Eocene-Oligocene coals of the Gippsland and Australo-Antarctic basins - Paleoclimatic and paleogeographic context and implications for the earliest Cenozoic glaciations

A number of contemporaneous Middle to Late Eocene brown coals occurred in near-coastal settings across 1200 km of southern Australia. Palaeogeographically, all these coal basins faced the Australo-Antarctic Gulf and have a much lower gymnosperm proportion (< 10%), low Nothofagus proportion (< 10%), but very high (non-Nothofagus) angiosperms proportion. This suggests a different climatic regime separated a cooler and wetter Gippsland Basin flora that responded to the cooler Proto-Ross Sea Gyre rotating around a wide Pacific Ocean, and a warm-wet climate associated with a warm proto-Leeuwin current of the Australo-Antarctic Gulf.