Lower crust processes during the lithosphere thinning in eastern China: magma underplating, replacement and delamination.
文献类型：期刊论文
| 作者 | Zhai, MG; Fan, QC; Zhang, HF; Sui, JL |
| 刊名 | ACTA PETROLOGICA SINICA
 |
| 出版日期 | 2005-11-01 |
| 卷号 | 21期号:6页码:1509-1526 |
| 关键词 | Lower Crust Lithospheric Thinning North China |
| ISSN号 | 1000-0569 |
| 文献子类 | Review |
| 英文摘要 | Our recent study shows that the lower crust was thinned together with lithosphere mantle in eastern North China Block (NCB) at Mesozoic. This paper reveals that lower crust process is a key point to understand tectonic mechanism of lithosphereic thinning. The geochemical data from volcanic rocks and their xenoliths Possibly Support that a delamination of lower crust and lithosphere mantle occurred in northern and/or southern margins of the NCB only, linking to a post-collisional orogenic process. However, the delamination difficultly happens in the whole of eastern NCB and result in a loss of 80 similar to 120 km thickness of lithosphere. The lower crust xenoliths in Mesozoic and Cenozoic basalts within the NCB have two kinds. One is granulite-facies metamorphosed gabbros/two-pyroxinenites and eclogite-facies metamorphosed garnet pyroxenites. which formed at 140 similar to 120Ma. Another kind is Precambrian granulites that were strongly overprinted by Mesozoic metamorphism. A large-scale lower crust replacement took place at Mesozoic beneath the NCB. In other words, the recent lower crust of the NCB is not Precambrian one. Most of the present lower crust is composed of Mesozoic meta-gabbros and pyroxinenites. Otherwise, a lot of late Jurrasic granites in the NCB are similar to adakite in geochemistry, which possibly derived from partial melting of lowermost crust and survived a remnant of eclogite or gamet-amphibolite. A hot upwelling mantle is necessary for replacement of lower crust and partial melting of lowermost crust. Although a certain surviving eclogites could sink into mantle, it is unimaginable there was a thick enough eclogite layer that can drag 80 similar to 120 km thick lithosphere together to founder into asthenosphere beneath the NCB. On the contrary, magma underplanting perhaps is one of choosers. Forming of the present lower crust through underplating and its replacement to the old one are closely related to lithosphere mantle thinning. And the both of lower crust thinning/replacement and lithosphere mantle thinning are controlled by a same dynamic mechanism, and are cause and effect by each other. |
| WOS关键词 | LOWER CONTINENTAL-CRUST ; SINO-KOREAN CRATON ; NORTHERN MARGINAL REGION ; U-PB ; GEOLOGICAL SIGNIFICANCE ; INTRUSIVE COMPLEXES ; TRACE-ELEMENT ; ISOTOPIC COMPOSITIONS ; TECTONIC IMPLICATIONS ; GRANULITE XENOLITHS |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000234692900001 |
| 出版者 | SCIENCE PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/65220]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Zhai, MG |
| 作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China 2.Chinese Acad Sci, Key Lab Mineral Resources, Beijing 100029, Peoples R China 3.Chinese Seismol Bur China, Inst Geol, Beijing 100029, Peoples R China 4.State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zhai, MG,Fan, QC,Zhang, HF,et al. Lower crust processes during the lithosphere thinning in eastern China: magma underplating, replacement and delamination.[J]. ACTA PETROLOGICA SINICA,2005,21(6):1509-1526. |
| APA | Zhai, MG,Fan, QC,Zhang, HF,&Sui, JL.(2005).Lower crust processes during the lithosphere thinning in eastern China: magma underplating, replacement and delamination..ACTA PETROLOGICA SINICA,21(6),1509-1526. |
| MLA | Zhai, MG,et al."Lower crust processes during the lithosphere thinning in eastern China: magma underplating, replacement and delamination.".ACTA PETROLOGICA SINICA 21.6(2005):1509-1526. |
入库方式： OAI收割
来源：地质与地球物理研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。