This paper is the result of geothermal survey engineering.

Objective The study of the characteristics and genesis models of geothermal resources in the Nanchang basin has important guiding significance for the exploration and development of deep geothermal resources in the research area.

Methods Based on the analysis of the geological conditions such as the stratigraphic structure, geological structure, and geothermal field characteristics of the Nanchang Basin, t this article reveals the characteristics of geothermal resource occurrence in the Nanchang Basin, establishes a conceptual model of the geothermal system in the study area, and carries out geothermal resource quantity evaluation on this basis.

Results The heat reservoir types in the Nanchang Basin are divided into two types: clastic rock pore type and carbonate rock karst fracture type. Water quality analysis shows that the water quality of clastic rock thermal storage is SO₄−Na type, while the water quality of carbonate rock thermal storage is Cl·SO₄−Na type or Cl−Na type. The deep geothermal water in the Nanchang Basin primarily originates from atmospheric precipitation. Groundwater infiltrates through fractures and fissures along the margin of the red basin, then flows laterally northeastward and into deeper regions via pathways such as interlayer fissures. During this migration, it absorbs heat from the surrounding rocks through thermal conduction and leaches trace elements from the bedrock. The blocking effect of thrust faults interrupts this movement, causing the groundwater to accumulate and store in karst cavities within imbricate faults of the deep basement or rock slices, ultimately forming a hydrothermal geothermal system.

Conclusions Based on the analysis of the thermal storage conditions in the area, it is believed that the Changbei—Liantang and Huangxi—Houtian regions have favorable prospects for geothermal resource exploration; The geothermal resources in the Nanchang basin are 769.11×10⁸ GJ, equivalent to 26.28×10⁸ t of standard coal; The recoverable resource amount is 115.37×10⁸ GJ, equivalent to 3.94×10⁸ t of standard coal, with a high overall development potential.