Metamorphic and geochronological study of garnet-bearing basic granulites from Gushan, the eastern end of the Khondalite Belt in the North China Craton
文献类型：期刊论文
| 作者 | Wang LuoJuan1,2; Guo JingHui1; Peng Peng1; Liu Fu1 |
| 刊名 | ACTA PETROLOGICA SINICA
 |
| 出版日期 | 2011-12-01 |
| 卷号 | 27期号:12页码:3689-3700 |
| 关键词 | Garnet-bearing basic granulite Metamorphic P-T path Zircon U-Pb ages Paleoproterozoic Khondalite Belt |
| ISSN号 | 1000-0569 |
| 文献子类 | Article |
| 英文摘要 | Garnet-bearing basic granulites crop out near Gushan Town, the eastern end of the Khondalite Belt and just next to the Trans-North China Orogen. They occur as enclaves within sillimanite garnet gneisses and hypersthene monzonitic gneisses. Four metamorphic stages have been recognized on the basis of petrographic features and mineral compositions. The conventional thermobarometry and the calculated P-T pseudosections are used to determine the P-T conditions of different metamorphic stages. The early pre-peak metamorphic stage (M1) is represented by garnets' cores and their mineral inclusions, including clinopyroxene + plagioclase + quartz + ilmenite +/- rutile. The sodic cores of matrix plagioclases reveal that the highest metamorphic pressure could be over 11kbar. The peak metamorphic stage (M2) is documented by garnet + clinopyroxene + orthopyroxene + plagioclase + quartz + ilmenite, which formed at 850 similar to 900 degrees C, 9 similar to 10kbar. Symplectites and coronas of clinopyroxene + orthopyroxene + amphibole + plagioclase +/- ilmenite surrounding garnet porphyroblasts imply a near-isothermal decompression retrograde stage (M3). The P-T conditions of pyroxene + plagioclase symplectites and coronas were yielded at 760 similar to 820 degrees C, 5 similar to 8kbar. The occurrences of lower amphibolite-facies amphiboles suggest a late cooling stage (M4). The metamorphic temperature was lower than 690 degrees C. These data define a clockwise P-T path with near-isothermal decompressional section for garnet-bearing basic granulites. Metamorphic zircons from the garnet-bearing basic granulites yield two groups of U-Pb ages, 1945 +/- 25Ma and 1828 +/- 36Ma, which are consistent with main metamorphic episodes recorded in the Khondalite Belt and the Trans-North China Orogen, respectively. The combination of metamorphic and geochronological data indicates that garnet-bearing basic granulites have possibly experienced two independent metamorphic events, suggesting that garnet-bearing basic granulites underwent initial crust thickening followed by the exhumation to some extent at similar to 1. 95Ga caused by the collision between the Yinshan and Ordos blocks to form the Western Block, and that subsequently they were exhumed to the middle crust at similar to 1. 85Ga caused by the collision between the Eastern and Western blocks of the North China Craton. |
| WOS关键词 | MINERAL EQUILIBRIA CALCULATIONS ; HIGH-PRESSURE GRANULITES ; PB ZIRCON GEOCHRONOLOGY ; TEMPERATURE TIME PATHS ; U-TH-PB ; WESTERN BLOCK ; SANGGAN AREA ; SYSTEM K2O-FEO-MGO-AL2O3-SIO2-H2O-TIO2-FE2O3 ; REGIONAL METAMORPHISM ; COMPLEX CONSTRAINS |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000299019000015 |
| 出版者 | SCIENCE PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/74204]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Wang LuoJuan |
| 作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 2.NW Univ Xian, State Key Lab Continental Dynam, Xian 710069, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wang LuoJuan,Guo JingHui,Peng Peng,et al. Metamorphic and geochronological study of garnet-bearing basic granulites from Gushan, the eastern end of the Khondalite Belt in the North China Craton[J]. ACTA PETROLOGICA SINICA,2011,27(12):3689-3700. |
| APA | Wang LuoJuan,Guo JingHui,Peng Peng,&Liu Fu.(2011).Metamorphic and geochronological study of garnet-bearing basic granulites from Gushan, the eastern end of the Khondalite Belt in the North China Craton.ACTA PETROLOGICA SINICA,27(12),3689-3700. |
| MLA | Wang LuoJuan,et al."Metamorphic and geochronological study of garnet-bearing basic granulites from Gushan, the eastern end of the Khondalite Belt in the North China Craton".ACTA PETROLOGICA SINICA 27.12(2011):3689-3700. |
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。