Late Paleozoic tectonic evolution of the northern West Chinese Tianshan Belt
Late Paleozoic tectonic evolution of the northern West Chinese Tianshan Belt
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DOI：
10.3166/ga.19.237-247
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发表时间：
2006-08
期刊：
影响因子：
1.5
通讯作者：
Bo Wang;M. Faure;Dominique Cluzel;L. Shu;J. Charvet;S. Meffre;Q. Ma
中科院分区：
文献类型：
--
作者：
Bo Wang;M. Faure;Dominique Cluzel;L. Shu;J. Charvet;S. Meffre;Q. Ma
西天山北部划分为石炭纪浊积岩、蛇绿混杂岩和伊犁岩浆弧三个亚单元。地层学和岩石学研究表明，浊积岩和蛇绿混杂岩形成俯冲杂岩。形成北天山缝合带的蛇绿混杂岩系是北天山洋盆俯冲过程中洋内构造作用和随后的再沉积变形作用的结果。伊犁弧型花岗岩的单颗粒锆石U-Pb年代学研究表明，其年龄范围为361~309 Ma。变形浊积岩的第一手运动学结果表明，该缝合带被二叠纪韧性右行走滑断裂改造。研究区的演化模式可划分为三个事件：1)晚泥盆世至石炭纪，伊犁地块以下洋盆俯冲产生伊犁岩浆岩和俯冲杂岩；2)晚石炭世盆地完全闭合；3)二叠纪右行走滑断裂活动，产生拉分盆地和碱性岩浆作用。印度-欧亚碰撞过程中的一次显著的重新激活引发了古生代单元向北推覆准噶尔盆地新生代沉积，从而掩盖了这一晚古生代缝合带的大部分。
The northern West Chinese Tianshan is divided into three subunits: Carboniferous turbidite, ophiolitic mélange and Yili magmatic arc. Stratigraphical and petrological studies suggest that the turbidite and ophiolitic mélange form a subduction complex. The ophiolitic mélange that forms the North Tianshan suture was a result of intra-oceanic tectonism and subsequent redeposition and deformation during the subduction of the North Tianshan oceanic basin. The Yili arc-type granitoids are constained by single zircon U-Pb radiochronology between 361 and 309 Ma. The first-hand kinematic results on the deformed turbidite suggest that this suture zone was reworked by a Permian ductile dextral strike-slip fault. An evolutionary model of the study area allows three events to be distinguished: 1) Late Devonian to Carboniferous subduction of the oceanic basin below the Yili Block producing Yili magmatic rocks and subduction complex, 2) Late Carboniferous complete closure of this basin, 3) Permian right-lateral strike-slip faulting generating pull-apart basins and alkaline magmatism. A prominent reactivation during the Indo-Eurasia collision provoked the northward thrusting of the Paleozoic units upon the Cenozoic sediments of the Junggar Basin, consequently, hiding the bulk of this Late Paleozoic suture.