| 造山的高原——青藏高原巨型造山拼贴体和造山类型 |
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| 引用本文： | 许志琴,李海兵,杨经绥.造山的高原——青藏高原巨型造山拼贴体和造山类型[J].地学前缘,2006,13(4):1-17. |
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| 作者姓名： | 许志琴 李海兵 杨经绥 |
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| 作者单位： | 中国地质科学院,地质研究所,国土资源部大陆动力学重点实验室,北京,100037 |
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| 基金项目： | 国土资源部科技专项基金;中国地质调查局研究项目 |
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| 摘 要： | 青藏高原是一个巨型碰撞造山拼贴体,它的形成与始特提斯、古特提斯和新特提斯洋盆的先后开启、消减、闭合以及古大陆的裂解、诸地体的移动、会聚和拼合有关。造山类型形成于不同时期海(洋)盆俯冲、地体碰撞和陆内会聚的不同阶段。多地体/多岛弧/多弧前海的构架表明,诸多的俯冲型山链可以产生在地体边界的活动陆缘一侧,古特提斯南、北两洋盆的双向俯冲构筑了双向俯冲型山链;碰撞型山链由于地体边界与块体驱动方向的几何学关系形成“正向碰撞型”和“斜向碰撞型”造山类型。“斜向碰撞型山链”与走滑断裂的形成、规模及其运动学直接相关。50~60Ma印度/亚洲碰撞不仅形成青藏高原造山拼贴体的最后成员———喜马拉雅山链,而且在拼贴体的北缘由于陆内俯冲作用使早期形成的山链在整修后又一次崛起。青藏高原的周缘山链铸成屏障与外侧的克拉通相隔。青藏高原巨型碰撞造山拼贴体的形成是亚洲大陆自北往南的增生和造山迁移的生长结果,其所反映的活动长期性、非原地性、俯冲/碰撞/陆内造山类型的多样性、碰撞造山的多期性以及造山的复合叠置性比世界上任何一个复合山链(或造山拼贴体)来得复杂、多彩。
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| 关 键 词： | 造山的高原 青藏高原 巨型造山拼贴体 造山类型 |
| 文章编号： | 1005-2321（2006）04-0001-17 |
| 收稿时间： | 2006-05-22 |
| 修稿时间： | 2006-05-22 |
An orogenic plateau-the orogenic collage and orogenic types of the Qinghai-Tibet plateau |
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| XU Zhi-qin,LI Hai-bing,YANG Jing-sui.An orogenic plateau-the orogenic collage and orogenic types of the Qinghai-Tibet plateau[J].Earth Science Frontiers,2006,13(4):1-17. |
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| Authors: | XU Zhi-qin LI Hai-bing YANG Jing-sui |
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| Abstract: | The Qinghai-Tibet plateau, a major collisional orogenic collage up to 1 500 km wide, was formed by tectonic processes related to the opening, consumption and closure of the Proto-Tethyan, Paleo-Tethyan and Neo-Tethyan oceans.The breakup of Gondwanan supercontinents produced numerous continental blocks and microcontinents that eventually converged and collided against Asia. Thus, the plateau contains a long record of oceanic (or small oceanic basin) subduction, terrane collision and intra-continental convergence. The present-day collage is composed of numerous distinct terranes separated by ophiolites, arc volcanic rocks and fore-arc sedimentary rocks.The observable tectonic framework suggests that volcanic arcs and related mountain chains are common on active continental margins, such as those that occurred on both sides of Paleo-Tethys.Subduction and collision was both normal and oblique, depending on the direction of block movements and on the configurations of individual blocks. Oblique collision led to the formation of strike-slip faults, many of which played a major role in mountain building.The initial of India and Asia in 50-60 Ma not only formed the High Himalaya along the southern margin of the plateau but caused uplift of pre-existing Palaeozoic mountain belts farther to the north.These rejuvenated belts now form significant intra-continental mountain chains accompanied by intra-continental subduction. The Qinghai-Tibet orogenic collage formed by progressive accretion of blocks and terranes to the Asian continent as orogenesis migrated from north to south over a protracted period of time.The tectonic evolution of the region was episodic, with multiple periods of basin formation, subduction and intracontinental block collisions.The plateau has had a longer and more complex geologic history than many of the other orogenic belts in the world. |
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| Keywords: | orogenic plateau Qinghai-Tibet plateau huge orogenic collage orogenic types |
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