The gravity field and tectonic features in the southeast of the Anza Basin, Kenya

Abstract

The southeast of the Anza Basin in Kenya, located in the East African Rift System, has developed a very thick Mesozoic and Cenozoic sedimentary cover. However, the low level of exploration in this area restricts us from understanding its structural system and evaluating its oil-gas exploration potential. In this study, we processed and interpreted the gravity anomaly data obtained from the study area based on our understanding of its structural characteristics, and the conclusions drawn from the results are as follows. Under the influence of dextral shear stress of the central Africa shear zone, large-scale NW-oriented basement faults and small-scale NE-oriented caprock faults developed in the study area with the latter cutting off the former. The basement depth of the study area varies greatly and is characterized by "one uplift between two depressions". The very thick Mesozoic and Cenozoic cover layer was deposited in depressions. Controlled by the NW-tensional fault as well as the NE-fault developed along the structural weak zone, the study area is divided into four tectonic units: the eastern depression, the central uplift, the southern uplift and the western depression, showing the structural pattern of the "east-west zone and north-south block".

Keywords

• anza basin
• gravity anomaly
• fault structure
• basement structure