Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-30T19:44:54.108Z Has data issue: false hasContentIssue false
  • English
  • Français

The Pan-African Toro Complex (northern Nigeria): magmatic interactions and structures in a bimodal intrusion

Published online by Cambridge University Press:  01 May 2009

J. Déléris ,
A. Nédélec ,
E. Ferré ,
G. Gleizes ,
R.-P. Ménot ,
C. K. Obasi  and
J.-L. Bouchez
J. Déléris
Affiliation:
Pétrophysique, Umr Cnrs 5563, Université Paul-Sabatier, 38 rue des Trente-Six-Ponts, 31400 Toulouse, France
A. Nédélec
Affiliation:
Pétrophysique, Umr Cnrs 5563, Université Paul-Sabatier, 38 rue des Trente-Six-Ponts, 31400 Toulouse, France
E. Ferré
Affiliation:
Pétrophysique, Umr Cnrs 5563, Université Paul-Sabatier, 38 rue des Trente-Six-Ponts, 31400 Toulouse, France Department of Geology and Mining, University of Jos, PMB 2084, Jos, Nigeria
G. Gleizes
Affiliation:
Pétrophysique, Umr Cnrs 5563, Université Paul-Sabatier, 38 rue des Trente-Six-Ponts, 31400 Toulouse, France
R.-P. Ménot
Affiliation:
Département de Géologie–Pétrologie, ura cnrs 10, Université Jean-Monnet, 23 rue du Docteur Paul Michelon, 42023 Saint-Etienne Cedex 02, France
C. K. Obasi
Affiliation:
Department of Geology and Mining, University of Jos, PMB 2084, Jos, Nigeria
J.-L. Bouchez
Affiliation:
Pétrophysique, Umr Cnrs 5563, Université Paul-Sabatier, 38 rue des Trente-Six-Ponts, 31400 Toulouse, France
Get access Rights & Permissions [Opens in a new window]

Abstract

The Toro Complex is one of the Pan-African Older Granites of Nigeria, first described as a reversely zoned pluton made of a central dioritic mass surrounded by a broad granitic rim. It has been thoroughly reinvestigated both from the petrographic and structural points of view, with the help of systematic anisotropy of magnetic susceptibility (AMS) measurements. The granite main body is a hornblende–biotite porphyritic monzogranite characterized by an early submagmatic fabric displaying a concentric pattern of foliations and west plunging lineations (stage 1). This fabric is overprinted by a later one due to solid-state strain along north-south subvertical dextral shear zones (stage 2). In the vicinity of the diorite, an evengrained granite displays magmatic structures that are contemporaneous with this strike-slip event. The diorite–granite contact is a complex zone where field, petrographic and geochemical data enable recognition of the effects of mixing and mingling between a mafic and a felsic magma. Tonalites cropping out within this contact zone are interpreted as hybrid rocks. The reverse zonation of the diorite itself is also the result of some hybridization process. Magmatic interactions mainly resulted from in situ infiltration of granitic liquid into the dioritic mass. The detailed history of this bimodal intrusion began with the emplacement of the granitic magma acquiring a first stage fabric. Before full crystallization of the granitic core, intrusion of the dioritic magma permitted reheating of the granitic magma that then crystallized with specific structural characters. The second stage structures, whether characterized by magmatic fabric near the diorite or by solid-state strain features in north–south shear zones elsewhere in the granite, are related to late Pan-African dextral strike-slip tectonics in the basement of northern Nigeria. The bimodal Toro Complex is therefore considered as a late Pan-African syntectonic pluton.

