Stephen E Obrike | Newcastle University (original) (raw)

Papers by Stephen E Obrike

Research paper thumbnail of Hydro‑geochemical evolution, quality, and health risk assessment of groundwater in crystalline basement aquifer in Keffi, Nigeria

International Journal of Energy and Water Resources, 2023

Hydro-geochemical evaluation of groundwater in the near-surface basement aquifer in the Keffi are... more Hydro-geochemical evaluation of groundwater in the near-surface basement aquifer in the Keffi area was assessed for its quality and associated human health risks. Physico-chemical properties of groundwater samples from 15 motorized boreholes were collected and analyzed. Measured physical parameters reveal the groundwater to be slightly acidic to neutral with pH values in the range of 5.7–7.3, electric conductivity values in the range of 50–360 µS/cm, and total dissolved solids between 32 and 275 mg/L. The result of the chemical analysis reveals the mean concentration values of the major cations and anions in the order of Na+ > Mg2+ > Ca2+ > K+ and HCO3− > Cl− > SO42− > NO32−. The study area is characterized by three main water types (Ca–HCO3, Na–Ca–HCO3, and Ca–Mg–Cl), with Ca–HCO3 water type constituting 66.7% of the total groundwater samples, while the Na–Ca–HCO3 and Ca–Mg–Cl account for 26.7% and 6.6%, respectively. Silicate weathering, dilution, ionic exchange, and mineral dissolution of aquifer minerals are found as the dominant factors responsible for groundwater quality. Major contributions to health indices of groundwater in the study area are in the order Fe>Pb>Cu>Mn>Zn>Ni for adults and Cu>Pb>Zn>Mn>Fe>Ni for children. The computed hazard index value for all sampled locations in the study area is below unity (<1) with relatively higher values for agricultural areas and built-up sections with poor sanitation.

Research paper thumbnail of Regional Groundwater Quality in the Niger Delta

Journal of Mining and Geology, 2023

The Niger Delta is a sedimentary basin with thick accumulated sediments transported from a vast a... more The Niger Delta is a sedimentary basin with thick accumulated sediments transported from a vast and geologically complex catchment covering an area of roughly 38,000km. It is equally hydrologically diverse with fresh, saline and iron water interacting in places. At the same time, it supports a fragile ecology and is host to an expanding population and economy, with a growing demand for potable water. The heavy-dependence on groundwater in the region and the fears of its unsustainability triggered by a combination of overuse, weak regulations, pollution, increasing user
population and industrialization are the considerations that compelled this assessment. As the human population grows, more demand will be placed on groundwater. This necessitates a better understanding of our groundwater systems and managing them in a thoughtful manner to ensure sustainable quality. Using archival records, spatial distribution of physicochemical data on water quality from 960 producing boreholes drilled to different depths spread across the region, groundwater quality was overlain on Google Earth Pro for visual enhancement followed by computation of Water Quality Index (WQI) to evaluate the suitability of groundwater quality in current use in the Niger Delta. Analysis of hydrochemical data suggests that the aggregate quality of groundwater in the Niger Delta is considered generally very good and compares favourably with WHO standards for drinking water. However, relatively high iron/manganese and chloride values are localized in time and space. In the coastal areas however, seawater intrusion was implicated as responsible for high salinity which has been identified as one of the major influences on the hydrochemistry of groundwater in both shallow unconfined aquifers as well as in deeply embedded aquifers. The complex multilayered aquifer system offering filtration and impeding the migration of pollutants is considered the major factor for the reduced vulnerability of deeper aquifers in the area. This study is crucial for the formulation of policies relating to water supply and public health, leading to the development of effective groundwater schemes in the Niger Delta and other neighbouring regions with similar geological formations and anthropogenic activities.

Research paper thumbnail of Foundation Settlement in Reclaimed Mangrove Swamplands: A Case Study of Eastern Bypass, Port Harcourt, Nigeria

Journal of Mining and Geology, 2023

Useable land is scarce in the mangrove swamps of the Niger Delta. This is because it is underlain... more Useable land is scarce in the mangrove swamps of the Niger Delta. This is because it is underlain at the top by very soft to soft fibrotic silty and sandy clay (locally called Chikoko) and subject to diurnal submergence by tidal flow, thus making it difficult to develop without improvement. Reclamation by hydraulic sandfill is the commonest approach to transform such mangrove swamp areas into useable land but the ground response to sandfill placement and requirements for subsequent use are not fully understood. The purpose of this paper is to analyze the ground response to loading through settlement analysis of in-situ CPT and laboratory data using the case study of the Eastern Bye-pass, PortHarcourt which was reclaimed in 3 phases, (1980-92, 1992-2000 and 2000-2020). The first was inspired by the necessity for a link road between Marine Base and Ogbunabali while the two subsequent phases were necessitated by 2 strategic development needs. Reclamation involved the transformation of some 3 km mangrove swamps through the placement of approximately 2.5 m thick hydraulic sandfilling over the fibrotic and bioturbated silty and sandy clay soil rich in partially decomposed vegetal matter. Although 97% Consolidation settlement was to be achieved in 3rd year, the road link was constructed before the end of the 3 years and has since been in satisfactory operational use, mainly due to the combined action of frictional bearing capacity, immediate settlement and drainage qualities of the river sand used as fill and also of the rapid settlement of the mangrove swamp soil occasioned by enhanced drainage
from bioturbation.

