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- ItemExploration for iron ore in Agbado-Okudu, Kogi State, Nigeria(Arabian Journal of Geosciences, 2017-12-31) Nurudeen Kolawole Olasunkanmi, Olufemi S. Bamigboye & Adebayo AinaThis report details the result of geophysical exploration for iron ore; which involved vertical magnetic intensity (ΔZ) and gravity measurements, to delineate the geometry and depth extent of the deposit and acquiring quantitative and qualitative information for pre-drilling purposes in Agbado-Okudu. It is located about 3 km from Jakura along Lokoja-Jakura marble quarry and within low latitude precambrian basement complex district of Kogi State, Nigeria. A total of 517 magnetic measurement points along 16 traverses and 330 gravity reading along 11 profiles on the deposit in northeast–southwest azimuth were undertaken. The magnetic and gravity data enhancement involved linear regression curve fitting and fast Fourier transform, which were used to construct residual magnetic (RM) and gravity (RG) anomalies, analytic signal amplitude, Euler deconvolution at varying spectralindices (SI), power spectrum, and source parameter image (SPI), using the submenu of Geosoft Oasis Montaj software. Interpretation of the RM and RG anomalies revealed a primary causative body which perfectly correlates the positive anomalies and iron ore deposit, in form of a horizontal or gently dipping dyke with strike length of 600 m and average width of 110–130 m, within the gneiss complex in the north and trending south ofthe area. A secondary causative body associated withthe negative anomalies and inferred as a vertical/near vertical thin sheet striking northeast–southwest coincided with the granitic and quartzitic intrusion. The NW–SE and E–W lineament trend conformed Kibarian and Liberian orogeny cycles of generallyknown structural trends in Nigeria, which shows that the iron ore deposit is structurally controlled. Depths to sources were estimated within range ≤ 2–24 m and 37.5–60 m, regarded as shallow and relatively deep depths, respectively. Ten vertical boreholes ranging in depth between 50 and 100 m are recommended, five of which require a priority attention to ascertain the thickness of the primary causative body.
- ItemInterpretation of high resolution aeromagnetic data of Kaoje and its environ, western part of the Zuru Schist belt, Nigeria: implication for Fe–Mn occurrence(Heliyon, 2020-06-30) Nurudeen Olasunkanmi* , Olufemi Bamigboye, Olatunji Saminu, Naheem Salawu , Toba BamideleThis study presents an appraisal of mineralization potential and the geologic record of Kaoje and environs using high-resolution aeromagnetic data. The data were analyzed using the fast Fourier transform technique for reduction-to-equator (RTE), analytic signal (AS), total horizontal derivative (THDR), tilt derivative (TDR), spectral analysis and Euler deconvolution at varying spectral indices. The reduced to equator residual magnetic intensity range from -73.4 to 205.6 nT and are associated with contrasting lithology of the Sedimentary and Basement Complex rocks. The anomalies and analytic signal amplitude unfold and update the extension of Zuru Schist to the southern region of Kaoje, elongated banded gneiss within the schist body, pegmatite intrusion through the migmatite and NNW-SSE trending schist hosted manganite and sandstone-hosted goethite. Estimated depth to shallow and deeper magnetic sources ranged from 0 to 59 m and 225–415 m respectively, and the corresponding Euler solutions revealed perfect clustering along notable geologic features and minerals. The iron mineralization are revealed as sourced from the magmatic bodies that lie beneath the sedimentary rocks and a corresponding sphere geologic model within northwest and southwest of Kaoje at a depth range of 0–225 m. The structural trends suggested the tectonic events in the area and indicate an imprint of Zungeru-Anka transcurrent fault that serves as a conduit for iron mineralizing fluid to Kaoje.
