Lithofacies evaluation of the mamu formation, southeastern nigeria: implications for depositional setting and maastrichtian sea regression

Abstract

Lithofacies analysis was carried out on the sediments and sedimentary rocks of the Mamu formation for the purpose of interpretation of the depositional setting and the Maastrichtian sea history. Both field and laboratory methods were employed in the study. Nine (9) lithofacies were identified and grouped into three lithofacies associations based on their stacking patterns. The three facies associations include the lagoonal/swamp, tidal flat (dominantly inter-tidal), and the shoreface. Vertical succession indicated deposition in a prograding deltaic system (marginal marine) influenced by both fluvial and marine (tide and wave) processes. The general coarsening upward pattern displayed by the lithofacies and facies association suggests sediment deposition during the regressive phase of the ancient sea.