气候变化领域集成服务门户(CCPortal): Origin and tectonic significance of Eocene sodic lamprophyres in the Southern Qiangtang Orogen, Tibet

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DOI	10.1016/j.jseaes.2023.105629
	Origin and tectonic significance of Eocene sodic lamprophyres in the Southern Qiangtang Orogen, Tibet
	Qin, Zhipeng; Du, Qiuding; Zhang, Gangyang; Duo, Ji; Li, Mingli; Huang, Cheng
发表日期	2023
ISSN	1367-9120
EISSN	1878-5786
卷号	250
英文摘要	Sodic lamprophyres have important implications on crust-mantle interactions and tectonic evolutionary pro-cesses. This study presents detailed mineralogical and geochemical dataset to elucidate the origin of the sodic lamprophyres in the Gumu area and geodynamic implications for the Southern Qiangtang Orogen. The Gumu sodic lamprophyres (GSLs)with a zircon 206Pb/238U age of 42 Ma are primarily composed of amphibole (45%-57%), plagioclase (20%-30%) and clinopyroxene (10%). They exhibit sodic alkaline series affinity with high Na2O content (3.65 wt% on average) and Na2O/K2O ratio (2.26 on average). The GSLs show OIB-like geochemistry, including enrichment in LREEs and LILEs, positive zircon epsilon Hf(t) (+1.16 to + 7.39), slightly higher epsilon Nd(t) (-0.38 to + 0.9), and lower initial 87Sr/86Sr (0.70522 to 0.70589) values), and they were likely derived by the partial melting of an asthenosphere mantle source previously modified by slab fluids under spinel-garnet facies at about 1,321 degrees C-1,399 degrees C and 2.1-2.7 GPa. Integrating published regional contemporaneous mafic-intermediate rocks from the Qiangtang Orogen and this study, we propose that the GSLs formed in an intracontinental setting during asthenosphere upwelling triggered by delamination of the lithosphere. The GSLs provide new perspective for reconstructing the Eocene tectonomagmatic process in the Southern Qiangtang Orogen.
关键词	Sodic lamprophyres Asthenosphere upwelling Delamination Southern Qiangtang Orogen Eocene
英文关键词	EAST-WEST EXTENSION; U-PB AGE; VOLCANIC-ROCKS; TRACE-ELEMENT; NORTHERN TIBET; MANTLE; GEOCHEMISTRY; EVOLUTION; MAGMATISM; TERRANE
WOS研究方向	Geosciences, Multidisciplinary
WOS记录号	WOS:000972400800001
来源期刊	JOURNAL OF ASIAN EARTH SCIENCES
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283053
作者单位	Chengdu University of Technology; Ministry of Natural Resources of the People's Republic of China; Chengdu University of Technology; Southwest Petroleum University; Southwest Petroleum University; Southwest Petroleum University
推荐引用方式 GB/T 7714	Qin, Zhipeng,Du, Qiuding,Zhang, Gangyang,et al. Origin and tectonic significance of Eocene sodic lamprophyres in the Southern Qiangtang Orogen, Tibet[J],2023,250.
APA	Qin, Zhipeng,Du, Qiuding,Zhang, Gangyang,Duo, Ji,Li, Mingli,&Huang, Cheng.(2023).Origin and tectonic significance of Eocene sodic lamprophyres in the Southern Qiangtang Orogen, Tibet.JOURNAL OF ASIAN EARTH SCIENCES,250.
MLA	Qin, Zhipeng,et al."Origin and tectonic significance of Eocene sodic lamprophyres in the Southern Qiangtang Orogen, Tibet".JOURNAL OF ASIAN EARTH SCIENCES 250(2023).