摘要
渤南地区郯庐断裂带具有很好的油气勘探前景,但由于其构造特征复杂,目前对渤南地区油气成藏条件、主控因素及富集规律的认识尚不明晰.通过对三维地震和地质资料的分析解释,结合前人研究成果,探讨了渤南地区郯庐断裂带构造特征的时空差异及其对盆地结构的控制作用.研究表明,渤南地区郯庐断裂带具有3组分支断裂,每组分支断裂由2~4条断裂构成,均表现出了明显的走滑特征,整体由东向西、由深至浅走滑程度逐渐减弱.新生代古新世-早始新世郯庐断裂带渤南段左旋走滑,东部分带活动明显、强度大,中带和西带不活动或活动较弱,渤南地区中生代发育的NWW向伸展断裂系统复活,形成北断南超的复式半地堑或南北双断式结构;中始新世以来,渤南地区郯庐断裂带转为右旋走滑,3组分支断裂均开始活动,表现为强烈的走滑兼伸展运动,强度由东向西逐渐减弱,中带分支断裂形成的中央构造脊将黄河口凹陷分割成东、西两个次洼,并开始逐渐发育一系列次级断层,与主断裂构成帚状断裂组合;新近纪-第四纪郯庐断裂渤南段表现为右旋走滑兼挤压,主走滑断裂不连续,代之以大量规模较小的次级断裂系统.太平洋区板块俯冲方向、俯冲速率的变化以及深部动力背景的变迁共同造成了渤南地区郯庐断裂不同分支构造发育演化及其控盆作用的差异性,由于右旋走滑位移量小于先期的左旋走滑,现今渤南地区构造单元分布仍具左旋特征.
Tan-Lu fault zone in the south area of Bohai Sea has a good prospect for oil and gas exploration.However,due to its complicated structural features,the understanding of hydrocarbon accumulation conditions,main controlling factors and enrichment regularity is not clear at present.On the basis of the previous studies,3D seismic data and geological information,the structural characteristics and spatiotemporal differences of Tan-Lu fault zone in the south area of Bohai Sea and the control of the development and evolution of Tan-Lu fault zone on the basin structure are studied in this paper.The results show that Tan-Lu fault zone in the south area of Bohai Sea has three branches,each of which is composed of 2-4 faults presenting strike-slip characteristics.The strike-slip strength gradually weakens westward.From Paleogene to Early Eocene,Tan-Lu fault zone in the south area of Bohai Sea presented sinistral strike-slip characteristics.The eastern branch experienced intense strike-slip movement,whereas the middle and western branches moved slightly,and the NWW-trending extensional faults which developed in Mesozoic renewed.Basin in the south area of Bohai Sea shows as a halfgraben with northern-faulted and southern-overlapped structural setting or a graben with both northern and southern faulted settings.From the Middle Eocene,Tan-Lu fault zone turned into dextral strike-slip movement.The three branches started to activate and showed both strike-slip and extensional properties.The intensity of fault activity gradually weakened from east to west.The middle branch divided the Huanghekou sag into two subsags.A series of secondary faults formed the broom-like structure combined with the main fault.From Neogene to Quaternary,Tan-Lu fault zone presented dextral strike-slip as well as extrusion movement in the study area and a large number of small-scale secondary faults have developed.The change of subduction direction and rate of Pacific plate and the variation of deep geodynamics mechanism induce the differences of the evolu
作者
张婧
李伟
吴智平
李春锐
杨波
张晓庆
Zhang Jing Li Wei Wu Zhiping Li Chunrui Yang Bo Zhang Xiaoqing(School of Geosciences, China University of Petroleum, Qingdao 266580, China Laboratory for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China Research Institute of Bohai Oil Field, CN（X）C Tianjin Branch Company, Tianjin 300452, China)
出处
《地球科学（中国地质大学学报）》
EI
CSCD
北大核心
2017年第9期1549-1564,共16页
Earth Science-Journal of China University of Geosciences
基金
国家油气重大专项课题(No.2011ZX05023-006-05)
关键词
构造特征
构造演化
走滑运动
新生代
郯庐断裂带
渤南地区
油气
structural characteristics
structural evolution
strike-slip movement
Cenozoic
Tan-Lu fault zone
south area of Bohai Sea
hydrocarbons
