Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-21T19:50:11.431Z Has data issue: false hasContentIssue false
  • English
  • Français

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
Get access Rights & Permissions [Opens in a new window]

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

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anderson, E. M. 1936. The dynamics of the formation of cone-sheets, ring-dykes, and cauldron-subsidence. Proceedings of the Royal Society of Edinburgh 56, 128–56.CrossRefGoogle Scholar
Brown, D. J., Bell, B. R. & McLeod, G. W. 2006. A re-interpretation of the “Centre 3 screens” of Ardnamurchan, NW Scotland. Scottish Journal of Geology 42, 83–5.CrossRefGoogle Scholar
Carr, H. W., Groves, D. I. & Cawthorn, R. G. 1994. The importance of syn-magmatic deformation in the formation of Merensky Reef potholes in the Bushveld complex. Economic Geology and the Society of Economic Geologists Bulletin 89, 1398–1410.CrossRefGoogle Scholar
Chambers, L. M., Pringle, M. S. & Parrish, R. R. 2005. Rapid formation of the Small Isles Tertiary centre constrained by precise 40Ar/39Ar and U–Pb ages. Lithos 79, 367–84.CrossRefGoogle Scholar
Elliot, M. T., Cheadle, M. J. & Jerram, D. A. 1997. On the identification of textural equilibrium in rocks using dihedral angle measurements. Geology 25, 355–8.2.3.CO;2>CrossRefGoogle Scholar
Emeleus, C. H. & Bell, B. R. 2005. British regional geology: the Palaeogene volcanic districts of Scotland (4th edition). Nottingham: British Geological Survey.Google Scholar
Emeleus, C. H., Cheadle, M. J., Hunter, R. H., Upton, B. G. J. & Wadsworth, W. J. 1996. The Rum Layered Suite. In Layered igneous rocks (ed. Cawthorne, R. G.), pp. 403–40. Amsterdam: Elsevier.Google Scholar
Gibb, F. G. F. 1976. Ultrabasic rocks of Rhum and Skye: the nature of the parent magma. Journal of the Geological Society, London 132, 209–22.CrossRefGoogle Scholar
Higgins, M. D. 1991. The origin of laminated and massive anorthosite, Sept Iles layered intrusion, Québec, Canada. Contributions to Mineralogy and Petrology 106, 340–54.CrossRefGoogle Scholar
Holness, M. B., Cheadle, M. J. & McKenzie, D. 2005. On the use of changes in dihedral angle to decode late-stage textural evolution in cumulates. Journal of Petrology 46, 1565–83.CrossRefGoogle Scholar
Irvine, T. N., Anderson, J. C. & Brooks, C. K. 1998. Included blocks (and blocks within blocks) in the Skaergaard intrusion: Geologic relations and the origins of rhythmic modally graded layers. Geological Society of America Bulletin 110, 1398–1447.2.3.CO;2>CrossRefGoogle Scholar
O'Driscoll, B., Donaldson, C. H., Troll, V. R., Jerram, D. A. & Emeleus, C. H. 2007. An origin for harrisitic and granular olivine from the Rum Layered Suite, NW Scotland: A crystal size distribution study. Journal of Petrology 48, 253–70.Google Scholar
O'Driscoll, B., Troll, V. R., Reavy, R. J. & Turner, P. 2006. The Great Eucrite intrusion of Ardnamurchan, Scotland: re-evaluating the ring-dyke concept. Geology 34, 189–92.CrossRefGoogle Scholar
Renner, R. & Palacz, Z. A. 1987. Basaltic replenishment of the Rhum magma chamber: evidence from unit 14. Journal of the Geological Society, London 144, 961–70.CrossRefGoogle Scholar
Richey, J. E. & Thomas, H. H. 1930. The Geology of Ardnamurchan, North-west Mull and Coll. Memoir of the Geological Survey of Great Britain (Scotland), 393 pp.Google Scholar
Rochette, P., Aubourg, C. & Perrin, M. 1999. Is this magnetic fabric normal? A review and case studies in volcanic formations. Tectonophysics 307, 219–34.Google Scholar
Skelhorn, R. R. & Elwell, R. W. D. 1971. Central subsidence in the layered hypersthene-gabbro of Centre 2, Ardnamurchan, Argyllshire. Journal of the Geological Society, London 127, 535–51.CrossRefGoogle Scholar
Streckeisen, A. 1976. To each plutonic rock its proper name. Earth Science Reviews 12, 1–33.CrossRefGoogle Scholar
Thompson, R. N. 1983. Thermal aspects of the origin of Hebridean Tertiary acid magmas. II. Experimental melting behaviour of the granites at 1 kbar P H2O. Mineralogical Magazine 47 (343), 111–21.CrossRefGoogle Scholar
Upton, B. G. J., Skovgaard, A. C., McClurg, J., Kirstein, L., Cheadle, M., Emeleus, C. H., Wadsworth, W. J. & Fallick, A. E. 2002. Picritic magmas and the Rum ultramafic complex, Scotland. Geological Magazine 139, 437–52.CrossRefGoogle Scholar
Wager, L. R. & Brown, G. M. 1968. Layered igneous rocks. Edinburgh: Oliver and Boyd, 588 pp.Google Scholar
Walsh, J. N. 1975. Clinopyroxenes and biotites from the Centre 3 igneous complex, Ardnamurchan, Argyllshire. Mineralogical Magazine 40, 335–45.Google Scholar
Walsh, J. N. & Henderson, P. 1977. Rare earth patterns of rocks from the Centre 3 Igneous Complex, Ardnamurchan, Argyllshire. Contributions to Mineralogy and Petrology 60, 31–8.CrossRefGoogle Scholar
Wells, M. K. & McRae, D. G. 1969. Palaeomagnetism of the hypersthene-gabbro intrusion, Ardnamurchan, Scotland. Nature, London 223, 608–9.Google Scholar
Woodcock, N. & Strachan, R. 2000. Geological History of Britain and Ireland. Blackwell Science, 423 pp.Google Scholar