The Formation Mechanism of Hydrothermal Resources in the Chuxiong Basin, SW China: Insights from the coupling of hydrological process and deep temperature field

Understanding the deep geothermal field and high-temperature hydrothermal activities is of great significance for the formation machanism of hydrothermal geothermal resources. Therefore, we focus on the Chuxiong Basin near the South Tibet-West Yunnan high-temperature geothermal belt, the largest high-temperature geothermal belt in China. Based on hydrochemical studies and geothermal field calculations, we clarified the control mechanism of deep-circulating water-rock interactions on the hydrochemical types, and finally revealed the geothermal formation mechanism of the hot springs. The results show that the hydrochemical type of the hot springs in Chuxiong Basin is HCO₃–Na, with precipitation serving as the primary recharge source. The Cenozoic and Cretaceous of the basin in the context of high heat flow (72.1 mW/m² on average) are buried shallowly and have low temperatures. However, due to the large thickness of Jurassic deposits in the central part of the basin, the Jurassic and Triassic are buried deeply and have high temperatures. Large, deep faults control the spatial distribution of heat flow and serve as pathways for the ascent of deep hydrothermal fluids. Based on these conclusions, a convective system of deep groundwater circulation under the control of deep large faults is revealed, which provides an important reference for the development and utilization of high-temperature geothermal resources.