Palynofacies and palaeoenvironmental significance of the Albian – Cenomanian succession of the Epunsa-1 well, onshore Tano Basin, western Ghana

•Palynofacies assemblages (P-1, P-2, P-3) have been revealed in the Epunsa-1 well.•Kerogen types indicate types II/III and III.•Paleoenvironment is wetlands in a humid and warm coastal plain in a semi-arid climate.•Miospores suggest Albian – Cenomanian age for the sediments.

Palynofacies analysis carried out on thirty-three (33) cutting samples between the intervals 2990–5960 ft from the Epunsa-1 well onshore Tano Basin, identified three palynofacies types (P-1 to P-3). Palynofacies 1 (P-1) reflects deposition in shallow marine environment adjacent to active fluvial sources under a mud-dominated oxic (distal shelf) condition, Palynofacies 2 (P-2) was deposited in a shallow marine to fluvio-deltaic environment under a heterolithic oxic shelf condition and Palynofacies 3 (P-3) was deposited in a fluvio-deltaic environment in proximity to the source of vegetation under a dysoxic shelf condition.Visual kerogen analysis and spore colour for evaluation of hydrocarbon potential and thermal maturation respectively indicate early mature oil/gas prone to immature gas prone source rocks in the studied interval in the Epunsa-1 well.The presence of Afropollis, Classopollis, Ephedripites, and elaterate pollen as well as pteridophytic fern spores suggest a paleoenvironment with parent plants inhabiting moist biotopes or wetlands in a humid and warm coastal plain in a semi-arid/arid climate. Biostratigraphically significant elaterate pollen and associated taxa indicate Albian – Cenomanian age for the sediments.