Résumé -Géologie et système pétrolier du bassin offshore du Benin (Benin) -Cet article résume l'évolution tectono-sédimentaire et le système pétrolier du Bassin Offshore du Bénin (BOB). Conformément à l'évolution structurale, la succession stratigraphique de ce bassin a été divisée en quatre séquences : anté-rift (allant jusqu'à la fin du Jurassique) ; rift (Néocomien-Crétacé inférieur) ; transitionnelle (Cénomanien-Santonien) et post-rift (Maastrichtien-Holocène). Un seul système pétrolier d'âge Crétacé supérieur a été identifié avec certitude dans ce bassin. Les roches mères de ce système contiennent du kérogène de Type II-III, avec un COT (Carbone Organique Total) moyen de 2,9 %. L'huile est produite à partir des faciès gréseux de la formation d'Abeokuta. Les données actuelles d'exploration et les caractéristiques géochimiques des sables bitumineux qui affleurent par endroits dans la partie continentale de la baie du Dahomey mettent en évidence l'existence d'un autre système pétrolier d'âge Crétacé inférieur (Néocomien à Albien) dans ce bassin.
Abstract -Geology and Petroleum Systems of the Offshore Benin Basin (Benin) -This paper summarizes the tectonosedimentary development and petroleum system of the Offshore Benin Basin (OBB). In accordance with structural development, the stratigraphic succession of this basin was divided into 4 sequences: pre-rift (up to Late Jurassic); rift (Neocomian to Lower Cretaceous); transitional (Cenomanian to Santonian) and post-rift (Maastrichtian
The largest city in Benin, West Africa (Cotonou), is reliant upon groundwater for its public water supply. This groundwater is derived from the Godomey well field which is located approximately 5 Km north of the coast of the Atlantic Ocean and in close proximity to Lake Nokoue—a shallow lake containing water with elevated concentration of chloride and other elements. Historical data indicate increased chloride concentration in a number of wells nearest to the lake, with unknown contribution from groundwater encroachment from the coastal area. Hence, there is substantial interest in better characterizing this groundwater system for the purpose of determining appropriate management practices and degree of sustainability. Among the efforts attempted to date are a series of numerical models ranging from assessment of flow to a recent effort to include density-dependent transport from the lake. In addition, substantial field characterization has been pursued including assessment of shallow water chemistry along the region of the coastal lagoon and border of the lake, characterization of hydraulic response to pumpage in the aquifer system, estimation of the distribution of electrical resistivity with depth along the coastal lagoons, and installation of multi-level piezometers at seven locations in the lake. When integrated across methods, these numerical and field results indicate that the lake remains a primary concern in terms of a source of salinity in the aquifer. Further, the coastal region appears to be more complex than previously suggested and may represent a future source of salt-water encroachment as suggested by current presence of saline waters at relatively shallow depths along the coast. Finally, hydraulic testing suggests that both natural and pumping-based fluctuations in water levels are present in this system. Substantial additional characterization and modeling efforts may provide a significantly greater understanding of the behavior of this complex groundwater system and, thereby, an improved ability to manage the potential for negative impacts from salt-water and anthropogenic contaminants entering this sole source of fresh water for southern Benin
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.