Zircon Lu-Hf isotopic compositions of ultra-high pressure metamorphic rocks from Dabie Terrain, China

	Zircon Lu-Hf isotopic compositions of ultra-high pressure metamorphic rocks from Dabie Terrain, China
	Chen D G ; Ni T ; Xie L W
刊名	ACTA PETROLOGICA SINICA
	2007-02-01
卷号	23 期号:2 页码:331-342
关键词	Lu-Hf isotopes metamorphic growth zircon inherited zircon ultra-high pressure metamorphism Dabie mountain
ISSN号	1000-0569
文献子类	Article
英文摘要	Zircon Lu-Hf isotope analyses were carried out for ultra-high pressure(UHP) eclogite, jadeite quartzite and gneiss from Shuanghe, and eclogite and gneiss from Huangzhen, Southern Dabie Terrain by using LA-MC-ICP-MS technique. The results show that eclogites from Shuanghe and Huangzhen and jadeite quartzite have low Lu-176/Hf-177 and low Hf-176/Hf-177 ratio, whereas gneisses from two localities have high Hf-176/Hf-177, high and spread Lu-176/Hf-177 compositions. Zircon Hf isotope distributions are mainly depended on the formation age of metamorphic precursor. Metamorphic zircon succeeded basically Hf isotopes of their protolith. Metamorphic growth zircons have relative low Lu-176/Hf-177 but high Hf-176/Hf-177 ratio, inherited and re-crystallized protolith zircons have high Lu-176/Hf-177 and low Hf-176/Hf-177 ratio. In some cases Hf isotope compositions of metamorphic and inherited zircons are undistinguishable within the same range. It mainly controlled by origin of protolith and zircon ablation during metamorphism. The low Lu/Hf ratio of metamorphic growth zircons were caused by the decreasing of Lu and increasing of Hf, and the high Hf-176/Hf-177 ratio originated from the addition of high radiogenic Hf-176 from other high Lu/Hf minerals evolution. The initial Hf isotope composition of et and the model age of depleted mantle TDMindicate that their age and origin are all different for metamorphic precursor. The source material of eclogites from Shaunghe show the mixture of magma derived from depleted mantle of 2.5Ga with at least 2.7Ga late Archean crust. The granitic gneiss from Shaunghe has the same age, but different degree of mantle and crust mixing. The material for eclogite precursor from Huangzhen was formed mainly from the recycling of juvenile crust, which was derived depleted mantle with few crust contamination. The gneiss and eclogite from Huangzhen shares the common source material. The material of gneiss precursor from both localities was derived from mixing of weak depleted mantle and old crust. The zircon Lu-Hf isotope of UHP metamorphic rocks from Dabie orogen mainly reflects magmatic activity character and tectonic setting of north margin of Yantze Craton during 0.7 similar to 0. 8Ga and 1. 8 similar to 1.9Ga.
WOS关键词	U-PB AGE ; EAST-CENTRAL CHINA ; CRUSTAL EVOLUTION ; ECLOGITE ; SHUANGHE ; MANTLE ; SHAN ; ORTHOGNEISSES ; GEOCHRONOLOGY ; GEOCHEMISTRY
WOS研究方向	Geology
语种	英语
出版者	SCIENCE CHINA PRESS
WOS记录号	WOS:000245763200013
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/68242]
专题	中国科学院地质与地球物理研究所
通讯作者	Chen D G
作者单位	1.Univ Sci & Technol China, CAS Key Lab Crust Mantle Mat & Environm, Sch Earth & Space Sci, Anhua 230026, Peoples R China 2.NW Inst Nucl Technol, Xian 710024, Peoples R China 3.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	Chen D G,Ni T,Xie L W. Zircon Lu-Hf isotopic compositions of ultra-high pressure metamorphic rocks from Dabie Terrain, China[J]. ACTA PETROLOGICA SINICA,2007,23(2):331-342.
APA	Chen D G,Ni T,&Xie L W.(2007).Zircon Lu-Hf isotopic compositions of ultra-high pressure metamorphic rocks from Dabie Terrain, China.ACTA PETROLOGICA SINICA,23(2),331-342.
MLA	Chen D G,et al."Zircon Lu-Hf isotopic compositions of ultra-high pressure metamorphic rocks from Dabie Terrain, China".ACTA PETROLOGICA SINICA 23.2(2007):331-342.