Movilidad de Zr y Hf y generación de fosfatos secundarios en una unidad de reemplazo de la pegmatita Ángel, Distrito Comechingones, Córdoba

DEMARTIS, MANUEL; MELGAREJO, JOAN CARLES; COLOMBO, FERNANDO; ALFONSO, P.; CONIGLIO, JORGE; PINOTTI, LUCIO; D´ERAMO, FERNANDO

San Juan

Congreso; XI Congreso de Mineralogía y Metalogenia; 2013

Asociación Mineralógica Argentina y Universidad Nacional de SanJuan

In the Ángel pegmatite, Comechingones pegmatitic field, Córdoba, a replacement unit developed during the late stage of the pegmatite crystallization. At least two metasomatic events occurred during this replacement, affecting the primary mineral association. Primary zoned zircon crystals with Hf-rich rims (up to 26.91 wt.% HfO2) were strongly altered, with concomitant leaching of Zr and Hf. The hydrothermal fluid responsible for this alteration was enriched in fluorine, thus enhancing Zr and Hf mobility, and was also particularly enriched in P, which led to the crystallization of a secondary Zr- and Hf-bearing phosphate. Electron microprobe analyses of the Zr-Hf-phosphate do not match any known mineral phase, probably corresponding to one or more new minerals.