The physiographic features of the continental margin of eastern Australia, the Tasman Basin, Lord Howe Rise, and the Coral Sea Platform are described and discussed geologically. Three guyots, each having more than 14,000 feet of relief and a platform depth of less than 150 fathoms, are mapped and described.
The present continental slope of southeastern Australia west of the Tasman Basin marks the maximum eastward development of the Australian continent. Lord Howe Rise is considered orogenic in origin and probably of Early Paleozoic age. The Tasman Basin is a stable area underlain by permanent ocean-type crust which may have acted as a nucleus for the eastward growth of the island arcs which lie between the Tasman Basin and the South Pacific Basin.