Hostname: page-component-745bb68f8f-grxwn Total loading time: 0 Render date: 2025-01-11T06:43:34.708Z Has data issue: false hasContentIssue false
  • English
  • Français

Physical properties of carbonatite magmas inferred from molten salt data, and application to extraction patterns from carbonatite–silicate magma chambers

Published online by Cambridge University Press:  01 May 2009

J. A. Wolff
J. A. Wolff
Affiliation:
Department of Geology, University of Texas at Arlington, UTA Box 19049, Arlington, TX 76019, USA
Get access Rights & Permissions [Opens in a new window]

Abstract

Little is known about the physical properties of carbonatite magmas, making it difficult to predict dynamic behaviour in carbonatite-bearing magmatic systems. The viscosity of calcium-rich carbonatite magma is approximately estimated from molten salt data to be 0.1 Pa s at 700–800°C, while density is estimated at 2.3−2.5 × 103 kg m−3. The corresponding values for natrocarbonatite are 0.01 Pa s and 2.0−2.1 × 103 kg m−3. It is thus possible for carbonatite to be negatively buoyant with respect to some silicate magmas. The surface tension in air of carbonatite magmas is estimated at 0.25 and 0.21 N m−1 for Ca-carbonatite and natrocarbonatite respectively. Knowledge of the interfacial tension between carbonatite and silicate liquids is critical before the formation and behaviour of silicate–carbonatite emulsions can be properly understood. Interfacial tension is constrained to < 0.09 N m−1 by the application of multiphase drop theory to experimentally-produced textures, and this value receives some support from geological observations. The mechanics of extraction from layered carbonatite-silicate magma chambers are briefly examined using the recommended density and viscosity values and the equations of Blake & Ivey (1986); the degree of eruptive mingling is dependent on which liquid was uppermost in the chamber.

Type
Articles
Information
Geological Magazine , Volume 131 , Issue 2 , March 1994 , pp. 145 - 153
Copyright
Copyright © Cambridge University Press 1994

