Vp. Kovach et al., SM-ND ISOTOPIC SYSTEMATICS OF THE KURUMKAN SUBGROUP, THE IENGRA GROUPOF ALDAN SHIELD, Stratigraphy and geological correlation, 4(3), 1996, pp. 213-219
The first data on the Nd isotopic composition in high-Al gneisses and
associated garnet-hypersthene-biotite plagiogneisses of the Kurumkan S
ubgroup, the Iengra Group of Aldan Shield are presented. The obtained
results show that rocks of the subgroup accumulated after similar to 2
.9 Ga, i.e., during the Late Archean or Early Proterozoic, and not the
Early Archean evolutionary stage of the shield. Protoliths of garnet-
hypersthene-biotite gneisses were not older than 2.3 Ga, and their for
mation marks the Early Proterozoic stage of continental crust generati
on in the Aldan granulite-gneiss region.