INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
An association of secondary Al-Li-Be-Ca-Sr phosphates in the San Elías pegmatite, San Luis, Argentina
GALLISKI, M.A.; CERNÝ, P.; MÁRQUEZ ZAVALÍA, M.F.; CHAPMAN, R.
MINERALOGICAL ASSOC CANADA
Lugar: Toronto, Canada; Año: 2012 vol. 50 p. 933 - 942
The complex association of secondary phosphates from the Li-bearing, rare-element San Elías pegmatite in the Eastern Pampean ranges of Argentina shows widespread albite-hosted dendritic montebrasite in its northern part and lepidolite in the south. This dendritic montebrasite survived low-temperature processes virtually intact, but subrectangular blocks of montebrasite along the margins of quartz core were extensively modified in three stages: (i) two generations of secondary montebrasite intimately intergrown with hydroxylherderite, augelite, and fluorapatite, (acid hydrous fluids, locally channeled, at ~450°-420°C/~2 kbar); (ii) goyazite-crandallite and hydroxylapatite formed after P-T equilibration between the pegmatite and its host rock along the path of metamorphic cooling, which introduced Ca, Sr and minor S from the host rocks into the pegmatite (at about