Biostratigraphic Study of the Calcareous Nannofossils of Well 02, Shallow Offshore, Niger Delta, Nigeria

Abstract

A calcareous nannofossils biostratigraphic study has been carried out on the strata penetrated of well 02 located in the shallow offshore area of the Niger Delta, Nigeria. The study is aimed at establishing the age and nannofossils biozonations of the well. The samples were prepared using smear slide technique. Forty calcareous nannofossils species were identified and used to make biostratigraphic deductions of zonations and dating of the sequence. The distribution of the calcareous nannofossils enabled the establishment of three zones of Helicosphaera ampliaperta (NN4),Sphenolithus heteromorphus (NN5) and Catinaster coalitus (NN8) belonging to early Miocene - late Miocene following standard zonation schemes of previous workers. The zones were based on the first and last occurrences of marker species. Nannofossil abundance / diversity patterns calibrated with chronostratigraphical bioevents reveals four condensed sections when correlated to the Global Cycle Chart. This is associated with the 16.0 Ma, 14.8 Ma and 13.4 Ma and 10.89 Ma maximum flooding surfaces.