Li isotopic disequilibrium of the Cenozoic subcontinental lithospheric mantle in East Asia

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• 作者：Youngwoo Kil ; Haemyeong Jung ; Kyounghee Yang
• 关键词：Key wordsLi isotopic disequilibrium ; spinel peridotite ; southwestern Japan ; South Korea ; eastern China
• 刊名：Geosciences Journal
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：20
• 期：5
• 页码：597-607
• 全文大小：761 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Earth sciences
  Geosciences
  
• 出版者：The Geological Society of Korea, co-published with Springer
• ISSN：1598-7477
• 卷排序：20

文摘

Mantle-derived spinel peridotite xenoliths, enclosed in alkali basalt and dating between 18.9 Ma and <1.2 Ma occur in southwestern Japan (On-yama and Arato-yama), South Korea (Baegryeong Island, Asan and Pyeongtaeg, Boeun, Jeju Island, and Goseong), and eastern China (Qixia and Nushan). Sample locations were specifically selected to evaluate spatial differences in lithium (Li) isotopes in the spinel peridotite xenoliths, which have undergone both enrichment and depletion processes under mantle conditions. Li concentrations and isotopic compositions of coexisting olivine, orthopyroxene, and clinopyroxene in the spinel peridotite xenoliths from these units reveal both elemental and isotopic disequilibrium. The observed Li isotopic disequilibrium between xenolith minerals may reflect fractional infiltration of Li isotopic compositions from the host magma by later metasomatism during transport from the mantle to the surface.