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Weathering microenvironments on feldspar surfaces: implications for understanding fluid-mineral reactions in soils

Published online by Cambridge University Press:  05 July 2018

M. R. Lee ,
D. J. Brown ,
M. E. Hodson ,
M. Mackenzie  and
C. L. Smith
M. R. Lee*
Affiliation:
Department of Geographical and Earth Sciences, University of Glasgow, Gregory Building, Lilybank Gardens, Glasgow G12 8QQ, Uk
D. J. Brown
Affiliation:
Department of Geographical and Earth Sciences, University of Glasgow, Gregory Building, Lilybank Gardens, Glasgow G12 8QQ, Uk
M. E. Hodson
Affiliation:
Department of Soil Science, School of Human and Environmental Sciences, The University of Reading, Whiteknights, Reading RG6 6DW, Uk
M. Mackenzie
Affiliation:
Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ, Uk
C. L. Smith
Affiliation:
Department of Geographical and Earth Sciences, University of Glasgow, Gregory Building, Lilybank Gardens, Glasgow G12 8QQ, Uk
*
*E-mail: [email protected]
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Abstract

The mechanisms by which coatings develop on weathered grain surfaces, and their potential impact on rates of fluid-mineral interaction, have been investigated by examining feldspars from a 1.1 ky old soil in the Glen Feshie chronosequence, Scottish highlands. Using the focused ion beam technique, electron-transparent foils for characterization by transmission electron microscopy were cut from selected parts of grain surfaces. Some parts were bare whereas others had accumulations, a few micrometres thick, of weathering products, often mixed with mineral and microbial debris. Feldspar exposed at bare grain surfaces is crystalline throughout and so there is no evidence for the presence of the amorphous ‘leached layers’ that typically form in acid-dissolution experiments and have been described from some natural weathering contexts. The weathering products comprise sub-urn thick crystallites of an Fe-K aluminosilicate, probably smectite, that have grown within an amorphous and probably organic-rich matrix. There is also evidence for crystallization of clays having been mediated by fungal hyphae. Coatings formed within Glen Feshie soils after ∼1.1 ky are insufficiently continuous or impermeable to slow rates of fluid-feldspar reactions, but provide valuable insights into the complex weathering microenvironments on debris and microbe-covered mineral surfaces.

Keywords

alkali feldsparTEMsmectiteweathering
Type
Research Article
Information
Mineralogical Magazine , Volume 72 , Issue 6 , December 2008 , pp. 1319 - 1328
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2008

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Footnotes

†

Present address: Institut für Mineralogie, Westfälische, Wilhelms-Universität Münster, Corrensstrasse 24, 48149 Münster, Germany

§

Present address: Department of Mineralogy, The Natural History Museum, London SW7 5BD, UK

