Pb Isotope Modeling

FIGURE 4.8 Crustal growth curves based upon transport-balance modeling (Nagler Si Kramers, 1998), U-Pb zircon ages from juvenile crust (Condie, 2000) and Nb/U ratios for the depleted mantle (Collerson Si Kamber, 1999). The Nagler and Kramers model assumes either 0% crust at 4.4 Ga (A) or 10% crust at 4.4 Ga (B), and their calculations are consistent with Pb isotope modeling and Hf-isotope studies. 

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