Type
Articles
Information
Geological Magazine , Volume 133 , Issue 5 , September 1996 , pp. 535 - 552
Copyright
Copyright © Cambridge University Press 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ajibade, A. C., & Fitches, W. R. 1988. The Nigerian Precambrian and the Pan-African orogeny. In Precambrian geology of Nigeria (ed. Geological Survey of Nigeria ), pp. 45–53. Kaduna.Google Scholar
Baker, D. R. 1991. Interdiffusion of hydrous dacitic and rhyolitic melts and the efficacy of rhyolite contamination of dacitic enclaves. Contribution to Mineralogy and Petrology 106, 462–73.CrossRefGoogle Scholar
Barbarin, B. 1990. Plagioclase xenocryst and mafic magmatic enclaves in some granitoids of the Sierra Nevada batholith, California. Journal of Geophysical Research 95, 17747–56.CrossRefGoogle Scholar
Barbarin, B., & Didier, J. 1991. Macroscopic features of mafic microgranular enclaves. In Enclaves and granite petrology (eds Didier, J., and Barbarin, B.), pp. 253–61. Amsterdam: Elsevier.Google Scholar
Bessolles, B., & Trompette, R. 1980. La chaîne panafricaine: zone mobile d’Afrique centrale et zone mobile soudanaise. Mémoire Bureau de Recherches Géologiques et Minières 92, 375 pp.Google Scholar
Bertrand, J. M., & Caby, R. 1978. Geodynamic evolution of the Central Saharan Pan-African mobile belt: a new interpretation of the Hoggar shield (Algerian Sahara). Geologische Rundschau 67, 357–88.CrossRefGoogle Scholar
Black, R., Caby, R., Moussine-Pouchkine, A., Bayer, R., Bertrand, J. M., Bouluer, A. M., Fabre, J., & Lesquer, A. 1979. Evidence for late Precambrian plate tectonics in West Africa. Nature 278, 223–5.CrossRefGoogle Scholar
Blake, S., & Campbell, I. H. 1986. The dynamics of magmamixing during flow in volcanic conduits. Contributions to Mineralogy and Petrology 94, 72–81.CrossRefGoogle Scholar
Blake, D. H., Elwell, R. W. D., Gibson, I. L., Skelhorn, R. R., & Walker, G. P. L. 1965. Some relationships resulting from the intimate association of acid and basic magmas. Quarterly Journal of the Geological Society, London 121, 31–49.CrossRefGoogle Scholar
Blundy, J. D., & Sparks, R. S. J. 1992. Petrogenesis of mafic inclusions in granitoids of the Adamello Massif, Italy. Journal of Petrology 33, 1039–1104.CrossRefGoogle Scholar
Borradaile, G. J. 1988. Magnetic susceptibility, petrofabrics and strain. Tectonophysics 156, 1–20.CrossRefGoogle Scholar
Bouchez, J.-L., Delas, C, Gleizes, G., Nédélec, A., & Cuney, M. 1992. Submagmatic microfractures in granites. Geology 20, 35–38.2.3.CO;2>CrossRefGoogle Scholar
Bouchez, J.-L., & Gleizes, G. 1995. Two stage deformation of the Mont-Louis-Andorra granite pluton (Variscan Pyrenees) inferred from magnetic susceptibility anisotropy. Journal of the Geological Society London 152, 669–79.CrossRefGoogle Scholar
Bouchez, J.-L., Gleizes, G., Djouadi, T., & Rochette, P. 1990. Microstructure and magnetic susceptibility applied to emplacement kinematics of granites: the example of the Foix pluton (French Pyrenees). Tectonophysics 184, 157–71.CrossRefGoogle Scholar
Caby, R. 1989. Precambrian terranes of Benin-Nigeria and north-east Brazil and the late Proterozoic south Atlantic fit. Geological Society of America Special Paper 230, 145–58.CrossRefGoogle Scholar
Castaing, C., Feybesse, J.-L., Thiéblemont, D., Triboulet, C., & Chevremont, P. 1994. Paleogeographical reconstructions of the Pan-African - Brasiliano orogen: closure of an oceanic domain or intracontinental convergence between major blocks? Precambrian Research 69, 327–44.CrossRefGoogle Scholar
