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A new K—Ar age from uppermost Tremadoc rocks of north Wales

Published online by Cambridge University Press:  01 May 2009

B. P. Kokelaar ,
F. J. Fitch  and
P. J. Hooker
B. P. Kokelaar
Affiliation:
School of Environmental Sciences, Ulster Polytechnic, Shore Road, Newtownabbey, Co. Antrim BT37 0QB
F. J. Fitch
Affiliation:
Department of Geology, Birkbeck College, University of London, Malet Street, London WC1E 7HX
P. J. Hooker
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ
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Summary

New conventional K–Ar dating of virtually unaltered pargasite phenocrysts extracted from a metabasalt of the uppermost Tremadocian Rhobell Volcanic Group, cropping out near Dolgellau, Gwynedd, north Wales, yields an age of 508 ± 11 Ma. This result provides a valuable new time-scale calibration point although incompatible with some other versions of the radiometric time-scale for the Lower Palaeozoic which have indicated ages of less than 508 ± 11 Ma for the Tremadoc/Arenig boundary.

Type
Articles
Information
Geological Magazine , Volume 119 , Issue 2 , March 1982 , pp. 207 - 211
Copyright
Copyright © Cambridge University Press 1982

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