Browsing by Issue Date, starting with "2010-05-19"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
- Main characteristics and genesis of the Vale de Pães skarn (Cuba-Vidigueira, Ossa Morena Zone, Portugal)Publication . Salgueiro, R.; Inverno, C.; A., MateusThe Vale de Pães (Cuba-Vidigueira) mineralisation is composed of magnetite ± sulphides and hosted in a Pre-Variscan metamorphic sequence intruded by igneous rocks belonging to the Beja Igneous Complex. Its mineral and chemical features are compatible with a zoned Fe-skarn: Mg-rich (Fo + Di90, oxidised) and Ca-rich (Grs + Di81-39, oxidised or relatively reduced). In the Fe-Mg skarn, magnetite deposition occurred along with the anhydrous mineral assemblage at ≈ 600 °C; sulphides precipitated from the retrograde stage onset (≤ 550 °C) and during the hydrated and carbonate phases formation period (< 420 °C). In the Fe-Ca skarn, magnetite precipitated during the retrograde stage (< 550 °C) together with the hydrated mineral association, and was followed by sulphides at ≈ 400°C. The mineralising process involved moderate-high salinity fluids and was controlled by variations in redox potential and pH.