Progressive Western Australian Collision with Asia: Implications for Regional Orogography, Oceanography, Climate and Marine Biota

The western margin of Australia has migrated over 30° northward in the last fifty million years. As it progressed, it carried evidence of greenhouse to icehouse climate and ocean transitions in the sedimentary sequences. In the last ten million years Australia collided with the Asian plate to the north, leading to the uplift of the Indonesian archipelago and Papua New Guinea highlands and restricting the interchange between the Indian and Pacific oceans. This created the near “modern” oceanography of the region with the onset of the Indonesian Throughflow and related Leeuwin Current. It also resulted in the ongoing crustal stress along the North West Shelf causing substantial seismicity and faulting. Recent sediment coring by the International Ocean Discovery Program (IODP) and RV Sonne has yielded superb palaeoclimatic and palaeoceanographic archives that will uncover details of the evolution of this margin through the late Neogene to Recent. Knowledge of the past evolution of Australia’s western margin is essential if we are to better predict the consequences of ocean/climate variability for future climate change.