Biostratigraphical investigation of middle-early Miocene sediments from a section of AK-1 well, onshore Niger Delta: Insights from calcareous nanofossils

Biostratigraphic analysis was carried out on KA-1 well, onshore Niger Delta Basin of Nigeria. A total forty (40) ditch cutting samples were collected from the studied section at 30 feet depth intervals with ranging 7590-4800feet. The objectives this study are to determine age and biozonation section. Using simple smear slide method, processed analyzed for nannofossils using a reflected binocular microscope. Calcareous nannofossil assemblages well low diversity abundance. Some depths yielded almost monospecific while some have no records calcareous nannofossils. Species include Helicospharea ampliaperta, Sphenolithus heteromorphus, Cyclicargolithus floridanus, scissura Discoaster deflander. These belong NN4 zone middle early Miocene age. Keywords: Biozonation, nannofossils, Oligotrophic, Delta.