## 4 Results and Discussion  
### Physiochemical and Hydrochemical Parameters of the Geothermal Springs  
The chemical composition of groundwater was not uniform but varied over a wide range. This implies that the groundwater was heterogenous in composition. Results show that geothermal spring water was more mineralised than thermal boreholes. This phenomenon supports the previous findings by [PERSON] [36] and [PERSON] et al. [15]. This could be attributed to the rock-water interaction in the deeper aquifer resulting in higher mineralisation. The water temperature of springs in the study area ranged between 41.3 \({}^{\circ}\)C and 67.7 \({}^{\circ}\)C (Table 2). Based on Taylor and Phillips classification,Siloam hot boreholes (SH1 and SH2), Mphephu, and Sagole springs are thermal (hot) waters with temperatures ranging between 41 \({}^{\circ}\)C to 49 \({}^{\circ}\)C. Siloam and Tshipise geothermal springs can be classified as scaling (hyperthermal) with temperatures ranging between 53 \({}^{\circ}\)C and 69 \({}^{\circ}\)C. There is approximately 1 \({}^{\circ}\)C seasonal difference in the thermal property of the geothermal spring in summer compared to winter. The high temperature in summer results in more transfer of moisture (evaporation and evapotranspiration) to the atmosphere until the dew point is reached, hence there is potential to rain more intensely in summer, resulting in more dissolution of minerals in the water. The statistical results of the hydro-chemical and isotopic analyses for the studied geothermal springs and boreholes within Soutpansberg Group are shown in Table 2.  
Guidelines for Domestic Water Quality [37] delineate values of 7-9, except for Siloam geothermal spring water (SAW) and Siloam hot borehole (SH2), which had pH values of 9.39 and 9.19, respectively. The TDS values were generally less than 450 mg/l, ranging from 120.84 to 390.61 mg/l for all the samples with a slight difference with respect to seasons. Therefore, the TDS values fell within the South African Guidelines for Domestic Water Quality [37] value of 450 mg/L. However, previous studies showed that the TDS values for Tshipise geothermal spring were higher than 450 mg/L [15; 18], which is contrary to the present findings. This could be a result of the decrease in water temperature (decreasing from 58 \({}^{\circ}\)C from [PERSON] et al. (2011) to 55.7 \({}^{\circ}\)C in the present study) of the spring and mixing of different water types. The dominant ionic compositions found in the studied site waters were sodium (Na\({}^{+}\)), bicarbonate (HCO\({}_{3}\)-), sulphate (SO\({}_{4}\)\({}^{2-}\)), and chloride (Cl\({}^{-}\)) (Table 2). That is, the water was rich (high concentrations) in those dominant ions. The high Na+ concentrations probably originated from chemical weathering processes of sodium-rich plagioclase feldspars in the sandstone and shale. The general order of dominant cations is Na\({}^{+}\)\(>\) Ca\({}^{2+}\)\(>\) K\({}^{+}\)\(>\) Mg\({}^{2+}\), and the sequence of the abundance of the anions are in the order: Cl\({}^{-}\)\(>\)SO\({}_{4}\)\({}^{2-}\)\(>\) HCO\({}_{3}\)\({}^{-}\)\(>\) F\({}^{-}\)\(>\) NO\({}_{3}\)\({}^{-}\)\(>\) PO\({}_{4}\)\({}^{3-}\). The Piper and Durov diagrams were used to assess the water types and geochemical processes leading to the respective water types [38; 39]. Piper diagram can classify into six fields, which are: 1) Ca-HCO\({}_{3}\) type; 2) Na-Cl type; 3) Ca-Mg-Cl type; 4) Ca-Na-HCO\({}_{3}\) type; 5.) Ca-Cl type; and 6) Na-HCO\({}_{3}\) type [38]. The Piper diagram revealed that most of the geothermal spring water fell in the Na-Cl water type, except the Siloam geothermal spring (SAW-WT29 and WT30) fell into the Na-HCO\({}_{3}\) water type (Figure 4). Although this study supports the recent findings by [PERSON] et al. [18], it contradicts [PERSON] et al. [15], which reported NaHCO\({}_{3}\) and Na-Ca-HCO\({}_{3}\) water types for Sagole and Mphephu springs, respectively.