Sedimentology, facies architecture and sequence stratigraphic studies were conducted on the exposed sediments of Lower Bima Member from the Yola Sub-basin with the aim of interpreting the depositional environment within stratigraphic framework. From texture and sedimentary structure, ten lithofacies were identified and the facies were associated into three; gravelly dominated, the sandy dominated, and the fine grained dominated facies associations. The three facies associations formed the alluvial - braided river, braided river and lacustrine facies successions. Analysis of facies has permitted an overall determination of five architectural elements; gravelly bedded set, tough cross stratified set, planar cross stratified set, horizontally stratified set and overbank stratified set. Sequence stratigraphic framework shows alluvial fan (proximal and distal facies) at the base, temporally transiting into lacustrine as the lake level rose, followed by a period perhaps due to rift margin faults reactivation and re-establishment of alluvial fan braided river and braided river deposits on towards the top. Transition from alluvial lacustrine and alluvial fluvial reflects a vertical and lateral facies distribution.
Key words: Facies Architecture; Sequence Stratigraphy; Bima Formation; Yola Sub-basin
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