Morphosedimentary evolution of a delta-sourced, drift-aligned sand barrier-lagoon complex, western Bight of Benin
MetadataShow full item record
The coast of eastern Ghana and Togo is bounded by a major Holcene sand barrier complex hinged on the Volta Delta to the west and subject to high rates of longshore sand drift (1-1.5 x 10 m³/yr). In spite of its proximity to this major detaic sediment source, this barrier system shows marked longshore variations in progadation following the middle Holocene eustatic sillstand. It is a 'hybrid' system in terms of internal facies composition and plan-view morphology, in that it has evolved from an essentially regressive to a stationary (synonymous with cessation of progradation) system. Both transgressive and barrier-inlet facies have also developed through time and space. These temporal and spatial changes in patterns of development reflect variations in longshore sand transport and deposition over the last 5000 years. Such variations have been controlled by sediment supply from the Volta, by antecedent topography, by lagoonal and river drainage, by sediment cell development and maturation, and in the very recent past, by anthropogenic perturbation. Barrier progradation in the western Bight of Benin diminished considerably or ceased probably as early as 3400 yr B.P. as a single major equilibrium 'drift aligned' bight cell matured, permitting transport of Volta sand toward the rest of the eastern bight in Benin and Nigeria.......