Study On The Structure And Evolution Characteristics Of Seven Hulin River Depression In Hulin Basin

On the basis of extensive collection of previous research data and field work,this paper makes a comprehensive and in-depth study on the tectonic evolution of the seven Hulin depression in the Hulin basin in the eastern part of Heilongjiang province.The content includes the seismic data quality analysis of the seven Hulin depression,stratigraphic division and fine stratigraphic calibration,fine structure interpretation,regional structural features and fracture system research,and structural trap development characteristics.The characteristics of tectonic evolution and basin restoration of the seven Hulin River depression in Hulin basin are mainly studied,and the subsidence center of the basin is analyzed.Based on recent research results of seven Hulin River depression in Hulin basin,combined with previous studies,we draw the following conclusions:Under the influence of tectonic movement,the boundary of the first three member of the first member of the tiger in the first stage is double break and two super.Seven the overall trend of the Hulin Hedong depression is consistent with the fracture characteristics,the fault in this area is developed,the fault goes to the North East and the East,and the type of the large fault is mainly the strike slip normal fault.According to the regional tectonic characteristics,the seven Hulin depression can be divided into five secondary structural units,such as the northern gentle slope zone,the southern steep slope zone,the West subconcave,the East subconcave,the middle low uplift zone and the eastern fold belt.According to the fault distribution and tectonic evolution of the seismic section,the fault activity is divided into three stages.From the section of the section,the fault activity is divided into three stages.The Cretaceous Yun Mun mountain formation has developed the controlled Basin fault before the erosion,the tiger two period to the Cretaceous development base involved type fault,the tiger two to the Fujin formation caprock type fracture fault.In the layer and plane,the number of one or two faults in the early faults mostly controlled by the basin or the controlled tectonic zone is small but elongated and large;the late fault development is many,the basin sag and uplift are distributed and extended longer,and the middle faults are concentrated in the East and West subfoveal,and the extension is short and the number is few.The fault system in this area is complex and the fracture style is rich in seven main types: graben type,Horst type,Y shape,anti Y shape,complex Y shape,ladder like and negative flower fracture combination.The basin evolution has undergone the Cretaceous uplift and erosion,the continuous settlement of the Hulin formation and the uplift and erosion of the Fujin formation,and the subsidence of the basin.The subsidence center of the basin has been migrated many times,and the thickness of the strata is related to tectonic movement and basin control.