Ages des formations filoniennes à fluorine-barytine-quartz du district de Paulhaguet (Haute-Loire, Massif central français)

K/Ar dating of hydrothermal K-feldspars and illites has shown two hydrothermal episodes. The first, Hettangian, resulted in fluorite and barite deposition, as in other parts of the Massif Central. The second, Barremian, not known untill now, was responsible for the extensive silicification forming the «quartz roots» which limit mining at depth