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A new, high precision U–Pb date from the oldest known rocks in southern Britain

Published online by Cambridge University Press:  27 October 2009

D. I. SCHOFIELD ,
I. L. MILLAR ,
P. R. WILBY  and
J. A. EVANS
D. I. SCHOFIELD*
Affiliation:
British Geological Survey, Kingsley Dunham Centre, Nottingham, NG12 5GG, UK
I. L. MILLAR
Affiliation:
NERC Isotope Geoscience Laboratories, Kingsley Dunham Centre, Nottingham, NG12 5GG, UK
P. R. WILBY
Affiliation:
British Geological Survey, Kingsley Dunham Centre, Nottingham, NG12 5GG, UK
J. A. EVANS
Affiliation:
NERC Isotope Geoscience Laboratories, Kingsley Dunham Centre, Nottingham, NG12 5GG, UK
*
†Author for correspondence: [email protected]
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Abstract

A new high precision U–Pb zircon age of 710.8 ± 1.5 Ma for granophyric granitic rock from the Stanner Hanter Complex of the Welsh Borderland lies just within error of an older Rb–Sr isochron age. ϵNd values of −0.3 and −1.2 combined with TDM of 1394 Ma and 1468 Ma indicate that the magma incorporated an older crustal source component. The Nd data highlight differences with western Avalonia, the widely considered Late Neoproterozoic north American counterpart to southern Britain, and point toward a closer similarity with other Peri-Gondwanan terranes that incorporate older, cratonic source material.

Keywords

Late NeoproterozoicAvaloniaU–Pb datingGondwana
Type
Rapid Communication
Information
Geological Magazine , Volume 147 , Issue 1 , January 2010 , pp. 145 - 150
Copyright
Copyright © Cambridge University Press 2009

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