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The Ameki Formation (middle Eocene) of Nigeria contains a diverse, primarily molluscan macrofauna that probably lived in a shallow‐shelf marine environment. Naticids, followed by muricids, were the most abundant and most successful borers. Cannibalism was high among the naticids. Though small (< 10 mm) gastropods were the most frequently exploited food source, there is no strict correlation between predator and prey sizes. Coarseness of sculpture and shell thickness similarly did not constitute effective deterrents to borers. Comparison of the predator‐prey pattern in the Ameki with that of Eocene assemblages from the Paris Basin and Alabama and a Recent West African shelf assemblage shows that since the Eocene, pelecypods have replaced gastropods as the most frequently exploited food source of predatory borers, and muricids have become better represented numerically.

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The extensive tarsand deposits of Ondo and Ogun States of Nigeria have previously been investigated only by the use of geological methods. In a recently completed exploration programme covering a 17 km2 area north of Agbabu, in the Ifesowapo Local Government area of Ondo State, the electrical resistivity technique was used extensively along with other exploration methods. The electrical resistivity survey was made up of 32 Schlumberger vertical electrical soundings (VES). The resistivity curves were interpreted by curve matching and computer based automatic interpretation techniques. Apparent resistivity values obtained varied between less than 10 ohm-m to greater than 1000 ohm-m. The results permitted fair to excellent correlation between the geoelectrical and Stratigraphic data, particularly the delineation of lithological boundaries and zone of bitumen saturation. The lithological boundaries and zone of bitumen saturation. The geophysical results also confirmed the regional block faulting and the consistent, increase in overburden thickness southwards.

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