79 research outputs found

    Geochronological constraints on the magmatic and hydrothermal evolution of the tras-os-montes hercynian domain (Galica, Spain) : position of the AU, SN-W mineralizing events.

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    International audienceThe study area is located in the Galicia-Trás-os-Montes Zone (GTMZ zone, Arenas et al. 1986, Fig. 1), that belongs to the internal zone of the Hercynian belt and is composed of a relative autochthonous and parautochthonous units overthrusted by allochthonous complexes (Ribeiro et al. 1990). This domain of Palaeozoic schists is affected by a low to high temperature – medium pressure metamorphism. These rocks exhibit a well-developed regional schistosity related to nappes emplacement (D1 and D2 events) and are affected by NS-trending crenulation lineation and folds (D3 event) The late D3 event is characterized by a high-temperature metamorphism leading to development of local migmatite. Both parautochthonous and allochthonous units are intruded by syn- and post-kinematic plutons. Four generations of granites (G1 to G4) are identified by their textural and geochemical characteristics and by crosscutting relationships. Gold deposits are spatially associated with the G3 granites whereas Sn-W deposits are represented, in the study area, by disseminated and vein-type mineralization spatially close to the G2 granites (fig. 1)

    Relations between Au / Sn-W mineralizations and late hercynian granite: Preliminary results from the Schistose Domain of Galicia-Trás-os-Montes Zone, Spain

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    International audienceAu and W-Sn mineralization of the Schistose Domain of Galicia-Trás-os-Montes are spatially related to late hercynian granites. The Bruès (Au) and the Mina Soriana W-(Sn) deposits are studied. Both show some similarities and are assumed to form in the same tectonic and metamorphic context, on top of the granites. The role of the granite as a source for mineralizing fluids and rheological control for vein emplacement is re-adressed and discussed
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