Hydrogeochemical formation mechanism of springs in Huanglong, a world natural heritage, Sichuan, China

Schematic diagram illustrating water–rock interaction, calcite dissolution and travertine deposition processes in alpine karst spring systems. Huanglong World Natural Heritage site is characterized by a remarkable alpine karst landscape, where secondary carbonate rock salt deposits emerge on the surface to form unique geological features. These include calcareous pools, travertine beach flows, and travertine waterfalls – extraordinary examples of high-altitude cold-water travertine formations. This study investigates the hydrochemical characteristics and formation mechanisms of the springs in the Huanglong Scenic Area using mathematical statistics, cluster analysis, the Gibbs model, and the proportion coefficients of major ions. The objective is to identify the sources of hydrochemical components and to understand the evolution of travertine deposition in the region. Results indicate that the hydrochemical composition of the springs primarily originates from the weathering and dissolution of carbonate minerals. Ca2+ dominate the cationic composition, while HCO3− are the principal anions present. Minor components include Mg2+, Cl−, SO42− and NO3− ions. The overall hydrochemical type of the springs is classified as HCO3-Ca.The study reveals that water–rock interactions are the main processes influencing the hydrochemical characteristics of the springs. While human tourism activities also have an impact, there is no significant evidence of alternating cation adsorption affecting the hydrochemistry. These findings offer valuable insights into the hydrochemical nature of Huanglong springs, contributing to the broader understanding of travertine formation in alpine karst environments. The study's outcomes provide essential data for the sustainable management and conservation of water resources in the Huanglong Scenic Area. By enhancing knowledge of the natural processes governing this World Heritage site, this research supports effective water resource planning and allocation, ensuring the preservation of its unique geological features for future generations.