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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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References

Barber, A. J., Beach, A., Park, R. G., Tarney, J. & Stewart, A. D. 1978. The Lewisian and Torridonian rocks of north-west Scotland. London: Geologists' Association.Google Scholar
Barber, A. J. & Brown, K. 1988. Mud diapirism: the origin of melanges in accretionary complexes? GEOL TODAY 4, 89–94.CrossRefGoogle Scholar
Cas, R. A. F. & Wright, J. V. 1987. Volcanic successions modern and ancient. London: Allen & Unwin.CrossRefGoogle Scholar
Dixon, J. M. & Simpson, D. G. 1987. Centrifuge modelling of laccolith intrusion. J STRUCTURAL GEOL 9, 87–103.CrossRefGoogle Scholar
Kokelaar, B. P. 1982. Fluidisation of wet sediments during the emplacement and cooling of various igneous bodies. J GEOL SOC LONDON 139, 21–33.CrossRefGoogle Scholar
Kokelaar, P. 1986. Magma-water interactions in subaqueous and emergent basaltic volcanism. BULL VOLCANOL 48, 275–289.CrossRefGoogle Scholar
Lawson, D. E. 1972. Torridonian volcanic sediments. SCOTT J GEOL 8, 345–362.CrossRefGoogle Scholar
Leat, P. T. & Thompson, R. N. 1988. Miocene hydrovolcanism in NW Colorado, USA, fuelled by explosive mixing of basic magma and wet unconsolidated sediment. BULL VOLCANOL 50, 229–243.CrossRefGoogle Scholar
Stewart, A. D. 1982. Late Proterozoic rifting in NW Scotland: the genesis of the ‘Torridonian’. J GEOL SOC LONDON 139, 413–420.CrossRefGoogle Scholar
Walker, B. H. & Francis, E. H. 1987. High-level emplacement of an olivine-dolerite sill into Namurian sediments near Cardenden, Fife. TRANS R SOC EDINBURGH: EARTH SCI 77, 295–307.CrossRefGoogle Scholar