In the Cretaceous period, the continental breakup of Gondwana started near Tasmania. About 83 million years ago a rift entered the east coast of Tasmania from the south and split off the Lord Howe Rise. Sea floor spreading continued to move this continental sliver away to the east from Tasmania and Australia, and the rift jumped into the Lord Howe Rise and separated off the East Tasman Plateau. The East Tasman Plateau microcontinent was originally off the southeast of Tasmania; it is a circular piece of continental rocks surrounded by oceanic crust. Volcanism occurred there 36 million years ago.[1]