Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-18T10:38:16.487Z Has data issue: false hasContentIssue false

Experimental study of the equilibrium between pollucite, albite and hydrothermal fluid in pegmatitic systems

Published online by Cambridge University Press:  05 July 2018

Ansom Sebastian
Affiliation:
Laboratoire de Géologie, Ecole Normale Supérieure, URA 1316, rue Lhomond, 75005 Paris, France
Martine Lagache
Affiliation:
Laboratoire de Géologie, Ecole Normale Supérieure, URA 1316, rue Lhomond, 75005 Paris, France

Abstract

Pollucite is a silicate mineral of the rare element caesium, occurring in granitic pegmatites. Experiments have been carried out at 450, 600, and 750°C, 1.5 kbar, to study the equilibrium between pollucite, albite and the co-existing hydrothermal solution. When pollucite co-exists with albite, the alkaline composition of the solution is buffered. The Cs/Na ratio of the solution has been determined to be 0.11 at 450°C 0.22 at 600°C and 0.23 at 750°C. Pollucite contains about 15 mol.% of sodium, whereas albite is almost purely sodic. In nature, pollucite with more than 82 mol.% caesium has never been found. This can be explained by the absence of solutions in granitic pegmatites having a higher Cs/Na ratio than those determined by us.

Type
Petrology and Experimental Studies
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1990

