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DOI | 10.1130/B35278.1 |
Tectonic transition from oceanic subduction to continental collision: New geochemical evidence from Early-Middle Triassic mafic igneous rocks in southern Liaodong Peninsula, east-central China | |
Fang, Wei1; Dai, Li-Qun1,2; Zheng, Yong-Fei1,2; Zhao, Zi-Fu1,2; Ma, Li-Tao1 | |
2020-07-01 | |
发表期刊 | GEOLOGICAL SOCIETY OF AMERICA BULLETIN |
ISSN | 0016-7606 |
EISSN | 1943-2674 |
出版年 | 2020 |
卷号 | 132期号:7-8页码:1469-1488 |
文章类型 | Article |
语种 | 英语 |
国家 | Peoples R China |
英文摘要 | In contrast to the widespread occurrence of mafic arc magmatism during oceanic subduction, there is a general lack of such magmatism during continental subduction. This paradigm is challenged by the discovery of Early-Middle Triassic mafic igneous rocks from the southeastern margin of the North China Block (NCB), which was subducted by the South China Block (SCB) during the Triassic. Zircon U-Pb dating for these mafic rocks yields 247 +/- 2-244 +/- 5 Ma for their emplacement, coeval with the initial collision between the two continental blocks. These Triassic mafic rocks generally exhibit ocean island basalt (OIB)-like trace element distribution patterns, intermediate (Sr-87/Sr-86), ratios of 0.7057-0.7091, weakly negative epsilon(Nd)(t) values of -1.2 to -3.8, and epsilon(HF)(t) values of -1.3 to -3.2. Such geochemical features indicate origination from a metasomatic mantle source with involvement of felsic melts derived from dehydration melting of the previously subducting Paleo-Tethyan oceanic crust. The syn-magmatic zircons of Triassic age show variable Hf-O isotopic compositions, indicating that the crustal component was composed of both altered basaltic oceanic crust and terrigenous sediment. High Fe/Mn and Zn/Fe ratios suggest that the mantle source would mainly consist of ultramafic pyroxenites. The melt-mobile incompatible trace elements were further fractionated relative to melt-immobile trace elements during partial melting of these pyroxenites, giving rise to basaltic melts with OIB-like geochemical signatures. The mafic magmatism may be caused by tectonic extension due to rollback of the subducting Paleo-Tethyan oceanic slab in response to the initial collision of the NCB and SCB in the Early Triassic. Therefore, the syn-subduction mafic magmatism provides new geochemical evidence for tectonic transition from oceanic subduction to continental collision in east-central China. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000545115400008 |
WOS关键词 | CRUST-MANTLE INTERACTION ; ZIRCON U-PB ; HF-O ISOTOPE ; METAMORPHIC CHEMICAL GEODYNAMICS ; LINZIZONG VOLCANIC SUCCESSION ; SULU OROGENIC BELT ; HUWAN SHEAR ZONE ; TRACE-ELEMENT ; ICP-MS ; MELTING EXPERIMENTS |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/289422 |
专题 | 地球科学 |
作者单位 | 1.Univ Sci & Technol China, Sch Earth & Space Sci, CAS Key Lab Crust Mantle Mat & Environm, Hefei 230026, Peoples R China; 2.Chinese Acad Sci, Ctr Excellence Comparat Planetol, Hefei 230026, Peoples R China |
推荐引用方式 GB/T 7714 | Fang, Wei,Dai, Li-Qun,Zheng, Yong-Fei,et al. Tectonic transition from oceanic subduction to continental collision: New geochemical evidence from Early-Middle Triassic mafic igneous rocks in southern Liaodong Peninsula, east-central China[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2020,132(7-8):1469-1488. |
APA | Fang, Wei,Dai, Li-Qun,Zheng, Yong-Fei,Zhao, Zi-Fu,&Ma, Li-Tao.(2020).Tectonic transition from oceanic subduction to continental collision: New geochemical evidence from Early-Middle Triassic mafic igneous rocks in southern Liaodong Peninsula, east-central China.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,132(7-8),1469-1488. |
MLA | Fang, Wei,et al."Tectonic transition from oceanic subduction to continental collision: New geochemical evidence from Early-Middle Triassic mafic igneous rocks in southern Liaodong Peninsula, east-central China".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 132.7-8(2020):1469-1488. |
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