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

Barker, D. S. 1989. Field relations of carbonatites. In Carbonatites (ed. Bell, K.), pp. 38–69. London: Unwin Hyman.Google Scholar
Barker, D. S. & Nixon, P. H. 1989. High-Ca, low-alkali carbonatite volcanism at Fort Portal, Uganda. Contributions to Mineralogy and Petrology 103, 166–77.CrossRefGoogle Scholar
Blake, S. & Campbell, I. H. 1986. The dynamics of magma-mixing during flow in volanic conduits. Contributions to Mineralogy and Petrology 94, 72–81.CrossRefGoogle Scholar
Blake, S. & Ivey, G. N. 1986. Magma-mixing and the dynamics of withdrawal from stratified reservoirs. Journal of Volcanology and Geothermal Research 27, 153–78.Google Scholar
Bogoch, R. & Magaritz, M. 1983. Immiscible silicate-carbonate liquids as evidenced from ocellar diabase dykes, southeast Sinai. Contributions to Mineralogy and Petrology 83, 227–30.Google Scholar
Brooker, R. A. & Hamilton, D. L. 1990. Three-liquid immiscibility and the origin of carbonatites. Nature 346, 459–62.CrossRefGoogle Scholar
Clarke, L. B. & LeBas, M. J. 1990. Magma mixing and metasomatic reaction in silicate-carbonate liquids at the Kruidfontein carbonatitic volcanic complex, Transvaal. Mineralogical Magazine 54, 45–56.CrossRefGoogle Scholar
Cooper, A. F., Gittins, J. & Tuttle, O. F. 1975. The system Na2CO3−K2CO3−CaCO3 at 1 kilobar and its significance in carbonatite petrogenesis. American Journal of Science 275, 534–60.Google Scholar
Dawson, J. B. 1989. Sodium carbonatite extrusions from Oldoinyo Lengai, Tanzania: implications for carbonatite complex genesis. In Carbonatites (ed. Bell, K.), pp. 255–77. London: Unwin Hyman.Google Scholar
Dawson, J. B., Bowden, P. & Clark, G. C. 1968. Activity of the carbonatite volcano Oldoinyo Lengai, 1966. Geologische Rundschau 57, 865–79.CrossRefGoogle Scholar
Dawson, J. B. & Hawthorne, J. B. 1973. Magmatic sedimentation and carbonatitic differentiation in kimberlite sills at Benfontein, South Africa. Journal of the Geological Society, London 129, 61–85.Google Scholar
Dawson, J. B., Pinkerton, H., Norton, G. E. & Pyle, D. M. 1990. Physicochemical properties of alkali carbonatite lavas: data from the 1988 eruption of Oldoinyo Lengai, Tanzania. Geology 18, 260–63.2.3.CO;2>CrossRefGoogle Scholar
Dawson, J. B., Smith, J. V. & Steele, I. M. 1989. Combeite (Na2.33Ca1.74others0.12)Si3O9 from Oldoinyo Lengai, Tanzania. Journal of Geology 97, 365–72.CrossRefGoogle Scholar
Dawson, J. B., Smith, J. V. & Steele, I. M. 1992. 1966 ash eruption of the carbonatite volcano Oldoinyo Lengai: mineralogy of lapilli and mixing of silicate and carbonate magmas. Mineralogical Magazine 56, 1–16.CrossRefGoogle Scholar
Freestone, I. & Hamilton, D. L. 1980. The role of liquid immiscibility in the genesis of carbonatites – an experimental study. Contributions to Mineralogy and Petrology 73, 105–17.Google Scholar
Freundt, A. & Tait, S. R. 1986. The entrainment of high-viscosity magma into low-viscosity magma in eruption conduits. Bulletin of Volcanology 48, 325–39.CrossRefGoogle Scholar
Gittins, J. 1989. The origin and evolution of carbonatite magmas. In Carbonatites (ed. Bell, K.), pp. 580–600. London: Unwin Hyman.Google Scholar
Hay, R. L. 1978. Melilitete-carbonatite tuffs in the Laetolil Beds of Tanzania. Contributions to Mineralogy and Petrology 67, 357–67.CrossRefGoogle Scholar
Hay, R. L. 1989. Holocene carbonatite-nephelinite tephra deposits of Oldoinyo Lengai, Tanzania. Journal of Volcanology and Geothermal Research 37, 77–91.CrossRefGoogle Scholar
Hinch, E. J. & Acrivos, A. 1980. Long slender drops in a simple shear flow. Journal of Fluid Mechanics 98, 305–28.CrossRefGoogle Scholar
Ivey, G. N. & Blake, S. 1985. Axisymmetric withdrawal and inflow in a density-stratified chamber. Journal of Fluid Mechanics 161, 115–37.CrossRefGoogle Scholar
Janz, G. J. 1988. Thermodynamic and transport properties for molten salts: correlation equations for critically evaluated density, surface tension, electrical conductance, and viscosity data. Journal of Physical and Chemical Reference Data no. 17, suppl. 2, 309 pp.Google Scholar
Janz, G. J., Allen, C. B., Bansal, N. P., Murphy, R. M. & Tomkins, R. P. T. 1979. Physical properties: data compilations relevant to energy storage. II. Molten salts: data on single and multi-component salt systems. NSRDS-NBS 61, Part II, U. S. Government Printing Office, 432 pp.Google Scholar
