Abstract

Palynological analysis of 100 ditch samples from a section of OGU-7 well Niger Delta, was carried out to determine the age of the sediment, palynostratigrahic zones,depositional environments,and palaeoclimatic conditions using data sets from palynology.The well penetrated the paralic Agbada Formation. The analyzed sample were from stratigraphic depth interval of 1792 -9140 m. Palynological slides were prepared following standard palynological preparation technique involving hydrochloric (HCl) and hydrofluoric (HF) acids. The palynomorphs yielded eighty (80) species. The section was dated Oligocene-early Miocene due to the occurrence of the diagnostic maker species such as Cicatricosisporites dorogensis, Arecipites exilimuratus, Echiperiporites estelae. Interval zone of Retitricolporites irregularis-Leiosphaeridia sp, taxon range zone of Cicatricosisporites dorogensis, and concurrent range zone of Echiperiporites estelae-Echiperporites icacinoides zones were established in line with the international stratigraphic guide which could contribute to the harmonization of biozonation scheme in the Niger Delta Basin. The depositional environment was deduced from the PMI values (0% freshwater, 1-50% brackish and 51% to 100% marine); indicating freshwater to brackish (coastal) environments of deposition for the studied sediment. The palaeoecological grouping of the palynomorphs were used to delineate the palaeoclimatic signals ranging (wetter to drier phases) from the distribution pattern of Zonocostites ramonae (Rhizophora) and Monoporites annulatus (Poaceae).

Key words: Niger Delta; Palynomorphs; Depositional environments; Palynostratigraphic zones; Palaeoclimate; International stratigraphic guide; Agbada Formation.