Overlapping Sr-Nd-Hf-O isotopic compositions in Permian mafic enclaves and host granitoids in Alxa Block, NW China: Evidence for crust-mantle interaction and implications for the generation of silicic igneous provinces

doi:10.1016/j.lithos.2015.05.016

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 岩石圈演化国家重点实验室

	Overlapping Sr-Nd-Hf-O isotopic compositions in Permian mafic enclaves and host granitoids in Alxa Block, NW China: Evidence for crust-mantle interaction and implications for the generation of silicic igneous provinces
	Dan, Wei 1,2; Wang, Qiang 1,3; Wang, Xuan-Ce 4; Liu, Yu 2; Wyman, Derek A.5; Liu, Yong-Sheng 6
刊名	LITHOS
	2015-08-01
卷号	230 页码:133-145
关键词	Enclave Zircon Hf-o Isotopes Magma Mixing Crustal Growth Permian Alxa Block
DOI	10.1016/j.lithos.2015.05.016
文献子类	Article
英文摘要	In general, the mantle provides heat and/or material for the generation of the silicic igneous provinces (SIPs). The rarity of mafic microgranular enclaves (MMEs), however, hampers understanding of the mantle's role in generating SIPs and the process of crust-mantle interaction. The widespread distributed MMEs in the newly reported Alxa SIP provide an opportunity to study these processes. This study integrates in situ zircon U-Pb age and Hf-O isotope analyses, whole-rock geochemistry and Sr-Nd isotope results for the MMES and host granitoids in the Alxa Block. SIMS zircon U-Pb dating reveals that there are two generations of MMEs and host granitoids. The MMEs in the Bayannuoergong batholith were formed at ca. 278 Ma, similar to the age (280 Ma) of host granitoids, and the MMEs and host granitoids in the Yamaitu pluton were formed at ca. 272-270 Ma. All MMEs have relatively low SiO2 (50.7-61.4 wt.%) and Th (0.8-2.8 ppm), but relatively high MgO (2.6-4.9 wt.%), Cr (23-146 ppm) and Ni (6-38 ppm) contents compared to the host granitoids, with SiO2 (63.6-77.5 wt.%), Th (5.2-41 ppm), MgO (0.23-2.1 wt.%), Cr (10-38 ppm) and Ni (5-14 ppm). All MMEs have whole rock Sr-Nd and zircon Hf-O isotope compositions similar to their corresponding host granitoids. The 280 Ma MMEs have lower whole rock epsilon(Nd)(t) (-13.5) and higher initial Sr-87/Sr-86 values (0.7095) and zircon delta O-18 values (6.3 parts per thousand) compared to the epsilon(Nd)(t) (-11.5), initial Sr-87/Sr-86 values (0.7070) and zircon delta O-18 values (5.6 parts per thousand) of the 270 Ma MMEs. The occurrences of quartz xenocysts, K-feldspar megacrysts, corroded feldspars and acicular apatites indicate that the MMES are the products of the mixing between mantle- and crust-derived magmas. The striking similarities in the zircon Hf-O isotopic compositions in both MME-host granitoid pairs indicate that the granitoids and MMEs have similar sources. The granitoids are proposed to be mainly sourced from magmas generated by remelting of newly formed mafic rocks, which were generated by earlier basaltic magmas underplating, or injected into, the mid-to-lower crust. The continuing basaltic magma underplating and remelting of earlier-formed mafic rocks in the mid-to-lower crust indicate that the mantle provided both heat and materials for the generation of the Alxa SIP. The scenario also suggests that basaltic magma underplating may play a more important role in the crustal growth in the Alxa SIP than it is generally recognized in other SIPs. (C) 2015 Elsevier B.V. All rights reserved.
WOS关键词	ZIRCON U-PB ; UNDERPLATED BASALTIC CRUST ; SIERRA-NEVADA BATHOLITH ; WESTERNMOST NORTH CHINA ; BIMODAL VOLCANIC-ROCKS ; LACHLAN FOLD BELT ; MICROGRANULAR ENCLAVES ; SOUTH CHINA ; PALEOPROTEROZOIC EVOLUTION ; MELT GENERATION
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
WOS记录号	WOS:000357839000010
