Palynofacies analysis, organic thermal maturation and kerogen type of upper creataceous-paleocene rocks in auchi sheet 266, Benin flank, western extension of the Anambra basin, Southwestern Nigeria

Thirty four (34) samples collected from Outcrops and ditch- cutting from Borehole in Benin Flank, Western Extension of the Anambra Basin, South-western Nigeria were investigated to deduce the kerogen type and maturity stage. Twenty Four (24) outcrop and Ten (10) ditch- cutting samples were subjected to palynofacies analysis. Palynofacies were analyzed to determine the kerogen type and maturity stage of Mamu and Nsukka Formation. The result from the palynofacies analysis reveals the presence of miospores (pollen and spores), woody plant materials (black wood and phytoclast), amorphous organic matter, which were used to characterize the samples of its kerogen type and maturity. The borehole well samples was divided into three palynofacies zones which are palynofacies zones A,B and C ,based on cluster analysis of the palynomacerals while The outcrop samples were subdivided into two (2) palynofacies zones A and B based on cluster analysis of the palynomacerals. The Ternary plot of AOM- Phytoclasts- Palynomorphs indicated predominantly type III kerogen with perhaps limited occurrence of type II kerogen. The spore colour observations indicated that the kerogen of Mamu and Nsukka Formation are immature to early mature but may generate gas on maturity.