Figure 2

(a,d) Cathodoluminescence images of representative zircon grains from the samples ZN1 and ZN21, and corresponding ²⁰⁶Pb/²³⁸U ages of the individual analyzed spots. (b,e) U-Pb concordia diagrams of zircon grains; (c,f) bar plot shows the weighted mean ²⁰⁶Pb/²³⁸U ages.