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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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