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The Skye Main Lava Series: liquid density and the absence of basaltic hawaiites

Published online by Cambridge University Press:  01 May 2009

A. C. Cattell
A. C. Cattell
Affiliation:
Department of Geology, University of Exeter, Exeter EX4 4QE, U.K.
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Abstract

Basaltic hawaiite lavas are virtually absent in the Eocene Skye Main Lava Series, in contrast to relatively abundant basalts and hawaiites. Fractional crystallization from basalt to basaltic hawaiite involves extraction of a large proportion of plagioclase, and liquid densities thereby increase. From basaltic hawaiite to hawaiite titanomagnetite is a significant fractionating phase, and liquid densities decline. The coincidence between a gap in erupted compositions and a density maximum implies that liquid density exerted a strong control on ‘eruptibility’ of magmas; basaltic hawaiites were too dense to be erupted. Density maxima occur in basalt suites if plagioclase fractionates before Fe–Ti oxides, and may explain compositional gaps in erupted magmas. Compositional gaps are not the inevitable result of density maxima; the density of the rock column above, and the fluid dynamics within, the magma chamber where differentiation occurs are also critical factors.

Type
Articles
Information
Geological Magazine , Volume 126 , Issue 6 , November 1989 , pp. 681 - 684
Copyright
Copyright © Cambridge University Press 1989

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References

Bottinga, Y. & Weill, D. F. 1970. Densities of liquid silicate systems calculated from partial molar volumes of oxide components. American Journal of Science 269, 169–82.CrossRefGoogle Scholar
Dicken, A. P. 1981. Isotope geochemistry of Tertiary Igneous rocks from the Isle of Skye, N.W. Scotland. Journal of Petrology 22, 155–89.CrossRefGoogle 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. Contributions to Mineralogy and Petrology 75, 279–89.CrossRefGoogle Scholar
Moorbath, S. & Thompson, R. N. 1980. Strontium isotope geochemistry and petrogenesis of the early Tertiary lava pile of the Isle of Skye, Scotland, and other basic rocks of the British Tertiary Province: an example of magma-crust interaction. Journal of Petrology 21, 295–321.CrossRefGoogle Scholar
McBirney, A. R. 1984. Igneous Petrology. Freeman, Cooper & Co. 504 pp.Google Scholar
Sparks, R. S. J. & Huppert, H. E. 1984. Density changes during the fractional crystallization of basaltic magmas: fluid dynamical implications. Contributions to Mineralogy and Petrology 85, 300–9.CrossRefGoogle Scholar
Stolper, E. M. & Walker, D. 1980. Melt density and the average composition of basalt. Contributions to Mineralogy and Petrology 74, 7–12.CrossRefGoogle Scholar
Thompson, R. N. 1972. Evidence for a chemical discontinuity near the basalt andesite transition in many anorogenic volcanic suites. Nature 236, 106–10.CrossRefGoogle Scholar
Thompson, R. N. 1974. Primary basalts and magma genesis I. Skye, N.W. Scotland. Contributions to Mineralogy and Petrology 45, 317–41.CrossRefGoogle Scholar
Thompson, R. N., Dicken, A. P. & Hendry, G. L. 1983. Continental flood basalts…arachnids rule O.K.? In Continental Basalts and Mantle Xenoliths (eds. Hawkesworth, C. J., Norry, M. J.), pp. 158–85. Shiva Press.Google Scholar
Thompson, R. N., Esson, J. & Dunham, A. C. 1972. Major element chemical variation in the Eocene lavas of the Isle of Skye, Scotland. Journal of Petrology 13, 219–53.CrossRefGoogle Scholar
Thompson, R. N., Gibson, I. L., Marriner, G. F., Mattey, D. P. & Morrison, M. A. 1980. Trace-element evidence of multistage mantle fusion and polybaric fractional crystallization in the Palaeocene lavas of Skye, N.W. Scotland. Journal of Petrology 21, 265–93.CrossRefGoogle Scholar