摘要
伊宁地块是西天山造山带的重要组成部分,其上广泛出露晚古生代火山岩浆岩和沉积建造,对剖析该地块的形成演化具有重要意义。伊宁地块以中部近EW向展布的乌孙山—塔勒得断裂为界可划分为南、北两大构造带,两者在基底建造、岩浆岩的组成与时代及其地球化学特征、盆地形成和构造演化等方面均呈现显著不同。其中,南构造带由晚泥盆世—早石炭世早期大哈拉—喀勒峻岛弧带和阿腾套弧后伸展盆地构成,推测海沟位于岛弧带之南(那拉提南缘断裂附近);北构造带由早石炭世中晚期阿吾拉勒叠加岛弧带、特克斯—新源弧前盆地和清水河—苏布台弧后盆地-扇三角洲构成。在重新梳理并详细总结伊宁地块的最新划分依据及方案基础上,首次提出伊宁地块形成与演化的南、北构造带两拼接和演化三阶段新认识:①晚泥盆世—早石炭世早期,南构造带初始弧-盆构造体系形成;②早石炭世中晚期,北构造带的沟-弧-盆构造体系形成并增生;③早—晚石炭世,初始的南构造带与增生的北构造带拼贴缝合,完成地块拼贴与增生,最终形成统一的伊宁地块。
The Yining Block is an important part of the West Tianshan orogenic belt.There are many Late Paleozoic volcano-magmatic rocks and sedimentary formations exposed on this block,which is of great significance to decipher its formation and evolution.The Yining Block can be divided into two tectonic units,namely the south and north,bounded by Wusun mountain-Taled fault in EW direction at the central part of the block.They are significantly different in basement construction,composition and age of magmatic rocks,geochemical characteristics,basin formation and tectonic evolution.The south tectonic belt is composed of Dahala-Kalajun island arc zone and Atengtao back-arc extensional basin from Late Devonian to early Early Carboniferous,with the trench being located in the south of the island arc zone(near the southern margin of Nalati fault);the north tectonic belt consists of Awulale superimposed island arc zone,Tekes-Xinyuan fore-arc basin,Qingshuihe-Subutai back-arc basin and fan delta in the middle and late Early Carboniferous.On the basis of resorting and summarizing the latest division scheme of Yining Block,a new understanding of the formation and evolution of Yining Block,namely two collages and three-stage evolution on the two tectonic belts,is put forward for the first time.The detailed processes include:①from Late Devonian to early Early Carboniferous,the initial arc-basin system is primarily formed in the south tectonic belt;②during the middle and late Early Carboniferous,the trench-arc-basin system in the north tectonic belt is generated and superimposed by the other belt;③in the early Late Carboniferous,the initial south tectonic belt and the accretionary north tectonic belt are collaged and sutured,completing the collision and accretion of this block.These processes result in the formation of the unified Yining Block.
作者
李永军
王祚鹏
杨高学
LI Yong-jun;WANG Zuo-peng;YANG Gao-xue(School of Earth Science and Resources,Chang'an University,Xi'an 710054,Shaanxi,China;Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits of Ministry of Natural Resources,Xi'an 710054,Shaanxi,China;School of Geological Engineering and Geomatics,Chang'an University,Xi'an 710054,Shaanxi,China)
出处
《地球科学与环境学报》
CAS
北大核心
2021年第2期215-223,共9页
Journal of Earth Sciences and Environment
基金
国家自然科学基金项目(41273033)
新疆维吾尔自治区地质专项项目(Y15-1-LQ01,T16-1-LQ02)。
关键词
火山岩浆岩
沉积建造
早—晚石炭世
晚泥盆世
构造单元
构造演化
伊宁地块
西天山
volcano-magmatic rock
sedimentary construction
Early-Late Carboniferous
Late Devonian
tectonic unit
tectonic evolution
Yining Block
West Tianshan