New palaeontological discoveries and revised mapping of Lower Palaeozoic sedimentary rocks located west of the Catombal Range, between Wellington and Yeoval in central New South Wales, underpins a new model for the Ordovician and Silurian geological history of this region. West of the abandoned Gunners Dam gold mine, large blocks of deep-water siltstones, spiculite, and laminated chert contain Late Ordovician graptolites, including Dicellograptus and Climacograptus (associated with the dendroid Dendrograptus). Along strike to the north near Arthurville, west of Wellington, lensoidal outcrops of sandstone, conglomerate and limestone (previously assigned to the Oakdale Formation) contain a new brachiopod genus and species, described here as Narrawaella wellingtonense, that is associated with conodonts and ungulate brachiopods of Late Ordovician (Katian) age. We interpret all these Upper Ordovician rocks as allochthonous, having been redeposited into Silurian sediments of the Cowra Trough. Similar occurrences of allochthonous Upper Ordovician limestones at Eurimbla and Cumnock to the south, and comparable deposits previously recognised in the Hill End Trough further to the east, suggest this model is widely applicable to areas peripheral to the Macquarie Arc in central New South Wales.
|Number of pages||15|
|Journal||Proceedings of the Linnean Society of New South Wales|
|Publication status||Published - 2011|
- Allochthonous blocks
- Upper Ordovician