Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-15T17:13:04.377Z Has data issue: false hasContentIssue false
  • English
  • Français

Analytical Transmission Electron Microscope Studies of Plagioclase, Muscovite, and K-Feldspar Weathering

Published online by Cambridge University Press:  02 April 2024

Jillian F. Banfield  and
Richard A. Eggleton
Jillian F. Banfield*
Affiliation:
Department of Geology, Australian National University, P.O. Box 4, Canberra, A.C.T. 2601, Australia
Richard A. Eggleton
Affiliation:
Department of Geology, Australian National University, P.O. Box 4, Canberra, A.C.T. 2601, Australia
*
1Present address: Department of Earth and Planetary Sciences, The Johns Hopkins University, 21218, Baltimore, Maryland, USA.
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Analytical and high-resolution transmission electron microscopy of weathered plagioclase and K-feldspar provided microtextural and chemical data that suggest a sequential formation of weathering products. An alteration layer < 1 µm thick on feldspar surfaces had short-range order and was termed protocrystalline. Relative to the parent feldspars the protocrystalline layer was depleted in Ca, Na, K, and Si and significantly enriched in Fe. On plagioclase, the protocrystalline material was replaced by Ca-Fe-K-smectite, another protocrystalline material, and spherical halloysite. Abundant tubular halloysite on the corroded surface apparently formed by reprecipitation of components released by plagioclase dissolution. The K-feldspar was markedly more resistant to weathering than the plagioclase.

Recrystallization of the patchily developed protocrystalline rind produced Fe-bearing, aluminous smecrite, which was ultimately replaced by spherical halloysite and laths of kaolinite. Muscovite laths within plagioclase crystals were converted initially to illite by loss of K, then to randomly interstratified illite/smectite, and then to smectite that contained Mg, little K and Fe, and was more aluminous and contained less Ca than the smectite that originally replaced the plagioclase. Smectite was replaced epitactically by kaolinite. Kaolinite was the stable weathering product of the feldspars and muscovite in the profiles. It probably formed in equilibrium with a solution whose composition was no longer controlled by the microenvironment within the feldspar, but approached that of meteoric water.

Keywords

Analytical electron microscopyHigh-resolution transmission electron microscopyIlliteKaoliniteK-feldsparMuscoviteNoncrystalline intermediatePlagioclaseSmectiteWeathering
Type
Research Article
Information
Clays and Clay Minerals , Volume 38 , Issue 1 , February 1990 , pp. 77 - 89
Copyright
Copyright © 1990, The Clay Minerals Society

