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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

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