Zircon grain morphology observed under SEM-BSE (A, C, E, G, I) and zircon section observed under SEM-BSE (insert in D), SEM-CL (B, D, H, I), and optically (F, transmitted light). In C and D, Ap, Zrn, Thr are apatite, zircon, thorite grains, resp. Dark circles in F are LA-ICP-MS craters; d06 to d08: trace-element analyses; b11 to b14: U-Pb isotopic analyses, with the related age (in Ma, ± 2σ).