Project Abstract

The study area is located within the Anambra Basin in Nigeria, specifically around Okpekpe and Imiegba in the south-western region. This research project focuses on the sedimentology of the Maastrichtian sedimentary successions exposed in this area. The Maastrichtian age represents the latest age of the Cretaceous period, known for significant geological events such as the extinction of dinosaurs. The sedimentary successions in the study area exhibit a variety of lithofacies, including sandstones, siltstones, and shales. These lithologies provide valuable information about the depositional environments and processes that occurred during the Maastrichtian period. By analyzing the sedimentology of these successions, researchers can reconstruct past environmental conditions and interpret the geological history of the region. The sedimentary rocks in the study area show evidence of deposition in shallow marine environments, with influences from both fluvial and deltaic processes. The presence of cross-bedding, ripple marks, and mudcracks suggests deposition in a dynamic sedimentary setting characterized by fluctuating water levels and energy conditions. These sedimentary structures provide insights into the paleogeography of the area and the interactions between different depositional systems. In addition to sedimentary structures, the study also investigates the mineralogical composition of the rocks in the Maastrichtian successions. By analyzing the mineralogy, researchers can identify the source areas of the sediments and infer the tectonic history of the basin. The presence of minerals such as quartz, feldspar, and clay minerals can indicate the weathering processes that occurred during sediment transport and deposition. Furthermore, the study aims to assess the diagenetic alterations that have affected the Maastrichtian sedimentary rocks in the study area. Diagenesis refers to the physical and chemical changes that occur in sediments after deposition, leading to the formation of new minerals and textures. Understanding the diagenetic history of the rocks can provide insights into the burial history, fluid flow patterns, and reservoir quality of the sedimentary successions. Overall, this research project on the sedimentology of the Maastrichtian sedimentary successions around Okpekpe and Imiegba in the Anambra Basin contributes to our understanding of the geological evolution of the region. By analyzing sedimentary facies, mineralogy, sedimentary structures, and diagenetic processes, researchers can reconstruct past environments and unravel the complex history of sediment deposition in the area.

Project Overview

1.1   General Introduction

Sedimentology is the scientific study of sediments and sedimentary rocks. It involves studying the processes that result in their formation (erosion and weathering), transport, deposition and diagenesis (Gary Nichols, 1999). Sedimentologists apply their understanding of modern processes to interpret geologic history through observation of sedimentary rocks and sedimentary structures. The aim of sedimentolgy is to derive information on the depositional conditions which acted to deposit the rock unit, and the relation of the individual rock units in a basin into a coherent understanding of the evolution of the sedimentary sequences and basins, and thus the Earth’s geologic history as a whole. Sedimentary rocks are crucial part of sedimentary basins whereby they are either consolidated or unconsolidated. Detrital rocks are formed by the sedimentation of minerals and rock fragments that were obtained from the mechanical breakdown and chemical decomposition of pre-existing rocks and transported to a place of deposition from the source area. These sediments later form sedimentary rocks such as siltstone, sandstone, shale or conglomerate after undergoing lithification. Although, most sedimentary rocks bear evidence of their depositional environment, transporting media and original mineralogical composition, such evidences can be reflected by the textural characteristics, sedimentary structures and mineralogical composition.

1.2   Aim and Objectives

This work involves the sedimentological studies of the Maastrichtian sedimentary successions exposed around Okpekpe and Imiegba South Western Anambra Basin, Nigeria.

The Objectives include:

Detailed geological field mapping of the study area.
Representative samples were obtained for laboratory analysis such as grain size analysis, thin section petrography and heavy mineral separation results.
In order to determine the textural characteristics, depositional setting and source area tectonics of the study area.
1.3   Geographical Location and Accessibility

The study area is demarcated by Latitudes 0070 111       N to 0070 131N 3511 and longitudes 0060 251 E to 0060 261 E 5211, which is the South-Western part of the Anambra Basin, the contact between Mamu and Ajali Formation.(Fig 1.1)

Accessibility is through major road and footpath which cuts across Apana, Okpekpe and Imiegba and serves as routes to the exposed outcrops during the mapping exercise.

Fig. 1.1: Location Map of the Study Area

1.4   Settlement and Land Use

Linear and Nucleated settlement pattern were found in the study location and the major occupation of the inhabitants is farming.

The lands in the study areas are used for agricultural purposes.

1.5   Relief and drainage

The outcrops studied have a hilly and undulated topography. The study area is well drained by ephemeral streams and rivers.

1.6   Climate and Vegetation

The two main seasons that dominates the climate in the studied area are the rainy season and the dry season.

Vegetation is part of the rain forest vegetation in Nigeria and it’s typical of a transition belt between the forest and Savannah (grassland) belt.

1.7   Review of Previous Work

Several studies by different geologists have been carried out on the Mamu Formation, this includes the stratigraphic and biostratigraphic studies of the Mamu Formation (Petters, 1987, Ladipo 1988, Adeniran 1991).

Friedman (1961) used grain texture as a paleoenvironmental tool and sedimentary structures such as cross-bedding to establish paleocurrent direction. Sedimentological studies of sandstone unit in the basin have been carried out by some geologist such as Murat (1972), Nwajide (1996) and Reyment (1977) because the Anambra Basin has attracted more attention within the last decades.

Reyment (1964) described the Mamu Formation as a regressive deltaic offlap sequence. Olufemi (1985) studied the subsurface geology of the Mamu Formation in Southwestern section of the Anambra basin, through standard exploitation criteria. Reyment (1965), Hoque and Ezepue (1977) have suggested continental and fluvio-deltaic settings as a regressive phase of a short lived Maastrichtian transgression. Ladipo (1986) argued a tidally influence regime in a shelf or shore-line environment. Amajor (1984), Agagu et al; (1985): Umeji and Nwajide 2007 mainly concentrated on the sedimentology and stratigraphy of the formation at the depo-center along Onitsha-Nsukka axis.. Previous work on the Ajali sandstone by Reyment (1965) indicates that the Ajali sandstone is thickest at the Udi plateau area where it attains over 300m and extends continuously in thin outcrops to the South-East of Okigwe.

Purchase Detail
Hello, we’re glad you stopped by, you can download the complete project materials to this project with Abstract, Chapters 1 – 5, References and Appendix (Questionaire, Charts, etc) for N5000 ($15) only,
Please call 08111770269 or +2348059541956 to place an order or use the whatsapp button below to chat us up.
Bank details are stated below.

Bank: UBA
Account No: 1021412898
Account Name: Starnet Innovations Limited