Fluid Transport and Metasomatic Storage in the Mantle

  • D. K. Bailey
Part of the NATO ASI Series book series (ASIC, volume 218)


Alkaline intra-plate magmatism ranges from felsic to ultramafic, with the latter melts showing extremely low SiO2 activity, carbonatite being associated throughout, and all having mantle signatures. In all its forms this magmatism shows evidence of enhanced volatile activity, ranging from the chemistry of the melts through to the style of eruption, which frequently takes the form of high velocity eruptions that entrain mantle xenoliths. Volatile activity is thus not a function of degree of differentiation (“evolution”) and must signify high activity in the source mantle. The paradox of primitive magmas rich in alkalis, volatiles, and incompatible elements has led to proposals for source enrichment. Much is now known about the chemistry of the magmas and mantle nodules, and in addition to the more obvious alkalis, hydrogen, carbon and sulphur, the magmatism requires provision of significant P, Ti and Fe, and especially Ca. Minerals containing these elements, such as phlogopite, amphibole, clinopyroxene, phosphates and titanates, are present in metasomatised mantle xenoliths. These could not be samples of lithosphere that had experienced previous temperatures significantly higher than the vapour-present peridotite solidus, unless there had been subsequent cooling followed by a new influx of lithophile elements. Percolation of fluids, and of flux-induced melts, along geotherms ranging from “shield” to “oceanic” could lead to intensive lithophile enrichment near the solidus, and metasomatism in the sub-solidus. Combined petrographic and chemical data provide some limits on the essential composition of the fluids, which must be able to introduce at least Ca, K, Al, Si, H, and C to deep mantle peridotite. Experimental results provide the framework for exploring the consequences of fluid activity under different PT conditions. Most of the observed variations in magmatism and mantle xenoliths can be related to the interplay between geothermal gradients and the vapour-present mantle solidus.

Repetition of alkaline igneous activity through old lesions in the lithosphere, from the Precambrian onwards, requires a magma generating system in which the source of the energy and the special chemistry is below the lithpsphere but the control of its siting is in the lithosphere itself. As the lithosphere plates are continually moving, the ultimate cause of the igneous activity cannot be a unique anomaly in the deep mantle. Hence, the most likely means of introduction of the alkaline characteristics into the lithosphere is by migration of tenuous fluids. Alkaline ultramafic melts erupted at high velocity must achieve their distinctive eruption chemistry by interaction with enriched mantle below the point of lift-off; and pick up their nodule suite from this level and above.


