LaCe ages are reported for two sets of Finnish pegmatites, Lövböle and Mustikkamäki, and for an Amîtsoq gneiss, Greenland. When λβ 138La value (2.29 × 10-12 yr-1) obtained by radioactivity measurement  is used for the chronological calculation, the LaCe ages (2129, 2325, 3271 Myr) evaluated for these rocks are 18-35% older than the SmNd ages for the same samples. To make the LaCe age fit to the SmNd age for the same sample, a new value of (2.77 ± 0.21) × 10-12 yr-1 is evaluated for λβ 138La. In this calculation, the LaCe and SmNd ages reported for a Bushveld gabbro  have been also taken into account together with those for the Lövböle pegmatite and the Mustikkamäki pegmatite, while the Amîtsoq gneiss (GGU110999) has been omitted because of the complicated thermal history of this sample.
ASJC Scopus subject areas
- Geochemistry and Petrology
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science