Fluid inclusion and stable isotope geochemistry of rare-metal pegmatites, Sierra Grande de San Luis, Argentina

VAN DEN KERKHOF, A.; PLESSEN, B.; SOSA GRACIELA; MONTENEGRO TERESITA; LUDERS V.

Budapest

Congreso; European Current Research on Fluid Inclusions (ECROFI) 2019; 2019

Department of Mineralogy, Geochemistry and Petrology, University of Szeged

In the Sierra Grande de San Luis, Nb-Taenrichedpegmatites (398-411 Ma) outcrop in theeastern Conlara Metamorphic Complex, while 404-444 Ma Sn-enriched pegmatites (Sosa et al., 2002)outcrop in the more western Pringles MetamorphicComplex. The pegmatitic bodies are concordantlyemplaced in fine-grained quartz-mica schist. Thepegmatites represent the residual fluids of S-typesyn-tectonic, meta- to peraluminous leucogranitesof Famatinian age (Ortiz Suárez and Sosa, 1991;Galliski et al., 2019). The Nb-Ta-enrichedpegmatites show a more complex mineralogy andcontain beryl, spodumene and amblygonite,suggesting a higher internal fractionation, whereasthe Sn-pegmatites are smaller and show a simplermineralogy (principally Ab-Qtz, ?albite-type?).