THE ACHALA BATHOLITH (CORDOBA, ARGENTINA) - A COMPOSITE INTRUSION MADE OF 5 INDEPENDENT MAGMATIC SUITES - MAGMATIC EVOLUTION AND DEUTERIC ALTERATION

The Achala batholith in the Sierra Grande de Cordoba (Argentina), is a major intrusion of Devonian to Early Carboniferous age. In this compl ex batholith, five different magmatic suites are distinguished by thei r geochemical characteristics and a specific metallogenic specializati on; each one includes various petrographic facies ranging from tonalit e to evolved leucogranites. Differences between these magmatic suites, magmatic evolution and deuteric alteration are discussed using conten t in major and trace elements geochemistry and mineral composition. Th ere is a clear correlation between petrographic facies, whole rock geo chemistry and mineral chemistry of biotites and of the core of the pla gioclases, reflecting the magmatic differentiation. Muscovite, partial reequilibration of the plagioclase and part of the peralumineous char acter of the batholith, are due to an extensive deuteric alteration. C opyright (C) 1996 Elsevier Science Ltd & Earth Sciences & Resources In stitute