气候变化领域集成服务门户(CCPortal): Protolith origin of the Lanling high-pressure metamorphic terrane in central Qiangtang, Tibet, reveals the subduction of the Permian-Triassic ocean island and abyssal submarine fan in the Paleo-Tethys Ocean

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DOI	10.1016/j.gr.2023.05.002
	Protolith origin of the Lanling high-pressure metamorphic terrane in central Qiangtang, Tibet, reveals the subduction of the Permian-Triassic ocean island and abyssal submarine fan in the Paleo-Tethys Ocean
	Tian, Yang; Liang, Xiao; Wang, Genhou; Tang, Yu; Chen, Shang; Gao, Xi; Yang, Bo; Guo, Zhen; Wang, Yaxi; Wen, Junhao
发表日期	2023
ISSN	1342-937X
EISSN	1878-0571
起始页码	404
结束页码	417
卷号	121
英文摘要	Unraveling the protolith origin of high-pressure and low-temperature (HP-LT) metamorphic rocks is the key to understanding the tectonic evolution of active continental margins. A comprehensive study, including field observations, geochemical analyses and zircon U-Pb geochronological dating, was conducted on the Lanling HP-LT terrane to determine its protolith origin and the presubduction paleogeography of the Paleo-Tethys Ocean. The metabasites can be divided into two geochemical groups: Group A samples exhibit low TiO2 values (1.15-1.81 wt%) and subalkaline basalt affinity with rare earth element (REE) distribution patterns and trace element abundances similar to enriched mid-ocean ridge basalts (EMORB); Group B samples have higher TiO2 values (2.75-3.32 wt%) and show alkaline basalt affinity and ocean island basalt (OIB) geochemical signatures. Lanling metabasites are likely derived from a longdepleted mantle source combined with crustal contamination based on the following evidence: (1) positive eNd(t) values (+4.8 to +5.6) and a scattered distribution of Isr(t) values (0.704684 to 0.710999), (2) abundant Precambrian zircon grains, and (3) a volcanic arc trend in the tectonic discrimination diagram. Zircon U-Pb dating yields a timing of ca. 272-241 Ma for the protolith age of the Lanling eclogites. The protoliths of the OIB- and E-MORB-type metabasites in Lanling are postulated to be ocean island magmatites and basaltic crust of the Paleo-Tethys Ocean, respectively. Moreover, the Lanling quartzose schists contain only ancient detrital zircons with ages of >500 Ma and show protolith lithostratigraphy and provenance similar to those of the late Paleozoic clastic flysch in the South Qiangtang block (SQB). Based on the above observations and other geological evidence, a hypothetical model of the Permian- Triassic ocean island and adjacent abyssal submarine fan in the Paleo-Tethys Ocean is proposed to explain the protolith origin of the Lanling HP-LT terrane and the presubduction paleogeography in central Qiangtang. & COPY; 2023 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
关键词	HP-LT rocks central Qiangtang Protolith Provenance Geochemistry Paleo-Tethys Ocean
英文关键词	CYCLADIC BLUESCHIST UNIT; NORTHERN TIBET; TECTONIC EVOLUTION; ISOTOPIC CHARACTERISTICS; GEOLOGICAL SIGNIFICANCE; CONTINENTAL SUBDUCTION; SOUTHERN QIANGTANG; WESTERN TIANSHAN; ZIRCON; PROVENANCE
WOS研究方向	Geosciences, Multidisciplinary
WOS记录号	WOS:001013575600001
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/283412
作者单位	China University of Geosciences - Beijing; China University of Geosciences - Beijing; Southern University of Science & Technology
推荐引用方式 GB/T 7714	Tian, Yang,Liang, Xiao,Wang, Genhou,et al. Protolith origin of the Lanling high-pressure metamorphic terrane in central Qiangtang, Tibet, reveals the subduction of the Permian-Triassic ocean island and abyssal submarine fan in the Paleo-Tethys Ocean[J],2023,121.
APA	Tian, Yang.,Liang, Xiao.,Wang, Genhou.,Tang, Yu.,Chen, Shang.,...&Wen, Junhao.(2023).Protolith origin of the Lanling high-pressure metamorphic terrane in central Qiangtang, Tibet, reveals the subduction of the Permian-Triassic ocean island and abyssal submarine fan in the Paleo-Tethys Ocean.GONDWANA RESEARCH,121.
MLA	Tian, Yang,et al."Protolith origin of the Lanling high-pressure metamorphic terrane in central Qiangtang, Tibet, reveals the subduction of the Permian-Triassic ocean island and abyssal submarine fan in the Paleo-Tethys Ocean".GONDWANA RESEARCH 121(2023).