A Report of Geologic mapping project of Area B, Igayaza Isingiro district in south western Uganda.
Abstract
This report documents the aims, methods, findings, interpretations, conclusions and recommendations for the Igayaza-Isingiro geological mapping exercise and field excursion to south western Uganda. The mapping was a 10 days exercise that ran from 30th January,2022 to 8th February, 2022. This mapping exercise was aimed at enabling students to acquire geological mapping skills, including data acquisition, processing and interpretation of the field data. These were the major steps undertaken, equipping students with skills of geologic mapping such as collecting field data, interpreting data and correctly representing it on a base map, collecting samples as well as acquiring knowledge on how to use field equipment such as GPS, geologic compass, hammers among others. A lot was learnt during the mapping exercise and different methods like lecturing, observation, consultation, taking measurements and research were used for data collection
The report is comprised of a detailed geological study of area B which was my main area of study.
Our group mapped area B, which is situated on the NW limb of the Gayaza synclinorium and is part of the Karagwe-Ankolean system which belongs to the Meso-Neo Proterozoic cover formations.
The information about the mapping exercise is discussed in six main chapters; introduction, stratigraphy, regional synthesis, structures, petrography and metamorphism and conclusion.
The introduction defines the objectives of the field trip, the location of the mapped area, methods and materials used. Stratigraphically, rocks were deposited in the order of shales, sandstones that later metamorphosed to quartzites that occupy the top of ridges which were later intruded by granites. Quartzites overlie shales which overlie slates. Slates are underlined by phyllites and finally granites at the base. 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. Metamorphism of these rocks was low-grade regional metamorphism evidenced by foliation and some index minerals such as chlorite. It increased towards the arena. In conclusion, the mapped area B is located in the lower Karagwe-Ankolean and it has generally a hilly topography with intervening lowlands (arenas)