| 苏鲁超高压变质带中蛇纹岩的地球化学特征及岩石成因 |
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| 引用本文： | 郭翟蓉,王建,张佳佳,李爱.苏鲁超高压变质带中蛇纹岩的地球化学特征及岩石成因[J].世界地质,2018,37(2):423-435. |
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| 作者姓名： | 郭翟蓉 王建 张佳佳 李爱 |
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| 作者单位： | 吉林大学 地球科学学院, 长春 130061 |
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| 基金项目： | 国家自然科学基金项目（41472051）. |
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| 摘 要： | 青岛的仰口和日照的梭罗树是苏鲁超高压变质带中重要的蛇纹岩出露区。系统的岩石地球化学分析表明,仰口和梭罗树地区的蛇纹岩具有高Mg、低Al_2O_3/Si O_2、贫高场强元素(Nb、Th、Zr和Hf)和重稀土元素(HREE)的特征,其原岩是经历了不同程度部分熔融后的地幔残余,符合弧前地幔橄榄岩的特征。经模拟估算,仰口蛇纹岩的原岩熔融程度15%,梭罗树蛇纹岩的原岩熔融程度在20%~25%之间。蛇纹岩富流体迁移元素(U、Pb和LREE),且LREE和HFSE无明显相关性的地球化学特征表明,研究区蛇纹岩原岩在弧前地幔楔环境下,受到俯冲板片释放的含H_2O流体作用发生蛇纹石化,形成了流体迁移元素富集的蛇纹岩。
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| 关 键 词： | 蛇纹岩 地幔楔橄榄岩 部分熔融 流体迁移元素 地球化学 |
| 收稿时间： | 2017-10-20 |
| 修稿时间： | 2018-01-04 |
Geochemistry and petrogenesis of serpentinites in Sulu ultrahigh-pressure metamorphosed belt |
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| GUO Zhai-rong,WANG Jian,ZHANG Jia-jia,LI Ai.Geochemistry and petrogenesis of serpentinites in Sulu ultrahigh-pressure metamorphosed belt[J].World Geology,2018,37(2):423-435. |
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| Authors: | GUO Zhai-rong WANG Jian ZHANG Jia-jia LI Ai |
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| Institution: | College of Earth Sciences, Jilin University, Changchun 130061, China |
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| Abstract: | Yangkou in Qingdao and Suoluoshu in Rizhao are the important outcrops of serpentinites in the Sulu ultrahigh-pressure metamorphosed belt. Through systematic analysis of petrogeochemistry, it can be found that serpentinites from Yangkou and Suoluoshu are with high contents of Mg, low ratios of Al2O3/SiO2 and relatively depleted HFSE (Nb,Th,Zr and Hf) and HREE, which illustrate characteristics of the forearc mantle peridotites. It reveals that protoliths of these studied serpentinites are residual mantle peridotites formed from different degrees of partial melting. Estimation from modelling suggests that the partial melting degree is less than 15% for protoliths of Yangkou serpentinites, and 20%~25% for the Suoluoshu serpentinites. Serpentinites are rich in fluid-mobile elements and show no obvious correlation between LREE and HFSE, which indicates that protoliths of studied serpentinites have undergone serpentinization by hydrous fluids released from the subducted slab and formed serpentinites enriched in fluid-mobile elements in the forearc mantle wedge. |
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| Keywords: | serpentinite mantle wedge peridotites partial melting fluid-mobile elements geochemistry |
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