Dredged calcareous sediments associated with the volcanic edifices of Gascoyne, Taupo, Derwent Hunter, Stradbroke, Britannia, Moreton and Recorder Seamounts (Tasmantid Seamount chain) and Nova Bank, Argo Bank, Capel Bank and Gifford Guyot (Lord Howe Seamount chain) have yielded a diverse biota including abundant foraminiferids and calcareous algae. These fossils constrain hypotheses on the age and environment of formation of the seamounts and also give data on oceanographic conditions existing at the time of accumulation of the sediments. All sediments accumulated in normal marine salinities.