Fieldwork and field excursion report of Kibuku Area, Semliki Basin within the Albertine Graben, Ntoroko District, Western Uganda
MetadataShow full item record
The field work took a duration of weeks at Kibuku within the Semliki Basin in Ntoroko district, Western Uganda. This report is made up of a seven-fold chapters with a detailed account on the objectives, materials and methods, lithology and stratigraphy, basin and facies analysis, structures and Geophysics of the Semliki basin, these specifically summarize the petroleum system potential, and chronology of the study area. Outcrop studies near Kichwamba about the basement showed a highly metamorphosed and complex assemblage of volcanic, intrusive, igneous and metamorphic rock types majorly quartzite and gneisses. The area was marked by distinct structural features in the basement which included faults and zone of intensive fracturing comprising different sets of joints. Prevalence of deformation documented by flower structures in the shallow sedimentary section of former Turaco sites in the Graben indicates that non tectonic processes are transgressional. 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 comprised sands, clays and siltstone ranging from tertiary to recent in age representing a prolonged and nearly continuous phase of cyclic sedimentation in the biggest part of the basin. The prominent cyclic pattern of clays and sands in the study area reflected 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 volcanic. Integration of the gravity and magnetic interpretation suggested that the Northern part of the Semliki basin consisted of many faults with many structural trends. A summary and economic assessment of petroleum system showed that there was possibility of having petroleum and this is backed by the presence of all the potential petroleum system in the area.