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The Thermodynamic Status of Compositionally-Variable Clay Minerals: A Discussion

Published online by Cambridge University Press:  28 February 2024

Stephen U. Aja
Affiliation:
Department of Geological Sciences, McGill University, 3450 University Street, Montréal, Canada H3A 2A7
Philip E. Rosenberg
Affiliation:
Department of Geology, Washington State University, Pullman, Washington 99164, USA
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Abstract

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According to Lippmann (1977, 1982) wide compositional variations and excess enthalpies of mixing calculated with electrostatic models imply that clay minerals of variable composition are dis-equilibrium solids. However, recent ATEM analyses of illite samples indicate compositional homogeneity of single illite grains and limited compositional variations in sedimentary basins. Moreover, Lippmann's electrostatic model may be inadequate inasmuch as it neglects polarization energy which is known to be a significant component of lattice energy even in dominantly ionic structures. Contrary to the assumptions of Lippmann, I/S minerals have also been shown to undergo Ostwald ripening.

May et al. (1986) reported that smectites do not reversibly control equilibria and further argued that conceptual and experimental deficiencies inherent in the solubility method prevent the attainment and demonstration of equilibrium in experiments with complex aluminosilicates of variable composition. However, equilibrium may be assumed if: (1) steady states are approached from both under- and over-saturation, (2) the slopes of univariant lines representing mineral-solution equilibria are rational over a wide range of solution compositions and temperature, and (3) results are reproducible in experiments of long duration. Recent solubility studies of smectites, chlorites, and illites meet these criteria indicating that clay minerals of variable composition are true phases capable of attaining equilibrium.

