• P-ISSN 0974-6846 E-ISSN 0974-5645

Indian Journal of Science and Technology

Article

Indian Journal of Science and Technology

Year: 2020, Volume: 13, Issue: 41, Pages: 4319-4331

Original Article

Geochemistry and mineral chemistry of quartz mica schists within Iseyin-Oyan Schist Belt, Southwestern Nigeria

Received Date:10 September 2020, Accepted Date:13 October 2020, Published Date:03 December 2020

Abstract

Background/Objectives: The Iseyin-Oyan schist belt is made up metasedimentary rocks, gneisses, granites and pegmatite intrusions. The study was aimed at identifying the schist within this belt and assess their metamorphism, geochemical characteristics and tectonic origin. Methods: Detailed geologic field mapping was undertaken where rocks were located, studied in-situ and identified. Samples of the schist were prepared for petrographic studies. Mineralogical contents were determined using X-Ray Diffraction technique. Polished sections were studied for mineral chemistry using Scanning Electron Microscope-Energy Dispersive Spectroscopy. Rock samples were analysed using X-Ray Fluorescence Spectroscopy and Inductively Coupled Plasma Emission Spectrometry. Geochemical data were elucidated using diverse geochemical discrimination diagrams. Findings: The schists are quartz mica schists and occur in close association with amphibolites, intrusive granitoids and pegmatites. The Mineral assemblage indicates upper (at the western part) to lower (at the central part) amphibolite facies grade metamorphism in the area. Pyrope-almandine garnets occur in quartz mica schist at the western parts reinforcing higher pressure-temperature metamorphic conditions. The concentration (in %) of SiO2 ranged from 56.4-71.6; Al2O3, 13.7-21.1; Fe2O3, 2-8; MgO, 0.7-2.4; and K2O, 2.1-5.5 supporting the evidence for differential degrees of metamorphism. Large iron lithophile and high field strength elements are similar to the average upper continental crust. Pronounced negative Europium anomaly pointed to the major roles played by feldspars during the geological processes. Plagioclase ranged from albite-oligoclase and oligoclase- andesine. The precursors of the quartz mica schist are possibly arkosic and greywacke sands deposited within the active continental margins. Evidence of uplift and overturning suggested for the differential metamorphism may be due to these events usually associated with active continental margins. Applications: This study has identified the once named undifferentiated schist in the study area to be quartz mica schist with details in their grades of metamorphism elucidated.
Keywords: Quartz mica schist; geochemistry; mineral chemistry; Iseyin-Oyan schist belt; precambrian basement complex

References

  1. Fagbohun BJ, Omitogun AA, Ayotunde OA, Ayoola FJ. Remote Detection and Interpretation of Structural Style of the Zuru Schist Belt, Northwest Nigeria. Geocarto International. 2020. Available from: https://doi.org/10.1080/10106049.2020.1753822
  2. Elueze AA. Rift system for Proterozoic schist belts in Nigeria. Tectonophysics. 1992;209:167–169.
  3. Garba I. Origin of Pan-African mesothermal gold mineralisation at Bin Yauri, Nigeria. Journal of African Earth Sciences. 2000;31(2):433–449. Available from: https://dx.doi.org/10.1016/s0899-5362(00)00098-1
  4. Woakes M, Rahaman MA, Ajibade AC. Some metallogenic features of the Nigerian Basement. Journal of African Earth Sciences. 1983;6:655–664. Available from: https://doi.org/10.1016/0899-5362(87)90004-2
  5. Jones HA, Hockey RD. The Geology of part of Southestern Nigeria. Nigeria Geological Survey Bulletin. 1964;31:87.
  6. Burke KC, Dewey JF. Orogeny in Africa. In: Dessauvagie TFJ, Whiteman AJ., eds. Africa Geology. (pp. 583-608) Ibadan, University of Ibadan Press. 1972.
  7. Adetunji A, Ocan OO. Tectonic Environments and Rare Metal Mineralization In Pegmatites Of Komu Area, Southwestern Nigeria. Global Journal of Geological Sciences. 2010;8:109–115. Available from: https://doi.org/10.4314/gjgs.v8i2.62767
  8. Akintola AI, Ikhane PR, Laniyan TA, Akintola GO, Kehinde-Phillips OO, Ojajuni PO. Compositional trends and rare metal (Ta- Nb) mineralization potential of Precambrian pegmatites in Komu area, Southwestern Nigeria. International Journal of Current Research. 2012;4(2):31–39. Available from: https://doi.org/10.1179/037174503225011 270
  9. Rahaman MA. Review of the Basement geology of Southwestern Nigeria. In: Kogbe CA., ed. Geology of Nigeria. (pp. 39-56) Elizabeth Publishing Company. 1976.
  10. Zhang W, Hu Z, Liu Y, Chen H, Gao S, Gaschnig RM. Total Rock Dissolution Using Ammonium Bifluoride (NH4HF2) in Screw-Top Teflon Vials: A New Development in Open-Vessel Digestion. Analytical Chemistry. 2012;84(24):10686–10693. Available from: https://dx.doi.org/10.1021/ac302327g
  11. Blatt HJ, Middleton GV, Murray RC. Origin of Sedimentary Rocks. New Jersey. Prentice-Hall. 1980.
  12. Roser BP, Cooper RA, Nathan S, Tulloch AJ. Reconnaissance sandstone geochemistry, provenance, and tectonic setting of the lower Paleozoic terranes of the West Coast and Nelson, New Zealand. New Zealand Journal of Geology and Geophysics. 1996;39(1):1–16. Available from: https://dx.doi.org/10.1080/00288306.1996.9514690
  13. Taylor SR, Mclennan SM. The Continental Crust: Its Composition and Evolution. (pp. 1-312) Oxford, Blackwell.. 1985.
  14. Mcdonough W, Sun SS. The composition of the Earth. Chemical Geology. 1995;120:223–253.
  15. Bhatia MR. Plate Tectonics and Geochemical Composition of Sandstones. The Journal of Geology. 1983;91:611–627.
  16. Roser B, Korsch RJ. Determination of tetonic setting of sandstone-mudstone suites using SiO2 content and K20/Na20 ratio. Journal of Geology. 1986;94:635–650.
  17. Caby R, Bertrand JML, Black R. Pan-African ocean closure and continental collision in the Hoggar-Iforas segment, Central Sahara. In: Kroner A., ed. Precambrian Plate Tectonics. (pp. 407-434) Elsevier. 1981.
  18. Rieder M, Cavazzini G, D’yakonov YS, Frank-Kamenetskii VA, Gottardi G, Guggenheim S, et al. Nomenclature of the micas. Mineralogical Magazine. 1999;63(2):267–279. Available from: https://dx.doi.org/10.1180/minmag.1999.063.2.13
  19. Tischendorf G, Gottesmann B, Forster HJ, Trumbull RB. On Li-bearing micas: estimating Li from electron microprobe analyses and an improved diagram for graphical representation. Mineralogical Magazine. 1997;61:809–834. Available from: https://doi.org/10.1180/minmag.1997.061.409.05
  20. Deer WA, Howie RA, Zussman J. An introduction to Rock forming Minerals. England, Longman. 1966.
  21. Coleman RG, Lee DE, Beatty LB, Brannock WW. Eclogites and Eclogites; Their Differences and Similarities. Geological Society of America Bulletin. 1965;76:83–508.

Copyright

© 2020 Abdus-Salam et al. 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. Published By Indian Society for Education and Environment (iSee)

DON'T MISS OUT!

Subscribe now for latest articles and news.