Project Abstract

Abstract
The Niger Delta Basin is a region of significant geological and economic importance, known for its extensive sediment deposits and hydrocarbon reserves. This study aimed to determine the sedimentological and geochemical characteristics of the sediment in the Niger Delta Basin to provide insights into the depositional environment, provenance, and potential resource implications. Sediment samples were collected from various locations in the Niger Delta Basin and analyzed using a combination of sedimentological and geochemical techniques. Sedimentological analysis involved the description of sediment grain size, sorting, and texture, as well as the identification of sedimentary structures. Geochemical analysis included the determination of major and trace element concentrations, as well as isotopic composition. The sediment in the Niger Delta Basin was found to be predominantly composed of fine-grained particles, indicating a low-energy depositional environment. The sediment exhibited variable sorting, with some samples showing moderately well-sorted characteristics. Sedimentary structures such as cross-bedding and laminations were observed, suggesting deposition in fluvial and deltaic environments. Geochemical analysis revealed that the sediment in the Niger Delta Basin is enriched in organic matter, consistent with its hydrocarbon-rich nature. The sediment also showed elevated concentrations of elements such as iron, aluminum, and potassium, indicative of a predominantly terrigenous source. Isotopic analysis further supported the terrigenous origin of the sediment, with values consistent with continental crust compositions. Overall, the sedimentological and geochemical characteristics of the sediment in the Niger Delta Basin suggest a complex depositional history involving input from multiple sources and depositional environments. The findings of this study have implications for understanding the evolution of the Niger Delta Basin, as well as for the exploration and exploitation of its hydrocarbon resources. By providing detailed insights into the sediment properties of the basin, this research contributes to the broader understanding of sedimentary basins and their resource potential.

Project Overview

INTRODUCTION

The mineralogical and chemical composition of clastic sedimentary rocks are controlled by various factors, including (1) the composition of their source rocks, (2) environmental parameters influencing the weathering of source rocks (e.g., atmosphericchemistry, temperature, rainfall and topography), (3) duration of weathering (4)transportation mechanisms of clastic material from source region to depocenters, (5)depositional environment (e.g., marine versus fresh water), and (6) post-depositional processes (e.g., diagenesis, metamorphism) (Hayashi et al., 1997). Numerousinvestigations are substantiating the above aspects pertaining to genesis of both ancient andmodern siliciclastic sediments (e.g., Dickenson et al., 1983; Nesbitt and Young, 1982, 1984; Bhatia, 1983; Roser and Korsch, 1988; McCann, 1991; Condie et al., 1992; Condie, 1993; McLennan et al., 1993; Nesbitt et al., 1996; Cullers, 2000; Hessler and Lowe 2006; Nagarajan et al., 2007; Spalletti et al., 2008). Several studies have also been focused on the identification of palaeotectonic settings of provenances based on geochemical signatures of siliciclastic rocks (e.g., Dickinson and Suczek, 1979; Bhatia, 1983; Bhatia and Crook, 1986; Roser and Korsch 1986; McLennan and Taylor, 1991). Among the terrigenous sedimentary rocks, shales are considered to represent the average crustal composition of the provenance much better than any other siliclastic rocks (e.g., McCulloch and Wasserburg, 1978). Shales retain most of the mineral constituents of the source and their bulk chemistry preserves the near-original signature of the provenance and more faithfully reveal palaeoweathering conditions (e.g., Pettijohn, 1975; Graver and Scott, 1995). The present note examines the geochemistry of sediment from part of the subsurface Niger Delta Basin province, attempts to constrain there paleo redox and tectonic setting and provenance. Owing to limitations of analytical facilities, the present work is based on chemical analyses data of major and select trace elements of the investigated sediment of the study area.