DEPARTMENT OF GEOLOGY

This fieldwork exercise was carried out in Igarra within the Nigerian Basement Complex terrain to provide practical training in geological mapping, rock identification, structural analysis, and field observation techniques. The exercise involved detailed study of various rock units, their mineralogical composition, textures, structures, modes of occurrence, and geological relationships. Rock types identified during the exercise include quartzite, schist, metaconglomerate, granite, pegmatite, aplite, hornfels, sandstone, shale, mudstone, claystone, siltstone, and fault breccia. Structural features such as foliations, folds, fractures, joints, shear zones, and intrusive contacts were also observed and interpreted. Evidence of regional metamorphism, contact metamorphism, brittle deformation, and igneous intrusion associated with the Pan-African Orogeny was recognized within the study area.The field exercise was supervised by lecturers from the Department of Geology, who guided students in structural measurements, rock description, geological interpretation, sedimentary logging, and geological mapping techniques. The exercise enhanced practical understanding of the geology, hydrogeology, engineering significance, and economic importance of rocks within the Nigerian Basement Complex

This study examines the sedimentological and biostratigraphical characteristics of Well X-1 in the Greater Ughelli Depobelt of the Niger Delta Basin, Southern Nigeria, in order to determine the age, depositional environment, and hydrocarbon potential of the penetrated strata. Seventy two ditch cutting samples collected between 4500 ft and 11460 ft were analyzed using reflected light microscopy to document lithology, grain size, sorting, and other sedimentological attributes. Four main lithofacies were identified. These are sandstone, shale, sandy shale, and shaly sand. Forty nine lithozones were delineated and used to interpret the vertical depositional succession. The sandstone and sandy shale units form a continuous reservoir interval between 5340 ft and 7260 ft, while the thick shale units below 7860 ft represent the probable source rock. A shale dominated interval above 4740 ft was interpreted as the seal or cap rock. Biostratigraphical interpretation using foraminiferal biofacies, F zone data, P zone data, and the Niger Delta chronostratigraphic chart revealed five maximum flooding surfaces at 6265 ft, 6688 ft, 7247 ft, 7771 ft, and 10280 ft, together with eight sequence boundaries occurring between 5899 ft and 10602 ft. These surfaces correspond to ages ranging from the Aquitanian to the Chattian. Foraminiferal abundance patterns show a dominance of calcareous benthonic species, which indicates deposition in a shelf environment. The alignment of the Bolivina 27 shale marker at 28.1 Ma with the basal shale supports its interpretation as the source rock interval. The combination of sedimentological and biostratigraphical evidence confirms the presence of the essential elements of a petroleum system, with favourable timing for hydrocarbon generation, migration, and entrapment

Hydrocarbon Reservoir Characterization and Evaluation of TOKS Field, Greater Ughelli Depobelt, Niger Delta Basin, Southern Nigeria was carried out with the aim to achieve optimal evaluation and characterization of the reservoirs in wells of TOKS field. The study utilizes an integration of well logs, seismic data, and core data to offer unique insights into the intricate
complexities of subsurface formations.

The materials (data) used for this study includes one (1) SegY 3D seismic, seven (7) well logs and four (4) checkshot from TOK’s well in the TOK’s Field, these were use to generate logs that consist of lithology log (gamma ray log), resistivity log and porosity logs (density, neutron, sonic). The data also included base map and information
used on the sandstone tops and base. The data collected were analyzed using petrophysical and well correlation, ischore thickness map, seismic horizon interpretation, stratigraphic modelling, structural modelling, upscalling and petrophysical method to evaluate and characterize the reservoirs.

