Palynomorph assemblages from marine Eocene sediments on the west Tasmanian continental margin and the South Tasman Rise

Abstract

Eocene sediments have been sampled at five localities on the continental margin off western Tasmania and on the South Tasman Rise. Palynomorph assemblages recovered from these show that carbonaceous, pollen‐rich sediments in the Strahan Sub‐basin sampled by gravity coring during the RV Sonne cruise of 1985, which were probably laid down in shallow water, belong to the Proteacidites asperopolus Zone of late Early to early Middle Eocene age. Sediments at sites on the western margin of the South Tasman Rise, sampled by dredging during a 1995 cruise of the RV Rig Seismic, are referable to the Middle Eocene Lower Nothofagidites asperus Zone and suggest open‐marine conditions at that time. Dinoflagellate cysts and acritarchs (particularly Tritonites species) allow finer time resolution within the Middle Eocene. Dinoflagellate cyst assemblages from the southernmost sites contain a high percentage of taxa belonging to the high‐latitude Eocene ‘Transantarctic Flora’. Show more