Abstract: Palynological analysis was carried out on twenty (20) ditch cutting samples from a section (1284.73–
1496.57 m) of the Amansiodo-1 well, Anambra Basin, southeastern Nigeria with the aim of determining the age,
biozone, and depositional environment of the sediments within the depth interval. The laboratory techniques of
digesting sediments in hydrochloric and hydrofluoric acids for silicates and carbonates removal were followed to
process the samples for the recovery of palynomorphs. Fifty two (52) palynomorph specimens were recovered. An
assemblage zone of Echitriporites trianguliformis Zone has been established. The section was dated to the upper
Maastrichtian due to the occurrences of age diagnostic marker species such as: Cingulatisporites ornatus, Distaverrusporites
simplex, Proteacidites sigalii, Dinogymnium cf auclaense, Echitriporites trianguliformis and Retidiporites
magdalensis. Based on the palynomorph marine index and environmental indicator flora, the section was
inferred to be deposited in marine to brackish (coastal) environments with little influence of fresh water.
Keywords: southeastern Nigeria, Anambra Basin, palynology, paleoenvironment, Amansiodo-1 well