Open AccessThe perigranitic W-Au Salau deposit (Pyrenees, France): polyphase genesis of a late Variscan intrusion related deposit
Author(s) -
Thomas Poitrenaud,
Éric Marcoux,
Romain Augier,
Marc Poujol
Publication year - 2021
Publication title -
bulletin de la société géologique de france
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.584
H-Index - 53
eISSN - 1777-5817
pISSN - 0037-9409
DOI - 10.1051/bsgf/2020044
Subject(s) - geology , breccia , scheelite , geochemistry , skarn , mineralization (soil science) , zircon , porphyritic , dolomitization , mineralogy , tungsten , quartz , geomorphology , paleontology , fluid inclusions , structural basin , organic chemistry , facies , soil science , chemistry , soil water
A field study combined with a laboratory study and 3D modeling have been performed in order to decipher the genesis of the Salau deposit W-Au mineralization (Pyrenees, France), one of the most important for tungsten in Europe. Results show the existence of two superimposed ore types, emplaced ca. 10 km depth and within decreasing temperature conditions: a calcic silicates skarn with rare scheelite and disseminated sulphides followed by a mineralized breccia with massive sulphides (pyrrhotite and chalcopyrite dominant), coarse-grained scheelite and gold, representing the main part of the ore mined in the past. This breccia is localized in ductile-brittle shear-zones which crosscut the granodiorite. U/Pb dating on zircon, apatite and scheelite, previously realized, confirmed this polyphase evolution. These two types of mineralization, linked to the emplacement of two successive intrusions as confirmed by sulphur isotopic analysis, granodioritic then leucogranitic, can be classified as belonging to the Intrusion-Related Gold Deposit type (IRGD). The emplacement of the high-grade gold and scheelite breccia was initiated by the progressive localization of the regional deformation in the Axial Zone of the Pyrenees during the Permian within E-W dextral-reverse faults.