Australia, Coastal Geomorphology

The Australian coastline is about 20,000 km long (Fig. 1) and has many long gently curving sandy beaches interspersed with sectors of cliffs and steep coast. The beaches on the western and southern coasts, from Broome in the northwest to Wilsons Promontory in Victoria and the western coasts of the Bass Strait islands and Tasmania, are predominantly calcareous, whereas those of the eastern and northern coasts are generally quartzose, except in the vicinity of fringing coral reefs. Many of the beaches form the seaward margins of depositional sand barriers bearing multiple beach ridge or dune topography (Bird 1973; Thom 1984), and on the western and southern coasts, the calcareous sands of the older (Pleistocene) dunes have been partially lithified by secondary carbonate precipitation to form dune calcarenites (calcareous aeolianites). These are extensive between Broome and Cape Leeuwin on the Western Australian coast, between Streaky Bay in South Australia and Cape Otway in Victoria,...