New and recalculated radiometric data supporting a carboniferous age for the emplacement of the Bathurst batholith,New South Wales

The Bathurst batholith is a complex of massive granitic intrusions cutting across deformed early and middle Palaeozoic rocks of the Lachlan Fold Belt of New South Wales. An adamellite from Dunkeld, near the western edge of the batholith, has yielded K‐Ar ages of 304 ± 4 m.y. (total‐rock) and 301 ± 6 m.y. (biotite).

Recalculated radiometric ages on rocks from the eastern end (Hartley) and northern edge (Yetholme), together with the new data from the western end (Dunkeld) of the Bathurst batholith yield a mean age of emplacement of 310 m.y. (8 values, standard deviation = 6.8 m.y.). This age is supported by Re‐Os data from molybdenite at Yetholme. As yet these data do not allow establishment of temporal relationships between separate intrusive phases of the Bathurst batholith, although the Durandal Adamellite at Yetholme appears to be the oldest phase yet dated.