Metamorphism, geochemistry and U-Pb zircon SHRIMP geochronology of the high-pressure granulites in the central Greater Himalayas
文献类型：期刊论文
| 作者 | Ji, JQ; Zhong, DL; Song, B; Chu, MF; Wen, DJ |
| 刊名 | ACTA PETROLOGICA SINICA
 |
| 出版日期 | 2004-09-01 |
| 卷号 | 20期号:5页码:1283-1300 |
| 关键词 | high pressure granulite the Greater Himalayas metamorphism zircon U-PbSHRIMP dating Yadong city |
| ISSN号 | 1000-0569 |
| 文献子类 | Article |
| 英文摘要 | The studied high pressure mafic granulite (HP-granulite) outcrops in the Greater Himalayas 40 kilometers north to Yadong City in the southern Tibetan Plteau. It exposes in the footwall of the southern Tibetan detachment system (STDS) as the enclaves of the parageiness. The HP-granulite is marked by the early mineral assemblages garnet (Grt) + clinopyroxene (Cpx) Plgioclase (Pl) and the later assemblages amphibole + Plgioclase + biotite(Bio) orthopyroxene(Opx). The metamorphic reaction textures indicate the following reactions: Grt + Cpx + Qtz = Opx + Pl, Grt + Qtz = Opx + Pl, Grt + Cpx + L = Hbl + Pl + Bio + Mt,Cpx + L = Hbl + Mt. Thermobarmetric estimates based on equilibrium texture and mineral chemistry indicate that the early mineral assemblages formed at P = c.1.2 similar to 1.5 GPa, T = c. 780 similar to 850degreesC with the geothermal gradient of 15degreesC similar to 18degreesC/km, and the later retrograde assemblages experienced near-isothermal decomposition to P = 4 similar to 6kbar, T = 730 similar to 760degreesC with the geothermal gradient of 38degreesC similar to 50degreesC /km. Metamorphic texture, P and T evolution shows HP-granulite had experienced a rapid change of tectonic background from thicken crust to thinning or heating crust. The U-Pb SHRIMP ages of zircons collected from the HP-granulite show most ages are around 17 Ma, and other mainly around 98 Ma. Because the estimated metamorphic temperatures are higher than the closure temperature of zircon U-Pb chronological system, the later age of 17 Ma should be the cooling age during rapid exhumation related to the activity of STDS and MCT in the Greater Himalayas. The Greater Himalayan belt as well as the lesser Himalayan belt is regarded to be the part of Indian continent. The HP-granulite must have been the continental thoelitic basalt metamorphosed due to the collision between Indian and Eurasian continents. The HP-granulite provides a new clue to study the process of collision and convergence between India and Asia, and how and why the Greater Himalayas uplift. |
| WOS关键词 | SOUTHERN TIBET ; GARNET ; PLAGIOCLASE ; HORNBLENDE ; GEOTHERMOMETER ; CALIBRATION ; EXTRUSION ; TECTONICS ; GEOBAROMETERS ; EQUILIBRIA |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000224589100023 |
| 出版者 | SCIENCE CHINA PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/79785]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Ji, JQ |
| 作者单位 | 1.Peking Univ, Lab Orogen Belts & Crustal Evolut, Beijing 100871, Peoples R China 2.CAS, Inst Geol & Geophys, Beijing 100029, Peoples R China 3.CAGS, Inst Geol, Beijing SHRIMP Ctr, Beijing 100037, Peoples R China 4.Natl Taiwan Univ, Dept Geol, Taibei, Taiwan |
| 推荐引用方式 GB/T 7714 | Ji, JQ,Zhong, DL,Song, B,et al. Metamorphism, geochemistry and U-Pb zircon SHRIMP geochronology of the high-pressure granulites in the central Greater Himalayas[J]. ACTA PETROLOGICA SINICA,2004,20(5):1283-1300. |
| APA | Ji, JQ,Zhong, DL,Song, B,Chu, MF,&Wen, DJ.(2004).Metamorphism, geochemistry and U-Pb zircon SHRIMP geochronology of the high-pressure granulites in the central Greater Himalayas.ACTA PETROLOGICA SINICA,20(5),1283-1300. |
| MLA | Ji, JQ,et al."Metamorphism, geochemistry and U-Pb zircon SHRIMP geochronology of the high-pressure granulites in the central Greater Himalayas".ACTA PETROLOGICA SINICA 20.5(2004):1283-1300. |
入库方式： OAI收割
来源：地质与地球物理研究所
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