TITLE:
Petrographic and Geochemical Characterization of the Kibalian Formations in the Lassa Area (Haut-Uélé Province, Democratic Republic of the Congo): Implications for Hydrothermal Alteration and Mineral Exploration
AUTHORS:
Blaise Mutombo Kabulu, Richard Logro Sapa, Divine Biaya Tshiala, Herman Sadimoke Ibingo, Jean-Paul Bakajika Kabongo, Jean-Luc Albini Tshupa, Junior Lele Mambwiya, Joseph Lelo Nkenge, Adalbert Jules Makutu Ma Ngwayaya, Giresse Kabemba Kalonji
KEYWORDS:
Kibalian Greenstone Belt, Petrography, Geochemistry, Hydrothermal Alteration, Mineral Exploration
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.9,
September
21,
2026
ABSTRACT: This study investigates the petrographic, geochemical, and metallogenic characteristics of the Kibalian formations in the Lassa area of Haut-Uélé Province, northeastern Democratic Republic of the Congo. The aim is to improve geological knowledge and assess the mineral potential of this poorly documented region. Geological field investigations were conducted at thirteen sampling stations, where representative rock samples were collected. Three samples were selected for petrographic analysis by thin-section microscopy, and three representative samples were analysed by X-ray fluorescence (XRF) to determine their major-oxide and trace-element compositions. Petrographic investigations identified three principal lithological units: dolerite, granite, and banded iron formation. Geochemical analyses revealed marked compositional differences among these lithologies. The quartz-vein sample has a high SiO2 content and elevated Cr, Cu, and Zn concentrations, whereas the BIF samples show iron enrichment and geochemical signatures consistent with hydrothermal alteration. Reflected-light microscopy confirmed the occurrence of pyrite within the quartz vein. Together, the petrographic, geochemical, and metallographic observations indicate that hydrothermal-fluid circulation played an important role in the evolution of the study area and suggest favourable conditions for hydrothermal mineralization. Although no direct gold analyses were performed, the results identify the Lassa area as a promising target for further mineral-exploration studies.