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Oxygen isotope evidence for major fluid flow along the contact zone of the Rum ultrabasic intrusion

Published online by Cambridge University Press:  01 May 2009

R. C. Greenwood
Affiliation:
Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD, U.K.
A. E. Fallick
Affiliation:
Scottish Universities Research and Reactor Centre, East Kilbride, Glasgow G75 0QU, Scotland, U.K.
C. H. Donaldson
Affiliation:
Department of Geography and Geology, University of St Andrews, Fife, Scotland KY16 9ST, U.K.

Abstract

Recent studies indicate that the Rum Tertiary ultrabasic intrusion formed in situ, and was not emplaced as a fault-bounded plug. The suggestion that the Main Ring Fault was the primary pathway for the flow of meteoric-hydrothermal fluids on Rum is therefore seriously flawed. Oxygen isotope evidence is presented indicating that the contact zone of the intrusion was the major pathway for meteoric fluids during cooling of the pluton. δ18O depletions of over 12‰ correlate with hydrothermal alteration assemblages, indicating that the bulk of the interaction with meteoric fluids took place at low temperatures (200–450 °C).

Type
Rapid Communications
Copyright
Copyright © Cambridge University Press 1992

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References

Bailey, E. B. 1945. Tertiary igneous tectonics of Rhum (Inner Hebrides). Quarterly Journal of the Geological Society of London 100, 165–88.CrossRefGoogle Scholar
Brown, G. M. 1956. The layered ultrabasic rocks of Rhum, Inner Hebrides. Philosophical Transactions of the Royal Society of LondonSeries B, 240, 153.Google Scholar
Clayton, R. N. & Mayeda, T. K. 1963. The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotope analyses. Geochimica et Cosmochimica Acta 27, 4352.CrossRefGoogle Scholar
Dunham, A. C. 1970. The emplacement of the Tertiary igneous complex of Rhum. In Mechanisms of Igneous Intrusion (eds Newall, G. and Rast, N.), pp. 2332. Geological Journal Special Issue no. 2.Google Scholar
Emeleus, C. H. 1987. The Rhum layered complex, Inner Hebrides, Scotland. In Origins of Igneous Layering (ed. Parsons, I.), pp. 263–86. Reidel Publishing Company.CrossRefGoogle Scholar
Emeleus, C. H. & Forster, R. M. 1979. Field Guide to the Tertiary Igneous Rocks of Rhum, Inner Hebrides. Nature Conservancy Council. 44 pp.Google Scholar
Emeleus, C. H., Wadsworth, W. J. & Smith, N. J. 1985. The early igneous and tectonic history of the Rhum Tertiary Volcanic Centre. Geological Magazine 122, 451–7.CrossRefGoogle Scholar
Forester, R. W. & Harmon, R. S. 1983. Stable isotope evidence for deep meteoric/hydrothermal circulation: Island of Rhum, Inner Hebrides, Scotland. 4th International Symposium on Water/Rock Interaction, Misasa, Japan, pp. 135–6.Google Scholar
Forester, R. W. & Taylor, H. P. 1977 a. 18O/18O, D/H, and 16C/12C studies of the Tertiary igneous complex of Skye, Scotland. American Journal of Science 277, 136–77.CrossRefGoogle Scholar
Forester, R. W. & Taylor, H. P. 1977 b. 18O-depleted rocks from the Tertiary Complex of the Isle of Mull, Scotland. Earth and Planetary Science Letters 32, 1117.CrossRefGoogle Scholar
Greenwood, R. C., Donaldson, C. H. & Emeleus, C. H. 1990. The contact zone of the Rhum ultrabasic intrusion: evidence of peridotite formation from magnesian magmas. Journal of the Geological Society, London 147, 209–12.CrossRefGoogle Scholar
Norton, D. & Taylor, H. P. 1979. Quantitative simulation of the hydrothermal systems of crystallizing magmas on the basis of transport theory and oxygen isotope data: an analysis of the Skaergaard intrusion. Journal of Petrology 20, 421–86.CrossRefGoogle Scholar
Norton, D., Taylor, H. P. & Bird, D. K. 1984. The geometry and high-temperature brittle deformation of the Skaergaard intrusion. Journal of Geophysical Research 89, B12, 10178–92.CrossRefGoogle Scholar
Palacz, Z. A. 1985. Sr-Nd-Pb isotopie evidence for crustal contamination in the Rhum Intrusion. Earth and Planetary Science Letters 74, 3544.CrossRefGoogle Scholar
Parmentier, E. M. & Schedl, A. 1981. Thermal aureoles of igneous intrusions: some possible indications of hydrothermal convective cooling. Journal of Geology 89, 122.CrossRefGoogle Scholar
Robinson, M. A. & McClelland, E. A. 1987. Palaeomagnetism of the Torridonian of Rhum, Scotland: evidence for limited uplift of the Central Intrusive Complex. Earth and Planetary Science Letters 85, 473–87.CrossRefGoogle Scholar
Taylor, H. P. 1968. The oxygen isotope geochemistry of igneous rocks. Contributions to Mineralogy and Petrology 19, 171.CrossRefGoogle Scholar
Taylor, H. P. 1987. Comparison of hydrothermal systems in layered gabbros and granites and the origin of low 18O magmas. In Magmatic Processes: Physicochemical Principles (ed. Mysen, B. O.), pp. 337–58. The Geochemical Society, Special Publication no. 1.Google Scholar
Taylor, H. P. & Forester, R. W. 1971. Low-O18 igneous rocks from the intrusive complexes of Skye, Mull, and Ardnamurchan, Western Scotland. Journal of Petrology 12, 465–97.CrossRefGoogle Scholar
Volker, J. A. & Upton, B. G. J. 1990. The structure and petrogenesis of the Trallval and Ruinsival areas of the Rhum ultrabasic complex. Transactions of the Royal Society of Edinburgh: Earth Sciences 81, 6988.CrossRefGoogle Scholar
Wadsworth, W. J. 1961. The layered ultrabasic rocks of southwest Rhum, Inner Hebrides. Philosophical Transactions of the Royal Society of London Series B, 244, 2164.Google Scholar