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

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Authors:Neiva, A. M. R.
Author Affiliations:Primary:
Univ. Coimbra, Dep. Mineral. and Geol., Coimbra, Portugal
Volume Title:Chemical transport in metasomatic processes
Volume Authors:Helgeson, Harold C., editor
Source:NATO Advanced Study Institutes Series. Series C: Mathematical and Physical Sciences, Vol.218, p.681-699; Chemical transport in metasomatic processes, Corinthia, Greece, June 3-16, 1985, edited by Harold C. Helgeson. Publisher: D. Reidel Publishing Company, Dordrecht-Boston, International. ISSN: 0377-2071
Publication Date:1987
Note:In English. 20 refs.; illus. incl. 8 tables
Summary: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 T 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. The muscovite- ripidolite schist from Borralha, Portugal, was contact and metasomatically altered into a muscovite schist with some almandine-spessartine by fluids which originated in tungsten-quartz veins. Both schists were studied for major and trace elements. The metasomatism was accompanied by increase in W, Nb, Ta, Sn, Rb, Cs and decrease in T and log (fH2O/fHF). The muscovite of the metasomatic schist is enriched in F, W, Sn, Rb, Cs, while garnet is enriched in Nb and Ta. [E A.W.H.]
Subjects:Chemical composition; Geochemistry; Granites; Greisenization; Hydrothermal alteration; Igneous rocks; Major elements; Metal ores; Metamorphic rocks; Metasomatism; Mineral deposits, genesis; Mineralization; Plutonic rocks; Processes; Schists; Tin ores; Trace elements; Tungsten ores; Europe; Iberian Peninsula; Panasqueira Portugal; Portugal; Southern Europe; Borralha; Central Portugal; Hydrothermal processes
Abstract Numbers:88M/3813
Record ID:1988057006
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
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