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Clay mineralogy in southern Africa river muds

  • M. Setti (a1), A. Lόpez-Galindo (a2), M. Padoan (a3) and E. Garzanti (a3)


The composition, morphology and crystal order of clay minerals in silt-sized sediments carried in suspensions from 25 major rivers across tropical southern Africa have been studied by X-ray diffractometry and scanning and transmission electron microscopy. Our goal was to determine the spatial variability of clay-mineral associations in diverse geological settings, and in climatic conditions ranging from humid Angola and Zambia to hyperarid Namibia and the Kalahari. Specific attention was paid to the micromorphology and chemical composition of smectite particles. The relative abundance of smectites, illite/mica, kaolinite and chlorite enabled identification of regions characterized by different physical and chemical processes: (1) negligible chemical weathering is documented in Namibia, where river muds mostly contain illite/mica or smectite derived from Damara metasedimentary or Etendeka volcanic rocks; (2) kaolinite documenting intense weathering, reaches a maximum in the Okavango, Kwando and Upper Zambezi, sourced in subequatorial Angola and Zambia; (3) suspended-load muds in the Limpopo and middle Zambezi catchments display intermediate features, with varied assemblages and smectite compositions reflecting diverse parent lithologies. Clay mineralogy and chemical composition are confirmed as a most effective tool to unravel present and past climatic conditions on a continental scale.


