A report of geologic mapping project of area G, held in Igayaza, Isingiro district, Gayaza area, western Uganda from 30th January, 2022 to 8th February, 2022

Abstract

The report entails an assembly of aims, methods, findings, explanations of the findings, conclusions and recommendations for the Igayaza-Isingiro geological mapping project carried out in south-western Uganda from 30th January, 2022 to 8th February, 2022. The area (Igayaza-Isingiro in south western Uganda) lies within the Karagwe-Ankolean system of rocks (ca. 1400-950 Ma) which is also known to be the northern most extension of the Kibaran belt. This mapping project was aimed at obtaining hands-on experience in the field geological mapping project execution, from field mapping to geological reporting. It involved various activities and engagements which made it educative, and memorable at the same time. We learnt field geological mapping and field data collection techniques and procedures. Methods such as observation, traversing, sampling were used during data collection. The lithology of the area mainly comprised of quartzites at the ridge summits and shales which were found along either sides of ridges and in valleys in between the ridges. The grades of metamorphism varied from low grade evidenced by presence of relict bedding and index minerals like chlorite and muscovite. Sandstones were metamorphosed to quartzites while shales were metamorphosed to phyllites. Arenas which were broad stadium like feature were mostly affected by contact metamorphism brought about by granitic intrusions. Equipment used to collect data included hand-held GPS, compass, camera, tape measure, notebook, lenses, geological hammer, to mention but a few. Samples collected were made into thin sections and analyzed under a microscope and the results explored in this report. The microscopic analysis was purposed on clarity of whether the macroscopically identified minerals in the field are parallel with their microscopic identification on the various rocks, and thus their petroleum potential.

The structural data and its resultant graphical plots helped in determining the history of deformation in the area. Different lithologies including shales, phyllitic shales, quartzites, breccias and ironstones in the study area, G, were encountered. Different outcrops exhibited structures like joints, faults, beddings, quartz veins indicative of deformational history. Despite that deformation history, economic activities like farming, quarrring and brick making were carried out.