Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-23T16:35:07.115Z Has data issue: false hasContentIssue false

Hydrothermal clay mineral formation in a biotite-granite in northern Switzerland

Published online by Cambridge University Press:  09 July 2018

Tj. Peters
Affiliation:
Mineralogisches-Petrographisches Institut, University of Berne, Balzerstrasse 1, Berne, Switzerland
B. Hofmann
Affiliation:
Mineralogisches-Petrographisches Institut, University of Berne, Balzerstrasse 1, Berne, Switzerland

Abstract

Clay minerals of several hydrothermally altered zones in a 1200-m biotite-granite core from a drillhole in northern Switzerland were studied microscopically, by XRD and by electron microprobe. The minerals principally affected by the hydrothermal alteration were plagioclase (An5-An20) and, to a lesser extent, biotite. Illite, regularly interstratified illite-smectite and dioctahedral chlorite-smectite, dioctahedral chlorite, trioctahedral chlorite and kaolinite were detected in the alteration products. Commonly, two or more clay minerals occurred together in pseudomorphs after plagioclase. The mineral chemistry of the clay minerals showed a predominance of the substitution KAl for Si and, to a lesser extent, MgSi for Al. Fluid-inclusion data and the absence of pure smectite and epidote indicated temperatures of ∼200°C for the fluid that caused this alteration.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1984

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Browne, P.R.L. & Ellis, A.J. (1970) The Ohaki-Broadlands hydrothermal area, New Zealand: Mineralogy and related geochemistry. Am. J. Sci. 269, 97131.CrossRefGoogle Scholar
Eggleston, R.A. & Bailey, S.W. (1967) Structural aspects of dioctahedral chlorite. Am. Miner. 22, 673689.Google Scholar
Gubser, R. (1975) Programm EMMA, Computerbibliothek ETH-Z, Zurich.Google Scholar
Gunter, W.P. & Eugster, H.P. (1980) Mica-feldspar equilibrium in supercritical alkali chloride solutions. Contr. Mineral. Petrol. 75, 235250.Google Scholar
Kamineni, D.C. & Dugal, J.J.B. (1982) A study of rock alteration in the Eye-Dashwa Lakes Pluton, Atikokan, Northwestern Ontario, Canada. Chem. Geol. 36, 3557.CrossRefGoogle Scholar
Kuebler, B. (1964) Les argiles, indicateurs de métamorphisme. Rev. Inst. franc. Pétrole 19, 10931112.Google Scholar
Lovering, T.S. (1941) The origin of the tungsten ores of Boulder County, Colorado. Econ. Geol. 36, 229279.Google Scholar
Meunier, A. (1982) Superposition de deux altérations hydrothermales dans la syenite monzonitique du Bac de Montmeyre (sondage INAGI, Massif Central, France). Bull Minéral. 105, 386394.Google Scholar
Meunier, A. & Velde, B. (1982) Phengitization, sericitization and potassium-beidellite in a hydrothermally altered granite. Clay Miner. 17, 285299,Google Scholar
Meyer, C. & Hemley, J.J. (1967) Wall Rock Alteration. Pp. 166235 in: Geochemistry of Hydrothermal Ore Deposits (Barnes, H. L., editor). Holt Rinehart and Winston, New York.Google Scholar
Mueller, G. (1963) Zur Kenntnis di-oktaedrischer Vierschicht-Phyllosilikate (Sudoit-Reihe der Sudoit- Chlorit-Gruppe). Proc. Int. Clay Conf., Stockholm, 1, 121130.Google Scholar
Reynolos, R.C. (1980) Interstratified clay mineral. Pp. in: Crystal Structues of Clay Minerals and their X-ray Identification (Brindley, G. W. & Brown, G., editors). Mineralogical Society, London.Google Scholar
Steiner, A. (1968) Clay minerals in hydrothermally altered rocks at Wairakei. Clay Miner. 16, 193213.Google Scholar
Storey, B.C. & Lintern, B.C. (1981) Alteration, fracture infills and weathering of the Strath Halladale Granite. Institute of Geological Sciences, London. Report no. ENPU 81–3, 32 pp.Google Scholar
Sudo, T. (1959) Mineralogical Study on Clays of Japan. Maruzen, Tokyo.Google Scholar
Thompson, J.B. (1982) Composition space: An algebraic and geometric approach. Pp. 132 in. Reviews in Mineralogy 10, Mineralogical Society of America.Google Scholar
Velde, B. (1977) Clays and Clay Minerals in Natural and Synthetic Systems. Elsevier, Amsterdam.Google Scholar