摘要
利用研究区的地震勘探资料对辽西凹陷北部断裂体系进行分析,发现区内存在典型的走滑断层,这些走滑断裂均在前新生界基底收敛于新生代辽西凹陷中心部位,应该为先存基底断层在新生代始新世沙河街组三段沉积以来(40 Ma左右)右旋走滑再活动的产物。其与辽河西部凹陷内新生代郯庐右旋走滑断层可较好地延伸走向相连或平行相接,在活动时间和展布特征上与辽河拗陷陆上部分及辽东凹陷内的新生代郯庐右旋走滑断层均具有很好的走向连续一致性,这表明40 Ma以来,郯庐断裂带在整个辽河拗陷均具有东西两支平行展布的特征,且该特征应源于郯庐断裂带在该区前新生代东西两支的发育模式。区内走滑断层的存在,在凹陷内部形成系列洼中隆构造构成的中央构造带,这一构造带是油气聚集的有力圈闭发育区带。
The north part of the Liaoxi graben is located in the transition region from onshore part to the offshore part of the Liaohe sub-basin in the Bohai Bay Basin. Thus investigations on fault system in this area are the key to understand how the Tan-Lu Fault Zone extends from the onshore to offshore of the basin. In this study,we analyzed the fault system in the north part of the Liaoxi graben with abundant new exploration seismic data. The result shows that typical Cenozoic dextral strike-slip faults occurred in the study area,and these strike-slip faults belong to Tan-Lu Fault Zone. All the strike-slip faults within the graben merge at depth basement level with a central subvertical basement fault,and they were induced by the reactivity of the pre-existing subvertical basement fault after the deposition of the third member of the Eocene Shahejie formation( ~ 40 Ma). The strike-slip faults in the north part of the Liaoxi graben connect with the Cenozoic strike-slip faults in the west part of the onshore Liaohe sub-basin,and are similar with the strike-slip faults in the other areas of the Bohai Bay Basin in aspects of kinematics,evolutionary history,and distribution. It indicates the TLFZ in the whole Liaohe sub-basin consists of two branches,furthermore,this Cenozoic distribution characteristics is inherited from that of the Pre-Cenozoic TLFZ. Due to the existence of the strike-slip faults within graben,many anticline structures occurred in the location of fault restraining bends and stepovers along the strike-slip faults,forming a central structural belt which is very benefit to the hydrocarbon accumulation.
作者
黄雷
刘池洋
王飞龙
吴奎
王广源
赵志平
HUANG Lei;LIU Chiyang;WANG Feilong;WU Kui;WANG Guangyuan;ZHAO Zhiping(State Key Laboratory of Continental Dynamics,Northwest University,Xi'an 710069,China;Tianjin Branch of CNOOC China Limited,Tianjin 300452,China)
出处
《西北大学学报（自然科学版）》
CAS
CSCD
北大核心
2019年第2期258-267,共10页
Journal of Northwest University（Natural Science Edition）
基金
国家自然科学基金资助项目(41602111)
陕西省高校青年创新团队(2019-45)
关键词
渤海海域
辽河拗陷
郯庐断裂带
右旋走滑
油气聚集
Bohai Sea
Liaohe sub-basin
Tan-Lu Fault Zone
dextral strike-slip motion
hydrocarbon accumulation
