Sr and Nd isotopic compositions of late Paleozoic Youngjuand Andong granites in the northeastern Yeongnam Massif ,Korea

Abstract : Rb-Srwhole-rock isochron ages and Sr and Nd isotopic ratios have been determined for Youngju and Andong granites in the northeastern Yeongnam Massif,Korea. Six samples of Youngju granites yield an isochron age of 267 ± 27 Ma with an initial Sr ratio of 0.71505± 0.00026. Seven samples of Andong granites give an isochron age of 361 ± 41 Ma and an initial Sr ratio of 0.70944± 0.00011. The isochron ages indicate that Youngju and Andong granites were emplaced in middle Permian and late Devonian of late Paleozoic, respectively. Calculated εSr (T) and εNd (T) values at 267 Ma for Youngju granites are 152.2~156.4 and -19.7~ -18.0, and those values at 361 Ma for Andong granites are 73.8~79.7 and -11.4~ -8.0. Model ages of Youngju and Andong granites are 2.4~3.3 Ga and 1.4~1.8 Ga, respectively, suggesting that the Youngju granitic magma was derived from highly LREE-enriched lower crust formed in Late Archean, whereas the Andong granitic magma from slightly LREE-enriched lower crust formed in Proterozoic. Initial 87Sr/86Sr ratios of the granites in Ogcheon Belt and Yeongnam Massif display abroad range,but have two peaks around 0.709 and 0.715 regardless of emplacement age. It is likely that these two kinds of sources which are isotopically different have widely existed in the lower crust of Ogcheon Belt and Yeongnam Massif.
Type de document :
Article dans une revue
GeochemicalJournal, 2000, 33 (3), pp.153-165
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Contributeur : Andrée-Aimée Toucas <>
Soumis le : mercredi 3 août 2011 - 15:30:13
Dernière modification le : jeudi 11 octobre 2018 - 01:16:06

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  • HAL Id : emse-00613212, version 1

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J.I Lee, Yong-Joo Jwa, Chung-Hwa Park, M.J Lee, Jacques Moutte, et al.. Sr and Nd isotopic compositions of late Paleozoic Youngjuand Andong granites in the northeastern Yeongnam Massif ,Korea. GeochemicalJournal, 2000, 33 (3), pp.153-165. 〈emse-00613212〉

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