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Isotopic U–Pb ages of zircon and monazite from the Leinster Granite, southeast Ireland

Published online by Cambridge University Press:  01 May 2009

P. J. O'Connor ,
M. Aftalion  and
P. S. Kennan
P. J. O'Connor
Affiliation:
Geological Survey of Ireland, Beggars Bush, Haddington Road, Dublin 4, Ireland
M. Aftalion
Affiliation:
Scottish Universities Research & Reactor Centre, East Kilbride, Glasgow G75 0QU, U.K.
P. S. Kennan
Affiliation:
Department of Geology, University College Belfield, Dublin 4, Ireland
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Abstract

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A more precise age for the synkinematic emplacement of the large S-type Leinster batholith (southeast Ireland) has been obtained by U–Pb dating of zircon and monazite separates from the two main granite varieties of the Northern Pluton. A concordant age of 405±2 Ma derived from monazite is considered to reflect both the age of intrusion and the main regional deformation event (D1) in southeast Ireland. The monazite age is in good agreement with an earlier, less precise whole-rock Rb–Sr isochron determination. The zircon data indicate recent Pb loss effects and the existence of a small component of inherited radiogenic Pb derived from a crustal precursor during the generation of the batholith.

Type
Correspondence and Notes
Information
Geological Magazine , Volume 126 , Issue 6 , November 1989 , pp. 725 - 728
Copyright
Copyright © Cambridge University Press 1989

References

Brindley, J. C. 1973. The structural setting of the Leinster Granite, Ireland – a review. Scientific Proceedings of the Royal Dublin Society 5A, 27–36.Google Scholar
Brown, P. E., Miller, J. A. & Grasty, R. L. 1968. Isotopic ages of later Caledonian granitic intrusions in the British Isles. Proceedings of the Yorkshire Geological Society 36, 251–76.Google Scholar
Brück, P. M. 1974. Granite varieties and structures of the Northern and Upper Liffey Valley Units of the Leinster batholith. Bulletin of the Geological Survey of Ireland 1, 381–93.Google Scholar
Brück, P. M. & O'Connor, P. J. 1977. The Leinster batholith: geology and geochemistry of the Northern Units. Bulletin of the Geological Survey of Ireland 2, 107–41.Google Scholar
Cliff, R. A. 1985. Isotopic dating in metamorphic belts. Journal of the Geological Society of London 142, 97–110.Google Scholar
Colthurst, J. R. J. & Smith, D. G. 1977. Palaeontological evidence for the age of the Lower Palaeozoic rocks of the Slievenamon inlier, Co. Tipperary. Proceedings of the Royal Irish Academy 77B, 145–58.Google Scholar
Gupta, L. N. 1972. Growth trends of zircons from the northern part of the Leinster Granite. Scientific Proceedings of the Royal Dublin Society 4A, 351–70.Google Scholar
Gupta, L. N. 1973. Unusually large zircons from the Leinster pluton. Mineralogical Magazine 39, 253–5.Google Scholar
Gupta, L. N. & Elsdon, R. 1985. Zircon studies of Unit I of the Leinster Granite. Irish Journal of Earth Sciences 7, 65–78.Google Scholar
Jaffey, A. H., Flynn, K. F., Glendenin, L. E., Bentley, W. C. & Essing, A. M. 1971. Precision measurements of half-lives and specific activities of 238U and 235U. Physics Review C4, 1889–1906.Google Scholar
Krogh, T. E. 1973. A low contamination method for hydrothermal decomposition of zircon and extraction of U and Pb for isotopic age determinations. Geochimica et Cosmochimica Acta 37, 485–94.CrossRefGoogle Scholar
Kulp, J. L., Long, L. E., Griffin, C. E., Mills, A. A., Lambert, R. St., J.Giletti, B. J. Giletti, B. J. & Webster, R. K. 1960. Potassium–argon and rubidium–strontium ages of some granites from Britain and Eire. Nature 185, 495–7.Google Scholar
Lambert, R. St. J. & Mills, A. A. 1961. Some critical points for the Palaeozoic time scale from the British Isles. Annals New York Academy of Science 91, 378–8.Google Scholar
O'Connor, P. J. & Brück, P. M. 1978. Age and origin of the Leinster Granite. Journal of Earth Sciences of the Royal Dublin Society 1, 105–13.Google Scholar