The study was specifically carried out on channel and deltaic sediments of outcrops in Afikpo Basin South East Nigeria and seafloor sediments offshore Niger Delta Nigeria to determine sediments distribution, grain size, deposition and preservation.The outcrop sections in Afikpo Basin were studied by visual observation and photographing of lithostratigraphic architectures during the field work. Empirical technique was used to predict seafloor facies from multibeam bathymetry and acoustic backscatter data collected in the study area. Side scan sonar and echo sounder seafloor data from the Niger Delta Basin were also used to predict sediment types and deposition trend derived during geophysical seabed survey using onboard instrumentation offshore. Mud covers a wide range of backscatter variance because it can be found trapped in pockets on the seafloor. Gravelly-muddy sand was found close to the seabed surface, and it has very low to medium-bathymetry variance. Mud (silt and clay) covers 61 percent of the study area. Sandstone reservoir outcrops showing mouth bar architecture occurred at Akpoha Town east of Afikpo town. The field work on outcrop established the rock types as sandstones and shales, well rounded sediment, pink to pinkish white colour, well sorting, cross bed and herringbone structures, Kaolinitic materials found as matrix and quatz minerals present, Bioturbations, matrix, drape materials, and bedding plain (sharp or gradational). It was revealed that sediments on the seabed vary from gravelly-muddy sand, muddy sand, and mud. The ridges have relatively low bathymetric relief (2-3m). The trend of deposition of these sedimentary units as seen from geoacoustic sensors imageries and outcrops within the study areas shows a coarsening upward sequence. This is typical of a deltaic and shallow marine depositional setting which shows different environments affected by variety of processes ranging from wave, currents, tidal and other fluvial process.

1. Adewumi, A., & Oladoyin, A. (2015). Field geology of nigeria report for 2015/2016 academic session. Department of Geological Sciences, Achievers University, Owo, Ondo State.
2. Alexander, J. (1993). A discussion on the use of analogues for reservoir geology. Geological Society, London, Special Publications, 69(1), 175-194.
3. Arnot, M. J., & Good, T. R. (1997). Photogeological and image-analysis techniques for collection of large-scale outcrop data. Journal of Sedimentary Research, 67(5).
4. Barnes, J. W., & Lisle, R. J. (2013). Basic geological mapping. John Wiley & Sons.
5. Boboye. (2021). Sedimentological characteristics and mineralogical studies of some cretaceous sandstones in nigeria: implications for depositional environment and provenance. Journal of Sedimentary Environments, 6(4), 531-550.
6. Bonne, K. P. (2014). Reconstruction of the evolution of the niger river and implications for sediment supply to the equatorial atlantic margin of africa during the cretaceous and the cenozoic. Geological Society, London, Special Publications, 386(1), 327-349.
7. Bryant, I., & Flint, S. (1992). Quantitative clastic reservoir geological modelling: problems and perspectives. The geological modelling of hydrocarbon reservoirs and outcrop analogues, 1-20.
8. Chapin. (1994). Reservoir architecture of turbidite sheet sandstones in laterally extensive outcrops, ross formation, western ireland.
9. Chuku, & Ibe. (2015). Topography and lithofacies of the seafloor in meren field, offshore western niger delta. International Journal of Science Inventions Today, 4(6), 524551.
10. Chuku, & Odigi. (2019). Shoreline changes using seabed bathymetric, sediments scan and profiles observations in zarum gas field offshore niger delta. Earth Environmental Science Research Reviews.
11. Chuku, & Ugwueze. (2023). Geophysical methods of investigating the seafloor for the emplacement and monitoring of subsea facilities offshore niger delta (nigeria).
12. Chuku, & Umoh. (2023). Recent sedimentary processes of the seabed in the gulf of guinea, sw niger delta: evidence from multibeam bathymetry and facies prediction. Ajayi Crowther Journal of Pure and Applied Sciences, 2(2).
13. Clark, J. D., & Pickering, K. T. (1996). Submarine channels: processes and architecture. Vallis Press.
14. Clarke, H. (1996). Shallow-water imaging multibeam sonars: A new tool for investigating seafloor processes in the coastal zone and on the continental shelf. Marine Geophysical Researches, 18, 607-629.
15. Collinson, J. (1970). Deep channels, massive beds and turbidity current genesis in the central pennine basin. Proceedings of the Yorkshire Geological Society, 37(4), 495-519.
16. Dartnell, P., & Gardner, J. V. (2004). Predicting seafloor facies from multibeam bathymetry and backscatter data. Photogrammetric Engineering & Remote Sensing, 70(9), 1081-1091.
17. Daukoru, J. W. (1975). Pd 4 (1) petroleum geology of the niger delta. In World petroleum congress (pp. WPC–16121).
18. Dreyer. (1992). Sedimentary architecture of field analogues for reservoir information (safari): A case study of the fluvial escanilla formation, spanish pyrenees (I. D. B. Stephen S. Flint, Ed.).
19. Ekwenye. (2020). A re-evaluation of the stratigraphic and palaeogeographic evolution of the paleogene sedimentary successions of the niger delta. Jordan Journal of Earth and Environmental Sciences, 11(2), 146-156.
20. et al, U. (2023). Assessment of environment of deposition and reservoir quality of well tmg c-2 in the western niger delta. LAUTECH Journal of Engineering and Technology, 17(1), 116-130.
21. Floris, F. J., & Peersmann, M. R. (2002). Integrated scenario and probabilistic analysis for asset decision support. Petroleum Geoscience, 8(1), 1-6.
22. Hughes, C. (2000). Acoustic seabed surveying-meeting the new demands for accuracy, coverage and spatial resolution. Geomatica, 54(4), 473-485.
23. McCaffrey, K., Jones, R., Holdsworth, R., Wilson, R., Clegg, P., Imber, J., . . . Trinks, I. (2005). Unlocking the spatial dimension: digital technologies and the future of geoscience fieldwork. Journal of the Geological Society, 162(6), 927-938.
24. Momta, P. S. (2018). Sedimentary processes and sedimentation in the shallow offshore, eastern niger delta, gulf of guinea. In Sedimentation engineering. IntechOpen.
25. Pringle. (2004). Virtual geological outcrops-fieldwork and analysis made less exhaustive? Geology Today, 20(2), 64-69.
26. Pringle. (2006). Virtual outcrop models of petroleum reservoir analogues: a review of the current state-of-the-art. First break, 24(3).
27. Reynolds, A. D. (1999). Dimensions of paralic sandstone bodies. AAPG bulletin, 83(2), 211-229.

Chuku, H.C. (2023). Outcrop and Seafloor Sedimentation Study of Parts of Afikpo and Offshore Niger Delta Basins. International Journal of Humanities, Arts and Social Sciences, 9(1), 29-37. doi: https://dx.doi.org/10.20469/ijhss.9.20004-1