemistry. Their mineralogy shows variable proportions of QAP constituents and micas, with minor phases represented by Fe-Ti oxides, apatite (Ap), titanite (Tt), allanite (Aln).

Microgranular enclaves, abundantly distributed in the porphydic facies, provide valuable information for a better understanding of parental magma evolution.

The high-Ca content of the melt makes this body quite distinctive compared to its larger northern neighbour, the Achala batholith.

Pegmatite and aplite bodies, as well as fluorite bearing breccias and quartz veins, barren or mineralized, are also present within the CA-AC batholith.