##plugins.themes.bootstrap3.article.main##

African formations intruded by the “Younger Granites” ring complex. In the study area, the “Younger Granites” are represented by volcanic to acid plutonic rocks with hyperalkaline trends (pyroclastic rocks, rhyolites, microgranites, granites, syenites), forming in the North, a circular structure called Gouré ring complex. Preliminary geochronological datings of the Mounio granites have yielded Carboniferous ages. However, recent investigations carried out in this province have identified structures similar to Pan-African deformation structures, such as folds and several generations of schistosity/foliation. Analysis of the relationship between deformation and magmatism has removed any ambiguity regarding the relative age of the deformation. This study focuses on the radiometric dating of the “Younger Granites” of Gouré area, in order to update the geochronological data. Thus, three samples (pyroclastitic rock, rhyolite, microgranite) were dated by the K-Ar method on total rock using a mass spectrometertype MI 1201 IG. Radiometric dating results assign a Lower Permian age (293-287 Ma) to the “Younger Granites” Ring Complex of the Mounio Province in Niger, classically considered to be Carboniferous in age.

References

  1. Moreau C., Demaiffe D., Bellion Y., Boullier A.-M. A tectonic model for the location of Palaeozoic ring complexes in Aïr (Niger, West Africa). Tectonophysics, 1994; 234.129-146. doi: 10.1016/0040-1951(94)90208-9.
     Google Scholar
  2. Vail J. R. Ring complexes and related rocks in Africa. Journal of African Earth Sciences, 1989; 8(1):19-40. doi: 10.1016/S0899-5362(89)80006-5.
     Google Scholar
  3. Bowden, P., Black, R., Martin, I~ F., Ike, I. C., Kinnaird, J. A. and Batchelor, R.A. Niger-Nigeria alkaline ring-complexes: a classical example of African Phanerozoic anorogenic told-plate magmatism. In: Alkaline Igneous Rocks. J. G. Fltton and B. J. G. Upton Eds, Geol. Soc. Spec. Publ.1987;30:357-379. doi: 10.1002/gj.3350220622.
     Google Scholar
  4. Karche J. P. et Vachette M. Age et migration de l’activité magmatique dans les complexes paléozoïques du Niger, conséquences. Bull. Soc. Géol. Fr., 1978; 20:941-953.
     Google Scholar
  5. Karche J. P. et Vachette M. Migration des complexes subvolcaniques à structure annulaire du Niger. Conséquences. C. R. Ac. Sci., Paris, t. 281. P. 2033-3036. 1976.
     Google Scholar
  6. Bowden P., Van Breemen D., Hutchinson J. et Turner D. C. Paleozoic and Mesozoic ages trends for some ring complexes in Niger and Nigeria. Nature, 1976;259, 5541: 297-299.
     Google Scholar
  7. Breemen O. Van, Hutchinson J. et Bowden P. Age and origin of the Nigerian mesozoic granites: a Rb-Sr isotopic study, contrib. Mineral. Petrol., 1975;50:157-172. doi: 10.1007/BF00371037.
     Google Scholar
  8. Breemen, O. Van and Bowden, P. Sequential age trends for some Nigerian Mesozoic granites. Nature, 1973;242:9-11. doi: 10.1038/physci242009a0.
     Google Scholar
  9. Mignon R. Etude géologique et prospection du Damagaram-Mounio et du Sud-Maradi, Rapport BRGM, 68 p. 1970.
     Google Scholar
  10. PRDSM. Notice de la carte geologique du damagaram-mounio (Echelles 1/100 000 et 1/200 000), Assistance technique dans le domaine géoscientifique (SOFRECO), 2ème édition, 62p. 2013.
     Google Scholar
  11. Caby R. Terrane assembly and géodynamic evolution of central-western Hoggar, a 730 Macratonic black in the panafrican belt of the northern African Continent. Precambrien research, 2003;36:335-344. doi: 10.1016/j.jafrearsci.2003.05.003.
