Thermal pulse induced by emplacement of Ramba leucogranites in southern Tibet
文献类型：期刊论文
| 作者 | Chu, Xu2; Akca, Ozan2; Gaidies, Fred3; Gennaro, Ivano1,2; Ji, Weiqiang4 |
| 刊名 | JOURNAL OF METAMORPHIC GEOLOGY
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| 出版日期 | 2022-09-22 |
| 页码 | 21 |
| ISSN号 | 0263-4929 |
| 关键词 | chemical affinity contact aureole diffusion Ramba Dome RSCM |
| DOI | 10.1111/jmg.12690 |
| 英文摘要 | The thermal histories of Himalayan leucogranites provide critical information for unravelling the post-collisional geodynamics of the Himalayas. The Ramba Dome is located at the intersection of the Tethyan Himalayan leucogranite belt with the Yadong-Gulu Rift and hosts several generations of granitic intrusions. Of these intrusions, the 8-Ma two-mica granites and garnet leucogranite dykes are the youngest of Himalayan leucogranites. In this study, we focus on the carbonaceous staurolite schist located similar to 1.3 km from the intrusion to constrain the thermal history of the aureole that marked the cessation of leucogranite magmatism. The schist contains euhedral garnet and staurolite porphyroblasts in a foliated matrix of muscovite + biotite + chlorite + - plagioclase + quartz + graphite. The staurolite shows minor compositional variations from the inclusion-free core to the inclusion-rich rim. By contrast, the garnet features a distinctive bell-shaped Mn profile and increasing Mg# from the garnet core to rims. In a graphite-bearing equilibrium phase diagram for a modified bulk composition with garnet cores removed, the garnet rim composition suggests a peak temperature of similar to 550 degrees C, consistent with an independent thermometer based on the Raman spectra of carbonaceous materials (RSCM; 548 +/- 9 degrees C). The P-T condition lies within the narrow low-variance field bracketed by the staurolite-in and chlorite-out boundaries, indicating minimal overstepping of staurolite nucleation and growth. On the other hand, the garnet core composition indicates 520 degrees C at 2.5 kbar, about 40 degrees C higher than the predicted garnet-in boundary (similar to 480 degrees C). This apparent temperature overstep corresponds to a small chemical affinity (<5 kJ/mol 12 O) for garnet nucleation, comparable to previous estimates. The sharp boundaries of the high-Ca sector zoning in the core indicate limited diffusion modification (similar to 1.5 Ma if at the peak temperature). The short thermal pulse involves advective heat transfer by leucogranite emplacement, followed by rapid cooling toward the end of Himalayan magmatism and rapid exhumation likely facilitated by the Yadong-Gulu Rift. |
| WOS关键词 | CARBONACEOUS-MATERIAL GEOTHERMOMETER ; TECTONIC EVOLUTION ; BRITISH-COLUMBIA ; REGIONAL METAMORPHISM ; RAMAN-SPECTROSCOPY ; MIXING PROPERTIES ; KINETIC CONTROL ; NELSON AUREOLE ; REACTION-RATES ; GARNET GROWTH |
| 资助项目 | National Natural Science Foundation of China[41888101] ; Connaught New Researcher Award |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| 出版者 | WILEY |
| WOS记录号 | WOS:000859340400001 |
| 资助机构 | National Natural Science Foundation of China ; National Natural Science Foundation of China ; Connaught New Researcher Award ; Connaught New Researcher Award ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Connaught New Researcher Award ; Connaught New Researcher Award ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Connaught New Researcher Award ; Connaught New Researcher Award ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Connaught New Researcher Award ; Connaught New Researcher Award |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/108346]  |
| 专题 | 地质与地球物理研究所_岩石圈演化国家重点实验室 |
| 通讯作者 | Chu, Xu |
| 作者单位 | 1.Univ Geneva, Dept Earth Sci, Geneva, Switzerland 2.Univ Toronto, Dept Earth Sci, Toronto, ON, Canada 3.Carleton Univ, Dept Earth Sci, Ottawa, ON, Canada 4.Chinese Acad Sci, Inst Geol & Geophys, Beijing, Peoples R China |
| 推荐引用方式 GB/T 7714 | Chu, Xu,Akca, Ozan,Gaidies, Fred,et al. Thermal pulse induced by emplacement of Ramba leucogranites in southern Tibet[J]. JOURNAL OF METAMORPHIC GEOLOGY,2022:21. |
| APA | Chu, Xu,Akca, Ozan,Gaidies, Fred,Gennaro, Ivano,&Ji, Weiqiang.(2022).Thermal pulse induced by emplacement of Ramba leucogranites in southern Tibet.JOURNAL OF METAMORPHIC GEOLOGY,21. |
| MLA | Chu, Xu,et al."Thermal pulse induced by emplacement of Ramba leucogranites in southern Tibet".JOURNAL OF METAMORPHIC GEOLOGY (2022):21. |
入库方式： OAI收割
来源：地质与地球物理研究所
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