| Discovery and Genetic Mechanism of Basic Granulite in the Altay Orogenic Belt, Xinjiang, NW China |
| |
| 作者姓名： | LI Zilong CHEN Hanlin YANG Shufeng DONG Chuanwan XIAO Wenjiao LI Jiliang YE Ying and WANG Jian |
| |
| 作者单位： | LI Zilong，CHEN Hanlin，YANG Shufeng，DONG Chuanwan，XIAO Wenjiao，LI Jiliang，YE Ying and WANG JianDepartment of Earth Sciences，Faculty of Science，Zhejiang University，Hangzhou 310027; Institute of Geology and Geophysics，Chinese Academy of Sciences，Beijing 100023 |
| |
| 摘 要： | Altay granulite (AG), which represents the product of high-grade metamorphism in the lower crust, was newly found in the Wuqiagou area, Fuyun County in the Altay orogenic belt, Northwest China. It is composed mainly of hypersthene, augite, basic plagioclase, amphibole and brown biotite. Its mineral compositions of amphibole and biotite are rich in Mg/(Mg+Fe2+) and Ti. Geochemically, the AG is enriched in Mg/(Mg+Fe2+) and A12O3, and poor in CaO, with depletion of U, Th, K and Rb contents. Furthermore, geochemical data reflect that the protolith of the AG is igneous-genetic calc-alkaline basalt formed under an island arc environment. The AG has ZREE of 92.38-96.58 ppm and enriched LREE model with weak positive Eu anomaly of 1.09-1.15. In the MORB normalized spider diagram, the AG shows tri-doming pattern with a strong negative Nb anomaly and medium negative P and Ti anomalies, reflecting that the AG has tectonic relation with subduction or subduction-related materials. The P-T conditions of peak metamorphi
|
| 关 键 词： | 麻粒岩 原始石器时代 构造框架 遗传机制 造山带 中国 西北地区 |
Discovery and Genetic Mechanism of Basic Granulite in the Altay Orogenic Belt, Xinjiang, NW China |
| |
| Authors: | LI Zilong CHEN Hanlin YANG Shufeng DONG Chuanwan XIAO Wenjiao LI Jiliang YE Ying and WANG Jian |
| |
| Institution: | LI Zilong,CHEN Hanlin,YANG Shufeng,DONG Chuanwan,XIAO Wenjiao,LI Jiliang,YE Ying and WANG JianDepartment of Earth Sciences,Faculty of Science,Zhejiang University,Hangzhou,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing |
| |
| Abstract: | Abstract Altay granulite (AG), which represents the product of high‐grade metamorphism in the lower crust, was newly found in the Wuqiagou area, Fuyun County in the Altay orogenic belt, Northwest China. It is composed mainly of hypersthene, augite, basic plagioclase, amphibole and brown biotite. Its mineral compositions of amphibole and biotite are rich in Mg/(Mg+Fe2+) and Ti. Geochemically, the AG is enriched in Mg/(Mg+Fe2+) and Al2O3, and poor in CaO, with depletion of U, Th, K and Rb contents. Furthermore, geochemical data reflect that the protolith of the AG is igneous‐genetic calc‐alkaline basalt formed under an island arc environment. The AG has ΣREE of 92.38–96.58 ppm and enriched LREE model with weak positive Eu anomaly of 1.09–1.15. In the MORB normalized spider diagram, the AG shows tri‐doming pattern with a strong negative Nb anomaly and medium negative P and Ti anomalies, reflecting that the AG has tectonic relation with subduction or subduction‐related materials. The P‐T conditions of peak metamorphism of the AG are 750–780°C and >0.6–0.7 GPa. Retrograde metamorphism implies that the protolith of the Altay granulite might undergo a metamorphic process along a clockwise P‐T trajectory. Therefore, the formation and evolution of the AG may have a genetic association with continental collision/orogeny and the AG was taken into the Late Paleozoic meta‐strata by way of tectonic emplacement. |
| |
| Keywords: | granulite protolith and tectonic setting P-T condition genetic mechanism Altay orogenic belt Northwest China |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《Acta Geologica Sinica》浏览原始摘要信息 |
| 点击此处可从《Acta Geologica Sinica》下载免费的PDF全文 |
|
