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Compositional variation of some rare earth minerals from the Fen complex (Telemark, SE Norway): implications for the mobility of rare earths in a carbonatite system

Published online by Cambridge University Press:  05 July 2018

Tom Andersen*
Affiliation:
Institutt for Geologi, Universitetet i Oslo, Boks 1047, Blindern, N0316 Oslo 3, Norway

Abstract

Rare earth minerals in ankeritic ferrocar-bonatite and associated magnetite ore, as well as in hematite-calcite-(dolomite) carbonatite (rødberg) derived from the ferrocarbonatite by post-magmatic alteration, have been studied by electron microprobe. The minerals found are monazite, parisite, and bastnäsite (identifications confirmed by X-ray diffraction) as well as an aluminous silicate with allanite composition, and possibly, synchysite. The rare earth element (REE) distribution patterns of the minerals change from light rare earth (LREE)-enriched in magnetite ore and ferrocarbonatite to less LREE-enriched, or middle REE-enriched in the most strongly re-equilibrated carbonatites. Two distinct mineral varieties, monazite-(Ce,Nd) and a Nd-fluorocarbonate, have been found in rødberg. The LREE were leached from their host minerals during re-equilibration of the carbonatite, most likely because of the influence of fluoride-bearing hydrothermal solutions.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1986

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References

Alderton, D.H.M., Pearce, J.A., and Potts, P.J., (1980) Rare earth mobility during granite alteration; evidence from southwest England. Earth. Planet. Sci. Lett. 49, 149-65.CrossRefGoogle Scholar
Amli, R. (1974) Mineralogiske og geokjemiske undersokelser vedrorende Scandium, Niob og sjeldne jordarter i Fensfeltet, Ulefoss.(In Norwegian). Unpubl. report., Mineralogical-Geological Museum, Oslo, 51 pp. + appendix.Google Scholar
Andersen, T. (1983) Iron ores in the Fen central complex, Telemark (S. Norway): Petrography, chemical evolution and conditions of equilibrium. Norsk Geol. Tidsskr. 63, 73-82.Google Scholar
Andersen, T. (1984) Secondary processes in carbonatites: petrology of ‘rodberg’ (hematite-calcite-dolomite carbonatite) in the Fen central complex, Telemark (South Norway). Lithos. 17, 227-45.CrossRefGoogle Scholar
Andersen, T.and Neumann, H. (1985) Identity of ‘freyalite', an alleged rare earth rich variety of thorite, and its premetamict composition. Am. Mineral. 70, 1059-64.Google Scholar
Barth, T.F.W., and Ramberg, I.B. (1966) The Fen circular complex. In Carbonatite.(O. F. Tuttle and J. Gittins, eds.). Interscience, New York, pp. 225-57.Google Scholar
Brogger, W.C. (1921) Die Eruptivgesteine des Kristianiagebietes IV Das Fengebiet in Telemark, Norwegen. Vit. selsk. skr. I Mat. Nat. Kl.1920, no. 9, Kristiania.Google Scholar
Clark, A.M. (1984) Mineralogy of the rare earth elements. In Rare Earth Geochemistr. Developments in Geochemistry 2 (P. Henderson, ed.). Elsevier, Amsterdam, 33-62.CrossRefGoogle Scholar
Drake, M.J., and Weill, D.F. (1972) New rare earth element standards for electron microprobe analysis. Chem. Geol. 10, 179-81.CrossRefGoogle Scholar
Felsche, J., and Herrmann, A.G. (1970) Yttrium and the Lanthanides. In Handbook of Geochemistr.(K. H. Wedepohl, ed.). Springer, Berlin. 11-15.Google Scholar
Haskin, L.A., Haskin, M.A., Frey, F.A., and Wilderman, T.R. (1968) Relative and absolute abundances of the rare earths. In Origin and distribution of the elements (L. H. Ahrens, ed.). Pergamon Press,, New York, pp. 889912.Google Scholar
Humphris, S. (1984) The mobility of the rare earth elements in the crust. In Rare Earth Geochemistr. Developments in Geochemistry 2 (P. Henderson, ed.). Elsevier, Amsterdam, 317-42.CrossRefGoogle Scholar
Jensen, B.B. (1967) Distribution patterns of rare earth elements in cerium rich minerals. Norsk Geol. Tidssk. 47, 919.Google Scholar
Mineyev, D.A. (1963) Geochemical differentiation of the rare earths. Geochemistry (USSR. 12, 1129-49.Google Scholar
Mitchell, R.H., and Brunfelt, A.O. (1975) Rare earth element geochemistry of the Fen alkaline complex, Norway. Contrib. Mineral. Petrol. 52, 247-59.CrossRefGoogle Scholar
Moller, P., Morteani, G., and Schley, F. (1980) Discussion of REEdistribution patterns of carbonatites and alkaline rocks. Lithos. 13, 171-9.CrossRefGoogle Scholar
Saebo, P.C. (1971) Mineralogical investigations of the Fen Area. Yearly report 1970(in Norwegian). Unpublished report, Forskningsgruppen for Sjeldne Jordarter, Oslo, 11 pp.Google Scholar
Semb, A. (1971) Contents and distribution of rare earth elements in minerals form the Fen deposit.Unpublished report, Dept. of Chemistry, Nuclear Chemistry Division, University of Oslo, 33 pp.Google Scholar
Semenov, E.I. (1963) Mineralogija redkich semel’.(Mineralogy of the rare earths, in Russian), Izdatel'stvo Akademii Nauk SSSR, Moskva, 412 ppGoogle Scholar
Shannon, R.D. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Ada Crystallog. A32, 751-67.CrossRefGoogle Scholar