     Google Scholar
  12. Abdelsalam M.G., Liégeois J.P., Stern R.J. The Saharan Metacraton. Journal of African Earth Sciences, 2002; 34(3-4):119-136. doi: 10.1016/S0899-5362(02)00013-1.
     Google Scholar
  13. Ferré E., Gleizes G. and Caby R. Obliquely convergent tectonics and granite emplacement in the Trans-Saharan belt of Eastern Nigeria : a synthesis. Precambrian research, 2002;114:199-219 p. doi: 10.1016/S0301-9268(01)00226-1.
     Google Scholar
  14. Black R., L. Latouche, J-P. Liégeois, R. Caby, J. M. Bertrand. Pan-African displaced terranes in the Tuareg shield (central Sahara). Geology, 1994;22:641-644.
     Google Scholar
  15. Koner A. and Stern R.J. Pan African orogeny. In: Selley, R.C., Cocks, L.R.M., Plimer, R.I. (Eds.), Encycl. Geol. 1, 2005:1-12.
     Google Scholar
  16. Ferré E., Deleris J., Bouchez J. L., Lar A.U., and Peucat J. J. The Pan-African reactivation of Eburnean and Archaean provinces in Nigeria: structural and isotopic data. J. Geol. Soc. London, 1996;153:719-728. doi: 10.1144/gsjgs.153.5.0719.
     Google Scholar
  17. Castaing C., Triboulet C., Feybesse J. L. et Chèvremont P. Tectonometamorphic evolution of Ghana, Togo and Benin in the light of the Pan-African/Brasiliano orogeny. Tectonophysics, 1993; 218:323-342. doi.10.1016/0040-1951(93)90322-B.
     Google Scholar
  18. Ajibade, A. C. et Wright, J. B. The Togo-Benin-Nigeria Shield: evidence of crustal aggregation in the Pan-African belt. Tectonophysics, 1989; 165: 125-129. doi: 10.1016/0040-1951(89)90041-3.
     Google Scholar
  19. Caby R. Precambrian terranes of Benin- Nigeria and Northeast Brazil and the late Proterozoic south Atlantic fit. Geol. Soc. Am. Special Pap., 1989;230:145-158.
     Google Scholar
  20. Breemen O. Van, Pidgeon, R. T. et Bowden, P. Age and isotopic studies of some Pan-African granites from north-central Nigeria. Precambrian Res., 1977;4:307-319. doi: 10.1016/0301-9268(77)90001-8.
     Google Scholar
  21. Black R., Liégeois J. P., Navez J. & Vialette Y. Terrains exotiques dans les zones internes de la chaîne panafricaine transsaharienne : les clefs fournies par l’Aïr sud-oriental (République du Niger), C.R. Acad. Sci. Paris. 1991.
     Google Scholar
  22. Ba H., Black R., Benziane B., Diombana D., Hascoet-Fender J., Bonin B., Fabre J., Et Liegeois J. P... La province des complexes annulaires alcalins sursaturés de l'adrar des Iforas, Mali. Journal of African Earth Sciences, 1985;3(1/2):pp. 123-142. doi: 10.1016/0899-5362(85)90031-4.
     Google Scholar
  23. Ngako V., Nionfang E., Tongwa Aka F., Affaton P., Metuk Nnange J. The North–South Paleozoic to Quaternary trend of alkaline magmatism from Niger–Nigeria to Cameroon: Complex interaction between hotspots and Precambrian faults. Journal of African Earth Sciences, 2006;45(3):241-256. doi:10.1016/j.jafrearsci.2006.03.003.
     Google Scholar
  24. Black, R., Lameyre, J. and Bonin, B. The structural setting of alkaline ring-complexes. J. Aft. Earth ScL, 1985;3:5-16.
     Google Scholar
  25. Ajakaiye D. E., Bowden P., Hall D. H., Verheijen P. J. T. Age migrations and aeromagnetic anomalies in anorogenic ring complexes from northern Nigeria. Conférence abstracts. Journal of African Earth Sciences, 1985;3(1/2):273-277.
