The formations crossed by the forage belong to the Bushimay System. They are essentially made up from top to bottom of soft formations (loose) including Sands and Sandstones subject to frequent landslides and which require appropriate protection methods and hard formations including limestone with hard sub-horizontal layers. Two essential parameters make it possible to interpret the ground crossed in the forage: the nature of the cuttings and the speed of penetration of the forage tool. The nature of the cuttings relates to the description of the different geological formations.

The hydrogeological problems posed by the KANJIYA borehole are multiple. Kanjiya is a district located in the commune of Bipemba in the town of Mbujimayi. Although a network of 24 boreholes has been established in the town of Mbujimayi, the KANJIYA borehole has never been studied as a whole from a hydrogeological point of view. It was therefore necessary to categorise the water table, determine its hydrodynamic parameters and study its behaviour during pumping tests. The data was collected by lithological description of the cuttings taken every metre from the sediments traversed by the borehole (the rotary) with a planned depth of 117.60 meters. The data from the flow tests and the existing geological and hydrogeological knowledge allowed us to categorise the water table and its hydrodynamic parameters and to reconstruct the lithological successions of the hydrogeological units. It has been shown in this work that KANJIYA belongs to a zone of the Bushimay system and the vertical lithological section shows the succession: clayey sand, more or less soft sandstone, weathered limestone, hard limestone, hard limestone, fissured limestone, cavity and hard limestone. The water table is encountered in a fissured limestone at a depth of 84.50 meters; its behaviour during pumping tests shows that it is semi-captive. The hydrodynamic parameters are favourable for exploitation at a flow rate of over 80 m3 per hour. A low drawdown, a slow descent of the hydrostatic level and a rapid rise in the water table when pumping stops would explain the influence of a more altered and fissured aquifer.

The drilling allows us to know the true underground geology through the information provided by the cores which reflect the geological formations crossed, based on those made in this kimberlite massif, several logging have been traced and allowed an in-depth study on the different kimberlite facies encountered. The different sections made it possible to make a geological correlation between the different formations crossed by taking into account the facies intersected by the survey. The vertical drilling represented on the cuts that had been carried out by MIBA for the estimation of reserves made it possible to position the additional boreholes well in order to be able to intersect the enclosing formations. These kimberlite facies were encountered, the green kimberlite facies and/or lithic kimberlite with hematite-goethite, ferruginous products; xenokimberlite facies with hematite – goethite, chalcopyrite; epiclastites with hematite, goethite, chalcopyrite and carbonate formations of the Upper Bushimayian.

One of the main objectives of structural geology is to describe the different microstructures, to understand the origin and distribution of the forces that generated them on the spatio-temporary level. Building on this momentum, a structural study was carried out on geological formations of Proterozoic age in the locality of Mpumbu, Lupatapata territory, Kasai Oriental province of the Democratic Republic of the Congo. This area is mainly crisscrossed by sedimentary formations belonging to the Bushimay supergroup. This sedimentary sequence is unaffected by regional metamorphism while highlighting two distinct successive components: sedimentary and metamorphic. The locality of Mpumbu is full of the following formations: sandstone, dolomitic limestone and shale. Brittle and planar deformations affect the majority of rocks and attest to the compressive stresses typical of this terrain. We solved the problem using Win-tensor software. Two preferential orientations of breaks have been exposed: North-South and East-West. The stress study revealed that the main stress initiating the observed deformations is oriented N57° and is inclined by 3°. Apart from the deformation, a chronological study was revealed: the breaks oriented preferably East-West intersected or often offset by a North-South oriented detachment prove their anteriorities compared to the last. Finally, a slight tilt to the north or northwest of different Mpumbu formations indicates that the region has undergone a certain inclination to the tertiary during the kimberlite intrusion of the various kimberlites in the perimeter of Bakwanga.