The result shows that TOKS 1000 and TOKS 3000 are the reservoir intervals. The
Petrophysical analysis of TOK 1000 for the TOKS wells 14, 15,16,17,18, 19 and 51 shows porosity value of 0.3054, 0.3103, 0.3042, 0.3252, 0.3055, 0.3108, 0.3857, water saturation values of the wells as 0.2750, 0.2645, 0.2788, 0.2521, 0.2684, 0.2638 and 0.2972, the shale volume results shows 0.05, 0.05, 0.04, 0.04, 0.05, 0.07 and the Net to gross (NTG) ratio result shows 0.95, 0.95, 0.95, 0.96, 0.96, 0.95, 0.93. The Petrophysical analysis of TOK 3000 for the TOKS wells 14, 15,16,17,18 and 19 shows porosity value of 0.3491, 0.3121, 0.3135, 0.2993, 0.3353, 0.2881 and 0.3857, water saturation values of the wells as 0.2349, 0.2627, 0.2615, 0.2741,
0.2446, 0.2846 and 0.2972, the shale volume results shows 0.08, 0.05, 0.05, 0.04, 0.08, 0.05 and 0.07 and the Net to gross (NTG) ratio result shows 0.92, 0.95, 0.95, 0.96, 0.92, 0.95 and 0.93. The seismic interpretation (Horizon and seed) of reservoir tops of TOKS 1000 and TOKS 3000 correspond to trough events. Facies models of both TOKS 1000 and TOKS 3000 aid in the determination of Fine sand, Coarse Sand and Shale lithofacies. The seismic interpretation of reservoir tops of TOKS 1000 and TOKS 3000 reveal trough events. Four (4) zones and five (5) layers were delineated in the TOKS wells. Isochore map shows the thickness of TOKS 3000 reservoir zone. The Subsurface map helps us to identify areas with our reservoir. This structural model helps in understanding the reservoir's structural features. The Net To Gross (NTG) value at the reservoir zones ranges from 0.78 to 0.91 for TOKS 1000 and ranges from 0.76 to 0.92 for TOKS 3000. The porosity value at the reservoir zones ranges from 0.28 to 0.39 for TOKS 1000 and ranges from 0.25 t0 0.36 for TOKS 3000. The water saturation values at the reservoir zones ranges from 0.18 to 0.5 and ranges from 0.25 to 0.39. The prospective reservoirs were coarse grained. The overall results shows From the reservoir characterization and evaluation of TOKS Field, Greater Ughelli Depobelt, Niger Delta Basin, Nigeria shows that the evaluated reservoirs have favourable petrophysical characteristics that will lead to excellent production of hydrocarbon from their porespores hence regarded as prospective wells.

This study examines the sedimentology, geochemical appraisal and palynofacies of the Maastrichtian–Paleocene Araromi Formation, situated in the eastern Dahomey Basin of southwestern Nigeria. The primary objectives is to evaluate the depositional environments, organic matter quality, and the hydrocarbon‐generation potential of the formation, thereby contributing to a broader understanding of the basin’s petroleum system.Integrated field observations and lithological analyses reveal an alternation of sandstones, shales, limestones, and siltstones, which collectively indicate a dynamic depositional system that evolved from fluvial to shallow marine settings. These facies transitions reflect varying energy conditions and sediment supply, suggesting periodic marine incursions during the late Maastrichtian to early Paleocene.Geochemical results show moderate to high Total Organic Carbon (TOC) values, accompanied by Hydrogen Index data consistent with a mixed assemblage of Type I and Type III kerogens. This mixture confirms the presence of both oil-prone and gas-prone organic matter, implying that the Araromi Formation possesses substantial potential for hydrocarbon generation under appropriate thermal maturity conditions.Palynofacies analyses further support these interpretations by revealing moderate palynological diversity. The presence of terrestrial pollen and spores, alongside abundant marine dinoflagellate cysts, confirms deposition during the late Maastrichtian to early Paleocene interval and indicates fluctuating terrestrial and marine influence. Amorphous organic matter dominates the offshore equivalents, suggesting deposition under reducing conditions that favored the preservation of hydrogen-rich organic material.Finally, the combined sedimentological, geochemical, and palynological evidence establishes the Araromi Formation as a significant source rock within the Dahomey Basin. The findings not only enhance understanding of the basin’s stratigraphic evolution and petroleum system but also highlight the formation’s relevance for future hydrocarbon exploration and development in southwestern Nigeria.

