Abstract: Based on the recent 3D seismic data，it is represented that the Yihantong fault（FZ3）is a main interior fracture of the Fangzheng Fault-Depression，which shows an obvious constraints in the Paleogene sedimento-tectonic evolution of the fault-depression.In addition，two other interior fractures，namely，the FZ4 and FZ5 faults, are determined by the data.Combined with characteristics of the FZ6 and FZ7 faults，the new understanding of the interior framework of Fangzheng Fault-Depression can be summarized to be that it is zonated transversely with the Yihantong fault being a boundary，and divided into three segments longitudinally.The sedimento-tectonic evolution in the Paleogene，separated into four periods，namely，the faulting period(Paleocene-Eocene)，the compression and uplifting period(end of the Eocene)，the differential subsidence period(Oligocene)and the inversion period(end of the Paleogene)，is reconstructed，which indicates that the east belt of the fault-depression，characterized with deeper subsidence and better developed strata，should be a new and important field for the future oil-gas exploration.

Key words: Heilongjiang Province,Fangzheng Fault-Depression, fault structure, sedimento-tectonic evolution, Paleogene

摘要： 依据黑龙江东部方正断陷新的三维地震资料，重新厘定了其主干断层——伊汉通断层（FZ3），发现该断层规模明显变大，对断陷的沉积-构造演化具有明显的控制作用。依据对伊汉通断层的新认识和FZ4、FZ5断层的发现，以及FZ6和FZ7断层的特征，确定方正断陷内部结构具有南北向（走向）分段、东西向（横向）分带的特点，并将方正断陷的沉积-构造演化划分成古近纪古新世—始新世的断陷期、始新世末的挤压隆起期、渐新世的差异沉降期和古近纪末期的挤压反转期4个阶段，指出东部凹陷埋藏深、面积大，是方正断陷新的油气勘探领域。

CLC Number: 

• P54