Multistage development of a hydrothermal W deposit during the Variscan late-orogenic evolution: the Puy-les-Vignes breccia pipe (Massif Central, France)

The Puy-les-Vignes W deposit, located in the northwestern French Massif Central (FMC), is a rare occurrence of wolframite-mineralized hydrothermal breccia pipe hosted high-grade metamorphic gneisses. We present an integrated study this deposit aiming to characterize ore-forming system link with Variscan late-orogenic evolution FMC. Based on set representative samples from host rocks and mineralization, we describe detailed paragenetic sequence provide major trace element geochemistry granitic W–Nb–Ta–Sn–Ti oxide minerals, situ U/Pb 40 Ar/ 39 Ar geochronology, fluid inclusion quartz wolframite. demonstrate that formation W-mineralized results multistage development related four episodes during late Carboniferous. first episode corresponds emplacement unexposed peraluminous granite at ca. 324 Ma, which generated microgranite dykes exposed present-day surface. second quartz-supported wolframite mineralization 318 Ma paleodepth 7 km. mineralizing fluids have H 2 O–NaCl–CO –CH 4 –N composition, moderate-salinity (< 9 wt.% NaCl eq) were trapped high-temperatures (> 400 °C) lithostatic hydrostatic pressure variations caused by hydrofracturing rocks. Wolframite deposition interpreted result W-rich intermediate-density magmatic exsolved evolved leucogranite interacted volatile-rich metasedimentary country and/or possibly mixed low-salinity deep origin. third magmatic-hydrothermal Nb–Ta overprinting be intrusion 311 rare-metal granite, part regional magmatism 315–310 period. Finally, last disseminated Bi ± Au–Ag emplaced 300 shares similar mineralogical features Carboniferous orogenic gold deposits records, therefore, long-lived extends over timespan 25 million years setting dominated protracted high-temperature low-pressure metamorphism. Although local environment ore atypical, our show mineral assemblages, alteration styles, characteristics are those other peri-granitic