Hostname: page-component-77c89778f8-fv566 Total loading time: 0 Render date: 2024-07-17T17:57:51.075Z Has data issue: false hasContentIssue false
  • English
  • Français

Melting the roof of a chamber containing a hot, turbulently convecting fluid

Published online by Cambridge University Press:  21 April 2006

Herbert E. Huppert  and
R. Stephen J. Sparks
Herbert E. Huppert
Affiliation:
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge CB3 9EW, UK
R. Stephen J. Sparks
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Site, Cambridge CB2 3EQ, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

The input of a hot, turbulently convecting fluid to fill a chamber can result in the roof of the chamber melting. The rate of melting of the roof is here analysed experimentally and theoretically. Three separate cases are considered. The melt may be heavier than the fluid and initially sink through it. The intense motion in the fluid then mixes the falling melt in with it. Alternatively, the melt may be less dense than the fluid and form a separate layer between the roof and the fluid. This melt layer can itself be in quite vigorous convective motion. An intermediate case is shown to be possible, wherein the melt is initially denser than the fluid, and sinks. As its temperature increases and its density decreases, it becomes less dense than the surrounding fluid and rises. Experimental simulations of each of these three cases are described. The experiments employ a roof of either wax or ice which is melted by the aqueous salt solution beneath it. The second case, that of a light melt, has important geological applications. It describes the melting of the continental crust by the emplacement of a hot, relatively dense input of fluid basaltic rock. Both the basaltic layer and the resultant granitic melt layer crystallize and increase their viscosities as they cool. These effects are incorporated into the analysis and the rate of melting and the temperatures of the two layers are calculated as functions of time. The process is exemplified by the formation of the Cerro Galan volcanic system in Northwestern Argentina over the last 5 million years. An Appendix analyses the thermal history of the fluid in a chamber that does not melt and compares the results obtained with those derived previously.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 188 , March 1988 , pp. 107 - 131
Copyright
© 1988 Cambridge University Press

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

Campbell, I. H. & Turner, J. S. 1987 A laboratory investigation of assimilation at the top of a basaltic magma chamber, J. Geol 95, 155–172.Google Scholar
Carslaw, H. S. & Jaeger, J. C. 1959 Conduction of Heat in Solids. Oxford University Press.
Denton, R. A. & Woods, I. R. 1979 Turbulent convection between two horizontal plates. Intl J. Heat Mass Transfer 22, 1339–1346.Google Scholar
Francis, P. W., Sparks, R. S. J., Hawkesworth, C. J., Thorpe, R. S., Pyle, D. M. & Tait, S. R. 1988 Petrology and geochemistry of volcanic rocks of the Cerro Galan ealdera, Northwest Argentina. Geol. Mag. (sub judice).Google Scholar
Holman, J. P. 1976 Heat Transfer. MacGraw-Hill.
Huppert, H. E. 1986 The intrusion of fluid mechanics into geology. J. Fluid Mech. 173, 557–594.Google Scholar
Huppert, H. E. & Sparks, R. S. J. 1980 The fluid dynamics of a basaltic magma chamber replenished by influx of hot, dense ultrabasic magma. Contr. Miner. Petr. 75, 279–289.Google Scholar
Huppert, H. E. & Sparks, R. S. J. 1985 Komatiites I: Eruption and flow. J. Petr. 26, 694–725.Google Scholar
Huppert, H. E. & Sparks, R. S. J. 1988a The generation of granitic magmas by intrusion of basalt into continental crust. J. Petr. (in press).Google Scholar
Huppert, H. E. & Sparks, R. S. J. 1988b The fluid dynamics of crustal melting by injection of basaltic sills. Proc. R. Soc. Edin: Earth Sci. (in press).Google Scholar
Huppert, H. E., Sparks, R. S. J., Turner, J. S. & Arndt, N. T. 1984 Emplacement and cooling of komatiite lavas. Nature 309, 19–22.Google Scholar
Kerr, R. C. & Lister, J. R. 1988 Island are and mid-ocean ridge volcanism, modelled by diapirism from linear source regions. Earth Planet. Sci. Lett. (sub judice).Google Scholar
McKenzie, D. P. 1984 The generation and compaction of partially molten rock. J. Petr. 95, 713–765.Google Scholar
Marsh, B. D. 1979 Island arc development: some observations, experiments and speculations. J. Geol. 87, 687–713.Google Scholar
Marsh, B. D. 1981 On the crystallinity, probability of occurrence and rheology of lava and magma. Contr. Miner. Petr. 78, 85–98.Google Scholar
Shaw, H. R. 1972 Viscosities of magmatic liquids: an empirical method of prediction. Am. J. Sci. 272, 870–893.Google Scholar
Sparks, R. S. J., Huppert, H. E. & Turner, J. S. 1984 The fluid dynamics of evolving magma chambers, Phil. Trans. R. Soc. Lond. A 310, 511–534.Google Scholar
Turner, J. S. 1973 Buoyancy Effects in Fluids. Cambridge University Press.
Turner, J. S., Huppert, H. E. & Sparks, R. S. J. 1986 Komatiites II: Experimental and theoretical investigations of post-emplacement cooling and crystallization. J. Petr. 27, 397–437.Google Scholar
Whitehead, J. A. & Luther, D. S. 1975 Dynamics of laboratory diapir and plume models. J. Geophys. Res. 80, 705–717.Google Scholar
Wyllie, P. J. 1971 The Dynamic Earth. Wiley.