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Crystallization Conditions of Fundamental Particles from Mixed-Layer Illite-Smectite of Bentonites Based on Isotopic Data (K-Ar, Rb-Sr and δ18O)

Published online by Cambridge University Press:  01 January 2024

Norbert Clauer*
Centre de Géochimie de la Surface (CNRS-ULP), 1 rue Blessig, 67084-Strasbourg, France
Nicole Liewig
Centre de Géochimie de la Surface (CNRS-ULP), 1 rue Blessig, 67084-Strasbourg, France
Marie-Claire Pierret
Centre de Géochimie de la Surface (CNRS-ULP), 1 rue Blessig, 67084-Strasbourg, France
Theofilos Toulkeridis
Politecnico-Geociencias, Universidad San Francisco de Quito, 17-12-841 Quito, Ecuador
*E-mail address of corresponding author:


Rb-Sr and oxygen isotope studies, in addition to K-Ar isotopic determinations published previously, are reported on diagenetic and hydrothermal fundamental particles (particle thickness of 0.03 to 0.05 nm and particle ab size of 0.02–0.05 µm) of the East-Slovak Basin. The combined data set allows us to ascertain the crystallization conditions of the illite material from two bentonite units collected at two basinal sites located ~20 km apart, and characterized by prolonged diagenetic conditions induced by progressive burial. A bentonite rock characterized by a short hydrothermal event from the Zempleni mountains to the SW of the East-Slovak basin is also studied.

For the two first sites, the δ18O values increase in one case and decrease in the other, when the size of the diagenetic fundamental particles from bentonite samples increases. These variations suggest that temperature increased in one and decreased in the second of the two samples collected in the basin, while the particles were growing. In the case of the hydrothermal bentonite, the δ18O values of the different size-fractions consisting of fundamental particles remain about constant, suggesting constant temperature and fluid chemistry.

The Rb-Sr dates of the fundamental particles of the three bentonite rocks were systematically higher than the corresponding K-Ar ages. The 87Sr/86Sr ratios, which are initially involved in the particle nucleation, appeared higher than that of contemporaneous sea-water. In all cases, the initial 87Sr/ 86Sr ratio decreases when particle size increases, which implies supply of external Sr into the bentonite units. This external Sr seems to have had an 87Sr/86Sr ratio close or identical to that of the contemporaneous sea water. This means that Sr, probably of sea-water origin, progressively diffused from host shales into the bentonite units, during burial diagenesis. In turn it favors the suggestion made previously about diffusion of K from shales into the bentonite layers during illitization of the smectite from these units.

