Hydrogeochemical characteristics and geothermometry of hot springs in the Altai region, Mongolia

Abstract

This study determines the properties of hot spring waters and associated rocks, calculates reservoir temperatures and depths in the Mongolian Altai region, and constructs a conceptual model for geothermal water based on these results. The hot springs consist of HCO3–Na, SO4–Na, and HCO3–SO4–Na mixed waters. They exhibit alkaline pH levels and temperatures in the range 21.3–35°C. X-ray diffraction analyses of outcrop rocks reveal silicate and carbonate-type minerals such as quartz, albite, orthoclase, dolomite, mica and actinolite, while correlation analysis indicates that the chemical composition of the hot spring water is directly related to rock mineral composition, where dissolution of albite, orthoclase and dolomite minerals has played an important role. Reservoir water circulation depths are 2615–3410 m according to quartz and chalcedony geothermometry. The results indicate that the spring water in the Mongolian Altai region comprises a low mineral content with alkaline pH levels and that the reservoir temperature can reach up to 106°C. We also propose a conceptual model for geothermal water in the Chikhertei hot spring. The geothermal water in the Mongolian Altai region has the potential for use in heating systems.Thematic collection: This article is part of the Hydrochemistry related to exploration and environmental issues collection available at: https://www.lyellcollection.org/cc/hydrochemistry-related-to-exploration-and-environmental-issues