三塘湖盆地断裂构造特征

摘要

The faults and Structures in Santanghu basin were studied qualitatively and quantitatively by means of observed gravitational data, seismic and geologic research results. It is suggested that two major faults in this basin are distributed in NW direction, which are cut off bythe secondary faults in NW, NNW, NE, near-EW and near-SN in the depression zone. Under the long-term compressional stress, this ba- sin assumes such structural framework as ＂two uplifts and one depression＂, and impacted by the faulting activities, the depression belt ap- pears distribution in sag-swell alternation. It is concluded that having undergone the multi-stage tectonic movements, Santanghu basin is characterized by complex structures, faults development, the Mesozoic and Cenozoic sedimentary cap rocks distribution controlled by the%利用实测重力资料，结合地震、地质等研究成果，对三塘湖盆地断裂及构造特征进行定性和定量研究认为，盆地中2条主断裂呈北西向展布，坳陷带内的北西、北北西、北东、近东西和近南北向的次级断裂切断了主断裂；由于盆地长期处于挤压应力之下，使得盆地整体呈“两隆夹一坳”的构造格局，坳陷带因受断裂活动影响，形成了凹凸相间分布。三塘湖盆地经过多期构造运动改造，构造复杂，断裂发育，断层控制中、新生代沉积盖层的分布。