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The Torridonian Stac Fada Member: an extrusion of fluidised peperite?

Published online by Cambridge University Press:  03 November 2011

I. S. Sanders  and
J. D. Johnston
I. S. Sanders
Affiliation:
I. S. Sanders and J. D. Johnston, Department of Geology, Trinity College, Dublin 2, Ireland.
J. D. Johnston
Affiliation:
I. S. Sanders and J. D. Johnston, Department of Geology, Trinity College, Dublin 2, Ireland.
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Abstract

Contact relations and petrography of the volcanic breccia known as the Stac Fada Member, near Stoer, show that it is not a simple sediment-gravity flow, but was generated lower in the sedimentary succession by phreatomagmatic activity and rose to the surface as buoyant peperitic slurry. A previously undescribed part of the member, 9 m below the intrusive base of the main ‘flow’, has an intrusive top. Vesicle trains within the breccia matrix suggest that the slurry was boiling at a temperature of at least 160°C.

Keywords

hydrovolcanismmud diapir.
Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 80 , Issue 1 , 1989 , pp. 1 - 4
Copyright
Copyright © Royal Society of Edinburgh 1989

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