摘要
通过对大同盆地内沉积地层的岩性、结构、厚度等地质特征及相应的沉积环境和沉积相进行研究,结合构造的演化及控制作用,认为大同盆地形成于中生代晚侏罗世末期—早白垩世早期,其构造演化可分划为白垩纪箕状断陷形成、新近纪典型箕状断陷发育和第四纪盆地定型3个阶段。该区充填历程复杂,包括3个构造层,分别为白垩纪初始沉降、新近纪快速断陷、第四纪盆地扩展坳陷;3期断裂发育期,分别为白垩纪早期、保德组沉积早期及泥河湾组沉积晚期;5个不整合面。大同盆地及其周边地区,在燕山运动以前存在EW向褶皱构造,燕山运动后NW—SE向的挤压作用叠加在近EW向构造之上。此后尽管遭受了十分强烈的剥蚀作用,但是在近EW向和NE向两组褶皱向斜核部的叠加部位,仍残留晚古生代及中生代地层。
Integrating the tectonic evolution and control,and geological characteristics(e.g.,structure and thickness)of the sedimentary sequence,the sedimentary facies and environment of the Datong basin are summarized.It is suggested that the Datong basin was formed in the Early Mesozoic(end Late Jurassic to Early Cretaceous),and its tectonic evolution comprises three stages:fault depression formation,half-graben development,and basin formation.This area was not only filled with tectonic layers during the three periods,but also developed faults in the early of Cretaceous,early deposition of Baode Formation and late deposition of Nihewan Formation.Besides five unconformities was showed in the field survey.In the Datong basin and its surrounding areas,EW-trending fold structure likely existed before the Yanshanian movement,and NW-directed compression may have superimposed on the EW-trending structure after the movement.After that,despite strong denudation,the Late Paleozoic and Mesozoic strata remained in the superimposing synclinal nuclei of the EW-and NE-trending folds.
作者
刘爱荣
徐永婧
刘成林
庞尔成
LIU Airong;XU Yongjing;LIU Chenglin;PANG Ercheng(No.211 Geological Team,Shanxi Province Geological Prospecting Bureau,Xinzhou,Shanxi034000,China;No.217 Geological Team,Shanxi Province Geological Prospecting Bureau,Datong,Shanxi037008,China)
出处
《现代地质》
CAS
CSCD
北大核心
2021年第5期1296-1310,共15页
Geoscience
基金
国家自然科学基金基础科学中心项目(41688103)。
关键词
大同盆地
地质特征
构造演化
箕状断陷
早白垩世
Datong basin
geological characteristic
tectonic evolution
half-graben-like depression
Early Cretaceous
