Global Journal of Geological Sciences

An Evaluation Of The Suitability Of Some Basement Rocks From Oban Massif, Southeastern Nigeria, For Engineering Construction Purposes

2024-07-23T12:31:25+00:00

The physical and engineering properties of some basement rocks from parts of Oban Massif, Southeastern Nigeria were investigated to ascertain their suitability for civil engineering construction purposes. A total of 19 representative rock samples comprising of granites and granodiorites, were obtained from three quarries in Akamkpa Local Government Area of Cross River State, southeastern part of Nigeria. The rock samples were crushed into aggregates and their physical and mechanical properties were assessed. The results obtained showed that the specific gravity ranged from 2.60-2.72, water absorption 0.30-0.96%, aggregate impact value 12-30%, aggregate crushing value, 12-33%, flakiness and elongation Indices both ranged from 14-29%, the uniaxial compressive strength fell between 190 and 209NM/m,²and the Los Angeles abrasion gave 14-41%. Petrographic studies suggested the rocks are granites and granodiorites. Results obtained from the research were compared with known engineering specifications. Such comparisons showed empirical relationships between the physical and the mechanical characteristics of the materials tested. These empirical relationships can, thus, be employed to save cost in future site investigations. Petrographic studies and engineering properties indicate that aggregates derived from the fresh basement rocks in the study areas are capable of withstanding heavy traffic, foundation loads and are generally suitable for most civil engineering construction purposes. It is also expected that the interpretation and ranking of the test results will provide a suitable guide to prospective clients of quarry operators as they can now have some scientific basis for selecting materials needed for different construction works. To achieve this, quarry operators must test and advertise/publicize the properties of their products for public consumption.

bioavailability and environmental implications of major and trace metals in manihot esculenta (cassava) grown on shaly and calcareous soils in parts of southern benue trough, nigeria.

2024-07-23T12:45:54+00:00

The study was carried out to investigate the concentration of major and trace metals in shaly and calcareous soil and their uptake in cassava plant parts in order to compare the levels of this metals in both soils as well as the cassava plant growing on the soil. Soil samples (0-30 cm and 30-60 cm) depth and cassava plants (leaves, stems and tubers) were collected from cultivated farm lands and analyzed for major and trace metals. (Ca, K, Al, Na, Fe, Cu, Zn, Pb, Co and Mo) using inductively coupled plasma mass spectrometery (ICP-MS). The pH and L01 of the soil sample were also measured. Results show that calcareous soils were moderately acidic to basic while shaly soils were acidic to neutral. The organic matter content were relatively higher in surface soils than subsurface soils. Levels of metals were generally higher in shaly soils compared to calcareous soils except for Ca, Na, and Mo. Values of enrichment factors revealed deficiency to minimal enrichment (Ef<2) of Al, K, Ca, Fe and Na, moderate enrichment (Ef2-5) of Cu, Zn, and Co and significant enrichment (Ef5-20) of Mo and Pb for shaly soils. In the case of calcareous soils, minimal enrichment was noticed for Al, Fe, K, Cu and Ca while Na, Zn, Pb and Co showed moderate enrichment with only Mo indicated very high enrichment. The principal analysis for cancerous and shaly soils in the study area indicate that the main source of metals are environment, geochemical and anthropogenic activities.

A Proposed Dam Site Investigation Using Integrated Geophysical And Geotechnical Methods; A Case Study Of Loko Area, Northeastern Nigeria