Samples of three wetland soils were collected from the Idobgo Area of Benin City, Edo State and were subjected to engineering property tests with the principal objective of predicting their engineering behaviour. These samples were subjected to four basic engineering property tests. The tests are; specific gravity, compaction test, Atterberg limit tests, and particle size analysis. Results from the specific gravity tests show 2.34 Atterberg limits results is: Liquid limit 90.61%, plastic limits: 44.74%, and 45.87%. plasticity index. With a particle size distribution of 99.2% clay, and 0.8%.all these results show that the clay soils around the Idobgo, Benin area will need a lot of stabilization to be suitable for construction

This project presents a detailed petrographic and geochemical study of granitic rocks in the IgarraUgbogbo area of Edo State Nigeria, within the Nigerian Basement Complex. In order to characterize the mineralogical composition, and interpret their petrogenesis and tectonic setting. To address the significant knowledge gaps in the understanding of this segment of the Pan-African orogenic belt using integrated field mapping with laboratory analysis, Five representative fresh samples (SJ01–SJ05) were collected and subjected to polarizing microscopy for petrographic study and X-ray fluorescence (XRF) spectrometry for whole rock major and trace element geochemistry. Petrographic analysis reveals that the granites are medium to coarse grained with a hypidiomorphic granular texture, indicating slow plutonic cooling. Modal composition is dominated by quartz (21- 31%), plagioclase (31-35%), and microcline (20-26%), with biotite (7-10%) as the main mafic mineral. Minor hornblende, muscovite, and accessory zircon and opaque minerals are present. Textural features such as undulose extinction in quartz and sericitization of feldspars indicate post crystallization deformation and hydrothermal activity. Geochemical data classify the rocks as metaluminous to weakly peraluminous (ASI = 0.98-1.05), high-silica (69.23-71.44 wt. % SiO₂) granites with calc-alkaline affinity. They are enriched in Large Ion Lithophile Elements (LILE: e.g., Rb, Ba) and depleted in High-Field-Strength Elements (HFSE: e.g., Nb, Ta, Y), a signature characteristic of crustal-derived magmas. Trace element discrimination diagrams consistently plot the samples in the syn collision to post-collision granite fields. The integrated results lead to the conclusion that the Igarra granites are I-type granitoids formed primarily by partial melting of pre-existing crustal igneous rocks during the Pan-African Orogeny and their emplacement occurred in a post-collisional tectonic environment, accompanied by minor deformation and hydrothermal alteration. This study provides a crucial petrogenetic framework for the Igarra basement and contributes valuable data for understanding crustal evolution and mineral exploration potential in southwestern Nigeria.

This study presents a detailed palynological analysis of subsurface well samples from the Araromi-2 well in the eastern Dahomey Basin, Southwestern Nigeria, to establish a biostratigraphic framework and interpret paleodepositional environments. 33 samples were recovered and ten (10) ditch cutting samples from depths of 830 ft to 1880 ft were processed using standard palynological techniques involving hydrochloric (HCl) and hydrofluoric (HF) acid digestion, heavy liquid separation, and microscopic examination. The analysis yielded a rich and diverse assemblage of palynomorphs, including spores, pollen, and dinoflagellate cysts. The stratigraphic distribution of key taxa such as Proxapertites operculatus, Retidiporites magdalenensis, Palaeocystodinium australinium, and Cyathidites minor enabled the recognition of the Palaeocystodinium australinium - Cyathidites minor Assemblage Zone. This zone indicates a Late Maastrichtian to Early Paleocene (Danian) age for the studied interval, correlating with the upper Araromi Formation. Palynofacies analysis revealed a vertical transition from amorphous organic matter (AOM)-dominated assemblages in the lower sections to phytoclast-rich assemblages upwards. This trend indicates a regressive sequence, transitioning from a shallow, anoxic marine environment to a marginal marine and finally a deltaic/coastal plain setting. The study concludes that the Araromi Formation records a critical phase of the basin's evolution across the Cretaceous-Paleogene boundary. The findings refine the biostratigraphic zonation of the basin and underscore the value of integrated palynological and palynofacies studies in petroleum exploration and paleoenvironmental reconstruction.

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.