Report on Igayaza-Isingiro field geological mapping project and geological excursion to South-Western Uganda.

Abstract

The Gayaza mapping project was carried out by third year undergraduate students of Geology and petroleum geoscience and production at the department of geology and petroleum studies, Makerere University. The project is aimed at giving the students efficient training on geological mapping techniques, data collection and analysis, presentation of the geological data and report writing. The study area was Gayaza village in Isingiro district located Western Uganda. This study area is part of the karagwe-Ankolean system of rocks which is the name given to the rocks of the Kibaran belt in Uganda. The area is divided into different areas and each area was assigned to different groups of students to carry out the geologic mapping. The mapped area which is fully discussed in this report is area H. The area was traversed while making observations of rock units, mineralogy and structures at the same time taking measurements on attitudes of the different geological structures. Samples of rocks at each stop made were taken and thin sections were made in the laboratory. The thin sections were then analyzed under petrographic microscopes. Measurements of the different structures were made, recorded and analyzed using stereo net software to interpret the orientation of the different geological features. A base map of area H was also produced in the field and this was digitized using Arch GIS software to produce the geological map of the area. From the field observations, the lithologies identified in the area H were grey shales, ferruginous shales and quartzites. The rocks mainly contained quartz and iron oxide veins. The major minerals included quartz, feldspars, clay minerals and biotite. The major structures noted included joints, folds, bedding, and faults. The folds are both regional and cross folds. A new theory is also proposed for the events that formed the two fold trends.