| 青藏高原腹地中新世从造山阶段向造高原阶段的转变及其动力学机制 |
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| 引用本文： | 王刚,伊海生,刘顺,沈军辉.青藏高原腹地中新世从造山阶段向造高原阶段的转变及其动力学机制[J].地球物理学报,2010,53(6):1384-1398. |
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| 作者姓名： | 王刚 伊海生 刘顺 沈军辉 |
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| 作者单位： | 1.成都理工大学地球科学学院，成都 610059;2.成都理工大学沉积地质研究院,成都 610059;3.地质灾害防治与地质环境保护国家重点实验室，成都 610059 |
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| 基金项目： | 地质灾害防治与地质环境保护国家重点实验室"科技减灾、重建家园"专项，国家自然科学基金项目 |
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| 摘 要： | 通过对前人研究的综述，发现青藏高原新生代地质演化与高原东南缘构造演化密切相关.俯冲下插的印度地壳在藏南发生部分熔融并注入青藏高原中部地壳，这些塑性流变的地壳物质在高原东南缘先后沿两个通道流出高原内部：早期为印支通道，开放时间为35 Ma以前并持续到12 Ma；后期为川滇通道，开放时间为12 Ma至今.由于喜马拉雅东构造结与四川盆地之间强烈的挤压，印支通道不断变窄，并在12 Ma被关闭.两个通道的差异，通道的打开和关闭，造成高原中地壳物质流出速率在中新世发生明显变化，在23 Ma以来流出速率小于注入速率，在12 Ma流出速率最小，部分熔融的印度地壳物质不断滞留于高原地壳内部，使得地势相对平坦、面积巨大的青藏高原逐渐形成并分别向南和向北扩展.通过简单的力学分析，本文将高原腹地变形划分为两个阶段：大于35~23 Ma的造山阶段，受控于造山机制；23 Ma至今的造高原阶段，受控于造高原机制.
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| 关 键 词： | 青藏高原 塑性流变 印支通道 川滇通道 造山阶段 造高原阶段 |
| 收稿时间： | 2009-08-18 |
The deformation transfer from orogen stage to plateau stage in the central part of Tibetan Plateau during Miocene time and it's tectonic mechanism |
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| WANG Gang,YI Hai-Sheng,LIU Shun,SHEN Jun-Hui.The deformation transfer from orogen stage to plateau stage in the central part of Tibetan Plateau during Miocene time and it's tectonic mechanism[J].Chinese Journal of Geophysics,2010,53(6):1384-1398. |
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| Authors: | WANG Gang YI Hai-Sheng LIU Shun SHEN Jun-Hui |
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| Institution: | 1.College of Earth Sciences, Chengdu University of Technology，Chengdu 610059， China;2.Institute of Sedimentary Geology, Chengdu University of Technology，Chengdu 610059， China;3.State Key Laboratory of Geohazard Prevention and Geoenvironment Protection，Chengdu 610059， China |
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| Abstract: | Based on a review of the previous researches, we find that the geology evolution of the Tibetan Plateau is closely related to the tectonic deformation of the southeastern margin of the plateau. The subducting India crust partially melts under south Tibet and injects into the middle plateau crust. The weak, rheological plateau middle crust materials flowed away from the plateau via two tunnels: the old one is the Indochina Tunnel, opened before 35 Ma and closed at 12 Ma, the younger is the Chuandian Tunnel, opened at 12 Ma and continues till now. Because of the intense press deformation between the Eastern Himalayan Syntax and the Sichuan Basin, the width of the Indochina Tunnel became narrow from the Eocene to the middle Miocene and closed at 12 Ma. The flowing velocity of the weak middle crust materials changed significantly during the Miocene time because of the opening and closing of the two tunnels and the differences of mechanic properties of the middle crust under the Indochina Tunnel and the Chuandian Tunnel. The velocity of flowing out is less than the velocity of injection from 23 Ma to now, and reached to the minimum at 12 Ma. The rheological middle crust materials enclosed in the plateau crust cause the high and flat plateau surface to develop and outward expand from the central plateau to both south and north. With the mechanical analysis, the evolution of the central plateau is divided into two stages, the orogen stage controlled by the orogen mechanism, from 35 Ma ago till 23 Ma, and the plateau stage controlled by the plateau mechanism, from 23 Ma till now. |
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| Keywords: | Tibetan Plateau Rheological deformation Indochina tunnel Chuandian tunnel Orogen stage Plateau stage |
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