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Granulometric and Sedimentologic Study of Beach Sediments, Lagos, Southwestern Nigeria

DOI: 10.4236/ijg.2019.103017, PP. 295-316

Keywords: Lagos, Beach Sediments, Standard Deviation, Skewness, Kurtosis, Graphic Mean

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Abstract:

Grain size analysis and sedimentology of beach sediments in Lagos, southwestern Nigeria have been studied. Ten fresh beach sediment samples were randomly collected at a depth of 25 cm - 40 cm along Lagos and Badagry axis. The sediments were analyzed by wet sieving method. Ternary diagrams indicate that the beach sediment is silty. The graphic mean ranges from 1.02ф (medium grained) to 2.21ф (fine grained) with an average of 1.61ф (medium grained). The preponderance of medium grained sediments and lack of coarse sands suggest moderate to high energy conditions of deposition. Graphic standard deviation ranges from 0.01ф - 0.81ф (very well sorted to moderately well sorted), with an average of 0.52ф (moderately well sorted). This is probably due to rapid back and forth flow of the depositing medium. Inclusive graphic skewness ranges from -0.38 to 1.41 (strongly coarse skewed to strongly fine skewed), with an average of 0.41 (strongly fine skewed). The graphic kurtosis values are between 0.44 and 1.37, which indicates very platykurtic to leptokurtic; with an average of 0.78 (platykurtic). This variation suggests that part of the sediment achieved its sorting elsewhere in high-energy environment. Histograms of the sediments exhibit both unimodal and bimodal trends. The arrangement is dominantly asymmetrical with varying modal class, which could be attributed to variation in the energy of the transporting medium. Bivariate plots (simple skewness vs. standard deviation and mean size vs. standard deviation) show the samples plotting mainly in the river sand zone, which suggests that the sediments were initially river sediments before reworking to the present site; other parameters that discriminate between river channel deposits, overbank deposits and overbank-pool deposits show the beach sediments plotting in the river channel zone. Linear discriminant functions analysis indicates a shallow marine beach environment in agitated water, with inputs from aeolian source. The Passega C-M diagram suggests suspension and rolling as the mode of deposition.

