Abstract
Chemical and mineralogical analyses of the clay fraction of eleven soils containing a large amount of vermiculite clay and representing a wide range of parent materials revealed that two types of vermiculite clays exist: (1) An aluminous type in which Al3+ substitutes for Si4+ in tetrahedral positions in the same order of magnitude as in the coarse grained vermiculites and micas, and with Al3+ as the dominant octahedral ion. (2) A silicious type in which only Si4+ occupies the tetrahedral positions, and with Fe3+ and Mg2+ as the dominant octahedral ions. The aluminous vermiculite clay was found to occur in soils derived from acid igneous rocks and is usally associated with mica, whereas the silicious type was found to occur in soils derived from basic igneous rocks which do not contain mica. Because of this close association of these two types to their parent material, it was concluded that the aluminous vermiculite is a product of alteration of mica whereas the silicious type is a product of synthesis from primary oxides of silica, alumina, iron, and magnesium. Both types of vermiculite clays tend to be dioctahedral in contrast to the trioctahedral nature of the coarse-grained vermiculite.
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References
Alexiades, C. A., Jackson, M. L.: Quantitative determination of vermiculite in soils. Soil Sci. Soc. Am. Proc. 29, 522–527 (1965).
: Quantitative clay mineralogical analysis of soils and sediments. Clays Clay Minerals Proc. Natl. Conf. 14 (1965), 35–52 (1966).
Barshad, I.: Vermiculite and its relation to biotite as revealed by base exchange reactions, X-tay analyses, d. t. a. curves and water content. Am. Mineralogist 33, 655–678 (1948).
: The effect of interlayer cations on the expansion of the mica type of crystal lattice. Am. Mineralogist 35, 225–238 (1950).
: Significance of the presence of exchangeable magnesium ions in acidified clays. Science 131, 988–990 (1960b).
: X-ray analysis of soil colloids by a modified salted paste method. In: Clays Clay Minerals, Proc. Natl. Conf. 7 (1939, 350–364) (1960a).
: Chemistry of soil development. In: Chemistry of the Soil, ed. by F. E. Bear. New York: Reinhold Publ. 1955, 1964.
: Thermal analysis techniques for mineral identification and mineralogical composition. In: Methods of Soil Analysis, ed. by C. A. Black, Monograph No. 9. American Society of Agronomy, Madison, Wisconsin 1965.
: The effect of a variation in precipitation on the nature of clay minerals formation in soils from acid and basic igneous rocks. Proc. of Int'l Clay Cong. 1966, Jerusalem, Israel, vol. 1, 167–173. Israel Program for Scientific Translations, Jerusalem 1966.
Boettcher, A. L.: Vermiculite, hydrobiotite and biotite in the Rainy Creek Igneous Complex near Libby, Montana. Clay Minerals 6, 283–296 (1966).
Cook, M. G., Rich, C. I.: Negative charge of dioctahedral micas as related to weathering. Clays and Clay Minerals, Proc. Natl. Conf. 11 (1962), 47–64 (1963).
Deer, W. A., Howie, R. A., Zussman, J.: Rock forming minerals, vol. 3. (Sheet Silicates). New York: John Wiley & Sons 1965.
Dekimpe, C., Gastuche, M. C., Brindley, G. W.: Ionic Coordination in alumino-silicic gels in relation to clay mineral formation. Am. Mineralogist 46, 1370–1381 (1961).
Foster, M. D.: Interpretations of the composition of vermiculites and hydrobiotites. Clays and Clay Minerals, Proc. Natl. Conf. 10 (1961), 70–89 (1963).
Jackson, M. L., Mackenzie, R. C.: Chemical analysis in the quantitative mineralogical examination of clays. In: C. I. Rich and G. W. Kunze (ed.), Soil clay mineralogy, p. 313–330. Chapel Hill: University of North Carolina Press 1964.
Newman, A. C., Brown, G. W.: Chemical changes during the alteration of micas. Clay Minerals 6, 297–310 (1966).
Raman, K. V., Jackson, M. L.: Layer charge relations in clay minerals of micaceous soils and sediments. Clays and Clay Minerals, Proc. Natl. Conf. 14 (1965) 53–67 (1966).
Sawhney, B. L., Jackson, M. L.: Soil montmorillonite formulas. Soil Sci. Soc. Am. Proc. 22, 115–118 (1958).
Walker, G. F.: Distinction of vermiculite, chlorite and montmorillonite in clays. Nature 164, 577 (1949).
: Vermiculite minerals. In: X-ray identification and crystal structure of clay minerals. 1951, Ch. VII, p. 199–223. (G. W. Brindley, ed.). 1961, Ch. VII, 297–324 (G. Brown, ed.). London: Mineralogical Society 1951, 1961.
: Differentiation of vermiculites and smectites. Clay Minerals Bull. 3, 154–163 (1957).