Research paper thumbnail of Hydraulic characteristics of a typical basement complex aquifer in Ajaokuta, southwestern Nigeria

Ife Journal of Science, 2006

Research paper thumbnail of Hydrogeophysical investigation and estimation of groundwater potentials of the Lower Palaeozoic to Precambrian crystalline basement rocks in Keffi area, north-central Nigeria, using resistivity methods

Arabian Journal of Geosciences, 2012

The use of resistivity sounding and two-dimensional (2-D) resistivity imaging was investigated wi... more The use of resistivity sounding and two-dimensional (2-D) resistivity imaging was investigated with the aim of delineating and estimating the groundwater potential in Keffi area. Rock types identified are mainly gneisses and granites. Twenty-five resistivity soundings employing the Schlumberger electrode array were conducted across the area. Resistivity sounding data obtained were interpreted using partial curve matching approach and 1-D inversion algorithm, RESIST version 1.0. The 2-D resistivity imaging was also carried out along two traverses using dipole-dipole array, and the data obtained were subjected to finite element method modeling using DIPRO inversion algorithm to produce a two-dimensional subsurface geological model. Interpretation of results showed three to four geoelectrical layers. Layer thickness values were generally less than 2 m for collapsed zone, and ranged from 5 to 30 m for weathered bedrock (saprolite). Two major aquifer units, namely weathered bedrock (saprolite) aquifer and fractured bedrock (saprock) aquifer, have been delineated with the latter usually occurring beneath the former in most areas. Aquifer potentials in the area were estimated using simple schemes that involved the use of three geoelectrical parameters, namely: depth to fresh bedrock, weathered bedrock (saprolite) resistivity and fractured bedrock (saprock) resistivity. The assessment delineated the area into prospective high, medium and low groundwater potential zones.

Research paper thumbnail of Preliminary Structural Study of Landsat Imagery over Wamba and Environs, Nasarawa State, Northcentral Nigeria

Research Journal of Applied Sciences, 2012

Research paper thumbnail of Hydro-geochemical characterization and water quality appraisal of groundwater in areas adjoining primordial landfills in the Maastrichtian Lafia Formation, Middle Benue Trough

International Journal of Energy and Water Resources, 2022

This study assessed the groundwater quality in areas adjoining primordial landfills in Lafia town... more This study assessed the groundwater quality in areas adjoining primordial landfills in Lafia town and its suitability for drinking purposes. Physico-chemical properties of twenty groundwater samples collected from boreholes, unlined and lined hand-dug wells at twenty different locations around three dumpsites were analysed for the appraisal of the water quality. Results of measured physical parameters show pH values in the range of 5.13–7.30, electrical conductivity (EC) values as between 89 and 7754 µS/cm and total dissolved solids (TDS) values that ranges from 59.63 to 5195 mg/L. The major cation and anions have mean concentrations in the order Ca2+ > Na+ > K+ > Mg2+ and SO42− > HCO3− > Cl− > CO3−. The Piper plot reveals three dominant water types (Ca–Cl–SO4, Ca–Na–HCO3−, and Na–Cl–SO4). Heavy metal pollution assessment reveals relatively higher modified heavy metal index (m-HMI) values for wells of close proximity to the landfills. The water quality index (WQI) classification reveals 35% of the groundwater sampled locations have water categorized as unsuitable for drinking purposes, 30% of the groundwater samples categorized as very poor and 25% of the groundwater samples classified as poor. While groundwater categorized as good to excellent constituted only 10% of the total groundwater samples analysed.

Research paper thumbnail of Engineered slope failure susceptibility modelling using high spatial resolution geospatial data

Bulletin of Engineering Geology and the Environment, 2021

Given the increased hazards faced by transport corridors such as climate induced extreme weather,... more Given the increased hazards faced by transport corridors such as climate induced extreme weather, it is essential that local spatial hotspots of potential landslide susceptibility can be recognised. In this research, an evidential reasoning multi-source geospatial integration approach for the broad-scale recognition and prediction of landslide susceptibility in transport corridors was developed. Airborne laser scanning and Ordnance Survey DTM data is used to derive slope stability parameters, while Compact Airborne Spectrographic Imager (CASI) imagery and existing national scale digital map datasets are used to characterise the spatial variability of land cover, land use and soil type. A novel approach to characterisation of soil moisture distribution within transport corridors was developed that incorporates the effects of the catchment contribution to local zones of moisture concentration in earthworks. The derived topographic and land use properties are integrated within the evidential reasoning approach to characterise numeric measures of belief, disbelief and uncertainty regarding slope instability spatially within the transport corridor. The model highlighted the importance of slope, concave curvature and permeable soils with variable intercalations accounting for over 80% of slope instability and an overall predictive capability of 77.75% based on independent validation dataset.

Research paper thumbnail of Basement morphology of the middle Benue Trough, Nigeria, revealed from analysis of high-resolution aeromagnetic data using grid-based operator methods

Journal of African Earth Sciences, 2020

Basement morphology of the middle Benue Trough, Nigeria, revealed from analysis of high-resolutio... more Basement morphology of the middle Benue Trough, Nigeria, revealed from analysis of high-resolution aeromagnetic data using grid-based operator methods,

Research paper thumbnail of Discerning mineral association in the near infrared region for ore sorting

International Journal of Mineral Processing, 2017

The preconcentration or early rejection of gangue minerals in mineral processing operations is in... more The preconcentration or early rejection of gangue minerals in mineral processing operations is investigated using sorting, based on interpretation of near infrared sensor data collected from ore particles. The success of sorting depends on the distribution of minerals between particles, the arrangement or association of minerals within particles and the ability of near infrared to distinguish relevant minerals. This paper considers minerals association, using common alteration minerals found in a hydrothermally-formed copper ore, with sensitivity in the near infrared region. The selected NIR-active minerals were arranged along the view of NIR line scanner to stimulate adjacent natural minerals association. It was found that spectral dominance may depend on minerals near infrared sensitivity and or the position of a mineral along the NIR scanner line of view. Analysis also revealed that only free occurring waste mineral spectra can be targeted for discrimination. Where spectra appeared mixed, such material cannot be preconcentrated using near infrared sensors.

