The Fe-Mn phosphate mineral assemblages from La Viquita Pegmatite,San Luis, Argentina

GALLISKI, MIGUEL ÁNGEL; RODA ROBLES, ENCARNACIÓN; HATERT, FRÉDÉRIC; MARQUEZ ZAVALIA, MARIA FLORENCIA DE FATIMA; MARTÍNEZ, VIVIANA

Ksiaz

Simposio; 7th International Symposium on Granitic Pegmatites; 2015

Uniwersytet Slaski

Accessory Fe-Mn phosphate nodules are common in the LCT (Li,Cs,Ta) rare-element pegmatites of the San Luis Ranges, Argentina. Most of these phosphates occur in pegmatites of beryl-type and spodumene subtype. As usual in other pegmatite fields, the primary assemblages are not very complex, consisting in members of the series triphylite-lithiophilite, beusite-lithiophilite, graftonite-beusite, triplite-zweiselite, and rarely bobfergusonite. The derived species form secondary assemblages that are mineralogically more complex and normally shed light on the conditions of the subsolidus alteration process. In this contribution we describe the phosphates occurring in La Viquita, a spodumene subtype, complex rare-element pegmatite of the Rare-Element-Li (REL) class according to the classification of Cerný & Ercit (2005).