气候变化领域集成服务门户(CCPortal): Sediment recycling by continental subduction indicated by B-Hf-Pb-Nd isotopes from Miocene-Quaternary lavas in the northern margin of Tibet

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DOI	10.1016/j.lithos.2023.107109
	Sediment recycling by continental subduction indicated by B-Hf-Pb-Nd isotopes from Miocene-Quaternary lavas in the northern margin of Tibet
	Zhang, Xiu-Zheng; Wang, Qiang; Kerr, Andrew C.; Wei, Gang-Jian; Qi, Yue; Liu, Ying; Yang, Yu-Cheng
发表日期	2023
ISSN	0024-4937
EISSN	1872-6143
卷号	444
英文摘要	Although it has been argued that sediment recycling plays an important role in the differentiation of the con-tinental crust, boron (B) isotopic data does not support a direct input of subducted sediments into arc magmas. This raises questions about the viability of sediment recycling as a process in the differentiation of continental crust. Here, we report B isotopic data from Miocene-Quaternary lavas derived from different sources in the northern margin of Tibet. These lavas have high B contents and negative 811B values close to those of continental sediments. Strongly peraluminous rhyolites have the highest B (93 to 1559 ppm) contents with negative 811B (-9.7 to-17.9) values. Adakitic dacites and trachyandesites exhibit the lowest B (18 to 29 ppm) contents with markedly negative 811B (-12.0 to-35.7) values whereas olivine leucitites have B (37.2 to 59.3 ppm) contents with negative 811B (-8.3 to-15.6) values. These lavas also have enriched Hf-Pb-Nd isotopic compositions similar to those of sediments. This data, combined with numerical modelling and geophysical and tectonic data for Cenozoic continental subduction in the northern margin of Tibet, indicates that: (1) the strongly per-aluminous rhyolites were generated by partial melting of mica-bearing continental sedimentary rocks subducted to the depth of mid-to-lower crust; (2) adakitic lavas were derived by partial melting of sediment-bearing thickened lower crust underwent dehydration and eclogites-facies metamorphism; and (3) olivine leucitites were generated by partial melting of enriched mantle metasomatized by sediment-bearing eclogite-facies crust -derived melts. Thus, at continental convergent margins, continental subduction is an important mechanism for sediment recycling and the evolution of continental crust.
关键词	Boron isotopes Continental subduction Sediment recycling Miocene-Quaternary Tibetan Plateau
英文关键词	MANTLE BENEATH TIBET; ARC LAVAS; VOLCANIC-ROCKS; CRUSTAL; BORON; GEOCHEMISTRY; SYSTEMATICS; CONSTRAINTS; EVOLUTION; MAGMAS
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:000955774900001
来源期刊	LITHOS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283066
作者单位	Chinese Academy of Sciences; Guangzhou Institute of Geochemistry, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Cardiff University; Chinese Academy of Sciences
推荐引用方式 GB/T 7714	Zhang, Xiu-Zheng,Wang, Qiang,Kerr, Andrew C.,et al. Sediment recycling by continental subduction indicated by B-Hf-Pb-Nd isotopes from Miocene-Quaternary lavas in the northern margin of Tibet[J],2023,444.
APA	Zhang, Xiu-Zheng.,Wang, Qiang.,Kerr, Andrew C..,Wei, Gang-Jian.,Qi, Yue.,...&Yang, Yu-Cheng.(2023).Sediment recycling by continental subduction indicated by B-Hf-Pb-Nd isotopes from Miocene-Quaternary lavas in the northern margin of Tibet.LITHOS,444.
MLA	Zhang, Xiu-Zheng,et al."Sediment recycling by continental subduction indicated by B-Hf-Pb-Nd isotopes from Miocene-Quaternary lavas in the northern margin of Tibet".LITHOS 444(2023).