2024-07-23T12:38:58+00:00

The need for dam construction in the Loko area of northeastern Nigeria becomes necessary due to consistent flooding in the area and the demand for water for agricultural and domestic purposes. It is therefore very important to carryout adequate pre-construction investigations aimed at investigating the suitability of the area for dam siting. Geophysical and geotechnical investigation was carried out along River Loko. Detailed geologic mapping carried out showed that the area is 75% covered with alluvium while basalts and fine – medium grained granites underly the smaller portion of the area. A total of 10 Vertical Electrical Soundings were carried out using Schlumberger array. Disturbed soil samples were collected at a depth interval of 0.3m, from the surface to 1.2m, from three trial pits. Results of the geophysical survey show a 3 – 4-layer model consisting of H, HA, AH-type curves, interpreted with Interpex IX1D software. Results of the particle size distribution show that most of the samples are very uniform having a coefficient of uniformity of less than 5 according to (AASHTO) classification all the soil samples collected at the three trial pits are specifically A-3 soil group, which indicates that the material are fine sands. The Atterberg limit results indicate that most of the soil samples fall within the medium plasticity index. Soils with high plasticity (22.35) and medium plasticity (9) are usually semi-impervious to impervious, hence, suitable for dam foundation. The result of the unsoaked CBR compared with the standard, according to AASHTO, indicates that all samples fall under 7-20 which shows a general rating as ‘fairly soil’ and can be used as ‘sub-base’. Compaction results show that for Pit 1, the sample at 0.3m, with MDD 1700kg/m³ at OMC 20.0%, is the best sample. For Pit 2, the sample at 0.9m, with MDD 2400kg/m³ at OMC 10.0%, is the best, and for Pit 3, the sample at 0.3m, with MDD 1800kg/m³ at OMC 11.0%, is the best. The interpretations of the undrained shear strength result indicate that all the samples have ‘soft consistency’ since their values range from 23.0 to 25.7 KN/m². Based on the availability of construction material, perennial discharge from the river in addition to suitable geology and engineering properties, the area is feasible for an earth dam construction. Deep foundation is recommended for a massive rock filled dam, and some remediation is required in the design process to reduce the threat posed by thin fractures which may possibly cause subsurface seepage.

Application Of Enhanced Seismic Semblance Attribute To The Characterisation Of Elements Of Deepwater Upper Slope Channels, Offshore Western Niger Delta

2024-07-23T13:01:36+00:00

Deepwater depositional elements are the building blocks of submarine systems and represent the basic mappable elements in seismic volumes. This study utilizes good quality 3-D seismic data of 300 km² areal coverage in water depth of 500 m to characterise the planform morphology and distribution of channel elements in the upper slope of deepwater western, Niger Delta. The seismic interval of interest (between 500 and 1650 milliseconds two-way time (TWT), informally termed ‘Channel System’, was subdivided into six (6) seismic units - Intra Channels (IC) 1, 2, 3, 4, top channel system (TCS), and undeformed hemipelagites (UH). Seismic interpretation was carried out for each of the seven horizons to derive their respective subsurface TWT maps. The median surface between two successive maps were derived to capture their internal architecture within the seismic units based on reconditioning the seismic volume semblance attribute. The resulting semblance attribute maps, from the Intra Channel 1 (IC1) unit through the overlying units to the Undeformed Hemipelagites (UH) unit presented an enhanced planform morphology of various NE-SW trend channels. The IC1 is imprinted with three channels of varying sinuosity, IC2 is characterised by one non-sinuous channel and one sinuous channel, IC3 indicates three non-sinuous channel, and one sinuous channel, IC4 and the TCS’ are both characterised by several sub-parallel channels and one sinuous channel, while the topmost UH unit displayed several straight slope gullies upslope with imprint of one precursor sinuous channel. The identified channel forms vary in morphology, sinuosity and distribution both spatially and across the stratigraphic succession in the upper slope. The progressive temporal disappearance of the channels is linked to the associated background hemipelagites that acted as blankets over the precursor channels.

