黄骅坳陷中北区和歧口凹陷断裂构造特征及古应力分析

主要分析了黄骅坳陷中北区和歧口凹陷断裂构造特征。根据三维地震资料编制的Ｔ４和Ｔ０断裂纲要图表明，研究区断裂为伸展正断层，以ＮＥ向、ＮＮＥ向和ＥＷ向断裂为主。在不同时期，歧口凹陷断层走向发生明显变化，由沙一下段ＮＥ向变为上第三系的近ＥＷ向。在不同地段，伸展断裂具有不同的优势方向。横向变换带上发育的断裂也为伸展断裂，具有与主断层垂直相交的方向。通过对断裂古应力分析，黄骅盆地是伸展型盆地，推测其伸展作用为三维放射状，横向变换带也具有三维伸展特征，不存在横向挤压和走滑剪切作用。

CHARACTERISTICS OF FAULTS AND PALEOSTRESS ANALYSIS IN NORTH AND MIDDLE AREA OF HUANGHUA SUBBASIN AND QIKOU DEPRESSION

This paper mainly analyses the characteristics of the faults of the north and middle area in Huanghua subbasin and Qikou depression. According to the two schemetic maps of the faults from 3D seismic data, the extensional faults in this area trend mainly NE, NEE, EW, and minor other secondary direction. The episodic tectonic deformation development led to sharp differences among the strikes of the faults formed during different stages in south part of Qikou depression. The strikes of extensional faults developed in different areas have preferential direction. Moreover, the faults developed in transverse transfer zones are extensional and its trends are pendicular to master fault. Based on paleostress analysis of the faults, the extension of Huanghua subbasin and Qikou depression are 3D radial and the transverse transfer zones are characterized also by 3D radial extension without transverse compression and strike slip shearing.