%0 Journal Article
%A Noronha, F.
%A Vindel, Elena
%A López García, José Ángel
%A Dória, A.
%A García García, Eugenia
%A Boiron, Marie Christine
%A Cathelineau, Michel
%T Fluids related to tungsten ore deposits in Northern Portugal and Spanish Central System: a comparative study
%D 1999
%@ 0214-2708
%U https://hdl.handle.net/20.500.14352/58397
%X A comparative study of P-T-X fluid evolution in several Iberian tungsten deposits has beencarried out using microthermometric and Raman data on representative deposits of Northern Portugal(Panasqueira and Borralha) and Spanish Central System (San Rafael, Cabeza Mediana, Cabeza Lijar).ThTee main types of fluids have been distinguished: (i) magmatic hypersaline aqueous fluids (onlypresent in Spanish Central System); (ii) "metamorphic" aqueous-carbonic fluids (H20-NaCI-C02-CH4); and (iii) aqueous fluids (H20-NaCI). The fluid evolution is characterized by dilution of aqueous carbonicfluids, accompanied by a decrease of the volatile phase density and cooling. The W-mineralisationIS always related to aqueous-carbonic fluids, resulting from the interaction betweenwater and C-hearing metamorphic host rocks. The Hercynian granites of Iberia are thus considered tohave played a role on ore forming processes rather distinct than that previously thought, as no typicalmagmatic signature is found except in the earliest stages responsible for the greisen formation in theSpanish Central System. The main role of the granites appears to be a heat supply at the origin of fluidconvection, rather than a fluid or a metal source.
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