Formation mechanism of high-altitude glacial mineral water in the Kunlun Mountains of Tibetan Plateau: Insights from isotopes and hydrochemistry

Study region The Kunlun Mountains on Tibetan Plateau Study focus The Tibetan Plateau, well known as Asian Water Tower, holds immense potential for the formation of glacial mineral water. The present research focuses on the hydrochemical and isotopic signatures and formation pattern of natural glacial mineral water in the alpine region on Tibetan Plateau. New hydrological insights for the region The investigated mineral groundwater has outstanding water quality and slightly alkaline nature. It is with fresh hydrochemical facies of HCO3-Na·Ca type with total dissolved solids (TDS) in the range of 384–964 mg/L, and featured by notably rich strontium with the concentrations of 0.67–0.81 mg/L, far exceeding the recommended mineral water minimum threshold of 0.20 mg/L. The mineral groundwater is originated from the glacier meltwater of mountainous area with elevation over 4500 m. It subsequently infiltrates into the bedrock and move within the groundwater system with a residence time of approximately 52 years. Its hydrochemical constituents are naturally governed by water-rock interactions of silicates dissolution, cation exchange, and celestite and strontianite dissolution. A conceptual model is proposed to outline the formation pattern of glacial mineral water in alpine region on Tibetan Plateau. Findings of this study can fill the study gap regarding glacial mineral water on Tibetan Plateau, and further contribute to the future study and development of natural glacial mineral water in alpine regions worldwide.