Research paper thumbnail of Hydro-Geophysical Assessment of Groundwater Potential and Aquifer Vulnerability of the Turonian Makurdi Formation in North Bank area, Makurdi, Middle Benue Trough, Nigeria

Journal of Mining and Geology, 2022

Electrical resistivity investigation was carried out in North Bank and its environs in Makurdi, B... more Electrical resistivity investigation was carried out in North Bank and its environs in Makurdi, Benue State, with a view to determining the depth to aquifer, aquifer thickness, groundwater potential of the area and aquifer vulnerability. Twenty-one (21) Vertical electrical sounding (VES) was carried out using the Schlumberger electrode array with the aid of ABEM Terrameter (SAS 3000C) with maximum electrode spacing of 200m. The VES data obtained were interpreted using partial curve matching approach and modelled using WinResist software. Modelled field curves reveal essentially three to four geo-electrical layers and two main aquiferous zones corresponding to the upper silty-sandstone and lower medium to coarse grained felspathic sandstones of the Makurdi Formation. The upper silty-sandstone aquifer is characterized by low to moderate resistivity value distribution (37 - 2039 ohm-m) with layer thickness in the range of 3m to 15m. Computed hydraulic and geo-electric characteristics (Dar Zarrouk parameters, hydraulic conductivity and transmissivity) depicts it as unconfined, vulnerable to infiltrating surface contaminants, with low groundwater potential (0.63 m day < T 199.65 m day ) and only suitable for small community water supply projects and private consumption. The lower felspathic sandstone aquifer is characterized by relatively thicker sequence of aquiferous materials (3m – 54m). The aquiferous zone is generally unconfined to semi-confined in nature, with groundwater potential (30.96 m day < T ≤ 542.73 m day ) seen to be largely moderate. The aquifer is deemed suitable for industrial, irrigational and municipal water supply purposes

Research paper thumbnail of Mineralogical, Geochemical and Geotechnical Characteristics of the Maastrichtian clay Member of the Lafia Formation in Doma and Shabu areas, Middle Benue Trough

Journal of Mining and Geology, 2019

The Maastrichtian clay member of the non-fossiliferous Lafia Formation as exposed in Doma and Sha... more The Maastrichtian clay member of the non-fossiliferous Lafia Formation as exposed in Doma and Shabu was investigated to assess its physical and compositional characteristics with a view to establishing its potential use as
industrial raw material. The mineralogical determination by X-ray diffraction (XRD) of the clays show prominent peaks of kaolinite as the major clay mineral with diffused mixed layer of illite-smectite-chlorite and mica. Chemical analysis by X-ray Fluorescence reveals a dominance of SiO2 (54.14 – 58.02), Al2O3 (20.14 – 23.68), Fe2O3 (13.07 – 9.23), TiO2 (1.65 – 2.67) and H2O+ (4.23 – 11.05), while CaO , MgO, K2O, Na2O, MnO and P2O5 contribute less than 1% of the total elemental composition. The clays exhibit liquid limits in the range of 41-58%, plasticity index (22 - 36%), linear shrinkage (5.2 - 6.4%), Water Absorption Capacity (6.0 - 7.2%) and Loss on ignition (9.2 - 10.18%). The physical, mineralogical and chemical compositions in comparison with international specifications suggest that these clay deposits could be exploited for paints, cement, refractory ceramics and bricks production.

Research paper thumbnail of Groundwater Investigation Across the Crystalline Basement Rocks in Rogo Area, Kano State Northern Nigeria, Using Resistivity Methods

Journal of Mining and Geology, 2021

One-dimensional (1D) resistivity sounding (VES) and two-dimensional (2D) resistivity imaging meth... more One-dimensional (1D) resistivity sounding (VES) and two-dimensional (2D) resistivity imaging methods were employed in groundwater investigation in order to delineate potential aquifers and estimate their transmissivities in Rogo area. Main basement rock units in the area are granites and schistose quartzite rocks of Precambrian to Lower Paleozoic age. Twelve resistivity soundings (VES) were carried out across the area using Schlumberger electrode configuration. The field resistivity sounding data obtained were interpreted with partial curve matching approach and 1D inversion algorithm, IPI2Win. The 2D resistivity imaging survey was conducted along two traverses employing dipole-dipole electrode configuration and the resistivity data acquired were subjected to finite element method modelling using DIPRO inversion algorithm to generate a geologically realistic, 2D subsurface geological model. Three to five geoelectrical layers, as well as weathered bedrock (saprolite) and fractured bedrock (saprock) aquifers were delineated. Seven resistivity sounding curve types (namely H, HA, HK, KH, QH, HKH and KQH) were also identified with the H and HA types being the dominant curve types. Anisotropy coefficient (λ) values ranged from 1.03 to 2.65 with a mean of 1.31. Aquifer transmissivity computed for the weathered bedrock aquifer units varied from 16.01 to 53.3 m /day, with an average value of 30.91 m /day. The study revealed that the Rogo area has moderately high aquifer transmissivity and hence generally exhibits good groundwater potentials.

