Boron geochemical characteristics in different types of geothermal water and its indications for the genesis mechanism of geothermal systems

Abstract

Objective Boron is a relatively conservative element in geothermal fluids that often accompanies geothermal systems, and its origin plays an important role in revealing the genesis mechanisms of different types of geothermal systems. Methods In this study, the geothermal systems of the Daggyai in Tibet and the Yinchuan Basin in Ningxia were selected for investigating the source of boron in geothermal water and its related geochemical processes in different types of geothermal systems. These study areas are typical of high-temperature and medium-low-temperature geothermal systems in China, and both have extremely high boron concentrations. Results Results showed that the boron in the neutral/weakly alkaline geothermal water of the Daggyai was primarily contributed by dissolution filtration of the surrounding rocks and magmatic fluid input, while the boron in the acidic geothermal water was primarily contributed by the input of shallow cold water from the subsurface. Boron in the geothermal water of Yinchuan primarily originated from the recharge of deep paleosedimentary water. On this basis, the genetic mechanisms of different types of geothermal systems were discussed by combining the regional geological background and the hydrochemical characteristics of geothermal water. Conclusion This study suggests that the geochemical characteristics of boron in geothermal water have the potential to identify the genesis mechanisms of different types of geothermal systems.

Keywords

• boron
• geothermal systems
• geothermal water
• genetic mechanism
• magmatic heat source
• paleosedimentary water