Geological mapping project report of area B Igayaza Isingiro district
This report comprises a detailed compilation of aims, methods, findings, interpretations, conclusions and recommendations for the Igayaza-Isingiro geological mapping exercise and field excursion to south western Uganda. The geological mapping process of Igayaza village was conducted from 30th May to 6th June 2022 where we had a journey from Kampala district in Central Uganda; in particular Makerere University to Isingiro district in western Uganda. This report is a summary of the Geologic mapping project carried out in Gayaza, Isingiro district on the Gayaza synclinorium, within the Karagwe-Ankolean system of rocks. This excursion was aimed at equipping students with skills of geologic mapping such as recording field data, interpreting it and correctly representing it on a base map, measure and correctly interpret the different field structures, collect relevant samples and learn how to use field equipment such as the GPS and geologic compass among others. The report is comprised of a detailed geological study of area B which is situated on the NW limb of the Gayaza synclinorium that I and my group members mapped that is the mineralogy, metamorphism, stratigraphy, structural data and economic activities as well as the regional synthesis which covers Gayaza synclinorium and surrounding areas of Western Uganda within the Karagwe-Ankolean system. Area B (the mapped area) lies between UTM coordinates of Eastings (254000-256000) and Northings (9917000-9919000) in Kabingo sub county, Isingiro district. The area is generally characterized by a hilly topography with intervening areas of low relief (V-shaped valleys and the arenas) which could have evolved due to differential weathering. It is also characterized by parallel and dendritic drainage and savannah vegetation. Settlement in the area is generally linear with people settling along the roads and the area is difficult to access because of its hilly nature. The lithology is comprised of thin arenaceous formations that were predominated by quartzites while the thick argillaceous formations constituted shales. The quartzites were mainly found at the ridge summits while the shales were found along the flanks of ridges and in valleys between ridges. The grades of metamorphism were varying from low grade regional metamorphism which was evidenced by presence of beddings and some index minerals such as chlorite, muscovite. Sandstones and shales were metamorphosed to quartzites and phyllites respectively. Contact metamorphism occurred around granitic intrusions that formed most of the arenas (broad stadium like structures). The major structures in the area were: beddings, faults, folds and joints all exhibiting two major trends; NW-SE trend which is similar to that of the regional folds and NE-SW direction similar to that of the cross folds whereas the minor ones include: micro-folds, micro-faults, quartz veins, foliation, laminations and mud cracks, these were mapped at different scales. The economic potential of the area is low since no economic minerals have been discovered. However, some of the economic activities carried out include; farming, cattle keeping, quarrying and brick making. At the end of the mapping exercise, hotspot presentation was done where students would take lecturers to the most interesting areas.