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非洲中部的Muglad盆地 (简称M盆地 )位于中非断裂系中段东端南侧 ,是一个内陆转换型盆地。盆地北部 (走滑 )断陷带以剪切走滑特征为主 ,北部NGL坳陷和南部KK坳陷以拉分走滑特征为主 ,南、北两部明显左行错位 ,两者之间存在与中非走滑断裂系基本平行的近东西向调节转换构造带。早白垩世中非大断裂的右行走滑运动使早白垩世M盆地主体部位诸断陷边界主断层以西倾为主 ,断陷均呈东断西超 ,下白垩统东厚西薄 ;晚白垩世中非大断裂左行走滑 ,M盆地被改造 ,形成了北北西走向东倾断裂系统 ,具有北“箕”南“堑”的特征。M盆地的走滑性质使其白垩系沉积速率大 ,生油条件好 ,沉降中心从早至晚自北而南转移 ,决定了南部KK坳陷的达富尔群泥岩纯净 ,封盖性能好 ,石油地质条件优越 ,大油田均发现于KK坳陷。但火成岩欠发育 ,地热梯度较低。图 6参 9(王孝陵摘 )
The Muglad Basin in central Africa (M basin) is located in the eastern end of the middle section of the Central African fault system, is a inland conversion basin. The northern (strike-slip) fault zone in the basin is dominated by shear strike-slip features. The northern NGL depression and the southern KK depression are dominated by pull-slip features. The left and right north and south lines are obviously dislocated. There is a near-easterly-westward transition zone structurally parallel to the Central African strike-slip fault system. The right-lateral slippery movement of the Early Cretaceous faults led to the main faulting of faults in the main part of the Early Cretaceous M basin westward, with the faults of the East and West of the fault and the Lower Cretaceous to the east and west of the fault. The late Cretaceous During the left-middle slip of the Central-Greater China Fault, the M basin was remodeled to form a NW-trending east-dip fracture system with the characteristics of a north “Kei” south “grab”. The strike-slip nature of the M basin led to a large Cretaceous deposition rate and favorable oil generation conditions. The settlement center moved from north to south from early to late, which determined the purity and sealing properties of the Darfurian mudstone in the southern KK depression. Excellent petroleum geological conditions, large oil fields are found in the KK depression. But the igneous rock is less developed and the geothermal gradient is lower. Figure 6 Senate 9 (Wang Xiaoling pick)