【摘要】 拉分盆地指沿着走滑断裂带弯曲部位,由于拉张而产生的地形上的低洼处,多形成于走滑断裂带次级断裂的间列部位。拉分盆地研究对于探讨走滑断裂扩展方式及分段性意义重大;分布于大型走滑断裂带上的拉分盆地,对于断裂带上地震临震预测具有一定的指示作用;此外,该类盆地往往与油气资源、成矿热液的运移、聚集、产出关系密切。本文在综述前人对拉分盆地演化过程中几何学、地貌学特征变化的基础上,选取了发育于富蕴断裂带上的小型拉分盆地为研究对象,借助后差分测量仪器——SOUTH北极星9600及其配套软件SOUTHGPS与SOUTHCASS7.0等研究手段,获得了该盆地的等高线模型,并结合拉分盆地三维沉降模型与富蕴断裂带走滑断裂特征,估算其滑脱面的深度为40m;根据地震前后盆地的拉分与沉降的模式;探讨了拉分构造中水平错断与垂直沉降的转化关系以及拉分盆地的三维演化问题。更多还原

【Abstract】 The pull-apart basin formed around the steps of the strike-slip fault refers to a low terrain area due to tensile force from the fault.The study of pull-apart basins especially the ones occurring along the large-scale strike-slip faults not only plays an important role in the research on strike-slip fault’s expansion and segmentation but also has some significance in the prediction of impending earthquake along the fault.Besides,these basins usually provide space for the migration,accumulation and production of oil,gas and mineral resources.The authors summarized the geometric and geomorphologic features of the evolution of the pull-apart basin based on previous research results,and chose a small pull-apart basin along the Fuyun fault to study its geometric and geomorphologic characteristics.Based on the survey using the differential global positioning system(DGPS) measurement instruments——SOUTH 9600 Polaris and data processing using SOUTH GPS and SOUTH CASS7.0 software,the authors constructed the contour pattern of the basin.Then,according to the model which explains the offsetting and sinking change of the pull-apart basin before and after the earthquake,the authors calculated the depth of its detachment,which turns out to be about 40 m below the surface.On such a basis,the relationship between the pull-apart’s horizon offset and vertical sinking is concluded,and the three-dimensional evolution features of the pull-apart basin are deduced.更多还原