Palynological Investigation of Oligocene - Lower Miocene Sediments in Well Z, offshore Niger Delta, Nigeria.

Palynological investigation of the ditch cutting rock samples from well Z, offshore Niger Delta has been carried out. The rock succession is characterised by the alternation of fossilferous grey sandy shale with shells and shell fragments intercalating with medium coarse grained, sub rounded to rounded sandstone with scattered mica flakes with appreciable thickness at the base and more paralic at the top, characteristically of the paralic Agbada Formation. Palynological analysis yielded a well preserved and well distributed biostratigraphic relevant Miospores among which fifty nine Miospores were identified. On the basis of the first and last downhole occurrences of these Palynological events, nine miospore biozones were erected. The zones are Zonocostites ramonae, Monoporites annulatus, Dualidites laevigatus, Pachydermites diederixi, Canthium sp, Gemmamonoporites sp, Retibrevitricolpites protrudens, Inaperturopollenites hiatus and Perfotricolporites digitatus.These zones were compared with the pre existing standard palynological zones in Niger delta and other adjoining basins in Nigeria and used to delineate the Oligocene (Chatian) / Lower Miocene intervals in the well.