Inorganic geochemistry and hydrocarbon potential of the Voltaian Basin of Ghana, West Africa

Interest in hydrocarbon prospects of Neoproterozoic sedimentary basins is on the rise, globally. This follows significant oil and gas discoveries from these basins in Asia, North America, the Middle East, and North Africa. The Voltaian Basin of Ghana covers significant parts of the country and is largely accepted as a Neoproterozoic basin, however, unlike other Neoproterozoic basins, the Voltaian Basin has little information on its hydrocarbon prospects. The current study seeks to provide an insight into the hydrocarbon potential of the basin leveraging on the inorganic geochemistry of outcrop samples of shales obtained using the Inductive Coupled Plasma Mass Spectrometry (ICP-MS) analytical method. The paleoclimatic conditions were warm – humid and arid allowing for a weak to moderate weathering of the studied samples from Sr/Cu, and C-values, also with ICV values of >1 suggesting a probable single recycling event. The sedimentation rate was somewhat rapid in an oxic depositional environment, an inference from Ce/Tm and V/(V + Ni), V/Ni, Ni/Co, U/Th, Th/U, V/Cr values. Restricted conditions prevailed in the basin and appear to have favored primary organic matter production considering Ni/Al, and Cu/Al proxies. The organic matter preservation, however, appears not to have been favored in the oxic conditions. The proxies on paleoredox conditions, upwelling and sedimentation rate, terrestrial material input, and water depth all correlated positively with TOC, suggesting their positive effect on the TOC content on the Voltaian Basin of Ghana. Detrital material input did not necessarily affect the TOC content.