Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-27T08:02:27.957Z Has data issue: false hasContentIssue false

Carbonatite-related contact metasomatism in the Fen complex, Norway: effects and petrogenetic implications

Published online by Cambridge University Press:  05 July 2018

Tom Andersen*
Affiliation:
Mineralogisk-Geologisk Museum, Sars gate 1, N-0562 Oslo 5, Norway

Abstract

In the Fen complex (Telemark, S.E. Norway), carbonatites of different compositions have penetrated feldspathic fenites (alkali feldspar(s) + aegirine augite ± alkali amphibole) or older carbonatites, inducing different types of contact metasomatic alterations in their wall-rocks. (1) Pyroxene søvite has induced alkali metasomatism (i.e. fenitization s.s.), with alkali feldspars remaining stable and aegirine-augite transformed to nearly pure aegirine. (2) Søvite and dolomite carbonatite with phlogopite and/or alkali or alkali-calcic amphibole have caused replacement of feldspathic fenite by phlogopite, i.e. magnesium metasomatism. (3) Granular (dyke facies) ferrocarbonatite has increased the ferromagnesian components in calcite in wall-rock søvite. (4) Heterogeneous (pyroclastic) ferrocarbonatite induced pseudomorphic replacement of phlogopite by chlorite (leaching of alkalis). The different contact metasomatic processes reflect contrasts in compositional character among carbonatite magmas in the Fen complex, which may be evaluated in terms of differences in alkali and magnesium carbonate activities. The different types of carbonatite magma represent the products of local evolutionary trends, and are genetically related to spatially associated silicate rocks, rather than to a single ‘primitive’ carbonatite parent magma.

Type
Petrology and Geochemistry
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1989

