DEPARTMENT OF GEOLOGY

This study represents a comparative mineralogical and geochemical evaluation of clay deposits from Igo and Okhoro, located within the Benin Formation of Southern Nigeria, with the aim of determining their industrial suitability and economic potential. Field observations revealed that the Igo clay occurs as reddish to brownish lateritic clay interbedded with sands, whereas the khoro clay is predominantly light grey with brown patches and is more quartz-rich. X-ray Fluorescence (XRF) analysis of the Igo samples shows high concentrations of silica (SiO₂: with mean value 68.57%) and alumina (Al₂O₃: with mean value 22.59%), with relatively low levels of fluxing oxides. In contrast, the Okhoro samples contain lower silica (mean 59.25%), comparable alumina (mean 21.86%), but noticeably higher iron oxide (Fe₂O₃: up to 7.34%) Trace element concentrations in both locations were generally low, indicating minimal impurity influence on industrial applications. The X-ray Diffraction (XRD) data reveal that the Igo clays are dominated by kaolinite (24.5–45%) and quartz (36–62%), with significant amounts of feldspar minerals (orthoclase and albite) and muscovite. Okhoro samples, however, are overwhelmingly quartz-dominated (88.6–98.04%) with only minor kaolinite (0.98–9.42%) and no detectable feldspars, signifying a highly mature, intensely weathered sediment. These mineralogical differences indicate that Igo represents a submature kaolinite-quartz-feldspathic clay, while Okhoro represents a supermature quartzose deposit. Comparisons with industrial specifications show that both clay types meet some requirements for refractory bricks, hough beneficiation is needed to adjust fluxing oxide levels. Igo clays, due to their higher kaolinite content and natural feldspar fluxes, exhibit stronger potential for ceramic applications, including tiles, earthenware, and fillers for paint or rubber after processing. Okhoro clays, because of their extreme quartz dominance , are more suitable as construction fillers, low-grade refractory blends, or materials for brick manufacturing. Overall, the Igo clay deposit displays broader and more economically valuable industrial potential than the Okhoro deposit, which is limited by its mineralogical maturity.

This study presents an in-depth structural analysis of the Ugbobo area and its environs, situated within the Igarra Basement Complex in southwestern Nigeria. The primary objective of this research is to shed light on the geological events that have shaped this region, providing valuable insights into its deformational and geological history. To achieve this goal, Landsat imagery was utilized to systematically gather and examine fracture data through various analytical techniques. These techniques include rose plots, stereonets, and pole plots, which enabled the assessment of structural orientations and deformations in the study area. The results obtained from the rose plot analysis revealed a dominant NNE-SSW fracture trend, indicating deformation that can be attributed to the pre-Pan African orogeny. This finding suggests a polyphase deformational history, pointing to significant tectonic activity in the region. Furthermore, the analysis of pole plots showed clustering of poles in the western and eastern directions. The stereonet analysis revealed that the fracture lines are concentrated towards the eastern and western quadrants, indicating that many of these planes are dipping steeply in those directions. The comprehensive understanding of these structural patterns is crucial for reconstructing the deformational and geological history of the terrain. This study contributes significantly to the existing knowledge of the Igarra Basement Complex, providing new insights into the region's tectonic evolution. The findings of this research have important implications for future geological investigations and exploration activities in the area.

Groundwater potential assessment using the Vertical Electrical Sounding (VES) technique was conducted in Uwasota and environs, Benin City, Southern Nigeria. Four VES
measurements were acquired using the Schlumberger electrode array. The data were
quantitatively interpreted using curve matching and computer iteration techniques to
generate geoelectric parameters. The VES results revealed subsurface lithologies consisting of topsoil, lateritic soil, dry sand, and saturated sand, all within the Benin Formation. Resistivity analysis allowed for the delineation of potential aquifer zones and estimations of groundwater depth. This study provides valuable insight into the
subsurface hydrogeological conditions and delineates areas suitable for groundwater
development in Uwasota and environs, contributing to improved groundwater resource management in the region.

The study of geo-electrical resistivity provides critical insights into subsurface characteristics and aquifer dynamics, particularly in regions with varying geological formations. This research investigates the efficiency of Vertical Electrical sounding (VES), a geophysical technique, for groundwater exploration within the hydrological setting of Uwasota Benin city, southern Nigeria. The primary aim of this study is to characterize the geo-electrical layers, assess aquifer thickness and resistivity. A total of 4 VES was acquired using Schlumberger electrode array. The data was interpreted quantitatively using the partial curve matching and computer iteration techniques to generate the first order geo-electric parameters and to also delineate subsurface lithological variations and identify potential aquifer zones.

