【摘要】 通过对三维地震、钻井岩心及录测井资料的详细分析解释,发现青东凹陷古近纪不同演化阶段的构造特征存在着差异性:孔店期-沙四早期青东凹陷以NW向断层控盆为主,整体断层数量较少,但规模较大;沙四晚期断层数量明显增多,各个方向控盆断层均有发育,NW向的青东12断层消亡,主要以NWW和近EW向断层活动为主;沙三-沙二期控盆断层走向主要为NE和NEE向。这种构造格局的转变导致了相应的盆地转型,青东凹陷孔店期表现为受郯庐断裂带左旋走滑应力场控制之下的一系列北东断南西超的北西向半地堑,地层沉积厚度大;沙四期青东凹陷表现为NWW与近EW向兼有的复合盆地格局,为盆地转型阶段;沙三期、沙二期受郯庐断裂带右旋走滑应力场的影响,盆地格局完全转为近EW和NE(E)向,开始发育北断南超的半地堑和双断式堑垒构造。更多还原

【Abstract】 Based on the three dimensional seismic, drilling, and core data, the structural features of the Qingdong sag is analyzed. The results show that the structure features varied for each evolution stage of Paleogene. The basin is mainly controlled by the NW-trending faults from the deposit stage of Kongdian Formation to the later deposit stage of the 4th member of Shahejie Formation, however, the faults were scarce but large. The number of faults increased significantly in the early deposit stage of the 4th member of Shahejie Formation, then the basin controlling faults of every direction developed, but the Qingdong 12 fault of NW direction disappeared, while the active faults were mainly NWW and EW trending. The basin controlling faults mainly trended to NE and NEE in the deposit stage of the 2nd and 3rd member of Shahejie Formation. So, the evolution of the structure pattern led to the transformation of the basin. The sag was made up of NW-trending half-garbens with faulting in northwest and overlapping in southeast in the deposit stage of Kongdian Formation, and was controlled by sinistral strike-slip stress field of the Tanlu fault zone which resulted in thick sedimentary strata. During the deposit of the 4th member of Shahejie Formation, the sag was at a transitional period being characterized by composite basin pattern with NWW and EW-trending . Under the influence of dextral strike-slip stress of the Tanlu fault zone, the basin pattern transformed to be mainly EW and NE trending, and began the development of the half-garbens with faulting in north and overlapping in south and graben-horsts.更多还原