Depositional Environments of Niamey Area Proterozoic Deposits (Western Niger)

This study uses a field approach based on the description of the different lithofacies of the Niamey area Proterozoic deposits, which are located on the southeastern edge of the West African Craton. The studied deposits represent a link between Taoudenni, Gourma and Volta basins. Three kinds of lithofacies have been distinguished. At the bottom, quartzitic sandstones with hummocky beds (Ny1 lithofacies), overlain by fine quartzites or glauconite sandstones, with oblique beds (Ny2 lithofacies). The presence of glauconite is an indicator of a shallow marine environment. These lowermost deposits are covered at the top by siliceous matrix-supported conglomerates with faceted and striated pebbles, considered as possible tillite (Ny3 lithofacies).