Crustal evolution of the Gyeonggi massif, South Korea: Nd isotopic evidence and implications for continental growths of East Asia

We investigated the Sm-Nd isotopic characteristics of the Gyeonggi massif, Korea, in order to delineate its crustal growth history. Nd isotopic depleted-mantle model ages (T-DM), obtained from 32 new measurements of basement and supracrustal samples and from the literature, suggest that the Gyeonggi massif is as old as Middle Archean (>3.0 Ga) and was primarily extracted from the mantle during the Late Archean (2.9-2.5 Ga). In addition, minor crustal formation occurred during the Early Proterozoic (ca. 1.9-1.8 Ga). Late Archean-Early Proterozoic crustal growth of the Gyeonggi massif is comparable with that of the Sino-Korean or Yangtze craton. The T-DM distribution pattern alone is not sufficient to determine the crustal affinity of the Gyeonggi massif with either of the Chinese cratons. However, Late Proterozoic crustal evolution of the Gyeonggi massif appears to favor its tectonic correlation with the Yangtze craton. (C) 2002 Elsevier Science B.V. All rights reserved.