Paleoecologic and Organic Geochemical Assessment of Cretaceous Hydrocarbon Source Rocks in the Gulf of Guinea: New Insights from Eastern Dahomey and Benue Rift Basins with Implications for the Cenomanian-Coniacian Petroleum System, #50722 (2012)

Black shales of the Afowo and Eze-Aku Formation (CenomanianTuronian) in the Dahomey and Lower Benue Basins respectively contain a large abundance of planktonic foraminifera e.g. Rotalipora greenhornesis, Hedbergella delyioensis, Heterohelix moremani, Heterohelix cenomana, Heterohelix globulosa, Hedbergella planispira, Whiteinella inonata, Praeglobotruncana sp.(?) and no significant benthic foraminifera. This assemblage was deposited under a deepwater, euxinic environment of the neritic to upper bathyal probably not deeper than 250 m. Paleogeographic interpretations indicate a northeasterly shoaling of marine conditions characterized by the dominance of benthic foraminifera e.g. Ammobaculites sp., Ammotium sp., Lenticulina sp. and Bolivina sp. in the time equivalent shales of the Yolde Formation (Upper Benue Basin).