DEPARTMENT OF GEOLOGY

Due to industrialization, population growth and urbanization in Yenagoa and environs, anthropogenic activities are increasing daily and could introduce contaminants into soil and water resources.This study evaluated the causes, distribution, and environmental effects of heavy metal pollution in groundwater, surface water, and soil in Yenagoa and environs, Niger Delta, Southern Nigeria. The study sought to compare concentrations with control values for soil, surface and ground water, and regulatory standards (WHO and NSDWQ) for groundwater, as well as assess the degree and variability of heavy metal pollution across various anthropogenic sites, including waste disposal sites, mechanic shops, cassava mills, and areas affected by crude oil spills. A total of one hundred and twelve (112) samples were randomly collected for each season, including 77 soil samples depth 30cm and 35 surface and ground water samples. These samples were then evaluated using standard laboratory technique, Atomic Absorption Spectrophotometer (AAS) during both the wet and dry seasons. Soil contamination levels were measured using pollution indicators such the Geo-accumulation Index (Igeo), Enrichment Factor (EF), Contamination Factor (CF), and Pollution Load Index (PLI), and groundwater quality was assessed in relation to allowable limits. Results showed that all site types exhibited elevated concentrations of key heavy metals including iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr), and vanadium (V). Crude oil spill sites recorded the highest soil contamination, with lead reaching 15.354 mg/kg and

Due to industrialization, population growth and urbanization in Yenagoa and environs, anthropogenic activities are increasing daily and could introduce contaminants into soil and water resources.This study evaluated the causes, distribution, and environmental effects of heavy metal pollution in groundwater, surface water, and soil in Yenagoa and environs, Niger Delta, Southern Nigeria. The study sought to compare concentrations with control values for soil, surface and ground water, and regulatory standards (WHO and NSDWQ) for groundwater, as well as assess the degree and variability of heavy metal pollution across various anthropogenic sites, including waste disposal sites, mechanic shops, cassava mills, and areas affected by crude oil spills. A total of one hundred and twelve (112) samples were randomly collected for each season, including 77 soil samples depth 30cm and 35 surface and ground water samples. These samples were then evaluated using standard laboratory technique, Atomic Absorption Spectrophotometer (AAS) during both the wet and dry seasons. Soil contamination levels were measured using pollution indicators such the Geo-accumulation Index (Igeo), Enrichment Factor (EF), Contamination Factor (CF), and Pollution Load Index (PLI), and groundwater quality was assessed in relation to allowable limits. Results showed that all site types exhibited elevated concentrations of key heavy metals including iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr), and vanadium (V). Crude oil spill sites recorded the highest soil contamination, with lead reaching 15.354 mg/kg and

The Greater Ughelli Depobelt within the Niger Delta Basin represents a mature hydrocarbon province where precise lithostratigraphic, biostratigraphic, and source rock characterizations remain critical for mitigating exploration risks. This study presents a comprehensive evaluation of the ABC-1 well, combining sedimentological analysis, microfossil biostratigraphy, and organic geochemistry to reconstruct the paleoenvironment, establish a chronostratigraphic framework, and assess the oil and gas potential. Lithological analysis of ditch cutting samples reveals a classic deltaic succession belonging to the Agbada and Akata Formations, characterized by alternating sequences of sandstones, siltstones, and marine shales. Biostratigraphic dating, utilizing index planktonic foraminifera and palynomorph assemblages, indicates an age range from Late Oligocene to Early Miocene. Identified biozones correspond to specific global chronostratigraphic markers, allowing for the delineation of major maximum flooding surfaces (MFS) and sequence boundaries (SB) that define the structural and stratigraphic traps within the depobelt.

This study examines how important geotechnical properties of soil affect the stability, safety, and overall performance of engineering structures. Soil samples were taken from depths of 1.0 m, 2.0 m, 3.0 m, and 4.0 m, and tested for moisture content, grain size distribution, Atterberg limits, specific gravity, compaction behaviour, and triaxial shear strength. These tests helped to determine the soil’s physical and mechanical characteristics and how they respond to different loading and environmental conditions. Grain size results showed that the soil is mainly sandy, which explains its high permeability and low tendency to compress. The Atterberg limits indicated low to moderate plasticity, meaning the soil has limited swelling and shrinking capability. Specific gravity values suggested the presence of quartz-rich materials, while compaction tests provided the optimum moisture content (OMC) and maximum dry density (MDD) needed for proper construction. The triaxial test also gave the shear strength values required for evaluating bearing capacity and slope stability. The results shows that the soil has good engineering qualities when properly compacted, making it suitable for foundations, road bases, embankments, and similar structures. The study highlights the need for thorough geotechnical investigation before construction to avoid structural failures and recommends continuous monitoring and soil improvement methods where weaker layers occur.

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.