Fig. 13

U–Pb zircon geochronology of orthogneiss samples OG34 (a–c), OG36 (d–f), OG49 (g–i) and OG9 (j–l). a, d, g, j Cathodoluminescence (CL) images of zircon. Dashed orange and white circles indicate the position of the LA-ICP-MS spots analysed for U–Pb ages and trace elements, respectively. b, e, h, k Concordia diagrams. Empty dashed ellipses represent dates excluded from the Concordia age calculation, as they likely suffered from Pb loss or mixing with metamorphic rims. c, f, i, l Trace element content of zircon. REE patterns are normalized to chondrite values (McDonough & Sun, 1995)