Clays and Clay Minerals

, Volume 52, Issue 4, pp 473–483 | Cite as

Mixed-layer kaolinite-smectite minerals in a red-black soil sequence from basalt in Sardinia (Italy)

  • Simona Vingiani
  • Dominique RighiEmail author
  • Sabine Petit
  • Fabio Terribile


Clay minerals from soils of a red-black soil complex developed from basaltic parent material in Sardinia are formed along a short toposequence (200 m). At the foot of the sequence, a clay-rich, black Vertisol forms, whereas at the summit, the soil is a dark reddish-brown Inceptisol. X-ray diffraction, infrared spectroscopy (FTIR), cation exchange capacity (CEC) and permanent and variable charges analyses were used, and the data show that clay minerals varied according to soil horizon and topographic position of the soil. Clay minerals in the Inceptisol are dominated by kaolinite and mixed-layer kaolinitesmectite (K-S, K:S >0.5), whereas the Vertisol contains smectites and K-S with K:S proportions <0.5. In the Vertisol, the proportion of kaolinitic layers in the K-S increases from the C horizon (K:S ∼0.35–0.40) to the Ap horizon (K:S ∼0.40–0.45). This soil clay-mineral distribution, in relation to topography, is similar to that reported for other (kaolinitic) red-black (smectitic) soil associations in subtropical and tropical areas. The sequence forms by downward drainage on summits and slopes, and buildup of ions in ‘lows’ produces smectites. Fourier transform infrared spectra indicate that two types of smectite are formed in the C horizon of the Vertisol; one is more ferric (Fe-beidellite, nontronite), the other more aluminous. Mineralogical evolution in the soil profile (from C to Ap horizon) shows a decreasing proportion of ferric smectite layers (compared to the more aluminous smectite layers). This would indicate that ferric smectite layers are preferentially transformed (or dissolved) to give kaolinite layers, with Fe precipitating as oxides and/or oxy-hydroxides or retained partly in kaolinite layers. Because the surface properties of clay minerals are related to mineralogy, the CEC (33–41 cmol kg−1) in the brown Inceptisol is ∼50% pH-dependent charge while in the Vertisol up to ∼75% of the CEC (48–61 cmol kg−1) comes from accessible permanent charges.

Key Words

Basalt (weathering) Fe-beidellite Italy Mixed-layer Kaolinite-smectite Nontronite Red-black Soil Sequence Sardinia Vertisol 


