Abstract
U-Pb dating of zircons from the Yxsjöberg and Svärdsjö leptites yields a discordia age of 1900 ± 19 Ma and for zircons from the synorogenic granite near Svärdsjö, 1873+11 -10 Ma. Calculation with the systematics of Wickman (1983: Uranium-lead isotope systematics: The case of crystals with discrete cores. Lithos 16, in press) gives an age of 1925 Ma for the granite zircons.