Castro, A., De La Rosa, J. D., & Stephens, W. E. 1990. Magma mixing in the subvolcanic environment: petrology of the Gerena interaction zone near Seville. Contributions to Mineralogy and Petrology 105, 9–26.CrossRefGoogle Scholar
Castro, A., & Stephens, W. E. 1992. Amphibole-rich polycrystalline clots in calc-alkaline granitic rocks and their enclaves. Canadian Mineralogist 30, 1093–1112.Google Scholar
Cocirta, C. 1986. Les enclaves microgrenues sombres du massif de Bono (Sardaigne septentrionale). Signification pétrogénétique des plagioclases complexes et de leurs inclusions. Comptes rendus de l’Académie des Sciences 302, 441–6.Google Scholar
Cruden, A. R. 1990. Flow and fabric development during the diapiric rise of magma. Journal of Geology 98, 681–98.CrossRefGoogle Scholar
Czamanske, G. K., Ishihara, S., & Atkin, S. A. 1981. Chemistry of rock-forming minerals of the Cretaceous—Paleocene batholith in southwestern Japan and implications for magma genesis. Journal of Geophysical Research 86, 10431–69.CrossRefGoogle Scholar
Dada, S. S., Lancelot, J. R., & Briqueu, L. 1989. Age and origin of the annular charnockitic complex at Toro, northern Nigeria: U—Pb and Rb—Sr evidence. Journal of African Earth Sciences 9, 227–34.CrossRefGoogle Scholar
Debon, F. 1991. Comparative major element chemistry in various “microgranular enclave — plutonic host” pair. In Enclaves and granite petrology (eds Didier, J., and Barbarin, B.), pp. 293–312. Amsterdam: Elsevier.Google Scholar
Didier, J., Fernandez, A., & El, Mouraouha A. 1989. A model for the genesis of granitic magmas by crustal melting around mafic intrusions: The Peyron diorite near Burzet (Ardèche, Massif Central Français). In Magma—Crust Interactions and Evolution, pp. 163–92. Athens: Theophrastus Publications.Google Scholar
Dorais, M. J., Whitney, J. A., & Roden, M. F. 1990. Origin of mafic enclaves in the Dinkey Creek pluton, central Sierra Nevada batholith, California. Journal of Petrology 31, 853–81.CrossRefGoogle Scholar
Eberz, G. W., & Nicholls, I. A. 1990. Chemical modification of enclave magma by post-emplacement crystal fractionation, diffusion and metasomatism. Contributions to Mineralogy and Petrology 104, 47–55.CrossRefGoogle Scholar
Falconer, J. D. 1911. The geology and geography of northern Nigeria. London: MacMillan, 295 pp.Google Scholar
Fernandez, A., & Barbarin, B. 1991. Relative rheology of coeval mafic and felsic magmas: nature of resulting interaction processes and shape and mineral fabrics of mafic microgranular enclaves. In Enclaves and granite petrology (eds Didier, J., and Barbarin, B.), pp. 263–75. Amsterdam: Elsevier.Google Scholar
Fernandez, A., & Gasquet, D. R. 1994. Relative rheological evolution of chemically contrasted coeval magmas: example of the Tichka plutonic complex. Contributions to Mineralogy and Petrology 116, 316–26.CrossRefGoogle Scholar
Ferré, E., Déléris, J., Bouchez, J.-L., Lar, A. U., & Peucat, J.-J. 1996. The Pan-African reactivation of Eburnian and Archaean provinces in Nigeria: structural and isotopic data. Journal of the Geological Society, London 153 (in press).CrossRefGoogle Scholar
Ferré, E., Gleizes, G., Bouchez, J.-L., & Nnabo, P. 1995. Internal fabric and strike-slip emplacement of the Pan- African granite of Solli Hills, northern Nigeria. Tectonics 14, 1205–19.CrossRefGoogle Scholar
