Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-14T16:51:17.406Z Has data issue: false hasContentIssue false

Mixing of supernatant and interstitial fluids in the Rhum layered intrusion

Published online by Cambridge University Press:  05 July 2018

Iain M. Young*
Affiliation:
Department of Geology, University of St Andrews, Fife, Scotland, KY16 9ST

Abstract

An alternative explanation for the occurrence of chrome-spinel layers in the Eastern Layered Series of the Rhum intrusion is suggested by extreme concentrations of chrome-spinel in small-scale structures in the layer at the unit 7–8 boundary (Brown, 1956). These take the form of downward pointing cones several centimetres across and deep, and lined or wholly filled with chrome-spinel; lamination in the underlying allivalite exhibits quaquaversal dips around these cones. By comparing these structures to fluid escape structures in clastic sediments, it is proposed that spinel is the product of mixing and reaction of upward moving interstitial liquid and more primitive liquid newly emplaced in the chamber. Further evidence for the presence of a second liquid during spinel crystallization is provided by spherical silicate inclusions within spinel grains. Complex zoning in feldspars in the underlying allivalite suggests that the newly emplaced primitive liquid was able to penetrate the crystal mush on the intrusion floor.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1984

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

Brown, G. M. (1956) Phil. Trans. R. Soc. B240, 153.Google Scholar
Donaldson, C. H. (1982) Mineral. Mag. 45, 201-9.CrossRefGoogle Scholar
Dunham, A. C., and Wadsworth, W. J. (1978) Ibid. 42, 347-56.Google Scholar
Harker, A. (1908) Mem. Geol. Surv. Scotland.Google Scholar
Henderson, P. (1975) Geochim. Cosmochim. Acta. 39, 1035-44.CrossRefGoogle Scholar
Henderson, P. and Suddaby, P. (1971) Contrib. Mineral. Petrol. 33, 2131.CrossRefGoogle Scholar
Henderson, P. and Wood, R. J. (1981) Ibid. 78, 225-9.Google Scholar
Huppert, H. H., and Sparks, R. S. J. (1980) Ibid. 75, 279-89.Google Scholar
Irvine, T. N. (1975) Geochim. Cosmochim. Acta. 39, 9911020.CrossRefGoogle Scholar
Irvine, T. N. (1977) Carnegie Inst. Washington Yearb. 76, 465-72.Google Scholar
Irvine, T. N. (1980) In Physics of Magmatic Processes (Hargraves, R. B., ed.), Princeton Univ. Press, Princeton, N.J. Google Scholar
Irvine, T. N. (1981) Carnegie Inst. Washington Yearb. 80, 317-24.Google Scholar
Lee, C. A. (1980) J. Geol. Soc. 138, 327-41.CrossRefGoogle Scholar
Lowe, D. R. (1975) Sedimentology. 22, 157204.CrossRefGoogle Scholar
Maaloe, S. (1978) Mineral. Mag. 42, 337-45.CrossRefGoogle Scholar
Morse, S. A. (1981) Geochim. Cosmochim. Acta. 45, 46179.Google Scholar
Murck, B. W., and Campbell, I. H. (1982) EOS. 63, 455.Google Scholar
Musgrave, D. L., and Reeburgh, W. S. (1982) Nature. 299, 331-3.CrossRefGoogle Scholar
Robins, B. (1982) Contrib. Mineral. Petrol. 81, 290-5.CrossRefGoogle Scholar
Vermaak, C. F. (1976) Econ. Geol. 71, 1270-98.CrossRefGoogle Scholar
Wadsworth, W. J. (1961) Phil. Trans. R. Soc. B244, 2164.Google Scholar