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  1. Anderson, S.J. and Sposito, G. (1991) Cesium-adsorption method for measuring accessible structural surface charge. Soil Science Society of America Journal, 55, 1569–1576.Google Scholar
  2. Beccaluva, L., Civetta, L., Macciotta, G. and Ricci, C.A. (1985) Geochronology in Sardinia: results and problems. Rendiconto Società Italiana di Mineralogia e Petrografia, 40, 57–72.Google Scholar
  3. Bühmann, C. and Grubb, P.L.C. (1991) A kaolin-smectite interstratification sequence from a red and black complex. Clay Minerals, 26, 343–358.Google Scholar
  4. Diaz, M.C. and Torrent, J. (1989) Mineralogy of iron oxides in two soil chronosequences of central Spain. Catena, 16, 291–299.Google Scholar
  5. Delvaux, B. and Herbillon, A.J. (1995) Pathways of mixed-layer kaolin-smectite formation in soils. Pp. 457–461 in: Clays Controlling the Environment (G.J. Churchman, R.W. Fitzpatrick and R.A. Eggleton, editors). CSIRO Publishing, Melbourne, Australia.Google Scholar
  6. Ente Autonomo del Flumendosa (1998) Nuovo studio dell’idrologia superficiale della Sardegna. Regione Autonoma della Sardegna, Assessorato della Programmazione, (X. Bilancio, editor). Assetto del Territorio-Centro Regionale di Programmazione, Cagliari, CD-rom.Google Scholar
  7. Herbillon, A.J., Frankart, R. and Vielvoye, L. (1981) An occurrence of interstratified kaolinite-smectite minerals in a red-black soil toposequence. Clay Minerals, 16, 195–201.Google Scholar
  8. Ildefonse, P. (1987) Analyse petrographique des alterations prémétéoriques et météoriques de deux roches basaltiques (basaltes de Belbex, Cantal et Hawaiite de M’Bouda, Cameroun). Doctoral thesis, Université Paris 7, Paris, 142 pp.Google Scholar
  9. Jeanroy, E. (1972) Analyse totale des silicates naturels par spectrométrie d’absorption atomique. Application au sol et à ses constituants. Chimie Analytique, 54, 159–166.Google Scholar
  10. Kantor, W. and Schwertmann, U. (1974) Mineralogy and genesis of clays in red-black toposequences in Kenya. Journal of Soil Science, 25, 67–78.Google Scholar
  11. Lanson, B. (1993) DECOMPXR, X-ray Decomposition Program. ERM, Poitiers, France.Google Scholar
  12. Lanson, B. (1997) Decomposition of experimental X-ray diffraction patterns (profile fitting): a convenient way to studyclayminerals. Clays and Clay Minerals, 45, 132–146.Google Scholar
  13. Madejová, J., Komadel, P. and Čičel, B. (1994) Infrared study of octahedral site populations in smectites. Clay Minerals, 29, 319–326.Google Scholar
  14. Mehra, O.P. and Jackson, M.L. (1960) Iron oxide removal from soils and clays by a dithionite-citrate system buffered with sodium bicarbonate. Clays and Clay Minerals, 7, 317–327.Google Scholar
  15. Millot, G. (1964) Geologie des Argiles. Masson, Paris.Google Scholar
  16. MIPAF (Ministero delle Politiche Agricole e Forestali) (2000) Metodi di Analisi Chimica del Suolo. Collana di metodi analitici per l’agricoltura. Franco Angeli, Italy.Google Scholar
  17. Olis A.C., Malla P.B. and Douglas L.A. (1990) The rapid estimation of layer charges of 2:1 expanding clays from a single alkylammonium ion expansion. Clay Minerals, 25, 39–50.Google Scholar
  18. Porcu, A. (1983) Geologia del Graben di Ottana (Sardegna centrale). Rendiconto Seminari Facoltà di Scienze dell’Università di Cagliari, 53, 1–32.Google Scholar
  19. Reynolds, R.C. (1985) NEWMOD: A Computer Program for the Calculation of One-dimensional Diffraction Powders of Mixed-layer Clays. R.C. Reynolds, 8 Brook Rd., Hanover, New Hampshire 03755 USA, 315 pp.Google Scholar
  20. Righi, D., Terribile, F. and Petit, S. (1999) Pedogenic formation of kaolinite-smectite mixed layers in a soil toposequence developed from basaltic parent material in Sardinia (Italy). Clays and Clay Minerals, 47, 505–514.Google Scholar
  21. Soil Survey Staff (1999) Soil Taxonomy. A Basic System of Soil Classification for Making and Interpreting Soil Surveys, 2nd edition. USDA-NRCS, Agriculture Handbook N. 436, US Government Print Office, Washington, DC.Google Scholar
  22. Thornthwaite, C.W. and Mather, J.R. (1957) Instruction and Tables for Computing Potential Evapotranspiration and the Water Balance. Publications in Climatology, 10, Centerton, New Jersey.Google Scholar
  23. Wilson, M.J. (1987) Soil smectites and related interstratified minerals: recent developments. Proceedings of the International Clay Conference, Denver, pp. 167–173.Google Scholar
  24. Wilson, M.J. (1999) The origin and formation of clay minerals in soils: past, present and future perspectives. Clay Minerals, 34, 7–25.Google Scholar
  25. Yerima, B.P.K., Calhoun, F.G., Senkayi, A.L. and Dixon, J.B. (1985) Occurrence of interstratified kaolinite-smectite in El Salvador Vertisols. Soil Science Society of America Journal, 49, 462–466.Google Scholar

Copyright information

© The Clay Minerals Society 2004

Authors and Affiliations

  • Simona Vingiani
    • 1
  • Dominique Righi
    • 2
    Email author
  • Sabine Petit
    • 2
  • Fabio Terribile
    • 1
  1. 1.DISSPAUniversità di Napoli Federico II, Facoltà di AgrariaPortici (NA)Italy
  2. 2.Faculté des SciencesUMR-CNRS 6532 “HydrASA”Poitiers CedexFrance

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