渤海湾盆地黄骅坳陷中北区新生代幕式沉降过程  

Cenozoic Episodic Subsidence in the Middle and North Part of Huanghua Depression,Bohai Bay Basin

作　　者：祁鹏[1] 任建业[1,2,3] 卢刚臣[1,4] 史双双[1] 佟殿君[1] 张俊霞[5] 

机构地区：[1]中国地质大学资源学院,湖北武汉430074 [2]中国地质大学构造与油气资源教育部重点实验室,湖北武汉430074 [3]教育部含油气盆地构造研究中心中国地质大学分中心,湖北武汉430074 [4]东方地球物理公司研究院大港分院,天津300280 [5]中国地质大学经济管理学院,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2010年第6期1041-1052,共12页Earth Science-Journal of China University of Geosciences

基　　金：国家重大科技专项(No.2008ZX05023-004-06);国家自然科学基金项目(No.40672089);国家重点基础研究发展计划"973"项目(No.2007CB41170502)

摘　　要：黄骅坳陷中北区是位于渤海湾盆地中部的一个重要新生代构造单元.构造层序界面分析、同生断裂活动和盆地沉降史回剥分析表明该区经历了幕式沉降过程,沉降中心显示出规律性的迁移演化特征.馆陶组底界面为区域性裂后不整合界面,将研究区的演化划分为裂陷期和裂后期.在裂陷期的充填序列中,沙一段底界面为整个研究区都可以识别的显著的角度不整合界面,以此界面为界,盆地的裂陷期进一步划分为裂陷Ⅰ幕和裂陷Ⅱ幕.裂陷I幕发育了Es3-Es2地层,断裂几何学和断裂的性质表明该幕构造活动为北西南东向伸展作用所致,而裂陷II幕发育了Es1-Ed地层,为近南北向拉伸作用的结果.裂后期,从早到晚则表现为由稳定热沉降到加速沉降的过程.分析认为上述盆地的幕式沉降过程与区域应力场的转变密切相关,受控于周缘板块的动力学事件,尤其是晚始新世之后,太平洋板块对欧亚大陆向西的加速俯冲,促使了郯庐断裂右旋活动向南延伸和穿过黄骅坳陷的兰聊断裂北段的活化,形成了位于渤海海域的南北向伸展叠加区,从根本上改变了黄骅坳陷中北区应力场的分布,由此导致了盆地同裂陷阶段的幕式演化.The middle and north area of Huanghua depression,located in the middle of the Bohai Bay basin,is a significant Cenozoic tectonic unit.This study area underwent the episodic subsidence and the subsidence center migrated regularly which was interpreted through the analysis of the tectonic-sequence surface,syn-sedimentary fault’s activity and the back-stripping of the subsidence history.The bottom interface of Guantao Formation is a regional post-rifting unconformity surface and divides the basin’s Cenozoic evolution into rifting and post-rifting stage.In the filling sequence of the rifting stage,the bottom interface of the first member of Shahejie Formation is also a regional recognizable angle disconformity surface in the whole basin and divides the rifting stage into Episodic Ⅰ and Episodic Ⅱ.The geometry feature and property of the fault system shows that the tectonic deformation of the study area was controlled by the NW-SE extending stress field in the rifting Episodic Ⅰ from Es3 to Es2.However,the extending stress field turned to NS in the Episodic Ⅱ from Es1 to Ed.In the post-rifting stage,the middle and north area of Huanghua depression underwent stable subsidence at early stage and accelerated subsidence at late stage.This episodic subsidence process is closely related to the change of the regional extending stress field orientation which was controlled by the tectonic events of the surrounding plates.Especially,the accelerated westward subduction from the Pacific Plate to the Eurasia Plate triggered the southward expanding of the dextral slipping of the Tanlu fault and the activity of the north section of the Lanliao fault through the Huanghua depression after the Late Eocene.The continued dextral slipping between the east and west boundary faults created a NS trending extensional overlap at the Bohai Sea,completely changed the stress field distribution in the middle and north area of Huanghua depression,and generated the episodic evolution in the rifting stage.

关 键 词：黄骅坳陷 幕式沉降 新生代 地质构造 

分 类 号：P542[天文地球—构造地质学]