Petrographic and Mineralisation Potentials of Precambrian Pegmatities and Associated Rock Units of Olode Area, Southwestern Nigeria

Authors

  • S. I. Okonkwo Federal University of technology, Owerri, P.M.B. 1526, Owerri, Imo State, Nigeria
  • S. O. Idakwo Ibrahim Badamasi Babangida University, Lapai, P.M.B. 11, Lapai, Niger State, Nigeria

DOI:

https://doi.org/10.30564/jgr.v2i4.2312

Abstract

The geology of the Olode area, south-western Nigeria was investigated petrographically and geochemically in order to elucidate the mineralisation potential of the rock units in the area. The area under study is generally change to underlained by granite gneiss, mica schist and pegmatites. Petrographical studies indicated prevalence of anhedral quartz (30 - 50%), plagioclase (14 -20%), orthoclase (12 - 15%), muscovite (11 - 15%), tourmaline (6 - 10) and other minerals (8 - 11%) for the pegmatite. The high value of SiO2 and Al2O3 is consistent with the petrographical study. High values and wide range in Ba (34 - 737 ppm) and Zr (3.8 - 132.6 ppm) strongly support a mixture of igneous and sedimentary. The bivariant plots of Rb vs K/Rb, Zn vs K/Rb and Th vs K/Rb indicated a partial series of fractionation, suggesting that the pegmatites are of rare element classes while granite gneiss and mica schist belong to the barren muscovite and rare element classes. This was supported by high ratios of K/Cs and K/Ba but low Th/U values indicating distinctively low rare metal mineralization. The plot of Na2O/Al2O3 vs K2O/Al2O3 revealed an igneous precursor for all the rock units. The negative Eu anomalies especially in the pegmatitic rock unit indicates fractionation and point toward a late metasomatic effect and their relatively weak negative Ce anomalies, also suggest their rare metal mineralization. The pegmatites, granite gneiss and mica schist of Olode area considered as barren as all the samples plotted below the ordiyenkos and Beus’ line of mineralization.

Keywords:

Pegmatite and associated rocks; Geochemistry; Mineralisation; Gordiyenkos and Beus’ line; Olode

References

[1] Wright, J. B. Controls of mineralization in the older and younger tin fields of Nigeria. Econ. Geol., 1970, 65: 945-951.

[2] Okunlola, O.A., Jimba, S. Compositional trends in relation to Ta-Nb mineralization in Precambrian pegmatites of Aramoko-Ara-Ijero area, southwestern Nigeria. Journal of Mining and Geology, 2006, 42(2): 113-126.

[3] Okunlola, O. A., Ofonime, U. B. Geological setting, petrographical features and age of raremetal (Ta-Nb) mineralization of pegmatites of Komu area, Southwestern Nigeria. African Journal of Science and Technology (AJST); Science and Engineering Series, 2006, 7(1): 96-110.

[4] Okunlola, O.A., Somorin, E.B. Compositional features of Precambrian pegmatites of Itakpe area, central Nigeria. Global Journal of Geological Sciences, 2005, 4(2): 221-230.

[5] Okunlola, O.A, Oyedokun, M.O. Compositional trends and rare metal (Ta-Nb) mineralization potential of pegmatite and association lithologies of Igbeti area, Southwestern Nigeria. Journal of RMZ- Materials and Geoenvironment, 2009, 56(1): 38-53.

[6] Cerny, P. Geochemical and petrogenetic features of mineralization in rare element granitic pegmatites in the light of current research. Applied Geochemistry, 1991, 18: 48-68.

[7] Cerny, P. Magmatic vs metamorphic derivation of rare element granitic pegmatites. Krystallinikum, 1998, 24: 7-36.

[8] Jacobson, R., Webb, J.S. The Pegmatites of Central Nigeria. Geological Survey of Nigeria, 1946, 17:1-61.

[9] Garba, I. Geochemical discrimination of newly discovered rare-metal bearing and barren pegmatites in the Pan-African (600±150 Ma) basement of northern Nigeria. Applied Earth Science, 2003, 112(3): 287-292.[10]DOI: https://doi.org/10.1179/037174503225011270

[10] Okunlola, O.A. Metallogeny of Tantalite-Niobium Mineralization of Precambrian Pegmatites of Nigeria. Mineral Wealth, 2005, 104: 38-50.

[11] Akintola, A. I., Omosanya, K. O., Ajibade O. M., Okunlola, O. A., Kehinde-Philips, O. O. Petrographic and Geochemical Evaluations of Rare - Metal (Ta-Nb) Potentials of Precambrian Pegmatities of Awo Area Southwestern, Nigeria. International Journal of Basic and Applied Sciences IJBAS-IJENS, 2011, 11(4): 57-70.

[12] Caby, R., Betrand, J.M.L., Black, R. Pan-African Ocean Closure and Continental Collision in the Hogger-Iforas Segment, Central Sahara. In: Kroner, A., Ed., Precambrian Plate Tectonics , Elsevier, Amsterdam, 1981: 407-437.

