Ar-40/Ar-39 thermochronology of the Kampa Dome, southern Tibet: Implications for tectonic evolution of the North Himalayan gneiss domes
文献类型：期刊论文
| 作者 | Quigley, Mark; Yu Liangjun; Liu Xiaohan; Wilson, Christopher J. L.; Sandiford, Mike; Phillips, David |
| 刊名 | TECTONOPHYSICS
 |
| 出版日期 | 2006-08-01 |
| 卷号 | 421期号:3-4页码:269-297 |
| 关键词 | Tibet Himalaya Gneiss Domes Ar-40/ar-39 Thermochronology |
| ISSN号 | 0040-1951 |
| DOI | 10.1016/j.tecto.2006.05.002 |
| 文献子类 | Article |
| 英文摘要 | Structural and thermochronological studies of the Kampa Dome provide constraints on timing and mechanisms of gneiss dome formation in southern Tibet. The core of Kampa Dome contains the Kampa Granite, a Cambrian orthogneiss that was deformed under high temperature (sub-solidus) conditions during Himalayan orogenesis. The Kampa Granite is intruded by syn-tectonic leucogranite dikes and sills of probable Oligocene to Miocene age. Overlying Paleozoic to Mesozoic metasedimentary rocks decrease in peak metamorphic grade from kyanite + staurolite grade at the base of the sequence to unmetamorphosed at the top. The Kampa Shear Zone traverses the Kampa Granite - metasediment contact and contains evidence for high-temperature to low-temperature ductile deformation and brittle faulting. The shear zone is interpreted to represent an exhumed portion of the South Tibetan Detachment System. Biotite and muscovite Ar-40/Ar-39 thermochronology from the metasedimentary sequence yields disturbed spectra with 14.22 +/- 0.18 to 15.54 +/- 0.39 Ma cooling ages and concordant spectra with 14.64 +/- 0.15 to 14.68 +/- 0.07 Ma cooling ages. Petrographic investigations suggest disturbed samples are associated with excess argon, intracrystalline deformation, mineral and fluid inclusions and/or chloritization that led to variations in argon systematics. We conclude that the entire metasedimentary sequence cooled rapidly through mica closure temperatures at similar to 14.6 Ma. The Kampa Granite yields the youngest biotite Ar-40/Ar-39 ages of similar to 13.7 Ma immediately below the granite-metasediment contact. We suggest that this age variation reflects either varying mica closure temperatures, re-heating of the Kampa Granite biotites above closure temperatures between 14.6 Ma and 13.7 Ma, or juxtaposition of rocks with different thermal histories. Our data do not corroborate the "inverse" mica cooling gradient observed in adjacent North Himalayan gneiss domes. Instead, we infer that mica cooling occurred in response to exhumation and conduction related to top-to-north normal faulting in the overlying sequence, top-to-south thrusting at depth, and coeval surface denudation. (c) 2006 Elsevier B.V. All rights reserved. |
| WOS关键词 | K-AR ; FLUID INCLUSIONS ; ARGON DIFFUSION ; EXCESS ARGON ; KANGMAR DOME ; AGE SPECTRA ; GRAIN-SIZE ; BIOTITE ; HISTORY ; CHINA |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000239620900006 |
| 出版者 | ELSEVIER SCIENCE BV |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/66080]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Quigley, Mark |
| 作者单位 | 1.Univ Melbourne, Sch Earth Sci, Melbourne, Vic 3010, Australia 2.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China |
| 推荐引用方式 GB/T 7714 | Quigley, Mark,Yu Liangjun,Liu Xiaohan,et al. Ar-40/Ar-39 thermochronology of the Kampa Dome, southern Tibet: Implications for tectonic evolution of the North Himalayan gneiss domes[J]. TECTONOPHYSICS,2006,421(3-4):269-297. |
| APA | Quigley, Mark,Yu Liangjun,Liu Xiaohan,Wilson, Christopher J. L.,Sandiford, Mike,&Phillips, David.(2006).Ar-40/Ar-39 thermochronology of the Kampa Dome, southern Tibet: Implications for tectonic evolution of the North Himalayan gneiss domes.TECTONOPHYSICS,421(3-4),269-297. |
| MLA | Quigley, Mark,et al."Ar-40/Ar-39 thermochronology of the Kampa Dome, southern Tibet: Implications for tectonic evolution of the North Himalayan gneiss domes".TECTONOPHYSICS 421.3-4(2006):269-297. |
入库方式： OAI收割
来源：地质与地球物理研究所
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