Abstract: The basement of the Tertiary continental rift basin in Bohai Bay is North China platform, in the south of which lies Dongpu depression. We discovered from seismic sections a big old overthrust fault (Xinluo overthrust fault) inside the basement at the upthrow side of the boundary fault(Lanliao fault) of Dongpu depression. Well Luo 1, designed according to this geological concept, has shown preliminary evidence. On seismic sections, the two big faults (Xinluo and Lanliao faults) intersect to form a large roof-like overthrust fault block zone. This fault block zone adjacent to oil source depression should have unique and ideal condition for petroleum occurrence, and may become a new area for oil-gas exploration. The discovery of this overthrust fault in the platform area has both practical and academic significance. This paper describes the seismic" reflection configuration of the overthrust fault and its fault block zone, analyses the trapping condition and oil-gas accumulation mechanism of this fault block zone, and points out some problems in seismic interpretation and geological research of the overthrust fault.

摘要： 东濮凹陷位于渤海湾第三系大陆裂谷盆地的南端。通过地震反射时间剖面,在东濮凹陷边界的兰聊断层上升盘内幕之中,解释了一条规模较大的古老的逆冲断层系统——新罗逆断层。东倾的新罗逆断层与西倾的兰聊断层,在剖面上呈“人”字形交切,在空间上构成一个规模较大的屋脊状逆断块带。该断块带紧邻生油凹陷,具有独特而理想的石油地质条件,可能成为一个油气勘探新领域。罗1井钻遇一条逆断层得已验证。在传统的地台区发现这种逆断层不仅具有实际勘探意义,而且有一定理论和学术价值。本文阐述了逆断层及其所形成的逆断块带的地震反射模式,分析预测了它的圈闭条件和成油机制,并指出该逆断层地震资料解释和地质研究应注意的一些问题。