Crayon1 (@Crayon1)

Among these, the Salau deposit was the most important tungsten minein France, with a production of 13,950 t WO3 between 1970 and 1986, with an exceptional high average grade of 1.5% WO3. The deposit is located at the contact between the la Fourque granodioritic intrusion and metacarbonate host rocks. The ore, traditionally considered as a scheelite skarn, has a complex mineralogy and morphology, affected by a late “hy- drothermal alteration” (Fonteilles et al. 1989). Similar skarn occurrences exist in the vicinity of Salau, such as Aurenere, in Spain (Fig. 1). In addition to scheelite, the Salau deposit also contains gold in economic concentrations (1–10 g/t; Guiraudie et al. 1963; Fonteilles et al. 1989). However, the ore-forming processes and the paragenetic position of gold remain unclear. Some authors considered that sulfides, related to the late “hydrothermal alter- ation,” are the retrograde stage of the scheelite skarn formation (Fonteilles et al. 1988). Other studies interpreted these sulfides as the expression of a shear zone mineralization without a genetic link with the La Fourque intrusion (Ledru and Autran 1987). This results, in part, from the fact that neither the emplacement age of the intrusive rocks nor metal deposition has been dated. The age of intrusion and skarn is interpreted to be late Variscan (Derré 1973). Similarly, deformation along the shear zone is the latest deformation event in the deposit (Kaelin 1982)