| Authors |
Peter MAWEJJE, Vincent KATO, Jacqueline NNAKIRIJJA, Keith TUNDE, Unity BIRUNGI, Mebra TAMUWA, Henry MULINDWA, |
| Abstract |
Kibiro is one of the main geothermal prospects of Uganda. Work in this geothermal prospect started way back in 1993 around the hot spring area of Kibiro, but the reservoir and the heat source have not been established. In the year 2011 a project called Uganda Geothermal Resources Development Project 1199 (UGRDP)sponsored by government of Uganda, was inaugurated to do further work on main geothermal areas of Uganda which included Katwe, Kibiro, Buranga and Panyimur geothermal fields. Based on geological explorations so far done over Kibiro, several observations and findings have been made. Maximum surface temperature of 85 degrees Celsius have been measured in the hot springs. Findings show that geothermal surface manifestations cover a much wider area than previously thought. several hundreds of observation points were made and the area covered by surface manifestations delineated. All the geographical spatial data was compiled into a geo-database including the old datasets for spatial analysis in GIS environment. Zonation within the manifestation area was done based on three minerals to identify areas which are likely to have high or low temperature zones, as well as up flow zones. The zonation was based on silica, sulphur and calcite or travertine. Two areas of interest including the hot spring area have been identified. According to observations made, the geothermal system is primarily along boarder faults of the rift and subordinate volcanism has been observed elsewhere within the rift.Since sediment-filled grabens exist in this environment, strata bound aquifers are also likely. The hydrothermal fluids are directly controlled by the main fault scarp. Up flow zones along the escarpment are more pronounced at intersections with other smaller faults, especially where the fault density is higher which also increase secondary permeability. The data available is now being used to make geothermal geological model, but further studies of structure need to be done. After the geological model is out, the next stage will be integrating data from other exploration disciplines i.e. geophysics and geochemistry. Information from oil wells and companies is being scrutinized so as to throw some more light on seisimic layering, lithology and temperature gradient. |