Fourcade, S., & Allègre, C. J. 1981. Trace elements behaviour in granite genesis: a case study — the calc-alkaline plutonic association from the Quérigut Complex (Pyrenees, France). Contributions to Mineralogy and Petrology 76, 177–95.CrossRefGoogle Scholar
Fridrich, C. J., & Mahood, G. A. 1984. Reverse zoning in the resurgent intrusions of the Grizzly Peak cauldron, Sawatch Range, Colorado. Geological Society of America Bulletin 95, 779–87.2.0.CO;2>CrossRefGoogle Scholar
Frost, T. P., & Mahood, G. A. 1987. Field, chemical and physical constraints on mafic—felsic magma interaction in the Lamarck Granodiorite, Sierra Nevada, California. Geological Society of America Bulletin 99, 272–91.2.0.CO;2>CrossRefGoogle Scholar
Gapais, D. 1989. Shear structures within deformed granites: mechanical and thermal indicators. Geology 17, 1144–7.2.3.CO;2>CrossRefGoogle Scholar
Giret, A., Bonin, B., & Léger, J.-M. 1980. Amphibole compositional trends in oversaturated and undersaturated alkaline plutonic ring-complexes. Canadian Mineralogist 18, 481–95.Google Scholar
Gleizes, G., Nédélec, A., Bouchez, J.-L., Autran, A., & Rochette, P. 1993. Magnetic susceptibility of the Mont-Louis-Andorra ilmenite-type granite (Pyrenees): a new tool for the petrographic characterisation and regional mapping of zoned granite plutons. Journal of Geophysical Research 98, 4317–31.CrossRefGoogle Scholar
Holden, P., Halliday, A. N., Stephens, W. E., & Henney, P. J. 1991. Chemical and isotopic evidence for major mass transfer between mafic enclaves and felsic magma. Chemical Geology 92, 135–52.CrossRefGoogle Scholar
Huppert, H. E., & Sparks, R. S. 1988. The generation of granitic magmas by intrusion of basalt into continental crust. Journal of Petrology 29, 599–624.CrossRefGoogle Scholar
Hutton, D. H. W. 1982. A tectonic model for the emplacement of the Main Donegal Granite, NW Ireland. Journal of the Geological Society, London 139, 615–31.CrossRefGoogle Scholar
Ishihara, S. 1977. The magnetite-series and ilmenite-series granitic rocks. Mining Geology 27, 293–305.Google Scholar
Johnston, A. D., & Wyllie, P. J. 1988. Interaction of granitic and basic magmas: experimental observations on contamination processes at 10 kbar with H2O. Contributions to Mineralogy and Petrology 98, 352–62.CrossRefGoogle Scholar
Kennedy, W. Q. 1964. The structural differentiation of Africa in the Pan-African (±500 m. y.) tectonic episode. Annual Report of the Institute for African Geology, University of Leeds 8, 48–9.Google Scholar
Koyaguchi, T. 1985. Magma mixing in a conduit. Journal of Volcanology and Geothermal Research 25, 365–9.CrossRefGoogle Scholar
Larsen, L. L., & Smith, E. I. 1990. Mafic enclaves in the Wilson Ridge Pluton, Northwestern Arizona: implications for the generation of a calc-alkaline intermediate pluton in an extensional environment. Journal of Geophysical Research 95, 17693–716.CrossRefGoogle Scholar
Leake, B. E. 1978. Nomenclature of amphiboles. Canadian Mineralogist 16, 501–20.Google Scholar
Lindsley, D. H., & Andersen, D. J. 1983. A two-Pyroxene thermometer. In Proceedings of the thirteenth lunar and planetary science conference, part 2, pp. A887A906. Journal of Geophysical Research 88, suppl.Google Scholar
Macleod, W. N., Turner, D. C., & Wright, E. P. 1971. The geology of the Jos Plateau. Geological Survey of Nigeria Bulletin, 32, 2 vols. 1, 118 p.Google Scholar
