Geothermal and Mineralogic Analysis of Hot Springs in the Puracé-La Mina Sector in Cauca, Colombia

Abstract

Thermal waters are natural resources of great value to geothermal sciences, the tourism industry, and health. In this work, geochemical classification of physicochemical results of 17 sources at the Puracé-La Mina (Cauca, Colombia) sector was implemented in order to strengthen and determine their potential applications and enhance the continental tourism in Colombia. The analyzed parameters were developed following the Standard Methods 22nd edition, at Universidad Nacional de Colombia-Manizales. According to the results obtained by means of a geochemical classification, it was found that most of the sources have a sulfated-acid nature which makes them heated vapor waters and volcanic waters. Likewise, it was observed that all the sources are immature waters and still do not reach chemical equilibrium. On the other hand, mineralogical and chemical characterization by means of XRD and XRF showed a high content of silica isomorphous minerals with a low concentration. In addition, the presence of Fe2O3 was observed, which is insoluble at pH > 5 and remains in the rock. Nevertheless, considering that mine sources possess pH ± 2 and temperatures of 40°C, leaching is possible for iron justifying its presence in the water. Instead, elements like Na+, K+, Mg2+, and Ca2+ have high mobility at the conditions of mine sources (low pH) as a consequence of hydrolysis processes, which produce variations in water composition.

Physical-Chemical Characterization and Mineralogic Analysis of Hydrothermal Systems Located in the Coconuco and the San Juan Sectors in Cauca, Colombia

“…In this case, values above 10% were observed which are attributed to different events such as the oxidation of compounds and elements, degasification of CO 2 , and decrease in temperature, which generates an increase in H + ions that were considered in the load balance. This process was mentioned in previous works [24]. On the other hand, errors were greater when the total sum of ions was less than 5 mEq/L [28].…”

“…Bearing in mind that in the area study which is located close to the Puracé volcano, the absorption of magmatic gas in the meteoric water occurs as a consequence of S, generating waters of the sulphate acid type [15] as observed in previous publications [24]. The Coconuco sector that is located in the Caldera de Chagartón presents in its lithological section flows of ashes and andesitic lavas, among others, that can cause that the fluids suffer neutralization due to the hydrolysis of the rocks, producing water with more content in carbonates which generates steam-heated waters in the San Juan sector [15].…”

“…A Metrohm Swiss-made device was used for the pH-L measurements, and a Metrohm Swiss-quality titration equipment was used for the multiprobe analysis. The methods of analysis are detailed in [24].…”

“…Currently, the San Juan sector is located on the Puracé National Natural Park declared by UNESCO as a biosphere reserve in 1979. The lithological cross section is described in [24]. The purpose of the present work is the characterization and analysis of the physicalchemical properties of 8 sources in the Coconuco sector 4 Geofluids sampling performed was simple or timely.…”

“…The analysis was carried out using the EVA [26] and TOPAS software [27]. The details of the analysis are described in [24]. ions, total hardness, and calcium were noticed.…”