DETERMINATION OF THE SEDIMENTOLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF THE SEDIMENT IN THE NIGER DELTA BASIN

Project Abstract

The Niger Delta Basin is a region of significant economic importance due to its vast oil and gas reserves. Understanding the sedimentological and geochemical characteristics of the sediments in this basin is crucial for petroleum exploration and environmental management. This study aimed to determine the sedimentological and geochemical properties of the sediment in the Niger Delta Basin. Sediment samples were collected from various locations within the basin and analyzed using standard laboratory techniques. The sedimentological analysis included grain size distribution, sediment texture, and sedimentary structures. The geochemical analysis involved determining the organic matter content, total organic carbon, total nitrogen, and major and trace element concentrations. The results of the sedimentological analysis revealed that the sediments in the Niger Delta Basin are predominantly fine-grained with high clay content. The presence of sedimentary structures such as cross-bedding and ripple marks indicated deposition in a fluvial and tidal environment. The geochemical analysis showed that the sediments had high organic matter content, with total organic carbon values ranging from 1.5% to 5.8%. The total nitrogen content ranged from 0.1% to 0.5%, indicating varying levels of marine influence. The major element analysis revealed that the sediments were primarily composed of silica, alumina, and iron oxide, which are typical of clastic sediments derived from the erosion of basement rocks. Trace element concentrations varied among the samples, with elevated levels of elements such as manganese, lead, and zinc observed in some locations. Overall, the sedimentological and geochemical characteristics of the sediment in the Niger Delta Basin indicate a complex depositional environment influenced by both fluvial and marine processes. The high organic matter content suggests the potential for hydrocarbon accumulation in the basin, making it a favorable target for petroleum exploration. Additionally, the presence of trace elements in the sediments highlights the importance of environmental monitoring and management to mitigate potential pollution risks associated with oil and gas activities in the region. Understanding the sedimentological and geochemical properties of the sediment in the Niger Delta Basin is essential for making informed decisions regarding resource exploration and environmental protection in this economically significant region.

Project Overview

<p> </p><p>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.</p><div><br> </div><br><p></p>