Zircon ages and Hf isotopic composition of gneisses from the Rongcheng ultrahigh-pressure terrain in the Sulu orogenic belt
文献类型：期刊论文
| 作者 | Li X H; Chen F K; Li C F; Zhang H F; Guo J H; Yang Y H |
| 刊名 | ACTA PETROLOGICA SINICA
 |
| 出版日期 | 2007-02-01 |
| 卷号 | 23期号:2页码:351-368 |
| 关键词 | Sulu orogen gneiss Neoproterozoic zircon age Nd-Hf isotope Rongcheng |
| ISSN号 | 1000-0569 |
| 文献子类 | Article |
| 英文摘要 | In this study, U-Pb age and Hf isotopic composition of zircon grains and Nd isotopic composition of whole-rocks of gneisses, collected from the Rongcheng ultrahigh-pressure (UHP) metamorphic terrain of the Sulu orogenic belt, were analysed for discussion on the origin and provenance of the protoliths. Zircon grains of three gneiss samples gave ages of about 770Ma to 710Ma, obtained by the SHRIMP U-Pb method. These ages are interpreted as formation time of magmatic protoliths of the gneisses, which were contemporaneous with the maginatism during the breakup of the supercontinent Rodinia. Single-stage depleted-mantle Nd modal ages of fourteen gneiss samples range from 1.70Ga to 2.30Ga (average similar to 1. 93Ga), indicating a Paleoproterozoic average crustal residence time for gneisses in the Rongcheng UHP terrain. This age is coincident with the average crustal formation time of the the Yangtze block, likely suggesting Yangtze affinity for the UHP terrain. Initial epsilon(Hf) values ( at 750Ma) and Hf modal ages of zircon grains from the fourteen gneiss samples are variable. Zircon grains from two gneiss samples commonly gave very low initial enf values ( average - 16. 4) and a high mean Hf modal age of about 2.70Ga. Seven gneiss sample contain zircon grains that yield a mean initial enf value of -7.7 and Hf modal age of 2.15Ga. These results suggest that part of gneiss's protoliths in the Rongcheng UHP terrain were formed in Neoproterozoic mainly by remelting Archean to Paleoproterozoic crustal material and further indicate existence of Archean crustal section probably of the Yangtze affinity beneath the Rongcheng UHP terrain. The other six gneiss samples mostly contain young zircon grains, having mean initial enf values' of -0.56 to 6.6. Part of them give Hf modal ages of 0.81Ga to 0.94Ga. This evidence strongly suggests magmatic activity of mantle origin, new crustal formation and coeval crust-mantle interaction during the breakup of the supercontinent Rodinia in Neoproterozoic. Underplating of magmas of mantle origin caused remelting of the overlying Archean - Paleoproterozoic crustal section to form granitic magma along rift zones or marginal regimes of the Yangtze block. |
| WOS关键词 | COESITE-BEARING ECLOGITES ; ARCHEAN CRUSTAL EVOLUTION ; GA CONTINENTAL-CRUST ; U-PB GEOCHRONOLOGY ; EASTERN CHINA ; SOUTH CHINA ; YANGTZE CRATON ; METAMORPHIC ROCKS ; NORTH CHINA ; TECTONIC EVOLUTION |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000245763200015 |
| 出版者 | SCIENCE CHINA PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/67588]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Li X H |
| 作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 2.Grad Univ Chinese Acad Sci, Sch Earth Sci, Beijing 100039, Peoples R China 3.Chinese Acad Sci, Inst Geol & Geophys, Lab Radiogen Isotope Geochem, Beijing 100029, Peoples R China 4.China Univ Geosci, State Key Lab Geoproc & Mineral Resources, Beijing 100083, Peoples R China |
| 推荐引用方式 GB/T 7714 | Li X H,Chen F K,Li C F,et al. Zircon ages and Hf isotopic composition of gneisses from the Rongcheng ultrahigh-pressure terrain in the Sulu orogenic belt[J]. ACTA PETROLOGICA SINICA,2007,23(2):351-368. |
| APA | Li X H,Chen F K,Li C F,Zhang H F,Guo J H,&Yang Y H.(2007).Zircon ages and Hf isotopic composition of gneisses from the Rongcheng ultrahigh-pressure terrain in the Sulu orogenic belt.ACTA PETROLOGICA SINICA,23(2),351-368. |
| MLA | Li X H,et al."Zircon ages and Hf isotopic composition of gneisses from the Rongcheng ultrahigh-pressure terrain in the Sulu orogenic belt".ACTA PETROLOGICA SINICA 23.2(2007):351-368. |
入库方式： OAI收割
来源：地质与地球物理研究所
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