## 5 Conclusions  
Through remote sensing geological interpretation, field geological survey, geophysical exploration, geological drilling, long-term observation, pumping test, and hydrochemistry test and other technical means and working methods, this study analyzed the geothermal characteristics and geological characteristics of Lushan geothermal belt, basically found out the formation mechanism and thermal control structure of Lushan geothermal zone, and estimated the reserves of geothermal resources. The main conclusions are drawn as followings:  
1. Lushan geothermal springs are exposed in the Checun-xiatang deep fault zone. The Checun-Xiatang deep fault zone is the northern boundary of Lushan geothermal belt, the Erlangmiao-Wentang fault zone and Shuimozhuang-Lichun fault zone are its southern boundary, and the Modaling-Huanghuai watershed is its western boundary. The Checun-Xiatang fault and its parallel secondary near East-West faults are the primary heat control and conduction structures, which are the main channels for upward convection of deep heat sources; the north-east faults are the secondary heat conduction and water conduction structures, which control the outcropping of five hot springs. 2. Lushan geothermal (hot spring) belongs to uplift fracture type, convection type, fracture vein type geothermal atresia water. It has no good heat insulation overburden, and is mainly recharged by atmospheric precipitation. Hydrochemical type of Shentang hot spring water belongs to HSiO\({}_{4}\)-HCO\({}_{3}\)-Na, and the others belong to HCO\({}_{3}\)-SO\({}_{4}\)-Na type. The temperature and quantity of all geothermal spring water are hardly affected by seasons. The results of geophysical exploration show that there is low resistivity layer in the 600-800 m underground, which is supposed to be the reservoir of geothermal water. 3. The water temperature of Shangtang, Zhongtang, and Xiatang hot springs is from 60 to 90 \({}^{\circ}\)C, which belongs to the hot water of low-temperature geothermal resources. The water temperature of Wentang and Shentang hot springs is from 40 to 60 \({}^{\circ}\)C, which belongs to the warm water of low-temperature geothermal resources. The minimum recoverable amount of Lushan geothermal field is 397.94 m\({}^{3}\)/h, and the maximum value is 671.4 m\({}^{3}\)/h. The annual recoverable heat energy is 4.41 \(\times\) 10\({}^{11}\) MJ. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Geothermal Field** & **Shangtang** & **Zhongtang** & **Wentang** & **Xiatang** & **Shentang** & **Total** \\ \hline \hline \begin{tabular}{c} Recoverable Mount \\ (m\({}^{3}\)/h) \\ \end{tabular} & 280.4 & 13.94 & 2.0 & 250.0 & 125.0 & 671.34 \\ \hline \begin{tabular}{c} Recoverable Heat \\ (kW) \\ \end{tabular} & 15,098.7 & 783.1 & 58.8 & 14,043.2 & 5131.7 & 35,115.5 \\ \hline \
\begin{tabular}{c} Annual Recoverable \\ Heat Energy (MJ) \\ \end{tabular} & \(1.89\times 10^{11}\) & \(9.83\times 10^{9}\) & \(7.39\times 10^{8}\) & \(1.76\times 10^{11}\) & \(6.44\times 10^{10}\) & \(4.41\times 10^{11}\) \\ \hline
\begin{tabular}{c} Equivalent to \\ Standard Coal (t/a) \\ \end{tabular} & \(6.45\times 10^{6}\) & \(0.34\times 10^{6}\) & \(0.025\times 10^{6}\) & \(6.01\times 10^{6}\) & \(2.20\times 10^{6}\) & \(15.05\times 10^{6}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Estimation of geothermal energy. **Author Contributions**: Q.Z. : conceptualization, formal analysis, and writing original draft; Z.B. : data curation, investigation, and methodology; Y.X. : investigation and project administration; S.L. : supervision; L.Z. : validation and writing--review and editing; J.Q. : funding acquisition and writing--review and editing. All authors have read and agreed to the published version of the manuscript. **Funding**: This research was supported by National Natural Science Foundation of China (Grant No. 41831289; Grant No. 41772250; Grant No.