Mineralogical and Geochemical Variations in the Regolith of Mokuro-Itagunmodi Area, Ife-Ilesa Schist Belt, Southwestern Nigeria

The geochemistry of regolith overlying basement rocks in Mokuro-Itagunmodi area along selected road-cut sections and petrography of the rocks were investigated with a view to determining the mineralogy, major and trace element concentrations and their distribution patterns in relation to the bedrock...

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Autor principal: Ajidahun, Emmanuel Jeminiyi
Formato: Thesis
Idioma:inglês
Publicado em: 2015
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Acesso em linha:http://localhost:8080/xmlui/handle/123456789/3456
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author Ajidahun, Emmanuel Jeminiyi
author_facet Ajidahun, Emmanuel Jeminiyi
author_sort Ajidahun, Emmanuel Jeminiyi
collection DSpace
description The geochemistry of regolith overlying basement rocks in Mokuro-Itagunmodi area along selected road-cut sections and petrography of the rocks were investigated with a view to determining the mineralogy, major and trace element concentrations and their distribution patterns in relation to the bedrock. Regoliths at four selected locations along Ife- Mokuro – Itagunmodi road were sampled across the regoliths according to the thicknesses of each regoliths. Selected major (Si, Al, Ti, Fe, Mn, Mg, Na and K) and trace (Cr, V, Co, Ni, Cu, Zn, As Pb and Mo) elements were determined in 34 representative regolith samples using the Energy Dispersive X – Ray Fluorescence (ED-XRF) analytical technique. The mineralogical constituents of eight of these samples were also determined using the X-Ray Diffraction (XRD) technique. In addition, petrographic studies of bedrock sample were carried out using the petrographic microscope. The results showed that tremolite-anthophyllite schist and amphibolite constituted mainly the slightly migmatized to non-migmatized metasedimentary and metaigneous rocks of the area. The results further showed that Al2O3 ranged between 23 wt % and 25 wt % whilst Fe2O3 ranged between 22 wt % and 30 wt % in the mottled zone indicating a bauxitic laterite. Significant depletion in SiO2, CaO, Na2O, K20 and MgO was observed whilst Al2O3, Fe2O3, TiO2, MnO, Cr, Co, V and Cu were relatively enriched. The element associations of Cr- Ni- Cu- V- Zn suggested strong maficultramafic influence whilst the strong and significant relationships of Fe and Mn with As, Co, Cu, Ni and Zn ( 'r' = 0.68, 0.91, 0.86, 0.87, 0.86 and 0.50; p < 0.01) resulting from adsorption and co-precipitation in the surficial environments indicated a redistribution of potential pathfinder elements into oxides of Fe and Mn. The XRD analysis results indicated the presence of kaolinite, quartz, chlorite, goethite, rutile, chromite, illite, smectite. and montmorillonite as the major mineral constituents of the regolith. Kaolinite, quartz, chlorite and goethite had mean relative proportions of 35.68 %, 29.95 %, 16.32 % and 12.02 % respectively. In conclusion, the element associations and distribution patterns reflected strong mafic ultramafic influence, however, the effect of heterogenous bedrock could not be ruled out. Furthermore, the clay mineral distribution showed an early stage of weathering in a well drained environment. The relatively high Ni and As enrichment indicated disseminated nickeliferous sulphide and gold mineralization for exploration application.
