Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-25T09:00:00.296Z Has data issue: false hasContentIssue false
  • English
  • Français

The early igneous and tectonic history of the Rhum Tertiary Volcanic Centre

Published online by Cambridge University Press:  01 May 2009

C. H. Emeleus ,
W. J. Wadsworth  and
N. J. Smith
C. H. Emeleus
Affiliation:
Department of Geological Sciences, University of Durham, South Road, Durham DH1 3LE, U.K.
W. J. Wadsworth
Affiliation:
Department of Geology, University of Manchester, Manchester M13 9PL, U.K.
N. J. Smith
Affiliation:
Department of Geological Sciences, University of Durham, South Road, Durham DH1 3LE, U.K.
Get access Rights & Permissions [Opens in a new window]

Abstract

Early Tertiary igneous activity on Rhum was preceded by doming and the formation of a major arcuate fault system, the Main Ring Fault (MRF), within which Lewisian gneisses, Torridonian sediments and younger rocks were uplifted by as much as 2 km. Doming and uplift are attributed to the diapiric rise of acid magma which ultimately formed the granophyres and felsites of Rhum. Felsite emplacement was accompanied and immediately preceded by the formation of explosion breccias and tuffisites. This phase involves massive gas escape along the MRF fractures; it marked a period of major subsidence within the MRF during which fossiliferous Jurassic sediments and relics of Tertiary lava flows were brought to low structural levels within the MRF. Finally, a further period of uplift, again of about 2 km, took place once more bringing gneisses and basal Torridonian sediments within the MRF to high structural levels. The driving force for this last phase of uplift may have been provided by a further uprise of acid magma or, more realistically, may have been directly connected with emplacement of layered ultrabasic rocks which now form the core of the Rhum centre.

Type
Articles
Information
Geological Magazine , Volume 122 , Issue 5 , September 1985 , pp. 451 - 457
Copyright
Copyright © Cambridge University Press 1985

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

Almond, D. C. 1977. The Sabaloka igneous complex, Sudan. Philosophical Transactions of the Royal Society of London 287 A, 595–633.Google Scholar
Bailey, E. B. 1926. Domes in Scotland and South Africa: Arran and Vredefort. Geological Magazine 63, 481–95.CrossRefGoogle Scholar
Bailey, E. B. 1945. Tertiary igneous tectonics of Rhum (Inner Hebrides). Quarterly Journal of the Geological Society of London 100, 165–188.CrossRefGoogle Scholar
Binns, P. E., McQuillin, R. & Kenolty, N. 1974. The Geology of the Sea of the Hebrides. Institute of Geological Sciences Report No. 73/14, 43 pp.Google Scholar
Black, G. P. 1954. The acid rocks of Western Rhum. Geological Magazine 91, 257–72.CrossRefGoogle Scholar
Brown, G. M. 1956. The layered ultrabasic rocks of Rhum, Inner Hebrides. Philosophical Transactions of the Royal Society of London 240B, 1–53.Google Scholar
Brown, G. M. 1963. Melting relations of Tertiary granitic rocks in Skye and Rhum. Mineralogical Magazine 33, 533–62.CrossRefGoogle Scholar
Dunham, A. C. 1964. A petrographic and geochemical study of back-veining and hydridization at a gabbro–felsite contact in Coire Dubh, Rhum, Inverness-shire. Mineralogical Magazine 33, 887–902.CrossRefGoogle Scholar
Dunham, A. C. 1968. The felsites, granophyre, explosion breccias and tuffisites of the north-eastern margin of the Tertiary igneous complex of Rhum, Inverness-shire. Quarterly Journal of the Geological Society of London 123, 327–52.CrossRefGoogle Scholar
Dunham, A. C. & Emeleus, C. H. 1967. The Tertiary geology of Rhum, Inner Hebrides. Proceedings of the Geologists' Association 78, 391–456.CrossRefGoogle Scholar
Emeleus, C. H. 1980. Rhum: Solid Geology Map, 1:20000. Edinburgh: Nature Conservancy Council.Google Scholar
Emeleus, C. H. 1981. A thrust at Welshman's Rock, Isle of Rhum. Scottish Journal of Geology 17, 1–6.CrossRefGoogle Scholar
Emeleus, C. H. 1982. The central complexes. In Igneous Rocks of the British Isles, Part 7, The Tertiary (ed. Sutherland, D. S.) pp. 369–414. Chichester: John Wiley.Google Scholar
Emeleus, C. H. 1983. Tertiary igneous activity. In Geology of Scotland, 2nd edn. (ed. Craig, G. Y.), pp. 357–98. Edinburgh: Scottish Academic Press.Google Scholar
Emeleus, C. H. & Forster, R. M. 1979. Field Guide to the Tertiary Igneous Rocks of Rhum. London: Nature Conservancy Council, 44 pp.Google Scholar
Harker, A. 1908. The Geology of the Small Isles of Inverness-shire (Rhum, Canna, Eigg, Muck, etc.). Memoir. Geological Survey of Scotland. Edinburgh: H.M.S.O. 210 pp.Google Scholar
Hughes, C. J. 1960. The Southern Mountains igneous complex, Isle of Rhum. Quarterly Journal of the Geological Society of London 114, 111–38.CrossRefGoogle Scholar
Smith, N. J. 1985. The age and structural setting of limestones and basalts on the Main Ring Fault in Southeast Rhum. Geological Magazine 122, 439–45.CrossRefGoogle Scholar
Smith, R. L. & Bailey, R. A. 1968. Resurgent cauldrons. In Studies in Volcanology – a Memoir in Honor of Howell Williams (ed. Coats, R. R., Hay, R. A. and Anderson, C. A.), pp. 613–22. Memoir Geological Society of America no. 116.Google Scholar
Speight, J. M., Skelhorn, R. R., Sloan, T. & Knapp, R. J. 1982. The dyke swarms of Scotland. In Igneous Rocks of the British Isles, Part 7, The Tertiary (ed. Sutherland, D. S.), pp. 449–59. Chichester: John Wiley.Google Scholar
Wadsworth, W. J. 1961. The layered ultrabasic rocks of South-West Rhum, Inner Hebrides. Philosophical Transactions of the Royal Society of London 244B, 21–64.Google Scholar
Wager, L. R. & Brown, G. M. 1968. Layered Igneous Rocks. Edinburgh: Oliver and Boyd. 588 pp.Google Scholar
Wedd, C. B. 1910. In The Geology andGlenelg, Lochalsh and the South-east Part of Skye, pp. 116–21. Memoir. Geological Survey of Scotland. Edinburgh: H.M.S.O.Google Scholar
Walker, G. P. L. 1975. A new concept in the evolution of the British Tertiary intrusive centres. Journal of the Geological Society of London 131, 121–41.CrossRefGoogle Scholar
Williams, P. J. 1985. Pyroclastic rocks in the Cnapan Breaca felsite, Rhum. Geological Magazine 122, 447–50.CrossRefGoogle Scholar
Forster, R. M. 1980. A geochemical and petrological study of the Tertiary minor intrusions of Rhum, Northwest Scotland. Unpublished Ph.D. thesis, University of Durham.Google Scholar
McClurg, J. 1982. Geology and structure of the northern part of the Rhum ultrabasic complex. Unpublished Ph.D. thesis, University of Edinburgh.Google Scholar
Volker, J. A. 1983. The geology of the Trallval area, Rhum, Inner Hebrides. Unpublished Ph.D. thesis, University of Edinburgh.Google Scholar