关键词: 裂谷盆地, 构造演化, 差异性, 构造动力学机制, 中非

Abstract: In this study, differences in tectonic evolution of basins in various locations are analyzed. Based on these results and regional tectonic events, mechanisms for tectonic dynamics of rift basins in Central Africa are discussed. Rift basins in Central Africa include two systems:West African systems are dominated by dextral strike-slip double faults, whereas those in Central Africa are mainly single sinistral strike-slip faults. In the study area, there are two types of basins:strike-slip basins and extensional basins. The former is located within the strike-slip fault belt, and is roughly parallel to the fault belt. It shows strong strike-slip movement and tectonic inversion. The latter is located at the ends of the strike-slip fault belt and intersects obliquely with the fault belt. It has strong extensional movement but relatively weak tectonic inversion. Rift basins in Central Africa experienced three episodes of rifting-depression tectonic cycles. In the Early Cretaceous, basins in Central Africa all underwent intense rifting. In the Late Cretaceous, basins at different locations experienced rifting of varying intensities and tectonic inversion. In the Paleogene, only roughly NW-SE striking basins underwent the third rifting episode, while other basins were subjected to depression. Rift basins in Central Africa resulted from terrestrial responses to stress differences between the three blocks in mainland Africa during tectonic movements of the African continental plate. The dynamic tectonic sources were different for the three rifting episodes, the expansion of the Mid-Atlantic Ocean in the Early Cretaceous, the rapid expansion of the South Atlantic Ocean and expansion of the Indian Ocean in the Late Cretaceous, and the major collision between the African and Eurasian Plates and spreading of the mid-ocean ridge in the Northwest Indian Ocean in the Paleogene.

Key words: rift basins, tectonic evolution, differences, tectonic dynamics, strike-slip faults, Central Africa