李三忠, 索艳慧, 郭玲莉, 戴黎明, 周立宏, 楼达. 渤海湾盆地大歧口凹陷变换构造与板内变形差异[J]. 海洋地质与第四纪地质, 2017, 37(4): 98-109. DOI: 10.16562/j.cnki.0256-1492.2017.04.006
引用本文: 李三忠, 索艳慧, 郭玲莉, 戴黎明, 周立宏, 楼达. 渤海湾盆地大歧口凹陷变换构造与板内变形差异[J]. 海洋地质与第四纪地质, 2017, 37(4): 98-109. DOI: 10.16562/j.cnki.0256-1492.2017.04.006
LI Sanzhong, SUO Yanhui, GUO Lingli, DAI Liming, ZHOU Lihong, LOU Da. TRANSFER ZONES AND DIFFERENCES IN INTRA-PLATE DEFORMATION IN GREAT QIKOU SAG OF THE BOHAI BAY BASIN[J]. Marine Geology & Quaternary Geology, 2017, 37(4): 98-109. DOI: 10.16562/j.cnki.0256-1492.2017.04.006
Citation: LI Sanzhong, SUO Yanhui, GUO Lingli, DAI Liming, ZHOU Lihong, LOU Da. TRANSFER ZONES AND DIFFERENCES IN INTRA-PLATE DEFORMATION IN GREAT QIKOU SAG OF THE BOHAI BAY BASIN[J]. Marine Geology & Quaternary Geology, 2017, 37(4): 98-109. DOI: 10.16562/j.cnki.0256-1492.2017.04.006

渤海湾盆地大歧口凹陷变换构造与板内变形差异

TRANSFER ZONES AND DIFFERENCES IN INTRA-PLATE DEFORMATION IN GREAT QIKOU SAG OF THE BOHAI BAY BASIN

  • 摘要: 以大歧口凹陷大面积高精度三维地震资料为基础,并结合前人的研究成果,系统分析了大歧口凹陷变换构造与板内其他块体间的变形差异。从对不同级别构造的控制作用分析,大歧口凹陷的变换构造带可以划分为3个级别:(1)近南北向的主变换带(也称一级变换带),自西向东依次为孔店东变换带、沿岸变换带和羊二庄变换带,分别对应了大歧口凹陷西部、沿岸和羊二庄3条基底走滑断裂带。这3个主变换带起到了协调大歧口凹陷东西两侧构造样式差异的作用。(2)近东西向的次变换带(也称二级变换带),自北向南依次对应大歧口凹陷的汉沽、海河-新港和歧中3条控凹断裂。这3条近东西向的控凹断裂起到了调节黄骅坳陷北、中、南三区变形差异的作用,致使大歧口凹陷主变换构造带近南北向的发育。(3)三级变换带,一般垂直于主控断裂发育,起到传递断裂之间伸展量的作用。大歧口凹陷变换构造带主要有边界主控断层的影响、先期基底构造的控制和新生代不均匀伸展作用的影响3个成因。变换构造带的存在和发育使大歧口凹陷内部不同时期的不同块体存在时空上的差异变形,造成了凹陷内部构造样式的差异。受太平洋板块后退式俯冲和印度-欧亚板块挤压碰撞作用的影响,黄骅坳陷新生代以来处于右旋拉张应力场作用下,表现出早期裂陷、后期拉分断陷的特征; 其区域主构造应力场由孔店-沙四期的WNW—ESE向拉伸变为沙三-东营期的NW—SE向拉伸,到新近纪又发展为近N—S向拉伸,总体呈顺时针旋转,而这样一个构造演化过程正好可以用黄骅坳陷内大歧口凹陷的发育和演化拉分模式来成功解释。

     

    Abstract: Based on the newly acquired high-resolution 3D seismic data, we analyzed the transfer zones and their bearing on differences in intra-plate deformation in the Great Qikou Sag of the Bohai Bay Basin. The transfer zones in the Great Qikou Sag can be subdivided into three orders: (1) The first-order N—S-trending major transfer zones from west to east, i.e. the East Kongdian Transfer Zone, the Coastal Transfer Zone, and the Yangerzhuang Transfer Zone, corresponding to three basement-involved strike-slip faults, respectively. The three zones play an important role in reconciling the differences in structural styles of the west and east sides of the Great Qikou Sag. (2) The three second-order transfer zones roughly in E—W trending, including the Hangu, Haihe-Xingang, and Qizhong transfer zones, corresponding to the three subbasin-controlling faults from north to south, respectively. They play a role in adjusting the differences between the south, the middle, and the north parts of the Huanghua Depression. (3) The third-order transfer zones are generally perpendicular to its master fault, with the function to transmit the extension among faults. The origin of transfer zones in the Great Qikou Sag varies. The master boundary faults control over the basement-involved structures and differentiation of Cenozoic extension. The existence and development of different transfer zones in the Great Qikou Sag may cause different deformation in different periods and different faulted-blocks in the Huanghua Depression, resulting in differences in structural styles of the different parts of the Great Qikou Sag. For examples the Huanghua Depression is influenced by the roll-back subduction of the Pacific Plate and the collision between the Indian Plate and the Eurasian Plate. The depression is under a dextral transtensional stress field in the Cenozoic, resulting in rifting during the early evolutionary period, and pull-apart faulting during the later evolutionary period. Its principal regional stress underwent clockwise rotation in Cenozoic, from the NWW—SEE-trending extension during the Kongdian- Shasi period to the NW—SE-trending extension during the Shasan-Dongying period, and near N—S-trending extension during the Neogene. Such an evolutionary process can be used to successfully explain the development and evolution of the pull-apart Great Qikou Sag.

     

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