Research paper thumbnail of Upper Lithospheric Structure of the Middle Benue Trough, Nigeria, Derived from Analysis of Satellite Gravity Data

Journal of Mining and Geology, 2021

The middle Benue Trough is the central segment of the Benue Trough, an elongate northeast orienta... more The middle Benue Trough is the central segment of the Benue Trough, an elongate northeast orientated intra-cratonic rift basin in Nigeria. This study provides new information on the morphology/geometry of the upper lithospheric structures (Moho, crystalline crust thickness and crustal stretching factor) and tectonics in the middle Benue Trough and adjacent basement complex regions by analysis and three-dimensional (3D) inverse modelling of satellite Bouguer gravity anomaly data. Results from 3D inverse modelling reveal Moho depths varying from c. 24 ± 2 to 32 ± 3 km and crystalline crustal thickness values ranging between c. 20 ± 2 and 32 ± 3 km. Shallow Moho and thin crust occur beneath the Trough axial region, whereas deep Moho and thick crust underlay the basement complex regions and the Trough northwestern region. It also shows the presence of a prominent northeast-southwest (NE-SW)
orientated, shallow Moho structures (c. 24 ± 2 to 27 ± 3 km deep) and thin crust (c. 20 ± 2 to 26 ± 3 km thick) within the Trough axial region. Comparisons of Moho depths with topography and Bouguer gravity anomaly values using profiles highlight that the observed broad, longer-wavelength near-positive Bouguer gravity anomalies over the
Trough axial region are strongly associated with elevated (shallow) Moho and isostatic effect of lower topography. Crustal stretching factor (â) values obtained across the area range between c. 1.03 and 1.59 with moderately high values (c. 1.25 – 1.59) occurring in the Trough axial region. The tectonic implication of the results is that the
crust/lithosphere beneath middle Benue Trough has been strongly affected/modified by intense regional, extensional and/or wrench (strike-slip) tectonics associated with past rifting events.

Research paper thumbnail of Compositional Characteristics and Industrial Assessment of the Asu River Group Shale in Mpu Area, Southeastern Nigeria

miCompositional and physical characteristics of the shale from Mpu, southeastern Nigeria, were as... more miCompositional and physical characteristics of the shale from Mpu, southeastern Nigeria, were assessed to evaluate their potential as industrial raw materials. The mineralogical determination by x-ray diffraction (XRD) of the shale, indicate kaolinite as the major clay mineral with diffused peaks of illite and smectite, with quartz as the non-clay mineral. Chemical analysis of the samples reveals the predominance of SiO2 (58.62-59.80) and Al2O3 (21.23-22.10) with a silica/alumina ratio of 2.51.The shale is also characterized by significant Fe2O3 (1.62-3.68), TiO2 (1.48-1.56), K2O (1.64-1.78) values, while CaO, MgO, Na2O, MnO and P2O5 have individual values < 1%. Samples from the study area are essentially made up of clay fractions (<65µm) above 70%, some of the physical parameters of the shale specimens include linear shrinkage (4.80-5.20), plastic limit (22.0-27.0), liquid limit (53.0-58.0), plasticity index (28.0-34.0) and loss on ignition (9.50-9.80) values. Mineralogical and chemical compositions suggest that the shale deposit could be exploited for ceramics, paint, pottery and refractory industries.

Research paper thumbnail of Geotechnical analysis of two Nigerian soils for use as clay liners

Bulletin of Engineering Geology …, Jan 1, 2009

The cretaceous Auchi shale and the Tertiary Imo shale in SW Nigeria were investigated for their s... more The cretaceous Auchi shale and the Tertiary Imo shale in SW Nigeria were investigated for their suitability for use as a clay seal in waste disposal landfills. Geotechnical analyses indicated they are highly plastic inorganic clays. Although their geotechnical and chemical properties were within the range suggested by various authors for use as mineral seals, care would need to be taken with the Okada shales as they contain smectite and would be difficult to work and liable to cracking.

Research paper thumbnail of Hydrochemical Analysis and Evaluation of Water Quality in Angwan Jeba and its Environs, Nasarawa State, Northcentral Nigeria

Research Journal of …, Jan 1, 2011

Abstract: Angwan Jeba and its environs lies within the Basement Complex of northcentral Nigeria a... more Abstract: Angwan Jeba and its environs lies within the Basement Complex of northcentral Nigeria and is underlain by migmatitic gneiss, biotite gneiss, biotite schist, muscovite schist and older granites with minor intrusions of pegmatite and quartz veins. The study involved ...

Research paper thumbnail of Mineralogical, Geochemical, Physical And Industrial Potentials Of Shale From Okada Area, Southwestern, Nigeria

Journal of Mining and Geology, Jan 1, 2008

Mineralogical, geochemical and physical characteristics of the shale from Okada, Southwestern Nig... more Mineralogical, geochemical and physical characteristics of the shale from Okada, Southwestern Nigeria were evaluated to determine its industrial potentials. The x-ray analysis of the Okada shale shows prominent quartz, kaolinite and mixed layer peaks. The result of the ...

