气候变化领域集成服务门户(CCPortal): Growth of the continental crust induced by slab rollback in subduction zones: Evidence from Middle Jurassic arc andesites in central Tibet

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DOI	10.1016/j.gr.2023.01.001
	Growth of the continental crust induced by slab rollback in subduction zones: Evidence from Middle Jurassic arc andesites in central Tibet
	Hu, Wan-Long; Wang, Qiang; Yang, Jin-Hui; Hao, Lu-Lu; Wang, Jun; Qi, Yue; Yang, Zong-Yong; Sun, Peng
发表日期	2023
ISSN	1342-937X
EISSN	1878-0571
起始页码	8
结束页码	22
卷号	117
英文摘要	Andesitic rocks have similar compositions to average continental crust and have played a central role in improving our understanding of the formation and evolution of the continental crust. Here we present data for andesites from the Jiaqiong area of the Bangong-Nujiang suture zone (BNSZ), Central Tibet. LA-ICP-MS zircon U-Pb ages demonstrate that these andesites were generated during the Middle Jurassic (169-164 Ma). The Jiaqiong andesites have variable Mg-# (molar 100 x Mg/[Mg + Fe] = 35-63) values, and Cr (3.02-175 ppm) and Ni (5.70-47.7 ppm) contents. These andesitic rocks are enriched in light rare earth elements (REEs) ([La/Yb](N) = 5.2-14.6) and yield relatively flat heavy REE patterns ([Gd/Yb](N) = 1.4-2.1) with negative Ta, Nb, and Ti anomalies. They also have moderately high initial Sr-87/Sr-86 (0.7077-0.7092) ratios and variable negative epsilon(Nd)(t) (-11.0 to -3.3) and zircon epsilon(Hf)(t) (-13.7 to + 2.1) values. These geochemical characteristics suggest that the Jiaqiong andesites were most probably produced by partial melting of melange rocks. Combining our data with the regional geology, particularly that of nearby ophiolites and Jurassic andesitic rocks, we conclude that the formation of these andesites was triggered by asthenospheric upwelling and hot corner flow caused by the rollback of the northward-subducting Bangong-Nujiang Tethyan oceanic lithospheric slab during the Middle Jurassic. The melanges provided the material for the formation of andesites, and probably make a substantial contribution to the vertical growth of the continental crust in subduction zones. (c) 2023 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
关键词	Middle Jurassic Melange diapir melting Crustal growth Slab rollback Central Tibet
英文关键词	NUJIANG SUTURE ZONE; U-PB GEOCHRONOLOGY; HIGH-MG ANDESITES; TRACE-ELEMENTS; ISOTOPIC COMPOSITIONS; GEOCHEMICAL EVIDENCE; INITIAL SUBDUCTION; OPHIOLITIC MELANGE; SOUTHERN QIANGTANG; RIDGE SUBDUCTION
WOS研究方向	Geosciences, Multidisciplinary
WOS记录号	WOS:000925285100001
来源期刊	GONDWANA RESEARCH
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/282910
作者单位	Chinese Academy of Sciences; Guangzhou Institute of Geochemistry, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Chinese Academy of Sciences; Institute of Geology & Geophysics, CAS; Chinese Academy of Sciences; Guiyang Institute of Geochemistry, CAS; Chinese Academy of Sciences
推荐引用方式 GB/T 7714	Hu, Wan-Long,Wang, Qiang,Yang, Jin-Hui,et al. Growth of the continental crust induced by slab rollback in subduction zones: Evidence from Middle Jurassic arc andesites in central Tibet[J],2023,117.
APA	Hu, Wan-Long.,Wang, Qiang.,Yang, Jin-Hui.,Hao, Lu-Lu.,Wang, Jun.,...&Sun, Peng.(2023).Growth of the continental crust induced by slab rollback in subduction zones: Evidence from Middle Jurassic arc andesites in central Tibet.GONDWANA RESEARCH,117.
MLA	Hu, Wan-Long,et al."Growth of the continental crust induced by slab rollback in subduction zones: Evidence from Middle Jurassic arc andesites in central Tibet".GONDWANA RESEARCH 117(2023).