Silurian Brachiopods from the Bredbo Area North of Cooma, New South Wales, Australia

Abstract

The brachiopod faunas are described from three successive stratigraphic units in the Bredbo area, between Canberra and Cooma - the Cappanana Formation, Colinton Volcanics and lower Rothlyn Formation. The first two have type localities in the area. There are 16 species in all, most of which occur at least in the Cappanana Formation, but there are no implications of a useful biostratigraphic succession. Many species are common to the Delegate River Mudstone south of Cooma and the Canberra Formation in Canberra, and the only previously unknown species is a probable Rhynchotrema, represented by just a few specimens. Comparison with faunas of known age in the Canberra-Yass area indicate a Wenlock (Early Silurian) age, most likely Sheinwoodian. This supports the most recently proposed stratigraphic framework, and the likelihood that the volcanic units in the region were probably erupted over relatively brief intervals of time.