Edwin Ayuk Ndip^{1, 2,}, Christopher M. Agyingi¹, Matthew E. Nton², Michael A. Oladunjoye²

The Mamfe Basin is an intra-continental basin in southwestern Cameroon. Shale from Cretaceous strata in the Mamfe Formation has been poorly characterized in terms of their palaeo-environmental conditions and origin of the organic matter. Also, the thermal maturity of the shale has not been well established. The aim of this study is to determine the origin of the organic matter, evaluate the thermal maturity, palaeo-environmental conditions, and thereby deduce their hydrocarbon generative potential. Biomarker geochemical analyses was carried out on the organic matter extracts of some selected shale samples from Mamfe Formation having total organic carbon content ranging from 0.69 and 4.50 wt. % (av. =1.82 wt. %). Base on the total organic carbon content, the shales are described to have good hydrocarbon generative potentials. Thermal maturity parameters base on 20S/(20S +20R), and ββ/(ββ + αα) C₂₉ sterane ratios along with CPI and OED indicate that the analysed samples from Mamfe Formation sit at mature oil window generation. The origin of the organic matter have been deduced to be mainly of terrestrial plant source with minor lacustrine and marine influences. Palaeo-environmental conditions were decipher to be of sub-oxic to anoxic conditions that have preserved the organic matter. This study have highlight valuable insight based on the biomarker geochemistry of the shales of the Mamfe Basin thereby reducing petroleum exploration risk.

mamfe formation, shale, organic matter, total organic carbon, biomarker geochemistry