Las mineralizaciones de wolframio asociadas a la granodiorita de Santa Coloma (Andorra)

Abstract

The late Hercynian Santa Coloma granodiorite intruded Paleozoic metasediments of upper Ordovician to Devonian age. Several forms of tungsten-bearing ores are found associated to the Santa Coloma granodiorite in the Central Pyrenees: veins, filled joints and skarns. Fluid inclusion study in quartz crystals from veins suggests that the mineralising fluid was a polysaline brine (22 wt% NaCI eq.) wich was trapped at 360 ±30 °C and 2.5 ±0.3 kbar, even the first mineralizing stage could be formed at higher temperatures (up to 500°C). Preliminary data of 8 MS of sulphides from skarn and vein mineralizations show values near 5 ± 1%o suggesting a sulphur of magmatic origin