References

Bain, D.C., Mellor, A., Robertson-Rintoul, M.S.E. and Buckland, S.T. (1993) Variations in weathering processes and rates with time in a chronosequence of soils from Glen Feshie, Scotland. Geoderma, 57, 275–293.CrossRefGoogle Scholar
Banfield, J.F. and Barker, W.W. (1994) Direct observation of reactant-product interfaces formed in natural weathering of exsolved, defective amphibole to smectite: Evidence for episodic, isovolumetric reactions involving structural inheritance. Geochimica et Cosmochimica Ada, 58, 1419–1429.CrossRefGoogle Scholar
Banfield, J.F. and Eggleton, R.A. (1990) Analytical transmission electron microscope studies of plagio-clase, muscovite and K-feldspar weathering. Clays and Clay Minerals, 38, 77–89.CrossRefGoogle Scholar
Banfield, J.F., Ferruzzi, G.G., Casey, W.H. and Westrich, H.R. (1995) HRTEM study comparing naturally and experimentally weathered pyroxenoids. Geochimica et Cosmochimica Ada, 59, 19–31.CrossRefGoogle Scholar
Berner, R.A. and Holdren, G.R. (1979) Mechanism of feldspar weathering. 2. Observations of feldspars from soils. Geochimica et Cosmochimica Ada, 43, 1173–1186.CrossRefGoogle Scholar
Blum, A.E. (1994) Feldspars in weathering. Pp. 595–630 in: Feldspars and their Reactions (Parsons, I., editor), Kluwer, Dordrecht, The Netherlands.Google Scholar
Casey, W.H., Westrich, H.R., Massis, T., Banfield, J.F. and Arnold, GW. (1989) The surface of labradorite feldspar after acid hydrolysis. Chemical Geology, 78, 205–218.CrossRefGoogle Scholar
Eggleton, R.A. (1987) Noncrystalline Fe-Si-Al oxyhydr-oxides. Clays and Clay Minerals, 35, 29–37.CrossRefGoogle Scholar
Eggleton, R.A. and Buseck, P.R. (1980) High resolution electron microscopy of feldspar weathering. Clays and Clay Minerals, 28, 173–178.CrossRefGoogle Scholar
Heaney, P.J., Vicenzi, E.P., Giannuzzi, LA. and Livi, K.J.T. (2001) Focused ion beam milling: A method of site-specific sample extraction for microanalysis of Earth and planetary materials. American Mineralogist, 86, 1094–1099.CrossRefGoogle Scholar
Hellmann, R., Eggleton, CM., Hochella, M.F. Jr. and Crerar, DA. (1990) The formation of leached layers on albite surfaces during dissolution under hydro-thermal conditions. Geochimica et Cosmochimica Ada, 54, 1267–1281.CrossRefGoogle Scholar
Hodson, M.E. (2003) The influence of Fe-rich coatings on the dissolution of anorthite at pH 2.6. Geochimica et Cosmochimica Ada, 67, 3355–3363.CrossRefGoogle Scholar
Hodson, M.E., Langan, S.J., Kennedy, F.M. and Bain, D.C. (1998) Variation in soil surface area in a chronosequence of soils from Glen Feshie, Scotland and its implications for mineral weathering rate calculations. Geoderma, 85, 1–18.CrossRefGoogle Scholar
Kawano, M. and Tomita, K (1994) Growth of smectite from leached layer during experimental alteration of albite. Clays and Clay Minerals, 42, 7–17.CrossRefGoogle Scholar
Kawano, M. and Tomita, K. (1996) Amorphous aluminium hydroxide formed at the earliest weathering stages of K-feldspar. Clays and Clay Minerals, 44, 672–676.CrossRefGoogle Scholar
Lee, M.R. and Smith, C.L. (2006) Scanning transmission electron microscopy using a SEM: Applications to mineralogy and petrology. Mineralogical Magazine, 70, 579–590.CrossRefGoogle Scholar
Lee, M.R., Bland, P.A. and Graham, G. (2003) Preparation of TEM samples by focused ion beam (FIB) techniques: applications to the study of clays and phyllosilicates in meteorites. Mineralogical Magazine, 67, 581–592.CrossRefGoogle Scholar
Lee, M.R., Brown, D.J., Smith, C.L., Hodson, M.E., MacKenzie, M. and Hellmann, R. (2007) Characterisation of mineral surfaces using FIB and TEM: A case study of naturally-weathered alkali feldspars. American Mineralogist, 92, 1383–1394.CrossRefGoogle Scholar
Lee, M.R., Hodson, M.E., Brown, D.J., MacKenzie, M. and Smith, C.L. (2008) The composition and crystallinity of the near-surface regions of weathered alkali feldspars. Geochimica et Cosmochimica Ada, 72, 4962–4975.CrossRefGoogle Scholar
Muir, I.J., Bancroft, G.M. and Nesbitt, H.W. (1989) Characteristics of altered labradorite surfaces by SIMS andXPS. Geochimica et Cosmochimica Acta, 53, 1235–1241.CrossRefGoogle Scholar
Nugent, M.A., Brantley, S.L., Pantano, C.G. and Maurice, P.A. (1998) The influence of natural mineral coatings on feldspar weathering. Nature, 395, 588–591.CrossRefGoogle Scholar
Parham, W.E. (1969) Formation of halloysite from feldspar: low temperature artificial weathering versus natural weathering. Clays and Clay Minerals, 17, 13–22.CrossRefGoogle Scholar
Robertson-Rintoul, M.S.E. (1986) A quantitative soil-stratigraphic approach to the correlation and dating of post-glacial river terraces in Glen Feshie, western Cairngorms. Earth Surface Processes Landforms, 11, 605–617.CrossRefGoogle Scholar
Sanchez-Navas, A., Martin-Algarra, A. and Nieto, F. (1998) Bacterially-mediated authigenesis of clays in phosphate stromatolites. Sedimentology, 45, 519–533.CrossRefGoogle Scholar
Smith, C.L., Lee, M.R. and MacKenzie, M. (2006) New opportunities for nanomineralogy using FIB, STEM/ EDX and TEM. Microscopy Analysis, 111, 17–20.Google Scholar
Tazaki, K. (1986) Observation of primitive clay precursors during microcline weathering. Contributions to Mineralogy and Petrology, 92, 86–88.CrossRefGoogle Scholar
Tazaki, K. and Fyfe, W.S. (1987) Primitive clay precursors formed on feldspar. Canadian Journal Earth Science, 24, 506–527.CrossRefGoogle Scholar
Velbel, M.A. (1993) Formation of protective surface layers during silicate mineral weathering under well leached oxidizing conditions. American Mineralogist, 78, 405–414.Google Scholar
White, A.F. and Brantley, S.L. (2003) The effect of time on the weathering of silicate minerals: why do weathering rates differ in the laboratory and field? Chemical Geology, 202, 479–506.CrossRefGoogle Scholar
Wirth, R. (2004) Focused Ion Beam (FIB): A novel technology for advanced application of micro- and nanoanalysis in geosciences and applied mineralogy. European Journal of Mineralogy, 16, 863–876.CrossRefGoogle Scholar
Zhu, C, Veblen, D.R., Blum, A.E. and Chipera, SJ. (2006) Naturally weathered feldspar surfaces in the Navajo Sandstone aquifer, Black Mesa, Arizona: Electron microscopic characterization. Geochimica et Cosmochimica Acta, 65, 3459–3474.Google Scholar