Stratigraphic Insights And Depositional Systems Of Osm Well, Megbe Field, Niger Delta Basin

2024-07-23T13:10:30+00:00

Foraminiferal biostratigraphy and paleoenvironmental analysis of the sediments penetrated by OSM well in the Coastal Swamp Delta Depobelt, Niger Delta Basin was carried out in order to determine foraminiferal biozonation, relative age, paleobathymetry and depositional environment of the area of interest. A total of twenty-eight (28) foraminifera species were recovered; three (03) foraminifera species were planktonic, while eight (8) and seventeen (17) foraminifera species were calcareous and agglutinated benthic foraminifera respectively. Four planktonic foraminifera biozones of Blow (1979) were identified: namely (N17-N16, N16-N15, N15-N14 and N13-N12). The result of the analysis indicates that the entire analyzed interval (6140ft – 12800ft) was deposited during the Middle Miocene to Late Miocene within a coastal deltaic to an inner neritic depositional setting.

Paleocene Ostracods Of The Eastern Dahomey Basin Of Nigeria: Implications For Paleoenvironmental, Paleobiogeographic And Hydrocarbon Exploration Efforts

2024-08-30T12:31:28+00:00

This study investigates the paleoenvironmental conditions, paleo-biogeographic affinities, and paleoecological significance of Paleocene ostracods from the Ewekoro Formation in the eastern Dahomey Basin, Nigeria. Less attention has been given to ostracods study in Nigeria. The research aimed at understanding the paleoecological and paleobiogeographic distributions of the ostracods from borehole data in the eastern Dahomey Basin of Nigeria and their relationship to other African basins. The carbonates samples were analysed using sedimentological and micropaleontological methods. Eleven carbonates samples that were carefully collected from borehole BH-22 and processed based on Nagy et al. (1988) procedure were used for this study, yielding 18 well-preserved ostracod species. These species include Soundanella laciniosa triangulata, Bardia ilaroensis, Nigeroloxoconcha acgyptiaca, Paracosta kefensis, Xestoleberis tunisiensis, and others. The identified assemblages reflect a heterogenous neritic zone, ranging from high-energy nearshore to low-energy outer neritic settings. Species such as Bardia ilaroensis and Nigeroloxoconcha aegyptiaca, indicate shallow marine or estuarine environments, while Cytherella species suggest deeper, low-energy conditions. The paleobiogeographic distribution supports a Trans-Saharan Seaway connection during the Paleocene–Eocene, linking the Southern Tethys and West African provinces. Ostracod species between the eastern Dahomey Basin and regions in North Africa, the Middle East, and other parts of West Africa indicate significant faunal interchange. For hydrocarbon exploration in the basin, the limestone units and interbedded light grey sandstone of the Ewekoro Formation suggest potential reservoirs, while black shales indicate potential source rock. The identified ostracods provide biostratigraphic markers enhancing the predictability of reservoir and source rock distribution in the basin.

Geochemistry Of Awi Sandstone, Calabar Flank, Southeastern (Se) Nigeria: Constraints On The Metal Enrichment, Provenance, And Tectonic Setting

2024-09-02T13:07:02+00:00

As the global population continues to rise, the search for crucial metals has become a primary concern for mineral explorers due to their non-renewable nature. To keep pace with increasing need for solid mineral exploration and exploitation, it is then important to find new deposits and engage in sustainable extraction practices. The aim of the study is to analyze the geochemical composition of Awi sandstone, focusing on metal enrichment, origin, and the tectonic setting of the protolith. For this purpose, fifteen (15) fresh samples from the Awi sandstones were collected for geochemical analysis using inductively coupled plasma mass spectrometry (ICP-MS). Results indicate that Ba, Rb, Sr, Cr, Zn, Ni, Y, and Cu are present in higher concentrations while As, Be, Bi, Cd, Hf, Hg, Mo, Sc, U, and Pb are depleted. The findings also suggest an increase in abundance of LREE and a decrease in availability of HREE. The TiO₂versus Zr discrimination diagram with the primary element suggests that the parent rock of Awi sandstone was mainly of intermediate-felsic igneous origin. The classification plot of Na₂O+K₂O to SiO₂, and the R1-R2 plot, indicate that the majority of Awi sandstones originated from granodiorite protolith. The plots comparing Th/Yb to Ta/Yb, Th/Ta to Yb, and (K₂O/Na₂O) to SiO₂ suggest that these Awi sandstones were formed in a passive to active continental margin environment. So which of the elements listed may probably denote crucial ore deposit.

