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Stability of naujakasite in hyperagpaitic melts, and the petrology of naujakasite lujavrite in the llímaussaq alkaline complex, South Greenland

Published online by Cambridge University Press:  05 July 2018

T. Andersen  and
H. Sørensen
T. Andersen*
Affiliation:
Department of Geosciences, University of Oslo, P.O. Box 1047 Blindern, N-0654 Oslo, Norway
H. Sørensen
Affiliation:
Geological Institute, Copenhagen University, Øster Voldgade 10, DK-1350 København K, Denmark
*
*E-mail: tom.andersen@geo.uio.no
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Abstract

Naujakasite (Na6(Fe,Mn)Al4Si8O26) is a characteristic, rock-forming mineral of hyperagpaitic naujakasite lujavrite (arfvedsonite + naujakasite + steenstrupine + albite ± relict nepheline ± microcline ± ussingite) from the Ilímaussaq complex, South Greenland, and is only known from this complex. The qualitative stability relationships of naujakasite-bearing, low-variance liquidus mineral assemblages at near-solidus conditions in lujavritic magma can be modelled within the six-component system Si-Al-Fe-Na-O-H. The modelling suggests that an uncommon combination of elevated water activity and low oxygen fugacity is needed to stabilize arfvedsonite + naujakasite mineral assemblages in highly sodic liquids. These conditions are incompatible with the stable coexistence of aegirine and arfvedsonite. They are met in the arfvedsonite-bearing lujavrites of Ilímaussaq, but apparently not in rocks of similar composition in the Khibina and Lovozero complexes, Kola Peninsula, where aegirine- or aegirine-arfvedsonite-bearing mineral assemblages are characteristic. Liquid lines of descent leading to crystallization of naujakasite have to pass through the albite+nepheline+arfvedsonite liquidus field in the Si-Al-Fe-Na-O-H system, reaching this field at the high-Na side of the albite-nepheline-arfvedsonite plane.

Keywords

nepheline syeniteagpaitic rocksnaujakasitewater activityoxygen fugacityIlímaussaq complexGreenland
Type
Research Article
Information
Mineralogical Magazine , Volume 69 , Issue 2 , April 2005 , pp. 125 - 136
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2005

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Footnotes

Contribution to the Mineralogy of llímaussaq no. 125

References

Bøggild, O.B. (1930) Igalikite and naujakasite, two new minerals from South Greenland. Meddelelser om Gronland, 92(9), 12 pp.Google Scholar
Danø, M. and Sørensen, H. (1959) An examination of some rare minerals from the nepheline syenites of South West Greenland. Bulletin Grønlands Geologiske Undersegelse, 20, 35 pp. (also Meddelelser om Grønland, 162(5)).Google Scholar
Khomyakov, A.P. (1995) Mineralogy of Hyperagpaitic Alkaline Rocks. Oxford Science Publications, Clarendon Press, Oxford, UK, 223 pp.Google Scholar
Khomyakov, A.P., Nechelyustov, G.N., Ferraris, G. and Ivaldi, G. (2000) Manganonaujakasite, Na6(Mn,Fe)Al4Si8O26, a new mineral from the Lovozero alkaline massif, Kola Peninsula. Zapiski Vserossiiskogo Mineralogicheskogo Obshchestva, 129(4), 48–53 (in Russian).Google Scholar
Khomyakov, A.P., Sørensen, H., Petersen, O.V. and Bailey, J.C. (2001) Naujakasite from the Ilímaussaq alkaline complex, South Greenland, and the Lovozero alkaline complex, Kola Peninsula, Russia: a comparison. Pp. 95 — 108 in The Ilímaussaq Alkaline Complex, South Greenland: Status of Mineralogical Research with new Results (Sørensen, H., editor). Geology of Greenland Survey Bulletin, 190.Google Scholar
Larsen, L.M. and Seirensen, H., (1987) The Ilímaussaq intrusion — progressive crystallization and formation of layering in an agpaitic magma. Pp. 473—488 in: Alkaline Igneous Rocks (Fitton, J.G. and Upton, B.G.J., editors). Special Publication 30, Geological Society, London.Google Scholar
Markl, G. and Baumgartner, L. (2002) pH changes in peralkaline late-magmatic fluids. Contributions to Mineralogy and Petrology, 144, 331–346.CrossRefGoogle Scholar
Markl, G., Marks, M., Schwinn, G. and Sommer, H. (2001) Phase equilibrium constraints on intensive crystallization parameters of the Ilímaussaq complex, South Greenland. Journal of Petrology, 42, 2231–2258.CrossRefGoogle Scholar
Marks, M., Vennemann, T., Siebel, W. and Markl, G. (2004) Nd-,O-, and H-isotopic evidence for complex, closed system fluid evolution of the peralkalineIlímaussaq intrusion, South Greenland. Geochimica et Cosmochimica Acta, 68, 3379–3395.CrossRefGoogle Scholar
Petersilie, I.A. and Sørensen, H. (1971) Hydrocarbon gases and bituminous substances in rocks from the Ilímaussaq alkaline intrusion, South Greenland. Lithos, 3, 59–76.CrossRefGoogle Scholar
Sood, M.K. (1981) Modern Igneous Petrology. J. Wiley & Sons, New York, 244 pp.Google Scholar
Sood, M.K. and Edgar, A.D. (1970) Melting relations of undersaturated alkaline rocks from theIlímaussaq intrusion and Grønnedal-íka complex, South Greenland, under water vapour and controlled partial oxygen pressure. Meddelelser om Grønland, 181(12), 41 pp.Google Scholar
Sørensen, E. (1982) Water-soluble substances in Kvanefjeld lujavrite. Unpublished Report Risø National Laboratory, Roskilde, Denmark, 4 pp.Google Scholar
Sørensen, H. (1997) The agpaitic rocks - an overview. Mineralogical Magazine, 61, 485–498.CrossRefGoogle Scholar
Sørensen, H. (2001) Brief introduction to the geology of theIlímaussaq alkaline complex, South Greenland, and its exploration history. Pp. 7–23 in: TheIlímaussaq alkaline complex, South Greenland: status of mineralogical research with new results (Sørensen, H., editor). Geology of Greenland Survey Bulletin, 190.Google Scholar
Sørensen, H. and Larsen, L.M. (2001) The hyper-agpaitic stage in the evolution of theIlímaussaq alkaline complex, South Greenland. Pp. 83—94 in The Ilímaussaq alkaline complex, South Greenland: status of mineralogical research with new results (Sørensen, H., editor). Geology of Greenland Survey Bulletin, 190.Google Scholar
Upton, B.G.J., Emeleus, C.H., Heaman, L.M., Goodenough, K.M. and Finch, A.A. (2003) Magmatism of the mid-Proterozoic Gardar Province, South Greenland: chronology, petrogenesis and geological setting. Lithos, 68, 43–65.CrossRefGoogle Scholar
Ussing, N.V. (1912) Geology of the country around Julianehaab, Greenland. Meddelelser om Grønland, 38, 376 pp.Google Scholar