This study integrates sedimentological, mineralogical, and palynological analyses to evaluate the depositional environments and hydrocarbon potential of the XY Well in the Niger Delta Basin. The well penetrates the Agbada Formation, which forms part of the paralic sequence of the Niger Delta. A total of 190 ditch cutting samples were analyzed using standard sedimentological and palynological procedures to determine their lithological composition, textural characteristics, mineral assemblages, and fossil content. The lithological succession consists predominantly of alternating sandstone, shale, sandy shale, and clayey sand units typical of deltaic successions.
Mineralogical studies revealed quartz, pyrite, glauconite, iron oxide, mica, and carbonate minerals, suggesting mixed continental and marine influences, moderate diagenetic alteration, and cyclic depositional energy conditions. The sand units are moderately to well sorted, subrounded to rounded, and interpreted as potential reservoir facies, whereas the shales serve as potential source and seal rocks. Palynological analysis yielded 964 palynomorphs comprising 496 pollen grains, 458 spores, and 10 dinoflagellate cysts. Diagnostic taxa such as Praedapollis africanus, Peregrinipollis nigericus, and Retibrevitricol porites obodoensis enabled the
establishment of three biostratigraphic zones (P620, P580, and P560) corresponding to the Miocene age. Thirteen informal palynological zones were also recognized, reflecting alternating terrestrial, marginal marine, and shallow marine environments. Integration of the sedimentological and palynological results indicates a regressive–transgressive depositional cycle characteristic of a prograding delta system comprising delta plain, delta front, and prodelta
facies. The study concludes that the Agbada ormation penetrated by the XY Well exhibits favorable reservoir and source rock characteristics, confirming its significance in the hydrocarbon system of the Greater Ughelli Depobelt of the Niger Delta Basin.

This project presents an integrated 3D seismic interpretation and identification of hydrocarbon prospects of Yeager Field, which is located within the prolific Niger Delta Basin of Nigeria. There search has been performed using high-resolution 3D seismic data, integrated with well-login formation provided by the Shell Petroleum Development Company (SPDC) to identify subsurface structural and stratigraphic features that are relevant to hydrocarbon accumulation. A comprehensive fault mapping, horizon interpretation, seismic-to-well tie, velocity modeling, and depth conversion were undertaken and complemented by seismic attribute analysis comprising RMS amplitude, maximum amplitude, average energy, and average magnitude attributes. Thirty five (35) faults were identified dominated by growth faults, rollover anticlines, and synthetic-antithetic fault systems typical of the extensional regime of the Niger Delta. Several structural closures with trapping potential were identified from the time and depth structure maps, while seismic attributes indicated amplitude anomalies that suggested the presence of hydrocarbon in the reservoir sands of the Agbada Formation. The seismic-to-well tie provided a reliable time-depth relationship that increased the accuracy of horizon correlation by more than forty percent. The results indicate that fault-assisted closures, especially the rollover anticlines resulting from the growth faults, are the primary trapping mechanism in the field. Potential hydrocarbon prospects have been delineated using this integrated approach, providing a robust geological framework for future exploration and development planning in the study area. The importance of advanced 3D seismic interpretation in reducing exploration risk and optimizing hydrocarbon recovery in the complex structural setting of the Niger Delta Basin cannot be overemphasized.

The petrographic and mineralogical analysis of siliciclastic and carbonate facies within the southeastern Dahomey Basin, Nigeria, was studied with the aim of interpreting their provenance, depositional environment, diagenetic evolution, and reservoir potential. Thirty three samples were collected and analyzed. Analysis involved X-ray diffraction (XRD) for mineralogical characterization and thin-section petrography for micro-structural and textural evaluation. Six representative samples were analyzed, comprising three siliciclastic units from depths of 1610– 1870 ft and three carbonate units from 730–930 ft across two wells within the study area. The siliciclastic samples are dominated by quartz, feldspar (orthoclase and albite), and muscovite, indicating derivation from granitic and gneissic sources of the Precambrian Basement Complex. Moderate textural maturity and the presence of albitized feldspars suggest limited reworking and shallow burial diagenesis. The carbonate samples, composed mainly of bioclastic and peloidal packstones to wackestones, reflect shallow-marine to outer shelf depositional settings, influenced by mixed carbonate–siliciclastic sedimentation during transgressive phases. Diagenetic features such as sparry calcite cementation, muscovite preservation, and feldspar albitization point to a multi-stage, low-thermal diagenetic history under closed-system conditions. High quartz content, low clay development, and early marine cementation collectively indicate moderate to good reservoir quality, with porosity largely preserved by mechanical rather than chemical processes. The results of petrography and mineralogy of Siliciclastics and Carbonate facies in Southeastern Dahomey Basin revealed that the units are potential for hydrocarbon-bearing reservoirs.

