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Origin of some of the Rhum harrisite by segregation of intercumulus liquid

Published online by Cambridge University Press:  05 July 2018

Colin H. Donaldson*
Affiliation:
Department of Geology, University of St. Andrews, St. Andrews, Fife KY16 9ST, Scotland

Abstract

New field observations of certain harrisite occurrences are presented, including: interruption of layers; splitting of very thick layers into several smaller ones; existence of small isolated lenses and pods of harrisite and of upwardly extending tongues of harrisite; harrisite forming parts of the matrix of breccias; and isolated pods of harrisite along the western margin of the intrusion. These layers, lenses, tongues, and pods seem to have crystallized within the cumulus mush rather than at the mush magma boundary. It is proposed that the rock in these instances represents segregated, intercumulus melt which ‘ponded’ beneath relatively impermeable layers in the cumulus mush. Several ways in which supercooling may have arisen to cause skeletal olivine growth are considered and previous estimates are thought to need reduction by 10–20°C. It is suggested that segregation of upward-filtering melt in other layered intrusions might produce layers indistinguishable from ‘uniform’ cumulate.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1982

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References

Blatt, H., Middleton, G., and Murray, R. (1980). Origin of Sedimentary Rocks. Prentice-Hall, New Jersey.Google Scholar
Brown, G. M. (1956) Phil. Trans. R. Soc. B240, 1-53.Google Scholar
Chalmers, B. (1964) Principles of Solidification. Wiley, New York.Google Scholar
Chen, C. F., and Turner, J. S. (1980) J. Geophys. Res. 85, 2573-93.CrossRefGoogle Scholar
Donaldson, C. H. (1974) Geol. Soc. Am. Butt. 85, 1721-6.Google Scholar
Donaldson, C. H. (1975a) Unpubl. Ph.D. thesis, Univ. St. Andrews.Google Scholar
Donaldson, C. H. (1975b) J. Geol. 83, 33-45.CrossRefGoogle Scholar
Donaldson, C. H. (1976) Contrib. Mineral. Petrol. 57, 187-213.CrossRefGoogle Scholar
Donaldson, C. H. (1977) Mineral. Mag. 41, 323-36.CrossRefGoogle Scholar
Donaldson, C. H. (1979) Contrib. Mineral. Petrol. 69, 21-32.CrossRefGoogle Scholar
Drever, H. I., and Johnston, R. (1972) Meteoritics, 7, 327-40.CrossRefGoogle Scholar
Dunham, A. C., and Emeleus, C. H. (1967) Proc. Geol. Assoc. 78, 391-418.CrossRefGoogle Scholar
Emeleus, C. H., and Forster, R. M. (1979) Field Guide to the Tertiary Igneous Rocks of Rhum, Inner Hebrides. Nature Conservancy Council.Google Scholar
Fyfe, W. S., Price, N. J., and Thompson, A. B. (1978) Fluids in the Earth's Crust. Elsevier, Amsterdam.Google Scholar
Harker, A. (1908) Mere. Geol. Surv. Scotland. Google Scholar
Henderson, P., and Williams, C. T. (1979) In Origin and Distribution of The Elements (Ahrens, L. H., ed.), Pergamon, London.Google Scholar
Hess, G. B. (1973) In Studies in Earth and Space Sciences (Shagam, R., ed.), Geol. Soc. Am. Mem. 135, 503-20.Google Scholar
Huppert, H. E., and Turner, J. S. (1981) J. Fluid Mech. 106, 299-329.CrossRefGoogle Scholar
Irvine, T. N. (1974) Geol. Soc. Am. Mere. 138.Google Scholar
Irvine, T. N. (1978) Geophys. Lab. Yearb. 77, 743-51.Google Scholar
Irvine, T. N. (1980) In Physics of Magmatic Processes (Hargraves, R. B., ed.), Princeton Univ. Press, Princeton, NJ.Google Scholar
Kushiro, I. (1969) Geophys. Lab. Yearb. 67, 158-161.Google Scholar
Lee, C. A. (1981) J. Geol. Soc. 138, 327-41.CrossRefGoogle Scholar
Lofgren, G. E., and Donaldson, C. H. (1975) Contrib. Mineral. Petrol. 49, 309-19.CrossRefGoogle Scholar
Loomis, T. P., and Gottschalk, R. R. (1981) Ibid. 76, 1-11.Google Scholar
Maaloe, S. (1981) J. Geol. Soc. 138, 223-36.CrossRefGoogle Scholar
Propach, G. (1976) Lithos, 9, 203-9.CrossRefGoogle Scholar
Rice, A. (1981) J. Geophys. Res. 86, 405-17.CrossRefGoogle Scholar
Saratovkin, D. D. (1959) Dendritic Crystallization. Consultant's Bureau, New York.Google Scholar
Spera, F. J. (1980) In Physics of Magmatic Processes (Hargraves, R. B., ed.), Princeton Univ. Press, Princeton, NJ.Google Scholar
Stolper, E., Walker, D., Hager, B. H., and Hays, J. F. (1981) J. Geophys. Res. 86, 6261-72.CrossRefGoogle Scholar
Taylor, H. P., and Forester, R. W. (1971) J. Petrol. 12, 465-97.CrossRefGoogle Scholar
Turner, J. S., and Gustafson, L. B. (1978) Econ. Geol. 73, 1082-1100.CrossRefGoogle Scholar
Wadsworth, W. J. (1961) Phil. Trans. R. Soc. B244, 2164.Google Scholar
Waff, H. S. (1980) J. Geophys. Res. 85, 1815-25.CrossRefGoogle Scholar
Wager, L. R. (1963) Spec. Paper Mineral. Soc. Am. 1, 1-9.Google Scholar
Wager, L. R. (1968) In Basatts (Hess, H. H., and Poldervaart, A., eds.), Interscience, New York.Google Scholar
Wager, L. R. and Brown, G. M. (1968) Layered lgneous Rocks. Oliver & Boyd, Edinburgh.Google Scholar
Wager, L. R. and Deer, W. A. (1939) Meddels. Gronland, 105, 1-352.Google Scholar
Wager, L. R. Brown, G. M., and Wadsworth, W. J. (1960) J. Petrol. 1, 73-85.CrossRefGoogle Scholar
Walker, D., Stolper, E. M., and Hays, J. F. (1978) J. Geophys. Res. 83, 6005-13.CrossRefGoogle Scholar
Walker, D., Shibata, T., and De Long, S. E. (1979) Contrib. Mineral. Petrol. 70, 111-25.CrossRefGoogle Scholar
Weedon, D. (1960) Q. J. Geol. Soc. 116, 3754.CrossRefGoogle Scholar
Williams, H., and McBirney, A. R. (1979) Volcanology. Freeman Cooper, Los Angeles.Google Scholar
Wyllie, P. J. (1963) Spec. Paper Mineral. Soc. Am. 1, 204-12.Google Scholar
Yoder, H. S., and Tilley, C. E. (1962) J. Petrol. 3, 342-532.CrossRefGoogle Scholar