Subsidence patterns in the Nigerian sector of Benin (Dahomey) Basin: Evidence from three offshore wells

Abstract

The application of one-dimensional (1-D) backstripping analysis was used to determine subsidence patterns in three offshore wells (Ayetoro – 1, Baba – 1 and Epiya  – 1) located in the Nigeria sector of Benin (Dahomey) Basin. Biostratigraphic data obtained in the three wells indicated that the oldest sediment penetrated varied from Cenomanian to Campanian in age while the youngest sediments are Eocene to Neogene in age. Results of subsidence analysis of the Cretaceous to Tertiary sediments revealed four main phases of subsidence, these are (i) Early late Cretaceous phase characterised by accelerated tectonic subsidence and gradual uplift  patterns; (ii)  Late Cretaceous phase characterised by relatively high uniform rates of subsidence and minor uplift; (iii) Paleogene to Neogene phase was  characterised by variable rates of tectonic subsidence and uplift; and (iv) Quaternary phase began with accelerated tectonic subsidence and followed by reduced  rates of tectonic subsidence. The results obtained showed that quantitative analysis of tectonic subsidence is feasible in the area of study area.
 

Keywords: Backstripping, Subsidence and Uplift, Benin (Dahomey) Basin, Cretaceous, Tertiary.