方正断陷三维区下切谷的形成及分布特征研究

Research on the Formation and Distribution Characteristics of Entrenched Valleys in the 3D of the Fangzheng Fault

发育在方正断陷的下切谷主要分布在区域不整合面之上,从区域上无法简单地用"顺源堆积"来解释。于是从断陷的构造演化角度出发,确认了方正断陷下切谷形成的两种填充模式。根据下切谷的定义和其在地震上的特征,在地震剖面上详细刻画出宝泉岭组底界面T3和白垩系顶界面T5的下切谷分布图。大致确定了下切谷在平面上的分布范围,进而能够更准确地判断物源方向,寻找出沟前扇体。因此,下切谷的研究为方正断陷三维区白垩系和下第三系细分层沉积相的研究提供了重要的指导依据。

The development in the entrenched valleys of the Fangzheng fault mainly distributed in the area above uncomformity surface,it can＇t be simply explained by using＂ accumulate along the source ＂in the region.So from the angle of the structural evolution,two filling mode about the formation of the entrenched valleys of the Fangzheng fault are notarized.According to the definition and the characteristics in seismic profile of the entrenched,the entrenched valleys distribution about the Baoquanling group＇s bottom interface（T3） and the Cretaceous system＇s top interface（T5） can be highly detailed out.As a result,the entrenched valleys distribution on plane roughly can be defined,and the provenance direction can be judged more accurately,then the precingular fan are loohed for.So,the search on the entrenched valleys offers important guideline basis for the research of the sedimentary facies,that about the Cretaceous system and the Eofene system subdivision of reservoir in the 3D of the Fangzheng fault.