Research paper thumbnail of The Kano-Kazaure highway, north central Nigeria: the significance of the engineering geology in construction

Bulletin of Engineering …, Jan 1, 2011

Kano–Kazaure highway traverses granitic rock with minor occurrences of metasediments and fine san... more Kano–Kazaure highway traverses granitic rock with minor occurrences of metasediments and fine sandy deposits. The soil profiles were studied to determine their suitability in the proposed dualization of the highway route as part of the Trans-Sahara international highway construction project. The soils derived from the granitic rocks are well graded, with a high maximum dry density and low optimum moisture content. The soils derived from the schistose and quartzite zone are also suitable for road base and sub-base but the transported loose silty fine sand/sandy silty soils of the Chad Formation are only limited suitability

Research paper thumbnail of Hydro‑geochemical evolution, quality, and health risk assessment of groundwater in crystalline basement aquifer in Keffi, Nigeria

International Journal of Energy and Water Resources, 2023

Hydro-geochemical evaluation of groundwater in the near-surface basement aquifer in the Keffi are... more Hydro-geochemical evaluation of groundwater in the near-surface basement aquifer in the Keffi area was assessed for its quality and associated human health risks. Physico-chemical properties of groundwater samples from 15 motorized boreholes were collected and analyzed. Measured physical parameters reveal the groundwater to be slightly acidic to neutral with pH values in the range of 5.7–7.3, electric conductivity values in the range of 50–360 µS/cm, and total dissolved solids between 32 and 275 mg/L. The result of the chemical analysis reveals the mean concentration values of the major cations and anions in the order of Na+ > Mg2+ > Ca2+ > K+ and HCO3− > Cl− > SO42− > NO32−. The study area is characterized by three main water types (Ca–HCO3, Na–Ca–HCO3, and Ca–Mg–Cl), with Ca–HCO3 water type constituting 66.7% of the total groundwater samples, while the Na–Ca–HCO3 and Ca–Mg–Cl account for 26.7% and 6.6%, respectively. Silicate weathering, dilution, ionic exchange, and mineral dissolution of aquifer minerals are found as the dominant factors responsible for groundwater quality. Major contributions to health indices of groundwater in the study area are in the order Fe>Pb>Cu>Mn>Zn>Ni for adults and Cu>Pb>Zn>Mn>Fe>Ni for children. The computed hazard index value for all sampled locations in the study area is below unity (<1) with relatively higher values for agricultural areas and built-up sections with poor sanitation.

Research paper thumbnail of Regional Groundwater Quality in the Niger Delta

Journal of Mining and Geology, 2023

The Niger Delta is a sedimentary basin with thick accumulated sediments transported from a vast a... more The Niger Delta is a sedimentary basin with thick accumulated sediments transported from a vast and geologically complex catchment covering an area of roughly 38,000km. It is equally hydrologically diverse with fresh, saline and iron water interacting in places. At the same time, it supports a fragile ecology and is host to an expanding population and economy, with a growing demand for potable water. The heavy-dependence on groundwater in the region and the fears of its unsustainability triggered by a combination of overuse, weak regulations, pollution, increasing user
population and industrialization are the considerations that compelled this assessment. As the human population grows, more demand will be placed on groundwater. This necessitates a better understanding of our groundwater systems and managing them in a thoughtful manner to ensure sustainable quality. Using archival records, spatial distribution of physicochemical data on water quality from 960 producing boreholes drilled to different depths spread across the region, groundwater quality was overlain on Google Earth Pro for visual enhancement followed by computation of Water Quality Index (WQI) to evaluate the suitability of groundwater quality in current use in the Niger Delta. Analysis of hydrochemical data suggests that the aggregate quality of groundwater in the Niger Delta is considered generally very good and compares favourably with WHO standards for drinking water. However, relatively high iron/manganese and chloride values are localized in time and space. In the coastal areas however, seawater intrusion was implicated as responsible for high salinity which has been identified as one of the major influences on the hydrochemistry of groundwater in both shallow unconfined aquifers as well as in deeply embedded aquifers. The complex multilayered aquifer system offering filtration and impeding the migration of pollutants is considered the major factor for the reduced vulnerability of deeper aquifers in the area. This study is crucial for the formulation of policies relating to water supply and public health, leading to the development of effective groundwater schemes in the Niger Delta and other neighbouring regions with similar geological formations and anthropogenic activities.

Research paper thumbnail of Foundation Settlement in Reclaimed Mangrove Swamplands: A Case Study of Eastern Bypass, Port Harcourt, Nigeria

Journal of Mining and Geology, 2023

Useable land is scarce in the mangrove swamps of the Niger Delta. This is because it is underlain... more Useable land is scarce in the mangrove swamps of the Niger Delta. This is because it is underlain at the top by very soft to soft fibrotic silty and sandy clay (locally called Chikoko) and subject to diurnal submergence by tidal flow, thus making it difficult to develop without improvement. Reclamation by hydraulic sandfill is the commonest approach to transform such mangrove swamp areas into useable land but the ground response to sandfill placement and requirements for subsequent use are not fully understood. The purpose of this paper is to analyze the ground response to loading through settlement analysis of in-situ CPT and laboratory data using the case study of the Eastern Bye-pass, PortHarcourt which was reclaimed in 3 phases, (1980-92, 1992-2000 and 2000-2020). The first was inspired by the necessity for a link road between Marine Base and Ogbunabali while the two subsequent phases were necessitated by 2 strategic development needs. Reclamation involved the transformation of some 3 km mangrove swamps through the placement of approximately 2.5 m thick hydraulic sandfilling over the fibrotic and bioturbated silty and sandy clay soil rich in partially decomposed vegetal matter. Although 97% Consolidation settlement was to be achieved in 3rd year, the road link was constructed before the end of the 3 years and has since been in satisfactory operational use, mainly due to the combined action of frictional bearing capacity, immediate settlement and drainage qualities of the river sand used as fill and also of the rapid settlement of the mangrove swamp soil occasioned by enhanced drainage
from bioturbation.

