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Petrographic and geochemical study of the Maastrichtian Ajali Sandstone, North Central Nigeria

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Warianty tytułu
Języki publikacji
EN
Abstrakty
EN
he Upper Cretaceous Ajali Sandstone is an extensive stratigraphic unit of the Anambra Basin in southern Nigeria. It consists of friable, white cross-bedded sandstones exhibiting a fining upward sequence. Structures such as bioturbation, planar and herringbone cross beds indicate variability in depositional environment ranging from fluviatile to deltaic. Petrographic and geochemical compositions (major and trace elements) of these sandstones have been investigated to determine their provenance, tectonic setting and weathering conditions. Fifteen sandstone samples examined are rich in quartz but poor in feldspar and lithic fragments. Texturally, the framework grains of the sandstones are fine- to medium-grained, sub-angular to sub-rounded, moderately sorted to poorly sorted, positively skewed and leptokurtic. The sandstones are texturally immature as depicted by their sub-angular edges of grains, but mineralogically mature in terms of high percentage of quartz. The high chemical index of alteration (CIA) values (71.0–99.2%) for these sandstones suggests that they were derived from highly weathered rocks in the source area. The composition of the major oxides in the sandstones revealed that SiO2 (49.1–99.7%), Al2O3 (0.2–30.3%), Fe2O3 (0.4–1.8%) and TiO2 (0.06–3.2%) were the most abundant elements in all sandstone samples indicating a high detrital quartz and clay mineral content. The Al2O3/TiO2 ratios (1.47 to 12.48), Ti/Zr (6.48–18.63) and Zr/Cr (2.24–22.36) suggest that the sandstones were derived from variable basement complex rocks, including some contribution from mafic or ultramafic components. Inferences from the plots of K2O/Na2O versus SiO2 indicated a passive margin tectonic setting for the sandstones. The high loading of CaO and Na2O in more than 50% of the samples is indicative of terrigenous input, mainly in the form of carbonates and silicates. These results are generally consistent with a derivation of the sandstones from adjacent igneous and metamorphic basement complexes (Cameroon–Adamawa highlands and Oban Massif) while the extensive and blanket-like geometry of the Ajali Sandstone is indicative of an excellent reservoir for groundwater in the Anambra Basin.
Rocznik
Strony
79--90
Opis fizyczny
Bibliogr. 43 poz., rys., tab., wykr.
Twórcy
autor
  • Delta State University, Department of Geology, P.M.B. 1, Abraka, Nigeria
  • University of Lagos, Department of Geosciences, Lagos, Akoka, Nigeria
  • Federal University of Petroleum Resources, Department of Earth Sciences, P.M.B. 1221, Effurun, Nigeria
  • Delta State University, Department of Geology, P.M.B. 1, Abraka, Nigeria
Bibliografia
  • 1. Agagu, O.K., Fayose, E.A., Petters, S.W., 1985. Stratigraphy and sedimentation in the Senonian Anambra Basin ofeastern Nigeria. Journal of Mining and Geology, 22: 25-36.
  • 2. Akande, S.O., Ogunmoyero, I.B., Petersen, H.I., Nytoft, H.P., 2007. Source rock evaluation of coals from the Lower Maastrichtian Mamu Formation, SE Nigeria. Journal of Petroleum Geology, 30: 303-324.
  • 3. Amajor, L.C., 1984. Sedimentary facies of the Ajali Sandstone(Upper Cretaceous), southern Benue Trough. Journal of Mining and Geology, 28: 7-17.
  • 4. Armstrong-Altrin, J.S., Lee, Y.I., Verma, S.P., Ramasamy, S., 2004. Geochemistry of sandstones from the Upper Miocene Kudankulam Formation, southern India: implications for provenance, weathering, and tectonic setting. Journal of Sedimentary Research, 74: 285-297.
  • 5. Banerjee, I., 1979. Quantitative analysis of stratigraphic sequences. Journal of Mining and Geology, 16: 111-118.