Geothermal Gradient Mantle Xenolith Mantle Peridotite Chemical Transport Alkaline Magmatism 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bailey, D.K. 1966. ‘Carbonatite volcanoes and shallow intrusions in Zambia.’ In: O.F. Tuttle and J. Gittins (Eds.), Carbonatites. J. Wiley and Sons, New York, London & Sydney, 127–54.Google Scholar
  2. Bailey, D.K. 1970. ‘Volatile flux, heat focussing and the generation of magma.’ Geol. J. Special Issue, No. 2, 177–86.Google Scholar
  3. Bailey, D.K. 1972. ‘Uplift, rifting and magmatism in continental plates.’ J. Earth Sciences (Leeds), 8, 225–39.Google Scholar
  4. Bailey, D.K. 1977. “Lithosphere control of continental rift magmatism.’ J1. geol. Soc. Lond., 133, 103–6.CrossRefGoogle Scholar
  5. Bailey, D.K. 1980. ‘Volatile flux, geotherms, and the generation of the kimberlite-carbonatite-alkaline magma spectrum.’ Mineral. Mag. 43, 695–9.CrossRefGoogle Scholar
  6. Bailey, D.K. 1982. ‘Mantle metasomatism — continuing chemical change within the Earth. Nature, 296, 525–30.CrossRefGoogle Scholar
  7. Bailey, D.K. 1983. ‘The chemical and thermal evolution of rifts.’ Tectonophys.,94, 585–597.CrossRefGoogle Scholar
  8. Bailey, D.K. 1984. ‘Kimberlite: “The Mantle Sample” formed by ultrametasomatism.’ In: Kimberlites. I Kimberlites and Related Rocks, J. Kornprobst (Ed.), 323–33, Elsevier, Amsterdam.Google Scholar
  9. Bailey, D.K. 1985. ‘Fluids, melts, flowage and styles of eruption in alkaline ultramafic magmatism.’ Trans.geol.Soc.S.A. 88(2), 449–457.Google Scholar
  10. Bailey, D.K. 1987. ‘Mantle metasomatism: perspective and prospect.’ J. Geol. Soc. Lond., Spec. Vol. “Alkaline Rocks”.Google Scholar
  11. Boyd, F.R. and Nixon, P.H. 1975. ‘Origins of the ultramafic nodules from some kimberlites of Northern Lesotho and the Monastery Mine, South Africa.’ Phys. Chem. Earth, 9, 431–54.CrossRefGoogle Scholar
  12. Brey, G., Brice, W.R., Ellis, D.J., Green, D.H., Harris, K.L. and Ryabchikov, I.D. 1983. ‘Pyroxene-carbonate reactions in the upper mantle.’ EarthPlanet. Sci. Lett.,62, 63–74.CrossRefGoogle Scholar
  13. Brögger, W.C. 1921. ‘Die Eruptivgesteine des Kristianiagebietes. IV. Das Fengebiet in Telemark Norwegen.’ Norsk. Vidensk. Selsk. Skr. I, Math. Naturv kl., No. 9.Google Scholar
  14. Campbell Smith, W. 1956. ‘A review of some problems of African carbonatites.’ Q. J. Geol. Soc. Lond., cxii, 189–220.Google Scholar
  15. Chayes, F. 1963. ‘Relative abundance of intermediate members of the oceanic Basalt-Trachyte association.’ J. geophys. Res., 68, 1519–1534.CrossRefGoogle Scholar
  16. Clark, S.P. and Ringwood, A.E. 1964. ‘Density distribution and constitution of the mantle.’ Rev. Geophys., 2, 35.CrossRefGoogle Scholar
  17. Eggler, D.H. and Wendlandt, R.F. 1978. ‘Phase relations of a kimberlite composition.’ Cam. Inst. Wash. Yr. Bk., 77, 751–56.Google Scholar
  18. Kennedy, C.S. and Kennedy, G.C. 1976. ‘The equilibrium boundary between graphite and diamond.’ J. Geophys. Res., 81, 2467–2470.CrossRefGoogle Scholar
  19. Lloyd, F.E. and Bailey, D.K. 1975. ‘Light element metasomatism of the continental mantle: the evidence and the consequences.’ In: “Physics and Chemistry of the Earth”, 9, 389–416 (eds. L.H. Ahrens, J.B. Dawson, A.R. Duncan and A.J. Erlank). Pergamon Press, Oxford and New York.CrossRefGoogle Scholar
  20. Maund, J. 1985. The volcanic geology, petrology and geochemistry of Caldeira volcano, Graciosa, Azores, and its bearing on contemporaneous felsic-mafic oceanic island volcanism. Ph.D. Thesis, University of Reading.Google Scholar
  21. Olafsson, M. and Eggler, D.H. 1983. ‘Phase relations of amphibole, amphibole-carbonate, and phlogopite-carbonate peridotite: petrologic constraints on the asthenosphere.’ Earth Planet. Sci. Lett., 64, 305–15.CrossRefGoogle Scholar
  22. Oldenburg, D.W. 1981. ‘Conductivity structure of oceanic upper mantle beneath the Pacific plate.’ Geophys. J.R. Astron. Soc., 65, 359–94.CrossRefGoogle Scholar
  23. Sclater, J.G., Jaupart, C. and Galson, D. 1980. ‘The heat flow through oceanic and continental crust and the heat loss of the Earth.’ Rev. Geophys. Space Phys., 18, 269–311.CrossRefGoogle Scholar
  24. Smyth, C.H. Jr. 1927. ‘The genesis of alkaline rocks.’ Proc. Amer. Phil. Soc., 66, 535–80.Google Scholar
  25. Wendlandt, R.F. and Eggler, D.H. 1980. ‘The origins of potassic magmas: 2. Stability of phlogopite in natural spinel lherzolite and in the system KA1SiO4-MgO-Si02-H2O-CO2 at high pressures and high temperatures. Am. J. Sci., 280, 421–58.CrossRefGoogle Scholar
  26. Wyllie, P.J. 1979. ‘Petrogenesis and the physics of the Earth.’ In: The Evolution of the igneous rocks, Ed. H.S. Yoder, Jr., 481–520, Princeton University Press.Google Scholar
  27. Yoder, H.S. Jr. 1973. ‘Contemporaneous basaltic and rhyolitic magmas.’ Am. Mineral., 58, 153–171.Google Scholar

Copyright information

© D. Reidel Publishing Company 1987

Authors and Affiliations

  • D. K. Bailey
    • 1
  1. 1.Department of GeologyUniversity of ReadingReadingUK

Personalised recommendations