Results of U-Pb zircon dating for leucogneiss AJAH09 of the Laguépie unit: (a) CL images showing the texture of zircon with dark resorbed metamict cores and luminescent oscillatory zoned rims. Some representative spots made on rims are indicated with their ²⁰⁶Pb/²³⁸U age; (b) Concordia diagram showing all the U-Pb analyses. Color range corresponds to Th/U ratio values. The rim data are the sub-concordant ellipses just below 400 Ma; (c) regression of rim U-Pb data in a Tera-Wasserburg plot; (d) weighted average of ²⁰⁶Pb/²³⁸U common lead corrected ages obtained in zircon rims.