Type
Research Article
Copyright
Copyright © 1992, The Clay Minerals Society

References

Aagaard, P. and Helgeson, H. C., Activity/composition relations among silicates and aqueous solutions: II. Chemical and thermodynamic consequences of ideal mixing of atoms on homological sites in montmorillonites, illites and mixed-layered clays Clays & Clay Minerals 1983 31 207217 10.1346/CCMN.1983.0310306.Google Scholar
Aja, S. U., Illite equilibria in solutions: III. A reinterpretation of the data of Sass et al. (1987) Geochim. Cosmochim. Acta 1991 55 34313435 10.1016/0016-7037(91)90501-U.Google Scholar
Aja, S. U. and Rosenberg, P. E., Do equilibrium solubility models apply to clay minerals of variable composition? Geol. Soc. Amer. Abstr. with Program 1991 23 A151.Google Scholar
Aja, S. U., Rosenberg, P. E. and Kittrick, J. A., Illite equilibria in solutions: I. Phase relationships in the system K2O-Al2O3-SiO2-H2O between 25° and 250°C Geochim. Cosmochim. Acta 1991 55 13531364 10.1016/0016-7037(91)90313-T.Google Scholar
Aja, S. U., Rosenberg, P. E. and Kittrick, J. A., Illite equilibria in solutions: II. Phase relationships in the system K2O-MgO-Al2O3-SiO2-H2O Geochim. Cosmochim. Acta 1991 55 13651374 10.1016/0016-7037(91)90314-U.Google Scholar
Badault, D. and Risacher, F., Authigenic smectite on diatom frustules in Bolivian saline lakes Geochim. Cosmochim. Acta 1983 47 363375 10.1016/0016-7037(83)90259-4.Google Scholar
Baronnet, A., Ostwald ripening in solution. The case of calcite and mica Estudios Geologicos 1982 38 185198.Google Scholar
Eberl, D. D., Srodon, J., Kralik, M., Taylor, B. and Peterman, Z. E., Ostwald ripening of clays and metamorphic minerals Nature 1990 248 474477.Google Scholar
Gaudette, H. E., Illite from Fond du Lac County, Wisconsin Amer. Mineral. 1965 50 411417.Google Scholar
Gaudette, H. E., Eades, J. L. and Grim, R. E., The nature of illites Proc. 13th Natl. Conf. Clays Clay Mineral. 1966 3348.Google Scholar
Giggenbach, W. F., Construction of thermodynamic stability diagrams involving dioctahedral potassium clay minerals Chem. Geol. 1985 49 231242 10.1016/0009-2541(85)90158-5.Google Scholar
Glynn, P. D. and Reardon, E. J., Solid-solution aqueous-solution equilibria: thermodynamic theory and representation Amer. J. Sci. 1990 290 164201 10.2475/ajs.290.2.164.Google Scholar
Giiven, N., Electron optical observations in Marblehead illite Clays & Clay Minerals 1972 37 111.Google Scholar
Güven, N., Smectites in Hydrous Phyllosilicates (exclusive of micas) Reviews in Mineralogy 1988 19 497559.Google Scholar
Grim, R. E. and Bradley, W. F., A unique clay from the Goose Lake, Illinois, area J. Amer. Ceram. Soc. 1939 22 157164 10.1111/j.1151-2916.1939.tb19442.x.Google Scholar
Hower, J. and Mowatt, T. C., The mineralogy of illites and mixed-layer illite/montmorillonites Amer. Min. 1966 51 825854.Google Scholar
Huheey, J. E., Inorganic Chemistry: Principles of Structure and Reactivity. 1983 New York Harper and Roe 936.Google Scholar
Inoue, A., Velde, B., Meunier, A. and Touchard, G., Mechanism of illite formation during smectite-to-illite conversion in a hydrothermal system Amer. Min. 1988 73 13251334.Google Scholar
Jiang, W., Essene, E. J. and Peacor, D. R., Transmission electron microscopic study of coexisting pyrophyllite and muscovite: Direct evidence for the metastability of illite Clays & Clay Minerals 1990 38 225240 10.1346/CCMN.1990.0380301.Google Scholar
Kittrick, J. A., Stability of montmorillonites: I. Belle Fourche and Clay Spur montmorillonites Soil Sci. Soc. Amer. Proc. 1971 35 140145 10.2136/sssaj1971.03615995003500010040x.Google Scholar
Kittrick, J. A., Solubility of two high-Mg and two high-Fe chlorites using multiple equilibria Clays & Clay Minerals 1982 30 167179 10.1346/CCMN.1982.0300302.Google Scholar
Kittrick, J. A., Some equilibrium considerations in the formation of chlorite in soils and sediments Soil Sci. Soc. Amer. J. 1984 48 687689 10.2136/sssaj1984.03615995004800030044x.CrossRefGoogle Scholar
Kittrick, J. A., Solubility measurements of phases in three illites Clays & Clay Minerals 1984 32 115124 10.1346/CCMN.1984.0320205.Google Scholar
Kittrick, J. A. and Peryea, F. J., Experimental validation of the monophase structure model for montmorillonite stability Soil Sci. Soc. Amer. J. 1988 52 199201 10.2136/sssaj1988.03615995005200040059x.Google Scholar
