Foraminiferal Biostratigraphic Study of “VC” Well in the Central Niger Delta

Abstract

 Ditch cutting samples obtained from the interval of 2340 metres to 3350 metres of the “VC” well, located within the coastal swamp depobelt of the Central Niger Delta, were analyzed in order to establish a foraminiferal biostratigraphic framework for the Agbada Formation. The study yielded moderately diverse planktonic and benthic foraminiferal assemblages with good preservation. Key planktonic foraminiferal events identified include the first downhole occurrence of Epistominella vitrea, the last downhole occurrence of Globigerinoides primordius, and the co-occurrence of Praeorbulina glomerosa and Orbulina suturalis. These bioevents constrain the studied interval to the Middle to Late Miocene and correlate with the Blow’s Neogene Zones N9–N15The lithofacies and lithological succession, characterized by alternating sand and shale units with silt intercalations, are typical of the Agbada Formation and are associated with three foraminiferal microzones, namely Neogene Zone Sixteen, Neogene Zone Fifteen, and Neogene Zones Fourteen to Nine. These zones were defined on the basis of the Top Regular Occurrence (TRO) of Florilus ex gr. costiferum at 2500 metres, the isolated occurrence of Globorotalia acostaensis at 2530 metres, alongside the First Downhole Occurrence (FDO) of Globorotalia continuosa at 2640 metres and Praeorbulina glomerosa at 3250 metres, respectively. Consequently, the sediments were dated as Middle to Late Miocene.