Petrography and Geochemistry of Orin-Ekiti Basement Rocks, Southwestern Nigeria: Implications on Bauxitization
Abel Ojo Talabi, Akin Ojo Oyinloye, Olusola Amos Olaolorun, Romanus Ayoola Obasi, Akinola Bolaji Eluwole, Olajide Femi Adebayo and Oladimeji Lawrence Ademilua
American Journal of Applied Sciences
The petrography and geochemistry of Orin-Ekiti Basement rocks were evaluated to determine their mineralogical and chemical composition, assessed their petrogenesis and susceptibility to the formation of bauxitic clay. Ten representative rock samples were selected for thin section petrography and bulk rock geochemical analysis using Petrographic microscope and XRF, Rh Tube, 3k Watt respectively. Field observations revealed charnockites as the dominant rock in the study area with other lithotypes including granite, granite gneiss and banded gneiss. Optical examinations indicated the dominance of quartz in all the rocks suggesting the rocks are product of acidic magma. The order of oxides concentration (wt%) is SiO2>Al2O3>Fe2O3>CaO>K2O>MgO>Na2O>TiO2>P2O5. Based on silica content only, the rocks in this study are classified as felsic (granite, granite gneiss and banded gneiss) with SiO2>65% and ultramafic (charnockites) with SiO2<45%. Charnockites with low SiO2, high Al2O3 and TiO2 compared to other rocks in the study area is considered more favourable to form bauxite. The rocks in the study area are classified into calcic-alkali and calcic groups with igneous protolith.
© 0000 Abel Ojo Talabi, Akin Ojo Oyinloye, Olusola Amos Olaolorun, Romanus Ayoola Obasi, Akinola Bolaji Eluwole, Olajide Femi Adebayo and Oladimeji Lawrence Ademilua. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.