1989 Volume 39 Issue 215 Pages 219-222
Selected samples of Precambrian basement gneisses and Mesozoic granitic rocks from the Korean Peninsula are examined by non-destructive gamma-ray spectrometry. The Th/U ratios estimated for the gneisses from the peninsular interior appear to be significantly higher than those for the gneisses from the exterior localities, whereas such a difference is inconspicuous in the granitic rocks. This observation is consistent with the spatial distribution of Th/U values for source materials of Mesozoic ore leads estimated on the basis of a simple two-stage model comprising the second stage evolution in the Precambrian basement.
