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The Centre 3 layered gabbro intrusion, Ardnamurchan, NW Scotland

Published online by Cambridge University Press:  21 September 2007

B. O'Driscoll
B. O'Driscoll*
Affiliation:
Department of Geology, Museum Building, Trinity College Dublin, Dublin 2, Ireland
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Abstract

Detailed remapping of the Palaeogene Ardnamurchan Centre 3 gabbros, NW Scotland, suggests that this classic sequence of ring-intrusions forms a composite layered lopolith. The area mapped by previous studies as the Great Eucrite gabbro intrusion comprises 70% by area of Centre 3. Field observations suggest that most of the other smaller ring-intrusions of Centre 3 (interior to the Great Eucrite) constitute either distinct petrological facies of the same intrusion, or included country-rock or peridotite blocks. These observations, together with syn-magmatically deformed inward-dipping modal layering, are used here to support the interpretation that significant central sagging occurred in the intrusion at a late stage in its crystallization history.

Keywords

Ardnamurchangabbroslayered intrusionlopolith
Type
Original Article
Information
Geological Magazine , Volume 144 , Issue 6 , November 2007 , pp. 897 - 908
Copyright
Copyright © Cambridge University Press 2007

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