Amazonite from miarolitic NYF-pegmatites and primary accessory minerals of the A-type La Chinchilla granite, Sierra de Velasco, La Rioja province, Argentina

LIRA R.; PARRA F.; BARDELLI F. M.; GALLISKI M. A.; SCARLATTA L. R.

Ksiaz

Simposio; 7th International Symposium on Granitic Pegmatites; 2015

Uniwersytet Slaski

Amazonite crystals were found inpockets of miarolitic pegmatites of a highly evolved miarolitic A-type granite(La Chinchilla pluton) in the Sierra de Velasco, Sierras Pampeanas of NWArgentina (66º58´00´´W, 29º10´30´´S). The La Chinchilla miarolitic pegmatitesare localized in the Velasco Pegmatite District (Galliski 1994), which wasoriginally characterized for clustering pegmatites of the RE class. This mightbe the first documented mention of miarolitic pegmatite amazonite in thecountry. Here we present field, petrographic and mineralogical data ofamazonite and of Nb-,Ta-rich accesory minerals from the parental granites.