- ItemShear Sense Analyses of Basement Complex Rocks in Parts of SW Nigeria(International Journal of Earth Sciences Knowledge and Applications, 2022-08-31) Olufemi S. Bamigboye, Toba E. Bamidele , Adeonipekun D. Adedoyin , Taofeeq A. Issa , Omolayo A. OmorinoyeThe study area, Oko/Olla is part of Osi sheet 224 southwest and falls within the Basement Complex of South-Western Nigeria. Field and petrological studies revealed that the area is underlain by metamorphic complexes and late intrusives which include: migmatite, granite gneiss, porphyroblastic gneiss, banded gneiss, fine grain granite, diorite with aplite and pegmatite occurring as intrusions. Migmatite is the dominant rock within the study area. The petrogenetic affiliation of the rocks as indicated by the rocks and mineral assemblage represented by plagioclase +alkali feldspar +biotite ±muscovite ±hornblende in the quartzo-feldpartic rocks of the area, are suggestive of amphibolites facies of metamorphism. Kinematic markers which include folds, boudins, σ– and δ–type porphyroclasts, and strike-slip and dip-slip faults were used as shear sense indicators. Detailed analysis of folds revealed asymmetric fold shapes with preponderance of Z– shape folds. The dominant Z–shape drag folds are consistent with the ductile and brittle dextral shear sense indicated by asymmetric boudins and porphyroclasts geometry. Structural analysis from this study indicates that the ductile fabric was overprinted by brittle deformations resulting from the uplift of the area to a low temperature-pressure conditions which is more favorable for brittle deformations. This over printing relationship is suggestive of continued movement of Olla and Oko areas after uplift of the areas during Pan African thermo-tectogenesis. It is therefore concluded on the basis of petrological evidences as well as clear overprinting relationships as revealed by decisive kinematic markers that although there are some sinistral and conflicting shear sense indicators in the area, dominant network of dextral ductile and brittle shear sense in the study area is consistent with the N-S regional structure in the Basement Complex of Nigeria
- ItemGranulometric and Geochemical Analyses of Stream Sediments from Part of Southwestern Nigeria: Implication for Mineralization Potential(International Journal of Earth Sciences Knowledge and Applications, 2025-08-31) O. S. Bamigboye, O. A. Omorinoye , T. E. Bamidele , H. A. UmarThis work investigates the mineralization potential of an area bounded by longitude 4˚ 52′ to 5˚ 00′ E and latitude 8˚ 22′ to 8˚ 28′N represented on Ilorin Sheet 223. The methods adopted in this work include field mapping, granulometric, heavy mineral, stream sediment and statistical analyses. The result of the granulometric analysis reveals that the sediments range from very coarse sand to coarse sand, are poorly sorted and exhibit very platykurtic distribution. The result of Factor Analysis identified eight distinct Factor groups. Factor 1 of the group was interpreted to be related to hydrothermal sulphide ore mineralization that is complex and formed at low temperature, while Factor 2 is interpreted to imply goldassociated gangue minerals. Factor 3 was interpreted to indicate the presence of a vein deposit that is mafic in composition, while Factors 7 and 8 were interpreted to indicate the presence of low temperature hydrothermal sulphide mineralization. Heavy minerals identified in the samples include zircon, sillimanite, goethite, hematite and olivine among others. The conclusion drawn from this work is that the southeastern and northwestern parts of the study area have enhanced ore-forming elements; hence, the area is mineralized with pockets of such sulphide. The northeastern part is barren. It was also concluded that exploratory work should focus on the southeastern and northwestern parts of the area. In addition, mineralization in the area consist mainly of low-temperature hydrothermal sulphide ore deposits, including gold.
- ItemGeochemical and Mineralogical Investigation of Iron Mineralization in Ardogu and its Environment, Central Nigeria: Implications for Origin and Resource Potential(Journal of the Geological Society of Sri Lanka, 2023-06-30) O.S. Bamigboye , S.A. Adepoju , O.A. Omorinoye , T.E. Bamidele , and I. AdefilaGeochemical and mineralogical studies of iron ores in Ardogu and its environments, in central Nigeria were done to characterize it for iron mineralization and resource potential. Thirty core ironstone samples were selected from ten drilled boreholes for geochemical and mineralogical analyses. Geochemical results of selected samples reveal higher concentrations of Fe2O3 with low contents of SiO2, Al2O3, P2O5, CaO and MnO. The geochemical based ternary plot classified the iron ores as ironstone. A petrographical investigation of 10 selected samples reveals the composition of oolites and pisolites with the presence of few quartz grains within the iron rich mineral grains. Qualitative and quantitative mineralogical study using x-ray diffraction shows mineral assemblages including; iron oxides, silicates and carbonates. Mineralogical compositions and textural characteristics of the ironstones suggest genesis related to syngenetic and diagenetic processes. The paleoenvironment during deposition of the Fe-rich sediments is suggested to be an anoxic, organic rich and reducing condition during early diagenesis but with the development of the oolitic and pisolitic textures, there were prevalent oxidizing and dehydrating conditions. The similarity between the chemical data of the studied ironstones with some published data within Bida Basin shows economically viable market values.