Textural Characteristics of River Ogbagha Sediments in Okpella Area, Southwest Nigeria

Abstract

The aim of the paper is to discuss the textural characteristics of River Ogbagha sediments in Okpella area of southwestern Nigeria. The study involved both field and laboratory operations. The sample locations were captured using global positioning system (GPS). The sieve analysis was carried out using a set of eight sieves and a bottom pan that were agitated for approximately ten minutes. Six samples were collected and used for textural analysis. The calculated statistical parameters used are graphic mean, standard deviation (sorting), graphic skewness and kurtosis. The textural analysis shows graphic mean values range from 0.48 to 0.73 interpreted as coarse-grained sediments. The standard deviation (sorting) values range from 0.63 to 1.25 indicative of poorly sorted to moderately well sorted sediments deposited under relatively high current velocity and turbulence. The skewness values range from -0.14 to 0.81 indicative of negative to strongly positive skewness. The graphic kurtosis values range from 0.45 to 0.84 interpreted as very platykurtic. The bivariate plots of standard deviation against mean and that of the standard deviation against skewness established that the sediments are of river sand origin. It is recommended that more detailed geological and geochemical mapping be carried out to deepen the knowledge of the study area.