Geología, estructura interna y mineralogía del yacimiento pegmatítico Maria del Huerto, Distrito Conlara, San Luis, Argentina

ROQUET, MARÍA BELÉN; OYARZÁBAL JULIO; GALLISKI MIGUEL ANGEL

Avances en Mineralogía, Metalogenia y Petrología 2006

Estudio Sigma S.R.L.

Lugar: Buenos Aires; Año: 2006; p. 309 - 316

María del Huerto pegmatite is located at 32º 31´ 46´´S and 65º 24´ 17´´W, 20 km  west of Concarán, San Luis, Argentina. This deposit is part of the Villa Praga-Las Lagunas group, of Conlara pegmatitic field. The pegmatite is hosted predominantly in a granodioritic lens ; it has tabular form with NE-SW strike and sub-vertical dip. The internal structure shows from the margin inwards: border, wall, intermediate external, intermediate internal and core zones. Some Ms units replacement have been recognized and Qtz-Pl-Ms±Brl unit. The mineral assemblage comprises: Qtz-Pl-Ms-Mc-Spd-Brl-Grt-Ap-Tur-Dick-Ill-Mn and Fe secondary oxides. The (Al,Si) ordering in the blocky K-feldspars correspond to maximum microcline. The muscovite belongs to the 2M1 polytype. Based in the mineralogy the pegmatite  is classified as a complex type, spodumene-subtype, with LCT geochemical signature.   Key words: pegmatite-mineralogy-internal structure-K-feldspar order-muscovite politypes.