Browsing by Author "Akinade S. Olatunji"

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    Assessment of gold mineralisation in Osu–Amuta–Itagunmodi areas, Southwestern Nigeria
    (Arabian Journal of Geosciences, 2020-06-22) Jerry O. Olajide-Kayode; Shakirat O. Mustapha; Akinade S. Olatunji; Olugbenga A. Okunlola
    Gold is artisanally mined from eluvial deposits within Osu–Amuta–Itagunmodi areas of Ilesa Schist Belt, southwestern Nigeria. Mine site selection and mining operations are done without any understanding of mode of occurrence, compositional characteristics and extent of gold mineralisation. The present study was aimed at determining the host lithologies, extent and associated geochemical features of the gold mineralisation. Fifty rock samples were cut into thin section for examination and analysed using inductively coupled plasma–mass spectrometry (ICP-MS). Forty-eight soil samples collected from Artisanal Gold Mine (AGM) pits to a depth of 5 m (n = 9), and along defined horizontal profile lines from the mine pits (n = 39) were analysed for elemental constituents, and mineralogical compositions in vertical profile samples using ICPMS and X-ray diffraction (XRD) techniques, respectively. The quartz-biotite schist, quartzite, talc-chlorite schist and amphibolite had Au concentration (ppb) that ranged from 1.3 to 14.4 (average 3.95), BDL–0.9 (average 0.63), 0.9–4.6 (average 2.18) and 0.5–2.7 (average 1.56), respectively. Vertical and lateral profile soil samples were Osu: 4.5–7.6 (average 6.17) and 0.9–78.8 (average 8.54); Amuta: 4.1–6.8 (average 5.2) and 2.8– 19.8 (average 7.40); and Itagunmodi 3.9–13.2 (average 7.43) and 0.5–14.8 (average 4.33). Evaluation of the horizontal profile soils revealed higher Au concentrations than the artisanal mine workings, indicating additional mineralisation potentials in the study area. Au concentrations were in the order of quartz-biotite schist > talc-chlorite schist > amphibolite >> quartzite, with anomalous concentrations detected in quartz-biotite and talc-chlorite schists. Elevated concentrations also occurred in residual soils overlying quartzite and amphibolite lithologies. Mineralisation is hydrothermal in nature, extends beyond current artisanal mine workings and has potential for further exploration. Keywords artisanal mining . Ilesa Schist Belt . hydrothermal alteration . gold mineralization potential
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    Assessment of the quality of soils around artisanal gold mine pits in Osu and Itagunmodi areas, Southwestern Nigeria.
    (International Medical Geology Association, 2018-12-12) Shakirat O.Mustapha; Jerry O. Olajide-Kayode; Akinade S. Olatunji
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    Corrigendum to “Potentially Harmful Element toxicity in Geophagic clays consumed in parts of southeastern Nigeria”. [Journal of Trace Elements and Minerals 4C (2023) 100050]
    (Elsevier, 2024-03-12) Jerry O. Olajide-Kayode; Tesleem O. Kolawole; Opeoluwa O. Oyaniran; Shakirat O. Mustapha; Akinade S. Olatunji
    An assessment of geophagic clays consumed by adults and children in Calabar and Okon-Eket areas of southeast- ern Nigeria was done in order to evaluate possible toxicity of Potentially Harmful Elements (PHEs)- Cd, As, Pb, Cu and Zn (CALCZ). Thirteen clay samples obtained from open markets and clay mines were air-dried, pulver- ized and analysed for their elemental constituents using Inductively Coupled Plasma Mass Spectrometry (ICPMS). Ecological and health risk assessments of the clays were conducted using Index of Geoaccumulation (I geo ), Con- tamination Factor (CF) and Degree (C Deg ), Pollution Index (PI), Ecological Risk Factor (Er) and Index (RI), Hazard Index (HI) and Cancer Risk Index (CRI). The clays had PHE concentrations (ppm) in the order: Zn (13.0–148.0) > Pb (16.7–55.6) > Cu (5.7–23.0) > As (BDL-15.0) > Cd (BDL-0.2). I geo values for Cd, As, Cu and Zn in the clays were < 0, while Pb had a value of (-1) to 1. The clays from Calabar and Okon-Eket had Pb CF values of 1.8 and 1.7, and PI values of 1.4 and 1.3, respectively. Results of I geo , CF and PI calculations revealed moderate Pb contami- nation in the clays. Low HQ and HI of the PHEs indicates that they pose no immediate risk of non-carcinogenic nor carcinogenic effects to the geophagic individuals. However, the moderate Pb contamination in the clays is a source of health concern, especially for geophagic children.
