[ Corrélation lithostratigraphique entre le bassin versant de Bushimay (Province du Kasai oriental, RDC) et celui de Lomami (Province de Lomami, RDC) ]
Alphonse Tshimanga Kambaji1, Hippolyte Mutombo Mbwebwe2, and Télesphore Mayiba3
1 Professeur Ordinaire à l’Université de Lubumbashi, RD Congo
2 Chef des Travaux à Université Officiel de Mbuji-Mayi, RD Congo
3 Université officielle de Mbuji-Mayi, RD Congo
Original language: French
Copyright © 2025 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This research work focuses on the lithostratigraphic correlation between the Bushimay watershed (Kasai Oriental Province, DRC) and that of Lomami (Lomami Province). The two study areas are located in the northern part of the central core of the Kasai Block of the Congo Craton. The drilling work made it possible to specify the lithostratigraphy and de facto the geological correlation. The set of stratigraphic logs calls for the following comment: A lithostratigraphic succession from top to bottom of the series, with variable thicknesses, of: ochre clayey sand of the Kalahari, top of cover formations consisting of sandstone with variable grain size and thin intercalary layers of argillites, breccia mainly with sandstone matrix, calcareous and/or granitic pebbles, Intrusion of a kimberlitic breccia whose age would be the same as that of the Bakuanga breccias, i.e. nearly 70 Ma classified in group 1, Proterozoic limestone and dolomite quasi-contemporary in sedimentation with the doleritic and basaltic magmatic pulses, an Archean basement consisting of ultrabasic rocks, in this case serpentinite and pyroxenite in contact with the granitoids. The transition from ultrabasites to the granitoids is characterized by a zone with quartz veinlets. This lithostratigraphic succession is similar in both the Bushimay and Lomami basins, with the only difference being that the basement (f) has not been intersected by drilling or identified in outcrops in the Lomami basin. This fact is probably justified by the increasingly greater thicknesses of the cover rocks from the W to the E. This basement outcrops to the W of the Bushimay basin and plunges towards the E from Boya. Everything appears that from Boya towards the E we move towards the interior of a sedimentation basin that becomes deeper and deeper and thus promotes deposits of increasingly thick sediments.
Author Keywords: Lithostratigraphic correlation, Bushimay watershed, Lomami watershed, Eastern Kasai Province, Democratic Republic of the Congo.
Alphonse Tshimanga Kambaji1, Hippolyte Mutombo Mbwebwe2, and Télesphore Mayiba3
1 Professeur Ordinaire à l’Université de Lubumbashi, RD Congo
2 Chef des Travaux à Université Officiel de Mbuji-Mayi, RD Congo
3 Université officielle de Mbuji-Mayi, RD Congo
Original language: French
Copyright © 2025 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
This research work focuses on the lithostratigraphic correlation between the Bushimay watershed (Kasai Oriental Province, DRC) and that of Lomami (Lomami Province). The two study areas are located in the northern part of the central core of the Kasai Block of the Congo Craton. The drilling work made it possible to specify the lithostratigraphy and de facto the geological correlation. The set of stratigraphic logs calls for the following comment: A lithostratigraphic succession from top to bottom of the series, with variable thicknesses, of: ochre clayey sand of the Kalahari, top of cover formations consisting of sandstone with variable grain size and thin intercalary layers of argillites, breccia mainly with sandstone matrix, calcareous and/or granitic pebbles, Intrusion of a kimberlitic breccia whose age would be the same as that of the Bakuanga breccias, i.e. nearly 70 Ma classified in group 1, Proterozoic limestone and dolomite quasi-contemporary in sedimentation with the doleritic and basaltic magmatic pulses, an Archean basement consisting of ultrabasic rocks, in this case serpentinite and pyroxenite in contact with the granitoids. The transition from ultrabasites to the granitoids is characterized by a zone with quartz veinlets. This lithostratigraphic succession is similar in both the Bushimay and Lomami basins, with the only difference being that the basement (f) has not been intersected by drilling or identified in outcrops in the Lomami basin. This fact is probably justified by the increasingly greater thicknesses of the cover rocks from the W to the E. This basement outcrops to the W of the Bushimay basin and plunges towards the E from Boya. Everything appears that from Boya towards the E we move towards the interior of a sedimentation basin that becomes deeper and deeper and thus promotes deposits of increasingly thick sediments.
Author Keywords: Lithostratigraphic correlation, Bushimay watershed, Lomami watershed, Eastern Kasai Province, Democratic Republic of the Congo.
Abstract: (french)
Ce travail de recherche porte sur la corrélation lithostratigraphique entre le bassin versant de Bushimay (Province du Kasai oriental, RDC) et celui de Lomami (Province de Lomami). Les deux Zones d’étude sont localisées dans la partie Nord du noyau central du Bloc Kasaï du Craton du Congo. Les travaux de forage ont permis de préciser la lithostratigraphie et de facto la corrélation géologique. L’ensemble de Logs stratigraphiques appellent le commentaire ci-dessous: Une succession lithostratigraphique de haut en bas de la série, avec des épaisseurs variables, de: sable ocre argileux du Kalahari, sommet de formations de la couverture constitué du grès à granulométrie variable et minces couches intercalaires d’argilites, brèche essentiellement à matrice gréseuse, galets calcaires et/ou granitiques, Intrusion d’une brèche kimberlitique dont l’âge serait le même que celui des brèches de Bakuanga, soit près de 70 M.a. classée dans le groupe 1, calcaire et dolomie protérozoïques quasi-contemporains dans la sédimentation avec les pulsations magmatiques doléritiques et basaltiques, un socle archéen constitué de roches ultrabasiques, en l’occurrence la serpentinite et la pyroxénite au contact des granitoïdes. Le passage des ultrabasites vers les granitoides est caractérisé par une zone à veinules quartzifères. Cette succession lithostratigraphique est similaire tant dans le bassin de Bushimay que dans celui de Lomami au seul distinguo que le socle (f) n’a pas été recoupé par les forages ou identifié en affleurements dans le bassin de Lomami. Ce fait est vraisemblablement justifiable par des épaisseurs des roches de couverture de plus en plus grandes de l’W à l’E. Ce socle affleure à l’W du bassin de Bushimay est plonge vers l’E à partir de Boya. Tout apparait que de Boya vers l’E l’on chemine vers l’intérieur d’un bassin de sédimentation devenant de plus en plus profond et favorisant de ce fait de dépôts de sédiments de plus en plus épais.
Author Keywords: Corrélation lithostratigraphique, Bassin versant de Bushimay, Bassin versant de Lomami, Province du Kasaï oriental, République Démocratique du Congo.
