Research Article Open Access

Petrography and Geochemistry of Orin-Ekiti Basement Rocks, Southwestern Nigeria: Implications on Bauxitization

Abel Ojo Talabi1, Akin Ojo Oyinloye1, Olusola Amos Olaolorun1, Romanus Ayoola Obasi1, Akinola Bolaji Eluwole1, Olajide Femi Adebayo1 and Oladimeji Lawrence Ademilua1
  • 1 Ekiti State University, Nigeria
American Journal of Applied Sciences
Volume 15 No. 4, 2018, 230-239

DOI: https://doi.org/10.3844/ajassp.2018.230.239

Submitted On: 15 September 2017
Published On: 1 January 2018

How to Cite: Talabi, A. O., Oyinloye, A. O., Olaolorun, O. A., Obasi, R. A., Eluwole, A. B., Adebayo, O. F. & Ademilua, O. L. (2018). Petrography and Geochemistry of Orin-Ekiti Basement Rocks, Southwestern Nigeria: Implications on Bauxitization. American Journal of Applied Sciences, 15(4), 230-239. https://doi.org/10.3844/ajassp.2018.230.239

Abstract

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.

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Keywords

  • Basement Rocks
  • Bauxitization
  • Thin Section
  • Geochemical Analyses
  • Protolith