准噶尔盆地南缘地震速度异常解释

准噶尔工地南缘是地震速度异常较发育的地区，通过对阜康断裂带地质构造、岩性特征的分析，查明断裂上盘是由巨厚的上古生界至中生界所组成的逆冲断块以及沿山麓分布的冲积扇体，具有很高的层速度（＞３９００ｍ／ｓ），它们是造成该区地震速度陷阱的两个重要因素。针对该区地震速度平面变化剧烈的特点，采用人机联作分层制作速度平面图的方法，查清了盆地南缘地震速度的变化规律，从而提高了地震资料的处理质量，更准确地反映了地下构造形态，先后排除了台３＃区、小泉沟背斜、独北背斜的地震过度陷阶，进一步落实了独南背斜、西湖背斜的构造形态，有利地指导了该区的油气勘探工作。

INTERPRETATION OF SEISMIC VELOCITY ANORMALY IN SOUTHERN MARGIN OF JUNGGAR DASIN

The southern margin of Junggar Basin is the area that developed seismic velocity anomaly in general.By analysing the geologic structures and lithologic characteristics of Fukang fault zone,it is ascertained that layer veloci-ties of enormously thick thrust block(Upper Paleozoic-Mesozoic)and alluvial fan body distributed along the foot of the mountain are very high(>3 9 00m/s),they were two important factors which formed Seismic velocity pitfalls.Con-sidering the characteristics of stepness in lateral seismic velocity vatiations.the seismic velocity trends in southern margin of Junggar Basin were ascertained using interactive processing for layering to draw velocity sections,thus im-proving processing quality of seismic data and reflecting subsurface structural patterns more correctly. Seismic velocity pitful of WelI Tai 3 area,Xiaoquangou anticline and Dubei anticline were removed and structural patterns of Dunan anticline and Xihu anticline further determined.It is advantageous to guide oilgas exploration work in this area.