Abstract

Molecular geochemical characterisation “biological markers” of Cretaceous sediments of Dukul Formation in Yola sub-basin of Northern Benue Trough, northeastern Nigeria was conducted with the an objective of determining the organic matter source inputs or origin, paleodepositional or paleoredox conditions, preservation stages and overall assessment of thermal maturity in relation to the effect of Tertiary volcanic plugs in the Northern Benue Trough. However, based on preliminary lithostratigraphic description, the sections revealed shelf or perhaps, shallow marine depositional environment for the sediments of Dukul Formation. The samples of Dukul Formation consists of a mixed terrestrially and aquatic or marine organic matter source origin. They were interpreted to be deposited under suboxic/dysoxic depositional condition to relatively anoxic marine conditions but with a dominance of the terrigeous organic matters. Biomarker maturity parameters suggest that the analysed shale samples of Dukul Formation have reached the early to peak stage of maturity and this suggest peak-hydrocarbon generation. Hydrocarbon might have been generated and could be find elsewhere in the basin. Thus, the Tertiary volcanic plugs in the Northern Benue Trough had enhanced thermal maturation of these samples.

Key words: Biomarkers; Paleoredox; Thermal Maturity; Dukul Formation; Yola Sub-basin