大同盆地云岗组石窟段河流相沉积特征  

Sedimentary Features of Fluvial Facies in the Shiku Member of Yungang Formation in Datong Basin

作　　者：艾骁 陈相兆[1] 孙柏涛[1] AI Xiao;CHEN Xiang-zhao;SUN Bai-tao(Institute of Engineering Mechanics,China Earthquake Administration,Key Laboratory of Earthquake Engineering and Engineering Vibration,China Earthquake Administration,Harbin 150080,China)

机构地区：[1]中国地震局工程力学研究所,中国地震局地震工程与工程振动重点实验室,哈尔滨150080

出　　处：《科学技术与工程》2021年第9期3495-3504,共10页Science Technology and Engineering

基　　金：国家重点研发计划(2019YFC1509301);国家自然科学青年基金项目(51708524);中国地震局工程力学研究所基本科研业务费专项(2017B04)。

摘　　要：大同盆地云岗组分布于大同云岗盆地、宁武静乐盆地、沁水盆地北部等地区。其命名地点在山西大同市云岗镇,其中石窟段为云岗组中段。经前人研究发现,大同盆地云岗组为辫状河沉积。通过对研究区野外露头中三条典型剖面的研究,全面分析了石窟段河流相沉积特征,并完成了如下工作:(1)制作了研究区野外露头中三条典型剖面的素描图并建立了界面划分方案;(2)在界面划分的基础上进行各单元内部岩相、沉积构造及沉积特征的分析;(3)综合各单元的沉积特征,并通过剖面之间的横向对比,明确了研究区各期次河流相沉积之间时间与空间上的联系;(4)明确了研究区河流相沉积模式并建立了相应沉积相模式概图。上述工作完成后,从研究区沉积模式概图可见古河流大致沿着自北向南的方向由北部山间汇入大同盆地,形成辫状河道沉积。沉积相总体按照自西向东的方向呈现出泛滥平原—河道沉积—泛滥平原的变化趋势。研究成果为大同盆地侏罗纪的进一步研究及未来大同地区的煤矿开采工作提供资料基础。Yungang Formation in Datong Basin is distributed in Yungang Basin,Jingle Basin and Northern Qinshui Basin.The naming place locates in Yungang Town,Datong City,Shanxi Province,and the Shiku Member is the middle section of Yungang Formation.It has been found in previous studies that the Yungang Formation in Datong Basin is mainly braided river deposit.In this research,three typical sections in the field outcrop of the study area were examined,the sedimentary features of the river facies in the Shiku Member were comprehensively analyzed,and following works were completed.Firstly,a sketch map was made for the three sections in the field outcrop of the study area,and an interface division scheme was established.Secondly,all the internal lithofacies,sedimentary structure and sedimentary characteristics of each unit were analyzed on the basis of interface division.Thirdly,on the basis of the sedimentary characteristics of each unit and through horizontal comparison between sections,the temporal and spatial relationship between fluvial facies deposits in the study area was clarified.Finally,the fluvial facies sedimentary model of the study area was clearly defined and the corresponding formation sketch.The research results may provide a data base for further studies of Jurassic sedimentary environment evolution in Datong Basin and future coal mining in Datong area.

关 键 词：大同盆地 云岗组 石窟段 辫状河沉积 沉积特征 

分 类 号：P512.2[天文地球—地质学]