黄骅坳陷王官屯地区古近纪逆冲断层分析

The Analysis of Tertiary Reverse Thrust Faults of No.2 Wangguantun in Huanghua Depression

重力滑动逆断层一直以来是拉张型盆地中形成的逆断层中一个重要的类型,其研究意义重大。在油气运移与聚集中起着重要的作用,是油气勘探的重点目标之一。通过对黄骅凹陷王官屯地区古近纪精细构造解析,对区域内特殊断层重新分析认识,结果发现前人对区域内出现的逆断层的解释存在出入。利用构造平衡原则,分析逆冲断层发育过程发现,这条断层并非晚期形成的逆冲断层,而是在早期形成的一条生长系数不大的生长断层。由于晚期沉积中心迁移,使得断层面倾角由陡变缓,甚至平躺。最后在晚期,在重力作用的促使下,使断层上盘沿着断层面滑动,并使得该断层呈现出逆断层的性质。这类断层虽然在形态上与前人所认为的晚期形成的逆断层极为相似(早期生长系数小,断距差别不大),但在成因上却有巨大的差异。这两种断层的石油地质意义完全不同,这一发现对该地区的构造研究乃至其他地区类似构造都有重要意义,为石油勘探提供新的理论基础。

The gravitational decollement thrust fault is a kind of most essential fault in extensional basin,the study significance is significant.It is important in the petroleum migration and accumulation.Now there is a mode in the understand of this kind of fault by the most scholar,but it cann＇t explane well in some area,so a new view is proposaled to explane the property and origin of this kind of fault,and this study will provide theoretical guidance for searching hydrocarbon reservoir in relation to this kind of fault in petroliferous basin.