Figure 7. Paleogeographic map of the Tasmanian region at the Eocene/Oligocene boundary (33.5 Ma) based partly on Royer and Rollet (1997, fig. 8) and Leg 189 results. Solid circles = DSDP Leg 29 sites. Open circles with dots = Leg 189 sites. Most oceanic crust was covered with deep water, and most of the Tasmania/South Tasman Rise region was covered in bathyal seas. A deep water connection between the restricted Australo-Antarctic Gulf to the west and the Pacific Ocean had just been established south of the STR, allowing the onset of circum-Antarctic circulation.