摘要
依托歧口凹陷最新超大面积三维地震对歧口凹陷结构构造、断裂活动及盆地演化特征开展系统研究,明确歧口凹陷古近纪早期(沙三早期)几个次凹间连通较好,到沙一末期、东营期逐渐受潜山构造的不断隆升而以水下低隆起相隔,控制了物源及水体。歧口凹陷具多期断裂活动叠加、断裂复杂的特点,其内部主要断裂在沙三期活动弱或不活动,沙一期、东营期是断裂主要活动期;歧口凹陷断裂活动有4幕:沙三中期、沙一中期、东营末期及明化镇末期,与研究区内规模较大的3期角度不整合:沙三1亚段底、沙一上亚段底和馆陶组底的形成关系密切。歧口凹陷具有显著的幕式构造演化的特征,可分为同裂陷和热沉降2个阶段,进一步可细化为裂陷Ⅰ幕(沙三段—沙二段沉积时期)、裂陷Ⅱ幕(沙一段—东营组沉积时期)、稳定热沉降幕(馆陶组—明化镇组沉积早期)和加速沉降幕(明化镇组沉积中后期)。
We use the new obtained super-large area 3D seismic data to deduce the structure feature,fault activities tectonic evolution in the Qikou sag.The results show that a good connection between sub-sags would occur at early Paleogene Period（Es3）.The separation between water and deposits was happened by the gradually uplift of the buried hill at the end of Es1-Ed tectonics.The superimposition of different phase tectonics was observed in the Qikou sag.With exception of boundary faults,the main faults in the Qikou sag were not active or moved weakly at the Es3 Period.We divide the tectonic activities into 4 epoches in the Qikou sag,including mid-Es3 Epoch,mid-Es1 Epoch,Ed Epoch end and Nm Epoch end.The unconformities exist between Es13,Ed and Ng,respectively.Two typical episodic stages in the Qikou sag could be divided,such as chasmic stage and thermal-depress stage.The two typical stages subdivide into four sub-epoches like as chasmic Ⅰ（Es3-Es2）,chasmic Ⅱ（Es1-Ed）,stable-thermal-depress epoch（Ng-Nmx） accelerrate-thermal-depress epoch（after Nmx）.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2011年第3期373-382,共10页
Natural Gas Geoscience
基金
中国石油天然气股份公司重大专项(编号:2008E-0601)资助
关键词
歧口凹陷
盆地结构
断裂活动
盆地演化
裂陷
热沉降
伸展
走滑
Qikou sag
Basin structure
Fault activity
Basin evolution
Rifting
Thermal subsidence
Extension
Strike-slip
