| Slab break-off and the formation of Permian mafic-ultramafic intrusions in southern margin of Central Asian Orogenic Belt, Xinjiang, NW China | |
Xie-Yan Song ; Wei Xie; Yu-Feng Deng; Anthony J. Crawford; Wen-Qin Zheng; Guo-Fu Zhou; Gang Deng; Song-Lin Cheng; Jun Lic
| |
| 2011 | |
| Source Publication | Lithos
 |
| Volume | 127Issue:1-2Pages:128-143 |
| Abstract | The Baishiquan and Pobei Early Permian mafic-ultramafic intrusions were emplaced into Proterozoic metamorphic rocks in the Central Tianshan and the Beishan Fold Belt, northern Xinjiang, NW China. The Baishiquan intrusion comprises mainly gabbro, and mela-gabbro sills occurring within and along the margins of the gabbro body. In the Pobei intrusion, two distinct gabbroic packages, a lower gabbro and the main gabbro, are intruded and overlain by small cumulate wehrlite bodies. Both intrusions are characterized by enrichments of large ion lithophile elements and Th and U relative to the high field strength elements, and show strong negative Nb and Ta anomalies and positive K and Pb anomalies, leading to higher Th/Yb and Nb/Yb than in mid-ocean ridge basalt and ocean island basalt. These features are comparable with subduction-related mafic rocks and post-collisional magmas. Geological and geochemical considerations indicate that the parental magmas of the two intrusions were derived from decompression melting of ascending asthenosphere and reacted with overlying subduction-modified lithospheric mantle. We believe that these parental magmas were generated by post-collisional extension along the Chinese Tianshan, perhaps triggered by slab break-off or delamination of thickened lithosphere. Relatively lower ((143)Nd/(144)Nd)(i); and higher ((87)Sr/(86)Sr)(i); than other Permian mafic-ultramafic intrusions in the eastern Chinese Tianshan indicate that the parental magmas of these two intrusions experienced significant contamination by old crustal rocks. |
| Keyword | Central Asian Orogenic Belt Nw China Permian Mafic–ultramafic Intrusion Slab Break-off |
| Subject Area | 矿床地球化学 |
| Indexed By | SCI |
| Language | 英语 |
| Document Type | 期刊论文 |
| Identifier | http://ir.gyig.ac.cn/handle/352002/4889 |
| Collection | 矿床地球化学国家重点实验室_矿床地球化学国家重点实验室_期刊论文 矿床地球化学国家重点实验室 |
| Recommended Citation GB/T 7714 | Xie-Yan Song,Wei Xie,Yu-Feng Deng,et al. Slab break-off and the formation of Permian mafic-ultramafic intrusions in southern margin of Central Asian Orogenic Belt, Xinjiang, NW China[J]. Lithos,2011,127(1-2):128-143. |
| APA | Xie-Yan Song.,Wei Xie.,Yu-Feng Deng.,Anthony J. Crawford.,Wen-Qin Zheng.,...&Jun Lic.(2011).Slab break-off and the formation of Permian mafic-ultramafic intrusions in southern margin of Central Asian Orogenic Belt, Xinjiang, NW China.Lithos,127(1-2),128-143. |
| MLA | Xie-Yan Song,et al."Slab break-off and the formation of Permian mafic-ultramafic intrusions in southern margin of Central Asian Orogenic Belt, Xinjiang, NW China".Lithos 127.1-2(2011):128-143. |
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