Abstract
Preliminary investigations in the Younger Granite Province of Nigeria have revealed that precious and semi-precious minerals like rubies, sapphires, emeralds, aquamarine, zircon and fluorite can be found in the region. The gem minerals are shown to have been produced either by direct deposition along fissures, veins and greisens by hydrothermal fluids or as a result of hydrothermal fluids reacting with wall-rocks. These wall rocks are either biotite granites from which the hydrothermal fluids originated or basement rocks or any other rocks which the biotite granites intrude and their residual hydrothermal fluids have invaded. The hydrothermal fluids appear to have been rich in alkalis (Na+, K+, etc.), rare elements (Be, Zr, F, REE, etc.) and siliceous. As these fluids rose through fractures and channel ways through the rocks, they either deposited the gem minerals in the fractures at the appropriate stability conditions or reacted with the wall-rocks producing the gem minerals at the expense of elements like Ca and A1 in the minerals of these rocks.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abaa, S.I.: Some petrographic and chemical aspects of mineralization in the Ririwai biotite granite, Nigeria. Bull. Geol. 1: No. 1. A.B.U. Zaria 1–18 (1978)
Abaa, S.I.: Some geochemical characteristics of the alkaline rocks of the Mada Younger granite complex, Nigeria. Journ. Afri. Eart Sci. 3:115–121 (1985)
Alexiyev, E.I.: Genetic significance of the rare earth elements in the Younger Granites of northern Nigeria and the Camerouns. Geochem. Int. 7:127–132 (1970)
Bowden, P.; Breemen, O. Van.: Isotopic and chemical studies on Younger Granites from northern Nigeria. In: Proc. Conf. on Afri. Geol. 42–49, Ibadan, (1972)
Bowden, P.; Turner, D.C.: Peralkaline and associated ring complexesin the Niger-Nigerian province, West Africa. In: The Alkaline rocks H. Sorensen, Ed. 330–351. London: Wiley (1974)
Bowden, P.; Bennett, J.N.; Whitley, J.E.; Moyes, A.B.: Rare earths in Nigerian Mesozoic Granites and related rocks. In: Origin and Distribution of the Elements, L.H. Ahrens, Ed. 479–491 (1979)
Bowden, P.; Bennet, J.N.; Kinnaird, J.A.; Whitley, J.E.; Abaa, S.I.; Stavrakis, P.K.: Uranium in the Niger-Nigerian Younger Granite Province Min. Mag. 44:370–389 (1981)
Bowden, P.; Kinnaird, J.A.; Abaa, S.I.; Ike, E.G.; Turaki, U.M.: Geology and Mineralization of the Nigerian Anorogenic Ring Complexes. Geol. Jb. B56, Handover, 1–65 (1984).
Buchanan, M.S.; Macleod, W.N.; Turnover, D.C.; Berridge, N.G.; Black, R.; The Geology of the Jos Plateau Younger Granite Complexes. Bull. Geol. Surv. Nigeria, 2:32, 9–63 (1971)
Burt, D.M.: Acidity-Salinity diagrams application to greisen and porphyry deposits. Econ. Geol. 76:832–843 (1981)
Carson, D.J.T.; Jambor, J.L.: Phyllic overprinting: A fundamental cause of varaitionin zoning at prophyry copper deposits (abs.) Geol. Assoc. Canada, Annual Meeting, Vancouver 2:11 (1977)
Jackson, N.Ja.; Moore, J.M.; Rankin, A.H.: Fluid inclusion and mineralization at Cligga Head, Cornwall, England. Geol. Soc. (London) Journ. 134:343–349 (1977)
Kinnaird, J.A.; Bowden, P.; Ixer, R.A.: The Tirwai lode- a zinc-tin rich greisen-wall rock assemblage form northern Nigeria. Trans. Inst. Min. Metall. Sec. B, 189–196 (1984)
Kovalenko, V.I.: The reactions between granite and aqueous hydrofluoric acid in relation to the origin of fluorine bearing granites. Geochimiya 4:503–515 (1976)
Manning, D.C.: An experimental study of the effect of fluorine on the crystallization of granitic melts. In: Metallization Associated with Acid Magmatism, A.M. Evans, Ed. pp 191–203. London — New York: John Wiley (1982)
Roader, E.: Fluid inclusions as tools in mineral exploration. Econ. Geol. 72:503–525 (1977)
Rose, A.W., Burt, D.M.: Hydrothermal alteration; In: Geochemistry of hydrothermal Ore Deposits. H.L. Barnes. Ed. pp 173–235. London — New York: Wiley (1979)
Sales, R.J.; Meyer, C.: Wall rock alteration at Butte, Montana. Amer. Inst. Min. Engr. Trans. 178:9–35 (1984)
Stumm, W.; Morgan, J.J.: An introduction emphasizing chemical equilibrium in Natural waters. In: Aquatic chemistry, pp 583, London. Wiley (1970)
Wilson, J.W.J.; Kesler, S.E.; Cloke, P.L.; Kelly, W.C.: Fluid inclusion geochemistry of the Granisle land Bell porphyry copper deposits, British Columbia. Econ. Geol. 75:45–61 (1980)
Woodcock, J.R.; Hollister, V.F.; Porphyry molybdenite deposits of the North American Cordillera. Mineral. Sci. Eng. 10:3–18 (1978)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Abaa, S.I. Hydrothermal fluids responsible for the formation of precious minerals in the Nigerian Younger Granite Province. Mineral. Deposita 26, 34–39 (1991). https://doi.org/10.1007/BF00202362
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00202362