Origin of postcollisional magmatic rocks in the Dabie orogen: Implications for crust-mantle interaction and crustal architecture

doi:10.1016/j.lithos.2011.06.010

	Origin of postcollisional magmatic rocks in the Dabie orogen: Implications for crust-mantle interaction and crustal architecture
	Zhao, Zi-Fu 1; Zheng, Yong-Fei 1; Wei, Chun-Sheng 1; Wu, Fu-Yuan 2
刊名	LITHOS
	2011-09-01
卷号	126 期号:1-2 页码:99-114
关键词	Postcollisional Magmatism Crust-mantle Interaction Orogenic Lithospheric Mantle Crustal Architecture Zircon Hf Isotope Dabie Orogen
ISSN号	0024-4937
DOI	10.1016/j.lithos.2011.06.010
文献子类	Article
英文摘要	Zircon Hf and whole-rock Sr-Nd isotopic compositions were determined for postcollisional mafic-ultramafic and felsic intrusive rocks in the Dabie orogen. The results provide not only insights into the character of their source rocks and the nature of crust-mantle interaction, but also constraints on the crustal architecture of continental collision orogen. SHRIMP zircon U-Pb dating gave concordant ages of 121 +/- 6 to 131 +/- 2 Ma for the bimodal intrusives. Zircon Hf isotope analyses gave negative epsilon(Hf)(t) values of -26.3 +/- 0.6 to -7.0 +/- 0.5 for the mafic-ultramafic rocks, with two-stage Hf model ages of 1.62 to 2.83 Ga. Zircons from felsic granitoids also gave negative epsilon(Hf)(t) values of -31.6 +/- 0.5 to -16.9 +/- 0.9 with two-stage Hf model ages of 2.25 to 3.16 Ga. Both the mafic-ultramafic and felsic rocks have high initial Sr-87/Sr-86 raios of 0.7065 to 0.7084 and very low epsilon(Nd)(t) values of -21.7 to -11.7 for whole-rock. The crust-like geochemical signatures in the mafic-ultramafic rocks suggest their derivation from partial melting of an orogenic lithospheric mantle source that is enriched in radiogenic isotopes as well as incompatible trace elements such as LILE and LREE. It would be generated by reaction of the overlying subcontinental lithospheric mantle (SCLM) wedge peridotite with the felsic melt derived from the subducted continental crust during the continental collision. Therefore, these postcollisional mafic-ultramafic rocks record recycling of the subducted continental crust and consequent crust-mantle interaction in the continental subduction zone. The granitoids have Hf model ages as old as Paleoarchean, which cannot be derived from partial melting of surrounding orthogneisses alone, but requires involvement of more ancient Archean crust in their source region. Thus, their source represents a mixture of crustal rocks from Paleoproterozoic and Paleoarchean basement. In combination of the present and previous studies, the Dabie orogen is suggested to have a three-layer crustal structure prior to the postcollisional magmatism: Central Dabie in the upper with dominantly young Hf model ages of late Mesoproterozoic to Neoproterozoic, North Dabie in the middle with dominantly middle Paleoproterozoic Hf model ages, and the source region of the postcollisional granitoids in the lower with Paleoproterozoic to Paleoarchean Hf model ages. (C) 2011 Elsevier B.V. All rights reserved.
WOS关键词	ZIRCON U-PB ; SUBDUCTED CONTINENTAL-CRUST ; PRESSURE METAMORPHIC ROCKS ; HF ISOTOPE COMPOSITION ; OCEAN-ISLAND BASALTS ; TRACE-ELEMENT FRACTIONATION ; EARLY CRETACEOUS GRANITOIDS ; EAST-CENTRAL CHINA ; ULTRAHIGH-PRESSURE ; YANGTZE CRATON
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000295064200007
资助机构	Chinese Academy of Sciences(KZCX2-YW-Q08-3) ; Chinese Academy of Sciences(KZCX2-YW-Q08-3) ; Chinese Ministry of Science and Technology(2009CB825004) ; Chinese Ministry of Science and Technology(2009CB825004) ; Natural Science Foundation of China(40921002 ; Natural Science Foundation of China(40921002 ; 41073025) ; 41073025) ; Chinese Academy of Sciences(KZCX2-YW-Q08-3) ; Chinese Academy of Sciences(KZCX2-YW-Q08-3) ; Chinese Ministry of Science and Technology(2009CB825004) ; Chinese Ministry of Science and Technology(2009CB825004) ; Natural Science Foundation of China(40921002 ; Natural Science Foundation of China(40921002 ; 41073025) ; 41073025) ; Chinese Academy of Sciences(KZCX2-YW-Q08-3) ; Chinese Academy of Sciences(KZCX2-YW-Q08-3) ; Chinese Ministry of Science and Technology(2009CB825004) ; Chinese Ministry of Science and Technology(2009CB825004) ; Natural Science Foundation of China(40921002 ; Natural Science Foundation of China(40921002 ; 41073025) ; 41073025) ; Chinese Academy of Sciences(KZCX2-YW-Q08-3) ; Chinese Academy of Sciences(KZCX2-YW-Q08-3) ; Chinese Ministry of Science and Technology(2009CB825004) ; Chinese Ministry of Science and Technology(2009CB825004) ; Natural Science Foundation of China(40921002 ; Natural Science Foundation of China(40921002 ; 41073025) ; 41073025)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/73642]
专题	中国科学院地质与地球物理研究所
通讯作者	Zhao, Zi-Fu
作者单位	1.Univ Sci & Technol China, Sch Earth & Space Sci, CAS Key Lab Crust Mantle Mat & Environm, Hefei 230026, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithosphere Evolut, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Zhao, Zi-Fu,Zheng, Yong-Fei,Wei, Chun-Sheng,et al. Origin of postcollisional magmatic rocks in the Dabie orogen: Implications for crust-mantle interaction and crustal architecture[J]. LITHOS,2011,126(1-2):99-114.
APA	Zhao, Zi-Fu,Zheng, Yong-Fei,Wei, Chun-Sheng,&Wu, Fu-Yuan.(2011).Origin of postcollisional magmatic rocks in the Dabie orogen: Implications for crust-mantle interaction and crustal architecture.LITHOS,126(1-2),99-114.
MLA	Zhao, Zi-Fu,et al."Origin of postcollisional magmatic rocks in the Dabie orogen: Implications for crust-mantle interaction and crustal architecture".LITHOS 126.1-2(2011):99-114.