Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-24T17:08:10.040Z Has data issue: false hasContentIssue false
  • English
  • Français

The composition and age of basalts dredged from the Blackstones igneous centre, western Scotland

Published online by Cambridge University Press:  01 May 2009

J. G. Mitchell ,
E. J. W. Jones  and
G. T. Jones
J. G. Mitchell
Affiliation:
School of Physics, The University, Newcastle-upon-Tyne, NE1 7RU
E. J. W. Jones
Affiliation:
Department of Geology, University College, Gower Street, London WC1E 6BT
G. T. Jones
Affiliation:
Department of Geology, University College, Gower Street, London WC1E 6BT
Get access Rights & Permissions [Opens in a new window]

Summary

A collection of basaltic rocks has been dredged from part of the Blackstones igneous centre, a major offshore intrusion situated about 50 km SW of Mull. The basalts are mainly olivine tholeiites and are closely similar to transitional basalts found on the Inner Hebrides. The mean of four concordant K—Ar dates obtained from the lavas indicates an age of 57.1 (± 0.9) Ma. The Blackstones complex thus appears to be coeval with other Tertiary centres of the area.

Type
Articles
Information
Geological Magazine , Volume 113 , Issue 6 , November 1976 , pp. 525 - 533
Copyright
Copyright © Cambridge University Press 1976

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

Bullerwell, W. 1963. In Summary of Progress of the Geological Survey of Great Britain for 1962, p. 67.Google Scholar
Bullerwell, W. 1972. Geophysical studies relating to Tertiary volcanic structure of the British Isles. Phil. Trans. R. Soc. A 271, 209–15.Google Scholar
Coombs, D. S. 1963. Trends and affinities of basaltic magmas as illustrated on the diopside-olivine-silica diagram. Spec. Pap. Min Soc. Amer. 1, 227–50.Google Scholar
Dunham, A. C. & Emeleus, C. H. 1967. The Tertiary geology of Rhum, Inner Hebrides. Proc. Geol. Ass. Lond. 78, 395–418.CrossRefGoogle Scholar
Durant, G. P., Dobson, M. R., Kokelaar, B. P., Macintyre, R. M. & Rea, W. J. 1976. Preliminary report on the nature and age of the Blackstones Bank igneous centre, Western Scotland. J. Geol. Soc. Lond. 132, 319–26.CrossRefGoogle Scholar
Esson, J., Dunham, A. C. & Thompson, R. N. 1975. Low alkali, high calcium olivine tholeiite lavas from the Isle of Skye, Scotland. J. Petrol. 16, 488–97.CrossRefGoogle Scholar
Evans, A. L., Fitch, F. J. & Miller, J. A. 1973. Potassium-argon age determination on some British Tertiary igneous rocks. J. Geol. Soc. Lond. 129, 419–43.CrossRefGoogle Scholar
Institute of Geological Sciences. 1972. Aeromagnetic map of Great Britain, 1st ed.Google Scholar
Kaneoka, I. 1972. The effect of hydration on the K–Ar ages of volcanic rocks. Earth Planet. Sc. Lett. 14, 216–20.CrossRefGoogle Scholar
Kuno, H. 1967. Differentiation of basalt magmas. In Basalts: The Poldervaart Treatise on Rocks of Basaltic Composition, vol. 2, pp. 623–88. Interscience.Google Scholar
Macdonald, G. A. & Katsura, T. 1964. Chemical composition of Hawaiian lavas. J. Petrol. 5, 82–133.CrossRefGoogle Scholar
Macintyre, R. M. 1973. Lower Tertiary geochronology of the North Atlantic continental margins. In Geochronology and Isotope Geology of Scotland (Field Guide and Reference).Google Scholar
Macintyre, R. M., McMenamin, T. & Preston, J. 1975. K–Ar results from Western Ireland and their bearing on the time and siting of Thulean magmatism. Scott. J. Geol. 11, 227–49.CrossRefGoogle Scholar
McQuillin, R., Bacon, M. & Binns, P. E. 1975. The Blackstones Tertiary igneous complex. Scott. J. Geol. 11. 179–92.CrossRefGoogle Scholar
Mellor, D. W. & Mussett, A. E. 1975. Evidence for initial 36Ar in volcanic rocks, and some implications. Earth Planet. Sc. Lett. 26, 312–318.CrossRefGoogle Scholar
Mitchell, J. G. 1972. Potassium-argon ages from the Cheviot Hills, Northern England. Geol. Mag. 109, 421–6.CrossRefGoogle Scholar
Pearce, J. A & Cann, J. R. 1973. Tectonic setting of basic volcanic rocks determined using trace element analyses. Earth Planet. Sc. Lett. 19, 290–300.CrossRefGoogle Scholar
Purdy, J. W., Mussett, A. E., Charlton, S. R., Eckford, M. J. & English, H. N. 1972. British Tertiary Igneous Province: Potassium-argon ages of the Antrim basalts. Geophys. J. R. Astron. Soc. 27, 327–35.CrossRefGoogle Scholar
Ridley, W. I., 1971. Some chemical features of basalts from the British Tertiary Province. Earth Planet. Sc. Lett. 11, 435–9.CrossRefGoogle Scholar
Roberts, D. G. 1970. Recent geophysical investigations on the Rockall Plateau and adjacent areas. Proc. geol. Soc. Lond. 1662, 87–93.Google Scholar
Thompson, R. N., Esson, J. & Dunham, A. C. 1972. Major element chemical variation in the Eocene lavas of the Isle of Skye, Scotland. J. Petrol. 13, 219–53.CrossRefGoogle Scholar