Research paper thumbnail of Hydraulic characteristics of a typical basement complex aquifer in Ajaokuta, southwestern Nigeria

Ife Journal of Science, 2006

Research paper thumbnail of Hydrogeophysical investigation and estimation of groundwater potentials of the Lower Palaeozoic to Precambrian crystalline basement rocks in Keffi area, north-central Nigeria, using resistivity methods

Arabian Journal of Geosciences, 2012

The use of resistivity sounding and two-dimensional (2-D) resistivity imaging was investigated wi... more The use of resistivity sounding and two-dimensional (2-D) resistivity imaging was investigated with the aim of delineating and estimating the groundwater potential in Keffi area. Rock types identified are mainly gneisses and granites. Twenty-five resistivity soundings employing the Schlumberger electrode array were conducted across the area. Resistivity sounding data obtained were interpreted using partial curve matching approach and 1-D inversion algorithm, RESIST version 1.0. The 2-D resistivity imaging was also carried out along two traverses using dipole-dipole array, and the data obtained were subjected to finite element method modeling using DIPRO inversion algorithm to produce a two-dimensional subsurface geological model. Interpretation of results showed three to four geoelectrical layers. Layer thickness values were generally less than 2 m for collapsed zone, and ranged from 5 to 30 m for weathered bedrock (saprolite). Two major aquifer units, namely weathered bedrock (saprolite) aquifer and fractured bedrock (saprock) aquifer, have been delineated with the latter usually occurring beneath the former in most areas. Aquifer potentials in the area were estimated using simple schemes that involved the use of three geoelectrical parameters, namely: depth to fresh bedrock, weathered bedrock (saprolite) resistivity and fractured bedrock (saprock) resistivity. The assessment delineated the area into prospective high, medium and low groundwater potential zones.

Research paper thumbnail of Preliminary Structural Study of Landsat Imagery over Wamba and Environs, Nasarawa State, Northcentral Nigeria

Research Journal of Applied Sciences, 2012

Research paper thumbnail of Hydro-geochemical characterization and water quality appraisal of groundwater in areas adjoining primordial landfills in the Maastrichtian Lafia Formation, Middle Benue Trough

International Journal of Energy and Water Resources, 2022

This study assessed the groundwater quality in areas adjoining primordial landfills in Lafia town... more This study assessed the groundwater quality in areas adjoining primordial landfills in Lafia town and its suitability for drinking purposes. Physico-chemical properties of twenty groundwater samples collected from boreholes, unlined and lined hand-dug wells at twenty different locations around three dumpsites were analysed for the appraisal of the water quality. Results of measured physical parameters show pH values in the range of 5.13–7.30, electrical conductivity (EC) values as between 89 and 7754 µS/cm and total dissolved solids (TDS) values that ranges from 59.63 to 5195 mg/L. The major cation and anions have mean concentrations in the order Ca2+ > Na+ > K+ > Mg2+ and SO42− > HCO3− > Cl− > CO3−. The Piper plot reveals three dominant water types (Ca–Cl–SO4, Ca–Na–HCO3−, and Na–Cl–SO4). Heavy metal pollution assessment reveals relatively higher modified heavy metal index (m-HMI) values for wells of close proximity to the landfills. The water quality index (WQI) classification reveals 35% of the groundwater sampled locations have water categorized as unsuitable for drinking purposes, 30% of the groundwater samples categorized as very poor and 25% of the groundwater samples classified as poor. While groundwater categorized as good to excellent constituted only 10% of the total groundwater samples analysed.

Research paper thumbnail of Engineered slope failure susceptibility modelling using high spatial resolution geospatial data

Bulletin of Engineering Geology and the Environment, 2021

Given the increased hazards faced by transport corridors such as climate induced extreme weather,... more Given the increased hazards faced by transport corridors such as climate induced extreme weather, it is essential that local spatial hotspots of potential landslide susceptibility can be recognised. In this research, an evidential reasoning multi-source geospatial integration approach for the broad-scale recognition and prediction of landslide susceptibility in transport corridors was developed. Airborne laser scanning and Ordnance Survey DTM data is used to derive slope stability parameters, while Compact Airborne Spectrographic Imager (CASI) imagery and existing national scale digital map datasets are used to characterise the spatial variability of land cover, land use and soil type. A novel approach to characterisation of soil moisture distribution within transport corridors was developed that incorporates the effects of the catchment contribution to local zones of moisture concentration in earthworks. The derived topographic and land use properties are integrated within the evidential reasoning approach to characterise numeric measures of belief, disbelief and uncertainty regarding slope instability spatially within the transport corridor. The model highlighted the importance of slope, concave curvature and permeable soils with variable intercalations accounting for over 80% of slope instability and an overall predictive capability of 77.75% based on independent validation dataset.

Research paper thumbnail of Basement morphology of the middle Benue Trough, Nigeria, revealed from analysis of high-resolution aeromagnetic data using grid-based operator methods

Journal of African Earth Sciences, 2020

Basement morphology of the middle Benue Trough, Nigeria, revealed from analysis of high-resolutio... more Basement morphology of the middle Benue Trough, Nigeria, revealed from analysis of high-resolution aeromagnetic data using grid-based operator methods,

Research paper thumbnail of Discerning mineral association in the near infrared region for ore sorting

International Journal of Mineral Processing, 2017

The preconcentration or early rejection of gangue minerals in mineral processing operations is in... more The preconcentration or early rejection of gangue minerals in mineral processing operations is investigated using sorting, based on interpretation of near infrared sensor data collected from ore particles. The success of sorting depends on the distribution of minerals between particles, the arrangement or association of minerals within particles and the ability of near infrared to distinguish relevant minerals. This paper considers minerals association, using common alteration minerals found in a hydrothermally-formed copper ore, with sensitivity in the near infrared region. The selected NIR-active minerals were arranged along the view of NIR line scanner to stimulate adjacent natural minerals association. It was found that spectral dominance may depend on minerals near infrared sensitivity and or the position of a mineral along the NIR scanner line of view. Analysis also revealed that only free occurring waste mineral spectra can be targeted for discrimination. Where spectra appeared mixed, such material cannot be preconcentrated using near infrared sensors.

