Rare earth elements compositions of Setouchi high Mg andesites (HMAs) and basalt; an implication for a mantle compositional shift beneath the SW Japan arc during the Japan Sea opening.
Rare earth elements compositions of Setouchi high Mg andesites (HMAs) and basalt; an implication for a mantle compositional shift beneath the SW Japan arc during the Japan Sea opening.
复制标题
濑户内高镁安山岩（HMA）和玄武岩的稀土元素成分；
DOI：
10.9795/bullgsj.55.31
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Y. Morishita
中科院分区：
文献类型：
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作者：
G. Shimoda;M. Nagai;Y. Morishita
为了评估日本海开口对日本西南弧下方地幔楔的影响，测定了日本西南弧濑户内火山带的原始高镁安山岩（HMA）和玄武岩的稀土元素（REE）成分。来自大阪地区的较老的 HMA (13.9 Ma) 比来自 Shodo-Shima 地区的较年轻的 HMA (12.7 Ma) 具有更高的轻稀土元素 (LREE) 和较低的重稀土元素 (HREE) 浓度。为了解释这些 REE 模式，进行了混合计算。结果表明，从Osaka HMA估计出的软流圈成分（MORB源物质）的30%~70%和先存地幔的70%~30%可以解释小豆岛HMA和玄武岩的REE模式。这一结果可能表明先前存在的地幔楔被软流圈成分所取代，这与日本海的开口有关。
In order to evaluate the effect of the Japan Sea opening upon the mantle wedge beneath the SW Japan arc, rare earth elements (REE) compositions were determined for primitive high magnesian andesites (HMAs) and a basalt from the Setouchi volcanic belt in the SW Japan arc. The older HMA from the Osaka area (13.9 Ma) has higher light rare earth elements (LREE) and lower heavy rare earth elements (HREE) concentrations than the younger HMA from the Shodo-Shima area (12.7 Ma). To explain these REE patterns, mixing calculations were conducted. The results show that 30 ~ 70 % of the asthenospheric component (MORB source like materials) and 70 ~ 30 % of the pre-existing mantle, which is estimated from the Osaka HMA, can account for the REE patterns of the Shodo-Shima HMA and basalt. This result may suggest a replacement of a pre-existing mantle wedge by an asthenospheric component, which is related to the Japan Sea opening.
DOI：
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发表时间：
1992
期刊：
--
影响因子：
--
作者：
I. Kaneoka;Y. Takigami;N. Takaoka;S. Yamashita;K. Tamaki
通讯作者：
I. Kaneoka;Y. Takigami;N. Takaoka;S. Yamashita;K. Tamaki