References

Aagaard, P. and Helgeson, H. C., 1982 Thermodynamic and kinetic constraints on reaction rates among minerals and aqueous solutions: I. Theoretical considerations Amer. J. Sci. 282 237 – 285.CrossRefGoogle Scholar
Ahn, J. H. and Peacor, D. R., 1987 Kaolinitization of biotite: TEM data and implications for an alteration mechanism Amer. Mineral. 72 353 – 356.Google Scholar
Anand, R. R., Gilkes, R. J., Armitage, T. and Hillyer, J., 1985 The influence of microenvironment on feldspar weathering in lateritic saprolite Clays & Clay Minerals 33 31 – 46.CrossRefGoogle Scholar
Banfield, J. F., 1985 The mineralogy and chemistry of granite weathering Australia Australian National University, Canberra.Google Scholar
Banfield, J. F. and Eggleton, R. A., 1988 A transmission electron microscope study of biotite weathering Clays & Clay Minerals 36 47 – 60.CrossRefGoogle Scholar
Banfield, J. F. and Eggleton, R. A., 1989 Apatite replacement and rare earth mobilization, fractionation, and fixation during weathering Clays & Clay Minerals 37 113 – 127.CrossRefGoogle Scholar
Beams, S. D., 1980 Magmatic evolution of the southeast Lachlan Fold Belt, Australia Australia Australian National University, Canberra.Google Scholar
Berner, R. A. and Holdren, G. R. Jr., 1977 Mechanism of feldspar weathering: I. Some observational evidence Geology 5 369 – 372.2.0.CO;2>CrossRefGoogle Scholar
Berner, R. A. and Holdren, G R Jr, 1979 Mechanism of feldspar weathering: II. Observations of feldspars from soils Geochim. Cosmochim. Acta 43 1173 – 1186.CrossRefGoogle Scholar
Carroll, D., 1970 Rock Weathering New York Plenum Press.CrossRefGoogle Scholar
Casey, W. H., Westrich, H. R. and Arnold, G. W., 1989 Surface chemistry of labradorite feldspar reacted with aqueous solutions at pH = 2, 3, and 12 Geochim. Cosmochim. Acta 52 2795 – 2807.CrossRefGoogle Scholar
Chou, L. and Wollast, R., 1985 Steady-state kinetics and dissolution mechanisms of albite Amer. J. Sci. 285 963 – 993.CrossRefGoogle Scholar
Churchman, G. T., 1980 Clay minerals formed from micas and chlorite in some New Zealand soils Clay Miner. 15 59 – 76.CrossRefGoogle Scholar
Churchman, G. T., Whitton, J. S., Claridge, G. G. C. and Theng, B. K. G., 1984 Intercalation method using formamide for differentiating halloysite from kaolinite Clays & Clay Minerals 32 241 – 248.CrossRefGoogle Scholar
Cliff, G. and Lorimer, G. W., 1975 The quantitative analysis of thin specimens J. Microscopy 103 203 – 207.CrossRefGoogle Scholar
Correns, C. W. and Von Englehardt, W., 1938 Neue Untersuchungen fiber die Verwitterung des Kalifeldspates Chemie der Erde 12 1 – 22.Google Scholar
Eggleton, R. A., 1987 Noncrystalline Fe-Si-Al-oxyhydroxides Clays & Clay Minerals 35 29 – 37.CrossRefGoogle Scholar
Eggleton, R. A. and Buseck, P. R., 1980 High-resolution electron microscopy of feldspar weathering Clays & Clay Minerals 28 173 – 178.CrossRefGoogle Scholar
Eswaran, H. and Bin, W. C., 1978 A study of a deep weathering profile on granite in peninsular Malaysia: III. Alteration of feldspars Soil Sci. Soc. Amer. J. 42 154 – 158.CrossRefGoogle Scholar
Feth, J. H., Roberson, C. E. and Polzer, W. L. (1964) Sources of mineral constituents in water from granitic rocks, Sierra Nevada, California, and Nevada: U.S. Geol. Surv. Water Supply Pap. 1531–1, 170 pp.Google Scholar
Fieldes, M. and Swindale, L. D., 1954 Chemical weathering of silicates in soil formation J. Sci. Tech. New Zealand 56 140 – 154.Google Scholar
Frederickson, A. F., 1951 Mechanism of weathering Geol. Soc. Amer. Bull. 62 221 – 232.CrossRefGoogle Scholar
Garrets, R. M., 1984 Montmorillonite/illite stability diagrams Clays & Clay Minerals 32 161 – 166.CrossRefGoogle Scholar
Garrels, R. M., Howard, P. and Swineford, A., 1959 Reactions of feldspar and mica with water at low temperature and pressure Clays and Clay Minerals, Proc. 6th Natl. Conf., Berkeley, California, 1957 New York Pergamon Press 66 – 88.Google Scholar
Guilbert, J. M. and Sloane, R. L., 1968 Electron optical study of hydrothermal fringe alteration of plagioclase in quartz monzonite, Butte District, Montana Clays & Clay Minerals 16 215 – 221.CrossRefGoogle Scholar
Guthrie, G. D. and Veblen, D. R., 1989 High resolution transmission electron microscopy of mixed-layer illite/smectite: Computer simulations Clays & Clay Minerals 36 1 – 11.CrossRefGoogle Scholar
Helgeson, H. C., 1971 Kinetics of mass transfer among silicates and aqueous solutions Geochim. Cosmochim. Acta 35 421 – 469.CrossRefGoogle Scholar
Helgeson, H. C., Murphy, W. M. and Aagaard, P., 1984 Thermodynamic and kinetic constraints on reaction rates among minerals and aqueous solutions. II. Rate constants, effective surface area, and the hydrolysis of feldspar Geochim. Cosmochim. Acta 48 2405 – 2432.CrossRefGoogle Scholar
Henmi, T. and Wada, K., 1976 Morphology and composition of allophane Amer. Mineral. 61 379 – 390.Google Scholar
Holdren, G. R. Jr. and Berner, R. A., 1979 Mechanism of feldspar weathering. I. Experimental studies Geochim. Cosmochim. Acta 43 1161 – 1171.CrossRefGoogle Scholar
