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篇目详细内容 |
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【篇名】 |
Sedimentary geochemistry of chert from the Middle–Upper Ordovician in Shihuigou area, North Qilian orogenic belt and its tectonic implication |
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【刊名】 |
Frontiers of Earth Science in China |
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【刊名缩写】 |
Front. Earth Sci. China |
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【ISSN】 |
1673-7385 |
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【EISSN】 |
1673-7490 |
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【DOI】 |
10.1007/s11707-007-0005-6 |
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【出版社】 |
Higher Education Press and Springer-Verlag |
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【出版年】 |
2007 |
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【卷期】 |
1
卷1期 |
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【页码】 |
30-36
页,共
7
页 |
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【作者】 |
DU Yuansheng;
ZHU Jie;
GU Songzhu;
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【关键词】 |
North Qilian orogenic belt; Ordovician; chert; sedimentary geochemistry; tectonics |
【摘要】 |
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The North Qilian orogenic belt is an elongate tectonic unit that lies between the North China plate to the north and the Middle Qilian microplate to the south, and is formed by a collision of the two plates in the Caledonian. The Shihuigou Section from Yongdeng County, Gansu Province, is in the eastern sector of the North Qilian Mountains, spanning the Ordovician island-arc zones. The Zhongpu Group is distributed in the Shihuigou area and composed of mediumbasic volcanic rocks and volcanic clastic rocks interspersed with cherts, limestones, slates, and metamorphic sandstones. The geochemistry of chert from the Zhongpu Group reveals that all cherts coexisting with island-arc volcanic rocks formed in a continental margin basin environment. Research results of the rare earth elements reveal that these cherts formed in a relatively deep-water basin with no significant terrestrial interference. Therefore, it is inferred that the North Qilian orogenic belt was previously an archipelagic ocean in the Ordovician. |
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