EVALUATION OF THE GEOCHEMICAL AND PETROGRAPHIC CHARACTERISTICS OF THE INKISI FORMATION IN THE SEDIMENTARY BASIN OF THE CENTRAL BASIN

The Congo Craton, located in the central depression, hosts an interior sedimentary basin covering over 800,000 km², subdivided into four intracontinental sub-basins: Busira, Lokoro, Lomami, and Bushimayi. The formation of this vast Neoproterozoic basin results from an initial stretching of the lithospheric crust followed by thermal subsidence, corresponding to the rebalancing of the lithosphere during the Pan-African orogenic cycle. This tectonic activity led to the formation of pull-apart basins, reflecting the generalized subsidence of the craton in the central depression. The general lithostratigraphic column of the basin comprises five sedimentary sequences, among which the Inkisi sandstone formation is central to our study as a potential reservoir rock. The analysis of the deposits and sedimentary evolution of this formation is essential for determining its porosity and permeability, key characteristics for a hydrocarbon reservoir.
The choice of the southwestern part of the basin, specifically on the outskirts of the provincial city of Kinshasa, is motivated by the accessibility of this rock and the absence of in-depth studies in this area. This research aims to enhance the understanding of the geological characteristics of the Inkisi formation, particularly in a context that has never been studied in depth. Geochemical analysis and the assessment of the alteration state of the rocks will provide unprecedented information on their petrographic potential. By highlighting aspects such as porosity and permeability, this study offers new perspectives for oil exploration in the central depression.
Despite the importance of the Inkisi formation, previous research has often overlooked a detailed analysis of its petrographic and sedimentary characteristics. Few studies have been conducted on the southwestern portion of the basin, particularly regarding geochemical properties and the alteration state. This study aims to fill these gaps by providing a comprehensive and integrated analysis that could serve as a basis for future research and the exploitation of natural resources in the region.