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    Mineralogy and Geochemistry of some Phosphate Deposits for Possible Rare Earth Elements Mineralization Potentials within Sokoto Basin, Northwestern Nigeria
    (Indian Journal of Science and Technology, 2022-12-14) Shakirat O. Mustapha; Akinade S. Olatunji; Felicia F. Ajayi; Roland A. Isibor
    Objective: Phosphate rocks found in some parts of Sokoto Sedimentary basins in Nigeria were studied to understand their mineralogy and geochemistry specifically to determine their abundance in Rare Earth Elements hosting minerals notably Apatite, Monazite and Xenotime as there is an increasing demand for these elements globally in the production of green technology. Methods: Field observations were carried out in places with reported phosphate occurrences and seven (7) representative phosphate samples were collected, crushed, pulverized, and analyzed using X-Ray Diffraction (XRD) analysis for their mineralogical composition while samples with significant fluorapatite concentrations were further analyzed with Lithium Borate fusion Inductively Coupled Plasma Mass Spectrometry (ICPMS) for their elemental composition. Findings: The phosphates typically occur as nodules intercalated with Shale occurring at depth of about 0.25 – 7m with a mineralogical composition including Fluoroapatite, Calcite, Smectite, Quartz, Kaolinite, Goethite, and Palygorskite. A high concentration of Fluorapatite was observed at Miyal’yako (79.28%) and Dillingo (36.60%) while interpretation of the relationship between P2O5 with other major oxides and trace elements revealed that the phosphates were primary type and typically formed in an oxidizing environment with fluctuating pH in the presence of calcite or gypsum. Novelty: The study pinpoints that, of the seven locations, only two showed high concentrations of fluoroapatites enough to suggest that they are areas of interest for further investigation in the search for REEs mineralization in Nigeria. Keywords: Rare Earth Elements; Phosphate; Mineralisation; Fluorapatite; Sokoto
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    Potentially Harmful Element toxicity in Geophagic clays consumed in parts of southeastern Nigeria
    (Elsevier, 2023-01-24) Jerry O. Olajide-Kayode; Tesleem O. Kolawole; Opeoluwa O. Oyaniran; Shakirat O. Mustapha; Akinade S. Olatunji
    An assessment of geophagic clays consumed by adults and children in Calabar and Okon-Eket areas of southeast- ern Nigeria was done in order to evaluate possible toxicity of Potentially Harmful Elements (PHEs)- Cd, As, Pb, Cu and Zn (CALCZ). Thirteen clay samples obtained from open markets and clay mines were air-dried, pulver- ized and analysed for their elemental constituents using Inductively Coupled Plasma Mass Spectrometry (ICPMS). Ecological and health risk assessments of the clays were conducted using Index of Geoaccumulation (I geo ), Con- tamination Factor (CF) and Degree (C Deg ), Pollution Index (PI), Ecological Risk Factor (Er) and Index (RI), Hazard Index (HI) and Cancer Risk Index (CRI). The clays had PHE concentrations (ppm) in the order: Zn (13.0–148.0) > Pb (16.7–55.6) > Cu (5.7–23.0) > As (BDL-15.0) > Cd (BDL-0.2). I geo values for Cd, As, Cu and Zn in the clays were < 0, while Pb had a value of (-1) to 1. The clays from Calabar and Okon-Eket had Pb CF values of 1.8 and 1.7, and PI values of 1.4 and 1.3, respectively. Results of I geo , CF and PI calculations revealed moderate Pb contami- nation in the clays. Low HQ and HI of the PHEs indicates that they pose no immediate risk of non-carcinogenic nor carcinogenic effects to the geophagic individuals. However, the moderate Pb contamination in the clays is a source of health concern, especially for geophagic children.