Conodont faunas from the Mid to Late Ordovician boundary interval of the Wahringa Limestone Member (Fairbridge Volcanics), central New South Wales

Twenty-nine conodont species are documented from the Wahringa Limestone Member and other isolated limestone pods of the Fairbridge Volcanics, in the Bakers Swamp area between Wellington and Orange, central New South Wales. Three conodont assemblages are recognised within the Wahringa Limestone Member. The oldest is characterised by the occurrence of Pygodus protoanserinus and Pygodus serra, indicative of a late Darriwilian age (Da3 to early Da4). The overlying assemblage B, bearing Belodina monitorensis, probably ranges across the Mid to Late Ordovician boundary. Assemblage C with abundant Belodina compressa in the upper part of the Wahringa Limestone Member is of late Gisbomian (Gi2) age. The conodont faunas are significant in being the first described from the Lachlan Orogen in New South Wales spanning the Mid to Late Ordovician interval, although resolution of the actual boundary level is limited in the section measured.24 page(s