Abstract
A mid-Permian rifting episode appears to have removed continental blocks (now forming parts of Asia) from Australian Gondwana, but the present continental margin of Northern Australia-central New Guinea was formed by a later episode of rifting during the Jurassic. With the exception of the north-west Australian offshore region west of the Scott Plateau, this rifted continental margin has been greatly modified during the Cainozoic by collisions with arc-trench systems. Collision resulted in fold and thrust mountains, locally with ophiolite emplacements, that now characterize most of northern New Guinea and the Banda Arc. The identification of the Australia-New Guinea rifted continental margin in what is now the fold and thrust mountain belt of New Guinea, islands of the Outer Banda Arc, East Sulawesi, and Buton, rests largely on stratigraphic correlation and the recognition of the pre-rift sequence, breakup unconformity, and the post-breakup marine transgression and prolonged subsidence in these now highly deformed rocks. One implication of the Jurassic continental rifting is that the pre-rift rocks of the region accumulated in an intracratonic basin of eastern Gondwana. Another important implication is that the continental blocks rifted from the Northern Australia-central New Guinea margin must have drifted northwards towards Asia as the Mesozoic Tethys ocean spread across the tropics and equatorial region. These continental fragments of Gondwana collided with parts of south-east Asia that had been derived from Gondwana in an earlier phase of rifting.