View : 26 Download: 0

Nd and Sr isotopic signatures of mesozoic granitoids in South Korea

Title
Nd and Sr isotopic signatures of mesozoic granitoids in South Korea
Authors
Na C.K.Kim K.H.Park S.S.
Ewha Authors
김규한
SCOPUS Author ID
김규한scopusscopus
Issue Date
1996
Journal Title
Resource Geology
ISSN
1344-1698JCR Link
Citation
Resource Geology vol. 46, no. 4, pp. 215 - 226
Indexed
SCIE; SCOPUS scopus
Document Type
Article
Abstract
Mesozoic granitic plutons in the Korean peninsula have εNd values ranging from -14.9 to +0.4 and initial 87Sr/86Sr ratios from 0.704 to 0.717 ( εSr = -2.5 ∼ 183.7). The Nd and Sr isotopic variations in the granitic rocks are inversely correlated and are clearly divided into two distinct groups namely: a mantle type as in the Mesozoic Kyongsang basin and a crust type as in the Precambrian terranes, based on geologic and geographic differences. Cretaceous granitic rocks in the Kyongsang sedimentary basin have εNd of -4.4 to +0.4 and initial 87Sr/86Sr ratios of 0.704 to 0.706 (εSr = -2.5 ∼ 33.5), indicating derivatives of the mantle source. While, andesitic rocks in the basin have Nd-Sr isotopic compositions (εNd = -12.6 ∼ -0.8, (87Sr/86Sr)i = 0.705 ∼ 0.707, εSr = 9.4 ∼ 38.9) similar with those of the Cretaceous plutonic rocks, implying cogenetic sources of the magma. On the other hand, Jurassic plutons from outside of the basin, including some Cretaceous granites in the Okehon geosynclinal zone, have much lower εNd of -21.0 to -13.6 and higher initial 87Sr/86Sr ratios of 0.711 to 0.717 (εSr = 97.3∼183.7) than the Cretaceous plutons in the Kyongsang basin, which suggests a significant crustal assimilation or contamination of the granitic magma. The two stage model ages of the Cretaceous and Jurassic granite plutons were calculated to be 0.5 to 1.1 Ga and 1.6 to 2.2 Ga, respectively. This data suggests that the source materials of these Mesozoic plutons in the Korean peninsula have evolved considerably since mid - Proterozoic times.
Appears in Collections:
사범대학 > 과학교육과 > Journal papers
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE