A report on the geologic field study and stratigraphic logging project of Semiliki Basin Albertine Graben in Ntoroko District Western Uganda.

Abstract

The area of study was the Albertine graben, South and East of the Lake Albert Basin; the respective target areas being Kichwamba and the Semiliki basin. The aim of the field study was to study the environments and processes of deposition of sediments, and to understand physical, sedimentological and sequence stratigraphic formations. This report comprises a detailed compilation of findings from the field and is made up of eight chapters that give a detailed account of the objectives, materials and methods, lithology and stratigraphy, basin and facies analysis, structures, Geophysics of the Semliki basin and discussion of results acquired. Synthesis studies of the evolution of the Albertine Graben suggest that the Albertine Graben basin is a tertiary intra-continental rift basin that developed on the Precambrian orogenic belt of the African Craton. The sediment sequence within the Kibuku study area is comprised of sands, clays and siltstone representing a prolonged and continuous phase of cyclic sedimentation in most of the basin. The prominent cyclic pattern of clays and sands in the study area reflect changing depositional environments whereby sands were probably deposited by high energy water in the fluvial system and finer sediment such as clays were deposited with decrease in energy in the lacustrine system. The interpretation of gravity data helped to understand the crustal thickness variation while magnetic data enabled the mapping of basement depth, composition and the presence of intra sedimentary volcanics.