Research paper thumbnail of Hydro-Geophysical Assessment of Groundwater Potential and Aquifer Vulnerability of the Turonian Makurdi Formation in North Bank area, Makurdi, Middle Benue Trough, Nigeria

Journal of Mining and Geology, 2022

Electrical resistivity investigation was carried out in North Bank and its environs in Makurdi, B... more Electrical resistivity investigation was carried out in North Bank and its environs in Makurdi, Benue State, with a view to determining the depth to aquifer, aquifer thickness, groundwater potential of the area and aquifer vulnerability. Twenty-one (21) Vertical electrical sounding (VES) was carried out using the Schlumberger electrode array with the aid of ABEM Terrameter (SAS 3000C) with maximum electrode spacing of 200m. The VES data obtained were interpreted using partial curve matching approach and modelled using WinResist software. Modelled field curves reveal essentially three to four geo-electrical layers and two main aquiferous zones corresponding to the upper silty-sandstone and lower medium to coarse grained felspathic sandstones of the Makurdi Formation. The upper silty-sandstone aquifer is characterized by low to moderate resistivity value distribution (37 - 2039 ohm-m) with layer thickness in the range of 3m to 15m. Computed hydraulic and geo-electric characteristics (Dar Zarrouk parameters, hydraulic conductivity and transmissivity) depicts it as unconfined, vulnerable to infiltrating surface contaminants, with low groundwater potential (0.63 m day < T 199.65 m day ) and only suitable for small community water supply projects and private consumption. The lower felspathic sandstone aquifer is characterized by relatively thicker sequence of aquiferous materials (3m – 54m). The aquiferous zone is generally unconfined to semi-confined in nature, with groundwater potential (30.96 m day < T ≤ 542.73 m day ) seen to be largely moderate. The aquifer is deemed suitable for industrial, irrigational and municipal water supply purposes

Research paper thumbnail of Mineralogical, Geochemical and Geotechnical Characteristics of the Maastrichtian clay Member of the Lafia Formation in Doma and Shabu areas, Middle Benue Trough

Journal of Mining and Geology, 2019

The Maastrichtian clay member of the non-fossiliferous Lafia Formation as exposed in Doma and Sha... more The Maastrichtian clay member of the non-fossiliferous Lafia Formation as exposed in Doma and Shabu was investigated to assess its physical and compositional characteristics with a view to establishing its potential use as
industrial raw material. The mineralogical determination by X-ray diffraction (XRD) of the clays show prominent peaks of kaolinite as the major clay mineral with diffused mixed layer of illite-smectite-chlorite and mica. Chemical analysis by X-ray Fluorescence reveals a dominance of SiO2 (54.14 – 58.02), Al2O3 (20.14 – 23.68), Fe2O3 (13.07 – 9.23), TiO2 (1.65 – 2.67) and H2O+ (4.23 – 11.05), while CaO , MgO, K2O, Na2O, MnO and P2O5 contribute less than 1% of the total elemental composition. The clays exhibit liquid limits in the range of 41-58%, plasticity index (22 - 36%), linear shrinkage (5.2 - 6.4%), Water Absorption Capacity (6.0 - 7.2%) and Loss on ignition (9.2 - 10.18%). The physical, mineralogical and chemical compositions in comparison with international specifications suggest that these clay deposits could be exploited for paints, cement, refractory ceramics and bricks production.

Research paper thumbnail of Groundwater Investigation Across the Crystalline Basement Rocks in Rogo Area, Kano State Northern Nigeria, Using Resistivity Methods

Journal of Mining and Geology, 2021

One-dimensional (1D) resistivity sounding (VES) and two-dimensional (2D) resistivity imaging meth... more One-dimensional (1D) resistivity sounding (VES) and two-dimensional (2D) resistivity imaging methods were employed in groundwater investigation in order to delineate potential aquifers and estimate their transmissivities in Rogo area. Main basement rock units in the area are granites and schistose quartzite rocks of Precambrian to Lower Paleozoic age. Twelve resistivity soundings (VES) were carried out across the area using Schlumberger electrode configuration. The field resistivity sounding data obtained were interpreted with partial curve matching approach and 1D inversion algorithm, IPI2Win. The 2D resistivity imaging survey was conducted along two traverses employing dipole-dipole electrode configuration and the resistivity data acquired were subjected to finite element method modelling using DIPRO inversion algorithm to generate a geologically realistic, 2D subsurface geological model. Three to five geoelectrical layers, as well as weathered bedrock (saprolite) and fractured bedrock (saprock) aquifers were delineated. Seven resistivity sounding curve types (namely H, HA, HK, KH, QH, HKH and KQH) were also identified with the H and HA types being the dominant curve types. Anisotropy coefficient (λ) values ranged from 1.03 to 2.65 with a mean of 1.31. Aquifer transmissivity computed for the weathered bedrock aquifer units varied from 16.01 to 53.3 m /day, with an average value of 30.91 m /day. The study revealed that the Rogo area has moderately high aquifer transmissivity and hence generally exhibits good groundwater potentials.

