Molecular geochemistry of Cretaceous Dukul Formation, Yola Sub-basin, Northern Benue Trough, Nigeria: Origin, paleoredox condition, and thermal maturity

Abstract

Molecular geochemical characterization “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 ori
gin, paleodepositional or paleoredox conditions, preservation stages and overall assess
ment 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 consist 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 sug
gest that the analyzed 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 finding elsewhere in the basin. Thus, the Tertiary volcanic 
plugs in the Northern Benue Trough had enhanced thermal maturation of these samples.