Hostname: page-component-8448b6f56d-qsmjn Total loading time: 0 Render date: 2024-04-19T09:53:41.876Z Has data issue: false hasContentIssue false
  • English
  • Français

XII.—The Structure and Form of the Granophyric Quartz-Dolerite Intrusion, Centre II, Ardnamurchan, Argyllshire

Published online by Cambridge University Press:  06 July 2012

R. R. Skelhorn ,
R. W. D. Elwell  and
R. C. Tyler
R. R. Skelhorn
Affiliation:
Department of Geology, Sir John Cass College, London
R. W. D. Elwell
Affiliation:
Department of Geology, King's College, London
R. C. Tyler
Affiliation:
Department of Geology, King's College, London.
Get access Rights & Permissions [Opens in a new window]

Synopsis

The Granophyric Quartz-dolerite is one of a number of intrusions having arcuate outcrops which are concentric with respect to Centre II, Ardnamurchan. It is composed of three rock types: porphyritic dolerite, aphyric dolerite and granophyre. The granophyre extensively net-veins the two kinds of dolerite. However, the development of the net-veining was only the last stage of its intrusive activity. Relationships between granophyre and aphyric dolerite are such as to indicate that at an earlier stage both were in a magmatic state at the same time; that is, they were intruded together, though movement of granophyre magma persisted after the aphyric dolerite had solidified. Evidence is presented to show that intrusion of the porphyritic dolerite was the first episode, and that this provided the host rock for the simultaneous intrusion of aphyric dolerite and granophyre. In its role as host rock, the porphyritic dolerite was at first incompletely crystallized, but for later intrusions it had consolidated. When both dolerites were solid they were net-veined by the granophyre.

The inner contact of the Granophyric Quartz-dolerite was formed by a later intrusion. The outer contact for much of its extent dips fairly gently outwards, and it would seem that where this is so intrusion was more nearly in a horizontal than a vertical sense. Locally, sheeted relationships between the three members of the Granophyric Quartz-dolerite, being gently inclined, support this conclusion. There are several possibilities as to the form the intrusion might have, and these are discussed.

Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 66 , Issue 12 , 1966 , pp. 285 - 306
Copyright
Copyright © Royal Society of Edinburgh 1966

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., Thomas, H. H. et al. , 1924. “Tertiary and post-Tertiary Geology of Mull, Loch Aline and Oban”, Mem. Geol. Surv. U.K.Google Scholar
Bailey, E. B., and McCallien, W. J., 1956. “Composite Minor Intrusions, and the Slieve Gullion Complex, Ireland”, Lpool Manchr Geol. J., 1, 466–501.CrossRefGoogle Scholar
Bishop, A. C., 1964. “Dark Margins at Igneous Contacts”, Proc. Geol. Ass. Lond., 74, 289–300.CrossRefGoogle Scholar
Butler, B. C. M., 1961. “Metamorphism and Metasomatism of Rocks of the Moine Series by a Dolerite Plug in Glenmore, Ardnamurchan”, Miner. Mag., 32, 866–897.Google Scholar
Chapman, C. A., 1962. “Diabase-granite Composite Dikes, with Pillow-like Structure, Mount Desert Island, Maine” J. Geol., 70,, 539–564.CrossRefGoogle Scholar
Elwell, R. W. D., Skelhorn, R. R. and Drysdall, A. R., 1962. “Net-veining in the Diorite of North-east Guernsey, Channel Islands”, J. Geol., 70, 215–226.CrossRefGoogle Scholar
Harker, A., 1904. “The Tertiary Igneous Rocks of Skye”, Mem. Geol. Surv. U.K.CrossRefGoogle Scholar
Kuno, H., 1960. “High-alumina Basalt”, J. Petrol., 1, 121–145.CrossRefGoogle Scholar
Richey, J. E., 1958. “Feldspathic Types of Basaltic Rocks”, Symp. Dolerite, Geol. Dept., Univ. Tasmania, 1957, 63.Google Scholar
Richey, J. E., Thomas, H. H. et al. , 1930. “The Geology of Ardnamurchan, North-West Mull and Coll”, Mem. Geol. Surv. U.K.Google Scholar
Shackleton, R. M., 1948. “Overturned rhythmic banding in the Huntly gabbro of Aberdeenshire”, Geol. Mag., 85, 358–360.CrossRefGoogle Scholar
Stewart, F. H., 1947. “The Gabbroic Complex of Belhelvie in Aberdeenshire”, Quart. J. Geol Soc. Lond., 102, 465–498.CrossRefGoogle Scholar
Stewart, F. H., and Johnson, M. R. W., 1960. “The Structural Problem of the Younger Gabbros of North-East Scotland”, Trans. Edin. Geol. Soc., 18, 104–112.CrossRefGoogle Scholar
Wager, L. R., and Bailey, E. B., 1953. “Basic Magma Chilled against Acid Magma,” Nature, Lond., 172, 68–70.CrossRefGoogle Scholar
Weedon, D. S., 1961. “Basic Igneous Rocks of the Southern Cuillin, Isle of Skye”, Trans. Geol. Soc. Glasg., 24, 190–212.CrossRefGoogle Scholar
Wells, M. K., 1954 a. “The Structure and Petrology of the Hypersthene-gabbro Intrusion, Ardnamurchan, Argyllshire”, Quart. J. Geol. Soc., Lond., 109, 367–397.CrossRefGoogle Scholar
Wells, M. K., 1954 b. “The Structure of the Granophyric Quartz-Dolerite Intrusion of Centre 2, Ardnamurchan, and the Problem of Net-Veining”, Geol. Mag., 91, 293–307.CrossRefGoogle Scholar
Wells, M. K., 1962. “Structure and Petrology of the Freetown Layered Basic Complex of Sierra Leone”, Short Paper Geol. Surv. Dept. Sierra Leone, No. 9.Google Scholar
Yoder, H. S., 1954. “The System Diopside-anorthite-water”, Yearb. Carneg. Instn, 53, 106–107.Google Scholar
Yoder, H. S., and Tilley, C. E., 1962. “Origin of Basalt Magmas : a Study of Natural and Synthetic Rock Systems”, J. Petrol, 3, 342–532.CrossRefGoogle Scholar