Structural controls of the northern Red River Fault Zone on the intensity of hydrothermal activity and distribution of hot springs in the Yunnan-Tibet geothermal belt

Abstract

Deep, large faults are well-developed in the Red River Fault Zone in Yunnan in southwest China. This study uses a classification approach and macro-scale analysis of faults and hot springs with data from the literatures and field work. By examining 68 hot springs, 6 faults, and 12 Quaternary basins in this area, controls of the northern Red River Fault Zone on the intensity of hydrothermal activity (temperature and flow rates) and distribution of hot springs are summarized. The results show that topography-related hydraulic gradients can cause geothermal water to rise after circulation. The hot springs are easy to occur along the active faults (76%), especially at fault intersections (37%). The circulation depth and elevated temperature of hot springs in the study area are positively correlated. The highest temperature hot springs correspond to low flow rates, and hot springs with the highest flow rate have low temperatures. The results are of practical significance for the search for thermal groundwater and for understanding geothermal resources potential in this area and similar areas.