Silurian evaporitic strata from New South Wales, Australia
During Silurian (Late Wenlockian to Ludlovian) time in the Cudgegong district, New South Wales, a minor regression is represented by local influx of clastic detritus and a brief period of subaerial exposure within a phase of carbonate deposition. Oolitic shoals, formed under shallow warm hypersaline marine conditions, became exposed on supratidal flats where minor dolomitization and gypsum crystallization took place. During diagenesis the gypsum was pseudomorphed by chlorite. Ooids and evaporite minerals have not been previously recorded from Silurian strata in eastern Australia but their occurrence at Cudgegong concurs with a palaeolatitude of approximately 5°N on the basis of geophysical data.