Browsing by Author "Barifaijo, E."

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    Correlation of geoelectric data with aquifer parameters to delineate the groundwater potential of hard rock terrain in Central Uganda.
    (2010) Batte, A.G.; Barifaijo, E.; Kiberu, J.M.; Kawule, W.; Muwanga, A.; Owor, M.; Kisekulo, J.
    Knowledge of aquifer parameters is essential for management of groundwater resources. Conventionally, these parameters are estimated through pumping tests carried out on water wells. This paper presents a study that was conducted in three villages (Tumba, Kabazi, and Ndaiga) of Nakasongola District, central Uganda to investigate the hydrogeological characteristics of the basement aquifers. Our objective was to correlate surface resistivity data with aquifer properties in order to reveal the groundwater potential in the district. Existing electrical resistivity and borehole data from 20 villages in Nakasongola District were used to correlate the aquifer apparent resistivity (ρ e) with its hydraulic conductivity (K e), and aquifer transverse resistance (TR) with its transmissivity (T e). K e was found to be related to ρ e by; [Math Processing Error]. Similarly, TR was found to be related to T by; [Math Processing Error]. Using these expressions, aquifer parameters (T c and K c) were extrapolated from measurements obtained from surface resistivity surveys. Our results show very low resistivities for the presumed water-bearing aquifer zones, possibly because of deteriorating quality of the groundwater and their packing and grain size. Drilling at the preferred VES spots was conducted before the pumping tests to reveal the aquifer characteristics. Aquifer parameters (T o and K o) as obtained from pumping tests gave values (29,424.7 m2/day, 374.3 m/day), (9,801.1 m2/day, 437.0 m/day), (31,852.4 m2/day, 392.9 m/day). The estimated aquifer parameter (T c and K c) when extrapolated from surface geoelectrical data gave (7,142.9 m2/day, 381.9 m/day), (28,200.0 m2/day, 463.4 m/day), (19,428.6 m2/day, 459.2 m/day) for Tumba, Kabazi, and Ndaiga villages, respectively. Interestingly, the similarity between the K c and K o pairs was not significantly different. We observed no significant relationships between the T c and T o pairs. The root mean square errors were estimated to be 18,159 m2/day and 41.4 m/day.
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    Geochemistry of the Potassic Basalts from the Bufumbira Volcanic Field in Southwestern Uganda.
    (2010) Barifaijo, E.; Muwanga, A.; Schumann, A.
    Bufumbira volcanic field is the southernmost of the four Ugandan small Pleistocene to Recent volcanic fields within the western branch of the East African rift system. The rocks consist of silica undersaturated and vesicular basalts with numerous primary structures. The rocks consist of basanites, leucitites, olivine basalts, trachytes, tephrites, trachyandesites and andesites. The basalts are picritic in the northern part of the field where they are dominated by olivine and are clinopyroxene rich in the southern part of the field. Leucite and plagioclase are common in the groundmass in varying proportions by volume for the entire field. Type 1 dunite and wehrlite upper mantle xenoliths characterize the northern part of the field whereas type II clinopyroxenite xenoliths are common in the southern part of the field. The various basalts are low in SiO2 wt %, Al2O3 wt % and Na2O wt % but high in MgO wt %, TiO2 wt %, CaO wt %, K2O wt % with K2O/Na2O = 1.08 to 2.07. These are potassic belonging to the kamafugite series. Plots discriminate two geochemical trends corresponding to the picritic and clinopyroxene rich basalts. The diagram of Na2O + K2O wt. % against SiO2 wt. % enables various rocks to plot in the designated fields for the different alkaline basalts. The field is enriched in trace, light rare earth (LREE) and high field trace elements (HFSE) where La/Yb = 31 – 55. The petrographic and geochemical studies elucidate enrichment of the upper mantle by both mineralogical (modal) and cryptic (geochemical) metasomatism.
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    Impact of industrial activities on heavy metal loading and their physico-chemical effects on wetlands of lake Victoria basin (Uganda)
    (2006) Muwanga, A.; Barifaijo, E.
    The diverse functions of wetlands are being adversely affected by human activities. This paper discusses the impact of these activities on heavy metal loading in different media within the wetlands. Water and sediment/soil samples were taken from areas with active industrial activities and from an area where there is no industrial activity. Sources of water pollution include effluents from a brewery (high pH) and areas associated with tanning activities, sewage treatment plant and former copper smelter (high electric conductivity values). Effluents from a battery assembly plant, water treatment plant, pharmaceutical industry and former copper smelter have relatively high Pb values (up to 1.4 ppm) otherwise most heavy metal concentrations are below maximum acceptable limits for water. This calls for mitigation measures. In sediments, high heavy metal values were associated with battery and metal fabricating industry (Pb), operations involving Zn scrap (Cd), former Cu smelter (Cu, Pb, Ni and Co), tannery and pharmaceutical industry (Cr), and soap and cosmetics industry (Hg). Fish have low levels of Hg. However, fish is known to bioaccumulate Hg through methylation, may cause increase in the Hg in the food chain. Industries which release effluents with high heavy metal contents should treat them before discharge.
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    The Potential for Gold Mineralisation in the Greenstone Belt of Busia District, South Eastern Uganda
    (African Journal of Science and Technology, 2007) Mbonimpa, A. B.; Barifaijo, E.; Tiberindwa, J. V.
    Busia district in south eastern Uganda is one of the areas in the country with a history of potential for gold mineralisation and exploitation. Gold was first discovered in the Archaean greenstone belt of Busia by Davies in 1932. Only small mining operations, mostly artisan in character, have taken place in the district since then except the newly opened mines by Busitema Mining Company. However, all recent work in the area indicates potential for gold exploitation. Both quartz vein-hosted and Banded Iron Formation (BIF)-hosted gold deposits occur in Busia district. The results of Electron Microprobe (EMP) analysis of 10 rock samples from the quartz vein deposits and AAS analysis of 10 rock, 27 soil and 18 stream sediment samples taken from Busia district are presented in this work.Gold occurs as electrum or native gold inclusions in pyrite with fineness in the range of 451 – 863; and as invisible gold in sulphide minerals (up to 5700 ppm in pyrite). The main ore minerals are pyrite, magnetite, ilmenite, galena, pyrrhotite, chalcopyrite, covellite and rutile. Gold values of the stream sediment samples average 7.7 ppm Au, the highest being 38.6 ppm Au. Soil sampling was done in the three areas proposed for follow-up by Mroz et al. (1991), of which the Tira area has the first priority soil anomaly (up to 4.8 ppm Au) followed by the Osapiri area (up to 2.8 ppm Au). There is a strong correlation between the distribution of lead and that of gold.