Beier Depression Tongbomiao Evolution Of Tectonic

Hailar Basin, which located in outer ring of Songliao Basin, is one of the typicallylarge sedimentary basins in China. It is no doubt that Hailar Basin is the next target forDaqing Oil Field Co. to Explore oil and gas resources. Hailar Basin has included16depressions and Beier Depression is located in central of Hailar Basin. According toprevious research, Beier Depression is a composite basin which early stage is rift basinand late stage is depressed basin. By the influence of ancient projections and control-concave fractures, the stratum in rift period of Beier Depression has two characters:segmentation and independence. Moreover, by the influence of several large-scaletectonic movements, the stratum in rift period was reformed violently, and this casedformation of faults system in this area. In the lecture by the results of previous studies,which include well logging data, Drilling data and earthquake data, the author analyzesthe feature about structural style and rift,which located in Tongbomiao Formation,Beier Basin, systematically and comprehensively. Furthermore, by such research, theauthor identifies unconformity, divides tectonic zones, constructs a modern stratumframework and makes a research about flat and section evolution in TongbomiaoFormation, Beier Basin. All these works has helped the author to recognize the featuresabout structures, natures, migrations and stores about oil and gas. At the same time, thislecture makes a basis for the next stage of exploration work.In the lecture seismic reflection zones in this area can be divided into5parts:T02,T5, T04, T22and T3, furthermore, T02and T5reflection zones can bedefined as1st tectonic unconformity reflections in extension environment, T04andT22reflection zones can be defined as1st tectonic unconformity reflections inextrusion environment,T23reflection zone can be defined as a1st tectonicunconformity reflections in extension environment. With the determination of1sttectonic unconformity reflection. We can divide the cover of platform in BeierDepression into3structural layers: Structural layer of Rift, which includes TongbomiaoFormation and Nantun Formation; Structural layer of Rift-Depression, which includesDamoguaihe Formation and Yimin Formation and Structural layer of Depression,which includes Qingyuangang FormationIn Mesozoic and Cenozoic periods, tectonic activities in Beier Basin were affectedby3main methods: Stretching rift, pull-apart and Sag of the third phase of construction;moreover, reformation in Nantun period, Yimin period and Qingyuangang period alsostand in a significant point in tectonic activities of Beier Basin. In sum, tectonicactivities, such as extension, extrusion, strike-slip and are pretty common tectonicactivities in this area and the present structural features are very complex. In this arearift zones which located in North-Northeast and Northeast-East are the main rift zones. Rift zones which located in North-Northeast and Northeast-East formed early andcontrolled the formation of the basin. Rift zones which located in Northwest-Westformed late and it mainly played a role about reformation. According to previousresearch, the tectonic style in this area can be located into3parts: extensional tectonicstyle, strike-slip tectonic style and positive reversal tectonic style.Furthermore, in the lecture ancient tectonic units of Tongbomiao Formation inBeier Basin were demonstrated by the theory of controlled faults in rift period andstructural framework which formed after Nantun period. In the lecture ancient tectonicunits in rift period of Beier Basin has been divided into7parts: Beixi third depression,Wunan secondary depression, Beizhong secondary depression, Beidong secondarydepression, Bayantala structural zone, Sudeerte structural zone and Buleihongbusiuplift zone.