Keller, W. D., 1970 Environmental aspects of clay minerals J. Sed. Petrol. 40 788 – 813.CrossRefGoogle Scholar
Keller, W. D., 1978 Kaolinization of feldspar as displayed in scanning electron micrographs Geology 6 184 – 188.2.0.CO;2>CrossRefGoogle Scholar
Lagache, M., Wyart, J. and Sabatier, G., 1961 Dissolution des feldspaths alcalins dans l’eau pure ou chargée de CO2 à 200°C C. R. Acad. Sci. Paris 253 2019 – 2022.Google Scholar
Lin, F.-C. and Clemency, C. V., 1981 The kinetics of dissolution of muscovites at 25°C and 1 atm, CO2 partial pressure Geochim. Cosmochim. Acta 45 571 – 576.Google Scholar
Lindsay, L., 1979 Chemical Equilibrium in Soils New York Wiley.Google Scholar
Lodding, W., 1972 Conditions for the direct formation of gibbsite from K-feldspar. Discussion Amer. Mineral. 57 292 – 294.Google Scholar
Loughnan, F. C., 1969 Chemical Weathering of Silicate Minerals Amsterdam Elsevier.Google Scholar
Lundstrom, I., 1970 Etch pattern and twinning in two plagioclases Arkiv Mineralogi och Geologi 5 63 – 91.Google Scholar
Marshall, C. E., 1962 III. Reactions of feldspars and micas with aqueous solutions Econ. Geol. 57 1219 – 1227.CrossRefGoogle Scholar
Minato, H., 1981 On the problem of genesis in kaolinite and halloysite by hydrothermal water J. Min. Soc. Japan 32 81 – 0150.Google Scholar
Nagasawa, K. and Miyazaki, S., 1976 Mineralogical properties of halloysite as related to its genesis Prog. Abst., Int. Clay Conf, Mexico City, 1976 Mexico. Univ. Nac. Auton. 223 – 224.Google Scholar
Nixon, R. A., 1979 Differences in incongruent weathering of plagioclase and microline—Cation leaching versus precipitates Geology 7 221 – 224.2.0.CO;2>CrossRefGoogle Scholar
Parham, W. E., 1969 Formation of halloysite from feldspar: Low temperature artificial weathering versus natural weathering Clays & Clay Minerals 17 13 – 22.CrossRefGoogle Scholar
Petrovic, R., 1976 Rate control in feldspar dissolution. I. Study of residual feldspar grains by X-ray photoelectron spectroscopy Geochim. Cosmochim. Acta 40 537 – 548.CrossRefGoogle Scholar
Petrovic, R., 1976 Rate control in feldspar dissolution. II. The protective effect of precipitates Geochim. Cosmochim. Acta 40 1509 – 1521.CrossRefGoogle Scholar
Petrovic, R., Berner, R. A. and Goldhaber, M. B., 1976 Rate control in dissolution of alkali feldspars. I. Study of residual grains by X-ray photoelectron spectroscopy Geochim. Cosmochim. Acta 40 537 – 548.CrossRefGoogle Scholar
Proust, D. and Velde, B., 1978 Beidellite crystallization from plagioclase and amphibole precursors. Local and long-range equilibrium during weathering Clay Miner. 13 199 – 209.CrossRefGoogle Scholar
Rausell-Colom, J., Sweatman, T. R., Wells, C. B. and Norrish, K., 1965 Studies in the artificial weathering of mica Proc. 11th School Agr. Sci., Nottingham, 1965 London Butterworth 40 – 72.Google Scholar
Rimsaite, J., Mortland, M. M. and Farmer, V. C., 1979 Natural amorphous materials, their origin and identification procedures Proc. Int. Clay Conf, Oxford, 1978 Amsterdam Elsevier 567 – 577.Google Scholar
Siefert, K. E., 1967 Electron microscopy of etched plagioclase feldspars Amer. Ceramics Soc. J. 50 660 – 661.CrossRefGoogle Scholar
Sudo, T. and Shimoda, S., 1978 Clays and Clay Minerals of Japan Tokyo Kodansha Ltd..Google Scholar
Tardy, Y., Bocquier, G., Parquet, H. and Millot, G., 1973 Formation of clay from granite and its distribution in relation to climate and topography Geoderma 10 271 – 284.CrossRefGoogle Scholar
Tazaki, K., Olphen, H. v. and Veniale, F., 1981 Analytical electron microscope studies of halloysite formation processes—Morphology and composition of halloysite Proc. Int. Clay Conf, Bologna, Pavia, 1981 Amsterdam Elsevier 573 – 584.Google Scholar
Tazaki, K. and Fyfe, W. S., 1987 Primitive clay precursors formed on feldspar Canadian J. Earth Sci. 24 506 – 527.CrossRefGoogle Scholar
Tsuzuki, Y. and Kawabe, I., 1983 Polymorphic transformations of kaolin minerals in aqueous solutions Geochim. Cosmochim. Acta 47 59 – 66.CrossRefGoogle Scholar
t’Serstevens, A., Rouxhet, P. G., Herbillon, A. J., Bradley, W. F. and Bailey, S. W., 1964 Alteration of mica surfaces by water and solutions Clays and Clay Minerals, Proc. 13 th Natl. Conf, Madison, Wisconsin, 1964 New York Pergamon Press 401 – 411.Google Scholar
White, A. J. R. Williams, I. S. and Chappell, B. W., 1977 Geology of the Berridale 1:100,000 Sheet 8625 .Google Scholar
Wilke, B. S., Schwertmann, U. and Murad, E., 1978 An occurrence of polymorphic halloysite in granite saprolite of the Bayerischer Wald, Germany Clay Miner. 13 67 – 77.CrossRefGoogle Scholar
Wilson, M. J., Bain, D. C. and McHardy, W. J., 1971 Clay mineral formation in deeply weathered boulder conglomerate in northeast Scotland Clays & Clay Minerals 19 345 – 352.CrossRefGoogle Scholar
Wollast, R., 1967 Kinetics of the alteration of K-feldspar in buffered solutions Geochim. Cosmochim. Acta 31 635 – 648.CrossRefGoogle Scholar
Wollast, R., Chou, L. and Drever, J. I., 1985 Kinetic study of the dissolution of albite with a continuous flow-through fluidized bed reactor The Chemistry of Weathering The Netherlands Reidel, Dordrecht 75 – 96.CrossRefGoogle Scholar