Regional Hydrogeochemical Mapping for Environmental Studies in the Mineralized Lom Basin, East Cameroon: A Pre-industrial Mining Survey

The present study is the first appraisal of regional hydrogeochemical programme for environmental assessment of the mineralized Lom Basin in East Cameroon. Fifty-two streamwater samples were collected and analysed for major cations (Ca 2+, Mg 2+, Na +, K +) and major anions (HCO 3 –, F– , Cl–, NO2–, NO3–, Br–, PO43–, SO42–). Calcium and HCO3– were the dominant ions. The chemical facies for the surface water were CaHCO3 and NaHCO3 types indicating a fresh water source. Major ion geochemistry demonstrated the potential to discriminate between natural and anthropogenic origins. Calcium ion, Mg2+, Na+, K+and HCO3– had similar distribution trends reflecting weathering from the parent rocks. Sulphate distribution correlated with the occurrence of sulphide minerals associated with hydrothermal gold mineralization in the area while the distribution patterns of NO3–and Cl– reflected pollution from domestic activities within the municipality. Overall, the chemistry of stream water in the Lom Basin is mainly controlled by silicate weathering with only minor anthropogenic influence. This study forms an analogue for hydrogeochemical mapping in other mineralized terrains in Cameroon.