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Al-Juboury, I. (2009) Palygorskite in Miocene rocks of northern Iraq: environmental and geochemical indicators. Acta Geologica Polonica, 59, 269–282.
April, R.H. (1981) Trioctahedral smectite and interstratified chlorite/smectite in Jurassic strata of the Connecticut Valley. Clays and Clay Minerals, 29, 31–39.
Biscaye, P.E. (1965) Mineralogy and sedimentation of recent deep-sea clay in the Atlantic Ocean and adjacent seas and oceans. Geological Society of America Bulletin, 76, 803–831.
Bradley, W.H. & Fahey, J.J. (1962) Occurrence of stevensite in the Green River Formation of Wyoming. American Mineralogist, 47, 996–998.
Bremner, J.M. & Willis, J.P. (1993) Mineralogy and geochemistry of the clay fraction of sediments from the Namibian continental margin and the adjacent hinterland. Marine Geology, 115, 85–116.
Campbell, I.B. & Claridge, G.G.C. (1987) Antarctica: Soils, Weathering Processes and Environment. Developments in Soil Sciences. Elsevier, Amsterdam.
Chamley, H. (1989) Clay Sedimentology. Springer, Berlin.
Duzgoren-Aydin, N.S., Aydin, A. & Malpas, J. (2002) Reassessment of chemical weathering indices: case study on pyroclastic rocks of Hong Kong. Engineering Geology, 63, 99–119.
Dyni, J.R. (1976) Trioctahedral smectite in the Green River Formation, Duchesne County, Utah. Geological Survey Professional Paper 967, United States Geological Survey.
Eitel, B., BlÜmel, W.D. & Mauz, B. (2001) Dust and loessic alluvial deposits in northwestern Namibia (Damaraland, Kaokoveld): sedimentology and palaeoclimatic evidence based on luminescence data. Quaternary International, 76/77, 57–65.
Eitel, B., Kadereit, A., BlÜmel, W.D., HÜser, K., Lomax, J. & Hilgers, A. (2006) Environmental changes at the eastern Namib Desert margin before and after the Last Glacial Maximum: new evidence from fluvial deposits in the upper Hoanib River catchment, northwestern Namibia. Palaeogeography, Palaeoclimatology, Palaeoecology, 234, 201–222.
Emeis, K.C. (1985) Particulate suspended matter in major world rivers, Part II: Results on the rivers Indus, Waikato, Nile, St. Lawrence, Yangtse, Parana, Orinoco, Caroni, and Mackenzie. Pp. 593–617 in: Transport of Carbon and Minerals in Major World Rivers, Part I (E.T. Degens, S. Kempe & R. Herrera, R., editors). Mitt. Geol.-Paläont. Institut Univ. Hamburg, Hamburg.
Emeis, K.C. & Stoffers, P. (1982) Particulate suspended matter in major world rivers: EDX analysis, scanning electron microscopy, and X-ray diffraction study of filters. Pp. 529–554 in: Transport of Carbon and Minerals in Major World Rivers (E.T. Degens, editor). Mitt. Geol.- Paläont. Institut Univ. Hamburg, Hamburg.
Ewart, A., Marsh, J.S., Milner, S.C., Duncan, A.R., Kamber, B.S. & Armstrong, R.A. (2004) Petrology and geochemistry of Early Cretaceous bimodal continental flood volcanism of the N. Etendeka, Namibia. Journal of Petrology, 45, 59–138.
Gaillardet, J., Dupré, B. & Alle`gre, C.J. (1999) Geochemistry of large river suspended sediments: silicate weathering or recycling tracer? Geochimica et Cosmochimica Acta, 63, 4037–4051.
Galán, E. (2006) Genesis of Clay Minerals. Pp. 1129–1162 in: Handbook of Clay Science (F. Bergaya, B.K.G. Theng & G. Lagaly, editors). Elsevier: Amsterdam, 1129-1162.
Galán, E. & Pozo, M. (2011). Palygorskite and sepiolite deposits in continental environments. Description, genetic patterns and sedimentary settings. Pp. 125–173 in: Developments in Clay Science (E. Gala`n & A. Singer, editors). Elsevier, Amsterdam.
Garzanti, E., Padoan, M., Setti, M., Najman, Y., Peruta, L. & Villa, I.M. (2013) Weathering geochemistry and Sr-Nd fingerprints of equatorial upper Nile and Congo muds. Geochemistry, Geophysics, Geosystems, 14, 292–316.
Garzanti, E., Padoan, M., Setti, M., Lόpez-Galindo, A. & Villa, I.M. (2014a) Provenance versus weathering control on the composition of tropical river mud (southern Africa). Chemical Geology, 366, 61–74.
Garzanti, E., Vermeesch, P., Padoan, M., Resentini, A., Vezzoli, G. & Ando`, S. (2014b) Provenance of passive-margin sand (southern Africa). The Journal of Geology, 122, 17–42.
Grauby, O., Petit, S., Decarreau, A. & Baronnet, A. (1993) The beidellite-saponite series: an experimental approach. European Journal of Mineralogy, 5, 623–635.
Gray, D.R., Foster, D.A., Meert, J.G., Goscombe, B.D., Armstrong, R., Trouw, R.A.J. & Passchier, C.W. (2008) A Damara Orogen perspective on the assembly of southwestern Gondwana. Pp. 257–278 in: West Gondwana: pre-Cenozoic Correlations across the South Atlantic Region (R.J. Pankhurst, R.A.J. Trouw, B.B. Brito Neves & M.J. De Wit, editors). Geological Society, London.
GÜven, N. (1988) Smectites. Pp. 497–559 in: Hydrous Phyllosilicates (Exclusive of Micas) (S.W. Bailey, editor). Reviews in Mineralogy, 19. Mineralogical Society of America.
Hanson, R.E. (2003) Proterozoic geochronology and tectonic evolution of southern Africa. Pp. 427–463 in: Proterozoic East Gondwana: Supercontinent Assembly and Breakup (M. Yoshida, B.F. Windley & S. Dasgupta editors). Geological Society, London.
Hardie, L., Smoot, J. & Eugster, H. (1978) Saline lakes and their deposits: a sedimentological approach. Pp. 7–41 in: Modern and Ancient Lake Sediments (A. Matter & M. Tucker, editors). Special Publications of the International Association of Sedimentologist. John Wiley & Sons, Ltd, Oxford.
Hay, W.W. (1998) Detrital sediment fluxes from continents to oceans. Chemical Geology, 145, 287–323.
