Geological influence of Groundwater Quality, Eastern Region of Mount Cameroon and West of the Penda Mboko River

Abstract

This research focuses primarily on exploring the role of silica in deciphering the geological controls and hydrogeochemical processes affecting groundwater in this challenging terrain. To assess the hydrochemical properties of groundwater and its quality, fifty samples were collected from hand dug wells, boreholes, springs and rivers. Electrical conductivity (EC), pH, temperature and total dissolved solids (TDS) were measured in situ. The mean concentration of major ions indicated Ca > Mg2+ > k+ > Na+ and HCO-3 > CL- > NO-3 > SO2-4. The majority of the water samples (76%) were found in the rock dominance zone, while only 14% were in the precipitation dominance zone, indicating that the interaction between rock and water is the main factor controlling the groundwater chemistry. Chemical geothermometry was used to estimate the groundwater temperature .The silica levels in the samples ranged from 5.8 to 58.7 mg/l, and chalcedony temperatures of over 60°C were detected at five sites, indicating a depth of over 1,000 metres. This study highlights the effectiveness of this combination of instruments in tracking water-rock interactions, regardless of factors such as flow depth, water properties, geological conditions and variations in interaction time. Examination of mineral saturation indices showed supersaturation with silicate minerals such as quartz, but undersaturated with carbonate, sulphate and halide minerals such as calcite, gypsum and anhydrite.