【摘要】 环渤海地区是我国大陆东部强震的多发区,也是我国地震重点监测地区,环绕渤海地区已经开发并投产了包括辽河、冀东、大港、胜利以及渤海海域在内的一系列油田,因此环渤海地区一直是我国地质与地球物理学科的研究重点.本文利用重力数据结合人工地震探测剖面应用调和级数法对该地区的莫霍面深度进行了反演计算,并应用地质、重、磁、地震层析成像、人工地震探测、地热、应力等方面的成果资料,对研究区的地球物理场、地壳结构、地球动力学特征进行了探讨,希望对环渤海地区的深部结构、地球动力学、油气资源等研究有所帮助.通过反演计算结果和动力学特征的分析,得到了以下的认识:1)该地区的布格重力异常主要特征为从陆地向海洋,异常从负异常向正异常变化,反映了地壳厚度自西向东逐渐变薄的总体特征.磁异常在研究区北部地区变化较为剧烈,呈正负交错状.大部分海域地区表现为负磁异常场区.重、磁异常走向主要为NE、NNE向;2)研究区地壳厚度在31～40km,总体趋势为自西向东逐渐减薄,通过与地震层析成像结果比较,两个结果十分吻合;3)渤海盆地动力学机制应是周边各个板块水平运动的远程效应所造成的多期构造应力场作用下多方向的伸展、拉张而成,渤海湾盆地的形成是四个时期、两种动力作用交替影响的结果.更多还原

【Abstract】 Bohai Sea region is both the earthquake-prone areas of eastern Chinese mainland and China’s focused earthquake monitoring areas,meanwhile it has been developed and put into production around the Bohai Sea area including a series of oilfield,like the Liaohe,Jidong,Dagang,Shengli and the Bohai Sea,which shows the Bohai Sea region has been the focus of geology and Geophysics.In this paper,combined with the artificial seismic profiles,we apply the harmonic progression method to inverse the Moho depth of the region with gravity data,and use the results of geology,gravity,magnetism,seismic tomography,artificial seismic exploration,geothermy,and stress to research the geophysical field,the crustal structure and geodynamics of the study area,which is hoped to be helpful to understand the deep structure Geodynamics,oil and gas resources around the Bohai Sea area.Through the the inversion results and analysis of dynamic characteristics,we get the following understandings: 1) Bouguer gravity anomalies of the study area change from negative anomalies to positive anomalies,when they are from land to sea,which reflects the general characteristics of the crustal thickness thinning gradually from west to east.Magnetic anomalies in the northern region of the study area change more dramatically,alternated with positive and negative number.Most of the waters show negative magnetic anomalies.The main trend of gravity and magnetic anomalies is NE,NNE.;2) The thickness of the crust around the Bohai Sea area ranges from 31km to 40km,and the general trend is thinning from west to east,which coincides with the results of seismic tomography;3) Kinetic mechanism of the Bohai Basin should be that the multi-phase tectonic stress field caused by remote effects of the horizontal movement of the surrounding plates has made the multi-direction stretch and tension,and what made the formation of the Bohai Bay Basin should be alternately affected by four periods and two kinds of dynamic actions.更多还原