Revisiting the "C-type adakites" of the Lower Yangtze River Belt, central eastern China: In-situ zircon Hf-O isotope and geochemical constraints

doi:10.1016/j.chemgeo.2013.02.024

	Revisiting the "C-type adakites" of the Lower Yangtze River Belt, central eastern China: In-situ zircon Hf-O isotope and geochemical constraints
	Li, Xian-Hua 1; Li, Zheng-Xiang 2,3; Li, Wu-Xian 4; Wang, Xuan-Ce 2,3; Gao, Yuya 1
刊名	CHEMICAL GEOLOGY
	2013-05-08
卷号	345 页码:1-15
关键词	Adakites Mineralization Zircon Hf-o Isotopes Yangtze River China Flat-slab
ISSN号	0009-2541
DOI	10.1016/j.chemgeo.2013.02.024
文献子类	Article
英文摘要	Adakites, or adakitic rocks, in a broad sense, have been used to describe a large range of igneous rocks with the common feature of high Sr/Y and La/Yb ratios that can be achieved though different mechanisms. Among them, the continental, or C-type, adakitic rocks are particularly controversial in terms of their sources and genesis. In this study we revisit both Cu-Au ore-bearing and barren "C-type adakitic rocks" in the Lower Yangtze River Belt (LYRB) of central eastern China, including comprehensive analyses of their in-situ zircon Hf-O isotopes, whole-rock geochemistry and Sr-Nd isotopes. These "C-type adakitic rocks" consist of monzodiorite, granodiorite and quartz monzonite that are classified as shoshonitic to high-K calc-alkaline series according to their chemical compositions. They are characteristically high in potassium (K2O = 2.4-4.5%, K2O/Na2O = 0.6-1.3), with continental crust-like isotopic compositions, i.e., whole-rock epsilon Nd(T) = -3.9 to -7.7, initial Sr-87/Sr-86 = 0.7054-0.7085, zircon epsilon Hf(T) = 0 to -11, and delta O-18 = 6%. to 9%.. The ore-bearing and barren rocks are cogenetic Fractional crystallization of hornblende, titanite, magnetite and apatite played a major role in their chemical variations, with the ore-bearing rocks being more felsic (SiO2 = 633-69.6%) and higher in Sr/Y (41.2-75.6) than the barren rocks (SiO2 = 573-65.0%, Sr/Y = 30.4-51.8). All these geochemical and isotopic features, in combination with regional geological data, suggest that the LYRB "C-type adakitic rocks" were unlikely to have been formed by melting of either a thickened and/or delaminated lower continental crust, or an altered oceanic crust as previously thought. These rocks are in general akin in geochemistry and isotopes to the Archean sanukitoids and the Setouchi high-Mg andesites in Japan, and are thus interpreted as being formed by melting of an enriched mantle source metasomatized by dewatering from a delaminated flat-slab. The flat subduction of an oceanic plateau and its subsequent delamination and foundering since the early Mesozoic beneath southeastern China (Li and Li, 2007) thus not only explain the temporal and spatial propagation of widespread Yanshanian igneous rocks regionally since ca. 195 Ma, but also the formation of a series of enigmatic "adakitic" rocks in the region, including the LYRB potassium-rich rocks that were inappropriately called the "C-type adakitic rock" by previous workers. (c) 2013 Elsevier B.V. All rights reserved.
WOS关键词	MC-ICP-MS ; U-PB AGES ; SOUTH CHINA ; INTRUSIVE ROCKS ; SOUTHEASTERN CHINA ; RIDGE SUBDUCTION ; IGNEOUS ROCKS ; LITHOSPHERIC EXTENSION ; CONTINENTAL-MARGIN ; METALLOGENIC BELT
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000319642400001
资助机构	Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Academy of Sciences(KZCX2-YW-15-2) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Chinese Ministry of Science and Technology(2012CB416702) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799) ; Australian Research Council(DP110104799)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/86296]
专题	中国科学院地质与地球物理研究所
通讯作者	Li, Xian-Hua
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 2.Curtin Univ, ARC Ctr Excellence Core Crust Fluid Syst, Perth, WA 6845, Australia 3.Curtin Univ, Inst Geosci Res, Dept Appl Geol, Perth, WA 6845, Australia 4.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China
推荐引用方式 GB/T 7714	Li, Xian-Hua,Li, Zheng-Xiang,Li, Wu-Xian,et al. Revisiting the "C-type adakites" of the Lower Yangtze River Belt, central eastern China: In-situ zircon Hf-O isotope and geochemical constraints[J]. CHEMICAL GEOLOGY,2013,345:1-15.
APA	Li, Xian-Hua,Li, Zheng-Xiang,Li, Wu-Xian,Wang, Xuan-Ce,&Gao, Yuya.(2013).Revisiting the "C-type adakites" of the Lower Yangtze River Belt, central eastern China: In-situ zircon Hf-O isotope and geochemical constraints.CHEMICAL GEOLOGY,345,1-15.
MLA	Li, Xian-Hua,et al."Revisiting the "C-type adakites" of the Lower Yangtze River Belt, central eastern China: In-situ zircon Hf-O isotope and geochemical constraints".CHEMICAL GEOLOGY 345(2013):1-15.