Application of geothermometric and hydrochemical methods to the investigation of thermal water of sources in the Northeastern of Algeria case of Setif city

Abstract

Thermal water in northeastern Algeria (Setif) is a promising, sustainable resource of energy. To date, thermal water has not been used as a source of renewable energy in Algeria as no clear strategy has yet been developed for its use. In this study, eight samples of thermal water springs distributed within the area of Setif city were assessed, and their physical and chemical parameters (such as temperature, potential of hydrogen, electrical conductivity, and major ionic composition, including the K+, Na+, Ca2+, Mg2+, Cl−, SO42− and HCO3−) were measured. The results show that the temperature, potential of hydrogen and the electrical conductivity range between 30 and 52 °C (as measured in field), 6.92 and 7.35, and 1170 and 3160 µS/cm, respectively. Furthermore, the results indicate the existence of four hydrogeochemical facies dominating the hydrogeological system, which are SO4–Ca, Na–SO4, HCO3–Na and Cl–Na. The interaction with Jurassic limestone and the existence of evaporates along the upwelling system, respectively, control this. Due to the high variation of temperature, different geothermometers were used to estimate the geothermal reservoir temperature, the application of silica geothermometer (Quartz), because it is the most suitable in our case, gives temperatures estimated at the origin of the order of 80° C. It is higher than that measured at emergence, it reflects an average dissipation of 48° C. According to an analysis of these findings and the geothermal gradient in the area, two aquifer systems of the thermal complex are supplied by a reservoir that is stored in fissured Jurassic limestone that is more than 2600 m deep.