【摘要】 依据海域油气勘探和地质资料,对辽东湾坳陷磷灰石裂变径迹年龄、典型地震剖面的深入研究和沉积构造特征及构造演化等综合分析表明:辽东湾坳陷在新生代发生了3期构造抬升及剥蚀事件,主要发生在中新世末—上新世初(对应的峰值年龄为5~7 Ma)、渐新世东营期末—中新世初(峰值年龄为18~22 Ma、24~26 Ma)、始新世沙河街组三段沉积末(峰值年龄为36~40 Ma)。这3期构造抬升事件的特点为南早北晚、南强北弱,说明在空间上具有差异性。在始新世,坳陷东部为一有巨厚沉积的较大型凹陷,沙河街组三段沉积后受断裂切割改造今辽东凸起开始显现并遭强烈剥蚀,致使较大型凹陷被辽东凸起分隔为两凹(今辽中、辽东凹陷)夹一凸结构。此改造过程与郯庐断裂活动特征及强度的改变有关,显示出辽东湾坳陷东、西部抬升特点和后期改造强度的明显不同。辽东湾坳陷古今构造格局及演变,与区域动力学环境及背景紧密相连,这3期构造抬升事件,在中国东部具有较广泛的响应表现和区域动力学背景,意义重要,对其研究有助于进一步完善和深化对中国东部及近海等新生代盆地的整体认识,为中国东部区域动力学环境及背景研究和油气勘探、资源评价提供基础资料和科学依据。更多还原

【Abstract】 On the basis of oil and gas exploration and geological data of the Bohai sea,we carried out the apatite fission track dating of the core,the interpretation of the seismic profiles,and the analysis of sedimentarytectonic characteristics and tectonic evolution of the Liaodong Bay Depression;the study suggested that there were three tectonic uplift and erosion events in the Liaodong Bay Depression in the Cenozoic,which occurred in the late Miocene-early Pliocene(corresponding peak age of 5-7 Ma),in the end of Dongying period in the Oligocene-early Miocene(corresponding peak age of 18-22 Ma and 24-26Ma),and in the end of the third period of the Shahejie in the Eocene(corresponding peak age of 36-40 Ma),respectively.These tectonic uplift events were different in different places:the events that happened in the southern part are earlier and stronger than in the northern part.In the Eocene,there was a big depression containing very thick sediment in the east of the study area.But after depositing,the third section of the Shahejie was reformed by fault-cutting,and the Liaodong Uplift was formed and eroded strongly,so that the structure of"a rise in between two sags"was formed in the larger depression.The transformation process is relevant to the changes in activity feature and intensity of Tan-Lu Fault;it may cause the difference in uplift characteristics and in the strength of later transformation between east and west in the Liaodong Bay Depression.The change in tectonic pattern of the Liaodong Bay Depression was related to regional dynamic environment and background closely.These three tectonic uplift events have profound impacts on East China.So our study is helpful in further improving and enhancing the entire understanding of Cenozoic basins in eastern China and offshore,and provides basic data and scientific basis for the study of regional dynamic environment and background,petroleum exploration and resource evaluation in East China.更多还原