Kittrick, J. A. and Peryea, F. J., The monophase model for Mg-saturated montmorillonite Soil Sci. Soc. Amer. J. 1989 53 292295 10.2136/sssaj1989.03615995005300010053x.Google Scholar
Lafon, G. M., Discussion of: Equilibrium criteria for two component solids reacting with fixed compositions in an aqueous phase-example: The magnesian calcites Amer. J. Sci. 1978 278 14551468 10.2475/ajs.278.10.1455.Google Scholar
Lanson, B. and Champion, D., The I/S-to-illite reaction in the late stage diagenesis Amer. J. Sci. 1991 291 473506 10.2475/ajs.291.5.473.Google Scholar
Lasaga, A. C., Defect calculations in silicates: Olivine Amer. Mineral. 1980 65 12371248.Google Scholar
Lippmann, F., The solubility products of complex minerals, mixed crystals, and three-layer clay minerals N. Jb. Miner. Abh. 1977 130 243263.Google Scholar
Lippmann, F., The thermodynamic status of clay minerals Proc. 7th Int. Clay Conf. 1982 475485.Google Scholar
Lonker, S. W., Fitz Gerald, J. D., Hedenquist, J. W. and Walshe, J., Mineral-fluid interactions in the Broadlands-Ohaaki geothermal system, New Zealand Amer. J. Sci. 1990 290 9951068 10.2475/ajs.290.9.995.Google Scholar
Loucks, R. R., The bound interlayer H2O content of potassic micas: Muscovite-hydromuscovite-hydropyrophyllite solutions Amer. Mineral. 1991 76 15631579.Google Scholar
Mankin, C. J. and Dodd, C. G., Proposed reference illite from the Ouchita Mountains of Southeastern Oklahoma Proc. 10th Natl. Conf. Clays Clay Min. 1963 372379.Google Scholar
May, H. M., Kinniburgh, D. G., Helmke, P. A. and Jackson, M. L., Aqueous dissolution, solubilities and thermodynamic stabilities of common aluminosilicate clay minerals: Kaolinite and smectites Geochim. Cosmochim. Acta 1986 50 16671677 10.1016/0016-7037(86)90129-8.Google Scholar
Merino, E. and Ransom, B., Free energies of formation of illite solid solutions and their compositional dependence Clays & Clay Minerals 1982 30 2939 10.1346/CCMN.1982.0300104.Google Scholar
Meunier, A. and Velde, B., Solid solution in I/S mixedlayer minerals and illite Amer. Min. 1989 74 11061112.Google Scholar
Nordstrom, D. K. and Munoz, J. L., Geochemical Thermodynamics 1985 Palo Alto Blackwell Scientific Publications 447.Google Scholar
Peryea, F. J. and Kittrick, J. A., Experimental evaluation of two operational standard states for montmorillonite in metastable hydrolysis reactions Soil Sci. Soc. A m. Proc. 1986 50 16131617 10.2136/sssaj1986.03615995005000060046x.Google Scholar
Price, G. D., Parker, S. C. and Leslie, M., The lattice dynamics of forsterite Mineral. Magazine 1987 51 157170 10.1180/minmag.1987.051.359.18.Google Scholar
Ransom, B. and Warren, E. A., How well do we know clay mineral structural formulas: An evaluation of errors inherent in XRD/BULK chemical and electron microscope techniques Geol. Soc. Amer. Abstr. with Program 1989 21 A44.Google Scholar
Rosenberg, P. E., Kittrick, J. A. and Aja, S. U., Mixedlayer illite/smectite: A multi-phase model Amer. Min. 1990 75 11821185.Google Scholar
Sass, B. M., Rosenberg, P. E. and Kittrick, J. A., The stability of illite/smectite during diagenesis: An experimental study Geochim. Cosmochim. Acta 1987 51 21032115 10.1016/0016-7037(87)90259-6.Google Scholar
Srodon, J., X-ray identification of illitic materials Clays & Clay Minerals 1984 32 337349 10.1346/CCMN.1984.0320501.Google Scholar
Talibudeen, O. and Goulding, K. W. T., Charge heterogeneity in smectites Clays & Clay Minerals 1983 31 3742 10.1346/CCMN.1983.0310106.Google Scholar
Tardy, Y. and Fritz, B., An ideal solid solution model for calculating solubility of clay minerals Clay Miner. 1981 16 361373 10.1180/claymin.1981.016.4.05.Google Scholar
Thorstensen, D. C. and Plummer, L. N., Equilibrium criteria for two-component solids reacting with fixed composition in an aqueous phase-example: The magnesian calcites Amer. J. Sci. 1977 277 12031223 10.2475/ajs.277.9.1203.Google Scholar
Urusov, V. S., Energetic theory of miscibility gaps in mineral solid solutions Forstschr. Mineral. 1975 52 141150.Google Scholar
Warren, E. A. and Curtis, C. D., The chemical composition of authigenic illite within two sandstone reservoirs as analyzed by ATEM Clay Miner. 1989 24 137156 10.1180/claymin.1989.024.2.03.Google Scholar
Weaver, C. E. and Pollard, L. D., The Chemistry of Clay Minerals. 1973 Amsterdam Elsevier.Google Scholar