Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-23T06:35:23.390Z Has data issue: false hasContentIssue false
  • English
  • Français

XVII.—The Major Ultrabasic and Basic Intrusions of St Kilda, Outer Hebrides

Published online by Cambridge University Press:  06 July 2012

R. R. Harding
R. R. Harding
Affiliation:
Department of Geology and Mineralogy, University of Oxford.
Get access Rights & Permissions [Opens in a new window]

Abstract

The structures and mineralogy of the Tertiary ultrabasic and basic intrusions are described. The ultrabasic rocks are thought to be remnants of a layered intrusion which once extended from Hirta to Boreray, and which probably formed by crystal accumulation. The eucrites may represent higher levels of this intrusion. A 350 feet-thick, fine-grained margin is described from the East Glen Bay Gabbro. The metamorphism of the ultrabasic and eucritic rocks, and the formation of the Glacan Mor Complex, probably occurred in a basic environment, before intrusion of the first acid rocks on St. Kilda. Five major-element and twenty-two trace-element analyses are presented.

Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 66 , Issue 17 , 1967 , pp. 419 - 444
Copyright
Copyright © Royal Society of Edinburgh 1967

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

References to Literature

Bailey, E. B., Clough, C. T. and Thomas, H. H., 1924. “Tertiary and Post-Tertiary Geology of Mull, Loch Aline and Oban”, Mem. Geol. Surv. U.K.Google Scholar
Barth, T. F. W., 1952. Theoretical Petrology. New York.Google Scholar
Bowen, N. L., 1913. “The Melting Phenomena of the Plagioclase Feldspars”, Amer. J. Sci., 35, 577–599.CrossRefGoogle Scholar
Bowes, D. R. and Wright, A. E., 1961. “Explosion Breccia Complex at Back Settlement, Argyll”, Trans. Edin. Geol. Soc., 18, 293–313.CrossRefGoogle Scholar
Brown, G. M., 1956. “The Layered Ultrabasic Rocks of Rhum, Inner Hebrides”, Phil, Trans., B, 240, 1–53.Google Scholar
Brown, G. M., 1957. “Pyroxenes from the Early and Middle Stages of Fractionation of the Skaergaard Intrusion, East Greenland”, Miner. Mag., 31, 511–543.Google Scholar
Carr, J. M., 1952. “An Investigation of the Sgurr na Stri —Druim Hain Sector of the Basic Igneous Complex of the Cuillin Hills, Skye”, D.Phil. Thesis, Oxford (unpublished).Google Scholar
Cockburn, A. M., 1935. “The Geology of St. Kilda”. Trans. Roy. Soc. Edin., 58, 21.CrossRefGoogle Scholar
Dearnley, R., 1962. “An Outline of the Lewisian Complex of the Outer Hebrides in relation to that of the Scottish Mainland”, Quart. J. Geol. Soc., 118, 143–176.CrossRefGoogle Scholar
Francis, E. H., 1960. “Intrusive Tuffs Related to the Firth of Forth Volcanoes”, Trans. Edin. Geol. Soc., 18, 32–50.CrossRefGoogle Scholar
Geikie, A., 1897. Ancient Volcanoes of Great Britain. London.CrossRefGoogle Scholar
Green, D. H., 1961. “Ultramafic Breccias from the Musa Valley, Eastern Papua”, Geol. Mag., 98, 1–26.CrossRefGoogle Scholar
Grout, F. F., 1932. Petrography and Petrology. New York and London.Google Scholar
Hatch, F. H., Wells, A. K. and Wells, M. K., 1952. The Petrology of the Igneous Rocks. London.Google Scholar
Hess, H. H., 1939. “Extreme Fractional Crystallization of a Basaltic Magma”, Trans. Amer. Geophys. Un., 3, 430–432.Google Scholar
Hytönen, K. and Schairer, J. F., 1961. “The Plane Enstatite-Anorthite-Diopside and its relation to Basalts”, in Year b. Carneg. Instn., 60, 125–141.Google Scholar
Reynolds, D. L., 1954. “Fluidization as a Geological Process and its bearing on the Problem of Intrusive Granites”, Amer. J. Sci., 252, 577–614.CrossRefGoogle Scholar
Richey, J. E. and Thomas, H. H., 1930. “The Geology of Ardnamurchan N.W. Mull, and Coll”, Mem. Geol. Surv. U.K.Google Scholar
Stewart, F. H., 1946. “The Gabbroic Complex of Belhelvie in Aberdeenshire”, Quart. J. Geol. Soc., 102, 465–488.CrossRefGoogle Scholar
Taubeneck, W. H. and Poldervaart, A., 1960. “Geology of the Elkhorn Mountains, N.E. Oregon; Part 2, the Willow Lake Intrusion”, Bull. Geol. Soc. Amer., 71, 1295–1322.CrossRefGoogle Scholar
Taylor, G. A., 1958. “The 1951 Eruption of Mt. Lamington, Papua”, Bull. Bur. Min. Resour. Aust., 38.Google Scholar
Taylor, H. P., and Noble, J. A., 1960. “Origin of the Ultramafic Complexes in Southeastern Alaska”, Int. Geol. Congr., 21, Pt. 13, 175–187.Google Scholar
Wadsworth, W. J., 1961. “The Layered Ultrabasic Rocks of South-West Rhum, Inner Hebrides”, Phil. Trans., B, 244, 21–64.Google Scholar
Wager, L. R., 1956. “A Chemical Definition of Fractionation Stages as a Basis for Comparison of Hawaiian, Hebridean and other Basic Lavas”, Geochim. et Cosmoch. Acta, 9, 217–248.CrossRefGoogle Scholar
Wager, L. R., 1960. “The Major-element Variation of the Layered Series of the Skaergaard Intrusion and a Re-estimation of the Average Composition of the Hidden Layered Series and of the Successive Residual Magmas”, J. Petrol., 1, 364–398.CrossRefGoogle Scholar
Wager, L. R. and Bailey, E. B., 1953. “Basic Magma Chilled Against Acid Magma”, Nature, Lond., 172, 68.CrossRefGoogle Scholar
Wager, L. R., Brown, G. M. and Wadsworth, W. J., 1960. “Types of Igneous Cumulates”, J. Petrol., 1, 73–86.CrossRefGoogle Scholar
Wager, L. R. and Vincent, E. A., 1962. “Ferrodiorite from the Isle of Skye”, Miner. Mag., 33, 26–36.Google Scholar
Weedon, D. S., 1960. “Basic Igneous Rocks of the Southern Cuillin, Isle of Skye”, Trans. Geol. Soc. Glasg., 24, Pt. 2.Google Scholar
Wyllie, P. J., 1959. “Discrepancies between Optic Axial Angles of Olivines measured over Different Bisectrices”, Amer. Min., 44, 49–64.Google Scholar
Zinovieff, P., 1958. “The Basic Layered Intrusion and the Associated Igneous Rocks of the Central and Eastern Cuillin Hills, Isle of Skye”. D.Phil. Thesis, Oxford (unpublished).Google Scholar