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

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.