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.