摘要
由于博格达山与周缘沉积盆地盆山关系复杂,准噶尔盆地东南缘博格达地区盆山分异过程长期以来是一个倍受争议的研究课题。通过地震剖面解释和碎屑重矿物含量、组合特征等综合研究,探讨博格达山侏罗纪隆升过程。结果表明:地震剖面能够直接反映研究区地下地质构造特征,研究区地震剖面中地层间不整合接触关系和厚度变化趋势分析显示,博格达山于中晚侏罗世发生过一期重要隆升运动。沉积重矿物记录了盆山分异的全部过程,为精细研究中晚侏罗世盆山分异过程提供技术方法,研究区沉积重矿物含量变化、组合特征以及特征指数(ZTR)等分析表明,早-中侏罗世博格达地区盆山结构相对稳定,中侏罗世晚期头屯河期(J 2t)开始发生盆山分异,不稳定重矿物含量增加,重矿物组合类型改变,同时ZTR指数等值曲线指向也发生转变,此时博格达地区由前期的汇水中心转为造山带,并且隆升剥蚀为周缘地区提供物源。结合剖面中构造特征分析成果,认为博格达地区中晚侏罗世盆山分异作用发生在头屯河期(J 2t)。
The complex evolution of the Bogda Mountain and its relationship between peripheral sedimentary basins are key to interpret the Palaeozoic evolution of the Tian Shan,which continues to be debated.In this work,we combined field section,seismic section and clastic heavy mineral to study the basin-mountain differentiation during the Middle-Late Jurassic.The result shows that the basin-mountain structure of the Bogda area was relatively stable in Early-Middle Jurassic and the differentiation was beginning to occur in the Middle-Late Jurassic(TouTunHe period).During this period,unstable heavy mineral content increased,combination type of heavy mineral changed,and ZTR index curve also changed.At the time,the Bogda area changed from the previous catchment center to the orogenic belt,and was eroded to provide sources for the surrounding areas.Combining the analysis of structural characteristics in the sections,the differentiation between the Bogda Mountain and southern Junggar Basin occurred in the TouTunHe period in Middle-Late Jurassic.
作者
宋燕
陈石
张艺楼
梁鑫鑫
梁媛媛
侯文
SONG Yan;CHEN Shi;ZHANG Yi-lou;LIANG Xin-xin;LIANG Yuan-yuan;HOU Wen(College of Geosciences,China University of Petroleum(Beijing),State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum(BeiJing),Beijing 102249,China)
出处
《科学技术与工程》
北大核心
2020年第3期924-934,共11页
Science Technology and Engineering
基金
国家自然科学基金(41502208)。
关键词
构造特征
重矿物
盆山分异
物源分析
博格达地区
structural feature
heavy mineral
differentiation between basin and mountain
source analysis
Bogda area
