西准噶尔克拉玛依增生楔形成机制

发布时间：2018-06-01 05:12

本文选题：洋壳 + 俯冲带　；参考：《中国科学:地球科学》2017年02期

【摘要】：增生楔是板块俯冲过程中的特征性产物.确定增生楔的产出部位、物质组成及形成机制,对揭示与板块俯冲有关的构造过程具有重要指示意义.中亚造山带是世界上最大的增生型造山带之一,它记录了古亚洲洋从产生到闭合的整个演化历程,伴随着多期次、多类型的壳幔相互作用.地处中亚造山带腹地的西准噶尔地区在古生代处于洋内弧演化阶段,是研究中亚造山带的关键地区.西准噶尔东部地区发育泥盆-石炭纪海相沉积岩、达尔布特及克拉玛依蛇绿混杂岩、碱性洋岛玄武岩、岛弧火山岩及逆冲推覆构造,具有典型的增生楔特征.本文在详细的岩石岩相学、构造地质学和火山岩地球化学研究基础上,结合大洋俯冲隧道过程,深入剖析克拉玛依增生楔的形成机制,发现西准噶尔克拉玛依增生楔是多阶段、多成因混杂堆积体.大洋俯冲隧道模型在西准噶尔克拉玛依增生楔的应用将为中亚造山带的陆壳增生及造山作用研究提供新的思路.
[Abstract]:Accretive wedge is a characteristic product of plate subduction. It is of great significance to determine the location, material composition and formation mechanism of the accretive wedge for revealing the tectonic process related to plate subduction. The Central Asian orogenic belt is one of the largest accretive orogenic belts in the world. It records the entire evolution of the paleo-Asian ocean from its origin to closure, with multiple periods and types of crust-mantle interaction. The West Junggar area, located in the hinterland of the Central Asian orogenic belt, is a key area in the study of the Central Asian orogenic belt. Devonian Carboniferous marine sedimentary rocks, Dalbout and Karamay ophiolite melange, alkaline oceanic island basalt, island arc volcanic rocks and thrusting nappe structures are developed in the eastern part of West Junggar, with typical accretive wedge characteristics. On the basis of detailed lithofacies, tectonic geology and volcanic geochemistry, combined with the process of oceanic subduction tunnel, the formation mechanism of Kelamayi accretive wedge is deeply analyzed. It is found that the Karamay accretive wedge in West Junggar is multi-stage. Polygenetic hybrid deposits. The application of the oceanic subduction tunnel model in the Kelamayi hyperplasia wedge in West Junggar will provide a new idea for the study of continental crust accretion and orogeny in the Central Asian orogenic belt.
【作者单位】：长安大学地球科学与资源学院;
【基金】：国家自然科学基金项目(批准号:41303027) 陕西省青年科技新星计划项目(编号:2016KJXX-71) 中央高校基本科研业务费专项资金项目(编号:310827153506,310827153407)资助
【分类号】：P542

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