Australia lets go of Antarctica
The last Gondwanan connection begins to fail, and the Southern Ocean starts to encircle the pole.
- When
- —
- Duration
- 11 million years
- Known to
- ± 3 million years
- Era
- Eocene, Cenozoic
Australia and Antarctica had remained joined long after the rest of Gondwana dispersed. Rifting accelerates through the middle and late Eocene and deep water eventually flows through the widening Tasman gateway. Australia carries its cargo of marsupials north into isolation, where they radiate free of placental competition. In the south, opening this gateway is one of the two conditions needed to thermally isolate Antarctica; the other is Drake Passage.