Fig. 7

XRF raw net peak intensities of Fe, Cu and Pb measured in three different regions (1, 2, 3) on each manuscript: P.PalauRib. Inv. 357, Inv. 399, Inv. 401 and Inv. 451v. This graph reports qualitative results only since the cross-section of the interaction between the element and the X-rays grows with the atomic number