Figure 4
From: Geochemistry of Gold Ores Mined During Celtic Times from the North-Western French Massif Central
Lead isotopic diagrams of the studied Ancient and Modern gold ores with the Au-bearing lodes and Sn-W occurences studied by Touray et al. 1989. Phase #1 corresponds to ores having a U/Pb <1 (Cambro-Ordovician model age); Phase #2 correponds to ores having a U/Pb >1 (Variscan model age).