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spelling oai:ir.oauife.edu.ng:123456789-34562023-05-13T11:10:31Z Mineralogical and Geochemical Variations in the Regolith of Mokuro-Itagunmodi Area, Ife-Ilesa Schist Belt, Southwestern Nigeria Ajidahun, Emmanuel Jeminiyi Geochemistry Regolith Petrography Bedrock Mafic ultramafic Heterogenous bedrock The geochemistry of regolith overlying basement rocks in Mokuro-Itagunmodi area along selected road-cut sections and petrography of the rocks were investigated with a view to determining the mineralogy, major and trace element concentrations and their distribution patterns in relation to the bedrock. Regoliths at four selected locations along Ife- Mokuro – Itagunmodi road were sampled across the regoliths according to the thicknesses of each regoliths. Selected major (Si, Al, Ti, Fe, Mn, Mg, Na and K) and trace (Cr, V, Co, Ni, Cu, Zn, As Pb and Mo) elements were determined in 34 representative regolith samples using the Energy Dispersive X – Ray Fluorescence (ED-XRF) analytical technique. The mineralogical constituents of eight of these samples were also determined using the X-Ray Diffraction (XRD) technique. In addition, petrographic studies of bedrock sample were carried out using the petrographic microscope. The results showed that tremolite-anthophyllite schist and amphibolite constituted mainly the slightly migmatized to non-migmatized metasedimentary and metaigneous rocks of the area. The results further showed that Al2O3 ranged between 23 wt % and 25 wt % whilst Fe2O3 ranged between 22 wt % and 30 wt % in the mottled zone indicating a bauxitic laterite. Significant depletion in SiO2, CaO, Na2O, K20 and MgO was observed whilst Al2O3, Fe2O3, TiO2, MnO, Cr, Co, V and Cu were relatively enriched. The element associations of Cr- Ni- Cu- V- Zn suggested strong maficultramafic influence whilst the strong and significant relationships of Fe and Mn with As, Co, Cu, Ni and Zn ( 'r' = 0.68, 0.91, 0.86, 0.87, 0.86 and 0.50; p < 0.01) resulting from adsorption and co-precipitation in the surficial environments indicated a redistribution of potential pathfinder elements into oxides of Fe and Mn. The XRD analysis results indicated the presence of kaolinite, quartz, chlorite, goethite, rutile, chromite, illite, smectite. and montmorillonite as the major mineral constituents of the regolith. Kaolinite, quartz, chlorite and goethite had mean relative proportions of 35.68 %, 29.95 %, 16.32 % and 12.02 % respectively. In conclusion, the element associations and distribution patterns reflected strong mafic ultramafic influence, however, the effect of heterogenous bedrock could not be ruled out. Furthermore, the clay mineral distribution showed an early stage of weathering in a well drained environment. The relatively high Ni and As enrichment indicated disseminated nickeliferous sulphide and gold mineralization for exploration application. 2015-04-02T10:30:23Z 2018-10-29T11:10:01Z 2015-04-02T10:30:23Z 2018-10-29T11:10:01Z 2015-04-02 Thesis http://localhost:8080/xmlui/handle/123456789/3456 en PDF application/pdf Nigeria
spellingShingle Geochemistry
Regolith
Petrography
Bedrock
Mafic ultramafic
Heterogenous bedrock
Ajidahun, Emmanuel Jeminiyi
Mineralogical and Geochemical Variations in the Regolith of Mokuro-Itagunmodi Area, Ife-Ilesa Schist Belt, Southwestern Nigeria
title Mineralogical and Geochemical Variations in the Regolith of Mokuro-Itagunmodi Area, Ife-Ilesa Schist Belt, Southwestern Nigeria
title_full Mineralogical and Geochemical Variations in the Regolith of Mokuro-Itagunmodi Area, Ife-Ilesa Schist Belt, Southwestern Nigeria
title_fullStr Mineralogical and Geochemical Variations in the Regolith of Mokuro-Itagunmodi Area, Ife-Ilesa Schist Belt, Southwestern Nigeria
title_full_unstemmed Mineralogical and Geochemical Variations in the Regolith of Mokuro-Itagunmodi Area, Ife-Ilesa Schist Belt, Southwestern Nigeria
title_short Mineralogical and Geochemical Variations in the Regolith of Mokuro-Itagunmodi Area, Ife-Ilesa Schist Belt, Southwestern Nigeria
title_sort mineralogical and geochemical variations in the regolith of mokuro itagunmodi area ife ilesa schist belt southwestern nigeria
topic Geochemistry
Regolith
Petrography
Bedrock
Mafic ultramafic
Heterogenous bedrock
url http://localhost:8080/xmlui/handle/123456789/3456
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