| dc.description.abstract | This report provides a comprehensive summary of the Semliki basin field study. The Semliki basin lies in the Central domain of the Albertine Graben; created by rifting that started in the early Miocene.
For smooth completion of the project, a set of basically five principal studies; conducted in selected areas were utilized. These studies involved making observations, gathering field evidence using the available equipment, analyzing, interpreting and formulation of reliable conclusions.
The paleoenvironments were deduced from existing structural features such as beddings, mud cracks. Tectonism is evidenced by the highly jointed and faulted basement rocks and sediments in the basin as well as the high thermal gradients.
The Semliki basin could probably have experienced conditions characteristic of fluvial-lacustrine environments. Deposition in the Semliki Basin is characterized by fluvial and lacustrine sediments. These sediments were noted to include sandstones, basal conglomerates, clays and silts. Evidence of lacustrine environment was confirmed by presence of thick argillaceous layers of sediments.
Intercalations between sands and clays suggest a fluvial system in its mature stage where water energy is not sufficient to maintain a straight channel thus meandering and depositing clays during flood events in flood plains and when water energy is rejuvenated, water finds a straighter route to flow thus cuts through the flood plain and depositing coarser sediments on the clay layers. Later, it deposits clays when energy reduces, meanders start and cycle continues.
The analysis of geophysical measurements revealed how the physical properties of the basin’s subsurface vary vertically and laterally. The lateral variations in gravity anomalies were related to anomalous rock density distributions.
The Semliki basin is generally of low density as evidenced from the negative gravity anomaly values that range vary from -221.3 to -111.3 mGals. The linear magnetic lows between 33643.0 to 33337.7 nT can be interpreted to represent fault zones.
The interpretation and analysis of seismic data deduced that the Semliki Basin has been affected by intense faulting. These faults tend to divide the region into separate compartments.
Notable features such as the existence of an oil seep at Kibuku, high heat flow, sandstone facies, claystone facies, fault systems and stratigraphic pinch outs aided the deduction of the Semliki basin’s potential of containing petroleum. | en_US |