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

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 ‘rødberg’ (hematite-calcite-dolomite carbonatite) in the Fen complex, Telemark (South Norway). Lithos 17, 227-45.CrossRefGoogle Scholar
Andersen, T. (1986) Magmatic fluids in the Fen carbonatite complex, S.E. Norway: Evidence of mid-crustal fractionation from solid and fluid inclusions in apatite. Contrib. Mineral. Petrol. 93, 491-503.CrossRefGoogle Scholar
Andersen, T. (1987a) Mantle and crustal components in a carbonatite complex, and the evolution of carbonatite magma: REE and isotopic evidence from the Fen complex, S.E. Norway. Chem. Geol. Isotope Geosci. Sect. 65, 147-66.CrossRefGoogle Scholar
Andersen, T. (1987a) A model for the evolution of hematite carbonafite, based on major and trace element data from the Fen complex S.E. Norway. Appl. Geochem. 2, 163-80.CrossRefGoogle Scholar
Andersen, T. (1988) Evolution of peralkaline calcite carbonatite magma in the Fen complex S.E. Norway. Lithos 22, 99-112.CrossRefGoogle Scholar
Andersen, T. and Qvale, H. (1986) Pyroclastic mechanisms for carbonatite intrusion: Evidence from intrusives in the Fen central complex S.E. Norway. J. Geol. 94, 762-9.CrossRefGoogle Scholar
Andersen, T. and Sundvoll, B. (1987) Strontium and neodymium isotopic composition of an early tinguaite (nepheline microsyenite) in the Fen complex, Telemark, Southeast Norway: Age and petrogenetic implications. Nor. geol. unders. Bull. 409, 29-34.Google Scholar
Andersen, T. and Taylor, P. N. (1988) Lead-isotope geochemistry of the Fen carbonatite complex S.E. Norway: Age and petrological implications. Geochim. Cosmochim. Acta 52, 209-15.CrossRefGoogle Scholar
Barth, T. F. W. and Ramberg, I. B. (1966) The Fen circular complex. In Carbonatites (Tuttle, O. F. and Gittins, J., eds.). Wiley-Interscience, New York, pp. 225-57.Google Scholar
Bergstøl, S. and Svinndal, S. (1960) The carbonatite and peralkaline rocks of the Fen area. Nor. geol. unders. 208, 99-105.Google Scholar
Brøgger, W. C. (1921) Die Eruptivgesteine des Kristianiagebietes, IV. Dos Fengebiet in Telemark, Norwegen. Vit. Selsk. Skr., I Mat. Nat. Klasse 1920, 1, Kristiania, 494 pp.Google Scholar
Castellan, G. W. (1971) Physical Chemistry, 2nd ed. Addison-Wesley. 866 pp.Google Scholar
Dahlgren, S. (1978) Nordagutu, bedrock map 1:50000 (preliminary edition). Nor. geol. Unders. Google Scholar
Dahlgren, S. (1987) The Satellitic Intrusions in the Fen carbonatite Alkaline Rock Province, Telemark, Southeastern Norway. Unpubl. Cand. Scient. Thesis, University of Oslo.Google Scholar
Dawson, J. B. (1962) Sodium carbonatite lavas from Oldoinyo Lengai, Tanganyika. Nature 195, 1075-6.CrossRefGoogle Scholar
Dawson, J. B. (1964) Reactivity of the cations in carbonate magmas. Geol. Assoc. Canada Proc. 15, 103-13.Google Scholar
Dawson, J. B., Garson, M. S. and Roberts, B. (1987) Altered former alkalic carbonatite lava from Oldoynio Lengai, Tanzania: Inferences for calcite carbonatite lavas. Geology 15, 765-8.2.0.CO;2>CrossRefGoogle Scholar
v. Eckermann, H. (1948) The alkaline district of Aln6 Island. Sver. Geol. Unders. Ser. Ca. 36, 176 pp.Google Scholar
Gittins, J. (1979) Problems inherent in the application of calcite-dolomite geothermometry to carbonatites. Contrib. Mineral. Petrol. 69, 1-4.CrossRefGoogle Scholar
Gittins, J. and McKie, D. (1980) Alkalic carbonatite magmas: Oldoinyo Lengai and its wider applicability. Lithos 13, 213-5.CrossRefGoogle Scholar
Greenwood, H. J. (1976) Metamorphism at moderate temperatures and pressures. In The evolution of the crystalline rocks (Bailey, D. K. and MacDonald, R., eds.). Academic Press, London, pp. 187259.Google Scholar
Heinrich, E. W. (1966) The geology of carbonatites. Rand McNally and Co., Chicago, 555 pp.Google Scholar
Hay, R. L. (1978) Melilitite-carbonatite tufts in the Laetolil beds of Tanzania. Contrib. Mineral. Petrol. 67, 357-67.CrossRefGoogle Scholar
Hey, M. H. (1954) A new review of the chlorites. Mineral. Mag. 30, 277-92.Google Scholar
Kjarsgaard, B. A. and Hamilton, D. L. (1988) Liquid immiscibility and the origin of alkali poor carbonatites. Ibid. 52, 43-55.CrossRefGoogle Scholar
Kresten, P. (1979) The Alnö complex. Discussion of the main features, bibliography, excursion guide. Nordic Carbonatite Symposium, Alnö 1979, 67 pp.Google Scholar
Kresten, P. (1988) The chemistry of fenitization: Examples from Fen, Norway. Chem. Geol. 68, 329-49.CrossRefGoogle Scholar
Kresten, P. and Morogan, V. (1986) Fenitization at the Fen complex, southern Norway. Lithos 19, 27-42.CrossRefGoogle Scholar
Le Bas, M. J. (1977) Carbonatite-Nephelinite Volcanism. Wiley, New York.Google Scholar
Le Bas, M. J. (1981) Carbonatite magmas. Mineral. Mag. 44, 133-40.CrossRefGoogle Scholar
Le Bas, M. J. (1987) Nephelinites and carbonatites. In Alkaline igneous rocks (Fitton, J. G. and Upton, B. G. J., eds.). Geol. Soc. Spec. Publ. No. 30, Blackwell, Oxford, pp. 5384.Google Scholar
McKie, D. (1966) Fenitization. In Carbonatites (Tuttle, O. F. and Gittins, J., eds.). Wiley-Interscience, New York, pp. 261-94.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
Morogan, V. (1988) Fenitization, hallmark of the ijolite-carbonatite magmatic association. Medd. Stockh. Universitets Geol. Inst. 274.Google Scholar
Ramberg, I. B. (1973) Gravity studies of the Fen complex, Norway, and their petrological significance. Contrib. Mineral. Petrol. 38, 115-34.CrossRefGoogle Scholar
Rice, J. M. (1977) Progressive metamorphism of impure dolomitic limestone in the Maryville aureol, Montana. Am. J. Sci. 277, 1-24.CrossRefGoogle Scholar
Sæether, E. (1957) The alkaline rock province of the Fen area in southern Norway. Det Kgl. Nor. Vit. Selsk. Skr. 1957, 1,148 pp.Google Scholar
Secher, K. and Larsen, L. M. (1980) Geology and mineralogy of the Sarfart6q carbonatite complex, East Greenland. Lithos 13, 199-212.CrossRefGoogle Scholar
Statham, P. J. (1976) A comparative study of techniques for quantitative analysis of X-ray spectra obtained with a Si(Li) detector. X-ray Spectrom. 5, 16-28.CrossRefGoogle Scholar
Treiman, A. H. and Essene, E. J. (1985) The Oka carbonatite complex, Quebec: geology and evidence for silicate-carbonate liquid immiscibility. Am. Mineral. 70, 1101-13.Google Scholar
Treiman, A. H. and Essene, E. J. and Schedl, A. (1983) Properties of carbonatite magma and processes in carbonatite magma chambers. J. Geol. 91, 437-17.CrossRefGoogle Scholar
Twyman, J. D. and Gittins, J. (1987) Alkalic carbonatite magmas: parental or derivative. In Alkaline igneous rocks (Fitton, J. G. and Upton, B. G. J., eds.). Geol. Soc. Spec. Publ. No. 30, Blackwell, Oxford, pp. 8594.Google Scholar
Verschure, R. H. and Maijer, C. (1984) Pluri-metasomatic resetting of Rb-Sr whole-rock systems around the Fen peralkaline-carbonatitic ring-complex, Telemark, South Norway. Terra Cognita 4, 191-2.Google Scholar
Verwoerd, W. J. (1966) Fenitization of basic igneous rocks. In Carbonatites (Tuttle, O. F. and Gittins, J., eds.). Interscience, New York, pp. 295308.Google Scholar
Woolley, A. R. (1982) A discussion of carbonatite evolution and nomenclature, and the generation of sodic and potassic fenites. Mineral. Mag. 46, 13-17.CrossRefGoogle Scholar
Wyllie, P. J. (1966) Experimental studies of carbonatite problems: The origin and differentiation of carbonatite magmas. In Carbonatites (Tuttle, O. F. and Gittins, J., eds.). Interscience, New York, pp. 311-52.Google Scholar