资助机构	Chinese Academy of Sciences(XDB03010600) ; Chinese Academy of Sciences(XDB03010600) ; Chinese Academy of Sciences(XDB03010600) ; Chinese Academy of Sciences(XDB03010600) ; Major State Basic Research Program (973 Program) of the People's Republic of China(2011CB808906) ; Major State Basic Research Program (973 Program) of the People's Republic of China(2011CB808906) ; Major State Basic Research Program (973 Program) of the People's Republic of China(2011CB808906) ; Major State Basic Research Program (973 Program) of the People's Republic of China(2011CB808906) ; National Natural Science Foundation of China(41025006 ; National Natural Science Foundation of China(41025006 ; National Natural Science Foundation of China(41025006 ; National Natural Science Foundation of China(41025006 ; China Postdoctoral Science Foundation(2013M531880) ; China Postdoctoral Science Foundation(2013M531880) ; China Postdoctoral Science Foundation(2013M531880) ; China Postdoctoral Science Foundation(2013M531880) ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS)(Y234021001) ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS)(Y234021001) ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS)(Y234021001) ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS)(Y234021001) ; 41303018 ; 41303018 ; 41303018 ; 41303018 ; 41421062) ; 41421062) ; 41421062) ; 41421062) ; Chinese Academy of Sciences(XDB03010600) ; Chinese Academy of Sciences(XDB03010600) ; Chinese Academy of Sciences(XDB03010600) ; Chinese Academy of Sciences(XDB03010600) ; Major State Basic Research Program (973 Program) of the People's Republic of China(2011CB808906) ; Major State Basic Research Program (973 Program) of the People's Republic of China(2011CB808906) ; Major State Basic Research Program (973 Program) of the People's Republic of China(2011CB808906) ; Major State Basic Research Program (973 Program) of the People's Republic of China(2011CB808906) ; National Natural Science Foundation of China(41025006 ; National Natural Science Foundation of China(41025006 ; National Natural Science Foundation of China(41025006 ; National Natural Science Foundation of China(41025006 ; China Postdoctoral Science Foundation(2013M531880) ; China Postdoctoral Science Foundation(2013M531880) ; China Postdoctoral Science Foundation(2013M531880) ; China Postdoctoral Science Foundation(2013M531880) ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS)(Y234021001) ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS)(Y234021001) ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS)(Y234021001) ; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS)(Y234021001) ; 41303018 ; 41303018 ; 41303018 ; 41303018 ; 41421062) ; 41421062) ; 41421062) ; 41421062)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/62322]
专题	地质与地球物理研究所_岩石圈演化国家重点实验室
作者单位	1.Chinese Acad Sci, State Key Lab Isotope Geochem, Guangzhou Inst Geochem, Guangzhou 510640, Guangdong, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 3.CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China 4.Curtin Univ, Dept Appl Geol, Perth, WA 6845, Australia 5.Univ Sydney, Sch Geosci, Sydney, NSW 2006, Australia 6.China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Fac Earth Sci, Wuhan 430074, Peoples R China
推荐引用方式 GB/T 7714	Dan, Wei,Wang, Qiang,Wang, Xuan-Ce,et al. Overlapping Sr-Nd-Hf-O isotopic compositions in Permian mafic enclaves and host granitoids in Alxa Block, NW China: Evidence for crust-mantle interaction and implications for the generation of silicic igneous provinces[J]. LITHOS,2015,230:133-145.
APA	Dan, Wei,Wang, Qiang,Wang, Xuan-Ce,Liu, Yu,Wyman, Derek A.,&Liu, Yong-Sheng.(2015).Overlapping Sr-Nd-Hf-O isotopic compositions in Permian mafic enclaves and host granitoids in Alxa Block, NW China: Evidence for crust-mantle interaction and implications for the generation of silicic igneous provinces.LITHOS,230,133-145.
MLA	Dan, Wei,et al."Overlapping Sr-Nd-Hf-O isotopic compositions in Permian mafic enclaves and host granitoids in Alxa Block, NW China: Evidence for crust-mantle interaction and implications for the generation of silicic igneous provinces".LITHOS 230(2015):133-145.