Authors: Olatunde Samod Durowoju*, University of Venda, John Ogony Odiyo, University of Venda, Thohoyandou, Georges-Ivo Ekosse Ekosse, University of Venda, Thohoyandou, South Africa
Topics: Water Resources and Hydrology, Environmental Science, Natural Resources
Keywords: Hydrochemistry, geochemical process, isotopic composition, Soutpansberg, Limpopo Province
Session Type: Paper
Start / End Time: 1:45 PM / 3:00 PM
Room: Gold, Sheraton, IM Pei Tower, Majestic Level
Presentation File: No File Uploaded
Limpopo Province has the highest number of geothermal springs, with about twenty-four known geothermal springs in the country; which were classified according to the residing mountains: Soutpansberg, Waterberg and Drakensberg. Mphephu, Sagole, Siloam and Tshipise geothermal springs fall within the Soutpansberg. This study is aimed at understanding the evolution, geochemical processes controlling the water chemistry, coupled with analyses of major ion hydrochemistry and environmental isotopes (δ18O, δ2H and 3H) data supported by conventional hydrogeological information have been undertaken. The dominant hydrochemical facies for geothermal springs within Soutpansberg are Na-Cl and Na-HCO3. Data indicate that geothermal spring water chemistry is controlled by water-rock interaction, silicate weathering, mineral dissolution, cation exchange, and inverse cation exchange. The isotopic composition of the springs ranges from −0.48‰ to −5.41‰ for δ18O, from −33.3‰ to −24‰ for δ2H, and from 0 to 1.6 TU for tritium. δ2H and δ18O isotope signatures reveal a significant infiltration before evaporation takes place. This implies that the geothermal water has been originating from local precipitation and no paleoclimate effect is evident. This corroborates with findings from the geothermal water age obtained by the radiocarbon method, which placed the recharge period during the Holocene. Hence, this is clearly indicated that this water is originating from the deep circulating local meteoric water.