29. Nullarbor Region

The Nullarbor is a vast Tertiary limestone plain cliffed along its 800 km long southern boundary by the Southern Ocean wave attack. The coastal zone is largely contained in aboriginal land, parks and reserves with very little development and formal access. It faces south to southeast into the Southern Ocean with waves ranging from moderate to high to low where attenuated by inshore reefs, while tides are micro. Beach sediments are carbonate-rich in the east, becoming quartz-rich from Twilight Cove to the west. The coast has two long cliffed sections (Nullarbor and Baxter cliffs) which are bounded by the Roe Plain and the Bilbunya barrier systems, whose beaches range from exposed high energy to low energy sheltered. Barrier systems also range from low energy regressive beach-foredune ridges to some massive areas of dune transgression including extensive clifftop dunes and coastal-glacial dunes extending in places over 100 km inland. It also includes Australia’s only star dunes. This chapter describes the coastal processes, beaches, barriers, sediment transport and sediment compartments.