[13] Annor, A.E., Freeth, S.J. Thermometric Evolution of the Basement Complex around Okene, Nigeria, with Special Reference to Deformation Mechanisms. Precambrian Research, 1985, 28: 269-281. DOI: https://doi.org/10.1016/0301-9268(85)90034-8

[14] Rahaman, M.A. Recent advances in the study of the basement complex of Nigeria. In Oluyide, P. O., Mbonu, W. C., Ogezi, A. E., Egbuniwe, I. G., Ajibade, A. C., Umeji, A. C. et al. (eds.) Pre Cambrian geology of Nigeria. Geological Survey of Nigeria Special Publication, Kaduna, Nigeria, 1988: 11-41.

[15] Toteu, S.F., Penaye, J., Djomani, Y.P. Geodynamic Evolution of the Pan-African Belt in Central Africa with Special Reference to Cameroon. Canadian Journal of Earth Science , 2004, 41: 73-85. DOI; https://doi.org/10.1139/e03-079

[16] Wright, J. B. Geology and mineral resources of West Africa. George Allen and Unwin, London, 1985: 187.

[17] Okunlola, O.A., Akintola, A.I. Geochemical features and rare metal Ta-Nb potentials of Precambrian pegmatites of Sepeteri area, southwestern Nigeria. Ife journal of Sciences, 2007, 9(2): 203 - 214.

[18] Akintola, O.F., Adekeye, J.I.D. Mineralization potentials of pegmatites in the Nasarawa area of central Nigeria. Earth Sci.Res. J. 2008, 12: 213-234.

[19] Adetunji, A, Ocan, O. O. Characterization and Mineralization Potentials of Granitic Pegmatites of Komu area, Southwestern Nigeria. Resource Geology, 2009, 60(1): 87-97.

[20] Snowden, P. A., Snowden D. V. Petrochemistry of the late Archean granites of Chinamora batholiths. Precambrian Res. 1981, 16: 103- 129.

[21] Omosanya, K.O., Ajibade, M.O., Akintola, A.I. Buckling of migmatized-gneiss at ago-sunmonu, SW, Nigeria. Int. J. Basic Appl. Sci., 2011, 11: 57-68.

[22] Kuster, D. Rare metal pegmatites of Wamba, central Nigeria their formation in relationship to late Pan-African granites. Mineral Deposita, 1990, 25:25-28.

[23] Cerny, P., Burt, D. M. Paragenesis, crystallochemical Characteristics and geochemical evolution of micas in granitic pegmatites. In Bailey, S. W. (ed.) Micas. Mineralogical Society of America Rev. Mineral, Chantily, VA, USA, 1984, 13: 257-297.

[24] Matheis, G., Caen-Vachette. Rb-Sr isotopic study of rare metal bearing and barren pegmatites in the Pan-African reactivation zone of Nigeria. J. Afr. Earth Sci, 1983, 1: 35-40.

[25] Cerny, P. Geochemical and petrogenetic features of mineralization in rare element granitic pegmatites in the light of current research. Applied Geochemistry, 1991a, 18: 48-68.

[26] Cerny, P. Rare-element granitic pegmatites-regional to global environments and Petrogenesis. GeoScience Canada, 1991b, 18:49-62.

[27] Černý, P. Geochemical and petrogenetic features of mineralization in rare-element granitic pegmatites in the light of current research. Appl Geochem, 1992, 7:393-416.

[28] Olarewaju, V. O., Rahaman, M. A. Petrology and Geochemistry of Older Granites from some parts of Northern Nigeria. J. Min. Geol. 1982, 18(2): 16-28.

[29] Garrels, R.M., Mackenzie, F.T. Evolution of Igneous and Sedimentary Rocks W.W. Norton and Company, Inc. New York, N.Y. 1971: 394.

[30] Condie, K.D. Trace element geochemistry of Archean granite rocks from the Barberton Region, South Africa, AM. Mineral. Earth Planet Sc. Letter, 1976, 300-400.

[31] Taylor, S.R., Rudnick, R.L., Mc Lennan, S.C, Eriksson, K.A. Rare earth element patterns in Archean high-grade metasediments and their tectonic significance. Geochim.Cosmochim. Acta, 1986, 50: 2267-2279.

[32] Taylor, S. R. The Application of trace element data to problems of petrology. In: L.Ahrens, F. Press, S. K. Runcorn and C. Urey (eds.). Physics and Chemistry of the Earth, Pergamon Press, Oxford, 1965, 6: 133-214.

[33] Piper, D.Z. Rare earth elements in sedimentary cycle: A summary. Chem.Geol., 1974, 14, 285-304.

[34] Beus, A.A. Distribution of tantalum and niobium in muscovites from granitic pegmatites. Geokhimiya, 1966, 10: 1216-1220.

[35] Gordiyenko, V.V. Concentration of Li, Rb, and Cs in potash feldspar and muscovite, a criteria for assessing rare metal mineralization in granite pegmatites. Int. Geology Rev., 1971, 13: 134-142.

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How to Cite

Okonkwo, S. I., & Idakwo, S. O. (2020). Petrographic and Mineralisation Potentials of Precambrian Pegmatities and Associated Rock Units of Olode Area, Southwestern Nigeria. Journal of Geological Research, 2(4), 62–74. https://doi.org/10.30564/jgr.v2i4.2312

Issue

Vol. 2 , Iss. 4 (October 2020)

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Copyright © 2020 S. I. Okonkwo, S. O. Idakwo

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