Continental crust growth during the evolution of accretionary orogens: insights from the early Paleozoic granitoids in the Western Kunlun orogen, Northwest China

doi:10.1016/j.lithos.2021.106253

	Continental crust growth during the evolution of accretionary orogens: insights from the early Paleozoic granitoids in the Western Kunlun orogen, Northwest China
	Wu, Kai 1; Zhang, Lipeng 2,3; Jiang, Xiaoyan 4; Chen, Yuxiao 5; Guo, Jia 6; Sun, Weidong2,3 ; Sui, Qinglin 2; Yuan, Honglin 1
	2021-10-01
发表期刊	LITHOS
ISSN	0024-4937
卷号	398 页码:15
通讯作者	Wu, Kai(wukai0302@gmail.com) ; Yuan, Honglin(hlyuan@nwu.edu.cn)
摘要	Accretionary orogens are the primary sites for continental growth, but the rate and amount of crust generation throughout its evolution are poorly constrained. In this contribution, our new results about the genesis of two intermediate-felsic plutons are combined with a compiled granitoid dataset to evaluate the amount and rate of crustal growth throughout the evolution of the Western Kunlun orogen, which is a typical accretionary orogen associated with the consumption of the Proto-Tethys during the early Paleozoic. The ca.446 Ma Sanshili pluton was formed through interactions between metasomatized mantle wedge-derived oxidized magmas and the lower arc crust, as indicated by high whole-rock Mg#, high Ce4+/Ce3+ ratios (308-861) of ca.446 Ma zircons, and the existence of inherited zircons with ages of 546-472 Ma. The Yirba dioritic to granodioritic pluton was emplaced at 474 +/- 3 Ma. Samples from the Yirba pluton are characterized by high K2O content, higher Mg-# (40-49) than pure crustal melts, slightly higher Y + Nb concentrations, and high Th/Nb ratios, and slightly enriched to depleted Hf-Nd isotopes. Combined with the presence of the 502-531 Ma inherited zircons, the Yirba pluton is suggested to from through differentiation of the metasomatized lithospheric mantle derivedmagmas beneath the juvenile intra-oceanic arc in combination with crustal reworking during regional extensions. The Yirba pluton, together with contemporary A(1)-type granites, thus marks an extension event at ca. 475 Ma in the Western Kunlun orogen. The compiled dataset reveals three magmatic flare-ups at 530-500 Ma, 480-470 Ma, and 445-430 Ma, corresponding to two slab rollback events and the slab break-off after the final closure of the Proto-Tethys. The three episodes of more intensive magmatism are associated with more radiogenic Hf-Nd isotopes and increased Nb/La and Nb/Y ratios, indicating more contributions from intraplate-like sources during lithospheric extensions. Meanwhile, element ratios (La/Yb, Sm/Yb, and Sr/Y) that are sensitive to crustal thickness are also elevated. These phenomena are consistent with rapid juvenile crust generation during extensional stages of accretionary orogens. Our study has also shown that the rate of new crust production is quite uniform for different extensional events. The crustal generation rate during slab break-off is much higher than that during slab rollback, although the proportions of juvenile inputs in granitoids formed during slab rollback are relatively higher. This may reflect extra inputs from partialmelting of oceanic slabs and subducting sediments like those in continental collision zones and/or rapid asthenospheric upwelling coupled with enhanced crust reworking during slab break-off. (C) 2021 Elsevier B.V. All rights reserved.
关键词	Accretionary orogen Crustal growth Slab rollback Western Kunlun Proto-Tethys
DOI	10.1016/j.lithos.2021.106253
收录类别	SCI
语种	英语
资助项目	National Natural Science Foundation of China[41903009] ; National Natural Science Foundation of China[41825007] ; National Natural Science Foundation of China[41703027] ; China Postdoctoral Science Foundation[2018M643711]
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS类目	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:000707450000001
出版者	ELSEVIER
引用统计	被引频次：4[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/176697
专题	深海极端环境与生命过程研究中心
通讯作者	Wu, Kai; Yuan, Honglin
作者单位	1.Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Peoples R China 2.Pilot Natl Lab Marine Sci & Technol Qingdao, Lab Marine Mineral Resources, Qingdao 266237, Peoples R China 3.Chinese Acad Sci, Inst Oceanog, Ctr Deep Sea Res, Qingdao 266071, Peoples R China 4.Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Peoples R China 5.Guangzhou Univ, Key Lab Water Qual & Conservat Pearl River Delta, Minist Educ, Sch Environm Sci & Engn, Guangzhou 510006, Peoples R China 6.Chengdu Univ Technol, Coll Earth Sci, Chengdu 610059, Peoples R China
推荐引用方式 GB/T 7714	Wu, Kai,Zhang, Lipeng,Jiang, Xiaoyan,et al. Continental crust growth during the evolution of accretionary orogens: insights from the early Paleozoic granitoids in the Western Kunlun orogen, Northwest China[J]. LITHOS,2021,398:15.
APA	Wu, Kai.,Zhang, Lipeng.,Jiang, Xiaoyan.,Chen, Yuxiao.,Guo, Jia.,...&Yuan, Honglin.(2021).Continental crust growth during the evolution of accretionary orogens: insights from the early Paleozoic granitoids in the Western Kunlun orogen, Northwest China.LITHOS,398,15.
MLA	Wu, Kai,et al."Continental crust growth during the evolution of accretionary orogens: insights from the early Paleozoic granitoids in the Western Kunlun orogen, Northwest China".LITHOS 398(2021):15.

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