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Role of CO2 on differentiation of ultramafic alkaline series: liquid immiscibility in carbonate-bearing phonolitic dykes (Polar Siberia)

Published online by Cambridge University Press:  05 July 2018

L. N. Kogarko
L. N. Kogarko*
Affiliation:
Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Science, 19 Kosygin Street, Moscow, 117975, Russia
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Abstract

The Maimecha-Kotui province in the North of Siberian platform is the largest province of ultramafic alkaline rocks in the world. The province comprises thirty-seven central-type complexes together with numerous dykes. The majority of dykes are radially disposed around the ultramafic alkaline massifs. Data are presented for dykes of the Dolbykha carbonatite complex, which comprises olivine and melilite nephelinites; nosean, calcite and cancrinite phonolites; calcite trachytes and calcite carbonatites.

Some peralkaline phonolitic dykes contain carbonate-bearing globules with sizes of 1−2 mm to 17−20 mm. Globules consist of polycrystalline calcitic aggregates together with albite, phlogopite, apatite, Sr-lueshite, zircon, ancylite, ilmenite and strontianite. The phonolites have phenocrysts of albite, phlogopite and ilmenite. Albite, phlogopite, calcite and nepheline are also present in the groundmass. Analysis of these materials in the light of experimental data on the liquid immiscibility in carbonate-silicate systems suggests that separation of carbonatite from phonolitic melts took place due to immiscibility in the liquid state. I propose that carbonate melts contained originally significantly higher alkali contents which were subsequently lost into the fluid phase due to the incongruent dissolution of calcium-sodium carbonates in aqueous fluid at low temperatures. The discovery of nyerereite in the carbonatite of Polar Siberia confirms this conclusion. I infer that one of the mechanisms for the genesis of carbonatite melt in Polar Siberia was liquid immiscibility in strongly differentiated phonolitic magmas.

The generation of the carbonatites was probably controlled by the depth (and PCO2) of the crustal magma chamber where differentiation took place and probably also by the alkalinity of melts, and the rapidity of magma ascent to the surface.

Keywords

liquid immiscibilitycarbonatitesphonolitesPolar Siberia
Type
Intraplate Alkaline Magmatism
Information
Mineralogical Magazine , Volume 61 , Issue 407 , August 1997 , pp. 549 - 556
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1997

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References

Amundsen, H.E.F. (1987) Evidence for Liquid Immiscibility in the Upper Mantle. Nature 327, 692-5.CrossRefGoogle Scholar
Bailey, D.K. (1993) Carbonate magmas. J. Geol. Soc. London, 150, 637-51.CrossRefGoogle Scholar
Baker, M.B. and Wyllie, P.J. (1990) Liquid Immiscibility in a Nepheline-Carbonate System at 25 kbar and Implications for Carbonatite Origin. Nature, 346, 168-70.CrossRefGoogle Scholar
Bell, K. (1989) (Editor) Carbonatites: Genesis and Evolution. Unwin Hyman, London, 618 pp.Google Scholar
Dernov-Pegarev, V.F. and Malinin, S.D. (1976) Solubility of Calcite in High Temperature Aqueous Solutions of Alkali Carbonate and the Problem of the Formation of Carbonatites. Geochimia, 5, 643—57.(in Russian), translated as. Geochem. lnternat., 13, 1-13.Google Scholar
Eggler, D.H. (1989) Carbonatites, Primary Melts and Mantle Dynamics. In Carbonatites: Genesis and Evolution (Bell, K., ed.). Unwin Hyman, London, pp. 561-79.Google Scholar
Egorov, L.S. (1991) ljolite Carbonatite Plutonism (Case History of the Maimecha-Kotui Complexes, Northern Siberia). Nedra, Leningrad, 260 pp. (in Russian).Google Scholar
Freestone, I.C. and Hamilton, D.L. (1980) The Role of Liquid Immiscibility in the Genesis of Carbonatites. Contrib. Mineral. Petrol., 73, 105-17.CrossRefGoogle Scholar
Hamilton, D.L., Kjarsgaard, B.A. (1993) The Immiscibility of Silicate and Carbonate Liquids. South Porrican J. Geol., 96, 139–42.Google Scholar
Kjarsgaard, B.A. and Peterson, T.D. (1991) Nepheline-Carbonatite Liquid Immiscibility at Shombole Volcano, East Africa. Mineral. Petrol., 43, 293-314.CrossRefGoogle Scholar
Kogarko, L.N. (1993) Geochemical Characteristics of Oceanic Carbonatites from the Cape Verde Islands. South African J. Geol.., 96, 119-125.Google Scholar
Kogarko, LN., Tugarinov, A.A. and Krigman, L.D. (1982) Phase Equilibria in the System Nepheline-Lueshite. Dokl. Acad. Nauk, 263, 985-7.(in Russian), translated as Dokl. Acad. Sci. USSR: Earth Sci. Sect., 263, 170–2.Google Scholar
Kogarko, L.N., Plant, D.A., Henderson, C.M.B., and Kjarsgaard, B.A. (1991) Na-rich Carbonate Inclusion in perovskite and Calzirtite from the Guli Intrusive Ca-carbonatite, Polar Siberia. Contrib. Mineral. Petrol.., 109, 124-9.CrossRefGoogle Scholar
Kogarko, L.N., Kononova, V.A., Orlova, M.P. and Woolley, A.R. (1995) Alkaline Rocks and Carbonatites of the World. Part two: Former USSR. Chapman and Hall, London UK, 224 pp.Google Scholar
Lee, W-J. and Wyllie, P.J. (1994) Experimental Data Bearing on Liquid Immiscibility, Crystal Fractionation and the Origin of Calciocarbonatites and Natrocarbonatites. lnternat. Geol. Rev.., 36, 797-819.CrossRefGoogle Scholar
Lee, W-J. and Wyllie, P.J. (1996) Liquid Immiscibility in the Join NaAlSi308-CaCO3 to 2.5 GPa and the Origin of Calciocarbonatite Magmas. J. Petrol.., 37, 1125-52.CrossRefGoogle Scholar
Lee, W-J. and Wyllie, P.J. (in press) Liquid Immiscibility between Nephelinite and Carbonate from 1.0 to 2.5 GPa compared with Mantle Melt Compositions. Contrib. Mineral. Petrol. Google Scholar
Nielsen, T. (1993) Alkaline Dyke Swarms of the Gardiner Complex and the Origin of Ultramafic Alkaline Complexes. Geochimia, 8, 112—-4 (in Russian), translated a. Geochem. Internat., 31, 112-4.Google Scholar
Peterson, T.D. (1989) Peralkaline Nephelinites. 1. Comparative Petrology of Shombole and Oldoinyo. Contrib. Mineral. Petrol., 101, 458-78.CrossRefGoogle Scholar
Pyle, J.M. and Haggerty, S.E. (1994) Silicate-carbonate Liquid Immiscibility in Upper Mantle Eclogites: Implications for Natrosilicic and Carbonatitic Conjugate Melts. Geochim. Cosmochim. Acta, 58, 2997-3011.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.). Geological Society Special Publication No.30, 85–94, Blackwell Scientific Publishers, Oxford and London.Google Scholar
Wyllie, PJ. (1989) Origin of Carbonatites: Evidence from Phase Equilibrium Studies. In Carbonatites: Genesis and Evolution (Bell, K., ed.). Unwin Hyman, London, 500-45.Google Scholar
Wyllie, PJ., Baker, M.B. and White, B.S. (1990) Experimental Boundaries for the Origin and Evolution of Carbonatites. Lithos, 26, 3-19.CrossRefGoogle Scholar