Research Article
Copyright © 2003, The Clay Minerals Society

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Clauer, N. and Chaudhuri, S., (1995) Clays in Crustal Environments. Isotope Dating and Tracing Berlin, Heidelberg Springer Verlag 10.1007/978-3-642-79085-0 358 pp.Google Scholar
Clauer, N. Keppens, E. and Stille, P., (1992) Sr isotopic constraints on the process of glauconitization Geology 20 133136 10.1130/0091-7613(1992)020<0133:SICOTP>2.3.CO;2.Google Scholar
Clauer, N. Chaudhuri, S. Kralik, M. and Bonnot-Courtois, C., (1993) Effects of experimental leaching on Rb-Sr and K-Ar isotopic systems and REE contents of diagenetic illite Chemical Geology 103 116 10.1016/0009-2541(93)90287-S.Google Scholar
Clauer, N. Środoń, J. Francu, J. and Šuchá, V., (1997) K-Ar dating of illite fundamental particles separated from illitesmectite Clay Minerals 32 181196 10.1180/claymin.1997.032.2.02.Google Scholar
Clayton, R.N. and Mayeda, T.K., (1963) The use of bromine penta-fluoride in the extraction of oxygen from oxides and silicates for isotopic analysis Geochimica et Cosmochimica Acta 27 4352 10.1016/0016-7037(63)90071-1.Google Scholar
Dequincey, O. Chabaux, F. Clauer, N. Liewig, N. and Muller, J.-P., (1999) Dating of weathering profiles by radioactive disequilibria: contribution of the study of authigenic mineral fractions Comptes Rendus de l’Academie des Sciences, Paris, IIa 328 679685.Google Scholar
Eberl, D.D. and Środoń, J., (1988) Ostwald ripening and interparticle diffraction effects of illite crystals American Mineralogist 73 13351345.Google Scholar
Eberl, D.D. Drits, V. and Środoń, J., (1998) Deducing growth mechanisms for minerals from the shapes of crystal size distributions American Journal of Science 298 499533 10.2475/ajs.298.6.499.Google Scholar
Eslinger, E.V. and Yeh, H.W., (1981) Mineralogy, O18/O16 and D/H ratios of clay-rich sediments from Deep-Sea Drilling Project site 180, Aleutian Trench Clays and Clay Minerals 29 309315 10.1346/CCMN.1981.0290409.Google Scholar
Hodell, D.A. Mueller, P.A. and Garrido, J.R., (1991) Variations in the strontium isotopic composition of seawater during the Neogene Geology 19 2427 10.1130/0091-7613(1991)019<0024:VITSIC>2.3.CO;2.Google Scholar
Inoue, A. Kohyama, N. and Kitagawa, R., (1987) Chemical and morphological evidence for the conversion of smectite to illite Clays and Clay Minerals 35 111120 10.1346/CCMN.1987.0350203.Google Scholar
Jackson, M.L., (1975) Soil Chemical Analysis — Advanced Course 2nd.Google Scholar
Kharaka, Y.K. Thordsen, J.J., Clauer, N. and Chaudhuri, S., (1992) Stable isotope geochemistry and origin of waters in sedimentary basins Isotopic Signatures and Sedimentry Records Berlin Springer Verlag 411466 10.1007/BFb0009873.Google Scholar
Kile, D.E. Eberl, D.D. Hoch, A.R. and Reddy, M.M., (2000) An assessment of calcite crystal growth mechanisms based on crystal size distributions Geochimica et Cosmochimica Acta 64 29372950 10.1016/S0016-7037(00)00394-X.Google Scholar
Kral, M. Lizon, I. and Janci, J., (1985) Geothermal Research of Slovakia Brastislava Geofond (in Slovak).Google Scholar
Nadeau, P.H. Wilson, M.J. McHardy, W.J. and Tait, J.M., (1984) Interstratified clays as fundamental particles Science 225 923925 10.1126/science.225.4665.923.Google Scholar
Ohr, M. Halliday, A.N. and Peacor, D.R., (1991) Sr and Nd isotopic evidence for punctuated clay diagenesis, Texas Gulf Coast Earth and Planetary Science Letters 105 110126 10.1016/0012-821X(91)90124-Z.Google Scholar
O’Neil, J.R. and Kharaka, Y., (1976) Hydrogen and oxygen isotope exchange reactions between clay minerals and water Geochimica et Cosmochimica Acta 40 241246 10.1016/0016-7037(76)90181-2.Google Scholar
Riotte, J. and Chabaux, F., (1999) (234U / 238U) activity ratios in freshwaters as tracers of hydrological processes: The Strengbach watershed (Vosges, France) Geochimica et Cosmochimica Acta 63 12631275 10.1016/S0016-7037(99)00009-5.Google Scholar
Rudinec, R., (1978) Paleogeographical, lithofacial and tectogenetic development of the Neogene in Eastern Slovakia and its relation to volcanism and deep tectonics Geologica Carpathica 28 225240.Google Scholar
Savin, S.M. Lee, M.C. and Bailey, S.W., (1988) Isotopic studies of phyllosilicates Hydrous Phyllosilicates (exclusive of micas) Washington, D.C. Mineralogical Society of America 189223 10.1515/9781501508998-012.Google Scholar
Sheppard, S.M.F., Valley, J.W. Taylor, H.P. Jr. and O’Neil, J.R., (1986) Characterization and isotope variations in natural waters Stable Isotopes in High-temperature Geological Processes Washington, D.C. Mineralogical Society of America 165183 10.1515/9781501508936-011.Google Scholar
Środoń, J., (1980) Precise identification of illite/smectite interstratifications by X-ray powder diffraction Clays and Clay Minerals 28 401411 10.1346/CCMN.1980.0280601.Google Scholar
Środoń, J., (1981) X-ray identification of randomly interstratified illite/smectite in mixtures with discrete illite Clay Minerals 16 297304 10.1180/claymin.1981.016.3.07.Google Scholar
Środoń, J., (1984) X-ray identification of illitic materials Clays and Clay Minerals 32 337349 10.1346/CCMN.1984.0320501.Google Scholar
Środoń, J. and Clauer, N., (2001) Diagenetic history of Lower Palaeozoic sediments in Pomerania (northern Poland) traced across the Teisseyre-Tornquist tectonic zone using mixedlayer illite-smectite Clay Minerals 36 1527 10.1180/000985501547321.Google Scholar
Środoń, J. Elsass, F. McHardy, W.J. and Morgan, D.J., (1992) Chemistry of illite-smectite inferred from TEM measurements of fundamental particles Clay Minerals 27 137158 10.1180/claymin.1992.027.2.01.Google Scholar
Steiger, R.H. and Jäger, E., (1977) Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology Earth and Planetary Science Letters 36 359362 10.1016/0012-821X(77)90060-7.Google Scholar
Šuchá, V. Kraus, I. Gerthofferova, H. Petes, J. and Serekova, M., (1993) Smectite to illite conversion in bentonites and shales of the East Slovak Basin Clay Minerals 28 243253 10.1180/claymin.1993.028.2.06.Google Scholar
Taylor, H.P. Jr. and Barnes, H.L., (1979) Oxygen and hydrogen isotope relationships in hydrothermal mineral deposits Geochemistry of Hydrothermal Ore Deposits New York John Wiley & Sons 236277.Google Scholar
Welte, D.H. Yükler, M.A. Radke, M. Teythaeuser, D., Atkinson, G. and Zuckerman, J., (1981) Application of organic chemistry and quantitative basin analysis to petroleum exploration Origin and Chemistry of Petroleum Oxford, UK Pergamon Press 6788 10.1016/B978-0-08-026179-9.50008-6.Google Scholar
Whitney, G. and Northrop, H.R., (1988) Experimental investigation of the smectite to illite reaction mechanisms and oxygen-isotope systematics American Mineralogist 73 7790.Google Scholar