  • 6. Benkhelil, J., 1989. The evolution of the Cretaceous Benue Trough, Nigeria. Journal of African Earth Sciences, 8: 251-282.
  • 7. Bhatia, M.R., 1983. Plate tectonics and geochemical composition of sandstones. Journal of Geology, 91: 611-627.
  • 8. Bhatia, M.R., Crook, A.W., 1986. Trace element characteristics of graywackes and tectonic setting discrimination of sedimentary basins. Contributions to Mineralogy and Petrology, 92:181-193.
  • 9. Burke, K.C., Dessauvagie, T.F.G., Whiteman, A.J., 1972. Geological History of the Benue Valley and Adjacent Areas (eds. T.F.J. Dessauvagie and A.J. Whiteman): 187-205. University of Ibadan, Nigeria.
  • 10. Dickinson, W.R., 1970. Interpreting detrital modes of greywacke and arkose. Journal of Sedimentary Petrology, 40: 695-707.
  • 11. Dickinson, W.R., Suczek, C.A., 1979. Plate tectonics and sandstone compositions. AAPG Bulletin, 63: 2164-2182.
  • 12. Dickinson, W.R., Beard, L.S., Brakenridge, G.R., Erjavec, J.L., Ferguson, R.C., Inman, K.F., Knepp, R.A., Lindberg, F.A., Ryberg, P.T., 1983. Provenance of North American Phanerozoic sandstone in relation to tectonic setting. GSA Bulletin, 94: 222-235.
  • 13. Fedo, C.M., Nesbitt, H.W., Young, G.M., 1995. Unraveling the effects of potassium metasomatism in sedimentary rocks and paleosols, with implications for weathering conditions and provenance. Geology, 23: 921-924.
  • 14. Feng, R., Kerrich, R., 1990. Geochemistry of fine-grained clastic sediments in the Archean Abitibi greenstone belt, Canada: implications for provenance and tectonic setting. Geochimica et Cosmochimica Acta, 54: 1061-1081.
  • 15. Folk, R.L., 1968. Petrology of Sedimentary Rocks. Hemphill's,Austin, Texas.
  • 16. Folk, R.L., Ward, W., 1957. Brazos River bar, a study in significance of grain size parameters. Journal of Sedimentary Petrology, 27: 3-26.
  • 17. Garver, J.I., Royce, P.R., Smick, T.A., 1996. Chromium and nickel in shale of the Taconic Foreland: a case study for the provenance of fine-grained sediments with an ultramafic source. Journal of Sedimentary Research, 66: 100-106.
  • 18. Gazzi, P., 1966. Le arenarie del flysch sopracretaceo dell' Appennino modenese; correlazioni con il flysch di Monghidoro. Mineralogica et Petrographica Acta, 12: 69-97.
  • 19. Getaneh, W., 2002. Geochemistry provenance and depositional tectonic setting of the Adigrat Sandstone, northern Ethiopia. Journal of African Earth Sciences, 35: 185-198.
  • 20. Harnois, L., 1988. The CIW Index: a new chemical index for weathering. Sedimentary Geology, 55: 319-322.
  • 21. Hayashi, K., Fujisawa, H., Holl and, H., Ohmoto, H., 1997. Geochemistry of ~1.9 Ga sedimentary rocks from northeastern Labrador, Canada. Geochimica et Cosmochimica Acta, 61: 4115-4137.
  • 22. Herron, M.M., 1988. Geochemical classification of terrigenous sands and shales from core and log data. Journal of Sedimentary Petrology, 58: 820-829.
  • 23. Hoque, M., 1977. Petrographic differentiation of tectonically controlled Cretaceous sedimentary cycles, southeastern Nigeria. Sedimentary Geology, 17: 235-245.
  • 24. Hoque, M., Ezepue, M., 1977. Petrology and paleogeography of Ajali Sandstone. Journal of Mining and Geology, 14: 16-22.
