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DOI	10.1130/B35091.1
	Circa 2.5 Ga granitoids in the eastern North China craton: Melting from ca. 2.7 Ga accretionary crust
	Li Y.; Zheng J.; Xiao W.; Wang G.; Brouwer F.M.
发表日期	2020
ISSN	167606
起始页码	817
结束页码	834
卷号	132 期号:2021-03-04
英文摘要	The Neoarchean crust-mantle interaction and crustal evolution of the North China craton are controversial and are instructive of the processes of continental crust growth and cratonic evolution. We present here a systematic study of the petrology, geochemistry, and geochronology of Neoarchean granitoids from the eastern North China craton to elucidate their petrogenesis and tectonic setting. The rocks were collected from the Jielingkou, Anziling, and Qinhuangdao plutons, and an amphibole-monzoporphyry dike in the Qinhuangdao pluton. Samples from the Jielingkou pluton, consisting dominantly of monzodiorite and diorite with minor monzonite and granodiorite, contain 52.2-64.4 wt% SiO2, 2.46-4.52 wt% MgO (Mg# = 0.41-0.54), 3.76-5.77 wt% Na2O, and K2O/Na2O ratios of 0.29-0.71. The Anziling pluton samples, comprising syenite and monzonite, display slightly higher SiO2 (60.9-66.7 wt%) and K2O/Na2O ratios (0.70-1.11), but lower MgO (1.54-2.33 wt%) and Mg# (0.40-0.47) values, compared to the Jielingkou rocks. The Qinhuangdao pluton samples, consisting mainly of granite and minor syenite and granodiorite, with some diorite and monzoporphyry dikes, are characterized by the highest SiO2 values (75.7-76.9 wt%) and K2O/Na2O ratios (0.73-1.41) and lowest MgO content (0.14-0.32 wt%) among the studied samples. The amphibole-monzoporphyry dike has intermediate SiO2 (56.3 wt%), high MgO (3.79 wt%), Na2O (5.55 wt%), and Mg# (0.45), and low K2O/Na2O ratio (0.66). Zircon U-Pb laser-ablation-inductively coupled plasma-mass spectrometry dating showed that all plutons have a ca. 2.5 Ga crystallization age. Zircon crystals have mildly positive εHf(t) values (+0.24 to +5.45) and a depleted mantle model age (TDM1) of ca. 2.7 Ga. We interpret the granitoid rocks as sanukitoid-related, Closepet-type granites, potassium-rich adakites, and potassium-rich granitoid rocks that crystallized in the late Neoarchean (2.5 Ga) and were derived from partial melting of mantle peridotite that was metasomatized with the addition of slab melt, thickened alkali-rich juvenile lower crust and juvenile metamorphosed tonalitic rocks. Mantle plume activity ca. 2.7 Ga is thought to have been responsible for the early Neoarchean tectono-thermal event in the eastern North China craton. This activity resulted in a major crustal accretion period in the craton, with subordinate crustal reworking at its margins. A steep subduction regime between ca. 2.55 Ga and ca. 2.48 Ga led to the remelting of older crustal material, with subordinate crustal accretion by magma upwelling from a depleted mantle source resulting in late Neoarchean underplating. This crustal reworking and underplating resulted in the widespread ca. 2.5 Ga plutons in the eastern North China craton. Continental crust growth in the North China craton thus occurred in multiple stages, in response to mantle plume activity, as well as protracted subduction-related granitoid magmatism during the Neoarchean. © 2019 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184811
作者单位	School of Earth Sciences, State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, 430074, China; State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; Geology and Geochemistry Group, Department of Earth Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, Netherlands
推荐引用方式 GB/T 7714	Li Y.,Zheng J.,Xiao W.,et al. Circa 2.5 Ga granitoids in the eastern North China craton: Melting from ca. 2.7 Ga accretionary crust[J],2020,132(2021-03-04).
APA	Li Y.,Zheng J.,Xiao W.,Wang G.,&Brouwer F.M..(2020).Circa 2.5 Ga granitoids in the eastern North China craton: Melting from ca. 2.7 Ga accretionary crust.Bulletin of the Geological Society of America,132(2021-03-04).
MLA	Li Y.,et al."Circa 2.5 Ga granitoids in the eastern North China craton: Melting from ca. 2.7 Ga accretionary crust".Bulletin of the Geological Society of America 132.2021-03-04(2020).