Location of samples from the French Alps (circles) and the Italian Alps (triangles) in the four types of diagrams, commonly used by archaeologists (left: x-axis = ²⁰⁷Pb/²⁰⁶Pb) and by geologists (right: ²⁰⁶Pb/²⁰⁴Pb x-axis). The 95% confidence ellipsoids do not allow to differentiate the deposits in the French Alps from the deposits in the Italian Tyrol. The hypothetical object (identified by the crossing of the lines) does not spatially approximate either of the two ore population groups except in the diagram ²⁰⁷Pb/²⁰⁴Pb vs ²⁰⁶Pb/²⁰⁴Pb where it can be interpreted as coming from the French Alps.