气候变化领域集成服务门户(CCPortal): Recycling of subducted Indian continental crust constrained by late Cretaceous mafic dykes in Central Lhasa block of the Tibetan plateau

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DOI	10.1016/j.lithos.2023.107276
	Recycling of subducted Indian continental crust constrained by late Cretaceous mafic dykes in Central Lhasa block of the Tibetan plateau
	Hao, Lu-Lu; Kerr, Andrew C.; Wang, Qiang; Ma, Lin; Qi, Yue; Xiao, Ming; Ou, Quan
发表日期	2023
ISSN	0024-4937
EISSN	1872-6143
卷号	454
英文摘要	The question of whether subducted continental crust can be recycled into post-collisional magmatism in continental collisional zones remains controversial. Post-collisional mantle-derived ultrapotassic rocks are widespread in western part of central Lhasa block (WCL) of the Tibet-Himalaya orogen and show arc-type trace-element signatures and very enriched Sr-Nd isotopes, which have been explained by the recycling of subducted Indian continental crust. However, due to the lack of late Cretaceous mafic magmatism in the WCL, the nature of the ancient subcontinental lithospheric mantle (SCLM) beneath the WCL has not been well constrained. It is therefore still unclear whether the enriched components of these ultrapotassic rocks were derived from subducted Indian continental crust or inherited from the ancient SCLM. Here we report the mafic dykes from the TangraYumco area in the WCL, which formed at similar to 90 Ma (whole-rock Ar-40-Ar-39, and zircon and titanite U-Pb ages). The diabase-porphyrites and diorite-porphyrites are similar to intraplate Nb-enriched basalts and magnesium adakitic rocks, respectively. This rock association reveals the lithospheric foundering process. Furthermore, the diabase-porphyrites generated by the interaction between the ancient SCLM and asthenosphere provide important constraints on the nature of the ancient SCLM, which shows distinct Nd isotopes to the postcollisional ultrapotassic rocks. In addition, the NW Lhasa block was in a rear-arc environment since the late Cretaceous and thus this SCLM was not significantly influenced by the ongoing northward subduction of the Indus-YarlungZangbu Neo-Tethys ocean. Finally, we propose that the post-collisional ultrapotassic rocks cannot be sourced from the ancient SCLM, but instead were derived from a relatively depleted mantle (e.g., juvenile lithospheric mantle) metasomatized by subducted Indian continental crust. Thus, this study confirms the recycling of subducted continental materials in continental collisional orogens.
关键词	Lithosphere-asthenosphere interaction Late Cretaceous mafic dykes Adakitic rocks Tibetan plateau Indian continental subduction Crustal recycling
英文关键词	SOUTHERN TIBET; ULTRAPOTASSIC ROCKS; TECTONIC EVOLUTION; INTRUSIVE ROCKS; NEOTETHYAN SLAB; MANTLE; MAGMATISM; COLLISION; BENEATH; AREA
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:001046885000001
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/283638
作者单位	Chinese Academy of Sciences; Guangzhou Institute of Geochemistry, CAS; Chinese Academy of Sciences; Cardiff University; Chengdu University of Technology
推荐引用方式 GB/T 7714	Hao, Lu-Lu,Kerr, Andrew C.,Wang, Qiang,et al. Recycling of subducted Indian continental crust constrained by late Cretaceous mafic dykes in Central Lhasa block of the Tibetan plateau[J],2023,454.
APA	Hao, Lu-Lu.,Kerr, Andrew C..,Wang, Qiang.,Ma, Lin.,Qi, Yue.,...&Ou, Quan.(2023).Recycling of subducted Indian continental crust constrained by late Cretaceous mafic dykes in Central Lhasa block of the Tibetan plateau.LITHOS,454.
MLA	Hao, Lu-Lu,et al."Recycling of subducted Indian continental crust constrained by late Cretaceous mafic dykes in Central Lhasa block of the Tibetan plateau".LITHOS 454(2023).