苏北盆地高邮凹陷古近系戴南组地震相研究

Study on the seismic facies of Dainan Formation of the Eogene in Gaoyou Sag, Subei Basin

为了全面地研究高邮凹陷戴南组的层序发育分布和沉积充填史,依据层序地层学的划分方法,将高邮凹陷戴南组划分为3个三级层序;根据地震反射参数,从内部反射结构和外部几何形态出发,结合反射同相轴的振幅和连续性,在高邮凹陷戴南组的地震反射剖面上识别出平行—亚平行席状、前积楔状、上超充填状、杂乱充填状以及杂乱席状等地震相类型.研究表明,这些地震相在平面上分布部位明确,纵向上具有继承性和差异性;地震相在空间上的分布与凹陷结构及构造演化有良好的对应关系.

Thestratigraphic sequence of Dainan Formation of Gaoyou Sag is divided in order to study the sequence distribution and the sedimentary filling history of it. Dainan Formation is divided into 3 sequences. And the seismic facies of Dainan Formation are identified according to the seismic reflection parameters and the amplitude and continuity of reflection events. They includes parallel and sub-parallel sheeted seismic facies, prograda-tional wedged seismic facies, onlap filling seismic facies, chaotic filling seismic facies and chaotic sheeted seismic facies. The plane locations of these seismic facies are definite, and they have succession and difference in vertical direction. Their spatial distribution corresponds to the structure and the tectonic evolution of Gaoyou Sag.