     Google Scholar
  26. PRDSM. Projet de géophysique aéroportée dans le secteur Sud Maradi, 2005, 55 p.
     Google Scholar
  27. Bruguier O., Dada S. and Lancelot J. R. Early Archaean component (>3.5 Ga) within a 3.05 Ga orthogneiss from northern Nigeria; U-Pb zircon evidence, Earth and Planetary Science Letters, 1994;125(1-4): 89-103. doi: 10.1016/0012-821x(94)90208-9.
     Google Scholar
  28. Liégeois J. P., Latouche L., Boughrara M., Navez J. and Guiraud M. 2003. The LATEA metacraton. (Central Hoggar, Tuareg shield, Algeria): behaviour of an old passive margin during the Pan-African orogeny. Journal of African Earth Sciences, 2003;37:161–190. doi:10.1016/j.jafrearsci.2003.05.004.
     Google Scholar
  29. Trompette R. Neoproterozoic (~600 Ma) aggregation of Western Gondwana: a tentative scenario. Precambrian Research, 1997;82:101-112.
     Google Scholar
  30. Villeneuve M. and Cornée J. J. Structure, evolution and palaeogeography of West African craton and bordering belts during the Neoproterozoic. - Prec. Res., 1994;69:307-326. doi:10.1016/0301-9268(94)90094-9.
     Google Scholar
  31. Stern R. J. Arc assembly and continental collision in the Neoproterozoic East African orogeny – implications for the consolidation of Gondwana, Annual Review of Earth and Planetary Sciences, 1994;22:319-351.
     Google Scholar
  32. Baraou I. S. & Konaté M. Kinematic evolution of the Pan-African shear zones of South Maradi, Southern Niger. Global Journal of Earth and Environnemental Science, 2020a;5(4):101-116. doi: 10.31248/GJEES2020.087.
     Google Scholar
  33. Baraou I. S. & Konaté M. New radiometric data from the South Maradi Pan-African formations, southern Niger. J. Geol. Soc. London, Special Publications. 2020b. doi :10.1144/SP502-2019-151.
     Google Scholar
  34. Black R. et Morosoff. W. Rapport provisoire sur les youngers granites de la région de Zinder-Gouré. B.R.G.M. Dakar. 1960.
     Google Scholar
  35. Black R. Note sur les complexes annulaires de Tchouni-Zarnouski et de Gouré, Bull. B.R.G.M. Fr., N°1. 1963.
     Google Scholar
  36. Tidjani A.D. Erosion éolienne dans le Damagaram Est (Sud-Est du Niger): Paramétrisation, quantification et moyens de lutte. Thèse de doctorat de l’Université Catholique de Louvain. 2008.
     Google Scholar
  37. Scott Sinnock, Robert G. Easterling. Empirically determined uncertainty in Potassium-Argon ages for Plio-Pleistocene basalts from crater flat, Nye County, Nevada. Sandia National Laboratories, Albuquerque, New Mexico 87185 and Livermore, California 94550. 1983.
     Google Scholar
  38. Dodson M.H. Closure Temperature in Cooling Geochronological and Petrological Systems, in Contrib Mineral Petrol, volume 40, pages 259 à 274. 1973. doi: 10.1007/BF00373790.
     Google Scholar
  39. Müller W., Aerden D., Halliday A.N. Isotopic dating of strain fringe increments: duration and rates of deformation in shear zones, in Science, volume 288, pages 2195 à 2198. 2000.
     Google Scholar
  40. Cohen, K.M., Finney, S.C., Gibbard, P.L. & Fan, J.-X. (2013; updated) The ICS International Chronostratigraphic Chart. Episodes 36:199-204. 2021. URL:http://www.stratigraphy.org/ICSchart/ChronostratChart2021-07.pdf.
     Google Scholar


Most read articles by the same author(s)