References

[1]  Inman, D.L. (1952) Measures for Describing the Size Distribution of Sediments. Journal of Sedimentary Research, 22, 125-145.
[2]  Shepard, F.P. and Moore, D.G. (1955) Central Texas Coast Sedimentation: Characteristics of Sedimentary Environment, Recent History and Diagenesis. AAPG Bulletin, 39, 1463-1593.
[3]  Folk, R.L. and Ward, W.C. (1957) Brazos River Bar: A Study on the Significance of Grain Size Parameters. Journal of Sedimentary Petrology, 27, 3-26.
https://doi.org/10.1306/74D70646-2B21-11D7-8648000102C1865D
[4]  Passega, R. (1957) Texture as Characteristic of Clastic Deposition. American Association of Petroleum Geologists, 41, 1952-1984.
[5]  Passega, R. (1964) Grain Size Representation by CM Patterns as a Geological Tool. Journal of Sedimentary Research, 34. 830-847.
https://doi.org/10.1306/74D711A4-2B21-11D7-8648000102C1865D
[6]  Mason, C.C. and Folk, R.L. (1958) Differentiation of Beach, Dune and Aeolian Flat Environments by Grain Size Analysis, Mustang Island, Texas. Journal of Sedimentary Research, 28, 211-226.
[7]  Shepard, F.P. (1960) Gulf Coast Barriers. In: Shepard, F.P., et al., Eds., Recent Sediments, Northwest Gulf of Mexico, American Association of Petroleum Geologists, 197-220.
[8]  Cadigan, R.A. (1961) Geologic Interpretation of Grain Size Distribution Measurement of Colorado Plateau Sedimentary Rocks. Journal of Geology, 69, 121-142.
https://doi.org/10.1086/626724
[9]  Friedman, G.M. (1961) Distribution between Dune, Beach and River Sands from Textural Characteristic. Journal of Sedimentary Petrology, 31, 529-545.
[10]  Friedman, G.M. (1967) Dynamic Processes and Statistical Parameters Compared for Size Frequency Distribution of Beach River Sands. Journal of Sedimentary Petrology, 37, 327-354.
[11]  Sahu, B.K. (1964) Depositional Mechanisms from the Size Analysis of Clastic Sediments. Journal of Sedimentary Research, 34, 1107-2821.
[12]  Klovan, J.E. (1966) The Use of Factor Analysis in Determining Depositional Environments from Grain-Size Distributions. Journal of Sedimentary Petrology, 36, 115-125.
https://doi.org/10.1306/74D7141A-2B21-11D7-8648000102C1865D
[13]  Passega, R. and Byrarnjee, R. (1969) Grain-Size Image of Clastic Deposits. Sedimentology, 13, 233-252.
https://doi.org/10.1111/j.1365-3091.1969.tb00171.x
[14]  Visher, G.S. (1969) Grain-Size Distribution and Depositional Processes. Journal of Sedimentary Petrology, 39, 1074-1106.
[15]  Solohub, J.T. and Klovan, J.E. (1970) Evolution of Grain Size Parameters in Lacustrine Environments. Journal of Sedimentary Petrology, 40, 81-101.
[16]  Tiara, A. and Scholle, P. (1979) Discrimination of Depositional Environments Using Settling Tube Data. Journal of Sedimentary Petrology, 49, 787-800.
https://doi.org/10.2110/jsr.49.787
[17]  Sly, P.G., Thomas, R.L. and Pelletier, B.R. (1983) Interpretation of Measures Derived from Water Laid Sediments. Sedimentology, 30, 219-233.
https://doi.org/10.1111/j.1365-3091.1983.tb00666.x
[18]  Musila, W.M. (1998) Floristic Composition, Structure and Distribution Patterns of Coastal Sand Dune Vegetation: A Case Study of the Coastal Dunes between Malindi and Mambrui. Moi University, Eldoret, 160 p.
[19]  Thakur, A.K., Ojha, C.S.P., Grischek, T., Ray, C. and Saandhu, C. (2010) Water Quality Improvement through River Bank Filteration in Extreme Environmental Conditions. Journal of Indian Water Works Association, 43, 106-115.
[20]  Hoque, M.A., Burgess, W.G. and Ahmed, K.M. (2010) Integration of Aquifer Geology, Groundwater Flow and Arsenic Distribution in Deltaic Aquifer—A Unifying Concept. Hydrological Processes, 444-445, 209-220.
[21]  Iwugo, O.K.O., D’arcy, B. and Andoh, R. (2003) Aspects of Land-Based Pollution of an African Coastal Megacity of Lagos. Proceedings of the International Specialised IWA Conference, Dublin.
[22]  Obaje, N.G., Musa, M.K., Odoma, A.N. and Hamza, H. (2011) The Bida Basin in North-Central Nigeria: Sedimentology and Petroleum Geology. Journal of Petroleum and Gas Exploration Research, 1, 1-13.
[23]  Omatsola, M.E. and Adegoke, S.O. (1981) Tectonic Evolution and Cretaceous Stratigraphy of the Dahomey Basin. Journal of Mining Geology, 18, 130-136.
[24]  Olanrewaju, A.E. (2018) Sedimentological Studies of the Beach Sediments in Lagos State, Southwestern Nigeria. Federal University of Technology, Akure, 76 p.
[25]  Jones, H.A. and Hockey, R.D. (1964) The Geology of Part of S.W. Nigeria. Geological Survey of Nigeria Bulletin No. 1, 1-16.
[26]  Agagu, O.A. (1985) A Geological Guide to Bituminous Sediments in Southwestern Nigeria. Department of Geology University of Ibadan.
[27]  Folk, R.L. (1968) Petrology of Sedimentary Rocks. Hemphill’s, Austin, 170.
[28]  Folk, R.L. (1974) The Petrology of Sedimentary Rocks. Hemphill Publishing Co., Austin, 182 p.
[29]  Boggs, F.W. (1957) Report on the Kenya Coastal Sand—Sabakiriverarea. Mines and Geological Department, Nairobi.
[30]  Friedman, G.M. and Sanders, J.E. (1978) Principles of Sedimentology. Wiley, New York.
[31]  Martins, L.R. (1965) Significance of Skewness and Kurtosis in Environmental Interpretation. Journal of Sedimentary Petrology, 35, 768-770.
https://doi.org/10.1306/74D7135C-2B21-11D7-8648000102C1865D
[32]  Shepard, F.P. (1954) Nomenclature Based on Sand-Silt-Clay Ratios. Journal of Sedimentary Petrology, 24, 151-158.
[33]  Folk, R.L., Andrews, P.B. and Lewis, D.W. (1970) Detrital Sedimentary Rock Classification and Nomenclature for Use in New Zealand. New Zealand Journal of Geology and Geophysics, 13, 937-968.
https://doi.org/10.1080/00288306.1970.10418211
[34]  Flemming, B.W. (2000) A Revised Textural Classification of Gravel-Free Muddy Sediments on the Basis of Ternary Diagrams. Continental Shelf Research, 20, 1125-1137.
https://doi.org/10.1016/S0278-4343(00)00015-7
[35]  Duane, D.B. (1964) Significance of Skewness in Recent Sediments, Western Pamlico Sound, North Carolina. Journal of Sedimentary Petrology, 34, 864-874.
[36]  Baruah, J., Kotoky, P. and Sarma, J. (1997) Textural and Geochemical Study on River Sediments: A Case Study on the Jhanji River, Assam. Journal of the Indian Association of Sedimentologists, 16, 195-206.
[37]  Ray, A.K., Tripathy, S.C., Patra, S. and Sarma, V.V. (2006) Assessment of Godavari Estuarine Mangrove Ecosystem through Trace Metal Studies. Environment International, 32, 219-223.
https://doi.org/10.1016/j.envint.2005.08.014
[38]  Moiola, R. and Weiser, D. (1968) Textural Parameters: An Evaluation. Journal of Sedimentary Petrology, 38, 45-53.
[39]  Mycielska-Dowgiałło, E. (2007) Research Methods for Textural Features of Clastic Deposits and the Significance of Interpretational Results. In: Mycielska-Dowgiałło, E. and Rutkowski, J., Eds., Research into the Textural Features of Quaternary Sediments and Some Dating Methods, The Family Alliance School of Higher Education Press, Warsaw, 95-180.
[40]  Mycielska-Dowgiallo, E. and Ludwikowska-Kedzia, M. (2011) Alternative Interpretations of Grain-Size Data from Quaternary Deposits. Geologos, 17, 189-203.
https://doi.org/10.2478/v10118-011-0010-9
[41]  Ludwikowska-Kędzia, M. (2000) Evolution of the Middle Segment of the Belnianka River Valley in the Late Glacial and Holocene. Dialog Press, Warsaw, 180.
[42]  Blott, S.J. and Kenneth, P. (2000) Gradistat: A Grain Size Distribution and Statistics Package for the Analysis of Unconsolidated Sediments. Earth Surface Processes and Landforms, 26, 1237-1248.
https://doi.org/10.1002/esp.261

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