西准噶尔沙尔布尔提山地区志留纪普里道利世—早泥盆世盆地充填序列及其沉积大地构造意义  

Sedimentary-tectonic significance of the Silurian-Devonian basin filling sequence in the Shaerbuerti Mountain area,western Junggar

作　　者：杜伟东 张欣松 尹家一 纵瑞文 DU Weidong;ZHANG Xinsong;YIN Jiayi;ZONG Ruiwen(Tianjin North China Geological Exploration Bureau of Nuclear Industry 247 Brigade,Tianjin 301800,China;Zijin Mining College,Fuzhou University,Fuzhou 350108,China;State Key Laboratory of Biogeology and Environmental Geology,School of Earth Sciences,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]天津华北地质勘查局核工业二四七大队,天津410083 [2]福州大学紫金地质与矿业学院,福建福州350108 [3]中国地质大学(武汉)生物地质与环境地质国家重点实验室,湖北武汉430074

出　　处：《沉积与特提斯地质》2025年第1期48-68,共21页Sedimentary Geology and Tethyan Geology

基　　金：国家自然科学基金(42002017,42072041)。

摘　　要：新疆西准噶尔北部谢米斯台山—沙尔布尔提山地区是中亚造山带的重要组成部分。志留纪普里道利世—早泥盆世期间,该地区沉积了一套由海相复理石到陆棚碳酸盐岩转变的盆地充填序列,其沉积体系的时空展布、岩相变化以及物源分析可为重建西准噶尔北部古地理格局以及古亚洲洋演化提供证据。本文对沙尔布尔提山地区的芒克鲁Ⅱ剖面进行了详细的岩相分析、砂岩碎屑统计、主、微量元素分析,来探讨沉积盆地的演化过程、构造背景和物源属性。芒克鲁Ⅱ剖面出露乌吐布拉克组与曼格尔组,剖面由底到顶依次出现盆地—斜坡背景层沉积、盆地浊积岩、陆棚边缘的异重流扇、陆棚、浅水颗粒滩的相序列,表现为向上变浅的盆地充填序列。沉积物以砂岩、砾岩和生物碎屑颗粒灰岩为主。砂岩成分以长石、岩屑为主,成分变异指数ICV=1.37,值大于1,指示了碎屑岩成熟度低。砂岩样品富集大离子亲石元素(LILEs),亏损高场强元素(HFSEs),轻稀土与重稀土元素比值(LREEs/HREEs)在2.89~7.41,均值6.15。物源判别及构造判别图解综合显示其物源主要来自长英质火山岩及安山岩的混合源区,物源区以大陆岛弧与大洋岛弧环境为主。研究表明,谢米斯台山–沙尔布尔提山岛弧火山岩可能为盆地充填过程提供了丰富的物源,盆地浊积岩向陆棚异重岩沉积的转变不仅代表了盆地充填的暂时性终止,也有可能代表了沙尔布尔提山地区在这一时期的俯冲碰撞活动基本结束。The Xiemisitai-Shaerbuerti Mountain region,located in West Junggar,Xinjiang,China,represents an important part of the Central Asian Orogenic Belt(CAOB).From the Silurian Pridoli epoch to early Devonian,a set of basin filling sequence transitioning from marine flysch to shelf carbonate is deposited in this region.The spatial-temporal distribution of the sedimentary system and analyses of lithofacies and sources can provide evidence for reconstructing the paleogeographic configuration of western Junggar and the evolution of the Paleo-Asian Ocean.This study conducted a detailed analysis of lithofacies,sandstone clasts,as well as major and trace elements in the MangkeluⅡsection of the Shaerbuerti Mountain area to explore the sedimentary basin's evolution,tectonic background,and provenance attributes.The MangkeluⅡsection consists of the Wutubulake Formation at the bottom and the Mangeer Formation at the top.The facies successions from bottom to top includes slope–basin background deposits,basin turbidites,hyperpycnal flow fans at the shelf margin,shelf,and shallow sea grain shoal,representing an upward-shallowing basin-fill sequence.The main sediments are sandstone,conglomerate,and bioclastic limestone.The sandstone is mainly composed of feldspar and lithics,with an index of compositional variability(ICV)of 1.37,which is greater than 1,indicating low maturity.The sandstone samples are enriched in large ion lithophile elements(LILEs)and depleted in high field strength elements(HFSEs),with a ratio of light rare earth elements to heavy rare earth elements(LREEs/HREEs)ranging from 2.89 to 7.41,averaging 6.15.The provenance and tectonic discrimination diagrams show a mixed source of intermediate-felsic volcanic rocks and andesites,derived mainly from continental and oceanic island arcs.Volcanic rocks from the Xiemisitai-Shaerbuerti Mountain island arc provided abundant material for the basin fill.The transformation of sedimentary facies from turbidites to hyperpycnites in the continental shelf may represent a tempora

关 键 词：西准噶尔 志留纪普里道利世—早泥盆世 复理石 岩相 物源 岛弧 

分 类 号：P534.3[天文地球—古生物学与地层学]