Johnson, R. E. & Sadhal, S. S. 1985. Fluid mechanics of compound multiphase drops and bubbles. Annual Revews of Fluid Mechanics 17, 289–320.CrossRefGoogle Scholar
Keller, J. 1989. Extrusive carbonatites and their significance. In Carbonatites (ed. Bell, K.), pp. 70–88. London: Unwin Hyman.Google Scholar
Keller, J. & Krafft, M. 1990. Effusive natrocarbonatite activity of Oldoinyo Lengai, June 1988. Bulletin of Vocanology 52, 629–45.CrossRefGoogle Scholar
Kjarsgaard, B. A. & Hamilton, D. L. 1988. Liquid immiscibility and the origin of alkali-poor carbonatites. Mineralogical Magazine 52, 43–55.CrossRefGoogle Scholar
Kjarsgaard, B. A. & Hamilton, D. L. 1989. The genesis of carbonatites by immiscibility. In Carbonatites (ed. Bell, K.), pp. 388–404. London: Unwin Hyman.Google Scholar
Kjarsgaard, B. A. & Peterson, T. D. 1991. Nephelinite–carbonatite liquid immiscibility at Shombole Volcano, East Africa: petrographic and experimental evidence. Mineralogy and Petrology 43, 293–314.CrossRefGoogle Scholar
LeBas, M. J. 1987. Nephelinites and carbonatites. In Alkaline Igneous Rocks (eds Fitton, J. G. and Upton, B. J. G.), pp. 53–83. Geological Society of London, Special Publication no. 30.Google Scholar
LeBas, M. J. 1989. Diversification of carbonatite. In Carbonatites (ed. Bell, K.), pp. 428–47. London: Unwin Hyman.Google Scholar
Lister, J. R. 1989. Selective withdrawal from a viscous two-layer system. Journal of Fluid Mechanics 198, 231–54.Google Scholar
Murase, T. & McBirney, A. R. 1973. Properties of some common igneous rocks and their melts at high temperatures. Geological Society of America Bulletin 84, 3563–92.2.0.CO;2>CrossRefGoogle Scholar
Nesbitt, B. E. & Kelly, W. C. 1977. Magmatic and hydrothermal inclusions in carbonatite of the Magnet Cove complex, Arkansas. Contributions to Mineralogy and Petrology 63, 271–94.CrossRefGoogle Scholar
Peterson, A. L., Wolff, J. A. & Turbeville, B. N. 1989. Eruption mechanisms of extrusive carbonatites on an ocean island: Brava, Cape Verde Islands. EOS, Transactions of the American Geophysical Union 70, 1421.Google Scholar
Peterson, T. D. 1989. Peralkaline nephelinites. I. Comparative petrology of Shombole and Oldoinyo L'engai, East Africa. Contributions to Mineralogy and Petrology 101, 458–78.CrossRefGoogle Scholar
Peterson, T. D. 1990. Petrology and genesis of natrocarbonatite. Contributions to Mineralogy and Petrology 105, 143–55.CrossRefGoogle Scholar
Pinkerton, H., Wilson, L., Norton, G. E. & Dawson, B. 1990. Thermal erosion at the base of active lava flows. International Volcanology Congress abstracts. Mainz, Germany.Google Scholar
Rallison, J. M. 1984. The deformation of small viscous drops and bubbles in shear flows. Annual Reviews of Fluid Mechanics 16, 45–66.CrossRefGoogle Scholar
Sparks, R. S. J. 1978. The dynamics of bubble formation and growth in magmas: a review and analysis. Journal of Volcanology and Geothermal Research 3, 1–37.CrossRefGoogle Scholar
Taylor, G. I. 1934. The formation of emulsions in definable fields of flow. Proceedings of the Royal Society of London, Series A 146, 501–23.Google Scholar
Torza, S. & Mason, S. G. 1970. Three-phase interactions in shear and electrical fields. Journal of Colloid Interface Science 33, 67–83.CrossRefGoogle Scholar
Treiman, A. H. 1989. Carbonatite magma: properties and processes. In Carbonatites (ed. Bell, K.), pp. 89–104. London: Unwin Hyman.Google Scholar
Treiman, A. H. & Schedl, A. 1983. Properties of carbonatite magma and processes in carbonatite magma chambers. Journal of Geology 91, 437–47.Google Scholar
Wilson, L. & Head, J. W. 1981. Ascent and eruption of basaltic magma on the Earth and Moon. Journal of Geophysical Research 86, 2971–3001.Google Scholar
Wilson, L., Sparks, R. S. J., Huang, T. C. & Watkins, N. D. 1978. The control of volcanic column heights by eruption energetics and dynamics. Journal of Geophysical Research 83, 1829–36.Google Scholar
Wolff, J. A., Wörner, G. & Blake, S. 1990. Gradients in physical parameters in zoned felsic magma bodies: implications for evolution and eruptive withdrawal. Journal of Vocanology and Geothermal Research 43, 37–55.Google Scholar
Woolley, A. R. & Kempe, D. R. C. 1989. Carbonatites: nomenclature, average chemical compositions, and element distribution. In Carbonatites (ed. Bell, K.), pp. 1–14. London: Unwin Hyman.Google Scholar