Semliki basin field study report

Abstract

This study presents observations from a comprehensive field excursion conducted in the Semliki Basin, situated within the Albertine Graben of Western Uganda. The primary objective of the excursion was to gain a deeper understanding of the formation, sedimentary environment and petroleum potential of the basin. Throughout the fieldwork, various sites within the basin were studied, including locations such as Kichwamba, Kisegi hill quarry, Kisegi River, Kibuku road cut, and Sempaya hot springs. Through detailed fieldwork and data collection using GPS and geological tools, the students aimed to achieve several specific objectives. These objectives included identifying lithologies present in the Semliki basin, analyzing and correlating structural features observed within both the basement and sedimentary layers, assessing different elements of the petroleum system, and identifying various facies and depositional environments. During the fieldwork, an extensive range of facies was logged and analyzed. These included fluvial, deltaic, and lacustrine sediments, all of which were significantly influenced by intensive tectonic activity within the basin. The sedimentary structures observed encompassed a diverse array, including cross-bedding, unconformities, faults and deformation bands. Of particular interest was the presence of hot springs within the area, indicating a notable geothermal gradient, which holds significant implications for source rock maturation and potential hydrocarbon generation. The integration of sedimentology, stratigraphy, and tectonics facilitated a comprehensive interpretation of the basin's geological history and provided valuable insights into its economic importance.