This project work is focused on the volumetric estimation of Agbeju Field, Niger Delta using 3Dseismic data and well logs. Data used for this project include 3-D seismic data in SEG-Y format and suites of five well logs (Agbeju 01, Agbeju 02, Agbeju 03, Agbeju 04 and Agbeju X01). 9 major faults and 24 minor faults were delineated on the seismic data. The lateral extent of 3 hydrocarbon bearing reservoirs were delineated and mapped as blocks (Sand A, Sand B and Sand C) and evaluated showing the petrophysical values across the reservoirs having average porosity of 0.32, average pay thickness of 98.46ft, average net-to-gross ratio of 0.84, and average water saturation of 0.625. From prospect identification, the area of the drilled prospects within the reservoirs ranges from 452.8634 acres – 1196.512 acres. The estimated volumes of hydrocarbons within the drilled prospects is given by Gas initially in place for Sand A (554MMSCF), Sand B (163MMSCF) and Sand C (258MMSCF) and Oil initially in place for Sand B (22.4MMBBL) and Sand C (83.93SMMBBL). The result of the characterization of these reservoirs shows good productive sands with fair to good hydrocarbon saturation of 0.375, with sufficient hydrocarbon volumes necessary for field development and production.

This study attempts to access the quality, spatial variation and economic viability of A and C reservoirs across eight wells in the Alero Field. Suites of wireline well log data for the wells of the Alero Field were evaluated to characterize the reservoirs. From the quantitative and qualitative analyses carried out, it was revealed that reservoir A has the following petrophysical characteristics across the wells; Gross thickness 14.85m to 193.01m, shale volume 16% to 28%; total porosity: 31%to34%; effective porosity: 25% to 29%; permeability: 9962.25mD to 12912.90mD;
water saturation: 7% to 24%, while for reservoir C across the wells; shale volume10% to 36%%; total porosity: 28% to 33%; effective porosity: 21%to 29%; permeability: 10174.20mD to 12498.70mD; water saturation: 5%to 59%. The results show both reservoirs to exhibit favourable properties across the wells, including moderate to high net-to-gross (NTG) ratios, effective porosity, high hydrocarbon saturation, and good permeability. However, variations in shale content (VSh), water saturation, as well as pay zone thickness across the wells suggest
spatial heterogeneity in reservoir quality. Overall, reservoir A is found to be a more promising candidate for oil production, showing better permeability (10174.20mD to 12498.70mD) and overall hydrocarbon saturation (75% to 93%).

The Niger Delta Basin is one of the most productive hydrocarbon regions globally, yet its complex depositional history, structural variations, and diagenetic processes present challenges 9 for reservoircharacterization and hydrocarbon exploration. This study integrates lithofacies analysis, mineralogical evaluation using X-ray diffraction (XRD), and petrophysical assessment to enhance the understanding of reservoir quality and hydrocarbon potential in the EstyWil-1 Well, located in the Northern Delta Depobelt. Lithofacies analysis indicates a transition from fluvial-deltaic to deep marine depositional environments, characterized by alternating layers of sandstone, shaly sandstone, sandy shale, and thick shale. Sandstone-rich intervals, particularly within distributary channels and delta-front facies, exhibit high porosity (25-32%) and permeability (500-1500 mD), making them favorable for hydrocarbon accumulation. In contrast, shaly interbeds and deep marine shale sequences serve as barriers that influencefluid flow and hydrocarbon entrapment. Mineralogical analysis reveals a predominance of quartz, along with kaolinite, illite, chlorite, and feldspar, all of which impact reservoir quality. High quartz content enhances porosity, whereas clay minerals, particularly illite and chlorite, contribute to permeability reduction. The presence of pyrite and carbonate minerals in deeper sections suggests reducing conditions, which favor organic matter preservation and potential hydrocarbon generation. Petrophysical analysis, incorporating gamma-ray, resistivity, neutron-density, and sonic logs, confirms the presence of hydrocarbon-bearing zones with low water saturation (Sw <40%) in productive intervals. Structural interpretations highlight the role of growth faults and rollover anticlines as primary trapping mechanisms that enhance hydrocarbon accumulation. By integrating sedimentological, petrophysical, and mineralogical data, this study provides a more comprehensive approach to reservoir characterization. The findings contribute to improved exploration strategies, optimized reservoir management, and enhanced oil recovery (EOR) techniques within the Niger Delta Basin.