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Zirconium-rich Sodic Pyroxenes in Felsic Volcanics from the Warrumbungle Volcano, Central New South Wales, Australia

Published online by Cambridge University Press:  05 July 2018

M. B. Duggan
M. B. Duggan*
Affiliation:
Bureau of Mineral Resources, G.P.O. Box 378, Canberra, ACT, 2601, Australia
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Abstract

Soda-rich pyroxenes in felsic rocks from the Warrumbungle Volcano, central New South Wales, contain up to 14.5 wt. % ZrO2, which is more than double the previously reported maximum ZrO2 in pyroxene. Zr is believed to enter aegirine as the component Na(Fe2+,Mn,Mg)0.5Zr0.5Si2O6 via the coupled substitution: (Fe2+,Mn,Mg)VI+ZrVI = 2(Fe3+)VI. This component exceeds 50 mol. % in some analyses.

Pronounced pyroxene Zr-enrichment is restricted to rocks in which sodic amphibole is the major ferromagnesian mineral, with pyroxene only a minor late-stage phase. The Zr-rich pyroxenes resulted from a combination of host lava peralkalinity, low oxygen fugacity, rapid disequilibrium crystallization and low mobility of the Zr ion. These factors collectively led to the development of interstitial Zr-enriched microdomains in the felsic hosts during their final stages of crystallization.

Keywords

zirconiumpyroxenesfelsic rocksWarrumbungle VolcanoNew South Wales, Australia
Type
Mineralogy
Information
Mineralogical Magazine , Volume 52 , Issue 367 , September 1988 , pp. 491 - 496
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1988

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References

Ernst, W.G. (1962) Synthesis, stability relations and occurrence of riebeckite and riebeckitearfvedsonite solid solutions. J. Geol. 70, 689-736.Google Scholar
Ewart, A. (1981) The mineralogy and chemistry of the anorogenic Tertiary silicic volcanics of S.E. Queensland and N.E. New South Wales. J. Geophys. Res. 86(BII), 102-425..Google Scholar
Mateen, A., and Ross, J.A. (1976) Review of mineralogy and chemistry of Tertiary central volcanic complexes in southeast Queensland and northeast New South Wales. In Volcanism in Australia(R. W. Johnson, ed.) Elsevier, New York, 21-39.Google Scholar
Ferguson, A.K. (1977) The natural occurrence of aegirine neptunite solid solution. Contrib. Mineral. Petrol. 60, 247-53.CrossRefGoogle Scholar
Hodges, F.N. and Barker, D.S. (1973) Solid solution in aenigmatite. Carnegie Inst. Washington, Ann. Rept Dir. Geophys, Lab. 72, 578-81.Google Scholar
Jones, A.P. and Peckett, A. (1980) Zirconium-bearing aegirines from Motzfeldt, South Greenland. Contrib. Mineral. Petrol. 75, 251-5 .CrossRefGoogle Scholar
Larsen, L.M. (1976) Clinopyroxenes and coexisting mafic minerals from the alkaline Illimaussaq Intrusion, South Greenland. J. Petrol. 17, 258-90.Google Scholar
Lindsley, D.H. (1971) Synthesis and preliminary results on the stability of aenigmatite. Carnegie Inst. Washington, Ann. Rept Dir. Geophys. Lab. 69, 188-90.Google Scholar
Neilson, T.F.D. (1979) The occurrence and formation of Ti-aegirines in peralkaline syenites. Contrib. Mineral. Petrol. 69, 235-44.Google Scholar
Papike, J.J., Cameron, K.L., and Baldwin, K. (1974) Amphiboles and pyroxenes: characterization of other than quadrilateral components and estimates of ferric iron from microprobe data. Geol. Soc. America, Ann. Mtg, Abstracts with programs, 105-34.Google Scholar
Ronsbo, J.G., Pedersen, A.K., and Engell, J. (1977) Titan-aegirine from early Tertiary ash layers in northern Denmark. Lithos, 10, 193-204.CrossRefGoogle Scholar
Stolz, A.J. (1985) The role of fractional crystallization in the evolution of the Nandewar Volcano, north-eastern New South Wales, Australia. J. Petrol. 26, 1002-26.Google Scholar
Stolz, A.J. (1986) Mineralogy of the Nandewar Volcano, northeastern New South Wales, Australia. Mineral. May. 50, 241-55.Google Scholar
Thompson, R.N. and Chisholm, J.E. (1969) Synthesis of aenigmatite. Ibid. 37, 25-35.Google Scholar
Watson, E.B. (1979) Zircon saturation in felsic liquids: Experimental results and applications to trace element geochemistry. Contrib. Mineral. Petrol. 70, 407-19.Google Scholar
Wellman, P. and McDougall, I. (1974) Potassiumargon ages on the Cainozoic volcanic rocks of New South Wales. J. geol. Soc. Australia, 21, 247-72.Google Scholar