  • 25. Ladipo, K.O., 1986. Tidal shelf depositional model for the Ajali Sandstone, Anambra Basin, southeastern Nigeria. Journal of African Earth Sciences, 5: 177-185.
  • 26. Ladipo, K.O., 1988. Paleogeography, sedimentation and tectonics of the Upper Cretaceous Anambra Basin, southeastern Nigeria. Journal of African Earth Sciences, 7: 865-871.
  • 27. Murat, R.C., 1972. Stratigraphy and paleogeography of the Cretaceous and lower Tertiary in southern Nigeria. In: African Geology (eds. T.F.J. Dessauvagie and A.J. Whiteman): 251-266. University of Ibadan Press, Nigeria.
  • 28. Nesbitt, H.W., Young, G.M., 1982. Early Proterozoic climates and plate motions inferred from major element chemistry of lutites. Nature, 299: 715-717.
  • 29. Nesbitt, H.W., Markovics, G., Price, R.C., 1980. Chemical processes affecting alkalies and alkaline earths during continental weathering. Geochimica et Cosmochimica Acta, 44: 1659-1666.
  • 30. Nwachukwu, S.O., 1972. The tectonic evolution of the southern portion of the Benue Trough, Nigeria. Geological Magazine, 109: 411-419.
  • 31. Olade, M.A., 1975. Evolution of the Nigeria's Benue Trough (aulacogen): a tectonic model. Geological Magazine, 112: 575-583.
  • 32. Osae, S., Asiedu, D.K., Banoeng-Yakubo, B., Koeberl, C., Dampare, S.B., 2006. Provenance and tectonic setting of Late Proterozoic Buem sandstones of southern Ghana: evidence from geochemistry and de trital modes. Journal of African Earth Sciences, 44: 85-96.
  • 33. Reyment, R.A., 1965. Aspects of Geology of Nigeria. University of Ibadan Press.
  • 34. Ronov, A.B., Balashov, Y.A., Girin, Y.P., Bratishko, R.K.H., Kazakov, G.A., 1974. Regularities of rare earth element distribution in the sedimentary shell and in the crust of the Earth. Sedimentology, 21: 171-193.
  • 35. Roser, B.P., Korsch, R.J., 1986. Determination of tectonic setting of sandstone-mudstone suites using SiO2 content and K2O/Na2O ratio. Journal of Geology, 94: 635-650.
  • 36. Roser, B.P., Korsch, R.J., 1988. Provenance signatures of sandstone-mudstone suite determined using discriminant function analysis of major element data. Chemical Geology, 67: 119-139.
  • 37. Short, K.C., Stauble, A.J., 1967. Outline of geology of Niger Delta. AAPG Bulletin, 51: 761-779.
  • 38. Simpson, A., 1947. Geology of the Escarpment, North of Enugu. Annual Report of Geological Survey of Nigeria: 9-14.
  • 39. Simpson, A., 1954. The Nigerian coal field: the geology of parts of Onitsha, Owerri, and Benue provinces. Geological Survey of Nigeria Bulletin, 24.
  • 40. Tattam, C.M., 1944. A Review of Nigeria Stratigraphy. Report of Geological Survey of Nigeria: 22-47.
  • 41. Taylor, S.R., McLennan, S., 1985. The Continental Crust: its Com- position and Evolution. Blackwell, London.
  • 42. Tijani, M.N., Nton, M.E., Kitagawa, R., 2010. Textural and geot chemical characteristics of the Ajali Sandstone, Anambra Basin, SE Nigeria: implication for its provenance. Comptes Rendus Geoscience, 342: 136-150.
  • 43. Wrafter, J.P., Graham, J.R., 1989. Ophiolitic detritus in the Ordovician sediments of south Mayo Ireland. Journal of the Geological Society, 146: 213-215.
Typ dokumentu
Bibliografia
Identyfikator YADDA
bwmeta1.element.baztech-99fdd11b-d24b-4173-bb27-6d5ccb9c0116
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