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Geophysical constraints on the nature of the Highland Boundary Fault Zone in western Scotland

Published online by Cambridge University Press:  01 May 2009

M. C. Dentith
Affiliation:
Department of Geology, University of Western Australia, Nedlands, Perth, WA 6009, Australia
A. Trench
Affiliation:
Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, U.K.
B. J. Bluck
Affiliation:
Department of Geology and Applied Geology, University of Glasgow, Glasgow G12 8QQ, U.K.

Abstract

Previously published models of gravity anomalies across the Highland Boundary Fault in western Scotland interpret this structure as a high-angle reverse fault. These gravity anomalies have been re-interpreted in the light of more extensive gravity data now available, and new density data from the Highland Border Complex. The new data suggest that earlier interpretations have overestimated the fault anomaly and used over-simplified density models. New gravity models of the Highland Boundary Fault Zone are presented which show that the interface between the Dalradian and Highland Border Complex dips to the northwest at an angle of about 20°. We interpret the contact between these two formations as a thrust fault. The interface between the Highland Border Complex and the Lower Old Red Sandstone is shown to be vertical as suggested by surface geology, with the latter rocks a few hundred metres thick.

Type
Articles
Copyright
Copyright © Cambridge University Press 1992

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