Hot Springs Outside the Colombian Andean Area

Abstract

The Geothermal Resources Research and Exploration working group of the Colombian Geological Service (SGC) conducted research in 7 departments of the Colombian territory (Cesar, Atlántico, Magdalena, Arauca, Casanare, Meta and Guaviare) located outside the Colombian Andean area, finding 16 springs with deep circulation mainly associated with fault systems. The springs were georeferenced and physicochemical parameters were determined in situ: temperature, pH, electrical conductivity, and Alkalinity and its H2S content were determined. Springs with temperatures between 30.7 and 45.6 were found; waters in a pH range between 4.3 and 8.5; waters with low conductivities, between 29 and 2066 μS/cm, except for a thermal spring in the department of Casanare with an electrical conductivity of 278,000 μS/cm; and low concentrations of H2S, with the exception of the spring located in the department of Cesar with 38.5 mg/L of H2S. The samples were analyzed in the laboratories of the SGC, to determine the anions and cations present, finding mainly sodium bicarbonated waters and sodium chlorides, stable isotopes of the water were also analyzed, for comparison with the meteoric line and to estimate the probable elevation of the recharge. To estimate the reservoir temperatures of the thermal sources, chemical geothermometers of Na-K and silica were calculated, as well as temperature estimation diagrams.