Geologic mapping project report of area A, Igayaza Isingiro District, South Western Uganda

Abstract

This geologic mapping exercise was carried out in Igayaza located in Isingiro district in southwestern part of Uganda. The area mapped is within the Karagwe Ankolean system of rocks which strati-graphically overly the Basement complex rocks. The Karagwe-Ankolean (K-A)system (1400-950Ma) in Uganda is the northern most extension of the Kibaran mobile belt. The sediments of this system occupy a continuous area in southern and central Kabale, southern Mbarara, Bushenyi, Isin-giro, Rakai and south eastern Masaka districts. The Buhweju plateau and surrounding hills in Bushenyi district belong to this system as well. This field work was aimed at imparting the skill required to carry out a geologic mapping exercise besides other aims such as familiarizing one’s self with field conditions and equipment, collection and interpretation of data among others. The area to be mapped was gridded, my group members and I exclusively mapped area A. This report contains data obtained within this region which includes the rock types, structures present, economic potential, stratigraphy, metamorphism of the area as well as the regional synthesis using the data obtained by other groups as well. In the mapped area, the major rock types observed include Quartzite, ferruginous shales, Phyllitics hale, Granite, phyllites and conglomerates. Mudstones and slates were also observed in other areas within the region that were out of the area A. All these rocks, being in a region greatly affected by various stress and deformation events such as faulting and folding possess the number of structures such as quartz veins, boudins, foliation, lamination and mud cracks, joints, beds and folds and folds most of which trended in the NW-Se direction, them a jorregional trend and a few in the NE-SW direction, the cross-fold trend. Some of these structures not only existed in a macro but also in a microscale as will be shown in the petrographic analysis. There are a number of economic activities in the mapped area such as quarrying of majorly quartz and its and mining of sand for the construction industry. Agriculture through growing of majorly Bananas in the valley sand the arena and rearing of livestock was also carried out.