Geology, geochemistry and economic potential of the bingo carbonatite and its associated Laterites in Beni territory, North Kivu, democratic republic of Congo (DRC)
The Bingo carbonatite complex and its surrounding geologic formations which are located in Beni, North Kivu in the Eastern part of the Democratic Republic of Congo, occur along the Western branch of the East African Rift System. The rocks in Bingo carbonatite have undergone intense weathering and many of them are laterites or ferruginous in composition. This research project was carried out at Bingo with the aim of doing the geology of the area by identifying the rock types which surround the carbonatite complex and its associated laterites and by updating the existing geologic map of the area. It was also conducted in order to evaluate the economic potential by giving evidence of minerals and metals which can be mined from the area. To achieve these objectives, petrographical and mineralogical analyses were performed using respectively a microscope and an X-ray diffractometer at the Kenyan Ministry Of Mining and Petroleum. Geochemical analyses were done using X-Ray fluorescence at the Kenyan Ministry of Mining and Petroleum and Atomic Absorption Spectrometry at the Soil Science Department/ the University of Nairobi. Flame photometry was used in order to check the precision of chemical results for Sodium, Potassium and Magnesium. Results of petrography and mineralogy revealed that apart from the fresh carbonatite, the surrounding rocks include nepheline syenite, fenites and granodiorite which had never been reported. The mineralogical analysis allowed finding rare minerals including carletonite and polyhalite which are also for the first time being reported in Bingo. Geochemical results suggest that the Bingo carbonatite is rich in Niobium as pyrochlore. Considering the content of Barium in samples, Bingo pyrochlore is of Bariopyrochlore type. Laterites show a great concentration in Nb, Ba, and some rare earth elements including La, Ce, Y as well as some radioactive minerals such as Th and U. Cerium has a very high concentration in some laterite samples (BS06: 41,500 ppm, BS08: 41,330 ppm, BS11 83,230 ppm) and in some weathered rock samples (BS14: 46,910 ppm, BS18: 56,890 ppm, BS19: 143,900 ppm). The highest Lanthanum concentration is 76,300 ppm in weathered rock sample BS19. Yttrium concentration is found in all samples except in sample BS22. Its highest concentration is 19,920 ppm found in weathered rock sample BS19. The concentrations of Y, La and Ce in rock samples BS14, BS18, BS19 and BS20 are high as well as in laterite samples. vii FeO ranges between 39 and 70.9 wt.-% and an average of 39.36 wt.-%. Manganese (MnO) ranges between 8 and 39 wt.-% and an average of 9.46 wt.-%. This is interpreted as a result of high weathering rate in the study area. The presence of apatite in the laterites is evidenced by the high content of P2O5. Phosphates range between 7 and 18 wt.-% with an average of 6.95 wt.-% in the samples. This work recommends that geophysical researches should be done in the study area so as to determine the extent of the Bingo laterites and more geochemical work using latest analytical technologies so as to study more the distribution of rare earth elements within the deposit. It also recommends that trenching and/or drilling should be executed in order to find some fresh samples of the surface weathered rocks.
The following license files are associated with this item: