Radiolarian and conodont biostratigraphy of siliceous rocks from the New England Fold Belt

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Abstract
Acid extraction of microfossils from siliceous rocks of the New England Fold Belt has yielded radiolarians, and less commonly conodonts, that are of biostratigraphic value. Rock units, the ages of which have until now been only indirectly estimated, are directly dated, and although some earlier argued ages are confirmed others are younger than previously supposed. Thus the Woolomin Formation, an accretionary subduction complex, has elements of Silurian age but also includes rocks as young as Carboniferous. The Wisemans Arm Formation, once considered to be Late Devonian, contains chert olistoliths as young as Namurian, and a Late Devonian age is indicated for the Watonga Formation, a sequence of ocean floor rocks previously correlated with the Woolomin Formation. These results suggest that some ideas on provenance linkage and terrane amalgamation in the New England Fold Belt need to be reassessed. Several Early Devonian radiolarian assemblages have been identified in the western part of the Hastings Block. Together with a fauna from near Taree in the southeast of the Tamworth Belt they confirm earlier lithological correlations, and support the idea of major strike‐slip displacement of the southern part of the Tamworth Belt.