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Amphibole weathering in a glaucophane-schist (Île de Groix, Morbihan, France)

Published online by Cambridge University Press:  09 July 2018

D. Proust
D. Proust*
Affiliation:
ERA no. 220 du CNRS “Pédologie, Pétrologie et Métallogénie de la Surface”, Université de Poitiers, 86022 Poitiers Cédex, France
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Abstract

The weathering of two co-existing sodic (glaucophane) and calcic (actinolite) amphiboles in a glaucophane-schist was studied by optical microscopy. XRD and the electron microprobe. In the early stages of weathering, two trioctahedral expandable phases occur as internal weathering products in the amphiboles: a sodic saponite in the glaucophane and a calcic ‘hectorite’ in the actinolite. Further weathering leads to the replacement of the ‘hectorite’ by a calcic saponite in the actinolite, while the saponites formed in the weathered glaucophane exhibit progressive calcium enrichment in their interlayer sites. These observations demonstrate the influence of the primary mineral compositions on initial weathering products.

Type
Research Article
Information
Clay Minerals , Volume 20 , Issue 2 , June 1985 , pp. 161 - 170
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1985

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References

Beaufort, D., Dudoignon, P., Proust, D., Parneix, J.C. & Meunier, A. (1983) Microdrilling in thin section: a useful method for the identification of clay minerals in situ. Clay Miner. 18, 219–222.Google Scholar
Delvigne, J., (1965) Pédogenèse en zone tropicale. La formation des minéraux secondaires en milieu ferrallitique. Mém. O.R.S.T.O.M. 13, 177 pp.Google Scholar
Hey, M.H. (1954) A new review of the chlorites. Mineral. Mag. 30, 277–292.Google Scholar
Ildefonse, P. (1980) Mineral facies developed by weathering of a meta-gabbro, Loire Atlantique (France). Geoderma 24, 257–273.Google Scholar
Jayaraman, N. (1940) Alteration of tremolite to talc in the dolomitic marbles of Yellandu Warang district (Hyderebad, Ontario). Proc. Indian Acad. Sci., sect. A 12, 65–71.Google Scholar
Leake, B.E. (1978) Nomenclature of amphiboles. Am. Miner. 63, 1023–1052.Google Scholar
Meunier, A. & Velde, B. (1982) X-ray diffraction of oriented clays in small quantities (0·1 mg). Clay Miner. 17, 259–262.CrossRefGoogle Scholar
Nicolas, J. & Sagon, J.P. (1966) Alteration en talc d'une diabase au Sud de Quintin (Côtes-du-Nord). Bull. Cr. Fr. Arg. XVIII, 47–50.Google Scholar
Nettleton, W.D., Flach, K.W. & Nelson, R.E. (1970) Pedogenic weathering of tonalite in Southern California. Geoderma 4, 387–402.CrossRefGoogle Scholar
Norton, D. & Knapp, R. (1977) Transport phenomena in hydrothermal systems: the nature of porosity. Am. J. Sci. 277, 913–936.Google Scholar
Pedro, G. & Delmas, B. (1980) Regards actuels sur les phénomènes d'altération hydrolytique. Cah. O.R.S.T.O.M., Pédol. XVIII, 217–234.Google Scholar
Proust, D. (1982) Supergene alteration of hornblende in an amphibolite from Massif Central, France. Proc. 7th Int. Clay Conf. Bologna and Pavia, 357–364.Google Scholar
Richter, D. & Simmons, G. (1977a) Microcracks in crystal igneous rocks: microscopy. Pp. 149–180 in: The Earth’s Crust: its Nature and Physical Properties (Heacock, J. G., editor). American Geophysical Union, Washington D.C. Google Scholar
Richter, D. & Simmons, G. (1977b) Microscopic tubes in igneous rocks. Earth Planet. Sci. Letters 34, 1–12.Google Scholar
Simmons, G. & Richter, D. (1976) Microcracks in rocks. Pp. 105–137 in: The Physics and Chemistry of Minerals and Rocks (Strens, R. G. J., editor). John Wiley and Sons, London.Google Scholar
Stephen, I. (1952) A study of rock weathering with reference to the soils of the Malvern Hills. II: weathering of appinite and “Ivy Scar rock”. J. Soil Sci. 3, 219–237.Google Scholar
Stringham, B.F. & Taylor, A. (1950) Nontronite at Bingham, Utah. Am. Miner. 35, 1060–1066.Google Scholar
Triboulet, C. (1977) Stabilité et relations de phases dans le système expérimental Na2O-Al2O3-MgO-SiO2- H2O. Applications à la pétrologie des glaucophanites et des roches qui leur sont assoeides. Thesis, Univ. Paris, 134 pp.Google Scholar
Wackermann, J.M. (1975) L'altération des massifs cristallins basiques en zone tropicale semi-humide. Etude mindéralogique et géochimique des arènes du Sénégal oriental. Conséquences pour la cartographie et la prospection. Thesis, Univ. Strasbourg, 373 pp.Google Scholar
Walker, T.R., Ribbe, P.N. & Honea, R.A. (1967) Geochemistry of hornblende alteration in Pliocene red beds. Baja California, Mexico. Bull. Geol. Soc. Am. 78, 1055–1060.Google Scholar
Wilson, M.J. & Farmer, V.C. (1970) A study of weathering in a soil derived from a biotite hornblende rock. II. Weathering of hornblende. Clay Miner. 8, 435–444.Google Scholar