How did sediments accumulate in the Congo basin’s central depression?

The central depression of the Congo basin, often referred to as the cuvette, has accumulated significant sediment through a long-term process of geological subsidence and erosion.12

The accumulation of material began as early as the late Precambrian period, at least 542 to 570 million years ago. This process involves the following factors:12

• Erosion: Sediments are derived from the erosion of geological formations located around the periphery of the cuvette.12
• Subsidence: The region has experienced a persistent tendency to subside, which has allowed for the creation of thick depositional strata.12
• Uplifting: This subsidence is accompanied by the uplifting of the basin's edges, particularly on the eastern side, a process influenced by the formation of the Western Rift Valley.12

The resulting deposits consist primarily of sands and sandstones of continental origin, which are topped by more recent Quaternary alluvial deposits. The amphitheatre-like arrangement of these strata around the main Congo River channel reflects this uniform and long-standing geological history.12