Research paper thumbnail of Upper Lithospheric Structure of the Middle Benue Trough, Nigeria, Derived from Analysis of Satellite Gravity Data

Journal of Mining and Geology, 2021

The middle Benue Trough is the central segment of the Benue Trough, an elongate northeast orienta... more The middle Benue Trough is the central segment of the Benue Trough, an elongate northeast orientated intra-cratonic rift basin in Nigeria. This study provides new information on the morphology/geometry of the upper lithospheric structures (Moho, crystalline crust thickness and crustal stretching factor) and tectonics in the middle Benue Trough and adjacent basement complex regions by analysis and three-dimensional (3D) inverse modelling of satellite Bouguer gravity anomaly data. Results from 3D inverse modelling reveal Moho depths varying from c. 24 ± 2 to 32 ± 3 km and crystalline crustal thickness values ranging between c. 20 ± 2 and 32 ± 3 km. Shallow Moho and thin crust occur beneath the Trough axial region, whereas deep Moho and thick crust underlay the basement complex regions and the Trough northwestern region. It also shows the presence of a prominent northeast-southwest (NE-SW)
orientated, shallow Moho structures (c. 24 ± 2 to 27 ± 3 km deep) and thin crust (c. 20 ± 2 to 26 ± 3 km thick) within the Trough axial region. Comparisons of Moho depths with topography and Bouguer gravity anomaly values using profiles highlight that the observed broad, longer-wavelength near-positive Bouguer gravity anomalies over the
Trough axial region are strongly associated with elevated (shallow) Moho and isostatic effect of lower topography. Crustal stretching factor (â) values obtained across the area range between c. 1.03 and 1.59 with moderately high values (c. 1.25 – 1.59) occurring in the Trough axial region. The tectonic implication of the results is that the
crust/lithosphere beneath middle Benue Trough has been strongly affected/modified by intense regional, extensional and/or wrench (strike-slip) tectonics associated with past rifting events.

Research paper thumbnail of Compositional Characteristics and Industrial Assessment of the Asu River Group Shale in Mpu Area, Southeastern Nigeria

miCompositional and physical characteristics of the shale from Mpu, southeastern Nigeria, were as... more miCompositional and physical characteristics of the shale from Mpu, southeastern Nigeria, were assessed to evaluate their potential as industrial raw materials. The mineralogical determination by x-ray diffraction (XRD) of the shale, indicate kaolinite as the major clay mineral with diffused peaks of illite and smectite, with quartz as the non-clay mineral. Chemical analysis of the samples reveals the predominance of SiO2 (58.62-59.80) and Al2O3 (21.23-22.10) with a silica/alumina ratio of 2.51.The shale is also characterized by significant Fe2O3 (1.62-3.68), TiO2 (1.48-1.56), K2O (1.64-1.78) values, while CaO, MgO, Na2O, MnO and P2O5 have individual values < 1%. Samples from the study area are essentially made up of clay fractions (<65µm) above 70%, some of the physical parameters of the shale specimens include linear shrinkage (4.80-5.20), plastic limit (22.0-27.0), liquid limit (53.0-58.0), plasticity index (28.0-34.0) and loss on ignition (9.50-9.80) values. Mineralogical and chemical compositions suggest that the shale deposit could be exploited for ceramics, paint, pottery and refractory industries.

Research paper thumbnail of Geotechnical analysis of two Nigerian soils for use as clay liners

Bulletin of Engineering Geology …, Jan 1, 2009

The cretaceous Auchi shale and the Tertiary Imo shale in SW Nigeria were investigated for their s... more The cretaceous Auchi shale and the Tertiary Imo shale in SW Nigeria were investigated for their suitability for use as a clay seal in waste disposal landfills. Geotechnical analyses indicated they are highly plastic inorganic clays. Although their geotechnical and chemical properties were within the range suggested by various authors for use as mineral seals, care would need to be taken with the Okada shales as they contain smectite and would be difficult to work and liable to cracking.

Research paper thumbnail of Hydrochemical Analysis and Evaluation of Water Quality in Angwan Jeba and its Environs, Nasarawa State, Northcentral Nigeria

Research Journal of …, Jan 1, 2011

Abstract: Angwan Jeba and its environs lies within the Basement Complex of northcentral Nigeria a... more Abstract: Angwan Jeba and its environs lies within the Basement Complex of northcentral Nigeria and is underlain by migmatitic gneiss, biotite gneiss, biotite schist, muscovite schist and older granites with minor intrusions of pegmatite and quartz veins. The study involved ...

Research paper thumbnail of Mineralogical, Geochemical, Physical And Industrial Potentials Of Shale From Okada Area, Southwestern, Nigeria

Journal of Mining and Geology, Jan 1, 2008

Mineralogical, geochemical and physical characteristics of the shale from Okada, Southwestern Nig... more Mineralogical, geochemical and physical characteristics of the shale from Okada, Southwestern Nigeria were evaluated to determine its industrial potentials. The x-ray analysis of the Okada shale shows prominent quartz, kaolinite and mixed layer peaks. The result of the ...

Research paper thumbnail of The Kano-Kazaure highway, north central Nigeria: the significance of the engineering geology in construction

Bulletin of Engineering …, Jan 1, 2011

Kano–Kazaure highway traverses granitic rock with minor occurrences of metasediments and fine san... more Kano–Kazaure highway traverses granitic rock with minor occurrences of metasediments and fine sandy deposits. The soil profiles were studied to determine their suitability in the proposed dualization of the highway route as part of the Trans-Sahara international highway construction project. The soils derived from the granitic rocks are well graded, with a high maximum dry density and low optimum moisture content. The soils derived from the schistose and quartzite zone are also suitable for road base and sub-base but the transported loose silty fine sand/sandy silty soils of the Chad Formation are only limited suitability