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

Appleman, D. E. and Evans, H. T. Jr. (1973) Least square unit-cell refinement with indexing. U. S. G.S.-GD-73-003, no. 20.Google Scholar
Barrer, R. M. and McCallum, N. (1953) Hydrothermal chemistry of silicates. Part IV. Rubidium and Caesium Aluminosilicates. J. Chem. Soc. London, 4029-35.Google Scholar
Burnham, C. W. and Nekvasil, H. (1986) Equilibrium properties of granitic magmas. Am. Mineral. 71, 239-63.Google Scholar
Burnham, C. W., Holloway, J. R. and Davis, N. F. (1969) The specific volume of water in the range 1000 to 8900 bars, 20°C to 900°. Am. J. Sci. 267A, 80-90.Google Scholar
Carron, J. P. and Lagache, M. (1980) Etude expérimentale du fractionnment des élements Rb, Cs, Sr et Ba entre feldspaths alcalins, solutions hydrothermales et liquides silicatés dans le systeme Q-Ab-Or-H2O à kb entre 700°C et 800°. Bull. Minéal. 103, 571-8.CrossRefGoogle Scholar
Černý, P. (1974) The present status of the analcime-pollucite series. Can. Mineral. 12, 334-41.Google Scholar
Černý, P. (1979) Pollucite and its alteration in geological occurrences and in deep burial radioactive waste disposal. In Scientific Basis for Nuclear Waste Management I (McCarthy, K. J., ed.) Plenum Publ. Corp., New York, 231-6.CrossRefGoogle Scholar
Černý, P. (1982) Mineralogy of rubidium and cesium. In Granitic Pegmatites in Science and Industry (Cerny, P., ed.) Mineral. Assoc. of Canada Short Course Handbook, 8, 149-61.Google Scholar
Černý, P. and Ferguson, R. B. (1972) The Tanco pegmatite at Bernic Lake Manitoba. IV. Petalite and Spodumene relations. Can. Mineral. 11, 660-78.Google Scholar
Černý, P. and Simpson, F. M. (1978) The Tanco Pegmatite at Bernic Lake, Manitoba. X. Pollucite. Ibid. 16, 325-33.Google Scholar
Černý, P., Trueman, D. L., Ziehlke, D. V., Goad, B. E. and Paul, B. J. (1981) The Cat Lake-Winnipeg River and the Wekusko Lake pegmatite fields, Manitoba. Man. Mineral. Res. Div., Econ. Geol. Rep. ER80-1.Google Scholar
Debron, G. (1965) Contribution à l'étude des ràactions d'àchange d'ions alcalins et alcalinoterreux dans les feldspathoides. Bull. Soc. fr. Minàal Cristallogr. 88, 69-96.Google Scholar
Goad, B. E. and (Černý, P. (1981) Peraluminous pegmatitic granites and their pegmatite aureoles in the Winnipeg River district, Southeastern Manitoba. Can. Mineral. 19, 177-94.Google Scholar
Hamilton, D. L. and Henderson, C. M. B. (1968) The preparation of silicate compositions by a gelling method. Mineral. Mag. 36, 832-8.Google Scholar
Henderson, C. M. B. and Taylor, D. (1969) An experimental study of the leucite and analcime mineral groups. First Rept. Progress in Experimental Petrology, Natural Environment Res. Council, 45-50.Google Scholar
Iiyama, J. T. (1964) Etude des réactions d'échange d'ions Na-K dans la série muscovite-paragonite. Bull. Soc. fr. Minéal. Cristallogr. 87, 532-41.Google Scholar
Iiyama, J. T. (1974) Behaviour of trace elements in feldspar under hydrothermal conditions. In The Feldspars (McKenzie, W. S. and Zussman, J., eds.) Manchester Univ. Press, New York, 553-73.Google Scholar
Kennedy, G. C. (1950) Pressure-volume-temperature relations in water. Am. J. Sci. 248, 540-64.CrossRefGoogle Scholar
Kume, S. and Koizumi, M. (1965) Synthetic pollucites in the system Cs2O.Al2O3.4SiO2-Cs2O.Fe2O3.4SiO2-H2O—their phase relationship and physical properties. Am. Mineral. 50, 587-92.Google Scholar
Lagache, M. and Weisbrod, A. (1977) The system: Two alkali feldspars-KCl-NaCl-H2O at moderate to high temperatures and low pressures. Contrib. Mineral. Petrol. 62, 77-101.CrossRefGoogle Scholar
Martin, R. F. and Lagache, M. (1975) Cell edges and infra-red spectra of synthetic leucites and pollucites in the system KAlSi2O6-RbAlSi2O6-CsAlSi2O6 . Can. Mineral. 13, 275-81.Google Scholar
Neuvonen, K. J. and Vesasalo, A. (1960) Pollucite from Luolamaki, Somero, Finland. Bull. Comm. Geol. Finlande, 188, 133-48.Google Scholar
Orville, P. M. (1963) Alkali ion exchange between vapor and feldspar phases. Am. J. Sci. 261, 201-37.CrossRefGoogle Scholar
Orville, P. M. (1972) Plagioclase cation-exchange equilibria with aqueous chloride solutions: results at 700°C and 800°C and 2000 bars in the presence of quartz. Ibid. 272, 234-272.CrossRefGoogle Scholar
Poty, B., Stalder, H. A. and Weisbrod, A. (1977) Fluid inclusion studies in quartz from fissures of Western and Central Alps. Schweiz. Mineral. Petrog. Mitt. 54, 717-52.Google Scholar
Roux, J. (1971) Fixation du Rubidium et du Césium dans la nepheline et dans l'albite à 600°C dans des conditions hydrothermales. C.R. Acad. Sci. Paris. Sér D, 278, 2397-400.Google Scholar
Solodov, N. A. (1966) Relationship between ionization potentials of elements and the concentration necessary for the formation of their own minerals. Dokl. Acad. Sci. U.S.S.R., Earth Sci. Sect. 165, 177-80.Google Scholar
Sourirajan, S. and Kennedy, G. C. (1962) The system H2O-NaCl at elevated temperatures and pressures. Am. J. Sci. 210, 115-41.CrossRefGoogle Scholar
Suito, K., Lacam, A. and Iiyama, J. T. (1974) Stabilité des solution solides de la série pollucite-leucite sous une pression d'eau de 30 kbars. C.R. Acad. Sci. Paris. Sér. D, 278, 2397-400.Google Scholar
Taylor, S. R. and McLennan, S. M. (1981) The composition and evolution of the continental crust: rare earth element evidence from sedimentary rocks. Phil. Trans. Roy. Soc. London A, 301, 381-99.Google Scholar
Volfinger, M. and Robert, J. L. (1980) Structural control of the distribution of trace elements between silicates and hydrothermal solutions. Geochim. Cosmochim. Acta, 44, 1455-61.CrossRefGoogle Scholar
Weisbrod, A. and Poty, B. (1975) Thermodynamics and geochemistry of the hydrothermal evolution of the Mayres pegmatite, South Eastern Massif Central (France). Pétrologie 1, 1-16 and 89-102.Google Scholar
Weisbrod, A. and Poty, B. (1976) Les inclusions fluides en pétrologie—géochimie; tendances actuelles. Bull. Soc. fr. Mineral. Cristallogr. 99, 140-52.Google Scholar
Wyart, J. and Sabatier, G. (1956) Transformations mutuelles des feldspaths alcalins. Reproduction du microcline et de l'albite. Ibid. 79, 574-81.Google Scholar
Wyart, J. and Sabatier, G. (1962) L'équilibre des feldspaths et des feldspathöides en présece de solution sodi-potassiques. Norsk. geol. Tidsskr. 42, 317-29.Google Scholar