气候变化领域集成服务门户(CCPortal): Lithospheric extension of the accretionary wedge: An example from the Lanling high-pressure metamorphic terrane in Central Qiangtang, Tibet

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DOI	10.1130/B36476.1
	Lithospheric extension of the accretionary wedge: An example from the Lanling high-pressure metamorphic terrane in Central Qiangtang, Tibet
	Liang, Xiao; Wang, Genhou; Cao, Wentao; Forster, Marnie A.; Lister, Gordon S.; Gao, Xi; Du, Jinxue; Li, Jiabin; Li, Jinsheng; Wang, Yaxi
发表日期	2023
ISSN	0016-7606
EISSN	1943-2674
起始页码	1688
结束页码	1708
卷号	135 期号:7-8
英文摘要	Deciphering the exhumation mechanism of high-pressure-low-temperature (HP-LT) metamorphic rocks can provide important insights into the tectonic evolution of oceanic subduction zones at active continental mar-gins. Here, we present a multidisciplinary study examining the exhumation tectonics of the Permo-Triassic eclogite-bearing HP -LT terranes of the Central Qiangtang meta-morphic belt (CQMB) in the central Tibetan Plateau. Field geological relations and mi-croscopic observations show that the HP-LT rocks in the Lanling area are separated from the epimetamorphic late Paleozoic ophiolite melange of the hanging wall by low-angle detachment faults and primarily exhibit five stages of deformation. The HP-LT ter-ranes were exhumed as a metamorphic core complex and show pervasive synexhumation top-to-the-SW and-S shear structures. The results of the petrological and mineralogical analysis and pseudosection modeling of ret-rograde eclogites indicate that these rocks are characterized by synexhumation mineral growth pulses with hairpin-type decompres-sional pressure-temperature trajectories. A compilation of previous geochronologi-cal data and our 40Ar/39Ar dating results of synexhumation minerals and shear bands in HP-LT rocks indicates continuous exhuma-tion at ca. 244-215 Ma prior to the continen-tal collision between the North Qiangtang Block (NQB) and South Qiangtang Block. Moreover, the CQMB is likely an autoch-thonous accretionary wedge resulting from northward subduction of the Paleo-Tethys Ocean beneath the NQB. Combined with ca. 243-230 Ma mantle upwelling to the north of Lanling, we infer that the CQMB, namely, the accretionary wedge of the Paleo-Tethys Ocean, experienced Middle-Late Tri-assic lithospheric extension in the NW-SE direction.
英文关键词	HF ISOTOPIC COMPOSITIONS; CORE COMPLEXES; NORTHERN TIBET; U-PB; CRUSTAL STRUCTURE; CONTINENTAL SUBDUCTION; TECTONIC EVOLUTION; SOUTHERN QIANGTANG; AGE SPECTRA; AEGEAN SEA
WOS研究方向	Geosciences, Multidisciplinary
WOS记录号	WOS:001051756900004
来源期刊	GEOLOGICAL SOCIETY OF AMERICA BULLETIN
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283393
作者单位	China University of Geosciences - Beijing; China University of Geosciences - Beijing; State University of New York (SUNY) System; SUNY Fredonia; Australian National University
推荐引用方式 GB/T 7714	Liang, Xiao,Wang, Genhou,Cao, Wentao,et al. Lithospheric extension of the accretionary wedge: An example from the Lanling high-pressure metamorphic terrane in Central Qiangtang, Tibet[J],2023,135(7-8).
APA	Liang, Xiao.,Wang, Genhou.,Cao, Wentao.,Forster, Marnie A..,Lister, Gordon S..,...&Wang, Yaxi.(2023).Lithospheric extension of the accretionary wedge: An example from the Lanling high-pressure metamorphic terrane in Central Qiangtang, Tibet.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,135(7-8).
MLA	Liang, Xiao,et al."Lithospheric extension of the accretionary wedge: An example from the Lanling high-pressure metamorphic terrane in Central Qiangtang, Tibet".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 135.7-8(2023).