A Geologic mapping Report of Area A, Igayaza, Isingiro district in South Western Uganda.
Abstract
This report provides a comprehensive overview of the Geologic mapping project conducted in the Igayaza area, Isingiro district, South-Western Uganda, specifically focusing on the Igayaza-synclinorium within the Karagwe-Ankolean system of rocks. The main objective of the project was to equip students with geologic mapping skills, including field data collection, interpretation, and representation on a base map, as well as sampling techniques and the use of field equipment like GPS and geologic compass.
Field studies involved traversing the mapping areas to collect geo-data and samples for laboratory analysis and data analysis. The report primarily focuses on the geological study of a specific area called "A," covering mineralogy, metamorphism, stratigraphy, structural data, and economic activities. The broader scope of the report includes a regional synthesis covering the Igayaza-synclinorium and surrounding areas within the Karagwe-Ankolean system.
In the mapped area A, the prominent rock types observed include Quartzite, ferruginous shales, Phyllitic shale, Granite, phyllites, and conglomerates. Mudstones and slates were also found in other regions outside of area A within the overall region. These rocks, existing in an area heavily influenced by various stress and deformation events like faulting and folding, exhibited several structural features such as quartz veins, boudins, foliation, lamination, mud cracks, joints, beds, and folds. The majority of these structures showed a trend in the NW-SE direction, which corresponds to the primary regional trend, while a few structures trended in the NE-SW direction, representing the cross-fold trend. These structures were present not only on a larger scale but also at a microscopic level, as will be further demonstrated in the petrographic analysis.
The area's topography is shaped by weathering, erosion, and the presence of arena topography and ridges. The drainage pattern is primarily controlled by the region's geological structures. The major economic activities in this area include cattle-keeping, farming in fertile valleys, and quarrying on rock outcrops and exposures. Human settlements are scarce and mostly confined to the valleys.