气候变化领域集成服务门户(CCPortal): Early Jurassic lithospheric delamination in the Amdo microcontinent, central Tibet: Inferred from coeval OIB- and MORB-like gabbros

CCPortal

DOI	10.1016/j.lithos.2023.107314
	Early Jurassic lithospheric delamination in the Amdo microcontinent, central Tibet: Inferred from coeval OIB- and MORB-like gabbros
	Zhai, Qing-Guo; Hu, Pei-Yuan; Tang, Yue; Liu, Yi-Ming; Wang, Wei
发表日期	2023
ISSN	0024-4937
EISSN	1872-6143
卷号	456
英文摘要	The Bangong-Nujiang suture zone (BNSZ) is the remnants of the Meso-Tethyan main oceanic basin in the Tibetan plateau. It is noted that several microcontinents, e.g., Amdo and Jiayuqiao, occur within the Meso-Tethyan ocean basin. These microcontinents were strongly reworked associated with the subduction and closure of this ancient ocean, thus they play a key role in understanding the evolution of this ocean. In this contribution, we report newly documented Early Jurassic gabbros (ca. 182-175 Ma) from the Amdo microcontinent in the middle segment of the BNSZ. The gabbros can be subdivided into two groups, i.e., OIB (ocean island basalt) and MORB (mid-ocean ridge basalt) groups. The OIB-group gabbros are characterized by highly enriched Nd-Hf isotopic characteristics (zircon eHf(t) = 11.7 to 8.9; whole-rock eNd(t) = 11.0 to 10.1). They are geochemically similar to OIB and are interpreted to be products of the partial melting of a relatively deep mantle source (> 85 km) and subsequent continental crustal inputting. The MORB-group gabbros belong to the tholeiitic series and have similar compositions to those of MORB. They were most likely derived from a depleted mantle source (zircon eHf(t) = +3.7 to +16.5; whole-rock eNd(t) = +4.9 to +8.1) in a relatively shallow depth (< 85 km). Integrating previous studies with the data presented in this contribution, we suggest that the generation of coeval OIB- and MORB-like gabbros are related to lithospheric delamination after the Qiangtang-Amdo collision and the closure of the Bangong-Nujiang ocean basin. This result will give new constraint on the evolution of the MesoTethyan Ocean.
关键词	Meso-Tethyan ocean Zircon U - Pb dating Nd-Hf isotope Geochemistry Petrogenesis
英文关键词	U-PB GEOCHRONOLOGY; HF ISOTOPIC COMPOSITIONS; NUJIANG SUTURE ZONE; NORTHERN TIBET; TECTONIC EVOLUTION; OPHIOLITIC MELANGE; CONTINENTAL-CRUST; BASEMENT ROCKS; TRACE-ELEMENT; LHASA TERRANE
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:001062273300001
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/283427
作者单位	China Geological Survey; Institute of Geology, Chinese Academy of Geological Sciences; Chinese Academy of Geological Sciences; Guizhou University; China Geological Survey; Chinese Academy of Geological Sciences; Institute of Geology, Chinese Academy of Geological Sciences
推荐引用方式 GB/T 7714	Zhai, Qing-Guo,Hu, Pei-Yuan,Tang, Yue,et al. Early Jurassic lithospheric delamination in the Amdo microcontinent, central Tibet: Inferred from coeval OIB- and MORB-like gabbros[J],2023,456.
APA	Zhai, Qing-Guo,Hu, Pei-Yuan,Tang, Yue,Liu, Yi-Ming,&Wang, Wei.(2023).Early Jurassic lithospheric delamination in the Amdo microcontinent, central Tibet: Inferred from coeval OIB- and MORB-like gabbros.LITHOS,456.
MLA	Zhai, Qing-Guo,et al."Early Jurassic lithospheric delamination in the Amdo microcontinent, central Tibet: Inferred from coeval OIB- and MORB-like gabbros".LITHOS 456(2023).