Physicochemical, Bacteriological And Hydrogeochemical Assessment Of Ground Water Within Uyo And Itu Areas Of Akwa Ibom State, Southeastern Nigeria

2024-09-02T13:20:03+00:00

Ten (10) groundwater samples collected from boreholes in Itu and Uyo localities of Akwa Ibom State were evaluated for physicochemical, bacteriological and hydrogeochemical assessment using standard analytical techniques. Results showed average pH of 4.49, temperature of 29.14 ^oC, EC of 45.30 μs/cm; TDS of 21.60 mg/l, Hardness of 4.30 mg/l, K of 2.49 mg/l. Mg was found to be 0.74 mg/l, Ca is 13.14 mg/l, SO4 has values of 3.9 mg/l, HCO3 concentration was also found to be 1.35 mg/l, Cl observed to be 4.07 mg/l. furthermore, NO₃ concentration was also observed to be 17.71 mg/l, Mn²⁺ had 0.049 mg/l concentration, BOD5 is 5.82 mg/l, P2O5 was found to be 12.00 mg/l, Cr is 0.025 mg/l, NH3 is 0.142 mg/l, Zn is 0.138 mg/l, Cy is 0.006 mg/l, Fe is 0.159 mg/l, Pb is 0.002 mg/l, Ni is 0.19 mg/l, Cu²⁺ is 0.034 mg/l, Turbidity is 0.40 mg/l, Salinity is 0.002 ppt, and Alkalinity is 2.40 mg/l.. Comparing these values with WHO (2011a) standards, it was discovered that some parameters, including Ni, Cr, Fe, Mn and NO₃-, had concentrations that were above the permissible limits in some locations while a few other locations showed concentrations which were within the permissible limits. Bacteriological investigations of faecal coliform count (FCC), total coliform count (TCC) and total heterotrophic count (THC) revealed an excessive presence of coliform. Hydrogeochemical assessment revealed no evidence of saline intrusion and the groundwater is of terrestrial origin. Based on different ionic concentrations, the Piper trilinear diagram revealed two fundamental types of water; the calcium sulphate and calcium bicarbonate waters. The groundwater was classified as acceptable for agricultural purposes based on the magnesium ratio and sodium adsorption ratio, which also indicate that the groundwater is excellent, soft and suitable.

Major And Trace Element Geochemistry Of Pegmatites In Umai, Oban Massif, Se, Nigeria: Constraints On Their Characterization And Mineralization Potential

2024-09-26T06:43:10+00:00

Pegmatites are highly sort for due to their ability to host diverse minerals such as lithium, tantalum, niobium, and gemstones. This study focuses on the geochemistry of the pegmatites in Umai, Oban Massif, SE, Nigeria. The aim is to characterize the pegmatites and infer their mineralization potential. Fifteen (15) fresh samplesere analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Fractional indices such as Ba/Rb, K/Rb, Na/K, K/Cs, Nb/Ta, Ta/Cs, and discrimination plots such as Na₂O+ K₂O vs SiO_2,Rb vs Sr, K/Rb vs Rb, K/Rb vs Cs, Be vs K/Nb, Ta vs K/Cs were utilized in this study. From the geochemical classification diagram of Na₂O+ K₂O vs SiO_2,the pegmatites in Umai are mainly granodioritic in composition. The K/Rb ratio for the samples analyzed are below 100 indicating mineralization. The Nb/Ta ratio for the samples is <1 indicating tantalite mineralization. Also, from the Ta Vs K/Cs plot some data plot on the tantalum mineralization field indicating tantalum mineralization. For some of the samples with Nb/Ta >1, they indicate columbite mineralization. Beryllium concentration >20ppm was observed in some samples analyzed suggesting possible beryllium mineralization.