Petrogenesis and tectonic implications of the Triassic rhyolites in the East Kunlun Orogenic Belt, northern Tibetan Plateau
Petrogenesis and tectonic implications of the Triassic rhyolites in the East Kunlun Orogenic Belt, northern Tibetan Plateau
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青藏高原北部东昆仑造山带三叠纪流纹岩岩石成因及构造意义
DOI：
10.1016/j.gsf.2021.101243
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发表时间：
2021-11
影响因子：
8.9
通讯作者：
Yu Zhang
中科院分区：
文献类型：
--
作者：
Fengli Shao;Yaoling Niu;Juanjuan Kong;Yi Liu;Guodong Wang;Yu Zhang
东昆仑造山带位于青藏高原北方，发育大量晚三叠世中酸性火山岩。在EKOB的伦敦东区，我们发现了高度分异的过碱性类香日德流纹岩（~209 Ma），其野外产状和矿物组合不同于广泛分布的安山-流纹质埃拉山火山岩（~232-225 Ma）。较老，更常见的钙碱性长英质火山岩可能起源于俯冲古特提斯洋壳角闪岩相条件下与大陆碰撞的部分熔融。鄂西高原的长英质鄂拉山火山岩和同碰撞花岗岩类是同一个与大陆碰撞有关的岩浆事件的不同产物。香日德流纹具有高场强元素丰度高的特点，特别是Nb和Ta含量很高，Ba、Sr、Eu、P和Ti含量很低，87 Sr/86 Sr比值很高（高达0.96），与典型的过碱性流纹有明显的相似性。香日德流纹岩的原始岩浆很可能是经历了长期分离结晶并受陆壳混染的碱性玄武质岩浆。从早期花岗岩类和钙碱性火山岩到晚三叠世碱性玄武质脉岩和过碱性流纹岩的岩石组合，提供了EKOB从同碰撞到后碰撞构造演化的重要信息。我们推断，从碰撞压缩到碰撞后伸展的转变发生在220 Ma左右。
The East Kunlun Orogenic Belt (EKOB), which is in the northern part of the Greater Tibetan Plateau, contains voluminous Late Triassic intermediate-felsic volcanic rocks. In the east end of the EKOB, we identified highly differentiated peralkaline-like Xiangride rhyolites (~209 Ma) that differ from the widespread andesitic-rhyolitic Elashan volcanics (~232–225 Ma) in terms of their field occurrences and mineral assemblages. The older, more common calc-alkaline felsic Elashan volcanics may have originated from partial melting of the underthrust Paleo-Tethys oceanic crust under amphibolite facies conditions associated with continental collision. The felsic Elashan volcanics andsyn-collisional granitoids of the EKOB are different products of the same magmatic event related to continental collision. The Xiangride rhyolites are characterized by elevated abundances of high field strength elements, especially the very high Nb and Ta contents, the very low Ba, Sr, Eu, P, and Ti contents; and the variably high87Sr/86Sr ratios (up to 0.96), exhibiting remarkable similarities to the characteristic peralkaline rhyolites. The primitive magmas parental to the Xiangride rhyolites were most likely alkali basaltic magmas that underwent protracted fractional crystallization with continental crust contamination. The rock associations from the early granitoids and calc-alkaline volcanic rocks to the late alkaline basaltic dikes and peralkaline-like rhyolites in the Triassic provide important information about the tectonic evolution of the EKOB fromsyn-collisional to post-collisional. We infer that the transition from collisional compression to post-collisional extension occurred at about 220 Ma.
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影响因子：
2.3
作者：
A. Peccerillo;C. Donati;A. P. Santo;A. Orlando;G. Yirgu;D. Ayalew
通讯作者：
A. Peccerillo;C. Donati;A. P. Santo;A. Orlando;G. Yirgu;D. Ayalew
DOI：
10.1201/9780429070877-9
发表时间：
2021
期刊：
Igneous Petrology
影响因子：
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作者：
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通讯作者：
Y. Niu;R. Batiza
影响因子：
1.8
作者：
Xu Zhi
通讯作者：
Xu Zhi
DOI：
--
发表时间：
--
期刊：
--
影响因子：
--
作者：
Editor B. o. Mysen;D. K. Bailey;R. Macdonald
通讯作者：
Editor B. o. Mysen;D. K. Bailey;R. Macdonald
DOI：
--
发表时间：
2004
期刊：
Plateau Earthquake Research
影响因子：
--
作者：
Hu Qing-hua
通讯作者：
Hu Qing-hua