Browsing by Author "Bamidele, T.E."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Geochemical 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) Bamigboye, O.S.; Adepoju, S.A.; Omorinoye, O.A.; Bamidele, T.E.; Adefila, IGeochemical 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.Item Shear Sense Analyses of Basement Complex Rocks in Parts of SW Nigeria(International Journal of Earth Sciences Knowledge and Applications, 2022) Bamigboye, O.S.; Bamidele, T.E.; Adedoyin, A.D.; Issa, T.A.; Omorinoye, O.A.The 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.