关键词: 断陷盆地, 滚动背斜, 反转构造, 花状构造, 油气勘探

Abstract:

The development and evolution of Muglud basin can be divided into three stages: (1)in the early Cretaceous, with the Africa-South America continent splitting, the first extension downchasm basin ocured; (2)in the late Cretaceous, with the original Atlantic Ocean formation, the second extension downchasm basin occurred; (3)in Kainozoic, with the regional subsidence, this basin evoluted into a sag basin. From the end of the late cretaceous, there were apparent movements, resulting in reverse structure. In the west-north basin, there were strik-slip movements along the great central African fracture. As a result, Tullus, Bagarra sub-basins were greatly reformed. The main structural styles of Muglud basin are half graben, half horst(or horst), extension fault-block, rollover anticline, compression anticline and flower structure. Among them, rollover anticline, compression anticline and horst are the main area of hydrocarbon enrichment. In the early Cretaceous, the basin was filled with mudstone of half-abyss and abyss facies, which controlled the distribution of hydrocarbon rocks. As the sediment center continuously moved southwards, good thick upper Cretaceous mudstone deposited in the south area, and formed regional cap-rock of giant oil field.Therefore,good potential region for oil and gas exploration in Muglud basin is decided by the above factors.

Key words: rift basin, rollover anticline, reverse structure, flower structure, oil and gas exploration