GRAIN SIZE ANALYSIS AND DEPOSITIONAL ENVIRONMENTS OF SEDIMENTS IN NIGER DELTA BASIN AT EKENWAN ROAD LOCATION, BENIN CITY

ABSTRACT Grain size analysis is a fundamental method  in sedimentology used to infer depositional environments of  sedimentary deposits. This study focuses on the grain size distribution of sediments collected along Ekenwan Road  in Benin City, Nigeria, within the Niger Delta Basin. The primary objective was to analyze the grain size characteristics of sediments at various depths and classify their depositional environments. A total of eleven sediment samples were collected and analyzed for grain size distribution using standard sieving and hydrometer techniques. Statistical parameters such as mean grain size, standard deviation, skewness, and kurtosis were calculated to classify the sediments and understand their depositional history. The results revealed that the sediments predominantly consist of medium to coarse sands, characteristic of a fluvial-deltaic environment, with minor silt and clay fractions indicating periods of low-energy conditions. Statistical analysis showed mean grain sizes ranging from-0.47 to 4.67 phi, indicating a broad spectrum of sediment textures. Sorting values ranged from well to poorly sorted (standard deviation: 0.38 to 3.95), while skewness varied from strongly coarse-skewed (-0.25) to strongly fine-skewed (0.55). The kurtosis values indicated a range from platykurtic (0.58) to leptokurtic (1.68). These variations in grain size distribution and statistical parameters suggest a dynamic depositional environment influenced by river channels, tidal flats, and possibly storm events. This study contributes to a better understanding of the geological history and diverse depositional settings within the Niger Delta Basin. The findings have implications for sedimentary facies analysis and could provide valuable insights for hydrocarbon exploration and environmental management