摘要
廊坊-固安凹陷(简称廊固凹陷)为第三纪断陷,构造位置属于渤海湾盆地西部、冀中坳陷北部的一个次级构造单元。该凹陷西以大兴断裂为界与大兴凸起相接,东以牛东-河西务主断裂为界,与武清凹陷相连。呈北东向延伸,长约70—80km,面积约2800km^2。该凹陷的发育受大兴断裂控制,下第三系呈典型的箕状凹陷。断陷内次级断层十分发育,特别是由于本区始新统—渐新统发育了厚达千余米的泥岩层,形成了固安-北寺垡和曹家务-柳泉2个泥岩上拱构造带,泥岩构造顶部则发育复杂的地堑断裂系。廊固凹陷典型的构造样式为基底卷入型张性断块组合,但从盖层构造变形特征分析,早第三纪末本区曾受到过挤压作用的影响。
The Langfang-Gu'an hollow is tectonically a second-order tectonic unit in the western part of the Bohai Bay basin and in the northern part of the central Hebei depression.It is bounded on the west by the Daxing fault and on the east by the Niudong-Hexiwu fault.It extends in a NE direction for about 70—80 km,covering an area of about 2800 km^2.Its development was controlled by the Daxing fault and the Paleogene occurs as a listric hollow.An Eocene-Oligocene pelite bed up to over one thousand meters thick is developed in the area,thus forming the Gu'an-Beisifa and Caojiawu-Liuquan pelite updoming belts.A complex graben fracture system is developed at the top of the pelite structure.The typical structural style of the hollow is an extensional block association with the basement involved,but an analysis of the deformation features of the cover structure indicates that this area underwent compression in the terminal Paleogene.
出处
《地质论评》
CAS
CSCD
北大核心
1996年第S1期83-88,共6页
Geological Review
关键词
廊固凹陷
基底卷入型张性断块组合
泥岩上拱
局部性挤压反转
Langfang-Gu'an hollow
extensional block association with the basement involved
pelite updoming
local compressional inversion
