Geochemical Characteristics and Geological Significance of Meta-Volcanic Rocks of the Bainaimiao Group, Sonid Right Banner, Inner Mongolia, China | |
Alternative Title | Geochemical Characteristics and Geological Significance of Meta-Volcanic Rocks of the Bainaimiao Group, Sonid Right Banner, Inner Mongolia, China |
Zhang Chao1; Quan Jingyu1; Liu Zhenghong2; Xu Zhongyuan2; Pang Xuejiao1; Zhang Yujin1 | |
2019 | |
Source Publication | JOURNAL OF EARTH SCIENCE
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ISSN | 1674-487X |
Volume | 30Issue:2Pages:272-285 |
Abstract | The Bainaimiao Group, which crops out in the Sonid Right Banner area of Inner Mongolia, China, comprises mainly metamorphosed volcano-sedimentary rocks. This group can be divided into two formations: a lower formation characterized by intermediate-felsic volcanic rocks, and an upper formation of intermediate-mafic volcanic rocks. Zircon dating indicates that biotite leptynite from the lower formation and chlorite-sericite schist from the upper formation crystallized at 499 +/- 2 and 478 +/- 2 Ma, respectively, corresponding to different volcanic events. Meta-volcanic rocks of the Bainaimiao Group belong to the calcalkaline series, and the SiO (2) concentrations suggest that their protoliths were mainly basalts and rhyolites. Greenschist rocks of the group are enriched in light rare earth elements (LREEs) relative to heavy rare earth elements (HREEs), with (La/Yb)(N) ratios of 3.08-10.9. In addition, they are enriched in large-ion lithophile elements, including Rb, Ba and K, and depleted in the high-field-strength elements Nb, Ta and Ti. The felsic meta-volcanic rocks also exhibit relative enrichments in LREEs compared with HREEs, with high (La/Yb)(N) ratios of 2.92-9.89, and are enriched in Rb, Ba, Zr and Hf, and depleted in Sr, Nb and Ta. These geochemical characteristics indicate that the meta-basic volcanic rocks were originated from partial melting of sub-arc mantle wedge that had been previously metasomatized by subducted-slab-derived fluids, whereas the meta-felsic volcanic rocks were generated by partial melting of continental crust. These results suggest that the meta-volcanic rocks of the Bainaimiao Group are the products of oceanic plate subduction magmatism along an active continental margin, which can be attributed to Early Paleozoic subduction of the Paleo-Asian Ocean plate beneath the northern margin of the North China Craton. |
Other Abstract | The Bainaimiao Group, which crops out in the Sonid Right Banner area of Inner Mongolia, China, comprises mainly metamorphosed volcano-sedimentary rocks. This group can be divided into two formations: a lower formation characterized by intermediate-felsic volcanic rocks, and an upper formation of intermediate-mafic volcanic rocks. Zircon dating indicates that biotite leptynite from the lower formation and chlorite-sericite schist from the upper formation crystallized at 499±2 and 478±2 Ma, respectively, corresponding to different volcanic events. Meta-volcanic rocks of the Bainaimiao Group belong to the calcalkaline series, and the SiO_2 concentrations suggest that their protoliths were mainly basalts and rhyolites. Greenschist rocks of the group are enriched in light rare earth elements (LREEs) relative to heavy rare earth elements (HREEs), with (La/Yb)N ratios of 3.08–10.9. In addition, they are enriched in large-ion lithophile elements, including Rb, Ba and K, and depleted in the high-field-strength elements Nb, Ta and Ti. The felsic meta-volcanic rocks also exhibit relative enrichments in LREEs compared with HREEs, with high (La/Yb)N ratios of 2.92–9.89, and are enriched in Rb, Ba, Zr and Hf, and depleted in Sr, Nb and Ta. These geochemical characteristics indicate that the meta-basic volcanic rocks were originated from partial melting of sub-arc mantle wedge that had been previously metasomatized by subducted-slab-derived fluids, whereas the meta-felsic volcanic rocks were generated by partial melting of continental crust. These results suggest that the meta-volcanic rocks of the Bainaimiao Group are the products of oceanic plate subduction magmatism along an active continental margin, which can be attributed to Early Paleozoic subduction of the Paleo-Asian Ocean plate beneath the northern margin of the North China Craton. |
Keyword | ASIAN OROGENIC BELT MO-AU DEPOSIT U-PB ORE GENESIS NE CHINA GEOCHRONOLOGY ACCRETION COLLISION ZIRCONS MARGIN Inner Mongolia Bainaimiao Group active continental margin northern margin of the North China Craton |
Indexed By | CSCD |
Language | 英语 |
Funding Project | [Nation Key R&D Program of China] ; [China Geological Survey] |
CSCD ID | CSCD:6460753 |
Citation statistics |
Cited Times:5[CSCD]
[CSCD Record]
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Document Type | 期刊论文 |
Identifier | http://ir.imr.ac.cn/handle/321006/153165 |
Collection | 中国科学院金属研究所 |
Affiliation | 1.中国科学院金属研究所 2.吉林大学 |
Recommended Citation GB/T 7714 | Zhang Chao,Quan Jingyu,Liu Zhenghong,et al. Geochemical Characteristics and Geological Significance of Meta-Volcanic Rocks of the Bainaimiao Group, Sonid Right Banner, Inner Mongolia, China[J]. JOURNAL OF EARTH SCIENCE,2019,30(2):272-285. |
APA | Zhang Chao,Quan Jingyu,Liu Zhenghong,Xu Zhongyuan,Pang Xuejiao,&Zhang Yujin.(2019).Geochemical Characteristics and Geological Significance of Meta-Volcanic Rocks of the Bainaimiao Group, Sonid Right Banner, Inner Mongolia, China.JOURNAL OF EARTH SCIENCE,30(2),272-285. |
MLA | Zhang Chao,et al."Geochemical Characteristics and Geological Significance of Meta-Volcanic Rocks of the Bainaimiao Group, Sonid Right Banner, Inner Mongolia, China".JOURNAL OF EARTH SCIENCE 30.2(2019):272-285. |
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