渤海湾盆地惠民凹陷中央隆起带张扭性断裂演化的构造物理模拟研究  

Analogue Modeling of Fault Evolution of Central Uplift Belt in Huimin Sag,Bohai Bay Basin

作　　者：王衍迪 王毛毛 闫兵 汤梦静[2] 贾红义[2] WANG Yandi;WANG Maomao;YAN Bing;TANG Mengjing;JIA Hongyi(College of Oceanography,Hohai University,Nanjing 210098,China;Geophysical Research Institute,Shengli Oilfield Company,SINOPEC,Dongying 257022,China)

机构地区：[1]河海大学海洋学院,南京210098 [2]中国石化胜利油田有限公司物探研究院,东营257022

出　　处：《高校地质学报》2024年第1期22-35,共14页Geological Journal of China Universities

基　　金：国家自然科学基金(42172232);中石化胜利油田分公司课题(YKK2005)联合资助。

摘　　要：惠民凹陷位于渤海湾盆地济阳坳陷西部,新生代时期经历了南北向伸展,形成了典型的“北断南超”半地堑结构。平面上,惠民凹陷中央隆起带发育了NE至近EW向的张扭断裂体系;垂向上,中央隆起带断裂体系从深部到浅部呈现出由雁列式分段到逐渐连接贯通的特征。目前对惠民凹陷中央隆起带断裂体系的结构特征有了较好的刻画,但是对于该断裂体系形成的运动学过程及其控制因素仍然停留在描述阶段。文章设计了一组张扭构造物理模拟实验,以探究惠民中央隆起带断裂构造演化过程及其控制因素。实验再现了惠民凹陷中央隆起带断裂体系在平面上由早期孤立分段、侧向传播、最终贯通的三个阶段;在剖面上也很好对应了中央隆起带沿走向由共轭断裂系向阶梯式断裂的结构转变特征。基于粒子成像测速(PIV)的应变分析,文章构建了三阶段的应变—断层距离统计图,揭示了各分段断裂由早期无连接,经历侧向生长,从软连接到硬连接的构造演化过程。研究证实在南北向区域伸展作用下,盆地基底NEE向先存断裂的活化是惠民凹陷中央隆起带张扭构造形成的根本原因。文章利用砂箱构造物理模拟实验揭示了惠民凹陷中央隆起带断裂发育的机制,可为类似的张扭性断陷盆地的断裂演化与油气成藏研究提供有益的启示。The Huimin Depression is located in the western part of the Jiyang Depression in the Bohai Bay Basin,which has undergone a north-south extension during the Cenozoic period,forming a typical half graben structure.In the plane,a NE to near-EW oriented transtensional fault system is formed in the Central Uplift Belt(CUB)of the Huimin Sag.Vertically,the fault system of the CUB shows the characteristics from en-echelon to gradual connection from deep to shallow level.The structural characteristics of the Huimin CUB fault system have been well characterized,but its kinematic processes and controlling factors remain descriptive.In this paper,a set of transtensional analog modeling experiments are designed to investigate the faults evolution of the Huimin CUB.Our experiment reproduces the three stages of the fault system in the CUB of the Huimin Sag from early isolated segmentation,lateral propagation,and finally linking in the plane.In the profiles,the experimental results also correspond well to the structural changes of the CUB from a conjugate structure to a stepped faulting pattern along the strike.Based on the strain analysis by particle imaging velocimetry(PIV),this paper constructs a three-stage strain-distance statistics diagram for each segmented fault.It reveals the structural evolution of each segmental fault from early disconnected through lateral growth,from soft-to hard-linkage.This paper reveals the mechanism of faults development in the Huimin CUB based on sandbox analog modeling experiments.It can provide insights for the study of fault evolution and hydrocarbon forma tion in other similar transtensional basins.

关 键 词：构造物理模拟 张扭构造 断层连接 构造转换带 惠民凹陷 中央隆起带 

分 类 号：P542[天文地球—构造地质学]