Hillier, S. (1995) Erosion, sedimentation and sedimentary origin of clays. Pp. 162–219 in: Origin and Mineralogy of Clays (B. Velde, editor). Springer, Berlin.
Johnsson, M.J., Stallard, R.F. & Lundberg, N. (1991) Controls on the composition of fluvial sands from a tropical weathering environment: Sands of the Orinoco River drainage basin, Venezuela and Colombia. Geological Society of America Bulletin, 12, 1622–1647.
Jones, B.F. (1986) Clay mineral diagenesis in lacustrine sediments. Pp. 291–300 in: Studies in Diagenesis (F.A. Mumpton, editor). U.S. Geological Survey Bulletin, 1578.
Khormali, F., Abtahi, A. & Owliaie, H.R. (2005) Late Mesozoic-Cenozoic clay mineral successions of southern Iran and their palaeoclimatic implications. Clay Minerals, 40, 191–203.
Konta, J. (1985) Mineralogy and chemical maturity of suspended matter in major rivers sampled under the, S.O.E/UNEP Project. Pp. 569–592 in: Transport of Carbon and Minerals in Major World Rivers, Part 3 (E.T. Degens, S. Kempe & R. Herrera, editors). Mitt. Geol.-Paläont. Institut Univ. Hamburg, Hamburg.
Lisitzin, A.P. (1972) Sedimentation in the World Ocean. Society of Economic Paleontologists and Mineralogists. Special Publications.
Mayayo, M.J., Torres-Ruiz, J., Gonzalez-Lόpez, J.M., Lόpez-Galindo, A. & Bauluz, B. (1998) Mineralogical and chemical characterization of the sepiolite/Mgsmectite deposit at Mara (Calatayud basin, Spain). European Journal of Mineralogy, 10, 367–383.
McCarthy, T.S. & Ellery, W.N. (1995) Sedimentation on the distal reaches of the Okavango Fan, Botswana, and its nearing on calcrete and silcrete (Ganister) formation. Journal of Sedimentary Research, A65, 77–79.
Millot, G. (1970) Geology of Clays. Springer-Verlag, New York.
Moore, D.M. & Reynolds, R.C. (1989) X-ray diffraction and the Identification and Analysis of Clay Minerals. Oxford University Press, New York.
Nesbitt, H.W. & Young, G.M. (1982) Early Proterozoic climates and plate motions inferred from major element chemistry of lutites. Nature, 299, 715–717.
Papke, K.G. (1970) Montmorillonite, bentonite, and fuller’s earth deposits in Nevada. Nevada Bureau Mines Bulletin, Nevada-Reno.
Papke, K.G. (1972) A seprolite-rich playa deposit in southern Nevada. Clays and Clay Minerals, 20, 211–215.
Paquet, H., Duplay, J., Valleron-Blanc, M.M. & Millot, G. (1987) Octahedral composition of individual particles in smectite-palygorskite and smectite-sepiolite assemblages. Pp. 73–77 in: Proceedings of the International Clay Conference, Denver, 1985 (L.G. Schultz, H. van Olphen & F.A. Mumpton, editors). The Clay Minerals Society, Bloomington, Indiana.
Parker, A. (1970) An index of weathering for silicate rocks. Geological Magazine 107, 501–504.
Pozo, M. & Casas, J. (1999) Origin of kerolite and associated M. clays in palustrine-lacustrine environments. The Esquivias deposit (Neogene Madrid Basin, Spain). Clay Minerals, 34, 395–418.
Setti, M., Marinoni, L., Lopez-Galindo, A. & Ben Aboud, A. (1997) XRD, SEM and T.M. investigation of smectites of the Core C.R. S-1 (Ross Sea, Antarctica). Terra Antartica, 4, 119–125.
Setti, M., Marinoni, L., Lόpez-Galindo, A. & Delgado- Huertas, A. (2000) Compositional and morphological features of smectites in sediments from C.P. 2/2A, Victoria Land Basin, Antarctica. Terra Antartica, 7, 581–587.
Setti, M., Marinoni, L. & Lόpez-Galindo, A. (2001) Crystal-chemistry of smectites in sediments of C.P. 3 drillcore (Victoria Land Basin, Antarctica): preliminary results. Terra Antartica, 8, 543–550.
Setti, M., Marinoni, L., Lόpez-Galindo, A. & Ben Aboud, A. (1998) TEM observations and Rare Earth Element Analysis on the clay minerals of the C.P. 1 Core (Ross Sea Antarctica). Terra Antartica, 5, 621–626.
Setti, M., Marinoni, L. & Lόpez-Galindo, A. (2004) Mineralogical and geochemical characteristics (major, minor, trace elements and R.E. of detrital and authigenic clay minerals in a Cenozoic sequence from Ross Sea, Antarctica. Clay Minerals, 39, 405–421.
Singer, A. (1984) The paleoclimatic interpretation of clay minerals in sediments: a review. Earth-Science Reviews, 21, 251–293.
Thiry, M. (2000) Palaeoclimatic interpretation of clay minerals in marine deposits: an outlook from the continental origin. Earth-Science Reviews, 49, 201–221.
Thomas, D.S.G. & Shaw, P.A. (1990) The deposition and development of the Kalahari Group sediments, central southern Africa. Journal of African Earth Sciences, 10, 187–197.
Velde, B. (1995) Origin and Mineralogy of Clays. Springer Verlag, Berlin.
Verrecchia, E.P. & Le Coustumer, M.N. (1996) Occurrence and genesis of palygorskite and associated clay minerals in a Pleistocene calcrete complex, Sde Boqer, Negev Desert , Israel. Clay Minerals, 31, 183–202.
Viers, J., Dupré, B. & Gaillardet, J. (2009) Chemical composition of suspended sediments in world rivers: new insights from a new database. Science of the Total Environment, 407, 853–868.
Weaver, C.E. (1989) Clays, Muds and Shales. Developments in Sedimentology, 44. Elsevier, Amsterdam.
Weaver, C.E. & Pollard, L.D. (1973) The Chemistry of Clay Minerals. Developments in Sedimentology, 15. Elsevier, Amsterdam.
Zabel, M., Schneider, R.R., Wagner, T., Adegbie, A.T., de Vries, U. & Kolonic, S. (2001) Late Quaternary climate changes in Central Africa as inferred from terrigenous input to the Niger Fan. Quaternary Research, 56, 207–217.


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Clay mineralogy in southern Africa river muds

  • M. Setti (a1), A. Lόpez-Galindo (a2), M. Padoan (a3) and E. Garzanti (a3)


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