Hydro-geochemical Signature in the Thermal Waters in Jebel Mara, Darfur Region Western Sudan

Abstract

Hydrochemical investigations, which are significant for the assessment of water quality, have been carried out to study the sources of dissolved ions in hot springs water of some part of Jebel Mara mountain, Darfur region, Sudan. The temperature of hot springs water was varies from 50°C to 60°C. Samples collected from hot springs near Koronga village at Jebel Mara, were analyzed for major solutes and trace elements as part of larger study to characterize the geochemical signature of these ground waters. In these study, four major cations (Ca++, Mg++, Na+ and K+), three major anions (Cl-, SO4 2- and HCO3) and some trace elements (Mn, Zn, Pb, Fe and P) were analyzed in these ground water samples. This study reveals that most waters taken from hot springs has high values of Hydrogen ion concentration (pH) , high values of electrical conductivity (E.C), and high concentrations of total hardness (T.H), total dissolved solids (T.D.S) , bicarbonates (HCO3), sodium (Na+) and Magnesium (Mg++). All these high values of pH, T.D.S, T.H, Na and HCO3 are mainly due to dissolution of these ions from rock bearing minerals of the study area. Normal values of trace elements like Iron (Fe), Copper (Cu), Lead (Pb), Iodine (I) and Zinc (Zn) whereas, high concentrations of Manganese (Mn). The study classified hot springs waters as Calcium-Magnesium-Sodium Bicarbonate type. Using USDA classification, water has been classified as C2 S1 (medium conductivity-salinity and low sodium content). The discharge values of hot springs measured to be between 1-2 L/S for all hot springs near Koronga village. The thermal waters are associated with Tertiary basalt and heat for these thermal waters is obtained during deep circulation in fracture basalt and is related to volcanic or tectonic activity. This study suggested that the geothermal waters of Jebel Mara area are of meteoric origin. Hot springs waters (thermal water) have also been used for medical therapy.