Hydrogeochemical characteristics at Doña Juana Complex (SW Colombia): A new area for geothermal exploration in the Northern Andes region

Abstract

The Doña Juana Volcanic Complex (DJVC) is an active volcanic zone located in southern Colombia, an area lacking geothermal exploration data. Using the results of hydrogeochemical analyses of hot springs, thermal waters were divided into two groups: Doña Juana System (DJS) and Las Animas System (AS). The DJS thermal waters are sulphate-bicarbonate and the AS dilute-chloride waters with relatively high concentrations of alkalis. The stable isotope and some element ratios suggested a mixing process between geothermal fluids and meteoric waters where AS is related to the upflow with a reservoir temperature around 180 °C estimated through solute geothermometers and mineral equilibrium geothermometry, showing a high temperature system in which the fault systems apparently play an important role in the flow of the geothermal fluids.