| 摘要: |
| 西天山位于中亚造山带的西南缘，经历了复杂的增生造山过程。它也是标志塔里木地块北部被动陆缘与西伯利亚地块南侧宽阔活动陆缘最后拼合的构造带。根据近年来的研究进展，将西天山划分为北天山弧增生体、伊犁地块北缘活动陆缘、伊犁地块、伊犁地块南缘活动陆缘、中天山复合弧地体、西天山（高压）增生楔和塔里木北部被动大陆边缘。同时综述了西天山蛇绿岩、高压变质岩、花岗岩类的年代学新资料，讨论了其增生造山的过程。西天山增生造山与早古生代帖尔斯克依古洋、早古生代晚期—晚古生代南天山洋和晚古生代北天山洋3个代表洋盆的演化相关，增生造山结束的时间可能是早石炭世末。二叠纪时期，西天山至整个中亚地区进入后碰撞演化阶段。现有资料证实西天山为晚古生代增生造山带，并非三叠纪碰撞造山带。 |
| 关键词: 西天山 蛇绿岩 高压变质岩 花岗岩 增生造山 |
| DOI： |
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| Accretionary orogenic process of Western Tianshan, China |
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GAO Jun1, QIAN Qing1, LONG Ling-li2, ZHANG Xi1, LI Ji-lei1, SU wen11,2
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1. Key Laboratory of Mineral Resources, Institute of Geology and Geophysics,Chinese Academy of Sciences, Beijing 100029, China;2. Beijing Institute of Geology for Mineral Resources, Beijing 100012, China
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| Abstract: |
| The Western Tianshan area is situated along the southwestern margin of the Central Asia Orogenic belt and has undergone an accretional orogenic process. It is also a tectonic zone where the wide active margin in the southern Siberia finally amalgamated with the passive margin of the northern Tarim. On the basis of recent research advances, we subdivide the Western Tianshan into following tectonic units: the North Tianshan Arc Accretionary Wedge, the Northern Active Continental Margin of the Yili block, the Yili block, the Southern Active Continental Margin of the Yili block, the Central Tianshan Composite Arc Terrane, the Western Tianshan (high-pressure) Accretionary Wedge and the Northern margin of the Tarim block. The new chronological data of ophiolites, high-pressure metamorphic rocks and granitoids have also been summed up in order to discuss the accretionary orogenic process of the western Tianshan. This orogenic process is related to the evolution of three paleo-oceanic basins, namely, the early Paleozoic ‘Terskey Ocean’, the latest early Paleozoic-late Paleozoic ‘South Tianshan Ocean’ and the late Paleozoic ‘North Tianshan Ocean’. The accretionary orogenesis terminated at the end Early Carboniferous. Subsequently, the Western Tianshan and the whole Central Asia may have evolved into a post-collisional stage in Permian. The data obtained up to now has demonstrated that the Western Tianshan Orogen is a late Paleozoic accretionary orogenic belt, instead of a Triassic collisional one. |
| Key words: Western Tianshan ophiolites high-pressure rocks granitoids accretionary orogenesis |