Mccurry, P., & Wright, J. B. 1971. On place and time in orogenic granite plutonism. Geological Society of America Bulletin 82, 1713–16.CrossRefGoogle Scholar
Morimoto, N. 1988. Nomenclature of pyroxenes. Bulletin de Mineralogie 111, 535–50.CrossRefGoogle Scholar
Naney, M. T., & Swanson, S. E. 1980. The effect of Fe and Mg on crystallisation in granitic systems. American Mineralogist 65, 639–53.Google Scholar
Nédélec, A., Paquette, J.-L., Bouchez, J.-L., Olivier, P., & Ralison, B. 1994. Stratoid granites of Madagascar: structure and position in the Panafrican orogeny. Geodinamica Acta 7, 48–56.CrossRefGoogle Scholar
Paterson, S. R., Vernon, R. H., & Tobish, O. T. 1989. A review of criteria for the identification of magmatic and tectonic foliations in granitoids. Journal of Structural Geology 11, 349–63.CrossRefGoogle Scholar
Platevoet, B., & Bonin, B. 1991. Enclaves and mafic-felsic associations in the Permian alkaline province of Corsica, France: physical and chemical interactions, between coeval magmas. In Enclaves and granite petrology (eds Didier, J., and Barbarin, B.), pp. 191–204. Amsterdam: Elsevier.Google Scholar
Rahaman, M. A. 1988. Recent advances in the study of the basement complex of Nigeria. In Precambrian geology of Nigeria, pp. 11–43. Kaduna: Geological Survey of Nigeria.Google Scholar
Reid, J. B. Jr, Evans, O. C., & Fates, D. G. 1983. Magma mixing in granitic rocks of the central Sierra Nevada, California. Earth and Planetary Science Letters 66, 243–61.CrossRefGoogle Scholar
Rochette, P., Jackson, M., & Aubourg, C. 1992. Rock magnetism and the interpretation of anisotropy of magnetic susceptibility. Reviews of Geophysics 30, 209–26.CrossRefGoogle Scholar
Speer, J. A. 1984. Micas in igneous rocks. In Micas (ed. Bailey, S. W.), pp. 299–356. Reviews in Mineralogy 13. Washington: Mineralogical Society of America.CrossRefGoogle Scholar
Turner, D. C. 1983. Upper Proterozoic schist belts in the Nigerian sector of the Pan-African province of West Africa. Precambrian Research 21, 55–79.CrossRefGoogle Scholar
Utke, A. W. 1987. New aspects on the evolution of the Late Proterozoic crust in NW-Nigeria. In Current Research in African Earth Sciences (eds Matheis, G., and Schandelmeier, H.), pp. 73–8. Rotterdam: Balkema.Google Scholar
Van Der Laan, S. R., & Wyllie, P. J. 1993. Experimental interaction of granitic and basaltic magmas and implications for mafic enclaves. Journal of Petrology 34, 491–517.CrossRefGoogle Scholar
Vogel, T. A., Younker, L. W., Wllband, J. T., & Kampmueller, E. 1984. Magma mixing: the Marsco suite, Isle of Skye, Scotland. Contributions to Mineralogy and Petrology 87, 231–41.CrossRefGoogle Scholar
Wager, L. R., & Bailey, E. 1953. Basic magma chilled against acid magma. Nature 172, 68–9.CrossRefGoogle Scholar
Weinberg, R. F. 1994. Re-examining pluton emplacement processes: discussion. Journal of Structural Geology 16, 743–6.CrossRefGoogle Scholar
Wiebe, R. A. 1994. Silicic magma chambers as traps for basaltic magmas: the Cadillac Mountain intrusive complex, Mount Desert Island, Maine. Journal of Geology 102, 423–38.CrossRefGoogle Scholar
Wones, D. R. 1981. Mafic silicates as indicators of intensive variables in granitic magmas. Mining Geology 31, 191–212.Google Scholar
Wones, D. R., & Eugster, H. P. 1965. Stability of biotite: experiment, theory and application. American Mineralogist 50, 1228–72.Google Scholar