Geochemistry of greisenized granites and metasomatic schist of tungsten- tin deposits in Portugal.

Abstract

Greisenization of S-type granites from Panasqueira and Alijo (Portugal) are compared for both major and trace elements. Tungsten-tin mineralization is connected with the Panasqueira greisenized cupola while tin-tungsten mineralization is connected with the granite and greisenized granite from Alijo. During greisenization Sn, W, Nb, Ta, Zn, Pb, Rb increase whereas temperature decreases. If tin mineralization dominates, Sn is concentrated in cassiterite and the muscovite of the greisenized granite is depleted in Sn, but richer in W and F than the muscovite of the parental granite. If tungsten mineralization dominates, the muscovite of the greisenized granite has similar W, more Sn and less F than the muscovite of the parental granite. Wolframite is the main carrier of W. F is concentrated in topaz and fluorite.-from Author