摘要
印支—燕山期,研究区中古生界形成的逆冲推覆构造具有广泛分布、类型多样、地层卷入差别明显的特点,多阶段、多期次的构造演化过程,导致多个构造层及展布方向不同的构造带发育.本次通过对新、中、古生界叠置盆地的断裂性质、构造类型、特征进行分析解剖,系统总结了王官屯—乌马营地区上古生界逆冲推覆带各段的构造变形特征.研究认为:印支期研究区为宽缓背向斜构造特征,燕山期具有深层叠瓦冲断厚皮构造(基底卷入型)与浅层滑脱推覆薄皮构造(盖层滑脱型)的纵向双层变形结构;在不同方向的挤压应力作用下,下古生界具有由南向北高角度叠瓦逆冲拆离的背、向斜特征,上古生界—中生界则具有由北西向南东逆冲推覆构造特征,滑脱面为中奥陶统底部下马家沟组泥页岩层段与石炭系煤系地层;新生界则为构造反转与左旋剪切张扭构造,并对下伏中古生界挤压构造具有一定的改造作用.此外,文章总结了中古生界逆冲推覆带各段五种典型构造样式类型及其形成机制,通过构造演化研究认为,研究区经历了稳定地台期、宽缓背向斜产生期、滑脱推覆期、构造反转剪切-张扭改造期、断陷-拗陷沉降改造期,以不整合面为界,上、下正负向盆地构造表现为镜像对应的叠置关系,前新生界重要角度不整合面为印支—燕山期两期多幕剥蚀、削截的结果.
In the lndosinian-Yanshanian period,the MesozoicPalaeozoic thrust nappe structure was provided with wide distribution,various types and different formation in the study area.Multi-stage,multi-period tectonic evolution process,lead to a number of different structural layer and the distribution direction structure zone development. In the Tectonic interpretation,it has summarized the typical tectonic deformation characteristics in the nappe belt,based on the analysis of the fracture structure nature and type. Research suggests that it was the wide and flat back,syncline structure feature in the lndosinian period,deeply imbricated thrust thick skinned tectonics and shallow decollement thin skinned structure longitudinal double-layer structure deformation in Yanshanian period： deep imbricate thrust thick skinned tectonics and shallow decollement thin skinned tectonics in the Mesozoicpalaeozoic group. It also put forward that the lower Paleozoic has a far distance and high angle imbricate thrust clamping anticlinessynclines feature from south to north,for the involved structure. The upper Paleozoic-Mesozoic has a thrust nappe feature from northwest to southeast,for the decollement structure. The coal strata,in the bottom of the carboniferous strata and the mud shale section undering the middle ordovician Majiagou group are the slipping surface. The Cenozoic is a negative structure inversion gliding fracture and sinistral-transtensional tectonics as well as a modified effect on the Mesozoic and Paleozoic tectonic. Besides,It has summarized five kinds of the typical tectonic styles and the formation mechanism in the nappe belt. From such an analysis,the study area experienced a stable platform period,rolling anticline and syncline period,decollement nappe period,tectonic inversion period,faulteddepression sedimentation period. It is also an angle unconformity surface in the area,which was denuded for two phase of the multistage in lndosinian-Yanshanian period,By the unconformity surface,structure of the upper and lower basin performance for a corresponding superimposed relationship.
作者
董政
佘晓宇
许辉群
李冬冬
DONG Zheng;SHE Xiao-yu;XU Hui-qun;LI Dong-dong(Key Laboratory of Exploration Technology for Oil Gas Resources,Ministry of Education,Yangtze University,Jingzhou,Wuhan 430100,China;School of Geophysics and Oil Resources,Yangtze University,Wuhan 430100,China;Shenzhen Branch of CNOOC Limited,Guangdong Shenzhen 518054,China)
出处
《地球物理学进展》
CSCD
北大核心
2018年第5期1773-1782,共10页
Progress in Geophysics
基金
"大港南皮古生界碎屑岩潜山储层研究"项目资助
关键词
逆冲推覆
滑脱层
构造特征
构造演化
中、古生界
王官屯—乌马营地区
thrust nappe
slip layer
tectonic characteristics
tectonic evolution
Mesozoic-Palaeozoic
Wangguantun-Wumaying region
