2D projections of the measured lead isotope ratios, compared with the available data from the literature [22, 28–32 and literature cited therein].

<p>The two most widely used bivariate plots are shown: (a) <sup>206</sup>Pb/<sup>204</sup>Pb vs <sup>207</sup>Pb/<sup>204</sup>Pb plot; (b) <sup>206</sup>Pb/<sup>204</sup>Pb vs <sup>208</sup>Pb/<sup>204</sup>Pb plot.</p>