U-Pb Zircon dating from the orthogneiss sample PB-18-3. (A) Wetherill concordia diagram for all the 114 different analyses and the resulting discordia line with a upper intercept date of 2039.5 ± 23 Ma and a lower intercept date of 631 ± 6 Ma; note the intermediate position of some analyses between the upper and the lower clusters; (B) Wetherill concordia diagram with a close up on the upper concordant cluster that yields a concordia date of 2038 ± 12 Ma; (C) Wetherill concordia diagram with a close up on the lower concordant cluster yielding a concordia date of 621 ± 2 Ma.