## 5 Discussion  
Our 3-D MT model's primary goal is to shed light on the geometry of formation boundaries and significant resistivity anomalies. The lack of presence of deep wells in the region somewhat hinders our ability to fully understand and interpret the resistivity model. Our resistivity model shows very low resistivity values in the top layer (C1), with an average thickness of 200 m (Figure 10). Conductors C1 and C2 are connected in profile SW-NE of Figure 9. The Kalahari sediments in the area have a maximum thickness of 100-200 m [43]; therefore, we assume that the shallower conductive zone observed in our model is associated with a sedimentary cover. The heterogeneous electrical conductivity observed in the shallow conductor zone might be attributed to the presence of saline water resulting from dissolution processes within the upper layers of the Earth's crust and/or the presence of clay minerals. An analysis of groundwater in the study area showed extremely  
Figure 9: The resistivity cross-sections show resistivity distribution with depth. A shallow low-resistive layer, followed by a gradually increasing resistivity zone, are imaged. The **top** figure shows the SW-NE profile (orthogonal to faults in the region), and the **bottom** shows the S-N profile (across Chobe River, chosen to investigate the influence of the river on the hot spring) observed in the inset map. The black cross represents the location of the hot spring. Vertical exaggeration (V.E) = 5.0.  
elevated levels of total dissolved solids (TDSs), exceeding 9.5 g per liter [3]. Geothermal fluids are often acidic in shallow areas due to the presence of HCO\({}_{3}\)- or SO\({}_{4}\)-rich waters [3]. The deep high resistive zone extending downward to over 4 km depth (Figure 8) corresponds to compact basement formation, possibly Mesoproterozoic motasedimentary rocks of the Ghanzi Group. In a high-enthalpy geothermal region, resistivity distributions often are typically influenced by clay minerals, temperature, and formation lithology [44; 45; 46; 47; 48; 49; 50; 51]. The alteration products form a very conductive cap on top of a more resistive reservoir with a higher temperature [22; 50; 51]. In particular, at temperatures between 70 \({}^{\circ}\)C and 200 \({}^{\circ}\)C, hydrothermal alteration produces smectites that have a very high cation exchange potential, which significantly reduces the resistivity [22]. In that case, a reservoir with temperatures of more than 200 \({}^{\circ}\)C would be located at shallow depth (1000 m). As water temperatures at the hot spring are moderate, and there are no further geothermal manifestations in the area, this model is not applicable to the Kasane region. Previous studies at the Kasane Hot Spring classified the source of water for the hot spring as meteoric, with little isotopic change and that the hot springs have not experienced extensive water-rock interaction based on the hot spring's geochemistry [3]. The hot springs in the Kasane produce SO\({}_{4}\)\({}^{2-}\)-rich waters, with temperatures between 43 and 50 \({}^{\circ}\)C [2; 3]. The geochemical analysis of hot springs in Botswana and Zambia based on SiO\({}_{2}\) and K-Mg geothermometers conducted by [PERSON] [3] predicted the reservoir temperature to be between 84.8 and 93.6 \({}^{\circ}\)C. The Kasane Hot Spring region could be considered a low enthalpy geothermal zone. In nonvolcanic areas, low-enthalpy geothermal systems are usually associated with hot fluids confined in sedimentary or crystalline reservoirs, which may have natural permeability or enhanced fluid pathways [17; 18]. Low-enthalpy reservoirs are characterized by their lower reservoir temperatures, which are below 150 \({}^{\circ}\)C, in contrast to high-enthalpy geothermal systems, where temperatures surpass 150 \({}^{\circ}\)C [17; 18]. In [PERSON] geochemical study [3], it was determined that there is no magmatic influence present at the Kasane Hot Spring.