1980 Volume 14 Issue 1 Pages 57-61
When 193Nd/144Nd ratios of oceanic basalts are plotted against the observed Sm/Nd ratios, the points appear widely scattered. But when a reduction procedure is applied on the basis of a model for development of oceanic basalt REE patterns with DSm/DNd = 1.32, one can obtain a linear correlation between 143Nd/144Nd and 147Sm/144Nd, with two subparallel alignments. Ages (∼730 and 1600-1900Myr) deduced therefrom can be consistent with those presented for development of continental crust.